Propellant charge

Abstract

The invention is directed to a propellant charge for guns, to a combination of a propellant charge and a primer, to a firearms cartridge, and to a method for modifying the surface of a propellant charge. The propellant charge of the invention comprises multiple propellant grains, wherein an exterior part of part of the propellant grains has been subjected to a surface modification treatment comprising the successive steps of suspending propellant grains in water to prepare a slurry, adding an organic solvent to the propellant grains before, after and/or during the preparation of the slurry, mixing the slurry that comprises water and organic solvent for a period of 120 minutes or less, lowering the concentration of organic solvent, removing organic solvent, and drying the propellant grains to remove water; wherein part of the propellant grains has not been subjected to the surface modification treatment.

1 . A propellant charge for guns, comprising multiple propellant grains, wherein an exterior part of part of the propellant grains has been subjected to a surface modification treatment comprising the successive steps of
 suspending propellant grains in water to prepare a slurry,   adding an organic solvent to the propellant grains before, after and/or during the preparation of the slurry,   mixing the slurry that comprises water and organic solvent for a period of 120 minutes or less,   lowering the concentration of organic solvent,   removing organic solvent, and   drying the propellant grains to remove water;   wherein part of the propellant grains has not been subjected to the surface modification treatment.   
     
     
         2 . The propellant charge for guns of  claim 1 , wherein the organic solvent is added to the propellant grains before the preparation of the slurry. 
     
     
         3 . The propellant charge for guns of  claim 1 , wherein the organic solvent is added to the propellant grains after the preparation of the slurry. 
     
     
         4 . The propellant charge for guns of  claim 1 , wherein the organic solvent is added to the propellant grains during the preparation of the slurry. 
     
     
         5 . The propellant charge for guns of  claim 1 , wherein the surface modification treatment further comprises removing water and/or organic solvent after mixing the slurry that comprises water and organic solvent for a period of 120 minutes or less and before lowering the concentration of organic solvent. 
     
     
         6 . A propellant charge for guns, comprising multiple propellant grains, wherein an exterior part of part of the propellant grains has been subjected to a surface modification treatment comprising the successive steps of
 wetting propellant grains with water or water vapour,   adding an organic solvent to the propellant grains before, after and/or during the wetting of the propellant grains,   allowing the wet propellant grains and the organic solvent to interact for a period of 120 minutes or less,   lowering the concentration of organic solvent,   removing organic solvent, and   drying the propellant grains to remove water; wherein part of the propellant grains has not been subjected to the surface modification treatment.   
     
     
         7 . The propellant charge for guns of  claim 6 , wherein the organic solvent is added to the propellant grains before the wetting of the propellant grains. 
     
     
         8 . The propellant charge for guns of  claim 6 , wherein the organic solvent is added to the propellant grains after the wetting of the propellant grains. 
     
     
         9 . The propellant charge for guns of  claim 6 , wherein the organic solvent is added to the propellant grains during the wetting of the propellant grains. 
     
     
         10 . The propellant charge for guns of  claim 6 , wherein the surface modification treatment further comprises removing water and/or organic solvent after allowing the wet propellant grains and the organic solvent to interact for a period of 120 minutes or less, and before lowering the concentration of organic solvent. 
     
     
         11 . The propellant charge for guns of  claim 1 , wherein the propellant grains comprise nitrocellulose. 
     
     
         12 . The propellant charge for guns of  claim 1 , wherein the propellant grains comprise LOVA-propellant. 
     
     
         13 . The propellant charge for guns of  claim 1 , wherein the organic solvent is more volatile than water. 
     
     
         14 . The propellant charge for guns of  claim 1 , wherein the organic solvent comprises one or more selected from methyl acetate, ethyl acetate, isopropyl acetate, isobutyl acetate, t-butyl acetate, isopropyl ether, t-butyl methyl ether, ethyl ether, acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl isopropyl ketone, 2-butanone, 3-pentanone, 4-methyl-2-pentanone, 3,3-dimethyl-2-butanone, methyl formate, ethyl formate, propyl formate, acetol, 1,4-dioxane, 2,2-dimethoxy propane, acetonitrile and tetrahydrofuran. 
     
