Flame-retardant PC (polycarbonate) material as well as preparation method and application thereof

Abstract

The invention relates to a flame-retardant PC material as well as a preparation method and application thereof, and belongs to the technical field of engineering plastics. The flame-retardant PC material provided by the invention is prepared from the following components in parts by weight: 75 to 90 parts of PC resin, 7 to 13 parts of silicon copolymerized PC, 1 to 4 parts of reaction type organic silicon flame retardant, 3 to 8 parts of organic phosphorus flame retardant and 0.1 to 0.2 part of antioxidant, the weight ratio of the silicon copolymerized PC to the reactive organic silicon flame retardant is (2-10): 1. According to the flame-retardant PC material disclosed by the invention, the silicon copolymerized PC, the reactive organic silicon flame retardant and the organic phosphorus flame retardant are compounded, so that a very good flame-retardant synergistic effect can be generated, a molten drop phenomenon of the flame-retardant PC in a combustion process can be effectively controlled, an anti-dripping effect similar to PTFE (Polytetrafluoroethylene) is achieved, and the social demand of no PFAS (Polytetrafluoroethylene Acrylonitrile Butadiene Styrene) is met.

Description

Technical Field

[0001] The present invention belongs to the technical field of engineering plastics, and particularly relates to a flame-retardant PC material, a preparation method thereof, and an application thereof. Background Art

[0002] Polycarbonate (PC) is a crystalline thermoplastic engineering plastic, which has the characteristics of flame retardancy, high heat resistance, high impact resistance, high transparency, high dimensional stability, etc. With the development of science and technology, in recent years, materials modified based on polycarbonate have been increasingly widely used, such as in the fields of electronic and electrical, machinery, automobiles, chemical engineering, aerospace, and military industries.

[0003] At present, the main flame retardants used in polycarbonate composite materials are phosphate esters and sulfonates, and the addition amount of the flame retardant is generally relatively large, and a polytetrafluoroethylene (PTFE) anti-dripping agent needs to be added to achieve a V-0 flame retardancy rating. And PTFE belongs to per- and polyfluoroalkyl substances (PFAS), and such substances (PFAS) have various toxicities such as carcinogenicity, reproductive toxicity, developmental toxicity, and neurotoxicity. If the human body ingests or absorbs PFAS such substances, this carcinogenic substance PFAS may remain in the human body for several years, and can cause cancer, thyroid diseases, affect fetal development, liver damage, affect the immune system, and increase the risk of childhood asthma.

[0004] Therefore, there is an urgent need to find a new flame retardant system with high flame retardancy efficiency to meet the requirements of polycarbonate composite materials without PFAS. Summary of the Invention

[0005] The purpose of the present invention is to overcome the problems existing in the above-mentioned prior art, and provide a flame-retardant PC material, a preparation method thereof, and an application thereof.

[0006] The present invention is realized through the following technical solutions:

[0007] In the first aspect, the present invention provides a flame-retardant PC material, which comprises the following components by weight: 75-90 parts of PC resin, 7-13 parts of silicone copolymerized PC, 1-4 parts of reactive silicone flame retardant, 3-8 parts of organophosphorus flame retardant, and 0.1-0.2 part of antioxidant; the weight ratio of the silicone copolymerized PC to the reactive silicone flame retardant is (2-10):1.

[0008] The flame-retardant PC material of the present invention can efficiently improve the flame-retardant performance of polycarbonate without an anti-drip agent PTFE by the combined action of a reactive silicone flame retardant and silicone copolymerized PC. A 1.5-mm spline can achieve a V-0 flame-retardant performance. The reactive silicone flame retardant has active groups, and these active groups can react with PC more quickly during combustion. Through transesterification reaction, a certain cross-linked structure is formed, and a carbon layer is rapidly formed on the surface. On the other hand, silicone copolymerized PC provides a prepolymer for PC and the reactive silicone flame retardant, making the material easier to cross-link during combustion, reducing the melt fluidity, and thus reducing the occurrence of dripping phenomenon. At the same time, the decomposition of the organophosphorus flame retardant also produces inert gases or phosphorus oxygen free radicals to dilute the air, and produces phosphoric acid to promote carbonization, further preventing oxygen from contacting the material, thereby alleviating the combustion of the material. The present invention makes the PC material have excellent tensile properties, impact strength, flame-retardant performance, and melt index through the compounding of silicone copolymerized PC, reactive silicone flame retardant, and organophosphorus flame retardant, meeting the requirements of multiple fields.

