Chemical-resistant flame-retardant PC / PEN composition and preparation method thereof

Abstract

The invention particularly relates to a chemical-resistant flame-retardant PC / PEN composition and a preparation method thereof. The PC / PEN composition is prepared from the following raw materials in parts by weight: 62 to 68 parts of DOPO-siloxane modified copolymerized PC, 30 to 38 parts of DOPO-siloxane modified copolymerized PEN, 2 to 6 parts of epoxy modified PEN, 2 to 5 parts of modified silicon dioxide, 0.5 to 2 parts of decafluorobiphenyl oxyphosphate, 0.5 to 1.5 parts of a synergist, 0.2 to 0.8 part of an antioxidant, 0.5 to 1.5 parts of a hydrolysis stabilizer and 0.1 to 0.3 part of a lubricating agent. According to the invention, DOPO and siloxane structures are introduced to a PC / PEN main chain, and under the joint cooperation of epoxy group modified PEN and modified silicon dioxide, a PC / PEN phase interface is compatibilized, so that the reinforced, heat-resistant and chemical-resistant stable support is achieved; meanwhile, through decafluorobiphenyl oxyphosphate and the synergist, multi-component synergistic flame retardance is achieved, and the high-temperature resistance and flame retardance are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of PC / PEN composite materials and preparation technology, and in particular to a chemical-resistant flame-retardant PC / PEN composite and a preparation method thereof. Background Art

[0002] Polycarbonate (PC), with its excellent mechanical properties, optical characteristics, and safety and environmental friendliness, has found widespread application in electronics, automotive, battery systems, and optical components. Despite its impressive overall performance, PC also suffers from inherent drawbacks, particularly poor solvent resistance, insufficient abrasion resistance, and poor processing fluidity, which limit its application in some applications. To overcome these drawbacks, incorporating complementary polyethylene terephthalate (PET) or polyethylene naphthalate (PEN) resins into PC / PET or PC / PEN composites is a viable approach. In PC / PET composites, PET's rigidity and chemical resistance compensate for PC's notch sensitivity, while PC's toughness mitigates its brittleness. In PC / PEN composites, PEN's high-temperature resistance and gas barrier properties expand PC's applications in electronics and high-temperature materials. Furthermore, due to the relatively low prices of PET and PEN, composites can reduce raw material costs, offering significant economic advantages. However, during the compounding process of PC, PET, and PEN, thermodynamic incompatibility between PC, PET, and PEN can easily lead to phase separation during melt blending, significantly reducing the mechanical properties of the composite material. Furthermore, during high-temperature processing, the ester groups of PC, PET, and PEN are prone to exchange reactions, resulting in a serious decline in the composite material's performance. Furthermore, in hot and humid environments, slow ester exchange easily occurs at the interface between PC, PET, and PEN, leading to insufficient long-term performance. These issues are key factors that limit the application of PC materials and require resolution. Therefore, addressing the interface issues, temperature resistance, and chemical stability of PC composites is a prerequisite for expanding their high-end applications. Summary of the Invention

[0003] The purpose of the present invention is to provide a chemically resistant flame retardant PC / PEN composition and a method for producing the same in order to address the above-mentioned deficiencies in the prior art.

[0004] The objective of the present invention is achieved through the following technical solution: The present invention provides a chemical-resistant flame-retardant PC / PEN composition, comprising the following raw materials in parts by weight: 62-68 parts of DOPO-siloxane-modified copolymerized PC, 30-38 parts of DOPO-siloxane-modified copolymerized PEN, 2-6 parts of epoxy-modified PEN, 2-5 parts of modified silica, 0.5-2 parts of decafluorobiphenyloxy phosphate, 0.5-1.5 parts of a synergist, 0.2-0.8 parts of an antioxidant, 0.5-1.5 parts of a hydrolysis stabilizer, and 0.1-0.3 parts of a lubricant.

[0005] The PC / PEN composition achieved through chemically bonded flame retardancy and reactive compatibilization exhibits excellent mechanical properties, chemical resistance, and flame retardancy. Using DOPO-siloxane-modified copolymerized PC and DOPO-siloxane-modified copolymerized PEN as primary raw materials, the composition leverages PC's excellent toughness and processability while simultaneously incorporating PEN to enhance heat and chemical resistance. DOPO flame-retardant and siloxane chemical-resistant groups are introduced into the molecular chain. Furthermore, the epoxy groups of the epoxy-modified PEN react with the PC end groups to improve the interface and inhibit phase separation. Modified silica provides both compatibilization and enhancement, synergistic flame retardancy, and improved stability. Decafluorobiphenyloxy phosphate and a synergist work together to provide synergistic flame retardancy. Antioxidants and hydrolysis stabilizers enhance the composition's stability.

[0006] Furthermore, the DOPO-siloxane modified copolymer PC includes the following raw materials in parts by weight: 100 parts of bisphenol A, 105-110 parts of diphenyl carbonate, 6-10 parts of DOPO-HQ, 3-8 parts of hydroxyl-terminated polysiloxane, 0.003-0.01 parts of catalyst, 0.1-0.3 parts of antioxidant, and 0.5-1.5 parts of p-tert-butylphenol.

