A DIOLEFIN POLYMER OR COPOLYMER AND A PROCESS FOR THE PRODUCTION OF THE SAME

Abstract: 1,4-addition polymers or copolymers of diolefins useful as a functional or active polymer is provided which comprises, in combination, the following recurring units (A) and (B): wherein n = 4 to 6 and A/B mole ratio = 0 to 98/100 to 2.

Description: This invention relates to novel copolymers of diolefins such as hexadiene and a process for the production of the same. It is known that the homopolymerization of 1,5-hexadiene or the copolymerization thereof with α-olefins such as propylene using Ziegler-Natta type catalysts results in the 1,2-addition or cyclization of 1,5-hexadiene. "Ziegler-Natta Catalysts and Polymerization" by Academic Press (1979), page 549 reports that when 1,5-hexadiene is polymerized at +25 °C or -20 °C using a catalyst consisting of V(acetylacetonato)₃ and AlEt₂Cl, a 1,2-addition polymer is obtained. US-A-3472830 discloses the polymerization of unconjugated alkadienes, such as 1,5-hexadiene, through a 1,2 addition reaction. There is no disclosure in this document of any process which involves a 1,4-addition reaction. We have now developed 1,4-addition copolymers of diolefins having double bonds at both the terminals, such as 1,5-hexadiene, 1,7-octadiene, etc. by the copolymerization thereof with α-olefins such as propylene. We have also developed a process for the production of diolefin copolymers. Accordingly, the present invention provides a diolefin copolymer comprising, in combination, the following recurring structural units (A) and (B), wherein n = 4 to 6 and recurring unit (B) is present in an amount of at least 2 mole%. The accompanying drawings are to illustrate the principle and merits of the present invention in detail. Figure 1 (1) and (2) are NMR spectrum charts of a copolymer of the present invention (Example 1). Figure 2 (1) is an NMR spectrum chart of another polymer of the present invention (Example 2) and Figure 2 (2) is a partly enlarged view of Figure 2 (1) in the range of 4.5 to 6 PPM. We have investigated diolefin polymers having C-C double bonds in the side chains, and consequently, have found that a 1,4-addition copolymer can be obtained by the copolymerization of 1,5-hexadiene or 1,7-octadiene with propylene at a low temperature, e.g. -50°C in the presence of a catalyst consisting of a vanadium chelate compound and an organoaluminium compound. The diolefin copolymer of the invention generally has group at the terminals. The present invention also provides a process for the production of the diolefin copolymer comprising copolymerizing a diolefin represented by the general formula wherein n is 4 to 6 with propylene at a temperature of -50°C or below in the presence of a catalyst consisting of a vanadium compound represented by the general formula, wherein R¹ to R³ are hydrocarbon groups having 1 to 8 carbon atoms or hydrogen atoms, at least one of which must be hydrogen atom but all of which must not be hydrogen atoms, and an organo-aluminium compound which is represented by the general formula R n AlX 3-n wherein R is an alkyl group or aryl group, X is a halogen atom or a hydrogen atom and n is any numeral in the range of 1 ≦ n < 3. Catalyst (a) Vanadium Compound The vanadium compound used as one component of the catalyst in the present invention is represented by the following general formula, wherein R¹ to R³ have the same meaning as described above. Examples of the vanadium compound included in the above described general formula will be illustrated: (i) Cases where R² is hydrogen atom and R¹ and R³ are hydrocarbon groups R¹/R³ : CH₃/CH₃, CH₃/C₂H₅, C₂H₅/C₂H₅, CH₃/C₆H₅, C₂H₅/C₆H₅, C₆H₅/C₆H₅, CH₃/C₆H₅CH₂, C₆H₅CH₂/C₆H₅CH₂, C₂H₅/C₆H₅CH₂ and C₆H₅/C₆H₅CH₂ (ii) Cases where R² is a hydrocarbon group, one of R¹ and R³ is hydrogen atom and the other is a hydrocarbon group R²/R¹ or R³: CH₃/CH₃, C₂H₅/CH₃, CH₃/C₂H₅, C₂H₅/C₂H₅, C₆H₅/CH₃, CH₃/C₆H₅, C₆H₅/C₂H₅, C₂H₅/C₆H₅, C₆H₅/C₆H₅, C₆H₅CH₂/CH₃, CH₃/C₆H₅CH₂, C₆H₅CH₂/C₆H₅CH₂, C₆H₅CH₂/C₂H₅, C₂H₅/C₆H₅CH₂, C₆H₅CH₂/C₆H₅, C₆H₅/C₆H₅CH₂ (iii) Cases where R² is hydrogen atom, one of R¹ and R³ is hydrogen atom and the other is a hydrocarbon group R¹ or R³: CH₃, C₂H₅, C₆H₅, C₆H₅CH₂ Above all, the