Polycarbonate composition as well as preparation method and application thereof

Abstract

The invention provides a polycarbonate composition as well as a preparation method and application thereof, and belongs to the technical field of high polymer materials. The polycarbonate composition disclosed by the invention is prepared from the following components in parts by weight: 30 to 70 parts of polycarbonate, 10 to 35 parts of polyphenyl ether, 5 to 20 parts of polystyrene, 1 to 15 parts of styrene elastomer, 1 to 15 parts of flame retardant, 0.1 to 5 parts of titanium dioxide and 0.1 to 1 part of benzotriazole compound. According to the polycarbonate composition, polycarbonate and polyphenyl ether are used as matrix resin, and polystyrene, styrene elastomer, titanium dioxide and benzotriazole compounds are added, so that the polycarbonate composition has good mechanical properties, electrical insulation properties and flame retardancy at the same time.

Description

Technical Field

[0001] The present disclosure relates to the technical field of polymer materials, and particularly relates to a polycarbonate composition, a preparation method thereof, and an application thereof. Background Art

[0002] Polycarbonate has excellent transparency, mechanical properties, heat resistance, and dimensional stability, and is widely used in electrical equipment, such as the outer casing of a meter box. With the continuous advancement of the intelligentization of the distribution network and the increasing popularity of the use of high-power electrical appliances, and since the meter box is used in an outdoor environment with a relatively harsh use environment, the outer casing of the meter box has high requirements for the impact resistance, moisture resistance, heat resistance, flame retardancy, and other properties of the material. It is difficult for the outer casing of the meter box prepared only with polycarbonate to meet the existing requirements. Polyphenylene ether has the characteristics of non-toxicity, low density, strong heat resistance, high mechanical strength, good water resistance, excellent electrical properties, good flame retardancy, etc., and can be used as a raw material for the outer casing of the meter box. However, when polyphenylene ether resin is used alone, it has a high melt viscosity, poor moldability, and there is a problem that the molded product is easily embrittled due to thermal oxidative degradation during molding. Although polystyrene resin with excellent compatibility with polyphenylene ether resin can be blended to improve the molding processability, due to the too low heat resistance of polystyrene resin, even if the molding processability and fluidity are improved, the heat resistance is significantly reduced.

[0003] Currently, there is prior art that discloses blending polycarbonate and polyphenylene ether to prepare a composite material. However, the compatibility between polycarbonate and polyphenylene ether is poor, resulting in an uneven dispersion state of each component in the product, thereby causing a decline in the performance of the product, such as impact resistance, electrical insulation performance, heat resistance, and flame retardancy. In addition, currently, the flame retardancy of the product is mainly improved by adding a phosphorus-based flame retardant to the product, such as bis(diphenyl phosphate), hexachlorocyclotriphosphazene; through experiments and practical applications, it is found that the phosphorus-based flame retardant will gradually hydrolyze in the composite material formed by polycarbonate and polyphenylene ether in a wet environment, resulting in a significant decrease in the CTI value of the material and an increased risk of leakage and fire, bringing great potential safety hazards to the meter box used in a high-humidity environment. Summary of the Invention

[0004] The purpose of the present disclosure is to overcome the deficiencies of the prior art, and provide a polycarbonate composition, a preparation method thereof, and an application thereof.

[0005] To achieve the above purpose, the technical solutions adopted by the present disclosure are as follows: In the first aspect, the present disclosure provides a polycarbonate composition, comprising the following components in parts by weight: 30 - 70 parts of polycarbonate, 10 - 35 parts of polyphenylene ether, 5 - 20 parts of polystyrene, 1 - 15 parts of styrene elastomer, 1 - 15 parts of flame retardant, 0.1 - 5 parts of titanium dioxide, 0.1 - 1 part of benzotriazole compound.

[0006] In some embodiments, the benzotriazole compound is at least one of 2-(2'-hydroxy-3',5'-bis(a,a-dimethylbenzyl)phenyl)benzotriazole, 2'-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, and 2-(2'-hydroxy-5'-methylphenyl)benzotriazole.

[0007] In some embodiments, the average particle size of the titanium dioxide is 50 - 800 nm.

[0008] In some embodiments, the styrene elastomer is at least one of styrene-butadiene block copolymer, hydrogenated styrene-butadiene block copolymer, styrene-butadiene-styrene block copolymer, hydrogenated styrene-butadiene-styrene block copolymer, styrene-isoprene block copolymer, hydrogenated styrene-isoprene block copolymer, styrene-isoprene-styrene block copolymer, and hydrogenated styrene-isoprene-styrene block copolymer.