[0007] Furthermore, the method for preparing the DOPO-siloxane modified copolymer PC comprises the following steps: Step A1: bisphenol A, diphenyl carbonate, DOPO-HQ, hydroxyl-terminated polysiloxane, catalyst, and antioxidant were added to a reaction kettle. The temperature was raised to 180-190° C. under normal pressure with stirring under nitrogen protection for 1-2 hours. The temperature was then raised to 200-210° C., and the pressure was reduced to 10-50 kPa, and the reaction was continued for 1-1.5 hours. Step A2: The reactor is heated to 250-260° C. again, the pressure is reduced to below 50 Pa, and the reaction is carried out for 1.5-2.5 hours. After the reaction is continued for 1-1.5 hours, 4-tert-butylphenol is added. When the stirring torque reaches a constant set value, the material is discharged, pelletized, and vacuum dried to obtain DOPO-siloxane modified copolymer PC.

[0008] Furthermore, the hydroxyl-terminated polysiloxane is dihydroxypolymethylphenylsiloxane, the catalyst is lithium acetate and tetraphenylphosphonium hydroxide in a mass ratio of 1:1-2, and the antioxidant is a compound of antioxidant 1076 and antioxidant 168 in a mass ratio of 1:1.

[0009] Furthermore, the method for producing the DOPO-siloxane modified copolymer PEN comprises the following steps: Step B1, adding dimethyl 2,6-naphthalene dicarboxylate, ethylene glycol, DOPO-HQ and catalyst into a reaction kettle, gradually heating to 180-200° C. under nitrogen protection, and reacting for 2-3 hours; Step B2: Cooling to 180-190° C., adding hydroxyl-terminated polysiloxane to the reaction kettle and reacting for 0.5-1 h; Step B3, slowly heating to 240-250° C., reducing the pressure to 2-5 kPa, and reacting for 1-1.5 hours; continuing to heat to 270-280° C., reducing the pressure to below 100 Pa, and reacting for 1-2 hours, when the stirring torque reaches a constant set value, discharging and pelletizing to obtain the DOPO-siloxane modified copolymer PEN.

[0010] Furthermore, in step B1, the molar ratio of ethylene glycol to dimethyl 2,6-naphthalene dicarboxylate is 1.8-2.2; DOPO-HQ is present in an amount of 8-10 wt% of the ethylene glycol; and the catalyst is a mixture of tetrabutyl titanate and lithium acetate in a mass ratio of 3-4:1, with a total amount of 200-600 ppm. In step B2, the hydroxyl-terminated polysiloxane has a hydroxyl value of 45-56 mgKOH / g and is present in an amount of 7.5-8.5 wt% of the mass of the ethylene glycol.

[0011] In the present invention, by introducing DOPO structure as flame retardant unit in the synthesis of PC and PEN, the migration of small molecules is avoided, the flame retardancy of the PC / PEN composition is improved through chemical bonding, and the heat resistance and chemical stability are improved by introducing siloxane structure.

[0012] Furthermore, the manufacturing method of the epoxy-modified PEN is specifically as follows: vacuum-dried PEN resin, 3-8wt% glycidyl methacrylate, 1-3wt% styrene, 0.1-0.3wt% di-tert-butyl peroxide and 0.1-0.3wt% antioxidant 168 are premixed, added to a twin-screw extruder for melt reaction, and then water-cooled, pelletized and dried to obtain the epoxy-modified PEN.

[0013] Furthermore, the epoxy value of the epoxy-modified PEN is 0.03-0.04 mol / 100g. The temperature of the twin-screw extruder is 220-255°C, the rotation speed is 200-300 rpm, and the residence time is 1.5-3 min.

[0014] In the present invention, glycidyl methacrylate is grafted onto PEN so that its epoxy groups can react with the end groups of the matrix, thereby increasing the interfacial bonding strength and further improving the impact strength and stability of the PC / PEN composition.

[0015] Furthermore, the method for producing the modified silicon dioxide comprises the following steps: Step C1, adding silica to an ethanol-water (v / v=7) solution at a mass-to-volume ratio of 1:100 and ultrasonically dispersing the solution, adding ammonia water and γ-aminopropyltriethoxysilane dropwise thereto, reflux at 70-80° C. for 8-10 hours, centrifuging, washing, and drying to obtain amino-silica; Step C2: dissolving styrene-maleic anhydride copolymer in N,N-dimethylformamide at a mass-to-volume ratio of 1:50 to obtain a modified solution; adding the amino-silica obtained in step C1 to N,N-dimethylformamide at a mass-to-volume ratio of 1:70-80 to carry out ultrasonic dispersion; then slowly adding the modified solution thereto at 85-90° C. and reflux reaction for 10-12 hours; and obtaining modified silica after centrifugation, washing, and drying.

[0016] Furthermore, in step C1, the mass volume ratio of silica to ammonia water is 1:2.5-3, and the mass volume ratio of silica to γ-aminopropyltriethoxysilane is 2:1; in step C2, the mass ratio of styrene-maleic anhydride copolymer to amino silica is 1:2.

[0017] In this invention, dual modification enables the modified silica to react with the end groups in the PC / PEN molecular chains, forming chemical bonds that enhance the interfacial bonding strength and improve its dispersibility within the matrix. Furthermore, the modified silica also acts as a rigidity-reinforcing phase, contributing to the mechanical strength of the PC / PEN composite. The stability of the modified silica, combined with its synergistic effect with the silicon-phosphorus flame retardant system, enhances the chemical resistance and flame and smoke suppression properties of the material.

[0018] Furthermore, the synergist is at least one of layered double hydroxide, zinc borate, potassium diphenylsulfone sulfonate, and phosphorus-nitrogen intumescent flame retardant. As a preferred embodiment of the present invention, the synergist is a compound of phosphorus-nitrogen intumescent flame retardant and potassium diphenylsulfone sulfonate in a mass ratio of 3:1.

