PBT composition, and preparation method therefor and use thereof

Abstract

Disclosed are a PBT composition, and a preparation method therefor and a use thereof. The PBT composition comprises the following components in parts by weight: 44-56 parts of a PBT resin, 10-15 parts of N,N-ethylene-bis(tetrabromophthalimide), 25-35 parts of glass fiber, and 0.5-1 parts of an ultraviolet absorber. In the present invention, specific N,N-ethylene-bis(tetrabromophthalimide) is added to a glass fiber-reinforced PBT composition, and by incorporating a specific ultraviolet absorber, the resulting PBT composition exhibits minimal color difference change after aging, and is particularly suitable for workpieces having long-term outdoor service requirements, such as smart boat outboard motors, photovoltaic supports, air conditioner outdoor unit components, and new energy battery parts.

Description

A PBT composition, its preparation method and application Technical Field

[0001] This invention relates to the field of engineering plastics technology, and more specifically, to a PBT composition, its preparation method, and its application. Background Technology

[0002] Polybutylene terephthalate (PBT resin) is a widely used crystalline polyester engineering plastic with excellent mechanical, heat, electrical, solvent, fatigue, and creep resistance properties. PBT resin also features rapid crystallization, short molding cycles, excellent dimensional stability, and low water absorption, making it widely used in electronics, electrical engineering, home appliances, and automotive industries. Typically, adding a certain amount of glass fiber to PBT material can meet customer requirements for the strength and toughness of parts. For example, in motor stators and rotors, air fryers, and BDUs (Battery Units) for new energy batteries, glass fiber is generally added to improve the material's strength and toughness, thereby broadening its application scenarios. However, when glass fiber reinforced PBT materials are exposed to strong sunlight for extended periods, the material is prone to aging and degradation, resulting in exposed glass fibers, decreased surface gloss, and yellowing, affecting the material's appearance and performance and limiting its applications.

[0003] To address the issue of color difference changes in glass fiber reinforced PBT materials after aging, ultraviolet absorbers are typically added to reduce the impact of ultraviolet light and thus minimize color difference. While the addition of ultraviolet absorbers reduces color difference after aging, further increases in their dosage do not significantly improve color difference reduction after a certain point, limiting their application in outdoor products such as smart boat outdoor motors, photovoltaic brackets, air conditioner outdoor unit components, and new energy battery components. Therefore, there is a need in this field to develop a PBT composition with minimal color difference after aging and good mechanical properties. Summary of the Invention

[0004] The purpose of this invention is to overcome the defects or deficiencies of the existing glass fiber reinforced PBT compositions in terms of weather resistance, color difference after aging, and mechanical properties, and to provide a PBT composition.

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

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

[0007] To achieve the above objectives, the present invention employs the following technical solution:

[0008] A PBT composition comprising the following components in parts by weight: 44-56 parts PBT resin; 10-15 parts ethylene bis(tetrabromophthalimide); 25-35 parts glass fiber; 0.2-1.5 parts ultraviolet light absorber; and 0.1-2 parts ultraviolet light shielding agent; wherein the ultraviolet light absorber is a hindered amine light stabilizer.

[0009] In this invention, PBT resin is used as the matrix resin, and ethylene bis(tetrabromophthalimide) is selected as a synergistic ultraviolet absorber and ultraviolet shielding agent, which enables the PBT composition to have good flame retardant properties, good weather resistance, and small color difference before and after aging.

[0010] It should be noted that the PBT resin content in the PBT composition described in this invention is preferably not less than 40 wt.%.

[0011] It should be noted that the 44-56 parts of PBT resin mentioned in this invention can specifically be 44 parts, 45 parts, 46 parts, 47 parts, 48 ​​parts, 49 parts, 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, 55 parts, or 56 parts, etc., all of which can achieve this invention.

[0012] The ethylene bis(tetrabromophthalimide) used in this invention is 10-15 parts, specifically 10 parts, 10.5 parts, 11 parts, 11.5 parts, 12 parts, 12.5 parts, 13 parts, 13.5 parts, 14 parts, 14.5 parts, or 15 parts, etc., all of which can achieve the present invention.

