ABS (Acrylonitrile Butadiene Styrene) rubber powder, PC / ABS (Polycarbonate / Acrylonitrile Butadiene Styrene) composition containing ABS

Abstract

The invention belongs to the field of high polymer materials, and particularly discloses ABS rubber powder, a PC / ABS composition containing the ABS rubber powder as well as a preparation method and application of the ABS rubber powder. The ABS rubber powder prepared by the invention is high in density, relatively small and uniform in size, can effectively resist erosion of water and oxygen, can obviously improve the mechanical and anti-yellowing stability of a PC / ABS material, has relatively large radius of calcium ions, can effectively reduce the residual stress of a PC / ABS alloy, has a certain improvement effect on the mechanical property stability in long-term service, and is suitable for industrial production. The Ca element cooperates with the hindered phenol antioxidant to effectively and quickly decompose free radicals, so that the stability of the mechanical property and the yellowing resistance of the material in a humid and hot environment is further improved, and the PC / ABS composition has relatively high stability of humid and hot aging resistance, thermo-oxidative aging resistance and yellowing resistance, and is suitable for industrial production. And long-term service at damp and hot and high temperature is facilitated.

Description

An ABS powder, a PC / ABS composition comprising the same, a method for preparing the same, and applications thereof. Technical Field

[0001] This invention belongs to the field of polymer materials, specifically relating to an ABS powder, a PC / ABS composition including the powder, its preparation method, and its application. Background Technology

[0002] Because PC / ABS alloys combine the advantages of both PC and ABS resins, they are widely used in electronics, automotive parts, building materials, and daily consumer goods. For example, in the electronics industry, PC / ABS alloys are commonly used to manufacture housings and connectors; in the automotive parts industry, they are used in interior components and dashboards. These components need to operate for extended periods in high-temperature and high-humidity environments while maintaining stable mechanical properties and color appearance. In particular, the building materials and daily consumer goods industries have specific requirements for the weather resistance and long-term stability of PC / ABS alloys.

[0003] Currently, PC / ABS alloys are mainly prepared by emulsion graft polymerization of ABS and PC. However, this process has several technical shortcomings. For example, magnesium sulfate is often used as a coagulant in emulsion graft polymerization of ABS, inevitably resulting in magnesium sulfate residue in the ABS. Under humid and hot environments, this accelerates the thermo-oxidative degradation of the polybutadiene rubber phase in the ABS. The unsaturated double bonds in emulsion graft polymerized ABS are easily oxidized under the influence of moisture and heat, leading to molecular chain breakage and cross-linking. During high-temperature thermo-oxidative aging, this catalyzes the formation of quinone-based color-developing structures in the PC resin, resulting in decreased mechanical properties and yellowing of the alloy. To reduce costs and simplify the process, some manufacturers tend to reduce the amount of magnesium sulfate, but this leads to an incomplete core-shell structure in the obtained ABS, resulting in deteriorated interfacial compatibility in the PC / ABS system, further deteriorating the aging resistance and yellowing resistance of the PC / ABS alloy. Furthermore, water-based antioxidants are generally required to improve the thermo-oxidative stability of ABS obtained through emulsion graft polymerization. Reducing the amount of magnesium sulfate during emulsion graft polymerization can lead to insufficient stability of the ABS emulsion obtained from the graft polymerization. This affects the uniformity of the antioxidants added to the system within the ABS, limiting the effectiveness of the antioxidants in the ABS system. Furthermore, the decomposition of the antioxidants can produce quinone-based color-developing structures, further causing the PC / ABS alloy to experience reduced mechanical strength and decreased resistance to yellowing under humid and hot environments. These problems severely impact the material's service life and reliability, limiting its application in high-performance fields. Therefore, developing PC / ABS alloys with excellent mechanical properties and color stability under humid and hot environments has become an urgent problem for the industry to solve. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies in which PC / ABS materials prepared by emulsion graft polymerization of ABS as raw materials are prone to degradation in mechanical properties and yellowing resistance under humid and hot environments. This invention will provide an ABS powder and a PC / ABS composition including the powder, as well as the preparation method and application of the composition.

[0005] To achieve the above objectives, the following technical solutions are specifically provided: On one hand, the present invention provides an ABS adhesive powder, wherein the raw materials for preparing the ABS adhesive powder include acrylonitrile, butadiene and styrene, the Ca element content of the ABS adhesive powder is 5-500ppm, the Cl element content of the ABS adhesive powder is ≤500ppm, and the pH value of the aqueous solution of the ABS adhesive powder is 6.6-6.9.

[0006] This invention introduces Ca in the form of calcium acetate, which not only improves the gelation effect of ABS latex but also avoids the use of CaCl2 to introduce Ca, thus preventing high residual Cl levels and further mitigating the adverse effects of Cl on PC materials. Simultaneously, the ABS powder of this invention is slightly acidic, which helps avoid the alkaline nature of ABS powder prepared by traditional methods, which could lead to the breakage of carbonate bonds in PC and subsequent performance degradation, further improving the resistance to damp heat and thermo-oxidative stability of PC / ABS materials. The pH value of the aqueous solution of the ABS powder was tested using the JJ-119-84 laboratory pH meter calibration procedure. The test steps are as follows: Weigh 5g of the sample to be tested and place it in a sample bottle; add 10mL of ethanol (analytical grade) and 40mL of deionized water; ultrasonically vibrate for 1 minute, let stand for 10 minutes, and then test the pH value.

