High-transparency anti-warping laser-welded PC / PBT composite material and preparation method thereof

Abstract

This invention relates to the field of polymer material modification technology, and in particular to a high-transmittance, anti-warpage laser-welded PC / PBT composite material and its preparation method. The composite material comprises: 35-50 parts PBT resin, 15-30 parts siloxane copolymer PC resin, 18-28 parts modified glass fiber, 0.2-0.8 parts crystallization promoter, 0.6-1.5 parts transesterification inhibitor (diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate), 0.5-1.5 parts core-shell structured composite laser absorber, 0.2-0.5 parts antioxidant, and 0.1-0.5 parts functional lubricant; wherein the modified glass fiber is a flat glass fiber, its surface sequentially coated with an inner coating with a refractive index of 1.52-1.56 and an outer coating with a refractive index of 1.58-1.60. This composite material possesses high light transmittance, low warpage, excellent mechanical properties, and good heat resistance.

Description

Technical Field

[0001] This invention relates to the field of polymer material modification technology, and in particular to a high-transmittance, anti-warping laser-welded PC / PBT composite material and its preparation method. Background Technology

[0002] Laser transmission welding technology is increasingly widely used in fields such as automotive precision parts, electronic packaging, medical devices, and communication equipment due to its advantages such as high welding precision, small heat-affected zone, non-contact processing, and ability to weld complex geometries. In laser transmission welding, the two components to be welded are an upper light-transmitting component and a lower light-absorbing component. The laser beam penetrates the upper component and reaches the surface of the lower component. The lower component absorbs the laser energy and converts it into heat energy, causing the two components to melt at the joint interface, thus achieving a strong connection. Therefore, the material of the upper component must have sufficiently high transmittance to near-infrared laser light to ensure that the laser energy can effectively reach the welding interface.

[0003] Polycarbonate (PC) and polybutylene terephthalate (PBT) blends combine the excellent impact toughness and dimensional stability of PC with the good chemical corrosion resistance, processing fluidity and crystallinity of PBT, and have been widely used in the preparation of upper transparent components for laser welding.

[0004] However, existing PC / PBT composite materials still face the following technical bottlenecks when adapted to laser transmission welding processes: First, to improve the mechanical strength and rigidity of the upper component, glass fiber reinforcement is usually added. However, traditional circular cross-section glass fibers tend to be highly oriented along the melt flow direction during injection molding, resulting in significant anisotropic shrinkage and subsequent warping of the injection molded part. As an upper light-transmitting component, warping will prevent the welding surface from fitting tightly with the lower component, resulting in a generally large gap and severely affecting welding strength and sealing. Simultaneously, the significant difference between the refractive index of glass fiber and the PC / PBT resin matrix causes reflection loss at the fiber-resin interface when the laser passes through the upper component. Combined with the light scattering effect at the interface, this severely limits the infrared laser transmittance. Second, PC and PBT are prone to transesterification reactions during high-temperature melt blending, generating random copolymers that disrupt the molecular chain structure, leading to a significant decrease in the material's mechanical properties. For upper-layer components used in laser welding, the deterioration of mechanical properties not only affects the structural strength of the component itself, but also exacerbates warping deformation due to uneven distribution of internal stress in the material, further affecting the welding bonding accuracy. Thirdly, to meet the aesthetic requirements of products in the automotive and electronics industries, upper-layer transparent components typically need to have a dark appearance. Traditional carbon black dyes have strong absorption characteristics for near-infrared lasers, which significantly reduces the energy transfer efficiency when the laser penetrates the upper-layer component, making it difficult to meet the light transmittance requirements of laser welding for the upper-layer material. Fourthly, the heat distortion temperature of existing PC / PBT composite materials is generally low, making it difficult to meet the long-term heat resistance requirements of high-temperature applications such as automotive engine peripheral components, charging piles, and communication equipment housings.

[0005] Therefore, it is of great significance to develop a PC / PBT composite material that combines high laser transmittance, low warpage, excellent mechanical properties, and good heat resistance. Summary of the Invention

[0006] The purpose of this invention is to address the problems existing in the prior art by providing a high-transmittance, anti-warping laser-welded PC / PBT composite material and its preparation method. By selecting specific components and combining them with specific preparation processes, the composite material possesses high laser transmittance, low warping, and excellent mechanical properties and heat resistance.

