Low-precipitation PBT (Polybutylene Terephthalate) modified material for vehicle lamp decorative ring as well as preparation method and application of low-precipitation PBT modified material

Abstract

The invention discloses a low-precipitation PBT (polybutylene terephthalate) modified material for a vehicle lamp decorative ring as well as a preparation method and application of the low-precipitation PBT modified material. The PBT modified material is prepared from the following components in parts by weight: 50 to 70 parts of PBT resin, 10 to 50 parts of MXD6 resin, 1 to 7 parts of heat conduction agent, 0.2 to 0.4 part of nucleating agent, 0.6 to 0.8 part of antioxidant, 0.4 to 0.6 part of light stabilizer and 0.4 to 0.6 part of lubricant. The MXD6 resin with excellent barrier property is introduced to construct a multi-interface structure, the heat conducting agent is combined to inhibit the surface decomposition of the material to form a specific multi-interface-super labyrinth structure, and the nucleating agent with acid-base reaction activity is utilized to react with precipitates such as p-benzoic acid and low-molecular esters in the multi-interface-super labyrinth structure, so that the barrier property of the material is improved. Therefore, small molecular structures such as precipitates are eliminated from the source, small molecular compounds are prevented from being migrated to the surface of the material, then the haze of the material is reduced, and the material is particularly suitable for manufacturing automobile lamp decorative rings.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, and specifically relates to a low-emission PBT modified material for automotive headlight trim, its preparation method, and its application. Background Technology

[0002] With the continuous development of personalized automotive exterior design, headlights, as a core element of the vehicle's front fascia, are facing increasingly higher requirements for design integration and lighting intensity. Against this backdrop, headlight trim materials need to meet several stringent functional requirements, including excellent heat resistance, low leaching characteristics, good sealing properties, high surface gloss, high rigidity, and ease of assembly.

[0003] Currently, PBT (polybutylene terephthalate) is widely used in the manufacturing of automotive headlight trim rings. This material exhibits significant advantages in injection molding due to its excellent heat resistance, flowability, and coating adaptability. However, in practical applications, traditional PBT materials contain a high content of terminal carboxyl groups, resulting in highly active molecular chains. When the headlight trim ring is exposed to high operating temperatures for extended periods, the material surface is prone to thermal degradation, producing small-molecule volatiles. These precipitates severely affect the quality of subsequent vacuum evaporation processes, leading to defects in the aluminum plating layer such as decreased gloss, surface haze, and iridescent spots.

[0004] To improve the surface quality of the substrate, existing processes typically require spraying a primer onto the injection-molded parts. This not only increases the complexity of the manufacturing process but also pollutes the workshop environment. In recent years, low-VOC (volatile organic compound) PBT materials introduced to the market have improved surface gloss to some extent and enabled primer-free processes. However, due to the presence of a small number of terminal carboxyl groups and unreacted monomers or oligomers during the polymerization process, the ester groups in the polyester materials can still undergo hydrolysis reactions when in contact with moisture under high temperature and high humidity environments, continuously producing small molecule substances.

[0005] Furthermore, traditional automotive lighting trim materials are all modified composite materials. In addition to the base resin, their formulations contain various functional additives, many of which are small-molecule oligomers. Under high-temperature conditions, these additives can also become sources of small-molecule substances. Therefore, effectively reducing the content of small molecules in the material, inhibiting the migration of small molecules to the surface of the product, and controlling the amount of small molecules released through multiple pathways have become key challenges in improving the reliability of PBT materials in automotive lighting trim applications.

[0006] In other words, how to provide a low-emission PBT modified material for automotive headlight trim, by introducing MXD6 resin and the synergistic effect of each component to reduce material haze from the source, is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] The purpose of this invention is to provide a low-precipitation PBT modified material for automotive lamp trim rings, its preparation method, and its application. This low-precipitation PBT modified material for automotive lamp trim rings not only has a very small amount of small molecule volatilization and good adhesion of the aluminum layer, but also solves problems such as mold fouling on the mold surface, blurry or low gloss on the surface of the part, and fogging of transparent lamp covers. It is suitable for automotive lamps and other fields.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: The first aspect of the present invention provides a low-extraction PBT modified material for automotive headlight trim rings, wherein the PBT modified material comprises the following components by weight: 45-90 parts of PBT resin, 5-50 parts of MXD6 resin, 0.2-0.4 parts of nucleating agent, 0.6-0.8 parts of antioxidant, 0.4-0.6 parts of light stabilizer, and 0.4-0.6 parts of lubricant.

