Scratch-resistant high-weather-resistant flame-retardant polycarbonate composition and preparation method thereof

Abstract

The invention discloses a scratch-resistant high-weather-resistant flame-retardant polycarbonate composition and a preparation method thereof, and the scratch-resistant high-weather-resistant flame-retardant polycarbonate composition is prepared from the following components in parts by weight: 15-50 parts of polycarbonate resin A, 15-30 parts of polycarbonate resin B, 13-20 parts of polybutylene terephthalate, 15-20 parts of a flame retardant and 5-15 parts of modified magnesium sulfate whiskers, the polycarbonate resin A, the polycarbonate resin B, the flame retardant, the polybutylene terephthalate and the modified magnesium sulfate whisker are subjected to physical blending modification, so that the flame-retardant polycarbonate resin is prepared from the following components in parts by weight: 20-30 parts of polycarbonate resin A, 20-30 parts of polycarbonate resin B, 20-30 parts of flame retardant, 20-30 parts of modified magnesium sulfate whisker, 3-5 parts of methyl methacrylate-styrene-organic silicon core-shell copolymer, 3-5 parts of methyl methacrylate-butadiene-styrene copolymer, 0.5-2 parts of reactive compatilizer and 0.6-1.8 parts of other auxiliaries. The processing performance and the surface scratch resistance of the polycarbonate composition can be improved, and the methyl methacrylate-styrene-organic silicon core-shell copolymer and the methyl methacrylate-butadiene-styrene copolymer are added to further improve the toughness and the notch sensitive cracking performance of the polycarbonate composition.

Description

Technical Field

[0001] The invention relates to the field of polymer materials, in particular to a scratch-resistant, highly weather-resistant and flame-retardant polycarbonate composition and a preparation method thereof. Background Art

[0002] Engineering plastics are a type of plastic that can replace metals as structural materials, such as polyamide (PA), polycarbonate (PC), polyoxymethylene (POM), etc. Polycarbonate (PC) is the only transparent plastic among engineering plastics because it is amorphous and almost non-crystalline. Polycarbonate has good mechanical properties, high impact strength and mechanical strength, making it widely used in 2,500 parts of aircraft and aircraft. Good heat resistance and transparency make polycarbonate an indispensable non-metallic material in fighter jets. Polycarbonate is widely used in the electronics field due to its comprehensive electrical resistance and can be used as electrical connectors and insulating boards. Polycarbonate can be used in hollow panels and solid panels of commercial buildings, interior and exterior decoration of houses, etc. due to its light weight and sound insulation. Polycarbonate alloys can be used in automobile door panels, bumpers, dashboards, lampshades, windows, etc., and have huge potential market space. Polycarbonate has special optical properties. Its surface gloss is good, it will not fade after long-term exposure to light, and it has good photoconductivity. It can be used in lighting fixtures and other fields. Polycarbonate is reinforced with glass fiber and can be used in spacecraft and astronaut helmets.

[0003] However, the poor flame retardancy and abrasion resistance of polycarbonate also limit the application of polycarbonate in many market areas. As the safety requirements of the application market of polycarbonate materials become more and more stringent, in order to expand the application and market areas of polycarbonate, it is necessary to improve the defects of low flame retardancy and easy scratching of polycarbonate while maintaining the excellent transparency and mechanical properties of polycarbonate.

[0004] In recent years, the scratch resistance of polycarbonate has been improved both at home and abroad, generally by physical modification with polybutylene terephthalate or by blending with inorganic substances. The processing performance of the polycarbonate composition after blending modification has not been significantly improved, and the toughness of the obtained polycarbonate composition is also relatively low. Summary of the invention

[0005] In view of this, the present invention provides a scratch-resistant, highly weather-resistant and flame-retardant polycarbonate composition and a preparation method thereof. The processing performance and surface scratch resistance of the polycarbonate composition are improved by selecting polycarbonate with different molecular weights and bisphenol A bis(diphenyl phosphate), polybutylene terephthalate and surface-modified magnesium sulfate whiskers for physical blending and modification. The toughness and notch-sensitive cracking performance of the polycarbonate composition are further improved by adding methyl methacrylate-styrene-organic silicon core-shell copolymer and methyl methacrylate-butadiene-styrene copolymer.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention discloses a scratch-resistant, highly weather-resistant, flame-retardant polycarbonate composition, which is prepared from the following components in parts by weight:

[0008]

[0009] The total weight of the polycarbonate resin A, the polycarbonate resin B, the flame retardant, the polybutylene terephthalate, and the modified magnesium sulfate whisker is 100 parts.

[0010] As a further solution of the present invention: the melt index of the polycarbonate resin A is 10-12 g / 10 min; and / or the melt index of the polycarbonate resin B is 3-5 g / 10 min. By compounding high melt index polycarbonate and low melt index polycarbonate in a certain proportion, the optimization of processing performance and the balanced improvement of material toughness can be effectively achieved.

[0011] As a further solution of the present invention: the modification method of the modified magnesium sulfate whisker is: grinding and sieving the dried magnesium sulfate whisker, adding a coupling agent and anhydrous ethanol to obtain a suspension with a concentration of 10-15wt%; the amount of the coupling agent added is 3-5% of the suspension;

[0012] The precipitate obtained by the reaction under heating and stirring conditions is dried, sieved and ground to obtain modified magnesium sulfate whiskers.

[0013] As a further solution of the present invention: the reactive compatibilizer is maleic acid tincture grafted with acrylonitrile / butadiene / styrene copolymer.

[0014] As a further solution of the present invention: the other auxiliary agent is at least one of an antioxidant, a light stabilizer, and a lubricant.

[0015] As a further solution of the present invention: the antioxidant is at least one of a hindered phenol antioxidant and a phosphite antioxidant.

