SU762963A1 - Method of preparing catalyst for polymerization and copolymerization of olefins - Google Patents

Description

The invention relates to the preparation of catalysts for the polymerization and copolymerization of olefins on the basis of compounds of magnesium, titanium

. and 'aluminum. five

A method of producing a catalyst for the polymerization of olefins by reacting a compound of magnesium, for example diphenyl magnesium, titanium tetrachloride and diethyl aluminum chloride, is known [1]. .

The polymerization of olefins, such as ethylene, using such a catalyst is carried out in solution mode at a temperature of 140 ° C and a pressure of 15 to 20 at. The yield of polyethylene is 9.17 kg / g T1. However, the catalyst obtained in a known manner acts for a short time (10 minutes). 20

In addition, an expensive solvent pentamethylheptane is used in the polymerization.

There is also known a method of producing a catalyst for the polymerization of olefins, 25 for example, ethylene, by reacting butyl magnesium chloride with titanium tetrachloride. An organoaluminum compound (AOC) £ 232 is used as an activator.

The polymerization is carried out at 85 ° C and a pressure of 10 at. For example, the yield of polyethylene (PE) using a catalyst containing 0.0915 wt.% Is 5600 kg / g, or 140 kg PE / g · at. C ₂ H ₄ · h

However, the resulting catalyst provides only a low polymer yield per unit weight of the solid catalyst. For example, in the case of this example, the output is 0.13 kg of PE / g of solid catalyst * at. C ₂ H ^ -h, the yield per unit weight of the total catalyst is even lower, since the concentration of AOC used is high (2 g / l).

The closest to the invention to the technical essence and the achieved effect is a method of obtaining a solid catalyst for the polymerization and copolymerization of olefins by reacting an ether solution of ethyl magnesium bromide with titanium tetrachloride at a temperature of 100 ° C, molar ratio Τί: MD = 3: 1.

AOC is used as an activator. The output of polyethylene using such a catalyst at a polymerization temperature of 90 ° C, a pressure of 10 at and the content in the reaction zone

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40% by volume of hydrogen is only 6660 g / g Τί - · h, and the yield of a copolymer of ethylene with propylene (BOT) at a polymerization temperature of 80 ° C and pressure of 7 at - 1.73 kg / g of solid catalyst in 30 minutes or 3.46 kg / g solid catalyst —h [s].

In the indicated source, the polymerization time of ethylene was 1020 minutes, but the yield of the product was theoretically calculated during the polymerization time of 1 h. However, the practical yield of polyethylene during this time is inevitably much lower. In addition, using such catalysts, as indicated in the GZZ, it is impossible to obtain a BOT containing more than 10 mol.% Propylene.

The aim of the invention is to obtain a catalyst for the polymerization and copolymerization of olefins with increased activity and increased selectivity to the copolymerizable ole-g fin.

This goal is achieved by the fact that in the method of preparing a catalyst for the polymerization and copolymerization of olefins by reacting titanium tetrachloride with an ethereal solution of ethyl magnesium bromide, the resulting solid catalyst is further subjected to vacuum heat treatment at a residual pressure of 0.010.3 mm. and temperature 120180 ° C for 2-4 hours

Distinctive features of the invention are additional vacuum. mind ~ heat treatment with a residual ’, an exact pressure of 0.01-0.3 mm Hg. Art. and a temperature of 120-180 ° C for

2-4 hours

The catalyst according to the invention is suitable for homopolymerization of olefins such as ethylene, propylene, butene — 1 and others, as well as for the copolymerization of ethylene with propylene, butene-1 and other olefins.

The application of the proposed method is characterized by obvious advantages. In the polymerization of ethylene. using the catalyst obtained by the proposed method, in the suspension mode, the yield of polyethylene is increased by 50-70%, and in the solution mode - by 70-350%; the properties of the polyethylene obtained are not inferior to those of polyethylene synthesized using a catalyst obtained by a known method, and in a number of indicators the obtained PE exceeds it, for example, contains a much smaller number of double bonds in the macrochains.

