A high-flowability, high-toughness, high-gloss ABS resin and its preparation method

Abstract

This invention relates to a high-flowability, high-toughness, and high-gloss ABS resin and its preparation method, belonging to the field of synthetic resin technology. The invention involves introducing small-particle-size polystyrene latex as a seed latex during the preparation of EBR latex, constructing an EBR latex with a polystyrene core and a polybutadiene shell. This is followed by the preparation of high-rubber ABS resin powder. SAN resin, additives, and antioxidants are then added and thoroughly mixed before extrusion using a twin-screw extruder at 200–220°C to obtain the aforementioned high-flowability, high-toughness, and high-gloss ABS resin. The increased volume of the polystyrene particles within the rubber particles improves the mechanical properties of the ABS resin. Furthermore, the small-particle-size polystyrene particles melt into molten styrene during ABS resin processing, significantly improving the flowability and deformation capacity of the polybutadiene rubber particles, thus enhancing the flowability and gloss of the ABS resin.

Description

Technical Field

[0001] This invention belongs to the field of synthetic resin technology, specifically relating to a high-flowability, high-toughness, high-gloss ABS resin and its preparation method. Background Technology

[0002] ABS resin (acrylonitrile, butadiene, and styrene terpolymer) is widely used in automobile manufacturing, home appliances, and other fields due to its excellent mechanical properties, solvent resistance, and processing performance. Currently, industrial methods for preparing ABS resin can be divided into two types: continuous bulk method and emulsion blending method. Among these, the emulsion blending method is the most mature and widely applicable technology for preparing ABS resin.

[0003] The emulsion blending method for preparing ABS resin is divided into several units: EBR (polybutadiene latex) preparation, HRG (high-rubber ABS resin powder) preparation, SAN (styrene-acrylonitrile copolymer) preparation, and ABS compounding. ABS resin has a typical island-of-island structure, where the rubber phase (polybutadiene) is the dispersed phase, providing toughening, while SAN resin is the continuous phase, serving as the matrix resin. The properties of ABS resin are related to the properties of both the matrix resin and the dispersed rubber particles. Generally, assuming all components of the ABS resin remain constant, its flowability depends on the molecular weight of the SAN resin. A higher molecular weight SAN resin results in greater flowability but lower impact strength, leading to a fundamental contradiction between flowability and impact resistance. Improving the impact resistance of ABS resin comes at the cost of reduced flowability, and vice versa.

[0004] In practical applications of ABS resin, especially in the electrical and electronic fields, there are requirements for both impact strength and flowability. The industry desires to develop an ABS resin that balances both flowability and impact resistance to meet the processing and usage needs of specific fields. In the preparation of high-flow, high-toughness ABS resin, ABS resin manufacturers often melt-blend a large proportion of high-molecular-weight HRG powder with low-molecular-weight SAN resin, hoping to improve processing flowability with the low-molecular-weight SAN resin and improve toughness with the high-molecular-weight HRG powder. However, this method results in a decrease in the gloss of the ABS resin and a reduction in its thermo-oxidative aging resistance. Another method involves alloying, introducing engineering plastics such as polycarbonate into the ABS resin preparation process. The drawback of this method is that it significantly increases the cost of the ABS resin itself. Therefore, the industry urgently needs a method for preparing ABS resin with high flowability, high toughness, and high gloss. Summary of the Invention

[0005] The purpose of this invention is to provide a high-flowability, high-toughness, and high-gloss ABS resin and its preparation method. The technical content of this invention involves introducing small-particle-size polystyrene latex as a seed latex during the preparation of EBR latex, thereby constructing an EBR latex with a polystyrene core and a polybutadiene shell for subsequent ABS resin preparation. The polystyrene particles inside the rubber particles increase the volume of the rubber phase, which is beneficial for improving the mechanical properties of the ABS resin. Furthermore, the small-particle-size polystyrene particles melt into molten styrene during ABS resin processing, which can significantly improve the flowability and deformation capacity of the polybutadiene rubber particles, thus improving the flowability of the ABS resin. The beneficial effects of this invention are: using polystyrene as a seed in the preparation of EBR latex helps to increase the particle size of the EBR latex, improve the mechanical properties and flowability of the ABS resin, and enhance the gloss of the ABS resin.

