DE1265421B - Process for the polymerization of isoprene - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

C08d

German class: 39 c - 25/05

Number: 1265 421 ^; '''■ ^!

File number: P 29243IV d / 39 c

Filing date: April 24, 1962

Open date: April 4, 1968

In recent years, there has been much development of processes for making olefin polymers worked. Polymers of monoolefins, such as ethylene and propylene, are made by these processes have found acceptance in many branches of industry. The recent invention of certain so-called stereospecific catalysts in this field of diene polymerization, which promote the formation of Enabling polymers of a desired configuration has generated considerable interest. By The polymers formed using these catalysts often have exceptional physical properties Properties that make them equal to or even superior to natural rubber.

While diene polymers can be made in the presence of organolithium initiators, have the products often have a higher inherent viscosity than desired and are also difficult to process, for example, the injection speeds are slow, the edges of the molded body are coarse, and the polymers tend to puff and crumbly on the calender.

The present invention relates to an improved method for producing easily processable isoprene polymers, especially those with a high percentage of cis-1,4 addition.

It has been found that the presence of an auxiliary halogen when polymerizing isoprene in Presence of an organolithium initiator has certain beneficial effects on the properties of the polymer can be obtained. For example, the isoprene polymers produced according to the invention have a lower value Intrinsic viscosity than those made in other ways show better extrusion properties and good bonding during calendering, the polyisoprene products also have a cis content, which is at least as high as that of polymers that are used in the absence of a halogen as an auxiliary can be obtained. A notable advantage of the present inventive method is therefore that the inherent viscosity can be reduced without lowering the cis content. It is believed, that the halogens used as auxiliaries serve as modifiers and processing aids, without affecting the present invention any particular reaction mechanism should be specified.

The process of polymerizing isoprene in the presence of an organolithium initiator produced by Reaction of lithium with a polycyclic aromatic compound or a polyaryl-substituted one Ethylene with two to four aryl groups, the process used to polymerize isoprene

Applicant:

Phillips Petroleum Company,

Bartlesville, OkIa. (V. St. A.)

Representative:

Dr. F. Zumstein, Dr. E. Assmann

and Dr. R. Koenigsberger, patent attorneys,

8000 Munich 2, Bräuhausstr. 4th

Named as inventor:

Gerald Roy Kahle, Bartlesville, OkIa. (V. St. A.)

Claimed priority:
V. St. v. America September 11, 1961
(137 015)

Represent phenyl, is characterized in that the polymerization is carried out in the presence of a halogen compound of the formula (1) RX, (2) HX or (3) X ₂ , where X is a halogen and R is an aliphatic, cycloaliphatic or aromatic hydrocarbon radical with 1 to 12 carbon atoms and, if X is fluorine, R is an aliphatic or cycloaliphatic radical.

Examples of suitable halogen auxiliaries that can be used in the present invention include fluorine, Chlorine, bromine, iodine, hydrogen fluoride, hydrogen chloride, hydrogen bromide, hydrogen iodide, methyl chloride, Methyl bromide, methylene bromide, chloroform, bromoform, ethylene bromide, allyl bromide, isopropyl iodide, Isobutyl iodide, n-butyl chloride, n-butyl bromide, n-hexyl iodide, n-hexyl fluoride, n-dodecyl chloride, cyclopentyl fluoride, Cyclohexyl iodide, 4-methylcyclohexyl fluoride, 4-bromocyclohexane, bromobenzene, chlorobenzene, 4-iodotoluene, benzyl chloride, etc. Like. Of the specified The n-alkyl bromides are preferred for halogen auxiliaries.

The amount of halogen auxiliary used in the polymerization can vary considerably and

809 537/583

3 4

is generally used as gatom lithium in the initiator trilithium - ρ - terphenyl, 1,4 - dilithiumnaphthalene, expressed per gAtom of halogen additive. In all- 1,5 - dilithium naphthalene, 9,10-dilithium anthracene, in general, the amount of halide used is 9,10 - dilithium phenanthrene, 1,3,5 - trilithium benzene, in the range from 0.25 to 20 gAtom lithium, preferably 1,4-dilithium-2-n-hexylbenzene, 1,3,5-trilithium 1 to 10 gatom lithium per gatom halogen, 5 2,4,6 - triethylbenzene, 5,6 - dilithium acenaphthene, however, the amount used depends on the activity 2,4 - dilithium - 5,7 - diisopropylphenanthrene, 1,4 - dides Excipient. They differ considerably from lithium anthracene and 1,4 - dilithium - 2 - methyline their activity, and in some cases one becomes naphthalene.