In the process of copolymerization of ethylene with propylene in the presence of a catalyst obtained by the proposed method, the yield of crystalline BOT, containing 6 mol.% Of propylene, is 65% higher than with

catalyst obtained by a known method. Output 1 g T! A BEP containing 10 mol.% Propylene is 6.6 times higher, and if to obtain the same copolymer, but synthesized using a catalyst prepared by a known method, it is necessary to use a gas mixture of comonomers containing 40 mol.% Propylene. using the catalyst obtained by the proposed method - 20 mol.% propylene. The catalyst obtained by the proposed method allows to obtain copolymers with the content of the second co monomer at least up to 3 0 mol.%

Interaction tetrachloride. titanium with an ethereal solution of ethylmagnesium bromide is carried out at a molar ratio of Τί / MD above 3: 1.

In the process of polymerization or copolymerization of olefins, n-heptane is used as a hydrocarbon solvent, triethyl aluminum (TEA) or diisobutyl aluminum hydride (DIBAG) is used as AOC. The regulation of the molecular weight of polymers is carried out by introducing hydrogen into the reaction zone. The preferred temperature of homo - and copolymerization are in the range of 40-200 ° C. The optimal process pressures are 2-40 at.

Example 1 (control).

Preparation of solid catalyst (prototype).

In a glass reactor with a volume of 300 ml, equipped with a reflux condenser, in an atmosphere of argon load

6.3 g of metallic magnesium chips, 62 ml of dry diethyl ether are poured and 18 ml of ethyl bromide are gradually added dropwise with stirring, after which the reaction mixture is periodically heated to 40-50 ° C for 1 h.

The resulting ethereal solution of ethyl magnesium bromide is separated from the solid residue by filtration on a glass and ceramic-metal filter under argon atmosphere.

In a 200 ml metal reactor under argon atmosphere, 33 ml of a ZM ether solution of the ethylmagnesium bromide obtained are added and 80 ml of titanium tetrachloride are added with stirring (the molar ratio м to MD is 7.4: 1). The temperature in the reactor is increased to 100 ° C and the reaction the mass is stirred for 3 h, after which the excess T1SC is poured, the resulting solid product is washed four times with purified n-heptane until complete removal of unreacted T1SC and dried at 100-130 ^M C for 1 h.

The resulting purple-colored solid catalyst contains

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tatam chemical analytical opredele.niya 15.5 wt.% ΤΙ, 8,3 wt.% Mg, '52 wt.% of halogens (C1 + Br), its specific surface area (5 _y z) is 5.7 m ^ / g.

Polymerization of ethylene.

2.7 g of the obtained solid catalyst and 32 mg A1 (C <2 H ₆ ) >> (in the form of a 20% aqueous solution in α-heptane), sealed separately in glass ampoules, are placed in a 150 ml stainless steel reactor, the reactor is freed of air and traces of moisture, 100 ml of purified n-heptane are introduced into it and the temperature is raised to 90 ° C. The vapor pressure of n-heptane is 0.8 at. Then hydrogen is supplied to the reactor to a pressure of 3.8 at. and ethylene to a total pressure of 7.4 at. (The hydrogen concentration in this case is equal to 40.5% by volume.) The inclusion of a mixing device that breaks the ampoules with the components of the catalytic system begins the experiment on polymerization, during which the temperature and pressure in the reaction zone are automatically kept constant. After 2 h, the experiment is stopped, freeing the reactor from ethylene. The yield of the product is 6.8 g or 1260 g of PE / g of solid catalyst · h, or 8125 g of PE / g ч определ · h. Approx. Determination of the yield of PE by C3 in 15 min. and in terms of 1 h (in our example, this turned out to be possible, since the experiment was carried out on a kinetic installation that records the absorption of ethylene per unit time), the maximum theoretical yield (0 _max ) was 11000 g of PE / g ΐ »h.

The resulting PE has a characteristic viscosity (A] (decalin, 135 ° C) 2.3 dl / g, contains (according to IR spectroscopy) 0.05 CH _ъ -groups per 100 C atoms,

0.15 / C οΰζ -groups (double bonds) per 1000 'atoms''C'', density (3) 0.965 g / cm ^e , melting point (spl) - 135 ° C, breaking stress at tension' Cj) - 305 kgf / cm ² tensile yield strength (b) - 280 kgf / cm * ¹ ·, elongation at break (£ p) - 540%.