[0016] As a further solution of the present invention: the lubricant is pentaerythritol stearate.

[0017] As a further solution of the present invention: the flame retardant is bisphenol A bis(diphenyl phosphate).

[0018] In a second aspect, the present invention discloses a method for preparing the scratch-resistant and highly weather-resistant flame-retardant polycarbonate composition as described above, comprising the following steps:

[0019] (1) polycarbonate resin A, polycarbonate resin B, bisphenol A bis(diphenyl phosphate), polybutylene terephthalate, modified magnesium sulfate whisker, methyl methacrylate-styrene-organic silicon core-shell copolymer, methyl methacrylate-butadiene-styrene copolymer and reactive compatibilizer are uniformly mixed to obtain a mixture A;

[0020] (2) mixing an antioxidant, a lubricant and a light stabilizer to obtain a mixed material B;

[0021] (3) After the mixed material A and the mixed material B are uniformly mixed, the mixed material A and the mixed material B are fed into a twin-screw extruder, and the mixed material A and the mixed material B are melt-extruded and granulated to obtain a scratch-resistant and highly weather-resistant flame-retardant polycarbonate composition.

[0022] As a further scheme of the present invention: the operating parameters of the twin-screw extruder are: the temperature of zone one is 210-240°C, the temperature of zone two is 230-260°C, the temperature of zone three is 235-260°C, the temperature of zone four is 220-260°C, the temperature of zone five is 220-260°C, the temperature of zone six is ​​220-260°C, the temperature of zone seven is 220-260°C, the temperature of zone eight is 220-260°C, the die head temperature is 240-275°C, and the screw speed is 200-600rpm.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention selects polycarbonate A, polycarbonate B, flame retardant bisphenol A bis (diphenyl phosphate), and polybutylene terephthalate (i.e., PBT) of different molecular weights for blending and modification, wherein bisphenol A bis (diphenyl phosphate) can effectively improve the flame retardancy and processability of the material, and PBT can improve the surface scratch resistance of the entire material, so that the modified polycarbonate composition has excellent flame retardancy and scratch resistance. In addition, in order to further improve the shortcomings of the polycarbonate composition in terms of impact resistance and notch impact sensitivity, the present invention adds methyl methacrylate-styrene-silicon core-shell copolymer, methyl methacrylate-styrene-butadiene copolymer, and reactive compatibilizer. The introduction of the methyl methacrylate-styrene-silicon core-shell copolymer and the methyl methacrylate-styrene-butadiene copolymer compounding system greatly improves the material's impact resistance and notch impact sensitivity, while not significantly increasing the material cost, so that the modified polycarbonate composition can be smoothly industrialized and mass-produced.

[0025] The preparation process of the scratch-resistant and highly flame-retardant polycarbonate composition provided by the present invention is simple, easy to control, has low requirements on equipment, and the equipment used is all general polymer processing equipment, with low investment, which is conducive to industrial production. DETAILED DESCRIPTION

[0026] For ease of understanding of the present invention, the present invention will be described more fully below in conjunction with specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0028] The specific information of the raw materials used in the following examples and comparative examples is as follows:

[0029] Polycarbonate resin A, with a melt index of 10 g / 10 min, was selected from Teijin Co., Ltd. of Japan;

[0030] Polycarbonate resin B, with a melt index of 3.5 g / 10 min, was selected from Teijin Co., Ltd. of Japan;

[0031] Flame retardant, bisphenol A bis(diphenyl phosphate), phosphorus content 16%, selected from Zhejiang Wansheng Co., Ltd.;

[0032] Polybutylene terephthalate, with a melt index of 2 g / 10 min, selected from Wanhua Chemical Co., Ltd.;

[0033] Methyl methacrylate-styrene-silicon core-shell copolymer S-2001, selected from Mitsubishi Corporation of Japan;

[0034] Methyl methacrylate-styrene-butadiene copolymer M-722, selected from Mitsubishi Corporation of Japan;

[0035] Maleic acid tincture grafted acrylonitrile / butadiene / styrene copolymer, the mass fraction of maleic anhydride is 2wt%, selected from Sigma-Aldrich (Shanghai) Trading Co., Ltd.;

[0036] Hindered phenol antioxidant, β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate octadecyl ester, selected from BASF GmbH, Germany;

[0037] Phosphite antioxidant, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphate, selected from Shanghai Dianyao Fine Chemical Co., Ltd.;

[0038] Lubricant, pentaerythritol stearate, selected from Zhaoqing Sendeli Chemical Industry Co., Ltd.;

[0039] The light stabilizer is a compound of UV-P and UV-234 in a mass ratio of 1:1, and both are selected from BASF GmbH.

[0040] The preparation method of modified magnesium sulfate whisker is as follows: commercially available magnesium sulfate whisker is dried at 105°C for 6 hours, sieved and ground, and a magnesium sulfate whisker suspension with an initial concentration of 12% is prepared, and a KH-550 anhydrous ethanol solution with a doping amount of 3wt% (relative to the magnesium sulfate whisker suspension) is added, and the mixture is heated in a magnetic stirring reaction bath at 95°C and a stirring rate of 1000r / min for 25 minutes. The obtained mixed solution is filtered while hot, and the obtained filter cake is dried at 105°C for 10 hours, and then sieved and ground. After the sieved powder is dried at 105°C for 3 hours, it is placed in the air and left to stand for 48 hours to obtain surface-modified magnesium sulfate whisker.

[0041] All materials are commercially available conventional products.

[0042] It is to be understood that the above raw materials and reagents are only examples of some specific embodiments of the present invention, so that the technical solution of the present invention is clearer, and it does not mean that the present invention can only use the above reagents, and the specific scope in the claims shall prevail. In addition, the "parts" described in the examples and comparative examples, unless otherwise specified, refer to parts by weight.

