DE1104703B - Process for the preparation of 1,3-butadiene polymers - Google Patents

Description

GERMAN

The invention relates to the polymerization of 1,3-butadiene to form valuable polymers with a very high content of products with a cis-1,4 structure.

The use of catalysts based on metals of the VIII group of the periodic Systems, especially cobalt, and of alkyl aluminum monohalides for the polymerization of butadiene to polymers that essentially consist of cis-1,4 products and valuable elastomers Have properties has already been described.

In particular, it is known that compounds of the metals of Group VIII are dissolved in the solvent to use which is used for the reaction; various compounds and complex compounds of metals of group VIII, those in the solvents used for polymerization can be, are soluble, are suitable for this purpose.

According to this process, the catalyst becomes rapidly by reaction between the dialkyl aluminum halide and the compound of Group VIII metal (as opposed to when used of insoluble compounds of metals of Group VIII processes in which a certain induction period of the reaction can be determined, which leads to the formation of the catalyst, wherein this reaction then progresses for a certain time).

To control the average molecular weight of the polymer it is useful, however, right at the beginning of the Polymerization to have a certain known amount of catalyst.

If now polybutadiene is produced with the help of catalysts of this type, the molecular weight depends mainly on the amount of catalyst used and the amount of monomer, that is polymerized from. The molecular weight varies in inverse proportion to that used Amount of catalyst (metal of Group VIII) and increases proportionally to the amount of polymerize Butadiene too.

During a polymerization test it should therefore be determined that the molecular weight of the polymer regularly increases with sales.

This property of the polymerization process allows easy control of the molecular weight, which is very important because many mechanical and technological properties of the polymer that is considered Elastomer finds an important practical use, depend on the molecular weight.

The control of the molecular weight on the basis of the amount of catalyst fed in gives satisfactory results only if the process for the preparation is faultless
of 1,3-butadiene polymers

Applicant:

Montecatini Soc. Gen. per l'Industria

Mineraria e Chimica,

Milan (Italy)

Representative:
Dr.-Ing. A. v. Kreisler, Dr.-Ing. K. Schönwald,

Dipl.-Chem. Dr. ph.il. H. Seven eggs

and Dr.-Ing. Th. Meyer, patent attorneys,

Cologne 1, Deichmannhaus

Claimed priority:
Italy from November 26, 1958

Gerlando Marullo, Carlo Longiave, Renato Castelli

and Mario Ferraris, Milan (Italy),

have been named as inventors

pure starting material is used in the polymerization; is the sensitivity of the catalyst very high compared to numerous substances, and very small amounts of air, water, Alcohol, aldehydes, acids, oxidized substances in general, many sulfurized compounds and acetylene compounds to destroy or inactivate part of the catalyst. It therefore remains only part of the catalyst used is really effective, and the resulting average molecular weight of the polymer is therefore very different from the desired one. Also very small amounts of impurities that are adsorbed, for example, on the reactor walls, can cause inactivation of part of the catalyst and therefore result in it lead to the same disadvantages. These inadequacies, even in laboratory tests, hardly Avoid being practically inevitable when working on an industrial scale is working; an additional purification of the starting materials to ensure that they are as pure as laboratory reagents getting it would be too expensive.

109 540/445

3 4

It has now been found that one can see in the polymer examples, even with very little consation of butadiene is considerable with the aid of the concentrations mentioned above.

Catalysts the molecular weight of the polymer If the polymerization in the presence of one of the as desired is carried out independently of the aforementioned substances within certain limits, so is of the amount of catalyst used and the amount of 5 used, that the change in the mean molar amount of monomers and therefore also the independent weight of the polymer depends very much over time distinguished by the presence of small amounts of that which is in the absence of these sub-impurities, which punch the activity of the catalyst takes place. While in the absence of this can reduce, regulate, if you give the poly substances the molecular weight of polybutadiene The polymerization system adds various substances, which are added regularly as the polymerization proceeds has no other influence on the catalyst system, takes place in the presence of ethylene or others or its properties other than those of the aforementioned substances having molecular weight Molecular weight of the polymer obtained affects the polymer in a batch process. initially to, is then stabilized and remains constant