[0009] In some embodiments, the styrene elastomer is a maleic anhydride-modified styrene elastomer; preferably, the grafting rate of maleic anhydride in the maleic anhydride-modified styrene elastomer is 1.0 - 3.3%, and the preferred range is 1.6 - 2.4%.

[0010] In some embodiments, the maleic anhydride-modified styrene elastomer is at least one of maleic anhydride-modified hydrogenated styrene-butadiene-styrene block copolymer and maleic anhydride-modified hydrogenated styrene-isoprene copolymer.

[0011] In some embodiments, the flame retardant is at least one of bis(diphenyl phosphate) and hexachlorocyclotriphosphazene;

[0012] and / or, the melt index of the polycarbonate at 300 °C and 1.2 kg is 3 - 30 g / 10 min;

[0013] and / or, the weight-average molecular weight of the polyphenylene ether is 30000 - 80000;

[0014] and / or, the melt index of the polystyrene at 200 °C and 5.0 kg is 5 - 15 g / 10 min.

[0015] In some embodiments, the polycarbonate composition further comprises 0.2 - 2 parts by weight of an auxiliary agent, and the auxiliary agent is at least one of an antioxidant and a lubricant.

[0016] First, the present disclosure provides a method for preparing the polycarbonate composition as described above, comprising the following steps: mixing each component evenly in proportion, and subjecting the obtained mixture to melting, extrusion, and pelletizing to obtain the polycarbonate composition.

[0017] In a third aspect, the present disclosure provides the application of the polycarbonate composition in an electrical device.

[0018] Compared with the prior art, the beneficial effects of the present disclosure are as follows:

[0019] In the present invention, polycarbonate and polyphenylene ether are used as matrix resins, and polystyrene, styrene elastomer, titanium dioxide and benzotriazole compounds are added. During the processing, polystyrene can reduce the viscosity of polyphenylene ether, making the viscosities of polyphenylene ether and polycarbonate similar, improving the compatibility between polyphenylene ether and polycarbonate, and endowing the polycarbonate composition with good mechanical properties, heat resistance, electrical insulation properties and flame retardancy at the same time; the styrene elastomer can further enhance the compatibility between polystyrene, polyphenylene ether and polycarbonate, and enhance the mechanical properties, heat resistance, electrical insulation properties and flame retardancy of the polycarbonate composition; on the one hand, the benzotriazole compound can absorb the ultraviolet rays generated during the discharge process, reduce the carbonization effect of ultraviolet rays on the polycarbonate composition, and delay the formation of the carbon path; on the other hand, the benzotriazole compound can inhibit the hydrolysis reaction of the phosphorus-based flame retardant in a high-humidity environment, improving the electrical insulation properties of the polycarbonate composition; titanium dioxide in titanium dioxide can not only absorb, reflect and scatter ultraviolet rays, reduce the carbonization effect of ultraviolet rays on the polycarbonate composition, and reduce the conductivity of the carbon path; moreover, titanium dioxide can enhance the interfacial barrier effect of the polycarbonate composition, thereby improving the ability of the polycarbonate composition to resist water vapor erosion, and jointly acting with the benzotriazole compound to improve the normal-temperature electrical insulation properties and the electrical insulation properties of the polycarbonate composition in a wet environment. Detailed embodiments

[0020] To facilitate the understanding of the present disclosure, the present disclosure will be described more comprehensively below. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the understanding of the disclosure content of the present disclosure more thorough and comprehensive.

[0021] As used herein, the terms:

[0022] "Prepared from" is synonymous with "comprising". As used herein, the terms "comprising", "including", "having", "containing" or any other variation thereof are intended to cover non-exclusive inclusion. For example, a composition, step, method, article or device containing the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article or device.

[0023] The connective "consisting of" excludes any unrecited element, step, or component. If used in a claim, this phrase renders the claim closed-ended, excluding materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause within the body of a claim rather than immediately following the subject, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0024] When an equivalent, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values and lower preferred values, this should be understood to specifically disclose all ranges formed by any pairing of any upper range limit or preferred value with any lower range limit or preferred value, whether or not that range is separately disclosed. For example, when the range "1-5" is disclosed, the described range should be interpreted as including the ranges "1-4", "1-3", "1-2", "1-2 and 4-5", "1-3 and 5", etc. When a numerical range is described herein, unless otherwise stated, the range is intended to include its end values and all integers and fractions within that range.

[0025] In these examples, unless otherwise specified, the parts and percentages are by mass.