[0013] The hindered amine light stabilizer described in this invention is 0.2 to 1.5 parts, specifically 0.2 parts, 0.25 parts, 0.3 parts, 0.35 parts, 0.4 parts, 0.45 parts, 0.5 parts, 0.55 parts, 0.6 parts, 0.65 parts, 0.7 parts, 0.75 parts, 0.8 parts, 0.85 parts, 0.9 parts, 0.95 parts, 1 part, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, or 1.5 parts, etc., all of which can achieve the present invention.

[0014] The 0.1 to 2 parts of ultraviolet light shielding agent mentioned in this invention can be 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 part, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts, or 2 parts, etc., all of which can achieve the present invention.

[0015] Furthermore, the mass ratio of the hindered amine light stabilizer to the ultraviolet light shielding agent is 1:(0.5~2.5).

[0016] Specifically, the mass ratio of the hindered amine light stabilizer to the ultraviolet light shielding agent can be 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:1, 1:1.1, 1:1.2:1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2, 1:2.1, 1:2.2, 1:2.3, 1:2.4, or 1:2.5, etc., all of which can achieve the present invention.

[0017] The hindered amine light stabilizer content in this invention is not less than 0.5 wt% of the PBT composition.

[0018] Furthermore, the intrinsic viscosity of the PBT resin is 0.7~1.2 dL / g.

[0019] Furthermore, the intrinsic viscosity of the PBT resin is 0.75~0.9 dL / g.

[0020] Specifically, the test standard for intrinsic viscosity is ISO1628-5-2015.

[0021] Specifically, the hindered amine light stabilizer includes tertiary amine hindered amine light stabilizers and / or secondary amine hindered amine light stabilizers.

[0022] Specifically, the secondary amine hindered amine light stabilizer is N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-N,N'-dialdehyde hexamethylenediamine and / or poly{[6-[(1,1,3,3-tetramethylbutyl)amino]]-1,3,5-triazine-2,4-[(2,2,6,6,-tetramethyl-piperidinyl)imino]-1,6-hexamethylenediamine[(2,2,6,6-tetramethyl-4-piperidinyl)imino]} (LS-944).

[0023] The tertiary amine hindered amine light stabilizer is poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol-ALT-1,4-succinic acid).

[0024] Furthermore, the ultraviolet light absorber is a tertiary amine hindered amine light stabilizer. Using this type of ultraviolet light absorber provides better protection against color changes on the material surface.

[0025] Furthermore, the glass fiber is alkali-free chopped E glass fiber with a diameter of 7μm to 15μm and a length of 3mm to 5mm.

[0026] Furthermore, the PBT composition further includes 2 to 6 parts of a flame retardant synergist and 1 to 5 parts of a toughening agent.

[0027] Furthermore, the toughening agent includes one or more of ethylene-acrylate, ethylene-acrylate-glycidyl ester, ethylene-octene copolymer, ethylene-octene copolymer-glycidyl ester, or ethylene-vinyl acetate copolymer.

[0028] Furthermore, the synergistic flame retardant is an antimony-containing flame retardant, such as antimony trioxide or sodium antimonate.

[0029] Specifically, the ultraviolet light shielding agent is titanium dioxide.

[0030] Specifically, the average particle size D50 of the titanium dioxide is 0.1~1.5μm.

[0031] Specifically, the average particle size D50 was determined in accordance with the GB / T 19077.1-2016 standard.

[0032] Furthermore, the PBT composition further includes 0.1 to 5 parts of additives.

[0033] Specifically, the additives include one or more of antioxidants, lubricants, or anti-dripping agents.

[0034] The antioxidants described in this invention can be selected from commonly used antioxidants with reference to existing technologies, such as, but not limited to, one or more of hindered phenolic antioxidants, thioether antioxidants, hindered phenolic antioxidants, or diphenylamine antioxidants.

