DE1185375B - Process for the production of copolymers from ethylene and propylene - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

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German class: 39 c - 25/01

1185 375
S72158IVd / 39c
January 20, 1961
January 14, 1965

The invention relates to a process for the copolymerization of ethylene and propylene, with which the proportions of ethylene and propylene in the final polymer can be controlled so that a predetermined value is obtained while taking advantage of the liquid phase polymerization remain.

The copolymerization of ethylene and propylene in the presence of an inert hydrocarbon and a catalyst made from a mixture of a vanadium or titanium halide and a lower aluminum alkyl is known and in publications by Natta et al. In "La Chimica e 1'Industria", 39, no. 9, Pp. 733 to 743, September 1957. Vanadium or titanium halides suitable for use as catalyst components in polymerization include vanadium tetrachloride, trichloride, oxytrichloride, and titanium tetrachloride and trichloride. Aluminum alkyls suitable for use as the other component of the catalyst include e.g. B. aluminum triethyl, diethyl chloride, triisobutyl, trihexyl and other lower aluminum alkyls or alkyl halides. The molar ratio of aluminum to vanadium in the catalyst can be, for example, 1: 1 to 10: 1 and is preferably about 3: 1. The polymerization temperatures may range from the temperature of the environment preferably up to about 71 ⁰ C.

The difficulty that has arisen so far in the production of copolymers, which ethylene and contain propylene in a desired ratio, is that when working in liquid Phase the ethylene tends to polymerize much faster than the propylene, so that the initial polymer is largely crystalline polyethylene is when the reaction device was originally used with ethylene and propylene in that for the final copolymer desired ratio is charged and no further olefins are fed. in the The result is the composition of the copolymer as the reaction proceeds not uniformly, and in some cases the product also contains crystalline polypropylene, which forms towards the end of the reaction. Since the main application value of the polymers in use as Elastomers, which must be as amorphous as possible, is the presence of crystalline polymer harmful.

Natta et al. seek this difficulty through it to overcome that a gaseous mixture of ethylene and propylene with high space velocity is passed through a reaction medium, the process for the production of copolymers from ethylene and propylene

Applicant:

Sun Oil Company, Philadelphia, Pa. (V. St. A.)

Representative:

Dr.-Ing. W. Abitz, patent attorney,

Munich 27, Pienzenauer Str. 28

Named as inventor:

James Louis Jezl, Swarthmore, Pa .;

Habet Missak Khelghatian, Springfield, Pa .;

Louise Dentler Hague, Villanova, Pa. (V. St. A.)

Claimed priority:

V. St. v. America April 1, 1960 (19148)

Contains suspended catalyst and that the conversion per pass is limited so that the Composition of the gas remains practically constant when passing through the reaction medium. the Adapting a process of this kind to working on an industrial scale is obviously not easy, since you have to handle excessive amounts of gas for each unit amount of the copolymer formed.

In the method according to the invention for the copolymerization of ethylene and propylene is the Handling of large volumes of gas as used in the Natta et al. are necessary, avoided.

The copolymerization of ethylene and propylene according to the invention to form a copolymer, in which the ratio of the chain links of ethylene and propylene has a predetermined numerical value, takes place at increased pressure by means of a mixture of an organoaluminum compound with vanadium tetrachloride, vanadium trichloride, Vanadium oxytrichloride, titanium trichloride or titanium tetrachloride in the presence of an inert liquid Hydrocarbon and is characterized in that at the beginning of the polymerization ethylene and

409 768/416

3 4

Introducing propylene in a molar ratio which is low by ethylene to propylene, can be increased somewhat.

however, the equation The change in the value of α is not

β £ so large, and in the range of ethylene-propylene

- ~ - = α · —ρ ~ - ratios from 1: 5 to 5: 1, the correct P 5 value of α does not change by more than 1.