[0019] Furthermore, the antioxidant is at least one of hindered phenols and phosphites. Preferably, the antioxidant is a compound of antioxidant 1010 and antioxidant 168 at a mass ratio of 1-2:1.

[0020] Furthermore, the hydrolysis stabilizer is at least one of carbodiimides and epoxy compound hydrolysis stabilizers. In the present invention, preferably, the hydrolysis stabilizer is poly(1,3,5-triisopropylphenyl-carbodiimide).

[0021] Furthermore, the lubricant is at least one of pentaerythritol stearate, ethylene bisstearamide, and polytetrafluoroethylene lubricant. As a preferred embodiment of the present invention, the lubricant is compounded from pentaerythritol stearate, ethylene bisstearamide, and polytetrafluoroethylene lubricant in a mass ratio of 2-4:1:1.

[0022] The present invention also provides a method for producing the chemically resistant flame-retardant PC / PEN composition, comprising the following steps: Step S1, DOPO-siloxane modified copolymer PC, DOPO-siloxane modified copolymer PEN, and epoxy modified PEN are vacuum dried at 70-80° C. for 6-8 hours, modified silica and synergist are added to a mixer and premixed for 2-4 minutes to obtain a premix, which is then set aside; Step S2: adding DOPO-siloxane modified copolymer PC, DOPO-siloxane modified copolymer PEN, epoxy modified PEN, premix, antioxidant and lubricant to the main feed port of a twin-screw extruder; then heating decafluorobiphenyloxy phosphate into a liquid state and mixing it with a hydrolysis stabilizer; adding the decafluorobiphenyloxy phosphate from the side feed port after the melting zone of the twin-screw extruder; extruding, water-cooling, pelletizing and drying to obtain the chemical-resistant flame-retardant PC / PEN composition.

[0023] Furthermore, in step S3, the temperatures of the various zones in the twin-screw extruder are: 220-230°C in the feeding zone, 260-270°C in the melting zone, 255-265°C in the reaction zone, and 245-255°C in the die zone; the screw speed is 200-300 rpm; and the residence time is 3-4 minutes.

[0024] The present invention provides the following beneficial effects: By introducing DOPO and siloxane structures into the PC / PEN backbone to form flame-retardant units, the PC / PEN composition exhibits a synergistic flame retardant effect during combustion, resulting in high flame retardancy, no risk of precipitation, and excellent durability. Furthermore, the compatibilizing effect of epoxy-modified PEN strengthens the PC / PEN interfacial bonding, while the rigid naphthalene ring structure of PEN provides excellent resistance to chemical solvents. Double-grafted modified silica enhances compatibility with the reaction matrix, while its inherent mechanical properties and stability contribute to both reinforcement and flame retardancy. The synergistic flame retardant effect of decafluorobiphenyloxy phosphate and a synergist achieves a UL94 flame retardancy rating of V0. Furthermore, the combination of a hydrolysis stabilizer, antioxidant, and lubricant improves the processing and operational stability of the PC / PEN composition. Therefore, through molecular structure design, interface modification, and multi-component compounding, the present invention achieves synergistic breakthroughs in chemical stability, flame retardancy, and high-temperature resistance, resulting in a PC / PEN composition with overall performance far superior to conventional PC, contributing to the promotion of PC-based engineering plastics in high-end applications. DETAILED DESCRIPTION

[0025] In order to facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the embodiments. The contents mentioned in the embodiments are not intended to limit the present invention.

[0026] Example 1 This embodiment provides a chemically resistant flame-retardant PC / PEN composition, comprising the following raw materials in parts by weight: 65 parts of DOPO-siloxane modified copolymer PC, 34 parts of DOPO-siloxane modified copolymer PEN, 4 parts of epoxy-modified PEN, 3 parts of modified silica, 1.5 parts of decafluorobiphenyloxy phosphate, 1.0 part of a synergist, 0.5 part of an antioxidant, 1.0 part of a hydrolysis stabilizer, and 0.1 part of a lubricant.

[0027] Furthermore, the DOPO-siloxane modified copolymer PC includes the following raw materials in parts by weight: 100 parts of bisphenol A, 108 parts of diphenyl carbonate, 8 parts of DOPO-HQ, 5 parts of hydroxyl-terminated polysiloxane, 0.005 parts of catalyst, 0.2 parts of antioxidant, and 1.0 parts of p-tert-butylphenol.

[0028] Furthermore, the method for preparing the DOPO-siloxane modified copolymer PC comprises the following steps: Step A1: bisphenol A, diphenyl carbonate, DOPO-HQ, hydroxyl-terminated polysiloxane, a catalyst, and an antioxidant were added to a reactor, and the temperature was raised to 180° C. and reacted at normal pressure for 0.5 h under nitrogen protection while stirring. The temperature was then raised to 190° C. and reacted at normal pressure for 1 h. The temperature was then raised to 200° C., and the pressure was reduced to 50 kPa and continued to react for 0.5 h, and then further reduced to 10 kPa and continued to react for 1 h. Step A2: The reactor was heated to 255° C. again, the pressure was reduced to below 50 Pa, and the reaction was carried out for 2 h. After 1.5 h of reaction, 4-tert-butylphenol was added. When the stirring torque reached a constant set value, the material was discharged, pelletized, and vacuum dried to obtain DOPO-siloxane modified copolymer PC.

[0029] Furthermore, the hydroxyl-terminated polysiloxane is dihydroxypolymethylphenylsiloxane, the catalyst is lithium acetate and tetraphenylphosphonium hydroxide in a mass ratio of 1:1.5, and the antioxidant is a compound of antioxidant 1076 and antioxidant 168 in a mass ratio of 1:1.

