Process for preparing high-reactivity isobutene homo- or copolymers

Abstract

The present invention relates to a process for preparing high-reactivity isobutene homo- or copolymers with a content of terminal vinylidene double bonds per homo- or copolymer chain end of at least 70 mol % which comprises polymerizing isobutene or an isobutene-comprising monomer mixture in the presence of an aluminum trihalide-donor complex effective as a polymerization catalyst or of an alkylaluminum halide-donor complex, said complex comprising, as the donor, a mixture of at least two organic compounds with at least one ether function each.

Claims

1. A process for preparing high-reactivity isobutene homo- or copolymers with a content of terminal vinylidene double bonds per polyisobutene Chain end of at least 70 mol %, the process comprising: polymerizing isobutene or an isobutene-comprising monomer mixture in the presence of a complex, comprising a donor and an aluminum trihalide or an alkylaluminum halide, wherein the donor comprises a mixture of at least two ethers selected from the group consisting of dimethyl ether, diethyl ether, di-n-propyl ether, diisopropyl ether, di-n-butyl ether, di-sec-butyl ether, diisobutyl ether, di-n-pentyl ether, di-n-hexyl ether, di-n-heptyl ether, di-n-octyl ether, di-(2-ethylhexyl) ether, methyl n-butyl ether, methyl sec-butyl ether, methyl isobutyl ether, methyl tert-butyl ether, ethyl n-butyl ether, ethyl sec-butyl ether, ethyl isobutyl ether, ethyl tert-butyl ether, n-propyl n-butyl ether, n-propyl sec-butyl ether, n-propyl isobutyl ether, n-propyl test-butyl ether, isopropyl n-butyl ether, isopropyl sec-butyl ether, isopropyl isobutyl ether, isopropyl tert-butyl ether, methyl n-hexyl ether, methyl n-octyl ether, methyl 2-ethylhexyl ether, ethyl n-hexyl ether, ethyl n-octyl ether, ethyl 2-ethylhexyl ether, n-butyl n-octyl ether, n-butyl 2-ethylhexyl ether, tetrahydrofuran, tetrahydropyran, 1,2-dioxane, 1,3-dioxane, 1,4-dioxane, dicyclohexyl ether, diphenyl ether, anisole, phenetole, ditolyl ether, dixylyl ether, and dibenzyl ether, wherein acids employed in the process comprise only carboxylic acids, mineral acids, aluminum trihalides, alkylaluminum dihalides, and/or dialkyl aluminum halides.

2. The process of claim 1, wherein the mixture is a binary mixture having a molar ratio of the first ether to the second ether in in a range of 0.1:1 to 1:0.1.

3. The process according of claim 1, wherein the mixture of ethers comprises a first ether comprising a first hydrocarbon group bonded to the oxygen by a primary carbon and a second first hydrocarbon group bonded to the oxygen by a primary carbon and a second ether comprising a hydrocarbon group bonded to the oxygen by a secondary or tertiary carbon.

4. The process of claim 3, wherein the first ether is at least one selected from the group consisting of diethyl ether, di-n-butyl ether, and di-n-propyl ether.

5. The process of claim 4, wherein the second ether is at least one selected from the group consisting of diisopropyl ether, methyl tert-butyl ether, ethyl tert-butyl ether, and anisole.

6. The process of claim 3, wherein the second ether is at least one selected from the group consisting of diisopropyl ether, methyl tert-butyl ether, ethyl tert-butyl ether, and anisole.

7. The process of claim 1, wherein the mixture of the ethers comprises a first ether comprising a linear hydrocarbon group and a second ether comprising a branched hydrocarbon group.

8. The process of claim 1, wherein the mixture of the ethers comprises a first ether comprising two linear hydrocarbon groups and a second ether comprising two branched hydrocarbon groups.

9. The process of claim 1, wherein the mixture of ethers is selected from the group consisting of a mixture of diethyl ether and diisopropyl ether, a mixture of diethyl ether and methyl tert-butyl ether, a mixture of diethyl ether and ethyl tert-butyl ether, a mixture of di-n-butyl ether and diisopropyl ether, a mixture of di-n-butyl ether and methyl tert-butyl ether, and a mixture of di-n-butyl ether and ethyl tert butyl ether.

10. The process of claim 1, wherein the mixture of the ethers comprises: diethyl ether, di-n-propyl ether, and/or di-n-butyl ether; and diisopropyl ether, methyl tert-butyl ether, and/or ethyl tert-butyl ether.

