DE1255927B - Process for the polymerization of 1,3-butadiene - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

C08d

German class: 39 c -25/05

Number: 1 255 927

File number: P 30039 IV d / 39 c

Filing date: October 15, 1956

Opened on: December 7, 1967

Various processes for the polymerization of 1,3-butadiene are described in the literature, such as emulsion polymerization, alkali metal catalyzed polymerization, and by Polymerization catalyzed by alfine catalysts.

According to the present invention, a polybutadiene having a large percentage of 1,2-addition can be produced will.

The process according to the invention for the polymerization of 1,3-butadiene is characterized in that 1,3-butadiene is polymerized in the presence of a catalyst which is obtained by mixing a) an ether solution of a complex aluminum hydride of the formula MAlH ₄ , in which M is lithium, sodium , Means potassium, rubidium or cesium, with b) titanium tetrachloride has been obtained. The preferred catalyst system used consists essentially of lithium aluminum hydride and titanium tetrachloride. It will be understood that minor amounts of other non-catalytic materials may be present in the system.

The amount of complex aluminum hydride used is usually in the range of 0.5 to 15.0 moles per mole of titanium tetrachloride. However, a preferred proportion is in the range of 1.0 to 6.0 moles of complex aluminum hydride per mole of titanium tetrachloride. It was found to be strong improved yields of polymeric product can be obtained if one is preferred among these Ratio falling catalyst composition used. As indicated above, a small one can Amount of aluminum chloride present in the catalyst composition, e.g. B. up to 0.5 moles Aluminum chloride per mole of titanium tetrachloride, preferably from 0.03 to 0.5 moles of aluminum chloride per mole of titanium tetrachloride.

The polybutadiene produced according to the invention is a rubber-like polymer. The term "rubber-like polymer" relates to an elastomeric, vulcanizable substance which, after vulcanization, ie crosslinking, has the properties normally found in vulcanized rubber, including substances which, after mixing and curing, have a reversible extensibility at 27 ° C of more than 100% of the original length of a specimen with a contraction of at least 90 ° / ₀ within one minute after the pull necessary for elongation by 100% has subsided. With regard to the solubility of the rubber-like polymers of the present invention, it was possible to use the catalyst system according to the invention to obtain polymers which processes for the polymerization of 1,3-butadiene

Applicant:

Phillips Petroleum Company,

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

Representative:

Dr. F. Zumstein, Dr. E. Assmann

and Dr. R. Koenigsberger, patent attorneys,

Munich 2, Bräuhausstr. 4th

Named as inventor:
Robert Paul Zelinski,
David Richard Smith,
Bartlesville, OkIa. (V. St. A.)

Claimed priority:

V. St. v. America April 30, 1956 (581 344) -

contain essentially no gel as determined by the standard gel determination method. The test is carried out according to the procedure described below. The gel content is expected to be below 50%> so should outweigh g gel sample to be tested of the polymer from 0.10 to 0.13, while in a prospective gel content of above 50% ^eme sample in weight from 0.13 to 0.18 g is used. The sample is placed in a balanced stainless steel cage with a mesh size of 0.177 mm. The cage containing the polymer is then placed in a 113 ml wide-necked flask into which 100 ml of analytically pure benzene are pipetted. The piston is then tightly closed with a threaded cap fitted with a cardboard gasket and covered with a circular aluminum foil. The flask is then left in the dark for at least 24 hours, preferably not longer than 48 hours. Do not shake during this dissolution period. At the end of this period, the cage is removed from the flask and placed in a 56 ml wide neck flask. The weight of the gel adhering to the cage is calculated and referred to as the swollen gel. The cage containing the gel is then dried in a vacuum oven which is maintained at a temperature between 70 and 8O ⁰ C. The weight of the dry gel is then determined. The gel will then

709 707/552

3 4

as the percentages by weight of the temperature which are insoluble in benzene, it is often preferred to age the mixture

rubber-like polymer determined. The swelling of the diluent and the catalyst, e.g. B.

index is expressed as the weight ratio of swollen- at 30 to 100 ⁰ C for 10 minutes to 24 hours or

A gel that is too dry. longer, before polymerization.