Large amounts of the halogen adjuvant can also cite the initiator- polylithium substitution products

disturb. In such cases, only small amounts should be used due to the reaction of lithium with halide while in other cases suitable polyaryl-substituted ethanes are obtained, satisfactory results only with larger amounts. Examples of such initiators include 1,2-Dierhalts will. lithium -1,2 - diphenylethane, 1,2 - dilithium -1,1 - di-

In the present invention, phenylethane, 1,2-dilithiumtetraphenylethane, 1,2-Difahren Usable organolithium initiators contain lithium-l-phenyl-2- (l-naphthyl) -ethane and 1,2-dilute usually 1 to 4 lithium atoms per molecule. thium-1,2-di- (2-naphthyl) -ethane. These organolithium compounds can be used in one die in the present process

Hydrocarbon or in the polar medium on different organolithium initiators can also be adducts, can be produced in different ways, for example the reaction products of lithium with polydurch Replacing halogen in an organic cyclic aromatic compound or poly-halide by lithium or by the direct aryl-substituted ethylenes. To the polyAddition of lithium to a double bond or cyclic aromatic compounds with Lidurch Reaction of an organic halide can be reacted with thium, are preferred lithium-containing compound. wise condensed ring aromatic compounds,

The hydrocarbons from which the organo- 25 such as naphthalene, anthracene and phenanthrene; alkyllithium compounds are produced, contain in the substituted condensed ring aromatics, in which generally 4 to 30 carbon atoms inclusive, the alkyl groups contain 1 to 6 carbon atoms, in the molecule, and if the parent hydrocarbon such as 1-methylnaphthalene, 2-methylene is an aromatic hydrocarbon, it can be alkylnaphthalene, 1 - ethylnaphthalene, 1 - η - propylnaph substituents exhibit. The alkyl substituents can be thalin, 1-tert-butylnaphthalene, 2-amylnaphthalene, contain 1 to 6 carbon atoms, but should contain 2,4 - di - η - propylnaphthalene, 9 - methylanthracene, the number of carbon atoms in each alkyl-1-ethylanthracene, 1,4,5-triethylanthracene, 2,7-digroup Do not exceed 6, and methylphenanthrene and mixtures of these compounds should not be used per molecule there are more than 3 alkyl groups. fertilize. To the polyaryl-substituted ethylenes, the

As noted above, what can be used in the invention include the compounds according to usable organolithium compounds with two, three or four aryl groups, such as for example Substitution products and adducts. Subsequently phenyl and / or naphthyl, e.g. 1,1-diphenyl constitution products can both mono- and ethylene, I, 2 - diphenylethylene (stilbene), triphenyl-polylithium compounds be, depending on the carbon ethylene, tetraphenylethylene, 1-phenyl-1-naphthylhydrogen, from which they are derived, and 4 ° ethylene, 1,2-dinaphthylethylene, 1,1-diphenyl-i-naphnach the process of manufacture. ethylene, trinaphthylene. Other polycyclic

Monolithium substitution products can be replaced by aromatics such as biphenyls, terphenyls and dinaphthyl, Reacting lithium with halogen-containing poly- can also be used cyclic aromatic compounds including that used to make the initiators

Borrowed fused ring aromatics and polyphenyl lithium can be used in any desired form connections are made. Examples should be, for example, as wire, in chips or Monolithium initiators include lithium benzene, rather than shot or in a finely divided state. It will 1-lithium naphthalene, 2-lithium naphthalene, 4-lithium preferred that at least equimolar amounts of um-1-methylnaphthalene, 9-lithium anthracene, 9-lithi-lithium in the production of initiator reaction umphenanthrene, 5-lithium acenaphthene, 1-lithium 50 products are used, and in many cases 2,4,6-trimethylbenzene (lithium mesitylene), 1-lithium, an excess of lithium is used. 2-amylnaphthalene, l-lithium-4-hexylnaphthalene, 1-Li- The initiators described above can be

thium-2-ethyl-4-n-butylbenzene, 4-lithiumbiphenyl, quem in any manner known to those skilled in the art 3-lithium-3'-n-propylbiphenyl and 4-lithium-p-ter- are produced. In some cases it is beneficial to phenyl. Monolithic substitution products can 55 lithium with mixtures of hydrocarbons can also be implemented by reacting lithium with halogen, for example with a mixture of containing polyaryl-substituted methanes get naphthalene and anthracene in ether to complete the reaction will. Examples of such initiators include facilitate. Often the initiator becomes in one Lithium triphenyl methane, lithium diphenyl methane, Li-polar solvents or in other organic solvents thium - (di - 2 - naphthyl) - methane and lithium - (tri- 60 media formed. To a polymer with a possible 2-naphthyl) -methane. to obtain a high cis content, it is preferred

Polylithium substitution products can be drawn by the fact that the polar solvent used in the preparation of the initiator reaction of lithium with polycyclic aroma is replaced almost completely by a suitable atom per molecule, including condensed ⁶ 5 hydrocarbons, before the polymeric compounds with two or more halogenation, eg a high ring aromatic and polyphenyl compounds, get a boiling hydrocarbon such as a mineral oil. Advance. Examples of such initiators also include both the production of 1,4-dilithiumbenzene, 4,4'-dilithiumbiphenyl, 2,2 ', 2 "initiator and the polymerization in one

carried out in an inert atmosphere, such as in argon, helium or nitrogen.

