Polycarbonate composition as well as preparation method and application thereof

Abstract

The invention relates to a polycarbonate composition as well as a preparation method and application thereof. The polycarbonate composition is prepared from the following components in parts by weight: 80 to 96 parts of polycarbonate resin, 0.9 to 3.1 parts of flaky filler and 2.9 to 9.2 parts of phosphorus-containing flame retardant. Through cooperation of a certain amount of the silicon copolymerized polycarbonate resin with specific silicon content, the flaky filler and the specific phosphorus-containing flame retardant, the flame retardant rating of the polycarbonate composition can reach V-0 (1.5 mm) under the conditions of no halogen and no addition of a fluorine-containing anti-dripping agent. In addition, the polycarbonate composition provided by the invention also has a good appearance.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer material processing, and more specifically, to a polycarbonate composition, a preparation method thereof, and an application thereof. Background Art

[0002] Polycarbonate is a thermoplastic engineering plastic with excellent physical and mechanical properties and is widely used in various scenarios.

[0003] In scenarios such as new energy vehicles, it is required that the flame retardant grade of the polycarbonate material can reach V-0(1.5mm) and have good appearance. To improve the flame retardant performance of the polycarbonate material, on the one hand, a flame retardant needs to be added. Brominated flame retardants are the most commonly used flame retardants at present, but they produce a large amount of smoke and a large amount of toxic gases when burning, so a halogen-free flame retardant solution needs to be considered.

[0004] On the other hand, due to the presence of the benzene ring structure in the polycarbonate molecular chain, the resin has a high viscosity and cannot quickly drip with a small amount of melt, but produces large melt drops and accelerates ignition. Therefore, the current flame retardant system usually has difficulty in making the flame retardant grade of the polycarbonate material reach V-0(1.5mm) without adding the anti-dripping agent polytetrafluoroethylene. However, fluorine-containing substances such as polytetrafluoroethylene have been gradually controlled due to environmental protection problems. Therefore, a solution to improve the flame retardant performance without adding a fluorine-containing anti-dripping agent needs to be considered.

[0005] In some embodiments of Patent CN103467954A, the flame retardant grade of the polycarbonate composition can reach V-0(1.6mm), but it does not test whether the material can reach V-0(1.5mm), and it needs to add a polytetrafluoroethylene anti-dripping agent to make the material reach a better flame retardant grade. Summary of the Invention

[0006] The primary object of the present invention is to overcome the problem that the polycarbonate material in the above-mentioned prior art is difficult to reach a high flame retardant grade without halogen-free flame retardancy and without adding a fluorine-containing anti-dripping agent, and to provide a polycarbonate composition.

[0007] A further object of the present invention is to provide a preparation method of the above polycarbonate composition.

[0008] A further object of the present invention is to provide an application of the above polycarbonate composition in the preparation of new energy vehicle parts.

[0009] The above objects of the present invention are achieved by the following technical solutions:

[0010] A polycarbonate composition, comprising the following components in parts by weight:

[0011] Polycarbonate resin 80 - 96 parts,

[0012] 0.9 to 3.1 parts of flaky filler,

[0013] 2.9 to 9.2 parts of phosphorus-containing flame retardant;

[0014] The polycarbonate resin includes a silicon copolymer polycarbonate resin with a content of 20 wt% or more, and the silicon content of the silicon copolymer polycarbonate resin is 7.5 to 14 wt%;

[0015] The mass ratio of the phosphorus-containing flame retardant to the flaky filler is (2.5 to 4.2):1;

[0016] The phosphorus-containing flame retardant is bisphenol A-bis(diphenyl phosphate).

[0017] The inventors of the present invention found through research that by combining a certain amount of silicon copolymer polycarbonate resin with a specific silicon content, a flaky filler with a certain mass ratio, and a specific phosphorus-containing flame retardant, the flame retardant grade of the polycarbonate composition can reach V-0 (1.5 mm) without halogen and without adding a fluorine-containing anti-dripping agent.

