| 摘要 |
A furnace black having a volatile content of 3 to 8%, a pH between 1.5 and 4, a diphenyl guanidine uptake for a 0.5 gram sample of the black of 25 to 90% and an acid number below 14 is prepared by treating a furnace black with a chemical oxidizing agent more active than molecular oxygen at a temperature less than 450 DEG F. Specified oxidizing agents are nitric acid, nitric oxides, ozone and mixtures thereof. Preferred blacks to be treated are those having a nitrogen surface area between 80 and 130 square metres per gram, an oil absorption factor below 115 pounds of oil per 100 lb. of black and an electron microscope particle diameter between 15 and 35 millimicrons, particularly those produced according to British Patent 886,523. It is preferred that the chemical treatment is with nitric acid in aqueous solution varying in concentration from 5 to 50% HNO3 using proportions sufficient to provide from 5 to 50% of more HNO3 on the black. It is preferred to use equal parts of black and solution of HNO3 concentration between 10 and 30 and heating to around 250 DEG F. until dry. Vapour phase treatment of furnace blacks with nitric oxide may also be used by passing unheated mixtures of NO and air over the black while it is slowly rotated in a chamber heated to above 200 DEG C., and then purging with air to removed trapped vapours. Finally, the furnace blacks may be contacted with azone at about room temperature or slightly above. Preferably a slowly-rotating shallow bed of the black is slowly rotated while in contact with a gas containing 1 to 10% ozone, preferably at 150 DEG F.ALSO:A composition comprises a 100 parts saturated elastomer and at least 10 parts furnace black which has a volatile content of 3 to 8% a pH between 1.5 and 4, a diphenyl guanidine uptake for a 0.5 gram sample of the black of 25 to 90% and an acid number below 14, the bulk of the volatile content having been combined to the black by treatment at less than 450 DEG F. with a chemical oxidizing agent more active than molecular oxygen. Specified elastomers are butyl rubber, the halogenated butyls, and copolymers of ethylene, propylene, butene or other alpha-mono-olefins with minor amounts of a conjugated diene especially the terpolymer of ethylene, propylene and a minor amount of 2-cyclopentadiene. The oxidizing agent may be nitric acid, nitric oxides, ozone or mixture thereof. The usual compounding and vulcanizing agents may be present. |