[0006] The preparation method of a high-flowability, high-toughness, and high-gloss ABS resin according to the present invention comprises the following steps:

[0007] (1) By mass, place 0.5-5 parts of emulsifier and 0.5-3 parts of pH stabilizer in a reactor, add 50-100 parts of deionized water to dissolve them completely; then add 5-100 parts of styrene monomer, turn on the stirring device, and control the stirring speed at 30-400 rpm; after replacing the air in the reactor with nitrogen, raise the temperature to keep it constant at 55-70℃; then add 0.1-2 parts of initiator to the reactor to initiate the polymerization reaction, and the polymerization reaction time is 1-4 hours.

[0008] (2) Continuously add 50 to 100 parts of butadiene monomer to the reactor of step (1) for 6 to 12 hours; after the butadiene is added, heat the reactor to 72 to 80°C for aging for 2 to 4 hours; after aging, the product is discharged to obtain polybutadiene latex (EBR) with polystyrene core and butadiene shell.

[0009] (3) Take 50-70 parts of polybutadiene latex (EBR) from step (2) and place it in a graft polymerization reactor. Add 0.1-3 parts of redox system and start stirring. Set the stirring speed to 50-400 rpm. After heating to 50-70℃, add 10-30 parts of styrene, 10-30 parts of acrylonitrile and 0.2-1 parts of oxidant to the graft polymerization reactor. The addition time is 1-3 hours. After the addition is completed, heat to 72-80℃ for curing. The curing time is 0.5-1 hours to obtain ABS graft copolymer latex (i.e. HRG latex).

[0010] (4) After the maturation reaction in step (3) is completed, the reactor is cooled to 55-65°C, and 0.5-1 wt% of water-based antioxidant emulsion of HRG latex is added. Stirring is continued for 5-10 minutes to carry out flocculation (i.e., demulsification).

[0011] (5) Add the flocculated product obtained in step (4) to an equal volume of 0.5wt% sulfuric acid at 65-85℃ for demulsification. After demulsification, heat the mixture to 85-95℃ and keep it at that temperature for 5-10 minutes to obtain ABS high-adhesion powder slurry.

[0012] (6) Centrifuge and dehydrate the ABS high-polymer powder slurry obtained in step (5), and then dry it at 65-85℃ to obtain ABS resin high-polymer powder.

[0013] (7) 20-30 parts of ABS resin high-rubber powder, 70-80 parts of SAN resin, 0.3-1 parts of additive vinyl bis-stearamide, 0.1-0.5 parts of antioxidant 1076 and 0.1-0.5 parts of antioxidant 168 are thoroughly mixed and then extruded using a twin-screw extruder at 200-220°C to obtain the high-flowability, high-toughness and high-gloss ABS resin of the present invention.

[0014] The emulsifier used in step (1) of this invention is one or a mixture of several of potassium disproportionate, potassium oleate, and potassium fatty acid.

[0015] The pH stabilizer used in step (1) of this invention is one or a mixture of potassium carbonate, sodium carbonate, potassium bicarbonate, and sodium bicarbonate.

[0016] The initiator used in step (1) of this invention is one of potassium persulfate, sodium persulfate, and ammonium persulfate.

[0017] The redox system added in step (3) of the present invention is a mixture of oxidant cumene hydroperoxide, reducing agent ferrous sulfate, chelating agent sodium pyrophosphate, and co-reducing agent glucose or fructose. The molar ratio of oxidant, reducing agent, chelating agent and co-reducing agent in the redox system is 1:0.001~0.05:0.1~1:0.1~0.6.

[0018] The aqueous antioxidant emulsion added in step (4) of this invention is an aqueous antioxidant emulsion emulsified by compounding hydroquinone dicyclopentadiene and didodecyl thiodipropionate, with an effective solid content of 50%.

