RU665687C - Method of obtaining ethylene (co)polymers - Google Patents

Abstract

METHOD FOR PRODUCING (CO) POLYMERS OF ETHYLENE by polymerizing ethylene or copolymerizing it with ethylenically saturated monomers in a hydrocarbon solvent in the presence of a complex catalyst based on a titanium or vanadium compound, a metal-organic compound and a polymer carrier, characterized in that, in order to simplify the process technology and to obtain a product that does not require washing from catalyst residues, the product of the interaction of a partially cross-linked carbochain is used as an organometallic compound of elastomer containing vi- nilnye and / or M, -o-group with a: lyuminiyor- ganic or organomagnesium compound.

Description

The invention relates to the field of polymer chemistry, and more particularly to the production of ethylene (co) polymers widely used in various industries.

A known method for producing ethylene (co) polymers is the (co) polymerization of ethylene using heterogeneous and homogeneous catalysts, for example, Ziegler-Natta oxide or complex organometallic catalyst systems, as well as supported catalysts.

A disadvantage of the known methods is the presence of catalyst residues in the polymer. This degrades the properties, reduces the service life, and narrows the scope of the polymer. The use of special technological operations to remove catalyst residues complicates and increases the cost of polymer production.

Closest to this is a method for producing ethylene (co) polymers by polymerizing ethylene or copolymerizing it with ethylenically unsaturated monomers in a hydrocarbon solvent in the presence of a complex catalyst based on a titanium-vanadium compound of an organometallic compound and a polymer carrier, which is a gel swelling in the reaction medium.

The disadvantage of this method is the use as a cocatalyst of a low molecular weight metal-organic metal compound of the 1-1P group, which is present in the polymerization system as a solution. This circumstance leads to additional costs associated with the purification of the polymer of Group I-III metal detachments (solvent washing, alcohol treatment, etc.). Another disadvantage is the high corrosive properties of the polymerization solution, therefore, the high quality requirements of the equipment.

The aim of the invention is to simplify the process technology and to obtain a product that does not require washing from catalyst residues.

This goal is achieved in that an organometallic compound is a reaction product of a partially cross-linked carbochain elastomer containing vinyl and / or -O, -o groups with an organoaluminum or organomagnesium compound.

Ethylene is polymerized in a hydrocarbon or chlorohydrocarbon solvent at .0-250 ° C and an ethylene pressure of 0-100 atm. The complex catalyst is used in the form of granules with a diameter of 0.1-5 mm or a film. The polymerization is carried out in suspension mode (0-120 ° C) or in polyethylene solution mode (130-250 ° C),

In the first case, the polyethylene formed inside the catalyst granules is extracted, for example, with hot decane.

In the second, a solution of polyethylene can be withdrawn from the reaction zone continuously. In both cases, the catalyst after the polymer has been removed is again used in polymerization, and its activity remains practically unchanged for a long time. The polymerization rate, molecular weight of polyethylene vary by known methods, for example, by changing the nature of the components of the catalyst, the polymer carrier, the reaction conditions.

For the synthesis of a polymeric organometallic compound, soluble or swellable in a hydrocarbon solvent (co) polymers or (co) oligomers containing reactive groups in the main or side chain are used. Preferably, 1,2-polybutadiene (1,2-PB) and its derivatives are used, grafted copolymers of the ethylene propylene and diene terpolymers (CEPTT) with polar polymers, for example polyacryloitrile, polymethyl methacrylate polyacrylic acid, polyallyl 1 m alcohol, 1, PB.

. To apply the transition metal compound, (co) polymers, preferably rubber-like, are used. containing functional groups capable of chemically bonding a transition metal compound.

a) Preparation of a polymer organometallic compound.

To a hitch 1 weight.h. 1,2-polybutadiene containing 70% (mol) of hydrogenated units, mol. Weight 10000, placed in an ampoule and dissolved in 100 parts by weight absolute heptane in vacuo, an AIH heptane solution (i-C4H9) was added, starting from a molar ratio of A1 (double bond), 1. The mixture is kept in a vacuum installation (P RT, Art.) Diluted with abs.heptane to

completely dissolved and again evacuated.