[0026] "Parts by mass" refers to the basic measurement unit representing the mass ratio relationship of multiple components. 1 part can represent any unit mass, such as 1 g or 2.689 g, etc. If we say that the parts by mass of component A is a parts and the parts by mass of component B is b parts, it means the mass ratio of component A to component B is a:b. Or, it means the mass of component A is aK and the mass of component B is bK (K is any number representing a multiple factor). It should not be misunderstood that, different from the number of parts by mass, the sum of the parts by mass of all components is not limited to 100 parts.

[0027] "And / or" is used to indicate that either or both of the stated circumstances may occur. For example, A and / or B includes (A and B) and (A or B).

[0028] In a first aspect, the present disclosure provides a polycarbonate composition comprising the following components in parts by weight: 30-70 parts of polycarbonate, 10-35 parts of polyphenylene ether, 5-20 parts of polystyrene, 1-15 parts of styrene elastomer, 1-15 parts of flame retardant, 0.1-5 parts of titanium dioxide, and 0.1-1 part of benzotriazole compound.

[0029] The present invention uses polycarbonate and polyphenylene ether as matrix resins, and adds polystyrene, styrene elastomer, titanium dioxide and benzotriazole compounds. During the processing, polystyrene can reduce the viscosity of polyphenylene ether, making the viscosities of polyphenylene ether and polycarbonate similar, improving the compatibility between polyphenylene ether and polycarbonate, and enabling the polycarbonate composition to have good mechanical properties, electrical insulation properties and flame retardancy at the same time; the styrene elastomer can further enhance the compatibility between polystyrene, polyphenylene ether and polycarbonate, and enhance the mechanical properties, flame retardancy and electrical insulation properties of the polycarbonate composition; on the one hand, the benzotriazole compound can absorb the ultraviolet rays generated during the discharge process, reduce the carbonization effect of ultraviolet rays on the polycarbonate composition, and delay the formation of the carbon path; on the other hand, the benzotriazole compound can inhibit the hydrolysis reaction of the phosphorus-based flame retardant in a high-humidity environment, improving the electrical insulation properties of the polycarbonate composition; titanium dioxide in titanium dioxide can not only absorb, reflect and scatter ultraviolet rays, reduce the carbonization effect of ultraviolet rays on the polycarbonate composition, and reduce the conductivity of the carbon path; moreover, titanium dioxide can enhance the interfacial barrier effect of the polycarbonate composition, thereby improving the ability of the polycarbonate composition to resist water vapor erosion, and jointly acting with the benzotriazole compound to improve the normal-temperature electrical insulation properties and electrical insulation properties of the polycarbonate composition in a wet environment.

[0030] In different embodiments, the weight parts of the polycarbonate can be, but are not limited to, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts.

[0031] In different embodiments, the weight parts of the polyphenylene ether can be, but are not limited to, 10 parts, 12 parts, 15 parts, 17 parts, 20 parts, 23 parts, 25 parts, 28 parts, 30 parts, 33 parts, 35 parts.

[0032] In different embodiments, the weight parts of the polystyrene can be, but are not limited to, 5 parts, 7 parts, 9 parts, 11 parts, 13 parts, 15 parts, 17 parts, 20 parts.

[0033] In different embodiments, the weight parts of the styrene elastomer can be, but are not limited to, 1 part, 3 parts, 4 parts, 6 parts, 8 parts, 10 parts, 12 parts, 15 parts.

[0034] In different embodiments, the weight parts of the flame retardant can be, but are not limited to, 1 part, 3 parts, 5 parts, 7 parts, 9 parts, 11 parts, 13 parts, 15 parts.

[0035] In different embodiments, the weight parts of the titanium dioxide can be, but are not limited to, 0.1 part, 0.5 part, 0.8 part, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.3 parts, 4.5 parts, 4.8 parts, 5 parts.

[0036] In different embodiments, the parts by weight of the benzotriazole compound can be, but are not limited to, 0.1 part, 0.2 part, 0.3 part, 0.4 part, 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1 part.

[0037] In some embodiments, the benzotriazole compound is at least one of 2-(2'-hydroxy-3',5'-bis(a,a-dimethylbenzyl)phenyl)benzotriazole, 2'-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, and 2-(2'-hydroxy-5'-methylphenyl)benzotriazole.

[0038] The above-listed benzotriazole compounds can further improve the electrical insulation performance and flame retardancy of the product.

[0039] In some embodiments, the titanium dioxide is rutile titanium dioxide.

[0040] Specifically, the average particle size of the nano-titanium dioxide is 50 - 800 nm, and can be, for example, but not limited to, 50 nm, 80 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm; preferably 200 - 600 nm; the test method is GB / T 19077 - 2016.

