A flame-retardant polycarbonate composition, and a method for preparing and using the same

Abstract

The application belongs to the field of plastic materials, and specifically discloses a flame-retardant polycarbonate composition, a preparation method and application thereof.The flame-retardant polycarbonate composition comprises the following components in parts by weight: polycarbonate 89-101, phenylsiloxane 0.4-5.5 parts, core-shell structure elastomer 0.4-1 part, sulfonate flame retardant 0.05-0.2 parts, inhibitor 0.05-0.2 parts, anti-dripping agent 0.1-1.1 parts, and processing aid 0-3.1 parts.The core-shell structure elastomer and the inhibitor can improve the appearance of the material and eliminate defects such as material flowers, and the sulfonate flame retardant and the phenylsiloxane can play a good synergistic effect to improve the flame-retardant performance.In addition, the sulfonate flame retardant in the system has a small influence on the heat resistance of the polycarbonate, so the composition can still maintain high heat resistance, and under the comprehensive action, the flame-retardant polycarbonate composition has the advantages of good appearance, high heat resistance and high flame retardance.

Description

Technical Field

[0001] This invention belongs to the field of plastics, specifically relating to a flame-retardant polycarbonate composition, its preparation method, and its application. Background Technology

[0002] Polycarbonate possesses excellent properties such as high strength, high toughness, high heat resistance, good dimensional stability, and electrical insulation, and has been widely used in home appliances, medical devices, and electronic and electrical fields. In particular, when polycarbonate is used in electronic and electrical fields, it is usually required to have good halogen-free flame retardancy, heat resistance, and a good appearance to meet people's high-quality requirements for new electronic and electrical products.

[0003] In existing technologies, aromatic phosphate flame retardants or sulfonate flame retardants are added to meet the halogen-free flame retardancy requirements of polycarbonate. However, aromatic phosphate flame retardants significantly affect the heat resistance of polycarbonate, preventing it from meeting the required heat resistance. Although adding a small amount of sulfonate flame retardant to the system has little impact on the heat resistance of polycarbonate, and the material can achieve good heat resistance, the dosage of sulfonate flame retardants is low, making it difficult to stably achieve flame retardant performance for thin-walled materials (e.g., samples with a thickness of 1.6 mm). Furthermore, the characteristic of sulfonate flame retardants to catalyze the degradation of polycarbonate into char makes it extremely prone to material defects during processing, resulting in poor appearance of the manufactured parts.

[0004] Therefore, further research and improvement of polycarbonate compositions are still needed to obtain halogen-free flame-retardant polycarbonate products that simultaneously meet the requirements of good appearance and high heat resistance. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing polycarbonate materials in achieving both good appearance and high heat resistance with halogen-free flame retardancy. This invention will provide a flame-retardant polycarbonate composition, its preparation method, and its application.

[0006] To achieve the above objectives, the following technical solutions are specifically included:

[0007] On one hand, the present invention provides a flame-retardant polycarbonate composition comprising the following components in parts by weight: polycarbonate 89-101, containing 0.4-5.5 parts of phenylsiloxane, 0.4-1 parts of core-shell elastomer, 0.05-0.2 parts of sulfonate flame retardant, 0.05-0.2 parts of inhibitor, 0.1-1.1 parts of anti-dripping agent, and 0-3.1 parts of processing aid; wherein the inhibitor comprises at least one of lactone-type carbon free radical scavenger and bisphenol monoacrylate antioxidant.

[0008] In the flame-retardant polycarbonate composition of the present invention, the core-shell elastomer can inhibit the catalytic degradation effect of sulfonate flame retardants on polycarbonate during processing. Simultaneously, the inhibitor can suppress the catalytic degradation effect of sulfonate flame retardants on the core-shell elastomer and the self-crosslinking effect of the core-shell elastomer during preparation. Therefore, the flame-retardant polycarbonate composition effectively improves the appearance of the manufactured parts while maintaining its flame-retardant properties. Furthermore, the phenylsiloxane in the system, as a silicon-based flame retardant, exerts a good synergistic flame-retardant effect with the sulfonate flame retardant, avoiding the flame-retardant degradation effect of the core-shell elastomer on the material, thus ensuring good flame-retardant performance. In addition, because the core-shell elastomer can inhibit the catalytic degradation effect of sulfonate flame retardants on polycarbonate during processing, it has less impact on the heat resistance of polycarbonate and is halogen-free, making it more environmentally friendly. Therefore, the composition can still maintain high heat resistance. Under the combined effect, the flame-retardant polycarbonate composition can simultaneously achieve good appearance, high heat resistance, and high flame retardancy.

