DE2214271B2 - Process for the production of high molecular weight, low pressure copolymers and terpolymers of low density ethylene - Google Patents

Description

The invention relates to a process for the production of high molecular weight low pressure copolymers and terpolymers of low density ethylene by copolymers or Terpolymerization of ethylene with propylene and / or butene-1 with the help of mixed catalysts from one Titanium trichloride contact on the one hand and chlorine-containing organoaluminum compounds on the other hand in liquid phase.

For different areas of application, e.g. B. the production of loom pickers and other highly stressed Parts in the textile industry, in mechanical engineering and in the former industry, for example for screw conveyors, Gears, rollers, valves and slides, one needs types of polyethylene with high molecular weight settings. You can use the Ziegler method High molecular weight polyethylene types with RSV values of around 17 (measured in 0.03 percent solution in Manufacture decahydronaphthalene at 135 ° C). This corresponds to a molecular weight of about 1 million, calculated according to the solution viscosity. These products have a density of 0.94.

High molecular weight polyethylene types of lower density

are not known so far. The high-pressure process can probably be used to produce lower density types of pulpyethylene from 0.915 to 0.935. However, these polymers only have molecular weights of up to approx. 50,000 calculated from the solution viscosity

By polymerizing ethylene in butene-1 and / or propylene-containing C ₄ or CVC ₃ hydrocarbon cuts with contacts of halo-ortho-titanic acid esters on the one hand and chlorine-containing ones

ίο organometallic compounds of aluminum on the other hand it is not part of the state of the art processes belonging to it are possible, including low-density ethene-butene-1 copolymers with molecular weights produce up to about 500,000 (DE-OS 22 06 429).

is copolymers and terpolymers of ethylene with lower In contrast, density and extremely high molecular weight are not yet accessible.

It is the object of the present invention to provide a synthetic route which allows the advantages

the Ziegler process,

the low polymer density, the extremely high molecular weight and the copolymers or terpolymers to use at the same time.

vs This object is achieved according to the invention by that a solvent is used which

Propylene and / or butene-1, also butane and / or Contains propane on the one hand and butene-2 on the other hand. Surprisingly, this method makes it possible to

co- or -terpolymers with densities from 0.90 to 0.955 and Produce molecular weights up to about 5,000,000.

Suitable titanium trichloride contacts are in particular those obtained by reducing titanium tetrachloride at temperatures of 0 to - 10 ⁰ C with Äthylalumi-

i ^r > nium sesquichloride. The preparation of such contacts is carried out by reduction of titanium tetrachloride with kohlenwasserstoffverdünntem ethylaluminum sesquichloride at 0 to - 10 ⁰ C within 4 to 8 hours at a molar ratio of Ti to Al compound

μ from 0.5 to 2.0, preferably from 1.0 to 1.5. Before the Using this TiCh-containing contact can be separated from the mother liquor. The one containing TiCk However, suspension can also be used directly.

Chlorine-containing organoaluminum compounds are used to activate this titanium trichloride contact suitable in a molar ratio of 0.5 to 5.0, preferably 1.0 to 3.0, in particular 1.5 to 2.5. This activation is carried out in a manner known per se by adding ethylaluminum material to the separated TiCb contact

w quichloride, preferably in a 20% hydrocarbon solution. So much diethylaluminum monochloride is added to the unseparated TiCb suspension, which contains ethylaluminum dichloride from the reduction, that ethylaluminum sesquichloride is

"When activated with aluminum trialkyls, Aluminum dialkyl hydrides and aluminum dialkyl chlorides are formed in addition to the copolymers and terpolymers Mixtures of the individual homopolymers.

For this reason, ethylaluminum sesquichloride is preferred to activate the isolated TiCl ₃ , as described above and in a molar ratio of 0.5 to 5, preferably 1.0 to 3.0, in particular 1.5 to 2.5, such as when using a titanium trichloride activated in this way, a mixed catalyst is obtained which allows the ^b5 copolymers or terpolymers to be formed predominantly free of homopolymers.