The initiators to be used according to the invention give polyisoprene homopolymers and high cis copolymers in which the conjugated diene moiety has a low vinyl content having. The polyisoprene obtainable according to the invention has an approximate cis content of more than 65% and generally greater than 70%.

The temperature used in the inventive polymerization is generally in the range of -100 to +150 ⁰ C, preferably from - 75 to + 75 ° C. The particular temperature used will depend on the used in the polymerization initiator. The pressure applied during the polymerization need only be such that it keeps the materials practically completely in the liquid phase. The amount of initiator used during the polymerization will vary considerably, but will generally range from about 0.1 to about 200 grams of lithium per 100 grams of monomer, with the preferred range being from about 0.25 to about 60 grams of lithium per 100 grams of monomer .

The polymerization of the isoprene in the presence of the halogen compound and the organolithium initiator is preferably carried out in a suitable diluent, such as in Benzene, toluene, cyclohexane, methylcyclohexane, xylene, n-butane, η-hexane, n-pentane, n-heptane, isooctane. in the in general, a hydrocarbon is used as the diluent, for example a paraffin, Cycloparaffin or an aromatic hydrocarbon containing 4 to 10 carbon atoms inclusive in the Having molecule.

Numerous variations can be made in carrying out the polymerization in accordance with the present invention can be applied. The halogen compound can be in the system as a separate component, either as such or in solution in a solvent that does not adversely affect the polymerization exercises, to be introduced. It is convenient to introduce elemental halogen in the form of a solution, especially, if it is bromine or iodine. Halogen acids can be conveniently added to either be introduced as gases or solutions in suitable solvents. If desired, the halogen compound be added to the polymerization as part of the initiator. If the initiator is in a polar solvent is prepared, the halogen compound can be added to the solution and then replacing the polar solvent with a suitable hydrocarbon diluent or the halogen compound can be used after replacement with a suitable hydrocarbon diluent incorporated into the initiator.

For the successful polymerization of isoprene by known processes, it is necessary that the High purity monomers. It is an advantage of the process of the invention that olefinic Impurities do not have to be removed. It was found to have excellent results can be achieved if an isoprene-containing effluent is used, such as that in the isoamylene effluents occurs from dehydration processes. The economic advantage of such a procedure is obvious, and the gain in time and cost that would otherwise be spent on separating and purifying the isoprene would arise is very significant. As is known, engineered isoprene usually contains smaller amounts, for example up to 10%, of olefinic hydrocarbons.

The polyisoprene products with a high cis content obtained according to the invention can be liquids to be rubbery materials. The polymer solutions obtained can be mixed with various reagents treated to introduce functional groups resulting from the polymerization itself

ίο resulting terminal lithium atoms in the polymer molecule substitute. For example, the polymer can be reacted with carbon dioxide in solution are attached to the lithium atoms by —COOH groups to replace. Other functional groups that can be introduced include -SH, - OH, halogen. Optionally, the polymer solutions can be mixed with one alcohol or another Reagent treated to inactivate the catalyst or initiator and / or precipitate the polymer, which is then obtained without functional groups.

The rubber-like cis-polyisoprene produced according to the invention can be mixed up by known processes will. Vulcanizing agents, vulcanization accelerators, acceleration activators, reinforcing agents, Antioxidants, plasticizers or plasticizers, fillers and others Mixing ingredients, as they are normally used with rubbers, can also be used here can be applied. The isoprene rubbery polymers are valuable in applications where both natural as well as synthetic rubbers are used. For example, at the Manufacture of automobile tires, seals and other rubber-like articles are used. The following examples serve to provide a better understanding of the invention without restricting it. the Methods for determining the quality of the polymers in the examples are then compiled using Example 11.

example 1

A polymerization initiator was made by reacting lithium wire with methylnaphthalene (mixture of α- and / 2-methylnaphthalene 60:40) in the presence made from diethyl ether. The following recipe was used:

Methylnaphthalene, 1.0 mole

Lithium wire, gAtom 3.0

Diethyl ether, mole; 4.5

Temperature, ° C-25

Time, hours 19

Molarity ¹ ) 1.63

¹ J Determined by removing part of the reaction mixture and titrating with 0.1 N HCl.