[0007] Preferably, the ABS powder is obtained by emulsion graft polymerization and coagulation under the action of a coagulant, wherein the coagulant includes calcium acetate and sulfuric acid.

[0008] This invention uses calcium acetate and sulfuric acid as coagulants for ABS latex obtained by emulsion graft polymerization, avoiding the use of Mg-containing coagulants from the source, thus preventing the impact of Mg residue on the performance of the synthesized PC / ABS material. Furthermore, when using calcium acetate and sulfuric acid as coagulants for ABS latex coagulated by the emulsion method, this invention provides suitable charge, promoting stable and efficient demulsification and dehydration of the ABS polymer latex. This results in ABS powder with high density, small and uniform particles, effectively resisting water and oxygen erosion and improving the stability of the ABS powder. When used as a raw material for synthesizing PC / ABS alloys, it significantly improves their mechanical properties and resistance to yellowing under humid and hot environments. Meanwhile, sulfuric acid and calcium acetate can form calcium sulfate precipitate, some of which is removed by water washing, but some will remain in the ABS powder. When it is used as a raw material to form an alloy with PC, the residual calcium sulfate will not have a negative impact on PC and will not degrade the yellowing resistance of the composition. Moreover, the calcium ions in it have a large radius, which can create effective space in the polymer and are more likely to accumulate at the interface between the ABS and PC phases, playing a certain role in lubrication and buffering, improving the stress concentration between polymer molecular chains, effectively releasing the residual stress of the PC / ABS alloy, thereby improving the mechanical stability of the PC / ABS alloy, and thus improving the aging resistance of the composition in humid and hot environments and thermo-oxidative environments.

[0009] In one embodiment, the pH value of the aqueous solution of the ABS adhesive powder is 6.6-6.9, specifically 6.6, 6.7, 6.8, 6.9, etc., and specific values ​​between these values. For space limitations and for the sake of brevity, this invention will not exhaustively list all the specific values ​​included in the range. Preferably, the Ca element content of the ABS adhesive powder is 10-140 ppm, specifically 10 ppm, 20 ppm, 30 ppm, 40 ppm, 50 ppm, 60 ppm, 70 ppm, 80 ppm, 90 ppm, 100 ppm, 110 ppm, 120 ppm, 130 ppm, 140 ppm, etc., and specific values ​​between these values. For space limitations and for the sake of brevity, this invention will not exhaustively list all the specific values ​​included in the range.

[0010] Preferably, the Cl element content in the ABS powder is ≤10ppm, and more preferably less than 5ppm. This invention introduces Ca in the form of calcium acetate, which not only improves the gelation effect of ABS latex but also avoids the use of CaCl2 to introduce Ca, thus avoiding high residual Cl levels and further minimizing the adverse effects of Cl on PC materials.

[0011] Preferably, the Mg content in the ABS powder is ≤50ppm, more preferably ≤10ppm, and even more preferably ≤5ppm.

[0012] ICP was used to test the residual amounts of Ca, Mg, and Cl elements in ABS powder.

[0013] Preferably, the average particle size of the ABS powder is 200-500 nm, specifically 200 nm, 220 nm, 240 nm, 260 nm, 280 nm, 300 nm, 320 nm, 340 nm, 360 nm, 380 nm, 400 nm, 420 nm, 440 nm, 460 nm, 480 nm, 500 nm, etc., as well as specific values ​​between the above values. For space limitations and for the sake of brevity, this invention will not exhaustively list all the specific values ​​included in the range. The average particle size of the ABS powder is determined according to the method specified in GB / T 19077-2016 "Particle Size Distribution - Laser Diffraction Method". The particle size analyzer used is a Malvern Mastersizer 3000 Ultra laser particle size analyzer.

[0014] Preferably, the butadiene segment content in the ABS powder is 50%-80% by mass, specifically 50%, 52%, 54%, 56%, 58%, 60%, 62%, 64%, 66%, 68%, 70%, 72%, 74%, 76%, 78%, 80%, etc., and specific values ​​between the above points. For space limitations and for the sake of brevity, this invention will not exhaustively list all the specific values ​​included in the range; the styrene segment content in the ABS powder is 2%-20% by mass, specifically 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 1%, etc. The specific values ​​within the ranges of 1%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, etc., are not exhaustively listed here due to space limitations and for the sake of brevity. The mass percentage of acrylonitrile segments in the ABS powder is 10%-30%, which can be 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, etc., as well as the specific values ​​within the ranges of 1%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, etc., are not exhaustively listed here due to space limitations and for the sake of brevity.

[0015] Secondly, the present invention provides a method for preparing ABS rubber powder, comprising the following steps: S1, under inert gas protection, mixing solvent, initiator, chain transfer agent, electrolyte, emulsifier and a portion of surfactant, then adding butadiene, and carrying out a first-stage reaction under stirring and a first temperature; raising the temperature to a second temperature for a second-stage reaction, raising the temperature to a third temperature for a third-stage reaction; adding the remaining surfactant and mixing evenly to obtain polybutadiene latex; satisfying the following relationship: first temperature ≤ second temperature ≤ third temperature; S2, mixing the polybutadiene latex, styrene, acrylonitrile, solvent, initiator and chain transfer agent... S1. Electrolyte, emulsifier and catalyst are mixed and reacted in the fourth stage at a fourth temperature. Then surfactant is added to react in the fifth stage to obtain ABS polymer latex. S2. The ABS polymer latex, coagulant and solvent are mixed and coagulated in the first stage at a fifth temperature. The temperature is raised to the sixth temperature for the second stage of coagulation. The temperature is raised to the seventh temperature for the third stage of coagulation. The temperature is lowered to the eighth temperature for the fourth stage of coagulation. After solid-liquid separation, washing and drying, ABS powder is obtained. The following relationship is satisfied: the fifth temperature < the sixth temperature ≤ the seventh temperature, and the seventh temperature > the eighth temperature.

