Fluorine-free halogen-free flame-retardant PC plastic and preparation method thereof

Abstract

The application discloses a kind of fluorine-free halogen-free flame-retardant PC plastics and preparation method thereof, by the following components are made of by weight parts: 85~99.5 portion PC resin;0.1-7 portion halogen-free flame retardant;0.1-2 portion fluorine-free anti-dripping agent;0.1-0.3 portion chain extender;0.1-10 portion other auxiliary agent.The PC plastic of the application is mainly the purpose of the application is to provide a kind of fluorine-free halogen-free flame-retardant flame-retardant PC material and preparation method thereof, solve in halogen-free flame-retardant V0 grade PC material due to adding PTFE fluorine-containing anti-dripping agent causes potential PFAS environmental protection risk, and not add PTFE anti-dripping agent causes thin-wall flame-retardant V0 substandard problem.

Description

Technical Field

[0001] This invention relates to the field of engineering plastics technology, and in particular to a fluorine-free, halogen-free flame-retardant PC plastic and its preparation method. Background Technology

[0002] Polycarbonate (PC), one of the five major engineering plastics, is widely used in the electronics, electrical, and automotive industries due to its advantages such as transparency, flame retardancy, heat resistance, high impact resistance, and good electrical insulation. The oxygen index of PC resin is generally between 23 and 25; in vertical burning tests, it is generally rated V2. Currently, the electronics and electrical industries generally require an oxygen index of 28 or 32 or higher, and a V0 rating for vertical burning. Improving the flame retardancy of PC typically involves using halogen-free or halogenated flame retardants combined with polytetrafluoroethylene (PTFE) anti-dripping agents. Without PTFE anti-dripping agents, thin-walled flame-retardant PC cannot achieve a V0 rating. Currently, the international definition of halogen-free is based on limiting the content of chlorine and bromine: generally requiring each to be less than 900 ppm, with a total content of less than 1500 ppm, while there are no regulations regarding iodine or fluorine.

[0003] Polytetrafluoroethylene (PTFE) anti-dripping agents are high molecular weight PTFE compounds with a molecular weight of 3-6 million. The theoretical fluorine content in PTFE is around 76%. Currently, there are no international regulations regarding the environmental friendliness of PTFE. However, the fluorine-containing substances produced from the monomers used in the synthesis of PTFE, the solvents used in its polymerization, or the thermal decomposition of PTFE itself pose potential environmental hazards.

[0004] Since 2009, perfluorooctane sulfonic acid (PFOA) and its derivatives (PFOS) have been included in the Stockholm Convention to eliminate their use. The Stockholm Convention regulates the global elimination of perfluorooctanoic acid (PFOA), its salts, and PFOA-related compounds.

[0005] Perfluorohexanesulfonic acid (PFHxS), its salts and related compounds, and perfluorocarboxylic acid (C9-14 PFCA) were included in the Stockholm Convention and subsequently eliminated globally. Germany has proposed further restrictions on undecanoic acid (PFHxA), its salts and related substances.

[0006] PFAS stands for per / polyfluoroalkyl substances, which are perfluoroalkyl and polyfluoroalkyl compounds. Some PFAS are known to accumulate in the body and cause toxic effects. Some PFAS are reproductively toxic and can harm fetal development. Several PFAS have been shown to cause cancer. Some PFAS are also suspected of interfering with the human endocrine (hormonal) system, but testing in this area is ongoing.

[0007] Currently, a small number of patented halogen-free flame-retardant PCs do not require the addition of PTFE anti-dripping agents, and their flame-retardant effect generally only reaches a V0 rating of 3.2mm. To achieve V0 ratings of 1.6mm and thinner, a certain amount of PTFE anti-dripping agent needs to be added. Downstream customers' current requirements for halogen-free PCs are: flame retardancy meets standards, and the chlorine and bromine content of the material is below 900ppm for some materials and below 1500ppm for others; the fluorine content is below 50ppm.

[0008] Application publication number CN104403289A discloses a halogen-free flame-retardant PC material and its preparation method. It uses a benzenesulfonate silsesquioxane silicon-based flame retardant and an organic PTFE anti-dripping agent to achieve thin-wall V0 flame retardancy. The anti-dripping agent used is PTFE, which still contains fluorine.

