Bicyclic cage phosphonate phosphazene derivative flame-retardant pc / abs compositions and methods of making

Abstract

The application discloses a double-ring cage phosphonate phosphazene derivative flame-retardant PC / ABS composition and a preparation method thereof, which is prepared from the following raw materials in parts by weight: polycarbonate resin: 52-99.96%; acrylonitrile-butadiene-styrene copolymer: 0.01-20%; compatilizer: 0.01-5%; flame retardant: 0.01-15%; char-forming agent: 0.01-4%; antioxidant: 0-1%; processing aid: 0-2%; and color master batch: 0-1%. The application has the advantages that according to the combustion characteristics of the PC / ABS composition and the principle of molecular assembly design of the flame retardant, a double-ring cage phosphonate phosphazene derivative is introduced into the flame-retardant PC / ABS formula design as a flame retardant, the free radical inhibitor released by the flame retardant can capture the free radicals released by the material combustion reaction, reacts with the free radicals to generate non-combustible substances, destroys the chain growth of the combustion reaction, and realizes the flame retardation. The prepared flame-retardant PC / ABS composition can be applied to the fields of the automobile industry, the electrical instrument industry and the machinery industry.

Description

Technical Field

[0001] This invention relates to the field of polymer materials, and in particular to a bicyclic cage-like phosphate ester phosphazene derivative flame-retardant PC / ABS composition and its preparation method. Background Technology

[0002] PC / ABS is a thermoplastic compound made from a blend of polycarbonate (PC) and acrylonitrile-butadiene-styrene terpolymer (ABS). It combines the characteristics of both materials. ABS combines the properties of all three components: acrylonitrile has high hardness and strength, heat resistance and corrosion resistance; butadiene has impact resistance and toughness; and styrene has high surface gloss, easy coloring and easy processing. However, ABS has poor heat resistance and strength, while PC has high melt viscosity and poor processing performance. The internal stress and impact strength of the product are highly sensitive to the thickness of the product. Compared with ABS, PC / ABS alloy material has improved heat resistance and strength, and compared with PC material, its processing performance is improved and the internal stress of the product is reduced. PC / ABS can be used in thin-walled products such as mobile phone shells, automotive audio-visual systems, screw hole crack prevention, electronic appliances, sporting goods and other fields.

[0003] Flame-retardant PC / ABS possesses excellent mechanical properties, a high heat distortion temperature, high dielectric strength, good electrical insulation, and good flame-retardant effects. Therefore, it can be widely used in high-end chargers, lamp holders, switch panels, and other products. In recent years, flame-retardant PC / ABS alloys have needed to meet environmental regulations such as RoHS and REACH. Meeting both flame-retardant performance and environmental regulatory requirements is a crucial factor to consider in the development of flame-retardant PC / ABS technology.

[0004] Chinese patent CN102153590A discloses a bicyclic cage-like phosphate siloxane flame retardant and its preparation method. The desired product can be obtained by reacting 1-oxyphospha-4-hydroxymethyl-2,6,7-trioxabicyclo[2,2,2]octane with chlorosilane or alkoxysilane. The prepared bicyclic cage-like phosphate siloxane flame retardant contains multiple rigid bicyclic cage-like phosphate groups and silicon elements, which play a synergistic flame-retardant role. It has high thermal stability and char-forming properties, and can effectively reduce smoke generated during combustion. Chinese patent CN109735080A selects specific polycyclic aromatic hydrocarbon structure organophosphorus flame retardants and matches them with highly efficient functional additives through formulation design. With low-dosage, high-efficiency weather-resistant additives as an auxiliary, it synergistically improves the stability of flame-retardant PC / ABS blends under the combined effects of outdoor, long-term high humidity, high heat, and sunlight, greatly enhancing the material's rigidity, toughness, flame retardancy, and electrical insulation stability. Chinese patent CN107474510A discloses a high-flowability, high-rigidity halogen-free flame-retardant PC / ABS mixture and its preparation method. Using polyaryl phosphates, rare-earth phenyl phosphates, and metal-hybridized polysilsesquioxanes as flame retardants, the prepared PC / ABS mixture exhibits advantages such as good flowability, high strength, antistatic properties, and outstanding flame-retardant performance, making it suitable for manufacturing ultra-thin parts. Currently, many published inventions focus on the influence of different flame retardants on the performance of flame-retardant PC / ABS through formulation design. However, research on the effects of novel flame retardant structures or new forms of flame retardants on the performance of flame-retardant PC / ABS based on molecular assembly design principles is relatively limited. Improving flame-retardant efficiency and the performance of flame-retardant PC / ABS materials is of great significance for expanding the application areas of PC / ABS. Summary of the Invention

