A phosphaphenanthrene / siloxane dual-base macromolecular flame retardant toughened polycarbonate material

Abstract

The invention discloses a phosphaphenanthrene / siloxane dibasic macromolecular flame retardant and toughened polycarbonate material. The flame retardant and toughened polycarbonate material comprises: 80-99 parts by weight of polycarbonate (PC), 1-20 parts by weight of a phosphaphenanthrene / siloxane dibasic macromolecular flame retardant, 0-1 part by weight of an anti-dripping agent, 0-1 part by weight of an antioxidant, and 0-10 parts by weight of other additives. The invention applies the phosphaphenanthrene / siloxane dibasic macromolecular flame retardant with excellent thermal stability and a high-efficiency flame retardant and toughened structure to polycarbonate, so that the modified polycarbonate material has excellent anti-ignition performance, excellent self-extinguishing performance after leaving the flame, significantly reduced combustion heat release intensity, and significantly improved impact resistance. Compared with the prior art, the flame retardant and toughened polycarbonate material provided by the invention has more excellent comprehensive flame retardant performance and mechanical properties, and provides an excellent solution for the application of polycarbonate in the field of structural products requiring both excellent flame retardant performance and excellent mechanical properties.

Description

Technical Field

[0001] The invention belongs to the technical field of flame retardant modification of polymer materials, and in particular relates to a phosphaphenanthrene / siloxane double-base macromolecular flame retardant toughened polycarbonate material. Background Art

[0002] Polycarbonate is a thermoplastic engineering plastic with excellent comprehensive performance. It is not only reusable but also easy to recycle. It fully meets the requirements of the circular economy advocated by the country. It is an engineering plastic with excellent sustainability and has become an engineering plastic with a large consumption and a rapid growth in demand in the industry. In order to cope with the increasingly stringent performance and safety requirements of polycarbonate materials put forward by the increasingly developing modern manufacturing industry, the inherent anti-ignition performance (limiting oxygen index 24%-27%) and self-extinguishing performance (UL94 V-2 grade) of polycarbonate materials are far from meeting the fire safety performance requirements of most downstream applications. The development of high-performance flame-retardant polycarbonate materials with excellent flame retardant and physical and mechanical properties has become an important support and basic guarantee for the high-quality development of the polycarbonate industry.

[0003] In the research on flame retardant modification of polycarbonate, how to comprehensively improve the comprehensive flame retardant properties of materials in terms of anti-ignition, fast self-extinguishing, low heat release, etc., how to effectively avoid the deterioration of the physical and mechanical properties of materials by modified components while improving the flame retardant properties of materials, how to construct high-performance molecular structures or composite systems that can significantly improve the flame retardant properties of materials and significantly improve the physical and mechanical properties of materials through innovative design, etc., these are the current focus and direction of efforts of researchers, and are also effective ways to alleviate the current situation of structural overcapacity and structural shortage of domestic polycarbonate production capacity. Summary of the invention

[0004] The purpose of the present invention is to provide a phosphaphenanthrene / siloxane dibasic macromolecular flame retardant and toughened polycarbonate material. A phosphaphenanthrene / siloxane dibasic macromolecular flame retardant with excellent thermal stability and high-efficiency flame retardant and toughened structure is added to polycarbonate to prepare a flame retardant and toughened polycarbonate material with both excellent comprehensive flame retardant performance and excellent mechanical properties. The phosphaphenanthrene / siloxane dibasic macromolecular flame retardant used in the present invention comprises a series of phosphaphenanthrene / siloxane dibasic macromolecules with different structural characteristics. According to different application requirements, phosphaphenanthrene / siloxane dibasic macromolecular flame retardants with different group ratios and different aggregation degrees can be selected to achieve controllable adjustment and deep optimization of the flame retardant performance and physical and mechanical properties of polycarbonate, which has not been reported in current literature and published materials.

[0005] In order to achieve the above-mentioned purpose of the invention, the present invention provides a phosphaphenanthrene / siloxane di-based macromolecular flame retardant toughened polycarbonate material, comprising the following components in parts by weight: 80-99 parts by weight of polycarbonate (PC), 1-20 parts by weight of a phosphaphenanthrene / siloxane di-based macromolecular flame retardant, 0-1 part by weight of an anti-dripping agent, 0-1 part by weight of an antioxidant, and 0-10 parts by weight of other additives.

