Macromolecular flame retardant for transparent antistatic flame-retardant polycarbonate resin and preparation method thereof

Abstract

The invention belongs to the technical field of flame-retardant materials, and relates to a macromolecular flame retardant for transparent antistatic flame-retardant polycarbonate resin and a preparation method of the macromolecular flame retardant. In the formula, R1 is CH3; r2 is as shown in the specification; m in one part of R2 is a metal ion, and M in the other part of R2 is a boron-containing structural unit forming ionic association with SO3 <->; the molar ratio of the metal ions to the boron-containing structural unit forming ionic association with SO3 <-> is (3: 1)-(7: 1); r3 is as shown in the specification; the preparation method comprises the following steps: reacting 1, 3, 5, 7-tetramethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane and p-styrenesulfonic acid, then adding a solution containing M for reaction, and finally adding phenylphosphoryl dichloride for reaction to prepare a macromolecular flame retardant; according to the application, the macromolecular flame retardant and polycarbonate resin are subjected to melt blending to prepare the polycarbonate resin, and the flame retardant disclosed by the invention can realize integration of flame retardance and antistatic property; the method is simple; the application range is wide.

Description

Technical Field

[0001] This invention belongs to the field of flame retardant technology, and relates to a transparent antistatic flame retardant macromolecular flame retardant for polycarbonate resin and its preparation method. Background Technology

[0002] Polycarbonate (PC) is a typical aromatic engineering plastic, widely used in electronics, rail transportation, high-end consumer electronics, optical devices, and precision structural components due to its excellent transparency, impact resistance, and heat resistance. With the rapid development of electronics, electrical engineering, and information technology, these applications have placed more stringent comprehensive requirements on polycarbonate materials in terms of flame retardancy, electrostatic protection, and long-term stability of optical properties. However, polycarbonate is prone to softening and melting during heating or combustion. The carbonate bonds in its molecular backbone can break at relatively low temperatures, generating flammable small-molecule gases. Simultaneously, as the temperature rises, the viscosity of the polycarbonate melt decreases rapidly, making it highly susceptible to flaming molten dripping during combustion, thus posing a risk of secondary ignition and severely limiting its use in high-safety-level applications.

[0003] Sulfonate flame retardants are widely used in transparent polycarbonate flame retardant systems due to their low addition amount, high flame retardant efficiency, and relatively small impact on transparency. Organosilicon and siloxane flame retardants, on the other hand, can form a silicon-rich char layer during combustion, which helps suppress molten dripping and improve combustion behavior. Based on these characteristics, several technologies have attempted to improve the flame retardant properties of transparent polycarbonate through the synergistic effect of organosilicon and sulfonates.

[0004] For example, CN202410760262.1 discloses a sulfonate-grafted organosilicon flame retardant, which constructs an integrated silicon-sulfonate flame retardant structure by copolymerizing a sulfonate containing double bonds with a third monomer onto the surface of an organosilicon skeleton. This improves the problems of insufficient compatibility, migration and antagonism in traditional physical compound systems of organosilicon and sulfonate, thereby achieving a UL-94 V-0 flame retardant rating for transparent polycarbonate thin-walled parts under low addition conditions.

[0005] In addition, CN202511948912.6 reported a phenolic hydroxyl-terminated modified polysiloxane with side chains containing both phenyl and sulfonate groups. The polysiloxane-polycarbonate copolymer was prepared by melt transesterification polycondensation with diphenyl carbonate and bisphenol A to improve the molecular-scale dispersion and compatibility of sulfonate groups in the polycarbonate matrix, thereby taking into account the transparency and flame retardant properties of the material to a certain extent.

[0006] In addition, the presence of metal ions (located on the sulfonate group) in the above products can also improve the antistatic properties of polycarbonate;

[0007] However, the above-mentioned prior art also has the following limitations:

[0008] (1) In the prior art, when the content of sulfonate groups is low, the number of ion sites in the system is insufficient, making it difficult to form a continuous and stable ion conduction pathway. The antistatic performance mainly depends on the migration of charges on the sulfonate groups. The conduction path is discontinuous, and the surface resistivity is prone to high and fluctuating, resulting in unstable antistatic effect. When the content of sulfonate groups is increased to improve the antistatic performance, the sulfonate groups have strong hydrophilicity and are prone to hydration under the action of residual moisture in the processing or environmental moisture during use. As the density of ion groups increases, the enrichment of water molecules in local areas is enhanced, and the hydration gradually accumulates, easily forming a continuous hydration region. In the continuous hydration region, the sulfonate groups are prone to local enrichment and swelling, precipitation of metal ion clusters and their hydration structure. On the one hand, this will lead to the destruction of the original continuous conduction pathway or local over-concentration, thereby causing unstable surface resistivity and fluctuation of antistatic performance. On the other hand, the precipitated metal ion clusters and their hydration structure are different from the polycarbonate matrix in terms of polarity and refractive index, which easily form a micro-phase separation interface inside the material, increasing the light scattering center, resulting in decreased transparency and increased haze.

[0009] (2) The anti-dripping effect of existing flame retardants obtained by combining organosilicon and siloxane flame retardants with sulfonates mainly comes from the introduction of siloxane segments. Siloxane segments have high flexibility, which can improve the melt viscoelasticity of the system during the heating and melting process of polycarbonate, thereby inhibiting melt flow and delaying melt dripping to a certain extent. At the same time, siloxanes are prone to structural rearrangement at high temperatures and gradually transform into inorganic silicon-oxygen structures, forming a silicon-rich inorganic layer (SiO2) on the material surface, which plays a certain role in structural support and barrier for the melt. The anti-dripping mechanism of this type of flame retardant is essentially a physical mechanism based on melt viscoelasticity regulation and the formation of a silicon-rich layer on the surface, which has limited improvement.

[0010] Therefore, it is of great significance to study a transparent antistatic flame retardant macromolecular flame retardant for polycarbonate resin and its preparation method to solve the above problems. Summary of the Invention

[0011] The purpose of this invention is to solve the problems existing in the prior art and to provide a transparent antistatic flame retardant macromolecular flame retardant for polycarbonate resin and its preparation method.

[0012] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0013] A transparent, antistatic, flame-retardant macromolecular flame retardant for polycarbonate resin, with the following chemical structural formula:

[0014]

[0015] Where R1 is CH3; R2 is ; M in a portion of R2 is excluding Na + and K + In addition to the metal ions, the M in another part of R2 is SO3. - Boron-containing structural units that form ion-associative bonds; metal ions and SO3 - The molar ratio of boron-containing structural units forming ion-associations is 3:1 to 7:1; R3 is .

[0016] The transparent antistatic flame-retardant polycarbonate resin macromolecular flame retardant of the present invention has a symmetrical chemical structure. Due to adherence to the principle of minimum energy, it exhibits a helical conformation in space. R2 is encased in the middle of the molecular chain, while R1 and R3 are distributed on the outer side of the molecular chain. This makes the transparent antistatic flame-retardant polycarbonate resin macromolecular flame retardant overall hydrophobic, forming a molecular environment with low overall polarity. This, in turn, allows the sulfonate groups (i.e., M excluding Na) to be hydrophobic. + and K + Other metal ions (-SO3M) are not easily hydrated under the influence of residual moisture during processing or ambient humidity during use.

[0017] Even though sulfonate groups can undergo hydration, the sulfonate groups are spatially separated by hydrophobic structural units (i.e., Si–CH3 structural units in siloxane segments and aromatic structures formed by phenyl-substituted siloxane units). This results in a low enrichment of water molecules near the sulfonate groups, making it difficult for hydration to accumulate gradually and thus hindering the formation of continuous hydration regions.

[0018] Even if continuous hydration regions are formed, sulfonate groups are not prone to local enrichment and swelling, precipitation of metal ion clusters and hydration structures. On the one hand, because sulfonate groups are covalently linked to the side groups of the siloxane backbone and are part of the macromolecular structure, their local enrichment depends on the overall movement of the siloxane backbone, which is subject to greater resistance. On the other hand, because the continuous siloxane backbone and aromatic structural units (i.e., aromatic structures formed by phenyl-substituted siloxane units) together form spatial constraints on sulfonate groups, making it difficult for them to become locally enriched.

[0019] Since sulfonate groups are not prone to local enrichment at high concentrations, the problems arising from this do not exist.

