High-temperature processing formed PC flame-retardant material and preparation method thereof

Abstract

The application relates to a high-temperature processing formed PC flame-retardant material, and the proportion of each component is as follows in parts by weight: PC resin: 50-77 parts; silicon PC resin: 20-40 parts; halogen-free flame retardant: 1-5 parts; toughening agent: 2-5 parts; weather-resistant agent: 0.5-1 part; antioxidant: 0.5-1 part; hydrolysis-resistant agent: 0.5-1 part. The application uses PC resin and silicon PC resin as the base resin, determines the proportion of 50-77 parts of PC and 20-40 parts of silicon PC, and improves the high-temperature processing stability and basic flame retardancy of the material; the halogen-free flame retardant is compounded by using phosphazene flame retardant and organic silicon flame retardant at a ratio of 4:1, the toughening agent is compounded by using MBS and PTW at a ratio of 3:1, the weather-resistant agent is compounded by using UV234 and HALS 944 at a ratio of 2:1, the antioxidant is compounded by using antioxidant 168 and antioxidant 626 at a ratio of 2:1, and through the specific proportion of multi-component synergistic compounding, the synchronous improvement of the flame-retardant, toughening, weather-resistant and heat-oxidation aging resistance is realized.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a high-temperature processed PC flame-retardant material and its preparation method. Background Technology

[0002] Polycarbonate (PC) is a thermoplastic engineering plastic with excellent comprehensive properties, including superior impact resistance, dimensional stability, electrical insulation, and heat resistance. It is widely used in electronics, automobiles, office equipment, and building materials.

[0003] However, ordinary PC materials have limited flame retardant properties, which makes it difficult to meet the requirements of high-end applications for flame retardant ratings. Therefore, flame retardants are usually added for modification.

[0004] Currently, PC flame retardant modification is mainly divided into two categories: halogen-based flame retardants and halogen-free flame retardants. While halogen-based flame retardants have high flame retardant efficiency, they release toxic and harmful gases and corrosive substances during combustion, which does not conform to the current trend of environmentally friendly materials and has been gradually phased out by the market. In halogen-free flame retardant systems, phosphorus-based, silicon-based, and phosphazene-based flame retardants have become the mainstream choices, but existing halogen-free flame-retardant PC materials generally suffer from the following technical defects: 1. Poor high-temperature processing stability; flame retardants are prone to decomposition and volatilization during high-temperature melting and processing. That is, the processing temperature of PC materials is usually high. Conventional halogen-free flame retardants are prone to decomposition and volatilization during high-temperature melting and processing. This not only leads to a decrease in the flame retardant performance of the material, but also causes degradation of the PC matrix, resulting in a significant reduction in the mechanical properties and heat resistance of the material, making it unsuitable for high-temperature extrusion, injection molding and other processing technologies. 2. It is difficult to achieve both flame retardant performance and mechanical properties. When the amount of a single halogen-free flame retardant added is low, the flame retardant effect is insufficient. When the amount added is too high, it will damage the toughness and impact strength of PC material, resulting in poor toughening effect. At the same time, long-term performance such as weather resistance and hydrolysis resistance will also be affected. 3. Insufficient weather resistance and hydrolysis resistance, resulting in poor long-term performance; 4. The multi-component system has poor compatibility and limited overall performance improvement. Most existing flame retardants, toughening agents and additives are used as single varieties with unreasonable compounding ratios. The compatibility between the components is poor, and it is impossible to achieve synergistic improvement of flame retardancy, toughening, weather resistance and hydrolysis resistance. It is difficult to meet the comprehensive requirements of high-end application fields for the multi-faceted performance of materials.

[0005] Therefore, it is of great significance to develop a PC flame-retardant material that combines high-temperature processing stability, excellent flame retardant properties, good mechanical properties, and long-term service stability. Summary of the Invention

[0006] The purpose of this invention is to provide a high-temperature processed PC flame-retardant material to solve the above-mentioned problems in the prior art.

[0007] To achieve the above objectives, the present invention provides the following technical solution.

[0008] A high-temperature processed flame-retardant PC material, wherein the material comprises the following components by weight: 50-77 parts of PC resin; 20-40 parts of silicone PC resin; 1-5 parts of halogen-free flame retardant; 2-5 parts toughening agent; Weather resistant agent 0.5-1 part; Antioxidant 0.5-1 part; 0.5-1 part of hydrolysis resistant agent.