[0018] Among them, the silicon content of the silicon copolymer polycarbonate resin cannot be too low, otherwise it is not sufficient to provide a good flame retardant effect. The silicon content of the silicon copolymer polycarbonate resin cannot be too high, otherwise the system will be heterogeneous, resulting in poor dispersion of the phosphorus-containing flame retardant and unable to make the flame retardant grade of the polycarbonate composition reach V-0 (1.5 mm).

[0019] There is a synergistic flame retardancy between the phosphorus-containing flame retardant and the flaky filler, and the regulation of their mass ratio is crucial. The principle is: in the formula system of the present invention, the flame retardancy is mainly dominated by the condensed-phase carbonization and gas-phase dilution effects of the phosphorus-containing flame retardant, while a small amount of flaky filler assists in flame retardancy by enhancing the strength of the carbon layer; if the mass ratio of the phosphorus-containing flame retardant to the flaky filler is too large, the enhancement of the carbon layer strength by the flaky filler is insufficient; if the mass ratio of the phosphorus-containing flame retardant to the flaky filler is too small, the flaky filler will hinder the diffusion of the flame retardant gas generated by the decomposition of the phosphorus-containing flame retardant and cannot effectively inhibit the spread of combustion.

[0020] The selection of the type of phosphorus-containing flame retardant is also crucial. If other flame retardants (such as polyphosphates, triphenyl phosphate, sulfonate flame retardants, etc.) are selected, the flame retardant grade of the polycarbonate composition cannot reach V-0 (1.5 mm).

[0021] In addition, the selection of the types of fillers and flame retardants also affects the polycarbonate composition of the formula system of the present invention. If the types are not suitable, the appearance of the polycarbonate composition will deteriorate.

[0022] In the present invention, the silicon content of the silicon copolymer polycarbonate resin is measured by the infrared method.

[0023] In the present invention, the dosage of the polycarbonate resin may specifically be 80, 82, 84, 86, 88, 90, 92, 94 or 96 parts by weight; the dosage of the flaky filler may specifically be 0.9, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0 or 3.1 parts by weight; the dosage of bisphenol A-bis(diphenyl phosphate) may specifically be 2.9, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0 or 9.2 parts by weight.

[0024] In the present invention, the mass ratio of the phosphorus-containing flame retardant to the flaky filler may specifically be 2.5:1, 2.6:1, 2.7:1, 2.8:1, 3.0:1, 3.2:1, 3.5:1, 3.6:1, 3.8:1, 4.0:1, 4.1:1 or 4.2:1.

[0025] Preferably, the mass ratio of the phosphorus-containing flame retardant to the flaky filler is 3-4:1. When the mass ratio is controlled within this range, the flame retardant performance of the obtained polycarbonate composition is better (the total afterflame time is shorter).

[0026] In the present invention, the content of the silicone copolymer polycarbonate resin in the polycarbonate resin may specifically be 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, 65wt%, 70wt%, 75wt%, 80wt%, 85wt%, 90wt%, 95wt% or 100wt%.

[0027] In the present invention, the silicon content of the silicone copolymer polycarbonate resin may specifically be 7.5wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 13wt% or 14wt%.

[0028] Preferably, the silicon content of the silicone copolymer polycarbonate resin is 7.5-8.5wt%. By using the silicone copolymer polycarbonate resin within this silicon content dosage range, the flame retardant performance of the obtained polycarbonate composition is better (the total afterflame time is shorter).

[0029] Preferably, the content of the silicone copolymer polycarbonate resin in the polycarbonate resin is 20-70wt%.

[0030] The flame retardant performance of the silicone copolymer polycarbonate resin is superior to that of the conventional polycarbonate, but the price of the silicone copolymer polycarbonate resin is relatively expensive. The inventors of the present invention have found that when the polycarbonate resin of the present invention contains a certain amount of the conventional polycarbonate, the flame retardant grade of the polycarbonate composition can also reach V-0 (1.5mm), thus taking into account both the good flame retardant performance and low cost of the material, and the appearance is better.

[0031] It should be understood that the conventional polycarbonate resin refers to a polycarbonate without polysiloxane segments.

[0032] Preferably, the number-average molecular weight of the polycarbonate resin is 18,000 to 40,000; more preferably 24,000 to 32,000; further preferably 25,000 to 29,000.