[0043] Any range described in the present invention includes the end value and any numerical value between the end values ​​and any sub-range formed by the end value or any numerical value between the end values.

[0044] Example 1

[0045] (1) 50 parts of polycarbonate resin A, 15 parts of polycarbonate resin B, 15 parts of polybutylene terephthalate, and 5 parts of modified magnesium sulfate whisker are dried, and the dried polycarbonate resin A, polycarbonate resin B, polybutylene terephthalate, modified magnesium sulfate whisker, 15 parts of bisphenol A bis(diphenyl phosphate), 5 parts of methyl methacrylate-styrene-organic silicon core-shell copolymer, 5 parts of methyl methacrylate-butadiene-styrene copolymer, and 0.5 part of maleic acid tincture grafted acrylonitrile / butadiene / styrene copolymer are added into a stirrer (rotating speed is 500 rpm) for mixing.

[0046] (2) 0.2 parts of hindered phenol antioxidant, 0.2 parts of phosphite antioxidant, 0.3 parts of pentaerythritol stearate and 0.3 parts of light stabilizer were added to another mixer (rotating speed of 500 rpm) and mixed.

[0047] (3) Pour the mixture obtained in step (1) and step (2) into the same high-speed mixer (rotation speed is 500 rpm) and mix for 10 min.

[0048] (4) adding the mixed material in step (3) into a parallel twin-screw extruder through a feeder, and performing melt extrusion and granulation in the parallel twin-screw extruder (eight zones in total), wherein the process parameters include: a temperature of zone 1 of 230° C., a temperature of zone 2 of 240° C., a temperature of zone 3 of 250° C., a temperature of zone 4 of 250° C., a temperature of zone 5 of 250° C., a temperature of zone 6 of 250° C., a temperature of zone 7 of 245° C., a temperature of zone 8 of 245° C., a die head temperature of 260° C., and a screw speed of 500 rpm; the screw shape of the parallel twin-screw extruder is a single-threaded screw, the ratio of screw length L to diameter D (L / D) is 35, and the screw is provided with two meshing block zones and one reverse thread zone.

[0049] Example 2

[0050] (1) 15 parts of polycarbonate resin A, 30 parts of polycarbonate resin B, 20 parts of polybutylene terephthalate, and 15 parts of modified magnesium sulfate whisker are dried, and the dried polycarbonate resin A, polycarbonate resin B, polybutylene terephthalate, modified magnesium sulfate whisker, 20 parts of bisphenol A bis(diphenyl phosphate), 3 parts of methyl methacrylate-styrene-organic silicon core-shell copolymer, 3 parts of methyl methacrylate-butadiene-styrene copolymer, and 2 parts of maleic acid tincture grafted acrylonitrile / butadiene / styrene copolymer are added into a stirrer (rotating speed is 500 rpm) for mixing.

[0051] (2) 0.2 parts of hindered phenol antioxidant, 0.2 parts of phosphite antioxidant, 0.3 parts of pentaerythritol stearate and 0.3 parts of light stabilizer were added to another mixer (rotating speed of 500 rpm) and mixed.

[0052] (3) Pour the mixture obtained in step (1) and step (2) into the same high-speed mixer (rotation speed is 500 rpm) and mix for 10 min.

[0053] (4) adding the mixed material in step (3) into a parallel twin-screw extruder through a feeder, and performing melt extrusion and granulation in the parallel twin-screw extruder (eight zones in total), wherein the process parameters include: a temperature of zone 1 of 230° C., a temperature of zone 2 of 240° C., a temperature of zone 3 of 250° C., a temperature of zone 4 of 250° C., a temperature of zone 5 of 250° C., a temperature of zone 6 of 250° C., a temperature of zone 7 of 245° C., a temperature of zone 8 of 245° C., a die head temperature of 260° C., and a screw speed of 500 rpm; the screw shape of the parallel twin-screw extruder is a single-threaded screw, the ratio of screw length L to diameter D (L / D) is 35, and the screw is provided with two meshing block zones and one reverse thread zone.

[0054] Example 3

[0055] (1) 45 parts of polycarbonate resin A, 20 parts of polycarbonate resin B, 15 parts of polybutylene terephthalate, and 5 parts of modified magnesium sulfate whisker are dried, and the dried polycarbonate resin A, polycarbonate resin B, polybutylene terephthalate, modified magnesium sulfate whisker, 15 parts of bisphenol A bis(diphenyl phosphate), 3 parts of methyl methacrylate-styrene-organic silicon core-shell copolymer, 3 parts of methyl methacrylate-butadiene-styrene copolymer, and 0.5 part of maleic acid tincture grafted acrylonitrile / butadiene / styrene copolymer are added into a stirrer (rotating speed is 500 rpm) for mixing.

[0056] (2) 0.2 parts of hindered phenol antioxidant, 0.2 parts of phosphite antioxidant, 0.3 parts of pentaerythritol stearate and 0.3 parts of light stabilizer were added to another mixer (rotating speed of 500 rpm) and mixed.

[0057] (3) Pour the mixture obtained in step (1) and step (2) into the same high-speed mixer (rotation speed is 500 rpm) and mix for 10 min.

[0058] (4) adding the mixed material in step (3) into a parallel twin-screw extruder through a feeder, and performing melt extrusion and granulation in the parallel twin-screw extruder (eight zones in total), wherein the process parameters include: a temperature of zone 1 of 230° C., a temperature of zone 2 of 240° C., a temperature of zone 3 of 250° C., a temperature of zone 4 of 250° C., a temperature of zone 5 of 250° C., a temperature of zone 6 of 250° C., a temperature of zone 7 of 245° C., a temperature of zone 8 of 245° C., a die head temperature of 260° C., and a screw speed of 500 rpm; the screw shape of the parallel twin-screw extruder is a single-threaded screw, the ratio of screw length L to diameter D (L / D) is 35, and the screw is provided with two meshing block zones and one reverse thread zone.