The contacts are preferably used in a concentration of 0.1 to 10 mmol / 1, in the case of molar

Al to 11 ratios of 1.0 to 3.0, preferably 1.5 to 2 pounds. The polymerization is conducted at temperatures of 0 to 100 ⁰ C, preferably at temperatures of 50 to 90 ° C, in particular at 60 to 80 ° C, and at pressures up to 50 atmospheres, especially from 10 performed atu to 40 wt.

Suitable butane are n- and i-butane as well as any mixture of these substances. The butene-2 can be used in the cis or in the trans form and any mixtures thereof. The mixing ratio Propane / butane to butene-2 can vary within any limits. Mixing ratios of propane / butane to butene-2 of 50:50 to 90:10 are preferred.

Surprisingly, it has also been found that the proportion of propylene and / or 1-butene in the solvent can be present and allows the production of the substances according to the invention, depends on the polymerization temperature door

At a polymerization temperature of 0 to 100 ° C Sol! this proportion should not exceed 15 mol percent, namely the propylene proportion should be 5% and the butene-1 proportion Do not exceed 15%.

However, is polymerized at temperatures which are between 0 and 80,70,60 or 40 ⁰ C, the proportion of propylene can be 10, 25, 50 or 95 mole percent and the butene-1 moiety 25,60,95 or 95 mole percent.

This finding is surprising and valuable because one now has a multitude of Variation options in the hand to z. B. always starting from different gas mixtures comparable polymers to come or to z. B. starting from the same gas mixture, the polymers in to modify even further limits than was previously possible.

Also compared to older processes for the production of ethene-butene-1-copolymers such as DE-PS 14 45 303 it is surprising that for the production of ethylene copolymers or tert-polymers, if necessary, only a very low butene-1 ·· and / or propene content is required.

The new process allows polyethylene co- and terpolymers with a density of about 0.90 to 0.955 and molecular weights from about 30,000 to; produce about 5,000,000. Thereby polyethylene groups are obtained which up to now could neither be produced by the high pressure nor by the low or medium pressure process.

example 1

A mixture of 0.8 part by weight of butane, 0.28 part by weight of 2-butene and 0.12 part by weight of butene-1 (10 mol percent) is placed in a 5-liter laboratory autoclave. A contact of 0.00128 parts by weight of a titanium trichloride, which by reducing 1 mol of titanium tetrachloride (100 percent) at -5 ° C with 1.4 mol of ethylaluminum sesquichloride (molecular weight 123.7; 20 percent in hexane) within 6 hours, a subsequent post-reaction time of 15 hours at 0 to 10 ⁰ C and separating the precipitate was obtained, and 0.00206 parts by weight of ethylaluminum sesquichloride is added. The temperature is increased to 80 ° C. and ethylene is injected up to a pressure of 15 atmospheres. The polymerization is carried out ^{at 80 °} C. over a period of 4 hours.

The pressure is kept at 12 to 15 atmospheres by pushing in ethylene. After relaxing, cooling down and decomposition with 0.01 part by weight of methanol gives 0.336 part by weight of an ethylene-butene-1 copolymer with the following properties:

RSV example 30 dl / g 2 Afv: 2 500000 (calculated according to the Solution viscosity as polyethylene) density O322O g / cnv » Yield stress 149 kgf / cm ² Elongation at yield stress 23% Tear resistance 333 kgf / cm ² Elongation at break 410% Tensile impact strength > 1500 kp cm / cm ² Softening point 115 ° C IR analysis Double bonds / 1000 C trans <0.02 vinyl 0.06 vinyliden <0.02 CH3 / IOOC 1.8