[0009] In the first aspect, the PBT modified material comprises the following components by weight: 50-70 parts of PBT resin, 10-50 parts of MXD6 resin, 1-7 parts of thermal conductive agent, 0.2-0.4 parts of nucleating agent, 0.6-0.8 parts of antioxidant, 0.4-0.6 parts of light stabilizer and 0.4-0.6 parts of lubricant.

[0010] In the first aspect, the PBT modified material comprises the following components by weight: 50-70 parts of PBT resin, 10-50 parts of MXD6 resin, 1-7 parts of thermal conductive agent, 0.2-0.4 parts of nucleating agent, 0.6-0.8 parts of antioxidant, 0.4-0.6 parts of light stabilizer, 0.4-0.6 parts of lubricant, and 3-9 parts of compatibilizer.

[0011] In the first aspect, the intrinsic viscosity of the PBT resin is 0.8-1.1 dL / g, and the end carboxyl group content is ≤18.0 meq / kg; the relative viscosity of the MXD6 resin is 2.1-2.6.

[0012] In the first aspect, the nucleating agent is nano-talc, nano-alumina, or zinc oxide.

[0013] In the first aspect, the antioxidant is a 1:1:2 blend of three multifunctional antioxidants: pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and bis(2,4-di-tert-butylphenol) pentaerythritol diphosphite; the light stabilizer is poly{[6-[(1,1,3,3-tetramethylbutyl)amino]] The lubricant is a 2:1 mixture of hindered amine light stabilizers of different molecular weights, including 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 polysuccinate (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol). The lubricant includes at least one of pentaerythritol stearate, high molecular weight polyester wax, ultra-high molecular weight silicone, and ultra-high molecular weight polyethylene.

[0014] In the first aspect, the thermal conductive agent is a nanosheet thermal conductive agent, which is nanographene, nanographite sheets, or nanoboron nitride.

[0015] In the first aspect, the compatibilizer is a comb-shaped PBT / MXD6 compatibilizer, and the preparation method of the PBT / MXD6 compatibilizer includes: adding styrene and glycidyl methacrylate to molten caprolactam at a molar ratio of 95:5 under a nitrogen atmosphere, adding an initiator, and reacting at 78°C for 20 hours to obtain a polymer; pulverizing the polymer and washing it sequentially with deionized water and ethanol, filtering, and drying to obtain a pre-compatibilizer; mixing the pre-compatibilizer, MXD6 resin, and PBT resin at a weight ratio of 4:48:48 and adding the mixture to a twin-screw extruder, and performing melt extrusion granulation at 240-270°C to obtain the PBT / MXD6 compatibilizer.

[0016] The second aspect of this invention provides a method for preparing a low-precipitation PBT modified material for automotive headlight trim rings. The method includes: drying PBT resin and MXD6 resin at 120°C for 3-4 hours; weighing the raw material components according to the first aspect of the low-precipitation PBT modified material for automotive headlight trim rings; adding the weighed raw material components to a high-speed mixing tank in proportion for premixing to obtain a premix; adding the premix to a twin-screw extruder for screw shear melt blending, extrusion granulation, and obtaining the low-precipitation PBT modified material. The twin-screw extruder has a length-to-diameter ratio of (30-50):1, a main extruder speed of 320-380 rpm, and an extrusion temperature of 220-260°C.

[0017] A third aspect of the present invention provides a plastic part, characterized in that the plastic part is injection molded from the low-exploitation PBT modified material for automotive headlight trim rings described in the first aspect, and the plastic part is used to manufacture automotive headlight trim rings.

