Polysiloxane polycarbonate resin with high silicon content and large particle size as well as preparation method and application thereof

Abstract

The invention provides polysiloxane polycarbonate resin with high silicon content and large particle size as well as a preparation method and application of the polysiloxane polycarbonate resin. The polysiloxane polycarbonate resin with high silicon content and large particle size is formed by connecting bisphenol A polycarbonate chain segments and phenolic hydroxyl terminated polysiloxane through chemical bonds, the silicon element content in the polysiloxane polycarbonate resin with high silicon content and large particle size is 20-30 wt%; the phenolic hydroxyl terminated polysiloxane forms silicon groups with the average particle size of 1-5 microns in a bisphenol A polycarbonate chain segment matrix, and the particle size distribution index is less than 1.3; through raw material system optimization and silicon group form control, the notch impact strength of the resin at-40 DEG C reaches 70 KJ / m or above, meanwhile, the excellent normal-temperature high-strength performance is kept, and the resin is applied to low-temperature-resistant and weather-resistant products related to the automobile industry, new energy automobiles, the photovoltaic field, aerospace and the like.

Description

Technical Field

[0001] This invention relates to the field of polymer materials, and in particular to a high-silicon-content, large-particle-size polysiloxane polycarbonate resin, its preparation method, and its applications. Background Technology

[0002] Polysiloxane-polycarbonate (Si-PC) copolymers, as high-performance representatives in the field of polymer materials, combine the high mechanical strength and excellent heat resistance of polycarbonate (PC) with the outstanding high and low temperature toughness and weather resistance of polysiloxane (PDMS). In extreme environmental applications, such as automotive parts in frigid northern regions, battery pack shells for new energy vehicles, and aerospace structural components operating under high-altitude and low-temperature conditions, the materials must withstand both low-temperature testing and complex external forces. They must not only maintain good impact toughness in extreme low-temperature environments such as -40℃ to avoid sudden fracture due to embrittlement, but also possess excellent high strength at room temperature to meet structural load-bearing and safety protection requirements.

[0003] However, improving the performance of Si-PC copolymers in existing technologies has always faced a core bottleneck. To improve low-temperature performance, existing technologies often increase the silicon content. However, when the silicon content exceeds 15 wt%, the agglomeration tendency of siloxane segments increases significantly, further exacerbating the problem of uneven particle size distribution and creating a performance contradiction of "improved low-temperature toughness and decreased room-temperature strength." Simultaneously, the single solvent system (such as dichloromethane) and conventional reaction media used in traditional preparation processes lack the ability to precisely control the growth of siloxane segments, failing to guide them to form an ideal dispersion morphology. This results in either excessive agglomeration of silicon clusters with excessively large particle sizes or excessively fine dispersion with ineffective toughening. Furthermore, some processes use finished PC resin or low-purity bisphenol A monomers as raw materials. Finished PC resin, due to its large molecular weight, is difficult to participate in interfacial polycondensation reactions, while impurities in low-purity monomers interfere with the uniformity of the polymerization reaction, further disrupting the dispersion state of siloxane segments and exacerbating performance imbalances.

[0004] The current market demand for high-end Si-PC materials is increasingly urgent. Existing products, due to the challenge of controlling silicon cluster size, cannot achieve a synergistic improvement in both high and low temperature impact strength and overall strength, severely limiting their application in high-end fields. Therefore, how to optimize the preparation process and raw material system, precisely control the dispersion morphology of siloxane segments, obtain a silicon cluster structure with moderate particle size and uniform distribution, and overcome the technical bottleneck of "excessively large particle size leading to easy destruction, and excessively small particle size making toughening difficult," to achieve a synergistic improvement in both low-temperature high impact strength and room-temperature high strength, has become a key technical problem urgently needing to be solved in this field. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to provide a preparation scheme and application of high silicon content and large particle size polysiloxane polycarbonate resin. By optimizing the raw material system and preparation process, the dispersion morphology of siloxane segments is precisely controlled, breaking through the technical bottleneck that "when the silicon content is too high, the silicon agglomerate particle size is too large and easily subject to shear damage, while when the particle size is too small, it is difficult to form an effective toughening structure." This achieves a synergistic improvement in the low-temperature high impact performance and room-temperature high strength of Si-PC materials, meeting the application needs of high-end fields.

