US 3052577 A
Description (OCR text may contain errors)
3,052,577 SMOKE FORMING COMPQSITIONS Arthur J. Butler, Memphis, Tenn., and Norman J. Wilkaitis, East Alton, 11]., assignors to Olin Mathieson Chemical Corporation, East Alton, 11]., a corporation of Virginia No Drawing. Filed Apr. 9, 1958, Ser. No. 727,267 5 Claims. (Cl. 149-19) to rough handling or to the ballistic forces encountered when they are fired from shells.
Ordinary smoke forming compositions are prepared by mixing the granular pyrotechnic ingredients and then compressing them under considerable pressure to form a consolidated body. When such compressed material is subjected to jar or shock, it often fractures and thus exposes large surface areas which result in the production of a large open flame rather than the development of copious amounts of colored smoke. Recently such compositions have been provided with a binder consisting of a liquid polymer that is further polymerized after it has been added to the mixture. Although such mixes have proven successful, the preparation of such compositions is complicated because long curing under carefully controlled conditions is required to insure proper in situ polymerization of the binder.
It is, therefore, an object of the present invention to provide novel colored smoke producing compositions overcoming the disadvantages of the prior art. It is also an object of this invention to provide a novel and improved process for the production of colored smoke form-.
ing compositions. A more specific object of this invention is to provide consolidated colored smoke forming compositions which will burn satisfactorily under all operating conditions.
In accordance with this invention, generally stated, these and other objects are accomplished by providing colored smoke forming compositions containing from about 1% to about by weight of polyvinyl acetate, vinylidene chloride, or their copolymers as a binder. The binder is incorporated into the composition by mixing the composition with a solution of the binder and subsefluently removing the solvent from the mixture. While methylene chloride is the preferred solvent, other so-lvents, such as ethyl acetate, isopropyl acetate, methyl ethyl ketone, acetone, and the like can also be used. The mixture of the smoke forming composition and the binder solution can be molded, extruded or otherwise formed into any desired shape and upon removal of the solvent is transformed into a tough, resilient mass. In those cases where dimensional stability is not critical, the composition can be molded before removal of the solvent. In other instances, where shrinkage of any degree is to be avoided, it has been found preferable to remove a portion of the solvent so as to form a putty-like mass from which the remainder of the solvent is removed. Alternatively, the major portion of the solvent can be removed so as to provide a pyrotechnic mixture which is apparently dry but which is readily consolidated under moderate pressures, for example, between about 250 and 350 p.s.i.
While the plastic binder of this invention is applicable 3,952,577 Patented Sept. 4, 1962 to all types of smoke producing formulations, it has been found to be particularly suitable for use with those compositons containing a dye together with a fuel, an oxidizer, and a combustion controlling agent. Suitable fuels include sulfur, sucrose, charcoal and the like, while the oxidizers can be chosen from well known oxidizing agents such as potassium chlorate, potassium perchlorate, ammonium perchlorate, and similar compounds. The combustion controlling agent serves primarily as a deterrent and prevents the compositon from burning with an open flame. The preferred combustion controlling agent is sodium bicarbonate, but similar compounds, such as potassium bicarbonate, ammonium chloride, and the like, can also be used. In those cases Where the presence of a separate fuel is objectionable, the fuel can be eliminated and the amount of binder increased. In such instances, the vinyl polymer renders the composition cohesive and also provides fuel for the oxidizing agent.
Although the various components of the pyrotechnic compositions made in accordance with this invention can vary within wide limits, it has been found that superior results are obtained when such compositions contain between about 41% and about 49% dye, between about 7% and about 12% of a fuel, between about 15% and about 30% of a combustion controlling agent, and between about 18% and about 30% of an oxidizing agent.
In order to realize the advantages inherent to this invention, the binder must be maintained between about 1% and about 10% by weight of the smoke forming composition. Compositions containing less than about 1% of a binder do not exhibit suitable cohesive properties and crumble under rough handling conditions. When the vinyl plastic binder exceeds about 10% by weight of the composition, it has been found that it detracts from the color producing capabilities of the composition. In addition, amounts of the vinyl binder in excess of 10% do not enhance the properties of the composition but merely act as a diluent. The particular dyestufi used in the compositions will depend upon the color desired. Thus, auramine hydrochloride can be used in yellow smoke forming compositions while l-Inethylaminoanthraquinone, diethylaminorosidone, and the like can be used in red smoke forming compositions. Suitable green dyes include l,4-di-p-toluidinoanthraquinone and the like.
The invention will be further clarified and more readily understood in view of the following embodiments which exemplify practices that may be followed in carrying out the process of this invention. All proportions are expressed in parts by weight unless otherwise indicated.
In the preparation of a red smoke forming composition, about 11.1 parts sulfur, about 16 parts sodium bicarbonate and about 28.9 parts of potassium chlorate were screened separately through mesh screens. The sodium bicarbonate and sulfur were then tumbled together with about 42-parts l-methylaminoanthraquinone in a sweetie barrel for about 10 minutes. At the end of this period, the potassium chlorate was then added and mixing continued for an additonal 10 minutes to obtain a uniform mixture. The pre-mixing of the dye, sodium bicarbonate and sulfur was done to eliminate direct contact between the potassium chlorate and the sulfur. The mixture was then removed from the sweetie barrel and blended with about 25 parts of methylene chloride in which 2 parts of polyvinyl acetate had been dissolved. After the solution had been thoroughly mixed into the pyrotechnic composition, it was dried at room temperature for a period of about one hour at which time substantially all of the methylene chloride had left the composition. The resultant mixture appeared practically dry but not dusty and could be readily consolidated. The compositon was packed under about 300 psi into gremade cans approximately two inches in diameter and six inches long, and was then dried at 75 C. for about 30 hours. The resultant composition was a tough resilient mass which, upon burning, provided copious volumes of brilliant red smoke without flaming.
As another embodiment of this invention, a yellow smoke forming composition was prepared. This mixture had the following approximate composition:
Percent Auramine hydrochloride 40.0 Sodium bicarbonate 16.2 Potassium chlorate 35.3 Polyvinyl acetate 8.5
Here again, each of the components, with the exception of the binder, was separately screened through 100 mesh screens. These components were then tumbled together in a sweetie barrel for about minutes to obtain a uniform mixture. In this particular composition the polyvinyl acetate is present in larger proportions and serves as a fuel as well as a binder. This permitted the exclusion of sulfur or a similar fuel from the mix and thus simplified the mixing operation. After thorough mixing, the composition was removed from the sweetie barrel and blended with the polyvinyl acetate that had been previously dissolved in acetone. After the solution had been thoroughly mixed into the pyrotechnic composition, it was dried and loaded as in the previous example. The final product was a tough, resilient mass and upon burning provided copious volumes of brilliant yellow smoke without flaming. The elimination of the sulfur and increase in chlorate content provided a composition with a burning rate appreciably greater than that of the previous example.
In like manner, satisfactory green and yellow smoke forming compositions were prepared but the formulation was altered to accommodate the particular dye used. The green smoke formulation contained about 48% of a green dye constituting 30% auramine hydrochloride and 70% 1,4-di-p-toluidinoanthraquinone, about 9% sulfur, about 18% sodium bicarbonate, about 23% potassium chlorate, and about 2% polyvinyl acetate. The yellow smoke forming composition contained about 44% auramine, about 8.0% sulfur, about 28% sodium bicarbonate, about 18% potassium chlorate and about 2% polyvinyl acetate.
Each of the compositions prepared was thermally stable and burned uniformly, without flaming, with the evolution of large amounts of brilliantly colored smoke, even after they had been subjected to severe jolting and jarring.
While the above examples have been specifically directed to smoke producing compositions containing sulfur, sodium bicarbonate, potassium chlorate, and a dye, it will be readily appreciated that, in accordance with this invention, smoke producing formulations containing other oxidizers and fuels can also be used. These examples set forth various manipulative operations but the sequence of the various steps can be changed to meet particular circumstances. Thus, the solid materials can be added to a binder solution or the dry binder can be mixed with the other components and then subjected to the action of a suitable solvent which is subsequently removed.
Having thus described the invention, what is claimed is:
1. A colored smoke forming composition consisting essentially of between about 41% and about 49% of a dye selected from the group consisting of auramine hydrochloride, aur-amine, 1-methylaminoanthraquinone, diethylaminorosidone and 1,4-di-p-toluidinoanthraquinone, between about 7% and about 12% of a fuel selected from the group consisting of sulfur, sucrose and charcoal, an oxidizer selected from the group consisting of potassium chlorate, potasisum perchlorate and ammonium perchlorate, between about 15 and about 30% of a combustion controlling agent selected from the group consisting of sodium bicarbonate, potasisum bicarbonate and potassium chloride, and from about 1 percent to about 10 percent of a binder selected from the group consisting of polyvinyl acetate and vinylidene chloride.
2. A yellow smoke forming composition consisting essentially of about 42% 1-methylaminoanthraquinone, about 11% sulfur, about 29% potassium chlorate, about 16% sodium bicarbonate and about 2% polyvinyl acetate.
3. A yellow smoke forming composition consisting essentially of about 40% auramine hydrochloride, about 16.2% sodium bicarbonate, about 35.3% potassium chlorate and about 8.5% polyvinyl acetate as a combination binder and fuel.
4. A green smoke forming composition consisting essentially of about 48% of a green dye constituting 30% auramine hydrochloride and 1,4-di-p-toluidinoanthraquinone, about 9% sulfur, about 18% sodium bicarbonate, about 23% potassium chlorate and about 2% polyvinyl acetate.
5. A colored smoke forming composition consisting essentially of between about 41% and about 49% of a dye selected from the group consisting of auramine hydrochloride, auramine, 1-methylaminoanthraquinone, diethylaminorosidone and 1,4-di-p-toluidinoanthraquinone, between about 7% and about 12% of a fuel selected from the group consisting of sulfur, sucrose and charcoal, an oxidizer selected from the group consisting of potassium chlorate, potassium perchlorate and ammonium perchlorate, between about 15% and about 30% of a combustion controlling agent selected from the group consisting of sodium bicarbonate, potassium bicarbonate and potassium chloride, and from about 1 percent to about 10 percent of polyvinyl acetate as a binder.
References Cited in the file of this patent UNITED STATES PATENTS 1,709,636 Snelling Apr. 16, 1929 2,543,006 Finkelstein et al Feb. 27, 1951 2,673,193 Kolvoort Mar. 23, 1954 2,733,217 Woyski et a1 Jan. 31, 1956 FOREIGN PATENTS 655,585 Great Britain July 25, 1951 OTHER REFERENCES Military Explosives, TM 9-1910, TOl1A-1-34, April- 1955, pages 275276.
Gregory: Uses and Applications of Chemicals and Related Materials, 1939, p. 472.