The invention relates to a process for 15 to the end of the polymerization; in the last stage

Production of 1,3-butadiene polymers at high levels even shows a tendency to decrease; this

Molecular weight and essentially cis-1,4-structure is caused by the fact that in the polymerization of '

door through polymerization in the presence of soluble butadiene, the ratio between butadiene and the

Catalysts made from alkyl metal compounds and added substances decrease regularly,

bonds or complex compounds of metals 20 Since the molecular weight of this polymer

of the VIII. Group of the Periodic Table of the Ionization Processes mainly on the molar ratio

ments in which the polymerization in the presence between butadiene and the added substance in

of α-olefins or non-conjugated diolefins of the liquid phase (in addition to the specific activity

is carried out. of substance), it follows that it depends on each

Substances that can produce this effect are 25 of the various substances possible, an experiz. B. many unsaturated hydrocarbons, which can be created with mental diagram in which the mole aid of the aforementioned catalysts is shown as a function of the ratio of not at all polymerizable to high polymers butadiene to the substance in question. are, above all ethylene and higher α-olefins, in particular propylene and butene-1 and some not con-30 it is then possible to obtain the desired molecular weight of jugated diolefins, especially those with accumulated diolefins at will, by setting this ratio appropriately reproducible type of double bonds, in particular allene (propadiene) obtained, practically independently of the ver and its derivatives, such as 1,2-butadiene, ethylallene and the amount of catalyst used and the degree of conversion,
other higher homologues. The addition of ethylene, allene or other of the

The activity fluctuates markedly from a sub-35 of the aforementioned compounds can be simultaneous with

punch to another and is carried out for each substance approximately with the addition of butadiene or separately

proportionally to their concentration in the liquid poly-

merization system. fertilize the metals of group VIII (in particular

It can be assumed that these substances act from cobalt compounds to dialkylaluminum by displacing the growing polymeric butadiene monochloride or, after the catalyst has been prepared, chains from the catalyst and so the addition can also after the start of the polymer in a new chain cause. The middle fresation can be carried out; In this case, the sequence of these displacements, which determines the molecular weight-reducing effect on the weight of the polybutadiene obtained, depends on the moment of addition, and the molecular weight of the concentration and the nature of the tensile weight of the polymer is somewhat higher than that, deposited substance. It follows from this that the average molecular weight of the polybutadiene obtained from the beginning with the addition of the substance would also have been noted; in working in this way, a considerable reduction in the amount of punch in a given molar ratio with respect to low polymers in the product is obtained, more precisely, by the addition of a suitable sub- stance.
The percentages of the substance to be added, ie the catalyst used, depending on the desired mean value of the amount of Molesator and the conversion of the monomer, must of course be set within very wide limits so that they can be adjusted theoretically to a waver.

Polymers lead to a much higher mol- Da, as mentioned above, the effectiveness of the

molecular weight than that obtained by the addition of the controlled molecular weight control of the polymer

appropriate substance is to be achieved. Which varies greatly from one substance to another,

The effect produced by this substance is indeed single - the proportion to be set fluctuates accordingly,

There is a decrease in the molecular weight, which, if a certain value of the molecular weight

otherwise wants to get weight due to the amount of catalyst used.

and the degree of conversion obtained would be expected. 60 The lowest molar ratios in the liquid

In connection with the degree of activity of the phase between the various substances and

Various substances have been found to be necessary among butadiene to have a noticeable effect

the olefins ethylene have the highest activity based on the molecular weight of the polymer

shows. This activity increases rapidly and gradually with the following:

the increase in the molecular weight of the 65 used

Olefins from; Olefins with more than 4 carbon atoms for ethylene 1: 500

show a very low activity with respect to the Er- for propylene 1:10

lowering the molecular weight of the polymer. for butene-1 1: 5

The most active of the aforementioned substances appears to be 1: 25,000 for 1,2-butadiene

To be Allen, its effect, as from the following 70 for Allen 1: 50000

The upper limit of the various ratios varies accordingly, and their selection depends on the desired average molecular weight for the polymer.

