Light-proof and infrared-transmitting polycarbonate composite material and preparation method thereof

Abstract

The invention relates to the field of infrared materials, in particular to a light-proof and infrared-transmitting polycarbonate composite material and a preparation method thereof. The polycarbonate composite material is prepared from the following raw materials in parts by mass: 96 to 99 parts of polycarbonate, 0.1 to 0.8 part of antioxidant, 0.3 to 1 part of lubricant and 0.3 to 2 parts of pigment. Wherein the pigment is an aminoketone pigment BLACK HTG. The infrared light transmittance of the polycarbonate composite material under the thickness of 2.5 mm is larger than 80%, natural light and LED light cannot penetrate through the polycarbonate composite material, the market blank in the prior art is filled, and the application adaptability is high.

Description

Technical Field

[0001] This invention relates to the field of infrared materials, specifically to a light-blocking, infrared-transmitting polycarbonate composite material and its preparation method. Background Technology

[0002] Polycarbonate composites, with their excellent mechanical properties, impact resistance, heat resistance, and flame retardancy, are widely used in electronics, automobiles, machinery, and precision instruments. In the prior art, Chinese patent application CN101100520A discloses a method for manufacturing infrared-transparent black plastic products. This method involves mixing transparent colored pigments with transparent colorless resins and then mechanically processing the mixture to produce a black finished product. The black color is formed by mixing compatible transparent primary color pigments—cyan, magenta, and yellow—in different proportions, providing a fundamental approach for the preparation of infrared-transparent black plastics.

[0003] Currently, the conventional method for preparing black or colored plastics in the plastics processing and manufacturing field is the melt mixing method. This involves first dispersing carbon black or colored pigments in molten resin, then melting and mixing them with additives and other functional masterbatches. After all the substrates are uniformly mixed, extrusion granulation is completed. This method is a common processing method in the industry, but it has significant drawbacks in the preparation of infrared-transparent black plastics. The aforementioned existing preparation methods are prone to uneven pigment dispersion, leading to pigment agglomeration within the plastic. This directly affects the infrared transmittance of the material, causing the product performance to fail to meet application requirements, becoming a key issue restricting the development of infrared-transparent black polycarbonate.

[0004] Existing commercially available black infrared-transmitting polycarbonate products, while achieving infrared transmittance of over 80%, suffer from a significant shortcoming in light transmittance. They cannot effectively block LED lights and natural light, failing to meet the high-end demands of the electronics and automotive industries. Particularly in applications related to autonomous driving and in-vehicle sensing, such as in-vehicle infrared night vision systems, keyless entry systems, and in-vehicle life detection sensors, as well as in automotive lights and electronic device sensor windows, visible light leakage not only reduces the product's concealment, affecting design aesthetics and functional confidentiality, but the 80% infrared transmittance also cannot meet the high requirements of autonomous driving technology for signal transmission efficiency and response speed. The industry urgently needs higher-performance infrared-transmitting polycarbonate composite materials. Summary of the Invention

[0005] To address the aforementioned technical problems, the first aspect of this invention provides a light-blocking, infrared-transmitting polycarbonate composite material, the raw materials for which, by mass parts, comprise: 96-99 parts polycarbonate, 0.1-0.8 parts antioxidant, 0.3-1 parts lubricant, and 0.3-2 parts pigment; wherein the pigment is an amino ketone pigment, and the infrared transmittance of the polycarbonate composite material is >80%, and it is opaque to natural light and LED light beads (light).