, ... . . , Ep, .. ,. ,,, The following examples serve to explain

is determined and in which ^ the desired molar of _the | _invention ^F

ratio of ethylene to propylene in the copolymer, - ^ - the molar ratio of ethylene to Example 1

Propylene in the initial charge and α one This example illustrates the preparation of one

Factor means that when using vanadium-ethylene-propylene copolymers, which is about 50%

trichloride as a catalyst component contains the value of ethylene, using a VCl ₃ -

about 6, when using vanadium tetrachloride aluminum trihexyl catalyst. A resolution of the

the value of about 11 when using Vanadin- i _{5 above} n equation for ^ with a value of the con-

oxytrichloride has a value of about 18, when using ° Pc

of titanium trichloride a value of about 9 and at stantea = 6 results in a ratio of Ec: Pc = 1: 6.

Using titanium tetrachloride the value of a 3.8-1 pressure reaction vessel is filled with nitrogen

has about 30, then rinsed with ongoing polymerization and 85% of its capacity with

while maintaining the pressure, ethylene 20 isooctane is constantly filled. In the reaction device is

and introduces propylene in a molar ratio which is then a mixture of ethylene and propylene in the

the predetermined molar ratio in the mixed poly molar ratio of the monomers of 1: 6 to one

merisat corresponds and the copolymer formed is pressed in a pressure of about 2.8 atmospheres at 49 ⁰ C. then

according to known working methods. In the reaction device, a sufficient

The individual procedure is as follows: 25 amount of a suspension of a VCl ₃ aluminum tri-

A reaction device is first injected with nitrogen hexyl catalyst (V: Al ratio 1: 3),

Fabric flushed to oxygen and moisture so that in the reaction device 0.06 g of VCl ₃

remove, and then about 75 to 90% of its fascia is introduced. The polymerization starts immediately;

power with an anhydrous, inert pressure is achieved by introducing an equimolar

Hydrocarbon as a reaction medium, such as hexane, 30 mixture of ethylene and propylene in the reac

Heptane or isooctane, filled. It is then pressed in a device to ± 0.14 kg / cm ^{2 of} the original

the reaction device held a mixture of ethylene borrowed pressure. The polymerization is carried out in

and propylene, which continues the monomers in such a manner for 1 hour. It is important,

Contains proportions that the initial poly- formed both the pressure and the temperature very much

merisat to steer precisely for the product copolymer (± 0.14kg / cm ² and ± l, 10 ° C),

Has the desired monomer proportions, there is the introduction of the supplementary ethylene and

Stimulating the polymerization due to the catalyst to propylene in the reaction device

and then leads to the replenishment of the monomers, the pressure drop metered in the reaction device

which is consumed in the polymerization reaction in order to maintain a constant pressure in it.

that to get additional pro-40 in the reaction device. Any change in temperature causes

pylene and ethylene in the proportions which lead to a corresponding pressure fluctuation

the final copolymer. It helps that the supplementary olefin in the reaction

it has been shown that by this procedure the device starts at a different speed

Molar ratio of the dissolved in the reaction medium is measured as it is used to supplement the at the

Ethylene is required to propylene olefins consumed during the entire poly 45 reaction.

merization time can be kept at a value, you can then unreacted olefins from the

the formation of the desired copolymer from the reaction device and deactivates the catalyst

favored, and that no enrichment of the reactor by adding a small amount of methanol,

tion mixture on the less reactive Then the reactor contents are removed and the

Monomers occurs. 50 polymer by treatment with acetone from the

The ratio of ethylene to propylene precipitated in the solution. 210 g of solid poly starter are recovered Reactor charging is according to merisat. The polymer is determined using its Ultraobiger equation. red absorption spectrum according to that of N a 11 a et al.

The above factor α depends on the method proposed in each case on its ethy-

turned away from the catalyst as the relative polymer content was checked. The ethylene content of the above

sation speed of ethylene and propylene described manner copolymers produced

depending on the nature of the metal is determined by this method to 52%
halide component of the catalyst is considerable

changes. The aluminum compound used in each case, Example 2
dung has on the relative polymerization rate

apparently only a minor impact. One works according to the procedure of Example 1,

The values of the factor α are given as "about", but with the exception that the desired pro -

since it has been shown that they only really apply then, a copolymer with an ethylene content is used

when the desired ratio of ethylene to about 33% ^{sem S} ° U · The reaction device

Propylene in the copolymer is about 1. 65 is initially m in the manner described above

When the desired ratio of ethylene to with ethylene and propylene in the molar ratio of

Propylene is greater than 1, α should be slightly reduced, 1:12 charged. After the polymerization has started

and vice versa, when the desired ratio of the pressure in the reaction device is up to

5 6

The end of the polymerization is maintained by adding, as the following experiment shows,

you get ethylene and propylene in the molar ratio of no copolymer, its percentage

1: 2 introduces. The mixed crystalline components produced in this way is low.
polymer has an ethylene content of about 30%.

