Filler type flame retardant in acrylic pressure sensitive adhesive

Filler-type flame retardants belong to additive-type flame retardants, most of which are powdery inorganic compounds. Its rich source, and low price, are conducive to reducing the cost of polymer products, excellent thermal stability, non-toxic, and smoke suppression, but the filling volume is large, and flame retardant performance is poor.

Commonly used varieties of Filler-type flame retardant

Commonly used varieties are aluminum hydroxide, magnesium hydroxide, clay, magnesium silicate hydrate, calcium carbonate, and so on. Aluminum hydroxide and magnesium hydroxide are the main types of filler flame retardants. They absorb a large amount of heat in the combustion zone when they are decomposed so that the temperature of the combustion zone is reduced to the critical temperature of combustion. The combustion is self-extinguishing, and most of the metal oxides generated after decomposition have a high melting point and good thermal stability, and cover the surface of the combustion solid phase to block heat conduction and heat radiation.

Thus, it plays a flame-retardant role. The generated water is heated and evaporated to further absorb latent heat and reduce the temperature. At the same time, a large amount of water vapor is produced and the flammable gas is diluted to play a flame-retardant role.

The aluminum hydroxide and magnesium hydroxide can be rapidly dispersed into one body in the resin by ultrafine refining and surface modification with silicone coupling agent or fatty acid, so as to reduce the flame propagation speed, so that the amount of smoke, toxic gas, and corrosive gas generated during combustion is quite small, and significantly improve the flame retardant and smoke suppression effect.

Surface-modified superfine aluminum hydroxide (ATH) flame retardants are the focus of research and development all over the world. Liu Lijun et al. 9I modified the surface of high-performance flame retardant nano-alumina hydroxide, and the modified aluminum hydroxide increased the specific surface area, decreased the oil absorption value, and had good dispersion. After filling polypropylene, the melting phenomenon was obviously improved, the flame retardant effect was better, and the mechanical properties of the material were improved.

Acrylic pressure sensitive adhesive in the expansion of flame retardant

Intumescent flame retardant (IFR) is a compound flame retardant with P, N, and C elements as the core components. It is usually composed of a carbon source (carbon-forming agent), an acid source (dehydrating agent), and an air source (expansion agent). During combustion, the chemical reaction between the components generates a porous expanded carbon layer, which can play the role of heat insulation, oxygen insulation, smoke suppression, and melt drop prevention, so as to achieve the purpose of flame retardant.

But the expansive flame retardants must be matched with the flame retarded polymer in order to play a good flame retardant effect.