[0019] The SAN resin used in step (7) of this invention is produced by Tianjin Dagu Chemical Co., Ltd., and its brand name is AS-103. Detailed Implementation

[0020] Example 1

[0021] (1) By mass, place 2.5 parts of potassium disproportionated rosinate (emulsifier) ​​and 0.8 parts of potassium carbonate (pH stabilizer) into a reactor, and add 60 parts of deionized water to completely dissolve them. Add 50 parts of styrene monomer, turn on the stirrer, and control the stirring speed at 100 rpm. After replacing the air in the reactor with nitrogen, raise the temperature to a constant 60°C. Add 0.5 parts of potassium persulfate (initiator) to the reactor to initiate the polymerization reaction, and the polymerization reaction time is 3 hours.

[0022] (2) Continue to add 50 parts of butadiene monomer to the reactor continuously over a period of 10 hours. After the butadiene is added, heat the reactor to 75°C for curing for 4 hours. After curing, the product is discharged to obtain polybutadiene latex (EBR) with polystyrene core and butadiene shell.

[0023] (3) Place 60 parts of polybutadiene latex (EBR) in a graft polymerization reactor, add 0.8 parts of a redox system, start stirring, set the stirring speed to 100 rpm, and heat to 60°C. Then, add 30 parts of styrene, 10 parts of acrylonitrile, and 0.5 parts of cumene hydrogen peroxide (oxidant) dropwise to the graft polymerization reactor over a period of 2 hours. After the addition is complete, heat to 75°C for curing over a period of 0.5 hours to obtain HRG latex.

[0024] In the redox system, the molar ratio of oxidant cumene hydroperoxide, reducing agent ferrous sulfate, chelating agent sodium pyrophosphate, and co-reducing agent fructose is 1:0.005:0.5:0.3.

[0025] (4) After the aging reaction is completed, the reactor is cooled to 60°C, and 0.5 wt% of HRG latex aqueous antioxidant emulsion is added. Stirring is continued for 5 minutes to carry out flocculation.

[0026] The aqueous antioxidant emulsion is an antioxidant emulsion emulsified by compounding hydroquinone dicyclopentadiene and didodecyl thiodipropionate, with an effective solids content of 50%.

[0027] (5) The flocculated product obtained in step (4) is added to an equal volume of 0.5wt% sulfuric acid at 80°C for demulsification. After demulsification, the temperature is raised to 90°C and kept constant for 5 minutes to obtain ABS resin high-adhesion powder slurry.

[0028] (6) Centrifuge and dehydrate the ABS resin high-adhesion powder slurry, and then dry it in an oven at 65°C to obtain ABS resin high-adhesion powder.

[0029] (7) After thoroughly mixing 25 parts of ABS high-rubber powder, 75 parts of SAN resin, 0.5 parts of additive vinyl bis-stearamide, 0.1 parts of antioxidant 1076 and 0.1 parts of antioxidant 168, the mixture is extruded at 210°C using a twin-screw extruder to obtain the high-flowability, high-toughness and high-gloss ABS resin described in this invention.

[0030] Example 2

[0031] (1) By mass, place 3 parts of potassium oleate (emulsifier) ​​and 1 part of sodium carbonate (pH stabilizer) into a reactor, and add 60 parts of deionized water to completely dissolve them. Add 30 parts of styrene monomer, turn on the stirrer, and control the stirring speed at 200 rpm. After replacing the air in the reactor with nitrogen, raise the temperature and keep it constant at 65°C. Add 0.5 parts of ammonium persulfate (initiator) to the reactor to initiate the polymerization reaction, and the polymerization reaction time is 4 hours.

[0032] (2) Continue to add 70 parts of butadiene monomer to the reactor continuously over a period of 12 hours. After the butadiene is added, heat the reactor to 75°C for curing for 4 hours. After curing, the product can be discharged to obtain polybutadiene latex (EBR) with polystyrene core and butadiene shell.

