A needle flame resistant polycarbonate alloy material and a preparation method thereof

Abstract

The application discloses a kind of needle flame resistant flame-retardant polycarbonate alloy material and preparation method thereof, belong to polymer material technical field.The alloy material includes the following weight parts of component: polycarbonate resin 65-87 parts, ABS resin 3-15 parts, polymeric flame retardant with phosphorus-silicon-sulfonate structure 3-12 parts, toughening agent 0-3 parts, antioxidant 0.2-0.5 parts, lubricant 0.1-0.4 parts.The application introduces polymeric flame retardant with intramolecular synergistic flame-retardant effect, significantly improves the thin-wall flame-retardant performance and needle flame burning resistance of PC / ABS alloy, can make 1.5mm thickness material reach UL94 V-0 level, needle flame resistance time is more than 50 seconds, while maintaining good mechanical properties and flame-retardant durability, and does not contain PFAS substance, environmental protection is good, preparation process is simple, suitable for industrial production, can be widely applied in electronic appliances, automobile parts and other fields.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a needle flame resistant flame-retardant polycarbonate alloy material and its preparation method. Background Technology

[0002] PC / ABS alloy, as an engineering plastic with excellent comprehensive performance, successfully combines the high heat resistance and high mechanical strength of PC resin with the excellent processing fluidity and cost advantages of ABS resin. Therefore, it has been widely used in fields with extremely high requirements for material performance and safety, such as automotive and electronics. However, as products in these fields tend to be thinner and smaller, stringent requirements have been placed on the ability of materials to simultaneously meet the UL 94 V-0 flame retardant rating and withstand a 60-second needle flame test at a thickness of 1.5mm or even less. This has become the core technological bottleneck currently facing the development of PC / ABS alloy.

[0003] To address this challenge, existing technologies primarily focus on halogen-free phosphate esters and silicon-based flame retardant systems. For example, patent ZL202310773171.7 discloses a flame-retardant polycarbonate composition that incorporates multiple components, including polyborosiloxane, hexaphenoxycyclotriphosphazene, functionalized POSS, and DOPO flame retardant. This approach balances flame retardancy and mechanical properties through complex component combinations. Patent ZL202210484808.6 synthesizes hexachlorocyclotriphosphazene from hexachlorocyclotriphosphazene and 2-naphthol, then reacts it with octavinyl POSS to prepare a phosphorus-nitrogen-silicon synergistic flame retardant. This approach avoids the defects of physical blending through chemical bonding, while utilizing the cage-like structure of POSS to enhance the thermal stability of the char layer.

[0004] However, existing flame retardant technologies still have significant shortcomings in meeting the dual requirements of thin-walled PC / ABS materials for V-0 and 60-second needle flame testing. The technical solution of patent ZL202310773171.7 is essentially a simple mixture of multiple molecules. The components have poor compatibility with the PC / ABS matrix, and are prone to migration and precipitation during long-term use, leading to a decline in flame retardant performance and severe deterioration of the material's mechanical properties. More importantly, these physically blended components act asynchronously during combustion, resulting in low synergistic efficiency and an inability to quickly form a protective char layer with both strength and density in the early stages of a fire. Patent ZL202210484808.6 achieves thin-walled needle flame retardancy by synthesizing a POSS-based flame retardant containing phosphorus, nitrogen, and silicon, but its synthesis route is complex and costly. In summary, existing technologies all rely on the physical blending or complex synthesis of multiple components, resulting in poor compatibility between the components and asynchronous action during combustion, failing to construct a stable and synergistic flame retardant system within the material. As a result, the materials either struggle to form the high-strength protective char layer required for needle flame testing, or they lose long-term flame-retardant stability due to additive migration, failing to simultaneously meet the requirements of lightweight and high safety. Summary of the Invention

[0005] The primary objective of this invention is to provide a needle flame retardant PC / ABS material that overcomes the shortcomings of existing technologies, such as poor compatibility of flame retardants, insufficient flame retardant duration, and difficulty in simultaneously achieving thin-walled flame retardancy and resistance to prolonged burning.