[0035] In specific embodiments, the phosphite antioxidant is one or more of tris(2,4-di-tert-butylphenyl) phosphite (Irganox 168), bis(2,6-di-tert-butyl-4-tolyl) pentaerythritol phosphite (PEP-36), or 627A; the thioether antioxidant is one or more of distearate thiodipropionate, dilaurate thiodipropionate, or pentaerythritol-based dodecathiopropyl ester; the hindered phenolic antioxidant is N,N'-hexamethylene bis(3,5-di-tert-butyl-4-hydroxyphenylpropionamide) (Irganox 1098), pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (Irganox 1010), or 1,6-hexanediol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (Irganox 1098). 259), β-(4-hydroxy-3,5-di-tert-butylphenyl)propionate n-octadecyl ester (Irganox 1076) or 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)acrylic acid]-1,1-dimethyl}-2,4,8,10-tetraoxaspirocycloundecane (ADK AO-80); the diphenylamine antioxidant is one of butyl / octyl diphenylamine or dioctyl diphenylamine.

[0036] The lubricant described in this invention can be selected from commonly used lubricants with reference to the prior art, such as, but not limited to, one or more of ester lubricants, amide lubricants, polyethylene lubricants, or stearic acid lubricants.

[0037] Specifically, the ester lubricant is one or more of aliphatic stearate, oleic acid-based aliphatic polyester, or meso-aliphatic polyester; the amide lubricant is one or more of erucamide, oleamide, or EBS; the polyethylene lubricant is one or more of polyethylene-acrylic acid copolymer waxes A-C540, A-C580, and A-C5120; and the stearic acid lubricant is zinc stearate and / or calcium stearate.

[0038] Further, the PBT composition comprises the following components in parts by weight:

[0039] 48-52 parts PBT resin; 11-14 parts ethylene bis(tetrabromophthalimide); 3-5 parts synergistic flame retardant; 28-32 parts glass fiber; 2-4 parts toughening agent; 0.3-0.8 parts ultraviolet light absorber; 0.5-1.5 parts ultraviolet light shielding agent; 0.5-1.5 parts additives.

[0040] The present invention also provides a method for preparing the PBT composition, comprising the following steps:

[0041] S1. Mix the components of the above PBT composition, except for glass fiber, ethylene bis(tetrabromophthalimide) and synergistic flame retardant, evenly to obtain premix A; mix ethylene bis(tetrabromophthalimide) and synergistic flame retardant evenly to obtain premix B;

[0042] S2. The premix A and premix B described in step S1 are fed into the main feed port, and the glass fiber is fed into the extruder through the side feed port. The PBT composition is obtained by mixing, dispersing, melt extrusion, and granulation.

[0043] Specifically, the mixing speed in step S1 is 600-900 rpm, and the time is 2-4 minutes.

[0044] Specifically, the extruder mentioned in step S2 is a twin-screw extruder.

[0045] Specifically, the temperature of the twin-screw extruder is 200~230℃ in zone 1, 240~260℃ in zone 2, 235~255℃ in zones 3 to 5, 240~260℃ in zone 6, 240~260℃ in zone 7, 220~240℃ in zone 8, 220~240℃ in zone 9, and 240~260℃ in zone 10; the screw speed of the twin-screw extruder is 200~450 rpm.

[0046] The present invention also provides the application of the PBT composition in the preparation of home appliance parts, automotive parts, electronic and electrical parts, especially parts with long-term outdoor operating conditions, such as smart boat outdoor units, photovoltaic brackets, air conditioner outdoor unit parts, new energy battery components and other materials.

[0047] Compared with the prior art, the beneficial effects of the present invention are:

[0048] This invention provides a PBT composition that, by employing glass fiber to enhance mechanical properties and selecting ethylene bis(tetrabromophthalimide) as a flame retardant, along with a UV absorber, can improve the color difference of the PBT composition after aging, while also exhibiting good flame retardant and mechanical properties. Embodiments of the present invention

[0049] The present invention will be further described below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise stated, the raw materials and reagents used in the embodiments of the present invention are conventionally purchased raw materials and reagents.

[0050] 1. Raw materials used in the various embodiments and comparative examples of the present invention:

[0051] PBT resin: PBT 1200-211M, viscosity 0.83 dL / g, purchased from Changchun Chemical (Jiangsu) Co., Ltd.

