PC / ABS alloy material and preparation method thereof

Abstract

The invention discloses a PC (polycarbonate) / ABS (acrylonitrile butadiene styrene) alloy material and a preparation method thereof. The PC / ABS alloy material is prepared from the following raw materials: PC resin, ABS resin, ABS-g-GMA (glycidyl methacrylate), a polyborosiloxane polymer, hexaphenoxy cyclotriphosphazene, functionalized POSS (polyhedral oligomeric silsesquioxane), a DOPO (9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide) flame retardant and a semi-hindered phenol antioxidant. The PC / ABS alloy material has excellent mechanical properties, flame retardancy and low dielectric properties, and can be widely applied to the communication field requiring halogen-free flame retardancy.

Description

Technical Field

[0001] The invention belongs to the field of materials, and in particular relates to a PC / ABS alloy material and a preparation method thereof. Background Art

[0002] Polycarbonate / Acrylonitrile-Butadiene-Styrene (PC / ABS) is an important engineering plastic widely used in the automotive industry, building components, electronic engineering and other fields. However, the limiting oxygen index (LOI) of PC / ABS is only 19.8%, which is a flammable substance and cannot pass the vertical combustion (UL-94) test. Usually, flame retardants need to be added to improve the flame retardancy of PC / ABS alloys.

[0003] Melt blending is the simplest and most effective way to add flame retardants to PC / ABS alloys. Melt blending is a process of mixing PC, ABS and flame retardants or other additives. PC has a high melting point and a processing window of about 220℃ to 280℃. At high temperatures, the components can be evenly mixed in a molten state. This process can be achieved through a twin-screw extruder, internal mixer or other mixing equipment. Melt blending can not only improve the flame retardant properties of PC, but also optimize its other properties such as mechanical properties, transparency and thermal stability through formula design. Under the premise of meeting thermal stability, the flame retardant selection range of this method is relatively wide, and different flame retardants can be selected according to different needs.

[0004] At present, some research has been done on flame retardant PC / ABS alloys in the prior art. For example, Chinese patent CN103059546A discloses a flame retardant PC / ABS alloy free of halogen flame retardants. The flame retardant PC / ABS alloy free of halogen flame retardants comprises the following components in parts by weight: (a) 80-150 parts of polycarbonate; (b) 40-70 parts of ABS resin; (c) 12-30 parts of flame retardant; (d) 1-10 parts of compatibilizer; (e) 1-10 parts of toughening agent; and (f) 1-5 parts of lubricant, wherein the flame retardant is one or more of polyaryl phosphate, magnesium hydroxide, barium hydroxide and potassium perfluorobutyl sulfonate. Chinese patent CN 106633754A discloses a highly flame-retardant PC / ABS alloy material, which comprises, by weight percentage, 56.7-73.2wt% of polycarbonate PC, 10-20wt% of ABS resin, 3-6wt% of toughening agent, 10-18wt% of flame retardant, 0.1-0.5wt% of lubricant, 0.1-0.3wt% of antioxidant, and 0.1-0.3wt% of UV inhibitor. The flame retardant comprises, by weight percentage, 5-10.5% of phosphorus-containing flame retardant, 2-7% of silicon-based flame retardant, and 0.1-0.5% of anti-dripping agent. Chinese patent CN116285287A discloses a flame-retardant PC / ABS material and a preparation method thereof. A halogen-free flame-retardant PC / ABS composite material is prepared by introducing a synergistic flame retardant and an organic-inorganic hybrid spiral silica fiber into an intumescent flame-retardant system. The intumescent flame retardant is a compound of pentaerythritol, ammonium polyphosphate and melamine, and the synergistic flame retardant is a composition of silicone powder, triphenyl phosphate and potassium perfluorobutyl sulfonate. Chinese patent CN 112029254A discloses a halogen-free flame-retardant PC / ABS alloy material resistant to wet and hot aging and a preparation method thereof. The material comprises the following components by mass: 75-90 parts of PC resin, 5-10 parts of ABS resin, 5-15 parts of liquid halogen-free flame retardant, 2-4 parts of PE wax, 0.1-1 parts of antioxidant, and the phosphorus content of the liquid halogen-free flame retardant is 8-10ωt%, including bisphenol A-bis(diphenyl phosphate).Chinese patent CN 117866404A discloses a method for preparing a halogen-free flame-retardant PC / ABS / PET material, comprising the following preparation steps: mixture 1: mixing PC, ABS and compatibilizer A, melt extruding and granulating to obtain mixture 1; mixture 2: mixing PC, PET, a nucleating agent and a compatibilizer B, melt extruding and granulating to obtain mixture 2; halogen-free flame-retardant PC / ABS / PET material: mixing mixture 1, mixture 2, a compatibilizer C and a silicon-based flame retardant, melt extruding and granulating to obtain a halogen-free flame-retardant PC / ABS / PET material; compatibilizer A is acrylonitrile-styrene copolymer grafted with maleic anhydride or / and acrylonitrile-styrene copolymer grafted with glycidyl methacrylate; compatibilizer B is polyethylene grafted with maleic anhydride or / and polymethyl methacrylate grafted with maleic anhydride, and compatibilizer C is SEBS-g-GMA. It can be seen from the above patents that in the current existing technology, the flame retardant technical effect of PC / ABS alloy is mainly achieved by using one or more mixtures of phosphorus-containing flame retardants, sulfonate flame retardants, hydroxide flame retardants, silicon-based flame retardants, and anti-dripping agents. However, none of the above patents involve adjusting the dielectric properties of flame-retardant PC / ABS alloys. Summary of the invention

[0005] Based on this, one of the purposes of the present invention is to provide a PC / ABS alloy material, which has excellent mechanical properties, flame retardant properties and low dielectric properties and can be widely used in the communication field requiring halogen-free flame retardancy.

[0006] The specific technical solutions for achieving the above-mentioned invention objectives include the following.

[0007] A PC / ABS alloy material is prepared from the following raw materials in parts by weight:

[0008] 70-90 parts of PC resin,

[0009] ABS resin 10-30 parts,

[0010] The total weight of PC resin and ABS resin is 100 parts.

[0011]

[0012] The ABS-g-GMA is acrylonitrile-butadiene-styrene copolymer grafted with glycidyl methacrylate; the functionalized POSS is a functionalized polyhedral cage-type oligomeric silsesquioxane; and the DOPO flame retardant is 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0013] In some embodiments, the PC / ABS alloy material is prepared from the following raw materials in parts by weight:

[0014] 74-86 parts of PC resin,

[0015] ABS resin 14-26 parts,

[0016] The total weight of PC resin and ABS resin is 100 parts.

[0017]

[0018] In some embodiments, the PC / ABS alloy material is prepared from the following raw materials in parts by weight:

[0019] 78-82 parts of PC resin,

[0020] ABS resin 18-22 parts,

[0021] The total weight of PC resin and ABS resin is 100 parts.

[0022]

[0023] In some of the embodiments, the number average relative molecular weight of the PC resin is 23000-31000; the butadiene content of the ABS resin is 14%-18%.

[0024] In some of the embodiments, the butadiene content of the ABS-g-GMA is 58% to 62%, and the glycidyl methacrylate grafting rate is 0.8% to 1.2%.

[0025] In some embodiments, the end group of the functionalized POSS comprises an epoxy group; and the semi-hindered phenol antioxidant is triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate].

