DE1157399B - Process for the preparation of a polymer with a trans-1,4 structure from a conjugated diolefinic hydrocarbon - Google Patents

Description

It is known that the configuration of polymeric chains generated from conjugated diolefins has one significant influence on the physical properties. For example, Hevea rubber, which has a cis-1,4 configuration of isoprene units, the properties commonly used for Products such as automobile tires and the like are desired. Balata, on the other hand, has a trans-1,4 configuration from isoprene units and is a hard, plastic-like polymer that is found in tires can not be used, but for certain purposes, for example for the production of Golf ball covers, is very valuable.

Recent work in the field of polymerization has shown that various olefins including Butadiene and isoprene at relatively low temperatures and pressures to form high molecular weight polymers can be polymerized if a mixture of an organometallic reducing agent is used as the catalyst and reducible heavy metal compounds is used. Metal alkyls are used, Metal hydrides or metal alkyl hydrides in combination with halides, oxyhalides, alcoholates, Esters and the like of heavy metals such as titanium. Most of these catalyst systems lead to polymers which contain mixtures of the various possible configurations. For example, if butadiene using a titanium tetrachloride-aluminum triisobutyl catalyst is polymerized, the product is a mixture of the various possible configurations and contains substantial amounts of both of the ice as well as the trans material. However, if butadiene in the presence of a catalyst complex is polymerized, which was formed by mixing titanium tetraiodide and aluminum triisobutyl, a product is created that consists predominantly of cis-1,4 units is constructed. On the other hand, a product is obtained with a high proportion of trans-1,4 units, when using either isoprene or butadiene using a vanadium trichloride catalyst and aluminum triisobutyl polymerized. However, the product is insoluble and has a very high melting point, which is both a disadvantage.

The term "butadiene" used here and below denotes butadiene- (1,3) and is not intended to include butadiene (1,2) or derivatives of butadiene (1,3) such as chlorobutadiene. However, the invention is generally applicable to conjugated diolefinic hydrocarbons having 4 carbon atoms in the unsaturated chain. For example, isoprene can also form a polymer with a high trans-1,4 content being transformed.

Method of manufacture

of a polymer with a trans-1,4 structure

from a conjugated diolefinic

Hydrocarbon

Applicant:

Polymer Corporation Limited,
Sarnia, Ontario (Canada)

Representative: Dr. W. Muller-Bore

and Dipl.-Ing. H. Gralfs, patent attorneys,

Braunschweig, Am Bürgerpark 8

Claimed priority:
Canada, June 21, 1961 (No. 826 056)

Evalds Lasis and Mieczyslaw Marcinkowski,

Sarnia, Ontario (Canada),
have been named as inventors

It has been found that the addition of thioethers to certain catalyst systems described in the following and the normally certain conjugated diolefinic hydrocarbons convert into polymers of predominantly 1,4-configuration, to an increase in the trans-1,4-content the polymers of these hydrocarbons produced using such catalyst systems leads. It has been shown that using these catalyst systems, polybutadiene and polyisoprene can be generated in which more than 75% of the units and even more than 90% of the units in of the trans-1,4-configuration.

The process for making a polymer in which the units are predominantly in the trans-1,4 configuration stand by polymerizing a conjugated diolefinic hydrocarbon with 4 carbon atoms in the unsaturated chain in the presence of a catalyst mixture of a reducible, iodine-containing compound of a heavy metal from group IVB of the periodic table and a reducing, organometallic compound of lithium or a metal from group II of the periodic table is characterized in that one uses such a catalyst mixture which is a thioether has been added.

309 748/390

I 157 399

According to the process of the invention, a polybutadiene in particular can be produced in which the Units are predominantly in the trans-1,4 configuration. For this purpose, 1,3-butadiene is polymerized in the presence of a catalyst system which is a mixture of the following substances: as reducible Compound titanium tetraiodide or titanium trichloromoniodide, as a reducing compound a lithium alkyl or a compound of the formula R "MgX (R" is alkyl, aryl and polynuclear aromatic) Hydrocarbons; X is halogen) and an alkylthioether, in which each alkyl radical contains 1 to 4 carbon atoms. The molar ratio between reducing Connection and reducible connection is between 1: 1 and 3.5: 1, and the amount of the thioether is between 0.5 and 7.5 moles per mole of reducible compound.

