A kind of polycarbonate resin and its preparation method and application

Abstract

The present invention provides a polycarbonate resin and a preparation method and application thereof. The polycarbonate resin contains a structural unit shown in Formula I. By limiting the polycarbonate resin to contain the structural unit shown in Formula I, the polycarbonate resin has the advantages of good molecular chain flexibility, high Abbe number, high refractive index and low birefringence. At the same time, since the structure does not contain heteroatoms such as sulfur and nitrogen, the polycarbonate resin has excellent heat resistance and is not prone to yellowing and other undesirable phenomena during processing and application. In addition, the polycarbonate resin has simple raw materials for preparation, low cost, no acid catalyst is needed in the preparation process, and is very environmentally friendly. The polycarbonate resin can be applied to optical components, electronic products, medical products and other fields.

Description

Technical Field

[0001] The invention belongs to the technical field of optical plastics, and in particular relates to a polycarbonate resin and a preparation method and application thereof. Background Art

[0002] With the rapid development of smart phones and new energy vehicle industries, the demand for optical lens products is increasing rapidly. Polycarbonate is the preferred material for making optical lenses such as mobile phone lenses, car lenses, and VR / AR glasses due to its good dimensional stability, high light transmittance, high refractive index, and easy molding.

[0003] At present, bisphenol A is usually used to prepare polycarbonate resin, but the refractive index of the obtained bisphenol A polycarbonate is low, only 1.58, and there is a serious birefringence phenomenon, which cannot be used in the field of high-end optical materials. Therefore, in order to increase the refractive index of polycarbonate resin and reduce its birefringence phenomenon, it is urgent to develop new polycarbonate products to meet the needs of different customers.

[0004] CN101490130A reports a method of preparing a low birefringence polycarbonate by reacting isosorbide and bisphenol A as dihydroxy monomers with diphenyl carbonate; however, the refractive index of the polycarbonate is still low and the heat resistance is poor, which limits its application range.

[0005] CN112961336A reports a polyaromatic dihydroxy monomer which reacts with diphenyl carbonate to prepare a polycarbonate with a high refractive index and low birefringence; however, the polyaromatic dihydroxy monomer used in the polycarbonate has a very complex structure and is difficult to synthesize, making it difficult to achieve industrial scale-up.

[0006] CN115725063A reports a method of using anthracene ring and benzoquinone as raw materials to prepare a type of dihydroxy monomer with a new structure through reaction, and reacting with diphenyl carbonate to prepare a polycarbonate with high refractive index and low birefringence; however, a large amount of acidic reagents are used in the synthesis process of the dihydroxy monomer with a new structure, and the solubility is poor and purification is difficult, resulting in a low product yield. At the same time, the polycarbonate prepared by using the dihydroxy monomer has a large number of aromatic ring structures in the main chain, and thus has a small Abbe number, and is prone to color difference, resulting in limited product use.

[0007] Therefore, in view of the above technical problems, it is urgent to develop a polycarbonate resin having high refractive index, high Abbe number, low birefringence and excellent heat resistance. Summary of the invention

[0008] In view of the deficiencies in the prior art, the object of the present invention is to provide a polycarbonate resin and a preparation method and application thereof. The polycarbonate resin has the characteristics of high refractive index, low birefringence, high Abbe number and excellent heat resistance, which can meet the current market demand. At the same time, the raw material structure of the polycarbonate resin is simple, the synthesis is easy, and it is convenient to achieve industrial scale-up.

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides a polycarbonate resin, wherein the polycarbonate resin comprises a structural unit represented by formula I:

[0011] ;

[0012] In Formula I, X is selected from C1 to C6 (e.g., C1, C2, C3, C4, C5 or C6) straight or branched chain alkylene;