[0026] In some of the embodiments, the preparation method of the polyborosiloxane polymer comprises the following steps: adding 100g of hydroxyl-terminated polydimethylsiloxane, 18g-22g of boric acid and 20mL-30mL of anhydrous ethanol into a flask, stirring at 25°C-35°C for 10min-20min, then heating the mixture to 160°C-180°C, and condensing and refluxing at a speed of 400rpm-600rpm for 6h-8h, followed by reduced pressure filtration, and finally vacuum drying at 80°C-90°C for 22h-26h to obtain a polyborosiloxane polymer.

[0027] Another object of the present invention is to provide a method for preparing the PC / ABS alloy material.

[0028] The specific technical solutions for achieving the above-mentioned invention objectives include the following.

[0029] A method for preparing a PC / ABS alloy material comprises the following steps:

[0030] (1) drying the PC resin at a temperature of 100° C. to 110° C. for 2 to 4 hours, and then cooling the PC resin; adding the cooled PC resin, ABS resin, ABS-g-GMA, functionalized POSS, and semi-hindered phenol antioxidant into a mixer for mixing;

[0031] (2) adding polyborosiloxane polymer, hexaphenoxy cyclotriphosphazene, and DOPO flame retardant into another high-speed mixer and mixing;

[0032] (3) adding the mixed material prepared in step (1) to a parallel twin-screw extruder via a feeder, and adding the mixed material prepared in step (2) to the side (e.g., the third zone) of the parallel twin-screw extruder (eight zones in total) for melt extrusion and granulation, wherein the process parameters include: a temperature of zone 1 of 215° C. to 235° C., a temperature of zone 2 of 220° C. to 240° C., a temperature of zone 3 of 225° C. to 245° C., a temperature of zone 4 of 230° C. to 250° C., a temperature of zone 5 of 235° C. to 255° C., a temperature of zone 6 of 235° C. to 255° C., a temperature of zone 7 of 230° C. to 250° C., a temperature of zone 8 of 230° C. to 250° C., a die head temperature of 230° C. to 250° C., and a screw speed of 400 rpm to 800 rpm.

[0033] In some embodiments, the method for preparing the PC / ABS alloy material comprises the following steps:

[0034] (1) drying the PC resin at a temperature of 102° C. to 108° C. for 2.4 to 3.6 hours, and then cooling the PC resin; adding the cooled PC resin, ABS resin, ABS-g-GMA, functionalized POSS, and semi-hindered phenol antioxidant into a mixer for mixing;

[0035] (2) adding polyborosiloxane polymer, hexaphenoxy cyclotriphosphazene, and DOPO flame retardant into another high-speed mixer and mixing;

[0036] (3) adding the mixed material prepared in step (1) to a parallel twin-screw extruder via a feeder, and adding the mixed material prepared in step (2) to the side (e.g., the third zone) of the parallel twin-screw extruder (eight zones in total) for melt extrusion and granulation, wherein the process parameters include: a temperature of zone 1 of 220° C. to 230° C., a temperature of zone 2 of 225° C. to 235° C., a temperature of zone 3 of 230° C. to 240° C., a temperature of zone 4 of 235° C. to 245° C., a temperature of zone 5 of 240° C. to 250° C., a temperature of zone 6 of 240° C. to 250° C., a temperature of zone 7 of 235° C. to 245° C., a temperature of zone 8 of 235° C. to 245° C., a die head temperature of 235° C. to 245° C., and a screw speed of 500 rpm to 700 rpm.

[0037] In some of the embodiments, the screw shape of the parallel twin-screw extruder is a single-line thread; the ratio L / D of the screw length L and the diameter D is 35 to 55; the screw is provided with more than one (including one) meshing block area and more than one (including one) reverse thread area.

[0038] In some embodiments, the ratio L / D of the screw length L to the screw diameter D is 40-50; and the screw is provided with two meshing block areas and one reverse thread area.

[0039] In some of the embodiments, in step (1) and / or step (2), the stirrer is a high-speed stirrer with a rotation speed of 500 rpm-1500 rpm.

[0040] The functions of the raw materials of the PC / ABS alloy material of the present invention are as follows:

[0041] The type of ABS resin has an important influence on the mechanical properties of PC / ABS alloy materials. The PC / ABS alloy prepared by using ABS resin with a butadiene content of 14% to 18% as the matrix resin has higher tensile strength and bending modulus. This is mainly due to the fact that the ABS resin has a higher styrene content (61% to 65%) and a lower butadiene content (14% to 18%). This structure will reduce the mobility of the molecular chain, thereby making the material more resistant to external stress and deformation. At the same time, a higher styrene content is conducive to improving the compatibility between ABS resin and PC resin. The PC / ABS alloy prepared by using ABS-g-GMA with a butadiene content of 58% to 62% as a toughening compatibilizer has lower tensile strength and bending modulus, but has very excellent notched impact strength. This is mainly because ABS-g-GMA has a higher butadiene content (58% to 62%), and a large number of butadiene segments greatly improve the mobility of the entire molecular chain, so that the alloy can absorb a large amount of energy through plastic deformation under external force conditions, thereby showing extremely high impact toughness. In addition, the methacrylate glycidyl grafting rate of ABS-g-GMA is 0.8% to 1.2%, and its epoxy group can react with the terminal hydroxyl group of PC resin to improve the compatibility and interface adhesion between PC resin and ABS resin, thereby improving the mechanical properties of PC / ABS alloy materials.

[0042] The present invention improves the flame retardant properties of PC / ABS alloy materials by compounding polyborosiloxane polymer, hexaphenoxy cyclotriphosphazene, functionalized POSS and DOPO flame retardant. Among them, (1) the present invention obtains polyborosiloxane polymer by dehydration condensation reaction of hydroxyl-terminated polydimethylsiloxane and boric acid, which can simultaneously toughen and flame retard PC / ABS alloy materials. This is mainly because the polyborosiloxane polymer improves the melt strength of PC, participates in the formation of a highly expanded ceramic carbon layer, and improves the flame retardant properties of PC. At the same time, the polyborosiloxane polymer forms a micro-crosslinked island structure with PC through an ester exchange reaction, thereby toughening PC. (2) Hexaphenoxy cyclotriphosphazene belongs to cyclophosphazene flame retardant, which has good thermal stability and flame retardant properties. Hexaphenoxy cyclotriphosphazene promotes PC to form a dense carbon layer through acidic substances such as phosphoric acid and metaphosphoric acid generated by its own decomposition, thereby isolating oxygen in the air to achieve a flame retardant effect. At the same time, the nitrogen element in hexaphenoxy cyclotriphosphazene will be converted into non-flammable gases such as NH3 during combustion, diluting the oxygen around PC. (3) Functionalized polyhedral cage oligomeric silsesquioxane (POSS) is a typical silicone flame retardant. Its composite flame retardant system can effectively flame retard PC / ABS alloy materials. The end group of functionalized POSS contains epoxy groups, which can react with the terminal hydroxyl groups of PC resin to improve the dispersibility and compatibility of functionalized POSS in PC resin materials, thereby improving the flame retardant properties of PC / ABS alloy materials. In addition, functionalized POSS has low dielectric properties (test frequency is 5GHz, dielectric constant is 2.1~2.4), which is mainly because POSS has a three-dimensional structure similar to a cage, with an inorganic core formed by alternating silicon and oxygen (Si-O) in the center, and eight silicon atoms at the top corners connected to organic substituent groups (R groups). This cage structure allows a larger space inside the molecule, reduces the close stacking between molecules, and reduces the polarization degree of the molecule. Under the action of an electric field, the molecule is not easily polarized, thereby reducing the dielectric constant. The bond energy of Si-O bond is higher (445.2 kJ / mol), which is more difficult to be broken than CC bond (350.7 kJ / mol) and CO bond (359.1 kJ / mol). Therefore, the vibration and rotation of Si-O bond are less affected in the electric field, which reduces the response to the electric field and thus reduces the dielectric constant. (4) 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) is a synergistic flame retardant. On the one hand, the PO· free radicals produced by the thermal decomposition of DOPO capture the active free radicals HO· and H· in the gas phase during combustion, thereby inhibiting the free radical chain reaction and reducing the heat release. At the same time, some non-flammable gas is produced, thereby achieving the purpose of flame retardancy. On the other hand, when the polymer burns, DOPO will form phosphoric acid and polymetaphosphoric acid that promote carbonization, isolate oxygen and heat transfer, and achieve a flame retardant effect.