5
Example 3 Comparative experiment

The procedure of Example 1 is followed. A 64.41-capacity reaction vessel is charged.

but uses as the vanadium component of the catalytic converter with 56.81 isooctane and presses an equilyser instead of VCl _3, here VCl ₄ . At the beginning, ethylene and a pressure of 2.1 atmospheres (1.54 kg ethylene and pylene in a molar ratio of 1:10) are injected into the reactive molar amount of ethylene and propylene. The 2.18 kg Propylene at 35 ⁰ C). 27.6 g of pressure are then maintained by adding ethylene, aluminum triethyl and 12.8 g of vanadium tetrachloride and propylene in an equimolar ratio. The polymerization is carried out for 2 hours. At the end of the reaction period, a temperature of about 32 ° C. and a pressure of 2.1 atmospheres is continued, and copolymer is obtained which contains 54 mol percent while constantly containing an equimolar mixture of ethylene. Ethylene and propylene with sufficient speed

introduces speed to maintain the pressure. At the

Example 4 At the end of 2 hours, the reaction is terminated,

ao by adding methanol. You win that

It operates in accordance with Example 1, as described as a vanadium copolymer, in Example 1 of the catalyst component in place of the VCl ₃ in a yield BEHIER VOCl ₃ is used The copolymer. At the beginning, ethylene and propylene in the molar olefins, recovered from 57% and containing 87% in a ratio of 1:80, are injected into the reaction device on the device fed to the reaction device. The pressure becomes 35 ethylene, is about 20% crystalline and about maintained during the polymerization, as 33% is insoluble in boiling heptane,
one ethylene and propylene in the molar ratio of The above examples illustrate the invention

1: 4 feeds. The reaction product used is a mixing in the application of a batch process, Obtained polymer that contains 22 mole percent ethylene but the invention can also be continuous. 30 are performed. The process can be continuous

be trained by initially

Example5 filling device with solvent, ethylene

and propylene in the calculated proportions in the

The procedure is again as in Example 1, but the manner described for batch operation is used as the metal halide component of the 35 injected and then continuously into the reaction catalyst instead of the VCl _3, here TiCl ₄ . In the device a solution of ethylene, propylene and reaction device, ethylene and aluminum alkyl and a suspension of metal-propylene in a molar ratio of 1:20 are injected at the beginning. The pressure is maintained during the polymerization on the reaction device, the reaction product by introducing ethylene and propylene 40 together with solvent in an amount of space in a molar ratio of 3: 2. A subtract is made which is equal to the volume of the imported copolymer obtained, which is 58 mol percent of the reactants. Contains ethylene in continuous working. ten it is important that the average dwell

time of the reaction mixture in the reaction

Example6 45 direction does not exceed 2 hours, as nature

of the catalyst change over time

The procedure is as in Example 1 using what appears to be possibly due to the reduction of a TiCls-aluminum triethyl catalyst (Molver metal halides in a {lower valence ratio of Ti to Al equal to 1: 3). In the reaction state is based, and the relative polymer device is initially injected ethylene and propylene so the two olefins in a molar ratio of 1:15. During the change, so that the desired ratio in the polymerization, the pressure is not achieved by feeding the end product.
Ethylene and propylene in a molar ratio of 2: 3 The following table shows the results of one

maintain. A copolymer is used in a continuous test, in which, as the first charge, which contains 41 mole percent ethylene. 55 kung of a 4.73 l reaction device

