A polycarbonate composition, its preparation and use

Abstract

The application belongs to the field of polycarbonate materials, and specifically discloses a polycarbonate composition, a preparation method and application thereof. The polycarbonate composition contains light diffusers with specific particle sizes, flaky fillers, and wollastonite, and polyitaconic acid grafted PMMA, so that the polycarbonate composition has excellent toughness, dimensional stability and high gloss, and is suitable for new requirements of the air conditioner air deflector industry.

Description

Technical Field

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

[0002] Polycarbonate (PC) is a high-performance engineering plastic with comprehensive properties such as high mechanical strength, good impact toughness, dimensional stability, good heat resistance, and good electrical insulation. It is widely used in home appliances, digital products, IT products and other fields.

[0003] Air conditioner air deflectors are typically made of plastic such as PC. Their elongated shape means they are subject to long-term stress from gravity and the temperature of the hot air from the outlet, often leading to deformation. To overcome this problem, traditional plastic air deflectors require aluminum plates for support, forming a composite component that prevents deformation over long-term use. To reduce the use of aluminum plates, lower costs and weight, and achieve dimensional stability in one-piece molded plastic air guides, a known solution for low deformation of long plastic air guides is to increase the rigidity of the material. Traditional solutions typically involve adding flat or sheet-like fillers, such as talc, to further increase the modulus of the air guide component, thereby reducing material deformation. However, this approach usually requires adding a large proportion of talc (more than 15% of the PC mass) to achieve a modulus ≥5200MPa. The addition of a large proportion of talc has limited compatibility with PC. In practice, it not only reduces the overall toughness of the material, but the uneven surface of the sheet-like materials such as talc also significantly reduces the gloss of the material, failing to meet the requirements for high gloss and high toughness. Summary of the Invention

[0004] In view of the problems of poor structural stability, gloss and toughness of air conditioning air guide plate components in the prior art, the present invention will provide a polycarbonate composition, its preparation method and application.

[0005] To achieve the above objectives, the following technical solutions are specifically included:

[0006] In one aspect, the present invention provides a polycarbonate composition comprising the following components in parts by weight:

[0007] 100 parts polycarbonate, 0.5-6 parts sheet filler, 7-16 parts light diffusing agent, 0.1-3.5 parts wollastonite, and 0.5-6 parts polyitancetic acid grafted PMMA;

[0008] The light diffusing agent includes a first light diffusing agent and a second light diffusing agent. The average particle size of the first light diffusing agent is 3-12 μm, and the average particle size of the second light diffusing agent is 50-80 μm. The second light diffusing agent accounts for 0-50% of the mass of the light diffusing agent.

[0009] Wollastonite typically contains needle-like particles and has a high aspect ratio, which can significantly increase the modulus of the material. However, the presence of wollastonite has a more pronounced effect on reducing the toughness and gloss of the material than that of sheet fillers. Light diffusing agents are generally microspheres. The inventors of this invention have discovered that when light diffusing agents, sheet fillers, and wollastonite of specific particle sizes are present in a polycarbonate composition, a support structure with overlapping sheet, needle, and spherical particles can be achieved. This not only reduces the amount of talc used but also effectively reduces impact and gloss damage, ensuring the dimensional stability of the material. The role of itaconic acid-grafted PMMA is that, since PMMA has relatively poor compatibility with PC, itaconic acid-grafted PMMA preferentially migrates to the surface in the system, compensating for the unevenness caused by fillers and forming a mirror surface, thereby effectively improving gloss. Furthermore, during the preparation process, the carboxyl groups of itaconic acid grafted onto PMMA can react with the terminal hydroxyl groups of PC to form chemical bonds, which can improve the overall toughness of the product. This comprehensive approach achieves the effects of high toughness, high gloss, and high dimensional stability in the polycarbonate composition.

[0010] Preferably, the polycarbonate composition comprises the following components in parts by weight: 100 parts polycarbonate, 1-5 parts sheet filler, 8-15 parts light diffusing agent, 0.2-3 parts wollastonite, and 1-5 parts polyitancetic acid-grafted PMMA.

[0011] Preferably, the polycarbonate composition contains at least 50% polycarbonate by mass, more preferably at least 60%, and even more preferably at least 75%.

[0012] Preferably, the polycarbonate comprises bisphenol A type polycarbonate.

[0013] Preferably, the melt index of the polycarbonate is 6-30 g / 10 min. The melt index of the polycarbonate can be 6, 9, 12, 15, 18, 21, 24, 27, 30 g / 10 min, etc., as well as specific values ​​between the above 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.

