A polycarbonate composition, a method for preparing the same and use thereof

Abstract

This invention relates to the field of polymer materials technology, specifically to a polycarbonate composition, its preparation method, and its applications. The invention provides a polycarbonate composition comprising the following components in parts by weight: 18-42 parts polycarbonate, 8-32 parts polycarbonate-siloxane copolymer resin, 18-37 parts polymethyl methacrylate, 3-17 parts styrene-acrylonitrile copolymer, 0.3-4 parts oxazoline chain extender, and 3-27 parts toughening agent. This polycarbonate composition exhibits high hardness, excellent resistance to boss cracking, and a pearlescent effect, overcoming the shortcomings of existing polycarbonate compositions in robotics, home appliances, and new energy vehicles.

Description

Technical Field

[0001] This application relates to the field of polymer materials technology, and in particular to a polycarbonate composition, its preparation method and application. Background Technology

[0002] Polycarbonate is a common engineering plastic known for its excellent toughness and processability. However, when used in automotive interiors / exteriors, robot housings, and other applications, pure polycarbonate suffers from insufficient hardness, making it difficult to meet the scratch resistance requirements of these scenarios.

[0003] To improve the hardness of materials, existing technologies incorporate polymethyl methacrylate (PMMA) into polycarbonate. For example, a Chinese patent application describes a high-transparency, high-hardness PC-PMMA alloy and its preparation method. While this approach effectively increases the hardness of polycarbonate, the introduction of PMMA introduces two problems that severely limit the material's practical application: First, it makes bosses extremely prone to cracking. Automotive and robotic components commonly feature bosses—typically cylindrical protrusions perpendicular to the substrate—for assembly and fixation. These bosses serve multiple functions: providing support points for screw connections, offering precise positioning for component fastening, and forming a rigid protrusion integrally with the housing to support and fix core components like circuit boards. They also connect the upper and lower housings, ensuring overall assembly accuracy and structural stability. PC-PMMA alloy bosses are highly susceptible to cracking, leading to component assembly failure and even equipment malfunction. Second, the pearlescent effect of PC-PMMA alloys is poor, failing to meet aesthetic requirements.

[0004] Therefore, there is an urgent need to develop a polycarbonate composition that combines high hardness, good resistance to boss cracking, and excellent pearlescent effect. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defects and shortcomings of the existing polycarbonate compositions that cannot simultaneously achieve high hardness, good resistance to boss cracking and excellent pearlescent effect, and to provide a polycarbonate composition.

[0006] Another object of the present invention is to provide a method for preparing the above-described polycarbonate composition.

[0007] Another object of the present invention is to provide the application of the above-mentioned polycarbonate composition in the fields of robotics, home appliances or new energy vehicles.

[0008] Another object of the present invention is to provide a polycarbonate article.

[0009] The above-mentioned objective of this invention is achieved through the following technical solution: This invention protects a polycarbonate composition comprising the following components in parts by weight: 18-42 parts polycarbonate; 8-32 parts of polycarbonate-siloxane copolymer resin; 18-37 parts of polymethyl methacrylate; 3-17 parts of styrene-acrylonitrile copolymer; Oxazoline chain extender, 0.3-4 parts; Toughening agent 3-27 parts.

[0010] This invention addresses the problems of easy cracking of the boss column and poor pearlescent effect in high-hardness PC-PMMA alloys. Firstly, this invention introduces a synergistic improvement scheme combining a styrene-acrylonitrile copolymer and an oxazoline chain extender. The styrene-acrylonitrile copolymer can, to a certain extent, regulate interfacial interactions and improve the cracking problem of the boss column; the oxazoline chain extender, through a branching reaction, further optimizes the phase interface structure between polycarbonate and polymethyl methacrylate, reducing interfacial defects, thereby improving the pearlescent effect of the material while maintaining the high hardness of the alloy. The introduction of these materials can significantly improve the pearlescent effect of the material while enhancing the crack resistance of the boss column. Furthermore, a polycarbonate-siloxane copolymer resin is introduced. This resin, on the one hand, optimizes the processing performance of the material and reduces birefringence caused by internal stress, and when compounded with polycarbonate, it can effectively improve the pearlescent effect; on the other hand, it can synergistically work with the oxazoline chain extender to further enhance the bonding strength of the phase interface between polycarbonate and polymethyl methacrylate, thereby improving the crack resistance of the boss column.