The catalysts used in the process of the invention are made from soluble compounds and complexes of metals of Group VIII of the Periodic Table of the Elements and alkyl metal compounds. A particularly preferred one because of its easy and simple manufacture The catalyst is made from a cobalt chloride-pyridine complex and a dialkyl aluminum chloride obtain. Only these catalysts are used in the examples.

However, the process can also be carried out with the help of any other soluble catalysts based on organic or inorganic compounds of metals of Group VIII of the Periodic Table, in particular cobalt and nickel, and alkyl metal compounds be carried out, the production of butadiene polymers with a very high content of macromolecules with a cis-1,4 structure are suitable. These polymers can be stretched at room temperatures Crystallization can be brought.

The polybutadiene obtained in the presence of one of these substances always shows a very high content an cis-1,4 structure and from this point of view does not differ significantly from that Polybutadiene, which is obtained under the conditions described at the outset.

Surprisingly, it has been found that the workability when mastifying the according to the invention Process obtained polybutadiene is noticeably better compared with that of the Polymers that have the same molecular weight and the same content of cis-1,4 structure, but were obtained by the method described above; these can only be calendered with difficulty will.

The polymer obtained in the presence of ethylene or other of the listed compounds can if the other properties are the same, it can be processed in less than half the time it takes for Polymers is required which have been produced by the previously known processes.

The invention is illustrated in the following examples.

example 1

11 anhydrous benzene, Al (C ₂ Hg) ₂ Cl, CoCl ₂ in the form of a benzene solution of a cobalt chloride-pyridine complex in a concentration of 0.124 g / l and technical butadiene, in the amounts described in Table 1, are in a 3- 1 stainless steel autoclave fitted with a stirrer and a jacket for cooling liquid. In addition, a certain amount of ethylene is in the

ίο Autoclave introduced, determined by the help change in pressure measured by a mercury manometer in the autoclave.

The mixture is allowed to react at 15 ° C. for several hours with stirring and the polymerization then interrupted by introducing 50 ecm of methanol.

The polymer is then precipitated, washed with methanol and dried under vacuum at 40.degree.

The content of the cis-1,4 structure and the intrinsic viscosity are determined. The composition of the polybutadiene, with respect to the distribution of the three stereoisomeric trans-1,4-, cis-1,4- and 1,2-forms, is determined by infrared analysis of the solid polymer in the form of a flake. The optical densities are determined according to the baseline method at 10.36 μ for the trans double bond, at 11.00 μ for the vinyl double bond and at 13.60 μ for the cis double bond.

The coefficients used for the apparent molar absorbances are 10.6 and 12 for the trans-1,4, cis-1,4 and 1,2 bonds, respectively. The intrinsic viscosity becomes on polybutadiene solutions in toluene at 26 ° C with the help determined by Bischoff viscometers.

The molecular weight is calculated from the intrinsic viscosity using the formula

[η] = 1.53 · 10- * · Μ ⁰ · ⁸

(Johnson and Wolfangel, Ind. Chem. Eng., 44,

P. 752 [1952]).

The amount of the various reaction components used, the reaction time and the properties of the polybutadienes obtained are shown in Table 1, from which it can be seen that the molecular weight decreases as the amount of ethylene increases, while in the presence of this olefin it is almost independent on the amount of catalyst used and on the amount of monomer reacted.

