Flame-retardant ABS (acrylonitrile-butadiene-styrene) and preparation method thereof
By compounding aluminum hypophosphite with boron phenolic resin and using supercritical CO2 dispersion technology, the problems of environmental pollution and uneven dispersion when improving the flame retardant performance of ABS resin were solved, and a highly efficient halogen-free flame retardant ABS resin with excellent mechanical properties and processing performance was achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-13
- Publication Date
- 2026-03-10
AI Technical Summary
Improving the flame retardant properties of existing ABS resins often comes at the cost of sacrificing mechanical and processing properties, and traditional flame retardants suffer from environmental pollution and uneven dispersion.
Aluminum hypophosphite and boron phenolic resin were combined as flame retardants, and flame-retardant ABS was prepared by supercritical CO2-assisted dispersion process to ensure uniform dispersion of the flame retardant in ABS resin and high flame retardant effect with low addition amount.
It achieves high-efficiency halogen-free flame retardancy, maintains the mechanical and processing properties of ABS resin, and reduces melt viscosity, improving product surface quality and batch consistency.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of polymer material preparation technology, and specifically discloses a flame-retardant ABS and its preparation method. Background Technology
[0002] ABS resin (acrylonitrile-butadiene-styrene copolymer) is widely used in electronic and electrical housings, automotive interior parts, and other fields due to its excellent mechanical strength, processing performance, and surface gloss. However, the limiting oxygen index (LOI) of pure ABS resin is only 18%, classifying it as a flammable material, which severely limits its application in scenarios with stringent fire protection requirements. Currently, the industry mainly employs three types of flame-retardant technologies: (1) Halogenated flame retardant systems: represented by decabromodiphenyl ether (DBDPO), combined with antimony trioxide synergists, can increase the LOI to over 28%. However, this system produces a large amount of bromine-containing toxic gases (such as HBr) during combustion, and the bromides remaining in the product will continue to release endocrine disruptors. The EU RoHS directive has explicitly restricted the use of polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs).
[0003] (2) Phosphorus-nitrogen flame retardant system: This includes a compound system of inorganic phosphorus compounds such as red phosphorus and ammonium polyphosphate (APP) with melamine derivatives. Although the environmental friendliness has been improved, in order to achieve the UL94 V-0 rating (1.6mm thickness), it is usually necessary to add 20-30wt% flame retardant, which results in a decrease in material impact strength of more than 50% and a fluctuation in melt flow rate (MFR) of ±40%.
[0004] (3) Nanocomposite flame retardant technology: Nanomaterials such as layered silicates (e.g., montmorillonite) or carbon nanotubes are used to reduce the combustion rate through physical barrier effects. However, nanoparticles are prone to agglomeration in the matrix, which not only affects the stability of flame retardant efficiency but also causes "silver streaks" defects on the surface of injection molded products. In addition, the addition of nanofillers increases the melt viscosity, resulting in an increase of 15-20% in processing energy consumption.
[0005] The core contradiction facing existing technologies is that improving flame retardant properties often comes at the cost of sacrificing mechanical and processing properties.
[0006] Therefore, developing ABS resins that combine high flame retardancy, excellent mechanical properties, and good processing stability has become an urgent problem to be solved in the industry. Summary of the Invention
[0007] The purpose of this invention is to address the environmental pollution and bioaccumulation risks associated with halogenated flame retardants, the deterioration of material toughness and unstable melt flow when the amount of halogen-free flame retardant added is too high (>25wt%), and the uneven dispersion of nano-flame retardant systems affecting batch consistency and surface quality. The invention provides a flame-retardant ABS and its preparation method.