The polymerization process of the present 5 The inventive method may in one invention at any temperature in the conventional batchwise method or kon range from 0 to 150 ⁰ C are performed, which are carried out continuously. When batchwise preferred range is, however, in the range of 10 process the diluent and the to 8O ⁰ C. Preferably, the polymerization is added to the catalyst components prior to 1,3-butadiene in the presence of an inert Kohlenwasserstoffverdün- 10 reaction vessel. Often the crosslinking agents are carried out, although the polymerization can be carried out in that order, diluent, complex aluminum hydride and, without the use of such diluent, titanium tetrachloride. The polymerization reaction before the addition of the 1,3-butadiene, added
can under autogenous pressure or any In this latter procedure be carried out, it was found that ₅ that holds a polymer pressure, the reaction mixture substantially i having a low gel content in the liquid phase. Which is obtained when the titanium tetrachloride is added after and pressure thus depends on the particular one used, e.g. B. in proportions of about diluent and the temperature at which the 1 mol of titanium tetrachloride per mole of complex aluminum polymerization is carried out. It can take miniumhydride every 30 seconds. It was also, however, if desired, higher pressures applied _ao found to be advantageous to the titanium tetrachloride before. These pressures can be added by any suitable method of adding the 1,3-butadiene in increasing amounts, such as injecting a gas inert to the complex aluminum hydride and the deterioration of the polymerization mixture. During the polymerisation. addition, 1,3-butadiene and / or cata-

The amounts of the catalyst _a5 invention lysatorbestandteile and / or diluent in

Composition can be added at relatively wide desired intervals. To

Area fluctuate. The concentration of the entire completion of the individual polymerization

Catalyst composition usually moves rate, the whole reaction mixture can for inacti-

in the range from about 0.10 to 10 percent by weight of the catalyst, purification of the polymer

or higher, preferably in the range of 0.25 to ₃₀ and so on.

6 percent by weight, based on the total amount.

the 1,3-butadiene feed of the polymerization diluent, the catalyst components and

reaction vessel. 1,3-butadiene in relatively constant proportions

Such encryption are sharing a reaction zone is supplied to the polymerization process and suitable a entdünnungsmittel which do not adversely affect ₃₅ speaking amount of reaction mixture in verhältnisauf the polymerization reaction and the moderately uniform proportions from the zone abgeunter the process conditions are liquid. Ty- leads. The reaction zone can consist of a single pische, suitable solvents are e.g. B. aromatics, vessel with a device for mixing such as benzene, toluene, xylene, ethylbenzene and which consist of the reaction mixture to the mixture mixtures. According to the invention, straight ₄₀ can also be kept as homogeneous as possible. If desired and branched-chain paraffins are used, various such reaction vessels which up to 10 carbon atoms per molecule can be used in series, the effluent from containing. Typical examples of usable the first vessel in the second vessel etc. Paraffins are e.g. propane, η-butane, n-pentane, If desired, additional 1,3-butadiene, isopentane, η-hexane, isoxane, 2.2, 4-trimethylpentane 45 diluent and catalyst components for (isoctane), n-decane. Mixtures of these paraffin hydrocarbons added to any of the subsequent vessels can also be used as diluents. The use of a so-called tube means in the reaction vessel process according to the invention is also in the range of those used, although it is less favorable than the present invention in which the conversion is other diluents. In addition, 50 gradient from essentially zero at the input to any mixtures of the above can be increased to a maximum at the output. Additional hydrocarbons used as the diluent catalyst, 1,3-butadiene and diluents can be added to any of these, if desired

When performing the adjustment according to the invention between the inlet and outlet ends The complex aluminum hydride will usually be added to such a reaction vessel. Ether solution added to the reaction vessel. Appropriate- The dwell times in a continuous network Ether are z. B. Dialkyl ethers, such as diethyl ether, of course, vary within wider limits, in and cyclic ethers such as dioxane and tetrahydro-dependence on variables such as tempefuran. At least in some cases it appears that the temperature, the pressure, the ratio of the catalysts Complex with the complex aluminum hydride 60 components and the catalyst concentration. at is formed when it is added to the solvent- the residence time is a continuous process is given. If you use z. B. Diethyl ether than generally in the range of 1 second to Solvent, it appears to be an etherate of Li 24 hours, if the areas described contain ammonium aluminum hydride to build. Preferably there are kept. If a batch is used, the titanium tetrachloride is also used; in a suitable process, the reaction time can be 24 hours or Solvent dissolved, to, for. B. in the above-described amount.

benign hydrocarbon diluents. Various substances are known to be responsible for the invented

Execution of the process at lower temperatures.