[0011] In this invention, the amount of polycarbonate used can be 18, 20, 23, 25, 28, 31, 32, 35, 38, 40, or 42 parts by weight, or any range formed by any two of the above values; the amount of polycarbonate-siloxane copolymer resin used can be 8, 10, 12, 16, 20, 24, 28, 30, or 32 parts by weight, or any range formed by any two of the above values; and the amount of polymethyl methacrylate used can be 18, 20, 24, 26, 28, 31, 35, or 37 parts by weight. Or any two of the above values ​​within a range; the amount of styrene-acrylonitrile copolymer can be 3, 5, 8, 10, 13, 15, 17 parts by weight or any two of the above values ​​within a range; the amount of oxazoline chain extender can be 0.3, 0.5, 1, 1.5, 2, 3, 4 parts by weight or any two of the above values ​​within a range; the amount of toughening agent can be 3, 5, 8, 11, 15, 18, 21, 24, 25, 27 parts by weight or any two of the above values ​​within a range.

[0012] In this invention, the content of polycarbonate and polycarbonate-siloxane copolymer resin accounts for more than 30 wt% of the polycarbonate composition.

[0013] Furthermore, the polycarbonate has a melt flow rate of 3~23 g / 10 min at 300 °C and 1.2 kg.

[0014] In this invention, the melt flow rate of the polycarbonate can be measured according to ISO 1133:2022.

[0015] Preferably, the polycarbonate is an aromatic polycarbonate.

[0016] More preferably, the aromatic polycarbonate is a bisphenol A type polycarbonate.

[0017] Furthermore, the polycarbonate-siloxane copolymer resin has a siloxane content of ≥4%.

[0018] Furthermore, the polycarbonate-siloxane copolymer resin has a siloxane content of ≤20%.

[0019] In this invention, the siloxane content in the polycarbonate siloxane copolymer resin can be determined by atomic absorption spectroscopy to measure the mass percentage of silicon, and the siloxane segment content can be calculated accordingly.

[0020] The polycarbonate-siloxane copolymer resin has a melt flow rate of 3~15 g / 10min at 300 °C and 1.2 kg.

[0021] In this invention, the melt flow rate of the polycarbonate-siloxane copolymer resin can be measured according to ISO 1133:2022.

[0022] Furthermore, the melt flow rate of the polymethyl methacrylate at 230 °C and 3.8 kg is 2~25 g / 10 min.

[0023] In this invention, the melt flow rate of the polymethyl methacrylate can be measured according to ISO 1133:2022.

[0024] Furthermore, the melt flow rate of the styrene-acrylonitrile copolymer at 220 °C and 10 kg is 8~45 g / 10 min.

[0025] In this invention, the melt flow rate of the styrene-acrylonitrile copolymer can be measured according to ISO 1133:2022.

[0026] Preferably, the acrylonitrile content in the styrene-acrylonitrile copolymer is 20-40 wt%.

[0027] In this invention, the acrylonitrile content in the styrene-acrylonitrile copolymer can be determined by infrared calibration, specifically including the following steps: Using standard samples with known acrylonitrile content, a method for determining acrylonitrile content at 2237 cm⁻¹ was established. -1 The absorption peak at 700 cm⁻¹ is similar to that of styrene. -1 A standard curve is obtained to compare the peak area of ​​the absorption peak with the acrylonitrile content. The infrared spectrum of the sample is measured, and the acrylonitrile content in the sample is calculated based on the peak area ratio and the standard curve.

[0028] Furthermore, the toughening agent is an acrylate toughening agent.

[0029] Furthermore, the acrylate toughening agent includes acrylonitrile-styrene-acrylate high-adhesion powder and / or ethylene-acrylate copolymer.

[0030] Preferably, the ethylene-acrylate copolymer includes ethylene-methyl acrylate copolymer and / or ethylene-ethyl acrylate copolymer.

[0031] Furthermore, the oxazoline chain extender includes one or two of monooxazoline chain extenders and bisoxazoline chain extenders.