[0041] The nano-titanium dioxide within the above average particle size range can further improve the mechanical properties, flame retardancy, and electrical insulation performance of the product.

[0042] The present invention uses a styrene elastomer to improve the compatibility between polycarbonate, polyphenylene ether, and polystyrene. Examples of the styrene elastomer include styrene-butadiene block copolymer (SBR), hydrogenated styrene-butadiene block copolymer (SEB), styrene-butadiene-styrene block copolymer (SBS), hydrogenated styrene-butadiene-styrene block copolymer (SEBS), styrene-isoprene block copolymer (SIR), hydrogenated styrene-isoprene block copolymer (SEP), styrene-isoprene-styrene block copolymer (SIS), hydrogenated styrene-isoprene-styrene block copolymer (SEPS). The present invention preferably uses at least one of hydrogenated styrene-butadiene-styrene block copolymer and hydrogenated styrene-isoprene copolymer.

[0043] Specifically, the melt index of the styrene elastomer at 200 °C and 5 kg is 2 - 10 g / 10 min, and the test method is ISO 1133.

[0044] The present invention can modify the above-listed styrene elastomers to obtain modified styrene elastomers. Examples of modifiers for styrene elastomers include maleic anhydride, fumaric acid, metal salts of fumaric acid, etc. The present disclosure preferably uses maleic anhydride-modified styrene elastomers to improve the mechanical properties and flame retardancy of products.

[0045] Specifically, the preparation method of maleic anhydride-modified styrene elastomer is as follows: First, pre-mix styrene elastomer, dicumyl peroxide (DCP) and maleic anhydride (MAH), and then add them to an internal mixer. Under the conditions of a temperature of 140 - 180 °C and a rotation speed of 40 - 60 rpm, knead for 2 - 10 min. Then, extrude the kneaded product, inject water during the extrusion process, and extract the excess residual monomers and initiators by vacuum. The product obtained after extrusion and pelletizing is maleic anhydride-modified styrene elastomer.

[0046] In some embodiments, the grafting rate of maleic anhydride in the maleic anhydride-modified styrene elastomer is 1.0 - 3.3%, for example, it can be but not limited to 1.0%, 1.2%, 1.4%, 1.6%, 1.8%, 2.0%, 2.2%, 2.4%, 2.6%, 2.8%, 3%, 3.3%.

[0047] The maleic anhydride-modified styrene elastomer within the above performance parameter range can further improve the flame retardancy, electrical insulation performance and mechanical properties of products.

[0048] Specifically, the test method for the grafting rate of maleic anhydride in maleic anhydride-modified styrene elastomer includes the following steps:

[0049] Accurately weigh about 0.2 g of the MAH grafted product with an electronic balance, place it in a three-necked flask, add 50 ml of xylene, and add a small amount of water and DMF. Heat under reflux at 120 °C for 2 h, and then titrate the above solution with a calibrated KOH / ethanol solution with a concentration of 0.1 mol / L and an acetic acid / anhydrous ethanol solution. The indicator is thymol blue. The calculation formula for the grafting rate (G d ) is:

[0050]

[0051] W: mass of the elastomer-g-MAH sample (g);

[0052] V1: volume of the KOH / ethanol solution (mL);

[0053] C1: concentration of the KOH / ethanol solution (mol / L);

[0054] V2: volume of the acetic acid / xylene solution (mL);

[0055] C2: Concentration of acetic acid / xylene solution (mol / L).

[0056] Specifically, based on 100 parts by mass of the styrene elastomer, the mass of the dicumyl peroxide is 0.1 - 1 part, and the mass of the maleic anhydride is 3 - 10 parts.

[0057] In some embodiments, the maleic anhydride-modified styrene elastomer is at least one of a maleic anhydride-modified hydrogenated styrene-butadiene-styrene block copolymer and a maleic anhydride-modified hydrogenated styrene-isoprene copolymer.

[0058] In some embodiments, the flame retardant is a phosphorus-based flame retardant. Further preferably, the flame retardant is at least one of bis(diphenyl phosphate) and hexachlorocyclotriphosphazene.

[0059] Specifically, the polycarbonate of the present invention is preferably bisphenol A polycarbonate.

[0060] In some embodiments, the melt index of the polycarbonate at 300 °C and 1.2 kg is 3 - 30 g / 10 min; preferably 5 - 15 g / 10 min, and its test method is ISO 1133.

[0061] The polycarbonate within the above range can further improve the mechanical properties, flame retardancy, and electrical insulation properties of the product.

[0062] As the polymerization method of the polycarbonate, as long as the above object is satisfied, the interfacial polymerization method can be used. The polymerization method is not particularly limited, and any known method can be used.