Ether was made from the reaction mixture by pouring it into purified mineral oil (heavy white Mineral oil), which had been heated to 100 ° C and flushed with nitrogen, was removed. 30 ml of the ether-containing Reaction mixes were used per 125 ml of mineral oil. The temperature was 1 hour at Maintained 100 ° C while the mixture was stirred and nitrogen passed through. After cooling down to room

temperature it was diluted with 125 ml of n-pentane. Isoprene, parts by weight 100

The mixture obtained had a molarity of n-pentane, parts by weight 1000

0.165. Initiator, mM / 100 g M ¹ ) 2.5

Different amounts of n-butyl bromide were n-butyl bromide, mM / 100 g M alternating

during the polymerization of isoprene in the presence of 5 temperature, ⁰ C 50

the initiator dispersion described above is used. Time, hours 24

The recipe was as follows: ¹ J millimoles per 100 grams of monomer.

Pentane was charged first, then the reaction vessel was flushed with nitrogen and isoprene was added and then the initiator. If butyl bromide was used, it was added last. Table I. shows the results of the test series:

Table I.

attempt 1 U-QH ₉ Br Li-C ₄ H ₁ Br-
Molar ratio conversion ice cream 3,4 addition Intrinsic viscosity ⁴ ) Gel ⁸ ) 2 mM / 100 g M % % corrected % corrected % 3 0.63 8: 1 100 90.4 9.6 4.46 0 4th 1.25 4: 1 100 89.9 10.1 3.59 0 5 (control) 1.88 2.7: 1 100 89.2 10.8 3.11 0 2.5 2: 1 100 89.4 10.6 2.77 0 - - 100 88.6 11.4 4.60 0

The values show that butyl bromide has a Modi inherent viscosity of 5.71

fixing agent worked and, with increasing amount, gel ^B ),% 0

Inherent viscosity decreased. The in the presence of Mooney value at 100 ⁰ C (ML-4) ... 71.4

Polymers made with butyl bromide had a 30th grade

higher cis content and lower 3,4-addition The polymer was made according to the recipe of a tire than the control sample. mixture mixed up, weaving two different

_. . ₁ accelerator levels were used. A control

e 1 s ρ 1 e attempt was made with a mixture of 4 polymers

The initiator described in Example 1 was carried out, which was carried out in the presence of a lithium methyl Polymerization of isoprene according to the following naphthalene initiator, but without butyl bromide im Recipe used: system that was made. This polymer blend

had a raw Mooney value (ML-4 at 100 ⁰ C)

Isoprene, 100 parts by weight out of 51, a corrected cis content of 88.6% and

n-pentane, parts by weight 1000 40 an approximate 3,4 addition of 8.0%. All the crowds

Initiator, mM / 100 g M 1.75 were in one before the addition of hardeners

n-butyl bromide, mM / 100 g M 0.87 small Banbury mixer (Midget Banbury) 6 Mi temperature, ⁰ C 50 minutes at 121 ° C and then 5 minutes at 143 ° C, mixed hours 21. The processing behavior was

Conversion,% 100 45 observed and then the hardeners added,

, Micro structure,% the masses hardened and the physical properties

cis, corrected 90.3 shafts determined. The values are in the following

3,4 addition, corrected 9.7 Table reproduced:

Table II

A. B. control 100 100 100 50 50 50 3 3 3 3 3 3 1 1 1 5 5 5 1 1 1 2.25 2.25 2.25 0.5 0.7 0.5

Mixing recipes, parts by weight

rubber

Highly abrasion-resistant furnace soot

Zinc oxide

Stearic acid

Physical mixture comprising 65% of a complex diarylamine ketone reaction product and 35% N, N'-diphenyl-p-phenylenediamine

Aromatic oil

2,2'-dibenzylamidodiphenyl disulfide

sulfur

N-oxydiethylen-2-benzothiazylsulfenamide

continuation

control

Processing properties
MS-IV .. ₂ at 100 ⁰ C after mixing pressing at 9O ⁰ C

cm / minute

g / minute

Rating (Garvey's)

Bondability on the roller

Physical properties, cure for 45 minutes at 144 ° C

ν 10 ⁴ , mol / ccm ^D )

300% module ¹ ), kg / cm ²

Tensile strength ² ), kg / cm ²

Strain, %

Maximum tensile strength at 98 ^° C., kg / cm ² .

AT "), ⁰ C

Elasticity ^,%

Shore A hardness ^H )

Aged for hours in the oven at 100 ° C

300% module *), kg / cm ²

Tensile strength *), kg / cm ²

Strain*), %

Elasticity ⁰ )
Shore A hardness ^H )

25.5

141.7
114.2
12-good

1.51
88.6

261.1

610

137.5
24
68.9
57.5

107.2

140.6

380

25.2

68.7

61.5

1.68
102.6
248.5
570
140.6
22.8
68.8
59.5

124.4

138.1

320

22.5

69.9

63.0

27.0

144.8 115.2 12-good

1.51 77.33

232.0

660

129.7 23.6 67.1 58.0

101.2

113.2

345

25.2

67.3

62.0

') 30 minutes curing time.

² ) The masses were mixed and hardened for 6 minutes in a Midget-Banbury mixer at 121 ° C.