     
         15 . The propellant charge for guns of  claim 1 , wherein the period of time is from 15-120 minutes, preferably 20-100 minutes, such as 30-90 minutes. 
     
     
         16 . The propellant charge for guns of  claim 1 , wherein said lowering of the concentration of organic solvent is performed by adding an additional amount of water. 
     
     
         17 . The propellant charge for guns of  claim 16 , wherein the additional amount of water is 50-700% by weight of the initial amount of water. 
     
     
         18 . The propellant charge for guns of  claim 16 , wherein the additional amount of water is 100-500% by weight of the initial amount of water. 
     
     
         19 . The propellant charge for guns of  claim 1 , wherein the additional amount of water is 175-450% by weight of the initial amount of water. 
     
     
         20 . The propellant charge for guns of  claim 1 , wherein the propellant charge is in the form of a spherical propellant charge or a rifle propellant. 
     
     
         21 . A propellant charge and a primer, wherein said propellant charge is the propellant charge of  claim 1 . 
     
     
         22 . The combination of a propellant charge and a primer of  claim 21 , wherein said primer is present in an amount in the range of 1-10% by total weight of the main propellant charge, preferably 1.5-9%, such as 2-8%. 
     
     
         23 . A firearms cartridge comprising the combination of a propellant charge and a primer of  claim 21 . 
     
     
         24 . A method for modifying the surface of propellant grains, wherein said method comprises the successive steps of
 suspending propellant grains in water to prepare a slurry,   adding an organic solvent to the propellant grains before, after and/or during the preparation of the slurry,   mixing the slurry that comprises water and organic solvent for a period of 120 minutes or less,   lowering the concentration of organic solvent,   removing organic solvent, and   drying the propellant grains to remove water.   
     
     
         25 . The method for modifying the surface of propellant grains of  claim 24 , wherein the organic solvent is added to the propellant grains before the preparation of the slurry. 
     
     
         26 . The method for modifying the surface of propellant grains of  claim 24 , wherein the organic solvent is added to the propellant grains after the preparation of the slurry. 
     
     
         27 . The method for modifying the surface of propellant grains of  claim 24 , wherein the organic solvent is added to the propellant grains during the preparation of the slurry. 
     
     
         28 . The method for modifying the surface of propellant grains of  claim 24 , wherein the method further comprises removing water and/or organic solvent after mixing the slurry that comprises water and organic solvent for a period of 120 minutes or less and before lowering the concentration of organic solvent. 
     
     
         29 . A method for modifying the surface of propellant grains, wherein said method comprises the successive steps of
 wetting propellant grains with water or water vapour,   adding an organic solvent to the propellant grains before, after and/or during the wetting of the propellant grains,   allowing the wet propellant grains and the organic solvent to interact for a period of 120 minutes or less,   lowering the concentration of organic solvent,   removing organic solvent, and   drying the propellant grains to remove water.   
     
     
         30 . The method for modifying the surface of propellant grains of  claim 29 , wherein the organic solvent is added to the propellant grains before the wetting of the propellant grains. 
     
     
         31 . The method for modifying the surface of propellant grains of  claim 29 , wherein the organic solvent is added to the propellant grains after the wetting of the propellant grains. 
     
     
         32 . The method for modifying the surface of propellant grains of  claim 29 , wherein the organic solvent is added to the propellant grains during the wetting of the propellant grains. 
     
     
         33 . The method for modifying the surface of propellant grains of  claim 29 , wherein the method further comprises removing water and/or organic solvent after allowing the wet propellant grains and the organic solvent to interact for a period of 120 minutes or less, and before lowering the concentration of organic solvent.