[0033] In the present invention, the number-average molecular weight of the polycarbonate resin can be measured by gel permeation chromatography.

[0034] Preferably, the sheet-like filler is at least one of talc, mica or sheet barium sulfate.

[0035] More preferably, the sheet-like filler is talc. By using talc, the flame retardant property of the obtained polycarbonate composition is better (the total afterflame time is shorter), and the appearance is also better.

[0036] Preferably, the average particle size of the sheet-like filler is 3 to 20 μm.

[0037] In the present invention, the average particle size of the sheet-like filler can be measured by a particle size analyzer.

[0038] Preferably, the polycarbonate composition further comprises 1 to 5 parts of a toughening agent.

[0039] More preferably, the toughening agent is at least one of methyl methacrylate-butadiene-styrene graft copolymer or a silicone-based toughening agent.

[0040] Further preferably, the silicone-based toughening agent has a core-shell structure.

[0041] By using a silicone-based toughening agent, the flame retardant property of the obtained polycarbonate composition is better (the total afterflame time is shorter), and the appearance is also better.

[0042] Further preferably, the core is silicone / acrylic acid, and the shell is methyl methacrylate.

[0043] Preferably, the polycarbonate composition further comprises 0.1 to 2 parts of other additives.

[0044] More preferably, the other additives are at least one of a hydrolysis-resistant agent or an antioxidant.

[0045] Further preferably, the hydrolysis-resistant agent is at least one of carbodiimide, isocyanate, oxazoline or epoxide.

[0046] Further preferably, the antioxidant is at least one of phosphite antioxidants or hindered phenol antioxidants.

[0047] Further preferably, the phosphite antioxidant is at least one of bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite or 2,4-di-tert-butylphenol.

[0048] Further preferably, the hindered phenol antioxidant is at least one of N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxyhydrocinnamide), pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], triethylene glycol bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate], n-octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, or spiroglycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate].

[0049] The preparation method of the above polycarbonate composition includes the following steps: mixing each component, melt-extruding, and granulating to obtain the polycarbonate composition.

[0050] Preferably, the temperature of the melt-extrusion is 240-300 °C.

[0051] Preferably, the aspect ratio of the screw of the extruder for the melt-extrusion is 40-48:1, and the screw speed is 300-550 rpm.

[0052] The application of the above polycarbonate composition in the preparation of new energy vehicle parts is also within the protection scope of the present invention.

[0053] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0054] Through the cooperation of a certain amount of silicon copolymer polycarbonate resin with a specific silicon content, a sheet-like filler with a certain mass ratio, and a specific phosphorus-containing flame retardant, the present invention can achieve a flame retardancy rating of V-0 (1.5 mm) for the polycarbonate composition without halogen and without adding a fluorine-containing anti-dripping agent. In addition, the polycarbonate composition of the present invention also has good appearance. Specific Embodiments

[0055] To describe the technical solution of the present invention more clearly and completely, the following further details the present invention through specific examples. It should be understood that the specific examples described herein are only used to explain the present invention and are not used to limit the present invention, and various changes can be made within the scope defined by the claims of the present invention.

[0056] Some of the reagents selected in the examples and comparative examples of the present invention are described as follows:

[0057] Polycarbonate resin 1#: silicon copolymer polycarbonate resin, silicon content is 10%, PC 8010-10, LG, number average molecular weight 25,200;

[0058] Polycarbonate Resin 2#: Silicone copolymer polycarbonate resin with a silicone content of 8%, PC 8000-05, LG, number average molecular weight 28,600;

[0059] Polycarbonate Resin 3#: Silicone copolymer polycarbonate resin with a silicone content of 6%, PC S1240, Wanhua Chemical, number average molecular weight 25,000;

[0060] Polycarbonate Resin 4#: Silicone copolymer polycarbonate resin with a silicone content of 20%, CH9030LT, Cangzhou Dahua, number average molecular weight 24,000;

[0061] Polycarbonate Resin 5#: Conventional polycarbonate resin, PC2100, Wanhua Chemical, number average molecular weight 26,080;

