DE1570769B1 - Process for the production of block copolymers of alpha-olefins - Google Patents

Description

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It is already a process for the production of mixed polymer results in a thick or viscous one

Block copolymers of -olefins known, in suspension or even a gel. To the formation of

two different "olefins" one after the other in oversized amounts of soluble static mixed

To prevent a diluent in the presence of a catalyst, the time in the wesentsators be polymerized, the amount of more than one comonomer in an organo 5 borrowed

aluminum compound and the product that is present in the polymerization zone is limited. if

in the reduction of TiCl ₄ with an alkylaluminum - a mixture of α-olefins of one stage of the

umsesquichlorid is added in an inert hydrocarbon sequential polymerization, so

at 0 ⁰ C has been obtained. In this case, however, this should either be predominant, ie up to suspensions of the block copolymers in the order of 95 mol percent or more, from a single -olefin

Get diluents that are too viscous to exist, or they should only be a relatively short one

polymerized to the formation of larger amounts of soluble static time. If pure «olefins everyone

Schem copolymer is due. Stage of the successive polymerization

A process for the production of block copolymers has now been set up, so that should be done in the second stage of «-olefins, whereby at least 15 turned monomers are not added before the

at least two different -olefins are partially converted one after the other into monomers added in the first stage

a diluent in the presence of a catalyst, so that the concentration of in the first

sators, the monomer remaining from an organoaluminum compound stage sufficiently low

and the product, which is by reducing to avoid the formation of too large an amount of solute

To prevent titanium tetrachloride in solution in inert hydrocarbon-like static copolymer,

substances at a temperature between -20 and + 20 ° C. However, it has been found that the mechanical

with aluminum dialkyl chlorides, optionally with properties of those prepared according to the invention

In the form of aluminum alkyl sesquichlorides, which are not optimal among block copolymers,

Use of a molar ratio of aluminum if not two monomers together in the poly

dialkyl chloride to titanium tetrachloride from 0.55 to 1.5 25 merization zone for a certain time together

has been obtained, and possibly of water- are present, so that a certain degree of static

material are polymerized, found, in which the polymerization can occur.

Disadvantages of the known method thereby. A used according to the present invention

be avoided that a catalyst is used, catalyst can expediently be prepared thereby

in its production the aluminum dialkyl chloride 30 will be that the aluminum ethyl sesquichloride drip-

or aluminum alkyl sesquichloride, with stirring, always a stirred solution of titanium tetrachloride

gradually added to the solution of titanium tetrachloride in an inert hydrocarbon at 0 ⁰ C over

has been. a few hours is added, whereupon the obtained

The molar ratio of Al precipitate is preferably for a certain period of time in an inert

Dialkyl chloride to give TiCl ₁ 0.6 to 0.9, and preferably 35 hydrocarbon ^{heated from 60 to 100 0} C and

The two -olefins consist of ethylene and pro-then washed with an inert hydrocarbon

pylene, and the resulting polyolefin composition is contained to remove soluble by-products. Ge

between 0.5 and 40 percent by weight of ethylene units, if necessary, this heating and washing

The use of the specified catalyst has to be repeated one or more times,

the advantage that a relatively small part of the 4 ° wherein the temperature is increased each time, however

polymer formed does not exceed in the dilution 14O ⁰ C.

dissolves medium. Furthermore, the polymer, the organoaluminum compounds which dissolves in the diluent, called from a comparable method of the invention as activators for the low gehältnismäßig reduced specific vis- is TiCl ₄ -Reduktionsprodukte are suitable are viscosity by. This ensures that the suspensions formed in the case of poly- 45 aluminum trialkyls and triaryls, aluminum alkylmerization are easily handled by halides and aluminum alkyl hydrides. Aluminum can be handled and the recovery of the dialkyl chloride are particularly useful. Diluent for further use in which the successive poly-polymerisation is preferably simplified. Furthermore, merization can only have two stages, ie a stage in which suspensions are obtained which contain propylene added to the polymerization zone and higher polymer concentration, which is a stage in which ethylene in the polymerization zone is also very advantageous. In many cases it can be set. At least 400 g of monomer per liter of dilution polymerisation of ethylene and propylene can be fed to the polymerisation zone very appropriately after a medium. Step-by-step polymerization process With this process, it is still possible to carry out step 55, with an expedient addition of block copolymers ethylene that is used to produce the polymerization vessel, which is added to the polymerization vessel at a relatively high rate if the partial pressure of propylene contains a proportion of static copolymers . therein is at least 0.5 atmospheres. __ The catalysts produced by the process of the invention The catalysts used in the process according to the invention ver-ethylene-propylene block copolymer masses are attacked by oxygen and sit at low temperatures, for example water, and it is therefore necessary that those of O ⁰ C, better strength properties than the preparation of the catalyst and the polymeri-propylene homopolymers. sation essentially in the absence of air In order to obtain a free-flowing suspension of the polymer and water or in the presence of only limited amounts in the diluent, it is necessary to carry out 65 quantities of this rigidity. This allows the formation of static copolymers to be used to control polymerization diluents which dissolve in the diluent, for example an aliphatic hydrocarbon, because if the proportion of soluble is too high, the reaction temperature is preferably between

