Low-haze high-heat-resistance polycarbonate block copolymer and preparation method thereof

Abstract

The invention provides a low-haze high-heat-resistance polycarbonate block copolymer. The low-haze high-heat-resistance polycarbonate block copolymer comprises a block A as shown in a formula I and a block B as shown in a formula II, the molar ratio of the block A to the block B is (50: 50)-(95: 5). The invention also provides a preparation method of the composition. A bisphenol TMC rigid group is introduced into a polycarbonate molecular structure in a block form, so that the heat resistance, the impact resistance and the optical performance of polycarbonate are synergistically improved; the polycarbonate is especially suitable for optical devices, automobile precision parts, electronic packaging materials and other high-end industrial fields with strict requirements for high-temperature stability, mechanical properties, light transmittance and transparency. Experimental results show that the glass transition temperature (Tg) of the polycarbonate block copolymer provided by the invention reaches 200-210 DEG C, the vicat softening point reaches 190-210 DEG C, the heat distortion temperature (HDT) reaches 170-180 DEG C, and the light transmittance is gt; 89%, and the haze is lt; and 0.3%.

Description

Technical Field

[0001] This application relates to the field of polymer material synthesis technology, and in particular to a low-haze, high-heat-resistant polycarbonate block copolymer and its preparation method. Background Technology

[0002] Polycarbonate (PC) possesses excellent mechanical properties and chemical stability, making it widely used in the manufacturing of optical equipment, medical devices, and other fields. However, traditional PC is prone to thermal deformation, degradation, softening, and embrittlement at high temperatures, severely limiting its applications.

[0003] Existing technologies disclose various methods to improve the heat resistance of PC. For example, Chinese patent document CN115286780A introduces 4,4'-bis(4-hydroxyphenyl)-6,6'-diphenyl-2,2'-bipyrimidine into the PC structure to achieve a synergistic improvement in heat resistance and refractive index. However, this method requires strict temperature control and consumes a lot of solvent and water resources. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide a low-haze, high-heat-resistant polycarbonate block copolymer and its preparation method. The polycarbonate block copolymer provided by this application has excellent heat resistance, mechanical properties and optical transparency, and the method provided by this application has high solvent recovery rate and low water consumption.

[0005] This application provides a low-haze, high-heat-resistant polycarbonate block copolymer, comprising block A of Formula I and block B of Formula II:

[0006] Formula I; Formula II;

[0007] The molar ratio of block A to block B is 50:50 to 95:5.

[0008] In some specific implementations, the weight-average molecular weight of the polycarbonate block copolymer is 35,000 g / mol to 45,000 g / mol;

[0009] The haze of the polycarbonate block copolymer is 0.1%~0.3%;

[0010] The light transmittance of the polycarbonate block copolymer is 89.0%~92.0%.

[0011] The low-haze, high-heat-resistant polycarbonate block copolymer provided in this application comprises block A as shown in Formula I and block B as shown in Formula II, wherein the molar ratio of block A to block B is 50:50 to 95:5. This application introduces bisphenol TMC rigid groups into the polycarbonate molecule in the form of blocks, synergistically improving the heat resistance, impact resistance, and optical properties of polycarbonate. This makes polycarbonate particularly suitable for high-end industrial fields with stringent requirements for high-temperature stability, mechanical properties, light transmittance, and transparency, such as optical devices, precision automotive parts, and electronic packaging materials. Experimental results show that the polycarbonate block copolymer provided in this application has a glass transition temperature (Tg) of 200-210℃, a Vicat softening point of 190-210℃, a heat distortion temperature (HDT) of 170-180℃, a light transmittance >89%, and a haze <0.3%, exhibiting excellent heat resistance, mechanical properties, and optical transparency.

[0012] This application also provides a method for preparing the low-haze, high-heat-resistant polycarbonate block copolymer described in the above technical solution, comprising the following steps:

[0013] (1) Bisphenol A salt reacts with phosgene to obtain an oligomer solution;

[0014] (2) The oligomer solution is reacted sequentially with bisphenol TMC salt and end-capping agent to obtain a block oligomer solution;

[0015] (3) The block oligomer solution undergoes a polycondensation reaction under the action of a catalyst to obtain a block copolymer.

[0016] In some specific implementations, step (1) specifically includes: mixing the reaction solvent and phosgene in a three-way static mixer and then mixing and reacting them with the bisphenol A salt solution in a static tubular mixer by atomization spraying to obtain oligomers.

[0017] In some specific implementations, in step (1), the reaction solvent is one or more of dichloromethane, 1,2-dichloroethane, chlorobenzene, and o-dichlorobenzene;

[0018] The rate at which the reaction solvent is introduced is 125 g / min to 350 g / min;

[0019] The temperature of the phosgene is -10℃ to 0℃;

[0020] The concentration of phosgene in the solution after mixing phosgene and dichloromethane is 10wt%~20wt%.

