SU727149A3 - Ethylene (co) polymerization catalyst - Google Patents

Abstract

1517327 Supported Ziegler catalysts MITSUI TOATSU CHEMICALS Inc 20 Nov 1975 [26 Nov 1974] 47869/75 Heading C3P A catalyst for ethylene polymerization comprises (A) a comminuted composition which comprises (i) titanium tetrachloride and/or titanium trichloride; (ii) substantially anhydrous magnesium halide, e.g. MgCl2; (iii) siloxane polymer; (B) an organoaluminium compound. In the examples ethylene is homopolymerized or copolymerized with butene or propylene.

Description

This invention relates to polymer chemistry, in particular to catalysts for the (co) polymerization of ethylene. A catalyst is known for the (co) polymerization of ethylene based on an organoaluminum compound and a compound of titanium in a polymeric carrier 1. However, such a catalyst does not allow a polymer with a high bulk density to be obtained. Closest to the invention is the known catalyst for the (co) polymerization of ethylene, consisting of a titanium compound on a carrier, polyhydrosiloxane, and an organoaluminum compound 2. However, this catalyst has low activity. The purpose of the invention is to increase reactivity. This goal is achieved by the fact that, as a titanium compound on a carrier, the catalyst contains a joint grinding product of 1-35 parts by weight. four-chloride or 1-80 weight.h. three titanium chloride; 15-90 weight.h. anhydrous magnesium halide and 5-50 parts by weight. -alkyl-, di-Cg-C 5 -aryl-C-C-alkyl-Cd-C, 5-aryl polysiloxane with a molar ratio of organo-aluminum compound and titanium compound from 1: 1 to 500: 1. The operation of co-grinding the catalyst components into powder is carried out under vacuum or in an inert gas atmosphere using a conventional fine grinding machine, such as a ball mill, a vibration mill, a column mill, a jet mill, and the like. The co-grinding operation should be carried out essentially in the absence of oxygen, moisture or similar contaminants. Although the co-milling temperature is not critical, it is usually kept in the range of -30 to 150 ° C. The grinding time is 1 to 100 hours. The method or order of mixing the respective components is practically unlimited. Example 1. 2.4 g of titanium tetrachloride, 23.0 g of anhydrous magnesium chloride and 4.5 g of dimethyl polysiloxane with a viscosity of 100 cSt at a temperature of 25 ° C, put into a nitrogen atmosphere in a 600 ml vibrating mill, which contains about 80 steel balls with a diameter of 12 mm, and grind at room temperature for 14 hours. The resulting powder is separated from the steel balls under a nitrogen atmosphere. An activated titanium compound is obtained with a titanium content of 2.02%. Then 1 liter of n-heptane, 31 mg of activated titanium compound and 0.5 m of triisobutylaluminium are placed in a 2 liter stainless steel car in a nitrogen atmosphere. After that, the nitrogen in the autoclave is replaced by hydrogen hydrogen. Hydrogen is supplied until a pressure of 2.5 kg / cm is reached, and then ethylene is supplied to the autoclave until the total pressure reaches 6.0 kg / cm in the minimum meter. The autoclave is heated to a temperature of 90 ° C in order to start the polymerization. During the polymerization 8, the autoclave is continuously injected with ethylene to maintain a pressure of 9.5 kg / cm2 on a pressure gauge. After 2.25 hours from the start of polymerization, the supply of ethylene is stopped and unreacted gas is removed from the system. Then 10 ml of methanol is added to the reaction system, which is stirred for 30 minutes to decompose the catalyst. The rate of absorption of Aegilen 3.0 g / min at a time when the flow of ethylene stopped. The autoclave is then cooled and the content is removed, flooded to remove the solvent and dried at 60 ° C under reduced pressure, resulting in 525 g of polyethylene. The polyethylene obtained has a bulk weight of 0.40 g / ml, viscosity limit 1.72 an / g. The polymerization activity of the catalyst in the polymerization reaction is 7.53 kg / g cat. H (hereinafter the term cat means an activated titanium compound) or 376 kg / g titanium h, and the polymer yield is 16.94 kg / g cat or 827 kg / g titanium. The molecular weight distribution of polyethylene is determined by gel permeation chromatography using a 0.1% by weight solution of polyethylene in 1,2,4-trichlorobenzene. The ratio of the weight average molecular weight to the numeric average Iy and the molecular weight is 6.5 (Mw / Mn). The results of the experiment are as follows: Catalyst a) Activated compound tit Composition,%:, 9 dimethylpolysiloxane15, 1 Ti content,% 2.02 Amount, g 0.031 b) Amount of triisobutylpyuminium, Polymerization time, h 2.25 Polyethylene yield, g525 Ethylene absorption rate at suspension polymerization, g / min 3.0 Activity; kg / g cat-.ch 7.53 kg / g Ti-r376 Polyethylene yield per unit of catalyst or component, kg / g: catalyst 16.94. Ti847 MgCf ,, 22.0 Ultimate viscosity, dL / g1.72 Bulk density, 0.40 M: Mp 6.5 Density, g / ml 0.970 Example 2. Activated titanium