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10 and 90 ° C and in particular between 30 and 75 ° C. Thinner). The polymerization is expediently fed to the stirred reaction vessel in a propylene was fed at 50.degree. C., the 0.2 mol percent closed autoclave which contained the hydrogen. The polymerization continued immediately applied maximum pressure can withstand. This one. The addition of propylene was carried out over 6 ¹ I ₂ hours pressures can optionally contain up to 10 atmospheres 5 and during this time the reaction was conduct. Hydrogen can be added to reduce the vessel 410 g of propylene and the maximum melt viscosity of the block copolymer produced reached 3.9 kg / cm ² . The addition of propylene merisate serve. If desired, the was then interrupted and the polymerization continued at various stages of the polymerization until the partial pressure of propylene is carried out at the temperatures. It is also possible that the reaction vessel was 1.05 atmospheres. It was then borrowed, after a continuous polymerization, to work a highly mobile suspension of the polymer in a process, a monomer being obtained in one of the diluents. This suspension was continuously polymerized in the first autoclave and then treated with isopropyl alcohol, the suspension is fed to a second autoclave with water, washed and subjected to steam distillation, in which the polymerization with the second mono-15 and the polymer was finally dried is continued. At the end of the polymerization, further details about the polymerization and the mass obtained can be worked up in a manner known per se. The products obtained according to this example can be worked up, for example by treatment with corresponding comparative experiments in the table further with a suitable alcohol, which catalyst is compiled below , dissolves residues, whereupon 20. Wash and filter to remove the largest amount of the example diluent, the remainder of which by In the manner described in Example 1, a steam distillation was driven off, whereupon the mass polymer is prepared, but the propylene is dried. If desired, the remainder of the pressure can be ^{reduced to 0.28 kg / cm 2} before the diluent is removed by adding the ethylene, obtained in the filtration, with the diluent. . medium moistened product is dried directly. Example 3

In the following examples the invention is closer to the general one described in Example 1

explained. The comparative experiments explain the method a polymer was produced, wherein parts, which by the subject of the invention 3 ° but with a polymerization temperature of 60 ° C

educational processes to be overcome. Both was worked in. The propylene charge was

the Examples and Comparative Experiments consisted of 410 grams per liter and contained 0.17 mole percent

the diluent used from a petroleum hydrogen. The ethylene charge was 41 g per liter

fraction consisting of a mixture of at about diluent.

185 ° C boiling aliphatic hydrocarbons 35 _R.

and which is essentially free from aromatic Example 4

Connections is. According to Example 3, a polymer was produced

. . and the ethylene was added when the propylene

^{B e! s} P · ^{e l X} pressure was 1.76 kg / cm ² .

A catalyst is made by adding aluminum 40 _.

Sesquichloride to titanium tetrachloride prepared as follows: Example 5

550 ecm of titanium tetrachloride (5.0 mol) and 11 inert A polymer was prepared according to Example 3, but the hydrocarbon diluent was added, when the propylene was provided with a stirrer and with a pressure of 2.46 kg / cm ² . Nitrogen-flushed, 61-capacity reaction vessel fed to 45 _Λ , which was kept at a temperature of 0 ° C. Comparative Experiment A was. A 25 ° / _o strength (wt./wt.) Solution of aluminum following the general method of Example 1 miniumäthylsesquichlorid in an inert coal except that the hydrogen as a diluent, containing 4.0 mole of catalyst used in a polymer was prepared the way was prepared, aluminum diethyl chloride, the stirred titanium 5 ° that titanium tetrachloride of a solution of aluminum tetrachloride solution was gradually added in the course of 14 hours of ethyl sesquichloride and a ratio of that at 0 ° C added. After completion of the addition of aluminum diethyl chloride to titanium tetrachloride of 0.4, the stirring treatment was used for a further 2 hours. The propylene charge was 291 g carried out and then the temperature within per liter of diluent, and it contained 0.2 mol I ¹ I ₂ hours increased to 95 ° C. and at this level 55 percent hydrogen. The ethylene charge was 29 g held for an additional 2 hours. per liter of diluent. The ethylene was

The cooled suspension was decanted after the propylene ^{pressure had fallen to 1.76 kg / cm a} animals three times with 6.25 l of diluent each time. The washing treatment obtained at the end of the polymerization, washed and finally suspension, was so viscous that it was difficult to slurried in 6.25 liters of diluent by hand and a large amount of high mole weight could be added to the reaction vessel in this form containing soluble products. contained in the diluent.

In a dry, 2 1 capacity, oxygenated

Free reaction vessel, the following batch was a comparative experiment B

filled: 11 diluents which were used in the above 65 A polymer was prepared as in comparative experiment A

given way produced catalyst suspension, described produced, but the ethylene was only

equivalent to 5 mg-atoms of titanium, and 10 millimoles of aluminum added after the propylene pressure had dropped to 0.49 kg / cm ^a

miniumdiäthylchlorid (18 ° _o sodium / solution in the had sunk. The resulting suspension was movable

enough to be handled, but contained a relatively high proportion of soluble Substances with a relatively high viscosity.