[0021] The phosgene introduction rate is 25 g / min to 35 g / min;

[0022] The concentration of the bisphenol A salt solution is 10wt%~20wt%;

[0023] The bisphenol A salt solution is introduced at a rate of 300 g / min to 800 g / min.

[0024] The temperature of the bisphenol A salt solution is 35℃~40℃;

[0025] The pressure of the atomized spray is 0.5MPa~1.0MPa;

[0026] The temperature of the atomized spray is 45℃~50℃;

[0027] The reaction time is 5s to 15s.

[0028] In some specific implementations, step (2) specifically includes:

[0029] The oligomer solution is reacted sequentially with a bisphenol TMC salt solution, a capping agent solution, and an alkaline solution in a static tubular mixer to obtain a block oligomer solution.

[0030] In some specific implementations, in step (2), the concentration of the bisphenol TMC salt solution is 10wt%~20wt%;

[0031] The bisphenol TMC salt solution was introduced at a rate of 50 g / min to 150 g / min.

[0032] The temperature of the bisphenol TMC salt solution is 35℃~40℃;

[0033] The reaction time with bisphenol TMC salt solution is 50s~80s;

[0034] The capping agent is one or more of p-tert-butylphenol, phenol, cumylphenol, p-cyanophenol, isooctylphenol, benzoyl chloride, or p-tert-butylbenzoyl chloride;

[0035] The concentration of the capping agent solution is 10wt%~20wt%;

[0036] The rate at which the capping agent solution is introduced is 15 g / min to 25 g / min;

[0037] The temperature of the capping agent solution is 45℃~50℃;

[0038] The reaction time with the capping agent solution is 60s~80s;

[0039] The alkaline solution is one or more of sodium hydroxide solution or potassium hydroxide solution;

[0040] The concentration of the alkaline solution is 25wt%~35wt%;

[0041] The rate at which the alkaline solution is introduced is 30 g / min to 40 g / min;

[0042] The temperature of the alkaline solution is 45℃~50℃;

[0043] The reaction time with the alkaline solution is 50s~70s.

[0044] In some specific implementations, step (3) specifically includes:

[0045] Block oligomer solution, reaction solvent and catalyst solution are subjected to polycondensation reaction in an adiabatic reactor to obtain block copolymer.

[0046] In some specific implementations, in step (3), the outlet temperature of the adiabatic reactor is 65℃~70℃;

[0047] The reaction temperature of the adiabatic reactor is 50℃~55℃;

[0048] The reaction solvent is dichloromethane;

[0049] The rate at which the reaction solvent is introduced is 200 g / min to 500 g / min;

[0050] The temperature of the reaction solvent is 50℃~55℃;

[0051] The catalyst is one or more of trialkylamine, N-ethylpiperidine, or N-isopropylpiperidine;

[0052] The concentration of the catalyst solution is 5wt%~10wt%;

[0053] The catalyst solution is introduced at a rate of 20 g / min to 60 g / min;

[0054] The temperature of the catalyst solution is 50℃~55℃;

[0055] The polycondensation reaction takes 5 to 20 minutes.

[0056] In some specific implementations, step (3) further includes:

[0057] The reaction solution obtained from the polycondensation reaction was subjected to two-phase separation. The resulting oil phase was washed sequentially with dilute acid and deionized water until the conductivity of the aqueous phase was below 10 μS / cm. After removing the solvent, a polycarbonate block copolymer was obtained.

[0058] The preparation method provided in this application includes the following steps: (1) reacting bisphenol A salt with phosgene to obtain an oligomer solution; (2) reacting the oligomer solution sequentially with bisphenol TMC salt and a capping agent to obtain a block oligomer solution; (3) subjecting the block oligomer solution to a polycondensation reaction under the action of a catalyst to obtain a block copolymer. This application adopts a continuous interfacial polycondensation process, introducing rigid bisphenol TMC groups in the form of blocks into the polycarbonate backbone, which improves the conversion rate of bisphenol monomer and the solvent recovery rate, reduces the total reaction time, reduces water consumption, achieves efficient resource utilization and environmental friendliness improvement, and the process is simple. Attached Figure Description

[0059] Figure 1 This is a schematic diagram of the reaction equipment used in the embodiments of this application;

[0060] Figure 2 The high-temperature resistant polycarbonate block copolymer prepared in Example 1 1 H NMR spectrum. Detailed Implementation

[0061] It should be understood that the expression “one or more of…” individually includes each of the objects described after the expression, as well as various different combinations of two or more of the described objects, unless otherwise understood from the context and usage. The expression “and / or” combined with three or more described objects should be understood to have the same meaning, unless otherwise understood from the context.

[0062] The terms “including,” “having,” or “containing,” including the use of their grammatical synonyms, should generally be understood as open-ended and non-restrictive, for example, not excluding other unstated elements or steps, unless otherwise specifically stated or understood from the context.

[0063] It should be understood that the order of steps or the sequence of actions is not important as long as this application remains operational. Furthermore, two or more steps or actions can be performed simultaneously.