[0009] Preferably, the flame-retardant polycarbonate composition comprises the following components in parts by weight: 90-100 parts polycarbonate, 0.5-5 parts containing phenylsiloxane, 0.5-0.9 parts core-shell elastomer, 0.07-0.17 parts sulfonate flame retardant, 0.07-0.17 parts inhibitor, 0.2-1 parts anti-dripping agent, and 0-3 parts processing aid. Preferably, the polycarbonate (PC) in the flame-retardant polycarbonate composition has a mass percentage content of not less than 70%, more preferably not less than 80%, and even more preferably not less than 90%.

[0010] Preferably, the system of the present invention does not limit the type of polycarbonate. The polycarbonate is preferably bisphenol A type polycarbonate. Commercially available conventional polycarbonate or self-made polycarbonate can be used, such as polycarbonate with a melt flow rate of 1-60 g / 10 min. The melt flow rate is tested according to ISO 1133-1 2011 standard, and the test conditions are 300°C and 1.2 kg. More specifically, the melt flow rate of the polycarbonate can be 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60 g / 10 min, etc., as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0011] Preferably, the core-shell elastomer includes at least one of MBS (methyl methacrylate-butadiene-styrene terpolymer) and ABS.

[0012] ABS is an acrylonitrile-butadiene-styrene terpolymer. ABS includes resin-grade ABS and high-resin ABS powder. In resin-grade ABS, the contents of acrylonitrile, butadiene, and styrene are 25%-30%, 20%-35%, and 40%-50%, respectively. In high-resin ABS powder, the butadiene content is between 60% and 80%.

[0013] More preferably, the rubber content of the MBS is 50%-70%.

[0014] More preferably, the ABS used in the resin has a rubber content of 20%-35%.

[0015] More preferably, the rubber content of the ABS is 55%-80%.

[0016] Preferably, the sulfonate flame retardant includes at least one of potassium perfluorobutyl sulfonate and potassium benzenesulfonylbenzenesulfonate.

[0017] Preferably, the chemical structural formula of the lactone-type carbon free radical scavenger is shown in Formula I or Formula II below:

[0018]

[0019] In Formula I, R1, R2, R3 and R4 may be the same or different, representing hydrogen atoms or straight-chain or branched alkyl groups having 1 to 8 carbon atoms; R5, R6, R8 and R9 may be the same or different, representing hydrogen atoms or alkyl groups having 1 to 6 carbon atoms; R7 represents hydrogen atoms or hydroxyl groups; and n is an integer of 0, 1, 2 or 2.

[0020]

[0021] In Formula II, R1, R2, R3 and R4 may be the same or different, representing hydrogen atoms or straight-chain or branched alkyl groups having 1 to 8 carbon atoms.

[0022] More preferably, the lactone-type carbon radical scavenger includes

[0023]

[0024] Preferably, the chemical structural formula of the bisphenol monoacrylate antioxidant is as follows:

[0025]

[0026] In Formula III, R1, R2, R3, R4 and R5 may be the same or different, representing hydrogen atoms or straight-chain or branched alkyl groups having 1 to 8 carbon atoms.

[0027] More preferably, the bisphenol monoacrylate antioxidant includes

[0028]

[0029] Preferably, the mass ratio of the core-shell elastomer, sulfonate flame retardant, and inhibitor is 1:(0.09-0.22):(0.09-0.22). More preferably, the mass ratio of the core-shell elastomer, sulfonate flame retardant, and inhibitor is 1:(0.09-0.16):(0.16-0.20). Specifically, it can be 1:0.09:0.09, 1:0.09:0.15, 1:0.09:0.22, 1:0.15:0.09, 1:0.22:0.15, 1:0.22:0.22, etc., as well as the specific values ​​between the above values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific values ​​included in the range.

[0030] Preferably, the phenylsiloxane includes at least one of polyaminopropylphenylsilsesquioxane, phenylsilsesquioxane, and polyphenylmethylsiloxane.

[0031] Preferably, the number-average molecular weight of the phenylsiloxane is 400-30000 g / mol.

[0032] Compared to phenyl-free siloxanes, phenyl-containing siloxanes have better compatibility with the system, can further improve appearance defects, and have better flame retardant properties. The phenyl-containing siloxanes in the above range can achieve better flame retardant and improved appearance effects.