[0006] The invention provides a method for preparing a phosphaphenanthrene / siloxane dibasic macromolecular flame retardant and toughened polycarbonate material, comprising the following steps: mixing polycarbonate, a phosphaphenanthrene / siloxane dibasic macromolecular flame retardant, an anti-dripping agent, an antioxidant and other additives, melt-extruding, and granulating to obtain the phosphaphenanthrene / siloxane dibasic macromolecular flame retardant and toughened polycarbonate material.

[0007] The phosphaphenanthrene / siloxane dibasic macromolecular flame retardant used in the present invention has the following general chemical structure formula:

[0008]

[0009] The degrees of polymerization x, y, z, u, v and w in the general chemical structure formula cannot all be 0 at the same time.

[0010] More preferably, y and v are not 0, and x, z, u and w are not all 0 at the same time.

[0011] Preferably, the average molecular weight of the phosphaphenanthrene / siloxane di-based macromolecular flame retardant is 3000-20000.

[0012] Preferably, the ratio of the number of phosphaphenanthrene and cyclotetrasiloxane groups in the phosphaphenanthrene / siloxane di-based macromolecular flame retardant is 1:1-3:1.

[0013] Preferably, the phosphaphenanthrene / siloxane dibasic macromolecular flame retardant is prepared by free radical or anionic polymerization of the vinyl groups in the phosphaphenanthrene / siloxane dibasic monomer; the phosphaphenanthrene / siloxane dibasic monomer molecule is a combination of one or more of a monovinyl monomer, a divinyl monomer and a trivinyl monomer; the chemical structure of the phosphaphenanthrene / siloxane dibasic monomer molecule is as follows:

[0014]

[0015] The temperature of the free radical polymerization reaction is 40 to 240°C, and the reaction time is 4 to 48 hours; the free radical initiator used in the free radical polymerization reaction is a combination of one or more of azo initiators, peroxide initiators, dioxane and its derivatives, such as azobisisobutyronitrile, benzoyl peroxide, diisopropylbenzene peroxide, dioxane, etc. The temperature of the anionic polymerization reaction is -20 to 80°C, and the reaction time is 0.5 to 20 hours; the initiator used in the anionic polymerization reaction is a combination of one or more of alkali metal alkyl compounds, alkali metal aryl compounds and alkali metal benzyl compounds, such as alkyl lithium, phenyl lithium, benzyl lithium, etc.

[0016] Preferably, the phosphaphenanthrene / siloxane diradical monomer molecule can be prepared by an addition reaction between the PH bond in 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and the C=C bond in tetramethyltetravinylcyclotetrasiloxane (MVC), wherein the addition reaction temperature is between 135 and 180° C. and the reaction time is 3 to 12 hours.

[0017] Preferably, the anti-drip agent is a fluorine-containing polymer, which may include a fibrillated or non-fibrillated fluorine-containing polymer, and more preferably a fibrillated or non-fibrillated polytetrafluoroethylene (PTFE).

[0018] Preferably, the antioxidant is a combination of one or more of a hindered phenol antioxidant, an aromatic amine antioxidant and a phosphite antioxidant, and specific examples include: pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (antioxidant 1010), β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate octadecyl alcohol ester (antioxidant 1076), N,N'-1,6-hexylene-di-[3,5-di-tert-butyl-4-hydroxyphenyl]propionate] [phenylpropionamide] (antioxidant 1098), tris (2,4-di-tert-butylphenyl) phosphite (antioxidant 168), distearyl pentaerythritol diphosphite (antioxidant 618), bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite (antioxidant 626), bis (2,4-dicumylphenyl) pentaerythritol diphosphite (oxidant 686), tetrakis (2,4-di-tert-butylphenol) 4,4'-biphenyl diphosphite (antioxidant PEPQ).

[0019] The other additives are colorants, antistatic agents, antifogging agents, light stabilizers, heat stabilizers, lubricants, release agents, processing modifiers and other additives, without special requirements.

