초록 ▼

Gas generating pellets for an air bag system causes the initial inflating speed of the air bag to be increased at a reduced rate to prevent a passenger from being injured due to vigorous inflation of the air bag in the initial period, while maintaining sufficient ability to restrict the passenger af

Gas generating pellets for an air bag system causes the initial inflating speed of the air bag to be increased at a reduced rate to prevent a passenger from being injured due to vigorous inflation of the air bag in the initial period, while maintaining sufficient ability to restrict the passenger after 35 to 50 milliseconds from the start of the inflation. Combustion of the gas generating pellets for an air bag system are controlled such that in a tank test conducted with respect to a gas generator using the pellets, where a desired maximum tank pressure is P (kPa), and a period of time from the start of rising of the tank pressure to the time when the maximum tank pressure P (kPa) is reached is T milliseconds, the tank pressure measured after 0.25×T milliseconds is not higher than 0.20×P (kPa), and the tank pressure measured after 0.80×T milliseconds is not lower than 0.70×P (kPa). In particular, the gas generating pellets may be formed of a non-azide gas generating composition, and each pellet may be formed with a length of L (mm) and a hole having an inside diameter d(mm) of 0.2 to 1.5 (mm), such that the ratio L/d is 3.0 or larger.

대표청구항 ▼

Gas generating pellets for an air bag system causes the initial inflating speed of the air bag to be increased at a reduced rate to prevent a passenger from being injured due to vigorous inflation of the air bag in the initial period, while maintaining sufficient ability to restrict the passenger af

