Brominated flame-retardant PBT (polybutylene terephthalate) composition as well as preparation method and application thereof

Abstract

The invention discloses a brominated flame-retardant PBT (polybutylene terephthalate) composition as well as a preparation method and application thereof. The brominated flame-retardant PBT composition comprises the following components in parts by weight: 35-75 parts of PBT resin; 9 to 20 parts of decabromodiphenyl ethane; 2-8 parts of a flame retardant synergist; 0.3-8 parts of a stabilizer; wherein the stabilizer comprises a neutral metal oxide, a light stabilizer and carbodiimide, and the mass ratio of the neutral metal oxide to the light stabilizer to the carbodiimide is (0.1-25): (0.1-10): 1. PBT resin is adopted as matrix resin, decabromodiphenyl ethane is adopted as a flame retardant, and a stabilizer with a specific proportion is added, so that the heat retention stability can be effectively improved, and the flame retardant property is not influenced.

Description

Technical Field

[0001] This invention belongs to the field of polymer material modification technology, specifically relating to a bromine-based flame-retardant PBT composition, its preparation method, and its application. Background Technology

[0002] In flame-retardant polybutylene terephthalate (PBT) applications, brominated flame-retardant PBT systems remain the dominant choice due to their superior physical and recyclability compared to halogen-free flame-retardant PBT systems. Commonly used flame retardants for brominated flame-retardant PBT include: brominated epoxy resin (BER), brominated polystyrene (BPS), pentabromobenzyl polyacrylate (PBB-PA), decabromodiphenyl ethane (DBDPE), brominated polycarbonate (BPC), and bromotriazine (TBPC). When developing cost-effective modified brominated flame-retardant PBT materials, decabromodiphenyl ethane is considered the best choice.

[0003] However, when decabromodiphenyl ethane is used in conjunction with antimony-based flame retardant synergists, its degradation temperature decreases significantly. The decabromodiphenyl ethane molecule contains 10 bromine atoms, and the C-Br bond has a low bond energy, making it prone to breakage under heat, light, or free radical action, generating bromine free radicals and phenyl free radicals, initiating a chain degradation reaction. The biggest problem with decabromodiphenyl ethane when used in engineering plastics is its insufficient thermal stability. For example, at injection molding temperatures above 250°C, its heat retention mechanical properties decay too rapidly, making it unsuitable for applications with long molding cycles or intermittent downtime during injection molding. Summary of the Invention

[0004] The purpose of this invention is to overcome the defects or shortcomings of the existing decabromodiphenyl ethane flame-retardant PBT compositions in terms of poor heat retention performance, and to provide a bromine-based flame-retardant PBT composition.

[0005] Another object of the present invention is to provide a method for preparing the brominated flame-retardant PBT composition.

[0006] Another object of the present invention is to provide the application of the brominated flame-retardant PBT composition.

[0007] To achieve the above objectives, the present invention employs the following technical solution: A brominated flame-retardant PBT composition comprising the following components in parts by weight: 35-75 parts of PBT resin; 9-20 parts of decabromodiphenyl ethane; 2-8 parts of flame retardant synergist; Stabilizer 0.3~8 parts; The stabilizer includes a neutral metal oxide, a light stabilizer, and carbodiimide, with a mass ratio of (0.1~25):(0.1~10):1.

[0008] This invention provides a brominated flame-retardant PBT composition, using PBT resin as the matrix resin and decabromodiphenyl ethane as the flame retardant. The addition of a specific proportion of stabilizer can effectively improve thermal retention stability. Neutral metal oxides can capture hydrogen bromide and combine with bromine free radicals to terminate the chain reaction and inhibit the degradation of decabromodiphenyl ethane. However, excessive use of neutral metal oxides will result in uneven dispersion, leading to a decrease in mechanical properties and flame-retardant efficiency. The synergistic effect of light stabilizers in capturing free radicals and reacting with the terminal carboxyl groups of PBT resin in conjunction with carbodiimide inhibits PBT degradation, thereby improving the thermal retention stability of the brominated flame-retardant PBT composition without affecting the flame-retardant performance.

[0009] It should be noted that, in the brominated flame retardant PBT composition of the present invention, the content of PBT resin is preferably not less than 45 wt%.