[0006] The technical solution of the present invention: This invention discloses a high-silicon-content, large-particle-size polysiloxane polycarbonate resin, wherein the high-silicon-content, large-particle-size polysiloxane polycarbonate resin is formed by chemically bonding bisphenol A-type polycarbonate segments and phenolic hydroxyl-terminated polysiloxanes, wherein the silicon content in the high-silicon-content, large-particle-size polysiloxane polycarbonate resin is 20-30 wt%; the phenolic hydroxyl-terminated polysiloxanes form silicon clusters with an average particle size of 1-5 μm in the bisphenol A-type polycarbonate segment matrix, and the particle size distribution index is less than 1.3.

[0007] Furthermore, the segments of the phenolic hydroxyl-terminated polysiloxane contain dimethylsiloxane units and diphenylsiloxane units, with the diphenylsiloxane units accounting for 5-15% of the total molar fraction of the phenolic hydroxyl-terminated polysiloxane segments.

[0008] Furthermore, the bisphenol A polycarbonate segments are derived from bisphenol A monomers; the bisphenol A monomers are selected from one or more of 2,2-bis(4-hydroxyphenyl)propane, refined bisphenol A, or electronic-grade bisphenol A.

[0009] This invention provides a method for preparing high-silicon-content, large-particle-size polysiloxane polycarbonate resin, characterized by employing a phosgene-based interfacial polycondensation process, comprising the following steps: (1) Mix bisphenol A monomer, phenolic hydroxyl-terminated polysiloxane, sodium hydroxide and water, and stir until completely dissolved to generate a mixed aqueous phase of sodium bisphenol A salt and sodium phenolic hydroxyl-terminated polysiloxane salt; (2) Add dichloromethane and p-cumylphenol to the mixed aqueous phase of step (1), and add the phase transfer catalyst tetrabutylammonium bromide, and stir to form a stable oil-water two-phase system; (3) Control the temperature of the system in step (2) to be 15-30℃, the stirring speed to be 180-220rpm, and introduce phosgene into the system at a rate of 0.6-0.9kg / min to carry out interfacial polycondensation reaction for 1.5-2.5 hours. (4) After the reaction is completed, phenol is added to terminate the reaction. After standing and separating the layers, the organic phase is separated. The organic phase is acid-washed and water-washed until neutral. It is then poured into methanol to precipitate, filtered, and vacuum dried to obtain the high silicon content, large particle size polysiloxane polycarbonate resin.

[0010] Furthermore, in step (1), the mass ratio of bisphenol A monomer to phenol hydroxyl-terminated polysiloxane is 0.4-1.1:1.

[0011] Furthermore, in step (2), the volume ratio of dichloromethane to the mixed aqueous phase is 1.2-1.5:1, and the amount of p-cumylphenol added is 1-3% of the total mass of bisphenol A monomer and phenol hydroxyl-terminated polysiloxane.

[0012] Furthermore, the phosgene in step (3) is carbonyl chloride, and the amount of phosgene used is 1.05-1.2 times the total molar amount of phenolic hydroxyl groups of the bisphenol A monomer and the phenolic hydroxyl-terminated polysiloxane.

[0013] The present invention provides a resin composition characterized in that it comprises a high-silicon-content, large-particle-size polysiloxane polycarbonate resin prepared according to the present invention, as well as a plasticizer, an anti-aging agent, an antioxidant, an ultraviolet absorber, and a flame retardant.

[0014] The high-silicon-content, large-particle-size polysiloxane polycarbonate resin provided by this invention is applied to low-temperature and weather-resistant products.

[0015] Furthermore, the high-silicon-content, large-particle-size polysiloxane polycarbonate resin provided by this invention can be applied to low-temperature and weather-resistant products in the automotive industry, new energy vehicles, photovoltaic field, and aerospace.

[0016] Beneficial effects: 1. This invention optimizes the silicon content and silicon cluster morphology, enabling the resin to achieve a notched impact strength ≥70KJ / m² at -40℃ and a tensile strength ≥65MPa at room temperature, thus achieving a synergistic improvement in high and low temperature impact performance and high strength.

[0017] 2. Using dichloromethane as a solvent and p-cumylphenol as a reaction medium, along with precise process parameters, the phase separation of siloxane segments in the matrix is ​​effectively controlled, forming silicon clusters with moderate particle size and uniform distribution. Under external force, a mesh-like crack pattern is generated, which has anti-explosion and anti-fragmentation characteristics.