[0006] Another objective of this invention is to provide a method for preparing needle flame retardant PC / ABS material, which is simple and suitable for industrial production.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A needle-flame resistant flame-retardant polycarbonate alloy material, comprising the following components in parts by weight: 65-87 parts of polycarbonate resin; 3-15 parts of ABS resin; 3-12 parts of a polymeric flame retardant containing a phosphorus-silicon-sulfonate structure; 0-3 parts toughening agent; Antioxidant 0.2-0.5 parts; Lubricant 0.1-0.4 parts.

[0008] Preferably, the polycarbonate resin has a melt index of 8-12 g / 10min and the test conditions are 300℃ and 1.2kg.

[0009] Preferably, the melt index of the ABS resin is 18-20 g / 10min, and the test conditions are 220℃ and 10kg.

[0010] Preferably, the toughening agent is MBS resin.

[0011] Preferably, the antioxidant is B900 from BASF, Germany.

[0012] Preferably, the lubricant is Italian PETS-AHS.

[0013] In a key preferred embodiment of the present invention, the phosphorus-silicon-sulfonate ester-containing polymeric flame retardant is a polymeric flame retardant formed by chemically bonding phosphorus, sulfur, and silicon, three flame-retardant elements, onto the same polymer molecular chain. Its unique molecular structure is key to achieving a highly efficient intramolecular synergistic flame-retardant effect.

[0014] Furthermore, the polymeric flame retardant containing a phosphorus-silicon-sulfonate structure is prepared by a method comprising the following steps: First, a central intermediate containing phosphorus and sulfonate structures is constructed by acyl chlorination of phosphorus oxychloride and p-hydroxybenzene sulfonate. Secondly, the central intermediate is subjected to an etherification reaction with a vinyl phenolic compound (such as eugenol) to introduce polymerizable terminal vinyl groups, thereby obtaining a polymerizable monomer; Finally, the polymerizable monomer is grafted onto the hydrogen-terminated phenyl polysiloxane chain via a hydrosilylation reaction to obtain the polymeric flame retardant containing the phosphorus-silicon-sulfonate structure. Its molecular structure diagram is shown below: .

[0015] The present invention also provides a method for preparing the needle-flame resistant flame-retardant polycarbonate alloy material as described above, comprising the following steps: (1) Dry the polycarbonate resin and ABS resin separately until the moisture content is less than 0.025%; (2) Weigh the dried polycarbonate resin, ABS resin, polymeric flame retardant containing phosphorus-silicon-sulfonate structure, toughening agent, antioxidant and lubricant according to the weight parts, mix them evenly to obtain a premix; (3) The premix is ​​added to a twin-screw extruder for melt blending and extrusion granulation to obtain a needle flame retardant polycarbonate alloy material.

[0016] Preferably, in step (1), the drying temperature of the polycarbonate resin is 120-130°C, and the drying temperature of the ABS resin is 60-80°C.

[0017] Preferably, in step (3), the processing temperature of the twin-screw extruder is 230-270℃ and the screw speed is 250-300 RPM.

[0018] This invention effectively improves the flame retardancy and anti-melt dripping properties of PC / ABS materials by adding a polymeric flame retardant with a phosphorus-silicon-sulfonate structure. This polymeric flame retardant integrates phosphorus, sulfur, and silicon—three flame-retardant elements—onto a single molecular chain through chemical bonding. During combustion, it exerts a synergistic flame-retardant effect at the molecular level, rapidly forming a dense and high-strength protective char layer, thereby significantly improving the thin-wall flame retardancy (1.5mm UL94 V-0) and needle flame resistance (>50 seconds). Simultaneously, utilizing the compatibility of the phenyl group in the polymeric flame retardant with PC, and due to the significantly increased molecular weight of the flame-retardant component, it effectively solves the problem of insufficient flame-retardant aging time caused by small molecule migration, achieving a high property retention rate for needle flame-retardant PC / ABS materials. In addition, this flame-retardant PC / ABS material does not contain PFAS substances and complies with the EU's (EU) 2021 / 1297 ban on PFAS. It can be widely used in the production of mobile phones, TV LCD displays, polycarbonate sheets, photovoltaic panels, automotive instrument display housings, home appliances, and communication electronic components.