[0016] Preferably, in step S1, the first temperature is 50-60℃, the reaction time of the first stage is 6-12h, and the first stage reaction is carried out at a stirring rate of 100-110rpm.

[0017] Preferably, in step S1, the second temperature is 65-75°C, the reaction time in the second stage is 8-16 hours, and the second stage reaction is carried out at a stirring rate of 110-125 rpm.

[0018] Preferably, in step S1, the third temperature is 70-80℃, the reaction time of the third stage is 8-16h, and the third stage reaction is carried out at a stirring rate of 135-145rpm.

[0019] Preferably, in step S1, based on 100 parts by weight of dry polybutadiene latex, the solvent weighs 80-120 parts, the initiator weighs 0.1-1 parts, the chain transfer agent weighs 0.2-1.2 parts, the electrolyte weighs 0.1-1 parts, the emulsifier weighs 0.1-1 parts, and the total weight of the surfactant is 0.1-1 parts.

[0020] Preferably, in steps S1 and S2, the solvent includes water.

[0021] Preferably, in steps S1 and S2, the surfactants are each independently selected from alkynol surfactants, and more preferably, include, but are not limited to, at least one of methylpentynol, 2,4,7,9-tetramethyl-5-decyn-4,7-diol, and ethyl octynol.

[0022] Preferably, in steps S1 and S2, each of the emulsifiers is independently selected from at least one of octanoate, caprate, laurate, myristate, palmitate, stearate, oleate, linoleate, linolenic acid salt, rosinate, betaine, castor oil sulfate, dodecylbenzene sulfonate, dodecyl sulfonate, dodecyl sulfate, and alkylnaphthalene sulfonate.

[0023] Preferably, in steps S1 and S2, the chain transfer agent is independently selected from at least one of n-octylthiol, n-dodecylthiol, cyclohexylthiol, tert-dodecylthiol, tert-nonylthiol, 1,8-dimercapto-3,6-dioxooctane, mercaptoacetic acid, methyl 3-thiopropionate, 2-ethylhexyl 3-hydropropionate, 3-methoxybutyl 3-thiopropionate, pentaerythritol tetra-3-mercaptopropionate, n-butyl thioglycolate, benzylthiol, furfuryl thiol, thiosalicylic acid, 4-mercaptopyridine, or 4-aminobenzylthiophenol.

[0024] Preferably, in steps S1 and S2, the electrolyte includes, but is not limited to, potassium carbonate; and the initiator is independently selected from at least one of water-soluble initiators and redox initiators.

[0025] Preferably, the water-soluble initiator includes at least one of potassium persulfate, sodium persulfate, and ammonium persulfate.

[0026] Preferably, the redox initiator comprises a peroxide compound, a variable-valence transition metal salt, a chelating agent, and a reducing agent, wherein the peroxide compound includes, but is not limited to, one or a mixture of at least two of the following: benzoyl peroxide, dilauroyl peroxide, eicosanoyl peroxide, tert-butyl peroxide, tert-butyl pervalerate, methyl ethyl ketone peroxide, cyclohexanone peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, di-tert-butyl peroxide, and dicumyl peroxide; the variable-valence transition metal salt includes iron salts and / or copper salts, more preferably iron salts, including but not limited to ferric sulfate, ferrous sulfate, ferric chloride, and ferrous chloride. More preferably, ferrous salts, such as ferrous sulfate or ferrous chloride; chelating agents include, but are not limited to, at least one of: sodium pyrophosphate, ethylenediaminetetraacetic acid, disodium ethylenediaminetetraacetic acid, sodium ethylenediaminetetraethylenetetraacetic acid, sodium hydroxyethylethylenediaminetriacetic acid, N,N-bis(2-hydroxyethyl)glycine, diethylenetriaminepentaacetic acid, ethylene glycol bis(2-aminoethyl ether)tetraacetic acid, iminodiacetic acid, tetrasodium iminodisuccinate, sodium hydroxyethylethylenediaminetriacetic acid, and disodium hypocyanotriacetic acid; reducing agents include, but are not limited to, at least one of: glucose, lactose, sodium formaldehyde sulfoxylate, sodium sulfite, and sodium bisulfite.

[0027] Preferably, in step S2, the catalyst includes at least one of tetramethylethylenediamine and sodium formaldehyde sulfoxylate.

[0028] Preferably, in step S2, based on 100 parts of the dry base of ABS polymer latex, the initiator, chain transfer agent, emulsifier and surfactant each have an independent mass of 0.1 to 1 part, the catalyst has a mass of 0.2 to 2 parts, and the solvent has a mass of 100 to 140 parts.

[0029] Preferably, the solid content of the ABS polymer latex is 35wt%-45wt%, and the particle size range is 250-350nm.

[0030] Preferably, in step S2, the fourth temperature is 50-60℃, the reaction time of the fourth stage is 1-6h, the temperature of the fifth stage reaction is 50-60℃, and the reaction time of the fifth stage reaction is 0.5-3h.

[0031] Preferably, in step S3, the coagulant comprises calcium acetate and sulfuric acid, wherein the mass ratio of calcium acetate to sulfuric acid is 1:(0.4-5).

