The class of polymers of carbon monoxide and olefin(s) is well known in the art. Brubaker, U.S. Pat. No. 2,495,286 produced such polymers of relatively low carbon monoxide content in the presence of free radical initiators, e.g., peroxy compounds. G.B. 1,081,304 produced similar polymers of higher carbon monoxide content in the presence of alkylphosphine complexes of palladium compounds as catalyst. Nozaki extended the reaction to produce linear alternating polymers in the presence of arylphosphine complexes of palladium moieties and certain inert solvents. See, for example, U.S. Pat. No. 3,694,412. More recently, the production of the linear alternating polymers has become of greater interest because of the availability and the desirable properties of such polymers, now becoming known as polyketones or polyketone polymers. The more recent processes for the production of polyketone polymers are illustrated by a number of published European patent applications including 121,965, 181,014, 213,671 and 257,663. The processes generally involve the use of a catalyst composition formed from a compound of palladium, cobalt or nickel, the anion of a strong non-hydrohalogenic acid and a bidentate ligand of phosphorus, arsenic or antimony. The scope of the polymerization is extensive but, without wishing to be limited, many preferred catalyst compositions are produced from a compound of palladium, the anion of a non-hydrohalogenic acid having a pKa below 2 and a bidentate aromatic ligand of phosphorus.
The rate at which polymerization takes place will be determined in part by the ethylenically unsaturated hydrocarbons undergoing polymerization. In general, ethylene will polymerize at a rate considerably faster than ethylenically unsaturated hydrocarbons of three or more carbon atoms. Copolymers of ethylene and a second ethylenically unsaturated hydrocarbon of three or more carbon atoms are also formed at an acceptable rate in the presence of the above-described catalyst composition. When all the ethylenically unsaturated hydrocarbons are of three or more carbon atoms the rate of polymerization decreases.
It is known that the rate of production of linear alternating polymers containing at least a portion of ethylene can be improved or promoted by the presence of organic oxidizing agents including hydroquinones. In U.S. Pat. No. 4,810,774 and U.S. Pat. No. 4,824,935, it is disclosed that oxygen-containing generally acyclic aliphatic compounds such as ethers, ketones and esters will serve to promote catalytic activity in the polymerization or copolymerization of ethylene to form linear alternating polymers. It would be of advantage to provide a process for the production of linear alternating polymers of carbon monoxide and ethylenically unsaturated hydrocarbon of at least 3 carbon atoms wherein the catalytic activity of a palladium-containing polyketone polymerization catalyst has been promoted.