[0010] It should be noted that the amount of stabilizer used in this invention is 0.3 to 8 parts, for example, but not limited to 0.3 parts, 0.5 parts, 0.8 parts, 1 part, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, 2.2 parts, 2.5 parts, 2.8 parts, 3 parts, 3.2 parts, 3.5 parts, 3.8 parts, 4 parts, 4.2 parts, 4.5 parts, 4.8 parts, 5 parts, 5.2 parts, 5.5 parts, 5.8 parts, 6 parts, 6.2 parts, 6.5 parts, 6.8 parts, 7 parts, 7.2 parts, 7.5 parts, 7.8 parts, or 8 parts, etc., and the specific values ​​between the above-mentioned values ​​are not exhaustively listed in this invention due to space limitations and for the sake of brevity.

[0011] It should be noted that the stabilizer accounts for 0.3 to 8 wt% of the brominated flame retardant PBT composition.

[0012] It should be noted that the mass ratio of the neutral metal oxide, light stabilizer, and carbodiimide in the stabilizer is (0.1~25):(0.1~10):1, for example, but not limited to, 0.1:10:1, 0.5:9.8:1, 1:9.5:1, 2:9:1, 3:8.8:1, 4:8.5:1, 5:8:1, 6:7.8:1, 7:7.5:1, 8:7:1, 9:6.8:1, 10:6.5:1, 11:6:1, and 12:5. 8:1, 13:5.5:1, 14:5:1, 15:4.8:1, 16:4.5:1, 17:4:1, 18:3.8:1, 19:3.5:1, 20:3:1, 21:2.8:1, 22:2.5:1, 23:2:1, 24:1:1, 25:0.5:1 or 25:0.1:1, etc., and the specific point values ​​between the above point values, are not exhaustively listed in this invention due to space limitations and for the sake of brevity.

[0013] Furthermore, the mass ratio of the neutral metal oxide, light stabilizer, and carbodiimide in the stabilizer is (0.5~15):(0.3~5):1.

[0014] Furthermore, the neutral metal oxide includes one or more of zinc oxide, cerium oxide, or zirconium oxide.

[0015] Furthermore, the neutral metal oxide includes zinc oxide and / or cerium oxide.

[0016] Furthermore, the average particle size of the neutral metal oxide is 0.6~5μm.

[0017] Furthermore, the average particle size of the neutral metal oxide is 0.8~1.2 μm.

[0018] Specifically, the average particle size is D(50) particle size, which is tested using a laser particle size analyzer in accordance with GB / T 19077-2024.

[0019] Furthermore, the light stabilizer includes hindered amine light stabilizers.

[0020] Specifically, the hindered amine light stabilizer includes one or more of the following: poly[[6-[(1,1,3,3-tetramethylbutyl)amine]-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidinyl)imine]-1,6-dihexadiyl[(2,2,6,6-tetramethyl-4-piperidinyl)imine]]], poly(1,2,2,6,6-pentamethyl-4-piperidinyl-α-acrylate), bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, 2,2,6,6-tetramethyl-4-piperidinol benzoate, and polymers of succinic acid and (2,2,6,6-tetramethyl-4-piperidinol).

[0021] Furthermore, the carbodiimide includes monomeric carbodiimide and / or polymeric carbodiimide.

[0022] Furthermore, the carbodiimide is a polymeric carbodiimide.

[0023] Furthermore, the intrinsic viscosity of the PBT resin is 0.6~1.3 dL / g.

[0024] Specifically, the test standard for intrinsic viscosity is GB / T 14190-2017.

[0025] Specifically, the intrinsic viscosity is tested at a temperature of 25°C.

[0026] Furthermore, the decabromodiphenyl ethane has an average particle size of 1~5 μm.

[0027] Furthermore, the flame retardant synergist includes antimony trioxide and / or sodium antimonate.

[0028] Furthermore, to improve the initial mechanical strength of the brominated flame-retardant PBT composition, the brominated flame-retardant PBT composition further includes 10 to 45 parts of glass fiber.

[0029] Furthermore, the average diameter of the glass fiber is 7~13μm.

[0030] Furthermore, the brominated flame-retardant PBT composition also includes 0.1 to 8 parts of toughening agent.

[0031] Furthermore, the toughening agent includes ethylene-acrylate type toughening agents and / or ethylene-acrylate-GMA copolymer toughening agents.

[0032] Specifically, the toughening agent includes, but is not limited to, one or more of ethylene-methyl acrylate (E-MA), ethylene-butyl acrylate (E-BA), glycidyl methacrylate-ethylene-methyl acrylate terpolymer (E-MA-GMA), or glycidyl methacrylate-ethylene-butyl acrylate terpolymer (E-BA-GMA).

[0033] Furthermore, without affecting the thermal retention stability and flame retardant properties of the brominated flame retardant PBT composition, the brominated flame retardant PBT composition also includes 0.1 to 3 parts of processing aids.