[0018] 3. The preparation process is mature and controllable, the raw materials are readily available, the reaction conditions are mild, it is suitable for industrial production, the product has a wide range of applications, and can meet the material performance requirements of multiple high-end fields. Detailed Implementation

[0019] The present invention will be described below with reference to specific embodiments. It should be noted that the following embodiments are examples of the present invention and are used only to illustrate the invention, not to limit it. Other combinations and various modifications within the scope of the present invention can be made without departing from its spirit or scope.

[0020] The phosgene-based interfacial polycondensation reaction described in this invention is carried out under strict safety regulations to ensure the feasibility and environmental friendliness of the process. Specific safety measures include: Closed reaction system: The entire reaction and post-processing process is carried out in a special equipment with negative pressure and airtightness. All interfaces and valves have undergone strict airtightness tests to fundamentally prevent phosgene leakage.

[0021] Online monitoring and linkage: A highly sensitive online monitoring and alarm device for phosgene concentration is installed around the reactor. Once a trace leak is detected, the emergency absorption system can be immediately linked and the feed can be automatically cut off.

[0022] Tail gas harmless treatment: The tail gas generated during the reaction process and the system purging gas after the reaction are completely destroyed by two-stage or multi-stage alkaline solution (sodium hydroxide solution) absorption towers to ensure that the emission gas does not contain phosgene, and the by-product sodium chloride solution can be used for subsequent wastewater treatment.

[0023] Operating procedures: Operators must be professionally trained and equipped with personal protective equipment such as positive pressure air respirators. All operations must follow established safety procedures.

[0024] The phenol-terminated modified silicone oil was purchased from Hubei Langbowan Biomedical Co., Ltd., CAS: 158167-48-7.

[0025] Unless otherwise specified, all chemical reagents used in this invention are commercially available analytical grade reagents.

[0026] Preparation of phenolic hydroxyl-terminated polysiloxane A: S1: Add 2L of toluene to a 5L three-necked flask, cool to 0℃ in an ice-water bath under nitrogen protection, mix dimethyldichlorosilane (201.6g) and diphenyldichlorosilane (33.0g), slowly add toluene, stir for 30 minutes, control the temperature at 0℃, add 198g of deionized water dropwise, and react at 25℃ for 2.5h after the addition is complete to obtain hydroxyl-terminated oligomers; S2: Add 6.7g of concentrated sulfuric acid to the hydroxyl-terminated oligomer from step S1, heat to 45℃, and react for 5 hours; add 10wt% sodium hydroxide aqueous solution to neutralize to pH=7, let stand to separate the layers, separate the aqueous phase, and retain the organic phase; S3: Add 42.5g of phenol and 0.21g of p-toluenesulfonic acid to the organic phase of step S2, heat to 85℃, and react for 3.5 hours; remove toluene and unreacted phenol by vacuum distillation at 80℃ and -0.09MPa. S4: Dissolve the crude product in 500 mL of tetrahydrofuran, pour it into 2 L of methanol to precipitate, centrifuge and filter, and then dry it under vacuum at 60 °C for 10 hours to obtain phenolic hydroxyl-terminated polysiloxane A.

[0027] Preparation of phenolic hydroxyl-terminated polysiloxane B: S1: Add 2.2L of toluene to a 5L three-necked flask, cool to 0℃ in an ice-water bath under nitrogen protection, mix dimethyldichlorosilane (190.4g) and diphenyldichlorosilane (49.5g), slowly add toluene, stir for 30 minutes, control the temperature at 0℃, add 102g of deionized water dropwise, and react at 25℃ for 2.5h after the addition is complete to obtain hydroxyl-terminated oligomers; S2: Add 7.8 g of concentrated sulfuric acid to the hydroxyl-terminated oligomer from step S1, heat to 45°C, and react for 5 hours; add 10 wt% sodium hydroxide aqueous solution to neutralize to pH=7, allow to stand and separate the phases, separate the aqueous phase, and retain the organic phase; S3: Add 46.8 g of phenol and 0.21 g of p-toluenesulfonic acid to the organic phase of step S2, heat to 85 °C, and react for 3.5 hours; remove toluene and unreacted phenol by vacuum distillation at 80 °C and -0.09 MPa. S4: Dissolve the crude product in 500 mL of tetrahydrofuran, pour it into 2 L of methanol to precipitate, centrifuge and filter, and then dry it under vacuum at 60 °C for 10 hours to obtain phenolic hydroxyl-terminated polysiloxane B.