The periodic table referred to here is on page 342 of the Handbook of Chemistry and Physics, 33rd Edition, Chemical Rubber Publishing Company, Cleveland, Ohio, 1951.

Such reducible iodine-containing compounds are preferably used in the catalyst system Heavy metals of group IVB of the periodic table are used, in which the metal has a valence of 4. Heavy metals include all metals with an atomic number of 22 or more that belong to them Titanium, zirconium, hafnium and thorium; Titanium is preferred. The connections can be made through the general formula

MeJX "R '" ₃ _ »

where Me is a heavy metal from group IV B of the periodic table, I is iodine, X is halogen, R "'is a hydrocarbon radical, an oxyhydrocarbon radical or an organic, salt-forming radical and η is an integer from 1 to 3. The hydrocarbon radicals can be alkyl -, aryl, alkylaryl, or cycloalkyl hydrocarbon radicals; those having less than about 12 carbon atoms are most useful, and those having 1 to 6 carbon atoms are preferred. X can represent fluorine, chlorine, bromine or iodine. It will be understood that mixtures of halogen atoms as well as mixed hydrocarbon and oxyhydrocarbon radicals can be used. Examples of usable compounds are TiJ ₄ , TiCl ₃ J, TiCl ₂ J ₂ > TiClJ ₃ , TiJ ₃ Br, TiJ ₈ Br ₂ and TiJBr ₃ as well as TiCl ₂ J (C ₂ H ₅ ), TiClJ ₂ (C ₂ H ₅ ) and the other possible combinations of halogen atoms with the same or different hydrocarbon radicals, Examples of compounds containing salts or Chemical acids that can be used in the catalyst system include titanium monoiodo triacetate, titanium iodine dipropionate, titanium triiodo monobutyrate, titanium monoiodo trioxalate, titanium triiodo monoacetate, titanium monochlorodiodoacetate, titanium monochloromonic iodine diacetate. Suitable compounds with oxyhydrocarbon residues include

TiJ ₃ (OC ₂ H ₅ ) triiodine monoethyl titanate,
TiJ ₂ (OC ₄ Hg) ₂ diiododibutyl titanate,
TiJ (OC ₄ Hg) ₃ monoiod tributyl titanate,

TiCl ₂ J (OC ₄ H ₉ ) dichloromonoiodine monobutyl titanate

as well as numerous other combinations of halogens and oxyhydrocarbons. The hydrocarbon fraction the oxyhydrocarbon radicals can be substituted by alkyl, aryl, alkaryl or cycloalkyl hydrocarbons are formed. Those with less than about 12 carbon atoms are the most useful, hydrocarbons having 1 to 6 hydrocarbon atoms are preferred. For the sake of simplicity only titanium compounds have been mentioned above as reducible compounds, but are understood that the other heavy metals from Group IVB, as defined above, are also used in place of titanium can be used. The preferred ones containing iodine

ίο Compounds are titanium tetraiodide (TiJ ₄ ) and titanium trichloromoniodide (TiCl ₃ J).

The organometallic compounds to be used act as reducing agents for the heavy metal compound.

