3,143,538 United States Patent Office Patented Aug. 4, 1964

butyl, isobutyl, sec-butyl, decyl, hepty, octyl, nonyl, 3,143,538 penty and hexyl) mono- and dihalides and both alkenyl POLYMERZATION OF PPERYLENE and dialkenyl (e.g., allyl, butenyl, pentenyl and hexenyl) James J. Robertson, Akron, Ohio, assiggor to The Fire mono- and dihalides having the general formula Hydro stone Tire & Rubber Company, Akron, Ohio, a corpo carbon AIX in which X is halogen (chlorine, bromine ration of Ohio or iodine) and x and y are whole numbers that total No Drawing. Fied May 5, 1961, Ser. No. 109,803 3, such as CHAICl2, phenylbutylaluminum bromide, 7 Caias. (C. 260-94.3) ethylaluminum bromochloride, CHAICl2, C6H1AlCl2, This invention relates to the polymerization of piperyl (C2H5)2AlCl, (C4H9)2ACl, (C5Hg)2AlCl, etc. In any ene and other monomers with a three-component catalyst. 10 of these halides, the hydrocarbon groups can be the same The catalyst is made from a hydrocarbon lithium, a hy or different. drocarbon aluminum compound, and a trihalide of a The halides of the Group II metals include the tri metal of Group III of the Periodic Table. halides of boron, aluminum, and other metals of Group An advantage of this three-component catalyst is the III of the Periodic Table. The trichlorides are preferred, speed with which it polymerizes various monomers. On 5 but the tribromides, triiodides and mixed halides (e.g., certain monomers as, for example, isobutylene, it reacts bromodichlorides, bromochloroiodides) and salts of 2 with explosive violence. Although piperylene is polym or more metals of Group II can be used. erized only slowly with other diolefin catalysts, it is rapidly The catalyst of the invention is made by first mixing the polymerized by the catalysts of the invention. The micro hydrocarbon lithium with the halide of a Group III metal structure of the new polypiperylene is shown by infrared 20 to produce a reaction product. This step is conveniently analysis to be substantially entirely 1,4-addition. carried out in an inert solvent, such as an alkane or Suitable hydrocarbon lithiums are for instance alkyl cycloalkane. Then the hydrocarbon aluminum com lithium compounds such as methyllithium, ethyllithium, pound is added. Either or both mixing steps can be done butyllithium, amyllithium, hexyllithium, 2-ethylhexyl at room temperature or at any convenient temperature, lithium and n-hexadecyllithium. In addition to the satul 25 such as any temperature in the range of -100° C. to rated aliphatic lithium compounds, unsaturated com 250° C. The ratio of hydrocarbon lithium to the halide pounds are also suitable such as allyllithium, methallyl of a Group I metal to the hydrocarbon aluminum com lithium and the like. Aryl-, alkaryl- and aralkyllithium pound is in the molar ratio of 0.1 to 5/0.1 to 5/0.1 to 5. compounds such as phenyllithium, the several tolyl- and Any operable level of catalyst can be used, such as 0.001 Xylyl-lithiums, alpha- and beta-naphthyl lithium and the 30 to 5 percent of the weight of monomer. like are also suitable. Mixtures of the various hydrocar In addition to piperylene (which can be cis-piperylene, bon lithium compounds are also suitable. For instance, trans-piperylene or a mixture) other ethylenically un a catalyst can be prepared by reacting an initial hydro saturated monomers can be polymerized by the catalyst carbon lithium compound successively with an alcohol of the invention. Other conjugated diolefins contemplated and with an olefin such as propylene (i.e., a technique 35 are butadiene-1,3, isoprene and 2,3-dimethylbutadiene analogous to the "Alfin' technique) whereby a greater 1,3 and various copolymers of these with or without or lesser proportion of the lithium from the initial hydro piperylene. Alpha olefins can be polymerized by the carbon goes to form a lithium alkoxide and to form a catalyst of the invention, including styrene, methylstyrene, new organolithium compound with the olefin. Additional vinyltoluene, isobutylene, and the like. Copolymers of hydrocarbon lithium compounds are the hydrocarbon 40 any of the above monomers can be made in accordance polylithium compounds such as for instance any hydro with the invention. Other monomers can be substituted carbon containing from 1 to about 40 carbon atoms in for any of the above, including methylmethacrylate and which lithium has replaced a plurality of hydrogen atoms. other known acrylates and methacrylates, acrylonitrile and