[0028] Preparation of phenolic hydroxyl-terminated polysiloxane C: S1: Add 2L of toluene to a 5L three-necked flask, cool to 0℃ in an ice-water bath under nitrogen protection, mix dimethyldichlorosilane (201.6g) and diphenyldichlorosilane (33.0g), slowly add toluene, stir for 30 minutes, control the temperature at 0℃, add 198g of deionized water dropwise, and react at 25℃ for 2.5h after the addition is complete to obtain hydroxyl-terminated oligomers; S2: Add 9.4 g of concentrated sulfuric acid to the hydroxyl-terminated oligomer from step S1, heat to 45°C, and react for 5 hours; add 10 wt% sodium hydroxide aqueous solution to neutralize to pH=7, allow to stand and separate the phases, separate the aqueous phase, and retain the organic phase; S3: Add 52.4 g of phenol and 0.26 g of p-toluenesulfonic acid to the organic phase of step S2, heat to 85 °C, and react for 3.5 hours; remove toluene and unreacted phenol by vacuum distillation at 80 °C and -0.09 MPa. S4: Dissolve the crude product in 500 mL of tetrahydrofuran, pour it into 2 L of methanol to precipitate, centrifuge and filter, and then dry it under vacuum at 60 °C for 10 hours to obtain phenolic hydroxyl-terminated polysiloxane C.

[0029] Preparation of phenolic hydroxyl-terminated polysiloxane D: S1: Add 2L of toluene to a 5L three-necked flask, cool to 0℃ in an ice-water bath under nitrogen protection, mix dimethyldichlorosilane (179.2g) and diphenyldichlorosilane (66.0g), slowly add toluene, stir for 30 minutes, control the temperature at 0℃, add 206g of deionized water dropwise, and react at 25℃ for 2.5h after the addition is complete to obtain hydroxyl-terminated oligomers; S2: Add 8.9 g of concentrated sulfuric acid to the hydroxyl-terminated oligomer from step S1, heat to 45°C, and react for 5 hours; add 10 wt% sodium hydroxide aqueous solution to neutralize to pH=7, allow to stand and separate the phases, separate the aqueous phase, and retain the organic phase; S3: Add 44.6 g of phenol and 0.22 g of p-toluenesulfonic acid to the organic phase of step S2, heat to 85 °C, and react for 3.5 hours; remove toluene and unreacted phenol by vacuum distillation at 80 °C and -0.09 MPa. S4: Dissolve the crude product in 500 mL of tetrahydrofuran, pour it into 2 L of methanol to precipitate, centrifuge and filter, and then dry it under vacuum at 60 °C for 10 hours to obtain phenolic hydroxyl-terminated polysiloxane D.

[0030] Preparation of phenolic hydroxyl-terminated polysiloxane E: S1: Add 1.8L of toluene to a 5L three-necked flask, cool to 0°C in an ice-water bath under nitrogen protection, mix dimethyldichlorosilane (245.2g) and diphenyldichlorosilane (8.2g), slowly add toluene, stir for 30 minutes, control the temperature at 0°C, add 196g of deionized water, and react at 28°C for 2 hours to obtain hydroxyl-terminated oligomers; S2: Add 5.9 g of concentrated sulfuric acid to the hydroxyl-terminated oligomer from step S1, heat to 40 °C, and react for 4 hours; add 10 wt% sodium hydroxide aqueous solution to neutralize to pH=7, allow to stand and separate the phases, separate the aqueous phase, and retain the organic phase; S3: Add 40.3g of phenol and 0.20g of p-toluenesulfonic acid to the organic phase of step S2, heat to 85℃, react for 3 hours, and remove toluene and unreacted phenol by vacuum distillation at 80℃ and -0.09MPa. S4: Dissolve the crude product in 500 mL of tetrahydrofuran, pour it into 2 L of methanol to precipitate, centrifuge and filter, and then dry it under vacuum at 60 °C for 10 hours to obtain phenolic hydroxyl-terminated polysiloxane E.