[0013] R1 and R2 are each independently selected from H, C1~C20 (e.g. C1, C3, C5, C9, C11, C13, C15, C17, C19 or C20, etc.) straight chain or branched alkyl, C1~C20 (e.g. C1, C3, C5, C9, C11, C13, C15, C17, C19 or C20, etc.) straight chain or branched alkoxy, C5~C20 (e.g. C5, C9, C11, C13, C15, C17, C19 or C20, etc.) straight chain or branched alkoxy, any one of C7, C19 or C20 (e.g., C19 or C20) cycloalkyl, C5~C20 (e.g., C5, C9, C11, C13, C15, C17, C19 or C20) cycloalkyloxy, C6~C20 (e.g., C6, C9, C11, C13, C15, C17, C19 or C20) aryl, C6~C20 (e.g., C6, C9, C11, C13, C15, C17, C19 or C20) aryloxy;

[0014] R3 and R4 are each independently selected from any one of H, C1-C20 (e.g., C1, C3, C5, C9, C11, C13, C15, C17, C19 or C20, etc.) straight or branched alkyl, or connected to form a ring through a single bond, C1-C3 (e.g., C1, C2 or C3) alkylene, or C1-C3 (e.g., C1, C2 or C3) alkyleneoxy;

[0015] n is an integer from 0 to 5 (eg, 0, 1, 2, 3, 4 or 5).

[0016] The polycarbonate resin provided by the present invention contains a structural unit shown in Formula I. On the one hand, since the main chain contains a relatively long alkyl chain, the flexibility of the molecular chain is good, and thus the Abbe number is high. On the other hand, since the weight of the structural unit shown in Formula I per unit volume is high, the refractive index of the polycarbonate resin can be effectively increased, and a balance between the refractive index and the Abbe number can be achieved, while the birefringence is low. In addition, since the structural unit shown in Formula I does not contain heteroatoms such as sulfur and nitrogen, the obtained polycarbonate resin also has excellent heat resistance, is not prone to yellowing and other undesirable phenomena during processing and application, and can be applied to optical components, electronic products, medical products and other fields.

[0017] Preferably, X is selected from C1~C2 alkylene.

[0018] Preferably, R1 and R2 are each independently selected from any one of H, C1~C6 straight chain or branched alkyl, C1~C6 straight chain or branched alkoxy, C5~C10 cycloalkyl, C5~C10 cycloalkoxy, C6~C12 aryl, and C6~C12 aryloxy.

[0019] Preferably, R3 and R4 are each independently selected from any one of H or methyl, or are connected to form a ring through any one of a single bond, C1~C3 alkylene, and C1~C3 alkyleneoxy.

[0020] Preferably, n is an integer from 0 to 1.

[0021] Preferably, the structural unit represented by formula I is at least one of the structural units represented by formulas A1 to A3;

[0022] , , .

[0023] Preferably, the polycarbonate resin further contains a structural unit represented by the following formula II:

[0024] ;

[0025] In formula II, Y is selected from C1~C6 (e.g., C1, C3, C5 or C6, etc.) straight or branched chain alkylene;

[0026] R5-R6 are each independently selected from H, C1-C20 (e.g., C1, C3, C5, C9, C11, C13, C15, C17, C19 or C20, etc.) straight or branched alkyl, C1-C20 (e.g., C1, C3, C5, C9, C11, C13, C15, C17, C19 or C20, etc.) straight or branched alkoxy, C5-C20 (e.g., C5, C9, C11, C13, C15, C17, C19 or C20, etc.) straight or branched alkoxy, any one of C7, C19 or C20 (e.g., C19 or C20) cycloalkyl, C5~C20 (e.g., C5, C9, C11, C13, C15, C17, C19 or C20) cycloalkyloxy, C6~C20 (e.g., C6, C9, C11, C13, C15, C17, C19 or C20) aryl, C6~C20 (e.g., C6, C9, C11, C13, C15, C17, C19 or C20) aryloxy;

[0027] L is selected from any one of C1~C8 (e.g. C1, C3, C5 or C8) straight chain or branched alkyl, C6~C20 (e.g. C6, C9, C11, C13, C15, C17, C19 or C20) cycloalkyl, C6~C20 (e.g. C6, C9, C11, C13, C15, C17, C19 or C20) aromatic alkyl, C6~C20 (e.g. C6, C9, C11, C13, C15, C17, C19 or C20) diaromatic alkyl;

[0028] m is an integer from 0 to 5 (eg, 0, 1, 2, 3, 4 or 5).

