3,446,788 United States Patent Office Patented May 27, 1969 2 3,446,788 polybutadiene segment has a high content of cis 1,4 struc POLYMERIZATION OF BUTADENE BY A ture. Other objects will become apparent as the descrip CATALYST CONTAINING ALUMNUM tion proceeds. ALKYLS, ORGANONICKEL COMPOUNDS AND METAL FLUORDES According to the invention, butadiene or butadiene in Morford C. Throckmorton and William M. Saltman, combination with other diolefins is polymerized by con Akron, Ohio, assignors to The Goodyear Tire & Rub tact under solution polymerization conditions with a cat ber Company, Akron, Ohio, a corporation of Ohio alyst comprising (1) at least one organometallic com No Drawing. Filed Mar. 20, 1967, Ser. No. 624,219 pound in which the metal is selected from Groups I, II int. C. C08d 1/14, 3/08; B01j 1 1/84 and III of the periodic system, (2) at least one organo U.S. C. 260-94.3 10 Claims 0. nickel compound and (3) a metal fluoride selected from the group consisting of phosphorus pentafluoride, ABSTRACT OF THE DISCLOSURE vanadium pentafluoride, A method and a catalyst system for the solution uranium hexafluoride, polymerization of butadiene or butadiene in mixture with 5 osmium hexafluoride, other diolefins to form polymers containing a high con rhenium hexafluoride, tent of cis 14 addition is described. The solution iodine pentafluoride, polymerization is carried out under conventional antimony pentafluoride, polymerization conditions. The catalyst employed is a tin tetrafluoride, mixture of (1) organometallic compounds of metals of 20 antimony trifluoride, Groups I, II and III; (2) organonickel compounds and induim trifluoride, (3) a metal fluoride selected from the group consisting arsenic pentafluoride, of bismuth pentafluoride, phosphorus pentafluoride, 25 niobium pentafluoride, vanadium pentafluoride, tantalum pentafluoride, uranium hexafluoride, titanium tetrafluoride, osmium hexafluoride, zirconium tetrafluoride, rhenium hexafluoride, zinc difluoride, iodine pentafluoride, 30 platinum hexafluoride, antimony pentafluoride, hafnium tetrafluoride, tin tetrafluoride, thorium tetrafluoride, antimony trifluoride, lead tetrafluoride, indium trifluoride, cadmium difluoride, arsenic pentafluoride, titanium trifluoride, bismuth pentafluoride, iron trifluoride, niobium pentafluoride, cobalt trifluoride, tantalum pentafluoride, vanadium trifluoride, titanium tetrafluoride, palladium trifluoride, zirconium tetrafluoride, 40 germanium tetrafluoride, zinc difluoride, tellurium tetrafluoride, platinum hexafluoride, copper difluoride and silver difluoride. hafnium tetrafluoride, The organometallic compounds useful in this inven thorium tetrafluoride, tion are organocompounds of such metals as lithium, lead tetrafluoride, sodium, potassium, rubidium, cesium, magnesium, cadmium difluoride, calcium, strontium, beryllium, barium, zinc, cadmium, titanium trifluoride, aluminum, gallium and indium. By the term, "organo iron trifluoride, metallic' is meant alkyl, cycloalkyl, aryl, arylalkyl, cobalt trifluoride, alkaryl radicals are attached to the metal to form the vanadium trifluoride, organo compound of the particular metal. palladium trifluoride, Of the organometallic compounds useful in this inven germanium tetrafluoride, tion, it is preferred to use organoaluminum compounds, tellurium tetrafluoride, organomagnesium compounds, organozinc compounds copper difluoride and silver difluoride. and organolithium compounds. 5 5 By the term "organoaluminum compound' is meant any organoaluminum compound responding to the for This invention is directed to methods of polymerizing imula butadiene and butadiene in mixture with other diolefins R1 to form polymers having a high content of cis 1,4 addi / tion. It is also directed to catalyst systems useful for this 60 purpose. A R3R. Polymers of butadiene or butadiene in mixture with in which R1 is selected from the group consisting of other diolefins containing a high proportion of the buta alkyl (including cycloalkyl), aryl, alkaryl, arylalkyl, hy diene units in the cis 1,4 configuration possess prop drogen and fluorine, Ra and Ra being selected from the erties which make then useful as synthetic rubbers. 