DE1442818C - Process for the polymerization of ethylene - Google Patents

Description

3 4

of the dried hydrogel with chromium oxide obtained gel of silicon dioxide, aluminum oxide ,. Became 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

^ ίο glycol monoethyl ether, ethylene glycol monomethyl

0 ether, diethylene glycol monoethyl ether, diethylene

1 glycol monomethyl ether, ethylene cyanohydrin and

CH - C - R or R. - OH leniodohydrin.

^{31 2} According to the invention, KaUi-

(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, 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

η ι Q t) \ to remove excess reagent with the

\ ~ ": ³ treatment agents by means of any one for treatment

'- where R _{1 has} the meaning given above, R ₃ of slurries suitable measure kone an alkylene group with 2 to 3 carbon atoms is 25 clocked, for example in a means of a stirrer and η 1 or 2 means, (c) a group of the general agitated vessel or a conventional solvent-formula extractor, with a bed of the hydrogel continuously

D borrowed with fresh or circulated treatment

^1st medium is processed.

3 ° The hydrogel becomes with the treatment agent

⁴ ~ ⁴ '. for a sufficient period of time to

■■ to replace at least part of the water, treated,

_f OH preferably during 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 temperatures 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. ■ 4 ° stirring to work, being the preferred temperature

It was already known a also for catalytic between -18 and about 93 ° C depending on Purposes of preparing suitable metal oxide gel by taking the viscosity and the boiling point of the treatment that you lay clay jellies with organic solvents. Duration and temperature of the treatment contacted means and then heated. are related to each other in such a way that, if the temperature

I /, Nevertheless it must be regarded as surprising 45 that the time necessary for the treatment is increased, that in the polymerization of ethylene is permanently reduced, and vice versa, the catalyst used according to the invention, the ratio of treatment 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, heating bodies are made 60, for example by means of a furnace Catalysts are used, in the manufacture of which the u calcined gel treated in this way thereby removing residual water. This drying will with chromium oxide that has been impregnated with one usually at a temperature less than

j aqueous solution of a chromium compound, which when. 260 ^ C, so that a practically dry

j heating can be converted into chromium oxide, soaked and 65 nes, granular material results, which by usual

has subsequently been heated. .. Transport and conveyor systems easily handled

. Which can be used in the production of the erfindungsgeinäß. The dried hydraulic is then im Catalysts used Met.illoxydliydro- general the calcination part of it, so that

5 6

to remove strongly bound water. Preferably B e i s ρ i e 1 2

takes place calcining during a period of.

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

260 ° C and about 820 ° C; The production of a 0.75 percent by weight of chromium exceeds this

Temperature of the calcining operation preferably 5 containing silicon dioxide catalyst, the SiIi-

not the temperature that is required for the final ciumdioxide 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 written repeatedly. This catalyst and

,,,,.,. α ¹⁰ its untreated comparison sample were also

and Comparative Experiment A _{Fahs zm} ethylene polymerization as in Example 1

120.1 g of water glass (technical grade sodium silicate) used, with the exception of a few slightly underwurden with 600 ml of deionized water under different reaction conditions, the temperature in the table is 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 Hydrqgel was left 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 / l H 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

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

washed with about 1 liter of water. The mixture gelled and gelled in about 30 seconds

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

2 parts divided and 1 part under a radiator without filtered and with 4 1 of the previously specified ■ < *

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

Subjected to calcination for 5 hours at 538 ° C to form gels, 0.21 g of CrO ₃ and 58 ml of H ₂ O, 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 4 °. 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 eis ρ ie 1 4

activated in air for 5 hours at 871 ° C. The on this _and comparative 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
accomplished. At the end of that period it became .... . ,. _.
The reaction vessel is drained and the polymer ^and comparative experiment D
dries. The results using the in this example, the methanol-treated (Example 1) and the untreated treatment using a silicon dioxide impregnation and a polymerization batch such as hydrogel described, which by acidifying the delten (comparative experiment A) catalyst are in the water glass with Nitric acid in place of the 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 silicon dioxide gels were then dried at 538 ^° C. for 5 hours.

The two calcined gels were then impregnated with 9.> 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 and Comparative Experiment E

It became a _; Silica gel used, which had been made 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 wet hydrogel

- Was with boiling methanol in a Soxhlet extractor for a total of about 6 hours, changing the Contacted methanol and then dried under the heater (Example 7). All three Portions 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 of 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
° C

Yield to
Polymer

g / g catalyst

Melt index of the polymer ¹ )

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 ³ ) 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

The yield of 624 g / g obtained from this run, which only ran for 30 minutes, was estimated to be the more appropriate Doubled compared to the other approaches of 1 hour duration.

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

^s ) silicon dioxide, made from silicic acid. -

⁴ ) Low Stress Melt Index by ASTM Method D-1238-57 T (Condition E).

209 684/146

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: Such catalysts are produced by. the catalytic agent or the promoter at one 1. Process for the polymerization of ethylene carrier with gel structure is applied. There were at temperatures from 37 to 235 ° C in the presence of 5 both different oxides, for example those of catalysts made by drying one of beryllium, magnesium, zinc, aluminum, silicon Hydrogel, 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 its mixtures contains, in the case of increased and nickel, -as-also-numerous combinations Temperature and impregnation of the dried io of such oxides with one another and with others Hydrogels with chromium oxide have been obtained for oxides in a microporous gel state wherein at least a portion of the chromium is produced when used in catalysis. Bringing the ethylene into contact with the catalyst. Sator is initially present in the hexavalent state, like catalysts consists in the fact that the water- characterized in that the oxide contained in Ge * 5 is in a practically amorphous state is polymerized in the presence of catalysts, or produced in the sol state and then its in their manufacture, the hydrogel prior to dry solidification into a hydrogel by any one with a normally liquid, water-wide variety of known processes based on the miscible treatment agents of general special mass are applicable, is solidified. Formula ²⁰ Under the term "hydrogel" is the gelatinous O To understand solid, which by precipitation of a Ν metal hydroxide or a water-containing metal pu _n η j ο _nu oxyds is produced, which water in the gelatinous i ^ n ₃ - L ^ - K ₁ or K ₂ - uri - m. . Has solid. (1) (2) 25 In a common method of making Metal oxide gels used for catalytic applications has been brought into contact, where R _{1 is} determined, the metal, generally in the hydrogen atom or a methyl or ethyl form of a hydrolyzable salt, an acid, a group 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 η ι Q η \ hydrogel generally with water or the like. ¹ , 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 recover the bereaved and to remove sulfate ions. A wash with 1 ^l dilute solutions of volatile salts, such as B. I 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 What remains is a practically pure formula X - R ₃ -, where R _{3 has} the definition given above, dry oxide gel of the desired metal, and X is a chlorine, these gels are found in the dry, pure state 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 Gegengekenn that the hydrogel with 2 to wart of catalysts to polymerize, which 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 are obtained by drying a hydrogel, silicon dioxide, Aluminum oxide, thorium oxide, zirconium-For many catalytic conversions, there are catalysis oxide, borium oxide, titanium oxide or their mixtures Sators with an extremely large available upper contains, at elevated temperature and impregnation