[0059] Example 4

[0060] (1) 25 parts of polycarbonate resin A, 30 parts of polycarbonate resin B, 15 parts of polybutylene terephthalate, and 10 parts of modified magnesium sulfate whiskers are dried, and the dried polycarbonate resin A, polycarbonate resin B, polybutylene terephthalate, modified magnesium sulfate whiskers, 19 parts of bisphenol A bis(diphenyl phosphate), 3 parts of methyl methacrylate-styrene-organic silicon core-shell copolymer, 3 parts of methyl methacrylate-butadiene-styrene copolymer, and 0.5 part of maleic acid tincture grafted acrylonitrile / butadiene / styrene copolymer are added into a stirrer (rotating speed is 500 rpm) for mixing.

[0061] (2) 0.2 parts of hindered phenol antioxidant, 0.2 parts of phosphite antioxidant, 0.3 parts of pentaerythritol stearate and 0.3 parts of light stabilizer were added to another mixer (rotating speed of 500 rpm) and mixed.

[0062] (3) Pour the mixture obtained in step (1) and step (2) into the same high-speed mixer (rotation speed is 500 rpm) and mix for 10 min.

[0063] (4) adding the mixed material in step (3) into a parallel twin-screw extruder through a feeder, and performing melt extrusion and granulation in the parallel twin-screw extruder (eight zones in total), wherein the process parameters include: a temperature of zone 1 of 230° C., a temperature of zone 2 of 240° C., a temperature of zone 3 of 250° C., a temperature of zone 4 of 250° C., a temperature of zone 5 of 250° C., a temperature of zone 6 of 250° C., a temperature of zone 7 of 245° C., a temperature of zone 8 of 245° C., a die head temperature of 260° C., and a screw speed of 500 rpm; the screw shape of the parallel twin-screw extruder is a single-threaded screw, the ratio of screw length L to diameter D (L / D) is 35, and the screw is provided with two meshing block zones and one reverse thread zone.

[0064] Example 5

[0065] (1) 40 parts of polycarbonate resin A, 20 parts of polycarbonate resin B, 15 parts of polybutylene terephthalate, and 10 parts of modified magnesium sulfate whiskers are dried, and the dried polycarbonate resin A, polycarbonate resin B, polybutylene terephthalate, modified magnesium sulfate whiskers, 15 parts of bisphenol A bis(diphenyl phosphate), 3 parts of methyl methacrylate-styrene-organic silicon core-shell copolymer, 3 parts of methyl methacrylate-butadiene-styrene copolymer, and 1 part of maleic acid tincture grafted acrylonitrile / butadiene / styrene copolymer are added into a stirrer (rotating speed is 500 rpm) for mixing.

[0066] (2) 0.2 parts of hindered phenol antioxidant, 0.2 parts of phosphite antioxidant, 0.3 parts of pentaerythritol stearate and 0.3 parts of light stabilizer were added to another mixer (rotating speed of 500 rpm) and mixed.

[0067] (3) Pour the mixture obtained in step (1) and step (2) into the same high-speed mixer (rotation speed is 500 rpm) and mix for 10 min.

[0068] (4) adding the mixed material in step (3) into a parallel twin-screw extruder through a feeder, and performing melt extrusion and granulation in the parallel twin-screw extruder (eight zones in total), wherein the process parameters include: a temperature of zone 1 of 230° C., a temperature of zone 2 of 240° C., a temperature of zone 3 of 250° C., a temperature of zone 4 of 250° C., a temperature of zone 5 of 250° C., a temperature of zone 6 of 250° C., a temperature of zone 7 of 245° C., a temperature of zone 8 of 245° C., a die head temperature of 260° C., and a screw speed of 500 rpm; the screw shape of the parallel twin-screw extruder is a single-threaded screw, the ratio of screw length L to diameter D (L / D) is 35, and the screw is provided with two meshing block zones and one reverse thread zone.

[0069] Example 6

[0070] (1) 35 parts of polycarbonate resin A, 20 parts of polycarbonate resin B, 15 parts of polybutylene terephthalate, and 10 parts of modified magnesium sulfate whiskers are dried, and the dried polycarbonate resin A, polycarbonate resin B, polybutylene terephthalate, modified magnesium sulfate whiskers, 20 parts of bisphenol A bis(diphenyl phosphate), 3 parts of methyl methacrylate-styrene-organic silicon core-shell copolymer, 3 parts of methyl methacrylate-butadiene-styrene copolymer, and 1 part of maleic acid tincture grafted acrylonitrile / butadiene / styrene copolymer are added into a stirrer (rotating speed is 500 rpm) for mixing.

[0071] (2) 0.2 parts of hindered phenol antioxidant, 0.2 parts of phosphite antioxidant, 0.3 parts of pentaerythritol stearate and 0.3 parts of light stabilizer were added to another mixer (rotating speed of 500 rpm) and mixed.

[0072] (3) Pour the mixture obtained in step (1) and step (2) into the same high-speed mixer (rotation speed is 500 rpm) and mix for 10 min.

[0073] (4) adding the mixed material in step (3) into a parallel twin-screw extruder through a feeder, and performing melt extrusion and granulation in the parallel twin-screw extruder (eight zones in total), wherein the process parameters include: a temperature of zone 1 of 230° C., a temperature of zone 2 of 240° C., a temperature of zone 3 of 250° C., a temperature of zone 4 of 250° C., a temperature of zone 5 of 250° C., a temperature of zone 6 of 250° C., a temperature of zone 7 of 245° C., a temperature of zone 8 of 245° C., a die head temperature of 260° C., and a screw speed of 500 rpm; the screw shape of the parallel twin-screw extruder is a single-threaded screw, the ratio of screw length L to diameter D (L / D) is 35, and the screw is provided with two meshing block zones and one reverse thread zone.

