A glass fiber-reinforced polycarbonate composition, and a method of making and using the same

Abstract

The application belongs to the field of plastic materials, and specifically discloses a glass fiber reinforced polycarbonate composition, a preparation method and application thereof.In the glass fiber reinforced polycarbonate composition, the first copolymer, the second copolymer and the polytetrafluoroethylene are compounded, so that the impact resistance of the material is maintained, and the electrical leakage resistance and wear resistance of the material are simultaneously improved, so that the polycarbonate composition has good mechanical properties, electrical leakage resistance and wear resistance, and when the polycarbonate composition is applied to the preparation of a robot shell, a joint support and other parts, the structural stability of the robot under battery operation and severe motion friction and the safety of the electrical leakage resistance can be maintained, and the service life of the robot is improved.

Description

Technical Field

[0001] This invention belongs to the field of plastics, specifically relating to a glass fiber reinforced polycarbonate composition, its preparation method, and its application. Background Technology

[0002] Polycarbonate (PC) is a thermoplastic engineering plastic with excellent comprehensive performance. It possesses high light transmittance, high impact resistance, and excellent mechanical and thermal properties. It can be manufactured into various parts through injection molding, extrusion, and compression molding, and is widely used in automotive parts, aerospace, consumer electronics, home appliances, building materials, optical lenses, specialized protective equipment, and medical devices. With the miniaturization, high-frequency operation, and high-current / high-voltage development of electronic appliances, materials are required to have low leakage current, low circuit heating, and low capacitance effects, thereby improving the safety of components operating under high voltage and reducing component failure and fire hazards.

[0003] However, when PC plastic electronic and electrical components are switched on and off, uneven local electric fields are formed, which can trigger flashover discharge and material heating. This can easily lead to insulation damage on the material surface, forming conductive channels, causing leakage tracking, and compromising the material's electrical insulation properties. Furthermore, to improve the overall properties of PC materials, such as high modulus, glass fiber reinforced PC materials are generally used. However, conventionally used glass fiber has a high dielectric constant (Dk) and dielectric loss factor (Df). Excessive filling of glass fiber will degrade the insulation properties of PC, resulting in a significant decrease in its leakage resistance. In addition, PC material itself does not have particularly good wear resistance. When used in easily worn parts such as charger housings, power bank housings, power tool housings, robot (including humanoid or quadrupedal robot) housings and their joint supports, it cannot meet the wear resistance requirements. Moreover, the presence of glass fiber also significantly reduces its wear resistance, causing it to fail to meet the requirements of robots, power banks, and power tools in terms of wear resistance and leakage resistance.

[0004] Therefore, further research and improvement of glass fiber reinforced polycarbonate compositions are still needed to obtain polycarbonate products that are glass fiber reinforced, resistant to leakage current and wear. This improvement is of great significance for the differentiation of high-end PC products. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing glass fiber reinforced polycarbonate materials that cannot simultaneously achieve both leakage resistance and wear resistance. This invention will provide a glass fiber reinforced polycarbonate composition, its preparation method, and its application.

[0006] To achieve the above objectives, the following technical solutions are specifically included: On one hand, the present invention provides a glass fiber reinforced polycarbonate composition comprising the following components in parts by weight: PC resin 59-96, first copolymer 4.5-21 parts, second copolymer 4.5-21 parts, polytetrafluoroethylene (PTFE) 0.9-15.5 parts, glass fiber 4.8-31 parts, the first copolymer includes a copolymer of norbornene and ethylene (COC resin), and the second copolymer includes polyethylene terephthalate-1,4-cyclohexanediethanol ester (PCTG resin).

[0007] In the glass fiber reinforced polycarbonate composition of the present invention, COC resin and PTFE can improve the tracking resistance of the composition; PCTG resin can improve the interfacial bonding between COC and PC matrix resin, making it uniformly dispersed, thus avoiding a reduction in the material's impact resistance while achieving better tracking resistance; simultaneously, PTFE can improve the abrasion resistance of the composition. Therefore, the combination of COC resin, PCTG resin, and polytetrafluoroethylene significantly improves the material's tracking resistance and abrasion resistance while maintaining its impact strength, resulting in a carbonate composition that simultaneously possesses excellent mechanical properties, tracking resistance, and abrasion resistance.

[0008] Preferably, the glass fiber reinforced polycarbonate composition comprises the following components in parts by weight: 60-95 parts PC resin, 5-20 parts of a first copolymer, 5-20 parts of a second copolymer, 1-15 parts of polytetrafluoroethylene, and 5-30 parts of glass fiber. Preferably, the polycarbonate (PC) in the glass fiber reinforced polycarbonate composition comprises not less than 50% by weight, more preferably not less than 60%.