[0009] Application publication number CN106147187A discloses a high-gloss halogen-free flame-retardant PC material and its preparation method. It uses a combination of organosilicon silsesquioxane silicon-based flame retardant and organosilicon anti-dripping agent to achieve thin-wall V0 flame retardancy. However, the organosilicon anti-dripping agent used is organosilicon-coated PTFE, which still contains fluorine.

[0010] Application publication number CN112063148A discloses a hydrolysis-resistant PC composite material with high flame retardancy and its preparation method, which uses potassium perfluorobutyl sulfonate and PTFE as flame retardants, both of which contain fluorine.

[0011] The technical solutions disclosed in the aforementioned patents all contain anti-dripping agents, specifically fluorinated anti-dripping agents containing PTFE. With increasing domestic and international demands for halogen-free and environmentally friendly flame-retardant PC plastics, the domestic building electrical appliances, mobile phone casings, new energy battery casings, LED casings, and electric vehicle power connector casings industries will inevitably optimize the range and content of halogens in halogen-free flame-retardant PC. The definition of halogen-free will inevitably evolve from the previous halogen-free fluorinated flame retardant to completely halogen-free. Therefore, developing a fluorine-free halogen-free flame-retardant PC plastic will undoubtedly have broad market prospects and economic benefits in the aforementioned industries. Summary of the Invention

[0012] To overcome the potential environmental risks caused by the addition of PTFE anti-dripping agents to halogen-free flame-retardant V0 grade PC in existing technologies, the present invention aims to provide a fluorine-free and halogen-free flame-retardant PC material and its preparation method, thereby solving the problem of potential PFAS environmental risks caused by the addition of fluorine-containing PTFE anti-dripping agents to halogen-free flame-retardant V0 grade PC materials, while the problem of thin-walled flame-retardant V0 failing to meet standards when no PTFE anti-dripping agents are added.

[0013] Another objective of this invention is to provide applications of the aforementioned fluorine-free and halogen-free flame-retardant PC in fields such as building electrical appliances, mobile phone casings, new energy battery casings, LED casings, and electric vehicle power connector casings.

[0014] To achieve the above objectives, the present invention is implemented through the following technical solution: A fluorine-free, halogen-free flame-retardant PC material, characterized in that, based on the weight of the material, it comprises the following components: PC resin 60~99.5; Halogen-free flame retardant 0.1-7; Fluorine-free anti-dripping agent 0.1~2; Chain extender 0.1-0.3; Other additives: 0.1-30%.

[0015] The PC resin used in this invention is an aromatic polycarbonate. Preferably, it is a bisphenol A type aromatic polycarbonate, and the melt flow rate of the PC substrate is 5-25 g / 10 min.

[0016] The flame retardant of this invention can be one or a combination of several of the following: sulfonate flame retardants, phosphazene flame retardants, organophosphates, and silicone flame retardants. It can be a sulfonate flame retardant (e.g., Soros KSS, HES, HES-2); a phosphazene flame retardant such as Shandong Li'ang's HPCTP; an organophosphate (e.g., TPP, BDP, RDP); or a silicone flame retardant (e.g., Zhongyuan MR-01, Dow Corning FCA-107, FCA-117, Shin-Etsu KR-480).

[0017] The fluorine-free anti-dripping agent used in this invention is silicon nanotubes; the fluorine-free anti-dripping agent S890 from Dongguan Sanhe Chemical Co., Ltd. is selected.

[0018] The chain extender may be BASF's ADR-4468, whose main component is a copolymer of acrylic acid and styrene containing epoxy functional groups; or Nippon Shokubai's RPS-1005, whose main component is an oxazoline graft polymer.

[0019] In addition, other additives such as antioxidants, lubricants, light stabilizers, fluorescent whitening agents, and fillers can be added to improve other product properties.

[0020] A fluorine-free, halogen-free flame-retardant PC and its preparation method: comprising the following steps: 1) Weigh each component according to its weight percentage; 2) Mix PC, halogen-free flame retardant, fluorine-free anti-dripping agent, chain extender and other additives in a high-speed mixer for 8 minutes; 3) The premixed material is plasticized, extruded and granulated by a twin-screw extruder. The specific process is as follows: the extruder temperature control is 240-250℃ in zone 1, 250-260℃ in zone 2, 260-270℃ in zone 3, 260-270℃ in zone 4, 250-260℃ in zone 5, 240-250℃ in zone 6, 230-240℃ in zone 7, 220-230℃ in zone 8, and the die head is 220-230℃. The vacuum is controlled at -0.07MPa.