5 6

Destroy settlement. These substances include carbons in which the polymer is then reused

dioxide, oxygen and water. It is therefore very resolved to be given

important that the 1,3-butadiene is free from these substances

is. Any known methods for polymerizing 1,3-butadiene according to the invention can be used

Removal of these substances can be used. 5 can also arise in a similar way to commercial

when using a solvent at the common, synthetic or natural rubber,

This substance should preferably be free of mixing and vulcanization. Vulcanization

impurities such as water, oxygen and the like. accelerators, reinforcing agents and fillers, such as

In this context it is desirable that they can also be used when

Air and moisture from the reaction vessel, in 10 mixing the polymers according to the invention.

from which the polymerization is carried out. be turned.

Although the polymerization is preferred under the The following examples are illustrative

anhydrous or essentially anhydrous Be of the invention, without limiting it,
conditions is carried out, of course

some water is present in the reaction mixture 15 for example
be. Thus, it was found that satisfactory I _n some approaches, 1,3-butadiene can be obtained by polymerization using a catalyst system consisting of lithium, when 500 to 1,000 parts of water per aluminum hydride and titanium tetrachloride rubbery to a 1000 000 parts feeding of the reaction vessel polymerized polymer. These are there. It goes without saying that the 20 batches were carried out according to the following procedure, the amount of water in the reaction mixture.

must not be so large that the I _n a beverage bottle of Vs 1 was benzene catalyst is completely inactivated. introduced, after which lithium aluminum hydride was added after completion of the polymerization reaction. The lithium aluminum hydride was tion is the entire reaction mixture when pushing 25 in the form of a l, 14 molar solution in diethyl ether, methods such. B. by adding an alcohol used. The bottle was then treated with a polychloroprene decay of the rubbery polymer which had previously been extracted with acetone to inactivate the catalyst. The polymer is then blocked by alcohol and blocked so that part of the polychloroprene diluent was exposed by any suitable seal. Then titanium processing such as decantation or filtration was separated. tetrachloride, dissolved in 3 to 4 ml of benzene, almost For cleaning the rubber-like polymer momentarily, ie in the course of 1 to 3 seconds, the separated polymer can be introduced into the bottle in a suitable diluent by means of a syringe, redissolved and then through the 1,3-butadiene can be reprecipitated in the same way adding alcohol. That was added to 35. The bottle was then immersed in a polymer, then again, as indicated above, given a constant temperature bath and one separated and dried. There can be any specific amount of time circulated in this bath. Then the above-listed diluent at this point was removed from the bottle, and the contents were tipped down to redissolve the polymer in about 11% of isopropyl alcohol. The obtained sats can be used. The continuous mixture was stirred vigorously. The precipitating execution of the process according to the invention is the polymer was separated and dried in the entire drain from the reaction vessel in a vacuum oven. The yield of polymer pumped catalyst inactivation zone in which the and the percentage conversion were calculated. The polymer was tested for its gel content after the above-described activation of the catalyst, such as a standard test. z. B. an alcohol is treated. If an alcohol is used, the solution of polymer in benzene, which is obtained as a substance to inactivate the catalyst, if the polymer is dissolved for this test, this also causes the precipitation of the poly- is measured to determine its viscosity . In the event that other agents are used, and this viscosity is used as the intrinsic viscosity activation of the catalyst, the value of the polymer is considered. It should be noted that this double function is not fulfilled, also that with this method the insoluble part of the poly.
Neten substance, such as. B. an alcohol, necessary. The approaches described above were carried out with the following compositions and under the following conditions, by filtration or other suitable methods:
separated from the polymer and then dried.