[0033] Preferably, the anti-dripping agent comprises polytetrafluoroethylene.

[0034] Preferably, the processing aid comprises the following components in parts by weight: 0.1-1.5 parts antioxidant and 0.1-1.5 parts lubricant.

[0035] More preferably, the antioxidant is a hindered phenolic antioxidant.

[0036] On the other hand, the present invention provides a method for preparing the flame-retardant polycarbonate composition, comprising the following steps: mixing, melting, extruding and granulating the raw materials in sequence to obtain the flame-retardant polycarbonate composition.

[0037] Preferably, the melting temperature is 210–250°C.

[0038] Preferably, the rotation speed during melting is 200 to 600 revolutions per minute.

[0039] The present invention also provides the application of the flame-retardant polycarbonate composition described above in the preparation of electronic and electrical equipment such as charger housings and power bank housings.

[0040] Compared with existing technologies, the present invention has the following beneficial effects: The flame-retardant polycarbonate composition of the present invention can improve the appearance defects of the material, and at the same time, it exerts a good flame-retardant synergistic effect with phenylsiloxane-containing compounds, thereby improving the flame-retardant performance. In addition, the sulfonate flame retardant in the flame-retardant polycarbonate composition has little impact on the heat resistance of polycarbonate, so the composition can still maintain high heat resistance. Under the combined effect, the flame-retardant polycarbonate composition simultaneously possesses the advantages of good appearance, high heat resistance, and high flame retardancy. Detailed Implementation

[0041] To better illustrate the purpose, technical solution, and advantages of this invention, specific embodiments will be used to further explain the invention below. Unless otherwise specified, the experimental methods used in the embodiments and / or comparative examples are conventional methods; the materials and reagents used, unless otherwise specified, are commercially available. Unless otherwise specified, the raw materials used in each embodiment and comparative example of this invention are the same in each parallel experiment.

[0042] Raw material information involved in the following examples and comparative examples:

[0043] PC resin: PC 1300 10NP, LG Chem Ltd., South Korea;

[0044] Sulfonate flame retardant: Potassium perfluorobutyl sulfonate, FR-2025, 3M, USA;

[0045] Core-shell elastomer 1: MBS, M-521, Kanekachi, Japan;

[0046] Core-shell elastomer 2: ABS resin, ABS275, Takahashi Petrochemical;

[0047] Core-shell elastomer 3: ABS high-polymer powder, HR181, Kumho Chemical Co., Ltd., South Korea;

[0048] Core-shell elastomers: Elvaloy resins PTW, DuPont;

[0049] Inhibitor 1: Revonox 501, CAS: 1261240-30-5, lactone-type carbon radical scavenger, Chi-Ti Chemical Co., Ltd., Taiwan, China;

[0050] Inhibitor 2: GS, CAS:123968-25-2, Bisphenol A Monoacrylate Antioxidant, Qingdao Jiedejia;

[0051] Inhibitor 3: HP136, CAS: 181314-48-7, lactone-type carbon radical scavenger, BASF;

[0052] Hydroxylamine carbon radical scavenger: Revonox 420, Chi-Ti Chemical Co., Ltd., Taiwan, China;

[0053] 1. Contains phenylsiloxane: Polyphenylmethylsiloxane, CAS No. 63148-52-7, Sigma-Aldrich;

[0054] 2: Octaphenylsilsesquioxane containing phenylsiloxane, CAS No. 5256-79-1, Sigma-Aldrich;

[0055] Phenyl-free siloxanes: Polydimethylsiloxane (phenyl-free), CAS No. 9016-00-6, Sigma-Aldrich;

[0056] Anti-dripping agent: polytetrafluoroethylene, A3800, Mitsubishi Rayon;

[0057] Antioxidant: Hindered phenolic antioxidant, Antioxidant 1010, Sanfeng Chemical Co., Ltd.

[0058] Examples 1-13 and Comparative Examples 1-8

[0059] A method for preparing a flame-retardant polycarbonate composition includes the following steps:

[0060] (1) According to the amount of raw material components in Tables 1 and 2, each component is stirred and mixed in a high-speed mixer to obtain a premix;

[0061] (2) The premixed material is fed into a twin-screw extruder through the main feed port, melt-mixed and extruded and granulated in the twin-screw extruder to obtain the flame-retardant polycarbonate composition, wherein the screw length-to-diameter ratio is 45:1, the screw barrel temperature is 210-250℃, and the screw speed is 550rpm.