[0007] To achieve the above objectives, the present invention provides a high-transmittance, anti-warping laser-welded PC / PBT composite material, comprising the following components in parts by weight: 35-50 parts PBT resin, 15-30 parts siloxane copolymer PC resin, 18-28 parts modified glass fiber, 0.2-0.8 parts crystallization accelerator, 0.6-1.5 parts transesterification inhibitor, 0.5-1.5 parts composite laser absorber, 0.2-0.5 parts antioxidant, and 0.1-0.5 parts functional lubricant; The modified glass fiber includes flat glass fiber, an inner coating layer covering the surface of the flat glass fiber, and an outer coating layer covering the surface of the inner coating layer; the refractive index of the inner coating layer is 1.52-1.56, the refractive index of the outer coating layer is 1.58-1.60, and the difference between the refractive indices of the inner coating layer and the outer coating layer is 0.04-0.08. The transesterification inhibitor is diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate; The composite laser absorber is a core-shell structured nanoparticle, with the core being nano-antimony tin oxide and the shell being nano-indium tin oxide.

[0008] In some optional embodiments, the method for preparing the modified glass fiber includes: Flat glass fibers are placed in an acid solution for activation treatment to obtain activated glass fibers; Tetraethoxysilane, tetrabutyl titanate, ethanol and water are mixed and hydrolyzed to obtain an inner coating sol; activated glass fibers are immersed in the inner coating sol, removed, dried and then heat-treated to obtain glass fibers coated with an inner coating. Tetraethoxysilane, phenyltriethoxysilane, ethanol and water are mixed and hydrolyzed to obtain an outer coating sol; glass fibers coated with an inner coating are immersed in the outer coating sol, removed, dried and then heat-treated to obtain modified glass fibers.

[0009] In some alternative embodiments, the flat glass fiber has a cross-sectional aspect ratio of (2-5):1, a length of 3-5 mm, and a diameter of 8-15 μm.

[0010] In some optional embodiments, the activation treatment includes: immersing flat glass fibers in a hydrochloric acid solution with a concentration of 1-3 mol / L, ultrasonically treating for 10-30 min, washing with water until neutral, and drying at 80-100℃ for 2-4 h to obtain activated glass fibers.

[0011] In some alternative embodiments, the molar ratio of tetraethoxysilane, tetrabutyl titanate, ethanol and water in the inner coating sol is (6-9):(1-4):(30-50):(20-40).

[0012] In some optional embodiments, tetraethoxysilane, tetrabutyl titanate, ethanol, and water are mixed, the pH is adjusted to 2-3 with acid, and hydrolyzed at 20-40°C for 1-3 hours to obtain an inner coating sol. Activated glass fibers are immersed in the inner coating sol for 5-15 minutes, removed, dried at 80-120°C for 1-3 hours, and then heat-treated at 400-600°C for 0.5-2 hours to obtain glass fibers coated with the inner coating.

[0013] In some alternative embodiments, the molar ratio of the tetraethoxysilane, phenyltriethoxysilane, ethanol and water in the outer coating sol is (5-8):(2-5):(30-50):(20-40).

[0014] In some optional embodiments, tetraethoxysilane, phenyltriethoxysilane, ethanol, and water are mixed, the pH is adjusted to 2-3 with acid, and hydrolyzed at 20-40°C for 1-3 hours to obtain an outer coating sol. Glass fibers coated with the inner coating are immersed in the outer coating sol for 5-15 minutes, then dried at 80-120°C for 1-3 hours, and subsequently heat-treated at 400-600°C for 0.5-2 hours to obtain modified glass fibers.

[0015] In some optional embodiments, the crystallization promoter comprises a long-chain linear saturated carboxylate sodium salt and nano-boron nitride, with a mass ratio of (2-3):1; the carbon chain length of the long-chain linear saturated carboxylate sodium salt is C. 10 -C 22 The particle size of the boron nitride nanoparticles is 50-200 nm.

[0016] In some alternative embodiments, the long-chain linear saturated carboxylate sodium salt is sodium stearate.

[0017] In some optional embodiments, the preparation method of the composite laser absorber includes: Nano-sized antimony tin oxide, water, indium salt, and tin salt are mixed, the pH is adjusted to alkaline, and the reaction is carried out to obtain a composite laser absorber.

[0018] In some optional embodiments, the indium salt is selected from at least one of indium chloride and indium nitrate; the tin salt is selected from at least one of tin tetrachloride and tin nitrate; the molar ratio of the indium salt to the tin salt is (8-10):1; and the concentration of indium ions in the resulting solution is 0.05-0.15 mol / L.

