WO1998022515A1

WO1998022515A1 - Method for producing initiators for anionically initiated polymerization of monomers having at least one ethylenically unsaturated group

Info

Publication number: WO1998022515A1
Application number: PCT/EP1997/006117
Authority: WO
Inventors: Axel MÜLLER; Bela Ivan; Jesper Feldthusen Jensen
Original assignee: Basf Aktiengesellschaft
Priority date: 1996-11-20
Filing date: 1997-11-05
Publication date: 1998-05-28
Also published as: DE19648028A1; AU5318198A

Abstract

The invention relates to a method for preparing initiators of anionic polymerisation initiators, in which 1,1-diphenylvinyl terminated polyisobutene is metallized.

Description

Process for the preparation of initiators for the anionically initiated polymerization of monomers having at least one ethylenically unsaturated group

description

The present invention relates to a process for the preparation of anionic polymerization initiators of the general formula (I),

With

m = an integer from 1 to 6,

n = an integer from 1 to 1500,

R ¹ = residue of an m-functional carbocationic initiator,

2

R ³ , R ⁴ = independently of one another H, CH ₃ -—- 0 Si R ⁶ <

R7

N0 ₂ or - OCH ₃ ,

R ⁵ , R ⁶ -CH _?

R7 = -CH ₃ or -C (CH ₃ ) ₃ , M ^© = alkali metal ^® ,

) o, 5 •

R ⁹ R ⁹

R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ = independently of one another Ci to C ₅ alkyl or -C ₆ H ₅ (phenyl).

The compounds (I) are essentially homopolymers of isobutene. Homopolymeπsate of isobutene have a number of attractive properties. They are hydrophobic and stable against thermal and oxidative influences, they prove to be chemically relatively inert (for example, do not hydrolyze) and have low-temperature elasticity (they have a low glass transition temperature).

It is therefore e.g. It is desirable to be able to combine the properties of homopoly mer sates of isobutene with the properties of homopolymer sets of other monomers containing at least one ethylenically unsaturated group by suitable copoly erization of the isobutene with such monomers.

A disadvantage of this objective, however, is the fact that isobutene can essentially only be polymerized by means of carbocation (briefly: carbocationic polymerization), while the vast majority of the other monomers having at least one ethylenically unsaturated group essentially polymerize only by polymerization mechanisms that differ from carbocationic polymerization can be (for example, by anionically initiated polymerization, in short: anionic polymerization). This means that copolymers of isobutene are essentially only obtainable by first polymerizing the isobutene by means of carbocation-initiated polymerization and then adding further groups which have at least one ethylenically unsaturated group

Monomers continue chain growth with a change in the polymerization mechanism. As a starter for the living carbocationic polymerization of isobutene, initiator systems consisting of initiator (hereinafter called carbokatiom initiator) and comitiator are generally used, the comitiator requiring the formation of the carbocation. Suitable carbocationic initiators include compounds that have at least one tertiary Have a C atom, which has a substituent such as -Cl, -Br, J, -OH, -OCH ₃ or -0-C0 ₂ -CH ₃ , and thus have the potential to form a carbocation. If the carbocation initiator is capable of forming a carbocation at several points, it is a multifunctional carbocation initiator (for example an initiator which has two such tertiary carbon atoms = difunctional).

Multifunctional carbocationic initiators are suitable, for example, for the production of polyisobutene molecules, from which a number of polyisobutene blocks corresponding to the functionality of the carbocationic initiator radially points away from the carbocationic initiator residue. An example of a monofunctional carbocationic initiator is 2-chloro 2, 4, 4-trimethyl pentane. 1, 3, 5 tris (2-chloro-2-propyl) benzene may be mentioned as an example of a functional carbocationic initiator. The comitiators are usually Lewis acids such as T1CI ₄ or BCI ₃ . The use of a Lewis base such as N, N dimethylacetamide frequently proves to be advantageous for the course of the living carbocationic polymerization in order to reduce the charge density of the carbocations carrying the polymerization.

The living carbocationic polymerization of isobutene is usually carried out under an inert gas (e.g. nitrogen atmosphere) and in solution, for which solvents such as n-hexane, methylene chloride, chloroform or mixtures thereof are suitable.

As a result of the continuation of a carbocationic polymerization of isobutene with other monomers having at least one ethylenically unsaturated group with a change in the polymerization mechanism, block copolymers are obtained in particular when the change in the polymerization mechanism takes place toward anionic polymerization. Such block copolymers have a wide range of applications, as described, for example, in the older patent application DE-A 19 610 350 (for example as amphiphilic surfactants). This is especially true when the block copolymers are available in good purity and, for example, essentially no longer contain any homopolymer. The latter is the case when starting from carbocationically terminated polyisobutene (PIB) obtainable by living carbocationic polymerization of isobutene, block transfer coefficients f of almost 1 are reached (f is defined as M _n ^ex / M _n ^th , where M _n ^{ex was} determined experimentally number average molecular weight of the resulting block copolymer and M _n ^{th is} the number average molecular weight of the resulting block copolymer which starting from carbocationically terminated PIB, can be expected with ideal block transfer).

