Patent Number: 
Section: claims

1. A lightweight and rigid, lead-free, integral radiation shielding structural composition comprising at least two radiation shielding elements in elemental or alloyed form, or compounds thereof, having complementary radiation attenuation characteristics, dispersed in a thermoset or thermoplastic resin and further comprising at least one flame retardant. 2. The lightweight and rigid, lead-free integral radiation shielding structural composition of claim 1 that can shield x-rays having energies from about 100 kVp to about 200 kVp. 3. The lightweight and rigid, lead-free integral radiation shielding structural composition of claim 2 that can shield radiation equivalent to from about 0.50 mm to about 6 mm lead. 4. The lightweight and rigid, lead-free integral radiation shielding structural composition of claim 1 wherein the radiation shielding elements are selected from the group consisting of antimony, bismuth, iodine, tungsten, tin, tantalum, erbium, barium and alloys or compounds thereof. 5. The lightweight and rigid, lead-free integral radiation shielding structural composition of claim 1 that is dense and comprises:A) from about 5% to about 20% by weight resin; andthe balance of the structural composition comprising;B) from about 10% to about 85% in elemental weight % of at least one element selected from the group consisting of antimony, tin, barium and iodine; andC) from about 15% to about 90% in elemental weight % of at least one element selected from the group consisting of bismuth, tungsten, tantalum and erbium. 6. The lightweight and rigid, lead-free integral radiation shielding structural composition of claim 5 that is dense and comprises:A) from about 7% to about 12% by weight resin; andthe balance of the structural composition comprising;B) from about 15% to about 80% in elemental weight % of at least one element selected from the group consisting of antimony, tin, barium and iodine; andC) from about 20% to about 85% in elemental weight % of at least one element selected from the group consisting of bismuth, tungsten, tantalum and erbium. 7. The lightweight and rigid, lead-free integral radiation shielding structural composition of claim 1 that is dense and comprises:A) from about 5% to about 20% by weight resin; andthe balance of the structural composition comprising;B) from about 15% to 60% in elemental weight % of at least one selected from the group consisting of erbium, tungsten and tantalum; andC) from about 40% to about 85% in elemental weight % of bismuth. 8. The lightweight and rigid, lead-free integral radiation shielding structural composition of claim 7 that is dense and comprises:A) from about 7% to about 12% by weight resin; andthe balance of the structural composition comprising;B) from about 25% to 50% in elemental weight % of at least one selected from the group consisting of erbium, tungsten and tantalum; andC) from about 50% to 75% in elemental weight % of bismuth. 9. The lightweight and rigid, lead-free integral radiation shielding structural composition of claim 1 that is dense and comprises:A) from about 5% to about 20% by weight resin; andthe balance of the structural composition comprising;B) at least two elements, alloys or compounds thereof, selected from at least two different groups consisting of;i) antimony, tin, barium and iodine;ii) erbium, tungsten and tantalum; andiii) bismuth. 10. The lightweight and rigid, lead-free integral radiation shielding structural composition of claim 9 that is dense and comprises:A) from about 5% to about 20% by weight resin; andthe balance of the structural composition comprising;B) at least two elements selected from at least two different groups consisting of;i) up to about 85% in elemental weight % of at least one selected from the group consisting of antimony, tin, barium and iodine;ii) up to about 50% in elemental weight % of at least one selected from the group consisting of erbium, tungsten and tantalum; andiii) up to about 90% in elemental weight % of bismuth. 11. The lightweight and rigid, lead-free integral radiation shielding structural composition of claim 10 that is dense and comprises:A) from about 7% to about 12% by weight resin; andthe balance of the structural composition comprising;B) at least two elements selected from at least two different groups consisting of;i) up to about 30% in elemental weight of at least one selected from the group consisting of antimony, tin, barium and iodine;ii) up to about 40% in elemental weight of at least one selected from the group consisting of erbium, tungsten and tantalum; andiii) from about 30% to about 90% in elemental weight of bismuth. 12. The lightweight and rigid, lead-free integral radiation shielding structural composition of claim 10 that is dense and can shield x-rays having energies from about 101 kVp to about 129 kVp, comprising:A) from about 5% to about 20% by weight resin; andthe balance of the structural composition comprising;B) from about 40% to about 80% in elemental weight of at least one selected from the group consisting of tin and antimony; andC) the balance comprising at least one selected from the group consisting of tungsten, bismuth and tantalum. 