The data show that the polymers modified with butyl bromide have a better balance of the Properties than the control. Although the polymer modified with butyl bromide is a lot Mooney was higher than the control, it was equivalent in processability.

Example 3

Lithium was reacted with methylnaphthalene in diethyl ether and then the polar solvent replaced by mineral oil in a manner similar to that described in Example 1. The initiator became Polymerization of isoprene used. Two trials were carried out, with one trial n-butyl bromide was used. The following polymerization recipe was used:

A. B. Conversion,%
₄₅ ML-4 at 100 ° ^C )
Intrinsic viscosity ⁴ ) 100
54.0
5.99
traces
76.6
89.9
8.6
10.1 100
64.0
4.37
0
81.2
91.1
7.9
8.9 Micro structure,%
⁵⁰ ice cream, raw ice, corrected
3,4 addition, raw
3,4 addition, corrected ....

A. B. Isoprene, parts by weight 100 100 n-pentane, parts by weight 1000 1000 Initiator, mM / 100 g M 0.9 1.2 n-butyl bromide, mM / 100 g M .. - 0.6 Temperature, ⁰ C .... 50 50 Time, hours 26th 26th

In these experiments, pentane was first poured in, the reaction vessel was flushed with nitrogen, then isoprene and then the initiator added.

The bromide used in experiment B was added last as a solution in pentane.

The polymers were made from a recipe for a tire compound in a Midget-Banbury mixer Minutes at 112 ° C and then 5 minutes at 143 ° C mixed. The masses were cured and the physical properties were determined. A summary the values are shown in the following table:

809 537/583

11

Table III

Mixing recipe, parts by weight

rubber

Highly abrasion-resistant furnace soot.

Zinc oxide

Stearic acid

Physical mixture comprising 65% of a complex diarylamine ketone reaction product and contained 35% N, N'-diphenyl-p-phenylenediamine

Aromatic oil

2,2'-dibenzylamidodiphenyl disulfide

sulfur

N-oxydiethylen-2-benzothiazylsulfenamide

Processing properties mixed MS-IV ₂ at 100 ⁰ C pressing out at 90 ⁰ C

cm / minute

g / minute

Rating (Garvey's) .. Bondability on the roller

Physical properties, minutes cure at 144 ° C

ν · 10 ⁴ , mol / ccm ⁰ )

300% module *), kg / cm ² ....

Tensile strength ^), kg / cm ²

Elongation ^E ),%

Max. Tensile strength at 93 ° C, kg / cm ²

JI ¹⁷ X ⁰ C

Elasticity ⁶ ),%

Shore A hardness ^H )

Aged in the oven at 100 ^° C. for hours

300% module *), kg / cm ² ....

Tensile strength ^), kg / cm ²

Strain*), % ....'

JT ^F ), ° C

Elasticity ⁰ ),%

Shore hardness

A control

100

50

1 2.25

0.5

33.0

149

113.0 9+ good

1.56 84.4 192.6 530

123 22.1 71.6 56.5

65 73.8 325 24.4 71.1 57.5

100

50

31.5

140 118.0 11 good

1.53 86.5 229.9 560

148.3 23.8 69.6

57.5

77 86.1 320 25.7 69.8 59.0

The data show that this is in the presence of butyl bromide produced polymers had its higher cis content and better processing properties, although it had a higher raw Mooney value. The hardened mass also showed a better one Balance of properties than the polymer made in the absence of butyl bromide.

Example 4

An isoamylene dehydrogenation effluent containing 11 weight percent isoprene was obtained from a number of Polymerization experiments used, with 2.2 mM / 100 g M of the lithium methylnaphthalene initiator after Example 3 and 1.1 mM / 100 g M of n-butyl bromide were used. The isoamylene dihydrogenation effluent formed both the monomer and the solvent. The effluent had the following composition:

Table IV Drainage Analysis

component

Isopentane

n-pentane

3-methylbutene-1
2-methylbutene-1
2-methylbutene-2

Isoprene

trans-piperylene.

cis-piperylene ...

Cyclopentadiene.

α-acetylenes ....

Weight percent

0.5

0.5

0.4 32.0 55.6 11.0

0.08

0.01

10 ppm (parts per million) 20 ppm (parts per million)

The polymerization temperature was 50 ⁰ C. products from several attempts were mixed to a polymer having a raw Mooney value (ML-4 at 100 ° C) of 64.1, an intrinsic viscosity of 5.42, a corrected cis content of 88.3% and a corrected 3,4-addition content of 11.7%.

