CN108624027B - A kind of catalytic carbon-forming high-efficiency halogen-free flame-retardant PC/ABS mixture and preparation method thereof - Google Patents

Abstract

The invention discloses a catalyzed carbon-forming high-efficiency halogen-free flame-retardant PC/ABS mixture and a preparation method thereof. The mixture is composed of the following raw materials by mass percentage: PC resin 37-67%; ABS resin 14-37%; compatibilizer 0 ～5%; antioxidant 0.1～0.5%; chopped carbon fiber 5～15%; organic phosphate flame retardant 3～5%; phenoxyphosphazene 0.5～3%; Carbon agent 0～1%; the preparation method is: dry the raw materials except chopped carbon fiber, then fully mix them in a high-speed mixer, add them into the barrel of the co-rotating parallel twin-screw extruder through the main feeding bin, and feed them through the side. The chopped carbon fiber is added in the way of material, and it is melt extruded and pelletized. The mixture of the invention has the advantages of high strength, good flame retardant performance and low addition amount of flame retardant, and can be applied to ultra-thin notebook shells, high-speed rail interiors, drone shells and other high-end electrical fields.

Description

A kind of catalytic carbon-forming high-efficiency halogen-free flame-retardant PC/ABS mixture and preparation method thereof

technical field

The invention relates to the field of reinforced flame-retardant modification of PC/ABS alloys, in particular to a catalyzed carbon-forming high-efficiency halogen-free flame-retardant carbon fiber reinforced PC/ABS mixture and a preparation method thereof.

Background technique

Carbon fiber reinforced PC/ABS has the advantages of small specific gravity, high specific strength, high rigidity, and large modulus, which can meet the stringent requirements for density and strength of ultra-thin notebook computers and drones. However, carbon fiber reinforced PC/ABS also has the defect of poor flame retardant performance, and there is a large fire hazard when used, so it must be modified with flame retardant. At present, the commonly used flame retardants for PC/ABS alloys are mainly phosphorus flame retardants, such as organic phosphate flame retardants, red phosphorus, ammonium polyphosphate, etc. However, when phosphorus-based flame retardants are used alone in carbon fiber reinforced PC/ABS, due to the "candle wick ignition" effect of carbon fibers, the product has poor charring performance, low flame retardant efficiency, large amount of flame retardant, and flame retardant. It is difficult to meet the performance requirements of carbon fiber reinforced PC/ABS composites. Therefore, it is particularly urgent and important to study carbon fiber reinforced PC/ABS composites with high flame retardant properties.

Chinese invention patent application CN104403295A discloses a halogen-free flame-retardant high-gloss inorganic fiber-reinforced PC/ABS material and a preparation method thereof. The compound of sulfonate-based flame retardant and phosphorus-based flame retardant is used to improve fiber-reinforced PC/ABS. The flame retardant performance inhibits the flame retardant deterioration effect of the fiber filler to a certain extent; but its flame retardant efficiency is low, and a large amount (10-12%) is required to make the alloy reach UL94 (3.2mm) V-0 grade resistance. flammable grade, and UL94 (1.6mm) is still HB grade.

Chinese invention patent application CN103756276A discloses a highly environmentally friendly flame retardant carbon fiber reinforced PC/ABS blend material and a preparation method thereof. Pentaerythritol, phosphoric acid and urea are used to compound a flame retardant system, and the total amount of flame retardant added is 5-15 %, the vertical combustion grade (1.6mm) reaches V-0 grade; the flame retardant in this system is added in a large amount, which has a serious impact on the mechanical properties of the matrix, such as the flexural modulus and other mechanical properties of the matrix deteriorate significantly.

Chinese invention patent application CN107189394A discloses a carbon fiber reinforced flame-retardant electroplating PC/ABS alloy material for automobiles and a preparation method. DOPO-grafted silicon-based mesoporous materials and phosphorus-based flame retardants are selected to be compounded. The total amount of flame retardants is: 10-15%, and the vertical combustion grade (1.6mm) reaches V-0 level; the flame retardant system also has the defects of low flame retardant efficiency and large amount of flame retardant added.

To sum up, the existing flame retardant technology is difficult to overcome the candle wick ignition effect brought by carbon fiber fillers. Therefore, the development of high-efficiency halogen-free flame retardant carbon fiber reinforced PC/ABS mixture has important social significance and huge economic benefits.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a kind of catalyzed carbon-forming high-efficiency halogen-free flame-retardant carbon fiber reinforced PC/ABS mixture and preparation method thereof, which can be used to prepare high-efficiency flame-retardant electrical appliances and automobile systems. It can be used in ultra-thin notebook shells, high-speed rail interiors, drone shells and other high-end electrical appliances.