[0062] Flaky Filler 1#: HY-TA05, Shenzhen Haiyang Powder, talc powder, average particle size 4.0μm;

[0063] Flaky Filler 2#: GM-6, Anhui Guorui New Material Technology Co., Ltd., mica, average particle size 17.0μm;

[0064] Non-flaky Filler 1#: WFC5-4101, Hubei Fengjiashan Silicon Fiber Co., Ltd., fibrous, wollastonite, average particle size 5.9μm;

[0065] Non-flaky Filler 2#: Omya, Omyacarb 5T-JI, granular, calcium carbonate, average particle size 4.9μm;

[0066] Phosphorus-containing Flame Retardant 1#: Bisphenol A-bis(diphenyl phosphate), Adeka, FP-600;

[0067] Phosphorus-containing Flame Retardant 2#: Polyphosphate, FP-2200, Adeka;

[0068] Phosphorus-containing Flame Retardant 3#: Triphenyl phosphate, commercially available;

[0069] Other Flame Retardant 1#: Potassium perfluorobutanesulfonate, commercially available;

[0070] Other Flame Retardant 2#: Brominated triazine, commercially available;

[0071] Toughening Agent 1#: Silicone-based toughening agent, S-2001, Mitsubishi Rayon;

[0072] Toughening Agent 2#: MBS toughening agent, M-521, Nippon Zeon Co., Ltd.,;

[0073] Other Additive 1#: Antioxidant 1076, commercially available;

[0074] Other Additive 2#: Hydrolysis-resistant agent, carbodiimide, commercially available.

[0075] Unless otherwise specified, the components selected in each parallel example and comparative example (such as other auxiliary agent 1#) are all the same commercially available products.

[0076] The performance of the polycarbonate compositions provided in each example and comparative example of the present invention was determined according to the following test methods:

[0077] 1. Flame retardancy performance: Tested according to UL94, and the thickness of the specimen is 1.5 mm. Five specimens were prepared for each example and comparative example, and the afterflame time t1 after the first ignition and the afterflame time t2 after the second ignition of each specimen were tested according to the test standard, and the sum of t1 and t2 was calculated as the total afterflame time and recorded. Generally, under the same flame retardancy grade, the shorter the total afterflame time, the better the flame retardancy performance. In addition, according to the test standard, the flameless combustion time, whether it spreads to the fixture, whether it ignites absorbent cotton, etc. of each example were also tested or recorded to judge the flame retardancy grade of each example and comparative example.

[0078] 2. Appearance evaluation: The pellets of the above examples and comparative examples were aged and then injection molded into samples at 280 °C to form samples of 80*20*4 mm. Subsequently, the surface material flower situation of the samples was observed. No material flower was rated as grade 1, one material flower was rated as grade 2, and more than one material flower was rated as grade 3; generally, it is required that the appearance evaluation result of the specimen is grade 1 or 2 to be considered a qualified product.

[0079] The preparation process of the polycarbonate compositions of each example and comparative example of the present invention is as follows: Weigh each component according to the ratio, mix, and then extrude in a twin-screw extruder. After the melt granulation process, the polycarbonate composition is obtained. Among them, the temperature of the first zone of the twin-screw extruder is 230 °C, the temperature of the second zone is 240 °C, the temperature of the third zone is 250 °C, the temperature of the fourth zone is 250 °C, the temperature of the fifth zone is 250 °C, the temperature of the sixth zone is 250 °C, the temperature of the seventh zone is 250 °C, the temperature of the eighth zone is 240 °C, the temperature of the ninth zone is 230 °C, the temperature of the die head is 220 °C, the screw length-diameter ratio is 45:1, and the screw speed is 450 rpm.

[0080] Examples 1-11

[0081] Examples 1-11 provide a series of polycarbonate compositions, and their formulations are shown in Table 1.

[0082] Table 1 Formulations of Examples 1-11 (parts by weight)

[0083]

[0084]

[0085] Comparative Examples 1-12

[0086] Comparative Examples 1 to 12 provide a series of polycarbonate compositions, which are different from Example 1 in formulation, and the formulation is shown in Table 2.

