CN-121975293-A - High-temperature-resistant flame-retardant plastic pellet and preparation method thereof

CN121975293ACN 121975293 ACN121975293 ACN 121975293ACN-121975293-A

Abstract

The invention provides a high-temperature-resistant flame-retardant plastic particle and a preparation method thereof, and belongs to the field of high-molecular organic compounds. The modified halloysite nano tube comprises the following components of polycarbonate, acrylonitrile-butadiene-styrene copolymer resin, microcapsule ammonium polyphosphate, a carbon source, a modified halloysite nano tube, a toughening agent, an antioxidant, a lubricant and an anti-dripping agent, wherein the modified halloysite nano tube is obtained by grafting a halloysite nano tube through a coupling agent with an epoxy group. The composite material provided by the scheme aims to meet the dual requirements of daily use scenes (especially household appliances) on flame-retardant safety and structural reliability of the material. The stable and compact expanded carbon layer can be formed during combustion in the aspect of flame retardance, so that heat and oxygen are effectively isolated, UL94V-0 flame retardance is realized, and smoke density is remarkably reduced. The mechanical properties of the composite material keep good impact strength, rigidity and dimensional stability, and the composite material meets the assembly and use requirements of the household appliance shell and internal structural parts.

Inventors

LIN WEIWEN
LI LI
LI XIAOYONG
MIAO YONG

Assignees

广东长新塑创新材料有限公司

Dates

Publication Date: 20260505
Application Date: 20260227

Claims (9)

1. The high-temperature-resistant flame-retardant plastic pellet is characterized by comprising the following components in parts by mass: 40-50 parts of polycarbonate Acrylonitrile-butadiene-styrene copolymer resin 20-25 Microcapsule ammonium polyphosphate 13-22 Carbon sources 5-6 Modified halloysite nanotube 3-5 Toughening agent 3-4 Antioxidant 0.3-0.5 Lubricant 0.5-1.0 0.2 To 0.5 of anti-dripping agent; the modified halloysite nanotube is obtained by grafting a halloysite nanotube through a coupling agent with an epoxy group, and the use amount of the coupling agent is at least 3% of the mass of the halloysite nanotube.
2. The high temperature resistant flame retardant plastic pellet as defined in claim 1, wherein said toughening agent is a high molecular polymer having a flexible elastomer segment and containing a reactive group which chemically reacts with a terminal functional group of polycarbonate.
3. The high temperature resistant flame retardant plastic pellet as claimed in claim 1, wherein the melt volume flow rate of the polycarbonate is 8-12 cm3/10min, the butadiene content of the acrylonitrile-butadiene-styrene copolymer resin is 12-20wt%, and the polymerization degree n of the microcapsule ammonium polyphosphate is more than or equal to 1000.
4. The high temperature resistant flame retardant plastic pellet of claim 1, wherein the carbon source is a polyol and derivatives thereof.
5. The high temperature resistant flame retardant plastic pellet of claim 1, wherein the method for preparing the modified halloysite nanotubes comprises the steps of: s1, dissolving a coupling agent with an epoxy group in an ethanol water solvent, regulating the pH of the system to 4-5, and stirring to obtain a hydrolysis coupling agent solution; S2, dispersing the dried halloysite nanotubes in a hydrolysis coupling agent solution, heating to 80-85 ℃, stirring and reacting for at least 6 hours, centrifuging the system solution after the reaction is finished, separating the precipitate, washing the precipitate with ethanol, and drying to obtain modified halloysite nanotubes; The use amount of the coupling agent is 3-5% of the mass of the halloysite nanotube.
6. The high temperature resistant flame retardant plastic pellet of claim 1, wherein the antioxidant is a combination of hindered phenolic antioxidants and phosphite antioxidants, and the anti-drip agent is polytetrafluoroethylene.
7. The high temperature resistant flame retardant plastic pellet of claim 1, wherein the modified halloysite nanotube is first melt blended with a portion of the toughening agent during preparation to undergo a secondary grafting chain extension reaction to produce a secondary grafting modified halloysite nanotube.
8. The method for preparing the high-temperature resistant flame retardant plastic granules as claimed in any one of claims 1 to 7, which is characterized by comprising the following steps: S1, dispersing dry halloysite nanotubes in hydrolyzed coupling solution with epoxy groups for coupling reaction, separating and taking solid matters after the reaction is finished, and drying to obtain modified halloysite nanotubes; s2, carrying out melt blending secondary grafting reaction on the modified halloysite nanotube and the toughening agent to obtain a secondary grafted modified halloysite nanotube; s3, mixing the secondary grafted modified halloysite nanotube with the rest components to obtain a premix; and S4, carrying out premix melting reaction blending, extruding, cooling and granulating to obtain the high-temperature-resistant flame-retardant plastic granules.
9. The method for preparing high temperature resistant flame retardant plastic pellets according to claim 8, wherein the reaction temperature of the melt blending secondary grafting reaction in the step S2 is 160-170 ℃, and the melting section temperature of the premix melt reaction blending in the step S4 is 240-260 ℃.

