With the development of the automobile industry, the safety of automobiles has received increasing attention. As an important passive safety equipment, airbags are mainly composed of gas generators (inflators) and airbags, and are heavily equipped in automobiles. During operation, the gas released by the gas-generating drug in the gas generator fills the entire air bag, forming a collision buffer zone between the human body and the car interior, reducing the damage. As the cost of automobiles decreases, airbag materials generally use cheap PET non-insulation coating materials in order to reduce costs. Therefore, gas generators, especially the gas produced therein, have lower combustion temperatures. Since the existing formula generally has a relatively high combustion temperature, it is necessary to add a substance which can lower the temperature of the gas.
Basic magnesium carbonate is essentially a cooling agent. In the formulation of airbag gas generating agent, it mainly absorbs heat to generate water, carbon dioxide and magnesium oxide. Basic magnesium carbonate is a commonly used ingredient in extrusion formulations of foreign companies. The reason may be that some extruded type structures determine that only low burning rate formulations can be used. Even the formula contains only two components, lanthanum nitrate and basic copper nitrate. In some cases, the burning rate is too fast, so it is often necessary to use a cooling agent.
The role of basic magnesium carbonate in airbag gas generating agents has four aspects:
1.Reduce formula burning rate;
2.Reduce the heat;
4.Improve the quality of gas generator flame test and reduce the sparking of Mars. For the influence of formula residue, magnesium carbonate may improve the slagging performance of the formula and improve the flame quality.
In addition, the original intention of adding basic magnesium carbonate to the formulation is to simplify the process. However, basic magnesium carbonate co-mixing granulation has better cooling and lowering burning rate. The reason may be that the basic magnesium carbonate micropowder is added to the formula to directly absorb heat, reduce the combustion temperature, and reduce the burning rate. However, the granulation of the 40 mesh sieve alone, due to its large particle size, must not be partially decomposed, its role has not been fully exerted.