Examples of reducing organolithium compounds are alkyl lithium compounds such as methyl lithium, ethyl lithium, butyl lithium, amyl lithium, dodecyl lithium, or alkylenedilithium compounds such as methylenedilithium, ethylenedilithium, hexamethylenedilithium. In addition to the saturated aliphatic lithium compounds, unsaturated compounds such as allyl lithium and methallyl lithium can also be used, as well as aryl and alkylaryllithium compounds such as phenyllithium, tolyllithium, naphthyllithium, 1,4-diithiumbenzene. The length of the hydrocarbon is not critical, but generally those having 2 to 8 carbon atoms are preferred. Metallic lithium can also be used in the practice of the invention because it readily forms addition compounds with olefinic hydrocarbons. For example, if metallic lithium containing butadiene is added to the polymerization reactor in the practice of the invention, the metallic lithium will rapidly react to form butadienyl lithium. Here and in the following, such butadienyl lithium is to be considered as an organometallic compound of lithium.
Organometallic compounds of the metals from group II of the periodic table, which can be represented by the formula R! JM, in which M is the metal and R ^{0 is} a hydrocarbon radical, can also be used as the reducing compound of the catalyst system. This hydrocarbon radical is preferably an alkyl radical with a straight or branched chain, for example methyl, ethyl, propyl, isopropyl, η-butyl, isobutyl, pentyl, isohexyl. The alkyl groups can be the same or different, and generally those having 1 to 12 carbon atoms are preferred. Examples of suitable compounds are dimethyl zinc, diethyl zinc, di-n-butyl zinc, di-n-octyl zinc, dimethyl mercury, diisopropyl mercury, di-n-hexyl mercury, dimethyl magnesium, diisobutyl magnesium, di, n-decyl magnesium, di, n-decyl magnesium, dimethyl cadmium, dimethyl cadmium Dibutylberyllium, dipentylberyllium. Other organometallic compounds of the Group II metals which can be used are those in which only one of the valences of the metal is linked to a hydrocarbon radical while the other is linked to halogen. These Grignard-type compounds can be represented by the formula R "MX, in which M again denotes the metal, X represents a halogen which can be either fluorine, chlorine, bromine or iodine, and R" is a hydrocarbon radical either aliphatic or aromatic in nature . Examples of such Grignard compounds are ethyl magnesium chloride, ethyl magnesium bromide, ethyl

magnesium iodide, propyl magnesium chloride, pentyl against is also the optimal ratio higher, and

magnesium bromide, phenylmagnesium bromide, naph- even a ratio of 10: 1 can be used

methyl magnesium iodide. will.

The thioether is an essential component of the total amount of catalyst used to effect the Catalyst system. The most effective thioethers will allow 5 polymerization to be required by those skilled in the art

represented by the formula R - S - R ', in which R's are easily determined; it is based on the

an alkyl hydrocarbon radical and R 'an alkyl, special conditions such as temperature, impurity

Aryl, alkylaryl or cycloalkyl hydrocarbon radicals, etc. The molar ratio of the organometallic

is. They include simple or symmetrical connections to the heavy metal compound can via saturated aliphatic thioethers, which vary in the general io a wide range from about 1: 1 to 10: 1,

Formula depending on which heavy metal compound and

C _n H _{271 + 1} · S · C _n H ₂ M +! which organometallic compound is used.

Is for example the organometallic compound

where η is an integer, e.g. B. Dimethyl a lithium hydrocarbon, the molar ratio of sulfide, diethyl sulfide, di-n-propyl sulfide, diisopropyl-15 should be between about 1: 1 and 3: 1, and best results sulfide, di-n-butyl sulfide, dioctyl sulfide, and asymmetries are achieved when it is between 1.5: 1 and tric aliphatic thioethers, which is by the general 2.8: 1. If the organometallic compound is a formula magnesium compound, the ratio between C _n H _{2n + 1} · S _{· C 7n} H _{21n + 1 should be} about 1: 1 and 4: 1, and best results will be achieved