[0008] The technical solution adopted in this invention is as follows: In a first aspect, the present invention provides a method for preparing flame-retardant ABS, comprising the following steps: S1. Preparation of modified flame retardant: The flame retardant is mixed with 0.1%-0.5% of a silane coupling agent by mass to obtain the modified flame retardant; The flame retardant is a compound of aluminum hypophosphite (AHP) and boron phenolic resin (BFR) in a mass ratio of 2.5:1 to 3.5:1. S2. Preparation of rubber solution: By mass, 8.0 parts of rubber, 15.0~20.0 parts of acrylonitrile, 52~58 parts of styrene, 2.5~5 parts of phosphorus-containing acrylate monomer and 15 parts of rubber solvent are mixed, dissolved and filtered to obtain rubber solution. S3. Synthesis of ABS matrix resin: The rubber solution obtained in step S2 is placed in a reaction vessel and polymerized under stirring conditions of 100~170℃ and 40~90 rpm to obtain ABS resin containing phosphorus acrylate. S4. Preparation of flame-retardant ABS: 15-25 parts by weight of the modified flame retardant obtained in step S1 are mixed with 75-85 parts by weight of the ABS resin obtained in step S3, and then melt-blended and extruded using a supercritical extraction process to obtain the flame-retardant ABS.
[0009] Preferably, the flame retardant is a compound of aluminum hypophosphite (AHP) and boron phenolic resin (BFR) in a mass ratio of 3:1.
[0010] Preferably, in step S2, the rubber is polybutadiene rubber.
[0011] Furthermore, the Mooney viscosity of the polybutadiene rubber is 55~65 ML(1+4)100℃, and the viscosity of the styrene solution is 800~1000 cps.
[0012] Preferably, the rubber solvent is ethylbenzene, toluene, or xylene.
[0013] Preferably, the silane coupling agent is γ-aminopropyltriethoxysilane (KH-550).
[0014] Preferably, the phosphorus-containing acrylate monomer is selected from one or more of dihydrophosphate acrylate, triacrylate phosphite, and aminophosphate acrylate.
[0015] Preferably, in step S4, the specific operation is as follows: the material is fed to a twin-screw extruder, the extrusion temperature is 170~220℃, and the material is melt-blended and extruded under the conditions of screw speed of 200~220 rpm and supercritical CO2 for auxiliary dispersion.
[0016] Furthermore, in step S4, the process parameters for the supercritical CO2 are: pressure 14-18 MPa, temperature 45-60℃.
[0017] In a second aspect, the present invention provides a flame-retardant ABS prepared by the method described in the first aspect.
[0018] In flame-retardant ABS, the particle size distribution D90 of the flame retardant is less than 2 μm.
[0019] The beneficial effects achieved by this invention are as follows: First, it has high flame retardant efficiency and is environmentally friendly: through the synergistic effect of reactive phosphorus and AHP / BFR composite system, it achieves high efficiency and halogen-free flame retardancy with a low addition amount (8-15%).
[0020] Secondly, it maintains good mechanical properties: the introduction of reactive phosphorus monomers and the interfacial modification of silane coupling agents greatly reduce the damage of flame retardants to the continuous phase of the matrix, thereby maintaining the high toughness of the matrix resin.
[0021] Third, it has excellent processing performance: the supercritical CO2-assisted dispersion process ensures the ultrafine and uniform dispersion of the flame retardant, reduces the melt viscosity, makes the processing smoother, and results in high product surface quality.
[0022] Fourth, it has excellent overall performance: The data from the examples show that the product of this invention has balanced performance indicators, meets the UL94V-0 (1.6mm) standard and has LOI≥30%; maintains the original impact strength (≥22kJ / m²) and flow properties (MFR≥12g / 10min) of ABS; and has low odor (odor level <3.5) and low VOC (monomer content <500ppm). Detailed Implementation
[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the following embodiments.
[0024] It should be noted that the present invention is not limited to the following embodiments. Unless otherwise specified, all methods described are conventional methods. Unless otherwise specified, all raw materials are available from publicly available commercial sources.
[0025] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.
[0026] Example 1 Weigh 1 kg of flame retardant and place it in a high-speed mixer. Then, weigh out 0.1% (by weight of the flame retardant) of silane coupling agent KH-550 and add it to the mixer. Turn on the high-speed mixer and mix thoroughly for 1 minute before discharging. This process yields the modified flame retardant. The flame retardant is a blend of AHP and BFR in a mass ratio of 3:1.