[0018] Beneficial effects: This invention provides a low-extraction PBT modified material for automotive headlight trim rings, comprising, by weight, 45-90 parts PBT resin, 10-50 parts MXD6 resin, 1-7 parts thermal conductive agent, 0.2-0.4 parts nucleating agent, 0.6-0.8 parts antioxidant, 0.4-0.6 parts light stabilizer, and 0.4-0.6 parts lubricant. By introducing MXD6 resin with excellent barrier properties, a multi-interface structure is constructed. The thermal conductive agent is combined to inhibit surface decomposition, forming a unique multi-interface-hyperlabyrinth structure. Furthermore, the material utilizes acid-base... The reactive nucleating agent reacts with precipitates such as terebenzoic acid and low-molecular-weight esters within the multi-interface-super labyrinth structure, thereby eliminating the small molecule structures of precipitates at the source and preventing small molecule compounds from migrating to the material surface, thus reducing the material's haze. Furthermore, by combining antioxidants, light stabilizers, and lubricants to balance the comprehensive performance of the PBT modified material, the prepared PBT modified material exhibits low haze, good adhesion to aluminum layers, and good mechanical and thermodynamic properties, making it suitable for long-term use in the working environment of automotive lighting trim rings. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram of the reaction mechanism of each component in a low-precipitation PBT modified material for automotive headlight trim provided by the present invention; Figure 2 The images show the DSC curves of the PBT modified materials prepared in the embodiments and comparative examples of this invention. Detailed Implementation

[0021] The present invention will be described in detail below with reference to specific embodiments and examples, thereby making the advantages and various effects of the present invention more clearly apparent. Those skilled in the art should understand that these specific embodiments and examples are for illustrative purposes only and are not intended to limit the present invention.

[0022] Throughout this specification, unless otherwise specified, the terminology used herein should be understood as having the meaning commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the event of any conflict, this specification shall prevail.

[0023] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be obtained by purchasing them from the market or by existing methods.

[0024] This invention provides a low-emission PBT modified material for automotive headlight trim rings, wherein the PBT modified material comprises the following components by weight: 45-90 parts of PBT resin, 5-50 parts of MXD6 resin, 0.2-0.4 parts of nucleating agent, 0.6-0.8 parts of antioxidant, 0.4-0.6 parts of light stabilizer, and 0.4-0.6 parts of lubricant.

[0025] As one embodiment, the PBT modified material comprises the following components by weight: 50-70 parts PBT resin, 10-50 parts MXD6 resin, 1-7 parts thermal conductive agent, 0.2-0.4 parts nucleating agent, 0.6-0.8 parts antioxidant, 0.4-0.6 parts light stabilizer, and 0.4-0.6 parts lubricant.

[0026] Specifically, this invention provides a low-extraction PBT modified material for automotive headlight trim rings, comprising, by weight, 45-90 parts PBT resin, 10-50 parts MXD6 resin, 1-7 parts thermal conductive agent, 0.2-0.4 parts nucleating agent, 0.6-0.8 parts antioxidant, 0.4-0.6 parts light stabilizer, and 0.4-0.6 parts lubricant. By introducing MXD6 resin with excellent barrier properties, a multi-interface structure is constructed, and the thermal conductive agent is combined to inhibit surface decomposition, forming a unique multi-interface-hyperlabyrinth structure. Furthermore, it utilizes… Acid-base reactive nucleating agents react with precipitates such as terebenzoic acid and low-molecular-weight esters within a multi-interface-super labyrinth structure, thereby eliminating small molecule structures such as precipitates at the source and preventing small molecule compounds from migrating to the material surface, thus reducing the material's haze. Furthermore, by combining antioxidants, light stabilizers, and lubricants to balance the comprehensive performance of PBT modified materials, the prepared PBT modified materials exhibit low haze, good adhesion to aluminum layers, and good mechanical and thermodynamic properties, making them suitable for long-term use in the working environment of automotive lighting trim rings.

[0027] As one embodiment, the PBT modified material comprises the following components by weight: 50-70 parts PBT resin, 10-50 parts MXD6 resin, 1-7 parts thermal conductive agent, 0.2-0.4 parts nucleating agent, 0.6-0.8 parts antioxidant, 0.4-0.6 parts light stabilizer, 0.4-0.6 parts lubricant, and 3-9 parts compatibilizer.

[0028] In this application, the PBT modified material prepared without the addition of a compatibilizer also has a low haze, but the addition of a compatibilizer can improve the impact strength and heat distortion temperature of the material.

[0029] As one embodiment, the intrinsic viscosity of the PBT resin is 0.8-1.1 dL / g, and the end carboxyl group content is ≤18.0 meq / kg; the relative viscosity of the MXD6 resin is 2.1-2.6.