[0029] It should be noted that the above C6~C20 (such as C6, C9, C11, C13, C15, C17, C19 or C20, etc.) aromatic alkyl refers to a group formed after at least one H on the alkyl group is replaced by the above-mentioned aromatic group, including but not limited to: phenylalkyl, biphenylalkyl, naphthylalkyl, fluorenyl, etc. Preferably, the structural unit represented by formula II is at least one of the structural units represented by formulas B1~B2:

[0030] , .

[0031] Preferably, the molar percentage of the structural unit represented by formula I in the polycarbonate resin is ≥0.5%, for example, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 3%, 5%, 7%, 9%, 11%, 13%, 15%, 17%, 19%, 20%, 40%, 60% or 80%, and is further preferably >10%. Further limiting the molar percentage of the structural unit represented by formula I in the polycarbonate resin can make it have both the highest refractive index and the highest Abbe number.

[0032] Preferably, the glass transition temperature (Tg) of the polycarbonate resin is 130-160°C, for example, 130°C, 135°C, 140°C, 150°C or 160°C.

[0033] In a second aspect, the present invention provides a method for preparing the polycarbonate resin as described in the first aspect, characterized in that the preparation method comprises: subjecting a dihydroxy compound having a structure represented by formula III, optionally a dihydroxy compound having a structure represented by formula IV, and a carbonic acid diester to a condensation reaction to obtain the polycarbonate resin;

[0034] ;

[0035] In Formula III, R1 to R4 and n each independently have the same defined range as in Formula I;

[0036] ;

[0037] In Formula IV, R5-R6, L and m each independently have the same defined ranges as in Formula II.

[0038] The preparation method of the polycarbonate resin provided by the present invention is carried out by a melt polycondensation method, wherein a dihydroxy compound having a structure shown in formula III, optionally a dihydroxy compound having a structure shown in formula IV and a carbonic acid diester are subjected to an ester exchange reaction under heating conditions and by-products are removed to obtain the polycarbonate resin.

[0039] Preferably, the molar ratio of the sum of the dihydroxy compound having the structure represented by formula III and the dihydroxy compound having the structure represented by formula IV to the carbonic acid diester is 1:(1-1.1), for example, 1:1, 1:1.02, 1:1.04, 1:1.06, 1:1.08 or 1:1.1, etc., and more preferably 1:(1-1.05).

[0040] Preferably, the carbonic acid diester includes any one of diphenyl carbonate, ditolyl carbonate, dimethyl carbonate or diethyl carbonate, or a combination of at least two thereof, and more preferably diphenyl carbonate.

[0041] Preferably, the dihydroxy compound having the structure shown in Formula III is at least one of compounds C1 to C3:

[0042] , , .

[0043] Preferably, the dihydroxy compound having the structure shown in Formula IV comprises bisphenol A and / or 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene.

[0044] Preferably, the polycondensation reaction is carried out in the presence of a basic catalyst.

[0045] Preferably, the alkaline catalyst includes lithium hydroxide, sodium hydroxide, magnesium hydroxide, potassium hydroxide, calcium hydroxide, cesium hydroxide, strontium hydroxide, barium hydroxide, lithium carbonate, sodium bicarbonate, magnesium bicarbonate, sodium carbonate, magnesium carbonate, potassium carbonate, calcium bicarbonate, calcium carbonate, cesium carbonate, strontium carbonate, barium carbonate, lithium acetate, sodium acetate, magnesium acetate, potassium acetate, calcium acetate, strontium acetate, barium acetate, sodium stearate, magnesium stearate, potassium stearate, calcium stearate, lithium benzoate, sodium benzoate, potassium benzoate, calcium benzoate, Any one or a combination of at least two of cesium benzoate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, disodium phenyl phosphate, magnesium phenyl phosphate, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylbenzylammonium hydroxide, diethylamine, triethylamine, dimethylbenzylamine, triphenylamine, tetramethylammonium borohydride, tetrabutylammonium borohydride, tetrabutylammonium tetraphenylborate or tetraphenylammonium tetraphenylborate, and more preferably any one or a combination of at least two of sodium hydroxide, sodium bicarbonate or sodium carbonate.