This polymer was mixed and calendered as in Example 3. It combined well on the reel, had a Garvey die expression value of 12 and other good process properties. The mixed one The mass was cured for 45 minutes at 145 ° C. and the physical properties were determined. The results were as follows:

ν ■ 10 ⁴ , mol / ccm ⁰ ) 1.43

300% module ^£ ), kg / cm ² 77.3

Tensile strength ^E ), kg / cm ² 222.1

Elongation *),% 590

Max. Tensile strength at 93 ° C, kg / cm ² 121.3

JT ^F ), ° C 25.9

Elasticity ⁰ ),% 67.4

Shore A hardness ^H ) 56.5

Aged in the oven at 100 ^° C. for 24 hours

300% modulus, kg / cm ² 80.5

Tensile strength *), kg / cm ² 96.7

Elongation *),% 350

J T ^F ), ° C 27.8

Elasticity ⁰ ),% 67.3

Shore A hardness ^H ) 57.5

These data show that the present invention is applicable to the polymerization of isoprene, contained in isoamylene dehydrogenation effluents, and that a polymer with a high cis content, good processing properties and good physical properties can be obtained when this is how it is worked.

13 14

Example 5 Hydrogen bromide, mM / 100 g M .... alternating

The initiator from Example 3 was at the polymer temperature, ⁰ C 50

sation of isoprene used, with bromine water time, hours 24

substance was present in the system. There were two approaches following

made the following recipe: 5 First, pen tan was poured in, the reaction vessel was flushed with nitrogen and then isoprene and

Isoprene, parts by weight 100 then added the initiator and bromine water

n-pentane, parts by weight 1000 substance introduced as a gas. The results of the experiments

Initiator, mM / 100 g M alternating were as follows:

attempt initiator
mM / 100 g M HBr
mM / 100 g M Li-HBr-
Molar ratio conversion ice cream,
raw 0 /
/ 0
corri
greed 3,4-add
raw tion,%
corri
greed Own
viscosity ¹ ) GeF)
O,
/O 1
2 1.0
1.6 0.5
0.8 4: 1
4: 1 85
100 84.2
75.0 91.7
89.7 7.6
8.6 8.3
10.3 5.28
5.38 0
0

Example 6

A lithium-methylnaphthalene reaction product was made in diethyl ether and this solvent then replaced by mineral oil in a similar manner to Example 1. This initiator became Polymerization of isoprene using 100 parts by weight of monomer, 1000 parts by weight n-pentane and 1.5 mM / 100 g M of initiator used. The polymerization was carried out at 50 ° C for 24 hours long carried out. Two experiments were made, one used as a control and at another 2.0 mM / 100 g M of bromobenzene added. Both experiments resulted in a quantitative one Conversion. The following values show that a polymer with a higher cis content is obtained, if bromobenzene is present:

attempt initiator
mM / 100 g M Bromobenzene
mM / 100 g M Li-Br molar ratio ice cream
% corrected 3,4 addition
% corrected 1
2 1.5
1.5 2.0 1.5: 1 90.4
89.7 9.6
10.3

Example 7

Three halides, n-hexyl fluoride, n-butyl chloride and n-butyl bromide, were used in a series of experiments to polymerize isoprene using the same amounts of monomer and pentane as in Example 6 and the same initiator. The polymerization oetrug 50 ⁰ C, and the time was 24 hours. The initiator content was 2 mM / 100 g M. A control experiment was carried out in which no halogen auxiliary was present. Quantitative conversion occurred in all reactions and the polymers were gel free. The following results were obtained:

attempt Halo; Art * enid Li halide
Molar ratio ice cream 3,4 addition Intrinsic viscosity ⁴ ) n-hexyl-F mM / 100 g M % corrected % corrected 1 n-hexyl-F 2.0 2: 1 90.5 9.5 4.75 2 n-hexyl-F 1.0 4: 1 89.0 11.0 5.24 3 n-butyl-Cl 0.67 6: 1 89.6 10.4 5.60 4th n-butyl Br 2.0 2: 1 89.8 10.2 6.01 5 n-butyl Br 1.33 3: 1 89.6 10.4 4.33 6th n-butyl Br 1.0 4: 1 90.0 10.0 4.67 7th - 0.67 6: 1 90.7 9.3 5.11 8th - - 89.7 10.3 6.08

These values show that the polymers made in the presence of a halogen adjuvant were less Exhibited inherent viscosity than the control and that the cis content was generally higher.