[0020] The phosphaphenanthrene / siloxane dibasic macromolecular flame retardant used in the present invention constructs a particularly efficient gas phase / condensed phase two-phase synergistic flame retardant mechanism in the polycarbonate material through the "group synergistic flame retardant effect" between the phosphaphenanthrene and siloxane groups and the "group aggregation flame retardant effect" on the molecular scale, and comprehensively improves the comprehensive flame retardant properties of the polycarbonate material from the dimensions of anti-ignition, fast self-extinguishing, low heat release, etc.; the bonding and aggregation of siloxane groups on the molecular scale also enables the phosphaphenanthrene / siloxane dibasic macromolecule to obtain structural characteristics similar to silicone rubber, providing an important structural basis for it to play a rubber-like toughening role in the polycarbonate material; test results show that the phosphaphenanthrene / siloxane dibasic macromolecular flame retardant and toughened polycarbonate material provided by the present invention has a limiting oxygen index of more than 36%, a vertical combustion flame retardant level of UL94 V-0, and a flame retardant level of 50kW·m -2 The peak value of the combustion intensity under external thermal radiation decreases by more than 46%, the impact strength is increased to more than 130% of that before modification, and the tensile strength, elongation at break and flexural strength are also close to the relevant mechanical performance indicators of pure polycarbonate; compared with the prior art, the flame retardant and toughened polycarbonate material disclosed in the present invention has more excellent comprehensive flame retardant properties and mechanical properties, which provides excellent technical support for the application of polycarbonate in the field of structural products that require both excellent flame retardant properties and excellent mechanical properties. DETAILED DESCRIPTION

[0021] The present invention is further described below in conjunction with examples; these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention; the experimental methods in the following examples without specifying specific conditions are usually carried out according to conventional conditions in the art or according to the conditions recommended by the manufacturer; the raw materials, reagents, etc. used, unless otherwise specified, are all raw materials and reagents that can be obtained from commercial channels such as conventional markets; any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention belong to the scope of protection claimed by the present invention.

[0022] Example 1

[0023] Polycarbonate (94.5 parts by mass), phosphaphenanthrene / siloxane dibasic macromolecular flame retardant (phosphaphenanthrene / cyclotetrasiloxane group number ratio 2.84:1, average molecular weight 7732, 5 parts by mass), and anti-dripping agent (0.5 parts by mass) are uniformly mixed, melted, mixed, and extruded by a twin-screw extruder, and then granulated and dried to obtain pellets, which are then injection-molded by an injection molding machine to obtain a phosphaphenanthrene / siloxane dibasic macromolecular flame retardant and toughened polycarbonate material with a limiting oxygen index of 36.3%, UL94 V-0 grade, a heat release rate peak value decreased by 52% compared with that before modification, and an impact strength increased by 32% compared with that before modification.

[0024] Example 2

[0025] Polycarbonate (94.2 parts by mass), phosphaphenanthrene / siloxane dibasic macromolecular flame retardant (phosphaphenanthrene / cyclotetrasiloxane group quantity ratio 2.65:1, average molecular weight 8350, 5 parts by mass), anti-dripping agent (0.5 parts by mass), antioxidant (1010, 0.2 parts by mass; 168, 0.1 parts by mass) are uniformly mixed, melted, mixed and extruded by a twin-screw extruder, granulated and dried to obtain pellets, and then the pellets are injection molded by an injection molding machine to obtain a phosphaphenanthrene / siloxane dibasic macromolecular flame retardant toughened polycarbonate material with a limiting oxygen index of 36.8%, UL94 V-0 grade, a heat release rate peak value decreased by 55% compared with that before modification, and an impact strength increased by 35% compared with that before modification.

[0026] Example 3

[0027] Polycarbonate (86.4 parts by mass), phosphaphenanthrene / siloxane dibasic macromolecular flame retardant (phosphaphenanthrene / cyclotetrasiloxane group number ratio 2.19:1, average molecular weight 9890, 10 parts by mass), antioxidant (1076, 0.3 parts by mass; 618, 0.3 parts by mass), and other additives (3 parts by mass) are uniformly mixed, melted, mixed, and extruded by a twin-screw extruder, and then granulated and dried to obtain pellets, which are then injection-molded by an injection molding machine to obtain a phosphaphenanthrene / siloxane dibasic macromolecular flame retardant and toughened polycarbonate material with a limiting oxygen index of 37.2%, UL94 V-0 grade, a heat release rate peak value decreased by 57% compared with that before modification, and an impact strength increased by 39% compared with that before modification.