[0063] Specifically, in the polycarbonate composition, the mass percentage content of the polycarbonate is not less than 30%.

[0064] In some embodiments, the weight average molecular weight of the polyphenylene ether is 30,000 - 80,000; preferably 40,000 - 70,000; and its test method is gel permeation chromatography (GPC): The polyphenylene ether is dissolved in a tetrahydrofuran solution, and the polymer solution passes through a porous gel chromatography column at a certain flow rate. The smaller the molecule, the easier it is to penetrate into the gel micropores. Through the ultraviolet or differential refractive index concentration detector connected to the GPC instrument, a polymer concentration distribution diagram changing with time is obtained.

[0065] The polyphenylene ether within the above range can further improve the processability and mechanical properties of the product.

[0066] Examples of suitable polyphenylene ether resins (B) include poly(2,6-dimethyl-1,4-phenylene) ether, poly(2-methyl-1,4-phenylene) ether, poly(3-methyl-1,4-phenylene) ether, poly(2,6-diethyl-1,4-phenylene) ether, poly(2-methyl-6-allyl-1,4-phenylene) ether, poly(2,6-dichloromethyl-1,4-phenylene) ether, poly(2,3,6-trimethyl-1,4-phenylene) ether, poly(2,3,5,6-tetramethylphenylene) ether, poly(2,6-dichloro-1,4-phenylene) ether, for example, poly(2,6-diphenyl-1,4-phenylene) ether, poly(2,6-diphenyl-1,4-phenylene) ether, poly(2,5-dimethyl-1,4-phenylene) ether, etc. Additionally, as the polyphenylene ether resin (B), copolymers containing two or more monomer units can be used, and mixtures containing two or more of these resins can also be used.

[0067] The polyphenylene ether can be obtained as a commercial product or can be manufactured. As a commercially available polyphenylene ether resin, PPO640 from SABIC can be cited.

[0068] Specifically, in the polycarbonate composition, the mass percentage content of the polyphenylene ether is 10 - 35%.

[0069] In some embodiments, the melt index of the polystyrene at 200 °C and 5.0 kg is 3 - 25 g / 10 min; preferably 5 - 15 g / 10 min; and its test method is carried out in accordance with standard ISO 1133.

[0070] The polystyrene within the above range can improve the compatibility between the polycarbonate and the polyphenylene ether, thereby further improving the mechanical properties, electrical insulation properties, and flame retardancy of the product.

[0071] In some embodiments, the polycarbonate composition further comprises 0.2 - 2 parts by weight of other additives, and the other additives are at least one of an antioxidant and a lubricant.

[0072] Specifically, the antioxidant is at least one of phenolic antioxidants, phosphite antioxidants, divalent sulfur antioxidants or hindered amine antioxidants. Among them, the phenolic antioxidant can be selected from at least one of 2,6-di-tert-butyl-4-methylphenol, pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], n-octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, styrenated phenol, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene and 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid; the phosphite antioxidant can be selected from at least one of tris(nonylphenyl) phosphite, the reaction product of N-phenylaniline and 2,4,4-trimethylpentene, tris[2,4-di-tert-butylphenyl] phosphite and diethyl (3,5-di-tert-butyl-4-hydroxybenzyl)phosphonate; the divalent sulfur antioxidant can be selected from at least one of dilauryl thiodipropionate (DLTP) and distearyl thiodipropionate (DSTP); the hindered amine antioxidant can be selected from at least one of 2,2,6,6-tetramethylpiperidinyl benzoate, bis(2,2,6,6-tetramethylpiperidinyl) sebacate and tris(1,2,2,6,6-pentamethylpiperidinol) phosphite.

[0073] Specifically, the lubricant is at least one of low molecular weight lipid lubricants, metal soap lubricants, stearic acid composite ester lubricants and amide lubricants. Among them, the low molecular weight lipid lubricant can be selected from at least one of solid paraffin, liquid paraffin and low molecular weight polyolefin wax; the metal soap lubricant can be selected from at least one of calcium stearate, magnesium stearate, zinc stearate and barium stearate; the stearic acid composite ester lubricant can be selected from at least one of ethylene glycol stearate, glycerol stearate and pentaerythritol stearate; the amide lubricant can be selected from at least one of erucamide, methylenebisstearamide and N,N-ethylenebisstearamide.