zo if it is between 1.5: 1 and 3.5: 1. at

are shown in which m and η are different whole uses of a beryllium compound as metal numbers, e.g. B. methyl ethyl sulfide, isopropyl ethyl organic compound, the ratio between sulfide, isopropyl methyl sulfide, isopropyl butyl sulfide can be 1: 1 and 10: 1. In general, the ratio falls as do numerous combinations of other alkyl groups. thus in the range from about 1: 1 to 10: 1, preferably there is no theoretical limit for the number of 25, a ratio between about 1: 1 and 3.5: 1 carbon atoms in each alkyl group, however, the polymerization can within a wide range the most useful ones with 1 to 4 carbon temperature range can be carried out, in allatoms. It is also possible to use unsaturated aliphatic mean but it is not convenient to use over about thioethers, e.g. B. Vinyl thioether. Another 100 ⁰ C to work. Likewise, there is no critical suitable compounds are, for example, aromatic minimum 30, and the polymerization can still see thioether, by containing an aromatic substituent at a temperature of -75 ⁰ C or lower. Typical examples of such aromatic are listed. The reaction rate is ever-thioethers are phenylmethyl sulfide and phenylethyl- but low at the lower temperatures, the bevorsulfid. It is also possible to use mixtures of any ferred operating range is between about 0 and +70 ⁰ C. to use the above-mentioned thioether. The reaction can be carried out very conveniently as thio- 35; diethyl sulfide is preferred. When the reactants are in a non-reactive The catalyst complex can be dispersed on various liquid media. Establish particularly suitable routes. Since thioethers with organometallic liquids are aliphatic, cyclic and aroma compounds with the formation of thioetherate tables hydrocarbons such. B. butane, pentane, hexane, react, it is possible to produce the complex 40 heptane, cyclohexane, benzene, toluene, xylene and borrowed, the heavy metal compound, the organometallic other relatively low-boiling, non-reactive solution compound and the thioether in each desired agents that mix easily with each other from the reaction product onwards. For example, let them separate. In some systems, for example, the thioether can be introduced into the reaction vessel before the other reactants using titanium tetraiodide; The 45 phatic liquids are preferred, in other, thioethers, either to the heavy metal compound, for example, those based on titanium trichloride or to the organometallic compound monoiodide, on the other hand aromatic and cycloaliphae, can be added before these two components are added. The amount of diluent is not to be mixed together; the thioether can be critical, but should generally be so large that the viscosity of the reactor contents, even to a mixture of the heavy metal compound, is low enough to allow thorough mixing and adequate temperature control of the organometallic compound added before it comes into contact with the monomer to allow. The presence will be brought; the thioether can be introduced even during a non-reactive diluent which is not essential to the polymerization reaction in the polymerization practice of the invention. 55 and the diolefin to be polymerized can itself do that

The amount of thioether applied will form the single diluent.

as a ratio to the amount of metal- The invention is described below with reference to

expressed organic compound. It can strongly describe experimental results in more detail. Titanium tetra

vary, and even a very small amount leads to iodide was added as a solution in n-heptane, which was 1 g

an increase in the trans content in the product. Generally contained 60 per 100 ml of solvent. The rest of the

mine is the amount of thioether between about 0.1 and the solvent was either benzene, which was previously through

10 moles per mole of the organometallic compound. azeotropic distillation had been dried, or

The optimum depends on the polymerization heptane that has been dried over calcium hydride

conditions and can easily be determined by a person skilled in the art. Some of the examples show a blank sample in which

will. For example, if the polymerization at 65 was not present with thioether. Such blind tests

Temperatures of 0 to 30 ° C is carried out, does not form part of the invention, but were with

the optimal ratio between about 0.75: 1 and added to the influence of the addition of thio-

7.5: 1, at higher polymerization temperatures therefore to illustrate according to the invention.

The structural analysis of the polymers was carried out with the aid of an infrared spectrophotometer. The analyzes are based on the assumption that the polymers have an unsaturated bond on each monomer Unit included. The analysis results are given for polybutadiene as trans-1,4 and 1,2-content, it being understood that the remainder of the polymer is in the cis configuration, while for polyisoprene the values are given as trans-1,4 and 3,4-content and the remainder of the unsaturation in the cis-1,4-configuration stands. In some cases the percent crystallinity of the product was determined by X-ray analysis determined because there is a direct relationship between the crystallinity and the trans-1,4 content consists.

example 1

Butadiene was made in standard 200 ml polymerization vials polymerized, dried thoroughly, flushed with nitrogen and according to the following approach were loaded:

n-heptane 50.0 ml

Butadiene 30.0 ml

Diethyl sulfide variable

Lithium butyl 1.20 millimoles

Titanium tetraiodide 0.60 millimoles

The individual components were added to the bottles in the order given, and these were closed with crown caps. After the addition of the diethyl sulfide and before the addition of the lithium butyl, the bottles and their contents were cooled from room temperature to 10 ° C. That Lithium butyl was introduced as a two-molar solution in a mixture of n-pentane and η-hexane. The bottles were held at 30 ° C for 19 hours. Thereafter, the reaction was started by injecting a Excess of alcohol canceled. The polymer from each bottle was then placed in boiling Ethanol extracted containing 1% di-tert-butyl-p-cresol as a stabilizer, and then in a vacuum oven dried at 40 ° C. The products were examined by infrared analysis; the results are in Table I compiled.