[0005] To fill the gap in the prior art, this invention provides a bicyclic cage-like phosphate phosphazene derivative flame-retardant PC / ABS composition and its preparation method. Based on the principle of flame retardant molecular assembly design, a bicyclic cage-like phosphate phosphazene derivative is introduced as a flame retardant in the formulation design to prepare a flame-retardant PC / ABS composition. The flame-retardant PC / ABS composition prepared by this method can be applied in the automotive industry, electrical instrument industry, and machinery industry.

[0006] This invention is achieved through the following technical solution:

[0007] A flame-retardant PC / ABS composition and preparation method of a bicyclic cage-like phosphate ester phosphazene derivative, comprising the following raw materials in parts by weight:

[0008]

[0009] The polycarbonate resin has a number average molecular weight of 17,000-40,000, a weight average relative molecular mass of 20,000-50,000, and a melt flow rate (test conditions: 300℃*1.2kg): 10-25g / 10min.

[0010] The acrylonitrile-butadiene-styrene copolymer can be produced by emulsion grafting-blending polymerization or continuous bulk polymerization. The melt flow rate (test conditions: 220℃*10kg) is 5-25g / 10min, the butadiene content is 15-20%, and the butadiene particle size is 0.1-1.0μm with a bimodal particle size distribution. The butadiene content and particle size in the acrylonitrile-butadiene-styrene copolymer are limited to ensure that the prepared flame-retardant PC / ABS composition has excellent surface properties and toughness.

[0011] The compatibilizer may be one or a mixture of several of the following: methyl methacrylate / butadiene / styrene copolymer, methyl methacrylate / acrylate polymer, ethylene / acrylate / glycidyl methacrylate terpolymer, ethylene-butyl acrylate, acrylic-silicone rubber toughening agent, etc.

[0012] Preferred invention: methyl methacrylate-butadiene-styrene terpolymer.

[0013] The flame retardant is a bicyclic cage-like phosphate ester phosphazene derivative, with a molar ratio of phosphorus groups to phosphazene groups of 6:1, a phosphorus content of 9-12%, a nitrogen content of 3-5%, and the following general structural formula:

[0014]

[0015] The structural formula for B is as follows:

[0016]

[0017] The char-forming agent is ultrathin hollow zinc aluminate microspheres with a diameter (D50) of 1-30 μm, a shell thickness of 20-60 nm, and a moisture content of <0.3%.

[0018] The antioxidants mentioned are 2,2-bis[[3-(dodecylthio)-propionate]-1,3-propanediol ester (CAS No. 29598-76-3) and octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (CAS No. 29598-76-3). No. 2082-79-3; Triethylene glycol ether-di(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate, CAS No. 36443-68-2; Pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 6683-19-8; Tris[2,4-di-tert-butylphenyl]phosphite, CAS No. 31570-04-4; Bis(2,4-dicumylphenyl)pentaerythritol diphosphite, 154862-43-8, etc., one or more hindered phenols, organosulfur compounds or phosphites;

[0019] The preferred formulations of this invention are: pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris[2,4-di-tert-butylphenyl]phosphite.

[0020] The processing aids are one or more of silicone, pentaerythritol stearate, ethylene bis-stearamide, erucamide, and polyethylene wax.

[0021] Silicone is preferred in this invention.

[0022] The color masterbatch can be one or more of carbon black, zinc sulfide, iron oxide, etc., depending on the color requirements, with a color powder content of 20-99%, and the carrier is AS or lubricant.

[0023] The method for preparing the flame-retardant PC / ABS composition includes the following steps:

[0024] (1) Weigh out all raw materials according to the formula ratio; mix acrylonitrile-butadiene-styrene copolymer, polycarbonate resin, compatibilizer, flame retardant, charring agent, antioxidant, processing aid, color masterbatch, etc. evenly in a high-speed mixer and set aside.