[0030] Furthermore, the method for producing the DOPO-siloxane modified copolymer PEN comprises the following steps: Step B1: Add dimethyl 2,6-naphthalene dicarboxylate, ethylene glycol, DOPO-HQ and catalyst into a reactor, gradually increase the temperature to 200° C. under nitrogen protection, and react for 2.5 hours; Step B2: Cooling to 180° C., adding hydroxyl-terminated polysiloxane to the reaction kettle and reacting for 1 hour; Step B3: slowly raise the temperature to 245° C., reduce the pressure to 5 kPa, and react for 1 hour; continue to raise the temperature to 275° C., reduce the pressure to below 100 Pa, and react for 2 hours. When the stirring torque reaches a constant set value, the material is discharged and pelletized to obtain the DOPO-siloxane modified copolymer PEN.

[0031] Furthermore, in step B1, the molar ratio of ethylene glycol to dimethyl 2,6-naphthalene dicarboxylate is 2; DOPO-HQ is used at 9 wt% of the ethylene glycol content; and the catalyst is a compound of tetrabutyl titanate and lithium acetate in a 3:1 mass ratio, with a total usage of 400 ppm. In step B2, the hydroxyl-terminated polysiloxane, a dihydroxy-terminated polydimethylsiloxane, is used at 8 wt% of the mass of the ethylene glycol content.

[0032] Furthermore, the manufacturing method of the epoxy-modified PEN is specifically as follows: vacuum-dried PEN resin, 5wt% glycidyl methacrylate, 2wt% styrene, 0.13wt% di-tert-butyl peroxide and 0.15wt% antioxidant 168 are premixed in an 800rpm mixer at 60°C for 10 minutes; the mixture is added to a twin-screw extruder for melt reaction, and then water-cooled, pelletized and dried to obtain the epoxy-modified PEN.

[0033] Furthermore, the intrinsic viscosity of the PEN resin is 0.6 gL / g, and the temperature of the twin-screw extruder is divided into four sections from the feeding zone to the die head, namely 220° C., 245° C., 255° C., and 250° C., the rotation speed is 250 rpm, and the residence time is 2.5 min.

[0034] Furthermore, the method for producing the modified silicon dioxide comprises the following steps: Step C1, adding silica to an ethanol-water (v / v=7) solution at a mass-to-volume ratio of 1:100 and ultrasonically dispersing the solution, adding ammonia water and γ-aminopropyltriethoxysilane dropwise thereto, refluxing at 75° C. for 8 h, centrifuging, washing, and drying to obtain amino-silica; Step C2: dissolving styrene-maleic anhydride copolymer in N,N-dimethylformamide at a mass-to-volume ratio of 1:50 to obtain a modified solution; adding the amino-silica obtained in step C1 to N,N-dimethylformamide at a mass-to-volume ratio of 1:75 to carry out ultrasonic dispersion; then slowly adding the modified solution thereto at 85° C. and reflux for reaction for 12 hours; and obtaining modified silica after centrifugation, washing, and drying.

[0035] Furthermore, in step C1, the mass volume ratio of silica to ammonia water is 1:2.8, and the mass volume ratio of silica to γ-aminopropyltriethoxysilane is 2:1; in step C2, the mass ratio of styrene-maleic anhydride copolymer to amino silica is 1:2.

[0036] Furthermore, the synergist is compounded by a phosphorus-nitrogen intumescent flame retardant and potassium diphenylsulfone sulfonate in a mass ratio of 3:1.

[0037] Furthermore, the antioxidant is compounded by antioxidant 1010 and antioxidant 168 in a mass ratio of 1.5:1.

[0038] Furthermore, the hydrolysis stabilizer is compounded by poly(1,3,5-triisopropylphenyl-carbodiimide) and ethylene-glycidyl methacrylate copolymer in a mass ratio of 2:1.

[0039] Furthermore, the lubricant is compounded by pentaerythritol stearate, ethylene bisstearamide and polytetrafluoroethylene lubricant in a mass ratio of 3:1:1.

[0040] This embodiment also provides a method for producing the chemically resistant flame-retardant PC / PEN composition, comprising the following steps: Step S1, DOPO-siloxane modified copolymer PC, DOPO-siloxane modified copolymer PEN, and epoxy modified PEN are vacuum dried at 70-80° C. for 6-8 hours, modified silica and synergist are added to a mixer and premixed for 3 minutes to obtain a premix, which is then set aside; Step S2: adding DOPO-siloxane modified copolymer PC, DOPO-siloxane modified copolymer PEN, epoxy modified PEN, premix, antioxidant and lubricant to the main feed port of a twin-screw extruder; then heating decafluorobiphenyloxy phosphate into a liquid state and mixing it with a hydrolysis stabilizer; adding the decafluorobiphenyloxy phosphate from the side feed port after the melting zone of the twin-screw extruder; extruding, water-cooling, pelletizing and drying to obtain the chemical-resistant flame-retardant PC / PEN composition.

[0041] Furthermore, in step S3, the temperature of each zone in the twin-screw extruder is: 220°C in the feeding zone, 260°C in the melting zone, 255°C in the reaction zone, and 250°C in the head zone; the screw speed is 250 rpm; and the residence time is 3.5 min.