[0021] This invention further provides applications of the above-mentioned fluorine-free, halogen-free flame-retardant PC material in domestic building electrical appliances, mobile phone casings, new energy battery casings, LED casings, and electric vehicle power connectors.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention further improves the thin-wall flame retardancy of halogen-free PC by adding halogen-free flame retardant to the formula and further improving the melt strength of PC by adding fluorine-free anti-dripping agent PC and chain extender, thereby achieving 0.8-1.6mm V0 flame retardancy and realizing the fluorine-free replacement of materials. Implementation

[0023] The present invention will be further illustrated below through specific embodiments. The following embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following implementation rules.

[0024] In the material formulation of the examples, the PC resin selected is Covestro 2805 from Germany; Flame retardants: One or more of phosphazene flame retardants, organophosphates, and silicone flame retardants. These can be sulfonate flame retardants (HES); phosphazene flame retardants such as Shandong Li'ang's HPCTP and organophosphates (TPP); and silicone flame retardants such as Zhongyuan MR-01 and Shin-Etsu KR-480. Chain extenders: BASF chain extender ADR-4468; Nippon Shokubai chain extender RPS-1005; Fluorine-free anti-dripping agent: Dongguan Sanhe Chemical's fluorine-free anti-dripping agent S890; Other additives: Antioxidant [tris(2,4-di-tert-butylphenyl)] phosphite (168).

[0025] Comparative Examples 1-5 Weigh the components shown in Table 1 by weight percentage: PC resin (2805), halogen-free flame retardant (HES, HPCTP, TPP, KR480), AS-coated polytetrafluoroethylene anti-dripping agent (DB106) and other additives (168). Weigh them according to the proportions shown in Comparative Examples 1-5 in Table 1. First, mix them in a high-speed mixer for 8 minutes to obtain a premix. The premix is ​​then extruded, plasticized, and granulated by a twin-screw extruder and vacuumed to obtain modified PC. Specific data are listed in Table 2.

[0026] Examples 1 to 5 Weigh the components shown in Table 1 by weight percentage: PC resin (2805), halogen-free flame retardant (HES, HPCTP, TPP, KR480), fluorine-free anti-dripping agent (890) and other additives, antioxidant (168). Weigh them according to the proportions shown in Examples 1-5 of Table 1. First, mix them in a high-speed mixer for 8 minutes to obtain a premix. The premix is ​​then extruded, plasticized, and granulated by a twin-screw extruder and vacuumed to obtain modified PC. Specific data are listed in Table 2.

[0027] Examples 6-10 Weigh the components shown in Table 1 by weight percentage: PC resin (2805), halogen-free flame retardant (HES, HPCTP, TPP, KR480), fluorine-free anti-dripping agent (890), chain extender and antioxidant (168). Weigh them according to Examples 6-10 in Table 1. First, mix them in a high-speed mixer for 8 minutes to obtain a premix. The premix is ​​then extruded, plasticized and granulated by a twin-screw extruder and vacuumed to obtain modified PC. Specific data are listed in Table 2.

[0028] Examples 11-15 The components shown in Table 1 were weighed according to the following weight percentages: PC resin (2805), halogen-free flame retardant (HES, HPCTP, TPP, KR480), fluorine-free anti-dripping agent (890), chain extender RPS-1005 and antioxidant (168). The components were weighed according to Examples 11-15 in Table 1. The mixture was first stirred at high speed in a high-speed mixer for 8 minutes to obtain a premix. The premix was then extruded, plasticized and granulated by a twin-screw extruder and vacuumed to obtain modified PC. The specific data are listed in Table 2.

[0029] The particle material was prepared according to the method described in Table 1, dried in a forced-air oven at 120°C for 4-8 hours, and then the dried particles were injection molded on an injection molding machine to form samples for testing material properties. These samples were treated at 23°C and 50% humidity for 48 hours.

