DE1442818B1 - Process for the polymerization of ethylene - Google Patents

Description

3 4

of the dried hydrogel with chromium oxide obtained gels of silicon dioxide, aluminum oxide, thorium are, with at least part of the chromium oxide, zirconium oxide, boron oxide, titanium oxide or in contacting the ethylene with the combinations thereof, such as. B. Silica- Catalyst initially in the hexavalent state before aluminum oxide, can after all known lies, which is characterized in that in counter-5 processes are produced.

war is polymerized by catalysts, for which particularly suitable treatment agents are metha-

Manufacture the hydrogel before drying with nol, ethanol, propanol, isopropanol, n-butanol,

a normally liquid, water-miscible secondary butanol, isobutanol, acetaldehyde, acetone, methane

Treatment agents of the general formula ethyl ethyl ketone, ethylene glycol, glycerine, ethylene

lo glycol monoethyl ether, ethylene glycol monomethyl

O ether, diethylene glycol monoethyl ether, diethylene

Il glycol monomethyl ether, ethylene cyanohydrin and ethyl

CH ₃ -CR ₁ or R ₂ -OH leniodohydrin.

Preferably, according to the invention, cata-

(1) (2) 15 analyzers which have been brought into contact with at least one of the oxides silicon dioxide, aluminum oxide, zirconium oxide and thorium, in which R _{1 contains} an oxide.

Hydrogen atom or a methyl or ethyl group According to a preferred embodiment of the

and R _{2 means} (a) an alkyl group with 1 to 4 Koh- Invention is the metal oxide hydrogel after it has lenstoffatomen, (b) a group of the general 20 washed in the usual way or treated in a similar way formula to soluble non-volatile salts and

Remove excess reagent with the

¹ 3 »Treatment means by means of any for treatment

wherein R ₁ has the meaning given above, R ₃ koneine slurries suitable measure alkylene group having 2 to 3 carbon atoms taktiert 25, for example in a undnl means of a stirrer or 2, (c) a group of the moving vessel or a conventional solvent -Formula extractor, where a bed of hydrogel is continuous-

J ^ borrowed with fresh or circulated treatment

¹ medium is processed.

"_ _ _ _ 30 The hydrogel is mixed with the treatment agent

⁴ y ⁴ 'for a sufficient period of time to

to replace at least some of the water, treated, preferably for periods of about 0.1 up to about 100 hours and especially between

wherein R _{1 has} the meaning given above and 35 about 1 and about 10 hours.

R _{4 is} an alkylene group having 1 to 3 carbon atoms. The treatment conditions can be within

or (d) is a group of the general ones of an extremely wide range of temperature and formula X - R ₃ - wherein R ₃ varies the pressures given above, although it is often most convenient, definition and X is a chlorine, bromine -, iodine at room temperature and atmospheric pressure under or represents cyan substituents. 40 stirring to work, with the preferred temperature

It was already known that a metal oxide gel, which is also suitable for catalytic between -18 and about 93 ^° C., depending on the purpose, can be produced by taking the viscosity and the boiling point of the treatment into account that alumina jelly is mixed with organic solvents. Contact time and temperature of the treatment means and then heated. are related to each other in such a way that, if the temperature

In spite of this, it must be regarded as surprising that the time necessary for the treatment is increased so that the polymerization of ethylene is permanently reduced, and vice versa,
the catalyst used according to the invention, the ratio of treating agent to hydrogel

has been manufactured as stated above, cannot be varied within a wide range, however, only one greater polymerization activity and one will generally be in a range of about 2 to increased yield, but also polymers with a 50 about 50 parts by weight treatment agent per weight increased Melt index compared to those parts hydrogel preferred. When using larger result, as they arise under comparable conditions with amounts of treatment agent, no need Catalyst prepared in the usual way, special advantages; a greater benefit will be with the can be obtained. repeated contacting of the hydrogel with fresh