Gas generating pellets for an air bag system causes the initial inflating speed of the air bag to be increased at a reduced rate to prevent a passenger from being injured due to vigorous inflation of the air bag in the initial period, while maintaining sufficient ability to restrict the passenger after 35 to 50 milliseconds from the start of the inflation. Combustion of the gas generating pellets for an air bag system are controlled such that in a tank test conducted with respect to a gas generator using the pellets, where a desired maximum tank pressure is P (kPa), and a period of time from the start of rising of the tank pressure to the time when the maximum tank pressure P (kPa) is reached is T milliseconds, the tank pressure measured after 0.25×T milliseconds is not higher than 0.20×P (kPa), and the tank pressure measured after 0.80×T milliseconds is not lower than 0.70×P (kPa). In particular, the gas generating pellets may be formed of a non-azide gas generating composition, and each pellet may be formed with a length of L (mm) and a hole having an inside diameter d(mm) of 0.2 to 1.5 (mm), such that the ratio L/d is 3.0 or larger. ter, said tantalum impurity concentration uniformly distributed throughout the re-crystallized single crystal silicon carbide material. 3. The silicon carbide material of claim 1, wherein said axial region of re-crystallized single crystal silicon carbide has a tantalum impurity concentration of between 1016and 1017per cubic centimeter, said tantalum impurity concentration uniformly distributed throughout the re-crystallized single crystal silicon carbide material. 4. The silicon carbide material of claim 1, wherein said axial region of re-crystallized single crystal silicon carbide has a niobium impurity concentration of less than 1017per cubic centimeter, said niobium impurity concentration uniformly distributed throughout the re-crystallized single crystal silicon carbide material. 5. The silicon carbide material of claim 1, wherein said axial region of re-crystallized single crystal silicon carbide has a niobium impurity concentration of between 1016and 1017per cubic centimeter, said niobium impurity concentration uniformly distributed throughout the re-crystallized single crystal silicon carbide material. 6. The silicon carbide material of claim 1, wherein said density of secondary phase inclusions is less than 1 per cubic centimeter. 7. A silicon carbide material comprising an axial region of re-crystallized single crystal silicon carbide with a density of dislocations of less than 103per square centimeter, a density of micropipes of less than 10 per square centimeter, and a density of secondary phase inclusions of less than 10 per cubic centimeter. 8. The silicon carbide material of claim 7, wherein said axial region of re-crystallized single crystal silicon carbide has a tantalum impurity concentration of less than 1017per cubic centimeter, said tantalum impurity concentration uniformly distributed throughout the re-crystallized single crystal silicon carbide material. 9. The silicon carbide material of claim 7, wherein said axial region of re-crystallized single crystal silicon carbide has a tantalum impurity concentration of between 1016and 1017per cubic centimeter, said tantalum impurity concentration uniformly distributed throughout the re-crystallized single crystal silicon carbide material. 10. The silicon carbide material of claim 7, wherein said axial region of re-crystallized single crystal silicon carbide has a niobium impurity concentration of less than 1017per cubic centimeter, said niobium impurity concentration uniformly distributed throughout the re-crystallized single crystal silicon carbide material. 11. The silicon carbide material of claim 7, wherein said axial region of re-crystallized single crystal silicon carbide has a niobium impurity concentration of between 1016and 1017per cubic centimeter, said niobium impurity concentration uniformly distributed throughout the re-crystallized single crystal silicon carbide material. 12. The silicon carbide material of claim 7, wherein said density of secondary phase inclusions is less than 1 per cubic centimeter. 13. A silicon carbide material comprising an axial region of re-crystallized single crystal silicon carbide with a density of dislocations of less than 102per square centimeter, a density of micropipes of less than 10 per square centimeter, and a density of secondary phase inclusions of less than 10 per cubic centimeter. 14. The silicon carbide material of claim 13, wherein said axial region of re-crystallized single crystal silicon carbide has a tantalum impurity concentration of less than 1017per cubic centimeter, said tantalum impurity concentration uniformly distributed throughout the re-crystallized single crystal silicon carbide material. 15. The silicon carbide material of claim 13, wherein said axial region of re-crystallized single crystal silicon carbide has a tantalum impurity concentrat ion of between 1016and 1017per cubic centimeter, said tantalum impurity concentration uniformly distributed throughout the re-crystallized single crystal silicon carbide material. 16. The silicon carbide material of claim 13, wherein said axial region of re-crystallized single crystal silicon carbide has a niobium impurity concentration of less than 1017per cubic centimeter, said niobium impurity concentration uniformly distributed throughout the re-crystallized single crystal silicon carbide material. 17. The silicon carbide material of claim 13, wherein said axial region of re-crystallized single crystal silicon carbide has a niobium impurity concentration of between 1016and 1017per cubic centimeter, said niobium impurity concentration uniformly distributed throughout the re-crystallized single crystal silicon carbide material. 18. The silicon carbide material of claim 13, wherein said density of secondary phase inclusions is less than 1 per cubic centimeter. 19. A silicon carbide material, comprising: a single crystal silicon carbide seed crystal, said single crystal silicon carbide seed crystal having a growth surface; and a region of axially re-crystallized silicon carbide, said region of axially re-crystallized silicon carbide initiating at said growth surface of said single crystal silicon carbide seed crystal, said region of axially re-crystallized silicon carbide having a density of dislocations of less than 104per square centimeter, a density of micropipes of less than 10 per square centimeter, and a density of secondary phase inclusions of less than 10 per cubic centimeter. 20. The silicon carbide material of claim 19, wherein said density of dislocations in said region of axially re-crystallized silicon carbide is less than 103per square centimeter. 21. The silicon carbide material of claim 19, wherein said density of dislocations in said region of axially re-crystallized silicon carbide is less than 102per square centimeter. 22. The silicon carbide material of claim 19, wherein said axial region of re-crystallized single crystal silicon carbide has a tantalum impurity concentration of less than 1017per cubic centimeter, said tantalum impurity concentration uniformly distributed throughout the re-crystallized single crystal silicon carbide material. 23. The silicon carbide material of claim 19, wherein said axial region of re-crystallized single crystal silicon carbide has a tantalum impurity concentration of between 1016and 1017per cubic centimeter, said tantalum impurity concentration uniformly distributed throughout the re-crystallized single crystal silicon carbide material. 24. The silicon carbide material of claim 19, wherein said axial region of re-crystallized single crystal silicon carbide has a niobium impurity concentration of less than 1017per cubic centimeter, said niobium impurity concentration uniformly distributed throughout the re-crystallized single crystal silicon carbide material. 25. The silicon carbide material of claim 19, wherein said axial region of re-crystallized single crystal silicon carbide has a niobium impurity concentration of between 1016and 1017per cubic centimeter, said niobium impurity concentration uniformly distributed throughout the re-crystallized single crystal silicon carbide material. 26. The silicon carbide material of claim 19, wherein said density of secondary phase inclusions is less than 1 per cubic centimeter.