The rubbery polymer can also, such as compositions and conditions
described above, redissolved in a suitable diluent and reprecipitated, 1,3-butadiene, parts by weight 100

to clean the fabric. The diluent 60 _{Benz () 1 part by weight 880}

and the alcohol can, e.g. B. by fractional. . .

Distillation, separated and reintroduced in the process, lithium aluminum hydride

be used. According to the invention, a (LiAlH ₄ ), parts by weight can also be variable

Antioxidants can be used, such as. B. Titanium tetrachloride (TTC),

Phenyl- / 5-naphthylamine to prevent the oxidation of the chewing 65 parts by weight 2.66

to prevent chuk-like polymer. The anti (14 millimoles)

oxydans can be added to the reaction mixture before the temperature, ⁰ C 50

Precipitation of the polymer or at the dilution time, hours 17

These data for these runs are summarized in Table I.

Table I.

approach Molar ratio LiAlH 1 Millimoles Overall conversion Own gel Source index No. LiAlHJTTC 17.0 JVcHdiyocllOr viscosity of the gel Parts by weight 19.6 Weight percent % % 1 1.21 0.647 22.4 2.31 43 3.44 47.2 11 2 * 1.4 0.746 25.2 3.41 39 2.55 56.6 9 3 * 1.6 0.854 28.0 3.51 43 3.01 34.9 25th 4 * 1.8 0.96 30.8 3.62 33 3.13 32.9 22nd 5 * 2.0 1.07 34 3.73 27 3.67 25.7 28 6th 2.2 1.17 42 3.83 23 3.36 26.5 38 7th 2.4 1.29 49.5 3.95 28 3.15 16.4 35 8th 3.0 1.60 4.26 7th 3.45 38.4 24 9 3.5 1.89 4.55 5 2.53 56.5 13th

* The infrared analysis of the polymers produced in these runs are given in Example 28.

Example 2

In some approaches, following the procedure of Example 1, 1,3-butadiene became rubbery Polymer is polymerized. However, the titanium tetrachloride dissolved in 3 to 4 ml of benzene was removed by means of a syringe into the bottle much more slowly. With these approaches the time was from Begin adding titanium tetrachloride until all of the TTC has been added quickly, about 30 seconds compared to just a few seconds in example 1.

These runs were made with the following compositions and under the following conditions carried out.

Compositions and conditions

1,3-butadiene, parts by weight

Benzene, parts by weight

_{LiAlH 4} , parts by weight

TTC ₃ parts by weight

Temperature, ⁰ C

Time, hours

100 100 880 880 variable 1.0 (26.2 millimoles) 3.99 (21 millimoles) 2.66 (14 millimoles) 50 50 17th 18th

The results of the runs carried out with the composition and the conditions A are shown in Table II compiled.

Table II

Molar ratio LiAlH ₁ Millimoles Weight percent conversion Own gel Source index approach LiAlHJTTC 22.2 Catalyst, viscosity of the gel No. Parts by weight 26.2 based on % % 1.05 0.845 29 Monomers 44 1.52 36.1 6th 10 1.25 1.0 34.2 4.84 31 0.93 9.2 not measured 11 1.38 1.10 39.4 4.99 45 2.10 8.3 12th 12th 1.63 1.30 5.09 39 2.07 12.2 24 13 * 1.87 1.50 5.29 51 2.15 7.7 not measured 14th 5.49

* The infrared values of this approach are given in Example 28.

Five approaches, namely approaches 15, 16, 17, 18 and 19 were made with composition B. carried out according to the procedure described above. The mean conversion for these was Batches 21.2% · The polymer of these batches was mixed and the mixture had an inherent viscosity of 2.42 and a gel content of 9.2%

Example 3

In a number of approaches 1,3-butadiene was converted to a rubbery by the procedure of Example 1 Polymer is polymerized. However, a 6.06 weight percent solution of titanium tetra-

Chloride in benzene added in individual portions over 30 to 90 minutes. The 1,3-butadiene was 15 minutes after the last addition of

10

Titanium tetrachloride added. These approaches were made with the following composition and under the performed under the following conditions.