The last operations are repeated several times until the removal of low molecular weight products,

 The output of aluminum hydrogenated 1, -PB and 1.65 parts by weight

The product contains AI - 8.2 weight. %

b) Preparation of the catalyst.

To a hitch 1 weight.h. a crosslinked grafted copolymer based on SKEPT polyvinylpyridine (10 wt%), placed in an ampoule and swollen in heptane in vacuo, a solution in heptane VCI4 is added based on the molar ratio. The mixture was allowed to stand at 20 ° C for 15 hours, the polymer gel was washed thoroughly with abs. Heptane to remove the VCN not chemically bound in the gel, and transferred under argon atmosphere in a reactor. Then, 100 parts by weight are added thereto. absolute heptane and the compound obtained according to paragraph a. The mixture is maintained at 40 ° C for 10 hours. The resulting polymer compound is washed thoroughly with absolute heptane from low molecular weight products and stored in abs. heptane. The catalyst contains wt.%:

AI-2.9; V-1.7.

c) Polymerization of ethylene.

Polymerization of ethylene using the catalyst obtained in paragraph b was carried out in 200 parts by weight. heptane at

50 ° C. ethylene pressure of 5 atm. 40 hours. The polymerization rate during the experiment remains practically unchanged. At the end of the experiment, the reactor is opened, the polymer inside the catalyst granules is extracted

hot dean. The extract was cooled and the precipitated polymer was dried to constant weight. The productivity of the catalyst is 420 g PE / g. T1 h, intrinsic viscosity of polyethylene (9.1 dl / g, density (d) 0.96 g / cm. The polymer does not contain V and A1.

Example 2

a) Preparation of a polymer organometallic compound.