[0033] (3) Place 60 parts of polybutadiene latex (EBR) in a graft polymerization reactor, add 0.8 parts of a redox system, start stirring, set the stirring speed to 100 rpm, and heat to 65°C. Then, start adding 28 parts of styrene, 12 parts of acrylonitrile, and 0.8 parts of cumene hydrogen peroxide (oxidant) dropwise to the reactor over a period of 2 hours. After the addition is complete, heat to 75°C for curing over a period of 0.5 hours to obtain HRG latex.

[0034] In the redox system, the molar ratio of oxidant cumene hydroperoxide, reducing agent ferrous sulfate, chelating agent sodium pyrophosphate, and co-reducing agent glucose is 1:0.005:0.5:0.3.

[0035] (4) After the aging reaction is completed, the reactor is cooled to 60°C, and 0.5 wt% of HRG latex aqueous antioxidant emulsion is added. Stirring is continued for 5 minutes to carry out flocculation.

[0036] (5) The flocculated product obtained in step (4) is added to an equal volume of 0.5wt% sulfuric acid at 85°C for demulsification. After demulsification, the temperature is raised to 90°C and kept constant for 5 minutes to obtain ABS resin high-adhesion powder slurry.

[0037] (6) Centrifuge and dehydrate the ABS resin high-adhesion powder slurry, and then dry it in an oven at 65°C to obtain ABS resin high-adhesion powder.

[0038] (7) After thoroughly mixing 25 parts of ABS high-rubber powder, 75 parts of SAN resin, 0.5 parts of additive vinyl bis-stearamide, 0.1 parts of antioxidant 1076 and 0.1 parts of antioxidant 168, the mixture is extruded at 200°C using a twin-screw extruder to obtain the high-flowability, high-toughness and high-gloss ABS resin described in this invention.

[0039] Example 3

[0040] (1) By mass, place 1 part potassium oleate emulsifier, 1.5 parts potassium fatty acid emulsifier, and 1.2 parts sodium bicarbonate pH stabilizer into a reactor, and add 60 parts deionized water to completely dissolve them. Add 10 parts styrene monomer, turn on the stirrer, and control the stirring speed at 200 rpm. After replacing the air in the reactor with nitrogen, raise the temperature and keep it constant at 65°C. Add 0.5 parts sodium persulfate initiator to the reactor to initiate the polymerization reaction, and the polymerization reaction time is 4 hours.

[0041] (2) Continue to add 90 parts of butadiene monomer to the reactor continuously over a period of 12 hours. After the butadiene is added, heat the reactor to 75°C for curing for 4 hours. After curing, the product can be discharged to obtain polybutadiene latex (EBR) with polystyrene core and butadiene shell.

[0042] (3) Place 60 parts of polybutadiene latex (EBR) in a graft polymerization reactor, add 0.8 parts of a redox system, start stirring, set the stirring speed to 100 rpm, and heat to 70°C. Then, start adding 30 parts of styrene, 10 parts of acrylonitrile, and 0.6 parts of cumene hydrogen peroxide (oxidant) dropwise to the reactor over a period of 1.5 hours. After the addition is complete, heat to 75°C for curing over a period of 0.5 hours to obtain HRG latex.

[0043] In the redox system, the molar ratio of oxidant cumene hydroperoxide, reducing agent ferrous sulfate, chelating agent sodium pyrophosphate, and co-reducing agent fructose is 1:0.005:0.5:0.3.

[0044] (4) After the aging reaction is completed, the reactor is cooled to 60°C, and 0.5 wt% of HRG latex aqueous antioxidant emulsion is added. Stirring is continued for 10 min for flocculation.

[0045] (5) The flocculated product obtained in step (4) is added to an equal volume of 0.5wt% sulfuric acid at 70°C for demulsification. After demulsification, the temperature is raised to 90°C and kept constant for 5 minutes to obtain ABS resin high-adhesion powder slurry.

[0046] (6) Centrifuge and dehydrate the ABS resin high-adhesion powder slurry, and then dry it in an oven at 65°C to obtain ABS resin high-adhesion powder.