11. The process of claim 10, wherein a molar ratio of the donor to the aluminum trihalide and/or the alkylaluminum halide is in a range of from 0.4:1 to 1:1.

12. The process of claim 1, wherein the aluminum trihalide or alkylaluminum halide is selected from the group consisting of aluminum trichloride, ethylaluminum dichloride, iso-butylaluminum dichloride, diethylaluminum chloride, and diiso-butylaluminum chloride.

13. The process of claim 1, wherein the aluminum trihalide is present and is an aluminum trichloride-donor complex, wherein the alkylaluminum halide is present and is an alkyl aluminum chloride-donor complex, or wherein the alkylaluminum halide is present and is a dialkyl aluminum chloride-donor complex.

14. The process of claim 1, wherein a molar ratio of the aluminum trihalide or alkylaluminum halide to the isobutene monomer used in the case of homopolymerization of isobutene, or to a total amount of polymerizable monomers in the isobutene-comprising monomer mixture in the case of copolymerization of isobutene, based on each individual functional site of the aluminum trihalide or alkylaluminum halide, is in a range of 0.001:1 to 0.2:1.

15. The process of claim 1, wherein the polymerization is performed with a mono- or polyfunctional initiator which is at least one selected from the group consisting of organic hydroxyl compounds in which one or more hydroxyl groups are each bonded to an sp.sup.3-hybridized carbon atom, organic halogen compounds in which one or more halogen atoms are each bonded to an sp.sup.3-hybridized carbon atom, and water.

16. The process of claim 15, wherein the initiator comprises water, methanol, ethanol, 1-phenylethanol, 1-(p-methoxyphenyl)ethanol, n-propanol, isopropanol, 2-phenyl-2-propanol, n-butanol, isobutanol, sec-butanol, test-butanol, 1-phenyl-1-chloroethane, 2-phenyl-2-chloropropane, tert-butyl chloride, 1,3-bis(1-hydroxy-1-methylethyl)benzene, and/or 1,4-bis(1-hydroxy-1-methylethyl)benzene.

17. The process of claim 15, wherein a molar ratio of the initiator to the isobutene monomer in the case of homopolymerization of isobutene, or to a total amount of polymerizable monomers in the isobutene-comprising monomer mixture in the case of copolymerization of isobutene, based on each individual functional site of the initiator, is in a range of 0.0005:1 to 0.1:1.

18. The process of claim 1, wherein the polymerization is performed at a temperature in a range of −90° C. to +30° C.

19. The process of claim 15, wherein the initiator comprises water, and wherein a molar ratio of the initiator to the isobutene monomer in the case of homopolymerization of isobutene, or to a total amount of polymerizable monomers in the isobutene-comprising monomer mixture in the case of copolymerization of isobutene, is in a range of 0.0001:1 to 0.11.

20. The process of claim 1, wherein the content of the terminal vinylidene double bonds per polyisobutene chain end is more than 80 mol % to less than 100 mol %.

Description

EXAMPLES

(1) The polymerization reactions were carried out in glass tubes equipped with a cold finger condenser or, in some cases, in stainless steel reactor with PTFE lining under argon atmosphere at 10° C. As an example of a typical procedure, polymerization was initiated by adding isobutylene (3.25 g, 5.8×10.sup.−2 mol) to a mixture of a total volume of 5.25 mL, consisting of solutions of an ether (or a mixture of two ethers), 6 μL (3.3×10.sup.−4 mol) of deionized H.sub.2O and with MgSO.sub.4×7H.sub.2O (15% mol of H.sub.2O to .sup.iBuAlCl.sub.2) pre-activated .sup.iBuAlCl.sub.2 (0.38 mL, 1M) in n-hexane or toluene, and n-hexane (4.8 mL). After 10 min reaction time, ca. 2 mL of ethanol was poured into the reactor to terminate the polymerization. The quenched reaction mixtures were diluted by n-hexane, washed with 0.5 M nitric acid and deionized water to remove the aluminum-containing residues, evaporated to dryness under reduced pressure, and dried in vacuum (<60° C.) to give the polymeric products.

(2) Product yields were determined gravimetrically. The number average molecular weight M.sub.n and the weight average molecular weight M.sub.w was determined by means of Size Exclusion Chromatography (SEC, M.sub.nSEC) with polystyrene standards, or by .sup.1H NMR (M.sub.nNMR). The polydispersity PDI=M.sub.w/M.sub.n was calculated using the thus obtained values.