[0034] Specifically, the processing aids include, but are not limited to, one or more of antioxidants, lubricants, nucleating agents, or laser aids.

[0035] In this invention, commonly used antioxidants can be selected, such as, but not limited to, one or more of hindered phenolic antioxidants, phosphite antioxidants, or thioester antioxidants.

[0036] Specifically, the hindered phenolic antioxidant is one or more of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (Irganox 1010), 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione (antioxidant 1790), and octadecyl β-(4-hydroxy-3,5-di-tert-butylphenyl)propionate (Irganox 1076).

[0037] The phosphite antioxidant is one or more of tris(2,4-di-tert-butylphenyl) phosphite (antioxidant 168), bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphate (PEP-36), or 627A.

[0038] The thioester antioxidant is pentaerythritol tetra(3-lauryl thiopropionate).

[0039] The present invention may use commonly used lubricants, such as, but not limited to, one or more of pentaerythritol stearate, silicone, oxidized polyethylene wax, PE wax, or PP wax.

[0040] The present invention may use commonly used nucleating agents, such as, but not limited to, zinc ion polymers and / or talc.

[0041] The present invention can use commonly used laser additives, such as, but not limited to, basic copper phosphonate laser additives, or laser additives consisting of a mixture of titanium dioxide and pigments, or tin-antimony compound laser additives.

[0042] Furthermore, the brominated flame-retardant PBT composition comprises the following components in parts by weight: 40-60 parts of PBT resin; 10-15 parts of decabromodiphenyl ethane; 2.5-6 parts of flame retardant synergist; Stabilizer 1-5 parts; 15-40 parts glass fiber; 3-8 parts toughening agent.

[0043] The present invention also provides a method for preparing the above-mentioned brominated flame-retardant PBT composition, comprising the following steps: The components are mixed evenly, and then melted, extruded and granulated to obtain a bromine-based flame-retardant PBT composition.

[0044] In some preferred embodiments, the preparation method includes the following steps: All components except glass fiber are mixed evenly and fed into the extruder through the main feed port. Glass fiber is fed into the extruder through the side feed port. The mixture is melted, extruded, and granulated to obtain a brominated flame-retardant PBT composition. Specifically, the extrusion granulation temperature is 180~260℃.

[0045] Specifically, the length-to-diameter ratio of the extruder screw is 36:1 to 48:1.

[0046] This invention also protects the use of the above-mentioned brominated flame-retardant PBT composition in the manufacture of electronic components and household appliance parts. In particular, the above-mentioned brominated flame-retardant PBT composition can be used to manufacture parts with good flame-retardant properties and heat retention properties. Specifically, it can be used to manufacture materials for household appliance parts, and is particularly suitable for plug bridges and motor applications.

[0047] This invention also protects an electrical component made using the above-mentioned brominated flame-retardant PBT composition.

[0048] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a brominated flame-retardant PBT composition. By using a compounded neutral metal oxide, light stabilizer and carbodiimide as stabilizers, the thermal retention stability of the PBT composition can be effectively improved without affecting its flame-retardant properties. Detailed Implementation

[0049] The present invention will be further described in detail below with reference to specific embodiments. These embodiments are only used to explain the present invention and are not intended to limit the scope of the present invention. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods; the materials and reagents used are commercially available unless otherwise specified.