[0042] Example 2 This embodiment provides a chemical-resistant flame-retardant PC / PEN composition, comprising the following raw materials in parts by weight: 62 parts of DOPO-siloxane-modified copolymerized PC, 30 parts of DOPO-siloxane-modified copolymerized PEN, 2 parts of epoxy-modified PEN, 3 parts of modified silica, 1 part of decafluorobiphenyloxy phosphate, 0.7 parts of a synergist, 0.5 parts of an antioxidant, 0.8 parts of a hydrolysis stabilizer, and 0.12 parts of a lubricant.

[0043] Furthermore, the DOPO-siloxane modified copolymer PC includes the following raw materials in parts by weight: 100 parts of bisphenol A, 105 parts of diphenyl carbonate, 7 parts of DOPO-HQ, 3 parts of hydroxyl-terminated polysiloxane, 0.006 parts of catalyst, 0.13 parts of antioxidant, and 0.7 parts of p-tert-butylphenol.

[0044] Furthermore, the method for preparing the DOPO-siloxane modified copolymer PC comprises the following steps: Step A1: bisphenol A, diphenyl carbonate, DOPO-HQ, hydroxyl-terminated polysiloxane, catalyst, and antioxidant were added to a reaction kettle. The temperature was raised to 180° C. and reacted at normal pressure for 2 h under nitrogen protection while stirring. The temperature was then raised to 205° C. and the pressure was reduced to 50 kPa, and the reaction was continued for 1.5 h. Step A2: The reactor was heated to 250° C. again, the pressure was reduced to below 50 Pa, and the reaction was carried out for 2.5 hours. After the reaction was continued for 1.5 hours, 4-tert-butylphenol was added. When the stirring torque reached a constant set value, the material was discharged, pelletized, and vacuum dried to obtain DOPO-siloxane modified copolymer PC.

[0045] Furthermore, the hydroxyl-terminated polysiloxane is dihydroxypolymethylphenylsiloxane, the catalyst is lithium acetate and tetraphenylphosphonium hydroxide in a mass ratio of 1:1, and the antioxidant is a compound of antioxidant 1076 and antioxidant 168 in a mass ratio of 1:1.

[0046] Furthermore, the method for producing the DOPO-siloxane modified copolymer PEN comprises the following steps: Step B1: Add dimethyl 2,6-naphthalene dicarboxylate, ethylene glycol, DOPO-HQ and catalyst into a reactor, gradually increase the temperature to 200° C. under nitrogen protection, and react for 2.5 seconds; Step B2: Cooling to 185°C, adding hydroxyl-terminated polysiloxane to the reaction kettle and reacting for 1 hour; Step B3: slowly raise the temperature to 250° C., reduce the pressure to 5 kPa, and react for 1 hour; continue to raise the temperature to 275° C., reduce the pressure to below 100 Pa, and react for 2 hours. When the stirring torque reaches a constant set value, the material is discharged and pelletized to obtain the DOPO-siloxane modified copolymer PEN.

[0047] Furthermore, in step B1, the molar ratio of ethylene glycol to dimethyl 2,6-naphthalene dicarboxylate is 1.8; DOPO-HQ is 8 wt % of the ethylene glycol dosage; and the catalyst is compounded from tetrabutyl titanate and lithium acetate in a mass ratio of 4:1, with a total dosage of 300 ppm.

[0048] Furthermore, the manufacturing method of the epoxy-modified PEN is specifically as follows: vacuum-dried PEN resin, 4 wt% glycidyl methacrylate, 1.5 wt% styrene, 0.1 wt% di-tert-butyl peroxide, and 0.1 wt% antioxidant 168 are premixed in an 800 rpm mixer at 60° C. for 10 minutes; the mixture is added to a twin-screw extruder for melt reaction, and then water-cooled, pelletized, and dried to obtain the epoxy-modified PEN.

[0049] Furthermore, the intrinsic viscosity of the PEN resin is 0.65 gL / g, the temperature of the twin-screw extruder is divided into four sections from the feed zone to the die head, namely 220°C, 245°C, 255°C, and 250°C, the rotation speed is 300 rpm, and the residence time is 3 minutes. Furthermore, the method for producing modified silica comprises the following steps: Step C1, adding silica to an ethanol-water (v / v=7) solution at a mass-to-volume ratio of 1:100 and ultrasonically dispersing the solution, adding ammonia water and γ-aminopropyltriethoxysilane dropwise thereto, refluxing at 70° C. for 10 h, centrifuging, washing, and drying to obtain amino-silica; Step C2: dissolving styrene-maleic anhydride copolymer in N,N-dimethylformamide at a mass-to-volume ratio of 1:50 to obtain a modified solution; adding the amino-silica obtained in step C1 to N,N-dimethylformamide at a mass-to-volume ratio of 1:75 to carry out ultrasonic dispersion; then slowly adding the modified solution thereto at 90° C. and reflux for reaction for 10 hours; and obtaining modified silica after centrifugation, washing, and drying.

[0050] Furthermore, in step C1, the mass volume ratio of silica to ammonia water is 1:2.8, and the mass volume ratio of silica to γ-aminopropyltriethoxysilane is 2:1; in step C2, the mass ratio of styrene-maleic anhydride copolymer to amino silica is 1:2.

[0051] Furthermore, the synergist is a phosphorus-nitrogen intumescent flame retardant.

[0052] Furthermore, the antioxidant is compounded by antioxidant 1010 and antioxidant 168 in a mass ratio of 1.5:1.

[0053] Furthermore, the hydrolysis stabilizer is poly (1,3,5-triisopropylphenyl-carbodiimide).

[0054] Furthermore, the lubricant is compounded by pentaerythritol stearate, ethylene bisstearamide and polytetrafluoroethylene lubricant in a mass ratio of 3:1:1.

