Polymerization catalyst

Claim 2

In a method for forming a catalyst wherein a support material is combined with the catalyst component, the improvement comprising combining with said support material (1) from about 0.1 to about 50.0 weight percent of at least one chromium-containing compound wherein at least part of the chromium is in the trivalent state and convertible to the hexavalent state by heating in the presence of at least one of air and molecular oxygen, and (2) from about 0.1 to about 15.0 weight percent of at least one of a gallium-containing compound having the formula Ga(OR)m and a tin-containing compound having the formula Sn(OR''n, wherein m and n are equal to the valence of the gallium and tin, and wherein R and R'' are each selected from the group consisting of alkyl, aryl, cycloaklyl groups, and combinations thereof, each having one to 12 carbon atoms, inclusive with said weight percent based on the total weight of the catalysts; and heating the resulting combination of materials in the presence of at least one of air and molecular oxygen at a temperature of at least 1, 700* F. but below a temperature of about 2,000* F. at which the combined materials decompose for a time sufficient to activate the combined materials to be catalytically active for the polymerizatin of monomers.

Claim 3

The method according to claim 3 wherein said support is at least one of silica, alumina, zirconia, thoria, and mixtures thereof, the catalysts consisting of from about 0.1 to about 50.0 weight percent of chromium oxide calculated as chromium trioxide, and at least 0.1 weight percent of the final catalyst being chromium in the hexavalent state.

Claim 4

The method according to claim 3 wherein said support is silica-alumina, the gallium and the tin compounds are at least one of gallium ethoxide, gallium isopropoxide, tin ethoxide, and tin isopropoxide, and the chromium-containing compound is chromium trioxide.

Claim 5

The method according to claim 3 wherein said at least one chromium-containing compound and said at least one gallium- and at least one tin-containing compound are both dispersed with said support by way of substantially nonaqueous dispersants, said dispersants having a water content of less than 0.1 weight percent based on the total weight of the dispersants, and the dispersant for the chromium-containing compound is at least one of pyridine, N-methylpyrrolidone, N,N-diethylacetamide, N,N-dimethylacetamide, triethylamine, methyl-substituted pyridine, formamide, n-butylamine, dipropylamine, aniline, methylaniline, toluidine, phenylenediamine, diphenylamine, triphenylamine, and benzidine.

Claim 6

The method according to claim 6 wherein said support is silica-alumina, at least one of gallium ethoxide and stannic isopropoxide is first added to the support using a nonaqueous dispersion of the compound in one of toluene and isopropyl alcohol, and thereafter adding to the support chromium trioxide using a nonaqueous solution of the chromium trioxide in dimethylformamide, and the resulting combination of materials is heated at a temperature of from about 1,700* to about 1,800* F. for from about 1 to about 50 hours in the presence of air which contains less than 5 parts per million water.