[0006] This solution, through precise control of raw material types and proportions, combined with a specific extrusion process, solves the problems of insufficient infrared transmittance, visible light leakage, and poor processing stability in existing products. By adjusting the dosage of 0.3-2 parts of amino ketone pigment, this invention can completely block natural light and LED lights, solving the problems of poor concealment and insufficient design aesthetics caused by visible light leakage. It can effectively shield internal LED lights in automotive / electronic devices, enhancing the integrated design of automotive interiors. Furthermore, the composite material achieves an actual infrared transmittance of 85-88% at a thickness of 2.0mm, far exceeding the >80% limit of this solution. This is a significant improvement over the 80% transmittance of existing commercially available products, ensuring efficient infrared signal transmission and meeting the high requirements for signal transmission efficiency and response speed in automotive autonomous driving, automotive infrared sensing, and electronic device sensing windows. Simultaneously, the use of 0.1-0.8 parts of antioxidant effectively inhibits the thermal oxidative degradation of polycarbonate during high-temperature extrusion and subsequent use, preventing yellowing and degradation of mechanical properties, ensuring the long-term performance stability of the composite material. Additionally, with 96-99 parts of polycarbonate... Using polycarbonate as the main base material, the proportions of each raw material follow the principle of base material as the main component and additives as the auxiliary component. This allows the composite material to retain the excellent mechanical, impact resistance, heat resistance, and flame retardant properties of polycarbonate itself, making it suitable for the strength and environmental requirements of high-end applications such as automobiles and electronics. In terms of processing performance, the use of 0.3-1 part lubricant reduces the frictional resistance of melt mixing and extrusion, allowing polycarbonate, antioxidants, and amino ketone pigments to be mixed more evenly in twin-screw extrusion. This completely solves the problems of uneven pigment dispersion and agglomeration in existing technologies, avoids fluctuations in infrared transmittance and poor light-blocking effect caused by uneven local composition, and ensures the smoothness of extrusion granulation and subsequent injection molding. The resulting products have a smooth surface, no sticking to the mold, and no defects, making them suitable for large-scale industrial production. This fills the market gap in existing technologies that cannot simultaneously meet the requirements of "high infrared transmittance, complete visible light blocking, and stable material performance," effectively improving the application added value and application adaptability of the product.

[0007] As an example of implementation, the pigment described is BLACK HTG and is available from Jiangxi Dingrui New Materials Co., Ltd.

[0008] Aminoketone-based black pigments possess selective absorption / transmission properties for both visible and infrared light. They can completely block the visible light bands of natural light and LED lights, fundamentally solving the problem of visible light leakage in existing technologies. This achieves complete opacity in composite materials, meeting the requirements of automotive and electronic devices for concealment and functional confidentiality. Simultaneously, they exhibit no significant absorption or scattering in the infrared band above 800nm, ensuring efficient infrared light transmission, which aligns with the core requirements of autonomous driving and sensing components for infrared signal transmission. Furthermore, this pigment exhibits excellent compatibility with polycarbonate substrates. Compared to existing technologies where pigments such as mixed primary colorants and carbon black are prone to poor compatibility with resin substrates, resulting in uneven dispersion and agglomeration, BLACK HTG aminoketone-based black pigments are well-compatible with polycarbonate melt systems. During high-speed stirring and twin-screw extrusion, they can be uniformly dispersed in the substrate, avoiding problems such as fluctuations in infrared transmittance and uneven shading effects caused by localized pigment agglomeration. This ensures consistent optical properties across all parts of the composite material and prevents surface defects caused by agglomeration, thus meeting the appearance requirements of injection molding.

[0009] As an example of implementation, the antioxidants include one or more of hindered phenolic antioxidants, phosphite antioxidants, hindered amine antioxidants, and thioester antioxidants.

[0010] As an implementable example, the grades of the hindered phenolic antioxidants include one or more of the following: antioxidant 1010, antioxidant 1076, antioxidant GA80, antioxidant 2246, or antioxidant BHT (2,6-di-tert-butyl-4-methylphenol).

[0011] As an implementable example, the phosphite antioxidants include: monophosphite antioxidants or diphosphite antioxidants.

[0012] Furthermore, the grades of the monophosphite antioxidants include: Antioxidant 168 or Antioxidant TPP (triphenyl phosphite).

[0013] Furthermore, the grades of the aforementioned bisphosphite antioxidants include one or more of the following: antioxidant 626, antioxidant 618, antioxidant 9228, antioxidant P-EPQ (tetra(2,4-di-tert-butylphenyl)-4,4'-biphenyl diphosphite) or antioxidant AS-4500 (4,4'-butylidene bis-(3-methyl-6-tert-butylphenyl)-tetra(tetrazyl) diphosphite).

[0014] Furthermore, the phosphite antioxidant is designated as Antioxidant 168 and is available from Saint-Gobain Fine Chemicals Co., Ltd.

[0015] As an implementable example, the grades of the hindered amine antioxidants include one or more of the following: antioxidant 944, antioxidant 770, antioxidant 711, antioxidant 622, antioxidant 783, antioxidant 292, antioxidant 123, or antioxidant 2020.

[0016] As an implementable example, the grades of the thioester antioxidants include one or more of the following: antioxidant 636, antioxidant 412S, antioxidant DLTP (dilauryl thiodipropionate), antioxidant DSTDP (distearate thiodipropionate), or antioxidant DMTDP (dimyristyl thiodipropionate).