The older application DE-A 19 610 350 realizes the change from the living carbocationic polymerization of isobutene to an anionically initiated polymerization with high block transfer efficiency in that the carbocationically terminated PIB is obtained by adding a compound of the general formula (II)

With

R2 =, Q, naphthyl or phenanthryl,

R ⁴ R ⁵

R ³ , R ⁴ = independently of one another - H, CH ₃ , - 0 Si R ⁶ - R ⁷

- N0 ₂ or - ^■ OCH ₃ ,

R ⁵ , R ⁶ = -CH ₃ ,

R ⁷ = -CH ₃ or -C (CH ₃ ) ₃ ,

functionalized, then terminated by adding an alcohol or thiol with subsequent addition of ammonia and then metallizing the ether or thioether compound formed in this way with an alkali metal and / or alkaline earth metal to form an anionic polymerization initiator of the general formula (I).

A disadvantage of this procedure is that the ether or thioether compounds are sensitive to hydrolysis, which makes their storage difficult. This means that the initiator must be produced essentially fresh. The object of the present invention was therefore to provide a more economical process for the preparation of anionic polymerization initiators of the general formula (I).

Accordingly, we have found a process for the preparation of anionic polymerization initiators of the general formula (I), which is characterized in that a compound of the general formula (III)

m a solvent, which is the structural element

H _wc -, with W = N, 0, (O) ^{or s} -

Contained, metallized with an alkali metal and / or alkaline earth metal and then optionally knocked over with a salt containing M ^© .

It was known (for example from Transactions Far. Soc. 6_1, 150 (1965)) that 1, 1-diphenylethylene can be quantitatively metallized using n-butyllithium and that the resulting 1,1-diphenyl-n-hexyl-Li - thium is suitable as an anionic polymerization initiator for the anionic polymerization of methyl methacrylate.

However, it was also known (for example from Macromol. Symp. 107, 189 (1996)) that 3, 3, 5, 5-tetramethyl-1, 1-diphenylhexene is not accessible to quantitative metalation either by means of n-butyl lithium or by means of methyl lithium .

In view of the abovementioned prior art, the metallization which can be obtained essentially quantitatively by means of the method according to the invention must surprise.

This is all the more so according to J. Am. Chem. Soc. 100, 6137 (1978) the formation of a radical anion with subsequent coupling to a dianion had to be expected:

A hydrogen abstraction of the structural element may be the reason for their subordinate appearance

H

I, which e.g. The solvent w C can contain:

₂ toilets w - c - c - w

Suitable, a structural element

H

WC Solvents or solvent additives containing are, for example, tetrahydrofuran, D methoxyethane, tetrahydropyran, N, N, N ', N'-tetramethylethylenediamine, dioxane, diethyl ether, toluene and mixtures thereof.

Polar solvents or solvent additives are generally preferred.

Access to compounds of the general formula (III) is known to the person skilled in the art (cf. for example JL Price, Ph.D. Thesis, The Umversity of Akron, 1991, pp. 62 to 63, 98 to 100; Macromol. Reports, A32, 639 (1995); Macromol. Symp. 107, 189 (1996) and J. Macromol. Sci. -Pure Appl. Chem. A32, 1137 (1995)).

Normally, isobutene is first subjected to living carbocationic polymerization in a manner known per se, as described, for example, in the earlier application DE-A 19 610 350. The living carbocationic polymerization of isobutene is then functionalized by adding a compound of the general formula (II), among which 1, 1-diphenylethylene, ie, the compound with R ³ , R ⁴ = H, is particularly preferred (in each case only one compound of the general formula (II) added per active chain end). Thereafter, tert by adding an alcohol such as methanol, ethanol. - Butanol, benzyl alcohol or a corresponding thiol under

Ether or thioether formation stopped. Subsequent acidification in a polar solvent causes alcohol or thiol elimination and leads to the desired compound of the general formula (III).

A detailed description of the living carbocationic polymerization of isobutene can also be found in the literature listed below:

1. J.P. Kennedy and B. Ivan, "Designed Polymers by Carbonicromromecular Engineering: Theory and Practice," Hanser Publishers, Munich, New York, 1992

2. B. Ivan and J.P. Kennedy, Ind. J. Technol. 31, 183 (1993)

3. B. Ivan Makromol. Chem., Macromol. Symp., 75, 181 (1993)

4. M. Sawamoto, Prog. Polym. Sci., 16, 111 (1991)

5. B. Ivan, JP Kennedy, and PW Mackey, Polym. Preprmts, 31 (2), 215 (1990); Ibid, 31 (2), 217 (1990) 6. B. Ivan, JP Kennedy, and PW Mackey, in "Polymeric Drugs and Drug Delivery Systems", Eds. , RL Dünn and RM Ottenbrite, ACS Symp. Ser., Vol. 469, Am. Chem. Sol. , Washington, DC, 1991, pp. 194; ibid., 1991, pp. 203

