A pc composition, its preparation method and application

Abstract

The application discloses a PC composition and a preparation method and application thereof, and belongs to the technical field of high polymer materials. The composition is prepared by introducing magnesium oxide and silicon dioxide with specific sizes and whiteness into a PC base resin as a light-transmitting agent, so that the prepared product does not have a yellowing effect, has ideal whiteness, and can realize high light transmittance and high infrared light transmittance.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a PC composition, its preparation method, and its application. Background Technology

[0002] Polycarbonate (PC) possesses excellent mechanical and flame-retardant properties, making it an ideal thermoplastic engineering material widely used in the automotive industry. When used to manufacture automotive components with high light transmittance and high infrared transmittance, such as active air intake grilles, PC materials often require the introduction of specific organic or inorganic light-transmitting agents in a compound formulation. However, since active air intake grilles are generally white, these PC materials also require a high whiteness appearance. Specifically, materials used for such automotive components need an infrared transmittance of over 65%, a light transmittance of over 28%, and a whiteness of over 86.

[0003] However, traditional light-transmitting agents added to PC resin cannot achieve a high whiteness effect. In fact, some catalysts with high light transmittance or high infrared transmittance can even catalyze the yellowing effect of PC resin during product processing or use, further reducing whiteness. Summary of the Invention

[0004] Based on the deficiencies of the existing technology, the purpose of this invention is to provide a PC composition that introduces magnesium oxide and silicon dioxide of specific size and whiteness into the PC matrix resin as light transmittance agents, so that the prepared product will not have a yellowing effect, has ideal whiteness, and can achieve high light transmittance and high infrared light transmittance.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A PC composition comprising the following components in parts by weight:

[0007] 100 parts PC resin, 0.1-1.2 parts magnesium oxide, and 0.2-2.5 parts silicon dioxide;

[0008] The whiteness of the magnesium oxide is ≥95%;

[0009] The ratio of the average retained particle size of silicon dioxide to magnesium oxide is (2-7):1.

[0010] Different light-transmitting fillers have different infrared transmission wavelengths and refractive indices, resulting in varying whiteness. Therefore, when applied to a PC resin matrix, they lead to products with completely different light transmittance, light transmission properties, and apparent whiteness. Furthermore, some light-transmitting fillers can cause yellowing of the PC resin due to their catalytic effect, affecting the product's apparent whiteness. On the other hand, the light transmittance of light-transmitting fillers is also related to their particle size; products prepared using fillers of different sizes will have different light transmittance and infrared transmittance. Based on these factors, there is currently no PC composite material specifically designed for active air intake grilles that possess high whiteness, high light transmittance, and high infrared transmittance. Therefore, the technical solution of this invention introduces a specific combination of magnesium oxide and silicon dioxide into the PC resin matrix. The infrared transmission wavelength of magnesium oxide is 0.4-6 μm, and its refractive index is 1.736, which is very close to the refractive index of PC resin. It has high infrared transmittance and light transmittance. When combined with silicon dioxide, which has high whiteness and high scattering rate, it acts as a light transmittance agent and will not cause yellowing of PC resin due to catalysis. At the same time, the whiteness of magnesium oxide is limited to at least 95%, and the two different fillers are maintained within a specific range of retained average particle size ratio. While maintaining high whiteness, the final product has ideal light transmittance and infrared transmittance, which fully meets the comprehensive material indicators of infrared transmittance of more than 65%, light transmittance of more than 28%, and whiteness of more than 86 when used to manufacture automotive parts with high light transmittance and high infrared linearity, such as active air intake grilles.

[0011] Preferably, the PC composition comprises the following components in parts by weight:

[0012] 100 parts PC resin, 0.2-1 parts magnesium oxide, and 0.5-2 parts silicon dioxide.

[0013] Preferably, the PC composition includes a PC matrix resin and fillers, wherein the fillers include magnesium oxide and silicon dioxide.