[0020] It should be noted that Na + and K + With a large ionic radius and relatively weak ion-binding ability, Na+ is difficult to form stable ion-associated structures, thus reducing the stability of ion conduction pathways; at the same time, Na+... + and K +Hydration is more likely to occur, increasing the system's hygroscopicity. In humid and hot environments, ion migration is more frequent, leading to localized accumulation. Therefore, M is the value excluding Na. + and K + Other metal ions.

[0021] During combustion, the siloxane backbone undergoes an inorganic transformation at high temperatures to form a continuous SiO2 framework structure, which significantly improves the strength and structural integrity of the char layer. At the same time, it enhances the viscoelasticity of the melt at the combustion interface, inhibits melting and dripping. Sulfonate structural units participate in the high-temperature inorganic transformation process as reaction nodes and promote the continuity of the char layer. Phosphorus-containing structural units provide phosphorus sources and promote the densification of the condensed phase. The introduced boron-containing structural units work synergistically with the phosphorus-containing structural units to form a phosphate-borate glassy network in the 400-500℃ temperature range. They also form a Si-O-B synergistic inorganic phase with the siloxane structure, enabling the inorganic framework to couple with the glassy binder phase, thereby forming a large glassy network. This allows for the rapid formation of a continuous and dense protective layer in the early stages of combustion.

[0022] To achieve combustion crosslinking, the crosslinking temperature for forming a large glassy network needs to match the combustion temperature. This matching means that the crosslinking reaction can be initiated and the key structural construction completed before the polycarbonate undergoes severe thermal decomposition and reaches its maximum combustion temperature, thereby forming a stable load-bearing protective layer before the material is completely decomposed or undergoes severe melting and flow. If the crosslinking temperature is too high, the crosslinking process will lag behind the material decomposition process, making it difficult to play the role of inhibiting dripping and flame retardancy.

[0023] The main weight loss temperature or maximum weight loss rate temperature of polycarbonate is typically located at approximately 520–560 °C. Large molecular weight retardants used in transparent, antistatic, and flame-retardant polycarbonate resins contain significant amounts of SO3. - Sites, metal ions, and boron-containing structural units can all interact with SO3. - The reaction shows that the boron-containing structural units can lower the temperature of combustion crosslinking. By controlling the molar ratio of metal ions to boron-containing structural units to 3:1 to 7:1, the large network structure in the glassy state that was originally formed in the higher temperature range can be shifted to the range of about 400 to 500°C.

[0024] Furthermore, in the transparent antistatic flame-retardant polycarbonate resin macromolecular flame retardant of the present invention, the silicon-oxygen structure, as the source of the inorganic skeleton, should dominate to ensure the formation of a continuous SiO2 support structure and provide anti-dripping capability; sulfonate sites (SO3 - SO3 has a high content of sites that participate in the reaction, providing sufficient linkage sites. - Insufficient sites make it difficult to form a continuous network structure; low phosphorus content, if high content, will affect the flame retardant properties of sulfonates.

[0025] As a preferred technical solution:

[0026] The above-mentioned transparent antistatic flame retardant macromolecular flame retardant for polycarbonate resin has Li metal ions. + ,Sc 3+ Y 3+ La 3+ .

[0027] The transparent antistatic flame-retardant macromolecular flame retardant for polycarbonate resin described above has a melting temperature of not less than 120°C and an initial thermal decomposition temperature of not less than 300°C under a nitrogen atmosphere.

[0028] This invention also provides a method for preparing the transparent antistatic flame-retardant macromolecular flame retardant for polycarbonate resin as described above. First, 1,3,5,7-tetramethylcyclotetrasiloxane and octaphenylcyclotetrasiloxane are subjected to a ring-opening equilibrium copolymerization reaction to obtain intermediate A. Then, intermediate A is subjected to a hydrosilylation addition reaction with p-styrene sulfonic acid to obtain intermediate B. Next, a solution containing M is added to intermediate B, so that part of the sulfonic acid group (–SO3H) in intermediate B is converted into sulfonate group and the other part is converted into ion-associated structure, thereby obtaining intermediate C. Finally, intermediate C is subjected to a phosphorylation reaction with phenylphosphoryl dichloride so that all the chlorine in phenylphosphoryl dichloride is replaced, thereby obtaining the transparent antistatic flame-retardant macromolecular flame retardant for polycarbonate resin.

[0029] Where M includes Na + and K + Other metal ions and those that can react with SO3 - Boron-containing structural units that form ion-associative bonds; metal ions and SO3 - The molar ratio of boron-containing structural units forming ion associations is 3:1 to 7:1; the molar ratio of M in the M-containing solution to the sulfonic acid group (–SO3H) in p-styrenesulfonic acid is greater than 1 to ensure that the sulfonic acid group (–SO3H) can be fully converted into the sulfonate structure (–SO3). - M + (or ion-associated structure).

[0030] As a preferred technical solution:

[0031] The preparation method described above includes the following specific steps:

[0032] (1) 1,3,5,7-Tetramethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, silanol-containing end-capping agent and ring-opening equilibrium catalyst are mixed and subjected to ring-opening equilibrium copolymerization reaction at 80~140℃ for 4~6h to construct a siloxane main chain structure with hydroxyl-terminated ends and retain Si-H sites inside the molecular chain. After the reaction is completed, a neutralizing agent is added to neutralize the catalyst and deactivate it. The residual oligomeric ring is removed under reduced pressure to obtain intermediate A. 80~140℃ can promote the ring opening of cyclosiloxane and reach the equilibrium polymerization state, while avoiding the side reaction of Si-H structure caused by excessive temperature.

[0033] The chemical structural formula of intermediate A is:

[0034]

[0035] (2) Under the hydrosilylation catalyst, intermediate A and p-styrene sulfonic acid are subjected to hydrosilylation addition reaction at 50~80℃ for 3~6h to obtain intermediate B; 50~80℃ can realize the efficient hydrosilylation addition of Si-H and vinyl groups, while suppressing the occurrence of side reactions.

[0036] (3) Cool the reaction system in step (2) to 20~50℃, then add a solution containing M and react for 1~4h, so that part of the sulfonic acid group (–SO3H) in intermediate B is converted into sulfonate group and the other part is converted into ion-associated structure, thereby obtaining intermediate C; 20~50℃ can ensure that the reaction proceeds gently and avoid unstable conversion.

[0037] Chemical structural formula of intermediate C:

[0038]

[0039] (4) Under an anhydrous and inert atmosphere, the reaction system of step (3) is cooled to 0~10℃, and then intermediate C is mixed with acid-binding agent. Phenylphosphoryl dichloro is added dropwise at a rate of 1~3mL / min to carry out phosphorylation reaction for 0.5~2h. Then the temperature is raised to 20~50℃ to continue the phosphorylation reaction for 2~4h, thereby obtaining a transparent antistatic flame retardant macromolecular flame retardant for polycarbonate resin.

[0040] The hydroxyl group at one end of intermediate C undergoes a phosphorylation reaction with the P-Cl bond in phenylphosphoryl dichloride to form a P–O–Si bond. Simultaneously, HCl is released and captured by an acid-binding agent. Subsequently, the temperature is raised to 20~50℃ to continue the reaction, causing the remaining P–Cl bond in phenylphosphoryl dichloride to undergo a substitution reaction with the terminal hydroxyl group of another molecule, intermediate C, and be consumed. This results in the formation of a Si–O–P(=O)–O–Si linkage structure between molecules, thereby introducing phosphorus-containing structural units into the siloxane molecule and obtaining a transparent antistatic flame retardant macromolecular flame retardant for polycarbonate resin.

[0041] The temperature range of 0-10℃ is used to control the reaction rate of phenylphosphine dichloride and avoid side reactions. Then, the temperature is increased to 20-50℃ to promote the further substitution reaction of the P-Cl bond, thereby forming a stable Si-OP(=O)-O-Si bridging structure. The reason for increasing the temperature to 20-50℃ is that the second chlorine has steric hindrance and electronic effects, and the temperature needs to be increased to increase its activity.

[0042] If the reaction is terminated at a low temperature, the resulting product is mainly a monosubstituted phosphorylated structure (intermediates such as Si-OP(=O)-Cl or Si-OP(=O)(Ph)-Cl). In this structure, the phosphorus atom is only connected to one silicon-oxygen segment by a Si–O–P bond, while the other substitution site remains in the P–Cl form. During subsequent processing or use, this structure is prone to hydrolysis with water to generate P–OH, thus affecting the stability of the molecular structure. Furthermore, the monosubstituted phosphorylated structure is an asymmetric structure, and the hydrolysis of P-Cl to P=OH also leads to enhanced local polarity, creating a stronger hydrophilic environment around the molecular chain segment. Under these conditions, the sulfonate group is more likely to undergo hydration. Therefore, this type of structure is difficult to form a stable structural system, has limited flame retardant and anti-dripping effects, poor antistatic properties, and is also detrimental to the long-term stability of the material.