[0062] The test methods for various properties of the flame-retardant polycarbonate compositions of the present invention in the embodiments and comparative examples are as follows:

[0063] (1) Flame retardancy rating: Flame retardancy testing was conducted according to the procedure "Flammability Testing of Plastic Materials, UL94-2019". The flame retardancy rating was determined based on the burning rate, extinguishing time, resistance to dripping, and whether the dripping material was burning. The sample used for testing was 125mm long and 13mm wide. In this invention, the thickness was selected as 1.6mm during testing. According to the UL94-2019 procedure, the flame retardancy rating of materials can be classified as UL94 V0, V1, V2, etc.; a flame retardancy rating of V-1 or higher is considered qualified.

[0064] (2) Ball pressing temperature: The granules of the above examples and comparative examples were injection molded into round samples with a thickness of 4 mm and a diameter of 40 mm. The indentation diameter was tested at 125℃ ball pressing temperature according to the IEC60695-10-2 standard method. If the indentation diameter was ≤2 mm, it was determined to pass the 125℃ ball pressing temperature test. If the indentation diameter was >2 mm, it was determined to fail.

[0065] (3) Appearance evaluation: The granules of the above examples and comparative examples were injection molded into samples and held at 300℃ for 5 minutes. Then, they were injection molded into samples of 80*20*4mm. The surface of the samples was then observed. The proportion of the surface area of ​​the material defects to the surface area of ​​the sample was X. The material defects were recorded as excellent (X=0%), good (X≤5%), qualified (5%<X≤15%) and unqualified (X>15%) according to the size of the material defects. The test results are shown in Table 3.

[0066] Table 1 Flame-retardant polycarbonate compositions (parts by weight)

[0067]

[0068]

[0069] Table 2 Flame-retardant polycarbonate compositions (parts by weight)

[0070]

[0071] Table 3

[0072]

[0073]

[0074] As can be seen from the above embodiments, the flame-retardant polycarbonate composition of the present invention, with a thickness of 1.6 mm, has a flame retardant rating of V-1 or higher, a ball pressure test diameter of less than 2 mm at 125°C, and a qualified appearance, exhibiting excellent flame retardancy, heat resistance, and appearance.

[0075] In Comparative Example 1, only a high content of pure sulfonate flame retardant was added without the addition of inhibitors and core-shell elastomers to achieve superior flame retardant performance. However, because the flame retardant had a certain impact on the heat resistance of PC and catalyzed the degradation of PC, the heat resistance and appearance were poor. In Comparative Example 2, the addition of excessive amounts of sulfonate flame retardant, inhibitors, and core-shell elastomers, although the flame retardant content was sufficient, the excessive amount of core-shell elastomers in the system was detrimental to flame retardancy, leading to a decrease in flame retardant performance. Furthermore, the excessive amount of flame retardant in the system catalyzed the degradation of the sulfonate flame retardant. The high degree of degradation results in poor appearance performance; the lack of inhibitor in Comparative Example 5 makes it impossible to suppress the catalytic degradation effect and the self-crosslinking effect of the core-shell elastomer, resulting in poor appearance performance; the lack of core-shell elastomer in Comparative Example 6 makes it impossible to suppress the catalytic degradation effect of sulfonate flame retardant on polycarbonate during processing, resulting in poor appearance performance; as can be seen from Example 1 and Comparative Examples 1-2 and 5-6, adding a certain amount of sulfonate flame retardant, inhibitor and core-shell elastomer to PC can make the polycarbonate composition have the characteristics of high heat resistance, high flame retardancy and good appearance.

[0076] As can be seen from Examples 1-2 and Comparative Examples 7-8, Comparative Example 7 does not contain phenyl siloxane, and Comparative Example 8 does not contain phenyl siloxane. The flame retardant properties and appearance properties of Comparative Examples 7-8 deteriorate. Phenyl siloxane can further improve the flame retardant properties and appearance defects.

[0077] In Examples 1 and 5-7, the total weight parts of the core-shell elastomer, sulfonate flame retardant, and inhibitor were the same. However, the weight ratios of the core-shell elastomer, sulfonate flame retardant, and inhibitor were (1:0.16:0.16), (1:0.09:0.22), (1:0.12:0.20), and (1:0.22:0.09), respectively. As the content of sulfonate flame retardant increased, the content of inhibitor decreased, resulting in improved flame retardant performance and decreased appearance performance. When the weight ratio of the core-shell elastomer, sulfonate flame retardant, and inhibitor was maintained in the range of 1:(0.09-0.22):(0.09-0.22), the flame retardant and appearance performance of the material were excellent. Further preferred, the weight ratio of the core-shell elastomer, sulfonate flame retardant, and inhibitor was 1:(0.09-0.16):(0.16-0.20), resulting in even better flame retardant and appearance performance of the material.