[0064] This application provides a low-haze, high-heat-resistant polycarbonate block copolymer, comprising block A of Formula I and block B of Formula II:

[0065] Formula I; Formula II.

[0066] In some specific implementations, the molar ratio of segment A to segment B is 50:50 to 95:5, preferably 60:40 to 90:10, and more preferably 57:43, 70:30 and 90:10.

[0067] In some specific implementations, the weight-average molecular weight of the polycarbonate block copolymer is 35,000 g / mol to 45,000 g / mol, preferably 36,000 g / mol to 44,000 g / mol, and more preferably 36,500 g / mol to 43,500 g / mol;

[0068] In some specific implementations, the haze of the polycarbonate block copolymer is 0.1% to 0.3%, preferably 0.2% to 0.3%, more preferably 0.25%, 0.26%, or 0.29%;

[0069] In some specific implementations, the light transmittance of the polycarbonate block copolymer is 89.0% to 92.0%, preferably 89.0%, 89.2% or 89.3%.

[0070] The low-haze, high-heat-resistant polycarbonate block copolymer provided in this application comprises block A as shown in Formula I and block B as shown in Formula II, wherein the molar ratio of block A to block B is 50:50 to 95:5. This application introduces bisphenol TMC rigid groups into the polycarbonate molecule in the form of blocks, synergistically improving the heat resistance, impact resistance, and optical properties of polycarbonate. This makes polycarbonate particularly suitable for high-end industrial fields with stringent requirements for high-temperature stability, mechanical properties, light transmittance, and transparency, such as optical devices, precision automotive parts, and electronic packaging materials. Experimental results show that the polycarbonate block copolymer provided in this application has a glass transition temperature (Tg) of 200-210℃, a Vicat softening point of 190-210℃, a heat distortion temperature (HDT) of 170-180℃, a light transmittance >89%, and a haze <0.3%, exhibiting excellent heat resistance, mechanical properties, and optical transparency.

[0071] This application also provides a method for preparing the low-haze, high-heat-resistant polycarbonate block copolymer described in the above technical solution, comprising the following steps:

[0072] (1) Bisphenol A salt reacts with phosgene to obtain an oligomer solution;

[0073] (2) The oligomer solution is reacted sequentially with bisphenol TMC salt and end-capping agent to obtain a block oligomer solution;

[0074] (3) The block oligomer solution undergoes a polycondensation reaction under the action of a catalyst to obtain a block copolymer.

[0075] This application preferably employs a continuous interfacial polycondensation process using static mixers in series to prepare low-haze, high-heat-resistant polycarbonate block copolymers. See [link to relevant documentation]. Figure 1 , Figure 1This is a schematic diagram of the reaction equipment used in the embodiments of this application, wherein SM1 is a three-way static mixer, SM2 is a static tubular mixer with an inner diameter of 6mm, and 1 is an adiabatic reactor. The outlet of the three-way static mixer SM1 is connected to the inlet of the static tubular mixer SM2 through a spraying device (not shown in the figure), and the outlet of the static tubular mixer SM2 is connected to the adiabatic reactor 1.

[0076] This application first reacts bisphenol A salt with phosgene to obtain an oligomer solution with a bisphenol A structure, specifically including the following steps:

[0077] The reaction solvent and phosgene are mixed in a three-way static mixer and then sprayed with a bisphenol A salt solution in a static tubular mixer to obtain oligomers.

[0078] In some specific implementations, the reaction solvent includes, but is not limited to, dichloromethane, 1,2-dichloroethane, chlorobenzene, and o-dichlorobenzene, and may be one or more of these, preferably dichloromethane. In some specific implementations, the reaction solvent is introduced at a rate of 125 g / min to 350 g / min, preferably 150 g / min to 300 g / min, and more preferably 200 g / min to 230 g / min. In some specific implementations, the phosgene temperature is -10℃ to 0℃, preferably -5℃ to 0℃. This application uses phosgene below 0℃ as a raw material, utilizing the temperature difference to promote rapid reaction and avoid local overheating leading to side reactions. In some specific implementations, the phosgene introduction rate is 25 g / min to 35 g / min, preferably 28 g / min to 31 g / min. In some specific implementations, the concentration of phosgene in the solution after mixing phosgene and dichloromethane is 10 wt% to 20 wt%, preferably 13 wt% to 15 wt%. In some specific implementations, the mixing time is 5s to 15s, preferably 10s. This application directly mixes phosgene and the reaction solvent, then reacts them with a bisphenol A salt solution, eliminating the need for a pre-photochemical stage. This improves the phosgene monomer conversion rate to over 99%, shortens the total reaction time to below 30 minutes, and reduces the time by more than 50% compared to traditional processes.