[0030] In this application, the selected PBT resin is a low-precipitation PBT resin produced by solid-state polycondensation in a two-step process. The PBT resin produced by this method has low oligomer content, low precipitate, and low acid value. The intrinsic viscosity of this resin is 0.8~1.1 dL / g, the melt flow rate (250℃ / 2.16kg) is 25-80g / 10min, the terminal carboxyl group content is ≤18.0meq / kg, the soluble low molecular weight polymer content is ≤0.3%, and the volatile low molecular weight polymer content is ≤1.20%. MXD6 resin is a semi-aromatic polyamide containing an aromatic ring in its main chain, which has excellent barrier properties and can effectively block the precipitation of small molecules. Under normal circumstances, the compatibility between PBT resin and MXD6 is poor. However, in this application, without adding a compatibilizer, the PBT resin and MXD6 resin can be melted together by introducing a thermally conductive agent and a nucleating agent.

[0031] In one embodiment, the nucleating agent is nano-talc, nano-alumina, or zinc oxide.

[0032] In this application, nano zinc oxide is preferred as a nucleating agent. In addition to its heterogeneous nucleation function, nano zinc oxide can also conduct heat and react with acidic substances such as terephthalic acid, low molecular weight PBT, and ester molecules to form ionic polymers, which fundamentally interrupts the possibility of small molecules continuing to migrate, thereby reducing the haze of PBT modified materials.

[0033] In one embodiment, the antioxidant is a 1:1:2 blend of three multifunctional antioxidants: pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and bis(2,4-di-tert-butylphenol) pentaerythritol diphosphite; the light stabilizer is poly{[6-[(1,1,3,3-tetramethylbutyl)amino] The lubricant is a 2:1 mixture of hindered amine light stabilizers of different molecular weights, including 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 polysuccinate (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol). The lubricant includes at least one of pentaerythritol stearate, high molecular weight polyester wax, ultra-high molecular weight silicone, and ultra-high molecular weight polyethylene.

[0034] In this application, the antioxidant compound system exhibits excellent resistance to thermal oxidation, delaying the aging of polymer materials. It also possesses temperature resistance, extraction resistance, and durability, particularly reducing the migration and precipitation of small molecules in PBT-modified materials during use at high temperatures. The light stabilizer compound system exhibits excellent resistance to ultraviolet aging, delaying the photo-aging degradation of polymer materials. It also possesses good compatibility, extraction resistance, and durability, reducing the migration and precipitation of small molecules in PBT-modified materials during long-term light exposure.

[0035] In one embodiment, the thermal conductive agent is a nanosheet thermal conductive agent, which is nanographene, nanographite sheets, or nanoboron nitride.

[0036] In this application, the thermal conductive agent is a nanosheet-like thermal conductive agent with excellent flow orientation, capable of forming continuous thermal bridges. This enables efficient conduction of high-temperature heat from the surface of plastic parts, significantly reducing the decomposition rate of the plastic surface and the amount of small molecule precipitation. Furthermore, it can form a multi-interface-super labyrinth structure with the interfacial structure of multiple resin components, further increasing the difficulty of small molecule precipitation and movement. In a specific embodiment, nanosheet-like graphene is selected as the thermal conductive agent, with a thermal conductivity reaching up to 5000 W / (m・K).

[0037] In one embodiment, the compatibilizer is a comb-shaped PBT / MXD6 compatibilizer. The preparation method of the PBT / MXD6 compatibilizer includes: adding styrene and glycidyl methacrylate to molten caprolactam at a molar ratio of 95:5 under a nitrogen atmosphere, adding an initiator, and reacting at 78°C for 20 hours to obtain a polymer; pulverizing the polymer and washing it sequentially with deionized water and ethanol, filtering, and drying to obtain a pre-compatibility; mixing the pre-compatibility, MXD6 resin, and PBT resin at a weight ratio of 4:48:48 and adding the mixture to a twin-screw extruder, and performing melt extrusion granulation at 240-270°C to obtain the PBT / MXD6 compatibilizer.