[0078] In Examples 8, 1, and 9, the weight ratio of sulfonate flame retardant to inhibitor was 1:1, but the total weights of the two were 0.14 parts, 0.24 parts, and 0.3 parts, respectively. It can be observed that as the content of sulfonate flame retardant in the system increases, the flame retardant performance shows an upward trend, while the appearance performance shows a downward trend. Therefore, it is more appropriate to maintain the weight of sulfonate flame retardant or inhibitor in the system at 0.07-0.17, so that both flame retardant performance and appearance performance are good at the same time.

[0079] In Examples 1 and 10-11, the inhibitors were a lactone-type carbon radical scavenger and a bisphenol monoacrylate antioxidant, respectively, exhibiting excellent flame retardant and appearance effects. Comparative Example 5, without the addition of an inhibitor, showed poor flame retardant and appearance performance. In Comparative Example 3, a hydroxylamine carbon radical scavenger was used to replace an equal amount of the inhibitor, resulting in poor appearance performance. It is evident that the present invention selects specific types of inhibitors to suppress the catalytic degradation effect of sulfonate flame retardants on the core-shell elastomer and the self-crosslinking effect of the core-shell elastomer during the preparation process. Therefore, while maintaining its flame retardant properties, the material effectively improves the appearance of the molded parts.

[0080] In Examples 1 and 12-13, the core-shell elastomers were MBS, ABS resin, and ABS high-resin powder, respectively. Using MBS resulted in optimal flame retardancy and appearance. Compared to MBS, ABS had slightly inferior appearance, while high-resin powder resulted in slightly inferior flame retardancy. Therefore, MBS is the preferred core-shell elastomer among the three. Meanwhile, although Comparative Example 4 also added an equal amount of elastomer, it was not a core-shell structure, and its flame retardancy and appearance performance did not meet the requirements.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A flame-retardant polycarbonate composition, characterized in that, It includes the following components in parts by weight: The composition includes 89-101 parts polycarbonate, 0.4-5.5 parts phenylsiloxane, 0.5-1 part core-shell elastomer, 0.05-0.2 parts sulfonate flame retardant, 0.05-0.2 parts inhibitor, 0.1-1.1 parts anti-dripping agent, and 0-3.1 parts processing aid; the inhibitor includes at least one of lactone-type carbon free radical scavengers and bisphenol monoacrylate antioxidants; the core-shell elastomer includes at least one of MBS and ABS.

2. The flame-retardant polycarbonate composition according to claim 1, characterized in that, The sulfonate flame retardant includes at least one of potassium perfluorobutyl sulfonate and potassium benzenesulfonylbenzenesulfonate.

3. The flame-retardant polycarbonate composition according to claim 1, characterized in that, The mass ratio of the core-shell elastomer, sulfonate flame retardant, and inhibitor is 1:(0.09-0.22):(0.09-0.22).

4. The flame-retardant polycarbonate composition according to claim 3, characterized in that, The mass ratio of the core-shell elastomer, sulfonate flame retardant, and inhibitor is 1:(0.09-0.16):(0.16-0.20).

5. The flame-retardant polycarbonate composition according to claim 1, characterized in that, The phenyl-containing siloxane includes at least one of polyaminopropylphenylsilsesquioxane, phenylsilsesquioxane, and polyphenylmethylsiloxane.

6. The flame-retardant polycarbonate composition according to claim 1, characterized in that, The anti-dripping agent includes polytetrafluoroethylene.

7. The flame-retardant polycarbonate composition according to claim 1, characterized in that, The processing aid comprises the following components in parts by weight: 0.1-1.5 parts antioxidant and 0.1-1.5 parts lubricant.

8. A method for preparing the flame-retardant polycarbonate composition according to any one of claims 1-7, characterized in that, Includes the following steps: The raw materials are sequentially mixed, melted, extruded, and granulated to obtain the flame-retardant polycarbonate composition.

9. The use of the flame-retardant polycarbonate composition according to any one of claims 1-7 in the preparation of electronic and electrical equipment.

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