Table 1

Time Reaction conditions Al (C ₂ Hs) ₂ Cl CoCl ₂ Ethylene
pressure *) Ethylene
Butadiene moles
ratio in the properties cis-1,4-
salary of the polymer Molecular
weight attempt
No. hours Mole Millimoles mm Hg Butadiene liquid phase weight »/ 0 Tue] 3 0.0'36 0.0617 38.5 G 1: 271 G 93.6 415,000 8th 3 0.036 0.0925 44 100 1: 219 95.5 95.7 4.70 387,000 9 3 0.025 O ', 0925 54 99 1: 163 77.5 95.4 4.47 366,000 10 3 0.025 0.077 75 102 1:97 97.5 94.5 4.26 330000 11 3 0.025 0.1155 120 99 1: 51 80 95.4 3.90 227,000 12th 4th 0.030 0.077 164 101 1:34 94 93.1 2.90 185,000 13th 4th 0.030 0.077 215 99 1: 24 78 94.6 2.45 147,000 14th 4th 0.030 0.166 215 101 1: 24 47.5 95.0 2.07 145,000 15th 5 0.025 0.0923 321 100 1:16 90 93.6 2.02 123,000 16 5 0.025 0 ', 1155 835 101 1: 5.4 91.7 95.6 1.78 74,000 17th 102 81 1.18

*) All tests were carried out with 1000 ecm benzene at a temperature of 15 ° C.

Example 2

Two experiments are carried out in the autoclave used according to the previous example, in the 1000 ecm benzene, 2.4 g (0.02 mol) Al (C ₂ H ₅ J ₂ Cl and 0.0116 g ( 0.09 millimoles) of CoCl _{2 can be introduced} in the form of a benzene solution of a cobalt chloride-pyridine complex.

In the first experiment 101 g of technical butadiene and in the second experiment 102 g of butadiene of the same quality and also used 107 g of propylene.

After 3 hours of stirring at 15 ° C, the polymerization is carried out by adding 50 ecm of methanol in the Autoclave aborted. The polymer is, as described in the previous example, precipitated, washed and dried.

Table 2 shows the properties of the polybutadienes thus obtained. It can be seen that the polymers obtained in the presence of propylene have a markedly lower molecular weight; this polymer does not show the presence of appreciable amounts of polypropylene on infrared analysis.

Table 2

In the first of these two experiments, 99 g of butadiene and in the second 100 g of butadiene and 195 g of 1-butene are used. After 3 hours of polymerization at 15 ° C. with stirring, the catalyst is destroyed by adding 50 ecm of methanol to the autoclave and the polymers obtained are precipitated, washed and dried as described above.

From Table 3, which shows the properties of the products obtained, it can be seen that the polybutadiene produced in the presence of butene-1 has a much lower molecular weight than the other possesses; infrared analysis of this polymer shows the presence of significant amounts Polybutene-1 does not.

Table 3

Attempt no.

Attempt no.

18 (butadiene
alone)

19 (addition of
Propylene) ....

20 (butadiene
alone)

21 (addition of
Butene-1) ...

Properties of the polymer

weight

98
94.8

ice-1,4-content

94.4
95.3

Lv]

6.03
2.85

Molecular weight

570000
221000

Properties of the polymer

weight

100
99

cis-1,4-

salary

o / o

93.2
93.6

5.70
2.80

Molecular weight

528,000 216,000

Example 3

Two experiments are carried out in the autoclave used in the preceding examples, in the conditions already described 1000 ecm of benzene, 2.4 g (0.02 mol) of Al (C ₂ H _{5 I 2} Cl and 0.011 g (0.085 millimole ) CoCl _{2 can be introduced} in the form of a benzene solution of a cobalt chloride-pyridine complex.

Example 4

A series of polymerization experiments is carried out in the autoclave used in the preceding examples and according to the same procedure, a small amount of allene, measured in the gas phase with the aid of a burette, being introduced into the autoclave at the same time as the butadiene. After 2 hours of reaction, ¹ h at 15 ° C, the catalyst is destroyed by addition of 50 cc of methanol. After the usual precipitation, washing and drying, the intrinsic viscosities of the polybutadienes are determined and their structure is checked by infrared analysis.

Table 4 shows the amounts of the various reactants used and the properties the polybutadienes obtained are given; it is the lowering of the molecular weight brought about by all evident.