[0047] (7) After thoroughly mixing 25 parts of ABS high-rubber powder, 75 parts of SAN resin, 0.5 parts of additive vinyl bis-stearamide, 0.1 parts of antioxidant 1076 and 0.1 parts of antioxidant 168, the mixture is extruded at 220°C using a twin-screw extruder to obtain the high-flowability, high-toughness and high-gloss ABS resin described in this invention.

[0048] Comparative Example 1

[0049] Replace the styrene in step (1) of Example 1 with butadiene monomer, and the remaining steps are exactly the same, that is:

[0050] (1) By mass, place 2.5 parts of potassium disproportionated rosinate emulsifier and 0.8 parts of potassium carbonate pH stabilizer into a reactor, and add 60 parts of deionized water to completely dissolve them. Add 50 parts of butadiene monomer, turn on the stirring device, and control the stirring speed at 100 rpm. After replacing the air in the reactor with nitrogen, raise the temperature and keep it constant at 60℃. Add 0.5 parts of potassium persulfate initiator to the reactor to initiate the polymerization reaction, and the polymerization reaction time is 3 hours.

[0051] (2) Continue to add 50 parts of butadiene monomer to the reactor continuously over a period of 10 hours. After the butadiene is added, heat the reactor to 75°C for curing for 4 hours. After curing, the product can be discharged to obtain polybutadiene latex (EBR) with polystyrene core and butadiene shell.

[0052] (3) Place 60 parts of polybutadiene latex (EBR) in a graft polymerization reactor, add 0.8 parts of a redox system (the molar ratio of oxidant cumene hydroperoxide, reducing agent ferrous sulfate, chelating agent ferrous sulfate, and co-reducing agent glucose in the redox system is 1:0.005:0.5:0.3), start stirring, set the stirring speed to 100 rpm, and after heating to 60℃, start adding 30 parts of styrene, 10 parts of acrylonitrile, and 0.5 parts of cumene hydroperoxide to the reactor dropwise. The dropwise addition time is 2 hours. After the dropwise addition is complete, heat to 75℃ for curing, and the curing time is 0.5 hours to obtain HRG latex.

[0053] (4) After the aging reaction is completed, the reactor is cooled to 60°C, and 0.5 wt% of HRG latex aqueous antioxidant emulsion is added. Stirring is continued for 5 minutes to carry out flocculation.

[0054] (5) The flocculated product obtained in step (4) is added to an equal volume of 0.5wt% sulfuric acid at 80°C for demulsification. After demulsification, the temperature is raised to 90°C and kept constant for 5 minutes to obtain ABS resin high-adhesion powder slurry.

[0055] (6) Centrifuge and dehydrate the ABS resin high-adhesion powder slurry, and then dry it in an oven at 65°C to obtain ABS resin high-adhesion powder.

[0056] (7) Mix 25 parts of ABS high-rubber powder, 75 parts of SAN resin, 0.5 parts of vinyl bis-stearamide, 0.1 parts of antioxidant 1076, and 0.1 parts of antioxidant 168 thoroughly and then extrude them at 210°C using a twin-screw extruder to obtain ABS resin.

[0057] Table 1: Product performance data of the examples and comparative examples

[0058]

[0059] The ABS resins obtained in Examples 1-3 and Comparative Example 1 were prepared into standard test strips. The impact strength and tensile properties of the ABS resins were tested according to ASTM-D256 and ASTM-D638 standards, the flow properties of the ABS resins were tested according to ASTM D1238 (220℃, 10Kg) standard, and the gloss of the ABS resins was tested according to ASTM D523 standard. The results are shown in Table 1.

[0060] As can be seen from the table above, introducing polystyrene as the core of EBR rubber particles during the EBR preparation process can effectively improve the flowability and gloss of ABS resin without reducing the impact strength of ABS resin. The impact strength in Examples 1-3 is greater than that in the comparative example, proving that the ABS resin prepared by this invention has high toughness.