Table I. Example 2

Butadiene was polymerized as in Example 1, but the following approach was used:

Benzene 100 ml

Lithium butyl 1.44 millimoles

Titanium trichloromoniodide 0.60 millimoles

Di-n-butyl sulfide variable

Butadiene 20 ml

The ingredients were placed in the order shown, and the bottles and contents were cooled from room temperature to 0 ° C. after the addition of the sulfide and before the addition of the butadiene and held at this temperature for about 30 minutes. The lithium butyl was as a one molar solution in added to a mixture of n-pentane and η-hexane and the titanium compound as a 0.5 molar solution in benzene. The polymerization took place at about 32 ° C for 21 hours, whereupon the polymers as in Example 1 were separated and examined. The results are summarized in Table II.

Table II

bottle
No. Molar ratio
Sulfide too
Lithium butyl Around
change
(7 ") trans-
1.4 content
(7o) 1,2 content
(7o) 1
2
3 0
1.0
2.0 27.0
20.0
26.0 2.5
28.0
49.8 5.5
22.9
16.2

bottle
No.

Molar ratio Around trans- Sulfide too change 1.4 content Lithium butyl (%) (7o) 0 87 15.0 1 90 68.2 3 65 90.6 4th 36 94.4 5 26th 96.8

1.2 content (7o)

7.0 4.7 3.0 3.2 2.9

The polymers were completely soluble in toluene at room temperature. These results show that in the polymerization of butadiene using a titanium tetraiodide lithium alkyl catalyst the addition of a thioether has a strong influence on the catalyst system. Through this Addition it is converted into a catalyst system, which favors the formation of trans material, so that Polybutadiene is formed, which is 97% in the trans-1,4 configuration is present.

These results show the influence of the thioether through the increase in the trans content in the this catalyst system produced product. They indicate that there is a molar ratio of thioether too Lithium butyl of more than 2.0 is required to produce a polybutadiene whose trans content is above 50%.

Example 3

Butadiene was polymerized as in Example 2, but the diluent was heptane the following approach was used:

Heptane 100 ml

Lithium butyl 1.0 millimole

Titanium trichloromoniodide 0.4 millimoles

Diethyl sulfide 0.62 millimoles

Butadiene 15 ml

After the addition of the diethyl sulfide, the bottle and contents were aged for 30 minutes before the addition of the Butadiene took place. Polymerization was carried out for 68 hours 27 ° C., whereupon the polymer was separated off as in Examples 1 and 2. The percent crystallinity the polymer was determined by X-ray analysis. It became a crystallinity of 40.7% was determined, which corresponds to a trans content of about 90%.

Example 4

Butadiene was prepared using the same equipment and procedures as in both

play 1 and 2 polymerized, however the following approach was used:

Benzene 80 ml

Butadiene 20 ml

Naphthyl magnesium bromide ... 1.19 millimoles

Di- (n-butyl) sulfide variable

Titanium trichloromoniodide 0.40 millimoles

The individual components of the batch were introduced in the order given above. After the addition of the sulfide and before the addition of the titanium compound, the bottles and their contents were cooled ^{to 0 ° C. for about 30 minutes.} The magnesium compound was added as a 0.99 molar suspension in xylene and the titanium compound as a 0.5 molar solution in benzene. After polymerization for 18.5 hours at about 32.degree. C., the polymers were separated off and examined as described in Example 1. The results can be found in Table III.

Diethylmercury replaced, and the molar ratio of Sulfide to diethyl mercury was 1: 1. Conversion occurred in 40 hours of polymerization at 13 ° C of 49% and the product was found to contain 66.5% trans-1,4 material and 3.0% 1,2 material.

Molar ratio
Sulfide to Mg Table III trans-
1.4 content
(7o) 1,2 content
(%) bottle
No. 3.0
4.0
5.0 Around
change
CYo) 66.3
77.6
80.4 8.0
5.7
6.6 3
4th
5 57.0
46.0
39.0

The results of this example show the influence of thioether on the structural configuration of the Product when butadiene is polymerized with a catalyst system in which an organometallic Compound of a metal from group II of the periodic table used as a reducing agent will.