[0030] The dimensions and test conditions of the physical property test strips for this invention are as follows: Simply supported beam notched impact test: The spline dimensions are 80*10mm*4mm, the notch depth is 2mm, and it is a V-notch. The test is conducted using a simply supported beam notched impact tester according to the national standard GB / T1043.1-2008, with a pendulum energy of 4J. The test environment temperature is 23±2℃. Melt flow index: Dry the particles and test using a melt flow indexer. Test according to national standard GB / T3682-2018; Flame retardancy: The sample size is 123*13*(3.2,1.6,0.8)mm. The vertical burning test is performed using a vertical burner according to the national standard GB / T2408-2008. Table 1: Specific proportions (parts by weight) of the examples and comparative examples PC2805 99 96.3 93.3 96.3 97 98.6 96 93 96 96.7 98.8 96 93 96 96.7 98.8 96 93 96 96.7 Flame retardant HES 0.3 0.3 0.2 0.3 0.2 0.3 0.2 0.3 flame retardant HCPTP 3 3 3 3 Flame retardant TPP 6 6 6 6 MR-01 3 3 3 3 Kr-480 2 2 2 3 Anti-dripping agent / DB-106 0.5 0.5 0.5 0.5 0.5 Anti-dripping agent / S890 0.8 0.8 0.8 0.8 0.8 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Chain extender / ADR-4468 0.3 0.3 0.3 0.3 0.3 Chain extender / RPS-1005 0.3 0.3 0.3 0.3 0.3 Other additives / antioxidants 168 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Table 2: Performance Results of Examples and Comparative Examples Simple compression (KJ / m2) 67 45 25 77 61 68 46 25 78 64 66 44 26 80 62 64 48 32 81 61 Melt index (g / 10min) 14 17 27 12 14 14 18 30 13 15 10 16 25 9 10 11 14 22 7 13 Flame retardant 3.2mm V0 V0 V0 V0 VO V0 V0 V0 V0 V0 V0 V0 V0 V0 V0 V0 V0 V0 V0 V0 Flame retardant 1.6mm V0 V1 V1 V1 V0 V1 V2 V2 V2 V0 V0 V0 V0 V0 V0 V1 V0 V0 V0 V1 Flame retardant 0.8mm V1 V2 V2 V2 V0 V2 V2 V2 V2 V1 V0 V1 V1 V1 V0 V1 V0 V0 V0 V1 As can be seen from Tables 1 and 2, Comparative Example 1 and Example 1, the flame retardancy at 1.6mm and 0.8mm slightly decreased after the sulfonate flame retardant HES and the PTFE fluorinated anti-dripping agent were replaced by the fluorine-free anti-dripping agent S890. As can be seen from Tables 1 and 2, Comparative Example 1 and Example 6, the flame retardancy at 1.6mm and 0.8mm did not decrease after the sulfonate flame retardant HES and the PTFE fluorinated anti-dripping agent were replaced by the fluorine-free anti-dripping agent S890 and the chain extender ADR-4468; in fact, it slightly improved.

[0031] As can be seen from Tables 1 and 2, Comparative Example 2 and Example 2, the flame retardancy at 1.6 mm and 0.8 mm slightly decreased after the phosphazene flame retardant HCPTP and the fluorinated PTFE anti-dripping agent were replaced by the fluorine-free anti-dripping agent S890. However, as can be seen from Tables 1, Comparative Example 2 and Example 7, the flame retardancy at 1.6 mm and 0.8 mm slightly increased after the phosphazene flame retardant HCPTP and the fluorinated PTFE anti-dripping agent were replaced by the fluorine-free anti-dripping agent S890 and the chain extender ADR-4468.

[0032] As can be seen from Tables 1 and 2, Comparative Example 3 and Example 3, the flame retardancy at 1.6mm and 0.8mm slightly decreased after the phosphazene flame retardant TPP and the PTFE fluorinated anti-dripping agent were replaced by the fluorine-free anti-dripping agent S890. However, as can be seen from Tables 1, Comparative Example 3 and Example 8, the flame retardancy at 1.6mm and 0.8mm slightly increased after the phosphazene flame retardant TPP and the PTFE fluorinated anti-dripping agent were replaced by the fluorine-free anti-dripping agent S890 and the chain extender ADR-4468.