(3) Composition of reaction products was determined by the .sup.1H-NMR method and assigned to structures as described in An-Ru Guo, Xiao-Jian Yang, Peng-Fei Yan, Yi-Xian Wu, Journal of Polymer Science, Part A: Polymer Chemistry 2013, 51, 4200-4212, see especially pages 4205 and FIG. 5 on page 4206.

(4) In the context of the present invention the term “exo” refers to terminal ethylenic double bonds, vinylidene groups or α-double bonds, as shown in the formula on page 1. These terms are used synonymously throughout the text.

(5) The term “Total vinylidene” means the terminal ethylenic double bonds referred to as exo above and additionally double bonds located internally at the polymer backbone as shown in the formula on the right:

(6) ##STR00004##

(7) The term “trisubstituted” refers to β-double bonds, as shown in the formulae bottom left and bottom centre. These terms are used synonymously throughout the text.

(8) Furthermore “tetrasubstituted” structural elements can be found as shown in the formula at the top centre.

Example 1 (Comparative)

(9) A polymerization reaction was run as described above using diisopropylether (OiPr.sub.2) as the ether component. The molar ratio OiPr.sub.2 to iBuAlCl.sub.2 was kept at 1.2. A polyisobutene polymer with M.sub.nSEC=1130 g/mol (M.sub.nNMR=870 g/mol) was obtained in 61% yield. Polydispersity and double bond distribution of the polymer are shown on Table 1.

(10) TABLE-US-00001 TABLE 1 Total Example PDI Exo vinylidene Trisubstituted Tetrasubstituted 1 2.7 85 88 5 7

Example 2 (Comparative)

(11) A polymerization reaction was run as described above using diisopropyl ether as the ether component. The molar ratio OiPr.sub.2 to iBuAlCl.sub.2 was kept at 0.4. A polyisobutene polymer with M.sub.nSEC=1210 g/mol (M.sub.nNMR=1200 g/mol) was obtained in 94% yield. Polydispersity and double bond distribution of the polymer are shown on Table 2.

(12) TABLE-US-00002 TABLE 2 Total Example PDI Exo vinylidene Trisubstituted Tetrasubstituted 2 3.7 80 82 9 9

Example 3 (Comparative)

(13) A polymerization reaction was run as described above using diethyl ether (OEt.sub.2) as the ether component. The molar ratio OEt.sub.2 to iBuAlCl.sub.2 was kept at 0.4. A polyisobutene polymer with M.sub.nSEC=15040 g/mol (M.sub.nNMR=12890 g/mol) was obtained in 40% yield. Polydispersity and double bond distribution of the polymer are shown on Table 3.

(14) TABLE-US-00003 TABLE 3 Total Example PDI Exo vinylidene Trisubstituted Tetrasubstituted 3 2.1 53 53 23 24

Example 4 (Comparative)

(15) A polymerization reaction was run as described above using di-n-butyl ether (OBu.sub.2) as the ether component. The molar ratio OBu.sub.2 to iBuAlCl.sub.2 was kept at 0.4. A polyisobutene polymer with M.sub.nSEC=1200 g/mol (M.sub.nNMR=970 g/mol) was obtained in 89% yield. Polydispersity and double bond distribution of the polymer are shown on Table 4.

(16) TABLE-US-00004 TABLE 4 Total Example PDI Exo vinylidene Trisubstituted Tetrasubstituted 4 6.1 75 77 12 11

Example 5

(17) A polymerization reaction was run as described above using an equimolar mixture of diisopropyl ether and diethyl ether as the ether component. The molar ratio total ether to iBuAlCl.sub.2 was kept at 0.4. A polyisobutene polymer with M.sub.nSEC=1230 g/mol (M.sub.nNMR=1190 g/mol) was obtained in 80% yield. Polydispersity and double bond distribution of the polymer are shown on Table 5.

(18) TABLE-US-00005 TABLE 5 Total Example PDI Exo vinylidene Trisubstituted Tetrasubstituted 5 2.6 83 84 8 8

Example 6

(19) A polymerization reaction was run as described above using an equimolar mixture of di-n-butyl ether and diethyl ether as the ether component. The molar ratio total ether to iBuAlCl.sub.2 was kept at 0.4. A polyisobutene polymer with M.sub.nSEC=1710 g/mol (M.sub.nNMR=1350 g/mol) was obtained in 47% yield. Polydispersity and double bond distribution of the polymer are shown on Table 6.

(20) TABLE-US-00006 TABLE 6 Total Example PDI Exo vinylidene Trisubstituted Tetrasubstituted 6 3.9 83 84 10 6