following compounds are particularly preferable: (b) Organoaluminum Compound The organoaluminum compound used as the other component of the catalyst in the present invention is represented by the general formula R n AlX 3-n wherein R is an alkyl group or aryl group, X is a halogen atom or hydrogen atom and n is in the range of 1 ≦ n < 3, illustrative of which are alkylaluminum compounds having 1 to 18 carbon atoms, preferably 2 to 6 carbon atoms, such as dialkylaluminum monohalides, monoalkylaluminum dihalides, alkylaluminum sesquihalides, etc., mixtures thereof or complex compounds thereof. Examples of the organoaluminum compound are dialkylaluminum monohalides such as dimethylaluminum chloride, diethylaluminum chloride, diethylaluminum bromide, diethylaluminum iodide, diisobutylaluminum chloride and the like; monoalkylaluminum dihalides such as methylaluminum dichloride, ethylaluminum dichloride, methylaluminum dibromide, ethylaluminum dibromide, ethylaluminum diiodide, isobutylaluminum dichloride and the like; and alkylaluminum sesquihalides such as ethylaluminum sesquichloride and the like. The proportion of the vanadium compound and organoaluminum compound used in the present invention is 1 to 1000 mols of the organoaluminum compound per 1 mol of the vanadium compound, and the vanadium compound is used in a proportion of 1 x 10⁻⁵ to 0.5 mole to 1 mole of the diolefin used. Furthermore, the catalyst of the present invention is generally of a homogeneous system. Copolymerization of Diolefins Useful examples of the diolefin used in the present invention are 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene, etc. Copolymerization of these diolefins is preferably carried out in a solvent that is inert to the copolymerization reaction and liquid during the copolymerization. Illustrative of the solvent are hydrocarbons such as propane, butane, pentane, hexane, heptane, and toluene. Furthermore, it is possible to effect the copolymerization in propylene monomer. The copolymerization temperature is generally at most -50 °C. If it is particularly lower than -65 °C, there is obtained a copolymer having an M w (weight-average molecular weight)/ M n (number-average molecular weight) ratio of 1.05 to 1.4, namely that is approximately of a monodisperse system. With the increase of the copolymerization time, the yield and molecular weight of the copolymer can be increased. The thus obtained copolymer according to the present invention comprises the following structural units, in combination: In the above described structure, recurring unit (B) is present in an amount of at least 2 mole% and M n is about 2,000 to about 500,000 in terms of propylene, the structural units A and B being in random combination. According to the present invention, 1,4-added diolefin polymers such as those of 1,5-hexadiene, 1,7-octadiene, etc, can be produced with a selectivity of 100 %. The copolymer of the present invention having carbon to carbon double bonds in the side chains can be used for the modification of the properties of other compounds through the addition thereto. Thus, the copolymers of the present invention very useful as raw materials for adhesives, paints, blending solvents for increasing compatibility, surfactants, viscosity index improvers of lubricating oils, etc. utilizing the above described characteristics. The following examples are given in order to illustrate the present invention without limiting the same. Example 1 30 ml of toluene was charged in a 300 ml flask adequately purged with nitrogen gas and cooled to -78 °C, to which 42 millimoles of propylene and 50 millimoles of 1,5-hexadiene were then added at the same temperature. Thereafter, a solution of 20 millimoles of Al(C₂H₅)₂Cl in toluene and a solution of 1 millimole of V(acetylacetonato)₃ in toluene were added thereto and stirred to initiate the polymerization. After the polymerization was carried out at -78 °C for 4 hours, the polymerization product was contacted with 300 ml of a mixed solution of hydrochloric acid-ethanol and the resulting polymer was washed with 300 ml of ethanol five times, followed by drying at room temperature under reduced pressure. The molecular weight of the resulting polymer was