[0027] Weigh out 8.0% rubber, 18.0% acrylonitrile, 54% styrene, 5% dihydroacrylate phosphate, and 15% ethylbenzene according to the specified mass ratio, and add them together to a rubber dissolving tank. Dissolve the rubber at 10°C for 8 hours, then filter to obtain a rubber solution. The rubber is polybutadiene rubber with a Mooney viscosity of 55~65 mL (1+4) at 100°C, and the styrene solution viscosity is 800~1000 cps.
[0028] The prepared rubber slurry was transferred to a 5L transparent reactor, the reaction temperature was set at 102.5℃, the stirring speed was controlled at 40rpm, and the reaction was carried out for 8 hours to finally obtain ABS resin containing dihydrogen phosphate acrylate.
[0029] 15% by weight of the modified flame retardant and 85% by weight of the phosphorus-containing acrylate ABS resin were thoroughly mixed in a high-speed mixer, and then the mixture was fed into a twin-screw extruder. The extruder was divided into multiple zones with temperatures of 180 / 190 / 200 / 205 / 205 / 205 / 205 / 200 / 195 / 190℃. Under conditions of a screw speed of 200 rpm and a frequency of 6 Hz, halogen-free flame-retardant ABS resin was prepared using a supercritical CO2-assisted dispersion process. The supercritical CO2 process parameters were: pressure 16 MPa and temperature 50℃.
[0030] Example 2 The conditions not explicitly mentioned in Examples 2-5 and Comparative Examples 1-3 below are the same as in Example 1.
[0031] Weigh 1 kg of flame retardant and place it in a high-speed mixer. Then, weigh out 0.2% (by weight of the flame retardant) of silane coupling agent and add it to the mixer. Turn on the high-speed mixer and mix thoroughly for 1 minute before discharging. This process yields the modified flame retardant.
[0032] Weigh out 8.0% rubber, 18.2% acrylonitrile, 54.5% styrene, 4.3% triacrylate phosphite, and 15% ethylbenzene according to the specified proportions, and add them together to a rubber dissolving tank. After dissolving at 10°C for 8 hours, filter the solution to obtain the rubber latex.
[0033] The prepared rubber slurry was transferred to a 5L transparent reactor, the reaction temperature was set at 120℃, the stirring speed was controlled at 50rpm, and the reaction was carried out for 8 hours to finally obtain ABS resin containing triacrylate phosphite.
[0034] 20% of the modified flame retardant and 80% of the phosphorus-containing acrylate ABS resin were thoroughly mixed in a high-speed mixer, and then the mixture was fed into a twin-screw extruder. Halogen-free flame-retardant ABS resin was prepared using a supercritical CO2-assisted dispersion process at a screw speed of 210 rpm and a frequency of 7 Hz.
[0035] Example 3 Weigh 1 kg of flame retardant and place it in a high-speed mixer. Then weigh 0.3% (by weight of the flame retardant) of silane coupling agent and add it to the mixer. Turn on the high-speed mixer and mix thoroughly for 1 minute before discharging. This process yields the modified flame retardant.
[0036] Weigh out 8.0% rubber, 18.3% acrylonitrile, 55% styrene, 3.7% aminophosphate acrylate, and 15% ethylbenzene according to the specified proportions, and add them together to a rubber dissolving tank. After dissolving at 10°C for 8 hours, filter the solution to obtain the rubber latex.
[0037] The prepared rubber slurry was transferred to a 5L transparent reactor, the reaction temperature was set at 130.4℃, the stirring speed was controlled at 60rpm, and the reaction was carried out for 8 hours under these conditions to finally obtain ABS resin containing amino phosphate acrylate.
[0038] 25% of the modified flame retardant and 75% of the phosphorus-containing acrylate ABS resin were thoroughly mixed in a high-speed mixer, and then the mixture was fed into a twin-screw extruder. Halogen-free flame-retardant ABS resin was prepared using a supercritical CO2-assisted dispersion process at a screw speed of 220 rpm and a frequency of 8 Hz.