Example 2 (control).

Tzierdy catalyst produced according to example 1.

Polymerization of ethylene.

The polymerization is carried out under conditions equivalent to those of example 1, but 0.8 mg of a solid catalyst and 39 mg of Al (C _g H ₅ ) ^ are loaded into the _reactor. . Out of PE in 2 hours - 4.3 g or 2680 g of PE / g of solid catalyst · h or .17300 g of PE / g T1 h, e _{mo (kc} - 244.50 g of PE / g T! · H. The resulting PE has

2.3 dl / g.

Example 3 (control).

A solid catalyst was prepared according to example 1.

Polymerization of ethylene.

The polymerization is carried out under the conditions of example 1, but 0.7 mg of solid catalyst is charged to the reactor,

4 2 mg A! (C ₂ H ₅₎ =, and are polymerized _ς tion at a total pressure of 4 atm and a temperature of 70 ° C (ethylene partial pressure in this case is 3.6 atm.). Hydrogen is not supplied to the reaction zone. PE output in 2 hours - 6.55 g or

, 4680 g PE / .g solid catalyst · h

¹⁰ or 30200 g PE / g Τί · h, C _max =

'= 36400 g PE / g Τΐ · H

The resulting PE contains 0.05: 'sn ₃ / yo "s", 0.15 |> C-e4 yooo "

. "C", has a RC = 20.5 dl / g, / =

15. = 0.956 g / cm ² *, ι _{η / 4} - 136 ° С, * Ver =

= 360 kgf / cm * ¹ , b = 315 kgf / cm ² , £ p =

= 420%.

Example 4 (control).

'. A solid catalyst is obtained in accordance with Example 1.

Polymerization of ethylene.

4.0 mg of solid catalyst and

110 mg A1 (C _? H ₅ ) ^ (as a 20% solution in n-heptane), placed in

25 glass ampoules, loaded into a 300 ml stainless steel reactor, freed from air and moisture, injected with 150 ml of purified Η-heptane ', raise the temperature to

_ _p 160 ° C and serves ethylene to the total

21 atm pressure, turn on the stirrer, break up the ampoule with AOC and with a solid catalyst with a special device, starting the experience of polymerization, during which the temperature and pressure are automatically maintained constant. After 1 h, the experiment is stopped, the product yield is 12.1 g or 3030 g PE / g solid catalyst · h or 19 300 g PE / g * h, C _max =

40 = 2,570 PE / g · h. The PE contains 0.05 CH _3/100 "C", 0.77 "!> C1

= / 1000 "C", has [4,] = 4.7 DL / g,

p = 0.962 g / cm, 1 _ll , = 134 ° С, bl =

= 235 kgf / cm ² , <b = 235 kgf / cm, b _p =

₄₅ = 510%.

Example 5 (control). 'A solid catalyst is prepared according to example 1.

Polymerization of ethylene.

In conditions equivalent to the conditions of example 4, the reactor is loaded

1.8 mg of solid catalyst

107 mg A1 (C _g H ₂ ) _g and hydrogen is supplied to a partial pressure of 2 at. Polymerization is carried out under general pressure.

55 23 at (the concentration of hydrogen is 8.7% by volume). PE output in 1 hour 4.15 g or 2290 g PE / g solid catalyst — h, or 14 800 g PE / g T! · H, ^C mox = 16200 PE / g Τί .h, [M =

60 = 3.0 dl / g.

Example b (control).

Under conditions equivalent to those of Example 4, 2.5 mg was loaded into the reactor. solid catalyst, 93 mg A1 (Cr. H5> I are undergoing the process, with a total

Ί

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pressure 31 at and 200 ° C. The output of PE for 1 h - 2.1 g, or 840 g of PE / g of solid catalyst · h, or 5410 g of PE / g of T1-H. Relish ”915 ° g PE / g ΤΙ“ h, Pb] =

= 3.9 dl / g.

Examples 7-10 (control).

A solid catalyst was prepared according to example 1.

Copolymerization of ethylene with propylene.

