ChangShu LiangYi adhesive Tape Industry Co.,Ltd.

 

 

 

1.1 Inorganic hydrated metal compounds Flame-retardant inorganic hydrated metal compounds are mainly magnesium hydroxide [Mg(OH)2], aluminum hydroxide [Al(OH)3], hydrotalcite [Mg6Al2(OH)16CO3·4H2O], aluminum Calcium acid [3CaO·Al 2O3·6H2O] et al [4]. This kind of material has good thermal stability, flame retardant, non-toxic, non-volatile, non-corrosive gas, small smoke, no secondary pollution and so on. Aluminum hydroxide (ATH) is one of the earliest inorganic flame retardants available, and it is also the most widely used flame retardant in the world. The flame-retardant mechanism is: 1 Add aluminum hydroxide to the polymer to reduce the concentration of flammable polymer; 2 Start dehydration at about 250°C, endothermic, inhibit the temperature of the polymer; 3 Water vapor generated by decomposition decomposes combustible gas and oxygen Concentration prevents combustion from proceeding; 4 Formation of Al 2 O 3 on the surface of combustibles prevents combustion [1,5]. However, ATH has the disadvantage of a large amount of addition, and it usually needs to be added more than 50% to show good flame retardant effect [6]. The flame retardant mechanism of magnesium hydroxide is similar to that of ATH. Compared with ATH, its thermal stability and smoke suppression performance are significantly better than ATH. Magnesium hydroxide dehydration reaction occurs in a higher temperature range, it can be applied to flame-retardant pyrolysis polymer, application range is more extensive than ATH.

 

1.2 Red phosphorus flame retardant

Red phosphorus is an inorganic phosphorus flame retardant. It is one of the most widely used and studied flame retardants in this series of flame retardants. The flame-retardant mechanism was studied. It is believed that red phosphorus can make most of the high-polymers have good flame-retardant properties at a relatively low concentration. The treatment process is stable and has no effect on the physical electrical properties of the matrix. It can generate free radicals in the gas phase flame retardant, but also in the condensed phase to form a foam flame retardant. However, heat is easy to generate highly toxic gas phosphine (PH3), dust can easily explode, and is not easy to disperse in the polymer and other defects, limiting the application of the flame retardant. To this end, red phosphorus is physically or chemically modified, such as “packaging” red phosphorus particles, ie microencapsulated red phosphorus, to make up for its defects.

 

1.3 Boron compound flame retardant

Boron compound is a commonly used inorganic flame retardant, mainly zinc borate products. The flame retardant significantly improves the fire resistance of the product, has excellent flame retardant, smoke suppression, and arc extinguishing properties, and can emit less toxic and harmful smoke when the article is burned. The main flame retardant mechanism is endothermic and dilution effects, as well as the formation of thermal insulation. Zinc borate can lose crystal water when it is higher than 300°C, and it can play an endothermic cooling effect. About 38% of the zinc in zinc borate enters the gas phase in the form of zinc oxide or zinc hydroxide. Diluting the flammable gas to reduce its burning rate further increases its flame retardancy. Zinc borate flame retardants are generally used together with halogen compounds. During the combustion process, the surface of the combustible will be covered with some non-volatile zinc compounds and boric acid to isolate the air. This cover layer suppresses the occurrence of flammable gases and also prevents oxidation and heat. The presence of zinc compounds facilitates the dehydration reaction. In addition, the presence of boric acid can promote the production of large amounts of carbon. The increase in carbon is also beneficial to reduce the escape of combustibles, and has a good effect of suppressing smoke.

 

1.4 Terpenoids

Antimony trioxide, colloidal antimony pentoxide, and antimony sodium are the main products of antimony-based flame retardants. Among them, antimony trioxide is widely used. It is mainly used for the flame-retarding of plastic products and textiles. It can also be used as rubber. , wood flame retardants. The flame retardant mechanism [11] is generally considered to be: (1) yttria covers the surface of the inflammable material in a liquid or solid state and acts as a barrier to air; (2) it reduces the combustion temperature due to melting and volatilization of yttrium oxide and absorption of heat; (3) Ruthenium oxide, which has become vaporized, forms various halides and halogen radicals in the flame, and these decomposed products can dissipate the energy of the flame and change the chemical process of combustion, thereby acting as a suppressor.

 

Common flame-retardant insulating tapes include: Mara tape,Mylar tape, non-woven margin tape, rubber margin tape, polyimide tape, high temperature tape and so on.