[0074] Example 7

[0075] (1) 30 parts of polycarbonate resin A, 27 parts of polycarbonate resin B, 13 parts of polybutylene terephthalate, and 10 parts of modified magnesium sulfate whiskers are dried, and the dried polycarbonate resin A, polycarbonate resin B, polybutylene terephthalate, modified magnesium sulfate whiskers, 20 parts of bisphenol A bis(diphenyl phosphate), 4 parts of methyl methacrylate-styrene-organic silicon core-shell copolymer, 4 parts of methyl methacrylate-butadiene-styrene copolymer, and 1 part of maleic acid tincture grafted acrylonitrile / butadiene / styrene copolymer are added into a stirrer (rotating speed is 500 rpm) for mixing.

[0076] (2) 0.2 parts of hindered phenol antioxidant, 0.2 parts of phosphite antioxidant, 0.3 parts of pentaerythritol stearate and 0.3 parts of light stabilizer were added to another mixer (rotating speed of 500 rpm) and mixed.

[0077] (3) Pour the mixture obtained in step (1) and step (2) into the same high-speed mixer (rotation speed is 500 rpm) and mix for 10 min.

[0078] (4) adding the mixed material in step (3) into a parallel twin-screw extruder through a feeder, and performing melt extrusion and granulation in the parallel twin-screw extruder (eight zones in total), wherein the process parameters include: a temperature of zone 1 of 230° C., a temperature of zone 2 of 240° C., a temperature of zone 3 of 250° C., a temperature of zone 4 of 250° C., a temperature of zone 5 of 250° C., a temperature of zone 6 of 250° C., a temperature of zone 7 of 245° C., a temperature of zone 8 of 245° C., a die head temperature of 260° C., and a screw speed of 500 rpm; the screw shape of the parallel twin-screw extruder is a single-threaded screw, the ratio of screw length L to diameter D (L / D) is 35, and the screw is provided with two meshing block zones and one reverse thread zone.

[0079] Example 8

[0080] (1) 30 parts of polycarbonate resin A, 27 parts of polycarbonate resin B, 13 parts of polybutylene terephthalate, and 10 parts of modified magnesium sulfate whiskers are dried, and the dried polycarbonate resin A, polycarbonate resin B, polybutylene terephthalate, modified magnesium sulfate whiskers, 20 parts of bisphenol A bis(diphenyl phosphate), 4 parts of methyl methacrylate-styrene-organic silicon core-shell copolymer, 4 parts of methyl methacrylate-butadiene-styrene copolymer, and 1 part of maleic acid tincture grafted acrylonitrile / butadiene / styrene copolymer are added into a stirrer (rotating speed is 500 rpm) for mixing.

[0081] (2) 0.2 parts of hindered phenol antioxidant, 0.2 parts of phosphite antioxidant, 0.3 parts of pentaerythritol stearate and 0.3 parts of light stabilizer were added to another mixer (rotating speed of 500 rpm) and mixed.

[0082] (3) Pour the mixture obtained in step (1) and step (2) into the same high-speed mixer (rotation speed is 500 rpm) and mix for 10 min.

[0083] (4) adding the mixed material in step (3) into a parallel twin-screw extruder through a feeder, and performing melt extrusion and granulation in the parallel twin-screw extruder (eight zones in total), wherein the process parameters include: a temperature of zone 1 of 230° C., a temperature of zone 2 of 240° C., a temperature of zone 3 of 250° C., a temperature of zone 4 of 250° C., a temperature of zone 5 of 250° C., a temperature of zone 6 of 250° C., a temperature of zone 7 of 245° C., a temperature of zone 8 of 245° C., a die head temperature of 260° C., and a screw speed of 500 rpm; the screw shape of the parallel twin-screw extruder is a single-threaded screw, the ratio of screw length L to diameter D (L / D) is 50, and the screw is provided with two meshing block zones and one reverse threaded zone.

[0084] Comparative Example 1

[0085] (1) 30 parts of polycarbonate resin A, 27 parts of polycarbonate resin B, 13 parts of polybutylene terephthalate, and 10 parts of modified magnesium sulfate whiskers are dried, and the dried polycarbonate resin A, polycarbonate resin B, polybutylene terephthalate, modified magnesium sulfate whiskers, 20 parts of bisphenol A bis(diphenyl phosphate), and 1 part of maleic acid tincture grafted acrylonitrile / butadiene / styrene copolymer are added into a stirrer (rotating speed is 500 rpm) and mixed.

[0086] (2) 0.2 parts of hindered phenol antioxidant, 0.2 parts of phosphite antioxidant, 0.3 parts of pentaerythritol stearate and 0.3 parts of light stabilizer were added to another mixer (rotating speed of 500 rpm) and mixed.

[0087] (3) Pour the mixture obtained in step (1) and step (2) into the same high-speed mixer (rotation speed is 500 rpm) and mix for 10 min.

[0088] (4) adding the mixed material in step (3) into a parallel twin-screw extruder through a feeder, and performing melt extrusion and granulation in the parallel twin-screw extruder (eight zones in total), wherein the process parameters include: a temperature of zone 1 of 230° C., a temperature of zone 2 of 240° C., a temperature of zone 3 of 250° C., a temperature of zone 4 of 250° C., a temperature of zone 5 of 250° C., a temperature of zone 6 of 250° C., a temperature of zone 7 of 245° C., a temperature of zone 8 of 245° C., a die head temperature of 260° C., and a screw speed of 500 rpm; the screw shape of the parallel twin-screw extruder is a single-threaded screw, the ratio of screw length L to diameter D (L / D) is 35, and the screw is provided with two meshing block zones and one reverse thread zone.