Comparative experiment C

A catalyst was prepared in the manner described in Example 1, but using less aluminum ethyl sesquichloride so that the ratio of aluminum diethyl chloride to titanium tetrachloride was 0.5. The catalyst prepared in this way was placed in a reaction vessel containing the diluent in an amount of 7 mg atoms of titanium per liter of diluent together with 15 millimoles of aluminum diethyl monochloride per liter. Propylene with a hydrogen content of 0.2 mol percent was added to the reaction vessel at 50 ^° C., and the polymerization started immediately. After 420 grams of propylene per liter of diluent was added to the reaction vessel, the suspension became thick and the rate of polymerization decreased considerably. In this state, therefore, the addition of ethylene and further polymerization could not be carried out.

Comparative experiment D

A catalyst was prepared in the manner described in Example 1, with the modification that the Titanium tetrachloride solution was gradually added to the aluminum ethyl sesquichloride solution. The so The prepared catalyst was placed in a reaction vessel

ίο filled in, the diluent contained in an amount of mg atoms of titanium per liter of diluent together with 12 millimoles of aluminum diethyl chloride per liter. The temperature of the reaction vessel was increased to 60 ^° C. and propylene was introduced. The polymerization started immediately. However, after 330 liters of propylene per liter of diluent was added to the reaction vessel, the rate of polymerization decreased considerably and the suspension became viscous. In this condition

hence the addition of ethylene and further polymerization not feasible.

Polymeri Propylene Enamel
flow
index Properties of the polymer composition Bending module 1
ITag ig / cm ² · 10 ^-5
2 weeks - Soluble in thinner smer-
zes
End
Per reduced example station
temperature pressure at
Ethylene addition Pressure point
at lower
temperature - Weight percent duct specific
viscosity
the final
soluble respectively.
Comparison
attempt ⁰ C kg / cm ^B 9 ⁰ C 0.1 0.11 of the Monc
add
after
Propylene 2.1 Fabrics 50 1.05 13th -18 0.1 to 0.13 0.126 additive 2.1 0.63 1 50 0.28 32 - 5th 0.1 0.126 1.6 3.4 0.50 2 60 1.05 15th 0.098 0.11 1.6 3.9 0.41 3 60 1.76 8th -20 0.1 0.11 2.9 4.6 0.59 4th 60 2.46 6th -19 0.11 0.12 3.1 11.2 0.50 5 50 1.76 15th -16 0.11 to 0.12 0.126 to 0.13 3.4 6.9 2.5 A. 50 0.49 - -11 to -15 - 7.7 - 1.1 to 1.4 B. 50 - - - - 5.5 - - C. 60 - - 5.5 - D. 6.0

In the tests set out in the table, the melt flow index was measured according to ASTM test 1238-57 T using a temperature of 190 ° C. and a load of 10 kg. The flexural modulus was measured by a simple bar flexure test 1 day and 2 weeks after the specimen was molded. The lower temperature fracture toughness was measured according to ASTM Test No. 746-57 T using smooth, ungrooved specimens measuring 2.0 x 0.25 x 0.16 cm around a mandrel a 0.4 cm radius by a hammer operating at 2.1 m per second. The reduced specific viscosity was measured at 50 ⁰ C in a l% by weight (wt./wt.) Solution of soluble polymer in the polymerization diluent measured.

Claims (4)

Patent claims: 1. A process for the preparation of block copolymers of α-olefins, with at least two different -olefins one after the other in a diluent in the presence of a catalyst, which consists of an organoaluminum compound * and the product that, by reducing of titanium tetrachloride in solution in inert hydrocarbons at a temperature between -20 and +20 ⁰ C with aluminum dialkyl chlorides, optionally in the form of aluminum alkyl sesquichlorides, using a molar ratio of aluminum dialkyl chloride to titanium tetrachloride of 0.55 to 1.5, and optionally of Hydrogen are polymerized, characterized in that a catalyst is used, during the preparation of which the aluminum dialkyl chloride or aluminum alkyl sesquichloride has been gradually added to the solution of titanium tetrachloride with stirring. 2. The method according to claim 1, characterized in that the polymerization in two stages is carried out, wherein propylene is fed in one stage and ethylene in the other of the polymerization zone, preferably if the propylene pressure has reached at least 0.5 atm. 3. The method according to claim 1 or 2, characterized in that a catalyst is used in the preparation of which the product obtained by reducing the titanium tetrachloride is ^{heated in an inert hydrocarbon to 60 to 100 0} C and then washed with the inert hydrocarbon to remove soluble by-products. 7 8 4. The method according to claim 3, characterized in that it has been washed with hydrogen indicates that a catalyst is used, carried out one or more times in the washing treatment the production of which is the reduction product of and the heating temperature each time Titanium tetrachloride has been increased again in an inert coal, but a temperature of heated hydrogen and has not exceeded 140 ° C with the inert carbon 5. 009526/281