Equivalent to Exolit AP422

As an equivalent alternative to the original Exolit AP422, Equivalent to Exolit AP422 has basically the same core flame retardant properties and performs well in polyamide materials. Both are phosphorus-based flame retardants with similar flame retardant mechanisms. They can decompose to form polyphosphates at high temperatures, forming a carbon layer on the surface of the material to isolate oxygen and heat and inhibit the spread of combustion. According to tests, when 25% of Equivalent to Exolit AP422 is added to polyamide 6, the oxygen index can reach 32, which is close to the oxygen index (32.5) of the original Exolit AP422 added in the same proportion. The vertical burning test can reach UL94 V-0 level, and the difference in the afterburning time does not exceed 1 second. In the application of polyamide materials, Equivalent to Exolit AP422 has slightly better processing fluidity. During injection molding of polyamide 66, the melt flow rate is 25g/10min (the original product is 23g/10min), which makes the product surface smoother and is especially suitable for polyamide parts with complex structures, such as automotive connectors. It has good compatibility with polyamide. Scanning electron microscopy shows that the dispersed particle size is uniform and there is no obvious agglomeration. The decline in the mechanical properties of the product is comparable to that of the original product, with a tensile strength retention rate of about 85% and an impact strength retention rate of about 80%. In the long-term heat aging test, after being placed at 120°C for 1000 hours, Equivalent to Exolit AP422 can still maintain stable flame retardant properties, and the vertical burning rating of polyamide products has not decreased, while the original product performs the same under the same conditions. In addition, it has excellent hydrolysis resistance in polyamide. After boiling in water for 24 hours, the amount of flame retardant precipitation is only 0.3%, which is the same as the original product, ensuring that the material can still be reliably flame retardant in a humid environment. In general, Equivalent to Exolit AP422 can effectively replace the original product for polyamide materials, meeting the flame retardant and performance requirements.

The preparation process of Equivalent to Exolit AP422 is similar to that of the original Exolit AP422, but it has been optimized in details, and the product quality is guaranteed to be stable by strictly controlling the key links. Both are made of phosphate and amine compounds as raw materials and are prepared by condensation reaction, but Equivalent to Exolit AP422 uses a continuous reaction device to replace the intermittent reaction of the original product, so that the reaction temperature fluctuation is controlled within ±2℃ (the original product is ±5℃), and the purity difference between product batches is reduced to within 0.5%. In the purification process, Equivalent to Exolit AP422 adopts a two-stage crystallization process. The purity reaches 95% after the first crystallization and 99% after the second crystallization, which is equivalent to the purification effect of the original product, but the energy consumption is reduced by 10%. The drying process uses vacuum freeze drying to avoid local overheating that may be caused by hot air drying of the original product. The moisture content of the product is controlled below 0.1%, and the particle morphology is more regular and the fluidity is better. To ensure stable quality, multiple detection points are set during the production process. The particle size distribution and phosphorus content are tested once an hour. The particle size D50 is controlled at 15-20μm (consistent with the original product), and the phosphorus content fluctuates no more than 0.3%. The raw material procurement adopts fixed-point supply to ensure the stability of the purity of the phosphorus source and amine compounds. Each batch of raw materials must be tested by ICP-MS, and the heavy metal content is less than 10ppm. Through these process optimizations and quality control, the quality stability of Equivalent to Exolit AP422 is equivalent to that of the original product, which can meet the needs of large-scale industrial production.

Equivalent to Exolit AP422 has a wide range of applications and can be used in a variety of plastic materials. The amount to be added in different materials varies depending on the material properties and flame retardant requirements. In polyamide materials (such as PA6 and PA66), because polyamide is easy to drip when burning, 20-25% of Equivalent to Exolit AP422 must be added to achieve UL94 V-0 level. For example, electrical connectors made of PA6 can meet the flame retardant requirements by adding 23%. In polyester materials, such as polybutylene terephthalate (PBT), the amount to be added is slightly higher, 25-30%, because it is difficult to form a carbon layer when PBT burns. An additional 5% of a synergist (such as melamine cyanurate) can reduce the amount to 23%, still reaching the V-0 level. In polyolefin materials, such as polypropylene, 30-35% needs to be added when used alone, but when compounded with magnesium hydroxide (ratio 1:1), a total addition of 25% can reach V-1 level, which is suitable for cost-sensitive polypropylene products. In epoxy resin, the addition amount of Equivalent to Exolit AP422 is 15-20%, which can make the oxygen index of the cured epoxy resin reach 28, meeting the flame retardant requirements of electronic potting glue. The core of the difference in the amount added in different materials lies in the combustion characteristics of the materials. Materials with high oxygen content (such as polyester) require more flame retardants, while materials with certain flame retardancy (such as polyamide) can be appropriately reduced. In actual applications, the optimal addition amount needs to be determined according to the type of material and the flame retardant grade requirements.

During the processing of Equivalent to Exolit AP422, there are certain requirements for the wear resistance and temperature control accuracy of the equipment, and reasonable operation is required to avoid processing defects. Because the flame retardant contains phosphorus, it has a slight corrosive effect on metals. The screw and barrel of the processing equipment need to be made of wear-resistant materials, such as bimetallic alloys (containing chromium and molybdenum elements). Its service life is more than 3 times that of ordinary steel, which can reduce equipment wear. The temperature control accuracy must be controlled within ±3℃. If the temperature is too high (over 300℃), the flame retardant will decompose prematurely, causing bubbles and discoloration in the product. For example, in the processing of polyamide 6, the temperature must be controlled at 250-270℃; if the temperature is too low, the mixing is uneven and the mechanical properties of the product are reduced. The flame retardant needs to be dried before processing, and the moisture content is controlled below 0.05%, otherwise silver streaks are easily generated. The drying conditions are 80℃ and 4 hours. To avoid processing defects, the extruder screw length-to-diameter ratio must be ≥30:1 to ensure sufficient mixing; a gradient nozzle is used during injection molding to prevent flame retardant accumulation and clogging; the mold surface needs to be chrome-plated to reduce material adhesion and avoid flash on the product. If surface precipitation occurs, the processing temperature can be increased by 5-10℃ or the screw speed can be increased by 10%; if the mechanical properties decrease, 0.3% of processing aids (such as calcium stearate) can be added to improve dispersion. By matching appropriate equipment and optimizing processes, processing defects can be effectively avoided and product quality can be guaranteed.

Compared with the original Exolit AP422, Equivalent to Exolit AP422 has lower cost and comparable environmental protection, and can better balance cost performance and environmental protection requirements. In terms of cost, Equivalent to Exolit AP422 reduces production costs by 15-20% by optimizing raw material procurement (using industrial-grade phosphorus source after purification) and simplifying some processes. The selling price is 10-15% lower than the original product, which can significantly reduce the raw material costs of enterprises in large-scale applications. In terms of environmental protection, both products do not contain halogens and heavy metals, and have passed environmental certifications such as RoHS and REACH. They have low smoke density during combustion, no dioxin is generated, and the smoke density rating (SDR) is about 50. The production process of Equivalent to Exolit AP422 is more environmentally friendly. It adopts a water circulation system, and the water consumption per ton of product is reduced by 30% compared with the original product production. The wastewater can be recycled after treatment, and the COD emission concentration is <50mg/L, which is lower than the 80mg/L of the original product production.