[0074] The production method of the polycarbonate composition of the present invention is not particularly limited and is carried out using a blending device such as a mixer, a single-screw or twin-screw extruder. The addition order between components is not particularly strictly limited, and they can be added simultaneously or in a certain order. Two or more components can be selected from all components for pre-mixing or kneading. For example, titanium dioxide, benzotriazole compounds and polyphenylene ether can be pre-formed into a polyphenylene ether masterbatch, and then added to the melt of other components in the form of the masterbatch according to a set ratio for extrusion. Under the condition that the mixing ability of the equipment permits, when molding or producing parts, the masterbatch and the particles formed by other components can also be mixed and melt-processed according to a set ratio.

[0075] Specifically, the preparation method of the polycarbonate composition in the present invention includes the following steps:

[0076] After uniformly mixing polyphenylene ether, polystyrene, styrene elastomer, titanium dioxide and benzotriazole compounds, the obtained mixture is added to an extruder and granulated by melt extrusion to obtain a polyphenylene ether masterbatch;

[0077] After uniformly mixing the polyphenylene ether masterbatch, polycarbonate and flame retardant, the obtained mixture is added to an extruder and granulated by melt extrusion to obtain the polycarbonate composition.

[0078] In the present invention, polyphenylene ether, polystyrene, styrene elastomer, titanium dioxide and benzotriazole compounds are prepared into a polyphenylene ether masterbatch. Polystyrene can reduce the viscosity of polyphenylene ether, making the viscosity of polyphenylene ether similar to that of polycarbonate, improving the compatibility between polyphenylene ether and polycarbonate, and thus improving the mechanical properties, electrical insulation properties and flame retardancy of the polycarbonate composition.

[0079] Specifically, during the preparation of the polyphenylene ether masterbatch, the temperature of the melt extrusion granulation is 230 - 260 °C; the screw speed of the extruder is 400 - 600 r / min.

[0080] Specifically, during the preparation of the polycarbonate composition, the temperature of the melt extrusion granulation is 250 - 290 °C, and the screw speed of the extruder is 400 - 600 r / min.

[0081] In a third aspect, the present disclosure provides the application of the polycarbonate composition in electrical equipment, such as the outer shell of a meter box, the outer shell of office equipment, the outer shell of a lamp, etc.

[0082] To further illustrate the present invention, the following examples are used to describe in detail the polycarbonate composition provided by the present invention, its preparation method and application, but they should not be construed as limiting the protection scope of the present invention.

[0083] The raw materials used in the examples and comparative examples are described as follows, but are not limited to these materials:

[0084] Polycarbonate: Bisphenol A polycarbonate, with a melt index of 10 g / 10 min at 300 °C and 1.2 kg, Mitsubishi, S - 2000F;

[0085] Polyphenylene ether: With a weight - average molecular weight of 43000, SABIC, PPO640;

[0086] Polystyrene: With a melt index of 4.5 g / 10 min at 200 °C and 5.0 kg, Guoxiang Chemical, PS 350K;

[0087] Terpolymer of acrylonitrile-butadiene-styrene: Melt index at 200 °C and 5.0 kg is 4.2 g / 10 min, blond, ABS KF-725;

[0088] Flame retardant: Bisphenol A-bis(diphenyl phosphate), Adeka, FP-600;

[0089] Styrene elastomer A: Hydrogenated styrene-butadiene-styrene block copolymer, Asahi Kasei, H1041;

[0090] Styrene elastomers B-E are self-made, and the preparation method is as follows:

[0091] Pre-mix styrene elastomer A, MAH and DCP evenly, add to an internal mixer, mix at 150 - 160 °C, and obtain grafted products by twin-screw extrusion. By changing the addition amount of MAH, mixing time and temperature, styrene elastomers B-E with maleic anhydride grafting rates of 1.05%, 1.65%, 2.35% and 3.3% are obtained;

[0092] Styrene elastomer F: Hydrogenated styrene-isoprene copolymer, YH4051, Baling Petrochemical;

[0093] Styrene elastomer G: Styrene-butadiene block copolymer, SBS F875, Maoming Petrochemical;

[0094] Titanium dioxide 1: Rutile type, average particle size is 50 nm;

[0095] Titanium dioxide 2: Rutile type, average particle size is 220 nm;

[0096] Titanium dioxide 3: Rutile type, average particle size is 400 nm;

[0097] Titanium dioxide 4: Rutile type, average particle size is 0.6 μm;

[0098] Benzotriazole compound 1: 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, Hengjingrui, UV-P;

[0099] Benzotriazole compound 2: 2'-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, Chengfeng, UV-326;

[0100] Benzotriazole compound 3: 2-(2'-hydroxy-3',5'-bis(a,a-dimethylbenzyl)phenyl)benzotriazole, BASF, UV-234;

[0101] 2-Hydroxy-4-methoxybenzophenone: UV-9, Guohua Chemical.