[0079] Phosgene and the reaction solvent are mixed and then atomized and sprayed with a bisphenol A salt solution in a static tubular mixer. The phosgene solution forms micron-sized droplets in atomized form, which, when mixed with the bisphenol A salt solution, accelerate interfacial polymerization through turbulent mixing, improving mass transfer efficiency, increasing contact area, thereby enhancing reaction efficiency, increasing monomer conversion rate, shortening reaction time, and reducing byproduct formation. In some specific implementations, the atomization spraying pressure is 0.5 MPa to 1.0 MPa, preferably 0.6 MPa to 0.8 MPa. In some specific implementations, the atomization spraying temperature is 45℃ to 50℃, preferably 46℃ to 48℃. In some specific implementations, the droplet size formed by the atomization spraying is less than 50 μm, preferably less than 45 μm.

[0080] In some specific implementations, the bisphenol A salt solution is a sodium bisphenol A solution, and the chemical name of bisphenol A is 2,2-bis(p-hydroxyphenyl)propane, abbreviated as BPA. In some specific implementations, the sodium bisphenol A solution is obtained by reacting water, sodium hydroxide, and bisphenol A, wherein the molar ratio of sodium hydroxide to bisphenol A is 2:1. In some specific implementations, the concentration of the bisphenol A salt solution is 10wt%~20wt%, preferably 14wt%~16wt%. In some specific implementations, the influent rate of the bisphenol A salt solution is 300g / min~800g / min, preferably 320g / min~750g / min. In some specific implementations, the temperature of the bisphenol A salt solution is 35℃~40℃, preferably 35℃~37℃. In some specific implementations, the reaction temperature of phosgene and bisphenol A salt is room temperature, and the reaction time is 5s~15s, preferably 10s.

[0081] After obtaining the oligomers, the oligomer solution is reacted sequentially with a bisphenol TMC salt solution, a capping agent solution, and an alkaline solution in a static tubular mixer to obtain a block oligomer solution. In some specific implementations, the bisphenol TMC salt solution is a sodium bisphenol TMC solution, and the chemical name of bisphenol TMC is 4,4'-(3,3,5-trimethylcyclohexane-1,1-diyl)diphenol, abbreviated as BPTMC. In some specific implementations, the sodium bisphenol TMC solution is obtained by mixing and reacting water, sodium hydroxide, and bisphenol TMC, wherein the molar ratio of sodium hydroxide to bisphenol TMC is 2:1. In some specific implementations, the concentration of the bisphenol TMC salt solution is 10wt%~20wt%, preferably 17wt%~19wt%. In some specific implementations, the flow rate of the bisphenol TMC salt solution is 50g / min~150g / min, preferably 80g / min~120g / min. In some specific implementations, the temperature of the bisphenol TMC salt solution is 35℃~40℃, preferably 35℃~37℃. In some specific implementations, the reaction time between the oligomer and the bisphenol TMC salt solution is 50s~80s, preferably 60s~70s, and more preferably 65s.

[0082] In some specific implementations, the capping agent includes, but is not limited to, p-tert-butylphenol, phenol, cumylphenol, p-cyanophenol, isooctylphenol, benzoyl chloride, or p-tert-butylbenzoyl chloride, and may be one or more of these, preferably p-tert-butylphenol. In some specific implementations, the capping agent solution is a solution of the capping agent and the reaction solvent, and the concentration of the capping agent solution is 10wt%~20wt%, preferably 11wt%~13wt%. In some specific implementations, the infeed rate of the capping agent solution is 15g / min~25g / min, preferably 17g / min~23g / min. In some specific implementations, the temperature of the capping agent solution is 45℃~50℃, preferably 48℃~50℃. In some specific implementations, the reaction time with the capping agent solution is 60s~80s, preferably 65s~75s, more preferably 75s.

[0083] In some specific implementations, the alkaline solution includes, but is not limited to, sodium hydroxide solution or potassium hydroxide solution, and may be one or more of these, preferably sodium hydroxide solution. In some specific implementations, the concentration of the alkaline solution is 25wt%~35wt%, preferably 30wt%~32wt%. In some specific implementations, the rate at which the alkaline solution is introduced is 30g / min~40g / min, preferably 35g / min~37g / min. In some specific implementations, the temperature of the alkaline solution is 45℃~50℃, preferably 48℃~50℃. In some specific implementations, the reaction time with the alkaline solution is 50s~70s, preferably 55s~65s, more preferably 62s.

[0084] In some specific implementations, when the oligomer solution reacts sequentially with bisphenol TMC salt and capping agent, the pH value of the system does not exceed 13.

[0085] After obtaining the block oligomer solution, it is subjected to a polycondensation reaction under the action of a catalyst to obtain a block copolymer. Specifically, the block oligomer solution, reaction solvent and catalyst solution are subjected to a polycondensation reaction in an adiabatic reactor to obtain a block copolymer.