[0009] Preferably, the system of the present invention does not limit the type of polycarbonate, which includes bisphenol A type polycarbonate. Commercially available conventional polycarbonate or self-made polycarbonate can be used.

[0010] Preferably, the melt flow rate of the PC resin is 3-34 g / 10 min, wherein the melt flow rate is tested according to ISO 1133-1 2011 standard, and the test conditions are 300℃ and 1.2 kg. More specifically, the melt flow rate of the PC resin can be 3 g / 10 min, 4 g / 10 min, 6 g / 10 min, 8 g / 10 min, 10 g / 10 min, 12 g / 10 min, 14 g / 10 min, 16 g / 10 min, 18 g / 10 min, 21 g / 10 min, 23 g / 10 min, 25 g / 10 min, 27 g / 10 min, 29 g / 10 min, 30 g / 10 min, 32 g / 10 min, 34 g / 10 min, etc., as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific values ​​included in the range.

[0011] Preferably, the glass transition temperature (Tg) of the first copolymer is 80-145℃. More specifically, the glass transition temperature of the first copolymer can be 80℃, 85℃, 90℃, 95℃, 100℃, 105℃, 110℃, 115℃, 120℃, 125℃, 130℃, 135℃, 140℃, 145℃, etc., as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific values ​​included in the range. The glass transition temperature of the first copolymer is obtained by differential scanning calorimetry (DSC) testing according to ASTM D3418-2021.

[0012] Preferably, the melt mass flow rate of the first copolymer, tested according to ASTM D1238-2022 at 260°C and 2.16 kg, is 4-30 g / 10 min. More specifically, the melt mass flow rate of the first copolymer can be 4 g / 10 min, 6 g / 10 min, 8 g / 10 min, 10 g / 10 min, 12 g / 10 min, 14, 16 g / 10 min, 18 g / 10 min, 21 g / 10 min, 23 g / 10 min, 25 g / 10 min, 27 g / 10 min, 29 g / 10 min, 30 g / 10 min, etc., as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific values ​​included in the range.

[0013] COC resin monomers are ethylene and norbornene. The glass transition temperature indicates that the higher the norbornene content, the higher the glass transition temperature. When the norbornene content in COC resin is higher, the material has better leakage resistance. However, if the norbornene content in COC resin is too high, it will have an adverse effect on the impact strength of the material. Optimizing the glass transition temperature range of the above-mentioned COC resin can ensure that the norbornene content in COC resin is appropriate, thereby improving the leakage resistance of the material while avoiding a significant reduction in the impact strength of the material.

[0014] Preferably, the glass transition temperature of the second copolymer is 80-125°C. More specifically, the glass transition temperature of the first copolymer can be 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, etc., as well as specific values ​​between the above ranges. For space limitations and for the sake of brevity, this invention will not exhaustively list all the specific values ​​included in the ranges. The glass transition temperature of the second copolymer is obtained by differential scanning calorimetry (DSC) testing according to ASTM D3418-2021.

[0015] The glass transition temperature of PCTG resin can be represented by the content of 1,4-cyclohexanediethanol monomer (CHDM). A higher CHDM content results in a higher glass transition temperature and a greater effect on improving the compatibility of PC and COC. However, excessively high CHDM content in PCTG resin can decrease the material's impact resistance. Optimizing the aforementioned glass transition temperature range for PCTG resin ensures a suitable CHDM content, achieving better resistance to tracking while avoiding a reduction in impact resistance.

[0016] Preferably, the Rockwell hardness of the second copolymer, tested according to standard ASTM D785-23 under test conditions of R grade and 23°C, is 100-120. Specifically, it can be 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, etc., as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific values ​​included in the range.

[0017] Preferably, the mass ratio of the first copolymer to the second copolymer is (0.5-2):1, which can specifically be 0.5:1, 0.75:1, 1:1, 1.25:1, 1.5:1, 1.75:1, 2:1, etc., as well as specific values ​​between the above-mentioned values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0018] Preferably, the average particle size of the polytetrafluoroethylene is 8-30 μm, more preferably 10-20 μm, and can specifically be 8 μm, 9 μm, 11 μm, 13 μm, 15 μm, 17 μm, 19 μm, 21 μm, 23 μm, 25 μm, 27 μm, 29 μm, 30 μm, etc., as well as specific values ​​between the above ranges. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific values ​​included in the ranges. The average particle size of polytetrafluoroethylene can be tested using a sieving method.