[0052] Fiberglass: HMG436S-10-4.0, purchased from Taishan Fiberglass Co., Ltd.;

[0053] Ethylenebistetrabromophthalimide:

[0054] Ethylenebistetrabromophthalimide 1: Flame retardant BT-93W, purchased from Guangzhou Yuanda New Materials Co., Ltd.;

[0055] Ethylenebistetrabromophthalimide 2:BR-951, purchased from Shouguang Wantai Chemical Co., Ltd.;

[0056] Other brominated flame retardants:

[0057] Brominated flame retardant 1: Brominated epoxy flame retardant, F-2100, purchased from ICL, Israel;

[0058] Brominated flame retardant 2: Brominated polystyrene, SAYTEX 621, purchased from Albemarle, USA;

[0059] Brominated flame retardant 3: pentabromobenzyl polyacrylate, FR-1025, purchased from ICL, Israel;

[0060] Brominated flame retardant 4: Brominated polycarbonate, FG-8500, purchased from Teijin;

[0061] Synergistic flame retardant: Antimony White, S-05N, purchased from Foshan Chenti Trade Co., Ltd.;

[0062] Toughening agent: Ethylene-acrylate-glycidyl methacrylate (EMA-GMA), PTW, purchased from DuPont;

[0063] Ultraviolet light absorber:

[0064] UV absorber 1: tertiary amine hindered amine light stabilizer, Tinuvin 622SF, purchased from BASF;

[0065] UV absorber 2: tertiary amine hindered amine light stabilizer, HALS-622, purchased from Suqian Liansheng Technology Co., Ltd.;

[0066] UV absorber 3: secondary amine hindered amine light stabilizer, HALS-944, purchased from Suqian Liansheng Technology Co., Ltd.

[0067] UV absorber 4: Benzotriazole UV absorber, UV-234, purchased from Suqian Liansheng Technology Co., Ltd.;

[0068] UV shielding agent: titanium dioxide, R103, purchased from DuPont;

[0069] Additives:

[0070] Antioxidant: Antioxidant 1076, commercially available; Lubricant: Ester lubricant, commercially available; It should be noted that the same raw materials were used in the parallel experiments of each embodiment and comparative example in this invention.

[0071] 2. The PBT compositions described in the examples and comparative examples were prepared according to the formulations in Tables 1-2 by the following preparation method:

[0072] S1. Mix the components of the glass PBT composition other than glass fiber, ethylene bis(tetrabromophthalimide) and synergistic flame retardant at 700 rpm for 3 minutes until homogeneous to obtain premix A; mix the ethylene bis(tetrabromophthalimide) and synergistic flame retardant at 800 rpm for 3 minutes until homogeneous to obtain premix B;

[0073] S2. The premix A and premix B described in step S1 are fed into the main feed port, and the glass fiber is fed into the twin-screw extruder through the side feed port. The mixture is then mixed, dispersed, melt-extruded, and granulated to obtain the composition. The temperature of the twin-screw extruder is 215°C in zone 1, 250°C in zone 2, 245°C in zones 3 to 5, 250°C in zone 6, 250°C in zone 7, 230°C in zone 8, 230°C in zone 9, and 250°C in zone 10. The screw speed of the twin-screw extruder is 320 rpm.

[0074] 3. Performance Testing

[0075] (1) Tensile strength test: The PBT compositions prepared in each example and comparative example were tested according to standard ISO 527-2-2012;

[0076] (2) Notched impact strength of cantilever beam: The PBT compositions prepared in the above examples and comparative examples were tested according to the standard ISO 180-2019.

[0077] (3) Flame retardant performance test: The PBT compositions prepared in the above examples and comparative examples were tested according to the UL94-2013 vertical burning standard with a thickness of 0.8 mm;

[0078] (4) Weather resistance test: The PBT compositions prepared in the above examples and comparative examples were placed in a UV (power 20W, wavelength range 315-400nm) aging chamber and continuously irradiated for 1000 hours. The changes in L, a, and b values ​​before and after irradiation were tested to obtain ΔE; ΔE = (ΔL 2 +△a 2 +△b 2 ) 1 / 2 .