[0014] More preferably, the PC composition contains PC resin with a mass content of ≥90 wt%.

[0015] Preferably, the ratio of the retained average particle size of silicon dioxide to magnesium oxide is one or any two of the following: 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.2:1, 4.5:1, 4.8:1, 5:1, 5.2:1, 5.5:1, 5.8:1, 6:1, 6.2:1, 6.5:1, 6.8:1, 7:1.

[0016] The average retained particle size of magnesium oxide and silicon dioxide in the PC composition of the present invention is the average retained particle size of magnesium oxide and silicon dioxide in the product after the specified PC composition is melt extruded and granulated.

[0017] Preferably, the ratio of the average retained particle size of silicon dioxide to magnesium oxide is (2.3-4.2):1.

[0018] When the ratio of the retained particle size of the two fillers is preferably within the above range, the resulting product can achieve better whiteness and light transmittance.

[0019] Preferably, in the PC composition, the average retained particle size of magnesium oxide is 0.8 to 2.2 μm.

[0020] More preferably, the retained average particle size of the magnesium oxide is a range of one or any two of the following: 0.8 μm, 0.9 μm, 1 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.8 μm, 2 μm, and 2.2 μm.

[0021] Preferably, in the PC composition, the retained average particle size of the silica is 3 to 8 μm.

[0022] More preferably, the retained average particle size of the silica is one or any two of the following: 3μm, 3.5μm, 3.8μm, 4μm, 4.2μm, 4.5μm, 4.8μm, 5μm, 6μm, 7μm, 7.2μm, 7.5μm, 7.8μm, and 8μm.

[0023] In the technical solution of this invention, the test method for the retained average particle size of magnesium oxide and silicon dioxide is as follows: the PC composition is calcined in air at 800°C for 30 min, the remaining ash is ultrasonically dispersed in water for 20 min, then magnesium oxide and silicon dioxide are sieved using elemental analysis under a scanning electron microscope, and finally, particle size measurement software is used to measure the particle size of at least 50 magnesium oxide particles and 50 silicon dioxide particles, and the average value is calculated to confirm the retained average particle size.

[0024] Preferably, in the PC composition, the magnesium oxide is light magnesium oxide, and the average particle size of the magnesium oxide is 2 to 3 μm.

[0025] Preferably, in the PC composition, the average particle size of silica is 7–15 μm.

[0026] The average particle size of magnesium oxide and silicon dioxide mentioned above refers to the initial average particle size of the two fillers in the PC composition before melt extrusion granulation. Since the initial particle size and hardness of the two filler particles are different, their retained average particle size is also different after melt extrusion granulation.

[0027] Preferably, the whiteness of the magnesium oxide is 95-99%.

[0028] More preferably, the whiteness of the magnesium dioxide is a range of one or both of 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, and 99%.

[0029] More preferably, the whiteness of the magnesium oxide is ≥96%.

[0030] Magnesium oxide of different whiteness has different effects on the infrared transmittance of the product. After optimization, the use of magnesium oxide with the above-mentioned preferred whiteness can make the prepared PC composition have higher infrared transmittance.

[0031] Preferably, the whiteness of the silica is ≥99%.

[0032] Preferably, the whiteness of the magnesium oxide and silicon dioxide is tested directly using a whiteness meter.

[0033] The specific testing method is as follows: using the WGB-2A benchtop whiteness meter manufactured by Shanghai Precision Instruments, a light-shielding black tube is placed on the measuring space and zeroed using the instrument's zeroing potentiometer. After the instrument's zero position is stable, the black tube is removed; a standard whiteness plate is placed on top and the standard whiteness value is adjusted using the instrument's calibration potentiometer to calibrate the instrument, and then the standard whiteness plate is removed; the sample to be tested is measured to determine the whiteness value.

[0034] Preferably, the mass ratio of magnesium oxide to silicon dioxide is (0.625 to 1.25):1.