[0031] The embodiments of the present invention are carried out in a closed reaction device equipped with a tail gas alkaline solution absorption system;

[0032] Example 1 The preparation of high-silicon-content, large-particle-size polysiloxane polycarbonate resin includes the following steps: (1) Mix 35g of 2,2-bis(4-hydroxyphenyl)propane, 50g of phenol hydroxyl-terminated polysiloxane A, 28g of sodium hydroxide with 500mL of water and stir until completely dissolved to generate a mixed aqueous phase of sodium bisphenol A and sodium phenol oxyl-terminated polysiloxane. (2) Add 750 mL of dichloromethane, 1.7 g of p-cumylphenol, and 0.5 g of tetrabutylammonium bromide to the mixed aqueous phase of step (1), and stir to form a stable oil-water two-phase system. (3) Control the temperature of the system in step (2) to 20℃, the stirring speed to 200rpm, and introduce 16.9g of phosgene at a rate of 0.8kg / min. After the introduction is complete, continue the reaction for 2 hours. (4) After the reaction is completed, add 12g of phenol to terminate the reaction, let stand and separate the organic phase after separation; wash once with 5% dilute hydrochloric acid, and then wash with deionized water until neutral; pour into 1000mL of methanol to precipitate, filter and vacuum dry at 85℃ for 10 hours to obtain the high silicon content, large particle size polysiloxane polycarbonate resin.

[0033] Example 2 The preparation of high-silicon-content, large-particle-size polysiloxane polycarbonate resin includes the following steps: (1) Mix 20g of 2,2-bis(4-hydroxyphenyl)propane, 50g of phenol hydroxyl-terminated polysiloxane B, 22g of sodium hydroxide with 500mL of water and stir until completely dissolved to generate a mixed aqueous phase of sodium bisphenol A and sodium phenol oxyl-terminated polysiloxane. (2) Add 650 mL of dichloromethane, 2.1 g of p-cumylphenol, and 0.5 g of tetrabutylammonium bromide to the mixed aqueous phase of step (1), and stir to form a stable oil-water two-phase system. (3) Control the temperature of the system in step (2) to 20℃, the stirring speed to 200rpm, and introduce 15g of phosgene at a rate of 0.8kg / min. After the introduction is complete, continue the reaction for 2 hours. (4) After the reaction is completed, add 12g of phenol to terminate the reaction, let stand and separate the organic phase; wash once with 5% dilute hydrochloric acid, and then wash with deionized water until neutral; pour the organic phase into 1500mL of methanol to precipitate, filter and vacuum dry at 85℃ for 10 hours to obtain the high silicon content, large particle size polysiloxane polycarbonate resin.

[0034] Example 3 The preparation of high-silicon-content, large-particle-size polysiloxane polycarbonate resin includes the following steps: (1) Mix 49.5 g of 2,2-bis(4-hydroxyphenyl)propane, 45 g of phenol hydroxyl-terminated polysiloxane C, 30 g of sodium hydroxide with 500 mL of water and stir until completely dissolved to generate a mixed aqueous phase of sodium bisphenol A and sodium phenol oxyl-terminated polysiloxane. (2) Add 600 mL of dichloromethane, 0.94 g of p-cumylphenol, and 0.5 g of tetrabutylammonium bromide to the mixed aqueous phase of step (1), and stir to form a stable oil-water two-phase system. (3) Control the temperature of the system in step (2) to 20℃, the stirring speed to 200rpm, and introduce 21.5g of phosgene at a rate of 0.8kg / min. After the introduction is complete, continue the reaction for 2 hours. (4) After the reaction is completed, add 12g of phenol to terminate the reaction, let stand and separate the organic phase; wash once with 5% dilute hydrochloric acid, and then wash with deionized water until neutral; pour the organic phase into 1500mL of methanol to precipitate, filter and vacuum dry at 85℃ for 10 hours to obtain the high silicon content, large particle size polysiloxane polycarbonate resin.

[0035] Example 4 The preparation of high-silicon-content, large-particle-size polysiloxane polycarbonate resin includes the following steps: (1) Mix 35g of 2,2-bis(4-hydroxyphenyl)propane, 50g of phenol hydroxyl-terminated polysiloxane D, 28g of sodium hydroxide with 500mL of water and stir until completely dissolved to generate a mixed aqueous phase of sodium bisphenol A and sodium phenol oxyl-terminated polysiloxane. (2) Add 750 mL of dichloromethane, 1.7 g of p-cumylphenol, and 0.5 g of tetrabutylammonium bromide to the mixed aqueous phase of step (1), and stir to form a stable oil-water two-phase system. (3) Control the temperature of the system in step (2) to 20℃, the stirring speed to 200rpm, and introduce 16.9g of phosgene at a rate of 0.8kg / min. After the introduction is complete, continue the reaction for 2 hours. (4) After the reaction is completed, add 12g of phenol to terminate the reaction, let stand and separate the organic phase after separation; wash once with 5% dilute hydrochloric acid, and then wash with deionized water until neutral; pour into 1000mL of methanol to precipitate, filter and vacuum dry at 85℃ for 10 hours to obtain the high silicon content, large particle size polysiloxane polycarbonate resin.