[0087] Table 2 Formulations of Comparative Examples 1 to 12 (parts by weight)

[0088]

[0089]

[0090] The properties of the polycarbonate compositions of each example and comparative example were measured according to the above-mentioned test methods, and the test results are shown in Table 3.

[0091] Table 3 Performance test results of the polycarbonate compositions of each example and comparative example

[0092]

[0093]

[0094] In Table 3, when the test result of the total afterflame time is " / ", it indicates that the absorbent cotton was ignited during the flame retardancy test. The situation of igniting the absorbent cotton indicates that the flame retardancy of the sample is very poor. In this case, the total afterflame time obtained is not comparable to that obtained when the absorbent cotton was not ignited, so it is not recorded.

[0095] As can be seen from Table 3:

[0096] The flame retardancy grades of the polycarbonate compositions of Examples 1 to 11 all reach V-0, and the appearances are all qualified, indicating that the polycarbonate compositions of the present invention have good flame retardancy and appearance.

[0097] For Comparative Examples 1 and 2, the silicon content of the silicone copolymer polycarbonate resin added is too low or too high. The flame retardancy grade of Comparative Example 1 is only V-1, which cannot reach V-0, and the appearance of Comparative Example 1 is not as good as that of Example 1, and the appearance of Comparative Example 3 is poor. In Comparative Example 3, no silicone copolymer polycarbonate resin is added, and the flame retardancy grade of the polycarbonate composition is only V-2. In Comparative Examples 4 and 5, non-flaky fillers are added, and the flame retardancy grades of the polycarbonate compositions of both do not reach V-0, and the appearances are unqualified. The flame retardants selected in Comparative Examples 6 to 9 are not suitable, and the properties of the polycarbonate compositions are all poor. The mass ratios of the phosphorus-based flame retardant and the flaky filler in Comparative Examples 10 to 11 are not suitable, and the flame retardancy grades of the polycarbonate compositions do not reach V-0. In Comparative Example 12, too much flaky filler is added, the flame retardancy grade of the polycarbonate composition is poor, and the appearance is not as good as that of Example 1.

[0098] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation manners here. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A polycarbonate composition, characterized in that, Comprising the following components in parts by weight: Polycarbonate resin 80 - 96 parts, Flaky filler 0.9 - 3.1 parts, Phosphorus-containing flame retardant 2.9 - 9.2 parts; The polycarbonate resin comprises a silicone copolymer polycarbonate resin with a content of 20 wt% or more, and the silicon content of the silicone copolymer polycarbonate resin is 7.5 - 14 wt%; The mass ratio of the phosphorus-containing flame retardant to the flaky filler is (2.5 - 4.2):1; The phosphorus-containing flame retardant is bisphenol A-bis(diphenyl phosphate).

2. The polycarbonate composition according to claim 1, characterized in that, The number-average molecular weight of the polycarbonate resin is 18,000 - 40,000.

3. The polycarbonate composition according to claim 1, characterized in that, The content of the silicone copolymer polycarbonate resin in the polycarbonate resin is 20 - 70 wt%.

4. The polycarbonate composition according to claim 1, wherein The flaky filler is at least one of talc, mica or flaky barium sulfate.

5. The polycarbonate composition according to claim 1, characterized in that, The silicon content of the silicone copolymer polycarbonate resin is 7.5 - 8.5 wt%.

6. The polycarbonate composition according to claim 1, wherein The polycarbonate composition further comprises 1 - 5 parts of a toughening agent.

7. The polycarbonate composition according to claim 6, characterized in that, The toughening agent is at least one of methyl methacrylate-butadiene-styrene graft copolymer or a silicone-based toughening agent.

8. The polycarbonate composition according to claim 1, wherein The polycarbonate composition further comprises 0.1 - 2 parts of other additives.

9. A method for preparing the polycarbonate composition according to any one of claims 1 to 8, characterized in that, Comprising the following steps: mixing the components, melt-extruding, and pelletizing to obtain the polycarbonate composition.

10. Use of the polycarbonate composition according to any one of claims 1 - 8 in the preparation of new energy vehicle parts.

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