[0019] If the PTFE particle size is too large, its dispersion uniformity in the matrix is ​​poor, resulting in reduced wear resistance, electrical properties, and toughness of the material. If the PTFE particle size is too small, the particles are prone to agglomeration and difficult to disperse. In addition, the particle size generated on the material surface during friction is too small, resulting in poor wear resistance. Therefore, the optimal average particle size of PTFE mentioned above can simultaneously achieve good wear resistance, leakage current resistance, and impact resistance.

[0020] Preferably, the dielectric loss (Df) of the glass fiber at 1MHz is 0.001-0.007, specifically 0.001, 0.002, 0.003, 0.004, 0.005, 0.006, 0.007, etc., as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific values ​​included in the range. The dielectric loss value of the glass fiber can be tested according to the GB / T12636-1990 standard and using a wide-screen dielectric spectrum instrument.

[0021] Preferably, the average diameter of the glass fiber is 5-20 μm, more preferably 10-13 μm, and more specifically, it can be 5 μm, 7 μm, 9 μm, 11 μm, 13 μm, 15 μm, 17 μm, 19 μm, 20 μm, etc., as well as specific values ​​between the above values. For space limitations and for the sake of brevity, this invention will not exhaustively list all the specific values ​​included in the range. The average length of the glass fiber is 1-5 mm, specifically 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, etc., as well as specific values ​​between the above values. For space limitations and for the sake of brevity, this invention will not exhaustively list all the specific values ​​included in the range. The average diameter and length of the glass fiber can be tested using a scanning electron microscope.

[0022] Preferably, the glass fiber reinforced polycarbonate composition may further include 0.8-8.5 parts by weight of a toughening agent, the toughening agent including an organosilicon toughening agent, the organosilicon toughening agent containing an elastomeric core-shell structure of acrylate and siloxane substances.

[0023] Preferably, the glass fiber reinforced polycarbonate composition further includes processing aids comprising the following components in parts by weight: 0.1-1.5 parts antioxidant and 0.1-1.5 parts lubricant.

[0024] More preferably, the antioxidant includes at least one of hindered phenolic antioxidants, phosphite antioxidants, and organosulfur antioxidants. More specifically, it may include at least one of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010), pentaerythritol tetrakis(3-lauryl thiopropionate) (antioxidant 412S), and tris[2,4-di-tert-butylphenyl] phosphite (antioxidant 168).

[0025] More preferably, the lubricant comprises at least one of aliphatic carboxylic acid esters, erucamide, ethylene bis-stearamide, montan esters, polyethylene wax, and oxidized polyethylene wax.

[0026] On the other hand, the present invention provides a method for preparing the glass fiber reinforced polycarbonate composition, comprising the following steps: mixing, melting, extruding and granulating the raw materials in sequence to obtain the glass fiber reinforced polycarbonate composition.

[0027] Preferably, the melting temperature is 260~280℃.

[0028] The present invention also provides an application of the glass fiber reinforced polycarbonate composition described above in the preparation of humanoid robots, quadruped robots, mobile power devices, and power tools. In particular, when applied to the preparation of the shells and joint supports of humanoid robots or quadruped robots, as well as the shells of mobile power devices and power tools, the glass fiber reinforced polycarbonate composition has good mechanical properties, leakage resistance, and wear resistance, which can maintain the structural stability of robots, mobile power devices, and power tools under battery operation and violent friction, as well as the safety of leakage resistance, thereby improving the service life of robots, mobile power devices, and power tools.

[0029] Compared with the prior art, the present invention has the following beneficial effects: In the glass fiber reinforced polycarbonate composition of the present invention, the first copolymer, the second copolymer and polytetrafluoroethylene are compounded to maintain the impact strength of the material while synergistically improving the leakage resistance and wear resistance of the material. This makes the polycarbonate composition have good mechanical properties, leakage resistance and wear resistance at the same time. When it is applied to the preparation of robot shells and joint supports and other parts, it can maintain the structural stability of the robot under battery operation and violent movement friction as well as the safety of leakage resistance, and improve the service life of the robot. Detailed Implementation

[0030] To better illustrate the purpose, technical solution, and advantages of this invention, specific embodiments will be used to further explain the invention below. Unless otherwise specified, the experimental methods used in the embodiments and / or comparative examples are conventional methods; the materials and reagents used, unless otherwise specified, are commercially available. Unless otherwise specified, the raw materials used in each embodiment and comparative example of this invention are the same in each parallel experiment.