[0032] More preferably, in step S3, the sulfuric acid is concentrated sulfuric acid with a concentration greater than 92 wt%.

[0033] Preferably, in step S3, the solvent includes water.

[0034] Preferably, in step S3, the mass ratio of the ABS polymer latex to the coagulant is 100:0.5-7, more preferably 100:2.5-5; and the ABS polymer latex is measured by dry weight.

[0035] Preferably, in step S3, the fifth temperature is 65-85℃, the coagulation time of the first stage is 2-10 min, and the coagulation pressure of the first stage is 0.01-0.03 MPa.

[0036] Preferably, in step S3, the sixth temperature is 90-120℃, the coagulation time of the second stage is 5-12 min, the coagulation pressure of the second stage is 0.06-0.1 MPa, and the pH value of the second stage coagulation is 3-8.

[0037] Preferably, in step S3, the seventh temperature is 90-150℃, the third stage coagulation time is 5-12 min, and the third stage coagulation pressure is 0.06-0.3 MPa.

[0038] Preferably, in step S3, the eighth temperature is 90-110℃, the fourth stage coagulation time is 5-12 min, and the fourth stage coagulation pressure is 0.06-0.1 MPa.

[0039] Thirdly, the present invention provides a PC / ABS composition comprising the following components in parts by weight: 55-95 parts PC, 2-16 parts ABS powder, 3-27 parts SAN, and 0.1-2 parts hindered phenolic antioxidant.

[0040] This invention uses an acidic gel system with inert Ca ions to obtain ABS powder and blend it with SAN and PC. While ABS powder and SAN form ABS resin, ABS powder and PC combine to form PC / ABS alloy material. Because ABS powder has high density, small and uniform size, it can effectively resist the erosion of water and oxygen, and can significantly improve the mechanical and yellowing stability of PC / ABS material. In addition, the calcium ion radius in the residual calcium sulfate is large, which can effectively reduce the residual stress of PC / ABS alloy and improve the mechanical stability of long-term service. Calcium plays multiple synergistic roles in the system: (1) Chemical synergy: activates antioxidants and decomposes hydrogen peroxide through the Lewis acid effect; (2) Environmental regulation: complexes acidic substances and maintains the active environment of antioxidants; (3) Physical synergy: improves local stress, blocks diffusion, and stabilizes antioxidant dispersion.

[0041] The above factors collectively contribute to the hindered phenolic antioxidant maintaining its efficient and long-lasting free radical quenching ability under complex conditions such as humid heat and stress, thereby significantly improving the long-term yellowing resistance and mechanical stability of the PC / ABS alloy. In summary, the PC / ABS composition of this invention exhibits high resistance to humid heat aging, thermo-oxidative aging, and yellowing, which is beneficial for its long-term service under humid heat and high temperatures.

[0042] Preferably, the PC / ABS composition comprises the following components in parts by weight: 69-72 parts PC, 1-14 parts ABS powder, 15-24 parts SAN, and 0.5-1.5 parts hindered phenolic antioxidant.

[0043] Preferably, in the PC / ABS composition, the mass percentage of PC (polycarbonate) is not less than 30%, more preferably not less than 40%, and even more preferably not less than 45%.

[0044] More preferably, in the PC / ABS composition, the mass percentage of the ABS powder is 2%-16%, more preferably 4%-12%.

[0045] More preferably, in the PC / ABS composition, the SAN content by mass is 3%-27%, more preferably 15%-24%. The system of this invention does not limit the type of PC. The polycarbonate is preferably bisphenol A type polycarbonate, but self-made PC can also be used. For example, the melt flow rate of the polycarbonate can be 1-60 g / 10 min, wherein the melt flow rate is tested according to ISO 1133-1 2011 standard, and the test conditions are 300℃ and 1.2 kg. More specifically, the melt flow rate of the polycarbonate can be 1 g / 10 min, 5 g / 10 min, 10 g / 10 min, 15 g / 10 min, 20 g / 10 min, 25 g / 10 min, 30 g / 10 min, 35 g / 10 min, 40 g / 10 min, 45 g / 10 min, 50 g / 10 min, 55 g / 10 min, 60 g / 10 min, etc., as well as specific point values ​​between the above point values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific point values ​​included in the range.

[0046] Preferably, the number-average molecular weight of the PC is 25,000-40,000; specifically, it can be 25,000, 27,500, 30,000, 32,500, 35,000, 37,500, 40,000, etc., as well as specific values ​​between the above-mentioned values. For space limitations and for the sake of brevity, this invention will not exhaustively list all the specific values ​​included in the range. The number-average molecular weight of the PC is tested using an ultra-high performance polymer chromatography (APC) instrument, with polystyrene standards as the reference.

[0047] Preferably, the SAN is a copolymer of acrylonitrile and styrene. Based on the mass of the SAN, the mass percentage of acrylonitrile is 18%-30%, specifically 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, etc., as well as specific values ​​between the above ranges. For space limitations and for the sake of brevity, this invention will not exhaustively list all the specific values ​​included in the range. The mass percentage of acrylonitrile is determined by organic elemental analysis to test the nitrogen content.

[0048] Preferably, the mass ratio of ABS powder to SAN is 1:(2-5), which can be 11:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, etc., as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific values ​​included in the range. Preferably, the hindered phenolic antioxidant includes at least one of 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene (antioxidant 330), octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (antioxidant 1076), 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-triazine-2,4,6-(1H,3H,5H)trione (antioxidant 3114), and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010).