[0089] Comparative Example 2

[0090] (1) 40 parts of polycarbonate resin A, 27 parts of polycarbonate resin B, and 13 parts of polybutylene terephthalate are dried, and the dried polycarbonate resin A, polycarbonate resin B, polybutylene terephthalate, 20 parts of bisphenol A bis(diphenyl phosphate), 4 parts of methyl methacrylate-styrene-organic silicon core-shell copolymer, 4 parts of methyl methacrylate-butadiene-styrene copolymer, and 1 part of maleic acid tincture grafted acrylonitrile / butadiene / styrene copolymer are added into a mixer (rotating at 500 rpm) for mixing.

[0091] (2) 0.2 parts of hindered phenol antioxidant, 0.2 parts of phosphite antioxidant, 0.3 parts of pentaerythritol stearate and 0.3 parts of light stabilizer were added to another mixer (rotating speed of 500 rpm) and mixed.

[0092] (3) Pour the mixture obtained in step (1) and step (2) into the same high-speed mixer (rotation speed is 500 rpm) and mix for 10 min.

[0093] (4) adding the mixed material in step (3) into a parallel twin-screw extruder through a feeder, and performing melt extrusion and granulation in the parallel twin-screw extruder (eight zones in total), wherein the process parameters include: a temperature of zone 1 of 230° C., a temperature of zone 2 of 240° C., a temperature of zone 3 of 250° C., a temperature of zone 4 of 250° C., a temperature of zone 5 of 250° C., a temperature of zone 6 of 250° C., a temperature of zone 7 of 245° C., a temperature of zone 8 of 245° C., a die head temperature of 260° C., and a screw speed of 500 rpm; the screw shape of the parallel twin-screw extruder is a single-threaded screw, the ratio of screw length L to diameter D (L / D) is 35, and the screw is provided with two meshing block zones and one reverse thread zone.

[0094] Comparative Example 3

[0095] (1) 43 parts of polycarbonate resin A, 27 parts of polycarbonate resin B, and 10 parts of modified magnesium sulfate whiskers are dried, and the dried polycarbonate resin A, polycarbonate resin B, modified magnesium sulfate whiskers, 20 parts of bisphenol A bis(diphenyl phosphate), 4 parts of methyl methacrylate-styrene-organic silicon core-shell copolymer, 4 parts of methyl methacrylate-butadiene-styrene copolymer, and 1 part of maleic acid tincture grafted acrylonitrile / butadiene / styrene copolymer are added into a mixer (rotating at 500 rpm) for mixing.

[0096] (2) 0.2 parts of hindered phenol antioxidant, 0.2 parts of phosphite antioxidant, 0.3 parts of pentaerythritol stearate and 0.3 parts of light stabilizer were added to another mixer (rotating speed of 500 rpm) and mixed.

[0097] (3) Pour the mixture obtained in step (1) and step (2) into the same high-speed mixer (rotation speed is 500 rpm) and mix for 10 min.

[0098] (4) adding the mixed material in step (3) into a parallel twin-screw extruder through a feeder, and performing melt extrusion and granulation in the parallel twin-screw extruder (eight zones in total), wherein the process parameters include: a temperature of zone 1 of 230° C., a temperature of zone 2 of 240° C., a temperature of zone 3 of 250° C., a temperature of zone 4 of 250° C., a temperature of zone 5 of 250° C., a temperature of zone 6 of 250° C., a temperature of zone 7 of 245° C., a temperature of zone 8 of 245° C., a die head temperature of 260° C., and a screw speed of 500 rpm; the screw shape of the parallel twin-screw extruder is a single-threaded screw, the ratio of screw length L to diameter D (L / D) is 35, and the screw is provided with two meshing block zones and one reverse thread zone.

[0099] Comparative Example 4

[0100] (1) 57 parts of polycarbonate resin A, 13 parts of polybutylene terephthalate, and 10 parts of modified magnesium sulfate whisker are dried, and the dried polycarbonate resin A, polycarbonate resin B, polybutylene terephthalate, modified magnesium sulfate whisker, 20 parts of bisphenol A bis(diphenyl phosphate), 4 parts of methyl methacrylate-styrene-organic silicon core-shell copolymer, 4 parts of methyl methacrylate-butadiene-styrene copolymer, and 1 part of maleic acid tincture grafted acrylonitrile / butadiene / styrene copolymer are added into a stirrer (rotating speed is 500 rpm) for mixing.

[0101] (2) 0.2 parts of hindered phenol antioxidant, 0.2 parts of phosphite antioxidant, 0.3 parts of pentaerythritol stearate and 0.3 parts of light stabilizer were added to another mixer (rotating speed of 500 rpm) and mixed.

[0102] (3) Pour the mixture obtained in step (1) and step (2) into the same high-speed mixer (rotation speed is 500 rpm) and mix for 10 min.

[0103] (4) adding the mixed material in step (3) into a parallel twin-screw extruder through a feeder, and performing melt extrusion and granulation in the parallel twin-screw extruder (eight zones in total), wherein the process parameters include: a temperature of zone 1 of 230° C., a temperature of zone 2 of 240° C., a temperature of zone 3 of 250° C., a temperature of zone 4 of 250° C., a temperature of zone 5 of 250° C., a temperature of zone 6 of 250° C., a temperature of zone 7 of 245° C., a temperature of zone 8 of 245° C., a die head temperature of 260° C., and a screw speed of 500 rpm; the screw shape of the parallel twin-screw extruder is a single-threaded screw, the ratio of screw length L to diameter D (L / D) is 35, and the screw is provided with two meshing block zones and one reverse thread zone.