12 parts by weight of a mixture of 70% butane, 25% butene-2 and 5% butene-1 are placed in a 50-1-50 atmospheric tank. A contact of 0.0064 parts by weight of titanium trichloride, prepared as described in Example 1, and 0.0103 parts by weight of ethylaluminum sesquichloride is added. The temperature is raised to 6O ⁰ C is increased, the polymerization is conducted within 2 hours at 6O ⁰ C and a pressure of 30 atm. After adding 0.1 part by weight of methanol, the ^{mixture is cooled to 20 °} C. and the unreacted ethylene is depressurized with the butene-butane mixture. 3.2 parts by weight of a polyethylene are obtained which has the following properties:

j-> RSV 42 dl / g Mv about 4,000,000 density 0.9226 g / cm ³ Yield stress 154 kgf / cm ² Elongation at yield stress 23% 4 »tear resistance 348 kgf / cm ² Elongation at break 452% Tensile impact strength > 5500 kgf cm / cm ² IR analysis Double bonds / 1000 C ^4> trans <0.02 vinyl 0.05 vinyliden <0.07 CH3 / IOO 0.95

Example 3

1.8 parts by weight of a mixture of 60% butane, 20% butene-2 and 20% butene-1 are placed in a 5-liter laboratory autoclave. A contact of 0.0018 parts by weight of a titanium trichloride contact prepared as described in Example 1 and 0.0029 parts by weight of ethylaluminum sesquichloride is added. At 8O ⁰ C ethylene up to a pressure of 15 atm admitted. Hydrogen is added up to a partial pressure of 1 atm. After a polymerization time of 3 hours, 0.418 parts by weight of an ethene-butene-1 copolymer with a butene content of 11% are obtained.

RSV

f> 5 M F | 90 / 2.16 MF190 / 5

density Yield stress

6.44 dl / g Ä7v about 353,000 0.12 g / 10 min. 0.92 g / 10 min. 0.9180 g / cm ³ 78 kg / cm ²

Elongation at yield stress 33% tensile strength 101 kp / cm ²

Elongation at break 657%

IR analysis
Double bond / 1000 C

trans-middle class 0.36

vinyl 0.69

vinylidene 0.03

When 3 atmospheres of hydrogen are added, it becomes a copolymer with an RSV value of 23 d! / g.

Example 4

According to the information in Example 3, ethylene is 1.8 Parts by weight of a mixture of 60% butane, 25% butene-2 and 15% butene-1 are polymerized 0376 parts by weight of an ethene-butene-1 copolymer with a butene-1 content of 9%.

When νου 3 atmospheres hydrogen is added, a copolymer is formed with an RSV of 1.2 dl / g.

Example 7

According to the information in Example 3, ethylene in 1.8 parts by weight of a mixture of 45% butane, 25% Butene-2, 5% butene-1, 20% propane and 5% propene polymerized. 0368 parts by weight of a are obtained Ethene-propene-butene-1 terpolymers with the following Property values:

MF190 / 2.I6 U. MF190 / 5

density

Yield stress

Elongation at yield stress

Tear resistance

Elongation at break

IR analysis
Double bonds / 1000 C

trans-middle-class

vinyl

vinyliden

12.86 dl / g Ai. About 812 000 not measurable 0.9190 g / cm ³ 86 kp / cm ² 33%

169 kg / cm ² 573%

0.38 0.15 0.16

RSV

density

Yield stress

Elongation at yield stress

Tear resistance

Elongation at break

Example 5

According to the information in Example 3, ethylene in 1.8 parts by weight of a mixture of 50% butane, 40% Butene-2 and 10% butene-1 polymerized in the presence of 1 atm hydrogen pressure. 0.392 is obtained Parts by weight of an ethene-butene-1 copolymer with a butene-1 content of approx. 10% with the following Property values:

RSV 5.4 dl / g Ä? V about 284 000 density 0.9195 g / cm ³ Yield stress 93 kgf / cm ² Elongation at yield stress 33% Tear resistance 151 kgf / cm ² Elongation at break 587% IR analysis Double bonds / 1000 C trans-middle-class 036 vinyl 0.21 vinyliden 0.81