5

7. B. Ivan, J.P. Kennedy, and P.W. Mackey, U.S. Patent, 5,073,381 (Dec. 17, 1991)

8. J. P. Kennedy, V.S.C. Chang, R.A. Smith, and B. Ivan, Polym. 10 Bull., 1, 575 (1979)

9. B. Ivan, J.P. Kennedy, J. Polym. Sci., Part A: Chem. Ed., 28, 89 (1990)

15 10. B. Ivan, J.P. Kennedy, and V.S.C. Chang, J. Polym. Be., Polym. Chem. Ed., 18, 3177 (1980)

11. T. Kitayama, T. Nishiura, and K. Hatada, Polym. Bull. 26, 513

(1991) 20

12. T. Nishiura, T. Kitayama, and K. Hatada, Polym. Bull. 27, 615

(1992)

13. W. G. Ruth, C. G. Moore, W. J. Brittain, J. Si, and J. P. 25 Kennedy, Polym. Preprint, 34 (1), 479 (1993)

14. J.P. Kennedy, J.L. Price, and K. Koshimura, Macromolecules, 24, 6567 (1991)

30 15. J.P. Kennedy and M. Hiza, J. Polym. Be., Polym. Chem. Ed., 21, 3573 (1983)

16. M. Gyor, K. Kitayama, N. Fujimoto, T. Nishiura, and K. Hatada, Polym. Bull. 32, 155 (1994)

35

17. S. Nemes and J.P. Kennedy, J. Macromol. Be. -Chem. A28, 311 (1991)

18. S. Hadjikyriacou, Zs. Fodor, and R. Faust, J. Macromol, 40 Reports, A32, 639 (1995)

19th J. Feldthusen. B. Ivan, A.H.E. Müller, and J. Kops, Macromol. Reports A32, 639 (1995)

45 20. A. Takacs and R. Faust, Macromolecules, 28, 7266 (1995) 21. J. Feldthusen, B. Ivan. AHE Müller, and J. Kops, Macromol. Symp. Submitted

22. H. Everland, J. Kops, A. Nielsen, and B. Ivan, Polym. Bull., 31, 159 (1993)

If, in the further course of this document, reference is made to the literature citations listed above, this is done as "Ref. No.", whereby No. corresponds to the numerical rank of the literary quote.

According to the literature references mentioned above, for the living carbocationically initiated polymerization of isobutene, i.a. the following carbocationic initiators are particularly suitable:

Monofunctional carbocation initiators:

CH ₃ CH ₃ CH ₃ CH ₃ CH ₃ CX, CH ₃ C CH ₂ CX, (O) CX,

I I I I

CH ₃ CH ₃ CH ₃ CH ₃

CH ₃ CH ₃ (T) CX;

CH ₃

Difunctional carbocation initiators:

CH ₃ CH ₃ CH ₃ CH ₃ C _H3

XC (CH ₂ ) ₃ CX, XC - CH ₂ C CH ₂ CX, CH ₃ CH ₃ CH ₃ CH ₃ CH ₃

Trifunctional carbocation initiators:

Tetrafunctional carbocation initiator:

Hexafunctional carbocationic initiators:

with X -Cl, -Br, -J, -F, -OH, -OCH ₃ ,

0

^■ 0 CR ¹² or o- _R 13

and R ¹² , R ¹³ = Ci to C ₄ alkyl and

0 - C CH ₃ . X is preferably Cl or OH.

Among the aforementioned carbocationic initiators, the following are particularly favorable:

CH ₃ CH ₃ CH ₃ CH ₃ C CH ₂ C Cl, (O) ^{c cl} _'

I I \ - / I

In the carbocationic initiators mentioned above, the substituent X is always located on a tertiary carbon atom carrying two methyl groups. The initiator effect of these groups is also given when one of the two CH ₃ groups is replaced by H. Also suitable as such carbocationic initiators are compounds which, in addition to the carbocationic functionality, also have other functionalities.

The compounds may be mentioned as examples

R5

or 0 - Si - R ⁶ R ⁷

as well as compounds which have a potential allylic carbocation, for example (CH ₃ ) ₂ C = C CH ₂ Cl.

Further carbocationic initiators suitable according to the invention can be found in Ref. (1) to (22), in particular in Table I on page 14 ff of Ref. (1).