[0086] In some specific implementations, the reaction solvent includes, but is not limited to, dichloromethane, 1,2-dichloroethane, chlorobenzene, and o-dichlorobenzene, and may be one or more of these, preferably dichloromethane. In some specific implementations, the reaction solvent is introduced at a rate of 200 g / min to 500 g / min, preferably 250 g / min to 400 g / min. In some specific implementations, the reaction solvent is heated at a temperature of 50°C to 55°C, preferably 53°C to 55°C. In some specific implementations, the catalyst includes, but is not limited to, trialkylamines, N-ethylpiperidine, or N-isopropylpiperidine, and may be one or more of these, preferably trialkylamines, such as triethylamine. In some specific implementations, the catalyst solution concentration is 5 wt% to 10 wt%, preferably 6 wt% to 8 wt%. The catalyst solution is introduced at a rate of 20 g / min to 60 g / min, preferably 25 g / min to 59 g / min. In some specific implementations, the temperature of the catalyst solution is 50℃~55℃, preferably 53℃~55℃. In some specific implementations, the reaction temperature of the polycondensation reaction is 50℃~55℃, i.e., the reaction temperature of the adiabatic reactor is 50℃~55℃, preferably 52℃~54℃. In some specific implementations, the time of the polycondensation reaction is 5min~20min, preferably 10min. In some specific implementations, the outlet temperature of the adiabatic reactor is 65℃~70℃, preferably 67℃~69℃.

[0087] After the reaction is complete, the resulting reaction solution is subjected to two-phase separation to obtain an aqueous phase and an oil phase. The oil phase is washed sequentially with dilute acid and deionized water until the conductivity of the aqueous phase is below 10 μS / cm. After solvent removal, the polymer is obtained. The polymer is then pulverized and dried to obtain a polycarbonate block copolymer. In some specific implementations, the dilute acid is preferably hydrochloric acid with a concentration of 5wt% to 15wt%. The drying temperature is 100℃ to 140℃, preferably 120℃, and the drying time is 3h to 5h, preferably 4h.

[0088] The preparation method provided in this application includes the following steps: (1) reacting bisphenol A salt with phosgene to obtain an oligomer solution; (2) reacting the oligomer solution sequentially with bisphenol TMC salt and a capping agent to obtain a block oligomer solution; (3) subjecting the block oligomer solution to a polycondensation reaction under the action of a catalyst to obtain a block copolymer. This application adopts a continuous interfacial polycondensation process, introducing rigid bisphenol TMC groups in the form of blocks into the polycarbonate backbone, which improves the conversion rate of bisphenol monomers and the solvent recovery rate, reduces the total reaction time, reduces water consumption, achieves efficient resource utilization and environmental friendliness, and the process is simple. Experimental results show that in the preparation method provided in this application, the conversion rate of bisphenol monomers is >99%, the aqueous phase residue is <40ppm, the solvent recovery rate is >95%, and the water consumption per unit product is reduced by 40%.

[0089] The present application is further illustrated below with reference to embodiments. The scope of protection of the present application is not limited to the following embodiments.

[0090] The reaction apparatus used in the following embodiments is as follows: Figure 1 As shown, Figure 1 This is a schematic diagram of the reaction equipment used in the embodiments of this application, wherein SM1 is a three-way static mixer, SM2 is a static tubular mixer with an inner diameter of 6mm, and 1 is an adiabatic reactor. The outlet of the three-way static mixer SM1 is connected to the inlet of the static tubular mixer SM2 through a spraying device (not shown in the figure), and the outlet of the static tubular mixer SM2 is connected to the adiabatic reactor 1.

[0091] Example 1

[0092] (1) Preparation of prepolymerization reaction solution

[0093] Deionized water and sodium hydroxide were mixed with bisphenol A (molar ratio of sodium hydroxide to bisphenol A 2:1) and bisphenol TMC (molar ratio of sodium hydroxide to bisphenol TMC 2:1) respectively to prepare 15 wt% sodium bisphenol A salt and 18.5 wt% sodium bisphenol TMC salt respectively.

[0094] p-tert-butylphenol and dichloromethane were mixed to prepare a 12 wt% p-tert-butylphenol solution;

[0095] Triethylamine was mixed with dichloromethane to prepare a 6 wt% triethylamine solution in dichloromethane.

[0096] (2) Polymerization reaction

[0097] Dichloromethane solution was introduced into a three-way static mixer SM1 at a rate of 206.7 g / min and phosgene at 0°C at a rate of 27.9 g / min for mixing. The mixture was then atomized and sprayed into a static tubular mixer SM2 at a pressure of 0.8 MPa and a temperature of 50°C. The atomized droplets had a particle size of less than 45 μm. These droplets were then sequentially mixed with bisphenol A sodium salt at a feed rate of 762.6 g / min and a temperature of 35°C for 10 s, with bisphenol TMC sodium salt solution at a feed rate of 89.9 g / min and a temperature of 35°C for 65 s, with PTBP solution at a feed rate of 21.4 g / min and a temperature of 48°C for 75 s, and with 32 wt% NaOH solution at a feed rate of 36.2 g / min and a temperature of 50°C for 62 s. The pH of the system was maintained below 13 to complete the oligomerization reaction, and the reaction outlet temperature was controlled at 67°C.