[0046] Preferably, the molar ratio of the sum of the dihydroxy compound having the structure shown in formula III and the dihydroxy compound having the structure shown in formula IV to the alkaline catalyst is 1:(10 -3 ~10 -8 ), for example 1:10 -3 , 1:10 -4 , 1:10 -5 , 1:10 -6 , 1:10 -7 or 1:10 -8 etc., more preferably 1:(10 -4 ~10 -6 ).

[0047] Preferably, the preparation method specifically comprises the following steps: adding a dihydroxy compound having a structure shown in formula III, a dihydroxy compound having a structure shown in formula IV, a carbonic acid diester and a basic catalyst into a reactor, and replacing the air in the reactor with nitrogen for 3 to 5 times (for example, 3 times, 4 times or 5 times, etc.), maintaining the reactor at normal pressure, first heating to 160 to 190° C. (for example, 160° C., 165° C., 170° C., 175° C., 180° C., 185° C. or 190° C., etc.), reacting for 5 to 10 min (for example, 5 min, 6 min, 7 min, 8 min, 9 min or 10 min, etc.), and then reducing the pressure in the reactor to 15 to 35 kPa (for example, 15 kPa, 20 kPa, 25 kPa, 30 kPa or 35 kPa, etc.), reacting for 40 to 70 min (for example, 40 min, 50 min, 60 min or 70 min). min, etc.), then raise the temperature to 190-220°C (for example, 190°C, 195°C, 200°C, 205°C, 210°C, 215°C or 220°C, etc.), then reduce the pressure in the reactor to 5-25 kPa (for example, 5 kPa, 10 kPa, 15 kPa, 20 kPa or 25 kPa, etc.), react for 40-70 min (for example, 40 min, 50 min, 60 min or 70 min, etc.), then raise the temperature to 220-240°C (for example, 220°C, 225°C, 230°C, 235°C or 240°C, etc.), then reduce the pressure in the reactor to 1-5 kPa (for example, 1 kPa, 2 kPa, 3 kPa, 4 kPa or 5 kPa, etc.), react for 30-60 min (for example, 30 min, 40 min, 50 min or 60 min min, etc.), then raise the temperature to 240-260°C (for example, 240°C, 245°C, 250°C, 255°C or 260°C, etc.), and then reduce the pressure in the reactor to 0.1-1 kPa (for example, 0.1 kPa, 0.3 kPa, 0.5 kPa, 0.7 kPa, 0.9 kPa or 1 kPa, etc.), and continue the reaction for 40-70 min (for example, 40 min, 50 min, 60 min or 70 min, etc.), after the reaction is completed, introduce nitrogen, discharge the material from the reactor, and obtain the polycarbonate resin through water cooling, pelletizing and drying.

[0048] In a third aspect, the present invention provides a polycarbonate resin composition, comprising the polycarbonate resin as described in the first aspect and an additive.

[0049] Preferably, the mass percentage of the polycarbonate resin in the polycarbonate resin composition is 90-99.9%, for example, 90%, 92%, 94%, 96%, 98%, 99%, 99.2%, 99.4%, 99.6% or 99.9%.

[0050] Preferably, the additive comprises any one of an antioxidant, a dye, a bluing agent, a flame retardant, a release agent, an ultraviolet absorber, a lubricant, a crystal nucleating agent, a reinforcing agent, an antistatic agent or an antibacterial agent, or a combination of at least two thereof.