[0043] In the preparation method described above, the molar ratio of 1,3,5,7-tetramethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, p-styrenesulfonic acid, M in the M-containing solution, and phenylphosphodichloride is 1:1.01~1.1:4.04~4.4:4.08~4.84:0.476~0.498; the amount of silanol-containing end-capping agent added is 0.5~3wt% of the mass of 1,3,5,7-tetramethylcyclotetrasiloxane; the amount of ring-opening equilibrium catalyst added is 0.01~0.1wt% of the mass of 1,3,5,7-tetramethylcyclotetrasiloxane; the hydrosilylation catalyst is a Pt-containing catalyst, and the amount of Pt added is 20~50ppm of 1,3,5,7-tetramethylcyclotetrasiloxane (based on the molar amount of Si–H functional groups); the molar ratio of acid-binding agent to phenylphosphodichloride is 2.0~2.5:1.

[0044] In the preparation method described above, the silanol-containing end-capping agent is dimethylsilanediol and / or hydroxyl-terminated polydimethylsiloxane, with hydroxyl-terminated polydimethylsiloxane being recommended; the ring-opening polymerization catalyst is one or more of potassium hydroxide, sodium hydroxide, and tetramethylammonium hydroxide, with potassium hydroxide being recommended; the hydrosilylation catalyst is a Karstedt catalyst and / or a Speier catalyst, with a Karstedt catalyst being recommended; and the acid-binding agent is one or more of triethylamine, pyridine, and diisopropylethylamine, with triethylamine being recommended.

[0045] The present invention also provides a method for preparing a transparent antistatic flame-retardant polycarbonate resin, wherein the transparent antistatic flame-retardant polycarbonate resin as described above is melt-blended with a macromolecular flame retardant to obtain a transparent antistatic flame-retardant polycarbonate resin.

[0046] As a preferred technical solution:

[0047] The preparation method of the transparent antistatic flame-retardant polycarbonate resin as described above, wherein the amount of macromolecular flame retardant added to the transparent antistatic flame-retardant polycarbonate resin is 1~5wt% of the transparent antistatic flame-retardant polycarbonate resin.

[0048] The method for preparing a transparent antistatic flame-retardant polycarbonate resin as described above yields a transparent antistatic flame-retardant polycarbonate resin with a UL-94 flame retardancy rating of V-0, a limiting oxygen index of over 30%, a light transmittance of 83-92%, and a cantilever beam notched impact strength of not less than 50 kJ / m². 2 The surface resistivity is 10 5 ~10 8 Ω; After undergoing damp heat aging treatment at constant temperature and humidity of 85℃ and 85% relative humidity for 168 hours, the limiting oxygen index retention rate of the transparent antistatic flame-retardant polycarbonate resin is not less than 90%, the light transmittance retention rate is not less than 95%, and the surface resistivity does not exceed 10 Ω. 8 Ω, no obvious increase in haze or precipitation was observed.

[0049] Beneficial effects

[0050] (1) A transparent antistatic flame retardant macromolecular flame retardant for polycarbonate resin of the present invention has a siloxane as the main chain skeleton, phosphorus-containing connecting nodes are constructed in the molecule, and aromatic sulfonate ion groups are covalently introduced at the side chain position to form a structurally stable embedded multifunctional macromolecular system. This structure has a high molecular weight and excellent thermal stability, and is not easy to migrate or precipitate in the polycarbonate matrix. It can achieve the integration of flame retardant and antistatic functions while ensuring the transparency of the material.

[0051] (2) The present invention provides a transparent antistatic flame retardant macromolecular flame retardant for polycarbonate resin, wherein aromatic sulfonate ion groups are covalently fixed to the siloxane side chain, and its lithium ions and / or borate ions can form a stable and restricted ion association structure in the polycarbonate system, thereby endowing the material with durable and stable ionic antistatic properties without relying on the migration of small molecules; at the same time, the ionic structure can promote dehydration, aromatization and cross-linking reactions during combustion, and inhibit gas phase free radical reactions, thereby further enhancing the flame retardant synergistic effect.

[0052] (3) The present invention provides a transparent antistatic flame retardant for polycarbonate resin macromolecular flame retardant. Since the flame retardant adopts a macromolecular embedded structure design as a whole and each functional unit has high chemical stability, it is not easy to migrate, precipitate or degrade in the melting process and humid heat environment. It has good processing adaptability, humid heat resistance and long-term reliability, and is suitable for transparent structural parts of electronic appliances, automotive optical parts and high-end flame retardant transparent materials.

[0053] (4) The present invention provides a method for preparing a transparent antistatic flame retardant macromolecular flame retardant for polycarbonate resin. By constructing a Si–O–P(=O)–O–Si type phosphorus-containing linkage structure, and working synergistically with the siloxane skeleton and ionic functional units, it can simultaneously promote char formation of the condensed phase, improve the density of the char layer and enhance the structural stability of the high-temperature melt during combustion. The free radical capture effect of the phosphorus-containing structure, together with the silica skeleton and borate glass network formed by the high-temperature conversion of siloxane, can significantly improve the flame retardant efficiency and effectively suppress the dripping of polycarbonate melt, thereby achieving stable anti-dripping flame retardant performance.

[0054] (5) A method for preparing a transparent antistatic flame-retardant polycarbonate resin according to the present invention, wherein when a macromolecular flame retardant is used to prepare a transparent antistatic flame-retardant polycarbonate resin, the macromolecular flame retardant has both the flexibility of the siloxane chain segment and the local rigidity brought about by the aromatic structure and ion association, and can achieve uniform molecular-scale dispersion in the polycarbonate matrix, avoiding the phase separation problem caused by traditional small molecule flame retardants; while achieving flame retardant and antistatic properties, it will not significantly reduce the light transmittance, impact performance and processing fluidity of the material.

[0055] (6) In the transparent antistatic flame-retardant polycarbonate resin macromolecular flame retardant of the present invention, the phenyl-substituted silicon oxide unit is used to adjust the hydrophobicity and thermal stability of the flame retardant molecule and enhance its compatibility with the aromatic backbone of polycarbonate, which is beneficial to maintaining the transparency and mechanical properties of the material. Due to its high heat resistance and charring tendency, phenyl silicone resin can improve the flame retardant performance of polycarbonate by reducing the release of combustible volatiles and promoting the formation of a stable protective layer; in the present invention, the phenyl structure further helps to improve the charring ability and char layer structure stability of the system.

[0056] (7) The transparent antistatic flame retardant for polycarbonate resin of the present invention exhibits uniform antistatic properties under the influence of residual moisture during processing or ambient humidity during use; the transparent antistatic flame retardant for polycarbonate resin of the present invention has good anti-dripping effect. Attached Figure Description

[0057] Figure 1 Infrared spectrum of macromolecular flame retardant for transparent antistatic flame-retardant polycarbonate resin in Example 4;

[0058] Figure 2 The 1H NMR spectrum of the macromolecular flame retardant for transparent antistatic flame-retardant polycarbonate resin in Example 4;

[0059] Figure 3 Thermogravimetric analysis of the macromolecular flame retardant for transparent antistatic flame-retardant polycarbonate resin in Example 4;

[0060] Figure 4 The DSC curve of the macromolecular flame retardant for transparent antistatic flame-retardant polycarbonate resin in Example 4 is shown.

[0061] Figure 5 The high-temperature DSC curve of the macromolecular flame retardant for transparent antistatic flame-retardant polycarbonate resin in Example 4;

[0062] Figure 6 The high-temperature DSC curve is for Comparative Example 1;

[0063] Figure 7 This is the high-temperature DSC curve for Comparative Example 2. Detailed Implementation

[0064] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0065] The test methods involved in the performance indicators in the embodiments and comparative examples of this invention are as follows:

[0066] Number-average molecular weight: determined by gel permeation chromatography (GPC), referring to standard GB / T21863-2008 "Gel permeation chromatography (GPC) using tetrahydrofuran as eluent". The instrument was a gel permeation chromatograph equipped with a differential refractive index detector (model: Shimadzu, Japan), with a column temperature of 40℃, tetrahydrofuran as the mobile phase, and a flow rate of 1.0 mL / min. Narrow-distribution polystyrene standard samples were used for calibration.