[0104] Comparative Example 5

[0105] (1) 57 parts of polycarbonate resin B, 13 parts of polybutylene terephthalate, and 10 parts of modified magnesium sulfate whisker are dried, and the dried polycarbonate resin A, polycarbonate resin B, polybutylene terephthalate, modified magnesium sulfate whisker, 20 parts of bisphenol A bis(diphenyl phosphate), 4 parts of methyl methacrylate-styrene-organic silicon core-shell copolymer, 4 parts of methyl methacrylate-butadiene-styrene copolymer, and 1 part of maleic acid tincture grafted acrylonitrile / butadiene / styrene copolymer are added into a stirrer (rotating speed is 500 rpm) for mixing.

[0106] (2) 0.2 parts of hindered phenol antioxidant, 0.2 parts of phosphite antioxidant, 0.3 parts of pentaerythritol stearate and 0.3 parts of light stabilizer were added to another mixer (rotating speed of 500 rpm) and mixed.

[0107] (3) Pour the mixture obtained in step (1) and step (2) into the same high-speed mixer (rotation speed is 500 rpm) and mix for 10 min.

[0108] (4) adding the mixed material in step (3) into a parallel twin-screw extruder through a feeder, and performing melt extrusion and granulation in the parallel twin-screw extruder (eight zones in total), wherein the process parameters include: a temperature of zone 1 of 230° C., a temperature of zone 2 of 240° C., a temperature of zone 3 of 250° C., a temperature of zone 4 of 250° C., a temperature of zone 5 of 250° C., a temperature of zone 6 of 250° C., a temperature of zone 7 of 245° C., a temperature of zone 8 of 245° C., a die head temperature of 260° C., and a screw speed of 500 rpm; the screw shape of the parallel twin-screw extruder is a single-threaded screw, the ratio of screw length L to diameter D (L / D) is 35, and the screw is provided with two meshing block zones and one reverse thread zone.

[0109] The flame retardant polycarbonate compositions prepared in the above examples and comparative examples were subjected to the following performance tests:

[0110] Melt index: tested according to GB / T 3682-2000 standard, test temperature is 260℃, load is 2.16kg;

[0111] Scratch resistance test: Use a pencil hardness tester to test, the higher the value, the better the scratch resistance;

[0112] Impact performance: tested according to GB / T 1843-2008 standard, the specimen thickness is 4mm;

[0113] Flame retardant performance: tested according to UL-94 standard, the specimen thickness is 1.5mm, and the shorter the total burning time of T1+T2 of the 5 test samples, the better the flame retardant performance.

[0114] The performance test results are shown in Table 2.

[0115] Table 2

[0116]

[0117] As can be seen from Table 2, in Examples 1 to 7, when the PMMA (polybutylene terephthalate) content and the KSW (modified magnesium sulfate whisker) content in the formula are both at relatively high contents, the surface pencil hardness of the material can reach H, but as the addition amount continues to increase, the surface hardness does not continue to increase, on the contrary, the toughness of the material does decrease significantly, and when the addition amount of the two reaches a certain range value, the surface hardness of the material reaches a peak value, and at this time, the toughness of the material does not decrease significantly, because the surface pencil hardness of pure PMMA material can only be 2H, the surface pencil hardness of pure KSW is 3H, and the surface pencil hardness of pure polycarbonate material is only 3B, and the surface pencil hardness of the modified material obtained by blending the three has a theoretical maximum value, i.e., lower than 2H. From the performance data of the polycarbonate compositions prepared in Examples 1 to 7, it can be seen that the greater the content of bisphenol A bis(diphenyl phosphate) flame retardant in the formula, the lower the total combustion time and impact strength of the flame retardant test of the polycarbonate composition, while the processability of the material tends to increase. This is mainly because the greater the amount of bisphenol A bis(diphenyl phosphate) added as a flame retardant within a certain range of addition, the more obvious the flame retardant effect. The decrease in impact performance and the improvement in processability are attributed to the fact that bisphenol A bis(diphenyl phosphate) itself has a low melting point, and the overall melting point of the modified polycarbonate composition obtained after physical blending with polycarbonate is decreased. In addition, bisphenol A bis(diphenyl phosphate) promotes the accelerated plasticization of polycarbonate, thereby weakening the molecular force and reducing the overall toughness of the material. Therefore, it is necessary to add a toughening system to the formula to improve the overall toughness of the material. The present invention is a multi-matrix resin blending melt modification, and the addition of maleic acid tincture grafted acrylonitrile / butadiene / styrene copolymer increases the compatibility between the components of the polycarbonate composition, and significantly improves the solvent resistance and impact strength of the entire material. By comparing the various performance data of the polycarbonate compositions prepared in Examples 1 to 7, it is found that under the comprehensive effect of various factors, the comprehensive performance of the polycarbonate composition prepared in Example 7 is the best, and the ratio of each raw material is the best.

[0118] Compared with Example 8, the screw shape of the parallel twin-screw extruder used in Example 8 is a double-thread, and the ratio of the screw length L to the diameter D (L / D) is 50. The screw shape of the parallel twin-screw extruder used in Example 7 is a single-thread, and the ratio of the screw length L to the diameter D (L / D) is 35. By comparison, it can be found that the polycarbonate composition prepared by using the screw parameters of the parallel twin-screw extruder described in Example 7 has better solvent resistance and processability.

[0119] Compared with Comparative Example 1, in Comparative Example 1, no methyl methacrylate-styrene-organosilicon copolymer was added, and the melt index of the obtained polycarbonate composition increased, and the impact strength and the total burning time were significantly reduced. This is because methyl methacrylate-styrene-organosilicon copolymer belongs to a silicon-based core-shell structure encapsulating toughening agent, and its addition will reduce the thermal shear force of the material, and the molecular chain segments will not be significantly reduced during the extrusion process. The overall molecular weight of the protected material will not be significantly reduced, which improves the impact performance of the material. However, since its composition is rubber, it has the characteristic of being easy to burn, which reduces the overall flame retardant effect of the material. The macroscopic performance is that the toughness of the material obtained by the scheme of Example 7 is greatly improved, and the flame retardant effect and material fluidity are slightly reduced.