[0051] In a fourth aspect, the present invention provides an optical lens, comprising at least one of the polycarbonate resin described in the first aspect or the polycarbonate composition described in the third aspect.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] (1) The polycarbonate resin provided by the present invention contains the structural unit shown in Formula I, and has the advantages of good molecular chain flexibility, high Abbe number, high refractive index and low birefringence; at the same time, it does not contain heteroatoms such as sulfur and nitrogen, and is not prone to yellowing and other undesirable phenomena during processing and application, and can be used in optical components, electronic products, medical products and other fields;

[0054] (2) The raw material synthesis of the polycarbonate resin provided by the present invention is simple and low in cost, and no acid catalyst is required during the preparation process, which is very environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 The hydrogen nuclear magnetic resonance spectrum of the dihydroxy compound C1 provided in Preparation Example 1;

[0056] Figure 2 The hydrogen nuclear magnetic resonance spectrum of the dihydroxy compound C2 provided in Preparation Example 2;

[0057] Figure 3 This is the hydrogen nuclear magnetic resonance spectrum of the dihydroxy compound C3 provided in Preparation Example 3. DETAILED DESCRIPTION

[0058] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0059] Preparation Example 1

[0060] A dihydroxy compound C1, the synthesis route of which is as follows:

[0061] ;

[0062] The preparation method comprises: mixing 20 g of 1,2-dihydroxymethylethylene and 20 g of anthracene, dissolving the mixture in 150 mL of anhydrous toluene, subjecting the mixture to a reflux reaction at 160° C. for 4 h, cooling the mixture to room temperature after the reaction is completed, washing the mixture with water, and removing the anhydrous toluene by rotary evaporation. The obtained crude product is purified by recrystallization to obtain the dihydroxy compound C1.

[0063] Preparation Example 2

[0064] A dihydroxy compound C2, whose structural formula is: ;

[0065] The difference between the preparation method and Preparation Example 1 is that cyclohexene-1,4-diol is used to replace 1,2-dihydroxymethylethylene, and other substances, amounts and conditions are the same as those in Preparation Example 1.

[0066] Preparation Example 3

[0067] A dihydroxy compound C3, the synthesis route of which is as follows:

[0068]

[0069] The preparation method comprises: mixing a dihydroxy compound C1 (Preparation Example 1) and 2-bromoethyl acetate in a molar ratio of 1:2, dissolving the mixture in dichloromethane, heating the mixture under reflux for overnight reaction, cooling the mixture to room temperature, removing dichloromethane to obtain an intermediate product D1; then reacting the intermediate product D1 with an excess of aqueous sodium hydroxide solution at reflux temperature for 180 min, and purifying the mixture by recrystallization with tetrahydrofuran to obtain the dihydroxy compound C3.

[0070] Structural characterization:

[0071] (1) The dihydroxy compounds prepared in Preparation Examples 1 to 3 were tested respectively using a nuclear magnetic resonance spectrometer, and the nuclear magnetic resonance hydrogen spectrum of the dihydroxy compound C1 provided in Preparation Example 1 was obtained as follows: Figure 1 As shown, the nuclear magnetic resonance hydrogen spectrum of the dihydroxy compound C2 provided in Preparation Example 2 is obtained by testing as follows Figure 2 As shown, the nuclear magnetic resonance hydrogen spectrum of the dihydroxy compound C3 provided in Preparation Example 3 is obtained by testing as follows Figure 3 As shown;

[0072] from Figure 1~Figure 3 It can be seen that: Preparation Examples 1 to 3 successfully prepared dihydroxy compounds with specific structures.

[0073] Example 1

[0074] A polycarbonate resin comprising a structural unit represented by formula A1 and a structural unit represented by formula B2;

[0075] ;

[0076] ;

[0077] The preparation method of the polycarbonate resin provided in this embodiment comprises the following steps:

[0078] (1) At room temperature, 1.01 kg (4.20 mol) of diphenyl carbonate, 1.73 kg (3.94 mol) of 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene, 5 g (0.02 mol) of dihydroxy compound C1 and 3.17×10 -4 g (7.92×10 -6 mol) sodium hydroxide was added into a 5 L reactor, and the air in the reactor was replaced with nitrogen 5 times to maintain the reactor at normal pressure;

[0079] (2) Raise the temperature in the reactor to 190°C within 20 minutes, react for 10 minutes, then reduce the pressure in the reactor to 25 kPa within 5 minutes, and continue to react for 50 minutes;

[0080] (3) Raise the temperature in the reactor to 210°C within 10 minutes, reduce the pressure in the reactor to 15 kPa, and react for 60 minutes;

[0081] (4) Raise the temperature in the reactor to 230°C within 10 minutes, reduce the pressure in the reactor to 5 kPa, and react for 50 minutes;

[0082] (5) Within 10 min, the temperature in the reactor was raised to 260 °C, the pressure in the reactor was reduced to 0.1 kPa, and the reaction was continued for 60 min;

[0083] (6) After the reaction is completed, nitrogen is introduced to discharge the material from the kettle through the lower discharge valve, and the material is cut into pellets and collected after water cooling;

[0084] (7) The collected particles are dried under vacuum at 80° C. for 4 h to obtain the polycarbonate resin.