Example 5

Butadiene was polymerized as in Example 1, but the following approach was used:

Example 7

Isoprene was supplied in standard 200 ml polymerization bottles polymerized with crown lock. These bottles were thoroughly dried and filled with nitrogen rinsed and charged according to the following approach:

Benzene 60 ml

Isoprene 30 ml

Diethyl magnesium .. 1.75 · IO- ³ mol

Diethyl sulfide variable

Titanium trichloromoniodide 1.75 · IO- ³ mol

The individual components were added in the order given. The bottles were Maintained at 30 ° C. for 20 hours, whereupon the reaction was terminated by injecting excess ethanol became. The polymer from each bottle was then extracted into boiling ethanol containing the 1% di-tert-butyl-p-cresol contained as a stabilizer, and then dried in a vacuum oven at 30 ° C. The results are shown in Table V.

Table V

40

Benzene 60 ml

Butadiene 20 ml

Diethyl zinc 0.79

Titanium tetraiodide 0.72

IO- ³ moles IO- ³ moles

Diethyl sulfide variable

45

After the addition of the diethyl zinc and before the addition of the titanium tetraiodide, bottles and Contents cooled to 0 ° C. The diethyl sulfide was added immediately after the addition of the titanium tetraiodide. After 40 hours of polymerization at 13 ° C, the polymers were separated and examined, as described in Example 1. The results are shown in Table IV.

55

⁶⁰

Molar ratio
Sulfide too
Diethyl zinc Table IV trans-
1.4 content
(° / o) 1,2 content
(%) bottle
No. 0.5
4.0
7.0 Around
change
(%) 14.8
33.0
75.4 5.2
4.7
2.9 1
2
3 75
80
81

Example .6

Butadiene was polymerized as in Example 5, but the diethyl zinc was replaced by 1.8 · IO- ³ mol

bottle
No. Molar ratio
Sulfide to Di
ethyl magnesium Around
change
(7o) trans-
1.4 content
(° / o) 3,4 content
(%) 1
2 0
1 11.7
29.1 about 50
75 to 95 5
5

95% of the isoprene produced in bottle # 1, i.e. in the absence of thioether, was in the 1,4 configuration and only about 50% in the trans configuration. The presence of thioether resulted in one noticeable increase in the trans content of the polymer.

Example 8

Isoprene was polymerized as in Example 7 using the following approach:

Benzene 60 ml

Magnesium compound 1.33 · IO- ³ mol

Diethyl sulfide 0.67 · IO- ³ mol

Isoprene 15 ml

Titanium tetraiodide 0.72 · IO- ³ mol

After 60 hours of polymerization at 30 ° C., the polymers were separated off as in Example 7 and examined. The results can be found in Table VI.

Table VT

bottle
No. magnesium
link Around
change
CVo) trans-
1.4 content Crystal
line
CYo) 1
2 Methyl-
magnesium-
iodide
Diethyl
magnesium 12th
11 over 90
over 75 24
15th

309 748/390

The crystallinity became 24% for the polymer produced in bottle # 1, for that in bottle # 2 generated at 15%. It is known that in the case of polyisoprene these crystallinity values affect polymers that are more than 90% or more than 75% in the trans-1,4 configuration.

The above examples are only intended to show the influence of the addition of thioether to the catalyst system explain the method of the invention, but not limit the invention in any way. For example, a similar effect is obtained when iodine-containing titanium compounds other than those mentioned above are used in their place in the examples.

Claims (3)

PATENT CLAIMS: 1. A process for the preparation of a polymer whose units are predominantly in the trans-1,4 configuration present, by polymerization ao of a conjugated diolefinic hydrocarbon, of the 4 carbon atoms in the unsaturated one Chain contains, in the presence of a catalyst mixture of a reducible iodine-containing compound of a heavy metal of group IVB of the periodic table and a reducing organometallic compound of lithium or a metal of group II of the periodic table, characterized in that a catalyst mixture is used to which a thioether has been added is. 2. The method according to claim 1, characterized in that a catalyst mixture is used, in which the molar ratio of the reducing compound to the reducible compound is between 1: 1 and 3.5: 1 cherishes. 3. The method according to any one of the preceding claims, characterized in that one Catalyst mixture used in which the molar ratio of thioether to reducing compound is between 0.1: Γ and 10: 1. Considered publications:
Belgian patent specification No. 551 851. © 309 748090 11.63