[0038] In this application, a self-made compatibilizer can further improve the compatibilization effect of PBT resin and MXD6 resin. The preparation method of the self-made PBT / MXD6 compatibilizer includes: first, adding 300 g of caprolactam and 200 g of styrene / glycidyl methacrylate (molar ratio 95:5) mixed monomers into a three-necked flask equipped with a mechanical stirrer, adding 0.9 g of initiator azobisisobutyronitrile (AIBN), and stirring at 300 r / min for 5 min to ensure uniform mixing of the raw materials; then, placing the reaction system under constant temperature conditions of 150 r / min stirring speed, 0.5 L / min nitrogen flow rate, and 78℃ for 20 minutes. h, to obtain the polymer; after the polymerization reaction is completed, the polymer is mechanically pulverized and washed with deionized water to remove water-soluble caprolactam, and with hot ethanol to remove oily unconverted monomers. It is then vacuum dried for 48 h to obtain the pre-compatibilizer; finally, the pre-compatibilizer, MXD6 resin and PBT resin are mixed evenly in a weight ratio of 4:48:48 and fed into a twin-screw extruder. The mixture is melt-blended and granulated at 240℃-270℃ and 500 rpm to obtain the PBT / MXD6 compatibilizer; that is, the PBT / MXD6 compatibilizer prepared in this application is a comb-like PBT / MXD6 compatibilizer with styrene-glycidyl methacrylate as the main chain structure and PBT and MXD6 as grafts. It can minimize the thickening effect while maintaining good compatibility.

[0039] Based on a general inventive concept, this invention provides a method for preparing a low-precipitation PBT modified material for automotive headlight trim rings. The preparation method includes: drying PBT resin and MXD6 resin at 120°C for 3-4 hours; weighing the raw material components according to the first aspect of the low-precipitation PBT modified material for automotive headlight trim rings; adding the weighed raw material components to a high-speed mixing tank in proportion for premixing to obtain a premix; adding the premix to a twin-screw extruder for screw shear melt blending, extrusion granulation, and obtaining the low-precipitation PBT modified material; wherein the length-to-diameter ratio of the twin-screw extruder is (30-50):1, the main extruder speed is 320-380 rpm, and the extrusion temperature is 220-260°C.

[0040] Based on a general inventive concept, the present invention also provides a plastic part, characterized in that the plastic part is injection molded from the low-expiration PBT modified material for automotive headlight trim rings described in the first aspect, the plastic part being used to manufacture automotive headlight trim rings.

[0041] In summary, the PBT modified material provided in this application significantly increases the difficulty of small molecule precipitation by introducing MXD6 resin to construct a multi-resin interface and introducing sheet-like thermal conductive agents to construct a multi-interface-super labyrinth barrier system. Furthermore, by introducing nucleating agents with acid-base reactivity and thermal conductivity at the interface, easily migrating acid and ester small molecules are fundamentally eliminated. At the same time, based on the excellent flow orientation of the sheet-like thermal conductive agents, continuous thermal bridges can be formed, which can efficiently conduct high-temperature heat on the surface of plastic parts and significantly reduce the decomposition rate of the plastic surface.

[0042] This application addresses the problem of small molecule precipitation from three dimensions: (1) introducing thermally conductive agents to improve heat transfer efficiency and reduce the degradation of PBT materials; (2) constructing a multi-interface-super labyrinth barrier system; and (3) using reactive nucleating agents and thermally conductive fillers to chemically adsorb acid and ester small molecules to construct an ordered two-dimensional thermally conductive, barrier, and reactive system, the reaction mechanism of which is as follows: Figure 1 As shown, a low-precipitation PBT modified material for automotive lamp housings is prepared in one step by a twin-screw extrusion process using a customized screw configuration with medium-low shear and high dispersion. This material exhibits minimal small molecule volatility, good aluminum layer adhesion, low mold surface fouling, no blurred or low-gloss parts, and no fogging.

[0043] The present application is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the application. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national standards. If there is no corresponding national standard, then general international standards, conventional conditions, or conditions recommended by the manufacturer are followed.

[0044] The raw materials used in the examples and comparative examples are as follows: PBT resin: China Bluestar 1100 HQ.

[0045] MXD6 resin: Sinochem International, ZYMX-5006, relative viscosity 2.6.

[0046] Thermal conductive agent: Nano-graphene, Nanjing Xianfeng Nanotechnology Co., Ltd., model XFQ023.

[0047] Nucleating agent: Nano zinc oxide, Shanghai Yaotian New Material Technology Co., Ltd., model YT-Oy-02-1.

[0048] Light stabilizer: UV-944 / UV-622, Tianjin Lianlong New Material Co., Ltd., model RIASORB UV-944 / UV-622.

[0049] Antioxidant: Antioxidant 1010 / 3114 / 626, Tianjin Lianlong New Material Co., Ltd., model RIANOX1010 / 3114 / 626.

[0050] Lubricant: High molecular weight polyester wax, Clariant Licowax® PED 191.

[0051] MXD6 / PBT compatibilizer: homemade.