Compositions and conditions

1,3-butadiene, parts by weight 100

Benzene, parts by weight 880

_{LiAlH 4} , parts by weight 1.0 (26.2 millimoles)

Titanium tetrachloride (TTC), parts by weight 2.66 (14 millimoles)

LiAlH / TTC molar ratio 1.87

Temperature, ° C 50

Time, hours 18

Total amount of catalyst in percent by weight, based on

Monomer 3.66

The results of these runs are shown in Table III.

Table III

approach
No. 0 minutes Added solution
in milliliters by time 60 minutes 90 minutes conversion Inherent viscosity gel Swelling index of the gel 1 30 minutes 1 1.6 % % ' 20th 0 1 1.5 1.6 47 1.49 25.3 14th 21 0 1.5 2 2.6 54 2.06 11.3 not measured 22nd 0 0 0 4.6 44 2.16 11.4 not measured 23 0 5.6 48 1.61 7.3 not measured 24 * 37 3.69 14.8 not measured

* In this approach, the titanium tetrachloride solution was mixed with another milliliter of benzene containing a small amount of water, mixed.

Example 4

Two approaches were carried out in which 1,3-butadiene was polymerized to a rubber-like polymer using lithium aluminum hydride-titanium tetrachloride as a catalyst. Benzene was introduced into a beverage ^{bottle of 1} J ₅ l, after which lithium aluminum hydride was added in the form of a 1.14 molar solution in diethyl ether. The same bottle and procedure were used as in Example 1. The titanium tetrachloride was dissolved in benzene and the total volume of the solution was 6.6 ml for each batch. The titanium tetrachloride solution was then pipetted over about 30 seconds added in increments of 1 to 2 ml. After each portion was added, the bottle was shaken and it was found that

45. a precipitate formed. Then the 1,3-butadiene was injected into the bottle using a syringe given.

The two approaches were made with the following composition and under the following conditions carried out.

Compositions and conditions

1,3-butadiene, parts by weight

Benzene, parts by weight

_{LiAlH 4} , parts by weight

TTC, parts by weight

Aluminum chloride, parts by weight

Temperature, ⁰ C

Time, hours

Percentage by weight of catalyst, based on 1,3-butadiene molar ratio of LiAlH ₄ to TTC

* Added after the addition of titanium tetrachloride.

100 100 709 707/552 880 880 1.35 (35.4 millimoles) 1.35 3.73 (20 millimoles) 3.73 no 0.22 + (1.56 millimoles) 50 50 17th 17th 5.08 5.08 1.77 1.77

The results of these two runs are shown in Table IV.

Table IV Approach 25 Approach 26 A.
79
2.24
0 B.
80
1.80
3.3 composition
Conversion,%
Intrinsic viscosity ... Gd,%

10

The polymer from each of the above runs was analyzed in an infrared spectrometer. the Results are described in Example 6.

Example 5

ao

In some batches, 1,3-butadiene was polymerized according to the procedure of Example 1 to give a rubber-like polymer. In these approaches, the amounts of LiAlH ₄ and titanium tetrachloride were kept constant while the polymerization time as varied. These approaches have been used with the following

Compositions and carried out under the following conditions.

Compositions and conditions

A. B. 1,3-butadiene, weight share 100 100 Benzene, parts by weight .. 440 880 _{LiAlH 4} , parts by weight. 0.96 0.96 (25.2 millimoles) TTC, parts by weight ... 2.66 2.66 (14 millimoles) Temperature, ⁰ C 50 50 Time, hours variable variable Molar ratio UAMJTTC 1.8 1.8 Weight percent kata lysator, based on Monomers 3.62 3.62

The results of these runs are shown in Table V.