[0009] Preferably, the PC resin is a high molecular weight polycarbonate with a melt index of 8-12 g / 10 min (test conditions: 300℃, 1.2 kg), which has excellent basic mechanical properties and heat resistance. As the main matrix of the material, it ensures the core strength of the material. The silicone PC resin is a siloxane copolymer polycarbonate, which has excellent compatibility with ordinary PC. It can improve the high-temperature processing stability, flame retardancy and low-temperature toughness of the material. When used in combination with ordinary PC, it optimizes the high-temperature processing performance and flame retardancy of the matrix resin.

[0010] Preferably, the halogen-free flame retardant is a compound of phosphazene flame retardant and organosilicon flame retardant in a weight ratio of 4:1.

[0011] Preferably, the phosphazene flame retardant is a cyclic phenoxyphosphazene, which has high flame retardant efficiency, excellent thermal stability, and does not decompose at high temperatures, and can exert a synergistic flame retardant effect in both the gas phase and condensed phase. The organosilicon flame retardant is a polysiloxane flame retardant, which has good compatibility with the PC matrix and has both toughening and flame retardant effects. The combination of the two can achieve halogen-free and highly efficient flame retardancy, and there is no volatilization or decomposition during high-temperature processing.

[0012] Preferably, the toughening agent is a compound of MBS (methyl methacrylate-butadiene-styrene copolymer) and PTW (ethylene-butyl acrylate-glycidyl methacrylate copolymer) in a weight ratio of 3:1. MBS can effectively improve the room temperature toughness of PC, while PTW, as a reactive toughening agent, can react with the end groups of PC, improving the toughening effect while also improving the compatibility between components. The compound of the two provides synergistic toughening, avoiding the problem of decreased heat resistance caused by adding a single toughening agent, and is suitable for high-temperature processing.

[0013] Preferably, the weathering agent is a mixture of UV234 (ultraviolet absorber) and HALS944 (hindered amine light stabilizer) in a weight ratio of 2:1. UV234 can efficiently absorb ultraviolet rays, and HALS944 can capture photo-oxidative free radicals. The two are mixed to form a complete light-stabilizing system, which greatly improves the weather resistance and anti-aging performance of the material and extends the outdoor service life of the material.

[0014] Preferably, the antioxidant is a compound of antioxidant 168 and antioxidant 626 in a weight ratio of 2:1. Both are phosphite-based auxiliary antioxidants. After compounding, they have a significant synergistic effect, which can effectively inhibit the thermo-oxidative degradation of PC materials during high-temperature melting and processing, ensure the stability of the material during high-temperature processing, and avoid the decay of mechanical properties and heat resistance.

[0015] Preferably, the hydrolysis-resistant agent is polycarbodiimide, which can effectively capture the carboxyl groups generated by the hydrolysis of PC material, inhibit the hydrolytic degradation of PC in a humid and hot environment, improve the hydrolysis resistance stability of the material, and broaden the application range of the material in humid environments.

[0016] A method for preparing a high-temperature processed flame-retardant PC material as described in any one of claims 1-8, comprising the following steps: S1. Weigh out PC resin, silicone PC resin, halogen-free flame retardant, toughening agent, weather resistant agent, antioxidant and hydrolysis resistant agent according to the formula; dry PC resin and silicone PC resin at 120-130℃ for 4-6 hours; S2. Add the dried PC resin, silicone PC resin and other components into a high-speed mixer and stir at 300-500 r / min for 10-15 min to obtain a mixture. S3. The mixture is added to a twin-screw extruder for melt blending, extrusion and granulation. The twin-screw extruder has a length-to-diameter ratio of 40:1-50:1, a processing temperature of 260-300℃, and a screw speed of 200-300r / min. S4. Dry the obtained granules at 120℃ for 3 hours to remove surface moisture, then seal and package to obtain the finished product.

[0017] Compared with the prior art, the present invention has the following advantages: Compared with the prior art, the present invention has the following advantages: 1. Excellent high-temperature processing stability, maintaining stable performance under processing conditions of 260-300℃; 2. Halogen-free and environmentally friendly, with a flame retardant rating up to UL94 V-0; 3. High impact resistance and excellent toughness; 4. Excellent weather resistance and hydrolysis resistance; 5. The process is simple and suitable for continuous mass production. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the process of the present invention.

[0019] Figure 2 This is a performance comparison test data table for the present invention.

[0020] Figure 3 This is a physical image of the material used in this invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] A high-temperature processed PC flame-retardant material, with the following component proportions by weight: PC: 50-77 parts; Silicon PC: 20-40 parts; Halogen-free flame retardant: 1-5 parts; Toughening agent: 2-5 parts; Weather resistant agent: 0.5-1 part; Antioxidant: 0.5-1 part; Hydrolysis resistant agent: 0.5-1 part.