The copolymerization of ethylene with propylene is carried out in a reactor with a capacity of 200 ml and under the conditions of example 3, but the content of the solid catalyst, aluminum triethyl and the second monomer vary. Download catalyst components and the output of the copolymer is shown in the table.

Example 11 7 (control).

A solid catalyst was prepared under the conditions of Example 1.

Polymerization of propylene.

The polymerization of propylene is carried out under the conditions of example 3, but 69.5 mg of solid catalyst and 45.9 mg A1 (C _g H ₅ ) ^ are loaded into the reactor. Polypropylene (PP) yield per 100'min is 1.38 g or 20 g PP / g solid catalyst, or 130 g PP / g Ta;

SMAkalin = D ^l / ^G · The content of the eiotactic (insoluble in boiling n-heptane) fraction is 3539% by weight.

Example 12 (control).

A solid catalyst is obtained in conditions of: Example 1.

Butene-1 polymerization.

The polymerization of butene-ϊ is carried out at a temperature of 40 ° C and a pressure of 2 atom in the presence of 68.2 mg of solid catalyst and 50 mg A 1 (61 ^ 65) ^., The output of polybutene (PB) for 2 h is 1.66 g, or

24.4 g / g solid catalyst or '

157 g / g ΤΪ-’ECHLekalmch = 2.6 dl / g.

Example 13

Preparation of solid catalyst.

A solid catalyst is prepared under the conditions of example 1. The solid catalyst obtained (10 g) in an argon atmosphere is placed in a 30 ml glass ampoule (placed in an ultra thermostat at 150 ° C) and is subjected to evacuation from a forevacuum pump at a residual pressure of 0.1 mm Hg within 3 hours. The resulting solid gray catalyst contains 13.05% T1.12.5 Md, 65%

(CI + Br), its specific surface

30.7 m ^g / g.

Polymerization of ethylene.

Under conditions equivalent to those of example 1, 2.2 mg of the obtained solid catalyst and 64 mg of A1 (C _g H _c ) ^ are charged to the reactor. PE output in 2 hours 9.8 g, or 2225 g PE / g solid catalyst · h, or 17050 g PE / g T1 · h, _s = 22000 g PE / g · h, [%] =

= 2.4 dl / g.

Example 14

A solid catalyst was prepared under the conditions of Example 13.

Polymerization of ethylene.

Under conditions equivalent to those of example 13, 0.9 mg of solid catalyst and 40 mg of A1 (C ₂ H ₅ ) ₃ are charged to the reactor. The output of PE in 2 hours - 7.4 g or 4100 g of PE / g of solid catalyst "h, or 314000 g of PE / g T! · H

⁼ 36800 g PE / g T1 · h. PE contains 0.05 СНа groups per 100 C atoms, 0.10 / bonds per 1000 atoms

"C", [%] = 2/2 dl / g, p = 0.965 g / cm ' _ΠΑ 135 = 135 ° C, * * _P = 315 kgf / cm ² , b = 300 kgf / cm ² , £ p = 570%.

Example 15

A solid catalyst was prepared under the conditions of Example 13.

Polymerization of ethylene.

Under conditions equivalent to those of Example 3, 0.6 mg of the solid catalyst and 20 mg A! (C ₂ H ₅ ) _b are loaded into the reactor. PE yield for 2 hours - 7.7 g or 6420 g PE / g solid catalyst \ h or 49200 g PE / g. h, "

= 62100 g PE / g Τί · h, PE contains 0.05 CH ^ / 100 -C ", 0.10> e = ¢ // 1000

"WITH"; [g] = 22.3 dl / g, P = 0.955 g / cm \ 1 _P d - 137 ° C, b = 385 kgf / cm ¹ , b _t =

= 320 kgf / cm ¹ , Ep - 400%.

PRI me R 16.

Solid catalyst get in

conditions of example 13.

Polymerization of ethylene.