[0039] Example 4 Weigh 1 kg of flame retardant and place it in a high-speed mixer. Then, weigh out 0.4% (by weight of the flame retardant) of silane coupling agent and add it to the mixer. Turn on the high-speed mixer and mix thoroughly for 1 minute before discharging. This process yields the modified flame retardant.
[0040] Weigh out 8.0% rubber, 18.4% acrylonitrile, 55.5% styrene, 3.1% dihydrogen acrylate phosphate, and 15% ethylbenzene according to the specified proportions, and add them together to a rubber dissolving tank. After dissolving at 10°C for 8 hours, filter the solution to obtain the rubber latex.
[0041] The prepared rubber slurry was transferred to a 5L transparent reactor, the reaction temperature was set at 148.2℃, the stirring speed was controlled at 75rpm, and the reaction was carried out for 8 hours under these conditions to finally obtain ABS resin containing dihydrogen phosphate acrylate.
[0042] 18% of the modified flame retardant and 82% of the phosphorus-containing acrylate ABS resin were thoroughly mixed in a high-speed mixer, and then the mixture was fed into a twin-screw extruder. Halogen-free flame-retardant ABS resin was prepared using a supercritical CO2-assisted dispersion process at a screw speed of 200 rpm and a frequency of 6 Hz.
[0043] Example 5 Weigh 1 kg of flame retardant and place it in a high-speed mixer. Then, weigh out 0.5% (by weight of the flame retardant) of silane coupling agent and add it to the mixer. Turn on the high-speed mixer and mix thoroughly for 1 minute before discharging. This process yields the modified flame retardant.
[0044] Weigh out 8.0% rubber, 18.5% acrylonitrile, 55.5% styrene, 1.5% dihydrogen acrylate phosphate, 1.5% triacrylate phosphite, and 15% ethylbenzene according to the specified proportions, and add them together to a rubber dissolving tank. Dissolve the mixture continuously at 10°C for 8 hours, then filter to obtain the rubber solution.
[0045] The prepared rubber slurry was placed in a 5L transparent reactor, the reaction temperature was set at 165.2℃, the stirring speed was controlled at 90rpm, and the reaction was carried out for 8 hours under these conditions to finally obtain ABS resin of dihydrogen phosphate and triacrylate phosphite.
[0046] 20% of the modified flame retardant and 80% of the phosphorus-containing acrylate ABS resin were thoroughly mixed in a high-speed mixer, and then the mixture was fed into a twin-screw extruder. Halogen-free flame-retardant ABS resin was prepared using a supercritical CO2-assisted dispersion process at a screw speed of 220 rpm and a frequency of 8 Hz.
[0047] Comparative Example 1 Weigh 1 kg of halogen-free intumescent flame retardant and place it in a high-speed mixer. Then, weigh out 0.3% (by weight of the flame retardant) of silane coupling agent and add it to the mixer. Turn on the high-speed mixer and mix thoroughly for 1 minute before discharging. This process yields the modified flame retardant.
[0048] Weigh out 8.0% rubber, 18.3% acrylonitrile, 58.7% styrene, and 15% ethylbenzene according to the specified proportions, and add them together to a rubber dissolving tank. After dissolving at 10°C for 8 hours, filter the solution to obtain a rubber latex.
[0049] The prepared rubber slurry was transferred to a 5L transparent reactor, the reaction temperature was set at 130.4℃, the stirring speed was controlled at 60rpm, and the reaction was carried out for 8 hours to finally obtain ABS resin.
[0050] 25% of the modified flame retardant and 75% of the ABS resin were thoroughly mixed in a high-speed mixer, and then the mixture was fed into a twin-screw extruder. Halogen-free flame-retardant ABS resin was prepared using a supercritical CO2-assisted dispersion process at a screw speed of 220 rpm and a frequency of 8 Hz.
[0051] Comparative Example 2 The ratio of flame retardant AHP / BFR was adjusted to 4:1, and other conditions were the same as in Example 1, to complete the preparation of halogen-free flame-retardant ABS resin.