[0035] With a fixed total filler content, different ratios of magnesium oxide and silicon dioxide result in different optical properties of the product, especially its infrared transmittance and whiteness. Within the aforementioned preferred range, the product can achieve both better infrared transmittance and whiteness.

[0036] Preferably, the PC resin has a melt flow rate of 10-30 g / 10 min at 300°C and 1.2 kg load, according to GB / T 3682-2000.

[0037] More preferably, the melt flow rate of the PC resin at 300°C and 1.2 kg load is one or any two of the following: 10 g / 10 min, 12 g / 10 min, 15 g / 10 min, 18 g / 10 min, 20 g / 10 min, 22 g / 10 min, 25 g / 10 min, 28 g / 10 min, and 30 g / 10 min.

[0038] More preferably, the PC resin is a bisphenol a type PC resin.

[0039] Preferably, the PC composition further includes 0.1 to 5 parts of functional additives;

[0040] More preferably, the functional additives include, but are not limited to, at least one of antistatic agents, antibacterial agents, hydrolysis-resistant agents, antioxidants, UV stabilizers, and lubricants. Those skilled in the art can add various functional additives as needed without affecting the intended performance of the PC composition of the present invention. For example, to give the PC composition antistatic properties during application, those skilled in the art can add an antistatic agent to the product; to improve the demolding effect of the PC composition during processing, those skilled in the art can add a small amount of lubricant to the product for lubrication.

[0041] Another object of the present invention is to provide a method for preparing the PC composition, comprising the following steps:

[0042] The components are added to a screw extruder for melt extrusion and granulation to obtain the PC composition.

[0043] Preferably, the temperature zones of the screw extruder are set as follows: Zone 1 270-290℃, Zone 2 270-290℃, Zone 3 280-260℃, Zone 4 280-260℃, Zone 5 280-260℃, Zone 6 270-260℃, Zone 7 270-260℃, Zone 8 265-250℃, Zone 9 260-240℃, and Zone 10 260-240℃. The screw speed is 300-500 rpm, and the screw length-to-diameter ratio is (45-50):1.

[0044] Another object of the present invention is to provide the use of the PC composition in the preparation of white automotive parts.

[0045] Preferably, the automotive component includes at least one of an active grille shutter, a head-up display, and a radar dome.

[0046] The PC composition described in this invention, based on its optimized design of the selection and combination of inorganic fillers, enables the prepared product to simultaneously possess high light transmittance, high infrared transmittance, and high whiteness, making it highly suitable for the manufacture of automotive parts with extremely high requirements for optical and appearance performance.

[0047] The beneficial effects of the present invention are that it provides a PC composition in which magnesium oxide and silicon dioxide of specific size and whiteness are introduced into the PC matrix resin as light transmittance agents, so that the prepared product will not have a yellowing effect, has ideal whiteness, and can achieve high light transmittance and high infrared light transmittance. Detailed Implementation

[0048] To better illustrate the purpose, technical solution, and advantages of this invention, the invention will be further described below with reference to specific embodiments and comparative examples. The purpose of this description is to provide a detailed understanding of the invention, not to limit its scope. All other embodiments obtained by those skilled in the art without inventive effort are within the protection scope of this invention. Unless otherwise specified, the experimental reagents and instruments involved in the implementation of this invention are commonly used reagents and instruments.

[0049] Examples 1-15

[0050] An embodiment of the PC composition, its preparation method and application described in this invention, wherein the components of the PC composition are shown in Table 1.

[0051] The method for preparing the PC composition includes the following steps:

[0052] The components are mixed evenly, and then melt-extruded and granulated in a twin-screw extruder to obtain the PC composition.

[0053] During melt extrusion of the component, the temperature zones of the screw extruder are set as follows: Zone 1 280℃, Zone 2 280℃, Zone 3 270℃, Zone 4 270℃, Zone 5 270℃, Zone 6 265℃, Zone 7 265℃, Zone 8 260℃, Zone 9 250℃, Zone 10 250℃. The screw speed is 500 rpm, and the screw length-to-diameter ratio is 48:1.