[0023] 1. Matrix resin PC: General-purpose high molecular weight polycarbonate with a melt index of 8-12 g / 10 min (test conditions: 300℃, 1.2 kg); Silicon PC: Silicon siloxane copolymer polycarbonate.

[0024] 2. Halogen-free flame retardant It is a self-made compound of phosphazene flame retardant and organosilicon flame retardant in a weight ratio of 4:1; wherein, the phosphazene flame retardant is a cyclic phenoxyphosphazene; and the organosilicon flame retardant is a polysiloxane flame retardant.

[0025] 3. Toughening agent It is a self-made compound of MBS (methyl methacrylate-butadiene-styrene copolymer) and PTW (ethylene-butyl acrylate-glycidyl methacrylate copolymer) in a weight ratio of 3:1.

[0026] 4. Weather resistant agent It is a self-made compound of UV234 (ultraviolet absorber) and HALS 944 (hindered amine light stabilizer) in a weight ratio of 2:1. 5. Antioxidants It is a self-made compound of antioxidant 168 and antioxidant 626 in a weight ratio of 2:1. 6. Hydrolysis resistant agent Polycarbodiimide was selected. Example

[0027] By weight: 75 parts PP; 1 part compound antibacterial agent; 3 parts GMA grafted POE; 1 part polysiloxane; 10 parts talc; 6 parts compound toughening agent; 0.8 parts compound weathering agent; 0.8 parts compound antioxidant.

[0028] Preparation steps: 1. Mix at 500 rpm for 8 minutes in a high-speed mixer; 2. Twin-screw extrusion granulation; 3. The temperature zones are 170℃, 180℃, 190℃, 200℃, and 210℃, with the machine head at 210℃; 4. The main unit speed is 300 r / min. Example

[0029] 80 parts PP; 1.5 parts compound antibacterial agent; 2 parts GMA grafted POE; 1.5 parts polysiloxane; 8 parts calcium carbonate; 5 parts compound toughening agent; 0.7 parts compound weathering agent; 0.7 parts compound antioxidant.

[0030] The remaining processes are the same as in Example 1. Example

[0031] 70 parts PP; 0.8 parts compound antibacterial agent; 4 parts GMA grafted POE; 2 parts polysiloxane; 12 parts barium sulfate; 8 parts compound toughening agent; 0.9 parts compound weathering agent; 0.9 parts compound antioxidant.

[0032] The remaining processes are the same as in Example 1.

[0033] The performance test results of the above embodiments are as follows: Figure 2 As shown, the test results indicate that the PC flame-retardant material prepared in the embodiments of the present invention achieves a flame-retardant rating of UL94 V-0, and its mechanical properties and heat resistance are far superior to those of existing ordinary halogen-free PC materials. The performance retention rate after high-temperature processing is ≥96%, which fully demonstrates the technical advantages of the present invention. Example

[0034] This example is a comparative example, using a single PC resin (77 parts), a single phosphazene flame retardant (1 part), a single MBS toughening agent (2 parts), a single UV234 weather resistant agent (0.5 parts), a single antioxidant 168 (0.5 parts), and the remaining components are the same as in Example 3. The comparative material was obtained according to the same preparation process.

[0035] The flame retardant rating is UL94 V-1, the limiting oxygen index is 29.5%, the cantilever beam impact strength is 62kJ / m², and the performance retention rate after high-temperature processing is 85%, which is far inferior to the embodiment of the present invention, further proving the synergistic effect of the compounding of the components of the present invention.

[0036] Therefore, the material of this invention has the following advantages compared to the prior art: 1. Excellent high-temperature processing stability: Through the composite matrix of PC and silicone PC, combined with composite antioxidants, the flame retardants and additives do not decompose or volatilize during high-temperature processing at 260-300℃, the PC matrix does not undergo thermal and oxidative degradation, and the material performance does not decrease after processing, making it suitable for various high-temperature extrusion and injection molding processes.

[0037] 2. Halogen-free and highly efficient flame retardant: The halogen-free flame retardant is made by compounding phosphazene and organosilicon in a 4:1 ratio. It works synergistically to exert its flame retardant effect. Only 1-5 parts are needed to make the material meet the UL94 V-0 flame retardant standard. The limiting oxygen index is ≥32%. It is halogen-free and environmentally friendly, meeting the requirements of environmentally friendly materials.

[0038] 3. Balanced mechanical properties: The toughening agent, a 3:1 blend of MBS and PTW, has excellent compatibility with the PC matrix. While ensuring flame retardant properties, it significantly improves the material's impact strength and toughness, and maintains high tensile and flexural strength retention rates, achieving a good balance between flame retardant properties and mechanical properties.