Preferably, the hydrogel is achieved in the production 55 see proportions of the treatment liquid, of the catalyst with an aqueous liquid for wherein the hydrogel between the liquid removal soluble ions, if any, and changes are filtered.

excess reagent before performing this After contacting the treatment

Treatment has been washed. medium the hydrogel is dried in the usual way,

According to one embodiment of the invention, catalysts are used, for example by means of a furnace, heat bodies, and the like during their production in order to thereby remove the treatment agent and any calcined gel that has been treated in this way. This drying is has been impregnated with chromium oxide, that a, so that a practically Trocke-heating in the chromium oxide is usually at a temperature of less than aqueous solution of a chromium compound carried out ⁰ C at 260 transferable, impregnated and 65 nes, granular Material results, which has been subsequently heated by the usual. Transport and conveyor systems easily handled

Which can be used in the manufacture of the according to the invention. The dried hydrogel is then im Put catalysts used Metalloxydhydro- generally supplied to the calcination, so that

5 6

to remove strongly bound water. Preferably example 2
takes place calcining during a period of

0.5 to 25 hours at temperatures between approximately ^and comparative experiment B.

260 ⁰ C and about 82o C instead of ^0; The production of a 0.75 percent by weight chromium temperature of the calcining operation, preferably containing 5 silicon dioxide catalyst, the silicon dioxide catalyst of which does not exceed the temperature that is required for the final calcium dioxide base with methanol in the moist hydrogel

Catalyst activation is applied. condition had been treated was under practical

identical conditions as in example 1

Example 1 are repeated. This catalyst and

, ,,,. . ,. ίο its untreated comparison sample were also

and Comparative _Experiment A for ethylene polymerization as in Example 1

120.1 g of water glass (technical grade sodium silicate) were used, with the exception of a few slightly underwurden with 600 ml of deionized water under different reaction conditions, the temperature in the table was mixed. With the addition of 35 ml H ₂ SO ₄ - are listed where the results obtained are given in an ani-solution (20 ml concentrated H ₂ SO ₄ + 75 ml H ₂ O) 15,
with stirring, the solution gelled in about 1 minute. Example 3
The hydrogel was allowed to age overnight,

whereupon it was filtered and _{mixed with about 41 NH 4} NO ₃ solution. Acetone was used as a treatment agent for SiIi-

(25 g / IH ₂ O), subdivided into a few parts, used with calcium dioxide solution. 122.9 g of water glass were

contact times of about 15 minutes each, washed 20 with 600 ml of H ₂ O and diluted with 35 ml of the previously

became. The gelled material was then again _{acidified with the specified H 2} SO ₄ solution while stirring,

washed with about 11 water. The mixture gelled and gelled in about 30 seconds

Now the wet silica hydrogel was left to age overnight. It then became

2 parts divided and 1 part under a radiator without filtered and with 41 of the previously indicated

further treatment dried. 25 NH ₄ NO ₃ solution, which is divided into

The second portion of the wet hydrogel was then divided, with a contact time of approximately 10 minutes

subjected to the following treatment: The hydrogel was used for each wash. The hydrogel was

was washed with about 500 ml then with 11% of water with constant stirring. Still in the damp

Methanol was slurried for 1 hour and then in hydrogel state, the solid material became 600 ml

filtered. This treatment was two more times taking 30% acetone for 1 hour at room temperature

repeated. Finally the hydrogel was treated with stirring. It was then filtered and the

Soak in another amount of fresh metha treatment repeated four more times. After

nols left for 2 days, then filtered and final filtration, the silicon dioxide

dried on a heat body. Both the dried under a radiator and then with hydrogel

Methanol treated as well as the untreated 35 calcined in air at 538 ° C. for 5 hours.