Illustrations of suitable hydrocarbon polylithium com methacrylonitrile, and other known ethylenically unsatu pounds are alkylenedilithium compounds such as methyl 45 ratedThe monomers. polymerization is carried out in any hydrocarbon enedilithium, ethylenedilithium, trimethylenedilithium, solvent for the monomer, Such as pentane, heptane, oc pentamethylenedilithium, hexamethylenedilithium, deca tane, hexane, petroleum ether, benzene, toluene, a xylene, methylenedilithium, octadecamethylenedilithium and 1,2- or any other inert solvent for the monomer which is liquid dilithiumpropane. Other suitable polylithium hydrocar 50 at the temperature of the reaction. A mixture of solvents, bons are polylithium-aryl, -aralkyl and-alkaryl com e.g., commercial Xylene and pentane, can be used. Also, pounds such as 1,4-dilithiumbenzene, 1,5-dilithium naph excess piperylene can be used as solvent. The tempera thalene, 1,2-dilithium-1,3-diphenylpropane, and the like. ture of the polymerization can vary from -100° C. to Tri- and higher lithium hydrocarbons are also suitable, 250 C., although the range of -35 C. to 100° C. is such as 1,3,5-trilithiumpentane or 1,3,5-trilithiumbenzene. 55 usually preferred. Other compounds include the various lithium hydrocar Piperylene, which is a by-product of isoprene, usually bon amides. Likewise, there may be employed the contains as impurities cyclopentadiene and isopropenyl lithium-polynuclear aromatic hydrocarbon adducts pro acetylene, which are generally considered polymerization duced by simply reacting lithium metal with naphthalene, inhibitors and are often removed from the raw material anthracene, biphenyl, and the like polynuclear aromatic before polymerization as, for example, by reaction with hydrocarbons. The hydrocarbon acquires a negative maleic anhydride to remove the cyclopentadiene, and by charge without losing any of its hydrogens, and serves admixture with a reagent containing cuprous ions to re as the anion (the lithium losing an electron to serve as move the isopropenyl acetylene. For polymerization in the cation) of the salt. The hydrocarbon aluminum compounds include tri the system to which this invention relates, the piperylene alkylaluminums of 1 to 6 carbon atoms such as trimethyl 65 was not chemically freed from these inhibitors, but com aluminum, triethylaluminum, trihexylaluminum, dibutyl mercial piperylene, once distilled, was employed. Re aluminum, trioctylaluminum and phenyldibutylaluminum; moval of cyclopentadiene and alpha acetylenes makes pos and the corresponding unsaturated compounds, viz. tri sible the preparation of a polymer of greater molecular alkenylaluminums of 1 to 6 carbon atoms such as tri weight. allylaluminum, tributenylaluminum, tripentenylaluminum, 70 More active catalyst systems of the invention are pro trihexenylaluminum, tribenzylaluminum and styryldimeth duced in the presence of some ethylenically unsaturated ylaluminum; also both alkyl and dialkyl (methyl, propyl, monomer. The monomer is usually the one to be polym 3,143,538 3 erized by the completed catalyst, but not necessarily. The 4. monomer can be added at the time the hydrocarbon lith What is claimed is: ium is mixed with the Group III halide, but is usually 1. The method of making a polymer in an inert solvent, fully as effective if added just prior to the addition of the in which method the polypiperylene produced is substan hydrocarbon aluminum compound. As this activation of tially entirely of 1,4-addition configuration, from monomer the catalyst system by monomer appears to be catalytic, which includes at least a substantial amount of piperylene, even a very small amount added before reaction of the which method comprises admixing a hydrocarbon lithium aluminum compound with the intermediate catalyst re with a trihalide of a metal of Group III of the Periodic action product is effective. For example, 0.1 molar pro Table in the presence of some Inonomer, mixing the re portion of monomer is enough to activate a system con Sulting product and monomer to be polymerized with a taining 0.1 to 5 molar proportions of the catalyst. 