13. The lightweight and rigid, lead-free integral radiation shielding structural composition of claim 10 that is dense and can shield x-rays having energies from about 130 kVp to about 150 kVp, comprising:A) from about 5% to about 20% by weight resin; andthe balance of the structural composition comprising;B) from about 15% to about 60% in elemental weight of at least one selected from the group consisting of tungsten and tantalum; andC) the balance comprising bismuth. 14. The lightweight and rigid, lead-free integral radiation shielding structural composition of claim 1, that is lighter in weight than conventional lead-lined aluminum or polymer housings, per unit area, with equivalent or superior x-ray shielding compared to lead. 15. The lightweight and rigid, lead-free integral radiation shielding structural composition of claim 1, wherein the structural composition has a flexural modulus of from about 3000 to about 30,000 MPa. 16. The lightweight and rigid, lead-free integral radiation shielding structural composition of claim 1 wherein the flame retardant is at least one selected from the group consisting of non-toxic smoke retardant and non-toxic flame retardant. 17. The lightweight and rigid, lead-free integral radiation shielding structural composition of claim 16 wherein the flame retardant is at least one selected from the group consisting of aluminum trihydrate, magnesium hydroxide and zinc borate. 18. The lightweight and rigid, lead-free integral radiation shielding structural composition of claim 1 wherein the resin, or copolymer thereof, is at least one selected from the group consisting of epoxies, vinyl esters, unsaturated polyesters, phenolics, polyesters, polyamides, polyarylether ketones, polyether ether ketones, polysulfones, poly aryl sulfones, acrylics, polyimides, polyethylene, polypropylene, polyether imides, polyvinylidene fluoride, acrylonitrile-butadiene-styrene, polyurethanes, ethylene copolymers, poly vinyl chlorides, silicones, polycarbonates, polyphenyleneoxide, polycyanates, cyanate esters, bismaleimides and acetals. 19. The lightweight and rigid, lead-free integral radiation shielding structural composition of any one of claims 1, 3, 4, 5, 7, 11, 14, 15 or 18 further comprising from about 5 to about 30 phr fiber or particle reinforcement. 20. The lightweight and rigid, lead-free integral radiation shielding structural composition of claim 19 wherein the fiber reinforcement is at least one selected from the group consisting of glass, carbon fiber, boron fiber, steel, tungsten, aramid, ultra-high molecular weight polyethylene and polybenzoxazole. 21. A lightweight and rigid, integral radiation shielding structural composition comprising at least two radiation shielding elements in elemental or alloyed form, or compounds thereof, having complementary radiation attenuation characteristics, dispersed in a thermoset or thermoplastic resin further comprising at least one flame retardant. 22. The lightweight and rigid, integral radiation shielding structural composition of claim 21 that can shield radiation equivalent to from about 0.50 mm to about 6 mm lead. 23. The lightweight and rigid, integral radiation shielding structural composition of claim 21 wherein the radiation shielding elements are selected from the group consisting of antimony, bismuth, lead, iodine, tungsten, tin, tantalum, erbium, barium and alloys or compounds thereof. 24. The lightweight and rigid, integral radiation shielding structural composition of claim 21 that is dense and comprises:A) from about 5% to about 20% by weight resin; andthe balance of the structural composition comprising;B) from about 10% to about 85% in elemental weight % of at least one selected from the group consisting of antimony, tin, barium and iodine; andC) from about 15% to about 90% in elemental weight % of at least one selected from the group consisting of bismuth, lead, tungsten, tantalum and erbium. 25. The lightweight and rigid, integral radiation shielding structural composition of claim 24 that is dense and comprises:A) from about 7% to about 12% by weight resin; andthe balance of the structural composition comprising;B) from about 15% to about 80% in elemental weight % of at least one selected from the group consisting of antimony, tin, barium and iodine; andC) from about 20% to about 85% in elemental weight % of at least one selected from the group consisting of bismuth, lead, tungsten, tantalum and erbium. 26. The lightweight and rigid, integral radiation shielding structural composition of claim 21 that is dense and comprises:A) from about 5% to about 20% by weight resin; andthe balance of the structural composition comprising;B) from about 15% to about 60% in elemental weight % of at least one selected from the group consisting of erbium, tungsten and tantalum; andC) from about 40% to about 85% in elemental weight % of at least one selected from the group consisting of bismuth and lead. 27. The lightweight and rigid, integral radiation shielding structural composition of claim 26 that is dense and comprises:A) from about 7% to about 12% by weight resin; andthe balance of the structural composition comprising;B) from about 25% to about 50% in elemental weight % of at least one selected from the group consisting of erbium, tungsten and tantalum; andC) from about 50% to about 75% in elemental weight % of at least one selected from the group consisting of bismuth and lead. 28. The lightweight and rigid, integral radiation shielding structural composition of claim 21 that is dense and comprises:A) from about 5% to about 20% by weight resin; andthe balance of the structural composition