Portions of the drying gel were then prepared using 14.49 g of this dried

5 hours of calcination at 538 ⁰ C subjected to gels, 0.21 g of CrO ₃ and 58 ml of H ₂ O was a catalyst

to remove the more firmly bound water. Sator with a content of 0.75 percent by weight Cr

An amount of 12.81 g of the untreated calci- after air activation for 5 hours at 871 ° C

Nated silica gel was obtained with 0.19 g of CrO ₃ 40. The chromium oxide containing catalyst was

and 27 ml of H ₂ O stirred for about 10 minutes, to an ethylene polymerization similar to that in the case of

dried in a dish on a hot plate and used game 1 and the results of the experiment

activated in air for 5 hours at 871 ° C. are given in the table.

In the same way, 11.69 g of the methanol was obtained

treated and calcined silica gels with 45

0.17 g of CrO ₃ slurried in 38 ml of H ₂ O and then to B ice ρ ie 1 4

activated in air for 5 hours at 871 ° C. On these _and v _erg i _{calibration experiment C}
Wise prepared catalysts contained about

0.75 weight percent Cr calculated as metal. In this example, the treatment agent

The catalyst prepared in the above manner is used for silicon dioxide isopropanol. The GeI-

Sators were used for ethylene polymerization to the following manufacture and the treatment was essentially

Way used: The catalysts were in a with borrowed in the same way as in Example 3 through

Stirrer-equipped reaction vessel made of stainless steel, with the exception that 500 ml portions

Steel of about 11 capacity introduced, the previously used isopropanol in the treatment stage

was heated continuously and flushed with nitrogen.

was flushed. 0.34 kg of cyclohexane as a diluent. The treated gel and an untreated control agent were also added and the reaction sample was closed with 0.75 percent by weight of chromium. Then ethylene was used in that in Example 1. The results are taken from the reaction vessel to see a constant table.
To obtain a reaction pressure of 31.5 atmospheres, and the 60th

Reaction was carried out for 1 hour at about 132 ° C. Example 5
carried out. At the end of this period, the ^ ₇ . ,
The reaction vessel is drained and the polymer and comparative experiment D
dries. In this example, the results using the methanol treated according to the invention (Example 1) and the untreated treatment using a silicon dioxide impregnated and a polymerization approach such as hydrogel described, which is made by acidifying the delten (comparative experiment A) catalyst are in the water glass with Nitric acid listed in place of sulfur table. acid was formed. A quantity of 121.2 g of water

Glas was diluted with 600 ml of H ₂ O and acidified with 75 ml of HNO ₃ solution (21 ml of concentrated HNO ₃ + 75 ml of H ₂ O), gelation occurring in about 1 minute. The gel was aged overnight, filtered and washed with a total of 41% of an NH ₄ NO ₃ solution in individual portions, each with a contact time of 15 minutes. It was then washed again with 11 H ₂ O and, after finally filtering water, it was divided into 2 parts. 1 part was dried under a radiator and stored as an untreated control sample. The other part was treated twice with 500 ml portions of methanol with stirring at room temperature for 1 hour and filtration. The hydrogel was then left to soak in methanol for 2 days. It was then subjected to an additional treatment for 1 hour with stirring at room temperature with a fresh portion of methanol, filtered and dried on a heat sink. Both the methanol treated and the untreated dried silica gels were then dried at 538 ° C. for 5 hours.

The two calcined gels were then impregnated with 0.75% Cr, air activated and combined into one Ethylene polymerization approach similar to that described in Example 1 was used. The results are listed in the table.

Examples 6 and 7

as well as comparative experiment E

A silica gel was used which had been produced from silica instead of water glass (sodium silicate). 122.5 g of water glass, diluted with 650 ml of deionized water, were converted into silica in the acidic state by passage through a cation exchange resin. The volume was increased to 800 ml by the washing liquids from the column. Gelation was initiated by alternate additions of concentrated NH ₄ OH and HCl and a small amount of non-ion exchanged water glass (2.5 g).