Example 8

A lithium-methylnaphthalene reaction product in mineral oil was, as described in Example 1, established (molarity = 0.165). In each of three bottles were 48.5 ml (8 millimoles) of the mineral oil dispersion introduced. One bottle was filled with dry hydrogen chloride and the second bottle Isobutyl iodide and in the third bottle iodine dissolved in n-pentane. The addition of any of the halogen-containing Reagents required about 5 minutes. The following table shows the amounts of reagents used and the molarity of each dispersion:

initiator Added
Art leagens
Millimoles Molarity 2 HCl gas 4.0 0.13 3 Isobutyl iodide 4.0 0.13 4th iodine 2.0 0.10

Each of the products described above was used as an initiator for the polymerization of isoprene. The amounts of isoprene and n-pentane were the same as in Example 1. The polymerization ^{temperature was 50 °} C. and the reaction time was 41 hours. Quantitative conversion was achieved in each case and all polymers were gel free. The results are summarized in the following table:

attempt initiator initiator ice cream, raw / ο 3,4 addition. % corrected Intrinsic viscosity ¹ ) mM / 100gM 81.2 corrected raw 9.6 1 2 2.50 73.5 90.4 8.6 12.4 4.22 2 3 2.00 82.7 87.8 10.4 10.0 2.32 3 4th 2.25 90.0 9.2 4.32

These data show that good results are obtained from the dilithium dihydroanthracene described above

If the halogen-containing reagent ₂₀ was used as an initiator in two approaches to polymerize the organolithium initiator prior to adding the same
is added to the polymerization system.

Example 9

Lithium wire was made with methylnaphthalene using the ratios given in Example 1 of the components implemented. The reaction was carried out at -25 ° C for 18 hours. The molarity of the reaction mixture, determined by titration with 0.1 η hydrochloric acid, was 1.80.

27 millimoles of n-Butybromid was added to 15 ml of the lithium - methylnaphthalene - reaction mixture at 0 ⁰ C was added. The temperature was ^{kept at 5 °} C. for 1 hour and then the ether was removed by adding the mixture to 100 ml of refined mineral oil (heavy white mineral oil) which ^{had been heated to 100 °} C. and flushed with nitrogen. ^{The temperature was kept at 100 °} C. for 1 hour while stirring the mixture and passing nitrogen through. Then it was allowed to cool to room temperature. The molarity was 0.085.

The initiator described above was used to polymerize isoprene in n-pentane. The amounts of isoprene and n-pentane were the same as in Example 1. The initiator content was 5.0 mM / 100 g M. The polymerization was ^{carried out at 50 °} C. and a quantitative conversion was achieved after 22 hours. The product had an inherent viscosity ¹ ) of 3.25, a raw cis content of 8Ο.4 ^υ / ο (corrected 89.4) and a raw 3,4 addition of 9.6% (corrected 10.6).

Example 10

Dilithium dihydroanthracene was prepared by reacting 0.11 mole of n-butyllithium with 0.05 mole of dihydroanthracene in 100 ml of toluene. The mixture was placed in a bath at 50 ^° C. and shaken for 144 hours. The reaction was carried out in a nitrogen atmosphere. A solid product formed which was separated by centrifuging the mixture. It was washed twice with 50 ml of toluene and then with n-pentane, each time centrifuging and decanting the liquid. Unreacted butyllithium was removed by this washing. The solid product was finally dispersed in 100 ml of n-pentane. The dispersion had a molarity of 0.306.

sation of isoprene used. One approach used n-butyl bromide. The following will be the recipes and values listed:

Isoprene, parts by weight

n-pentane, parts by weight

Initiator, mM / 100 g M

n-butyl bromide, mM / 100 g M ..

Temperature, ⁰ C

Conversion,%

Time, hours

Intrinsic viscosity ^A )

Micro structure,%

ice, raw

ice, corrected

3,4 addition, raw

3,4 addition, corrected ....

attempt

100

1000

0.5 50 100 18 5.02

90.4

92.1

7.8

7.9

100 1000

50 100 18 6.53

90.4

91.1

8.8

8.9

The experiment using butyl bromide gave a polymer with a lower one Inherent viscosity and a slightly higher cis content than the control experiment.

Comparative experiment

N-butyl bromide was used to polymerize butadiene using the method similar to that lithium-methylnaphthalene reaction product prepared as described in Example 1 used as initiator. A control experiment was carried out in the absence of butyl bromide. The polymerization recipe was as follows:

1,3-butadiene, parts by weight 100

Cyclohexane, parts by weight 780

Initiator, mM / 100 g M 2.0

n-butyl bromide, mM / 100 g M alternating

Temperature, ⁰ C 50

Time, hours 6

Cyclohexane was charged first, the reaction vessel was flushed with nitrogen and then in sequence Butadiene, the initiator and butyl bromide filled in. The results were as follows:

attempt initiator
mM / 100 g M Butyl bromide
mM / 100 g M Li butyl bromide
Molar ratio conversion
0 /
/O Inherent viscosity Mik
ice cream rostrukti
trans ir,%
vinyl 4th
10
13th 2.0
2.0
2.0 1.0
2.0 4: 1
2: 1 100
98
98 1.81
2.12
2.14 43.0
44.7
50.6 50.0
48.1
42.4 7.0
7.2
7.0

The reactions were carried out with isopropyl alcohol ends that 1 percent by weight, based on the polymer, of 2,2'-methylene-bis- (4-methyl-6-tert.-butylphenol) contained. The polymers were coagulated in isopropyl alcohol and dried.