[0033] As can be seen from Tables 1 and 2, Comparative Examples 4 and 4, the flame retardancy at 1.6mm and 0.8mm slightly decreased after the silicon-based flame retardant MR-01 and the PTFE fluorinated anti-dripping agent were replaced by the fluorine-free anti-dripping agent S890. However, as can be seen from Tables 1, Comparative Examples 4 and 9, the flame retardancy at 1.6mm and 0.8mm slightly increased after the silicon-based flame retardant MR-01 and the PTFE fluorinated anti-dripping agent were replaced by the fluorine-free anti-dripping agent S890 and the chain extender ADR-4468.

[0034] As can be seen from Tables 1 and 2, Comparative Example 5 and Example 5, the flame retardancy at 1.6mm and 0.8mm slightly decreased after the addition of a PTFE fluorinated anti-dripping agent (a combination of silicone flame retardant KR-480 and sulfonate flame retardant HES) and the replacement of the PTFE fluorinated anti-dripping agent with a fluorine-free anti-dripping agent S890. Conversely, the flame retardancy at 1.6mm and 0.8mm slightly increased after the addition of a PTFE fluorinated anti-dripping agent (a combination of silicone flame retardant KR-480 and sulfonate flame retardant HES) and the replacement of the PTFE fluorinated anti-dripping agent with a fluorine-free anti-dripping agent S890 and a chain extender ADR-4468.

[0035] As can be seen from Tables 1 and 2, Examples 6-10 and Examples 11-15, the flame retardant effects of chain extender ADR-4468 and chain extender / RPS-1005 when combined with different flame retardants are different.

[0036] Based on Tables 1 and 2, the following preliminary conclusions can be drawn: Using existing fluorine-free anti-dripping agents (silicon nanotubes) alone to replace traditional PTFE-containing fluorinated anti-dripping agents will slightly reduce flame retardancy; using a combination of existing fluorine-free anti-dripping agents (silicon nanotubes) and chain extenders to replace traditional PTFE-containing fluorinated anti-dripping agents can perfectly replace them, but the type of chain extender has different effects on different flame retardants. A slight improvement in flame retardancy can be achieved.

Claims

1. A fluorine-free, halogen-free flame-retardant PC plastic, comprising, by weight: PC resin 96~99.5; Halogen-free flame retardant 0.1-7; Fluorine-free anti-dripping agent 0.1~2; Chain extender 0.1-0.3; Other additives: 0.1-0.2; The fluorine-free anti-dripping agent is silicon nanotubes; The chain extender is one of an acrylic acid-styrene copolymer containing epoxy functional groups or an oxazoline graft polymer.

2. The fluorine-free, halogen-free flame-retardant PC plastic according to claim 1, characterized in that, The PC resin is bisphenol A type polycarbonate, and its melt flow rate is 5~25g / 10min.

3. The fluorine-free, halogen-free flame-retardant PC plastic according to claim 1, characterized in that, The halogen-free flame retardant is one or a combination of several of the following: sulfonate flame retardants, phosphazene flame retardants, organophosphates, and silicon-based flame retardants.

4. The fluorine-free, halogen-free flame-retardant PC plastic according to claim 1, characterized in that, The other additives include one or more of antioxidants, lubricants, light stabilizers, fluorescent whitening agents, and fillers.

5. A method for preparing fluorine-free, halogen-free flame-retardant PC plastic according to any one of claims 1-4, comprising the following steps: (1) Weigh each component according to the weight percentage; (2) Mix PC resin, halogen-free flame retardant, fluorine-free anti-dripping agent, chain extender and other additives in a high-speed mixer for 8 minutes; (3) The premixed material is plasticized and extruded by a twin-screw extruder and granulated. The specific process is as follows: the temperature control of the extruder is 240-250℃ in zone 1, 250-260℃ in zone 2, 260-270℃ in zone 3, 260-270℃ in zone 4, 250-260℃ in zone 5, 240-250℃ in zone 6, 230-240℃ in zone 7, 220-230℃ in zone 8, and the temperature of the die head is 220-230℃. The vacuum is controlled at -0.07MPa.

6. The application of the fluorine-free, halogen-free flame-retardant PC plastic according to any one of claims 1-4 in building electrical appliances, mobile phone casings, new energy battery casings, LED casings, and electric vehicle power connector casings.