ίο The hydrogel was aged overnight, filtered, _{washed with 11 NH 4} NO ₃ solution and then washed with water until the washing liquids examined were negative for chlorine. The wet hydrogel was divided into three parts. One portion was dried under a radiator and stored as an untreated control sample (Comparative Experiment E). A second portion was treated twice with methanol and with stirring for a contact time of 30 minutes and then filtered. The hydrogel was soaked in methanol for 2 days and then filtered and dried on a heat sink (Example 6). The third portion of the moist hydrogel was contacted with boiling methanol in a Soxhlet extraction apparatus for a total of about 6 hours with repeated changes of the methanol and then dried under the heating element (Example 7). All three parts of the gel were then ^{calcined at 538 °} C. for 5 hours.

Each of the three silica gel samples were impregnated with 0.75% chromium, activated in air, and used in an ethylene polymerization similar to Example 1. The results of the polymerization are listed in the table.

Polymerization of ethylene

Chromium oxide catalyst on silicon

Dioxide gel carrier with a content of

0.75 parts by weight chromium catalyst,

activated 5 hours at 871 ° C

Used catalyst

(G)

Silica treatment

surface

Pore diameter reaction vessel made of stainless steel

with 11 contents and 0.34 kg of cyclohexane

as a diluent, trial of

1 hour at 31.5 atm

Reaction temperature
area
⁰ C

Yield to
Polymer

g / g catalyst

Enamel

index of

Polymers ⁴ )

Comparative experiment A ...
example 1

Comparative experiment B ...

Example 2 Example 3

Comparative experiment C ...
Example 4

Comparative experiment D ...
Example 5

Comparative experiment E ...

Example 6 Example 7

0.0816 0.0442

0.1005

0.024

0.0306

0.0626 0.0250

0.0878 0.0312

0.0810 0.0270 0.0300

without methanol

without

Methanol

acetone

without isopropanol

without ² ) methanol ² )

without ³ ) methanol ⁸ ) methanol (hot) ³ )

522 702

391 794 658

589 661

507 632

609 792 578

132 to 134
132 to 154

131 to 133

132 to 136

130 to 135

131 to 133
128 to 133

131 to 133

132 to 140

131 to 133
130 to 133

132 to 135

990

4675

1248 ¹ )

5140

3495

1356
4160

785
4210

580
2720
4015

1.52

1.04
1.74
1.72

0.83
0.82

1.24
2.66

0.85

1.74
1.48

^x ) The yield of 624 g / g obtained from this run, which ran for only 30 minutes, was estimated to be doubled for more appropriate comparison with the other 1 hour runs.

² ) Silica made from _{water glass acidified with HNO 3} (the other experiments used H ₂ SO ₄ ).

³ ) Silica made from silica.

⁴ ) Low Load Melting Index according to ASTM Method D-1238-57 T (Condition E).

209 527/528

9 10

It can be seen from the examples that, in comparison, in most cases a higher melt index

for the usual production not only has the activity of the than that in the presence of the usual catalyst

Catalysts will be improved if they are made under Versators Polyethylene. As from the table

The use of the above-mentioned treatment agents shows the surface properties of the

be put, but that also changed in the presence of 5 metal oxide, which is due to the increase in

Polyethylene produced by such a catalyst gives surface area and pore diameter.

Claims (4)

