Azide-Free Gas-Generating Composition for Vehicle Safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gas generators for safety arrangements, particularly in vehicle occupant restraint systems, face issues with poisonous sodium azide-based propellants that form dangerous compounds, low gas yield, and residue formation, leading to complex handling and filtration requirements.
Innovation Solution
An azide-free gas-generating composition using tetrakis(2,2,2-trinitroethyl)orthocarbonate (TNEOC) as an oxidizer in combination with nitrogenous organic compounds and aliphatic dicarboxylic acids, achieving high gas yield, smokelessness, and thermal stability, thereby reducing the risk of propellant damage and eliminating the need for costly filters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If sodium azide is used as the gas-providing main component, then the gas generator can provide sufficient gas volume, but the composition becomes poisonous and forms dangerous compounds with heavy metals
Solution Approach 1:
The invention extracts and removes the harmful sodium azide component from the gas-generating composition and replaces it with azide-free alternatives consisting of nitrogenous organic fuels and inorganic oxidizing agents, thereby eliminating the formation of poisonous compounds while maintaining gas-generating capability
Solution Approach 2:
The invention changes the chemical composition parameters by transitioning from sodium azide-based propellants to compositions based on nitrogenous organic fuels (like nitroguanidine) and inorganic oxidizing agents (like ammonium nitrate), fundamentally altering the chemical reaction pathway to avoid toxic byproducts
2Object-affected harmful factors
If nitrogenous organic fuels and inorganic oxidizing agents are used, then the composition is less poisonous, but solid substances are formed that require filter arrangements
Solution Approach 1:
The invention optimizes the compositional parameters by carefully selecting fuel-to-oxidizer ratios and using coated gas bag fabrics to manage the solid content of reaction products, reducing the need for complex filtration systems while maintaining safety
3Power
If high solid content compositions are used, then the combustion produces sufficient energy, but the gas yield lies distinctly below 80% by weight
Solution Approach 1:
The invention changes the compositional parameters by using nitrogenous organic fuels that contain nitrogen in their molecular structure, which directly contributes to gas generation upon combustion, thereby achieving high gas yield (at least 80% by weight) without sacrificing combustion energy
4Object-affected harmful factors
If ammonium nitrate is used as oxidizing agent, then the composition can be produced without heavy metals, but the propellant becomes hygroscopic and difficult to handle
Solution Approach 1:
The invention introduces phase-stabilizing additives as intermediary substances that modify the physical properties of ammonium nitrate, stabilizing its crystal structure and reducing hygroscopicity, thereby improving handling characteristics while maintaining the benefits of azide-free composition
Solution Approach 2:
The invention creates a composite propellant material combining ammonium nitrate with phase-stabilizing additives, where the additive component compensates for the hygroscopic nature of ammonium nitrate, resulting in a composite with improved handling properties
5Stability of the object's composition
If phase-stabilizing additives are added to ammonium nitrate, then the propellant structural stability is improved, but the composition becomes more complex
Solution Approach 1:
The invention optimizes the concentration parameters of phase-stabilizing additives to achieve sufficient structural stability with minimal additive content, thereby limiting the increase in composition complexity while maintaining propellant integrity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The composition achieves a gas yield of at least 80% by weight, maintains stability under temperature stress, and prevents the formation of toxic gases and solid particles, simplifying gas generator construction and reducing the risk of fabric damage.
Implementation Method 1
The oxidizer comprises tetrakis(2,2,2-trinitroethyl)orthocarbonate (TNEOC)... achieves a gas yield of at least 80% by weight
Implementation Method 2
Gas-generating compositions based on nitrogenous organic fuels and inorganic oxidizing agents are known. In the combustion of these compositions...
Implementation Method 3
maintains stability under temperature stress... TNEOC has an extraordinary stability as compared to other organic oxidizers
Data Source
AI summary
An azide-free gas-generating composition for use in gas generators for safety arrangements, in particular in gas generators for vehicle occupant restraint systems, includes a fuel and an oxidizer. The fuel is a compound having a melting point of at least 120 degrees C., and is selected from the group of nitrogenous organic compounds and of aliphatic dicarboxylic acids, and mixtures, derivatives and salts thereof. The oxidizer comprises tetrakis(2,2,2-trinitroethyl)orthocarbonate (TNEOC), with the TNEOC being present in a proportion of at least 10% by weight of the composition.