Petroleum hydrocarbon binder with reduced polycyclic aromatic hydrocarbon content
View Patent ↗A binder pitch material includes a petroleum pitch and asphalt fraction obtained from petroleum crude oil and has a significantly lower polycyclic aromatic hydrocarbon composition than a coal tar pitch having a like softening point. The pitch material is useful as a binder material for various applications such as clay pigeons.
1. A binder useful to produce an environmentally acceptable clay pigeon, which does not have reportable amounts of polycyclic aromatic hydrocarbons, comprising approximately 60 to about 75% wt., pulverized limestone or other suitable filler and the remainder comprising a thermoplastic frangible pitch material containing low concentrations of the polycyclic aromatic hydrocarbons comprising:
(i) a petroleum pitch having a softening point of at least about 100° C. and
(ii) an asphalt fraction having a softening point ranging from about 70° to about 160° C., wherein the asphalt fraction is produced by distillation or solvent extraction of asphalt containing petroleum crude oil, and optionally, up to about 50% of a solvent or cut back oil, and wherein the asphalt fractioni has a specific gravity ranging from about 0.90 to about 1.10:
whereby the resultant frangible pitch material has a softening point in the range of about 100° C. to about 130° C., a total identified polycyclic aromatic hydrocarbon content in the range of about 5000 mg/kg or less, and is an amorphous solid at room temperature.
2. A clay pigeon comprising a filler and a thermoplastic frangible pitch material containing low concentrations of polycyclic aromatic hydrocarbons comprising:
(i) a petroleum pitch having a softening point of at least about 100° C. and
(ii) an asphalt fraction having a softening point ranging from about 700 to about 160° C., wherein the asphalt fraction is produced by distillation or solvent extraction of asphalt containing petroleum crude oil, and optionally, up to about 50% of a solvent or cut back oil, and wherein the asphalt fractioni has a specific gravity ranging from about 0.90 to about 1.10:
whereby the resultant frangible pitch material has a softening point in the range of about 100° C. to about 130° C., a total identified polycyclic aromatic hydrocarbon content in the range of about 5000 mg/kg or less, and is an amorphous solid at room temperature.
3. A clay pigeon according to claim 2 comprising about 60 to 75% of the filler and the remainder comprising the pitch material.
4. A clay pigeon according to claim 2 comprising about 65 to about 90% of the filler and from about 10 to about 35% of the pitch material.
5. A clay pigeon according to claim 2 wherein the filler is limestone, gypsum, calcium carbonate, fly ash or heavy star.
6. A clay pigeon according to claim 2 wherein the filler is pulverized limestone.
7. A clay pigeon according to claim 2 wherein the petroleum pitch asphalt fraction comprises about 20% to about 40% petroleum itch and about 60 to about 80% asphalt.
8. A clay pigeon according to claim 2 wherein the petroleum pitch asphalt fraction comprises about 40 to 60% petroleum pitch and about 40 to 60% asphalt.
9. A clay pigeon according to claim 2 having a saucer shape wherein the pigeon has a thin central region and denser edge portions.
10. A clay pigeon according to claim 9 capable of withstanding a throwing force.
11. A clay pigeon according to claim 9 that is sufficiently brittle or frangible to allow the pigeon to readily disintegrate upon being hit.