These values show that the cis content and inherent viscosity of a butadiene polymer when used of butyl bromide increased. Therefore, the invention is specific to polyisoprene and not to other polymers, such as. B. polybutadiene, applicable.

All reactions of the previous example were carried out in an inert atmosphere.

The microstructures in the above examples were created using a commercially available

Raw cis content,%

Raw cis content, ^υ / ο + ^rone 3,4 addition,

Raw 3,4 addition,%

Raw cis content,% + raw 3,4 addition, ^u / ₀ infrared spectrometer determined. The samples were dissolved in carbon disulfide to form a solution with 25 g of polymer per liter of solution, the calibrations were based on deproteinized natural rubber as reference material, assuming that it contained 98% ice and 2% 3,4-addition product. The cis content was measured at the 8.9 micron band and the 3,4 addition at the 11.25 micron band. In the presence of a high cis polyisoprene, trans cannot be found because the trans content is measured at the 8.75 micron band. The raw ice and raw 3,4 addition is converted into corrected values as follows, assuming eis + 3,4 addition = 100:

100 = corrected cis content,%

100 = corrected 3,4 addition,%

^Λ ) 0.1 g of polymer was placed in a wire cage made of wire mesh with a mesh size of 0.175 mm and the cage was placed in 100 ml of toluene, which was located in a 125 ccm wide neck bottle. After standing at room temperature (about 25 ° C) for 24 hours, the cage was removed and the solution filtered through a sulfur absorption tube of porosity C to remove any solid particles present. The resulting solution was passed through a Medalia viscometer placed in a 25 ° C bath. The viscometer was previously calibrated with toluene. The relative viscosity is the ratio of the viscosity of the polymer solution to that of toluene. The inherent viscosity is calculated by dividing the natural logarithm of the relative viscosity by the weight of the original sample.

^B ) The determination of gel was carried out together with the determination of the intrinsic viscosity. The wire cage was calibrated for retention of toluene to correct for the weight of the swollen gel and to accurately determine the weight of dry gel. The empty cage was immersed in toluene and then drained for 3 minutes in a closed 60 cc wide mouth bottle. A piece of folded 6.35 mm metal mesh at the bottom of the bottle served as a support for the cage with a minimum of contact. The bottle containing the cage was weighed to 0.02 g during a draining time of at least 3 minutes, after which the cage was removed and the bottle reweighed to 0.02 g. The difference of the two

Claims (2)

Patent claims: 1. A process for the polymerization of isoprene in the presence of an organolithium initiator which has been prepared by reacting lithium with a polycyclic aromatic compound or a polyaryl-substituted ethylene with two to four aryl groups representing phenyl or naphthyl, characterized in that the polymerization is carried out in Presence of a halogen compound of the general formula (1) RX, (2) HX or (3) X ₂ , in which X is halogen and R is an aliphatic, cycloaliphatic or aromatic radical having 1 to 12 carbon atoms and, if X = fluorine 35 40 55 60 weighings is the weight of the cage plus the toluene retained thereon, and subtracting the weight of the cage from this value gives the weight of the toluene retained, ie the calibration for the cage. In the gel determination, after the cage with the sample contained therein had stood in toluene for 24 hours, it was removed from the bottle with tweezers and placed in the 60 cc bottle. The procedure for determining the swollen gel was the same as for calibrating the cage. The weight of the swollen gel was corrected by subtracting the cage calibration. ^c ) ASTM D 927-55 T. ^D ) Swelling method by Kraus, Rubber World, 135, pp. 67 to 73, pp. 254 to 260 (1956). This value is the number of net chains per unit volume of the rubber. The larger the number, the more the rubber is cross-linked (vulcanized). ^/; ) ASTM D 412-51 T. Scott Tensile Machine L-6. The tests were carried out at 26.7 ° C. ^F ) ASTM D 623-58. Procedure A. Goodrich Flexometer, load = 10.05 kg / cm ² , 0.44 cm stroke. The test piece is a regular circular cylinder 1.758 cm in diameter and 2.54 cm in height. ^G ) ASTM D 945-55 (modified). Yerzley oscilloscope. The test piece is a regular circular cylinder 1.758 cm in diameter and 2.54 cm in height. ") ASTM D 676-55 T. Shore hardness tester, type A. is, R is an aliphatic or cycloaliphatic radical. 2. The method according to claim 1, characterized in that 0.1 to 200 gAtom lithium used per 100 g of the monomer and 0.25 to 20 g atom of lithium per g atom of halogen. Considered publications:
German Auslegeschrift No. 1051 504;
Belgian patents Nos. 556 978, 570 049;
interpreted documents of the Belgian patent no. 592 247; French Patent No. 1,267,644;
British Patent No. 740,947;
U.S. Patent No. 2,518,573. 809 537/583 3. 68 ® Bundesdruckerei Berlin