65 group of alkyl (including cycloalkyl), aryl, alkaryl, It is an object of this invention to provide a method alkoxy and arylalkyl. Representative of the compounds whereby butadiene can be polymerized to a high con responding to the formula set forth above are: tent of cis 1.4 polybutadiene. Another object is to provide diethylaluminum fluoride, a catalyst system by which these polymerizations may be di-n-propylaluminum fluoride, accomplished. Another object is to form copolymers of 70 di-n-butylaluminum fluoride, isoprene or other diolefins and butadiene in which the diisobutylaluminum fluoride, 3,446,788 3 4. dihexylaluminum fluoride, n-, sec- or t-butyllithium, hexyllithium, styryllithium or dioctylaluminum fluoride, and phenylithium. Also, the organolithiumaluminum com diphenylaluminum fluoride. pounds may be used. These compounds respond to the formula R'R''LiAl where R' and R' may be alkyl, Also included are alkaryl or arylalkyl groups and R' and RR' may or may diethylaluminum hydride, not be the same group. Representative of these com di-n-propylaluminum hydride, pounds are n-butyltriisobutyllithium aluminum, tetra di-n-butylaluminum hydride, butyllithium aluminum, butyltriethyllithium aluminum, diisobutylaluminum hydride, tetraisobutyllithium aluminum and styryltrinormalpropyl diphenylaluminum hydride, lithium aluminum. di-p-tolylaluminum hydride, 0 Representative of other organometallic compounds dibenzylaluminum hydride, which may be employed in this invention are sodium, phenylethylaluminum hydride, potassium, calcium, beryllium, cadmium and mercury phenyl-n-propylaluminum hydride, alkyls, arkaryls, arylalkyls and aryls. p-tolylethylaluminum hydride, The component of the catalyst of this invention which p-tolyl-n-propylaluminum hydride, contains nickel may be any organonickel compound. It is p-tolylisopropylaluminum hydride, preferred to employ a soluble compound of nickel. These benzylethylalumium hydride, soluble nickel compounds are usually compounds of nickel benzyl-n-propylaluminum hydride, and with a mono or bi-dentate organic ligand containing up benzylisopropylaluminum hydride and 20 to 20 carbon atoms. "Ligand' is defined as an ion or other organoaluminum hydrides. Also included are molecule bound to and considered bonded to a metal diethylethoxyaluminum and dipropylethoxyaluminum. atom or ion. Mono-dentate means having one position through which covalent or coordinate bonds with the Also included are metal may be formed; bi-dentate means having two posi trimethylaluminum, 25 tions through which covalent or coordinate bonds with triethylaluminum, the metal may be formed. By the term "soluble' is meant tri-n-propylaluminum, soluble in inert solvents. Thus, any nickel salt of an triisopropylaluminum, organic acid containing from about 1 to 20 carbon atoms tri-n-butylaluminum, may be employed. Representative of such organonickel triisobutylaluminum, 30 compounds are nickel benzoate, nickel acetate, nickel tripentylaluminum, naphthenate, bis (alpha furyl dioxime) nickel, nickel oc trihexylaluminum, tanoate, nickel palmitate, nickel stearate, nickel acetyl tricyclohexylaluminum, acetonate, bis(salicylaldehyde) ethylene diimine nickel trioctylaluminum, and nickel salicaldehyde. Nickel tetracarbonyl also may triphenylaluminum, be employed as the nickel containing catalyst in this in tri-p-tolylaluminum, vention. The preferred component containing nickel is tribenzylaluminum, a nickel salt of carboxylic acid or an organic complex ethyldiphenylaluminum, compound of nickel. ethyl-di-p-tolylaluminum, The third components of the catalyst which are the ethyldibenzylaluminum, 40 metal fluorides listed above should be, of course, an diethylphenylaluminum, hydrous and as pure as possible. Since some of these diethyl-p-tolylaluminum, metal fluorides are gases, it may be more desirable to diethylbenzylaluminum and other triorganoaluminum dissolve them in a solvent and charge them to the polym compounds. erization system as liquid solutions. Such solvents may By the term "organomagnesium compounds' is meant be any alkyl, aryl, alkaryl or arylalkyl hydrocarbons, ben first any organomagnesium complex responding to the 45 Zene or heptane being usually preferred. formula RaMgxi where R may be alkyl, aryl, arylalkyl The three catalyst components may be charged sepa or alkaryl; X is a halogen, and a and b are mole fractions rately in either stepwise or simultaneous addition to the whose sum equals 2 while the ratio of a/b is greater than polymerization system or they may be mixed with one 2 but is not infinite. Representative among the com 50 another in an inert solvent and this "preformed' catalyst pounds responding to the formula set forth above are can then be added to the monomer-solvent polymeriza ethylmagnesium chloride complex, cyclohexylmagnesium tion system. bromide complex and phenylmagnesium chloride com The three component catalyst system of this invention plex. Such compounds are usually prepared in the ab has shown polymerization activity over a wide range of sence of ether. 55 catalyst concentrations and catalyst ratios. The three Also "organomagnesium compounds" means any or catalyst components inter-react to form the active cata ganomagnesium compound or any organomagnesium lyst. As a result, the optimum concentration for any one halide of the Grignard type corresponding to the formulas