[0014] More preferably, the polycarbonate has a melt index of 10-22 g / 10 min.

[0015] The melt index of polycarbonate has a certain impact on the strength of polycarbonate composition. Within the melt index range mentioned above, the composition has more suitable strength and better maintains the product's good toughness and dimensional stability.

[0016] Preferably, the sheet filler includes at least one of talc powder, mica powder, and glass flakes.

[0017] Preferably, the average particle size of the sheet-like filler is 0.65-11 μm. The average particle size of the sheet-like filler can be 0.6, 1, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11 micrometers, 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.

[0018] More preferably, the average particle size of the sheet filler is 4.2-5.3 μm. Within the above-mentioned range of average particle size of the sheet filler, the polycarbonate composition exhibits superior overall performance in terms of flexural modulus, impact strength, gloss, and dimensional stability.

[0019] The D50 of this invention is obtained by laser diffraction.

[0020] Preferably, the light diffusing agent includes at least one of the following: organosilicon light diffusing agents, poly(methyl methacrylate) (PMMA) light diffusing agents, polystyrene (PS) light diffusing agents, and nylon (PA) light diffusing agents.

[0021] More preferably, the light diffusing agent is a poly(methyl methacrylate) (PMMA) type light diffusing agent. Compared with other light diffusing agents, it has poorer compatibility with PC, better maintains the complete microsphere morphology in the system, is more conducive to the interaction with wollastonite and flake fillers, and is more conducive to improving the gloss of the material. In this invention, the light diffusing agent includes a first light diffusing agent and a second light diffusing agent. The average particle size of the first light diffusing agent is 3-12 μm, and the average particle size of the second light diffusing agent is 50-80 μm. The average particle size of the first light diffusing agent is smaller than that of the second light diffusing agent. The average particle size of the first light diffusing agent can be 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 9.5, 10, 11.5, 12 micrometers, etc., and the average particle size of the second light diffusing agent can be 50, 55, 60, 65, 70, 75, 80 micrometers, 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.

[0022] Within the range of average particle size of the aforementioned light diffusing agents, the polycarbonate composition exhibits superior overall performance in terms of flexural modulus, impact strength, gloss, and dimensional stability.

[0023] Preferably, the mesh size of the wollastonite is 325-1250 mesh. The mesh size of the wollastonite can be 325, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1250, etc., as well as specific mesh values ​​between the above values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific mesh values ​​included in the range.

[0024] More preferably, the wollastonite has a mesh size of 600-800 mesh.

[0025] Preferably, the aspect ratio of the silica is 10-20:1, and the aspect ratio of the wollastonite can be 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, etc., as well as specific point values ​​between the above point values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific point values ​​included in the range.

[0026] Within the aforementioned range of average wollastonite particle size, the polycarbonate composition exhibits superior overall performance in terms of flexural modulus, impact strength, gloss, and dimensional stability.

[0027] The mesh size of wollastonite is usually measured using conventional methods. This invention measures the mesh size of wollastonite powder particles using a grid sieving method.

[0028] Preferably, the polyacrylic acid content in the polyacrylic acid-grafted PMMA is 0.5-10% by weight, and more preferably, the polyacrylic acid content in the polyacrylic acid-grafted PMMA is 1.5-5% by weight.

[0029] Within the grafting rate range of polyitancastic acid-grafted PMMA mentioned above, the polycarbonate composition can achieve higher gloss while having higher flexural modulus, impact strength, and lower deformation.

[0030] On the other hand, the present invention provides a method for preparing the polycarbonate composition described above, comprising the following steps:

[0031] The raw materials are sequentially mixed, melted, extruded, cooled, and dried to obtain the polycarbonate composition.

[0032] Preferably, the melting temperature is 250–280°C.

[0033] Preferably, the rotation speed during melting is 400 to 600 revolutions per minute.

[0034] Preferably, the melting is carried out under vacuum conditions, wherein the vacuum degree is -0.07 to 0.08 MPa.

[0035] This invention also provides an application of the aforementioned polycarbonate composition in the preparation of air conditioning air guide plate components, wherein the polycarbonate composition meets the following requirements: gloss at a 60-degree angle ≥102, flexural modulus ≥5200MPa, and notched impact strength ≥50kJ / m. 2 After being manufactured into an air conditioning air guide plate, the dimensional deformation is less than 1 mm after being baked at 70°C for 168 hours. Therefore, the polycarbonate composition of the present invention has excellent toughness, dimensional stability and high gloss, and is suitable for the new needs of the air conditioning air guide plate industry.