The catalyzed carbon-forming halogen-free flame-retardant carbon fiber reinforced PC/ABS alloy prepared by the invention adopts an organic phosphorus-based flame retardant, a phenoxyphosphazene, and a zirconium phosphate modified triazine-based silicon-containing carbon-forming agent to form a compound flame-retardant system. Through the efficient catalytic char formation mechanism, the combustion charcoal layer is closely combined with the carbon fiber, which effectively overcomes the "candle wick ignition" effect of fiber-reinforced plastics. As a flame retardant, organic phosphate can improve the flame retardant performance of PC/ABS, and can reduce the melt viscosity of the alloy and improve the processing performance of the material; zirconium phosphate modified triazine silicon-containing carbon former and phenoxyphosphazene are used as synergistic flame retardant It has the functions of free radical capture, lamellar barrier and reinforcement of material strength. It is organically coupled with organic phosphates to catalyze carbon formation, so that the carbon layer formed by the polymer during the combustion process is closely combined with the carbon fiber, and the carbon layer is denser. Efficient halogen-free flame retardant. The flame retardant systems are all polyaryl compounds, which have good compatibility and dispersibility with PC/ABS, and the addition of flame retardants is small, which has little effect on the mechanical properties of the matrix.

The object of the present invention can be realized through the following technical solutions:

A high-efficiency halogen-free flame-retardant carbon fiber reinforced PC/ABS alloy catalyzed into carbon, which is composed of the following raw materials:

PC resin 37～67%

ABS resin 14～37%

Compatibilizer 0～5%

Chopped carbon fiber 5～15%

Antioxidant 0.1%‐0.5%

Organophosphate flame retardant 3～5%

Phenoxyphosphazene 0.5～3%

Zirconium phosphate modified triazine silicon-containing carbon-forming agent 0～1%

The organic phosphate flame retardant is tricresyl phosphate (TCP), lanthanum phenylphosphonate, cerium phenylphosphonate, hydroquinone bis (diphenyl) phosphate (HDP), resorcinol One or more of organic phosphate flame retardants such as bis(diphenyl phosphate) (RDP) and PX-200.

The phenoxyphosphazene is one or more of phenoxyphosphazenes such as hexaphenoxy triphosphazene, octaphenoxy cyclotetraphosphazene and decaphenoxy pentaphosphazene.

In order to further achieve the purpose of the present invention, preferably, the PC resin has a melt index of 5-25 g/10min (300°C/1.2 kg), and a number-average molecular weight of 20,000-50,000.

Preferably, the ABS resin has a melt index of 3-10g/10min (200°C/5kg), and a number-average molecular weight of 10,000-30,000.

Preferably, the antioxidant is one or more of N-alkoxy hindered amine antioxidants (NORs) such as Si-NOR or NOR116.

Preferably, the compatibilizer is one or more of organosilicon-modified ethylene vinyl acetate copolymer, polycarbonate organosilicon block copolymer and maleic anhydride grafted polystyrene.

Preferably, the zirconium phosphate modified triazine silicon-containing carbon-forming agent has a degree of polymerization of 5 to 10, a molecular weight of 2000 to 6000, and its structure is as follows:

Preferably, the bulk density of the chopped carbon fibers is 300-700 g/L, the length is 3-15 mm, and the diameter is 4-10 μm.

A preparation method of catalyzed carbon-forming high-efficiency halogen-free flame-retardant PC/ABS mixture, which is characterized by comprising the following steps:

1) Weigh PC resin, ABS resin and chopped carbon fibers by the above-mentioned weight percentages, and place them in a blast oven at 80 to 90°C for drying for 4 to 6 hours;

2) Weigh out the compatibilizer, antioxidant, organic phosphate, phenoxyphosphazene and zirconium phosphate modified triazine silicon-containing carbon-forming agent and place it in a vacuum oven at 60～80℃ for vacuum drying for 4～6 hours;

3) After thorough drying, mix the raw materials except the chopped carbon fiber by a high-speed mixer for 10-15 minutes;

4) Add the mixed raw materials into the barrel of the extruder through the main feeding bin of the co-directional parallel combination twin-screw extruder, and the feeding screw speed is 20-40 rpm;

5) The chopped carbon fiber is added into the barrel through the side feeding port, and the speed of the side feeding screw is 15-25 rpm;

6) The processing temperature of each section in the barrel, from the feeding port to the head outlet, is: 180-200°C, 190-210°C, 200-220°C, 205-225°C, 225-240°C, 230-250°C , the rotating speed of the host is 300-400 rpm, and the PC/ABS mixture is obtained after melt extrusion, granulation and drying.