[0019] The beneficial effects of the present invention are: 1. By using a polymeric flame retardant with a phosphorus-silicon-sulfonate structure and combining it with a PC / ABS matrix in a specific ratio, the present invention can enable the material to pass the UL94 V-0 rating with a thickness of 1.5mm and withstand the needle flame test for more than 50 seconds with an addition amount of 3-12 parts, effectively balancing the requirements of thin-wall flame retardancy and long-term burning resistance. 2. Due to the good compatibility between the polymeric flame retardant and the PC / ABS matrix, the material of this invention maintains good mechanical properties while achieving excellent flame retardant performance. As shown in the examples, its impact strength can be maintained above 60 KJ / m², achieving a good balance between flame retardancy and mechanical properties; 3. The preparation method of the present invention is simple, mild, and has high production efficiency, making it suitable for large-scale industrial production. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the molecular structure of the polymeric flame retardant containing a phosphorus-silicon-sulfonate structure according to the present invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Specific implementation examples are given below.

[0023] The technical solution of the present invention will be described in detail below with reference to specific embodiments. These embodiments are only used to explain the present invention and do not constitute any limitation on the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0024] Unless otherwise specified, the raw materials used in the embodiments of the present invention are all commercially available or prepared by known methods.

[0025] Example 1: Preparation of Polymerized Flame Retardants First, ethyl p-hydroxybenzenesulfonate and phosphorus oxychloride were reacted with an acyl chloride at 0-5°C in the presence of an acid-binding agent to construct an intermediate containing phosphorus-sulfur bonds. Then, it was vinylized with eugenol at about 30°C in the presence of an acid-binding agent and a polymerization inhibitor. Finally, it was grafted with terminal hydrogen phenyl polysiloxane at 75°C under platinum catalyst catalysis through a hydrosilylation reaction to obtain the polymeric flame retardant containing the phosphorus-silicon-sulfonate structure.

[0026] Examples 2-5 and Comparative Example 1 Weigh each raw material according to the weight proportions shown in Table 1. Dry the PC and ABS resins at 120-130℃ and 60-80℃ respectively until the moisture content is below 0.025%. Place the dried PC resin, ABS resin, self-made polymeric flame retardant, toughening agent MBS, antioxidant B900, and lubricant PETS-AHS in a mixer and stir for 5-10 minutes to obtain a mixture. Feed the mixture into a twin-screw extruder with an aspect ratio of 40, melt-blend at 230-270℃, and screw speed at 250-300 RPM, then extrude and granulate to obtain granules. Injection mold the granules into standard test specimens for performance testing.

[0027] Table 1: Raw material ratios (parts by weight) for each scheme

[0028] Performance testing: The performance of the materials obtained in each embodiment and comparative example was tested, and the test results are shown in Table 2.

[0029] Melt flow index: Tested according to ISO 1133 standard.

[0030] Tensile strength: tested according to ISO 527 standard.

[0031] Bending strength: tested according to ISO 178 standard.

[0032] Notched impact strength: tested according to ISO 179 standard.

[0033] Flammability: Tested according to UL94 standard on a 1.5mm thick sample.

[0034] Needle flame test: The test was conducted on a 1.5 mm thick sample according to IEC 60695-2-2 standard, and the endurance time was recorded.

[0035] Table 2: Performance Test Results

[0036] Results analysis: The test results in Table 2 show that: Flame retardant performance: Comparative Example 1, without the addition of the polymeric flame retardant of this invention, only achieved a V-2 rating on its 1.5mm sample, and its needle flame resistance time was only 13 seconds, far below the requirements. In contrast, Examples 2-4, with the addition of the polymeric flame retardant of this invention, all achieved a UL94 V-0 rating at a thickness of 1.5mm, and their needle flame resistance times all exceeded 50 seconds. Examples 3 and 4 reached 86 seconds and 97 seconds respectively, demonstrating extremely excellent thin-walled flame retardant and needle flame resistance performance.

[0037] Mechanical properties: Compared with Comparative Example 1, Examples 2-4, which added the flame retardant of the present invention, maintained relatively stable tensile strength and flexural strength. Although the notched impact strength fluctuated, it remained within the range of [missing information]. The above demonstrates that the polymeric flame retardant of this invention has good compatibility with the PC / ABS matrix, and while imparting excellent flame retardancy to the material, it does not seriously degrade its mechanical properties.