[0019] In some optional embodiments, the pH is adjusted to 8-10 with an alkaline solution, the reaction is carried out at 60-90°C for 2-6 hours, centrifuged, washed, dried, and then calcined at 400-600°C for 1-3 hours to obtain a composite laser absorber.

[0020] In some alternative embodiments, the antioxidant comprises hindered phenolic antioxidants and phosphite antioxidants in a mass ratio of 1:(1-2).

[0021] In some alternative embodiments, the hindered phenolic antioxidant is antioxidant 1098; the phosphite antioxidant is antioxidant 626.

[0022] In some alternative embodiments, the functional lubricant is poly(dimethylsiloxane-co-α-methylstyrene).

[0023] This invention also provides a method for preparing the aforementioned high-transmittance, anti-warping laser-welded PC / PBT composite material, comprising the following steps: The components are mixed and melt-blended extruded and granulated in a twin-screw extruder to obtain a high-transmittance, anti-warping laser-welded PC / PBT composite material.

[0024] In some optional embodiments, the method for preparing the high-transmittance, anti-warping laser-welded PC / PBT composite material includes the following steps: S1. Dry the PBT resin at 100-120℃ for 4-6 hours to obtain the dried PBT resin; dry the siloxane copolymer PC resin at 110-130℃ for 4-6 hours to obtain the dried siloxane copolymer PC resin. S2. The dried PBT resin, the dried siloxane copolymer PC resin, the crystallization accelerator, the transesterification inhibitor, the composite laser absorber, the antioxidant and the functional lubricant are mixed at a speed of 800-1200 r / min and a temperature of 40-60℃ for 10-20 min to obtain the premix. S3. The premixed material is added from the main feed port of the twin-screw extruder, and the modified glass fiber is added from the side feed port. The mixture is then melt-blended, extruded, and granulated to obtain granules. S4. Dry the granules at 100-120℃ for 3-5 hours to obtain a high-transmittance, anti-warping laser-welded PC / PBT composite material.

[0025] In some alternative embodiments, the twin-screw extruder has a screw length-to-diameter ratio of (36-48):1, a screw speed of 250-400 r / min, and a vacuum degree of -0.08 to -0.095 MPa.

[0026] In some optional embodiments, the temperature of each section of the twin-screw extruder is set as follows: Zone 1 200-220℃, Zone 2 220-240℃, Zone 3 240-260℃, Zone 4 245-265℃, Zone 5 245-260℃, Zone 6 240-255℃, Zone 7 235-250℃, and the die head temperature 245-260℃.

[0027] A schematic diagram of the preparation process of the high-transmittance, anti-warping laser-welded PC / PBT composite material in this invention is shown below. Figure 1 As shown.

[0028] Compared with the prior art, the present invention has the following beneficial effects: (1) In this invention, an inner coating with a refractive index of 1.52-1.56 and an outer coating with a refractive index of 1.58-1.60 are sequentially coated on the surface of flat glass fibers, forming a refractive index gradient transition layer between the fibers and the resin matrix, which reduces reflection and scattering losses at the fiber-resin interface; at the same time, the use of flat glass fibers reduces the orientation difference of the fibers in the injection molding flow direction. The combined effect of these two factors enables the 980nm infrared laser transmittance of the composite material to reach more than 28.5% (sample thickness 2.0mm).

[0029] (2) The present invention uses flat glass fibers, which have a lower degree of orientation in the injection molding shear flow field than round fibers, resulting in reduced anisotropic shrinkage. At the same time, the nano-boron nitride in the crystallization promoter is oriented along the melt flow direction during injection molding, which can induce PBT crystals to grow in a specific direction, so that the crystallization orientation matches the melt flow direction. The combined effect of these two factors allows the warpage (fitting gap) of the injection molded part of the composite material of the present invention to be controlled below 17 μm.

[0030] (3) In this invention, diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate is used as an ester exchange inhibitor. The molecule of this compound contains hindered phenolic structural units and phosphonate structural units, which have the functions of capturing free radicals and complexing with metal ions, respectively. It inhibits the ester exchange reaction within the melt blending temperature range, so that the notched impact strength of the simply supported beam of the composite material reaches 8.5 kJ / m. 2 above.

[0031] (4) The present invention uses a composite laser absorber with nano-tin antimony oxide as the core and nano-indium tin oxide as the shell, so that the composite material has high laser transmittance while maintaining a dark appearance.