[0032] Furthermore, the monooxazoline chain extender includes one or both of 2-vinyl-2-oxazoline and 2-isopropenyloxazoline.

[0033] Furthermore, the bisoxazoline chain extender includes one or more of 2,2'-(1,3-phenylene)-dioxazoline, 2,2'-bis(2-oxazoline), and 2,2'-(1,4-phenylene)-dioxazoline.

[0034] Preferably, the mass ratio of the monooxazoline chain extender to the bisoxazoline chain extender is 1:(0.5~2).

[0035] Furthermore, the polycarbonate composition further includes the following components in parts by weight: 0 to 4 parts of other additives.

[0036] Furthermore, the other additives include one or more of antioxidants, lubricants, and weather-resistant agents.

[0037] Typically, in polycarbonate compositions, the amount of antioxidant is 0-1 part, the amount of lubricant is 0-1 part, and the amount of weathering agent is 0-2 parts.

[0038] Preferably, the antioxidant includes one or more of hindered phenolic antioxidants, thioester antioxidants, phosphite antioxidants, and hindered amine antioxidants.

[0039] Preferably, the lubricant comprises one or more of oxidized polyethylene wax, pentaerythritol stearate, and ethylene-vinyl acetate copolymer wax.

[0040] Preferably, the weathering agent includes one or more of benzoxazinone weathering agents, triazine weathering agents, and benzotriazole weathering agents.

[0041] This invention protects a method for preparing the above-mentioned polycarbonate composition, comprising the following steps: According to the formula, the components are mixed, melt-extruded, and granulated to obtain the polycarbonate composition.

[0042] Furthermore, the extrusion granulation temperature is 230~270 ℃; the screw speed of the extruder for extrusion granulation is 350~600 rpm, and the screw length-to-diameter ratio is 36~48:1.

[0043] This invention protects the application of the above-mentioned polycarbonate composition in the fields of robotics, home appliances, or new energy vehicles.

[0044] Furthermore, the robot includes one or both of the following: a quadruped robot and a humanoid robot.

[0045] Furthermore, the humanoid robot includes one or both of the following: a robot shell and robot joints.

[0046] Furthermore, the household appliances include one or more of the following: robot vacuum cleaner, smart TV, and air purifier.

[0047] Furthermore, the new energy vehicle includes one or both of the following: an interior frame and exterior connectors.

[0048] This invention protects a polycarbonate article made from the aforementioned polycarbonate composition.

[0049] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a polycarbonate composition that combines high hardness, excellent resistance to boss cracking, and a pearlescent effect. It is suitable for applications in robotics, home appliances, and new energy vehicles, and is particularly suitable for automotive interior frames, automotive exterior connectors, and robot shells. Detailed Implementation The present invention will be further illustrated below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field.

[0050] Unless otherwise specified, all reagents and materials used in the following examples are commercially available.