[0031] Raw material information involved in the following examples and comparative examples: PC-1: TRIREX 3030PJ, melt flow rate of 3 g / 10 min, Samyang, South Korea; PC-2: TRIREX 3025PJ, melt flow rate of 10g / 10min, Samyang, South Korea; PC-3: Makrolon 2207, melt flow rate 34 g / 10 min, Covestro.

[0032] COC-1: APL6509T, Tg is 80℃, Mitsui Chemicals; COC-2: APL6013T, Tg 125℃, Mitsui Chemicals; COC-3: APL6015T, Tg 145℃, Mitsui Chemicals.

[0033] PCTG-1: PCTG DN011, Tg is 86℃, Rockwell hardness is 105, Eastman Chemical; PCTG-2: PCTG YF300, Tg is 110℃, Rockwell hardness is 119, SK Chemicals; PCTG-3: PCTG TX2001, Tg is 120℃, Rockwell hardness is 115, Eastman Chemical.

[0034] PETG: Polyethylene terephthalate-1,4-cyclohexanediol ester, PETG 401, Tg is 74℃, Eastman Chemical; PTFE-1: The particle size Dv50 of PTFE-0143 obtained after sieving is 8μm, Nanjing Tianshi New Materials; PTFE-2: The particle size Dv50 of PTFE-0148 obtained after sieving is 15μm, Nanjing Tianshi New Materials; PTFE-3: The particle size Dv50 of PTFE-0154 obtained after sieving is 30μm, Nanjing Tianshi New Materials.

[0035] Glass fiber-1: ECS303N-3-K / HL, average fiber diameter 13μm, average fiber length 3mm, Dk (dielectric constant) = 4.2~4.8, Df (dielectric loss) = 0.001 (1MHz), Chongqing International Composite Materials Co., Ltd.; Fiberglass-2: TLD-CS-T436S, with an average fiber diameter of 10μm, an average fiber length of 3mm, Dk=4.2~4.3, Df=0.0021 (1MHz), Taishan Fiberglass Co., Ltd. Glass fiber-3: ECS307-3, average fiber diameter 13μm, average fiber length 3 mm, Dk=6.6, Df=0.007 (1MHz), Chongqing International Composite Materials Co., Ltd.

[0036] Antioxidants: Hindered phenolic antioxidants, antioxidant 1010, commercially available; Lubricant: Polyethylene wax, commercially available.

[0037] Examples 1-17 and Comparative Examples 1-5 A method for preparing a glass fiber reinforced polycarbonate composition includes the following steps: (1) According to the amounts of raw material components in Tables 1 and 2, mix all components except glass fiber uniformly in a mixer to obtain a premix; (2) The premix is fed into a twin-screw extruder through the main feeding port, while glass fiber is fed through side feeding, and the mixture is melted, extruded and granulated in the twin-screw extruder to obtain a glass fiber reinforced polycarbonate composition, wherein the screw length-diameter ratio is 45:1, the barrel temperature is 260~280°C, and the screw rotation speed is 550 rpm.

[0038] The test methods for various properties of the glass fiber reinforced polycarbonate compositions of the examples and comparative examples of the present invention are as follows: (1) The notched Izod impact strength of the material with a thickness of 3.2 mm is tested according to the method in ASTM D256-2010, the test ambient temperature is 23°C, and an impact strength ≥ 60 J / m is considered qualified; (2) Wear resistance: the specific wear amount of the material is tested according to JIS K 7218-1986B method (conditions: load: 10 N, rotation speed: 80 m / min, sliding distance: 3 km), and the specific wear amount ≤ 7 mm 3 / N·km is considered qualified; (3) Tracking resistance: the tracking resistance of the material is tested with reference to the standard IEC 60112-2020, sample size: 3 mm × 100 mm × 100 mm square plate, a proof tracking index (PTI) ≥ 200 V is considered qualified; The test results are shown in Table 3.

[0039] Table 1 Glass fiber reinforced polycarbonate compositions (parts by weight) Table 2 Glass fiber reinforced polycarbonate compositions (parts by weight) Table 3 It can be seen from Examples 1 to 3 that within a certain range, as the melt mass flow rate of PC gradually increases, the impact resistance of the composition decreases, the tracking resistance increases first and then decreases, and the wear resistance increases first and then decreases, and the impact resistance, tracking resistance and wear resistance all remain good.

[0040] As the glass transition temperature of the COC resin in Example 4, Example 2 and Example 5 gradually increases, the impact resistance of the composition decreases, the tracking resistance increases first and then decreases, the wear resistance increases first and then decreases, and when the glass transition temperature is 80-145°C, the impact resistance, tracking resistance and wear resistance of the composition all remain good.