[0036] Compared with the prior art, the present invention has the following beneficial effects: the polycarbonate composition of the present invention contains light diffusing agents of specific particle size, flake fillers, wollastonite and polyitacrylic acid grafted PMMA, which makes the polycarbonate composition have excellent toughness, dimensional stability and high gloss, and is suitable for the new needs of the air conditioning air guide plate industry. Detailed Implementation

[0037] 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.

[0038] Raw material information involved in the following examples and comparative examples:

[0039] Polycarbonate 1: PC WY-106BR, melt index 6g / 10min, Lihuayi;

[0040] Polycarbonate 2: PC 2100, melt index 10g / 10min, Wanhua Chemical;

[0041] Polycarbonate 3: PC 2220, melt index 22g / 10min, Wanhua Chemical;

[0042] Polycarbonate 4: PC H-3000F, melt index 30g / 10min, Mitsubishi, Japan;

[0043] Talc 1: TYT-8005, D50 5.3 microns, Guangzhou Tianyuan Chemical Co., Ltd.;

[0044] Talc 2: TY90-20-A, D50 8.5 microns, Dongguan Sanzhi New Materials Co., Ltd.;

[0045] Talc 3: HTP Ultra 5L, D50 0.65 microns, Liaoning Aihai Yimi Mining Co., Ltd.;

[0046] Talc 4: TYT-3000A, D50 4.2 microns, Guangzhou Tianyuan Chemical Co., Ltd.;

[0047] Mica powder: ym-012, D50 10 microns, marlin;

[0048] First light diffusing agent (small particle size):

[0049] Light diffusing agent 1: JX-N3, polymethyl methacrylate microspheres, D50 3 microns, Shenzhen Juxin Plastics Import & Export Co., Ltd.;

[0050] Light diffusing agent 2: JX-7G, polymethyl methacrylate microspheres, D50 7 microns, Shenzhen Juxin Plastics Import & Export Co., Ltd.;

[0051] Light diffusing agent 3: JX-S12, polymethyl methacrylate microspheres, D50 12 microns, Shenzhen Juxin Plastics Import & Export Co., Ltd.;

[0052] Light diffusing agent 4: JX-N20, polymethyl methacrylate microspheres, D50 20 microns, Shenzhen Juxin Plastics Import & Export Co., Ltd.;

[0053] Second light diffusing agent (large particle size):

[0054] Light diffusing agent 5: JX-G50, polymethyl methacrylate microspheres, D50 50 microns, Shenzhen Juxin Plastics Import & Export Co., Ltd.;

[0055] Light diffusing agent 6: JX-P75, polymethyl methacrylate microspheres, D50 75 microns, Shenzhen Juxin Plastics Import & Export Co., Ltd.;

[0056] Light diffusing agent 7: JX-80R, polymethyl methacrylate microspheres, D50 80 microns, Shenzhen Juxin Plastics Import & Export Co., Ltd.;

[0057] Light diffusing agent 8: JX-100, polymethyl methacrylate microspheres, D50 100 microns, Shenzhen Juxin Plastics Import & Export Co., Ltd.;

[0058] Wollastonite 1: LY-0026 1250 mesh, Jiangxi Liyuan Powder Technology Co., Ltd., aspect ratio 10-20:1;

[0059] Wollastonite 2: LY-0023 800 mesh, Jiangxi Liyuan Powder Technology Co., Ltd., aspect ratio 10-20:1;

[0060] Wollastonite 3: LY-0020 400 mesh, Jiangxi Liyuan Powder Technology Co., Ltd., aspect ratio 20-30:1;

[0061] Wollastonite 4: WFC5-2101 325 mesh, Hubei Fengjiashan Silicon Fiber Co., Ltd., aspect ratio 11:1.

[0062] Itaconic acid-grafted PMMA raw materials are all self-made, and the self-making method is as follows:

[0063] PMMA (polymethyl methacrylate, purchased from Sinopec Baling Petrochemical Co., Ltd.) with a weight of M1 was dissolved in carbon tetrachloride to prepare a PMMA solution with a mass concentration of 2%. The solution was heated to 60°C, and an itaconic acid ethanol solution with a weight of M2 and an ammonium persulfate ethanol solution with a weight of 0.5 × M2 were added dropwise. After reacting for 4 hours, the product was first washed with ethanol to remove PMMA that is insoluble in ethanol. Then, the polyitaconic acid-grafted PMMA obtained from the reaction was precipitated with 10% sodium hydroxide solution. The product was then washed three times with water to obtain a solid product polyitaconic acid-grafted PMMA with a weight of M3. The grafting rate of polyitaconic acid-grafted PMMA is (M3-M1) / M1*100%. Different grafting rates can be achieved by adjusting the amount of itaconic acid added.