[0036] Example 5 The preparation of high-silicon-content, large-particle-size polysiloxane polycarbonate resin includes the following steps: (1) Mix 35g of 2,2-bis(4-hydroxyphenyl)propane, 50g of phenolic hydroxyl-terminated polysiloxane E, 28g of sodium hydroxide with 500mL of water and stir until completely dissolved to generate a mixed aqueous phase of sodium bisphenol A and sodium phenolic hydroxyl-terminated polysiloxane. (2) Add 750 mL of dichloromethane, 1.7 g of p-cumylphenol, and 0.5 g of tetrabutylammonium bromide to the mixed aqueous phase of step (1), and stir to form a stable oil-water two-phase system. (3) Control the temperature of the system in step (2) to 20℃, the stirring speed to 200rpm, and introduce 16.9g of phosgene at a rate of 0.8kg / min. After the introduction is complete, continue the reaction for 2 hours. (4) After the reaction is completed, add 12g of phenol to terminate the reaction, let stand and separate the organic phase after separation; wash once with 5% dilute hydrochloric acid, and then wash with deionized water until neutral; pour into 1000mL of methanol to precipitate, filter and vacuum dry at 85℃ for 10 hours to obtain the high silicon content, large particle size polysiloxane polycarbonate resin.

[0037] Comparative Example 1 The preparation of high-silicon-content, large-particle-size polysiloxane polycarbonate resin includes the following steps: (1) Mix 73g of 2,2-bis(4-hydroxyphenyl)propane, 40g of phenolic hydroxyl-terminated polysiloxane A, 22g of sodium hydroxide with 500mL of water and stir until completely dissolved to generate a mixed aqueous phase of sodium bisphenol A and sodium phenolic hydroxyl-terminated polysiloxane. (2) Add 600 mL of dichloromethane, 2.3 g of p-cumylphenol, and 0.5 g of tetrabutylammonium bromide to the mixed aqueous phase of step (1), and stir to form a stable oil-water two-phase system. (3) Control the temperature of the system in step (2) to 20℃, the stirring speed to 200rpm, and introduce 18g of phosgene at a rate of 0.8kg / min. After the introduction is complete, continue the reaction for 2 hours. (4) After the reaction is completed, add 12g of phenol to terminate the reaction, let stand and separate the organic phase; wash once with 5% dilute hydrochloric acid, and then wash with deionized water until neutral; pour the organic phase into 1000mL of methanol to precipitate, filter and vacuum dry at 85℃ for 10 hours to obtain the high silicon content, large particle size polysiloxane polycarbonate resin.

[0038] Comparative Example 2: The preparation of high-silicon-content, large-particle-size polysiloxane polycarbonate resin includes the following steps: (1) Mix 35g of 2,2-bis(4-hydroxyphenyl)propane, 50g of phenol-terminated modified silicone oil, 28g of sodium hydroxide and 500mL of water, and stir until completely dissolved to generate a mixed aqueous phase of sodium bisphenol A and sodium phenoloxy-terminated polysiloxane. (2) Add 750 mL of dichloromethane, 1.7 g of p-cumylphenol, and 0.5 g of tetrabutylammonium bromide to the mixed aqueous phase of step (1), and stir to form a stable oil-water two-phase system. (3) Control the temperature of the system in step (2) to 20℃, the stirring speed to 200rpm, and introduce 16.9g of phosgene at a rate of 0.8kg / min. After the introduction is complete, continue the reaction for 2 hours. (4) After the reaction is completed, add 12g of phenol to terminate the reaction, let stand and separate the organic phase after separation; wash once with 5% dilute hydrochloric acid, and then wash with deionized water until neutral; pour into 1000mL of methanol to precipitate, filter and vacuum dry at 85℃ for 10 hours to obtain the high silicon content, large particle size polysiloxane polycarbonate resin.

[0039] Performance testing: 1. Silicon content: GB / T 30307-2013 "Determination of Organosilicon Content in Plastics" The high-silicon-content, large-particle-size polysiloxane polycarbonate resins prepared in Examples 1-4 and Comparative Examples 1-2 were digested by nitric acid-hydrofluoric acid microwave digestion. The plasma power was 1150W, the atomizing gas flow rate was 0.8L / min, and the detection wavelength was 251.611nm.