[0049] Fourthly, the present invention provides a method for preparing the PC / ABS composition, comprising the following steps: sequentially mixing, melting, extruding, and granulating the raw materials to obtain the PC / ABS composition.

[0050] Preferably, the melting temperature is 210~250℃.

[0051] Preferably, the rotation speed during melting is 200~600 rpm.

[0052] Fifthly, the present invention also provides an application of the PC / ABS composition described above in the preparation of electronic appliances, automotive parts, building materials, and daily consumer goods, and is particularly suitable for use in the preparation of mobile energy storage housings, photovoltaic connectors, interior and exterior trim parts for new energy vehicles, and housings for artificial intelligence components.

[0053] Compared with the prior art, the present invention has the following beneficial effects: The ABS powder prepared by the present invention has high density, small and uniform size, which can effectively resist the erosion of water and oxygen, and can significantly improve the mechanical and yellowing resistance of PC / ABS materials. In addition, the calcium ions contained therein have a large radius, which can effectively reduce the residual stress of PC / ABS alloys and improve the stability of mechanical properties during long-term service. Furthermore, the Ca element, in conjunction with the hindered phenolic antioxidant, effectively and rapidly decomposes free radicals, further improving the stability of the mechanical properties and yellowing resistance of the material under humid and hot environments. In summary, the PC / ABS composition of the present invention has high resistance to humid and hot aging, heat and oxygen aging, and yellowing, which is beneficial for its long-term service under humid and hot conditions. Detailed Implementation

[0054] To better illustrate the purpose, technical solution, and advantages of this invention, specific embodiments will be used to further explain the invention below. Unless otherwise specified, the experimental methods used in the embodiments and / or comparative examples are conventional methods; the materials and reagents used, unless otherwise specified, are commercially available. Unless otherwise specified, the raw materials used in each embodiment and comparative example of this invention are the same in each parallel experiment.

[0055] The following examples and comparative examples involve the following raw material information: PC-1: PC2100, Wanhua Chemical, number average molecular weight 32000; PC-2: PC2220, Wanhua Chemical, number average molecular weight 26000; PC-3: PC7030PJ, Samyang, number average molecular weight 39000; SAN-1: SAN320, Kumho Petrochemical, acrylonitrile content 25%; SAN-2: SAN310T, Kumho... Petrochemical, acrylonitrile content 18.5% by mass; SAN-3: CN77, Benlin, acrylonitrile content 30% by mass; Hindered phenolic antioxidant-1: 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, AO330, Adico; Hindered phenolic antioxidant-2: Antioxidant 1076, BASF; Unhindered phenolic antioxidant: Hindered amine, 5050H, BASF.

[0056] Example 1: A method for preparing a PC / ABS composition, comprising the following steps: Preparing ABS powder according to steps S1-S5: S1: By weight, 100 parts water, 0.4 parts ammonium persulfate (initiator), 0.6 parts n-dodecyl mercaptan (chain transfer agent), 0.4 parts sodium carbonate (electrolyte), 0.4 parts potassium stearate (initiator and emulsifier), and 0.08 parts ethyl octyryl alcohol (surfactant) are added to a reaction vessel and stirred at room temperature until completely dissolved and mixed uniformly; nitrogen is introduced into the reaction vessel to replace the air, so that the oxygen content is less than 10 ppm; S2: Subsequently... Add 100 parts of butadiene monomer; heat the reactor to 55℃ and maintain the temperature for the first stage of polymerization for 9 hours, while controlling the stirring speed at 105 rpm; S3: after the first stage of polymerization, heat the system to 70℃ and maintain the temperature for the second stage of polymerization for 12 hours, while controlling the stirring speed at 120 rpm; after the second stage of polymerization, continue to heat to 75℃ and maintain the temperature for the third stage of polymerization for 12 hours, while controlling the stirring speed at 130 rpm; at the end of the polymerization reaction, add 0.32 parts of ethyl octyryl alcohol, stir for half an hour, cool down and discharge to obtain polybutadiene latex.

[0057] S4: Heat the polybutadiene latex from step S1 to 55°C. Based on 100 parts by weight of the dry basis of the polybutadiene latex, add 0.4 parts of ammonium persulfate (initiator), 0.6 parts of n-dodecyl mercaptan (chain transfer agent), 0.4 parts of potassium stearate (initiator and emulsifier), 1 part of tetramethylethylenediamine (catalyst), and 120 parts of water. Add the formulated amounts of acrylonitrile monomer and styrene monomer (as shown in Table 1). Add dropwise continuously for 2 hours. After the addition is complete, continue the reaction for 3 hours. Then add 0.4 parts of ethyl octyryl alcohol (surfactant) and continue the reaction for 2 hours to obtain ABS polymer latex.