[0102] Lubricant: Pentaerythritol stearate, Lonza, GLYCOLUBE-P;

[0103] Antioxidant: A mixture of antioxidant 1076 and antioxidant 608 with a mass ratio of 1:1, n-octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, Mitsui Chemicals, SONOX 1076; bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, Chemtura, antioxidant Revonox 608.

[0104] Examples and Comparative Examples

[0105] The compositions and parts by weight of the polycarbonate compositions in the examples and comparative examples are shown in Tables 1 and 2.

[0106] The preparation methods of the polycarbonate compositions in the examples and comparative examples include the following steps:

[0107] According to the parts by weight in Tables 1 and 2, polyphenylene ether, polystyrene, styrene elastomer, titanium dioxide and benzotriazole compounds are mixed evenly, and the obtained mixture is added into a twin-screw extruder, and after melt extrusion and pelletization, a polyphenylene ether masterbatch is obtained; among them, the ratio of the length to the diameter of the twin-screw extruder is 40:1, the screw speed is 400 rpm, and the melt extrusion temperature is 230-260 °C;

[0108] After mixing the polyphenylene ether masterbatch, polycarbonate and flame retardant evenly, the obtained mixture is added into an extruder, and after melt extrusion and pelletization, the polycarbonate composition is obtained; among them, the ratio of the length to the diameter of the twin-screw extruder is 40:1, the screw speed is 400 rpm, and the melt extrusion temperature is 260-290 °C.

[0109] Table 1

[0110]

[0111]

[0112] Table 2

[0113]

[0114] Performance Testing

[0115] The polycarbonate compositions obtained in the examples and comparative examples were subjected to performance testing, and the testing methods are as follows:

[0116] (1) Impact strength: According to ASTM D256-2010, the sample size is 3.2 mm * 12.7 mm * 64 mm, and the test condition is a 23 °C cantilever beam;

[0117] (2) Tensile strength: According to ASTM D638, the sample size is tensile specimen A1, and the test condition is 23 °C;

[0118] (3) Tracking Resistance (CTI value): According to the standard IEC60112-2020, the normal temperature CTI value of a sample with a size of 60*60*3 mm is tested.

[0119] (4) Wet Electrical Insulation Performance: A constant temperature and humidity chamber with a temperature of 50°C and a humidity of 90% is used to simulate the wet environment. After placing the polycarbonate composition in the wet environment for 168 h, the wet resistivity of the polycarbonate composition is tested, and the resistivity retention rate of the polycarbonate composition after being placed in the wet environment is calculated. The calculation formula is: Resistivity Retention Rate = Wet Resistivity / Normal Temperature Resistivity * 100%. The higher the wet resistivity retention rate, the better the moisture and heat resistance of the material.

[0120] (5) Flame Retardancy: According to GBT2408, the size of the test specimen is 1.5 mm * 12.7 mm * 130 mm. Five test specimens are tested, and the total burning time of t1 + t2 of the five test specimens is counted to determine the flame retardancy performance. Under the same flame retardancy grade, the shorter the total burning time, the better the flame retardancy performance.

[0121] The test results are shown in Table 3.

[0122] Table 3

[0123]

[0124]

[0125] As can be seen from Table 3, the impact strength of the polycarbonate composition of the present invention is 25.1 - 45.1 MPa, the CTI value of the tracking resistance is 300 - 350 V, the wet electrical insulation performance is 98.0 - 99.2%, the flame retardancy grade is V-0, and the total burning time is 19 - 39 s; it shows that the polycarbonate composition of the present invention simultaneously has high mechanical properties, flame retardancy, and electrical insulation performance.

[0126] Comparing Comparative Example 1 with Examples 4 - 9, it can be seen that when the styrene elastomer is a maleic anhydride - modified styrene elastomer, the impact strength of the obtained polycarbonate composition is 34.7 - 43.5 MPa, the CTI value of tracking resistance is 300 - 350 V, the wet - state electrical insulation property is 98.5 - 99.2%, and the flame - retardant rating is V - 0, and the total combustion time is 19 - 32 s; this shows that when the styrene elastomer is a maleic anhydride - modified styrene elastomer, the polycarbonate composition simultaneously has high mechanical properties, flame - retardancy, and wet - state electrical insulation properties; when the maleic anhydride content of the maleic anhydride - modified styrene elastomer is 1.6 - 2.4%, the impact strength of the obtained polycarbonate composition is 37.6 - 43.5 MPa, the CTI value of tracking resistance is 325 - 350 V, the wet - state electrical insulation property is 98.7 - 99.2%, and the total combustion time is 19 - 22 s; this shows that when the maleic anhydride content of the maleic anhydride - modified styrene elastomer is 1.6 - 2.4%, the polycarbonate composition simultaneously has high mechanical properties, flame - retardancy, and electrical insulation properties.