[0043] Hindered phenol antioxidants are primary antioxidants, among which the hindered phenol antioxidant β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate n-octadecanol is the leading product of PC plastic antioxidants at present, but it may produce quinone-based color groups during high-temperature processing, causing product discoloration. The semi-hindered phenol antioxidant triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate] does not form color groups and has little effect on the initial color, optical properties and mechanical properties of PC.

[0044] Compared with the prior art, the PC / ABS alloy material and the preparation method thereof provided by the present invention have the following beneficial effects:

[0045] 1. The present invention improves the flame retardant properties of PC / ABS alloy materials by compounding polyborosiloxane polymer, hexaphenoxy cyclotriphosphazene, functionalized POSS and DOPO flame retardant, and at the same time realizes the low dielectric properties of PC / ABS alloy materials by functionalized POSS, and improves the compatibility and toughness of PC / ABS alloy materials by ABS-g-GMA and polyborosiloxane polymer, and the epoxy groups of ABS-g-GMA and functionalized POSS can react with the terminal hydroxyl groups of PC resin, so as to improve the compatibility and interfacial adhesion between PC resin and ABS resin, and improve the dispersibility and compatibility of polyborosiloxane polymer, hexaphenoxy cyclotriphosphazene, functionalized POSS and DOPO flame retardant in PC resin material, thereby improving the mechanical properties, flame retardant properties and low dielectric properties of PC / ABS alloy materials, and uses semi-hindered phenol antioxidant triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate] to improve the thermal stability and oxidation resistance of PC / ABS alloy materials during processing and use.

[0046] 2. The preparation method of the PC / ABS alloy material of the present invention has simple process, is 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 The figure is a flow chart of the preparation process of the PC / ABS alloy material of the present invention. DETAILED DESCRIPTION

[0048] In order to facilitate the understanding of the present invention, the present invention will be described more fully below in conjunction with the accompanying drawings. 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 understanding of the disclosure of the present invention more thorough and comprehensive.

[0049] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in the present invention includes any and all combinations of one or more of the related listed items.

[0050] The reaction mechanism of the PC / ABS alloy material of the present invention is as follows (see the preparation process flow chart Figure 1 ):

[0051]

[0052] Among them, R1 is PC resin; R2 is ABS-g-GMA, or functionalized POSS.

[0053] It can be seen from the above reaction formula that the epoxy groups of ABS-g-GMA and functionalized POSS can react with the terminal hydroxyl groups of PC resin, thereby improving the compatibility and interfacial adhesion between PC resin and ABS resin, and improving the dispersibility and compatibility of polyborosiloxane polymer, hexaphenoxy cyclotriphosphazene, functionalized POSS and DOPO flame retardant in PC resin material, thereby preparing PC / ABS alloy material with excellent mechanical properties, flame retardant properties and low dielectric properties.

[0054] The raw materials used in the examples and comparative examples of the present invention are as follows:

[0055] PC resin, with a number average relative molecular mass of 27,000, was purchased from Covestro GmbH, Germany.

[0056] ABS resin, butadiene content of 16%, was purchased from Tianjin Dagu Chemical Co., Ltd.

[0057] ABS-g-GMA, with a butadiene content of 60% and a glycidyl methacrylate grafting rate of 1%, was purchased from The Dow Chemical Company, USA.

[0058] Hydroxyl-terminated polydimethylsiloxane was purchased from MacLean Chemical Reagent Co., Ltd.

[0059] Boric acid was purchased from MacLean Chemical Co., Ltd.

[0060] Anhydrous ethanol was purchased from Sinopharm Chemical Reagent Co., Ltd.

[0061] Hexaphenoxycyclotriphosphazene was purchased from Wuhan Haishan Technology Co., Ltd.

[0062] Functionalized POSS, end groups containing epoxy groups, was selected from Hybrid Plastics Company, USA.

[0063] DOPO flame retardant was purchased from Sinopharm Chemical Reagent Co., Ltd.

[0064] Triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate] was purchased from BASF AG.

[0065] The preparation method of the polyborosiloxane polymer used in the following examples and comparative examples comprises the following steps: adding 100 g of hydroxyl-terminated polydimethylsiloxane, 20 g of boric acid and 25 mL of anhydrous ethanol to a flask, stirring at 30° C. for 15 min, then heating the mixture to 170° C., and condensing and refluxing at a speed of 500 rpm for 7 h. Then, filtering under reduced pressure, and finally drying under vacuum at 85° C. for 24 h, a polyborosiloxane polymer is obtained.

[0066] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0067] Example 1 PC / ABS alloy material and preparation method thereof

[0068] The PC / ABS alloy material of this embodiment is prepared from the following raw materials in parts by weight:

[0069]

[0070]

[0071] The semi-hindered phenol antioxidant is triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate].

[0072] Please refer to Figure 1 The preparation method of the PC / ABS alloy material of this embodiment comprises the following steps:

[0073] (1) drying the PC resin at 100° C. for 4 hours and then cooling it; adding the cooled PC resin, ABS resin, ABS-g-GMA, functionalized POSS and semi-hindered phenol antioxidant into a mixer for mixing;

[0074] (2) adding polyborosiloxane polymer, hexaphenoxy cyclotriphosphazene, and DOPO flame retardant into another high-speed mixer and mixing;

[0075] (3) adding the mixed material prepared in step (1) into a parallel twin-screw extruder via a feeder, and adding the mixed material prepared in step (2) into the side (third zone) of the parallel twin-screw extruder (eight zones in total) for melt extrusion and granulation, wherein the process parameters include: a temperature of zone 1 of 215° C., a temperature of zone 2 of 220° C., a temperature of zone 3 of 225° C., a temperature of zone 4 of 230° C., a temperature of zone 5 of 235° C., a temperature of zone 6 of 235° C., a temperature of zone 7 of 230° C., a temperature of zone 8 of 230° C., a die head temperature of 230° C., and a screw speed of 400 rpm.

[0076] The screw shape of the parallel twin-screw extruder is a single-threaded screw; the ratio L / D of the screw length L and the diameter D is 35; the screw is provided with two meshing block areas and one reverse thread area; in step (1) and step (2), the mixer is a high-speed mixer with a rotation speed of 500 rpm.

[0077] Example 2 PC / ABS alloy material and preparation method thereof

[0078] The PC / ABS alloy material of this embodiment is prepared from the following raw materials in parts by weight:

[0079]

[0080]

[0081] The semi-hindered phenol antioxidant is triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate].