Lewis acids such as the Rompp Chemie Lexikon, Cm-G, 9th edition (1990), Thieme Verlag, p. 1444, column 2, listed Friedel-Crafts catalysts are suitable as initiators. Friedel-Crafts catalysts used with particular preference are T1CI ₄ and BCI ₃ . This applies in particular if the aforementioned carbocationic initiators are used and X = Cl. The choice of the coimtiator influences in particular the polydispersity mdex D of the molecular weight distribution of the resulting PIB. D is defined as M _w / M _n , where M _{w means} the weight average molecular weight. According to ref. (21), a favorable comitiator is the desired relative M _n values of the PIB from 1000 to 3000 with simultaneous D values from 1 to 1.15 BC1. For relative M _n values of the PIB from 4000 to 10000 with a molecular weight distribution that is as uniform as possible, a two-stage process is recommended according to ref. (21), in which m the first stage BC1 ₃ and m the second stage T1CI _{4 is used} as a comitiator. The sole use of T1CI ₄ in the aforementioned molecular weight range usually leads to polydispersity dices> 1.2. For targeted relative PIB mole- Specular weights> 10,000, however, is T1CI ₄ em a particularly inexpensive comitiator (see Ref. (21)).

As already mentioned, the living carbocationic polymerization of isobutene is normally carried out in solution. The solvent should in particular be chosen so that the PIB desired as a product is still dissolved with its degree of polymerization. As the desired molecular weight of the PIB increases, less polar solvents therefore have to be used. The required reduction in the solvent polatin also requires the aforementioned change from a weaker Lewis acid (BC1 ₃ ) to a stronger Lewis acid (T1CI ₄ ).

Solvents suitable for carrying out the living carbocationic polymerization of isobutene are e.g. m Ref. (1) to Ref. (22), in particular Ref. (1), Table I, p. 14 ff.

At this point, CHC1 and its mixtures with n-hexane and / or methylcyclohexane and CH ₃ C1 and its mixtures with n-hexane and / or methylcyclohexane may be mentioned as solvents.

The reaction temperature is usually from -70 to 80 ° C. To deactivate protic impurities, proton traps such as di tert are often added to the reaction mixture in small amounts. Butylpyridm added.

According to the invention, m can assume the values 1, 2, 3, 4, 5 or 6.

n can be e.g. 1 to 30, 10 to 30, 35 to 45,> 30 to 1500,> 30 to 750,> 30 to 500, 40 to 250 or 40 to 100.

To functionalize the living carbocationic polymerization of the isobutene with a compound of the general formula (II), the latter is added to the polymerization mixture after the isobutene has been consumed, advantageously in dissolved form, all at once. The preferred solvent is the solvent used for living carbocationic polymerization. For this reaction step too, the reaction temperature m is usually -60 to -80 ° C.

After the functionalization has been completed, as already described, tert by adding an alcohol such as methanol, ethanol. Butanol, benzyl alcohol and / or an appropriate thiol canceled. It is preferably terminated with methanol. Usually the alcohol or the thiol is added to the reaction mixture pre-cooled to its temperature.

As a result of the termination, a mixture is obtained which contains both the compound (III) and the functionalized PIB terminated with alkoxy or alkylthio. Depending on the chosen solvent, the prevailing temperature, the degree of polymerisation of the PIB, the amount of demolition agent etc. used, the molar ratio of compound (III) to correspond to the ether or thioether compound in the resulting product mixture is normally in the range of 10: 90 to 90:10.

By washing the product mixture with water (until the pH of the wash water is in the neutral range), comitiators used in the course of the living carbocationic polymerization can be removed from the product mixture in a simple manner. Subsequent removal of the solvent (as a rule by distillation at reduced pressure; typical boiling temperatures are 20 to 40 ° C; but higher boiling temperatures can also be used) gives the mixture of compound (III) and corresponding ether or thioether compound in pure form . The essentially pure compound (III) can be obtained from it in favorable cases by re-installation (eg ethanol). If this possibility does not exist, the mixture is expediently dissolved in a polar solvent (preferably a halogenated hydrocarbon) such as CHC1 ₃ , CH ₂ C1, chlorobenzene or tetrahydrofuran, and a protic (bransted) acid is added to the resulting solution and the mixture is left in a typical manner Temperatures in the range of 20 to 60 ° C for the purpose of the desired elimination with stirring for a few hours. Then it is advisable to add a non-polar solvent (eg a hydrocarbon) such as hexane or pentane and wash with water until the pH The wash water value is in the neutral range. Removal of the solvent from the organic phase (for example by distillation under reduced pressure) gives compound (III), which, in contrast to the corresponding ether or thioether compound, can be stored more easily.

In principle, catalytic amounts of the protic acid are sufficient. The acid can also be added in pure form (e.g. HC1 e gases). However, the acid is expediently added to water or an alcohol (e.g. methanol) in solution.

The stronger the protic acid and the higher the applied

Temperature, the faster the desired elimination will take place. Strong protic acids such as tri fluoromethanesulfonic acid or strong mineral acids such as HC1, HBr, HJ, H ₂ S0 or HN0 ₃ are used. As a rule, an increased amount of acid (usually 1 to 5 equivalents) will be added for reasons of the reaction rate. If the amount of acid added is too high, there is a risk of acid addition.