[0067] Limiting Oxygen Index (LOI): The limiting oxygen index (LOI) was determined using a JF-5 limiting oxygen index instrument, according to the ISO 4589-2 international testing standard. The sample size was 120×13×4mm. 3 Butane is used as the ignition source gas.

[0068] Transmittance: Determined according to GB / T2410-2008 "Determination of transmittance and haze of transparent plastics". A haze meter (model: TH110) was used, the sample thickness was 2 mm, the measurement wavelength was 550 nm, and each sample was tested in parallel 3 times. The average value was taken as the final test result.

[0069] Notched impact strength of cantilever beam: The test was conducted according to ISO 180:2019 "Determination of impact strength of plastic cantilever beams". The specimen size was 80mm × 10mm × 4mm, the notch type was Type A (notch depth 2mm, bottom half of notch 0.25mm), the pendulum energy was 2.75J, the test temperature was 23℃, and the specimen was conditioned at 23℃ and 50% relative humidity for 48h before the test.

[0070] Surface resistivity: Determined according to ASTM D257-14. The sample size was a 100mm × 100mm × 3mm flat strip, using concentric ring electrodes. The test voltage was 100V. Two test environments were set: 23℃ / 50%RH and 23℃ / 12%RH, to evaluate the antistatic stability of the material under different humidity conditions. The samples were conditioned in the corresponding environments for 48 hours before testing, and the stable resistivity value after 60 seconds of pressure application was recorded.

[0071] Water absorption rate: Determined according to GB / T1034-2008 "Determination of Water Absorption of Plastics". The sample size was a 50mm × 50mm × 3mm flat strip. After drying the sample in an 80℃ vacuum drying oven for 12 hours, it was removed, cooled to room temperature in a desiccator, and weighed, recorded as m1. The sample was then completely immersed in 25℃ deionized water for 24 hours. The sample was then removed, surface moisture was quickly absorbed with filter paper, and immediately weighed, recorded as m2. The water absorption rate was calculated using the following formula:

[0072] ;

[0073] Where: m1 is the mass of the dried sample (g); m2 is the mass of the sample after immersion in water (g). Each sample was tested in parallel 3 times, and the average value was taken as the final result.

[0074] In the following embodiments, 1,3,5,7-tetramethylcyclotetrasiloxane is represented by D4H, octaphenylcyclotetrasiloxane is represented by D4Ph, and the polycarbonate resin is manufactured by Lotte Chemicals of South Korea, with product number 1100.

[0075] Example 1

[0076] A method for preparing a transparent antistatic flame-retardant macromolecular flame retardant for polycarbonate resin, the specific steps of which are as follows:

[0077] (1) Solution preparation;

[0078] (1.1) Under dry and nitrogen protection conditions, D4H and D4Ph were added to a reactor equipped with a mechanical stirrer, thermometer and reflux condenser, and stirred until homogeneous, and used as the reaction raw material system for later use; the stirring speed was 400 rpm.

[0079] (1.2) Add hydroxyl-terminated polydimethylsiloxane (manufacturer: McLean, brand: 768543) and potassium hydroxide to the reaction raw material system obtained in step (1.1) for later use;

[0080] The amount of hydroxyl-terminated polydimethylsiloxane added was 0.5 wt% of the mass of D4H; the amount of potassium hydroxide added was 0.01 wt% of the mass of D4H.

[0081] (1.3) Dissolve p-styrene sulfonic acid in deionized water to prepare an aqueous solution of p-styrene sulfonic acid;

[0082] (2) Under nitrogen protection, the reaction system in step (1.2) was heated to 80°C to carry out ring-opening equilibrium copolymerization reaction for 4 hours to obtain the bi-hydroxyl-terminated siloxane intermediate A;

[0083] The molecular chain of intermediate A retains Si–H functional sites, and its structure is shown below:

[0084] ;

[0085] (3) Cool the reaction system obtained in step (2) to 60°C, add Karstedt catalyst under stirring, and add the aqueous solution of p-styrene sulfonic acid obtained in step (1.3) dropwise to the reaction system at a dropping rate of 1 mL / s. React at 60°C for 3 h to allow the Si–H functional groups in intermediate A to undergo a hydrosilylation addition reaction with p-styrene sulfonic acid, thereby obtaining intermediate B.

[0086] The amount of Pt added in the Karstedt catalyst is 20 ppm of D4H;

[0087] (4) After the reaction in step (3) is completed, the system is cooled to 30°C. A mixture of LiOH solution and H3BO3 solution is added to the system at a dropping rate of 0.5 mL / s, and the reaction is carried out for 2 hours under stirring at 500 rpm. After the reaction is completed, the water in the system is removed under reduced pressure, and dichloromethane is added to replace the solvent in the system. The amount of dichloromethane added is 3 times the total mass of the system after dehydration, so that the system is transformed into an anhydrous organic phase system, thereby obtaining grafted siloxane intermediate C containing both aromatic lithium sulfonate structure and boron coordination structure. The structure of intermediate C is shown below:

[0088] ;

[0089] (5) Under an anhydrous and nitrogen atmosphere, the reaction system obtained in step (4) is cooled to 5°C, and triethylamine is added under stirring. Then, liquid phenylphosphodichloro is added to the reaction system at a dropping rate of 1 mL / min, and the temperature of the system is controlled not to exceed 10°C during the dropping process. After the dropping is completed, the reaction is stirred at a low temperature of 5°C for 0.5 h. Then, the reaction system is heated to 40°C and kept at the temperature for 2 h, so that phenylphosphodichloro reacts with the hydroxyl groups at both ends of the siloxane molecular chain to form a stable Si–O–P(=O)(Ph)–O–Si phosphorus-containing connection node inside the molecule.

[0090] The molar ratio of triethylamine to phenylphosphodichloride is 2.0:1.

[0091] (6) After the reaction in step (5) is completed, dichloromethane, triethylamine, a small amount of unreacted phenylphosphodichloro and water are removed by depressurization to obtain a transparent antistatic flame retardant macromolecular flame retardant for polycarbonate resin, the structural formula of which is as follows:

[0092] .

[0093] The molar ratio of each raw material is: D4H:D4Ph:p-styrenesulfonic acid:LiOH:H3BO3:phenylphosphonodichloro = 1:1.01:4.04:3.06:1.02:0.476.

[0094] The final transparent antistatic flame-retardant polycarbonate resin macromolecular flame retardant had a melting temperature of 143℃ and an initial thermal decomposition temperature (i.e., the temperature at which 5 wt% of thermal weight loss occurs, the same below) of 330℃ under a nitrogen atmosphere, with a yield of 48%.

[0095] Example 2

[0096] A method for preparing a transparent antistatic flame retardant macromolecular flame retardant for polycarbonate resin is basically the same as in Example 1, except that the reaction system in step (2) is heated to 80°C and reacted for 6 hours.

[0097] In step (3), the reaction system is cooled to 50°C and reacted for 6 hours;

[0098] In step (4), the reaction system is cooled to 20°C and reacted for 4 hours;

[0099] In step (5), the reaction system obtained in step (4) is cooled to 10°C, triethylamine is added under stirring, and then liquid phenylphosphodichloro is added to the reaction system at a dropping rate of 3 mL / min, controlling the system temperature not to exceed 10°C during the dropping process; after the dropping is completed, the reaction is stirred at 10°C for 0.5 h, and then the reaction system is heated to 50°C and kept at that temperature for 4 h.

[0100] The final transparent antistatic flame retardant for polycarbonate resin macromolecular flame retardant has the same structure as in Example 1, with a yield of 45%.

[0101] Example 3

[0102] A method for preparing a transparent antistatic flame-retardant macromolecular flame retardant for polycarbonate resin is basically the same as in Example 1, except that: in step (1.2), the amount of hydroxyl-terminated polydimethylsiloxane added is 2 wt% of the mass of D4H; and the amount of potassium hydroxide added is 0.08 wt% of the mass of D4H.

[0103] The reaction system in step (2) is heated to 100°C under nitrogen protection;

[0104] In step (3), the amount of Pt added to the Karstedt catalyst is 50 ppm of D4H;

[0105] The molar ratio of each raw material is: D4H:D4Ph:p-styrenesulfonic acid:LiOH:H3BO3:phenylphosphonodichloro = 1:1.1:4.4:3.63:1.21:0.498, and the molar ratio of triethylamine to phenylphosphonodichloro is 2.5:1.

[0106] The final transparent antistatic flame retardant for polycarbonate resin macromolecular flame retardant has the same structure as in Example 1, with a yield of 54%.