[0082] The preparation method of the PC / ABS alloy material of the present embodiment comprises the following steps:

[0083] (1) drying the PC resin at 110° C. for 2 hours and then cooling it; adding the cooled PC resin, ABS resin, ABS-g-GMA, functionalized POSS and semi-hindered phenol antioxidant into a mixer for mixing;

[0084] (2) adding polyborosiloxane polymer, hexaphenoxy cyclotriphosphazene, and DOPO flame retardant into another high-speed mixer and mixing;

[0085] (3) adding the mixed material prepared in step (1) into a parallel twin-screw extruder via a feeder, and adding the mixed material prepared in step (2) into the side (third zone) of the parallel twin-screw extruder (eight zones in total) for melt extrusion and granulation, wherein the process parameters include: a temperature of zone 1 of 235° C., a temperature of zone 2 of 240° C., a temperature of zone 3 of 245° C., a temperature of zone 4 of 250° C., a temperature of zone 5 of 255° C., a temperature of zone 6 of 255° C., a temperature of zone 7 of 250° C., a temperature of zone 8 of 250° C., a die head temperature of 250° C., and a screw speed of 800 rpm.

[0086] The screw shape of the parallel twin-screw extruder is a single-threaded screw; the ratio L / D of the screw length L and the diameter D is 55; the screw is provided with two meshing block areas and one reverse thread area; in step (1) and step (2), the mixer is a high-speed mixer with a rotation speed of 1500 rpm.

[0087] Example 3 PC / ABS alloy material and preparation method thereof

[0088] The PC / ABS alloy material of this embodiment is prepared from the following raw materials in parts by weight:

[0089]

[0090]

[0091] The semi-hindered phenol antioxidant is triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate].

[0092] The preparation method of the PC / ABS alloy material of the present embodiment comprises the following steps:

[0093] (1) drying the PC resin at 102° C. for 3.6 hours and then cooling it; adding the cooled PC resin, ABS resin, ABS-g-GMA, functionalized POSS and semi-hindered phenol antioxidant into a mixer for mixing;

[0094] (2) adding polyborosiloxane polymer, hexaphenoxy cyclotriphosphazene, and DOPO flame retardant into another high-speed mixer and mixing;

[0095] (3) adding the mixed material prepared in step (1) into a parallel twin-screw extruder via a feeder, and adding the mixed material prepared in step (2) into the side (third zone) of the parallel twin-screw extruder (eight zones in total) for melt extrusion and granulation, wherein the process parameters include: a temperature of zone 1 of 220° C., a temperature of zone 2 of 225° C., a temperature of zone 3 of 230° C., a temperature of zone 4 of 235° C., a temperature of zone 5 of 240° C., a temperature of zone 6 of 240° C., a temperature of zone 7 of 235° C., a temperature of zone 8 of 235° C., a die head temperature of 235° C., and a screw speed of 500 rpm.

[0096] The screw shape of the parallel twin-screw extruder is a single-threaded screw; the ratio L / D of the screw length L and the diameter D is 40; the screw is provided with two meshing block areas and one reverse thread area; in step (1) and step (2), the mixer is a high-speed mixer with a rotation speed of 500 rpm.

[0097] Example 4 PC / ABS alloy material and preparation method thereof

[0098] The PC / ABS alloy material of this embodiment is prepared from the following raw materials in parts by weight:

[0099]

[0100]

[0101] The semi-hindered phenol antioxidant is triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate].

[0102] The preparation method of the PC / ABS alloy material of the present embodiment comprises the following steps:

[0103] (1) drying the PC resin at 108° C. for 2.4 hours and then cooling it; adding the cooled PC resin, ABS resin, ABS-g-GMA, functionalized POSS and semi-hindered phenol antioxidant into a mixer for mixing;

[0104] (2) adding polyborosiloxane polymer, hexaphenoxy cyclotriphosphazene, and DOPO flame retardant into another high-speed mixer and mixing;

[0105] (3) adding the mixed material prepared in step (1) into a parallel twin-screw extruder via a feeder, and adding the mixed material prepared in step (2) into the side (third zone) of the parallel twin-screw extruder (eight zones in total) for melt extrusion and granulation, wherein the process parameters include: a temperature of zone 1 of 230° C., a temperature of zone 2 of 235° C., a temperature of zone 3 of 240° C., a temperature of zone 4 of 245° 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 245° C., and a screw speed of 700 rpm.

[0106] The screw shape of the parallel twin-screw extruder is a single-threaded screw; the ratio L / D of the screw length L and the diameter D is 50; the screw is provided with two meshing block areas and one reverse thread area; in step (1) and step (2), the mixer is a high-speed mixer with a rotation speed of 1500 rpm.

[0107] Example 5 PC / ABS alloy material and preparation method thereof

[0108] The PC / ABS alloy material of this embodiment is prepared from the following raw materials in parts by weight:

[0109]

[0110]

[0111] The semi-hindered phenol antioxidant is triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate].

[0112] The preparation method of the PC / ABS alloy material of the present embodiment comprises the following steps:

[0113] (1) drying the PC resin at 105° C. for 3 hours and then cooling it; adding the cooled PC resin, ABS resin, ABS-g-GMA, functionalized POSS and semi-hindered phenol antioxidant into a mixer for mixing;

[0114] (2) adding polyborosiloxane polymer, hexaphenoxy cyclotriphosphazene, and DOPO flame retardant into another high-speed mixer and mixing;

[0115] (3) adding the mixed material prepared in step (1) into a parallel twin-screw extruder via a feeder, and adding the mixed material prepared in step (2) into the side (third zone) of the parallel twin-screw extruder (eight zones in total) for melt extrusion and granulation, wherein the process parameters include: a temperature of zone 1 of 225° C., a temperature of zone 2 of 230° C., a temperature of zone 3 of 235° C., a temperature of zone 4 of 240° C., a temperature of zone 5 of 245° C., a temperature of zone 6 of 245° C., a temperature of zone 7 of 240° C., a temperature of zone 8 of 240° C., a die head temperature of 240° C., and a screw speed of 600 rpm.

[0116] The screw shape of the parallel twin-screw extruder is a single-threaded screw; the ratio L / D of the screw length L and the diameter D is 45; the screw is provided with two meshing block areas and one reverse thread area; in step (1) and step (2), the mixer is a high-speed mixer with a rotation speed of 1000 rpm.

[0117] Example 6 PC / ABS alloy material and preparation method thereof

[0118] The PC / ABS alloy material of this embodiment is prepared from the following raw materials in parts by weight:

[0119]

[0120]

[0121] The semi-hindered phenol antioxidant is triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate].

[0122] The preparation method of the PC / ABS alloy material of the present embodiment comprises the following steps:

[0123] (1) drying the PC resin at 105° C. for 3 hours and then cooling it; adding the cooled PC resin, ABS resin, ABS-g-GMA, functionalized POSS and semi-hindered phenol antioxidant into a mixer for mixing;

[0124] (2) adding polyborosiloxane polymer, hexaphenoxy cyclotriphosphazene, and DOPO flame retardant into another high-speed mixer and mixing;

[0125] (3) adding the mixed material prepared in step (1) into a parallel twin-screw extruder via a feeder, and adding the mixed material prepared in step (2) into the side (third zone) of the parallel twin-screw extruder (eight zones in total) for melt extrusion and granulation, wherein the process parameters include: a temperature of zone 1 of 225° C., a temperature of zone 2 of 230° C., a temperature of zone 3 of 235° C., a temperature of zone 4 of 240° C., a temperature of zone 5 of 245° C., a temperature of zone 6 of 245° C., a temperature of zone 7 of 240° C., a temperature of zone 8 of 240° C., a die head temperature of 240° C., and a screw speed of 600 rpm.

[0126] The screw shape of the parallel twin-screw extruder is a single-threaded screw; the ratio L / D of the screw length L and the diameter D is 45; the screw is provided with two meshing block areas and one reverse thread area; in step (1) and step (2), the mixer is a high-speed mixer with a rotation speed of 1000 rpm.