comprising;B) at least two elements, alloys or compounds thereof, selected from at least two different groups consisting of;i) antimony, tin, barium and iodine;ii) erbium, tungsten and tantalum; andiii) bismuth and lead. 29. The lightweight and rigid, integral radiation shielding structural composition of claim 28 that is dense and comprises:A) from about 5% to about 20% by weight resin; andthe balance of the structural composition comprising;B) at least two elements selected from at least two different groups consisting of;i) up to about 85% in elemental weight % of at least one selected from the group consisting of antimony, tin, barium and iodine;ii) up to about 50% in elemental weight % of at least one selected from the group consisting of erbium, tungsten and tantalum; andiii) up to about 90% in elemental weight % of at least one selected from the group consisting of bismuth and lead. 30. The lightweight and rigid, integral radiation shielding structural composition of claim 29 that is dense and comprises:A) from about 7% to about 12% by weight resin; andthe balance of the structural composition comprising;B) at least two elements selected from at least two different groups consisting of;i) up to about 30% in elemental weight of at least one selected from the group consisting of antimony, tin, barium and iodine;ii) up to about 40% in elemental weight of at least one selected from the group consisting of erbium, tungsten and tantalum; andiii) from about 30% to about 90% in elemental weight of at least one selected from the group consisting of bismuth and lead. 31. The lightweight and rigid, integral radiation shielding structural composition of claim 29 that is dense and can shield x-rays having energies from about 101 kVp to about 129 kVp, comprising:A) from about 5% to about 20% by weight resin; andthe balance of the structural composition comprising;B) from about 40% to about 80% in elemental weight % of at least one selected from the group consisting of tin and antimony; andC) the balance comprising at least one selected from the group consisting of tungsten, bismuth, lead and tantalum. 32. The lightweight and rigid, integral radiation shielding structural composition of claim 29 that is dense and can shield x-rays having energies from about 130 kVp to about 150 kVp, comprising:A) from about 5% to about 20% by weight resin; andthe balance of the structural composition comprising;B) from about 15% to about 60% in elemental weight of at least one selected from the group consisting of tungsten and tantalum; andC) the balance comprising at least one selected from the group consisting of bismuth and lead. 33. The lightweight and rigid, integral radiation shielding structural composition of claim 21, that is lighter in weight than conventional lead-lined aluminum or polymer housings, per unit area, with equivalent or superior x-ray shielding compared to lead. 34. The lightweight and rigid, integral radiation shielding structural composition of claim 21, wherein the structural composition has a flexural modulus of from about 3000 to about 30,000 MPa. 35. The lightweight and rigid, integral radiation shielding structural composition of claim 21 wherein the flame retardant is at least one selected from the group consisting of non-toxic smoke retardant and non-toxic flame retardant. 36. The lightweight and rigid, integral radiation shielding structural composition of claim 35 wherein the flame retardant is at least one selected from the group consisting of aluminum trihydrate, magnesium hydroxide and zinc borate. 37. The lightweight and rigid, integral radiation shielding structural composition of claim 21 wherein the resin, or copolymer thereof, is at least one selected from the group consisting of epoxies, vinyl esters, unsaturated polyesters, phenolics, polyesters, polyamides, polyarylether ketones, polyether ether ketones, polysulfones, poly aryl sulfones, acrylics, polyimides, polyethylene, polypropylene, polyether imides, polyvinylidene fluoride, acrylonitrile-butadiene-styrene, polyurethanes, ethylene copolymers, poly vinyl chlorides, silicones, polycarbonates, polyphenyleneoxide, polycyanates, cyanate esters, bismaleimides and acetals. 38. The lightweight and rigid, integral radiation shielding structural composition of any one of claims 21, 22, 23, 24, 26, 30, 33, 34, or 37 further comprising from about 5 to about 30 phr fiber or particle reinforcement. 39. The lightweight and rigid, integral radiation shielding structural composition of claim 38 wherein the fiber reinforcement is at least one selected from the group consisting of glass, carbon fiber, boron fiber, steel, tungsten, aramid, ultra-high molecular weight polyethylene and polybenzoxazole. 40. The lightweight and rigid, integral radiation shielding structural composition of claim 21 wherein the composition comprises lead in elemental or alloyed form, or compounds thereof. 41. The lightweight and rigid, integral radiation shielding structural composition of claim 38 wherein the composition comprises lead in elemental or alloyed form, or compounds thereof. 42. The lightweight and rigid, integral radiation shielding structural composition of claim 38 wherein the composition comprises lead in elemental or alloyed form, or compounds thereof and wherein the flame retardant is at least one selected from the group consisting of non-toxic smoke retardant and non-toxic flame retardant.