Preferably, the vacuum pressure of the barrel in the twin-screw extrusion process should be controlled within 0.04MPa; when combining the melt-blending screw structure, there should be enough strong shear plasticizing structure space before side feeding, so that each group The parts are fully fused; the reverse thread structure should be avoided at the opening positions such as the air outlet and vacuum pumping to prevent the raw material from being ejected; after the carbon fiber is added to the screw, there should also be a certain space for strong shear plasticizing structure.

The organic phosphate flame retardant has the effect of flame retardant and plasticization in the system, and its flame retardant mechanism is to promote the endothermic dehydration of PC degradation products (hydroxyl compounds) into carbon during the decomposition process of the organic phosphate, and the surface of the material is dehydrated. The carbon layer is formed; the ‐OP group is heated to generate free radicals, which combine with the active free radicals in the polymer degradation process to delay the further decomposition of the polymer matrix; on the one hand, the water vapor generated by the dehydration reaction can dilute the concentration of flammable gases in the gas phase, and on the other hand On the one hand, it can reduce the surface temperature of the polymer and play a good flame retardant effect.

The flame retardant mechanism of the zirconium phosphate-modified triazine-based silicon-containing carbon-forming agent is mainly when the flame-retardant PC/ABS is burned, and its Zr ⁴⁺ rare earth element can capture the H· free radicals and OH· produced by the degradation of the polymer. free radicals, thereby effectively inhibiting the free radical chain reaction in the gas phase and exerting a high-efficiency flame retardant effect; zirconium phosphate is uniformly dispersed in the polymer in the structure of a monolayer, giving full play to its lamellar barrier effect and solid acid catalytic effect. , improve the strength, air tightness and thermal stability of the carbon layer, block the mass transfer and heat transfer process between the gas phase and the condensed phase; the triazine silicon-containing carbon-forming agent has good compatibility with PC/ABS, and the thermal decomposition products Nitrogen gas is generated, and it accumulates in the micro-nano space formed by the degradation of zirconium phosphate, carbon fiber and PC into carbon products. When the amount of aggregation reaches the upper limit of the space, it will break through the micro-nano carbon layer structure, blow out, and extinguish the flame; Synergistic effect, promote the flame retardant effect of organic phosphate flame retardant, and catalyze carbonization into halogen-free flame retardant.

The flame retardant mechanism of the phenoxyphosphazene is mainly when the flame retardant PC/ABS is flame retardant, and the Fries rearrangement reaction is promoted in the process of PC degradation through the synergistic effect of phosphorus and nitrogen, which promotes the cross-linking of PC to form carbon, and reduces the hydroxyl group in the degradation process. content, alleviate the breakage of PC main chain and improve the thermal stability of PC/ABS. At the same time, the polyphenoxy structure of polyphenoxy has good compatibility with PC/ABS, which improves the mechanical properties of carbon fiber reinforced PC/ABS mixture.

In addition to the antioxidant effect, the N-alkoxy hindered amine antioxidants (NORs) also have the function of promoting char formation at high temperature. The mechanism is that nitrogen-oxygen free radicals are formed at high temperature, which can quench the free radicals generated by the degradation of the polymerization-free matrix, thereby effectively inhibiting the progress of the free radical chain decomposition reaction and assisting in flame retardant.

By reasonably selecting flame retardant additives and various raw materials, adding carbon fiber and a small amount of flame retardant, the present invention can achieve high strength and flame retardant (UL94 standard up to V-0 level, thickness 1.6mm) performance while maintaining the material with a certain Impact strength and reasonable melt flow rate, realize the full plasticization of different components in the multi-component system and improve their blending properties, put forward parameters such as extrusion temperature, screw revolutions, vacuum pressure, and finally obtain a A high-efficiency halogen-free flame retardant carbon fiber reinforced PC/ABS alloy.

As can be seen from the above technical solutions, the present invention has the following advantages:

1. The PC/ABS mixture prepared by the present invention has the advantages of efficient catalysis into carbon, halogen-free and flame retardant. The degradation of PC/ABS into carbon is catalyzed by various synergistic effects of organophosphate, phenoxyphosphazene, and zirconium phosphate modified triazine-based silicon-containing carbon-forming agents. The "core ignition" effect improves the density and quality of the carbon layer; the invention exerts the synergistic flame retardant effect of phosphorus, nitrogen and silicon, the lamellar barrier effect and the free radical capture effect, greatly improves the flame retardant performance of the matrix, and realizes the carbon fiber reinforced PC/ABS alloy. Efficient halogen-free flame retardant.