[0085] Example 2

[0086] A polycarbonate resin comprising a structural unit represented by formula A1 and a structural unit represented by formula B2;

[0087] ;

[0088] ;

[0089] The preparation method of the polycarbonate resin provided in this embodiment is different from that in Example 1 in that: in step (1), the feeding amount of 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene is 1.58 kg (3.60 mol), the feeding amount of the dihydroxy compound C1 is 0.11 kg (0.4 mol), and the feeding amount of sodium hydroxide is 1.60×10 -3 g (4.00×10 -5 mol), other substances, amounts and steps are the same as those in Example 1.

[0090] Example 3

[0091] A polycarbonate resin comprising a structural unit represented by formula A1 and a structural unit represented by formula B2;

[0092] ;

[0093] ;

[0094] The preparation method of the polycarbonate resin provided in this embodiment is different from that in Example 1 in that: in step (1), the feeding amount of 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene is 1.48 kg (3.38 mol), the feeding amount of the dihydroxy compound C1 is 0.20 kg (0.69 mol), and the feeding amount of sodium hydroxide is 8.16×10 -3 g (2.04×10 -4 mol), other substances, amounts and steps are the same as those in Example 1.

[0095] Example 4

[0096] A polycarbonate resin comprising a structural unit represented by formula A1 and a structural unit represented by formula B2;

[0097] ;

[0098] ;

[0099] The preparation method of the polycarbonate resin provided in this embodiment is different from that in Example 1 in that: in step (1), the feeding amount of 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene is 0.89 kg (2.04 mol), the feeding amount of the dihydroxy compound C1 is 0.58 kg (2.04 mol), and the feeding amount of sodium hydroxide is 4.89×10 -4 g (1.22×10 -5 mol), other substances, amounts and steps are the same as those in Example 1.

[0100] Example 5

[0101] A polycarbonate resin comprising a structural unit represented by formula A1 and a structural unit represented by formula B2;

[0102] ;

[0103] ;

[0104] The preparation method of the polycarbonate resin provided in this embodiment is different from that in Example 1 in that: in step (1), the feeding amount of 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene is 0.36 kg (0.82 mol), the feeding amount of the dihydroxy compound C1 is 0.93 kg (3.26 mol), and the feeding amount of sodium hydroxide is 3.26×10 -3 g (8.16×10 -5 mol), other substances, amounts and steps are the same as those in Example 1.

[0105] Example 6

[0106] A polycarbonate resin comprising a structural unit represented by formula A1 and a structural unit represented by formula B2;

[0107] ;

[0108] ;

[0109] The preparation method of the polycarbonate resin provided in this embodiment is different from that in Example 1 in that: in step (1), the feeding amount of 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene is 9 g (0.02 mol), the feeding amount of the dihydroxy compound C1 is 1.17 kg (4.10 mol), and the feeding amount of sodium hydroxide is 9.88×10 -4 g (2.47×10 -5 mol), other substances, amounts and steps are the same as those in Example 1.

[0110] Example 7

[0111] A polycarbonate resin comprising a structural unit represented by formula A1 and a structural unit represented by formula B1;

[0112] ;

[0113] ;

[0114] The preparation method of the polycarbonate resin provided in this embodiment is different from that in Example 1 in that: in the 5 L reactor in step (1), 1.01 kg (4.20 mol) of diphenyl carbonate, 0.12 kg (0.55 mol) of bisphenol A, 1.05 kg (3.65 mol) of dihydroxy compound C1 and 6.72×10 -4 g (1.68×10 -5 mol) sodium hydroxide, and other substances, amounts and steps are the same as those in Example 1.