[0052] Comparative Example 3 Without using supercritical extraction, and with other conditions the same as in Example 1, halogen-free flame-retardant ABS resin was prepared.
[0053] Test Results The performance of the samples from Examples 1-6 and Comparative Examples 1-2 was tested, and the results are shown in Table 1: The impact performance of simply supported beams with notched beams was tested according to GB / T 1043.1-2008.
[0054] The melt mass flow rate (MFR) was tested according to GB / T 3682.1-2018, under the conditions of 220℃ and 10kg. Limiting oxygen index was tested according to ASTM D2863; Flame retardancy rating is tested according to UL94.
[0055] Odor was tested according to PV3900 standard; VOCs were tested according to the PV3341 standard.
[0056] Table 1 Comparison of test results for the examples and comparative products
[0057] The above description is a further explanation of the present invention, and is not intended to limit the scope of the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A process for the preparation of flame-retardant ABS, characterized in that, The method comprises the following steps: S1. Preparation of modified flame retardant: mixing flame retardant with 0.1%-0.5% silane coupling agent by mass of the flame retardant to obtain modified flame retardant; The flame retardant is prepared by compounding aluminum hypophosphite AHP and boron phenolic resin BFR at a mass ratio of 2.5:1-3.5:
1. S2. Preparation of rubber solution: mixing 8.0 parts by mass of rubber, 15.0-20.0 parts by mass of acrylonitrile, 52-58 parts by mass of styrene, 2.5-5 parts by mass of phosphorus-containing acrylate monomer and 15 parts by mass of rubber solvent, dissolving and filtering to obtain rubber solution; S3. Synthesis of ABS base resin: placing the rubber solution obtained in step S2 in a reaction kettle, and performing polymerization reaction at 100-170℃ and 40-90 rpm to obtain ABS resin containing phosphorus-containing acrylate; S4. Preparation of flame-retardant ABS: mixing 15-25 parts by mass of the modified flame retardant obtained in step S1 with 75-85 parts by mass of the ABS resin obtained in step S3, and then melt blending and extruding by supercritical extraction process to obtain the flame-retardant ABS.
2. The process for the preparation of flame retardant ABS according to claim 1, characterized in that, The flame retardant is prepared by compounding aluminum hypophosphite AHP and boron phenolic resin BFR at a mass ratio of 3:
1.
3. The process for the preparation of flame retardant ABS according to claim 1, characterized in that, In step S2, the rubber is polybutadiene rubber.
4. The process for the preparation of flame retardant ABS according to claim 3, characterized in that, The polybutadiene rubber has a Mooney viscosity of 55-65 ML (1+4) 100℃ and a styrene solution viscosity of 800-1000 cps.
5. The process for the preparation of flame retardant ABS as claimed in claim 1, wherein, The rubber solvent is ethylbenzene, toluene or xylene.
6. The process for preparing flame retardant ABS as claimed in claim 1, wherein, The silane coupling agent is γ-aminopropyl triethoxysilane (KH-550), γ-(2,3-epoxypropoxy) propyl trimethoxysilane (KH-560) or γ-(methacryloyloxy) propyl trimethoxysilane (KH-570).
7. The process for preparing flame retardant ABS as claimed in claim 1, wherein, The phosphorus-containing acrylate monomer is selected from one or more of dihydrogen acrylate phosphate, triacrylate phosphite and aminophosphate acrylate.
8. The process for the preparation of flame retardant ABS as claimed in claim 1 wherein, In step S4, the specific operation is: conveying to a twin-screw extruder, melt blending and extruding under the condition of screw rotation speed of 200-220 rpm and auxiliary dispersion by supercritical CO2.
9. The process for the preparation of flame retardant ABS according to claim 8, characterized in that, In step S4, the process parameters of the supercritical CO2 are: pressure 14-18 MPa and temperature 45-60℃.
10. Flame-retardant ABS prepared by the method of any one of claims 1-9.