1 2 desired area per weight unit. Often patent claims: Are such catalysts produced by the catalytic agent or the promoter on a 1. Process for the polymerization of ethylene carrier with gel structure is applied. There were at temperatures of 37 to 235 ° C in the presence of 5 both different oxides, for example those of catalysts, which by drying one of beryllium, magnesium, zinc, aluminum, SiIi hydrogel, the silicon dioxide, aluminum oxide, cium, zirconium, tin, Thorium, vanadium, chromium, thorium oxide, zirconium oxide, boron oxide, titanium-molybdenum, tungsten, uranium, manganese, iron, cobalt oxide or mixtures thereof, with increased and nickel, as well as numerous combinations of temperature and impregnation of the dried io of such oxides with each other and with other hydrogels obtained with chromium oxide, oxides in a microporous gel state for at least a portion of the chromium being produced when used in catalysis.
Bringing the ethylene into contact with the catalyst is initially present in the hexavalent state, type catalysts is that the water is characterized in that the oxide contained in the 15 is polymerized in a practically amorphous state in the presence of catalysts, or in the sol state and then in the manufacture of which the hydrogel is solidified prior to dry setting into a hydrogel by any one of a normally liquid water-wide variety of known methods applicable to the miscible treating agents of the general specific mass. Formula ²⁰ Under the term "hydrogel" is the gelatinous O to understand solid, which by precipitation of a π metal hydroxide or a water-containing metal £ jj Q £ _{0 (} j _er £ Qjj oxyds is produced, which is water in the gelatinous ^{31 2} solid. (1) (2) 25 In a common method of making Metal oxide gels used for catalytic applications has been brought into contact, wherein R _{1 is} determined, the metal, generally in the hydrogen atom or a methyl or ethyl form of a hydrolyzable salt, acid, group means and R ₂ (a) an alkyl group with alcoholates , an organic ester, and the like, having 1 to 4 carbon atoms, (b) hydrolyzing a group of the 30 suitable conditions to give a general formula of wet hydrogel. At this stage it becomes wet J ^ / Q £ λ hydrogel generally with water or the like. ³ 'wash, especially if non-volatile ions are used wherein R _{1 has} the meaning given above, hydrolysis was used. For example, if R _{3 is} an alkylene group with 2 to 3 carbon sodium silicate (water glass) in water with an acid, atoms and η means 1 or 2, (c) a group such as sulfuric acid that has been hydrolyzed, one of the general formula water washing is required to! omitted sodium and to remove sulfate ions. A wash with ^ ¹ dilute solutions of volatile salts, such as B. 40 ammonium nitrate, or ammonium chloride, is also HO - R ₄ - C - R ₄ - if effective, is such a base exchange step the non-volatile sodium and sulfate ions OH replaces the more volatile ammonium and nitrate ions. In the subsequent calcination of the washed wherein R _{1 has} the meaning given above 45 or base-exchanged hydrous gels and R _{4 is} an alkylene group with 1 to 3 carbon excess of water and other volatile matter atoms, or (d) a group of the general is removed and it remains a practically pure, mean formula X - R ₃ -, where R _{3 is} the above dry oxide gel of the desired metal,
given definition and X has a chlorine, In the dry, pure state these gels are found Represents bromine, iodine or cyan substituents. 50 often used as catalysts or carriers 2. The method according to claim 1, characterized in that for catalyst systems, for example in the case of hydration, that the hydrogel with the treatment, dehydration, isomerization, polymerization, medium at a temperature between -18 and cracking, hydro refining and hydrocracking of 93 ° C for a period of 0.1 to 100 hours hydrocarbons. that has been brought into contact. 55 So it is From U.S. Patent 2,825,721 3. The method according to claim 1 or 2, characterized in that ethylene at elevated temperature in Gegengemarked that the hydrogel with 2 to wart of catalysts to be polymerized by 50 parts by weight of treatment agent per weight impregnation of a dried hydrogel of z. B. partially hydrogel has been treated. SiO ₂ and / or Al ₂ O ₃ have been obtained with chromium oxide 4. The method of claim 1, 2 or 3, characterized in 60, wherein at least a portion of the chromium initially characterized in that metha- is present as the treatment agent in the hexavalent state. nol, isopropyl alcohol or acetone used. The invention now relates to a method has been. for the polymerization of ethylene at temperatures from 37 to 235 ° C in the presence of catalysts, 65 Which by drying a hydrogel, the silicon dioxide, aluminum oxide, thorium oxide, zirconium-For many catalytic conversions are catalysis oxide, boron oxide, titanium oxide or their mixtures Sators with an extremely large available upper contains, at elevated temperature and impregnation