Table V

approach
No. composition Polymerization time
hours conversion
% Inherent viscosity gel
% Swelling index of the gel 27 A. 4th 1 2.30 42.5 11 28 A. 5 6th 2.2 17.6 32 29 A. 6th 18th 2.17 17.8 44 30th A. 7th 25th 2.22 11.3 47 31 A. 16 47 2.20 17.5 56 32 B. 4th 5 2.88 30.7 18th 33 B. 5 12th 2.41 20.9 25th 34 B. 6th 15th 2.86 20.0 37 35 B. 7th 20th 2.82 17.2 33 36 B. 16 35 3.20 23.7 54

A number of the polymers prepared in accordance with the previous examples were carried out Infrared analysis examined to determine the percentage of polymer that was removed by cis-1,4 addition, trans-1,4-addition and 1,2-addition of butadiene is formed.

The polymers were dissolved in carbon disulfide, so that a solution containing 20 g of polymer per liter was obtained. The infrared spectrum of each of these solutions (% transmission) was in a commercially available infrared spectrometer.

The total% unsaturation present in the form of trans-1,4 was determined according to the following Equation calculated.

ε =

E. Tc

ε = extinction coefficient (liter x mole x " ¹ x cm" ¹ ); E = absorbance (10 g)

t = path length (cm), and

c = concentration (moles per double bonds per liter).

The absorbance was determined at the μ band at 10.35, and the extinction coefficient used was 1,21-10- ² (l · mol · ¹ cm- ^1). The percentage of total unsaturation present in the form of 1,2 (or vinyl) unsaturation was calculated according to the above equation, with the band at 11.0 μ and an extinction coefficient of 1.52 -10- ² (liter Mol- ¹ x cm- ¹ ) was used. The total unsaturation in% present in the form of cis-1,4- was calculated by subtracting the trans-1,4- and 1,2- (vinyl-) determined by the above methods from the theoretical assumption of a double bond per C ₄ -Unit in the polymers obtained unsaturation calculated.

The results of these tests are shown in Table VI below.

Table VI

approach Polymerization Molar ratio TTC Millimoles LiAlH ₁ Millimoles Infrared analysis trans-1,4 % No. example LiAlHJTCC Parts by weight 14th Parts by weight 19.6 1.2- 44.5 cis-1.4 2 I. 1.4 2.66 14th 0.746 22.4 26.5 27.5 29 3 I. 1.6 2.66 14th 0.854 25.2 38.0 21.5 34.5 4th I. 1.8 2.66 14th 0.96 28.0 45.0 17.0 33.5 5 I. 2.0 2.66 14th 1.07 30.8 47.5 14.5 35.5 6th I. 2.2 2.66 21 1.17 34.2 59.5 14.0 26.0 13th II 1.63 3.99 20th 1.30 35.4 56.5 11.5 29.5 25th IV 1.77 3.73 20th 1.35 35.4 73.0 4.5 15.5 26th IV 1.77 3.73 1.35 80.5 15.0

The polymers of batches 15, 16, 17, 18, 19, 21, 22 and 23 were made according to the following mixing recipe mixed with vulcanization components.

Mixing recipe

Parts by weight

Polymer 100 _a5

Highly abrasion-resistant furnace black 50

Zinc oxide 3.0

Stearic acid 4.0

Physical mixture of 65% ^em complex diarylamine ketone reaction product and 35% N, N'-di-

phenyl-p-phenylenediamine 1.0

Sulfur 1.75

N-CyclohexyW-benzthiazyl-sulfenamide 1.0

35

The rubber to which vulcanization components had been added was then cured at 153 ° C. for 30 minutes. The physical properties of the blend are shown in Table VII.

Table VII

Tensile strength, kg / cm * 23.20

300% modulus, kg / cm ^a 1450

Elongation,% 450

Claims (2)

Patent claims: 1. A process for the polymerization of 1,3-butadiene, characterized in that 1,3-butadiene is polymerized in the presence of a catalyst obtained by mixing a) an ether solution of a complex aluminum hydride of the formula MAlH ₄ , in which M lithium, sodium , Means potassium, rubidium or cesium, with b) titanium tetrachloride has been obtained. 2. The method according to claim 1, characterized in that the quantitative ratio of the complex Aluminum hydride and the titanium tetrachloride in the catalyst is 0.5 to 15.0 moles of hydride per mole of titanium tetrachloride. 709 707 / W2 11.67 Q Bundesdruckerei Berlin