[0079] Examples 1-8 and Comparative Examples 1-7

[0080] Table 1. Amounts (parts by weight) and properties of each component in the PBT composition in each example.

[0081]

[0082] Table 2. Amounts (parts by weight) and properties of each component in the PBT compositions of each comparative example.

[0083]

[0084] As can be seen from Table 1, the PBT compositions prepared in the embodiments of the present invention have good weather resistance, small color difference after aging, and good mechanical and flame retardant properties. Specifically, all embodiments can meet the 0.8mm V-0 flame retardancy and the color difference before and after aging ΔE < 10, preferably ΔE < 5, which can meet the requirements of long-term outdoor use.

[0085] As can be seen from Comparative Example 1, if only the specific ethylene bis(tetrabromophthalimide) is used without adding a UV absorber, the weather resistance of the product is generally poor, and the color difference ΔE before and after aging exceeds 10, which is significantly worse than that of the example.

[0086] As can be seen from Comparative Examples 2 to 5, even with the addition of UV absorbers and UV shielders, other types of flame retardants cannot meet the requirement of minimal color difference changes after aging.

[0087] As can be seen from Comparative Example 6, even with the addition of specific flame retardants and UV shielding agents, other UV absorbers cannot meet the requirement of minimal color difference changes after aging.

[0088] As can be seen from Comparative Example 7, if only ultraviolet light absorbers are used, it is impossible to meet the requirement of small color difference changes after aging.

[0089] 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 PBT composition, characterized in that, It comprises the following components by weight: 44-56 parts PBT resin; 10-15 parts ethylene bis(tetrabromophthalimide); 25-35 parts glass fiber; 0.5-1.5 parts ultraviolet light absorber; and 0.1-2 parts ultraviolet light shielding agent; wherein the ultraviolet light absorber is a hindered amine light stabilizer.

2. The PBT composition according to claim 1, characterized in that, The hindered amine light stabilizers include secondary amine hindered amine light stabilizers and / or tertiary amine hindered amine light stabilizers.

3. The PBT composition according to claim 1, characterized in that, The toughening agent includes one or more of ethylene-acrylate, ethylene-acrylate-glycidyl ester, ethylene-octene copolymer, ethylene-octene copolymer-glycidyl ester, or ethylene-vinyl acetate copolymer.

4. The PBT composition according to claim 1, characterized in that, The hindered amine light stabilizer is poly{[6-[(1,1,3,3-tetramethylbutyl)amino]]-1,3,5-triazine-2,4-[(2,2,6,6,-tetramethyl-piperidinyl)imino]-1,6-hexamethylene[(2,2,6,6-tetramethyl-4-piperidinyl)imino]} and / or poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol-ALT-1,4-succinic acid).

5. The PBT composition according to claim 1, characterized in that, The mass ratio of the ultraviolet light absorber to the ultraviolet light shielding agent is 1:(0.5~2.5).

6. The PBT composition according to claim 1, characterized in that, The ultraviolet light shielding agent is titanium dioxide.

7. The PBT composition according to claim 1, characterized in that, It also includes 2 to 6 parts of synergistic flame retardant and 1 to 5 parts of toughening agent.

8. The PBT composition according to claim 1, characterized in that, It also includes 0.1 to 5 parts of adjuvants.

9. A method for preparing the PBT composition according to any one of claims 1 to 8, characterized in that, Includes the following steps: S1. Mix the components of the above PBT composition, except for glass fiber, ethylene bis(tetrabromophthalimide) and synergistic flame retardant, evenly to obtain premix A; mix ethylene bis(tetrabromophthalimide) and synergistic flame retardant evenly to obtain premix B; S2. The premix A and premix B described in step S1 are fed into the main feed port, and the glass fiber is fed into the extruder through the side feed port. The PBT composition is obtained by mixing, dispersing, melt extrusion, and granulation.

10. The use of the PBT composition according to any one of claims 1 to 8 in the preparation of household appliance parts, automobile parts, and electronic and electrical parts.

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