Table 4

Reaction conditions *) AI (C ₂ Hg) ₂ Cl
Mole CoCl ₂
Millimoles All
cm ³ Butadiene
G weight
G Properties of the polymer Lv] Molecular
weight attempt
No. 0.036 0.077 0 103 101 cis-1,4-
salary 6.60 640,000 22nd 0.036 0.077 5 102 95.5 93.8 4.37 379,000 23 0.036 0.077 9 99 96.7 94.0 4.09 349,000 24 0.036 0.077 27 100 92.6 95.1 2.85 221,000 25th 0.036 0.0923 60 99 93.5 94.9 1.90 132,000 26th 0.036 0.1155 90 99 96.8 94.2 1.46 96,000 27 95.3

*) All experiments were carried out at 15 ° C for 2 ¹ k hours in 1000 ecm benzene.

Example 5

In the autoclave used in the previous examples and following the same procedure carried out a series of polymerization experiments, taking into the autoclave simultaneously with 1,3-butadiene also a small amount of 1,2-butadiene, measured in the gaseous state with the help of a burette, was introduced will. After 2V2 hours of reaction at 15 ° C the catalyst is destroyed by introducing 50 ecm of methanol into the autoclave.

After the usual precipitation, washing and drying, the intrinsic viscosity of the Determined polybutadienes obtained and subjected the Polvmere to infrared analysis.

Table 5 shows the amounts of the various reaction components used, as well as the properties of the polybutadienes obtained. The lowering caused by the presence of 1,2-butadiene the molecular weight is clear

recognizable.

Tabel

10

Reaction conditions *) Al (C ₂ Hs) ₂ Cl CoCl ₂ 1,2-butadiene 1,3-butadiene weight Properties of the polymer [»7] Molecular attempt
No. Mole Millimoles cm ³ cm ³ G cis-1,4-
salary certainly 0.036 0.077 0 100 97 ° / o 6.40 617,000 32 0.036 0.077 9 100 98 94.3 4.56 400,000 33 0.036 0.077 36 102 97.4 93 3.46 282,000 34 0.036 0.1 93 99 95.5 94.1 2.10 151,000 35 92.9

*) All tests were carried out at 15 ° C for 2½ hours in 1000 ecm benzene.

Example 6

A polymerization experiment with 1,3-butadiene is carried out in a reactor for continuous operation carried out. This experiment is carried out for 50 hours in the presence of ethylene.

The reactor consists of a vertical tower with a diameter of 100 mm and a height of 2500 mm. It is equipped with an agitator and a cooling jacket.

The reaction components are fed from two containers, of which the first two thirds of the Benzene used in the reaction, as well as diethylene aluminum monochloride and the cobalt chloride-pyridine complex contains. The second container holds a third of the benzene used as well as that total butadiene and ethylene. Another pair of containers is provided, which alternates with the first pair of containers is used and which is refilled while the first pair of containers is used got.

The contents of the tank are fed into the reactor via two small injection pumps. It will be in the Reactor, which has a free volume of 16 l, fed per hour:

4,001 benzene,

12.0 g diethyl aluminum monochloride,

44.00 mg CoCl ₂ , in the form of a benzene solution des

Cobalt chloride pyridine complex, 400 g butadiene,

4.2 g ethylene.

During the experiment, samples of the solution leaving the reactor are taken every 5 hours. The properties of these samples are given in the table below.

Table 6

50

The reactor is during the experiment between 14 and 17 ° C by circulating a cooling liquid of Maintained 12 to 13 ° C in the jacket.

The viscous polybutadiene solution leaving the reactor is collected in containers and so is the catalyst destroyed immediately by the addition of small amounts of methanol.

After discarding the polymer obtained during the first hours of the experiment, the in Product obtained for 45 hours, 16,350 kg, collected.