[0032] (5) The tensile strength of the composite material of the present invention reaches 121 MPa or above, the flexural strength reaches 178 MPa or above, the flexural modulus reaches 8480 MPa or above, and the heat distortion temperature reaches 140℃ or above, exhibiting good comprehensive mechanical properties and heat resistance. The PC / PBT composite material provided by the present invention can be used for precision plastic parts requiring laser welding, such as automotive sensor housings, headlight assemblies, electronic connectors, charging pile housings, communication equipment housings, and medical device housings. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the preparation process of the high-transmittance, anti-warping laser-welded PC / PBT composite material in this invention. Detailed Implementation

[0034] The following embodiments are provided to better understand the present invention and are not limited to the described embodiments. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0035] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0036] In the following embodiments and comparative examples of the present invention, the PBT resin was purchased from Changchun Chemical Co., Ltd., model 1100-211M, with an intrinsic viscosity of 1.00±0.015 dL / g and a heat distortion temperature of 4.6 kg / cm². 2 The temperature under load was 155℃; the siloxane copolymer PC resin was purchased from Idemitsu Koden, model FG1760, with a melt index of 16 g / 10 min (300℃ / 1.2 kg); the poly(dimethylsiloxane-co-α-methylstyrene) was purchased from Sigma-Aldrich, model 481487, with a number average molecular weight of approximately 3000-5000 g / mol.

[0037] Example 1 This embodiment provides a high-transmittance, anti-warping laser-welded PC / PBT composite material, comprising the following components in parts by weight: 42 parts PBT resin, 25 parts siloxane copolymer PC resin, 22 parts modified glass fiber, 0.5 parts crystallization promoter (sodium stearate and 100nm nano boron nitride in a mass ratio of 2.5:1), 0.8 parts transesterification inhibitor (diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate), 1 part composite laser absorber, 0.3 parts antioxidant (antioxidant 1098 and antioxidant 626 in a mass ratio of 1:1.2), and 0.3 parts functional lubricant (poly(dimethylsiloxane-co-α-methylstyrene)).

[0038] The preparation methods for modified glass fibers include: Flat glass fibers (with a cross-sectional aspect ratio of 3:1, a length of 4 mm, and a diameter of 12 μm) were immersed in a 2 mol / L hydrochloric acid solution, sonicated for 20 min, washed with deionized water until neutral, and dried at 90 °C for 3 h to obtain activated glass fibers.

[0039] Tetraethoxysilane, tetrabutyl titanate, ethanol, and water were mixed in a molar ratio of 7.5:2.5:40:30. The pH was adjusted to 2.5 with a 2 mol / L hydrochloric acid solution, and the mixture was hydrolyzed at 30°C for 2 hours to obtain an inner coating sol. Activated glass fibers were immersed in the inner coating sol for 10 minutes, then dried at 100°C for 2 hours, and finally heat-treated at 500°C for 1 hour to obtain glass fibers coated with the inner coating. The refractive index of this inner coating is 1.54.

[0040] Tetraethoxysilane, phenyltriethoxysilane, ethanol, and water were mixed in a molar ratio of 6.5:3.5:40:30. The pH was adjusted to 2.5 with a 2 mol / L hydrochloric acid solution, and the mixture was hydrolyzed at 30°C for 2 hours to obtain an outer coating sol. Glass fibers coated with the inner coating were immersed in the outer coating sol for 10 minutes, then dried at 100°C for 2 hours, and finally heat-treated at 500°C for 1 hour to obtain modified glass fibers. The refractive index of this outer coating is 1.59.

[0041] Methods for preparing composite laser absorbers include: 10g of nano-antimony tin oxide (30nm particle size) was dispersed in 200mL of deionized water. Indium chloride and tin tetrachloride were added, and the indium ion concentration was controlled at 0.1mol / L. The molar ratio of indium chloride to tin tetrachloride was 9:1. The pH was adjusted to 9 with 26% ammonia solution, and the reaction was carried out at 80℃ for 4h. After centrifugation, washing, and drying, the product was calcined at 500℃ for 2h to obtain a core-shell structured composite laser absorber, with nano-antimony tin oxide as the core and nano-indium tin oxide as the shell.

[0042] This embodiment also provides a method for preparing the high-transmittance, anti-warping laser-welded PC / PBT composite material, including the following steps: The PBT resin was dried at 110°C for 5 hours, and the siloxane copolymer PC resin was dried at 120°C for 5 hours.