2. The PC/ABS mixture prepared by the present invention has the advantages of small addition amount of flame retardant and excellent mechanical properties. The fluidity of PC/ABS mixture is improved by small molecular phosphate flame retardant, and the dispersion and orientation of carbon fiber is improved; PC/ABS is reinforced and toughened by chopped carbon fiber, compatibilizer and toughening agent, etc. Nitrile, organophosphorus flame retardants and zirconium phosphate modified triazine silicon-containing carbon-forming agents have good compatibility with PC/ABS, the addition amount is small, and the flame retardant system has little effect on the mechanical properties of the matrix, making carbon fiber reinforced halogen-free Combustion PC/ABS meets the mechanical and flame retardant performance requirements of high-end electronic and electrical products and automotive interior parts, and can be made into lightweight and high-strength ultra-thin parts.

Detailed ways

In order to facilitate further understanding of the present invention, the present invention will be described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

In the embodiment of the present invention, the product performance testing method is as follows:

Tensile performance test: according to GB/T 1040 standard, the test rate is 50mm/min.

Bending performance test: According to GB/T 9341 standard, the test rate is 20mm/min.

Impact performance test: According to GB/T1843 standard, the thickness of the test specimen is 4mm.

Vertical burning grade: Tested according to GB/T 2408 straight burning standard, the test specimen size is 80*10*4mm ³ .

Limiting oxygen index test: according to GB/T 2406.1 standard, the test sample size is 150*10*4mm ³ .

Melt index test: According to GB/T 3682 standard, the test temperature is 250℃, and the load is 2.16kg.

Example 1

The catalyzed carbon-forming halogen-free flame-retardant carbon fiber reinforced PC/ABS mixture of this embodiment is mainly made of the following raw materials by weight: PC resin (59%), ABS resin (14.7%), chopped carbon fiber (15%), EMA (5%), RDP (5%), phenoxyphosphazene (0.5%), zirconium phosphate modified triazine silicon-containing carbon-forming agent (0.5%), NOR116 (0.3%).

PC, ABS, EMA, RDP, NOR116, phenoxyphosphazene and zirconium phosphate modified triazine silicon-containing carbon-forming agent were mixed at high speed for 20 minutes and put into the main feeding bin of the twin-screw extruder. At 25 rpm, the chopped carbon fibers are placed in the side feeding bin of the twin-screw extruder. The speed of the side feeding screw is 30 rpm, and it is added to the main barrel of the extruder through the feeding screw. The control temperature (eight stages from the feeding port to the die outlet) is 200°C, 220°C, 220°C, 230°C, 235°C, 245°C, 245°C, and 250°C. In the twin-screw extrusion process, the vacuum pressure of the barrel should be Controlled within 0.04MPa; the product is obtained after melt extrusion, granulation, drying and other processes. Standard specimens were prepared by an injection molding machine for tensile, bending, impact, and flame retardancy tests. The results are shown in Table 1.

Example 2

The catalyzed carbon-forming halogen-free flame-retardant carbon fiber reinforced PC/ABS mixture in this embodiment is mainly made of the following raw materials by weight: PC resin (67%), ABS resin (16.7%), chopped carbon fiber (5%), EMA (5%), RDP (5%), phenoxyphosphazene (0.5%), zirconium phosphate modified triazine silicon-containing carbon-forming agent (0.5%), NOR116 (0.3%).

PC, ABS, EMA, RDP, NOR116, phenoxyphosphazene and zirconium phosphate modified triazine silicon-containing carbon-forming agent were mixed at high speed for 20 minutes and put into the main feeding bin of the twin-screw extruder. At 25 rpm, the chopped carbon fibers are placed in the side feeding bin of the twin-screw extruder. The speed of the side feeding screw is 30 rpm, and it is added to the main barrel of the extruder through the feeding screw. The control temperature (eight stages from the feeding port to the die outlet) is 200°C, 220°C, 220°C, 230°C, 235°C, 245°C, 245°C, and 250°C. In the twin-screw extrusion process, the vacuum pressure of the barrel should be Controlled within 0.04MPa; the product is obtained after melt extrusion, granulation, drying and other processes. Standard specimens were prepared by an injection molding machine for tensile, bending, impact, and flame retardancy tests. The results are shown in Table 1.