Its average characteristics are:

Gel = 0 '%

[η] = 2.59

Molecular weight = 195,000

Infrared analysis = 94.3% cis-1.4

2.9% trans-1.4

2.8% 1.2

Ent
took
after
hours Conc
tration
(Weight)
of the poly
butadiene
in the
solution
° / o gel
% M. mole
kular
weight cis-1,4-
salary
of the poly
meren
»/ 0 5 8.82 0 2.58 195,000 91.7 10 8.95 0.5 2.87 212,000 92.8 15th 9.13 0 2.45 182,000 94.2 20th 9.28 0 2.57 202 000 93.9 25th 8.60 0 2.75 211,000 95.1 30th 9.18 0 2.34 173,000 94.6 35 9.01 0 2.56 193,000 95.7 40 8.94 0 2.78 215,000 93.5 45 9.36 0 2.67 202 000 94.2

Example 7

There are two butadiene polymers with almost
chem molecular weight and similar cis-1,4 bond content. The first is made by regulating the molecular weight with the aid of the amount of catalyst and the amount of monomer that is polymerized. The second polymer, on the other hand, is produced in the presence of ethylene, and its molecular weight is therefore determined by the ratio of butadiene to ethylene in the reaction mass.

The reaction conditions and the properties of the two products are given in Table 7.

These two polybutadienes are in a roller mixer, which is provided with rollers 150-300 mm, using 90 g of polymer and processed at 40 ° C. The time to achieve a good degree of plasticization for the in Presence of ethylene product obtained 20 and for the other product 40 minutes.

The degree of plasticization is derived from the Mooney viscosity determined at 100 ° C.

11 »540/445

Tabel

attempt
No.

Al (C ₂ Hs) ₂ Cl
Mole

Reaction conditions *)

Ethylene

CoCl ₂
Millimoles

mm Hg

Butadiene S properties of the polymer

weight

cis-1,4-

Salary [η]

Molecular weight

0.02
0.02

0.167
0.0692

0
75

103 100 96

94

93.9
95.9

*) Both experiments were carried out at 15 ° C for 3 hours in 1000 ecm benzene.

3.80
3.83

320000
323,000

Example 8

In the same autoclave as described in the previous example, two polybutadienes with the same molecular weight and similar content of cis-1,4 bonds. The first is made by regulating the molecular weight with the aid of the amount of catalyst and the amount of Monomers, which is polymerized while the second by regulating the molecular weight with Is obtained using a suitable butadiene-ethylene ratio in the reaction liquid.

The reaction conditions and the properties of the two products are given in Table 8.

Both polymers were at 40 ° C in a roller mixer, as described in the previous example is treated using 90 g of polymer each; the degree of plasticization was due to the Mooney viscosity at 100 ° C determined.

The time to obtain a good degree of plasticization is for those produced in the presence of ethylene Sample 15 minutes and for the other minutes.

Tabel

attempt

Reaction conditions *)

Al (C ₂ Hs) ₂ Cl
Mole

CoCl ₂
Millimoles

Ethylene
mm Hg

Butadiene g properties of the polymer

weight

cis-1,4-content

Molecular weight

0.025
0.025

0.25
0.077

100

130

99
96

94.2
94.0

*) Both experiments were carried out at 15 ° C for 3 hours in 1000 ecm benzene.

2.84
2.88

220000
223,000

Claims (3)

Claims: 40 1. Process for the preparation of 1,3-butadiene polymers with a regulated high molecular weight and predominantly cis-1,4 structure through polymerization in the presence of a catalyst composed of metal alkyl compounds dissolved in hydrocarbons and compounds or complex compounds of metals of Group VIII of the Periodic System of elements, characterized in that the polymerization takes place in the presence of α-olefins or non-conjugated diolefins is carried out as regulators. 2. The method according to claim 1, characterized in that that the polymerization in the presence of ethylene, propylene, propadiene or 1,2-butadiene is carried out. 3. Process according to Claims 1 and 2, characterized in that a catalyst is used made from dialkyl aluminum monochloride and a cobalt chloride-pyridine complex has been. Considered publications:
Belgian patent specification No. 543 292. © 109 5W / 445 4.61