[0038] Formulation optimization: As the amount of flame retardant added increased (from 4 parts to 8 parts), the needle flame resistance time of the material significantly improved, indicating that the flame retardant efficiency increased with increasing addition amount. When the addition amount was 6 parts (Example 3), the material exhibited the best impact strength. With excellent flame retardant properties, it is a well-balanced and preferred formulation.

[0039] In summary, the needle-flame resistant polycarbonate alloy material provided by this invention successfully solves the technical problem in the prior art that thin-walled products cannot simultaneously achieve the UL94 V-0 flame retardant rating and long-term needle-flame resistance by introducing a phosphorus-silicon-sulfonate polymeric flame retardant with a specific structure into the PC / ABS matrix. At the same time, it maintains good mechanical properties and long-term flame retardant stability, and the preparation process is simple, which has high industrial application value.

[0040] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A needle-flame resistant flame-retardant polycarbonate alloy material, characterized in that, The components include the following parts by weight: 65-87 parts of polycarbonate resin; 3-15 parts of ABS resin; 3-12 parts of a polymeric flame retardant containing a phosphorus-silicon-sulfonate structure; 0-3 parts toughening agent; Antioxidant 0.2-0.5 parts; Lubricant 0.1-0.4 parts.

2. The needle-flame resistant flame-retardant polycarbonate alloy material according to claim 1, characterized in that, The polycarbonate resin has a melt index of 8-12 g / 10min, and the test conditions are 300℃ and 1.2kg; the ABS resin has a melt index of 18-20 g / 10min, and the test conditions are 220℃ and 10kg.

3. The needle-flame resistant flame-retardant polycarbonate alloy material according to claim 1, characterized in that, The phosphorus-silicon-sulfonate ester-containing polymeric flame retardant is a polymeric flame retardant formed by integrating three flame retardant elements, phosphorus, sulfur, and silicon, through chemical bonds onto the same polymer molecular chain.

4. The needle-flame resistant flame-retardant polycarbonate alloy material according to claim 3, characterized in that, The polymeric flame retardant containing a phosphorus-silicon-sulfonate structure is prepared by a method comprising the following steps: First, a central intermediate containing phosphorus and sulfonate structures is constructed by acyl chlorination of phosphorus oxychloride and p-hydroxybenzene sulfonate. Secondly, the central intermediate is subjected to an etherification reaction with a vinyl phenolic compound to introduce polymerizable terminal vinyl groups, thereby obtaining a polymerizable monomer; Finally, the polymerizable monomer is grafted onto the terminal hydrogen phenyl polysiloxane chain via a hydrosilylation reaction to obtain the polymeric flame retardant containing the phosphorus-silicon-sulfonate structure.

5. The needle-flame resistant flame-retardant polycarbonate alloy material according to claim 1, characterized in that, The toughening agent is MBS resin; the antioxidant is BASF B900 or a mixture of hindered phenolic / phosphite antioxidants with equivalent function; the lubricant is Italian Falgi PETS-AHS or a pentaerythritol stearate lubricant with equivalent function.

6. A method for preparing the needle-flame resistant flame-retardant polycarbonate alloy material as described in any one of claims 1-5, characterized in that, Includes the following steps: (1) Dry the polycarbonate resin and ABS resin separately until the moisture content is less than 0.025%; (2) Weigh the dried polycarbonate resin, ABS resin, polymeric flame retardant containing phosphorus-silicon-sulfonate structure, toughening agent, antioxidant and lubricant according to the weight parts, mix them evenly to obtain a premix; (3) The premix is ​​added to a twin-screw extruder for melt blending and extrusion granulation to obtain a needle flame retardant polycarbonate alloy material.

7. The preparation method according to claim 6, characterized in that, In step (1), the drying temperature of the polycarbonate resin is 120-130℃, and the drying temperature of the ABS resin is 60-80℃.

8. The preparation method according to claim 6, characterized in that, In step (3), the processing temperature of the twin-screw extruder is 230-270℃ and the screw speed is 250-300 RPM.

9. The application of the needle-flame resistant flame-retardant polycarbonate alloy material according to any one of claims 1-5 in the preparation of electronic and electrical components, automotive instrument display housings, household appliance housings, or photovoltaic modules.

10. The application according to claim 9, characterized in that, The application includes the preparation of thin-walled parts with a thickness of 1.5 mm or less, which meet the UL94 V-0 flame retardancy rating and withstand needle flame test for no less than 50 seconds.

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