[0051] Polycarbonate 1#: PC L-1225, with a melt flow rate of 20 g / 10 min at 300 ℃ and 1.2 kg, produced by Teijin Corporation; Polycarbonate 2#: PC CH8105, with a melt flow rate of 10 g / 10 min at 300 ℃ and 1.2 kg, produced by Cangzhou Dahua; Polycarbonate 3#: PC 2050, with a melt flow rate of 5 g / 10 min at 300 ℃ and 1.2 kg, produced by Wanhua Chemical. Polycarbonate-siloxane copolymer resin 1#: PC ST3-3025U, with a melt flow rate of 4.0 g / 10 min at 300 ℃ and 1.2 kg, produced by Sanyang; Polycarbonate-siloxane copolymer resin #2: PC ST6-3025U, with a melt flow rate of 8 g / 10 min at 300 ℃ and 1.2 kg, produced by Sanyang; Polycarbonate-siloxane copolymer resin #3: PC FG1760, with a melt flow rate of 13 g / 10 min at 300 ℃ and 1.2 kg, produced by Idemitsu; Polymethyl methacrylate 1#:TF9, with a melt flow rate of 20 g / 10 min at 230 ℃ and 3.8 kg, is manufactured by Mitsubishi Corporation; Polymethyl methacrylate 2#:TF8, with a melt flow rate of 10 g / 10 min at 230 ℃ and 3.8 kg, is manufactured by Mitsubishi Corporation; Polymethyl methacrylate 3#: CM-205M, with a melt flow rate of 3 g / 10min at 230 ℃ and 3.8 kg, produced by Chi Mei Industrial Co., Ltd. Oxazoline chain extender 1#: 2,2'-(1,3-phenylene)dioxazoline, commercially available; Oxazoline chain extender #2: 2,2'-bis(2-oxazoline), commercially available; Oxazoline chain extender #3: 2-vinyl-2-oxazoline, commercially available; Oxazoline chain extender #4: 2-isopropenyloxazoline, commercially available; Other chain extender #1: 4,4-methylenebis(2-methyl-6-ethylaniline), commercially available; Other chain extenders #2: Epoxy resin chain extender, ADR-4400, produced by BASF; Styrene-acrylonitrile copolymer 1#: PN-127H, with a melt flow rate of 18 g / 10min at 220 ℃ and 10 kg, and an acrylonitrile content of 24%, produced by Chi Mei Industrial Co., Ltd. Styrene-acrylonitrile copolymer 2#: SAN KFA-180, with a melt flow rate of 10 g / 10 min at 220 ℃ and 10 kg, and an acrylonitrile content of 32%, produced in Liaoning Jinfeng; Styrene-acrylonitrile copolymer 3#: SAN KFA-130, with a melt flow rate of 39 g / 10 min at 220 ℃ and 10 kg, and an acrylonitrile content of 26%, produced in Liaoning Jinfeng; Toughening agent 1#: Acrylonitrile-styrene-acrylate high-polymer powder, A600N, produced by AMG; Toughening agent 2#: Ethylene-methyl acrylate copolymer, AC-1125, produced by DuPont; Other additives #1: Lubricant, oxidized polyethylene wax, PED 191, produced by Clariant; Other adjuvants #2: Antioxidant, hindered phenolic antioxidant, Irganox 1010, commercially available; Other additives #3: Weathering agent, triazine weathering agent, UV-1577, produced by Rianlong; Unless otherwise specified, all components (e.g., other additives 1#) used in the parallel examples and comparative examples are the same commercially available products.

[0052] The polycarbonate compositions of the various embodiments and comparative examples of the present invention were prepared by the following process: According to the formula, the components are mixed, melt-extruded, and granulated to obtain the polycarbonate composition.

[0053] The twin-screw extruder has the following temperature zones: Zone 1: 240℃, Zone 2: 230℃, Zone 3: 250℃, Zone 4: 250℃, Zone 5: 240℃, Zone 6: 240℃, Zone 7: 250℃, Zone 8: 250℃, Zone 9: 230℃, Zone 10: 240℃. The twin-screw extruder has a screw speed of 500 rpm and a screw length-to-diameter ratio of 40:1.

[0054] Examples 1-19 Examples 1-19 provide a series of polycarbonate compositions, the weight parts of each component in the formulation are shown in Tables 1-2.

[0055] Table 1 Formulations of Examples 1-11

[0056] Table 2 Formulations of Examples 12-19

[0057] Comparative Examples 1-7 Comparative Examples 1 to 7 provide a series of polycarbonate compositions, the weight parts of each component in the formulation are shown in Table 3.

[0058] Table 3 Formulations of Comparative Examples 1-7

[0059] Performance testing of polycarbonate compositions (1) Test method Pencil hardness: Measured according to ISO 15184:2020 standard.

[0060] Boss column cracking time: After uniformly applying cutting oil to the surface of the injection-molded screw column (boss column) specimen with an inner diameter of approximately 2.4 mm, M3 screws were screwed in with a fixed assembly torque of 3.5 N·m to complete the stress loading. Subsequently, the assembled specimen was placed in a 60 ℃ oven for constant temperature baking. Timing started when the specimen was placed in the oven. The high temperature environment accelerated the release of internal stress in the specimen. The time when the screw column first cracked was continuously observed and recorded. This cracking time is the core indicator for measuring the stress cracking resistance of the material. The longer the cracking time, the better the resistance to boss column cracking.

