Metal oxide is a compound composed of oxygen and another metal chemical element, such as zinc oxide, iron oxide, calcium oxide, magnesium oxide, etc., which is an important rubber additive in the production of rubber products. When using reclaimed rubber to produce rubber products, the rational use of metal oxides can further improve the processing technology performance of rubber compounds and the comprehensive indicators of finished products while reducing the cost of raw materials. What are the metal oxides commonly used in the production of reclaimed rubber products? What is the specific role in rubber formulation?
1. Zinc oxide
Zinc oxide, commonly known as zinc oxygen powder or zinc white, is a non-toxic, tasteless, white fine powder amphoteric oxide, one of the active agents commonly used in the vulcanization system of recycled rubber products, and stearic acid is used in combination to produce zinc soap (complex of stearic acid and zinc) soluble in rubber, participate in the vulcanization reaction, accelerate the formation of sulfur cross-linked bonds, improve vulcanization efficiency and cross-linking, and improve the mechanical properties of reclaimed rubber vulcanized rubber (such as tensile strength, tensile stress, wear resistance).
Zinc oxide also has the functions of reinforcing, coloring and increasing the thermal conductivity of the rubber in reclaimed rubber. If the amount of zinc oxide is further increased on the basis of the dosage of active agent, the following effects will occur: the reinforcing effect can increase the tensile stress of the vulcanized rubber of the reclaimed rubber again; It has an obvious hardening tendency for reclaimed rubber compounds, especially fine-particle zinc oxide, to improve the shape stability of reclaimed rubber extruded products and moldless vulcanized products; Further improve the thermal conductivity of the rubber compound, which is very beneficial for hot air vulcanization and vulcanization of thick products.
When using latex reclaimed rubber to produce light-colored rubber products, zinc oxide is used as an inert reinforcing filler, which will not affect the color of the product.
2. Magnesium oxide
Magnesium oxide is a white loose powdered oxide, which can be used as an activator and vulcanization accelerator in the production of reclaimed rubber products, especially in the vulcanization system of neoprene/reclaimed rubber combined with rubber, magnesium oxide can be used as an auxiliary vulcanizing agent, and work together with other vulcanizing agents to promote the vulcanization reaction of recycled rubber. As an active agent, magnesium oxide can improve the vulcanization efficiency of rubber, speed up the vulcanization process, reduce the vulcanization time, and improve the physical and mechanical properties of reclaimed rubber products. In the vulcanization system of reclaimed rubber, magnesium oxide can be used in combination with zinc oxide.
Magnesium oxide can improve the heat resistance and anti-aging properties of recycled rubber products; Used as a reinforcing material, it can improve the hardness, wear resistance and tear strength of recycled rubber; In the process of compounding reclaimed rubber, magnesium oxide helps to improve the fluidity and processability of the rubber. Increase the bonding performance with the metal skeleton and improve the roll wrapping property of the rubber compound; Magnesium oxide is an alkaline oxide, which has the ability to absorb acid, and a lot of acid will be released during the process of regenerating rubber, and magnesium oxide can be used to adjust the acid-base balance and play a role in stabilizing the rubber compound.
3. Calcium oxide
Calcium oxide is a white powdered oxide, which can be used as an active agent and desiccant in the production of reclaimed rubber products. Calcium oxide can absorb the gas and water vapor generated in the vulcanization process in the rubber compound to prevent the porosity of reclaimed rubber products; Low-pressure vulcanized products and rubber compounds containing nylon fibers that are sensitive to moisture, or as accelerators for hard rubber in the middle layer of rubber-to-metal bonding. Calcium oxide is used as an active agent, and the resulting products are fragile and have poor aging resistance, so they are not recommended in the production of reclaimed rubber products.
Other metal oxides will also be used in the production of rubber products using reclaimed rubber, such as reclaimed rubber to produce engine seals, electrical insulation parts and other rubber products used in high temperature environments, alumina E4LYY1118 can be used appropriately to improve the heat aging resistance and insulation resistance of the finished product; Lead oxide can replace magnesium oxide and improve heat and water resistance. Metal oxides can not only be used as a vulcanization system compound in the production of reclaimed rubber products, but also can improve processing safety, improve the physical and mechanical properties and heat resistance of reclaimed rubber products, Xiaobian will continue to discuss related issues with you.
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