To a hitch 1 weight.h. the dry product obtained in paragraph 1a, a solution of heptane AI (i-C4H9) Cl2 is poured in vacuo starting from the molar ratio of AI (i-C4H9) Cl2 / HR3 1. The mixture is kept at. 10 hours. The reaction product is purified from low molecular weight aluminum-organic compounds in a vacuum unit as described in Example 1a, and stored in an inert atmosphere. b) Preparation of the catalyst. 1 part by weight a crosslinked 1.2 PB is placed in 200 weight.s. absolute benzene, 0.1 parts by weight are added to the swollen product. (C5H5) 2 TlCli and the mixture was held at. The resulting polymer compound is washed with abs. benzene and mixed with the product obtained according to the procedure of point a, starting from an A1 / T1 molar ratio of 100. The new mixture was kept at 40 ° C for 4 hours. The resulting gel-like catalyst was washed with absolute heptane to remove soluble compounds and placed in a reactor. Polymerization of ethylene. The polymerization was carried out in 150 parts by weight. abs. heptane at 135 ° C, an ethylene pressure of 10 atm for 25 hours. The polymerization rate during the experiment remained constant. The polymer was isolated in this example and the following by analogy with Example 1. The productivity of the catalyst was 60 g. PE / g T h d 0.96r / CM. The polymer does not contain T1 and A1. Example .. a) Preparation of a polymer organometallic compound. To a hitch 1 weight.h. partially cross-linked grafted copolymer SKEPT (80 parts by weight) and 1,2-PB (20 parts by weight), placed in an ampoule and swollen in 100 parts by weight heptane, a solution in heptane A1H (1-C4H9) 2 is poured in vacuo. starting from the molar ratio A1 / double bond of the copolymer 1.1. The mixture was kept at 50 ° C for 5 hours. The resulting compound was washed with absolute heptane to remove A1H (1-C4H9) 2, which did not react aluminum hydrogenation with the copolymer, and stored in heptane in an inert medium. b) Preparation of the catalyst. At a temperature of -78 ° C, a solution of TiCI4 heptane is poured into the ampoule with the product obtained under item a, starting from the AI / Ti 10 molar ratio. The mixture is gradually heated to 20 ° C (over 10 hours) and then kept at 12 hours. The reaction product is a black gel, extracted with absolute heptane, dried and stored under argon. The catalyst contains, wt.%: A1 6, 25.11-1.06. c) Polymerization of ethylene. 1 part by weight the catalyst obtained in paragraph b, is placed in a reactor, 100 ppm are added to it. abs. heptane and an hour later, when the catalyst swells, ethylene is fed into the system. Polymerization conditions: temperature 30 ° C, ethylene pressure 3 atm, time 10 hours. The polymerization rate during the experiment remains practically unchanged; Catalyst productivity 210 g. PE / g Ti h JTx -4.7 d - 0.96 g / cm3 polymer does not contain metals. PRI me R 4. Polymerization of ethylene. The polymerization was carried out on a catalysate prepared according to the procedure of Example 3. Palimerization conditions: temperature 160C, ethylene pressure 10 m, time 70 h. The polymerization rate remained constant during the experiment. Catalyst productivity 200 g PE / G.T1 h, ij. - 3.9. The polymer does not contain metals. -. P rIMv r 5v; a) Preparation of a polymer metallo-organic compound. To a hitch 1 weight.h. grafted cross-linked copolymer based on SKEPT and polyacrylonitrile (10 wt.%), placed in an ampoule and swollen in 100 wt.h. absolute heptane, a solution is added in heptane A10-C4H9) based on a molar ratio of 2. The mixture was kept at 70 ° C for 5 hours. the resulting compound is washed with absolute heptane. The product contains A1 - 3.1 wt.% .. - ./; ..,. b) Preparation of the catalyst. A solution of TiCU heptane is poured onto the product obtained according to a), from the molar ratio A1 / T1 20. The mixture is kept at 5 hours. The catalyst is washed thoroughly with absolute heptane and placed in a reactor. c) Tersopolymerization of ethylene, propi-i-yenyl vinyl norbornene. 200 parts by weight of a heptane absorber were added to a reactor with a catalyst swollen with 200 weight; vinylnorbornene, propylene (1 ati) and ethylene (2 ati). The polymerization was carried out at 3 ati, 5 hours. The catalyst productivity was 250 g PE / g T1 hours. The terpolymer contains 21% (mole) of propylene units. 7% (mol) - vinyl norbornene. Example 6 a) Preparation of a polymer organometallic compound. To a hitch 2 parts by weight a crosslinked copolymer containing 50 wt.% SKEPT. 40 wt.% 1,2PB and 10 wt.%. polyallyl alcohol, swollen in 100 parts by weight absolute heptane, a solution in sulfuric ether СзНуМдВг was added in an argon atmosphere, starting from a molar ratio Мд / ОН 1.2. The mixture is heated at 120 ° C for 10 h, the reaction product is washed thoroughly with ether, then heptane and dried in vacuum. The polymer product contains MD-3.3 weight,%. b) Preparation of the catalyst. The product obtained in paragraph a is placed in 100 parts by weight. abs. heptane, an HCI heptane solution was added thereto, starting from a molar ratio of T1 / Md 1.1. The mixture was kept at 2 h. The resulting compound was washed with abs. Heptane and a solution of absolute heptane A1H (1-C4Hd) 2 was added to it, starting from the molar ratio A1 / double bond of the copolymer 1.5. The new mixture was kept at 20 ° C for 10 hours. The resulting black polymer compound was extracted with abs, heptane to remove low molecular weight compounds and transferred to a metal reactor. The catalyst contains wt.%: MD - 1.5; A1 - 8.0; . Ti-3.2..20 c) Polymerization of ethylene. The polymerization was carried out in 200 parts by weight. absolute gasoline at 200 ° C, ethylene pressure of 50 atm. 70 hours. The rate of polymerization during the experiment remains 25 almost unchanged. The productivity of the catalyst is 350 g / PE / gT1-h. Using the method of (co) polymerization of ethylene provides the following advantages compared to existing methods; the possibility of carrying out the process of (co) polymerizing ethylene in suspension mode (0-120 ° C) or in a mode, a solution of polyethylene (130-250 ° C) in a hydrocarbon solvent, containing dissolved catalyst components; the possibility of producing polyethylene and its copolymers that do not contain residues of metal compounds did not resort to special technological operations for this. However, the stability of the catalyst for a long time and the possibility of its regeneration (by washing from the polymer) make it possible at relatively moderate speeds x polymerization continuous high-performance processes.