[0009] Preferably, the melt flow rate of the PC resin under the conditions of 300 °C and a load of 1.2 kg is 1-12 g / 10 min. More preferably, the melt flow rate of the PC resin under the conditions of 300 °C and a load of 1.2 kg is 3-10 g / 10 min.

[0010] Specifically, the melt flow rate of the polycarbonate resin can be measured according to ASTM D1238.

[0011] Preferably, the silicon content in the silicone copolymerized PC is 6%-20%; more preferably, the silicon content in the silicone copolymerized PC is 15%-20%.

[0012] Preferably, the reactive silicone flame retardant includes at least one of hydroxyl-terminated polydimethylsiloxane, amino-terminated polydimethylsiloxane, and organosilicon resin containing hydroxyl groups.

[0013] The above types of reactive silicone flame retardants can make the material have excellent flame-retardant performance and mechanical properties. If an organosilicon resin with a two-dimensional structure having hydroxyl groups is used, the effect is better.

[0014] Preferably, the viscosity of the reactive silicone flame retardant is 50-20000; more preferably, the viscosity of the reactive silicone flame retardant is 6000-20000.

[0015] Preferably, the total weight parts of the silicone copolymerized PC and the reactive silicone flame retardant are not less than 10 parts.

[0016] The research of the present invention finds that the total addition amount of the silicone PC and the reactive silicone flame retardant should reach at least 10 parts to ensure that the flame retardant grade reaches V0. More preferably, the total weight parts of the silicone copolymerized PC and the reactive silicone flame retardant are 10-12 parts.

[0017] Preferably, the organophosphorus flame retardant includes at least one of 9,10-dihydro-9-oxa-10-vinylphosphaphenanthrene-10-oxide (DOPO), bisphenol A-bis(diphenyl phosphate) (BDP), resorcinol bis[bis(2,6-dimethylphenyl) phosphate] (RDX), hydroquinone bis[bis(2,6-dimethylphenyl) phosphate], and hexaphenoxycyclotriphosphazene.

[0018] Preferably, the antioxidant includes at least one of hindered phenol antioxidants and phosphite antioxidants.

[0019] Specifically, the antioxidant includes at least one of antioxidant 1010, antioxidant 168, antioxidant 1098, and antioxidant 1076.

[0020] In the second aspect, the present invention provides a method for preparing the above-mentioned flame retardant PC material, which includes the following steps: weighing each component according to the above weight parts, mixing evenly to obtain a mixed raw material; then melting and extruding the obtained mixed raw material through a twin-screw extruder and granulating to obtain the flame retardant PC material.

[0021] The preparation method of the flame retardant PC material of the present invention is simple and suitable for industrial production.

[0022] Preferably, the length-diameter ratio of the screw of the twin-screw extruder is (40-60):1, the screw rotation speed is 200-500 revolutions per minute, and the temperature of the melt extrusion is 230°C-270°C.

[0023] In the third aspect, the present invention provides the application of the above-mentioned flame retardant PC material in the fields of electronics and electricity, machinery, automobiles, chemical engineering, aerospace, and military industry.

[0024] The present invention makes the PC material have low cost while having excellent tensile properties, impact strength, flame retardant properties, and melt index through the compounding of silicone copolymerized PC, reactive silicone flame retardant, and organophosphorus flame retardant. Therefore, it is suitable for applications in multiple fields such as electronics and electricity, machinery, automobiles, chemical engineering, aerospace, and military industry.

[0025] The present invention has the following beneficial effects: The flame-retardant PC material of the present invention uses a silicone copolymerized PC, a reactive silicone flame retardant, and an organophosphorus flame retardant in combination, which can produce a good flame-retardant synergistic effect, effectively control the melt dripping phenomenon of the flame-retardant PC during combustion, achieve an anti-dripping effect similar to PTFE, and meet the social demand for PFAS-free. And while effectively reducing the dosage of the flame retardant, maintaining the flame-retardant grade of the material to reach V-0, and at the same time ensuring that the material has excellent tensile properties, impact strength, flame-retardant properties, and melt index. Detailed Embodiments

[0026] To better illustrate the purpose, technical solution and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments. Those skilled in the art should understand that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0027] Unless otherwise specified, the test methods used in the examples are all conventional methods; the materials, reagents, etc. used, unless otherwise specified, can all be obtained from commercial channels.