[0098] After the oligomers are introduced into the adiabatic reactor 1, a dichloromethane solution at 55°C is introduced into the stirrer at a rate of 276.9 g / min and a triethylamine dichloromethane solution at 55°C at a rate of 27.7 g / min. The mixture is then stirred for 10 min to complete the polycondensation reaction.

[0099] (3) Post-processing

[0100] After the reaction, the water and oil phases were separated, and the aqueous phase was directly analyzed. The oil phase was first washed with 10wt% dilute hydrochloric acid, and then washed with deionized water until the conductivity of the aqueous phase was below 10 μS / cm. After removing the solvent from the oil phase, the obtained polymer was pulverized and dried in a vacuum oven at 120℃ for 4 hours to obtain a polycarbonate block copolymer.

[0101] Example 2

[0102] The difference from Example 1 is that the feed rate of the bisphenol BPA sodium salt solution is 436.4 g / min and the feed rate of the bisphenol TMC sodium salt solution is 140.9 g / min, while the other steps are the same.

[0103] Example 3

[0104] The difference from Example 1 is that the feed rate of the bisphenol BPA sodium salt solution is 327.3 g / min and the feed rate of the bisphenol TMC sodium salt solution is 327.1 g / min, while the other steps are the same.

[0105] Example 4

[0106] The difference from Example 3 is that the phosgene feed rate is 29.5 g / min, the phosgene ratio (the ratio of the total molar amount of bisphenol A and bisphenol TMC to the molar amount of phosgene) is 1:1.25, and the other steps are the same.

[0107] Example 5

[0108] The difference from Example 3 is that the phosgene feed rate is 30.6 g / min and the phosgene ratio is 1:1.30, while the other steps are the same.

[0109] Example 6

[0110] The difference from Example 3 is that the PTBP feed rate is 20.3 g / min and the PTBP molar amount is 3.6 mol, while the other steps are the same.

[0111] Example 7

[0112] The difference from Example 3 is that the PTBP feed rate is 20.9 g / min and the PTBP molar amount is 3.7 mol, while the other steps are the same.

[0113] Example 8

[0114] The difference from Example 3 is that the PTBP feed rate is 22.0 g / min and the PTBP molar amount is 3.9 mol, while the other steps are the same.

[0115] Example 9

[0116] The difference from Example 3 is that the PTBP feed rate is 22.6 g / min and the PTBP molar amount is 4.0 mol, while the other steps are the same.

[0117] Example 10

[0118] The difference from Example 3 is that the TEA feed rate is 39.4 g / min and the TEA content is 800 ppm, while the other steps are the same.

[0119] Example 11

[0120] The difference from Example 3 is that the TEA feed rate is 44.3 g / min and the TEA content is 900 ppm, while the other steps are the same.

[0121] Example 12

[0122] The difference from Example 3 is that the TEA feed rate is 49.2 g / min and the TEA content is 1000 ppm, while the other steps are the same.

[0123] Example 13

[0124] The difference from Example 3 is that the TEA feed rate is 58.9 g / min and the TEA content is 1200 ppm, while the other steps are the same.

[0125] Example 14

[0126] The difference from Example 3 is that, in the polycondensation stage, the feed rate of dichloromethane is 417.2 g / min, the solution concentration of the block oligomer is 13 wt%, and the other steps are the same.

[0127] Example 15

[0128] The difference from Example 3 is that, during the polycondensation stage, the feed rate of dichloromethane was 363.6 g / min. The solution concentration of the block oligomer was 14 wt%, and the other steps were the same.

[0129] Example 16

[0130] The difference from Example 3 is that, during the polycondensation stage, the feed rate of dichloromethane was 317.23 g / min. The solution concentration of the block oligomer was 15 wt%, and the other steps were the same.

[0131] Comparative Example 1

[0132] The comparative example is ordinary PC, with a melt flow index (MFR) of 3g / 10min (5min at 300℃ for 1200g).

[0133] Test case

[0134] The polycarbonate block copolymers prepared in the embodiments and comparative examples of this application were tested according to the following methods:

[0135] 1. Method for detecting bisphenol TMC content:

[0136] The ¹H NMR spectrum of the high-temperature resistant polycarbonate block copolymer was detected using nuclear magnetic resonance (NMR) spectrometry, taking Example 1 as an example, see [link to example]. Figure 2 , Figure 2 The high-temperature resistant polycarbonate block copolymer prepared in Example 1 1 H NMR spectrum Figure 2 In the figure, the peak with a chemical shift of δ=1.00 ppm is the proton characteristic absorption peak of the methyl group in the bisphenol TMC structural unit, and the peak with a chemical shift of δ=1.68 ppm is the proton characteristic absorption peak of the methyl group in the bisphenol A structural unit.

[0137] The bisphenol TMC content is calculated using the formula A(δ1.68) / [A(δ1.68)+A(δ1.0)]×100%, where A is the integral area.