[0050] 1. Raw materials used in each embodiment and comparative example: PBT resin: PBT resin 1: PBT TH6100, intrinsic viscosity 1.0 dL / g, purchased from Xinjiang Lanshan Tunhe Polyester Co., Ltd.; PBT resin 2: PBT MY08, intrinsic viscosity 0.82 dL / g, purchased from Zhejiang Meiyuan New Material Co., Ltd.; Decabromodiphenyl ethane: Decabromodiphenyl ethane 1: FR-102WE, with an average particle size of 1.65 μm, was purchased from Shandong Haiwang Chemical Co., Ltd. Decabromodiphenyl ethane 2:H-02NF, with an average particle size of 1.25 μm, was purchased from Taizhou Baili Chemical Co., Ltd. Flame retardant synergist: Antimony trioxide, S-12N, purchased from Hunan Xikuangshan Shanxing Antimony Industry Import and Export Co., Ltd.; Neutral metal oxides: Neutral metal oxide 1: Indirect zinc oxide, BAO-05 (Type I), after particle size screening, the average particle size after screening is 1.0 μm, purchased from Zhuzhou Zexiang Industrial Co., Ltd. Neutral metal oxide 2: Indirect zinc oxide, after grinding and particle size screening, with an average particle size of 2.0 μm, was purchased from Shijiazhuang Bojian Fine Chemical Co., Ltd. Neutral metal oxide 3: Indirect zinc oxide, which was ground and screened to an average particle size of 4 μm, was purchased from Shijiazhuang Bojian Fine Chemical Co., Ltd. Neutral metal oxide 4: cerium oxide, after particle size screening, with an average particle size of 4μm, was purchased from Shandong Desheng New Materials Co., Ltd. Neutral metal oxide 5: Zirconia, after particle size screening, with an average particle size of 4μm, was purchased from Shandong Desheng New Materials Co., Ltd. Light stabilizers: Light stabilizer 1: Poly[[6-[(1,1,3,3-tetramethylbutyl)amine]-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidine)imine]-1,6-dihexadiyl[(2,2,6,6-tetramethyl-4-piperidine)imine]]], CHIMASSORB944 FDL, purchased from BASF Group; Light stabilizer 2: bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, RIASORB UV-770DF, purchased from Tianjin Lianlong New Material Co., Ltd. Light stabilizer 3: a polymer of succinic acid and (2,2,6,6-tetramethyl-4-piperidinol), Tinuvin 622, purchased from BASF Group; Carbodiimide: Carbodiimide 1: Polymerized carbodiimide, Hymax 213, purchased from Shanghai Langyi Functional New Materials Co., Ltd.; Carbodiimide 2: Monomeric carbodiimide, model Stabilizer 7000, purchased from Raschig GmbH; Stabilizer: The mass ratio of stabilizer 1: neutral metal oxide 1: light stabilizer 1: carbodiimide 1 is 2:1.2:1; The mass ratio of stabilizer 2: neutral metal oxide 2: light stabilizer 1: carbodiimide 1 is 2:1.2:1; The mass ratio of stabilizer 3: neutral metal oxide 3: light stabilizer 1: carbodiimide 1 is 2:1.2:1; The mass ratio of stabilizer 4: neutral metal oxide 4: light stabilizer 1: carbodiimide 1 is 2:1.2:1; The mass ratio of stabilizer 5: neutral metal oxide 5: light stabilizer 1: carbodiimide 1 is 2:1.2:1; The mass ratio of stabilizer 6: neutral metal oxide 1: light stabilizer 2: carbodiimide 1 is 2:1.2:1; The mass ratio of stabilizer 7: neutral metal oxide 1: light stabilizer 3: carbodiimide 1 is 2:1.2:1; The mass ratio of stabilizer 8: neutral metal oxide 1: light stabilizer 1: carbodiimide 2 is 2:1.2:1; The mass ratio of stabilizer 9: neutral metal oxide 1: light stabilizer 1: carbodiimide 1 is 12:4:1; The mass ratio of stabilizer 10: neutral metal oxide 1: light stabilizer 1: carbodiimide 1 is 17:8:1; The mass ratio of stabilizer 11: neutral metal oxide 1: light stabilizer 1: carbodiimide 1 is 0.2:0.2:1; The mass ratio of stabilizer 12: neutral metal oxide 1: light stabilizer 1: carbodiimide 1 is 24:8:1; The mass ratio of stabilizer 13: neutral metal oxide 1: light stabilizer 1 is 2:1.2; The mass ratio of stabilizer 14: neutral metal oxide 1: carbodiimide 1 is 2:1; The mass ratio of stabilizer 15: light stabilizer 1: carbodiimide 1 is 1.2:1; The mass ratio of stabilizer 16: neutral metal oxide 1: light stabilizer 1: carbodiimide 2 is 0.05:1.2:1; The mass ratio of stabilizer 17: neutral metal oxide 1: light stabilizer 1: carbodiimide 2 is 30:1.2:1; Glass fiber: ECS11-4.5-534A, with an average diameter of 11μm, purchased from Jushi Group Co., Ltd. Toughening agent: Glycidyl methacrylate-ethylene-methyl acrylate terpolymer (E-MA-GMA), AX8900, Arkema China Investment Co., Ltd.; Processing aids: Antioxidant: Pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], commercially available; Lubricant: Pentaerythritol fatty acid ester, commercially available; It should be noted that the same raw materials were used in the parallel experiments in the examples and comparative examples.

[0051] 2. The PBT compositions in each embodiment and comparative example were prepared according to the formulations in Tables 1-2 and the following preparation methods: All components except glass fiber are mixed evenly and fed into the extruder through the main feed port. Glass fiber is fed into the extruder through the side feed port. The mixture is melted, extruded and granulated to obtain a bromine-based flame-retardant PBT composition. The extrusion granulation temperature is 180~260℃. The length-to-diameter ratio of the extruder screw is 40:1.