From the compounds (III) isolated as described above, the desired compound (I) can be obtained in a surprisingly essentially quantitative yield by final metalation according to the invention with an alkali and / or alkaline earth metal, which yield according to the earlier application DE-A 19 610 350 is outstanding Suitable for initiating anionic polymerizations of monomers having at least one ethylenically unsaturated group.

For this purpose, the compound (III) is a structural element

H

- w - c - |

having solvents such as tetrahydrofuran, dioxane or dimethoxyethane. This solution is then preferably fed to a reaction vessel which contains the metal (for example Li, K, Na, Rb, Cs, Mg or Ca) as a metal mirror or liquid form (for example in the form of a melt or an alloy) or in the form of a finely divided dispersion of a hydrocarbon included. Usually, the subsequent metallization proceeds satisfactorily at room temperature (25 ° C). The end of the metallization is due to a temporal constancy of

UV absorption spectrum of the reaction mixture displayed. ¹ H NMR analysis shows the quantity of the metalation after proton termination.

The organic solution of the compound (I) produced is then filtered off and the compound (I) is isolated if necessary by removing the solvent used (by distillation). The metalation is preferably carried out with a potassium / sodium alloy, the weight ratio of K: Na being 3 to 5: 1, since such alloys are liquid at 25 ° C. Due to the higher reactivity of K relative to Na, the corresponding K® compound (I) is formed selectively. Other M® compounds (I) can then be produced from the same, for example by falling over. Thus, LiCl additive to a solution containing the corresponding K® compound (I) normally leads to the solution containing the Li® compound (I) and KC1 fails. The anionic initiator activity of the compound (I) can be controlled by a suitable choice of M®. As the surface charge density of M® increases, the initiator activity generally drops. This enables adaptation to the reactivity of the 5 monomers to be anionically polymerized. Li® is, for example, preferred M® in the case of the anionically initiated polymerization of methyl methacrylate according to the invention, while in the case of the corresponding polymerization of tert. -Butyl methacrylate K® is preferred. For use of the connections according to the invention

10 gen (I) as an initiator for the anionic polymerization of monomers having at least one ethylenically unsaturated group, the compound (I) does not necessarily have to be isolated, since tetrahydrofuran, dioxane or dirhethoxyethane also suitable solvents for carrying out anionically

15 th polymerizations are (see e.g. A.H.E. Muller, Makromol. Chem. 182, 2863 (1981)).

The anionic polymerization can be carried out in a manner known per se. As a rule, it is designed to be alive by excluding protic impurities such as water and 0. The reaction temperatures are usually <-50 ° C.

Is the anionic polymerization sequentially designed

25 (first of all, a type of monomeric building blocks is successively linked to one another and, after this monomer type has been used, the linkage with another type of monomeric building blocks is continued), di, tri and higher block units of the comonomers can be generated as required.

30

Detailed descriptions of the sequential anionic polymerizations can be found e.g. m US-A 3,251,905; US-A 3 390 207; US-A 3 598 887; U.S.-A 4,219,627; Macromolecules 1994, 27, 4908; Polymer, 1991, Volume 32, Number 12, 2279; Macromolecules 1994,

35 27, 4615; Macromolecules 1994, 27, 4635 and Macromolecules 1991, 24, 4997). Of course, the polymer block produced by anionically initiated polymerization does not necessarily have to be a homopolymer. By adding appropriate monomer mixtures, copolyme blocks can also be obtained.

40 Of course, further modifications of the desired copolymeπsate of isobutene can alternately be achieved from the living anionic polymerization in a manner known per se to other initiated growth mechanisms. P. Rempp, E. Franta, J.E. Heart, Advances in Polymer Science,

45 1988, pp. 164 to 168 provide an overview of such switching options to other growth mechanisms. By adding a protic compound, the living anionic polymerization be terminated in a manner known per se. Often it is stopped by adding methanol or acid.

Of course, polymer-analogous reactions can follow the anionic polymerization. However, it is also possible to connect blocks produced by anionically initiated polymerization to blocks which can only be obtained by polycondensation or polyaddition of monomeric building blocks (for example polyester or polyurethane), for example by an anionically produced block provided with a suitable functional end group in the case of a polycondensation is added (for example RN Young, RP Quιrκ, LJ Fetters, Advances m Polymer Science, Vol. 56, p. 70, 1984). Corresponding linkages can also be generated via R ¹ if the carbocationic initiator chosen is one which, in addition to its carbocationic functionality, has other functional groups which are known per se and are suitable for this purpose.

Particularly suitable for aniomic polymerization initiated by means of a compound (I) are styrene and substituted styrenes, conjugated dienes such as 1,3-butadiene and isoprene, monomers to be polymerized by ring opening such as ethylene oxide, propylene oxide and ε caprolactam, esters from acrylic acid and C _l - to C ₂ alkanols, esters of methacrylic acid and Ci to C ₂ alkanols, Acrylnitπl, Vmylpyridm and substituted on the ring Vmylpyridm, Acrolem, Methacrolem, Acrylamide, Methacrylamide, N, N-Dιalkyl or N, N-Dιaryl -Acrylamide and N, N-Dιalkyl- or N, N-Dιaryl methacrylamides. Otherwise, the statements according to DE-A 19 610 350 apply.