[0138] 2. Determination of polymer molecular weight and small molecule content

[0139] The molecular weight of high-temperature resistant polycarbonate block copolymers was determined using a gel permeation chromatography (GPC) system, specifically a Shimadzu RESERVOIR TRAY model. The mobile phase was tetrahydrofuran, the flow rate was 1 mL / min, polystyrene (PSt) was used as the standard, the column temperature was 40 °C, and the test time was 30 min. The fraction with a molecular weight <4000 g / mol was defined as the low molecular weight content.

[0140] 3. Detection methods and conversion calculation of bisphenol TMC and bisphenol A residues in aqueous phase.

[0141] The residual amounts of bisphenol TMC and bisphenol A in the aqueous phase of the final reaction solution were determined using high-performance liquid chromatography (HPLC). The mobile phase was a methanol:water mixture (methanol:water = 8:2), the column temperature was 40℃, and the flow rate was 1 mL / min. Quantitative analysis was performed using either the external standard method or the internal standard method.

[0142] The conversion rate calculation formula is as follows:

[0143] Conversion rate (%) = [(Initial BPA or TMC quality − Residual BPA or TMC quality) / Initial BPA or TMC quality] × 100%

[0144] 4. Methods for testing transmittance, haze, and YI value

[0145] The granules were molded into square samples of 600mm × 60mm × 2mm using an injection molding machine (injection molding conditions: mold temperature 80℃, barrel temperature 300℃). The light transmittance was determined according to ISO 13468, the haze was determined according to ISO 14782, and the YI value was determined according to ASTM E313 (transmission method).

[0146] 5. Tg detection method

[0147] The glass transition temperature (Tg) was determined using differential scanning calorimetry (DSC) according to ISO 11357. Test conditions: heating rate 20℃ / min, nitrogen flow rate 20mL / min, sample mass 5mg~10mg.

[0148] 6. Solvent Recovery Rate Determination Method

[0149] After the reaction, the organic phase was separated by centrifugation, and the oil phase was subjected to vacuum distillation at 50°C and 0.1 MPa to collect dichloromethane. The purity of the recovered solvent was determined using a gas chromatograph (GC) of Agilent 7890B. The recovery rate was calculated using the following formula:

[0150] Recovery rate (%) = Initial input solvent mass / Recovered solvent mass × 100%

[0151] 7. Water resource consumption testing methods

[0152] Water consumption at each stage is monitored in real time using a flow meter. The formula for calculating unit water consumption is:

[0153] Unit water consumption = (Total process water consumption - Recycled water consumption) / Product output

[0154] 8. Melt Index Test Method

[0155] Melt flow rate (MFR) was tested using a melt flow rate meter according to ISO 1133 standard. Test conditions: temperature 330℃, load 2.16kg. Pellet was added to the barrel, preheated, and then a load was applied. The melt extruded material was cut, and the mass extruded per unit time was calculated (unit: g / 10min).

[0156] 9. Vicat softening temperature and heat distortion temperature test methods

[0157] The Vicat softening temperature was determined according to ISO 306 standard using a heat distortion tester (test conditions: load 50 N, heating rate 120 °C / h). The heat distortion temperature was determined according to ISO 75 standard (test conditions: load 1.80 MPa, heating rate 120 °C / h). The sample size was 80 mm × 10 mm × 4 mm.

[0158] 10. Tensile and bending performance test methods

[0159] Tensile strength, elongation at break, and modulus of elasticity were determined using a universal testing machine according to ISO 527 standard. The sample was dumbbell-shaped, and the testing speed was 50 mm / min. Flexural strength and flexural modulus were determined according to ISO 178 standard. The sample size was 80 mm × 10 mm × 4 mm, and the testing speed was 2 mm / min.

[0160] The results are shown in Tables 1-5:

[0161] Table 1 Data on different molar ratios of BPTMC / BPA

[0162]

[0163] Table 2 Data for different phosgene ratios

[0164]

[0165] Table 3. Data on different PTBP molar amounts

[0166]

[0167] Table 4 Data on different TEA contents

[0168]

[0169] Table 5 Data on different solution concentrations

[0170]

[0171] As shown in Tables 1 to 5, the polycarbonate block copolymers prepared in the embodiments of this application have good heat resistance and optical transparency. In particular, the heat resistance is significantly improved. For example, the polycarbonate block copolymer prepared in Example 3 has a glass transition temperature of up to 200.55℃, a Vicat softening temperature of 199.8℃, and a heat distortion temperature of 172.5℃, which are far superior to the ordinary polycarbonate in the comparative example. At the same time, the optical haze is low, only 0.25%, and the light transmittance reaches 89.3%, which has excellent optical clarity and meets the stringent requirements for material quality in high-end transparent application scenarios.

[0172] In summary, the polycarbonate block copolymer prepared by this invention achieves breakthroughs in key properties such as high heat resistance and low haze through synergy, effectively overcoming the common problems of insufficient heat resistance of ordinary polycarbonate, complex existing modification processes, and decreased optical performance. It has clear application potential and market competitive advantages in fields such as automotive lighting, optical devices, and high-end electronic packaging that require high transparency and high temperature resistance.