Example 3

The catalyzed carbon-forming halogen-free flame-retardant carbon fiber reinforced PC/ABS mixture in this embodiment is mainly made of the following raw materials by weight: PC resin (37%), ABS resin (37%), chopped carbon fiber (15%), EMA (5%), RDP (5%), phenoxyphosphazene (0.5%), zirconium phosphate modified triazine silicon-containing carbon-forming agent (0.5%), NOR116 (0.3%).

PC, ABS, EMA, RDP, NOR116, phenoxyphosphazene and zirconium phosphate modified triazine silicon-containing carbon-forming agent were mixed at high speed for 20 minutes and put into the main feeding bin of the twin-screw extruder. At 25 rpm, the chopped carbon fibers are placed in the side feeding bin of the twin-screw extruder. The speed of the side feeding screw is 30 rpm, and it is added to the main barrel of the extruder through the feeding screw. The control temperature (eight stages from the feeding port to the die outlet) is 200°C, 220°C, 220°C, 230°C, 235°C, 245°C, 245°C, and 250°C. In the twin-screw extrusion process, the vacuum pressure of the barrel should be Controlled within 0.04MPa; the product is obtained after melt extrusion, granulation, drying and other processes. Standard specimens were prepared by an injection molding machine for tensile, bending, impact, and flame retardancy tests. The results are shown in Table 1.

Example 4

The catalyzed carbon-forming halogen-free flame-retardant carbon fiber reinforced PC/ABS mixture in this embodiment is mainly made of the following raw materials by weight: PC resin (56.7%), ABS resin (14%), chopped carbon fiber (15%), EMA (5%), RDP (5%), phenoxyphosphazene (3%), zirconium phosphate modified triazine silicon-containing carbon-forming agent (1%), NOR116 (0.3%).

PC, ABS, EMA, RDP, NOR116, phenoxyphosphazene and zirconium phosphate modified triazine silicon-containing carbon-forming agent were mixed at high speed for 20 minutes and put into the main feeding bin of the twin-screw extruder. At 40 rpm, the chopped carbon fiber is placed in the side feeding bin of the twin-screw extruder. The speed of the side feeding screw is 25 rpm, and it is added to the main barrel of the extruder through the feeding screw. The control temperature (eight stages from the feeding port to the die outlet) is 200°C, 220°C, 220°C, 230°C, 235°C, 245°C, 245°C, and 250°C. In the twin-screw extrusion process, the vacuum pressure of the barrel should be Controlled within 0.04MPa; the product is obtained after melt extrusion, granulation, drying and other processes. Standard specimens were prepared by an injection molding machine for tensile, bending, impact, and flame retardancy tests. The results are shown in Table 1.

Example 5

The catalyzed carbon-forming halogen-free flame-retardant carbon fiber reinforced PC/ABS mixture of this embodiment is mainly made of the following raw materials by weight: PC resin (59%), ABS resin (14.2%), chopped carbon fiber (15%), EMA (5%), RDP (5%), phenoxyphosphazene (0.5%), zirconium phosphate modified triazine silicon-containing carbon-forming agent (1%), NOR116 (0.3%).

PC, ABS, EMA, RDP, NOR116, phenoxyphosphazene and zirconium phosphate modified triazine silicon-containing carbon-forming agent were mixed at high speed for 20 minutes and put into the main feeding bin of the twin-screw extruder. At 40 rpm, the chopped carbon fiber is placed in the side feeding bin of the twin-screw extruder. The speed of the side feeding screw is 25 rpm, and it is added to the main barrel of the extruder through the feeding screw. The control temperature (eight stages from the feeding port to the die outlet) is 200°C, 220°C, 220°C, 230°C, 235°C, 245°C, 245°C, and 250°C. In the twin-screw extrusion process, the vacuum pressure of the barrel should be Controlled within 0.04MPa; the product is obtained after melt extrusion, granulation, drying and other processes. Standard specimens were prepared by an injection molding machine for tensile, bending, impact, and flame retardancy tests. The results are shown in Table 1.

Example 6

The catalyzed carbon-forming halogen-free flame-retardant carbon fiber reinforced PC/ABS mixture in this embodiment is mainly made of the following raw materials by weight: PC resin (57%), ABS resin (14.2%), chopped carbon fiber (15%), EMA (5%), RDP (5%), phenoxyphosphazene (3%), zirconium phosphate modified triazine silicon-containing carbon-forming agent (0.5%), NOR116 (0.3%).