Under conditions equivalent to those of example 15, the reactor is loaded

2.6 mg of the solid catalyst, and instead of triethylaluminum - 50 mg of diiaobutylaluminium hydride A1 (g C _n H _h ) ₂ H. The output of PE in 2 hours is 9.2 g, or 1770 g of PE / g of solid catalyst · h or 13550 g of PE / g T1 · h, 0 _MO , “ _C = 17300 g. PE / g Τΐ-h, PE has [ ^g b} = 23.5 dl / g,

* Ь _В = 400 kgf / cm ² , Ъ _t - 360 kgf / cm ¹ ,

£ p - 410%.

Example 17

Solid catalyst get in

conditions of example 13. ’,

Polymerization of ethylene.

Under conditions equivalent to those of example 4, 2.1 mg of an aqueous catalyst and 33 mg of A1 (C ^ H-) _g are charged to the reactor. PE output (at a total pressure of 21 at and a polymerization temperature of 160 ° C for 1–10.7 g or 5100 g PE / g solid catalyst · h, or 39000 g PE / g · h, ~

- 67300 g of PE / g T ♦ h, PE contains 0.05 - CH _ъ / 100 "C", 0., 35> b = 6 </ 1000 "C", M = 3.5 dl / g, P = 0.962 g / cm

1 _PL = 134 ° C, b - 225 kgf / cm ¹¹ , A =

210 kgf / cm ¹ , £ p = 500%.

Example 18

Solid catalyst get in

conditions of example 13.

Polymerization of ethylene.

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In conditions equivalent to the conditions of example 5, the reactor is loaded

3.4 mg of solid catalyst and

102 mg A1 (C _g H ₅ PE yield per 1 h 12.4 g, or 3650 g PE / g solid catalyst —h 'or 28000 g PE / g T

Τΐ - h, С _{M (D} 4 _С = 34800 g PE / g · h.

PE has [4,} = 1/2 dl / g.

Example 19

A solid catalyst was prepared under the conditions of Example 18.

Polymerization of ethylene.

Under conditions equivalent to those of example 6, 2.4 mg of solid catalyst prepared according to example 13 and 49 mg A1 (Η θ) d. Into the reactor. The output of PE for 1 h - 8.2 g or 4310 g of PE / g of solid catalyst · h, or 26100 g of PE / g · h, With _MSA =

= 36000 'g PE / g TRH. PE has [4,} =

= 2.6 dl / g.

Example20.

A solid catalyst was prepared under the conditions of Example 13.

Polymerization of ethylene.

Under conditions equivalent to those of example 17, the reactor is charged

3.1 mg of solid catalyst, and instead of A 1 <C ₂ H ₅ ) _g - 148 Mg A 1 (g C _n ) H. The output of PE in 1 hour is 12.8 g or 4130 g of PE / g of solid catalyst — h, or 31600 g of PE / g-h, C ^ ax = 41300 g of PE / g "h. PE has [q,} = 4.0 dl / g.

Example 21

A solid catalyst was prepared under the conditions of Example 12.

Polymerization of ethylene.

Under conditions equivalent to those of example 18, the reactor is charged

6.2 mg of solid catalyst, and instead of A1 (C _g H§) d - 215 mg A 1 (iso-C ₄ Nd) H. The output of PE for 1 h - 13.3 g or 2950 g; PE / g solid catalyst · h, or 22600 g PE / g · 4, C _max = ₂₇₂₀₀ g PE / g-h. PE has [ί,] -2.0 dl / g.

Examples 22-28.

A solid catalyst was prepared under the conditions of Example 13.

Ethylene copolymerization.

The copolymerization of ethylene is carried out in a reactor with a capacity of 200 ml under the conditions of example 15, but the content of the solid catalyst, aluminum triethyl, the second monomer and the monomer used varies.

Download catalyst components, · yield and characteristic viscosity · of the copolymers obtained are shown in the table.

Example29.

A solid catalyst was prepared under the conditions of Example 13.

ten

Polymerization of propylene. Polymerization of propylene is carried out.

in the conditions of example 15 'in the reactor with a capacity of 200 ml, and load ·

45.4 mg of solid catalyst and

42.1 mg A1 (C ^ H ₅ ) ^. PE output for

100 min. 11.8 g or 260 g / g of solid catalyst * h or 1900 g / g Τΐ-h Mae ^ zlish ^{= 1} ' ³ dl / g. The content of the isotactic (insoluble in boiling H-heptane) fraction is 38–42 wt.%.