[0127] Comparing Example 4 with Examples 10 - 12, it can be seen that when the average particle size of titanium dioxide is 200 - 600 nm, the impact strength of the obtained polycarbonate composition is 35.9 - 43.5 MPa, the CTI value of tracking resistance is 300 - 350 V, the wet - state electrical insulation property is 98.6 - 99.2%, and the total combustion time is 19 - 24 s; this shows that when the average particle size of titanium dioxide is 200 - 600 nm, the polycarbonate composition simultaneously has high mechanical properties, flame - retardancy, and wet - state electrical insulation properties.

[0128] Comparing Example 4, Examples 13 - 14 with Comparative Example 5, it can be seen that replacing the benzotriazole - type compound with other analogs having similar effects will lead to a decrease in the mechanical properties, flame - retardancy, and electrical insulation properties of the polycarbonate composition.

[0129] Comparing Example 4 with Comparative Examples 1 - 4, it can be seen that lacking at least one of the styrene elastomer, titanium dioxide, and benzotriazole - type compound will lead to a decrease in at least one of the mechanical properties, flame - retardancy, and electrical insulation properties of the polycarbonate composition.

[0130] Finally, it should be noted that the above - mentioned embodiments are used to illustrate the technical solutions of the present disclosure rather than to limit the protection scope of the present disclosure. Although the present disclosure has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present disclosure can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present disclosure.

Claims

1. A polycarbonate composition, characterized in that The invention comprises the following components in parts by weight: 30-70 parts of polycarbonate, 10-35 parts of polyphenylene ether, 5-20 parts of polystyrene, 1-15 parts of styrene elastomer, 1-15 parts of flame retardant, 0.1-5 parts of titanium dioxide and 0.1-1 parts of benzotriazole compounds.

2. The polycarbonate composition according to claim 1, wherein The benzotriazole compound is at least one of 2-(2'-hydroxy-3',5'bis(a,a-dimethylbenzyl)phenyl)benzotriazole, 2'-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, and 2-(2ˊ-hydroxy-5ˊ-methylphenyl)benzotriazole.

3. The polycarbonate composition according to claim 1, characterized in that The average particle size of the titanium dioxide is 50-800 nm.

4. The polycarbonate composition according to claim 1, wherein The styrene elastomer is a styrene-butadiene block copolymer, a hydrogenated styrene-butadiene block copolymer, a styrene-butadiene-styrene block copolymer, a hydrogenated styrene-butadiene-styrene block copolymer, a styrene-isoprene block copolymer, a hydrogenated styrene-isoprene block copolymer, a styrene-isoprene-styrene block copolymer, and a hydrogenated styrene-isoprene-styrene block copolymer.

5. The polycarbonate composition according to claim 4, characterized in that The styrene elastomer is a maleic anhydride modified styrene elastomer; preferably, the grafting rate of maleic anhydride in the maleic anhydride modified styrene elastomer is 1.0-3.3%; more preferably, the grafting rate of maleic anhydride in the maleic anhydride modified styrene elastomer is 1.6-2.4%.

6. The polycarbonate composition according to claim 4, wherein The maleic anhydride modified styrene elastomer is at least one of a maleic anhydride modified hydrogenated styrene-butadiene-styrene block copolymer and a maleic anhydride modified hydrogenated styrene-isoprene copolymer.

7. The polycarbonate composition according to claim 1, wherein The flame retardant is at least one of bis(diphenyl phosphate) and hexachlorocyclotriphosphazene; and / or, the polycarbonate has a melt index of 3-30 g / 10 min at 300° C. and 1.2 kg; And / or, the weight average molecular weight of the polyphenylene ether is 30000-80000; And / or, the polystyrene has a melt index of 5-15 g / 10 min at 200° C. and 5.0 kg.

8. The polycarbonate composition according to claim 1, wherein The polycarbonate composition further comprises 0.2-2 parts by weight of an auxiliary agent, wherein the auxiliary agent is at least one of an antioxidant and a lubricant.

9. A method for preparing a polycarbonate composition according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: uniformly mixing the components according to a certain proportion, melting, extruding and granulating the obtained mixture to obtain the polycarbonate composition.

10. Use of the polycarbonate composition according to any one of claims 1 to 8 in electrical equipment.

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