compounds are prepared according to the procedure and under the conditions specified in Example 1, using different amounts of titanium tetrachloride and dimethyl polysiloxane. Then, using the obtained titanium compounds, ethylene is polymerized in Example 1. The test results are given in Table 1. Example 3. Activated titanium compounds are prepared according to the procedure described in Example 1 using various types of siloxane polymers with different viscosities. The polysiloxane used in experiment a is a mixture of cyclic dimethylpolysiloxanes with a viscosity of 1.3 cSt at a temperature of 25 ° C and a degree of polymerization of 1-9, and the polysiloxane used in experiment b is a linear polysiloxane with a viscosity of 300 cSt at a temperature of 25 ° C. Then, using the obtained compounds, ethylene is polymerized in Example 1. The results are shown in Table 2. Example 4. 2.5 g of titanium tetrachloride, 24.5 g of anhydrous magnesium chloride and 3.1 g of dimethyl polysiloxane with a viscosity of 100 cSt at a temperature of 25 s are placed in the same vibratory mill as in example 1 under nitrogen atmosphere and subjected to joint grinding at room temperature for 15 hours to obtain an activated titanium compound with a titanium content of 2.10% by weight. Then, 1.3 kg of n-butane, 0.040 g of activated titanium compound and 20 ml of c-heptane solution containing 0.5 ml of tri-e-butyl aluminum, are placed in a stainless autoclave with a capacity of 5 liters under nitrogen. After that, the nitrogen in the autoclave is replaced by ethylene, to which hydrogen is added under pressure until the partial pressure reaches 3 kg / cm, after which ethylene is introduced to a pressure of 12 kg / cm. The reaction system is heated to 85 ° C to start polymerization. Ethylene is continuously fed into the system in such a manner as to maintain a total pressure of 25 kg / cm, and the polymerization is continued for 2 hours. Then Example 1 is repeated to obtain 1090 g of a white polyene powder. The ethylene field obtained in this way has a limiting viscosity of 1.23 dl / g, a volume weight of 0.45 g / ml, and a M: MM ratio of 7.2. Polymerization, the catalyst activity is very high, as can be seen from the same data: Catalyst a) Activated compound, T. Number of activated compound, g0.040 b) Amount of triisobutyl aluminum, ml0.5 Polymerization time, h 2 Polymer yield, g1090 Activity: kg / g cat. h13.62 kg / g Ti-g 685 Polymer yield per unit of catalyst or component, kg / g: catalyst 27.24 Ti1370, 19 Ultimate viscosity; DL / g1,23 Bulk weight, g / ml0,45 Number of CH3 groups per 1000 carbon atoms0.3 M: MP7.0 Density, g / ml0.970 Example 5. Example 1 is repeated using 3.0 g of titanium trichloride, 22.5 g of anhydrous magnesium chloride and 4.5 g of dimethylpolysiloxane with a viscosity of 100 cSt a temperature of 25 s. An activated titanium compound with a titanium content of 2.53% by weight is obtained. Polymerization of polyethylene was carried out as in Example 1, using 40 of the above-mentioned activated titanium compound, the polymerization time was 2.5 hours. 532 g of polyethylene with a bulk weight of 0.39 g / ml and a viscosity of 1.70 was obtained. The polymerization activity of the catalyst used in the polymerization reaction is 6.65 kg / g cat-h and 2.63 kg / g Ti-r, and the yield per unit of catalyst or component 16.6 g / cat and 685 kg / g Ti. Attitude M Mp polymer 7.0. The test results are given below: Catalyst a) Activated titanium compound Composition,%: Tice.10.0, 0 dimethylpolysiloxane15, 0 T1 content,% 2.53 Amount, g0.040 b) Amount of triethobutylaluminum, ml 0.5 Polymerization time, h 2.5 Polyethylene yield, g 532 The rate of ethylene absorption in suspension polymerization, g / min2.5 Activity: kg / g cat. h6.65 kg / g Ti. g263 Polyethylene yield per unit of catalyst or component, kg / g: catalyst 16.6 Ti658, 1 Ultimate viscosity, dl / g.1.70 Volumetric weight ,, g / ml0.39 M: Mp; 7.0 Density g / ml0 , 969 Example 6. Activated titanium compounds are prepared in the same way as described in example 1, but instead of dimethylpolysiloxay, linear methyl phenylpolysiloxane with a viscosity of 450 cP (test 6, Table 3) and linear methyl ethylpolysiloxane with a viscosity of 300 cP (test -7 , Table 3). The polymerization reaction is carried out using an activated titanium compound under the same conditions as before. The results are shown in table 3. As can be seen from Table 3, both methylphenyl polysiloxane and methyl ethyl polysiloxane are capable of increasing the activity of the polymerization process, reducing the spread of the molecular weight distribution in the final polyethylene product, and increasing the bulk weight of the product in the same way as dimethyl polysiloxane. Example 7. Activated titanium compounds with different contents of titanium tetrachloride or trichloride, magnesium chloride and dimethylpolysiloxane (see Table 4) are prepared analogously to example 1. The polymerization uses the catalytic compounds obtained in example 1. The results are shown in t a bl. four .