[0025] (2) The above-mentioned resin and additive mixture is added through the main feed port of a twin-screw extruder, and after melting extrusion, granulation and drying at 220-240°C, the flame-retardant PC / ABS composition is obtained.

[0026] The above flame-retardant PC / ABS composition can be applied in the automotive industry, electrical instrumentation industry, and machinery industry.

[0027] The advantage of this invention lies in its selection of bicyclic cage-like phosphate ester phosphazene derivatives as flame retardants based on the molecular assembly design principle of flame retardants. The phosphate ester and phosphazene groups in the molecular structure play a flame-retardant role. During combustion, phosphate esters and phosphazenes decompose to produce substances such as phosphoric acid, metaphosphoric acid, polymetaphosphoric acid, carbon dioxide, ammonia, nitrogen, and water vapor. Phosphoric acid is a non-flammable liquid film that acts as a barrier to combustibles. Polymetaphosphoric acid can dehydrate and carbonize PC / ABS resin, forming a carbon layer that isolates air and further enhances the flame-retardant effect. Non-flammable gases such as nitrogen can dilute the oxygen concentration and block the oxygen supply. During combustion, the PO· groups produced by the flame retardant react with the H· and HO· active groups in the flame region, inhibiting the flame. The free radical capture terminates the combustion chain reaction. Through the above actions, the bicyclic cage-like phosphate ester phosphazene derivative can achieve good flame-retardant effects as a flame retardant for PC / ABS materials. Meanwhile, zinc aluminate is introduced as a charring agent in the formulation design, which can increase the thickness of the carbon layer and better block combustible gases. The zinc aluminate is in the form of ultra-thin hollow microspheres, and the wall thickness and particle size of the microspheres are limited. The characteristics of the microspheres can be used to increase the charring efficiency of zinc aluminate and further improve its flame retardant efficiency.

[0028] The beneficial effects of this invention are as follows:

[0029] 1) This invention selects a bicyclic cage-like phosphate ester phosphazene derivative as a flame retardant for PC / ABS materials. The phosphate ester and phosphazene groups in the molecular structure can play a flame-retardant role. During combustion, the phosphate ester and phosphazene decompose to produce phosphoric acid, metaphosphoric acid, polymetaphosphoric acid, carbon dioxide, ammonia, nitrogen, water vapor, and other substances. Phosphoric acid is a non-flammable liquid film that acts as a barrier to combustibles. Polymetaphosphoric acid can dehydrate and carbonize the PC / ABS resin, and the resulting char layer can isolate air, further enhancing the flame-retardant effect. Non-flammable gases such as nitrogen can dilute the oxygen concentration and block the oxygen supply. During combustion, the PO· groups produced by the flame retardant react with the H· and HO· active groups in the flame region, inhibiting the flame. The free radical capture terminates the combustion chain reaction.

[0030] 2) This invention selects ultrathin hollow zinc aluminate microspheres as a char-forming agent. Zinc aluminate can effectively increase the thickness and hardness of the carbon layer and better play the role of blocking combustible gases.

[0031] 3) In selecting flame retardants, this invention limits the ratio of bicyclic cage-like phosphate esters and phosphazene structures in the flame retardant to 6:1 by selecting the structure, which further limits the content of phosphorus and nitrogen elements and achieves a better synergistic effect.

[0032] 4) The char-forming agent zinc aluminate selected in this invention is in the form of ultrathin hollow microspheres, and the wall thickness and particle size of the microspheres are limited. The limited wall thickness ensures the shape of the microspheres, and the hollow feature can further increase the char-forming efficiency of zinc aluminate and improve its flame retardant efficiency.

[0033] 5) By limiting the proportions of each component in the flame-retardant PC / ABS composition and the performance of PC resin and ABS resin, this invention achieves UL94 V-0@1.6mm flame retardancy while also providing excellent mechanical properties.

[0034] The aforementioned beneficial effects result in flame-retardant PC / ABS compositions with excellent mechanical properties and flame-retardant performance, while also incorporating halogen-free environmental protection features and high performance characteristics. Detailed Implementation

[0035] To make the technical problem to be solved, the technical solution, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0036] The embodiments and comparative examples of the present invention use the following materials, but are not limited to the following materials:

[0037] PC, Product Name 2800, manufactured by Covestro;

[0038] ABS, product name PA-726M, manufactured by Chi Mei;

[0039] MBS, product name EM500, is manufactured by LG;

[0040] Bicyclic cage-like phosphate ester phosphazene derivative flame retardant, commercially available;

[0041] Ultra-thin hollow zinc aluminate microspheres, commercially available;

[0042] Bisphenol A bis(diphenyl phosphate) BDP, trade name WSFR-BDP, is produced in Wansheng, Zhejiang.