[0052] The raw material components in the low-precipitation PBT modified materials of Examples 1-9 and Comparative Examples 1-3 of this application, by weight, are shown in Table 1: Table 1. Formulation ratios of low-precipitation PBT modified materials in the examples and comparative examples. The preparation method for low-precipitation PBT modified materials by weighing the raw material components according to the formulation ratios provided in Examples 1-9 and Comparative Examples 1-3 includes the following steps: (1) Dry the PBT resin and MXD6 resin at 120℃ for 3-4 hours; (2) Add the weighed raw materials to the high-speed mixing tank in proportion for premixing to obtain a premix; (3) The premix is ​​added to the twin-screw extruder through the main feed port. The main speed of the twin-screw extruder is set to 350±30rpm and the extrusion temperature is 220-260℃. The low-precipitation PBT modified material is obtained by screw shear melt blending and extrusion granulation through a screw configuration with medium and low shear and high dispersion.

[0053] The performance of the low-precipitation PBT modified material prepared above was tested, and the test results are shown in Table 2. The specific test standards are as follows: (1) Mechanical testing: The low-precipitation PBT modified material was injection molded into ISO standard specimens for mechanical property testing (tensile strength test: test standard is ISO 527, tensile rate 50mm / min; bending performance test: test standard is ISO-178, bending rate 2mm / min; notched impact strength of simply supported beam: test standard is ISO-179). (2) Gloss test: The low-precipitation PBT modified material was injection molded into a standard color plate, and the gloss of the color plate was tested using a gloss meter at an angle of 85°. (3) Haze test: The low-exudation PBT modified material was injection molded into a standard color plate. Test standard: SKGY-0013; (4) Heat distortion temperature test: Refer to test standard ISO 75-2.

[0054] Table 2 Test Results From the above experimental data, we can see that: (1) Data from Comparative Example 1 and Comparative Example 2 show that after introducing the nucleating agent zinc oxide into PBT resin, the haze of the modified PBT material is significantly reduced. That is, the acidic small molecules in PBT resin can react and complex with zinc oxide, but the complexation is incomplete and other types of small molecules still migrate to the material surface. (2) Data from Examples 1-3 show that introducing MXD6 resin into PBT resin further reduces the haze of the PBT modified material, and the haze of the material gradually decreases with the increase of MXD6 content. That is, adding MXD6 resin can increase the difficulty of small molecule precipitation. (3) Data from Comparative Example 3 and Examples 4-6 show that introducing sheet-like thermal conductive nano-graphene and nucleating agent zinc oxide into PBT resin and MXD6 resin can significantly reduce the haze of PBT modified materials. Moreover, as the content of nano-graphene increases, the haze of the material gradually decreases. That is, the synergistic effect of nano-graphene, zinc oxide and MXD6 resin can significantly inhibit the precipitation of small molecules. (4) Data from Examples 4-9 show that adding the self-made PBT / MXD6 compatibilizer to PBT resin and MXD6 resin can not only reduce the haze of the material, but also improve the mechanical properties of the material. That is, the PBT / MXD6 compatibilizer can further improve the dispersion particle size and binding force between the two resins, and effectively reduce the precipitation of small molecules. At the same time, the compatibilizer plays a role in end capping in the formulation system, and also plays a role in reducing precipitation.

[0055] (5) The prepared PBT modified material was subjected to DCS testing, and the test results are as follows: Figure 2As shown, PBT resin and MXD6 resin were used in Example 2, but its DSC curve showed only one crystallization peak, that is, under certain conditions, PBT resin and MXD6 resin can be melted into one.

[0056] In summary, and in combination with Figure 1 Based on the reaction mechanism, this application introduces a nucleating agent nano-zinc oxide with acid-reactive ability, MXD6 resin with barrier ability, sheet-like nano-graphene with barrier ability and excellent thermal conductivity, and a self-made PBT / MXD6 compatibilizer to improve the compatibility between MXD6 resin and PBT resin. By combining these methods, such as reducing the local temperature of the material, increasing the migration path length of small molecules, reacting with acidic small molecules, and improving the bonding force between resins, the haze value of PBT materials used in automotive lighting rings can be effectively reduced.

[0057] Finally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0058] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0059] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A low outgassing PBT modified material for use in bezels for vehicle lamps, characterized in that, The PBT modified material comprises the following components in parts by weight: PBT resin 45-90 parts, MXD6 resin 5-50 parts, nucleating agent 0.2-0.4 parts, antioxidant 0.6-0.8 parts, light stabilizer 0.4-0.6 parts and lubricant 0.4-0.6 parts.