[0052] 3. Performance Testing: (1) Flame retardant performance test: The PBT compositions prepared in each example and comparative example were injection molded to obtain a sample strip of 127mm*12.7mm*0.8mm, and tested according to UL94-2024 standard; (2) Notched impact strength of cantilever beam: The PBT compositions prepared in each embodiment and comparative example were injection molded into specimens at 260°C. The specimen size was 80*10*4mm, the notch type was A, and the notch depth was 2mm. The notched impact strength was tested according to ISO 180-2023 and recorded as the initial notched impact strength. (3) Heat retention performance test: The PBT compositions prepared in each example and comparative example are kept in the barrel of the injection molding machine (260°C) for 10 minutes, and then 80*10*4mm specimens are injected. The notch type is A and the notch depth is 2mm. The test is carried out in accordance with the standard ISO180-2023. The heat retention notch impact strength is recorded, and the retention rate is calculated according to the retention rate (%) = heat retention notch impact strength / initial notch impact strength. Examples 1-12 and Comparative Examples 1-5 Table 1. Dosage (parts by weight) and properties of each component in the brominated flame-retardant PBT compositions in Examples 1-10

[0053] Table 2. Amounts (parts by weight) and properties of each component in the PBT compositions of Examples 11-12 and Comparative Examples 1-5

[0054] As can be seen from Tables 1 and 2, the brominated flame-retardant PBT compositions prepared by the present invention have good thermal retention properties and good flame-retardant properties. Specifically, they can all achieve V-0 flame retardancy, and the retention rate is not less than 60%; preferably not less than 70%.

[0055] As can be seen from Comparative Examples 1 to 3, if any component is missing from the stabilizer, the thermal retention performance of the prepared PBT composition will decrease significantly.

[0056] As can be seen from Comparative Examples 4 and 5, if the proportions of the three components in the stabilizer are not within the range of the present invention, the thermal retention performance of the obtained PBT composition will decrease significantly.

[0057] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A bromine flame-retardant PBT composition, characterized in that, The bromine flame-retardant PBT composition comprises the following components by weight: PBT resin 35-75 parts; Decabromodiphenyl ethane 9-20 parts; Flame retardant synergist 2-8 parts; Stabilizer 0.3-8 parts; The stabilizer comprises neutral metal oxide, light stabilizer and carbodiimide, and the mass ratio of the three is (0.1-25):(0.1-10):

1.

2. The bromine-based flame-retardant PBT composition according to claim 1, characterized in that, The mass ratio of the neutral metal oxide, the light stabilizer and the carbodiimide in the stabilizer is (0.5-15):(0.3-5):

1.

3. The bromine flame-retardant PBT composition according to claim 1 or 2, characterized in that, The neutral metal oxide comprises one or more of zinc oxide, cerium oxide or zirconium oxide; preferably, the neutral metal oxide is zinc oxide and / or cerium oxide.

4. The bromine-containing flame-retardant PBT composition according to claim 1 or 2, characterized in that, The light stabilizer comprises hindered amine light stabilizer.

5. The bromine-containing flame-retardant PBT composition according to claim 1 or 2, characterized in that, The carbodiimide comprises monomeric carbodiimide and / or polymeric carbodiimide; preferably, the carbodiimide is polymeric carbodiimide.

6. The bromine-containing flame-retardant PBT composition according to claim 1 or 2, characterized in that, At least one of the following three conditions is met: (a) the intrinsic viscosity of the PBT resin is 0.6-1.3 dL / g; (b) the flame retardant synergist comprises antimony trioxide and / or sodium antimonate; (c) the average particle size of the decabromodiphenyl ethane is 1-5 μm.

7. The bromine-containing flame-retardant PBT composition according to claim 1 or 2, characterized in that, At least one of the following three conditions is met: (a) the bromine flame-retardant PBT composition further comprises 10-45 parts of glass fiber; (b) the bromine flame-retardant PBT composition further comprises 0.1-8 parts of toughening agent; (c) the bromine flame-retardant PBT composition further comprises 0.1-5 parts of processing aid; the processing aid comprises one or more of antioxidant, lubricant, nucleating agent or laser aid.

8. A process for the preparation of the bromine flame-retardant PBT composition according to any one of claims 1 to 7, characterized in that, The method comprises the following steps: Mixing the components uniformly, melting, extruding and granulating to obtain the bromine flame-retardant PBT composition.

9. Use of the bromine flame-retardant PBT composition according to any one of claims 1-7 in electronic components and / or household appliance parts.

10. An electrical component, characterized in that, The bromine flame-retardant PBT composition is prepared by the method.

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