[0127] Example 7 PC / ABS alloy material and preparation method thereof

[0128] The PC / ABS alloy material of this embodiment is prepared from the following raw materials in parts by weight:

[0129]

[0130]

[0131] The semi-hindered phenol antioxidant is triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate].

[0132] The preparation method of the PC / ABS alloy material of the present embodiment comprises the following steps:

[0133] (1) drying the PC resin at 105° C. for 3 hours and then cooling it; adding the cooled PC resin, ABS resin, ABS-g-GMA, functionalized POSS and semi-hindered phenol antioxidant into a mixer for mixing;

[0134] (2) adding polyborosiloxane polymer, hexaphenoxy cyclotriphosphazene, and DOPO flame retardant into another high-speed mixer and mixing;

[0135] (3) adding the mixed material prepared in step (1) into a parallel twin-screw extruder via a feeder, and adding the mixed material prepared in step (2) into the side (third zone) of the parallel twin-screw extruder (eight zones in total) for melt extrusion and granulation, wherein the process parameters include: a temperature of zone 1 of 225° C., a temperature of zone 2 of 230° C., a temperature of zone 3 of 235° C., a temperature of zone 4 of 240° C., a temperature of zone 5 of 245° C., a temperature of zone 6 of 245° C., a temperature of zone 7 of 240° C., a temperature of zone 8 of 240° C., a die head temperature of 240° C., and a screw speed of 600 rpm.

[0136] The screw shape of the parallel twin-screw extruder is a single-threaded screw; the ratio L / D of the screw length L and the diameter D is 45; the screw is provided with two meshing block areas and one reverse thread area; in step (1) and step (2), the mixer is a high-speed mixer with a rotation speed of 1000 rpm.

[0137] Comparative Example 1

[0138] The PC / ABS alloy material of this comparative example is prepared from the following raw materials in parts by weight:

[0139]

[0140]

[0141] The semi-hindered phenol antioxidant is triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate].

[0142] The preparation method of the PC / ABS alloy material of this comparative example comprises the following steps:

[0143] (1) drying the PC resin at 105° C. for 3 hours and then cooling it; adding the cooled PC resin, ABS-g-GMA, functionalized POSS and semi-hindered phenol antioxidant into a mixer for mixing;

[0144] (2) adding polyborosiloxane polymer, hexaphenoxy cyclotriphosphazene, and DOPO flame retardant into another high-speed mixer and mixing;

[0145] (3) adding the mixed material prepared in step (1) into a parallel twin-screw extruder via a feeder, and adding the mixed material prepared in step (2) into the side (third zone) of the parallel twin-screw extruder (eight zones in total) for melt extrusion and granulation, wherein the process parameters include: a temperature of zone 1 of 225° C., a temperature of zone 2 of 230° C., a temperature of zone 3 of 235° C., a temperature of zone 4 of 240° C., a temperature of zone 5 of 245° C., a temperature of zone 6 of 245° C., a temperature of zone 7 of 240° C., a temperature of zone 8 of 240° C., a die head temperature of 240° C., and a screw speed of 600 rpm.

[0146] The screw shape of the parallel twin-screw extruder is a single-threaded screw; the ratio L / D of the screw length L and the diameter D is 45; the screw is provided with two meshing block areas and one reverse thread area; in step (1) and step (2), the mixer is a high-speed mixer with a rotation speed of 1000 rpm.

[0147] Comparative Example 2

[0148] The PC / ABS alloy material of this comparative example is prepared from the following raw materials in parts by weight:

[0149]

[0150]

[0151] The semi-hindered phenol antioxidant is triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate].

[0152] The preparation method of the PC / ABS alloy material of this comparative example comprises the following steps:

[0153] (1) drying the PC resin at 105° C. for 3 hours and then cooling it; adding the cooled PC resin, ABS resin, functionalized POSS and semi-hindered phenol antioxidant into a mixer for mixing;

[0154] (2) adding polyborosiloxane polymer, hexaphenoxy cyclotriphosphazene, and DOPO flame retardant into another high-speed mixer and mixing;

[0155] (3) adding the mixed material prepared in step (1) into a parallel twin-screw extruder via a feeder, and adding the mixed material prepared in step (2) into the side (third zone) of the parallel twin-screw extruder (eight zones in total) for melt extrusion and granulation, wherein the process parameters include: a temperature of zone 1 of 225° C., a temperature of zone 2 of 230° C., a temperature of zone 3 of 235° C., a temperature of zone 4 of 240° C., a temperature of zone 5 of 245° C., a temperature of zone 6 of 245° C., a temperature of zone 7 of 240° C., a temperature of zone 8 of 240° C., a die head temperature of 240° C., and a screw speed of 600 rpm.

[0156] The screw shape of the parallel twin-screw extruder is a single-threaded screw; the ratio L / D of the screw length L and the diameter D is 45; the screw is provided with two meshing block areas and one reverse thread area; in step (1) and step (2), the mixer is a high-speed mixer with a rotation speed of 1000 rpm.

[0157] Comparative Example 3

[0158] The PC / ABS alloy material of this comparative example is prepared from the following raw materials in parts by weight:

[0159]

[0160] The semi-hindered phenol antioxidant is triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate].

[0161] The preparation method of the PC / ABS alloy material of this comparative example comprises the following steps:

[0162] (1) drying the PC resin at 105° C. for 3 hours and then cooling it; adding the cooled PC resin, ABS resin, ABS-g-GMA, functionalized POSS and semi-hindered phenol antioxidant into a mixer for mixing;

[0163] (2) adding hexaphenoxy cyclotriphosphazene and DOPO flame retardant into another high-speed mixer and mixing;

[0164] (3) adding the mixed material prepared in step (1) into a parallel twin-screw extruder via a feeder, and adding the mixed material prepared in step (2) into the side (third zone) of the parallel twin-screw extruder (eight zones in total) for melt extrusion and granulation, wherein the process parameters include: a temperature of zone 1 of 225° C., a temperature of zone 2 of 230° C., a temperature of zone 3 of 235° C., a temperature of zone 4 of 240° C., a temperature of zone 5 of 245° C., a temperature of zone 6 of 245° C., a temperature of zone 7 of 240° C., a temperature of zone 8 of 240° C., a die head temperature of 240° C., and a screw speed of 600 rpm.

[0165] The screw shape of the parallel twin-screw extruder is a single-threaded screw; the ratio L / D of the screw length L and the diameter D is 45; the screw is provided with two meshing block areas and one reverse thread area; in step (1) and step (2), the mixer is a high-speed mixer with a rotation speed of 1000 rpm.

[0166] Comparative Example 4

[0167] The PC / ABS alloy material of this comparative example is prepared from the following raw materials in parts by weight:

[0168]

[0169] The semi-hindered phenol antioxidant is triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate].

[0170] The preparation method of the PC / ABS alloy material of this comparative example comprises the following steps:

[0171] (1) drying the PC resin at 105° C. for 3 hours and then cooling it; adding the cooled PC resin, ABS resin, ABS-g-GMA, functionalized POSS and semi-hindered phenol antioxidant into a mixer for mixing;

[0172] (2) adding polyborosiloxane polymer and DOPO flame retardant into another high-speed mixer and mixing;

[0173] (3) adding the mixed material prepared in step (1) into a parallel twin-screw extruder via a feeder, and adding the mixed material prepared in step (2) into the side (third zone) of the parallel twin-screw extruder (eight zones in total) for melt extrusion and granulation, wherein the process parameters include: a temperature of zone 1 of 225° C., a temperature of zone 2 of 230° C., a temperature of zone 3 of 235° C., a temperature of zone 4 of 240° C., a temperature of zone 5 of 245° C., a temperature of zone 6 of 245° C., a temperature of zone 7 of 240° C., a temperature of zone 8 of 240° C., a die head temperature of 240° C., and a screw speed of 600 rpm.