Then it is important to record the following. In the present document it is shown that the compounds (III) can be metallized essentially quantitatively to give compounds (I). In the older application DE-A 19 610 350 it is shown that the terminated with alkoxy or alkylthio, by means of a

Compound (I) functionalized, PIB can be metallized essentially quantitatively to give compounds (I). The metalation rates are approximately identical.

In conclusion, compounds (I) can be obtained in a particularly simple manner by polymerizing isobutene by the methods of living carbocation-initiated polymerization, functionalizing the polymerization by adding a compound of the general formula (II), then terminating by adding an alcohol or thiol and the resulting mixture of compounds (III) and the corresponding the ethers or thioethers as described with an alkali metal and / or alkaline earth metal.

That is, the meaning of the present invention ultimately lies in particular in the knowledge that there is an essentially quantitative change from a living carbocationic polymerization of isobutene to a compound (I) by functionalization with a compound (II), followed by termination with alcohol and / or thiol and final metalation does not require a separation of compounds (III) and the corresponding ethers or thioethers.

Examples

The following chemicals and analytical methods were used in the following exemplary embodiments:

Ethanol from Mundo, Mainz Kastell, denatured with methyl ethyl ketone;

Chloroform from Aldrich;

Calciumhydπd from Aldrich;

Acros from Acros (purity 99, used as purchased);

2 -Chlor -2, 4, 4 trimethylpentane (produced from 2,4,4 trimethyl-1-pentene from Aldrich (99%) by hydrochlorination using gaseous HC1 at 0 ° C (cf. B. Wang, MK Mishra, and JP Kennedy, Polym. Bull. 17, 205, (1987)); the liquid product was dried by adding CaCl ₂ (at -18 ° C. in a refrigerator) and the required amount was separated off by distillation immediately before use under reduced pressure;

Dichloromethane from Riedel -de Haen (purity 99.8%; was dried by adding CaH ₂ and the required amount was separated off by distillation immediately before use under an N atmosphere; the N ₂ atmosphere is essential in order to avoid phosgene formation, which polymerization can initiate);

N, N-dimethylacetamide from Aldrich (purity 99%, <0.005% water, used as purchased); 1, 1-diphenylethylene from Aldrich (purity 97%, used as purchased);

2, 6-D-tert. -butylpyrid from Aldrich (purity 97%, used as purchased);

Isobutene from BASF Aktiengesellschaft (in order to rid the same of oxygen and moisture, it was passed through a drying column from Aldrich ("Labclear filter") containing CaS0 and # 13 molecular sieve);

Aldrich's n-hexane was previously used at 97% by weight as a solvent for the carbocationic polymerization. % sulfuric acid are added and the mixture is kept under reflux at normal pressure for 48 h, in order to obtain olefm-free n-hexane; the organic phase was then washed with neutral water (pH 7) and then dried by adding CaH ₂ and the required amount was separated off under reduced pressure immediately before use;

LiCl from Merck was dried in vacuo at 200 ° C. for 48 hours (heated sand bath as heat source) and kept under an N ₂ atmosphere until use;

Aldrich methanol (99.9% purity, used as purchased);

Methyl methacrylate from Rohm was fractionally distilled and then mixed with CaH in the refrigerator at 18 ° C. immediately before use, the required amount was separated off under reduced pressure;

N from Messer Griesheim (purity 99.999%) was initiated in advance for its use as an inert gas for anionic

Polymerizations sent through three higher-connected wash bottles, which were charged with a dispersion of a K / Na alloy (weight ratio 3 to 5: 1) containing toluene added as a blue color indicator; Color deletion indicated metal consumption by reaction with 0 ₂ or H ₂ 0;

N ₂ from Messer Griesheim (purity 99.999%, used as inert gas for the carbocationic polymerization as purchased); Potassium from Merck (purity> 98%, stored in paraffin oil; before use for the production of the K / Na alloy, parts tarnished with hydroxide were removed mechanically);

- Sodium from Merck (purity> 99%, stored in paraffin oil; before use to produce the K / N alloy, parts tarnished with hydroxide were removed mechanically);

K / Na alloy: K and Na were melted in a weight ratio of 3 to 5: 1 under high vacuum; the resulting alloy was liquid at 25 ° C;

tert. Butyl methacrylate from Rohm was fractionally distilled and stored in the refrigerator at 18 ° C. after adding CaH ₂ ; immediately before use, the required amount was separated off under reduced pressure;

Tetrahydrofuran (industrial grade) was successively distilled three times: a) at normal pressure (1 atm) after addition of sodium; b) under reduced pressure (^ 10 mbar) after addition of a K / Na alloy (weight ratio 3 to 5: 1); c) under reduced pressure as in b); the last distillation was carried out immediately before use;