[0043] The dripping agent PTFE, trade name DB105, is produced by Suzhou Pulefei.

[0044] Organosiloxane flame retardant, trade name ADDITIVE 40-001, manufactured by Dow Corning;

[0045] Phenoxy polyphosphazene flame retardant, commercially available;

[0046] Lubricant, silicone powder, commercially available;

[0047] Antioxidant 1010, commercially available;

[0048] Antioxidant 168, commercially available;

[0049] Masterbatch, commercially available;

[0050] Preparation methods of Examples 1-4 and Comparative Examples 1-8:

[0051] Preparation method of flame retardant PC / ABS composition

[0052] (1) Weigh out all raw materials according to the formula ratio; mix acrylonitrile-butadiene-styrene copolymer, polycarbonate resin, compatibilizer, flame retardant, charring agent, antioxidant, processing aid, color masterbatch, etc. evenly in a high-speed mixer and set aside.

[0053] (2) The above-mentioned resin and additive mixture is added through the main feed port of a twin-screw extruder, and after melting extrusion, granulation and drying at 220-240°C, the flame-retardant PC / ABS composition is obtained.

[0054] Preparation of test strips for flame-retardant PC / ABS compositions:

[0055] The above materials were dried in a forced-air drying oven at 120℃ for 4 hours, and then injection molded into standard specimens at an injection molding temperature of 240-270℃. The prepared mechanical property specimens were then conditioned in a standard laboratory environment (23℃, 50%RH) for 24 hours before testing.

[0056] Test methods for each performance indicator:

[0057] Tensile properties: According to ISO 527 method, specimen size: 170*10*4mm, test speed 5mm / min. Flexural properties: According to ISO 178 method, specimen size: 80*10*4mm, test speed 2mm / min. Notched impact properties: According to ISO 179 method, specimen size: 80*10*4mm.

[0058] Flame retardant performance: According to UL94 method, the sample size is 127*12.7*1.6mm.

[0059] Limiting Oxygen Index (LOI); according to GB / T 2406.1, the sample size is 50*10*4mm.

[0060] Table 1: Composition and properties of flame-retardant PC / ABS compositions in Examples 1-4 and Comparative Examples 1-8

[0061]

[0062] As can be seen from the results of the examples and comparative examples in Table 1, under the same amount of flame retardant, the bicyclic cage-like phosphate phosphazene derivative and ultrathin hollow zinc aluminate microspheres used in this invention as flame retardants have better mechanical properties and oxygen index than conventional BDP and PTFE or BDP and organosilane systems (Example 1, Comparative Examples 1-2). While meeting the UL94 1.6mmV0 flame retardant requirement, the content of flame retardant can be significantly reduced, and the mechanical properties of the flame-retardant PC / ABS composition can be further improved (Examples 2-3). As can be seen from Examples 2 and Comparative Examples 3-6, under the same amount of addition, the flame retardant efficiency of the bicyclic cage-like phosphate phosphazene derivative flame retardant is significantly higher than that of BDP or BDP and phosphazene blend system. This is due to the performance advantage brought by the synergistic effect of the bicyclic cage-like phosphate and phosphazene groups. As can be seen from Examples 3 and Comparative Examples 7-8, the flame retardant efficiency of the charring agent used in this invention is higher than that of conventional PTFE and siloxanes. The improved flame retardant efficiency allows for a reduction in the amount of flame retardant added, thereby enhancing the mechanical properties of the flame-retardant PC / ABS composition. The PC / ABS composition prepared by this invention exhibits excellent mechanical and flame-retardant properties. The flame-retardant PC / ABS composition prepared by this invention can be applied in the automotive industry, electrical instrumentation industry, and machinery industry, among other fields.