[0120] Example 7 Compared with Comparative Example 2, in Comparative Example 2, no surface-modified magnesium sulfate whiskers were added, but polycarbonate A, polycarbonate resin B, bisphenol A bis(diphenyl phosphate) and polybutylene terephthalate were melt-blended. Although the impact strength of the obtained polycarbonate composition was slightly improved and the total burning time was significantly reduced, the surface strength hardness of the material could only reach level 2B, which shows that the surface-modified magnesium sulfate whiskers are indispensable for improving the scratch resistance of the polycarbonate composition in the present invention.

[0121] Compared with Comparative Example 3, Example 7 does not contain polybutylene terephthalate, but uses polycarbonate A, polycarbonate resin B, bisphenol A bis(diphenyl phosphate) and surface-modified magnesium sulfate whiskers for melt blending. Although the impact strength of the obtained polycarbonate composition is slightly improved and the total burning time is significantly reduced, the surface strength hardness of the material can only reach level 2B, which shows that polybutylene terephthalate is indispensable for improving the scratch resistance of the polycarbonate composition in the present invention.

[0122] Compared with Comparative Example 4, in Example 7, no polycarbonate resin B was added to Comparative Example 4, and the impact strength of the obtained polycarbonate composition decreased significantly, the total combustion time increased slightly, and the melt index of the material soared, which shows that the polycarbonate resin B is indispensable for improving the molecular weight of the polycarbonate composition in the present invention, which is manifested in the macroscopic effect of improving the impact strength of the entire material.

[0123] Compared with Comparative Example 5, Example 7 does not add polycarbonate in Comparative Example 5, but uses a single polycarbonate resin B. Although the impact strength and combustion performance of the obtained polycarbonate composition are significantly improved, the melt index decreases more significantly, making the material difficult to process. In addition, the price of polycarbonate resin B is relatively high, and it has strict requirements on the production process and production equipment, making it difficult to apply to large-scale industrial production.

[0124] Although this specification is described according to implementation modes, not every implementation mode includes only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0125] Therefore, the above description is only a preferred embodiment of the present application and is not intended to limit the scope of implementation of the present application; that is, all equivalent changes made according to the scope of the claims of the present application are within the protection scope of the claims of the present application.

Claims

1. A scratch-resistant, highly weather-resistant, flame-retardant polycarbonate composition, characterized in that: It is prepared from the following components in parts by weight: The total weight of the polycarbonate resin A, the polycarbonate resin B, the flame retardant, the polybutylene terephthalate, and the modified magnesium sulfate whisker is 100 parts.

2. The scratch-resistant and highly weather-resistant flame-retardant polycarbonate composition according to claim 1, characterized in that: The melt index of the polycarbonate resin A is 10-12 g / 10 min; and / or the melt index of the polycarbonate resin B is 3-5 g / 10 min.

3. The scratch-resistant and highly weather-resistant flame-retardant polycarbonate composition according to claim 1, characterized in that: The modification method of the modified magnesium sulfate whisker is: The dried magnesium sulfate whiskers are ground and sieved, and a coupling agent and anhydrous ethanol are added to obtain a suspension with a concentration of 10-15wt%; the amount of the coupling agent added is 3-5% of the suspension; The precipitate obtained by the reaction under heating and stirring conditions is dried, sieved and ground to obtain modified magnesium sulfate whiskers.

4. The scratch-resistant and highly weather-resistant flame-retardant polycarbonate composition according to claim 1, characterized in that: The reactive compatibilizer is maleic acid tincture grafted acrylonitrile / butadiene / styrene copolymer.

5. The scratch-resistant and highly weather-resistant flame-retardant polycarbonate composition according to claim 1, characterized in that: The other auxiliary agent is at least one of an antioxidant, a light stabilizer and a lubricant.

6. The scratch-resistant and highly weather-resistant flame-retardant polycarbonate composition according to claim 5, characterized in that: The antioxidant is at least one of a hindered phenol antioxidant and a phosphite antioxidant.

7. The scratch-resistant and highly weather-resistant flame-retardant polycarbonate composition according to claim 5, characterized in that: The lubricant is pentaerythritol stearate.

8. The scratch-resistant and highly weather-resistant flame-retardant polycarbonate composition according to claim 1, characterized in that: The flame retardant is bisphenol A bis(diphenyl phosphate).

9. The method for preparing the scratch-resistant and highly weather-resistant flame-retardant polycarbonate composition according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) polycarbonate resin A, polycarbonate resin B, bisphenol A bis(diphenyl phosphate), polybutylene terephthalate, modified magnesium sulfate whisker, methyl methacrylate-styrene-organic silicon core-shell copolymer, methyl methacrylate-butadiene-styrene copolymer and reactive compatibilizer are uniformly mixed to obtain a mixture A; (2) mixing an antioxidant, a lubricant and a light stabilizer to obtain a mixed material B; (3) After the mixed material A and the mixed material B are uniformly mixed, the mixed material A and the mixed material B are fed into a twin-screw extruder, and the mixed material A and the mixed material B are melt-extruded and granulated to obtain a scratch-resistant and highly weather-resistant flame-retardant polycarbonate composition.

10. The preparation method according to claim 8, characterized in that: The working parameters of the twin-screw extruder are: the temperature of zone 1 is 210-240℃, the temperature of zone 2 is 230-260℃, the temperature of zone 3 is 235-260℃, the temperature of zone 4 is 220- 260℃, the temperature of zone 5 is 220~260℃, the temperature of zone 6 is 220~260℃, the temperature of zone 7 is 220~260℃, The temperature of the eighth zone is 220-260°C, the die head temperature is 240-275°C, and the screw speed is 200-600rpm.

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