[0064] Based on the above-mentioned self-made preparation method, the following four surface modifiers can be prepared:

[0065] Surface modifier 1: Polyitacic acid grafted PMMA, with a polyitacic acid content of 0.5 wt%;

[0066] Surface modifier 2: polyitaconic acid grafted PMMA, with a polyitaconic acid content of 1.5 wt%;

[0067] Surface modifier 3: Polyitacic acid grafted PMMA, with a polyitacic acid content of 5.0 wt%;

[0068] Surface modifier 4: Polyitacic acid grafted PMMA, with a polyitacic acid content of 10 wt%.

[0069] Examples 1-23 and Comparative Examples 1-8

[0070] A method for preparing a polycarbonate composition includes the following steps:

[0071] (1) According to the amount of raw material components in Table 1-2, mix each component in a high-speed mixer for 10 minutes to obtain a premix;

[0072] (2) The premixed material is fed into a twin-screw extruder through a feeder. The screw speed is 500 rpm, the processing temperature is 260°C, and a double vacuum is used with a vacuum degree of -0.07 MPa. The premixed material is melt-dispersed, blended, and then extruded, cooled, dried, and pelletized to obtain the polycarbonate composition.

[0073] Performance testing:

[0074] (1) Flexural modulus: The polycarbonate composition particles of the above examples and comparative examples were dried in an oven at 120°C for 4-6 hours, and then injection molded at 300°C on an injection molding machine to form ISO 178-2010 standard strips. The flexural modulus was recorded by performing a flexural test at a rate of 2 mm / min according to the standard.

[0075] (3) Notched impact strength: The polycarbonate composition particles of the above examples and comparative examples were dried in an oven at 120°C for 4-6 hours, and then injection molded at 300°C on an injection molding machine to form ISO 180-2023 standard specimens. The notched impact strength of the cantilever beam was tested according to the standard, and the notched impact strength was recorded.

[0076] (4) 60-degree angle gloss: The polycarbonate composition particles of the above examples and comparative examples were dried in an oven at 120°C for 4-6 hours. They were then injection molded into 100*100*2.0mm square plates at 300°C on an injection molding machine. The square plates were tested using a gloss meter, and the gloss data at a 60-degree angle was selected and recorded.

[0077] (5) Deformation test during hot baking: The polycarbonate composition particles of the above examples and comparative examples were baked in an oven at 120°C for 4 hours, and then injection molded into air guide plate parts at 290°C. After the molded parts were placed at room temperature for 24 hours for qualitative determination, the parts were placed in an oven at 70°C, and the air guide plate was fixed by two brackets with a fixed distance of 60cm. After baking for 168 hours, the parts were taken out and cooled to room temperature. The deformation of the middle part of the air guide plate was tested, and it was required that it should not be greater than 1mm.

[0078] Table 1

[0079]

[0080]

[0081] Table 2

[0082]

[0083]

[0084] As can be seen from the above embodiments, the polycarbonate composition of the present invention has a gloss level of ≥102 at a 60-degree angle, a flexural modulus of ≥5200MPa, and a notched impact strength of ≥50kJ / m. 2 When the air conditioning air guide plate is baked at 70℃ for 168 hours and the dimensional deformation is less than 1mm, the polycarbonate composition is qualified and can meet the requirements of practical application.

[0085] (1) As can be seen from Examples 1-4, the variable is the melt flow rate of PC. With the increase of the melt flow rate of PC, the flexural modulus of the polycarbonate composition increases, the notched impact resistance decreases, the gloss increases, and the deformation gradually decreases to a negligible change. Therefore, the present invention selects a melt flow rate of PC of 6-36 g / 10 min, more preferably 10-22 g / 10 min, at which the melt flow rate of PC can maintain good toughness and dimensional stability.

[0086] (2) As can be seen from Examples 2, 5-7, the average particle size of talc powder in Examples 6, 7, 2 and 5 gradually increases, the flexural modulus gradually increases, and the notched impact, gloss and deformation gradually decrease. When the average particle size is 0.65-8.5μm, the polycarbonate composition is qualified in terms of flexural modulus, impact strength, gloss and deformation.