0. hydrocarbon aluminum compound of the formula The polymerization is carried out in the absence of air, Hydrocarbon. AlHalogeny conveniently accomplished by drying the reaction vessel in which there is at least some hydrocarbon and the sum in hot oven and then charging the vessel while hot, utiliz of x and y is 3, said hydrocarbon being selected from the ing the heat of the reaction vessel to volatilize sufficient group consisting of alkyl groups, alkenyl groups, aralkyl solvent to flush all air from the vessel. The reaction ves groups and phenyl; the hydrocarbon lithium, the trihalide sel is then sealed and agitated as by being turned end and the hydrocarbon aluminum compound being present over-end or rotated in a polymerization bath. The po in the molar ratio of 0.1 to 5/0.1 to 5/0.1 to 5, and polym lymerization is carried to a desirable percentage conver erizing the monomer at a temperature of -100 to 250 sion. The polymerization time in Example 1 (below) was 20 5 minutes and in each of Examples 2 and 3 (below) it was C., the catalyst concentration being 0.001 to 5 percent of overnight (i.e., 16 hours between the start and the next the weight of the monomer. observation, at which time polymerization had been com essentially2. The processpiperylene. of claim 1 in which the monomer is pleted or was interrupted). The product can be used 3. The process of claim 1 in which the trihalide is boron where polypiperylenes are used and generally wherever 25 trichloride. rubbery polypentadienes have been employed, as, for ex 4. The process of claim 1 in which the hydrocarbon ample, for extending rubbers in rubber compounding, and lithium is an alkyl lithium in which the alkyl group con the production of vulcanizates for tires, etc., and in re tains 1 to 6 carbon atoms. action products as in chlorination to produce a substitute - 5. The process of claim 1 in which the monomer is for chlorinated rubber. 30 essentially piperylene, the trihalide is boron trichloride The invention is illustrated by the following examples, and the molar ratio is substantially 1/1/1. in which all parts and percentages are by weight. 6. The process of polymerizing piperylene which com Examples 1-3 prises dissolving the piperylene in a hydrocarbon which is The conditions of the polymerizations, and the nature both liquid and a solvent for the monomer and the poly of the polymer products are summarized in the following 35 mer at the temperature employed, with 0.1 to 2 parts of table: three-component catalyst per 100 parts by weight of the piperylene at a temperature of -35 C. to 70° C., said catalyst consisting of ethyllithium, boron trichloride and Example Example Example trihexyl aluminum in the molar ratio of 0.1 to 5/0.1 to l 2 3 40 5/0.1 to 5, the ethyllithium being added to the boron tri Piperylene, g----- 100 100 100 chloride in the presence of the monomer, and the tri Hexane, g------200 200 600 Ethyllithium, minoles-- 4.0 2.0 2.0 hexyl aluminum being added to this, and thereby produc BCl3, minoles------4.0 2.0 2.0 ing polypiperylene which is substantially entirely of 1,4- A hexyla, mImoles- 2.0 2.0 4.0 addition configuration. Ratio, Lil BIAl- 1/1/0.5 1111 1/12 g. Catalyst.----- .18 0.87 i. 43 7. The process of claim 6 in which the molar ratio Temp., C----- 2 30 RT is substantially 1/1/1. Percent Conversion------50 40 100 Polyner, m.wt------CTOSS- Soluble Soluble linked low no. low mol. References Cited in the file of this patent wt. wt. 50 UNITED STATES PATENTS The table indicates the amount of the various catalyst 2,899,415 Truett ------Aug. 11, 1959 components in millimoles. The temperatures employed, 2,905,659 Miller et al. ------Sept. 22, 1959 proportions used, and solvents utilized are illustrative. In 2,931,791 Ernst et al. ------Apr. 5, 1960 Example 1 the conditions were such as to produce gelling, evidencing the production of a cross-linked polymer. The 55 FOREIGN PATENTS polymers of Examples 2 and 3 were soluble. 457,699 Belgium ------May 9, 1956 The rubbery polypiperylene of the invention is substan 223,817 Australia ------Sept. 11, 1959 tially entirely of 1,4-addition structure, and is at least 95 OTHER REFERENCES percent 1,4-addition structure, as measured by known Gaylord et al.: Linear and Stereoregular Addition infrared technique. 60 Polymers, June 18, 1959, page 402. ------UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 143,538 August 4, 1964 James J. Robertson It is hereby certified that error appears in the above numbered pat ent requiring correction and that the said Letters Patent should read as corrected below. Column l line S 66 and 67 for "dibutylaluminum" read -- dibutylhexylaluminum --; column 4 line 55, for "457, 699" read -- 547, 699 --. Signed and sealed this 12th day of January 1965.

(SEAL) Attest: ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents