초록 ▼

A high-density composite material and its use in the manufacture of less-lethal ammunition projectile is disclosed. The composite ammunition projectile material is produced from a compact mixture of fine iron powder, a highly damping, inert, non-toxic elastomer and an inert non-toxic thermoplastic e

A high-density composite material and its use in the manufacture of less-lethal ammunition projectile is disclosed. The composite ammunition projectile material is produced from a compact mixture of fine iron powder, a highly damping, inert, non-toxic elastomer and an inert non-toxic thermoplastic elastomer. The composite ammunition projectile material is first blended, then the projectile is injection molded or compression molded. The density of the composite ammunition projectile material is adjustable in terms of ratio of iron powder to elastomer to thermoplastic elastomer block co-polymer, but a minimum density of 2.4 gcm-3 is preferred. A blend comprising an elastomer and a thermoplastic elastomer with low creep is also disclosed.

대표청구항 ▼

Therefore what is claimed is: 1. A polymer-based ammunition, comprising: a composite material including a polymer matrix including at least one thermoplastic elastomeric polymer (TPE) component, and at least one soft elastomeric polymer component that at ambient temperatures is above its glass tran

Therefore what is claimed is: 1. A polymer-based ammunition, comprising: a composite material including a polymer matrix including at least one thermoplastic elastomeric polymer (TPE) component, and at least one soft elastomeric polymer component that at ambient temperatures is above its glass transition temperature; particles of a sufficiently high specific gravity material that are dispersed in the polymer matrix and present in an amount such that the composite material has a specific gravity of in a range from about 2 to 3; and the composite material having a shape of a pre-selected projectile. 2. The polymer-based ammunition according to claim 1 wherein the thermoplastic elastomeric polymer (TPE) component comprises a block copolymer having at least one elastomeric block. 3. The polymer-based ammunition according to claim 2 wherein the thermoplastic elastomeric polymer (TPE) component is selected from the group consisting of polystyrene-polyisobutylene block copolymers, polystyrene-polybutadiene block copolymers, polystyrene-polyisoprene block copolymers, polystyrene-poly(ethylene-butylene block copolymers, polystyrene-poly(ethylene-propylene) block copolymers, thermoplastic polyolefins (TPOs), and dynamically vulcanized TPVs. 4. The polymer-based ammunition according to claim 1, wherein the thermoplastic elastomeric polymer (TPE) component has a structure selected from the group consisting of linear, star, arborescent, comb, brush, centipede, hyperbranched, and dendritic. 5. The polymer-based ammunition according to claim 1, wherein the elastomeric polymer component is selected from the group consisting of polyisobutylene, polyisobutylene-isoprene copolymers, polyisobutylene-styrene copolymers, polyisobutylene-alkyl styrene copolymers, halogenated polyisobutylene-alkyl styrene terpolymers, polybutadiene, polyisoprene, polyethylene-propylene copolymers, polyethylene-propylene diene terpolymers. 6. The polymer-based ammunition according to claim 1, wherein the elastomeric polymer component is polyisobutylene, and wherein the thermoplastic elastomeric polymer (TPE) component is polystyrene-polyisobutylene-polystyrene (SIBS). 7. The polymer-based ammunition according to claim 1, wherein the elastomeric polymer component is a polyisobutylene-isoprene copolymer, and wherein the thermoplastic elastomeric polymer (TPE) component is polystyrene-polyisobutylene-polystyrene (SIBS). 8. The polymer-based ammunition according to claim 1, wherein the elastomeric polymer component is present in an amount from about 10% to about 90% by weight of the polymer matrix, and wherein the thermoplastic elastomeric polymer component is present in an amount from about 90 to about 10% by weight of the polymer matrix. 9. The polymer-based ammunition according to claim 1, wherein the elastomeric polymer component is present in an amount from about 40% to about 60% by weight of the polymer matrix, and wherein the thermoplastic elastomeric polymer component is present in an amount from about 60 to about 40% by weight of the polymer matrix. 10. The polymer-based ammunition according to claim 5 wherein the elastomeric polymer component has a structure selected from the group consisting of linear, star, arborescent, comb, brush, centipede, hyperbranched and dendritic. 11. The polymer-based ammunition according to claim 1, wherein the specific gravity of the composite material is at least about 2.44. 12. The polymer-based ammunition according to claim 1, wherein the high specific gravity material is present in the composite material in an amount of from about 50 to about 90% by volume of the total composite. 13. The polymer-based ammunition according to claim 1, wherein the high specific gravity material is present in the composite material in an amount of from about 60 to about 80% by volume of the total composite. 14. The polymer-based ammunition according to claim 1, wherein the high specific gravity material is present in the composite material in an amount of from about 10 to about 90% by volume of the total composite. 15. The polymer-based ammunition according to claim 1 wherein the composite material has a cylindrical or spherical shape. 16. The polymer-based ammunition according to claim 1 having a hardness value, as measured according to the Shore A scale, in a range of from about 15 to about 80. 17. The polymer-based ammunition according to claim 1 having a hardness value, as measured according to the Shore A scale, in a range of from about 30 to about 55. 18. The polymer-based ammunition according to claim 1 wherein the particles of a high specific gravity material are selected from the group consisting of iron powder, tungsten, copper, bismuth, and iron oxide. 19. The polymer-based ammunition according to claim 1 wherein the particles of a high specific gravity material are iron powder particles. 20. The polymer-based ammunition according to claim 19 wherein the iron powder particles have sizes in a range from about 71.4% of-100 to +325 U.S. Mesh and 23.2% of-325 U.S. Mesh, specific gravity, 7. 21. The polymer-based ammunition according to claim 1 produced by molding the composite material into any one of a cylindrical or spherical shape. 22. The polymer-based ammunition according to claim 21 wherein the step of molding is one of injection molding and compression molding. 23. The polymer-based ammunition according to claim 1 wherein the composite material has a dynamic mechanical compression creep below a threshold creep so that the polymer-based ammunition maintains its shape. 24. The polymer-based ammunition according to any one of claim 23 wherein said threshold dynamic mechanical compression creep is about 20%. 25. The polymer-based ammunition according to claim 23 wherein dimensions of the composite material do not change more than 10% for at least a year. 26. The polymer-based ammunition according to claim 1 wherein the composite material has a dynamic mechanical compression creep between 4 and 20% creep.