Example 6

According to the information in Example 3, ethylene in 1.8 parts by weight of a mixture of 40% butane, 30% Butene-2, 25% propane and 5% propene polymerized. 0374 parts by weight of an ethene-propene copolymer are obtained with the following property values:

W dl / g

Mv about 240 000

0.9260 g / cm ³

146 kgf / cm ²

22%

314 kgf / cm ²

443%

Example 8

According to the information in Example 3, ethylene is 1.8

Parts by weight of a mixture of 95% 1-butene, 3% butane and 2% 2-butene are polymerized at 60.degree

r> contains 0.412 parts by weight of an ethene-butene-1 copolymer with the following property values:

RSV

density

Yield stress

Elongation at yield stress

Tear resistance

Elongation at break

15.0 dl / g

Af ν about 1,040,000

0.9160 g / cm ³

72 kgf / cm ²

33%

174 kgf / cm ²

584%

Example 9

According to the information in Example 3, ethylene is 1.8 Parts by weight of a mixture of 76% propene, 19% butene-1, 3% butane and 2% butene-2 at 25 ° C polymerized. 0.143 part by weight of an ethene-propene-butene-1 terpolymer with the following is obtained Property values:

RSV 20.0 dl / g Mv about 1530 000 density 0.905 g / cm ³ Ether-soluble part 27.8% Yield stress 48 kgf / cm ² Elongation at yield stress 33% Tear resistance 92 kgf / cm ² Elongation at break 350%

Example 10

According to the information in Example 3, ethylene in 1.8 parts by weight of a mixture of 20% butene-1.60% Polymerized butane and 20% butene-2 at 70 ° C. 0.325 part by weight of an ethene-butene-1 copolymer is obtained with the following property values:

RSV 7.8 dl / g R3V 17.3 dl / g Mvetwa447Q00 Mv about 1,250,000 density 0.9310 g / cm ³ density 0.9235 g / cm ³ Yield stress 162 kgf / cm ^{2 h} "'yield stress 107 kgf / cm ² Elongation at yield stress 21% Elongation at yield stress 50% Tear resistance 316 kgf / cm ² Tear resistance 238 kgf / cm ² Elongation at break 426% Elongation at break 493%

IR analysis 0.20 Double bond / 1000 C 0.11 trans-middle workers 0.14 vinyl 11 vinyliden CHj / lOOC

Claims (6)

Patent claims: 1. Process for the production of high molecular weight low pressure copolymers and terpolymers of ethylene low density by co- or terpolymerization of ethylene with propylene and / or butene-1 with Using mixed catalysts made from a titanium halide contact on the one hand and chlorine-containing organoaluminum compounds on the other hand liquid phase using a solvent which is propylene and / or butene-1, furthermore Contains butane and / or propane, characterized in that a titanium halide is used known titanium trichloride and a solvent used which butene-2 contains 2. The method according to claim 1, characterized in that the ^{polymerization is carried out at 0 to 10O 0} C and a solvent is used whose propylene content is up to 5 mol percent or 1-butene is up to 15 mol percent 3. The method according to claim 1, characterized in that the polymerization is carried out at 0 to 80 ° C and a solvent is used, the proportion of which is up to 10 mol percent of propylene or up to 25 mol percent of butene-1 4. The method according to claim 1, characterized in that the ^{polymerization is carried out at 0 to 7O 0} C and a solvent is used whose propylene content is up to 25 mol percent or 1-butene is up to 60 mol percent. 5. The method according to claim 1, characterized in that the ^{polymerization is carried out at 0 to 60 0} C and a solvent is used whose propylene content is up to 50 mol percent or 1-butene is up to 95 mol percent 6. The method according to claim 1, characterized in that the polymerization is carried out at 0 to 40 ° C and a solvent is used, the proportion of which of propylene and / or butene-1 is up to 95 mol percent