Classifications

• • C—CHEMISTRY; METALLURGY
  • C06—EXPLOSIVES; MATCHES
  • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
  • C06B25/00—Compositions containing a nitrated organic compound
  • C06B25/18—Compositions containing a nitrated organic compound the compound being nitrocellulose present as 10% or more by weight of the total composition
  • C06B25/20—Compositions containing a nitrated organic compound the compound being nitrocellulose present as 10% or more by weight of the total composition with a non-explosive or a non-explosive or a non-thermic component

Definitions

• T his invention relates generally to the field of ordnance and is more particularly concerned with an improved gun propellant composition.
• Some better known propellants of this type are Cordite N and Cool Picrite both of w ich consist chiefly of nitroglycerin, nitrocellulose, nitroguanidine with ethyl centralite as a coolant alons with a small percentage of volatiles.
• the ignition of these compositions produces gases which are rich in ammonia and cause discomfort to the gun crew.
• F rthermore, nitroguani ine is not produced in quantity in this country and therefore might not be in adequate supply during time of need.
• the prior art cool compositions are suitable for use in guns which are fired slowly, however, t..ey tend to erode the gun barrel when the gun is fired rapidly.
• the Keck composition also produces great quantities of carbon deposits resulting from the high ratio of carbon to hydrogen and oxygen in the for nulation. The effect of the carbon deposits is cumulative and quickly causes th breech mechanism to seize and bind after a burst is tired, thereby rendering the gun inoperative.
• Another object is the provision of an improved gun propellant composition having a low adiabatic flame temperature and does not produce any carbon deposits upon ignition so that it is suitable for prolonged use in rapid fire guns.
• Still another object is the provision of a new and improved gun propellant which does not contain any critical materials.
• Propellants manufactured in accordance with this invention may contain a large percentage of about twelve percent nitration nitrocellulose.
• the propellants optionally may contain a few percent of an inorganic salt such as potassium sulfate, potassium nitrate, or cryolite used as a primary flash suppressant in accordance with conventional practice. In the event that the propellant is to be used for night firing, it is preferable that the flash suppressant be added.
• the propellant may also contain a coolant such as symmetrical-diethyldiphenylurea (centralite) or butyl stearate. A stabilizer such as centralite may be added.
• the propellant may contain a small quantity of basic lead carbonate which has a relatively low decomposition temperature and upon ignition of the propellant decomposes to form molten lead.
• This molten lead serves as a gun bore lubricant.
• Varying amounts of volatiles are employed as a processing additive. As used in this specification volatiles may be defined to mean such things as water, alcohol and ether.
• the process for preparing the instant gun propellant follows standard procedures for propellant manufacture.
• the nitrocellulose is mixed with alcohol and ether to form a colloidal mixture.
• the nitrocellulose may be colloided by the conventional method of forcing the alcohol and other into the fibers to form a solid colloid.
• the material is broken up mechanically and the proper amounts of the other constituents are added to give the desired ratio of nitrocellulose to coolant, stabilizer and flash suppressant (if any ⁇ .
• an excess amount of volatiles is added.
• the mix is then placed in a drying room and maintained at a slightly elevated temperature to vaporize the excess volatiles.
• a sample is withdrawn from the mix and its rate of burning is measured. As the percentage of volatiles decreases, the propellant becomes more quick, that is the linear burning rate is increased. This quicl'ness may be correlated to the ballistic properties of the propellant so that these properties may be controlled by providing the appropriate degree of quickness.
• the composition of the propellants may be varied to provide a nominal adiabatic flame temperature Within the range K. to 2200 K. by adjusting the relative proportions of coolant and nitrocellulose. Within this range the propellants all exhibit suitable ballistic properties. Of course propellants having higher adiabatic flame temperatures also possess good ballistic prop rties. However, the higher the flame temperature, the greater is the gun erosion rate. For that reason, this invention is concerned only with those propellants in the aforementioned flame temperature range since they do not erode the gun barrel as rapidly as conventional gun propellants having higher adiabatic flame temperatures.
• the propellant may contain from about two and one half percent by weight of coolant to about seven percent.
• the percent by weight of nitrocellulose in propellants embodying the principles of this invention may vary from about eighty-seven to ninety-two.
• the nitration is preferably about twelve percent which is lower than that used in Cordite hi or Cool licrite.
• the basic lead carbonate in the composition usually forms about one percent of the total weight of the propellant.
• the remainder of the composition may be volatiles or volatiles plus up to about three percent flash supressant.
• Example I Wt. percent Nitrocellulose 89 Centralite 6 Basic lead carbonate 1 Potassium sulfate Total volatiles 4 100
• Example 2 Nitrocellulose 91.4
• the calculated adiabatic flame temperatures of Examples 1 and 2 are 2000 K. and 2100 K. respectively.
• the propellant compositions of Examples 1 and 2 were manufactured in prototype lots (50,000-1Q0,000 pounds) according to the aforementioned conventional process. Each of the propellants were used in 3" shells and were evaluated by extensive gun firing tests. The internal pressure within the gun was measured and found not to be excessive, the muzzle velocity and range were also found to be good for Examples 1 and 2 and for all the compositions of Examples 3-5, each of which were tested in a similar manner.
• a cool gun propellant consisting essentially of about 87% to 92% by weight of about 12% nitration nitrocellulose, 2 /2% to 7% by weight coolant selected from the group consisting of symmetrical die'thyl diphenyl urea and symmetrical diethyl diphenyl urea plus butyl stearate, about 1% by weight basic lead carbonate and up to about 3 cryolite, the remainder being water, alcohol and ether, s aid coolant being dispersed throughout the propellant.
• a cool gun propellant consisting essentially of about 87% to 9 2% by weight of about 12% :of nitration nitrocellulose, 2 /2% to 7% by weight symmetrical diethyl diphenyl urea as coolant, about 1% by weight basic lead carbonate and up to about 3% by weight cryolite, the remainder being water, alcohol and ether, said coo lam being dispersed throughout the propellant.
• a cool gun propellant consisting essentially of about 87% to 92% by weight of about 12% nitration nitrocellulose, 2 /2% to 6% by weight butyl stealrate as coolant, about 1% by weight symmetrical diethyl diphenyl urea, about 1% by weight basic llead carbonate and up to about 3% cryolite, the remainder being Water, alcohol and ether, said coolant being dispersed throughout the propellant.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Lubricants (AREA)

Priority Applications (2)

Applications Claiming Priority (1)

Publications (1)

Family

ID=25182485

Family Applications (1)

Country Status (2)

Citations (5)

• 0
  • BE BE660895D patent/BE660895A/xx unknown
• 1959
  • 1959-03-25 US US801971A patent/US3116190A/en not_active Expired - Lifetime

Patent Citations (5)

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