[0040] 2. Average particle size and distribution index of silica clusters: According to the standard GB / T 30776-2014 "Electronic Grade Bisphenol A" (Appendix on Microscopic Morphology Analysis), the analysis was carried out by transmission electron microscopy (TEM) and image analysis. The accelerating voltage was 120kV. Five different fields of view were selected, and more than 50 silica clusters were counted in each field of view. The average particle size and distribution index (PDI = standard deviation of particle size / average particle size) were calculated using Origin software.

[0041] 3. -40℃ Notched Impact Strength: According to standard ISO 179-1:2010 "Plastics – Determination of Charpy impact properties – Part 1: Non-instrumental impact testing", a simply supported beam notched impact test was used. High-silica, large-particle-size polysiloxane polycarbonate resins prepared in Examples 1-4 and Comparative Examples 1-2 were prepared into 80mm × 10mm × 4mm samples with a V-notch (2mm depth, 45° angle). The samples were kept at -40℃ for 2 hours before testing. Five samples were tested in parallel for each group, and the average value was taken. 4. Tensile strength at room temperature: According to standard GB / T 1040.1-2006 "Determination of tensile properties of plastics - Part 1: General", the universal tensile test was adopted. The high silicon content and large particle size polysiloxane polycarbonate resins prepared in Examples 1-5 and Comparative Examples 1-2 were prepared into type 1A dumbbell specimens. The test was carried out at an ambient temperature of 23℃, humidity of 50%, and tensile speed of 50mm / min. Five samples were tested in parallel for each group, and the average value was taken.

[0042] Table 1: Test Results Table

[0043] The data above shows that the high silicon content and large particle size polysiloxane polycarbonate resins in Examples 1-3 exhibit precise control over the particle size and distribution of silicon clusters, achieving a balance between high impact strength at low temperatures and high strength at room temperature. In Example 4, compared to Example 1, the excessive diphenylsiloxane units in the polysiloxane resulted in decreased compatibility between the prepared polysiloxane and the PC matrix. The silicon cluster particle size approached the 5μm upper limit, leading to easy interface peeling during impact, reduced energy absorption efficiency, and decreased room temperature tensile strength. The high proportion of diphenyl units enhanced the rigidity of the polysiloxane chain segments, but reduced the efficiency of chemical bonding with the PC chain segments, resulting in stress concentration at the interface during tensile testing and failing to achieve the expected results. In Example 5, compared to Example 1, the insufficient diphenylsiloxane units and low phenyl content resulted in inadequate compatibility between the polysiloxane and the PC matrix. The silicon clusters could not form a stable micron-scale dispersion structure, with an average particle size of only 0.9μm and a particle size distribution index of 1.35. The -40℃ notched impact strength was low, and the room temperature tensile strength was also reduced. This was due to insufficient silicon content and the shape of the silicon clusters. The state is out of control, and the synergistic goal of high impact at low temperature and high strength at room temperature cannot be achieved at all. Compared with Example 1, the feeding ratio of bisphenol A to the prepared polysiloxane in Comparative Example 1 is unreasonable, resulting in low silicon content in the resin, uneven dispersion, an average particle size of only 0.6 μm, and a particle size distribution index as high as 1.42. During the impact process, it not only cannot absorb energy, but also becomes a stress concentration point, and the notch impact strength at -40℃ drops sharply. During room temperature stretching, the internal defects caused by silicon agglomeration make the stress transmission severely uneven, and the agglomeration point breaks first. The room temperature tensile strength is low, and the overall mechanical stability completely collapses, failing to achieve the expected effect at all. Compared with Example 1, Comparative Example 2 uses commercially available phenol-modified silicone oil to replace the phenol hydroxyl-terminated polysiloxane of the present invention. This silicone oil has no phenyl units and the phenol hydroxyl linkage is poor, resulting in low chemical bonding efficiency with the PC matrix. The prepared resin has severe silicon agglomeration, with an average particle size of 6.8 μm, far exceeding the 5 μm upper limit of claim 1, and a particle size distribution index as high as 1.85. During low-temperature impact testing, the ultra-large silicon clusters detach directly from the matrix, forming a brittle fracture surface that is completely unable to absorb impact energy, resulting in low notched impact strength at -40℃. During room-temperature tensile testing, the internal defects caused by silicon cluster agglomeration significantly weaken the matrix continuity, reducing room-temperature tensile strength. This not only fails to achieve high impact at low temperatures but also loses the advantage of high strength at room temperatures, thus failing to meet the expected application requirements.