- Titanium tetrachloride from Aldrich (purity 99.9%, used as purchased);

SEC (Size Exclusion Chromatography, see Macromol. Rapid Commun. 16, p. 400, 1995):

Eluent: tetrahydrofuran

Detectors: 2 x JASCO UVIDEC 100 III UV detector with variable wavelength set to 260 nm

Bischoff RI detector 8110 (refractive index detector)

Columns: 1 x 5 μ / 100 Ä / 60 cm;

1 x 5 μm / linear: 10 ² to 10 ⁵ Ä / 60 cm / PSS SDV gel (= poly (styrene / divmyl benzene) gel from Polymer Standards Service GmbH Mainz); Calibration: Using PIB and polymethyl methacrylate standards

¹ H NMR: 200 MHz measurement frequency, CDC1 ₃ as solvent

All examples were carried out under an N ₂ atmosphere, ie with the exclusion of oxygen and moisture.

example 1

Preparation of 3,3,5,5 tetramethyl - 1, 1 diphenylhex 1-ene (substance 1)

On the way to the preparation of compounds (I) according to the invention which contain isobutene with the lowest possible degree of polymerization, for the sake of simplicity, 2-chloro-2,4,4-trimethylpentane is assumed as the carbocationic initiator,

which already contains the desired isobutene unit chemically bound, whereby the carbocationic polymerization is limited to the formation of the carbocation.

2.05 g (0.014 mol) of 2-chloro-2,4,4 trimethylpentane (TMPC1) and 1.17 g were added to a mixture of 330 ml of n-hexane and 120 ml of CH ₂ C1 at room temperature (25 ° C.) (0.014 mol) N, N-dimethylacetamide (DMA) added. The resulting mixture was cooled to -78 ° C., 0.14 mol of T1CI4 dissolved in 100 ml of CH ₂ C1 ₂ (precooled to 78 ° C.) was added and the mixture was cooled to 15 mm at 78 ° C. A solution of 12.5 g (0.07 mol) 1, 1-diphenylethylene (DPE) m 80 ml of an n-hexane (50 ml) / CH ₂ C1 ₂ ( 30 ml) mixture (pre-cooled to 78 ° C) added. After the reaction mixture had been stirred at -78 ° C. for 30 minutes, 60 ml of methanol (which was brought to -78 ° C. was pre-cooled) canceled. Two-fold recrystallization m ethanol gave white needles of Compound 1 with a melting point of 56 ^¬ ° to 58 ° C.

5 Example 2

Preparation of a mixture of 1-methoxy-1,1-diphenyl (substance 2a) and of 1,1-diphenylvmyl-terminated PIB (substance 2b)

10

1.49 g (0.01 mol) TMPC1 and 0.87 g (0.01 mol) DMA were added to a mixture of 480 ml n-hexane and 160 ml CH ₂ C1 at room temperature (25 ° C.). The resulting mixture was cooled to 78 ° C. Then 22 ml of isobutene were added and

15 the mixture was stirred 5 mm at 78 ° C. Then a solution of 13.2 ml (0.12 mol) TιCl ₄ , 0.001 mol 2,6-Dι-tert. butylpyπdm, 60 ml of n-hexane and 40 ml of CH ₂ C1 (pre-cooled to 78 ° C) added. A further 10 mm thereafter, 20 ml of isobutene were added. Another 10 mm later became a solution of 9.0 g

20 (0.05 mol) DPE, 20 ml n-hexane and 10 ml CH ₂ C1 ₂ (pre-cooled to -78 ° C) are added. Then 20 mm was stirred at 78 ° C and finally stopped by adding 60 ml of methanol (pre-cooled to 78 ° C). A temperature of 78 ° C. was thus maintained during all reaction steps.

25

Excess DPE was removed by triple drop of acetone.

Subsequent SEC analysis revealed a number average molecular weight M _n of 3700 g / mol and a ratio M _w / M _n of 1.18 (M _w = weight average molecular weight).

According to ¹ H-NMR analysis, the product was composed of 87% by weight of substance 2b and 13% by weight of substance 2a.

35

Example 3

Production of pure PIB terminated with 1,1-diphenylvmyl (substance 3)

40

2 g of the product from Example 2 consisting of substance 2a and substance 2b was dissolved at room temperature (25 ° C.) 15 ml of CHC1 ₃ . 0.1 ml of a 32 wt. % ιgen aqueous HC1 solution added. The resulting mixture was then stirred at 25 ° C. for 45 hours. Subsequently, ¹ H-NMR analysis showed a proportion of more than 97% by weight of substance 2b. Example 4

Metallization of substance 1 and subsequent anionically initiated polymerization of methyl methacrylate

20 mg (6.85 10 ⁵ mol) 3, 3, 5, 5-tetramethyl-1, 1-dιphenylhex-1 -en were dissolved in 30 ml of tetrahydrofuran and the solution was transferred to a vessel containing 1.5 g K / Na Alloy (weight ratio 3 to 5 ^• 1) contained After 30 minutes of reaction at 25 ° C, the UV absorption behavior of the reaction mixture no longer changed. Excess metal was filtered off. Then 29 mg LiCl (10-fold excess) were added. The solution containing the anionic initiator was then cooled to 78 ° C. Finally, 1.04 g of methyl methacrylate were added and polymerization was carried out for 60 mm at -78 ° C. The mixture was then stopped with 5 ml of methanol

SEC analysis showed for the resulting polymer: M _n = 16200 g / mol, _w / M _n = 1.04, f> 0.96.