measured by GPC method, thus obtaining results of M n = 8,300 (in terms of propylene) and M w/ M n = 1.4. The polymer had a ¹³C-NMR spectrum as shown in Fig. 1 (1) whose assignments are as follows: This polymer was hydrogenated in the same manner as described in "Macromolecules" 19 (1986), 2409 and subjected to measurement of its ¹³C-NMR spectrum, thus obtaining results as shown in Fig. 1 (2). The assignments are as follows: The assignments of Fig. 1 (1) are found correct from the fact that the peaks identified to correspond to the carbon atoms having double bonds in Fig. 1 (1) disappear. It is found from the foregoing results and intensity ratio of ¹³C-NMR spectra that the resultant polymer is a random copolymer comprising 88.0 mole % of the foregoing structural unit A (polypropylene segment) and 12.0 mole % of the structural unit B (1,4-added hexadiene segment) and having groups at the terminals. Examples 2 to 4 Copolymerizations of propylene with 1,5-hexadiene were carried out in an analogous manner to Example 1 except changing the copolymerizing conditions as shown in Table 1. The results are also shown in Table 1. The H-NMR spectrum of the copolymer obtained in Example 2 is shown in Fig. 2, whose assignments are as follows: Examples 5 and 6 Copolymerizations of propylene and 1,5-hexadiene were carried out in an analogous manner to Example 1 except using V(2-methyl-1,3-butanedionato)₃ instead of the V(acetylacetonato)₃ as the vanadium compound and using the copolymerizing conditions as shown in Table 1. The results are also shown in Table 1. Example 7 Copolymerization of propylene and 1,7-octadiene was carried out in an analogous manner to Example 1 except employing the copolymering conditions as shown in Table 1. The results are also shown in Table 1.

Claims: A diolefin copolymer comprising, in combination, the following recurring units (A) and (B): wherein n = 4 to 6 and recurring unit (B) is present in an amount of at least 2 mole %. A diolefin copolymer as claimed in claim 1, wherein the recurring units (A) and (B) form a random linkage. A diolefin copolymer as claimed in claim 1 or claim 2, wherein the number-average molecular weight is in the range of from 2,000 to 500,000 in terms of propylene. A diolefin copolymer as claimed in any one of the preceding claims wherein the weight-average molecular weight to number-average molecular weight ratio is in the range of 1.05 to 1.4. A process for the production of a diolefin copolymer as claimed in claim 1, which comprises copolymerizing a diolefin represented by the general formula wherein n = 4 to 6 with propylene at a temperature of -50°C or below in the presence of a catalyst consisting of a vanadium compound represented by the general formula, wherein R¹ to R³ are hydrogen atoms or hydrocarbon groups having 1 to 8 carbon atoms, at least one of which must be hydrogen atom but all of which must not be hydrogen atoms, and an organoaluminum compound, which is represented by the general formula R n AlX 3-n wherein R is an alkyl group or aryl group, X is a halogen atom or hydrogen atom and n is any numeral in the range of 1 ≦ n < 3, the vanadium compound and organoaluminium compound being used in the proportion of 1 to 1,000 moles of the organoaluminium compound to 1 mole of the vanadium compound. A process as claimed in claim 5, wherein the vanadium compound is vanadium (acetylacetonato)₃, vanadium (2-methyl-1,3-butanedionato)₃ or vanadium (1,3-butanedionato)₃. A process as claimed in claim 5 or claim 6 wherein the vanadium compound is used in the proportion of 1 x 10⁻⁵ to 0.5 mole to 1 mole of the diolefin. A process as claimed in claim 5, wherein the copolymerization is carried out in the presence of a solvent which is inert to the copolymerization and liquid during the copolymerization. A process as claimed in claim 8, wherein the solvent is propane, butane, pentane, hexane, heptane or toluene. A process as claimed in claim 8, wherein the solvent is the propylene which is to be copolymerized in the reaction.

Inventors: DOI, YOSHIHARU, SOGA, KAZUO, UEKI, SATOSHI
Applicants: TOA NENRYO KOGYO KABUSHIKI KAISHA
Application year: 1988
Main classification: C08F36
IPC codes: C08F4, C08F236, C08F210, C08F36, C08F8