[0054] Comparative Examples 1-9

[0055] The only difference between each comparative example and the embodiment is the type and ratio of components, as shown in Table 2.

[0056] In the components described in each embodiment and comparative example,

[0057] PC resin 1 is LG 1300-22NP manufactured in South Korea, with a melt flow rate of 20 g / 10 min at 300℃ and 1.2 kg load.

[0058] PC resin 2 is 1300-10NP manufactured by LG in South Korea, with a melt flow rate of 10g / 10min at 300℃ and 1.2kg load;

[0059] Magnesium oxide 1 is light magnesium oxide YY-4 produced by Hebei Magnesium God Technology. After screening, the average particle size is 2μm and the whiteness is 97%.

[0060] Magnesium oxide 2 is light magnesium oxide YY-1 produced by Hebei Magnesium God Technology. After screening, the average particle size is 2μm and the whiteness is 96%.

[0061] Magnesium oxide 3 is light magnesium oxide YY-1 produced by Hebei Magnesium God Technology. After screening, the average particle size is 3μm and the whiteness is 96%.

[0062] Magnesium oxide 4 is a 90a type lightweight magnesium oxide produced by Yingkou Zhongwei Refractory Materials Co., Ltd., with an average particle size of 3μm and a whiteness of 95%.

[0063] Magnesium oxide 5 is 87a type lightweight magnesium oxide produced by Yingkou Zhongwei Refractory Materials Co., Ltd., with an average particle size of 3μm and a whiteness of 94%.

[0064] Silica 1 is MT-10 produced by Deshan Chemical. After screening, the average particle size is 7μm and the whiteness is 99%.

[0065] The silica 2 is MT-10 produced by Deshan Chemical. After screening, the average particle size is 15μm and the whiteness is 99%.

[0066] The silica 3 is MT-10 produced by Deshan Chemical. After screening, the average particle size is 12μm and the whiteness is 99%.

[0067] The silica 4 is HM-30S produced by Deshan Chemical, with an average particle size of 7μm and a whiteness of 99%.

[0068] Zinc oxide 1 is produced by Darcy Noodles as DXN-TS2000, with an average particle size of 3μm and a whiteness of 99%;

[0069] Zinc oxide 2 is ZnO-4 produced by Shenyang Longrun Fine Chemical Raw Materials Co., Ltd., with an average particle size of 15μm and a whiteness of 90%.

[0070] Magnesium fluoride produced by Wuhan Kemic Biomedical Technology has an average particle size of 3μm and a whiteness of 98%.

[0071] Unless otherwise specified, all components and raw materials used in the embodiments and comparative examples of this invention are commercially available, and the same type of components and raw materials are used in each parallel experiment.

[0072] It should be noted that the retained average particle size of magnesium oxide and silicon dioxide in the PC compositions of the various embodiments and comparative examples of the present invention was confirmed by the method mentioned above, which was directly tested after the product preparation was completed, and the corresponding parameter values ​​of the raw materials used were not adopted.

[0073] In Table 1, M represents the numerical value of the ratio of the retained average particle size of silica and magnesium oxide.

[0074] Table 1

[0075]

[0076]

[0077] Table 2

[0078]

[0079] To verify the performance of the PC composition described in this invention, the products prepared in each embodiment and comparative example were subjected to the following performance tests, with the specific steps as follows:

[0080] (1) Infrared transmittance: The products obtained from each example and comparative example were injection molded into test strips of 125×13×1mm, and then scanned in the infrared wavelength range of 780~1650nm using an Iambda 950 UV-Vis infrared spectrophotometer to test their infrared transmittance.

[0081] (2) Transmittance test: The products obtained from each example and comparative example were injection molded into test strips of 50×50×1.6mm, and then tested according to GB / T 2410-2008;

[0082] (3) Whiteness test: The products obtained from each example and comparative example were injection molded into test strips of 5×100×100mm, and then tested in accordance with GB / T 2913-1982.