In all of the above examples, the crystallinity of a 20% solution of olefins (95 mol% of the polymer formed, X-ray propylene and 5 mol% of ethylene) in isooctane is less than about 5% and the polymer is added. As a further charge, a 23% solution of olefins in equimolar proportions is essentially completely soluble in boiling heptane. A polymer with such a low 60 in isooctane that has a crystallinity content of 0.53 g is suitable as a starting material for aluminum triethyl per liter. A solution of 21.3 g of vanadium oxytrichloride serves as a catalyst for further processing into elastomers, which have excellent tensile strength and elasticity. in 1252 cm ^{3 of} isooctane. The temperature is currency-However, when the copolymerization conducted rend the polymerization 71 ⁰ C, the beginning is by adding to the beginning in the Reaktionsvor- 65 is pressure-5,6 atm. At the beginning of the catalyst towards ethylene and propylene is pressed in the proportions of one solvent in the reaction apparatus at intervals which is to have the final product, and is input thereto, and at a rate of supplementing olefins in the same proportions 10 ^cm3 / 10 minutes .

sample

No.

Time hours

Supplied

further loading

1 H.

Product withdrawn

1 H.

Mixed polymer
im withdrawn
kg

LB-drawn Good kg / 1 kg / l / h 0.022 0.011 0.030 0.036 0.035 0.023 0.037 0.025 0.037 0.025 0.041 0.189 0.041 0.054 0.037 0.045 0.038 0.038 0.039 0.079 0.029 0.043 0.037 0.055 0.033 0.041 0.037 0.021 0.032 0.030

Ethylene
in the product
Mole percent

Crystalline
Polyethylene

0 / / 0

3 *)

All in all

2.0 0.8 1.5 1.5 1.5 0.2 0.8 0.8 1.0 0.5 0.7 0.7 0.8 1.7 1.1 polymer

15.5

1.51 2.04 1.14 1.25 1.85 4.16 3.14 2.27 1.89 3.44 3.07 2.57 1.89 0.45 0.04 remains in the direction

0.95 2.04 1.25 1.21 1.21 8.18 2.35 2.16 1.89 3.71 2.61 2.54 2.31 1.10 0.72 reaction

0.041 0.050 0.064 0.068 0.068 0.073 0.073 0.068 0.073 0.073 0.050 0.064 0.064 0.068 0.027 0.077

0.998 44 47

61
61

61
63

*) According to Sample Nos. 3 is increased, the supply of the catalyst solution from 10.0 to 12.5 cm ^3/10 minutes. **) During sampling no. 5, pressure increase (0.07 at / 10 minutes); Pressure 5.63 to 5.98 at. Average throughput = 0.016 kg / hour. per liter of reactor space. Average residence time = 2 hours. Conversion of olefin into copolymer = 70%.

traces
0 to 5

0 to 5
0 to 5

N5
5 to 10

Claims (1)

Claim: Process for the production of copolymers from ethylene and propylene, in which the The ratio of ethylene to propylene in the copolymer has a predetermined numerical value has, by polymerizing a mixture of ethylene and propylene at elevated pressure by means of a mixture of an organoaluminum compound with vanadium tetrachloride, vanadium trichloride, Vanadium oxytrichloride, titanium trichloride or titanium tetrachloride in the presence of an inert, liquid hydrocarbon, d adur ch characterized in that ethylene and propylene are used in one at the beginning of the polymerization Mole ratio introduced by the equation Ep Pp = a Ec Pc Ep is determined and in which - ~ the desired moI- _pp copolymer, the molar ratio of Ethylene to propylene in the initial charge and α means a factor which when using vanadium trichloride as the catalyst component is about 6, when using vanadium tetrachloride is about 11, when using vanadium oxychloride is about 18, when using titanium trichloride Value of about 9 and, if titanium tetrachloride is used, the value of about 30, then continuously introduces ethylene and propylene in a molar ratio that corresponds to the predetermined molar ratio in the copolymer, and the copolymer formed according to methods known per se, with ongoing polymerization while maintaining the pressure wins. _p ratio of ethylene to propylene in the documents considered:
"La Chimica e l'Industria" (1957), pp. 733 to 743, to 831 (1958), 717 to 724 (1959). 409 768/416 1.65 © Bundesdruckerei Berlin