[0107] Example 4

[0108] A method for preparing a transparent antistatic flame-retardant macromolecular flame retardant for polycarbonate resin is basically the same as in Example 3, except that in step (1.2), the amount of hydroxyl-terminated polydimethylsiloxane added is 3 wt% of the mass of D4H; and the amount of potassium hydroxide added is 0.1 wt% of the mass of D4H.

[0109] In step (3), the amount of Pt added to the Karstedt catalyst is 30 ppm of D4H;

[0110] Step (5): Under an anhydrous and nitrogen atmosphere, the reaction system obtained in step (4) is cooled to 0°C. Triethylamine is added under stirring. Liquid phenylphosphodichloro is added to the reaction system at a dropping rate of 1 mL / min. The temperature of the system is controlled not to exceed 10°C during the dropping process. After the dropping is completed, the reaction is stirred at 0°C for 1 h. Then the reaction system is heated to 25°C and kept at that temperature for 2 h. This allows phenylphosphodichloro to undergo phosphorylation coupling with the hydroxyl groups at both ends of the siloxane molecular chain, forming a stable Si–O–P(=O)(Ph)–O–Si phosphorus-containing connection node inside the molecule.

[0111] The molar ratio of each raw material is: D4H:D4Ph:vinylbenzenesulfonic acid:LiOH:H3BO3:phenylphosphonodichloro = 1:1.1:4.1:3.376:1.126:0.476; the molar ratio of triethylamine to phenylphosphonodichloro is 2.2:1.

[0112] The final transparent antistatic flame-retardant polycarbonate resin with macromolecular flame retardant structure is consistent with that in Example 1, with the yield increased to 69%.

[0113] like Figure 1 The infrared spectral results shown indicate that at 3400 cm⁻¹ -1 A broad but weak absorption band appears nearby, which can be attributed to the stretching vibration of the Si-OH terminal segment of the siloxane chain; in the range of 2960~2850 cm⁻¹ -1 Obvious absorption peaks were observed within the range, attributed to the stretching vibrations of aliphatic -CH3 and -CH- groups, with a peak at approximately 3060 cm⁻¹. -1 Characteristic absorption of the aromatic ring CH is present nearby. At 1600 cm⁻¹ -1 The absorption peaks appearing on the left and right can be attributed to the stretching vibrations of the aromatic ring skeleton C=C, indicating that the aromatic group has been successfully introduced into the molecular structure. Furthermore, in the 1250~1180 cm⁻¹ range... -1 The peaks appearing within the range can be attributed to the stretching vibrations of the S=O bonds in the aromatic sulfonate groups, and partially overlap with the characteristic absorptions of the P=O bonds in the phosphate ester structure; at 1080 cm⁻¹ -1 A strong absorption peak can be observed at 950 cm⁻¹, which is the characteristic stretching vibration peak of the Si-O-Si bond in the siloxane backbone. Furthermore, a strong absorption peak can be observed at 950 cm⁻¹. -1 The absorption peaks appearing nearby can be attributed to the stretching vibrations of the Si-OP bond, while those at 840~740 cm⁻¹... -1 The absorption peaks within the specified range are related to the out-of-plane bending vibration of the aromatic ring CH and the related vibrations of the silicon-oxygen bond. The common presence of the above characteristic absorption peaks indicates that the aromatic sulfonate group and the phosphorus-containing structure have been successfully grafted and introduced into the siloxane backbone, thus verifying the formation of the macromolecular flame retardant structure.

[0114] like Figure 2The 1H NMR results show a dense set of multiplets in the 7.9–7.0 ppm range, attributed to proton signals from various aromatic rings in the molecule, including phenyl structures introduced by the siloxane chain, phosphorus-containing aryl structures, and aromatic hydrogens from aromatic sulfonate side groups. Due to the variety of aromatic rings and significant differences in their chemical environments, the signals in this region overlap and exhibit multiplet stacking. A distinct signal is visible near 2.50 ppm, representing the residual solvent peak of DMSO-d6. A characteristic peak appears in the 1.1–0.9 ppm region, which can be attributed to the methyl hydrogen signal from the -CH(CH3)- fragment in the side chain after hydrosilylation. Furthermore, a strong signal appears near 0.3–0.0 ppm, a typical resonance peak of numerous Si-CH3 groups in the siloxane backbone, a hallmark of siloxane structure. No significant Si-H characteristic peaks were observed in the 4.5–5.0 ppm range, indicating that the Si-H functional groups were largely consumed by the hydrosilylation reaction during the reaction. In summary, this further proves that the target macromolecular flame retardant structure has been successfully synthesized.

[0115] like Figure 3 Thermogravimetric analysis results show that the initial thermal decomposition temperature of this macromolecular flame retardant is 330°C, indicating that the overall quality of the material remains good before 330°C, and the system possesses a certain degree of initial thermal stability. As the temperature continues to rise, the sample exhibits a major decomposition stage between 450 and 520°C: the TG curve drops rapidly, while the DTG curve shows a sharp peak near 490–500°C, indicating that this stage is the main pyrolysis process of the material, involving further decomposition of the aromatic framework and phosphate ester structure, as well as the synergistic pyrolysis and rearrangement of organosilicon segments. The final char yield is 57.19%, a very high level, indicating that the system has outstanding char-forming ability and a high-temperature stable residual structure. This is due to the synergistic effect of phosphorus-promoted cross-linking char formation and the high-temperature stable phase formed by the silicon-oxygen structure.

[0116] like Figure 4 The DSC results show that the DSC curve of Example 4 is relatively flat throughout the heating process, with only a significant heat flow change around 133°C. A clear baseline shift occurs within this temperature range, indicating the glass transition process of the material. This transition peak is relatively concentrated and does not show obvious splitting, suggesting that the chain segment movement transition process in the system is relatively consistent and the internal structure of the material is relatively uniform. No obvious melting endothermic peaks or crystallization exothermic peaks were detected in the curves across the entire test temperature range, indicating that the material has not formed a detectable crystalline phase and the system is predominantly amorphous. This thermal characteristic is beneficial for maintaining structural stability at higher operating temperatures while avoiding performance fluctuations caused by crystallization or melting behavior.

[0117] like Figure 5As shown, high-temperature DSC results indicate that this phosphorus-containing aromatic sulfonate-grafted siloxane compound exhibits good thermal stability below 200℃, while showing significant endothermic changes in the 400–500℃ temperature range, corresponding to high-temperature crosslinking and structural densification processes. This behavior is closely related to the boron-containing structural units introduced into the system. Under high-temperature conditions, the boron-containing structure readily undergoes a synergistic reaction with the phosphorus-containing structure to form a phosphate-borate glassy structure, thus advancing the silicon-oxygen network densification process, which would normally occur at higher temperatures, to the 400–500℃ temperature range. Within this temperature range, the siloxane backbone gradually undergoes an inorganic transformation to form a Si-O-Si inorganic framework structure. Simultaneously, the phosphorus-containing structure promotes char layer densification, while the boron-containing structure forms a glassy phase with good adhesion, further forming a Si-OB synergistic inorganic structure with the silicon-oxygen structure. This couples the inorganic framework structure with the glassy binder phase, enabling the rapid formation of a continuous and dense protective layer in the early stages of combustion, thereby improving char layer strength and suppressing melting and dripping behavior during combustion.

[0118] Comparative Example 1

[0119] A method for preparing a transparent antistatic flame-retardant macromolecular flame retardant for polycarbonate resin is basically the same as in Example 4, except that in step (4), an equimolar amount of LiOH is used to replace H3BO3, thereby obtaining a grafted siloxane intermediate containing only an aromatic lithium sulfonate structure; that is, the molar ratio of each raw material is: D4H:D4Ph:p-styrene sulfonic acid:LiOH:phenylphosphonodichloro=1:1.1:4.1:4.502:0.476; the other conditions remain unchanged, and finally a macromolecular flame retardant without boron structural units is obtained, the structural formula of which is as follows:

[0120] .

[0121] like Figure 6 The figure shows the high-temperature DSC curve of Comparative Example 1. Compared with Example 4, Comparative Example 1 did not show significant endothermic changes in the 400-500℃ temperature range, only gradually showing a broad endothermic peak above approximately 500℃, with a peak temperature of about 520℃. This result indicates that without the introduction of boron-containing structural units, the high-temperature crosslinking and densification processes of the system are significantly delayed. The formation of its inorganic network mainly depends on the thermal rearrangement of the siloxane structure at higher temperatures and the crosslinking reaction involving phosphorus-containing structures. Since this crosslinking temperature range is close to the main decomposition temperature range of polycarbonate (approximately 520-560℃), the system is unlikely to form a stable inorganic framework structure before the material undergoes severe thermal decomposition and melt flow, thus weakening the formation rate and structural stability of the char layer. This result further illustrates that the introduction of boron-containing structural units can effectively reduce the high-temperature crosslinking temperature of the system, allowing the inorganic network structure to form in the early stages of combustion, thereby improving the density of the char layer and enhancing its anti-dripping and flame-retardant properties.