[0039] 4. Outstanding performance over long-term use: The compound weather-resistant agent enhances the material's weather resistance and anti-aging properties, the polycarbodiimide hydrolysis-resistant agent enhances the material's hydrolysis stability, and the antioxidant provides thermal stability. The material can be used for a long time in harsh environments such as outdoors and in humid heat, with slow performance degradation and a significantly extended service life.

[0040] 5. Simple preparation process: It adopts the conventional twin-screw extruder high-temperature granulation process, the process parameters are easy to control, no special equipment is required, it can realize industrial continuous production, the production cost is low, and it is suitable for large-scale mass production needs.

[0041] This invention uses a blend of PC resin and silicone PC resin as the matrix resin, determining a ratio of 50-77 parts PC to 20-40 parts silicone PC to improve the material's high-temperature processing stability and basic flame retardancy. The halogen-free flame retardant is a 4:1 blend of phosphazene flame retardant and organosilicon flame retardant; the toughening agent is a 3:1 blend of MBS and PTW; the weathering agent is a 2:1 blend of UV234 and HALS 944; and the antioxidant is a 2:1 blend of antioxidant 168 and antioxidant 626. Through this synergistic blending of multiple components in specific proportions, the simultaneous improvement of flame retardancy, toughening, weather resistance, and resistance to thermo-oxidative aging is achieved. The preparation process employs a high-temperature processing technology of 260-300℃, within which the material exhibits stable performance without flame retardant decomposition or matrix degradation.

[0042] The material of this invention can be widely used in fields such as electronic and electrical appliance housings, automotive interior parts, charging pile components, office equipment, and outdoor building materials. It is especially suitable for high-end application scenarios with stringent requirements for high-temperature processing performance, flame retardancy, mechanical properties, and long-term weather resistance and hydrolysis resistance.

[0043] The above is a detailed description of the present invention in conjunction with specific embodiments, and it should not be construed that the specific embodiments of the present invention are limited to these descriptions. For those skilled in the art, any equivalent substitutions or obvious modifications made without departing from the concept of the present invention, and which have the same performance or use, should be considered to fall within the patent protection scope defined by the submitted claims.

Claims

1. A high-temperature processed flame-retardant PC material, characterized in that: The material, by weight, comprises the following components: 50-77 parts of PC resin; 20-40 parts of silicone PC resin; 1-5 parts of halogen-free flame retardant; 2-5 parts toughening agent; Weather resistant agent 0.5-1 part; Antioxidant 0.5-1 part; 0.5-1 part of hydrolysis resistant agent.

2. The high-temperature processed PC flame-retardant material according to claim 1, characterized in that: The PC resin is a high molecular weight polycarbonate with a melt index of 8-12 g / 10 min.

3. The high-temperature processed PC flame-retardant material according to claim 1, characterized in that: The halogen-free flame retardant is a compound of phosphazene flame retardant and organosilicon flame retardant in a weight ratio of 4:

1.

4. The high-temperature processed PC flame-retardant material according to claim 4, characterized in that: The phosphazene flame retardant is a cyclic phenoxyphosphazene, and the organosilicon flame retardant is a polysiloxane flame retardant.

5. The high-temperature processed PC flame-retardant material according to claim 1, characterized in that: The toughening agent is a compound of MBS and PTW in a weight ratio of 3:

1.

6. The high-temperature processed PC flame-retardant material according to claim 1, characterized in that: The weathering agent is a mixture of UV234 and HALS944 in a weight ratio of 2:

1.

7. The high-temperature processed PC flame-retardant material according to claim 1, characterized in that: The antioxidant is a compound of antioxidant 168 and antioxidant 626 in a weight ratio of 2:

1.

8. The high-temperature processed PC flame-retardant material according to claim 1, characterized in that: The hydrolysis-resistant agent is polycarbodiimide.

9. A method for preparing a high-temperature processed flame-retardant PC material as described in any one of claims 1-8, characterized in that: Includes the following steps: S1. Weigh out PC resin, silicone PC resin, halogen-free flame retardant, toughening agent, weather resistant agent, antioxidant and hydrolysis resistant agent according to the formula; dry PC resin and silicone PC resin at 120-130℃ for 4-6 hours; S2. Add the dried PC resin, silicone PC resin and other components into a high-speed mixer and stir at 300-500 r / min for 10-15 min to obtain a mixture. S3. The mixture is added to a twin-screw extruder for melt blending, extrusion and granulation. The twin-screw extruder has a length-to-diameter ratio of 40:1-50:1, a processing temperature of 260-300℃, and a screw speed of 200-300r / min. S4. Dry the obtained particles at 120℃ for 3 hours to obtain the finished product.

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