[0055] This embodiment also provides a method for producing the chemically resistant flame-retardant PC / PEN composition, comprising the following steps: Step S1, DOPO-siloxane modified copolymer PC, DOPO-siloxane modified copolymer PEN, and epoxy modified PEN are vacuum dried at 70-80° C. for 6-8 hours, modified silica and synergist are added to a mixer and premixed for 3 minutes to obtain a premix, which is then set aside; Step S2: adding DOPO-siloxane modified copolymer PC, DOPO-siloxane modified copolymer PEN, epoxy modified PEN, premix, antioxidant and lubricant to the main feed port of a twin-screw extruder; then heating decafluorobiphenyloxy phosphate into a liquid state and mixing it with a hydrolysis stabilizer; adding the decafluorobiphenyloxy phosphate from the side feed port after the melting zone of the twin-screw extruder; extruding, water-cooling, pelletizing and drying to obtain the chemical-resistant flame-retardant PC / PEN composition.

[0056] Furthermore, in step S3, the temperature of each zone in the twin-screw extruder is: 225°C in the feeding zone, 265°C in the melting zone, 265°C in the reaction zone, and 255°C in the head zone; the screw speed is 300 rpm; and the residence time is 3 min.

[0057] Example 3 This embodiment provides a chemical-resistant flame-retardant PC / PEN composition, comprising the following raw materials in parts by weight: 67 parts of DOPO-siloxane-modified copolymerized PC, 36 parts of DOPO-siloxane-modified copolymerized PEN, 5 parts of epoxy-modified PEN, 4 parts of modified silica, 1.6 parts of decafluorobiphenyloxy phosphate, 1.3 parts of a synergist, 0.7 parts of an antioxidant, 1.3 parts of a hydrolysis stabilizer, and 0.28 parts of a lubricant.

[0058] Furthermore, the DOPO-siloxane modified copolymer PC includes the following raw materials in parts by weight: 100 parts of bisphenol A, 108 parts of diphenyl carbonate, 9 parts of DOPO-HQ, 7 parts of hydroxyl-terminated polysiloxane, 0.008 parts of catalyst, 0.25 parts of antioxidant, and 1.2 parts of p-tert-butylphenol.

[0059] Furthermore, the method for preparing the DOPO-siloxane modified copolymer PC comprises the following steps: Step A1: bisphenol A, diphenyl carbonate, DOPO-HQ, hydroxyl-terminated polysiloxane, a catalyst, and an antioxidant were added to a reaction kettle. The temperature was raised to 185° C. and reacted at normal pressure for 1.5 h under nitrogen protection while stirring. The temperature was then raised to 210° C. and the pressure was reduced to 50 kPa, and the reaction was continued for 1.5 h. Step A2: The reactor was heated to 260° C. again, the pressure was reduced to below 50 Pa, and the reaction was carried out for 2 h. After the reaction was continued for 1 h, 4-tert-butylphenol was added. When the stirring torque reached a constant set value, the material was discharged, pelletized, and vacuum dried to obtain DOPO-siloxane modified copolymer PC.

[0060] Furthermore, the hydroxyl-terminated polysiloxane is dihydroxypolymethylphenylsiloxane, the catalyst is lithium acetate and tetraphenylphosphonium hydroxide in a mass ratio of 1:1, and the antioxidant is a compound of antioxidant 1076 and antioxidant 168 in a mass ratio of 1:1.

[0061] Furthermore, the method for producing the DOPO-siloxane modified copolymer PEN comprises the following steps: Step B1: Add dimethyl 2,6-naphthalene dicarboxylate, ethylene glycol, DOPO-HQ and catalyst into a reactor, gradually increase the temperature to 200° C. under nitrogen protection, and react for 2.5 hours; Step B2: Cooling to 5190°C, adding hydroxyl-terminated polysiloxane to the reaction kettle and reacting for 1 hour; Step B3, slowly heating to 250° C., reducing the pressure to 5 kPa, and reacting for 1.5 hours; continuing to heat to 280° C., reducing the pressure to below 100 Pa, and reacting for 1.5 hours, when the stirring torque reaches a constant set value, discharging and pelletizing to obtain the DOPO-siloxane modified copolymer PEN.

[0062] Furthermore, in step B1, the molar ratio of ethylene glycol to dimethyl 2,6-naphthalene dicarboxylate is 2.2; DOPO-HQ is 10 wt % of the amount of ethylene glycol; and the catalyst is compounded from tetrabutyl titanate and lithium acetate in a mass ratio of 3:1, with a total amount of 500 ppm.

[0063] Furthermore, the manufacturing method of the epoxy-modified PEN is specifically as follows: vacuum-dried PEN resin, 8wt% glycidyl methacrylate, 2.6wt% styrene, 0.25wt% di-tert-butyl peroxide and 0.3wt% antioxidant 168 are premixed in an 800rpm mixer at 60°C for 10 minutes; the mixture is added to a twin-screw extruder for melt reaction, and then water-cooled, pelletized and dried to obtain the epoxy-modified PEN.

[0064] Furthermore, the intrinsic viscosity of the PEN resin is 0.65 gL / g, the temperature of the twin-screw extruder is divided into four sections from the feeding zone to the die head, namely 220°C, 250°C, 255°C, and 250°C, the rotation speed is 300 rpm, and the residence time is 4 minutes.