[0087] (3) As can be seen from Examples 2, 9-11 and Comparative Examples 4-5, although both the first and second light diffusing agents in the polycarbonate composition may result in acceptable impact strength and deformation, the first light diffusing agent can be used alone in the system of the present invention, but the second light diffusing agent cannot be used alone. When the first and second light diffusing agents are combined, the flexural modulus and gloss are better, and the mass of the second light diffusing agent should be less than 50% of the total mass of the light diffusing agent to ensure acceptable gloss. As can be seen from Examples 2, 12-14 and Comparative Example 3, when the scheme of combining the first and second diffusing agents is adopted, the size of the average particle size of the first or second diffusing agent, whether too large or too small, will affect the combination effect and affect whether the gloss is acceptable. Therefore, the average particle size of the first and second diffusing agents needs to be 3-12 μm and 50-80 μm, respectively.

[0088] (4) As can be seen from Examples 2 and 16-18, the average particle size of wollastonite in Examples 16, 2, 17 and 18 gradually decreases, the flexural modulus gradually increases, and the impact strength, gloss and deformation all gradually decrease. The average particle size of wollastonite can be selected from 325-1250 mesh, and when it is further preferred to be 600-800 mesh, the overall performance of the polycarbonate composition is better.

[0089] (5) Comparative Example 1 uses talc powder alone without wollastonite, and its flexural modulus, gloss, and deformation are all unqualified. Comparative Example 8 uses only wollastonite without talc powder, and its gloss and deformation are also unqualified. Comparative Example 6 does not add light diffusing agent, and its gloss and deformation are also unqualified. It is impossible to achieve the support structure of acicular wollastonite and spherical light diffusing agent overlapping, which results in the material's flexural modulus, dimensional stability, and gloss not meeting the requirements. Comparative Example 7 lacks surface modifier, and its impact strength and gloss are also unqualified. It can be seen that only when wollastonite, talc powder, light diffusing agent, and surface modifier are present at the same time can the material maintain better toughness and gloss.

[0090] (9) As can be seen from Examples 2 and 19-21, the grafting rate of the surface modifiers in Examples 19, 20, 2 and 21 gradually increases, the surface flexural modulus decreases slightly, the impact strength gradually increases, the gloss gradually decreases, and the deformation gradually increases. Itaconic acid grafted PMMA increases the compatibility and toughness of the system. On the one hand, as the grafting rate increases, the compatibility between PC and itaconic acid grafted PMMA is better, and the content of it migrating to the material surface decreases. This reduces the degree to which the unevenness formed by the filler is compensated for and the mirror surface is formed. Therefore, the gloss of the material will be reduced to a certain extent. The increase in compatibility will also lead to a decrease in modulus and an increase in toughness. The higher the modulus, the stronger the resistance to deformation. Therefore, the decrease in modulus increases the deformation.

[0091] 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 polycarbonate composition, characterized in that, The components include the following parts by weight: 100 parts polycarbonate, 1-5 parts sheet filler, 8-15 parts light diffusing agent, 0.2-3 parts wollastonite, and 1-5 parts polyitaconic acid grafted PMMA; The light diffusing agent includes a first light diffusing agent and a second light diffusing agent. The average particle size of the first light diffusing agent is 3-12 μm, and the average particle size of the second light diffusing agent is 50-80 μm. The second light diffusing agent accounts for 0-50% of the mass of the light diffusing agent.

2. The polycarbonate composition according to claim 1, characterized in that, The polycarbonate has a melt index of 6-30 g / 10 min, which is tested according to ISO 1133-1 2011 standard, with test conditions of 300℃ and 1.2 kg.

3. The polycarbonate composition according to claim 1, characterized in that, The sheet-like filler includes at least one of talc powder, mica powder, and glass flakes.

4. The polycarbonate composition according to claim 1, characterized in that, The average particle size of the sheet-like filler is 0.65-11 μm.

5. The polycarbonate composition according to claim 1, characterized in that, The light diffusing agent includes at least one of the following: organosilicon light diffusing agents, poly(methyl methacrylate) light diffusing agents, polystyrene light diffusing agents, and nylon light diffusing agents.

6. The polycarbonate composition according to claim 1, characterized in that, The wollastonite has a mesh size of 325-1250.

7. The polycarbonate composition according to claim 1, characterized in that, The polyitaconic acid content in the polyitaconic acid-grafted PMMA is 0.5-10% by weight.

8. A method for preparing the polycarbonate composition according to any one of claims 1-7, characterized in that, The process includes the following steps: mixing, melting, extruding, cooling, and drying the raw materials to obtain the polycarbonate composition.

9. The use of the polycarbonate composition according to any one of claims 1-7 in the preparation of an air conditioning air guide plate component.

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