[0044] This invention can also be implemented in various other ways. Without departing from the spirit and essence of this invention, those skilled in the art can make various corresponding changes and modifications according to this invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A high-silicon-content, large-particle-size polysiloxane polycarbonate resin, characterized in that, The high-silicon-content, large-particle-size polysiloxane polycarbonate resin is formed by chemically linking bisphenol A-type polycarbonate segments with phenolic hydroxyl-terminated polysiloxanes. The silicon content in the high-silicon-content, large-particle-size polysiloxane polycarbonate resin is 20-30 wt%. The phenolic hydroxyl-terminated polysiloxanes form silicon clusters with an average particle size of 1-5 μm in the bisphenol A-type polycarbonate segment matrix, and the particle size distribution index is less than 1.

3.

2. The high-silicon-content, large-particle-size polysiloxane polycarbonate resin according to claim 1, characterized in that, The segments of the phenolic hydroxyl-terminated polysiloxane contain dimethylsiloxane units and diphenylsiloxane units.

3. The high-silicon-content, large-particle-size polysiloxane polycarbonate resin according to claim 2, characterized in that, The diphenylsiloxane unit accounts for 5-15% of the total phenolic hydroxyl-terminated polysiloxane segments.

4. The high-silicon-content, large-particle-size polysiloxane polycarbonate resin according to claim 1, characterized in that, The bisphenol A polycarbonate segments are derived from bisphenol A monomers; the bisphenol A monomers are selected from one or more of 2,2-bis(4-hydroxyphenyl)propane, refined bisphenol A, or electronic grade bisphenol A.

5. The method for preparing the high-silicon-content, large-particle-size polysiloxane polycarbonate resin according to claims 1-4, characterized in that, The phosgene-based interfacial polycondensation process includes the following steps: (1) Mix bisphenol A monomer, phenolic hydroxyl-terminated polysiloxane, sodium hydroxide and water, and stir until completely dissolved to generate a mixed aqueous phase of sodium bisphenol A salt and sodium phenolic hydroxyl-terminated polysiloxane salt; (2) Add dichloromethane and p-cumylphenol to the mixed aqueous phase of step (1), and add the phase transfer catalyst tetrabutylammonium bromide, and stir to form a stable oil-water two-phase system; (3) Control the temperature of the system in step (2) to be 15-30℃, the stirring speed to be 180-220rpm, and introduce phosgene into the system at a rate of 0.6-0.9kg / min to carry out interfacial polycondensation reaction for 1.5-2.5 hours. (4) After the reaction is completed, phenol is added to terminate the reaction. After standing and separating the layers, the organic phase is separated. The organic phase is acid-washed and water-washed until neutral. It is then poured into methanol to precipitate, filtered, and vacuum dried to obtain the high silicon content, large particle size polysiloxane polycarbonate resin.

6. The method for preparing high-silicon-content, large-particle-size polysiloxane polycarbonate resin according to claim 5, characterized in that, In step (1), the mass ratio of bisphenol A monomer to phenolic hydroxyl-terminated polysiloxane is 0.4-1.1:

1.

7. The method for preparing high-silicon-content, large-particle-size polysiloxane polycarbonate resin according to claim 5, characterized in that, In step (2), the volume ratio of dichloromethane to the mixed aqueous phase is 1.2-1.5:1, and the amount of p-cumylphenol added is 1-3% of the total mass of bisphenol A monomer and phenol hydroxyl-terminated polysiloxane.

8. The method for preparing high-silicon-content, large-particle-size polysiloxane polycarbonate resin according to claim 5, characterized in that, The phosgene in step (3) is carbonyl chloride, and the amount of phosgene used is 1.05-1.2 times the total molar amount of phenolic hydroxyl groups of bisphenol A monomer and phenolic hydroxyl-terminated polysiloxane.

9. A resin composition, characterized in that, It comprises the high-silicon-content, large-particle-size polysiloxane polycarbonate resin as described in any one of claims 1-4, as well as plasticizers, anti-aging agents, antioxidants, ultraviolet absorbers, and flame retardants.

10. The application of the high silicon content, large particle size polysiloxane polycarbonate resin according to any one of claims 1-4, in low-temperature and weather-resistant products.

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