Example 30

Solid catalyst get in

conditions of example 13.

Butene-1 polymerization. The polymerization of butene-1 is carried out in

conditions of example 12, but load

48.1 mg of solid catalyst and 32 mg of A1 (C _g H _5. The yield of PB ea 2 h is 1.57 g or 32.6 g / g of solid catalyst · h

Getting a solid catalyst. The solid catalyst is prepared under the conditions of example 13, but the vacuum-thermal treatment of the solid catalyst is carried out at a temperature of 120 ° C and a vacuum of 0.01 mm Hg for 4 hours. The resulting solid catalyst is gray in color and contains, wt% : Τί 13.2, MD 11.0, (C1 + Br) 62.5, its Itching - 28.7 m ^g / g.

Polymerization of ethylene.

Under conditions equivalent to the conditions of example 15, 0.6 mg of the obtained solid catalyst and 23 mg of A1 ((Ng) d. Are loaded into the reactor. PE yield, 2 hours, 7.1 g or 5910 g / g of solid catalyst — h or 44,800 g / g Τί> h, C _MO c _C = 56700 g PE / g-h. The properties of the obtained PE are similar to those of the polyethylene of Example 15.

Example32.

Getting a solid catalyst. The solid catalyst was prepared under the conditions of Example 13, but the vacuum-heat treatment of the solid catalyst is carried out at a temperature of 180 ^F and C 0.3 mm Hg vacuum within 2 hours. The resulting solid gray catalyst contains, wt%: Τ 12.6,

MD 13.5, (C) + Br) 65.0, Its Itching 34.3 m ^g / g.

Polymerization of ethylene.

Under conditions equivalent to those of example 15, '0.7 mg of the solid catalyst prepared according to this example and 28 mg of A1 (C ^ H ₅ ) ^ are loaded into the reactor. PE yield 2 h 6.9 g or 4939 g PE / g solid catalyst · h or 39200 g PE / g · h. ^With max.s ⁼ 48200 PE / g-h. The properties of the obtained PE are similar to the properties of PE, obtained according to example 15.

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Comparison of catalysts efficiency in ethylene copolymerization processes

Example Suspension of solid catalyst mg The amount of A1 (C _g H ₅ ) ₃ mg Second monomer and his concentration in the initial mixture, mol. % The output of the copolymer for 100 min The content of the second monomer in the copolymer, mol. % gi ^{1b5 <!} 1 -'Zey.alkkl dl / g kg / g solid catalyst kg / g Τ ί 7 (control) eight (cont 10.7 18,8 ^C 3 ^H 6. (8,0) · 1.42 9.2 6.0 5.8 roll) 9 (cont 8.3 '7,7 Mon ₆ (20) 0.60 3.9 7.5 4.5 roll) ten (cont . 10.5 29.3 _S aan ₆ (30) 0.48 3.1 9.1 4.1 roll) 13.9 22.9 C ₃ H ₆ (40) 0.26 1.7 10.0 4.1 22 8.7 17.5 with _{gn 6} (8,0) 1.98 15.2 6.1 8.2 23 9.5 14.7 (20) ' 1.47 11.3 ten 5.7 24 10.3 21.7 (thirty) 1.07 8.02 20.3 3.6 ~ 25 21.3 10.2 FSA _s (40) 0.38 2.9 30.5 2.5 26 2.4 19.6 C ₃ H _b (1.9) 8.26 63.3 1.0 12.0 27 ' 2.1 21.0 from _{4 ne} (4.0) 1.02 7.82 2.0 5.8 28 44.6 35.0 C ₄ But (20) 0.30 2.30 6.2 3.8

Claims (1)

Claim A method for preparing a catalyst for the polymerization and copolymerization of olefins by reacting titanium tetrachloride with an ethereal solution of ethylene magnesium bromide, which, in order to obtain a catalyst with increased activity and selectivity to the copolymerizable olefin, the resulting solid catalyst is further subjected vacuum heat treatment with a residual pressure of 0.01-0.3 mm Hg. Art. and a temperature of 120-180 ° C for 2-4 hours