Description

High-temperature-resistant flame-retardant plastic pellet and preparation method thereof Technical Field The invention belongs to the field of high molecular organic compounds, and particularly relates to a high-temperature-resistant flame-retardant plastic particle and a preparation method thereof. Background The application of the flame-retardant plastic is a key material science technology in the field of household appliances, and the core aim is to actively prevent fire risks through the characteristics of the material on the premise of ensuring the function and cost controllability of the product, so as to meet the increasingly strict safety regulations and environmental protection requirements. The working environment of household appliances puts complex and severe comprehensive performance requirements on plastics. The primary and most mandatory requirement is flame retardant safety, which is generally evaluated according to UL 94 standards. For most plastic parts that directly contact or are adjacent to electrically charged components, such as housings, internal supports, connectors, etc., it is often desirable to achieve the highest V-0 rating, i.e., in vertical burn testing, the sample self-extinguishes within 10 seconds after removal of the fire source and does not produce a burning drip that ignites the underlying cotton pad. In addition, for the scenario that the overheat source may be generated due to the fault such as overload, bad contact, etc., such as the switch socket, the peripheral parts of the motor, the effect that the overheat element contacts the material is simulated by the test of the glow wire such as the test specified in IEC 60695-2-11, the material is required to be not ignited or flame is required to be extinguished briefly and within a prescribed time when the material contacts a specific high temperature glow wire (such as 750 ℃ or 850 ℃). In addition to the direct flame retardant properties, plastics for electrical applications must meet the multi-dimensional requirements of long-term reliability. In terms of thermal properties, the material should have a sufficiently high heat distortion temperature and relative temperature index to ensure that the part does not deform, soften or otherwise degrade under the temperature rise and seasonal environmental temperature fluctuations that occur during long-term operation of the appliance. Sufficient impact strength, tensile and flexural strength are maintained in mechanical properties to withstand the assembly stresses, accidental dropping and vibrations and loads from internal operation. In the electric safety level, the comparative tracking index of the material for supporting or insulating the charged component is a key index, the tracking resistance of the surface of the material under the action of an electric field and possible pollutants is measured, and the high CTI value can effectively prevent the electric leakage from firing. In recent years, environmental regulations have become an important force to drive the development of materials. Global RoHS directives, market and consumer expectations for environmental protection, are strongly driving the non-halogenation process. The traditional halogen-containing flame retardant can generate a large amount of smoke and corrosive toxic gas during combustion, so the development of halogen-free flame retardant plastic with low smoke amount and less toxic gas release during combustion has become the mainstream direction of industry. In order to meet the above comprehensive performance requirements, the technical scheme of flame retardant plastics is continuously developed and forms a system. The development and application of the flame retardant are at the core in the material chemistry level. The current mainstream halogen-free schemes include phosphorus, nitrogen and inorganic hydroxide systems. Phosphorus flame retardants (such as various organic phosphates and phosphates) are often used as flame retardant plasticizers for engineering plastics, and can play roles in both gas phase and condensed phase, so that the surface of the material is promoted to form carbon to isolate heat and oxygen, and the gas phase combustion reaction can be possibly interfered. Nitrogen-based flame retardants (such as melamine and its derivatives) produce large amounts of non-combustible gases, dilute oxygen and combustible concentrations, and assist in char formation, primarily by endothermic decomposition. Inorganic hydroxides, particularly aluminum hydroxide and magnesium hydroxide, depend on the endothermic decomposition reaction under high filling amount (more than 50% is usually needed to be added), reduce the surface temperature of the material and release steam to dilute the combustible gas, and the inorganic hydroxides are nontoxic and have remarkable smoke suppression effect, but have great influence on the mechanical property and processing fluidity of the material, and the compatibility o