[0174] The screw shape of the parallel twin-screw extruder is a single-threaded screw; the ratio L / D of the screw length L and the diameter D is 45; the screw is provided with two meshing block areas and one reverse thread area; in step (1) and step (2), the mixer is a high-speed mixer with a rotation speed of 1000 rpm.

[0175] Comparative Example 5

[0176] The PC / ABS alloy material of this comparative example is prepared from the following raw materials in parts by weight:

[0177]

[0178] The semi-hindered phenol antioxidant is triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate].

[0179] The preparation method of the PC / ABS alloy material of this comparative example comprises the following steps:

[0180] (1) drying the PC resin at 105° C. for 3 hours and then cooling it; adding the cooled PC resin, ABS resin, ABS-g-GMA and semi-hindered phenol antioxidant into a mixer and mixing them;

[0181] (2) adding polyborosiloxane polymer, hexaphenoxy cyclotriphosphazene, and DOPO flame retardant into another high-speed mixer and mixing;

[0182] (3) adding the mixed material prepared in step (1) into a parallel twin-screw extruder via a feeder, and adding the mixed material prepared in step (2) into the side (third zone) of the parallel twin-screw extruder (eight zones in total) for melt extrusion and granulation, wherein the process parameters include: a temperature of zone 1 of 225° C., a temperature of zone 2 of 230° C., a temperature of zone 3 of 235° C., a temperature of zone 4 of 240° C., a temperature of zone 5 of 245° C., a temperature of zone 6 of 245° C., a temperature of zone 7 of 240° C., a temperature of zone 8 of 240° C., a die head temperature of 240° C., and a screw speed of 600 rpm.

[0183] The screw shape of the parallel twin-screw extruder is a single-threaded screw; the ratio L / D of the screw length L and the diameter D is 45; the screw is provided with two meshing block areas and one reverse thread area; in step (1) and step (2), the mixer is a high-speed mixer with a rotation speed of 1000 rpm.

[0184] Comparative Example 6

[0185] The PC / ABS alloy material of this comparative example is prepared from the following raw materials in parts by weight:

[0186]

[0187] The semi-hindered phenol antioxidant is triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate].

[0188] The preparation method of the PC / ABS alloy material of this comparative example comprises the following steps:

[0189] (1) drying the PC resin at 105° C. for 3 hours and then cooling it; adding the cooled PC resin, ABS resin, ABS-g-GMA, functionalized POSS and semi-hindered phenol antioxidant into a mixer for mixing;

[0190] (2) adding the polyborosiloxane polymer and hexaphenoxy cyclotriphosphazene into another high-speed mixer for mixing;

[0191] (3) adding the mixed material prepared in step (1) into a parallel twin-screw extruder via a feeder, and adding the mixed material prepared in step (2) into the side (third zone) of the parallel twin-screw extruder (eight zones in total) for melt extrusion and granulation, wherein the process parameters include: a temperature of zone 1 of 225° C., a temperature of zone 2 of 230° C., a temperature of zone 3 of 235° C., a temperature of zone 4 of 240° C., a temperature of zone 5 of 245° C., a temperature of zone 6 of 245° C., a temperature of zone 7 of 240° C., a temperature of zone 8 of 240° C., a die head temperature of 240° C., and a screw speed of 600 rpm.

[0192] The screw shape of the parallel twin-screw extruder is a single-threaded screw; the ratio L / D of the screw length L and the diameter D is 45; the screw is provided with two meshing block areas and one reverse thread area; in step (1) and step (2), the mixer is a high-speed mixer with a rotation speed of 1000 rpm.

[0193] Comparative Example 7

[0194] The PC / ABS alloy material of this comparative example is prepared from the following raw materials in parts by weight:

[0195]

[0196] The semi-hindered phenol antioxidant is triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate].

[0197] The preparation method of the PC / ABS alloy material of this comparative example comprises the following steps:

[0198] (1) drying the PC resin at 105° C. for 3 hours and then cooling it; adding the cooled PC resin, ABS resin, ABS-g-GMA, and functionalized POSS into a mixer for mixing;

[0199] (2) adding polyborosiloxane polymer, hexaphenoxy cyclotriphosphazene, and DOPO flame retardant into another high-speed mixer and mixing;

[0200] (3) adding the mixed material prepared in step (1) into a parallel twin-screw extruder via a feeder, and adding the mixed material prepared in step (2) into the side (third zone) of the parallel twin-screw extruder (eight zones in total) for melt extrusion and granulation, wherein the process parameters include: a temperature of zone 1 of 225° C., a temperature of zone 2 of 230° C., a temperature of zone 3 of 235° C., a temperature of zone 4 of 240° C., a temperature of zone 5 of 245° C., a temperature of zone 6 of 245° C., a temperature of zone 7 of 240° C., a temperature of zone 8 of 240° C., a die head temperature of 240° C., and a screw speed of 600 rpm.

[0201] The screw shape of the parallel twin-screw extruder is a single-threaded screw; the ratio L / D of the screw length L and the diameter D is 45; the screw is provided with two meshing block areas and one reverse thread area; in step (1) and step (2), the mixer is a high-speed mixer with a rotation speed of 1000 rpm.

[0202] The following is a table of raw material compositions of Examples 1-7 and Comparative Examples 1-7.

[0203] Table 1 List of raw material compositions of Examples 1-7 and Comparative Examples 1-7

[0204]

[0205]

[0206] Examples 1 to 7 are for preparing PC / ABS alloy materials by adjusting the addition amounts of PC resin, ABS resin, ABS-g-GMA, polyborosiloxane polymer, hexaphenoxy cyclotriphosphazene, functionalized POSS, DOPO flame retardant, and semi-hindered phenol antioxidant. Comparative Example 1 is for preparing PC / ABS alloy materials without adding ABS resin, Comparative Example 2 is for preparing PC / ABS alloy materials without adding ABS-g-GMA, Comparative Example 3 is for preparing PC / ABS alloy materials without adding polyborosiloxane polymer, Comparative Example 4 is for preparing PC / ABS alloy materials without adding hexaphenoxy cyclotriphosphazene, Comparative Example 5 is for preparing PC / ABS alloy materials without adding functionalized POSS, Comparative Example 6 is for preparing PC / ABS alloy materials without adding DOPO flame retardant, and Comparative Example 7 is for preparing PC / ABS alloy materials without adding semi-hindered phenol antioxidant.

[0207] The PC / ABS alloy materials prepared in the above examples and comparative examples were subjected to the following performance tests:

[0208] Tensile strength: tested according to GB / T 1040-2006 standard, the tensile rate is 50mm / min.

[0209] Notched impact strength: tested in accordance with GB / T 1843-2008 standard.

[0210] Flame retardant performance: According to GB / T 2406.2-2009 standard test, the limiting oxygen index of the sample is determined by an oxygen index meter, and the sample size is 150mm×6.5mm×3mm.

[0211] Dielectric constant: Tested according to GB / T 5597-1999 standard, test frequency 5GHz.

[0212] The performance test results are shown in Table 2.

