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AC Blowing Agent Foaming Agent Azodicarbonamide CAS 123-77-3 Profor1
Chemical Auxiliary CatalystAzodicarbonamideAzobisformamide
Hangzhou Qingrong International Trade Co., Ltd.
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Product Description * For more specific technical data sheet, PLS feel free to contact us anytime. Technical Forum about ADCA BLOWING AGENTAC foaming agent is an important hydrazine foaming agent, which has excellent performance, large gas generation, decomposition non-toxic, odorless, non-pollution, and the price is relative low. However, the decomposition temperature of pure AC foaming agent is higher than that of many olefin polymers, so we have to increase the processing temperature during foaming processing, inevitably cause discoloration and aging of polymer. The pure AC foaming agent obtained by the current production process has large average particle size and wide particle size distribution, which is easy to cause excessive and uneven pore size of foaming products, such as PVC artificial leather, foamed wallpaper and so on. AC foaming agent is in the form of fine powder orginally, which is easy to absorb moisture or agglomerate due to static function. When the polymer is melted and foamed, the decomposition of caked AC foaming agent particles will produce larger pores, affecting the quality of the product. The decomposition of AC foaming agent is a strong exothermic reaction, with fast decomposition speed and high temperature, leading to overheating of polymer melt and decrease of viscosity of resin melt, resulting in open-cell foam and cell rupture of the finished product, and decrease of mechanical properties of structural foam. In addition, when the AC foaming agent is decomposed, it also bring a small amount of polycyanic acid, urea azole and other foreign matters onto the foam surface. Therefore, it is 100% necessary to modify to match different materials on different working conditions.The modification of AC foaming agent is to optimize or specialize the gas volume, particle size, decomposition temperature and decomposition rate of the foaming agent. The main ways of modification are during synthetic, change its normal working conditions by stirring speed and reaction temperature, or partially use different oxidants or other auxiliaries to reduce the average particle size of AC and the particle size distribution, as a normal way, ultrafine pulverization of AC foaming agent by mechanical method and classification at the same time. And also adding one or more additives to change its decomposition temperature and gas volume; Furthermore,mixing with other types of foaming agent to change its decomposition temperature and decomposition rate. Recently, put AC foaming agent dissolved in a certain solvent and recrystallized to change the particle size of AC. (1) Ultra-fine particle size. The pore size and uniformity of foam products are mainly determined by the particle size and diffusion width of foaming agent. Some foaming products, such as artificial leather, require small and dense bubble pore size, while the average particle size of ordinary AC foaming agent is thick and wide, which produces ultra-fine particle size AC foaming agent, that is, AC foaming agent with a particle size of D95 lower than 8. The AC foaming agent produced under the current process (such as urea method) can be crushed and graded to obtain different brands of ultra-fine AC foaming agent defined according to different particle size to meet the foaming needs of different plastics and rubber products.(2) Decrease the decomposition temperature The decomposition temperature of AC foaming agent produced under normal conditions is generally high around 200 C, some gum and rubber with low softening point and easy aging by heat need to decompose at a lower temperature, which is compatible with the softening temperature and cross-linking temperature of gum and rubber. Therefore, reducing the decomposition temperature of AC and developing low-temperature AC foaming agent has always been one of the main research topics of AC manufacturers. In the process of biurea oxidation to AC or in the finished AC, one or more activators are added in a certain proportion and uniformly mixed, various kinds of modified AC with low decomposition temperature can be obtained. At present, AC with decomposition temperature of 135C-195C is generally called low temperature AC foaming agent.(3) Enhance the dispersionAC foaming agent is easy to receive water in the air, and the molecular structure of AC contains azo group and carbonyl group, so it is easy to produce electrostatic effect. if the product is stored for too long or is squeezed in the process of transportation, AC may agglomerate and cause agglomeration phenomenon. In order to overcome the above shortcomings, the fine powder of some inert inorganic compounds can be fully mixed as dispersion auxiliaries and AC foaming agent, so that the AC particles can be partially separated, thus reducing the chance of agglomeration and avoiding caking phenomenon in the process of storage and transportation. The selection of dispersant must be based on the premise that it does not affect the quality of the product, and this kind of inert dispersing agent does not decompose and gasify itself, so although it improves the dispersibility of AC foaming agent, it must be at the cost of reducing the gas volume of AC foaming agent. When the addition ratio is 2%-5%, the gas evolution of AC foaming agent will be reduced by 2-- 3ml/g.(4) Reduce the decomposition residue In order to reduce the formation of solid residue during the decomposition of AC foaming agent, some metal oxides (such as zinc oxide) can be involved to inhibit the occurrence of secondary reaction during the decomposition of AC foaming agent, so as to reduce the formation of urea. At present, several brands of modified AC foaming agents without solid residue precipitation have been developed by us.(5) Inhibition of foamingThe presence of some monocarboxylic acids and their hydrazides and amines in metal ionic activators can inhibit the decomposition of AC foaming agents, A typical use of AC foaming agent containing inhibitor is to produce PVC wallpaper (6) CompoundingAdding some active or inert auxiliaries to AC foaming agent can improve or inhibit some properties of AC foaming agent, but there is a common disadvantage that impurities are introduced into AC foaming agent. In order to overcome this shortcoming, one or more foaming agents with specific functions and AC foaming agents can be mixed and compounded to meet some specific needs without introducing useless impurities. Production. Experience shows that foaming agents with the same structure can not meet all the properties required by the processing of plastics and rubber, but it is difficult to develop foaming agents and auxiliaries with new structures. Therefore, according to the different characteristics of various foaming agents, compounding them into one to improve some efficiency is an effective way to improve and optimize modified AC.
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