[0115] Example 8

[0116] A polycarbonate resin comprising a structural unit represented by formula A2 and a structural unit represented by formula B2;

[0117] ;

[0118] ;

[0119] The preparation method of the polycarbonate resin provided in this embodiment is different from that in Example 1 in that: in the 5 L reactor in step (1), 1.01 kg (4.20 mol) of diphenyl carbonate, 1.71 kg (3.90 mol) of 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene, 29 g (0.10 mol) of dihydroxy compound C2 and 1.60×10 -4 g (4.00×10 -6 mol) sodium hydroxide, and other substances, amounts and steps are the same as those in Example 1.

[0120] Example 9

[0121] A polycarbonate resin comprising a structural unit represented by formula A3 and a structural unit represented by formula B2;

[0122] ;

[0123] ;

[0124] The preparation method of the polycarbonate resin provided in this embodiment is different from that in Example 1 in that: in the 5 L reactor in step (1), 1.01 kg (4.20 mol) of diphenyl carbonate, 1.67 kg (3.80 mol) of 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene, 71 g (0.20 mol) of dihydroxy compound C3 and 1.52×10 -4 g (3.80×10 -6 mol) sodium hydroxide, and other substances, amounts and steps are the same as those in Example 1.

[0125] Example 10

[0126] A polycarbonate resin containing only the structural unit represented by formula A1;

[0127] ;

[0128] The preparation method of the polycarbonate resin provided in this embodiment is different from that in Example 1 in that: in the 5 L reactor in step (1), 1.01 kg (4.20 mol) of diphenyl carbonate, 1.17 kg (4.08 mol) of dihydroxy compound C1 and 1.63×10 -3 g (4.08×10 -5 mol) sodium hydroxide, and other substances, amounts and steps are the same as those in Example 1.

[0129] Comparative Example 1

[0130] A polycarbonate resin, which differs from Example 1 in that: in the 5 L reactor in step (1), 1.01 kg (4.20 mol) of diphenyl carbonate, 0.96 kg (4.20 mol) of bisphenol A and 5.04×10 -4 g (1.26×10 -5 mol) sodium hydroxide, and other substances, amounts and steps are the same as those in Example 1.

[0131] Comparative Example 2

[0132] A polycarbonate resin, which differs from Example 1 in that: in the 5 L reactor of step (1), 1.01 kg (4.20 mol) of diphenyl carbonate, 0.51 kg (2.24 mol) of bisphenol A, 0.80 kg (1.83 mol) of 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene, 1.63×10 -3 g (4.08×10 -5 mol) sodium hydroxide, and other substances, amounts and steps are the same as those in Example 1.

[0133] Comparative Example 3

[0134] A polycarbonate resin, which differs from Example 1 in that: in the 5 L reactor of step (1), 1.01 kg (4.20 mol) of diphenyl carbonate, 0.12 kg (0.53 mol) of bisphenol A, 1.56 kg (3.55 mol) of 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene, 1.63×10 -3 g (4.08×10 -5 mol) sodium hydroxide, and other substances, amounts and steps are the same as those in Example 1.

[0135] Comparative Example 4

[0136] A polycarbonate resin, which differs from Example 1 in that: in the 5 L reactor in step (1), 1.01 kg (4.20 mol) of diphenyl carbonate, 1.85 kg (4.20 mol) of 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene and 1.63×10 -3 g (4.08×10 -5 mol) sodium hydroxide, and other substances, amounts and steps are the same as those in Example 1.

[0137] Comparative Example 5

[0138] A polycarbonate resin, which differs from Example 1 in that: in the 5 L reactor in step (1), 1.01 kg (4.20 mol) of diphenyl carbonate, 1.53 kg (4.08 mol) of B2 monomer in patent CN115725063A and 1.63×10 -3 g (4.08×10 -5 mol) sodium hydroxide, and other substances, amounts and steps are the same as those in Example 1.