PC, ABS, EMA, RDP, NOR116, phenoxyphosphazene and zirconium phosphate modified triazine silicon-containing carbon-forming agent were mixed at high speed for 20 minutes and put into the main feeding bin of the twin-screw extruder. At 40 rpm, the chopped carbon fiber is placed in the side feeding bin of the twin-screw extruder. The speed of the side feeding screw is 25 rpm, and it is added to the main barrel of the extruder through the feeding screw. The control temperature (eight stages from the feeding port to the die outlet) is 200°C, 220°C, 220°C, 230°C, 235°C, 245°C, 245°C, and 250°C. In the twin-screw extrusion process, the vacuum pressure of the barrel should be Controlled within 0.04MPa; the product is obtained after melt extrusion, granulation, drying and other processes. Standard specimens were prepared by an injection molding machine for tensile, bending, impact, and flame retardancy tests. The results are shown in Table 1.

Example 7

The catalyzed carbon-forming halogen-free flame retardant carbon fiber reinforced PC/ABS mixture in this embodiment is mainly made of the following raw materials by weight: PC resin (58%), ABS resin (14.7%), chopped carbon fiber (15%), EMA (5%), RDP (3%), phenoxyphosphazene (3%), zirconium phosphate modified triazine silicon-containing carbon-forming agent (1%), NOR116 (0.3%).

PC, ABS, EMA, RDP, NOR116, phenoxyphosphazene and zirconium phosphate modified triazine silicon-containing carbon-forming agent were mixed at high speed for 20 minutes and put into the main feeding bin of the twin-screw extruder. At 40 rpm, the chopped carbon fiber is placed in the side feeding bin of the twin-screw extruder. The speed of the side feeding screw is 25 rpm, and it is added to the main barrel of the extruder through the feeding screw. The control temperature (eight stages from the feeding port to the die outlet) is 200°C, 220°C, 220°C, 230°C, 235°C, 245°C, 245°C, and 250°C. In the twin-screw extrusion process, the vacuum pressure of the barrel should be Controlled within 0.04MPa; the product is obtained after melt extrusion, granulation, drying and other processes. Standard specimens were prepared by an injection molding machine for tensile, bending, impact, and flame retardancy tests. The results are shown in Table 1.

Example 8

The catalyzed carbon-forming halogen-free flame-retardant carbon fiber reinforced PC/ABS mixture in this embodiment is mainly made of the following raw materials by weight: PC resin (60%), ABS resin (14.2%), chopped carbon fiber (15%), EMA (5%), RDP (5%), phenoxyphosphazene (0.5%), NOR116 (0.3%).

PC, ABS, EMA, RDP, NOR116, phenoxyphosphazene and zirconium phosphate modified triazine silicon-containing carbon-forming agent were mixed at high speed for 20 minutes and put into the main feeding bin of the twin-screw extruder. At 40 rpm, the chopped carbon fiber is placed in the side feeding bin of the twin-screw extruder. The speed of the side feeding screw is 25 rpm, and it is added to the main barrel of the extruder through the feeding screw. The control temperature (eight stages from the feeding port to the die outlet) is 200°C, 220°C, 220°C, 230°C, 235°C, 245°C, 245°C, and 250°C. In the twin-screw extrusion process, the vacuum pressure of the barrel should be Controlled within 0.04MPa; the product is obtained after melt extrusion, granulation, drying and other processes. Standard specimens were prepared by an injection molding machine for tensile, bending, impact, and flame retardancy tests. The results are shown in Table 1.

Comparative Example 1

To verify the enhancement and modification effect of mechanical properties, PC/ABS without carbon fiber, compatibilizer and flame retardant was used as a comparison.

The blank PC/ABS mixture of this comparative example is mainly made of the following raw materials by weight: PC resin (80%), ABS resin (19.7%), and antioxidant 1010 (0.3%).

After mixing PC and ABS at high speed for 20min, put it into the main feeding bin of the twin-screw extruder. The main feeding screw rotates at 40 rpm, and is added to the main barrel of the extruder through the feeding screw. The main rotating speed is 300 rpm, and the main barrel is heated. Section control temperature (from feeding port to die outlet) is 220°C, 240°C, 240°C, 250°C, 255°C, 255°C, 265°C, 270°C. In the twin-screw extrusion process, the vacuum pressure of the barrel should be controlled at Within 0.04MPa; the product is obtained after melt extrusion, granulation, drying and other processes. Standard specimens were prepared by an injection molding machine for tensile, bending, impact, and flame retardancy tests. The results are shown in Table 1.

Comparative Example 2

To verify the effect of flame retardant modification, PC/ABS with only the common flame retardant organophosphorus flame retardant added in the market was used as a comparison.