[0017] As an implementable example, the lubricant includes one or more of pentaerythritol stearate (PETS), glyceryl monostearate (GMS), paraffin wax, polyethylene wax, polypropylene wax, stearic acid, zinc stearate, or calcium stearate.

[0018] A second aspect of this invention provides a method for preparing a light-blocking, infrared-transmitting polycarbonate composite material, comprising the following steps: Polycarbonate, antioxidants, lubricants, and pigments are mixed in a high-speed mixer and added from the main feed port of a twin-screw extruder. The mixture is then melt-extruded to obtain a polycarbonate composite material.

[0019] As an feasible example, the twin-screw extruder has a rotational speed of 200-300 rpm, an extrusion temperature of 250-300℃, and an output rate of 20-30 kg / h.

[0020] Beneficial effects (i) The polycarbonate composite material provided by the present invention has excellent optical properties, achieving the dual characteristics of being opaque and highly transparent to infrared light. It can block natural light and LED light. The transmittance of infrared light above 800nm ​​reaches 85-88% at a thickness of 2.0mm and is also stable at over 85% at a thickness of 2.5mm, which is far superior to existing products.

[0021] (ii) The pigments in this invention have good dispersibility. The selected amino ketone pigment BLACK HTG has excellent compatibility with polycarbonate substrate, which solves the problems of uneven dispersion and agglomeration of traditional pigments and ensures that the optical properties of each part of the composite material are consistent.

[0022] (III) The present invention inhibits the thermal oxidative degradation of polycarbonate during high-temperature processing and use by using a reasonable antioxidant ratio, while retaining the excellent mechanical, impact resistance, heat resistance and flame retardant properties of the substrate, and can be used stably for a long time.

[0023] (iv) In this invention, the precise addition of lubricant, combined with a specific extrusion process, reduces the frictional resistance of melt mixing and extrusion, ensuring the smoothness of extrusion granulation and injection molding, resulting in defect-free product surfaces, and making it suitable for large-scale industrial production.

[0024] (v) The polycarbonate composite material prepared in this invention has high application adaptability, has a piano black appearance, can effectively shield the internal LED lights of the equipment to enhance the design sense, and at the same time, its high infrared transmittance meets the signal transmission needs of high-end scenarios such as autonomous driving, vehicle-mounted sensing and electronic device sensing windows, filling the market technology gap. Attached Figure Description

[0025] Figure 1 This is a graph showing the infrared transmittance of the polycarbonate composite material in Example 1.

[0026] Figure 2 The image shows the infrared transmittance test result of the polycarbonate composite material in Comparative Example 1.

[0027] Figure 3 The image shows the infrared transmittance test results for the polycarbonate composite material in Comparative Example 3. Detailed Implementation

[0028] Example 1 The first aspect of this example provides a light-blocking, infrared-transmitting polycarbonate composite material, the raw materials for which, by mass parts, include: 99.0 parts of polycarbonate; 0.3 parts lubricant; Antioxidant 0.3 parts; Pigment 0.4 parts.

[0029] The polycarbonate was purchased from Wanhua Chemical, model A1225; the antioxidant was antioxidant 168, purchased from Saint-Gobain Fine Chemicals Co., Ltd.; the lubricant was pentaerythritol stearate (PETS), purchased from Lonza Corporation, USA; and the pigment was amino ketone pigment, model BLACK HTG, purchased from Jiangxi Dingrui New Materials Co., Ltd.

[0030] The second aspect of this example provides a method for preparing a light-blocking, infrared-transmitting polycarbonate composite material, comprising the following steps: Polycarbonate, antioxidants, lubricants, and pigments are mixed in a high-speed mixer and added through the main feed port of a twin-screw extruder. The mixture is then melt-extruded to obtain a polycarbonate composite material. The twin-screw extruder operates at a speed of 263 rpm, an extrusion temperature of 270°C, and an output rate of 25 kg / h.

[0031] Example 2 The specific implementation method in this example is the same as in Example 1, except that the raw materials for preparing the polycarbonate composite material, by mass parts, include: 99.0 parts of polycarbonate; 0.3 parts lubricant; Antioxidant 0.2 parts; 0.5 parts pigment.

[0032] Example 3 The specific implementation method in this example is the same as in Example 1, except that the raw materials for preparing the polycarbonate composite material, by mass parts, include: 99.0 parts of polycarbonate; 0.3 parts lubricant; Antioxidant 0.3 parts; Pigment 0.6 parts.