[0058] S5. The mass ratio of ABS polymer latex: concentrated sulfuric acid: calcium acetate: water is 100:2:1:500 (dry basis), with a concentrated sulfuric acid concentration of 98 wt%. The ABS polymer latex, concentrated sulfuric acid, calcium acetate, and water are added separately to the first coagulation vessel. Simultaneously, steam is introduced to heat the material inside the vessel, maintaining the temperature at 75°C. The material is held in the first coagulation vessel for 5 minutes. Then, the slurry in the first coagulation vessel is transferred to the second coagulation vessel using a pump. Steam is introduced to further raise the temperature, bringing the material temperature in the second coagulation vessel to 95°C. At the same time, pH adjuster NaOH (based on...) is added using a pump. A 2wt% NaOH aqueous solution was added while simultaneously testing to maintain the pH of the slurry within the reactor at a range of 4.5. After the material remained in the second coagulation reactor for 10 minutes, it was transferred to the third coagulation reactor using a pump. Simultaneously, steam was introduced to further heat the material in the second coagulation reactor, raising its temperature to 125°C, and the material remained in the second coagulation reactor for another 10 minutes. The slurry was then transferred from the third coagulation reactor to the fourth coagulation reactor, where the temperature was controlled at 95°C using a cooling water jacket. After remaining in the fourth coagulation reactor for 10 minutes, the material was centrifuged to dehydrate, yielding wet powder. The wet powder was then thoroughly dried using a fluidized bed dryer to obtain ABS powder, denoted as A1.

[0059] S6. Preparation of PC / ABS composition: According to the raw material component dosage in Table 3, each component is stirred and mixed in a high-speed mixer to obtain a premix; the premix is ​​fed into a twin-screw extruder through the main feed port, melt-mixed and extruded and granulated in the twin-screw extruder to obtain a PC / ABS composition, wherein the screw length-to-diameter ratio is 45:1, the screw barrel temperature is 210-250℃, and the screw speed is 300rpm.

[0060] Compared with Example 1, Examples 2-20 and Comparative Examples 1-6 differ in the types and / or amounts of their raw materials. In Examples 2-11, A2-A11 were prepared respectively, and in Comparative Examples 1-4, A12-15 were prepared respectively. See Tables 1-3 for details.

[0061] The test methods for various properties of ABS powder and PC / ABS composition in the embodiments and comparative examples of the present invention are as follows: (1) The residual amount of Ca and Cl elements in ABS powder is tested by ICP. The test results are shown in Table 1. ND indicates that when the target element content is detected by the corresponding detection method, its content is lower than the detection limit of the method, that is, it has basically no target element.

[0062] (2) The pH value of the aqueous solution of ABS powder was tested using the JJ-119-84 laboratory pH (acidity) meter calibration procedure. The test steps are as follows: Weigh 5g of the sample to be tested and put the sample into a sample bottle; then add 10mL of ethanol (analytical grade) and 40mL of deionized water; after ultrasonic vibration for 1min, let it stand for 10min and then test its pH value.

[0063] (3) The average particle size of ABS powder was determined according to the method specified in GB / T 19077-2016 "Particle Size Distribution by Laser Diffraction". The particle size analyzer used was a Malvern Mastersizer 3000 Ultra laser particle size analyzer.

[0064] (4) Stability of resistance to damp heat aging: The impact strength of 3.0 mm IZOD notched samples was tested according to ASTM D256-2010 standard. The notch type was injection molding notch. The notch impact strength A1 before damp heat aging was recorded. The samples were then placed in a constant temperature and humidity chamber with a temperature of 85℃ and a humidity of 85% for 500 hours of damp heat aging. Then, the samples were placed in an environment with a room temperature of 25℃ and a humidity of 50% for 48 hours. Finally, the notch impact strength was tested using the same test method as before damp heat aging, and the notch impact strength A2 after damp heat aging was recorded. The retention rate of the notch impact strength before and after damp heat aging was calculated using the following formula: △A (%) = (A1-A2) / A1×100. The performance retention rate before and after damp heat aging was used as a criterion for judging the quality of damp heat performance. The higher the notch impact strength retention rate, the better the damp heat stability.

[0065] (5) Heat and oxygen aging stability: The impact strength of 3.0 mm IZOD notched samples was tested according to ASTM D256-2010 standard. The notch type was injection molding notch. The notch impact strength B1 before heat and oxygen aging was recorded. The samples were then placed in a constant temperature and humidity chamber and heat and oxygen aging was performed at 130℃ for 500 hours. Then, the samples were placed in an environment with a room temperature of 25℃ and a humidity of 50% for 48 hours. Finally, the notch impact strength was tested using the same test method as before heat and oxygen aging, and the notch impact strength B2 after heat and oxygen aging was recorded. The retention rate of notch impact strength before and after heat and oxygen aging was calculated using the following formula: △B (%) = (B1-B2) / B1×100. The performance retention rate before and after heat and oxygen aging was used as a criterion for judging the quality of heat and oxygen performance. The higher the notch impact strength retention rate, the better the heat and oxygen stability.

[0066] (6) Yellowing resistance: The L / a / b values ​​of each product test sample with injection molding of 125×13×2mm and 80℃ thermo-oxidative aging treatment for 500h were tested using a colorimeter. The number of sites on the test sample was 3, and the average value of the test results was taken. Then, the parallel samples were irradiated with 253.7nm (50W) UVC for 50h in an environment of 50% relative humidity and 25℃. The same test was performed on each sample. The color difference ΔE was calculated based on the difference of each value.

[0067] Table 1 Table 2 (parts by weight) Table 3 (parts by weight) Table 4 As can be seen from Examples 1 and Comparative Examples 1-3, in Comparative Example 1, sulfuric acid was replaced with an equal mass of acetic acid; in Comparative Example 2, calcium acetate was replaced with an equal mass of calcium sulfate; in Comparative Example 3, calcium chloride was replaced with an equal mass of calcium chloride; and in Comparative Example 4, calcium acetate was replaced with an equal amount of magnesium sulfate. When the inorganic acids and inorganic salts in Examples 1 and Comparative Examples 1-4 act as coagulants, they can neutralize the charge on the latex surface, disrupt the stability of the electric double layer, and cause particle aggregation, further compression, and dehydration, leading to latex demulsification and dehydration, thereby achieving latex coagulation and precipitation. In this invention, sulfuric acid and calcium acetate are used as a composite coagulant, which can maintain a suitable potential value, has a good demulsification effect, and while achieving efficient coagulation promotion, makes the particles more uniform, dense, and fine.