Claims

1. A method for preparing high flowability, high toughness, high gloss ABS resin, comprising the following steps: (1) 0.5-5 parts by mass of emulsifier and 0.5-3 parts by mass of pH stabilizer were placed in a reaction kettle, and 50-100 parts of deionized water was added to make it completely dissolved; adding 5-100 parts of styrene monomer, starting the stirring device, and controlling the stirring rate at 30-400 rpm; replacing the air in the reaction kettle with nitrogen, and then increasing the temperature to maintain a constant temperature of 55-70℃; then adding 0.1-2 parts of initiator to the reaction kettle to initiate the polymerization reaction, and the polymerization reaction time is 1-4 hours; (2) continuously adding 50-100 parts of butadiene monomer to the reaction kettle of step (1) in 6-12 hours; after the addition of butadiene is completed, the reaction kettle is heated to 72-80℃ for curing, and the curing time is 2-4 hours; after the curing is completed, the product is discharged to obtain a polybutadiene latex with polystyrene as the core and butadiene as the shell; (3) taking 50-70 parts of the polybutadiene latex of step (2) into a graft polymerization reaction kettle, adding 0.1-3 parts of an oxidation-reduction system, starting stirring, and setting the stirring rate at 50-400 rpm; after heating to 50-70℃, adding 10-30 parts of styrene, 10-30 parts of acrylonitrile, and 0.2-1 parts of an oxidizing agent dropwise into the graft polymerization reaction kettle, the dropwise adding time is 1-3 hours, after the dropwise adding is completed, heating to 72-80℃ for curing, and the curing time is 0.5-1 hour, to obtain an ABS graft copolymer latex, i.e. HRG latex; (4) after the curing reaction of step (3) is completed, the graft polymerization reaction kettle is cooled to 55-65℃, and 0.5-1 parts of water-based antioxidant emulsion of the HRG latex is added, and stirring is continued for 5-10 min for flocculation; (5) adding the flocculated product obtained in step (4) into an equal volume of 0.5wt% sulfuric acid at 65-85℃ for demulsification, heating to 85-95℃ for constant temperature for 5-10 min after demulsification, to obtain ABS resin high glue powder slurry; (6) centrifugal dewatering the ABS high glue powder slurry obtained in step (5), and then drying at 65-85℃ to obtain ABS resin high glue powder; (7) uniformly mixing 20-30 parts of the ABS resin high glue powder obtained in step (6), 70-80 parts of SAN resin, 0.3-1 parts of vinyl bis-stearamide, 0.1-0.5 parts of antioxidant 1076, and 0.1-0.5 parts of antioxidant 168, and then extruding with a twin-screw extruder at 200-220℃ to obtain high flowability, high toughness, and high gloss ABS resin.

2. The process for the preparation of high flow, high impact, high gloss ABS resin as claimed in claim 1, wherein: The emulsifier used in step (1) is one or a mixture of several of disulfated rosin acid potassium, potassium oleate, and potassium fatty acid.

3. The method for preparing a high-flowability, high-toughness, and high-gloss ABS resin as described in claim 1, characterized in that: The pH stabilizer used in step (1) is one or a mixture of several of potassium carbonate, sodium carbonate, potassium bicarbonate, and sodium bicarbonate.

4. The process for the preparation of high flow, high impact, high gloss ABS resin as claimed in claim 1, wherein the said process is characterized by: The initiator used in step (1) is one of potassium persulfate, sodium persulfate, and ammonium persulfate.

5. The process for the preparation of high flow, high impact, high gloss ABS resin as claimed in claim 1, wherein the said process is characterized by: The redox system added in step (3) is a mixture of oxidant cumene hydroperoxide, reducing agent ferrous sulfate, chelating agent sodium pyrophosphate, and co-reducing agent glucose or fructose, and the molar ratio of the oxidant, reducing agent, chelating agent, and co-reducing agent is 1:0.001-0.05:0.1-1:0.1-0.

6.

6. The process for preparing a high flow, high impact, high gloss ABS resin as claimed in claim 1, wherein: The aqueous antioxidant emulsion added in step (4) is an aqueous antioxidant emulsion obtained by emulsifying a mixture of hydroquinone dicyclopentadiene and dodecyl thiodipropionate, and the effective solid content is 50%.

7. A high flow, high toughness, high gloss ABS resin characterized in that: is prepared by the method of any one of claims 1-6.

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