[0213] Table 2 Properties of PC / ABS alloy materials of Examples 1-7 and Comparative Examples 1-7

[0214]

[0215]

[0216] From Table 2 we can see that:

[0217] As the amount of PC resin added decreases and the amount of ABS resin and ABS-g-GMA added increases, the tensile strength of PC / ABS alloy material gradually decreases and the impact strength gradually increases. This is because the tensile strength of the ABS resin substrate is lower than that of the PC resin, and the butadiene structural unit in the ABS resin and ABS-g-GMA plays a role in toughening the PC / ABS alloy material.

[0218] With the increase of the addition amount of polyborosiloxane polymer, hexaphenoxy cyclotriphosphazene, functionalized POSS and DOPO flame retardant, the flame retardant property of PC / ABS alloy material gradually improves. This is because, (1) the present invention obtains polyborosiloxane polymer by dehydration condensation reaction of hydroxyl-terminated polydimethylsiloxane and boric acid, which can simultaneously toughen and flame retard PC / ABS alloy material. This is mainly because polyborosiloxane polymer improves the melt strength of PC, participates in the formation of highly expanded ceramic carbon layer, and improves the flame retardant property of PC. At the same time, polyborosiloxane polymer forms a micro-crosslinked island structure with PC through ester exchange reaction, thereby toughening PC. (2) Hexaphenoxy cyclotriphosphazene belongs to cyclophosphazene flame retardant, which has good thermal stability and flame retardant property. Hexaphenoxy cyclotriphosphazene promotes PC to form a dense carbon layer through acidic substances such as phosphoric acid and metaphosphoric acid produced by its own decomposition, thereby isolating oxygen in the air to achieve flame retardant effect. At the same time, the nitrogen element in hexaphenoxy cyclotriphosphazene will be converted into non-flammable gases such as NH3 during combustion, diluting the oxygen around PC. (3) Functionalized polyhedral cage oligomeric silsesquioxane (POSS) is a typical silicone flame retardant. Its composite flame retardant system can effectively flame retard PC / ABS alloy materials. The end group of functionalized POSS contains epoxy groups, which can react with the terminal hydroxyl groups of PC resin to improve the dispersibility and compatibility of functionalized POSS in PC resin materials, thereby improving the flame retardant properties of PC / ABS alloy materials. (4) 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) is a synergistic flame retardant. On the one hand, the PO· free radicals generated by the thermal decomposition of DOPO capture the active free radicals HO· and H· in the gas phase during combustion, thereby inhibiting the free radical chain reaction, reducing the amount of heat release, and generating some non-flammable gases, thereby achieving the purpose of flame retardancy. On the other hand, when the polymer burns, DOPO will form phosphoric acid and polymetaphosphoric acid that promote carbonization, isolate oxygen and heat transfer, and achieve a flame retardant effect.

[0219] As the amount of functionalized POSS added increases, the dielectric constant of PC / ABS alloy material gradually decreases. This is because functionalized POSS has low dielectric properties (test frequency is 5GHz, dielectric constant is 2.1~2.4), which is mainly because POSS has a three-dimensional structure similar to a cage, the center is an inorganic core formed by alternating silicon and oxygen (Si-O), and the silicon atoms at the eight vertices are connected to organic substituent groups (R groups). This cage structure allows a larger space inside the molecule, reduces the close packing between molecules, and reduces the polarization degree of the molecules. Under the action of the electric field, the molecules are not easily polarized, thereby reducing the dielectric constant. The bond energy of the Si-O bond is higher (445.2kJ / mol), which is more difficult to be destroyed than the CC bond (350.7kJ / mol) and the CO bond (359.1kJ / mol). Therefore, the vibration and rotation of the Si-O bond are less affected in the electric field, reducing the response to the electric field, thereby reducing the dielectric constant.

[0220] In summary, by adjusting the addition amounts of PC resin, ABS resin, ABS-g-GMA, polyborosiloxane polymer, hexaphenoxy cyclotriphosphazene, functionalized POSS, DOPO flame retardant, and semi-hindered phenol antioxidant, with the synergistic cooperation of various additives, the PC / ABS alloy material of the present invention with excellent mechanical properties, flame retardant properties and low dielectric properties can be obtained.

[0221] Compared with Example 7, Comparative Example 1 is a PC / ABS alloy material prepared without adding ABS resin. Since the PC / ABS alloy prepared by using ABS resin with a butadiene content of 14% to 18% as the base resin has higher tensile strength and bending modulus, this is mainly due to the fact that the ABS resin has a higher styrene content (61% to 65%) and a lower butadiene content (14% to 18%). This structure will reduce the mobility of the molecular chain, thereby increasing the material's ability to resist external stress and deformation. At the same time, a higher styrene content is beneficial to improving the compatibility between ABS resin and PC resin. Therefore, the tensile strength and notched impact strength of Comparative Example 1 are lower than those of Example 7.

[0222] Compared with Example 7, Comparative Example 2 is a PC / ABS alloy material prepared without adding ABS-g-GMA. Since the PC / ABS alloy prepared by using ABS-g-GMA with a butadiene content of 58% to 62% as a toughening compatibilizer has a lower tensile strength and bending modulus, but has a very excellent notched impact strength. This is mainly because ABS-g-GMA has a higher butadiene content (content of 58% to 62%), and a large number of butadiene segments greatly improve the movement ability of the entire molecular chain, so that the alloy can absorb a large amount of energy through plastic deformation under the condition of external force, thereby showing extremely high impact toughness, and the methacrylate glycidyl grafting rate of ABS-g-GMA is 0.8% to 1.2%, and its epoxy group can react with the terminal hydroxyl group of PC resin to improve the compatibility and interface adhesion between PC resin and ABS resin, thereby improving the mechanical properties of PC / ABS alloy material. Therefore, the tensile strength and notched impact strength of Comparative Example 2 are lower than those of Example 7.

[0223] Compared with Example 7, Comparative Example 3 is a PC / ABS alloy material prepared without adding a polyborosiloxane polymer. Since the present invention obtains a polyborosiloxane polymer through a dehydration condensation reaction of hydroxyl-terminated polydimethylsiloxane and boric acid, it can simultaneously toughen and flame retard the PC / ABS alloy material. This is mainly because the polyborosiloxane polymer improves the melt strength of PC, participates in the formation of a highly expanded ceramic carbon layer, and improves the flame retardant properties of PC. At the same time, the polyborosiloxane polymer forms a micro-crosslinked island structure with PC through an ester exchange reaction, thereby toughening PC. Therefore, the notched impact strength and flame retardant properties of Comparative Example 3 are lower than those of Example 7.

[0224] Compared with Example 7, Comparative Example 4 is a PC / ABS alloy material prepared without adding hexaphenoxy cyclotriphosphazene. Since hexaphenoxy cyclotriphosphazene is a cyclophosphazene flame retardant, it has good thermal stability and flame retardant properties. Hexaphenoxy cyclotriphosphazene promotes PC to form a dense carbon layer through acidic substances such as phosphoric acid and metaphosphoric acid produced by its own decomposition, thereby isolating oxygen in the air to achieve a flame retardant effect. At the same time, the nitrogen element in hexaphenoxy cyclotriphosphazene will be converted into non-flammable gases such as NH3 during combustion, diluting the oxygen around PC. Therefore, the flame retardant performance of Comparative Example 4 is lower than that of Example 7.