[0173] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this application, based on the technical solution and application concept of this application, should be included within the scope of protection of this application.

Claims

1. A low-haze high-heat-resistant polycarbonate block copolymer, comprising an A block shown in formula I and a B block shown in formula II: wherein the molar ratio of the A block to the B block is 50:50-95:

5. Formula I; Formula II; The weight average molecular weight of the low-haze high-heat-resistant polycarbonate block copolymer is 35 000 g / mol-45 000 g / mol.

2. The block copolymer of claim 1, wherein The haze of the low-haze high-heat-resistant polycarbonate block copolymer is 0.1%-0.3%. The light transmittance of the low-haze high-heat-resistant polycarbonate block copolymer is 89.0%-92.0%. 3.A method for preparing the low-haze high-heat-resistant polycarbonate block copolymer according to claim 1 or 2, comprising the following steps: (1) reacting bisphenol A salt with phosgene to obtain an oligomer solution; (2) sequentially reacting the oligomer solution with bisphenol TMC salt and a capping agent to obtain a block oligomer solution; (3) performing polycondensation reaction on the block oligomer solution under the action of a catalyst to obtain a block copolymer. The step (1) specifically comprises: mixing a reaction solvent and phosgene in a three-way static mixer, and then mixing the mixture with a bisphenol A salt solution in a static tubular mixer by atomizing spraying to obtain an oligomer.

4. The preparation method according to claim 3, characterized in that, In the step (1), the reaction solvent can be one or more of dichloromethane, 1,2-dichloroethane, chlorobenzene and o-dichlorobenzene.

5. The preparation method according to claim 4, characterized in that, The feeding rate of the reaction solvent is 125 g / min-350 g / min. The temperature of the phosgene is -10℃-0℃. The concentration of the phosgene in the mixture of the phosgene and the reaction solvent is 10wt%-20wt%. The feeding rate of the phosgene is 25 g / min-35 g / min. The concentration of the bisphenol A salt solution is 10wt%-20wt%. The feeding rate of the bisphenol A salt solution is 300 g / min-800 g / min. The temperature of the bisphenol A salt solution is 35℃-40℃. The pressure of the atomizing spraying is 0.5 MPa-1.0 MPa. The temperature of the atomizing spraying is 45℃-50℃. The reaction time is 5 s-15 s. The step (2) specifically comprises:

6. The preparation method according to claim 3, characterized in that, sequentially reacting the oligomer solution with a bisphenol TMC salt solution, a capping agent solution and an alkali solution in a static tubular mixer to obtain a block oligomer solution. In the step (2), the concentration of the bisphenol TMC salt solution is 10wt%-20wt%.

7. The preparation method according to claim 6, characterized in that, The feeding rate of the bisphenol TMC salt solution is 50 g / min-150 g / min. The temperature of the bisphenol TMC salt solution is 35℃-40℃. The reaction time with the bisphenol TMC salt solution is 50 s-80 s. The capping agent is one or more of p-tert-butyl phenol, phenol, cumyl phenol, p-cyanophenol, isooctyl phenol, benzoyl chloride or p-tert-butyl benzoyl chloride. The concentration of the capping agent solution is 10wt%-20wt%. The feeding rate of the capping agent solution is 15 g / min-25 g / min. The temperature of the capping agent solution is 45℃-50℃. The reaction time with the capping agent solution is 60 s-80 s. The alkali solution is one or more of sodium hydroxide solution or potassium hydroxide solution. The concentration of the alkali solution is 25wt%-35wt%. ​ The feeding rate of the lye is 30-40 g / min; The temperature of the lye is 45-50℃; The reaction time with the lye is 50-70 s.

8. The preparation method according to claim 3, characterized in that, The step (3) specifically comprises: The block oligomer solution, the reaction solvent and the catalyst solution are subjected to polycondensation reaction in an adiabatic reactor to obtain a block copolymer.

9. The preparation method according to claim 8, characterized in that, In the step (3), the outlet temperature of the adiabatic reactor is 65-70℃; The reaction temperature of the adiabatic reactor is 50-55℃; The reaction solvent is dichloromethane; The feeding rate of the reaction solvent is 200-500 g / min; The temperature of the reaction solvent is 50-55℃; The catalyst is one or more of trialkylamine, N-ethylpiperidine or N-isopropylpiperidine; The concentration of the catalyst solution is 5-10 wt%; The feeding rate of the catalyst solution is 20-60 g / min; The temperature of the catalyst solution is 50-55℃; The polycondensation reaction time is 5-20 min.

10. The preparation method according to any one of claims 3 to 9, characterized in that, The step (3) further comprises: The reaction solution obtained by the polycondensation reaction is subjected to two-phase separation, and the obtained oil phase is sequentially washed with dilute acid and deionized water until the water phase conductivity is less than or equal to 10 μS / cm, and then the polycarbonate block copolymer is obtained by removing the solvent.

Images