[0122] Comparative Example 2

[0123] A method for preparing a transparent antistatic flame retardant macromolecular flame retardant for polycarbonate resin is basically the same as in Example 4, except that: the total molar amount of LiOH and H3BO3 in step (4) remains unchanged, and the molar ratio is adjusted to 1:3, that is, the molar ratio of each raw material is D4H:D4Ph:p-styrenesulfonic acid:LiOH:H3BO3:phenylphosphonodichloro=1:1.1:4.1:1.126:3.376:0.476.

[0124] The final structure of the transparent, antistatic, flame-retardant macromolecular flame retardant for polycarbonate resin is as follows:

[0125] .

[0126] like Figure 7 As shown, the high-temperature DSC curve of Comparative Example 2 begins to show endothermic changes at approximately 330–350 °C, with a slight endothermic shoulder near approximately 380–410 °C, followed by a relatively wide endothermic valley in the range of approximately 430–460 °C. Compared to Example 4, Comparative Example 2 shows localized endothermic changes at a lower temperature, indicating that the glass transition or inorganication reactions involving some boron-containing structural units occur earlier. However, due to the excessively high content of boron-containing structural units in the system, the ratio between metal ions and boron-containing structures is imbalanced, resulting in a dispersed characteristic in the high-temperature crosslinking and inorganic network construction process. This leads to poor uniformity and continuity of the inorganic network structure formed in this system, which is not conducive to constructing a stable and dense high-temperature carbon layer structure.

[0127] Comparative Example 3

[0128] A method for preparing a transparent antistatic flame retardant macromolecular flame retardant for polycarbonate resin is basically the same as in Example 4, except that the total molar amount of LiOH and H3BO3 in step (4) remains unchanged, and the molar ratio is adjusted to 1:1, that is, the molar ratio of each raw material is: D4H: D4Ph: p-styrene sulfonic acid: LiOH: H3BO3: phenylphosphonodichloro = 1:1.1:4.1:2.251:2.251:0.476.

[0129] The final structure of the transparent, antistatic, flame-retardant macromolecular flame retardant for polycarbonate resin is as follows:

[0130] .

[0131] Comparative Example 4

[0132] A method for preparing a transparent antistatic flame-retardant macromolecular flame retardant for polycarbonate resin is basically the same as in Example 4, except that step (5) omits the operation of heating the reaction system to 25°C and holding the reaction at that temperature for 2 hours. That is, the reaction is terminated at the low temperature stage, and finally a macromolecular flame retardant with a monosubstituted phosphorylated structure is obtained, the structure of which is as follows:

[0133] .

[0134] Comparative Example 5

[0135] A method for preparing a transparent antistatic flame retardant macromolecular flame retardant for polycarbonate resin is basically the same as in Example 4, except that LiOH in step (4) is replaced with NaOH.

[0136] The final structure of the transparent, antistatic, flame-retardant macromolecular flame retardant for polycarbonate resin is as follows:

[0137] .

[0138] Example 5

[0139] A method for preparing a transparent antistatic flame retardant macromolecular flame retardant for polycarbonate resin is basically the same as in Example 4, except that the reaction system in step (2) is heated to 140°C.

[0140] In step (3), the reaction system is cooled to 80°C;

[0141] In step (4), the reaction system is cooled to 50°C.

[0142] The final transparent antistatic flame retardant for polycarbonate resin macromolecular flame retardant has the same structure as in Example 1, with a yield of 53%.

[0143] Example 6

[0144] A method for preparing a transparent antistatic flame retardant macromolecular flame retardant for polycarbonate resin is basically the same as in Example 4, except that: LiOH in step (4) is replaced with Y(OH)3; the molar ratio of each raw material is: D4H:D4Ph:p-styrenesulfonic acid:Y(OH)3:H3BO3:phenylphosphonodichloro=1:1.1:4.1:3.376:1.126:0.476.

[0145] The final structure of the transparent, antistatic, flame-retardant macromolecular flame retardant for polycarbonate resin is as follows:

[0146] The melting temperature of the transparent antistatic flame-retardant polycarbonate resin using macromolecular flame retardant is 145℃, and the initial thermal decomposition temperature under nitrogen atmosphere is 333℃.

[0147] Example 7

[0148] A method for preparing a transparent antistatic flame retardant macromolecular flame retardant for polycarbonate resin is basically the same as in Example 4, except that: LiOH in step (4) is replaced with La(OH)3; that is, the molar ratio of each raw material is: D4H:D4Ph:vinylbenzenesulfonic acid:La(OH)3:H3BO3:phenylphosphonodichloro=1:1.1:4.1:3.376:1.126:0.476.

[0149] The structure of the final transparent antistatic flame-retardant polycarbonate resin macromolecular flame retardant is as follows:

[0150] The melting temperature of the transparent antistatic flame-retardant polycarbonate resin using macromolecular flame retardant is 146℃, and the initial thermal decomposition temperature under nitrogen atmosphere is 338℃.

[0151] Example 8

[0152] A method for preparing a transparent antistatic flame retardant macromolecular flame retardant for polycarbonate resin is basically the same as in Example 4, except that the total molar amount of LiOH and H3BO3 in step (2) remains unchanged, and the molar ratio is adjusted to 7:1; that is, the molar ratio of each raw material is D4H:D4Ph:vinylbenzenesulfonic acid:Li(OH)3:H3BO3:phenylphosphonodichloro=1:1.1:4.1:3.939:0.563:0.476.

[0153] The final structure of the transparent, antistatic, flame-retardant macromolecular flame retardant for polycarbonate resin is as follows:

[0154] The melting temperature of the transparent antistatic flame-retardant polycarbonate resin using macromolecular flame retardant is 142℃, and the initial thermal decomposition temperature under nitrogen atmosphere is 327℃.

[0155] Example 9

[0156] A method for preparing a transparent antistatic flame-retardant polycarbonate resin, the specific process of which is as follows:

[0157] The transparent antistatic flame-retardant polycarbonate resin of Example 4 was melt-blended with a macromolecular flame retardant to obtain a transparent antistatic flame-retardant polycarbonate resin; the amount of macromolecular flame retardant added to the transparent antistatic flame-retardant polycarbonate resin was 1 wt%; the melt processing temperature was 260°C.

[0158] The final transparent antistatic flame-retardant polycarbonate resin has a UL-94 flame retardancy rating of V-0, a limiting oxygen index of 35%, a light transmittance of 90%, and a cantilever beam notched impact strength of 76 kJ / m. 2When tested at 23℃ and 50%RH, its surface resistivity is 4.8×10⁻⁶. 6 After undergoing damp heat aging treatment at constant temperature and humidity of 85℃ and 85% relative humidity for 168 hours, the limiting oxygen index of the transparent antistatic and flame-retardant polycarbonate resin remained at 92%, the light transmittance remained at 98%, and the surface resistivity remained at 7.2×10⁻⁶. 6 Ω, no obvious increase in haze or precipitation was observed; according to the water absorption test method of GB / T1034-2008, the water absorption rate of this transparent antistatic flame-retardant polycarbonate resin is 0.32%.

[0159] Comparative Example 6

[0160] A method for preparing a transparent antistatic flame-retardant polycarbonate resin is basically the same as in Example 9, except that the transparent antistatic flame-retardant polycarbonate resin of Example 4 is replaced with a macromolecular flame retardant of Comparative Example 1.

[0161] The final polycarbonate resin obtained had a UL-94 flame retardancy rating of V-1, exhibiting dripping during combustion. Its surface resistivity was 7.5 × 10⁻⁶ under conditions of 23°C and 50% RH. 6 Ω. Furthermore, after 168 hours of damp heat aging treatment under constant temperature and humidity conditions of 85℃ and 85% relative humidity, the surface resistivity of the transparent antistatic flame-retardant polycarbonate resin is 1.9 × 10⁻⁶. 7 Ω.