[0028] Example 4

[0029] Polycarbonate (92.3 parts by mass), phosphaphenanthrene / siloxane dibasic macromolecular flame retardant (phosphaphenanthrene / cyclotetrasiloxane group number ratio of 1.65:1, average molecular weight of 10470, 7 parts by mass), anti-dripping agent (0.3 parts by mass), antioxidant (1010, 0.2 parts by mass; 626, 0.2 parts by mass) are uniformly mixed, melted, mixed and extruded by a twin-screw extruder, granulated and dried to obtain pellets, and then the pellets are injection-molded by an injection molding machine to obtain a phosphaphenanthrene / siloxane dibasic macromolecular flame retardant toughened polycarbonate material with a limiting oxygen index of 36.2%, UL94 V-0 grade, a heat release rate peak value decreased by 46% compared with that before modification, and an impact strength increased by 38% compared with that before modification.

[0030] Example 5

[0031] Polycarbonate (87.4 parts by mass), phosphaphenanthrene / siloxane dibasic macromolecular flame retardant (phosphaphenanthrene / cyclotetrasiloxane group number ratio 2.36:1, average molecular weight 13640, 12 parts by mass), anti-dripping agent (0.3 parts by mass), antioxidant (1010, 0.2 parts by mass; 168, 0.1 parts by mass) are uniformly mixed, melted, mixed and extruded by a twin-screw extruder, granulated and dried to obtain pellets, and then the pellets are injection molded by an injection molding machine to obtain a phosphaphenanthrene / siloxane dibasic macromolecular flame retardant toughened polycarbonate material with a limiting oxygen index of 37.1%, UL94 V-0 grade, a heat release rate peak value decreased by 52% compared with that before modification, and an impact strength increased by 41% compared with that before modification.

[0032] The present invention adds a phosphaphenanthrene / siloxane dual-base macromolecular flame retardant to polycarbonate. Compared with low molecular weight tetraphosphaphenanthrene tetramethylcyclotetrasiloxane which has a similar structure and can also improve the flame retardancy of the polymer, the macromolecular flame retardant of the present invention can more efficiently improve the flame retardancy of the polycarbonate, and at the same time can well maintain or even significantly improve the mechanical properties of the material in some aspects. Although the low molecular weight tetraphosphaphenanthrene tetramethylcyclotetrasiloxane improves the flame retardancy of the polycarbonate material, it will significantly deteriorate the toughness of the material and reduce the overall mechanical properties of the material. The performance comparison between the two is shown in Table 1.

[0033] Table 1 Comparison of the application effects of phosphaphenanthrene / siloxane dibasic macromolecules and low molecular weight tetraphosphaphenanthrene tetramethylcyclotetrasiloxane as single variable factors in polycarbonate materials

[0034]

Claims

1. A phosphaphenanthrene / siloxane dibasic macromolecular flame retardant toughened polycarbonate material, characterized in that: The flame retardant toughened polycarbonate material comprises the following components in parts by weight: 80-99 parts by weight of polycarbonate (PC), 1-20 parts by weight of a phosphaphenanthrene / siloxane dibasic macromolecular flame retardant, 0-1 parts by weight of an anti-dripping agent, 0-1 parts by weight of an antioxidant, and 0-10 parts by weight of other additives; The average molecular weight of the phosphaphenanthrene / siloxane dibasic macromolecular flame retardant is 3000-20000; the number ratio of phosphaphenanthrene to cyclotetrasiloxane groups in the phosphaphenanthrene / siloxane dibasic macromolecular flame retardant is 1:1-3:1; the chemical structure formula of the phosphaphenanthrene / siloxane dibasic macromolecular flame retardant is as follows: The degrees of polymerization x, y, z, u, v and w in the general chemical structure formula cannot all be 0 at the same time.

2. The phosphaphenanthrene / siloxane dibasic macromolecular flame retardant toughened polycarbonate material according to claim 1, characterized in that: The anti-drip agent is a fluorine-containing polymer, which includes a fibrillated or non-fibrillated fluorine-containing polymer.

3. The phosphaphenanthrene / siloxane dibasic macromolecular flame retardant toughened polycarbonate material according to claim 1, characterized in that: The antioxidant is a combination of one or more of hindered phenol antioxidants, aromatic amine antioxidants and phosphite antioxidants.

4. A method for preparing a phosphaphenanthrene / siloxane dibasic macromolecular flame retardant toughened polycarbonate material according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: mixing polycarbonate, phosphaphenanthrene / siloxane dibasic macromolecular flame retardant, anti-dripping agent, antioxidant and other additives, melt extruding and granulating to obtain the phosphaphenanthrene / siloxane dibasic macromolecular flame retardant toughened polycarbonate material.

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