[0028] Examples 1-9

[0029] The composition components of the flame-retardant PC material described in the embodiments of the present invention are shown in Table 1.

[0030] The preparation method of the flame-retardant PC material includes the following steps:

[0031] Weigh each component according to the weight parts shown in Table 1, and mix them evenly to obtain a mixed raw material; then shear and knead the obtained mixed raw material through a twin-screw extruder. The mixed raw material is melted, combined, then extruded, drawn into strips, cooled and pelletized to obtain the flame-retardant PC material; the length-diameter ratio of the screw of the twin-screw extruder is 42:1, the screw speed is 300 revolutions per minute, and the extrusion temperature is 240-260°C.

[0032] Comparative Examples 1-9

[0033] The differences between Comparative Examples 1-9 and the examples are only in the types and ratios of the components, as shown in Table 2.

[0034] Among the components of each example and comparative example,

[0035] The PC resin: PC1201-10P, LG Chem, and the melt flow rate of the PC resin under the conditions of 300°C and a load of 1.2 kg is 10 g / min;

[0036] The silicone copolymerized PC: S2060, Wanhua, with a silicon content of 20%;

[0037] The organophosphorus flame retardant: hexaphenoxycyclotriphosphazene, abbreviated as phosphazene, by Longxin Chemical Industry Co., Ltd.;

[0038] The reactive silicone flame retardant 1: hydrogen-terminated polydimethylsiloxane with a viscosity of 50, by Guangdong Baohangye Silicon Fluoride Materials Technology Co., Ltd.;

[0039] The reactive silicone flame retardant 2: hydrogen-terminated polydimethylsiloxane with a viscosity of 6000, by Guangdong Baohangye Silicon Fluoride Materials Technology Co., Ltd.;

[0040] The reactive silicone flame retardant 3: hydrogen-terminated polydimethylsiloxane with a viscosity of 10000, by Guangdong Baohangye Silicon Fluoride Materials Technology Co., Ltd.;

[0041] The reactive silicone flame retardant 4: hydroxyl-terminated polydimethylsiloxane with a viscosity of 6000, by Guangdong Baohangye Silicon Fluoride Materials Technology Co., Ltd.;

[0042] The silicone flame retardant 5: methyl-terminated polydimethylsiloxane with a viscosity of 6000, by Guangdong Baohangye Silicon Fluoride Materials Technology Co., Ltd.;

[0043] The antioxidant 168: by BASF;

[0044] The antioxidant 1076: by BASF;

[0045] Unless otherwise specified, the component raw materials used in each example and comparative example of the present invention are all commercially available raw materials, and the component raw materials used in each parallel experiment are the same kind.

[0046] Table 1 Component contents (parts) in the materials of the examples

[0047]

[0048]

[0049] Table 2 Component contents (parts) in the materials of the comparative examples

[0050]

[0051]

[0052] The flame-retardant PC materials prepared in each example and comparative example were subjected to the following performance tests, specifically as follows:

[0053] Test of tensile strength: according to ASTM D638 standard, the test speed is 50 mm / min;

[0054] Test of flexural strength: according to ASTM D790 standard, the test speed is 5 mm / min;

[0055] Testing of notched impact strength: ASTM D256 standard;

[0056] Melt index: ASTM D1238 standard, 300 °C / 1.2 kg;

[0057] Flame retardancy test: UL94 standard.

[0058] The test results are shown in Tables 3 and 4.

[0059] Table 3 Test results of material properties of the examples

[0060]

[0061] Table 4 Test results of material properties of the comparative examples

[0062]

[0063] It can be seen from Tables 3 and 4 that in the flame-retardant PC material of the present invention, the use of silicone copolymerized PC, reactive silicone flame retardant and organophosphorus flame retardant can form good flame-retardant synergism, and can play a role similar to that of the anti-dripping agent PTFE during combustion, reaching the flame-retardant grade V0.