[0043] The dried PBT resin, dried siloxane copolymer PC resin, crystallization accelerator, transesterification inhibitor, composite laser absorber, antioxidant and functional lubricant are added to a high-speed mixer and mixed for 15 minutes at a speed of 1000 r / min and a temperature of 50℃ to obtain a premix.

[0044] The premixed material is added through the main feed port of the twin-screw extruder, and the modified glass fiber is added through the side feed port for melt blending, extrusion, and granulation. The twin-screw extruder has a screw length-to-diameter ratio of 40:1, a screw speed of 320 r / min, and a vacuum degree of -0.09 MPa. The temperature settings for each section of the twin-screw extruder are as follows: Zone 1 215℃, Zone 2 235℃, Zone 3 250℃, Zone 4 255℃, Zone 5 255℃, Zone 6 250℃, Zone 7 245℃, and the die head temperature is 255℃.

[0045] The obtained granules were dried at 110℃ for 4 hours to obtain a high-transmittance, anti-warping laser-welded PC / PBT composite material.

[0046] Example 2 The only difference between this embodiment and Example 1 is that the PBT resin is 38 parts, the siloxane copolymer PC resin is 30 parts, and the modified glass fiber is 20 parts. The types, amounts, and preparation methods of the remaining components are the same as in Example 1.

[0047] Example 3 The only difference between this embodiment and Example 1 is that the PBT resin is 48 parts, the siloxane copolymer PC resin is 18 parts, and the modified glass fiber is 25 parts. The types, amounts, and preparation methods of the remaining components are the same as in Example 1.

[0048] Comparative Example 1 The only difference between this comparative example and Example 1 is that ordinary circular cross-section glass fibers (12 μm in diameter and 4 mm in length) are used instead of the modified glass fibers in Example 1. The types, amounts, and preparation methods of the remaining components are the same as in Example 1.

[0049] Comparative Example 2 The only difference between this comparative example and Example 1 is that the composite laser absorber in Example 1 is not added; instead, an equal amount of traditional carbon black masterbatch (PP substrate, 40% carbon black content) is used as a substitute. The types, amounts, and preparation methods of the remaining components are the same as in Example 1.

[0050] Comparative Example 3 The only difference between this comparative example and Example 1 is that an equal amount of ADK STAB AX-71 is used to replace diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate in Example 1. The types, amounts, and preparation methods of the remaining components are the same as in Example 1.

[0051] Comparative Example 4 The only difference between this comparative example and Example 1 is that no crystallization accelerator is added. The types, amounts, and preparation methods of the remaining components are the same as in Example 1.

[0052] Experimental Example 1 The PC / PBT composite materials prepared in Examples 1-3 and Comparative Examples 1-4 were injection molded into standard strips and flat specimens using a plastic injection molding machine at an injection temperature of 250-260℃. The molded specimens were then placed at a temperature of 23±2℃ and a relative humidity of 50±5% for at least 24 hours before performance testing. The test methods for each property are as follows: (1) Tensile strength: Tested according to ISO 527 standard, with specimen type 1A and test rate of 5 mm / min.

[0053] (2) Bending strength and bending modulus: tested according to ISO 178 standard, test rate 2 mm / min.

[0054] (3) Notched impact strength of simply supported beam: tested according to ISO 179-1 standard, test temperature 23℃.

[0055] (4) Heat distortion temperature: tested according to ISO 75-2 standard, load 1.80MPa.

[0056] (5) Infrared laser transmittance: The transmittance was tested at a wavelength of 980nm using an LPKF TMG3 transmittance meter with a sample thickness of 2.0mm.

[0057] (6) Warpage (fitting clearance): Place the injection-molded flat sample (100mm×100mm×2mm) on a standard platform and use a coordinate measuring machine to measure the warpage height difference between the four corners and the center point of the sample. The maximum height difference is used as the warpage evaluation index.

[0058] The test results are shown in Table 1.

[0059] Table 1 Test Results

[0060] The results above show that the overall performance of Examples 1-3 is significantly better than that of the comparative examples. This invention achieves a balance between high transmittance, low warpage, and excellent mechanical properties through the synergistic effect of modified glass fiber, transesterification inhibitor (diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate), core-shell structured composite laser absorber, and crystallization promoter.