[0061] Pearlescent effect: A 100*100*2mm square plate was injection molded. Color difference was measured at different parts of the plate using a colorimeter. The color difference was tested at the four corners and the center area of ​​the plate, a total of five times, and the average value was taken. Evaluation criteria: Color difference ≤ 0.5 is excellent, 0.5 < color difference ≤ 1 is good, 1 < color difference ≤ 1.5 is average, and color difference > 1.5 is poor. This patent requires that the smaller the color difference, the better the pearlescent effect.

[0062] (2) Experimental results Table 4 Performance test results of each embodiment and comparative example

[0063] As shown in Table 4, the polycarbonate compositions prepared in Examples 1 to 19 of this invention all have a pencil hardness ≥ H, a boss cracking time ≥ 34 h, and a color difference ≤ 0.8, indicating that the polycarbonate compositions of this invention have high hardness, excellent resistance to boss cracking, and pearlescent effect.

[0064] In comparison, Comparative Example 1, due to the absence of oxazoline chain extenders, resulted in a significant deterioration in the pencil hardness, Boss column crack resistance, and pearlescent effect of the polycarbonate composition; Comparative Example 2, due to the use of 4,4-methylenebis(2-methyl-6-ethylaniline) instead of oxazoline chain extenders, also resulted in a deterioration in the pencil hardness, Boss column crack resistance, and pearlescent effect of the polycarbonate composition; Comparative Example 3, due to the use of epoxy resin chain extenders instead of oxazoline chain extenders, also resulted in a deterioration in the pencil hardness, Boss column crack resistance, and pearlescent effect of the polycarbonate composition; Comparative Example 4, due to the absence of styrene- The addition of acrylonitrile copolymer resulted in a decrease in the resistance to Boss column cracking of the polycarbonate composition; Comparative Example 5, due to the absence of polycarbonate-siloxane copolymer resin, resulted in a decrease in the resistance to Boss column cracking and the pearlescent effect of the polycarbonate composition; Comparative Example 6, due to the absence of oxazoline chain extender and styrene-acrylonitrile copolymer, resulted in a decrease in the pencil hardness, resistance to Boss column cracking, and the pearlescent effect of the polycarbonate composition; Comparative Example 7, due to the absence of polycarbonate-siloxane copolymer resin and oxazoline chain extender, resulted in a decrease in the pencil hardness, resistance to Boss column cracking, and the pearlescent effect of the polycarbonate composition.

[0065] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A polycarbonate composition, characterized in that, The components include the following parts by weight: 18-42 parts polycarbonate; 8-32 parts of polycarbonate-siloxane copolymer resin; 18-37 parts of polymethyl methacrylate; 3-17 parts of styrene-acrylonitrile copolymer; Oxazoline chain extender, 0.3-4 parts; Toughening agent 3-27 parts.

2. The polycarbonate composition according to claim 1, characterized in that, The polycarbonate has a melt flow rate of 3~23 g / 10 min at 300 °C and 1.2 kg.

3. The polycarbonate composition according to claim 1, characterized in that, The melt flow rate of the polycarbonate-siloxane copolymer resin at 300 °C and 1.2 kg is 3~15 g / 10 min.

4. The polycarbonate composition according to claim 1, characterized in that, The polymethyl methacrylate has a melt flow rate of 2~25 g / 10 min at 230°C and 3.8 kg.

5. The polycarbonate composition according to claim 1, characterized in that, The melt flow rate of the styrene-acrylonitrile copolymer at 220°C and 10 kg is 8~45 g / 10 min.

6. The polycarbonate composition according to claim 1, characterized in that, The oxazoline chain extender includes one or two of monooxazoline chain extenders and bisoxazoline chain extenders; Preferably, the mass ratio of the monooxazoline chain extender to the bisoxazoline chain extender is 1:(0.5~2).

7. The polycarbonate composition according to claim 1, characterized in that, The polycarbonate composition further includes the following components in parts by weight: 0 to 4 parts of other additives.

8. A method for preparing the polycarbonate composition according to any one of claims 1 to 7, characterized in that, Includes the following steps: According to the formula, the components are mixed, melt-extruded, and granulated to obtain the polycarbonate composition.

9. The use of the polycarbonate composition according to any one of claims 1 to 7 in the fields of robotics, home appliances or new energy vehicles.

10. A polycarbonate component, characterized in that, It is prepared from the polycarbonate composition according to any one of claims 1 to 7.

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