2. The low outgassing PBT modified material for vehicle lamp bezels according to claim 1, characterized in that, The PBT modified material comprises the following components in parts by weight: PBT resin 50-70 parts, MXD6 resin 10-50 parts, heat-conducting agent 1-7 parts, nucleating agent 0.2-0.4 parts, antioxidant 0.6-0.8 parts, light stabilizer 0.4-0.6 parts and lubricant 0.4-0.6 parts.

3. The low outgassing PBT modified material for vehicle lamp bezels according to claim 1, characterized in that, The PBT modified material comprises the following components in parts by weight: PBT resin 50-70 parts, MXD6 resin 10-50 parts, heat-conducting agent 1-7 parts, nucleating agent 0.2-0.4 parts, antioxidant 0.6-0.8 parts, light stabilizer 0.4-0.6 parts, lubricant 0.4-0.6 parts and compatibilizer 3-9 parts.

4. The low-extraction PBT modified material for vehicle lamp bezels according to any one of claims 1-3, characterized in that, The PBT resin has an intrinsic viscosity of 0.8-1.1 dL / g and a carboxyl end group content of ≤18.0 meq / kg; the MXD6 resin has a relative viscosity of 2.1-2.

6.

5. The low-extraction PBT modified material for vehicle lamp bezels according to any one of claims 1-3, characterized in that, The nucleating agent is nano-talc powder, nano-aluminum oxide or zinc oxide.

6. The low-extraction PBT modified material for vehicle lamp bezels according to any one of claims 1-3, characterized in that, The antioxidant is a 1:1:2 compound of four [beta-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid] pentaerythritol ester, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione and bis(2,4-di-tert-butylphenol) pentaerythritol diphosphite; The light stabilizer is a 2:1 compound of poly{[6-[(1,1,3,3-tetramethylbutyl) amino]-1,3,5-triazine-2,4-[(2,2,6,6,-tetramethyl-piperidyl) imino]-1,6-hexanediy[(2,2,6,6-tetramethyl-4-piperidyl) imino]} and poly(butyric acid (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinethanol) ester) different molecular weight hindered amine light stabilizer; The lubricant comprises at least one of pentaerythritol stearate, high molecular weight polyester wax, ultra-high molecular weight silicone and ultra-high molecular weight polyethylene.

7. The low outgassing PBT modified material for vehicle lamp bezels of claim 2, wherein, The heat-conducting agent is a nano flake heat-conducting agent, and the heat-conducting agent is nano graphene, nano graphite flake or nano boron nitride.

8. The low outgassing PBT modified material for vehicle lamp bezels according to claim 3, characterized in that, The compatibilizer is a PBT / MXD6 compatibilizer with a comb structure, and a preparation method of the PBT / MXD6 compatibilizer comprises: Under a nitrogen atmosphere, styrene and glycidyl methacrylate are added to molten caprolactam at a molar ratio of 95:5, an initiator is added, and the mixture is reacted at 78°C for 20h to obtain a polymer; The polymer is crushed and then washed with deionized water and ethanol in sequence, filtered and dried to obtain a pre-compatibilizer; The pre-compatibilizer, MXD6 resin and PBT resin are mixed at a weight ratio of 4:48:48, and then added to a twin-screw extruder for melt extrusion granulation at 240-270°C to obtain a PBT / MXD6 compatibilizer.

9. A process for the production of a low outgassing PBT modified material for use in bezels for vehicle lamps, characterized in that, The preparation method comprises: The PBT resin and MXD6 resin are dried at 120 DEG C for 3-4 h; The low-out PBT modified material for the decorative ring of vehicle lamp according to any one of claims 1-8 is weighed with each component of raw materials; The weighed each component of raw materials is added into a high-speed mixing barrel in proportion to be premixed to obtain a premix; The premix is added into a double-screw extruder to be screw sheared, melt blended, extruded and granulated to obtain the low-out PBT modified material; The length-diameter ratio of the double-screw extruder is (30-50):1, the main machine rotating speed is 320-380 rpm, and the extrusion temperature is 220-260 DEG C.

10. A plastic article, characterized by The plastic part is injection molded by the low-out PBT modified material for the decorative ring of vehicle lamp according to any one of claims 1-8, and the plastic part is used to manufacture the decorative ring of vehicle lamp.

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