[0064] It can be seen from Examples 1 to 4 that the active groups of the reactive silicone flame retardant include but are not limited to hydrogen groups and hydroxyl groups. At the same time, the higher the viscosity, the better the flame retardancy and the better the impact performance. This is related to the degree of physical interlacing and entanglement of the silicone, silicone PC and PC molecular chains during melt extrusion blending. The higher the viscosity of polydimethylsiloxane, the higher the molecular weight, and more complex physical interlacing and entanglement can be formed with silicone PC and PC during melt extrusion. This interlacing and entanglement makes the material more likely to crosslink during combustion, and more complex networks are more easily formed, thus achieving an anti-dripping effect similar to that of PETS.

[0065] It can be seen from Examples 2 and Comparative Examples 1-6 that silicone copolymerized PC and reactive silicone flame retardant are both indispensable. Reducing too much of one of them, or replacing one with an equal ratio of the other, will result in a decrease in the flame retardancy effect. In addition, the addition of silicone copolymerized PC and reactive silicone flame retardant also helps to improve the impact performance of the material. This is due to the fact that the reactive silicone flame retardant can form more complex physical interlacing and entanglement with silicone PC and PC during melt extrusion, forming a more complex crosslinked network, and such a network helps to improve the impact and tensile properties.

[0066] It can be seen from Examples 5-9 and Comparative Examples 7-9 that to achieve a flame-retardant grade of V0, the ratio of silicone PC to reactive silicone flame retardant is (2-10):1, and the addition amount is at least 10 parts.

[0067] The flame-retardant PC material of the present invention not only has excellent flame-retardant performance, but also good physical properties, and can be used as a substitute material for PFAS (PTFE)-free. At the same time, it has good fluidity, is easy to process, and has low cost. It is a PC composition suitable for replacing PTFE in various fields and is more in line with the control of PFAS.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A flame-retardant PC material, characterized in that, By weight parts, it comprises the following components: 75 - 90 parts of PC resin, 7 - 13 parts of silicone copolymerized PC, 1 - 4 parts of reactive silicone flame retardant, 3 - 8 parts of organophosphorus flame retardant, 0.1 - 0.2 parts of antioxidant; the weight ratio of the silicone copolymerized PC to the reactive silicone flame retardant is (2 - 10):

1.

2. The flame-retardant PC material according to claim 1, wherein The melt flow rate of the PC resin under the conditions of 300 °C and a load of 1.2 kg is 1 - 12 g / 10 min.

3. The flame-retardant PC material according to claim 1, wherein The silicon content in the silicone copolymerized PC is 6% - 20%.

4. The flame-retardant PC material according to claim 1, characterized in that, The reactive silicone flame retardant includes at least one of hydroxyl-terminated polydimethylsiloxane, amino-terminated polydimethylsiloxane, and silicone resin containing hydroxyl groups.

5. The flame-retardant PC material according to claim 1, characterized in that The viscosity of the reactive silicone flame retardant is 50 - 20000.

6. The flame-retardant PC material according to claim 1 or 5, characterized in that The viscosity of the reactive silicone flame retardant is 6000 - 20000.

7. The flame-retardant PC material according to claim 1, wherein The total weight parts of the silicone copolymerized PC and the reactive silicone flame retardant are not less than 10 parts.

8. The flame-retardant PC material according to claim 1, wherein The organophosphorus flame retardant includes at least one of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, bisphenol A-bis(diphenyl phosphate), resorcinol bis[bis(2,6-dimethylphenyl) phosphate], hydroquinone bis[bis(2,6-dimethylphenyl) phosphate], hexaphenoxycyclotriphosphazene; and / or, the antioxidant includes at least one of hindered phenol antioxidants and phosphite antioxidants.

9. A method for preparing the flame-retardant PC material according to any one of claims 1-8, characterized in that, It includes the following steps: Weigh each component according to the said weight parts, mix evenly to obtain a mixed raw material; then extrude the obtained mixed raw material through a twin-screw extruder, pelletize, and thus obtain the flame-retardant PC material.

10. Application of the flame-retardant PC material according to any one of claims 1 - 8 in the fields of electronics and electricity, machinery, automotive, chemical industry, aerospace, and military industry.

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