[0041] As the glass transition temperature of the PCTG resin in Examples 6, 2 and 7 gradually increases, the impact resistance of the composition decreases, the leakage current resistance first increases and then decreases, and the abrasion resistance first increases and then decreases. Moreover, within the glass transition temperature range of 80-120°C, the impact resistance, leakage current resistance and abrasion resistance of the composition remain good.

[0042] With the total weight percentage of COC resin and PCTG resin remaining constant, as the proportion of COC resin gradually increases in Examples 8, 9 and 2, the impact resistance of the composition decreases, the leakage resistance gradually increases, and the wear resistance gradually increases. Moreover, within the mass ratio of (0.5-2):1, the impact resistance, leakage resistance and wear resistance of the composition remain good.

[0043] As the average particle size of PTFE gradually increases in Examples 10, 2 and 11, the impact resistance of the composition decreases, the leakage resistance first increases and then decreases, and the wear resistance first increases and then decreases. However, when the average particle size is between 8-30 μm, the impact resistance, leakage resistance and wear resistance of the composition remain good.

[0044] As the amount of PTFE used in Examples 12, 2 and 13 gradually increases, the impact resistance of the composition decreases, the leakage resistance first increases and then decreases, and the wear resistance increases. Moreover, when the amount of PTFE is 2-10 parts by weight, the impact resistance, leakage resistance and wear resistance of the composition remain good.

[0045] As the dielectric loss of the glass fiber increases in Examples 14, 2 and 15, the leakage resistance of the composition decreases, while the abrasion resistance and impact strength remain essentially unchanged.

[0046] Compared to Example 2, Comparative Example 1, lacking PTFE, exhibits better impact resistance, but its leakage current resistance and abrasion resistance are both poor. Comparative Example 2, lacking both COC resin and PCTG resin, shows good impact resistance, but its leakage current resistance and abrasion resistance still do not meet requirements. Comparative Example 3, lacking PCTG resin, meets the requirements for abrasion resistance and leakage current resistance, but its impact resistance is significantly deteriorated. Comparative Example 4, lacking COC resin, meets the requirements for abrasion resistance and impact resistance, but its leakage current resistance is significantly poor. Furthermore, as shown in Comparative Examples 1-4, the presence of at least one of COC resin, PCTG resin, and PTFE reduces impact strength. Therefore, as demonstrated in Examples 2 and Comparative Examples 2-4, the combined use of COC resin, PCTG resin, and PTFE can result in a composition that simultaneously possesses good impact resistance, leakage current resistance, and abrasion resistance.

[0047] 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. A glass fiber reinforced polycarbonate composition, characterized in that, It includes the following components in parts by weight: 59-96 parts PC resin, 4.5-21 parts first copolymer, 4.5-21 parts second copolymer, 0.9-15.5 parts polytetrafluoroethylene, 4.8-31 parts glass fiber, wherein the first copolymer is a copolymer of norbornene and ethylene, and the second copolymer is polyethylene terephthalate-1,4-cyclohexanediol ester.

2. The glass fiber reinforced polycarbonate composition according to claim 1, characterized in that, The melt flow rate of the PC resin is 3-34 g / 10 min. The melt flow rate is tested according to ISO 1133-1 2011 standard, and the test conditions are 300℃ and 1.2 kg.

3. The glass fiber reinforced polycarbonate composition according to claim 1, characterized in that, The glass transition temperature of the first copolymer is 80-145℃.

4. The glass fiber reinforced polycarbonate composition according to claim 1, characterized in that, The glass transition temperature of the second copolymer is 80-125℃.

5. The glass fiber reinforced polycarbonate composition according to claim 1, characterized in that, The mass ratio of the first copolymer to the second copolymer is (0.5-2):

1.

6. The glass fiber reinforced polycarbonate composition according to claim 1, characterized in that, The average particle size of the polytetrafluoroethylene is 8~30μm.

7. The glass fiber reinforced polycarbonate composition according to claim 1, characterized in that, The dielectric loss of the glass fiber at 1MHz is 0.001-0.

007.

8. The glass fiber reinforced polycarbonate composition according to claim 1, characterized in that, It also includes processing aids, which comprise the following components in parts by weight: 0.1-1.5 parts antioxidant and 0.1-1.5 parts lubricant.

9. A method for preparing the glass fiber reinforced polycarbonate composition according to any one of claims 1-8, characterized in that, The process includes the following steps: mixing, melting, extruding, and granulating the raw materials in sequence to obtain the glass fiber reinforced polycarbonate composition.

10. The use of the glass fiber reinforced polycarbonate composition according to any one of claims 1-8 in the preparation of humanoid robots, quadruped robots, mobile power supply devices, and power tools.

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