[0061] In summary, this invention utilizes flat glass fibers and sequentially coats their surfaces with inner and outer coatings exhibiting gradient refractive indices. By combining the synergistic effects of hindered phenol-phosphonate bifunctional transesterification inhibitors, core-shell composite laser absorbers, and compounded crystallization promoters, a PC / PBT composite material with high laser transmittance, low warpage, excellent mechanical properties, and good heat resistance is obtained.

[0062] Finally, it should be noted that the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A high-transmittance, anti-warping laser-welded PC / PBT composite material, characterized in that, The components include the following parts by mass: 35-50 parts PBT resin, 15-30 parts siloxane copolymer PC resin, 18-28 parts modified glass fiber, 0.2-0.8 parts crystallization accelerator, 0.6-1.5 parts transesterification inhibitor, 0.5-1.5 parts composite laser absorber, 0.2-0.5 parts antioxidant, and 0.1-0.5 parts functional lubricant; The modified glass fiber includes flat glass fiber, an inner coating layer covering the surface of the flat glass fiber, and an outer coating layer covering the surface of the inner coating layer; the refractive index of the inner coating layer is 1.52-1.56, the refractive index of the outer coating layer is 1.58-1.60, and the difference between the refractive indices of the inner coating layer and the outer coating layer is 0.04-0.

08. The transesterification inhibitor is diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate; The composite laser absorber is a core-shell structured nanoparticle, with the core being nano-antimony tin oxide and the shell being nano-indium tin oxide.

2. The high-transmittance, anti-warping laser-welded PC / PBT composite material according to claim 1, characterized in that, The method for preparing the modified glass fiber includes: Flat glass fibers are placed in an acid solution for activation treatment to obtain activated glass fibers; Tetraethoxysilane, tetrabutyl titanate, ethanol and water are mixed and hydrolyzed to obtain an inner coating sol; activated glass fibers are immersed in the inner coating sol, removed, dried and then heat-treated to obtain glass fibers coated with an inner coating. Tetraethoxysilane, phenyltriethoxysilane, ethanol and water are mixed and hydrolyzed to obtain an outer coating sol; glass fibers coated with an inner coating are immersed in the outer coating sol, removed, dried and then heat-treated to obtain modified glass fibers.

3. The high-transmittance, anti-warping laser-welded PC / PBT composite material according to claim 2, characterized in that, In the inner coating sol, the molar ratio of tetraethoxysilane, tetrabutyl titanate, ethanol and water is (6-9):(1-4):(30-50):(20-40).

4. The high-transmittance, anti-warping laser-welded PC / PBT composite material according to claim 2, characterized in that, In the outer coating sol, the molar ratio of tetraethoxysilane, phenyltriethoxysilane, ethanol and water is (5-8):(2-5):(30-50):(20-40).

5. The high-transmittance, anti-warping laser-welded PC / PBT composite material according to claim 1, characterized in that, The crystallization promoter comprises a long-chain linear saturated sodium carboxylate and nano-boron nitride, with a mass ratio of (2-3):1; the carbon chain length of the long-chain linear saturated sodium carboxylate is C. 10 -C 22 The particle size of the boron nitride nanoparticles is 50-200 nm.

6. The high-transmittance, anti-warping laser-welded PC / PBT composite material according to claim 1, characterized in that, The preparation method of the composite laser absorber includes: Nano-sized antimony tin oxide, water, indium salt, and tin salt are mixed, the pH is adjusted to alkaline, and the reaction is carried out to obtain a composite laser absorber.

7. The high-transmittance, anti-warping laser-welded PC / PBT composite material according to claim 1, characterized in that, The antioxidants include hindered phenolic antioxidants and phosphite antioxidants, with a mass ratio of 1:(1-2).

8. The high-transmittance, anti-warping laser-welded PC / PBT composite material according to claim 1, characterized in that, The functional lubricant is poly(dimethylsiloxane-co-α-methylstyrene).

9. The method for preparing high-transmittance, anti-warping laser-welded PC / PBT composite material according to any one of claims 1-8, characterized in that, Includes the following steps: The components are mixed and melt-blended extruded and granulated in a twin-screw extruder to obtain a high-transmittance, anti-warping laser-welded PC / PBT composite material.

10. The preparation method according to claim 9, characterized in that, The temperature settings for each section of the twin-screw extruder are as follows: Zone 1 200-220℃, Zone 2 220-240℃, Zone 3 240-260℃, Zone 4 245-265℃, Zone 5 245-260℃, Zone 6 240-255℃, Zone 7 235-250℃, and Die head temperature 245-260℃.

Images