[0083] The test results are shown in Tables 3 and 4.

[0084] Table 3

[0085]

[0086] Table 4

[0087]

[0088] As can be seen from Tables 3 and 4, the PC compositions of the various embodiments of the present invention have ideal optical and appearance properties. The infrared transmittance can reach more than 67%, specifically in the range of 68-72%, while the light transmittance can reach more than 29%, specifically in the range of 30-35%, and the whiteness can reach more than 87%. This meets the comprehensive index that materials used for such automotive parts need to have an infrared transmittance of more than 65%, a light transmittance of more than 28%, and a whiteness of more than 86. The main reason why this product can achieve this comprehensive effect is that the product introduces two fillers with a specific retention particle size ratio as colorants and light transmitters into the PC resin matrix.

[0089] In contrast, the fillers in Comparative Examples 1 and 2 are only magnesium oxide or silicon dioxide, and the optical performance of both products fails to meet the standards. Furthermore, the whiteness of Comparative Example 1 is low, failing to meet the appearance requirements. In Comparative Examples 3 and 7, the ratio of the average retained particle size of magnesium oxide and silicon dioxide does not conform to the scope of the product of this invention, and the products fail to meet the standards in terms of light transmittance and whiteness. At the same time, the infrared light transmittance of Comparative Example 7 is also low, with a maximum of only 60%. In Comparative Example 4, the whiteness of magnesium oxide did not reach 95%, resulting in a low whiteness and a decrease in light transmittance compared to the products of the examples, failing to meet the standard requirements. In addition, in Comparative Examples 5 and 6, the magnesium oxide in the products was replaced with zinc oxide and magnesium fluoride, two light transmittance agents commonly added to traditional resins. However, since the refractive and light transmittance properties of these two components are different from those of magnesium oxide, and the latter may even cause yellowing of PC resin after contact, the whiteness of the final products is low, and the light transmittance and infrared transmittance cannot reach the level of the products of the examples. However, if the silica in the product is replaced, as shown in Comparative Example 9, although the whiteness of the product is higher, its optical performance is worse.

[0090] As can be seen from Examples 4-10 and Example 15, the optical properties and whiteness of the prepared products vary depending on the ratio of the retained average particle size of magnesium oxide and silicon dioxide. When the preferred ratio is in the range of (2.3-6):1, the infrared transmittance of the product can reach 70% or more, and the whiteness can reach 90% or more.

[0091] As can be seen from Examples 4 and 11-14, when the ratio of the retained particle size of magnesium oxide and silicon dioxide is relatively stable, the addition ratio of the two will also affect the performance of the product. When the ratio is preferably (0.625-1.25):1, the overall performance of the product is better.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. An automotive component, characterized in that, The PC composition comprises the following components in parts by weight: 100 parts PC resin, 0.1-1.2 parts magnesium oxide, 0.45-2.5 parts silicon dioxide, and 0.1-5 parts optional functional additives; The whiteness of the magnesium oxide is 95-99%; The ratio of the retained average particle size of silicon dioxide to magnesium oxide is (2.3~4.2):1; the retained average particle size of magnesium oxide is 0.8~2.2μm, and the retained average particle size of silicon dioxide is 3~8μm.

2. The automotive component as described in claim 1, characterized in that, The mass ratio of magnesium oxide to silicon dioxide is (0.625~1.25):

1.

3. The automotive component as described in claim 1, characterized in that, The PC resin, according to GB / T 3682-2000, has a melt flow rate of 10~30 g / 10 min at 300℃ and 1.2 kg load.

4. The automotive component as described in any one of claims 1 to 3, characterized in that, The method for preparing the PC composition includes the following steps: The components are added to a screw extruder for melt extrusion and granulation to obtain the PC composition.

5. The automotive component as described in claim 1, characterized in that, The automotive components include at least one of an active grille shutter, a head-up display, and a radar dome.

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