[0162] Comparing Comparative Example 6 with Example 9 reveals that the flame retardant performance of Comparative Example 6 is reduced and dripping occurs. This is because the macromolecular flame retardant used in Comparative Example 6 does not contain boron structural units, making it difficult to promote premature cross-linking of the system through boron-involved bridging reactions under high-temperature conditions. In contrast, the flame retardant used in Example 9 more easily promotes the formation of cross-linked structures at high temperatures, allowing the protective layer to form before the polycarbonate matrix decomposes significantly, thereby improving char layer stability and suppressing dripping. In Comparative Example 6, the cross-linking and char formation processes are relatively delayed, resulting in a decrease in the flame retardant performance of the material. When the flame retardant structure does not contain boron, the Li-type sulfonate sites in the system lack effective coordination constraints and structural stabilization, making them more prone to hydration and ionic instability under humid and hot conditions, thus increasing surface resistivity and decreasing antistatic stability.

[0163] Comparative Example 7

[0164] A method for preparing a transparent antistatic flame-retardant polycarbonate resin is basically the same as in Example 9, except that the transparent antistatic flame-retardant polycarbonate resin of Example 4 is replaced with a macromolecular flame retardant of Comparative Example 2.

[0165] The final transparent antistatic flame-retardant polycarbonate resin has a UL-94 flame retardancy rating of V-0, but it still exhibits dripping molten material during combustion.

[0166] Comparing Comparative Example 7 with Example 9 reveals that the flame retardant performance of Comparative Example 7 is reduced. This is because when the molar ratio of Li to B is 1:3, the ratio of B to Li in the system is not optimally matched, which is not conducive to the formation of a uniform and stable cross-linked structure. Consequently, the continuity and stability of the protective layer formed during combustion are reduced, thus decreasing the flame retardant performance of the material.

[0167] Comparative Example 8

[0168] A method for preparing a transparent antistatic flame-retardant polycarbonate resin is basically the same as in Example 9, except that the transparent antistatic flame-retardant polycarbonate resin of Example 4 is replaced with a macromolecular flame retardant of Comparative Example 3.

[0169] The final transparent antistatic flame-retardant polycarbonate resin has a UL-94 flame retardancy rating of V-2 and a limiting oxygen index of 30%, and still drips during combustion.

[0170] Comparing Comparative Example 8 with Example 9 reveals that the flame retardant performance of Comparative Example 8 is reduced. This is because when the molar ratio of Li to B is 1:1, the ratio of Li to B in the system is not optimally matched. Although the boron-containing structural units can still participate in the high-temperature bridging reaction and promote the formation of cross-linked structures, the imbalance in the ratio is not conducive to the formation of a stable and uniform cross-linked network, which reduces the stability of the protective layer formed during combustion, thus decreasing the flame retardant performance of the material.

[0171] Comparative Example 9

[0172] A method for preparing a transparent antistatic flame-retardant polycarbonate resin is basically the same as in Example 9, except that the transparent antistatic flame-retardant polycarbonate resin of Example 4 is replaced with a macromolecular flame retardant of Comparative Example 4.

[0173] The final transparent antistatic flame-retardant polycarbonate resin has a UL-94 flame retardancy rating of V-2, a limiting oxygen index of 31%, a light transmittance of 84%, and a cantilever beam notched impact strength of 67 kJ / m. 2 When tested at 23℃ and 50%RH, its surface resistivity is 5.9×10⁻⁶. 6 Ω; After undergoing damp heat aging treatment at constant temperature and humidity of 85℃ and 85% relative humidity for 168 hours, the limiting oxygen index of the transparent antistatic flame-retardant polycarbonate resin remained at 50%, the light transmittance remained at 94%, and the surface resistivity remained at 1.4×10. 7 Ω; The water absorption rate of this transparent antistatic flame-retardant polycarbonate resin is 0.74%.

[0174] Comparing Comparative Example 9 and Example 9, it can be observed that Comparative Example 9 exhibits increased surface resistivity and water absorption, decreased cantilever beam notched impact strength, and significantly reduced limiting oxygen index and transmittance retention rates after hygrothermal aging treatment. This is because the reaction terminates at low temperatures, resulting in a product primarily composed of monosubstituted phosphorylated structures. These structures retain an unreacted P-Cl bond, failing to form a SOP(=O)-O-Si bridging structure, thus weakening molecular structural stability and spatial constraint. Simultaneously, the residual P-Cl bond is prone to hydrolysis under hygrothermal conditions, generating phosphoric acid species and introducing polar groups, leading to increased hygroscopicity and disrupting the stability of the ionic structure, thereby increasing surface resistivity and water absorption. Furthermore, the failure to form a complete Si–O–P(=O)–O–Si bridging structure results in decreased carbon layer density and thermal stability, thus reducing the material's mechanical properties, flame retardant stability, and transmittance retention rates. Bridging structures reduce the flexibility of materials, leading to brittleness and consequently, poorer mechanical properties.

[0175] Comparative Example 10

[0176] A method for preparing a transparent antistatic flame-retardant polycarbonate resin is basically the same as in Example 9, except that the transparent antistatic flame-retardant polycarbonate resin of Example 4 is replaced with a macromolecular flame retardant of Comparative Example 5.

[0177] The final transparent antistatic flame-retardant polycarbonate resin cantilever beam has a notched impact strength of 72 kJ / m. 2 Its surface resistivity was 2.6 × 10⁻⁶ when tested at 23℃ and 50%RH. 7 Ω; After undergoing damp heat aging treatment at constant temperature and humidity of 85℃ and 85% relative humidity for 168 hours, the surface resistivity of transparent polycarbonate is 4.1×10 Ω. 8 Ω, water absorption rate is 0.88%.

[0178] Comparing Comparative Example 10 and Example 9, it can be found that Comparative Example 10 has increased surface resistivity and water absorption, decreased cantilever beam notched impact strength, and significantly reduced resistivity after damp heat aging treatment. This is because compared to Li... + Na + The ions have a large radius and relatively weak ion binding ability, making it difficult to form stable ion-associated structures, thus reducing the stability of ion conduction pathways and leading to increased surface resistivity; at the same time, Na + It is more prone to hydration, which increases the hygroscopicity of the system. In humid and hot environments, it is easier for ions to migrate, resulting in an increase in water absorption.

[0179] Example 10

[0180] A method for preparing a transparent antistatic flame-retardant polycarbonate resin is basically the same as in Example 9, except that the amount of macromolecular flame retardant added to the transparent antistatic flame-retardant polycarbonate resin is 5 wt% of the transparent antistatic flame-retardant polycarbonate resin.

[0181] The final transparent antistatic flame-retardant polycarbonate resin has a UL-94 flame retardancy rating of V-0, a limiting oxygen index of 39%, a light transmittance of 86%, and a cantilever beam notched impact strength of 69 kJ / m. 2 When tested at 23℃ and 50%RH, its surface resistivity is 4.8×10⁻⁶. 6 After undergoing damp heat aging treatment at constant temperature and humidity of 85℃ and 85% relative humidity for 168 hours, the limiting oxygen index of the transparent antistatic and flame-retardant polycarbonate resin remained at 94%, the light transmittance remained at 93%, and the surface resistivity remained at 1.9×10⁻⁶. 6 Ω, no obvious increase in haze or precipitation was observed; according to the water absorption test method of GB / T1034-2008, the water absorption rate of this transparent antistatic flame-retardant polycarbonate resin is 0.38%.

[0182] Example 11

[0183] A method for preparing a transparent antistatic flame-retardant polycarbonate resin, the specific process of which is as follows:

[0184] The transparent antistatic flame-retardant polycarbonate resin of Example 6 was melt-blended with a macromolecular flame retardant to obtain a transparent antistatic flame-retardant polycarbonate resin; the amount of macromolecular flame retardant added to the transparent antistatic flame-retardant polycarbonate resin was 1 wt%; the melt processing temperature was 260°C.

[0185] The final transparent antistatic flame-retardant polycarbonate resin has a UL-94 flame retardancy rating of V-0, a limiting oxygen index of 35%, a light transmittance of 91%, and a cantilever beam notched impact strength of 75 kJ / m. 2 When tested at 23℃ and 50%RH, its surface resistivity is 5.8×10⁻⁶. 6 After undergoing damp heat aging treatment at constant temperature and humidity of 85℃ and 85% relative humidity for 168 hours, the limiting oxygen index of the transparent antistatic and flame-retardant polycarbonate resin remained at 92%, the light transmittance remained at 96%, and the surface resistivity remained at 8.6×10⁻⁶. 6 Ω, no obvious increase in haze or precipitation was observed; the water absorption rate of this transparent antistatic flame-retardant polycarbonate resin is 0.39%.