[0068] The high residual Cl content in the ABS powder of Comparative Example 3 and the high residual magnesium sulfate content in Comparative Example 4 both lead to accelerated degradation of the matrix of the composition, resulting in poor stability of the composition under wet heat aging and thermo-oxidative aging. In Comparative Example 1, the sulfuric acid was replaced with acetic acid, resulting in insufficient charge in the system and an inability to maintain a suitable potential value, leading to poor demulsification and failure to form dense and stable ABS powder, thus reducing the stability of the ABS powder and the composition containing it. Furthermore, the addition of calcium sulfate in Comparative Example 2 has low solubility and limited ion dissolution, which cannot provide sufficient effective charge neutralization to promote latex demulsification. Therefore, the resulting ABS powder also has poor density and stability, making it susceptible to water and oxygen erosion, resulting in decreased performance stability of the composition containing it.

[0069] Compared with Example 1, Comparative Example 5 uses a non-hindered phenolic antioxidant, while hindered amines catalyze the hydrothermal degradation of the PC matrix, resulting in a significant deterioration in material properties. Comparative Example 6 uses no antioxidant. It can be seen that when the ABS powder of the present invention contains Ca, it will synergize with the hindered phenolic antioxidant and significantly improve the composition's resistance to hydrothermal aging, thermo-oxidative aging, and yellowing.

[0070] In Examples 2, 1, and 3, when the butadiene monomer content in the ABS powder was the same, the mass ratios of styrene monomer and acrylonitrile monomer were (27:10), (17:20), and (6.2:30.8), respectively. As the styrene monomer content decreased and the acrylonitrile content increased, the composition's resistance to damp heat, thermo-oxidative aging, and yellowing initially increased and then slightly decreased. Furthermore, as shown in Examples 4-6, changes in the proportions of butadiene, styrene, and acrylonitrile monomers in the ABS powder had a certain impact on the composition's resistance to damp heat, thermo-oxidative aging, and yellowing. In the system of this invention, when the proportions of butadiene monomer, styrene monomer, and acrylonitrile monomer in the ABS powder were 50%-80%, 2%-20%, and 10%-31%, respectively, the composition maintained excellent levels of resistance to damp heat, thermo-oxidative aging, and yellowing.

[0071] In Examples 7, 1, 8, and 9, the amounts of calcium acetate used were 0.5 parts, 1 part, 3 parts, and 5 parts, respectively. During the coagulation process, as the amount of calcium acetate added increased, the residual calcium content in the ABS powder increased, and the stability against damp heat and thermo-oxidative aging first increased and then decreased; the stability against yellowing gradually increased. This is because, during the gelation process or Ca... 2+ It promotes the aggregation of emulsion particles, forming a denser granular structure, reducing porosity, thereby slowing down the diffusion of moisture and oxygen, delaying hydrolysis and oxidation reactions, and improving the stability of ABS. This, in turn, improves the moisture and heat resistance, thermo-oxidative aging resistance, and yellowing resistance of compositions containing it. However, its excessive residual calcium content can lead to stress concentration in the composition, resulting in a decrease in its mechanical properties, and thus a decrease in its moisture and heat resistance and thermo-oxidative aging resistance.

[0072] In the coagulation process of Examples 10, 1, and 11, the amounts of sulfuric acid used were 1 part, 2 parts, and 5 parts, respectively. While sulfuric acid and calcium acetate act as gel polymer latex, calcium sulfate precipitates are formed. During the coagulation process, as the amount of sulfuric acid increases, the amount of calcium sulfate precipitate increases, making it easier to be dissolved and washed away by water. The acid residue increases, resulting in a decrease in the residual Ca content and pH value in the ABS powder. Furthermore, the slightly increased residual acid content in the ABS promotes the alcoholysis of PC resin. Therefore, when the amount of sulfuric acid used during the gelation process is too high, the stability of the composition in terms of resistance to damp heat, thermo-oxidative aging, and yellowing decreases.

[0073] In Examples 14, 1, and 15, the number-average molecular weights of PC were 26,000, 32,000, and 39,000, respectively. As the molecular weight of PC increased, the resistance to damp heat first increased and then decreased, the resistance to thermo-oxidative aging gradually increased, and the resistance to yellowing remained basically unchanged. The preferred system of the present invention has a number-average molecular weight of PC in the range of 25,000-40,000, which makes the composition have better resistance to damp heat, thermo-oxidative aging, and yellowing.

[0074] In Examples 16, 1, and 17, the acrylonitrile content in SAN was 18.5%, 25%, and 30%, respectively. As the acrylonitrile content in SAN increased, the stability of the composition in terms of resistance to damp heat aging and resistance to heat and oxygen aging first increased and then decreased. The stability of resistance to yellowing remained basically unchanged at first, but then showed a decreasing trend. Therefore, the acrylonitrile content of SAN in the composition was in the range of 18-30%, which made the composition have better stability in terms of resistance to damp heat aging, resistance to heat and oxygen aging, and resistance to yellowing.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. An ABS adhesive powder, characterized in that, The raw materials for preparing the ABS powder include acrylonitrile, butadiene, and styrene. The Ca content of the ABS powder is 5-500 ppm; the Cl content of the ABS powder is ≤500 ppm; and the pH value of the aqueous solution of the ABS powder is 6.6-6.