The high value for f indicates the completeness of the metalation

Example 5

Metallization of the product mixture from Example 2 and subsequent anionically initiated polymerization of methyl methacrylate

0.9 ml of the product mixture of substance 2a and substance 2b according to example 2, 5 ml of tetrahydrofuran was dissolved. The polymer solution was dried over CaH for 24 h. It was then filtered. Thereafter, the tetrahydrofuran was removed in a high vacuum at room temperature (25.degree. C.) for 48 hours and the remaining product mixture was dissolved in 70 ml of tetrahydrofuran. 2 g of K / Na alloy (weight ratio 3 to 5: 1) were added to this solution. After a reaction time of about 70 mm at 25 ° C., the UV absorption behavior of the reaction mixture no longer changed. Excess metal was filtered off. 68 mg of LiCl were added to the filtrate to produce the corresponding Li macroinitiator. Finally, 2.4 g of methyl methacrylate were added and polymerized 60 mm at -78 ° C. The mixture was then tapped with 5 ml of methanol.

SEC analysis showed: f> 0.97 Example 6

Metallization of substance 3 from example 3 and subsequent anionically initiated polymerization of methyl methacrylate

The metalation was carried out as in Example 5. Likewise, the subsequent polymerization. SEC analysis showed f> 0.97.

Example 7

Metallization of substance 3 from Example 3 and subsequent aniomically initiated polymerization of tert. Butyl methacrylate

The metalation was carried out as in Example 5, but the LiCl addition was omitted. The polymerization was then carried out as in Example 5. Instead of methyl methacrylate, however, was tert. Butyl methacrylate used.

SEC analysis showed f> 0.95

Claims

claims

1. Process for the preparation of anionic polymerization initiators of the general formula (I)

With

m = an integer from 1 to 6,

n = an integer from 1 to 1500,

R ¹ = residue of an m-functional carbocationic initiator,

R2

R ³ , R ⁴ = independently of one another CH ^ Si-R ⁶ -

N0 ₂ or - OCH ₃ ,

R ⁵ , R ⁶ = -CH ₃ ,

0.5

R ⁹ R ⁹

_R 8 ß _R 10 _{or R} 8 pθ RIO

RU RU

R9, R ¹⁰ , R ¹¹ independently of one another Ci to Cs alkyl or C ₆ H ₅ (phenyl),

characterized in that a compound of the general formula (III)

a solvent, which is the structural element

H _wc -, with W = N, 0, (O) or S,

Contained, metallized with an alkali metal and / or alkaline earth metal and then optionally tipped over with a salt containing M®.

2. The method according to claim 1, characterized in that the solvent is tetrahydrofuran or dimethoxyethane.

3. The method according to claim 1 or 2, characterized in that the metalation is carried out with a K / Na alloy containing K and Na in the weight ratio 3 to 5: 1.

4. The method according to any one of claims 1 to 3, characterized in that CH ₃

Rl CH ₃ C and m = 1, or

CH ₃

CH ₃ CH ₃

Ri = CH ₃ C CH ₂ C and m = 1, or

CH ₃ CH ₃

CH ₃

R ⁱ = CH ₃ - OC - and m or CH ₃

CH ₃ CH ₃

R ¹ C (CH ₂ ) ₃ C - and m = 2 or

CH ₃ CH ₃

CH ₃ CH ₃ CH ₃

R ¹ ^• C CH ₂ C CH ₂ C - and m = 2, or

CH ₃ CH ₃ CH ₃

CH.

R = Ri ⁴ - (O) - ^c - ^{mi Rl4 = "F} - OCH3 or -CH ₃ \ /! And m = 1.

CH.

Method according to one of claims 1 to 4, characterized in that n = 1 to 30.

6. The method according to any one of claims 1 to 4, characterized in that n = 10 to 30.

7. The method according to any one of claims 1 to 4, characterized in that n = 35 to 45.

8. The method according to any one of claims 1 to 7, characterized in that m = 1 or 2.

9. The method according to any one of claims 1 to 8, characterized in that M® = K ^® or Li ^® .

10. The method according to any one of claims 1 to 9, characterized in that R ³ = H and R ² = phenyl.

11. The method according to any one of claims 1 to 10, characterized in that the metalation of the compound (III) in the presence of a compound

and / or in the presence of a connection

with -OR ¹⁵ or -SR ¹⁵ = residue of an alcohol or thiol.