Gas generant compositions comprising a thermally stable crystalline hydrate compound for cooling combustion flame temperature and improving ballistic performance

Patent metadata

Field	Value
Publication number	US-11548834-B2
Application number	US-201916369591-A
Country	US
Kind code	B2
Filing date	Mar 29, 2019
Priority date	Mar 29, 2019
Publication date	Jan 10, 2023
Grant date	Jan 10, 2023

Abstract

A gas generant composition for an automotive inflatable restraint system is provided with a fuel having a thermally stable crystalline hydrate compound with a water release temperature of greater than or equal to about 140° C. The thermally stable crystalline hydrate compound serves as a ballistic modifier, which can serve to increase burn rate, reduce pressure sensitivity, reduce temperature sensitivity, and the like. The thermally stable crystalline hydrate compound may be selected from the group consisting of: a copper phthalate hydrate, copper pyromellitate dihydrate, copper fumarate dihydrate, copper (3-nitrophthalate) dihydrate, and combinations thereof.

First claim

What is claimed is:

1. A gas generant composition for an automotive inflatable restraint system comprising a fuel having a thermally stable crystalline hydrate compound with a water release temperature of greater than or equal to about 140° C. measured by differential scanning calorimetry (DSC) with a heating rate of 5° C./minute with a tolerance of ±0.1° C./minute, wherein the thermally stable crystalline hydrate compound is selected from the group consisting of: copper pyromellitate dihydrate, copper fumarate dihydrate, copper (3-nitrophthalate) dihydrate, and combinations thereof.

2. The gas generant composition of claim 1 having a sensitivity to temperature coefficient (σ P ) of less than or equal to about 0.2%/° C.

3. The gas generant composition of claim 1 having a burning rate variability π k of less than or equal to about 0.25%/° C.

4. The gas generant composition of claim 1 having a linear burn rate of greater than or equal to about 18 mm per second at a pressure of about 21 megapascals (MPa), a linear burn rate pressure exponent of less than or equal to about 0.35, a gas yield of greater than or equal to about 5.7 moles/100 cm 3 , and a maximum flame temperature at combustion (T c ) of less than or equal to about 1700K (1,427° C.).

5. The gas generant composition of claim 1 , wherein the thermally stable crystalline hydrate compound is present at greater than 0% to less than or equal to about 12% by weight of the total gas generant composition.

6. The gas generant composition of claim 5 , wherein the fuel is a first fuel and the gas generant composition comprises one or more additional fuels present at greater than or equal to about 10% to less than or equal to about 20% by weight of the total gas generant composition; one or more oxidizers are present at greater than or equal to about 30% to less than or equal to about 70% by weight of the total gas generant composition; and one or more gas generant additives are present at greater than or equal to 0% to less than or equal to about 10% by weight of the total gas generant composition.

7. The gas generant composition of claim 6 , wherein:
the one or more additional fuels are selected from the group consisting of: guanidine nitrate, diammonium 5,5′-bitetrazole (DABT), copper bis guanylurea dinitrate, hexamine cobalt (III) nitrate, copper diammine bitetrazole, a melamine oxalate compound, and combinations thereof,
the one or more oxidizers are selected from the group consisting of: basic copper nitrate, alkali metal or alkaline earth metal nitrates, alkali metal, alkaline earth metal, or ammonium perchlorates, metal oxides, and combinations thereof; and
the one or more gas generant additives are selected from the group consisting of: silicon dioxide, aluminum oxide, and combinations thereof.

8. The gas generant composition of claim 1 , wherein the fuel having the thermally stable crystalline hydrate compound is a first fuel present at greater than 0% to less than or equal to about 12% by weight of the total gas generant composition and the gas generant composition further comprises:
guanidine nitrate present as a second fuel at greater than or equal to about 15% to less than or equal to about 50% by weight of the total gas generant composition;
a third fuel present at greater than or equal to 0% to less than or equal to about 20% by weight of the total gas generant composition;
basic copper nitrate present at greater than or equal to about 30% to less than or equal to about 70% by weight of the total gas generant composition; and
one or more slagging agents present at greater than or equal to 0% to less than or equal to about 5% by weight of the total gas generant composition.