9.

2. The ABS adhesive powder as described in claim 1, characterized in that, The ABS powder is obtained by emulsion graft polymerization and coagulation under the action of a coagulant, which includes calcium acetate and sulfuric acid.

3. The ABS adhesive powder as described in claim 1, characterized in that, The average particle size of the ABS powder is 200-500 nm.

4. The ABS adhesive powder as described in claim 1, characterized in that, The ABS powder contains 50%-80% butadiene segments by mass, 2%-20% styrene segments by mass, and 10%-30% acrylonitrile segments by mass.

5. A method for preparing ABS adhesive powder according to any one of claims 1-4, characterized in that, The process includes the following steps: S1. Under an inert gas atmosphere, a solvent, initiator, chain transfer agent, electrolyte, emulsifier, and a portion of a surfactant are mixed, and butadiene is added. A first-stage reaction is carried out under stirring and at a first temperature. The temperature is then raised to a second temperature for a second-stage reaction, and to a third temperature for a third-stage reaction. The remaining surfactant is added and mixed thoroughly to obtain polybutadiene latex. The following relationship is satisfied: First temperature ≤ Second temperature ≤ Third temperature; S2. The polybutadiene latex, styrene, acrylonitrile, solvent, initiator, chain transfer agent, electrolyte, emulsifier, and catalyst are mixed... The agents are mixed and the fourth stage reaction is carried out at the fourth temperature. Then, a surfactant is added to carry out the fifth stage reaction to obtain ABS polymer latex; S3, the ABS polymer latex, coagulant and solvent are mixed and the first stage coagulation is carried out at the fifth temperature. The temperature is raised to the sixth temperature for the second stage coagulation, and the temperature is further raised to the seventh temperature for the third stage coagulation. The temperature is lowered to the eighth temperature for the fourth stage coagulation. After solid-liquid separation, washing and drying, ABS powder is obtained; the following relationship is satisfied: the fifth temperature < the sixth temperature ≤ the seventh temperature, and the seventh temperature > the eighth temperature.

6. The method for preparing ABS adhesive powder as described in claim 5, characterized in that, Includes at least one of the following AK: A. In step S1, the first temperature is 50-60℃, the first stage reaction time is 6-12h, and the first stage reaction is carried out at a stirring rate of 100-110rpm; B. In step S1, the second temperature is 65-75℃, the second stage reaction time is 8-16h, and the second stage reaction is carried out at a stirring rate of 110-125rpm; C. In step S1, the third temperature is 70-80℃, the third stage reaction time is 8-16h, and the third stage reaction is carried out at a stirring rate of 135-145rpm. The reaction is carried out at pm; D. In step S1, based on 100 parts by weight of dry polybutadiene latex, the solvent weighs 80-120 parts, the initiator weighs 0.1-1 parts, the chain transfer agent weighs 0.2-1.2 parts, the electrolyte weighs 0.1-1 parts, the emulsifier weighs 0.1-1 parts, and the total weight of the surfactant is 0.1-1 parts; E. In step S2, the fourth temperature is 50-60℃, the fourth stage reaction time is 1-6 hours, the fifth stage reaction temperature is 50-60℃, and the fifth stage reaction time is 0.5-3 hours; F. In step S3, the fifth temperature is 65-85℃, the coagulation time of the first stage is 2-10 min, and the coagulation pressure of the first stage is 0.01-0.03 MPa; G. In step S3, the sixth temperature is 90-120℃, the coagulation time of the second stage is 5-12 min, the coagulation pressure of the second stage is 0.06-0.1 MPa, and the pH value of the second stage coagulation is 3-8; H. In step S3, the seventh temperature is 90-150℃, and the coagulation time of the third stage is... The coagulation time in the third stage is 5-12 minutes, and the coagulation pressure in the fourth stage is 0.06-0.3 MPa; I. In step S3, the eighth temperature is 90-110℃, the coagulation time in the fourth stage is 5-12 minutes, and the coagulation pressure in the fourth stage is 0.06-0.1 MPa; J. In step S3, the mass ratio of the ABS polymer latex to the coagulant is 100:0.5-4.5; K. In step S3, the coagulant includes calcium acetate and sulfuric acid, and the mass ratio of calcium acetate to sulfuric acid is 1:(0.4-5).

7. A PC / ABS composition, characterized in that, It comprises the following components in parts by weight: 55-95 parts PC, 2-16 parts ABS powder, 3-27 parts SAN, and 0.1-2 parts hindered phenolic antioxidant.

8. The PC / ABS composition as claimed in claim 7, characterized in that, Includes at least one of the following LN: L, the mass ratio of the ABS powder to SAN is 1:(2-5); M, the SAN is a copolymer of acrylonitrile and styrene, and the mass percentage of acrylonitrile is 18%-30% based on the mass of the SAN; N, the number average molecular weight of the PC is 25000-40000.

9. A method for preparing the PC / ABS composition according to any one of claims 1-8, characterized in that, The process includes the following steps: mixing, melting, extruding, and granulating the raw materials in sequence to obtain the PC / ABS composition.

10. The use of the PC / ABS composition according to any one of claims 1-8 in the preparation of electronic appliances, automotive parts, building materials, and daily consumer goods.

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