The catalyzed carbon-forming halogen-free flame-retardant carbon fiber reinforced PC/ABS mixture of this embodiment is mainly made of the following raw materials by weight: PC resin (61%), ABS resin (14.7%), chopped carbon fiber (15%), RDP (9%), Antioxidant 1010 (0.3%).

After mixing PC, ABS and RDP at high speed for 20min, put it into the main feeding bin of the twin-screw extruder. The control temperature of each heating section (from the feeding port to the die outlet) is 220 °C, 240 °C, 240 °C, 250 °C, 255 °C, 255 °C, 265 °C, 270 °C, and the vacuum pressure of the barrel in the twin-screw extrusion process should be Controlled within 0.04MPa; the product is obtained after melt extrusion, granulation, drying and other processes. Standard specimens were prepared by an injection molding machine for tensile, bending, impact, and flame retardancy tests. The results are shown in Table 1.

Table 1 Flame retardant properties, mechanical properties and melt index of PC/ABS blends

It can be seen from Examples 1 to 8 and Comparative Example 2 in Table 1 that the PC/ABS mixture using organic phosphate RDP alone as a flame retardant achieves a flame retardant grade of NR (see Comparative Example 2). However, the flame retardant efficiency of organic phosphate and phenoxy phosphazene has been effectively improved. Phenoxy phosphazene has a synergistic flame retardant effect of phosphorus and nitrogen, which can enhance the degradation and cross-linking of PC into carbon, and improve the formation of carbon layer. Speed and quality; zirconium phosphate modified triazine silicon-containing carbon-forming agent as a synergistic flame retardant has functions such as lamellar barrier and free radical capture, which makes the expanded carbon layer formed by combustion more compact and has anti-droplet effect. The active free radicals generated in the combustion process are captured to further improve the flame retardant efficiency, so that the entire flame retardant system is organically coupled and flame retardant is efficient. As in Example 4, the carbon fiber reinforced PC/ABS mixture added with RDP (5%), phenoxyphosphazene (3%) and zirconium phosphate modified triazine silicon-containing carbon former (1%), its limiting oxygen index Compared with the PC/ABS blend with only RDP (9%) added, the LOI can be increased from 26.1% to 33.1%, and reaches the V-0 flame retardant grade. It shows that the flame-retardant PC/ABS system of the present invention has the function of high-efficiency flame-retardant.

It can be seen from Examples 1 to 8 and Comparative Example 3 that the use of an organic phosphate flame retardant system can effectively improve the fluidity of the PC/ABS blend and greatly improve its processing performance. For example, compared with Example 1 and Comparative Example 3, the melt index is increased from 4.4g/10min to 18.0g/10min, which can meet the processing performance of ultra-thin parts.

It can be seen from Example 4 and Comparative Example 1 that, compared with ordinary PC/ABS alloys, the modified PC/ABS mixture provided by the present invention has the advantages of high efficiency flame retardancy, high strength and good fluidity. As in Example 4, RDP (5%), phenoxyphosphazene (3%), zirconium phosphate modified triazine silicon-containing carbon-forming agent (1%), and carbon fiber (15%) were added to the PC/ABS mixture, Compared with Comparative Example 1, its tensile strength, flexural strength, melt index and flame retardant properties are improved from 66MPa, 81MPa, 4.4g/10min and vertical combustion without grade to 75MPa, 120MPa, 22.7g/10min, and vertical combustion V‐ Level 0. Through the synergistic effect of organophosphate, phenoxyphosphazene, and zirconium phosphate modified triazine-based silicon-containing carbon-forming agent, the flame retardant efficiency is improved, and the small molecular phosphate ester improves the fluidity of PC/ABS blends, effectively solving the problem of Carbon fiber reinforced PC/ABS has the problem of excessive melt viscosity, difficult processing, and inability to make ultra-thin parts; PC/ABS is strengthened and toughened by chopped carbon fiber and compatibilizer, and a catalytic carbonization with small specific gravity and high strength is made Halogen-free flame retardant carbon fiber reinforced PC/ABS alloy.

The high-efficiency halogen-free flame-retardant carbon fiber PC/ABS mixture obtained by the invention has unique flame-retardant compounding mechanism, high-efficiency catalyzed carbon-forming halogen-free flame retardant, and has excellent mechanical properties, and can be widely used in Ultra-thin notebook casings, high-speed rail interiors, and drone casings.