9. The gas generant composition of claim 8 , wherein the third fuel comprises a melamine oxalate compound.

10. A gas generant composition for an automotive inflatable restraint system comprising a copper phthalate monohydrate compound represented by the structure

11. The gas generant composition of claim 10 having a sensitivity to temperature coefficient (σ P ) of less than or equal to about 0.2%/° C. and a burning rate variability π k of less than or equal to about 0.25%/° C.

12. The gas generant composition of claim 10 having a linear burn rate of greater than or equal to about 18 mm per second at a pressure of about 21 megapascals (MPa), a linear burn rate pressure exponent of less than or equal to about 0.35, a gas yield of greater than or equal to about 5.7 moles/100 cm 3 , and a maximum flame temperature at combustion (T c ) of less than or equal to about 1700K (1,427° C.).

13. The gas generant composition of claim 10 , wherein the copper phthalate monohydrate compound is present at greater than 0% to less than or equal to about 10% by weight of the total gas generant composition.

14. The gas generant composition of claim 13 further comprising one or more fuels present at greater than or equal to about 10% to less than or equal to about 20% by weight of the total gas generant composition; one or more oxidizers are present at greater than or equal to about 30% to less than or equal to about 70% by weight of the total gas generant composition; and one or more gas generant additives are present at greater than or equal to 0% to less than or equal to about 10% by weight of the total gas generant composition.

15. The gas generant composition of claim 14 , wherein:
the one or more fuels are selected from the group consisting of: guanidine nitrate, diammonium 5,5′-bitetrazole (DABT), copper bis guanylurea dinitrate, hexamine cobalt (III) nitrate, copper diammine bitetrazole, a melamine oxalate compound, and combinations thereof,
the one or more oxidizers are selected from the group consisting of: basic copper nitrate, alkali metal or alkaline earth metal nitrates, alkali metal, alkaline earth metal, or ammonium perchlorates, metal oxides, and combinations thereof; and
the one or more gas generant additives are selected from the group consisting of: silicon dioxide, aluminum oxide, and combinations thereof.

16. The gas generant composition of claim 10 , wherein the copper phthalate monohydrate compound is a first fuel present at greater than 0% to less than or equal to about 10% by weight of the total gas generant composition and the gas generant composition further comprises:
guanidine nitrate is a second fuel present at greater than or equal to about 15% to less than or equal to about 50% by weight of the total gas generant composition;
a third fuel present at greater than or equal to 0% to less than or equal to about 20% by weight of the total gas generant composition;
basic copper nitrate present at greater than or equal to about 30% to less than or equal to about 70% by weight of the total gas generant composition; and
one or more slagging agents present at greater than or equal to 0% to less than or equal to about 5% by weight of the total gas generant composition.

17. The gas generant composition of claim 16 , wherein the third fuel comprises a melamine oxalate compound.

18. A cool burning gas generant composition for an automotive inflatable restraint system comprising a copper phthalate monohydrate compound represented by the structure

having a maximum flame temperature at combustion (T c ) of less than or equal to about 1700K (1,427° C.), a sensitivity to temperature coefficient (σ P ) of less than

Assignees

• Autoliv Asp Inc

Inventors

• Mendenhall Ivan V
• Lund Gary K

Classifications

• C06B23/04 Primary

  for cooling the explosion gases {including antifouling and flash suppressing agents} · CPC title

• C06B41/00

  Compositions containing a nitrated metallo-organic compound · CPC title

• C06D5/06

  by reaction of two or more solids · CPC title

• C06B25/34 Primary

  the compound being a nitrated acyclic, alicyclic or heterocyclic amine · CPC title