[0065] Furthermore, the method for producing the modified silicon dioxide comprises the following steps: Step C1, adding silica to an ethanol-water (v / v=7) solution at a mass-to-volume ratio of 1:100 and ultrasonically dispersing the solution, adding ammonia water and γ-aminopropyltriethoxysilane dropwise thereto, refluxing at 80° C. for 10 hours, centrifuging, washing, and drying to obtain amino-silica; Step C2: dissolving styrene-maleic anhydride copolymer in N,N-dimethylformamide at a mass-to-volume ratio of 1:50 to obtain a modified solution; adding the amino-silica obtained in step C1 to N,N-dimethylformamide at a mass-to-volume ratio of 1:80 to carry out ultrasonic dispersion; then slowly adding the modified solution thereto at 90° C. and reflux for reaction for 12 hours; and obtaining modified silica after centrifugation, washing, and drying.

[0066] Furthermore, in step C1, the mass volume ratio of silica to ammonia water is 1:3, and the mass volume ratio of silica to γ-aminopropyltriethoxysilane is 2:1; in step C2, the mass ratio of styrene-maleic anhydride copolymer to amino silica is 1:2.

[0067] Furthermore, the synergist is compounded by a phosphorus-nitrogen intumescent flame retardant and potassium diphenylsulfone sulfonate in a mass ratio of 3:1.

[0068] Furthermore, the antioxidant is compounded by antioxidant 1010 and antioxidant 168 in a mass ratio of 1-2:1.

[0069] Furthermore, the hydrolysis stabilizer is poly (1,3,5-triisopropylphenyl-carbodiimide).

[0070] Furthermore, the lubricant is compounded by pentaerythritol stearate, ethylene bisstearamide and polytetrafluoroethylene lubricant in a mass ratio of 2:1:1.

[0071] This embodiment also provides a method for producing the chemically resistant flame-retardant PC / PEN composition, comprising the following steps: Step S1, DOPO-siloxane modified copolymer PC, DOPO-siloxane modified copolymer PEN, and epoxy modified PEN are vacuum dried at 70-80° C. for 6-8 hours, modified silica and synergist are added to a mixer and premixed for 4 minutes to obtain a premix, which is then set aside; Step S2: adding DOPO-siloxane modified copolymer PC, DOPO-siloxane modified copolymer PEN, epoxy modified PEN, premix, antioxidant and lubricant to the main feed port of a twin-screw extruder; then heating decafluorobiphenyloxy phosphate into a liquid state and mixing it with a hydrolysis stabilizer; adding the decafluorobiphenyloxy phosphate from the side feed port after the melting zone of the twin-screw extruder; extruding, water-cooling, pelletizing and drying to obtain the chemical-resistant flame-retardant PC / PEN composition.

[0072] Furthermore, in step S3, the temperature of each zone in the twin-screw extruder is: 230°C in the feeding zone, 270°C in the melting zone, 265°C in the reaction zone, and 255°C in the head zone; the screw speed is 300 rpm; and the residence time is 3.5 min.

[0073] Comparative Example 1 The difference between this comparative example and Example 1 is that this comparative example uses commercially available silicone PC (SABIC, EXL1414T) instead of the DOPO-siloxane modified copolymer PC in Example 1, and uses PEN resin (Teijin Chemicals, TN8065S) instead of the DOPO-siloxane modified copolymer PEN and epoxy-modified PEN in Example 1. The remaining components are the same as those in Example 1.

[0074] Comparative Example 2 The difference between this comparative example and Example 1 is that the epoxy-modified PEN, modified silica, decafluorobiphenyloxy phosphate and synergist in Example 1 are not added in this comparative example, and the remaining components are adjusted in equal proportions.

[0075] Comparative Example 3 The difference between this comparative example and Example 1 is that the epoxy-modified PEN, decafluorobiphenyloxy phosphate and synergist in Example 1 are not added in this comparative example, and nano-silica (Shandong Zhonglian) is used to replace the modified silica in Example 1, and the remaining components are adjusted in equal proportions.

[0076] Comparative Example 4 The difference between this comparative example and Example 1 is that this comparative example uses commercially available PC resin (SABIC, EXL1414T) and commercially available PEN resin (Teijin Chemicals, TN8065S) instead of the DOPO-siloxane-modified copolymerized PC and DOPO-siloxane-modified copolymerized PEN in the example, respectively, and the decafluorobiphenyloxy phosphate and synergist in Example 1 are not added. The remaining components are adjusted in equal proportions.

[0077] The chemical-resistant, flame-retardant PC / PEN compositions prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to performance testing. Tensile strength was tested according to ISO 527, notched impact strength was tested according to ISO 179, heat distortion temperature was tested according to ISO 75-2-2003 (1.8 MPa), and flame retardancy was tested according to UL 94. The chemical resistance test involved immersing the samples in 10% H₂SO₄, 10% NaOH, or acetone at room temperature for 7 days. The tensile strength of the samples after immersion was L2, while the tensile strength of the samples before immersion was L1. The tensile strength retention ratio was calculated as L2 / L1*100%. Each test group consisted of five samples, and the average value was taken. The specific test results are shown in the table below.