[0033] Comparative Example 1 The specific implementation method in this example is the same as in Example 2, except that the pigment used in the polycarbonate composite material is a composite pigment, model BLACK R, which was purchased from Jiangxi Dingrui New Material Co., Ltd.

[0034] Comparative Example 2 The specific implementation method in this example is the same as that in Comparative Example 1, except that the raw materials for preparing the polycarbonate composite material, by mass parts, include: 99.0 parts of polycarbonate; 0.3 parts lubricant; Antioxidant 0.2 parts; Pigment 0.6 parts.

[0035] Comparative Example 3 The specific implementation method in this example is the same as in Example 2, except that the pigment of the polycarbonate composite material is carbon black, model 660R, purchased from Cabot Corporation.

[0036] Comparative Example 4 The specific implementation method in this example is the same as in Example 2, except that the raw materials for preparing the polycarbonate composite material, by mass parts, include: 99.0 parts of polycarbonate; 0.2 parts lubricant; Antioxidant 0.2 parts; Pigment 0.6 parts.

[0037] The pigments are BLACK R pigment and 660R carbon black, with a mass ratio of 5:1.

[0038] Performance testing The infrared transmittance, natural light transmittance, and LED light transmittance of the polycarbonate composite materials (2.5 mm thickness) tested in Examples 1-3 and Comparative Examples 1-4 are detailed in Table 1. Figure 1-3 The infrared transmittance test diagram of the polycarbonate composite material in Example 1 is shown below. Figure 1 As shown; the infrared transmittance test graph of the polycarbonate composite material in Comparative Example 1 is shown in the figure. Figure 2 As shown; the infrared transmittance test graph of the polycarbonate composite material in Comparative Example 3 is shown in the figure. Figure 3 As shown.

[0039] Table 1

[0040] As can be seen from the test results in Table 1, the use of BLACK HTG as a pigment in this invention can enable the polycarbonate composite material to have a high infrared transmittance, which effectively prevents the transmission of natural light and LED light. Other types of pigments cannot achieve the technical effect of "not allowing natural light to pass through". Therefore, the polycarbonate composite material prepared in Examples 1-3 of this invention has high practical performance.

Claims

1. A light-blocking, infrared-transmitting polycarbonate composite material, characterized in that, The raw materials for preparation, by mass parts, include: 96-99 parts polycarbonate, 0.1-0.8 parts antioxidant, 0.3-1 part lubricant, and 0.3-2 parts pigment; The pigment is an amino ketone pigment; The polycarbonate composite material has an infrared transmittance of >80% and is opaque to natural light and LED beads.

2. The polycarbonate composite material according to claim 1, characterized in that, The antioxidants mentioned include one or more of hindered phenolic antioxidants, phosphite antioxidants, hindered amine antioxidants, and thioester antioxidants.

3. The polycarbonate composite material according to claim 2, characterized in that, The hindered phenolic antioxidants include one or more of antioxidant 1010, antioxidant 1076, antioxidant GA80, antioxidant 2246, or antioxidant BHT.

4. The polycarbonate composite material according to claim 2, characterized in that, The phosphite antioxidants mentioned include monophosphite antioxidants or diphosphite antioxidants.

5. The polycarbonate composite material according to claim 4, characterized in that, The grades of the monophosphite antioxidants include antioxidant 168 or antioxidant TPP.

6. The polycarbonate composite material according to claim 4, characterized in that, The grades of the bisphosphite antioxidants include one or more of antioxidant 626, antioxidant 618, antioxidant 9228, or antioxidant AS-4500.

7. The polycarbonate composite material according to claim 2, characterized in that, The hindered amine antioxidants include one or more of the following grades: antioxidant 944, antioxidant 770, antioxidant 711, antioxidant 622, antioxidant 783, antioxidant 292, antioxidant 123, or antioxidant 2020.

8. The polycarbonate composite material according to claim 1, characterized in that, The lubricant includes one or more of pentaerythritol stearate, glyceryl monostearate, paraffin wax, polyethylene wax, polypropylene wax, stearic acid, zinc stearate, or calcium stearate.

9. A method for preparing a polycarbonate composite material according to any one of claims 1-8, characterized in that, Includes the following steps: Polycarbonate, antioxidants, lubricants, and pigments are mixed in a high-speed mixer and added from the main feed port of a twin-screw extruder. The mixture is then melt-extruded to obtain a polycarbonate composite material.

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