Claims (9)

1. a catalyzed carbon-forming high-efficiency halogen-free flame-retardant carbon fiber reinforced PC/ABS mixture is characterized in that being made up of the raw material of following mass percent: Polycarbonate resin 37～67% Acrylonitrile-butadiene-styrene copolymer resin 14～37% Compatibilizer 0～5% Chopped carbon fiber 5～15% Antioxidant 0.1%-0.5% Organophosphate flame retardant 3～5% Phenoxyphosphazene 0.5～3% Zirconium phosphate modified triazine silicon-containing carbon-forming agent 0.5-1% The organic phosphate flame retardant is tricresyl phosphate, lanthanum phenylphosphonate, cerium phenylphosphonate, hydroquinone bis (diphenyl) phosphate or resorcinol bis (diphenyl phosphate) one or more of esters); Described phenoxyphosphazene is one or more in hexaphenoxy triphosphazene, octaphenoxy cyclotetraphosphazene and decaphenoxy pentaphosphazene phenoxy phosphazene; The antioxidant is an N-alkoxy hindered amine antioxidant; the N-alkoxy hindered amine antioxidant is one or more of Si-NOR and NOR116. 2. The high-efficiency halogen-free flame-retardant carbon fiber-reinforced PC/ABS mixture according to claim 1, characterized in that: the melt index of the polycarbonate resin is 5-25 g/10min; the polycarbonate resin The number average molecular weight of the resin is 20,000 to 50,000. 3. The high-efficiency halogen-free flame-retardant carbon fiber-reinforced PC/ABS mixture according to claim 1, wherein the melt index of the acrylonitrile-butadiene-styrene copolymer resin is 3-10 g/ 10min; the number-average molecular weight of the acrylonitrile-butadiene-styrene copolymer resin is 10,000-30,000. 4. The high-efficiency halogen-free flame-retardant carbon fiber-reinforced PC/ABS mixture according to claim 1, wherein the bulk density of the chopped carbon fiber is 300-700 g/L, the length is 3-15 mm, and the diameter is 3-15 mm. 4 to 10 μm. 5. The high-efficiency halogen-free flame-retardant carbon fiber-reinforced PC/ABS mixture according to claim 1, wherein the zirconium phosphate-modified triazine-based silicon-containing carbon-forming agent has a degree of polymerization of 5 to 10, and a molecular weight of 5 to 10. is 2000～6000, and the molecular structure is as follows:

6. The high-efficiency halogen-free flame-retardant carbon fiber-reinforced PC/ABS mixture according to claim 1, wherein the compatibilizer is an organosilicon-modified ethylene vinyl acetate copolymer, a polycarbonate organosilicon One or more of block copolymer and maleic anhydride grafted polystyrene. 7. the preparation method of the high-efficiency halogen-free flame-retardant carbon fiber reinforced PC/ABS mixture of catalyzing carbon into carbon according to any one of claims 1-6, is characterized in that comprising the following steps: (1) Dry PC resin, ABS resin and chopped carbon fiber; (2) drying the compatibilizer, antioxidant, organic phosphate, phenoxyphosphazene and zirconium phosphate modified triazine silicon-containing carbon-forming agent; (3) The dried raw materials except chopped carbon fibers are uniformly mixed by a high-speed mixer; (4) The mixed raw materials are added into the barrel of the extruder through the main feeding bin of the co-directional parallel combination twin-screw extruder, and the speed of the feeding screw is controlled to be 20-40 rpm; (5) Add the chopped carbon fiber into the barrel through the side feeding port, and control the speed of the side feeding screw to be 15-25 rpm; (6) The processing temperature of each section in the barrel, from the feeding port to the head outlet, is: 180-200°C, 190-210°C, 200-220°C, 205-225°C, 225-240°C, 230-250°C ℃, the rotating speed of the main machine is 300-400 rpm, and the PC/ABS mixture is obtained after melt extrusion, granulation and drying treatment. 8. the preparation method of the high-efficiency halogen-free flame-retardant carbon fiber reinforced PC/ABS mixture of catalyzed carbon-forming according to claim 7, is characterized in that: the drying of step (1) is to be placed in 80～90 ℃ of blast ovens to dry 4 ~6 hours; the drying in step (2) is vacuum drying in a vacuum oven at 60-80° C. for 4-6 hours. 9. the preparation method of the high-efficiency halogen-free flame-retardant carbon fiber reinforced PC/ABS mixture of catalyzed carbon-forming according to claim 7, is characterized in that: in the twin-screw extrusion process, the vacuum pressure of the barrel is controlled within 0.04MPa; Step (3 ) mixing time is 10～15min.