[0186] Example 12

[0187] A method for preparing a transparent antistatic flame-retardant polycarbonate resin, the specific process of which is as follows:

[0188] The transparent antistatic flame-retardant polycarbonate resin of Example 7 was melt-blended with a macromolecular flame retardant to obtain a transparent antistatic flame-retardant polycarbonate resin; the amount of macromolecular flame retardant added to the transparent antistatic flame-retardant polycarbonate resin was 1 wt%; the melt processing temperature was 260°C.

[0189] The final transparent antistatic flame-retardant polycarbonate resin has a UL-94 flame retardancy rating of V-0, a limiting oxygen index of 35%, a light transmittance of 90%, and a cantilever beam notched impact strength of 74 kJ / m. 2 When tested at 23℃ and 50%RH, its surface resistivity is 6.2×10⁻⁶. 6 After undergoing damp heat aging treatment at constant temperature and humidity of 85℃ and 85% relative humidity for 168 hours, the limiting oxygen index of the transparent antistatic and flame-retardant polycarbonate resin remained at 92%, the light transmittance remained at 96%, and the surface resistivity remained at 9.1×10⁻⁶. 6 Ω, no obvious increase in haze or precipitation was observed; the water absorption rate of this transparent antistatic flame-retardant polycarbonate resin is 0.42%.

[0190] Example 13

[0191] A method for preparing a transparent antistatic flame-retardant polycarbonate resin, the specific process of which is as follows:

[0192] The transparent antistatic flame-retardant polycarbonate resin of Example 8 was melt-blended with a macromolecular flame retardant to obtain a transparent antistatic flame-retardant polycarbonate resin; the amount of macromolecular flame retardant added to the transparent antistatic flame-retardant polycarbonate resin was 1 wt%; the melt processing temperature was 260°C.

[0193] The final transparent antistatic flame-retardant polycarbonate resin has a UL-94 flame retardancy rating of V-0, a limiting oxygen index of 34%, a light transmittance of 88%, and a cantilever beam notched impact strength of 71 kJ / m. 2 When tested at 23℃ and 50%RH, its surface resistivity is 6.3×10⁻⁶. 5 After undergoing damp heat aging treatment at constant temperature and humidity of 85℃ and 85% relative humidity for 168 hours, the limiting oxygen index of the transparent antistatic and flame-retardant polycarbonate resin remained at 90%, the light transmittance remained at 94%, and the surface resistivity remained at 8.2×10⁻⁶. 5 Ω, no obvious increase in haze or precipitation was observed; the water absorption rate of this transparent antistatic flame-retardant polycarbonate resin is 0.58%.

Claims

1. A transparent, antistatic, flame-retardant macromolecular flame retardant for polycarbonate resin, characterized in that, The chemical structural formula is: ； Where R1 is CH3; R2 is ; M in a portion of R2 is excluding Na + and K + In addition to the metal ions, the M in another part of R2 is SO3. - Boron-containing structural units that form ion-associative bonds; metal ions and SO3 - The molar ratio of boron-containing structural units forming ion-associations is 3:1 to 7:1; R3 is In R2 and R3, — represents the connection site.

2. The transparent antistatic flame retardant macromolecular flame retardant for polycarbonate resin according to claim 1, characterized in that, The metal ion is Li + ,Sc 3+ Y 3+ Or La 3+ .

3. The transparent antistatic flame retardant macromolecular flame retardant for polycarbonate resin according to claim 1 or 2, characterized in that, The melting temperature of the macromolecular flame retardant for transparent antistatic flame-retardant polycarbonate resin is not less than 120°C, and the initial thermal decomposition temperature under nitrogen atmosphere is not less than 300°C.

4. A method for preparing a macromolecular flame retardant for transparent antistatic flame-retardant polycarbonate resin as described in any one of claims 1 to 3, characterized in that, First, 1,3,5,7-tetramethylcyclotetrasiloxane and octaphenylcyclotetrasiloxane are subjected to a ring-opening equilibrium copolymerization reaction to obtain intermediate A. Then, intermediate A is subjected to a hydrosilylation addition reaction with p-styrenesulfonic acid to obtain intermediate B. Next, a solution containing M is added to intermediate B to obtain intermediate C. Finally, intermediate C is subjected to a phosphorylation reaction with phenylphosphoryl dichloride so that all the chlorine in phenylphosphoryl dichloride is replaced, thereby obtaining a transparent antistatic flame retardant macromolecular flame retardant for polycarbonate resin. Where M includes Na + and K + Other metal ions and those that can react with SO3 - Boron-containing structural units that form ion-associative bonds; metal ions and SO3 - The molar ratio of boron-containing structural units forming ion associations is 3:1 to 7:1; the molar ratio of M in the M-containing solution to the sulfonic acid group in p-styrenesulfonic acid is greater than 1.

5. The preparation method according to claim 4, characterized in that, The specific steps are as follows: (1) After mixing 1,3,5,7-tetramethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, silanol-containing end-capping agent and ring-opening equilibrium catalyst, ring-opening equilibrium copolymerization reaction was carried out at 80~140℃ for 4~6h to obtain intermediate A; (2) Under the hydrosilylation catalyst, intermediate A is subjected to hydrosilylation addition reaction with p-styrene sulfonic acid at 50~80℃ for 3~6h to obtain intermediate B; (3) Cool the reaction system in step (2) to 20~50℃, and then add a solution containing M and react for 1~4h; (4) Under an anhydrous and inert atmosphere, the reaction system of step (3) is cooled to 0~10℃, and then intermediate C is mixed with acid-binding agent. Phenylphosphoryl dichloride is added dropwise at a rate of 1~3mL / min to carry out phosphorylation reaction for 0.5~2h. Then the temperature is raised to 20~50℃ to continue the phosphorylation reaction for 2~4h, thereby obtaining a transparent antistatic flame retardant macromolecular flame retardant for polycarbonate resin.

6. The preparation method according to claim 5, characterized in that, The molar ratio of 1,3,5,7-tetramethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, p-styrenesulfonic acid, and M in the M-containing solution to phenylphosphodichloride is 1:1.01~1.1:4.04~4.4:4.08~4.84:0.476~0.498; the amount of silanol-containing end-capping agent added is 0.5~3wt% of the mass of 1,3,5,7-tetramethylcyclotetrasiloxane; the amount of ring-opening equilibrium catalyst added is 0.01~0.1wt% of the mass of 1,3,5,7-tetramethylcyclotetrasiloxane; the hydrosilylation catalyst is a Pt-containing catalyst, and the amount of Pt added is 20~50ppm of 1,3,5,7-tetramethylcyclotetrasiloxane; the molar ratio of acid-binding agent to phenylphosphodichloride is 2.0~2.5:

1.

7. The preparation method according to claim 5, characterized in that, The silanol-containing end-capping agent is dimethylsilanediol and / or hydroxyl-terminated polydimethylsiloxane; the ring-opening polymerization catalyst is one or more of potassium hydroxide, sodium hydroxide and tetramethylammonium hydroxide; the hydrosilylation catalyst is Karstedt catalyst and / or Speier catalyst; and the acid-binding agent is one or more of triethylamine, pyridine and diisopropylethylamine.

8. A method for preparing a transparent antistatic flame-retardant polycarbonate resin, characterized in that, The transparent antistatic and flame-retardant polycarbonate resin according to any one of claims 1 to 3 is melt-blended with a macromolecular flame retardant to obtain the transparent antistatic and flame-retardant polycarbonate resin.

9. The method for preparing a transparent antistatic flame-retardant polycarbonate resin according to claim 8, characterized in that, The amount of macromolecular flame retardant added to the transparent antistatic flame-retardant polycarbonate resin is 1~5wt% of the transparent antistatic flame-retardant polycarbonate resin.

10. The method for preparing a transparent antistatic flame-retardant polycarbonate resin according to claim 9, characterized in that, The obtained transparent antistatic flame-retardant polycarbonate resin has a UL-94 flame retardancy rating of V-0, a limiting oxygen index of over 30%, a light transmittance of 83-92%, and a cantilever beam notched impact strength of not less than 50 kJ / m. 2 The surface resistivity is 10 5 ~10 8 Ω; After undergoing damp heat aging treatment at constant temperature and humidity of 85℃ and 85% relative humidity for 168 hours, the limiting oxygen index retention rate of the transparent antistatic flame-retardant polycarbonate resin is not less than 90%, the light transmittance retention rate is not less than 90%, and the surface resistivity does not exceed 10. 8 Ω, no obvious increase in haze or precipitation was observed.

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