Ammonium nitrate propellants

• US 6,364,975 B1
• Filed: 11/26/1996
• Issued: 04/02/2002
• Est. Priority Date: 01/19/1994
• Status: Expired due to Term

• Current Assignee: Goodrich Corporation (Rtx Corporation)
• Original Assignee: Universal Propulsion Company Incorporated (Rtx Corporation)
• Inventors: Olander, Donald E., McSpadden, Hugh J., Fleming, Wayne C.
• Primary Examiner(s): Miller, Edward A.
• Application Number:
  US08/753,521
• Time in Patent Office: 1,953 Days
• Field of Search: 149/19.6, 149/19.4, 149/19.5, 149/46, 149/19.1
• US Class Current: 149/19.4
• CPC Class Codes: C06B 23/006 Stabilisers (e.g. thermal stabilisers) processes C06B21/0091; foam stabilisers C06B23/002
• CPC Class Codes: C06B 31/28 the salt being ammonium nitrate
• CPC Class Codes: C06B 31/30 with vegetable matter; with resin; with rubber
• CPC Class Codes: C06B 45/105 The resin being a polymer bearing energetic groups or containing a soluble organic explosive

Abstract

The present invention is directed to an age-stabilized and/or strengthened ammonium nitrate propellant composition wherein the strengthening agent is selected from the group consisting of azodicarbonamide, dicyandiamide, oxamide and mixtures thereof and wherein the age-stabilizing agent is a molecular sieve having a pore size of 13 angstroms or less.

Claims

1. An age-stabilized ammonium nitrate propellant composition consisting essentially of:

ammonium nitrate having a crystalline phase present in an amount from about 40% to about 85%,

a synthetic zeolite having a pore size from about 3 angstroms to about 13 angstroms present in an amount from about 0.2% to about 0.4%, and

a binder present in an amount from about 3% to about 40% by weight of said composition,

wherein said ammonium nitrate, synthetic zeolite and binder are each present in an amount effective to stabilize the crystalline phase of said ammonium nitrate, provide said composition a shelf-life of at least about 5 years, and produce a composition that is substantially smoke-free upon combustion.

2. An age-stabilized ammonium nitrate propellant composition consisting essentially of:

ammonium nitrate having a crystalline phase present in an amount from about 40% to about 85%,

a synthetic zeolite having a pore size from about 3 angstroms to about 13 angstroms present in an amount from about 0.2% to about 0.4%,

a binder present in an amount from about 3% to about 40% by weight of said composition, and

at least one of;

a nitroplasticizer present in an amount of about 5% to about 25%,

an energetic additive present in an amount of about 5% to about 25%,

a nitrate ester stabilizer present in an amount of about 0.1% to about 3%,

a curing agent present in an amount of about 0.5% to about 5%,

a cure catalyst present in an amount of up to about 0.3%,

an opacifier present in an amount of up to about 2%, or

an anti-oxidant present in an amount of up to about 1% by weight based on said composition,

wherein said ammonium nitrate, synthetic zeolite and binder are each present in an amount effective to stabilize the crystalline phase of said ammonium nitrate, provide said composition a shelf-life of at least about 5 years, and produce a composition that is substantially smoke-free upon combustion.

3. An age-stabilized ammonium nitrate propellant composition consisting essentially of:

ammonium nitrate having a crystalline phase present in an amount from about 40% to about 85%,

a synthetic zeolite having a pore size from about 3 angstroms to about 13 angstroms present in an amount from about 0.2% to about 0.4%, wherein said synthetic zeolite has a formula Na₁₂((AlO₂)₁₂(SiO₂)₁₂).27H₂O,

a binder present in an amount from about 3% to about 40% by weight of said composition, wherein said binder is a hydroxyterminated polybutadiene, and

at least one of;

a nitroplasticizer present in an amount of about 5% to about 25%,

an energetic additive present in an amount of about 5% to about 25%, wherein said energetic additive is selected from the group consisting of dinitroxydiethylnitramine, cyclotrimethylene trinitramine, cyclotetramethylene tetranitramine and mixtures thereof,

a nitrate ester stabilizer present in an amount of about 0.1% to about 3%, wherein said nitrate ester stabilizer is N-methyl-4-nitroaniline,

a curing agent present in an amount of about 0.5% to about 5%, wherein said curing agent is isophorone diisocyanate,

a cure catalyst present in an amount of up to about 0.3%, wherein said cure catalyst is selected from the group consisting of triphenyl bismuth, maleic anhydride, magnesium oxide, a tin dilaurate, metal acetylacetonate and mixtures thereof,

an opacifier present in an amount of up to about 2%, wherein said opacifier is carbon black, or

an anti-oxidant present in an amount of up to about 1% by weight based on said composition, wherein said anti-oxidant is selected from the group consisting of 2,2′

-bis(4-methyl-6-tert-butylphenol), 4,4′

-bis(4-methyl-6-tert-butyl phenol) and mixtures thereof

wherein said ammonium nitrate, synthetic zeolite and binder are each present in an amount effective to stabilize the crystalline phase of said ammonium nitrate, provide said composition a shelf-life of at least about 5 years, and produce a composition that is substantially smoke-free upon combustion.