Claims

1. A flame-retardant PC / ABS composition of a bicyclic cage-like phosphate ester phosphazene derivative, characterized in that: Raw materials according to the following parts by weight composition: Polycarbonate resin: 52-99.96%; Acrylonitrile-butadiene-styrene copolymer: 0.01-20%; Compatibilizer: 0.01-5% Flame retardant: 0.01-15%; Charring agent: 0.01-4%; Antioxidant: 0-1%; Processing aids: 0-2%; Masterbatch: 0-1%; The flame retardant is a bicyclic cage-like phosphate ester phosphazene derivative, with a molar ratio of phosphorus groups to phosphazene groups of 6:1, a phosphorus content of 9-12%, a nitrogen content of 3-5%, and the following general structural formula: The structural formula for B is as follows: ； The charring agent is ultrathin hollow zinc aluminate microspheres, and the diameter of the microspheres (D) 50 ): 1-30μm, shell thickness 20-60nm, moisture <0.3%.

2. The bicyclic cage-like phosphate ester phosphazene derivative flame-retardant PC / ABS composition according to claim 1, characterized in that: The polycarbonate resin has a number-average molecular weight of 17,000-40,000, a weight-average relative molecular mass of 20,000-50,000, and a melt flow rate (test conditions: 300℃*1.2kg): 10-25 g / 10min.

3. The bicyclic cage-like phosphate ester phosphazene derivative flame-retardant PC / ABS composition according to claim 1, characterized in that: The acrylonitrile-butadiene-styrene copolymer is produced by emulsion grafting-blending polymerization or continuous bulk polymerization. The melt flow rate is 5-25 g / 10 min under the test conditions of 220℃*10 kg. The butadiene content is 15-20%, and the butadiene particle size is 0.1-1.0 μm with a bimodal particle size distribution. The butadiene content and particle size in the acrylonitrile-butadiene-styrene copolymer are limited in order to ensure that the prepared flame-retardant PC / ABS composition has excellent surface properties and toughness.

4. The bicyclic cage-like phosphate ester phosphazene derivative flame-retardant PC / ABS composition according to claim 1, characterized in that: The compatibilizer is selected from one or a mixture of several of the following: methyl methacrylate / butadiene / styrene copolymer, methyl methacrylate / acrylate polymer, ethylene / acrylate / glycidyl methacrylate terpolymer, ethylene-butyl acrylate, acrylic-silicone rubber toughening agent, etc. The processing aids are one or more of silicone, pentaerythritol stearate, ethylene bis-stearamide, erucamide, and polyethylene wax.

5. The bicyclic cage-like phosphate ester phosphazene derivative flame-retardant PC / ABS composition according to claim 4, characterized in that: The compatibilizer is selected from methyl methacrylate-butadiene-styrene terpolymer; the processing aid is selected from silicone.

6. The bicyclic cage-like phosphate ester phosphazene derivative flame-retardant PC / ABS composition according to claim 1, characterized in that: The antioxidant is one or more of the following: 3-(dodecylthio)propionic acid-2,2-bis[[3-(dodecylthio)-propionyloxy]methyl]-1,3-propanediol ester; β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid n-octadecyl ester; triethylene glycol ether-di(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate; tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]pentaerythritol ester; tris[2,4-di-tert-butylphenyl]phosphite; bis(2,4-dicumylphenyl)pentaerythritol diphosphite.

7. The bicyclic cage-like phosphate ester phosphazene derivative flame-retardant PC / ABS composition according to claim 6, characterized in that: The antioxidants mentioned are: pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris[2,4-di-tert-butylphenyl] phosphite.

8. The bicyclic cage-like phosphate ester phosphazene derivative flame-retardant PC / ABS composition according to claim 1, characterized in that: The masterbatch mentioned above is a masterbatch containing one or more of carbon black, zinc sulfide, iron oxide, etc., according to the color requirements, with a color powder content of 20-99%, and AS or lubricant as the carrier.

9. A method for preparing the bicyclic cage-like phosphate ester phosphazene derivative flame-retardant PC / ABS composition according to any one of claims 1-8, characterized in that: Includes the following steps: (1) Weigh out all raw materials according to the formula ratio; mix acrylonitrile-butadiene-styrene copolymer, polycarbonate resin, compatibilizer, flame retardant, charring agent, antioxidant, processing aid, color masterbatch, etc. evenly in a high-speed mixer and set aside; (2) The above-mentioned resin and additive mixture is added through the main feed port of a twin-screw extruder, and after melt extrusion, granulation and drying at 220-240°C, the flame-retardant PC / ABS composition is obtained.

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