[0225] Compared with Example 7, Comparative Example 5 is for preparing PC / ABS alloy material without adding functionalized POSS, because functionalized polyhedral cage type oligomeric silsesquioxane (POSS) is a typical organosilicon flame retardant, its composite flame retardant system can effectively flame retardant PC / ABS alloy material, and the end group of functionalized POSS comprises epoxy group, and its epoxy group can react with the terminal hydroxyl group of PC resin, improves the dispersibility and compatibility of functionalized POSS in PC resin material, thus improves the flame retardant property of PC / ABS alloy material. In addition, functionalized POSS has low dielectric properties (test frequency is 5GHz, and dielectric constant is 2.1~2.4), this is mainly because POSS has the three-dimensional structure of similar cage, and the center is the inorganic kernel formed by alternate connection of silicon oxygen (Si-O), and the silicon atoms of eight vertices are connected to organic substituted groups (R groups). This cage structure makes molecular interior have larger space, reduces the close packing between molecules, reduces the polarization degree of molecule. Under electric field action, molecule is not easily polarized, thus reduces dielectric constant. The bond energy of Si-O bond is higher (445.2 kJ / mol), which is more difficult to be destroyed than CC bond (350.7 kJ / mol) and CO bond (359.1 kJ / mol). Therefore, the vibration and rotation of Si-O bond are less affected in the electric field, which reduces the response to the electric field and thus reduces the dielectric constant. Therefore, the flame retardant performance of comparative example 5 is lower than that of example 7, while the dielectric constant of comparative example 5 is higher than that of example 7.

[0226] Compared with Example 7, Comparative Example 6 is a PC / ABS alloy material prepared without adding DOPO flame retardant. Since 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) is used as a synergistic flame retardant, on the one hand, the PO· free radicals generated by the thermal decomposition of DOPO capture the active free radicals HO· and H· in the gas phase during combustion, thereby inhibiting the free radical chain reaction, reducing the heat release, and generating some non-flammable gas, thereby achieving the purpose of flame retardancy. On the other hand, DOPO will form phosphoric acid and polymetaphosphoric acid that promote carbonization when the polymer burns, isolating oxygen and heat transfer, and achieving a flame retardant effect. Therefore, the flame retardant performance of Comparative Example 6 is lower than that of Example 7.

[0227] Compared with Example 7, Comparative Example 7 is a PC / ABS alloy material prepared without adding a semi-hindered phenol antioxidant. Since the semi-hindered phenol antioxidant triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate] does not form a color-developing group, it has little effect on the initial color, optical properties and mechanical properties of PC. Therefore, the tensile strength and notched impact strength of Comparative Example 7 are lower than those of Example 7.

[0228] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0229] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A PC / ABS alloy material, characterized in that: It is prepared from the following raw materials in parts by weight: 70-90 parts of PC resin, ABS resin 10-30 parts, The total weight of PC resin and ABS resin is 100 parts. The ABS-g-GMA is acrylonitrile-butadiene-styrene copolymer grafted with glycidyl methacrylate; the functionalized POSS is a functionalized polyhedral cage-type oligomeric silsesquioxane; and the DOPO flame retardant is 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

2. The PC / ABS alloy material according to claim 1, characterized in that: It is prepared from the following raw materials in parts by weight: 74-86 parts of PC resin, ABS resin 14-26 parts, The total weight of PC resin and ABS resin is 100 parts.

3. The PC / ABS alloy material according to claim 2, characterized in that: It is prepared from the following raw materials in parts by weight: 78-82 parts of PC resin, ABS resin 18-22 parts, The total weight of PC resin and ABS resin is 100 parts.

4. The PC / ABS alloy material according to any one of claims 1 to 3, characterized in that: The number average relative molecular weight of the PC resin is 23000-31000; and / or the butadiene content of the ABS resin is 14%-18%; and / or the butadiene content of the ABS-g-GMA is 58%-62%, and the glycidyl methacrylate grafting rate is 0.8%-1.2%.

5. The PC / ABS alloy material according to any one of claims 1 to 3, characterized in that: The end group of the functionalized POSS comprises an epoxy group; and / or the semi-hindered phenol antioxidant is triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate].

6. The PC / ABS alloy material according to any one of claims 1 to 3, characterized in that: The preparation method of the polyborosiloxane polymer comprises the following steps: adding 100 g of hydroxyl-terminated polydimethylsiloxane, 18 g to 22 g of boric acid and 20 mL to 30 mL of anhydrous ethanol into a flask, stirring at 25° C. to 35° C. for 10 min to 20 min, then heating the mixture to 160° C. to 180° C., and condensing and refluxing at a speed of 400 rpm to 600 rpm for 6 h to 8 h, then filtering under reduced pressure, and finally drying under vacuum at 80° C. to 90° C. for 22 h to 26 h to obtain the polyborosiloxane polymer.

7. A method for preparing the PC / ABS alloy material according to any one of claims 1 to 6, characterized in that: The following steps are involved: (1) drying the PC resin at 100° C. to 110° C. for 2 to 4 hours, and then cooling; Add the cooled PC resin, ABS resin, ABS-g-GMA, functionalized POSS and semi-hindered phenol antioxidant into a blender for mixing; (2) adding polyborosiloxane polymer, hexaphenoxy cyclotriphosphazene, and DOPO flame retardant into another high-speed mixer and mixing; (3) adding the mixed material prepared in step (1) into a parallel twin-screw extruder via a feeder, and adding the mixed material prepared in step (2) into the side of the parallel twin-screw extruder for melt extrusion and granulation, wherein the process parameters include: a temperature of zone 1 of 215° C. to 235° C., a temperature of zone 2 of 220° C. to 240° C., a temperature of zone 3 of 225° C. to 245° C., a temperature of zone 4 of 230° C. to 250° C., a temperature of zone 5 of 235° C. to 255° C., a temperature of zone 6 of 235° C. to 255° C., a temperature of zone 7 of 230° C. to 250° C., a temperature of zone 8 of 230° C. to 250° C., a die head temperature of 230° C. to 250° C., and a screw speed of 400 rpm to 800 rpm.

8. The preparation method according to claim 7, characterized in that: PC / ABS alloy material includes the following steps: (1) drying the PC resin at a temperature of 102° C. to 108° C. for 2.4 to 3.6 hours, and then cooling the PC resin; adding the cooled PC resin, ABS resin, ABS-g-GMA, functionalized POSS, and semi-hindered phenol antioxidant into a mixer for mixing; (2) adding polyborosiloxane polymer, hexaphenoxy cyclotriphosphazene, and DOPO flame retardant into another high-speed mixer and mixing; (3) adding the mixed material prepared in step (1) into a parallel twin-screw extruder via a feeder, and adding the mixed material prepared in step (2) into the side of the parallel twin-screw extruder for melt extrusion and granulation, wherein the process parameters include: a temperature of zone 1 of 220° C. to 230° C., a temperature of zone 2 of 225° C. to 235° C., a temperature of zone 3 of 230° C. to 240° C., a temperature of zone 4 of 235° C. to 245° C., a temperature of zone 5 of 240° C. to 250° C., a temperature of zone 6 of 240° C. to 250° C., a temperature of zone 7 of 235° C. to 245° C., a temperature of zone 8 of 235° C. to 245° C., a die head temperature of 235° C. to 245° C., and a screw speed of 500 rpm to 700 rpm.

9. The preparation method according to claim 7 or 8, characterized in that: The screw shape of the parallel twin-screw extruder is a single-threaded screw; and / or the ratio L / D of the screw length L and the diameter D of the parallel twin-screw extruder is 35 to 55; and / or the screw of the parallel twin-screw extruder is provided with more than one meshing block area and more than one reverse thread area; in step (1) and / or step (2), the mixer is a high-speed mixer with a rotation speed of 500 rpm-1500 rpm.

10. The preparation method according to claim 9, characterized in that: The ratio L / D of the screw length L to the diameter D of the parallel twin-screw extruder is 40-50; and / or, the screw of the parallel twin-screw extruder is provided with two meshing block areas and one reverse thread area.

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