For comparison, activated titanium compounds are used, but without the use of dimethyl polysiloxane ,. The polymerization reaction is carried out analogously to example 1, the results are presented in table 4.

From Table 4 it can be seen that when dimethylpolysiloxane is reached, the catalytic activity increases, the bulk density of polyethylene improves and the factor M decreases.

M,

product.

Thus, on the basis of a comparison of the examples of the proposed and known methods, it can be concluded that the activity

catalyst according to the invention is 918 times higher than by a known method.

Ti

1L

about

(N

tN

h

about

-h

uHN with

00

with y

r

"

15

Claims (1)

Invention Formula The catalyst for the (co) polymerization of ethylene, consisting of a titanium compound on a carrier and an organoaluminum compound, is required so that, in order to increase the activity, it contains the joint grinding product 1- as a titanium compound on 35 weight.h. tetrachloride or 1-80 weight.h. titanium trichloride; 15-90 weight.h. anhydrous magnesium halide and 5-50 parts by weight. di-C, -C-alkyl, 727149 sixteen di-Cd-C-arylg or C, -C d-alk-C-C-arylpolysilrxane with a molar ratio of organo-aluminum compound and titanium compound from 1: 1 to 500: 1. Sources of information taken into account during the examination 1. Gaylord N. and Mark G. Linear and stereoregular polymers. M ,, Foreign literature, 1962, 1545177, (published 1972