[0078]

[0079] From the data in the table above, it can be seen that the chemically resistant flame retardant PC / PEN compositions prepared in Examples 1-3 have a tensile strength of more than 68 MPa and a notched impact strength of more than 65 kJ / m 2 , indicating that its mechanical properties are well maintained. The heat deformation temperature is greater than 108°C, and the flame retardancy rating reaches V0, indicating that it has good high temperature resistance and flame retardancy. In terms of chemical stability, the treated PC / PEN composition still maintains a high tensile strength, whether in acidic, alkaline, or ketone organic matter, and can basically be controlled within a 20% loss range, indicating that the PC / PEN composition has good acid, alkali, and organic solvent resistance stability. The present invention introduces DOPO and siloxane structures into the PC / PEN backbone, and with the combined cooperation of epoxy-modified PEN and modified silica, the PC / PEN phase interface is expanded to ensure its mechanical properties while providing reinforcement, heat resistance, and chemical stability. On the other hand, through the multi-component synergistic flame retardancy of DOPO and siloxane structures, decafluorobiphenyloxy phosphate, and synergist, the chemical stability, high temperature resistance, and flame retardancy of the PEC / PEN are synergistically improved.

[0080] The above specific embodiments are further explanations of the technical solutions and beneficial effects of the present invention, and are not intended to limit the implementation methods. For those skilled in the art, any obvious substitutions that do not depart from the concept of the present invention are within the scope of protection of the present invention.

Claims

1. A chemically resistant flame-retardant PC / PEN composition, characterized by: The invention comprises the following raw materials in parts by weight: 62-68 parts of DOPO-siloxane modified copolymer PC, 30-38 parts of DOPO-siloxane modified copolymer PEN, 2-6 parts of epoxy modified PEN, 2-5 parts of modified silica, 0.5-2 parts of decafluorobiphenyloxy phosphate, 0.5-1.5 parts of synergist, 0.2-0.8 parts of antioxidant, 0.5-1.5 parts of hydrolysis stabilizer, and 0.1-0.3 parts of lubricant.

2. The chemical-resistant flame-retardant PC / PEN composition according to claim 1, characterized in that: The DOPO-siloxane modified copolymer PC comprises the following raw materials in parts by weight: 100 parts of bisphenol A, 105-110 parts of diphenyl carbonate, 6-10 parts of DOPO-HQ, 3-8 parts of hydroxyl-terminated polysiloxane, 0.003-0.01 parts of catalyst, 0.1-0.3 parts of antioxidant, and 0.5-1.5 parts of p-tert-butylphenol.

3. The chemical-resistant flame-retardant PC / PEN composition according to claim 2, characterized in that: The method for producing the DOPO-siloxane modified copolymer PC comprises the following steps: Step A1: bisphenol A, diphenyl carbonate, DOPO-HQ, hydroxyl-terminated polysiloxane, catalyst, and antioxidant were added to a reaction kettle. The temperature was raised to 180-190° C. under normal pressure with stirring under nitrogen protection for 1-2 hours. The temperature was then raised to 200-210° C., and the pressure was reduced to 10-50 kPa, and the reaction was continued for 1-1.5 hours. Step A2: The reactor is heated to 250-260° C. again, the pressure is reduced to below 50 Pa, and the reaction is carried out for 1.5-2.5 hours. After the reaction is continued for 1-1.5 hours, 4-tert-butylphenol is added. When the stirring torque reaches a constant set value, the material is discharged, pelletized, and vacuum dried to obtain DOPO-siloxane modified copolymer PC.

4. The chemical-resistant flame-retardant PC / PEN composition according to claim 1, characterized in that: The epoxy-modified PEN is prepared by premixing vacuum-dried PEN resin, 3-8 wt% glycidyl methacrylate, 1-3 wt% styrene, 0.1-0.3 wt% di-tert-butyl peroxide, and 0.1-0.3 wt% antioxidant, and then adding the mixture to a twin-screw extruder for melt reaction. The mixture is then water-cooled, pelletized, and dried to obtain the epoxy-modified PEN.

5. The chemical-resistant flame-retardant PC / PEN composition according to claim 1, characterized in that: The synergist is at least one of layered double hydroxide, zinc borate, potassium diphenylsulfone sulfonate, and phosphorus-nitrogen intumescent flame retardant.

6. The chemical-resistant flame-retardant PC / PEN composition according to claim 1, characterized in that: The antioxidant is at least one of hindered phenols and phosphites.

7. The chemical-resistant flame-retardant PC / PEN composition according to claim 1, characterized in that: The hydrolysis stabilizer is at least one of carbodiimide and epoxy compound hydrolysis stabilizers.

8. The chemical-resistant flame-retardant PC / PEN composition according to claim 1, characterized in that: The lubricant is at least one of pentaerythritol stearate, ethylene bisstearamide, and polytetrafluoroethylene lubricant.

9. The method for producing the chemical-resistant flame-retardant PC / PEN composition according to any one of claims 1 to 8, wherein: The steps include: Step S1, DOPO-siloxane modified copolymer PC, DOPO-siloxane modified copolymer PEN, and epoxy modified PEN are vacuum dried at 70-80° C. for 6-8 hours, modified silica and synergist are added to a mixer and premixed for 2-4 minutes to obtain a premix, which is then set aside; Step S2: adding DOPO-siloxane modified copolymer PC, DOPO-siloxane modified copolymer PEN, epoxy modified PEN, premix, antioxidant and lubricant to the main feed port of a twin-screw extruder; then heating decafluorobiphenyloxy phosphate into a liquid state and mixing it with a hydrolysis stabilizer; adding the decafluorobiphenyloxy phosphate from the side feed port after the melting zone of the twin-screw extruder; extruding, water-cooling, pelletizing and drying to obtain the chemical-resistant flame-retardant PC / PEN composition.

10. The method for producing a chemically resistant flame-retardant PC / PEN composition according to claim 9, wherein: In step S3, the temperature of each zone in the twin-screw extruder is: 220-230°C in the feeding zone, 260-270°C in the melting zone, 255-265°C in the reaction zone, and 245-255°C in the die zone.

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