[0139] Application Example 1

[0140] A polycarbonate resin composition includes 99.9% by weight of a polycarbonate resin (Example 1) and 0.1% by weight of an antioxidant 1010.

[0141] Performance Testing:

[0142] (1) Glass transition temperature (Tg): measured by dynamic differential thermal analysis (DSC) according to the method provided in ASTM E1356.

[0143] (2) Refractive index (n D ): Under the condition of 1.0 mm film thickness, the refractive index n of the sample at 25°C was measured using an Abbe refractometer. D , the test wavelength is 589 nm.

[0144] (3) Abbe number (v): v = (nD-1) / (nF-nC), where nD refers to the refractive index at a wavelength of 589 nm, nC refers to the refractive index at a wavelength of 656 nm, and nF refers to the refractive index at a wavelength of 486 nm.

[0145] (4) Birefringence (Δn): The polymer was molded into a film with a thickness of 1 mm, and the birefringence Δn was measured using an ellipsometer.

[0146] The polycarbonate resins provided in Examples 1 to 10, Comparative Examples 1 to 3, and the polycarbonate resin composition provided in Application Example 1 were tested according to the above test method. The test results are shown in Table 1:

[0147] Table 1

[0148]

[0149] From the data in Table 1, we can see that:

[0150] The polycarbonate resins provided in Examples 1 to 10 and the polycarbonate composition provided in Application Example 1 can maintain a relatively high Abbe number while increasing the refractive index, and the heat resistance is not affected, and the birefringence is kept low, thereby meeting the dual requirements of optical lens products for lightness and thinness and low dispersion performance; whereas the polycarbonate resins provided in Comparative Examples 1 to 5 cannot have both high refractive index, high Abbe number and low birefringence.

[0151] The applicant declares that the present invention illustrates a polycarbonate resin and its preparation method and application through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A polycarbonate resin, characterized in that The polycarbonate resin contains the structural unit represented by formula I and the structural unit represented by formula B2: ； In formula I, X is selected from C1~C6 straight or branched chain alkylene; R1 and R2 are each independently selected from any one of H, C1~C20 straight or branched alkyl, C1~C20 straight or branched alkoxy, C5~C20 cycloalkyl, C5~C20 cycloalkoxy, C6~C20 aryl, and C6~C20 aryloxy; R3 and R4 are each independently selected from any one of H, C1~C20 straight chain or branched alkyl, or connected to form a ring through a single bond, C1~C3 alkylene, or C1~C3 alkyleneoxy; n is an integer from 0 to 5; 。 2. The polycarbonate resin according to claim 1, characterized in that The X is selected from C1~C2 alkylene; The R1 and R2 are each independently selected from any one of H, C1~C6 straight chain or branched alkyl, C1~C6 straight chain or branched alkoxy, C5~C10 cycloalkyl, C5~C10 cycloalkoxy, C6~C12 aryl, and C6~C12 aryloxy; The R3 and R4 are each independently selected from any one of H or methyl, or are connected to form a ring through any one of a single bond, C1~C3 alkylene, and C1~C3 alkyleneoxy.

3. The polycarbonate resin according to claim 1, characterized in that The n is an integer from 0 to 1.

4. The polycarbonate resin according to claim 1, characterized in that The structural unit represented by formula I is at least one of the structural units represented by formulas A1 to A3; 、 、 。 5. The polycarbonate resin according to claim 1, characterized in that The molar percentage of the structural unit represented by formula I in the polycarbonate resin is ≥0.5%.

6. A method for preparing a polycarbonate resin according to any one of claims 1 to 5, characterized in that: The preparation method comprises: subjecting a dihydroxy compound having a structure shown in Formula III, 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene and a carbonic acid diester to a polycondensation reaction to obtain the polycarbonate resin; ； In Formula III, R1-R4 and n each independently have the same defined ranges as in Formula I.

7. A polycarbonate resin composition, characterized in that The polycarbonate resin composition comprises the polycarbonate resin according to any one of claims 1 to 5 and an additive.

8. An optical lens, characterized in that: The optical lens comprises at least one of the polycarbonate resin according to any one of claims 1 to 5 or the polycarbonate resin composition according to claim 7.

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