DE1092201B - Process for the polymerization of ethylene - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

kl. 39c 25/01

INTERNAT. KL. C 08 f

PATENT OFFICE

EXPLAINING EDITORIAL 1092 201

LIBRARY

OF GERMAN

FATE OFFICE

I15172IVb / 39c

REGISTRATION DATE: JULY 30, 1958

NOTICE
THE REGISTRATION
AND ISSUE OF THE

ADSLEWRITING: NOVEMBER 3, 1960

It has been proposed to use certain tetracenes as catalysts in the polymerization of ethylene at high pressures of at least 500 atmospheres and elevated temperatures, e.g. B. between 150 and 200 ⁰ C to use. Tetracenes are defined as organic compounds of nitrogen that have the general formula:

R R

N = N-

R '

in which R and R 'can be alkyl, cycloalkyl or aryl groups or R is alkyl and R' is aryl or Can be cycloalkyl and R can be R 'and in which R and R' are also part of one and the same ring structure and can be substituted or unsaturated. A useful characteristic of these tetracenes as Catalysts is that, unlike some peroxide-type polymerization catalysts, they are not oxidizing Generate substances that tend to degrade the polymer.

It has now been found that other organic nitrogen compounds, the chains of nitrogen atoms contain catalysts which form like free radicals in the high-pressure polymerization of ethylene can behave.

The invention relates to a process for ethylene polymerization at a pressure above 500 atmospheres and a temperature of at least 120 ° C, characterized in that the catalyst is a polyazopolyene is used that contains more than 4 nitrogen atoms in the nitrogen chain.

Under the name of polyazopolyene, which contains more than 4 nitrogen atoms in the nitrogen chain, must Compounds are understood to be the linear arrangements of 5 or more nitrogen atoms in the molecule included, so are z. B. the ones who make the groups

-N = N-N-N = N-

!
contain 1,4-pentazdienes, the ones the group

-N = N-N-N-N = N method for the polymerization of ethylene

Applicant:

Imperial Chemical Industries Limited, London

Representative: Dipl.-Ing. A. Bohr, Munich 5,

Dr.-Ing. H. Fincke, Berlin-Lichterfelde, Drakestr. 51,

Dipl.-Ing. H. Bohr and Dipl.-Ing. S. Staeger, Munich 5,

Patent attorneys

Claimed priority: Great Britain July 31, 1957

John Carswell McGowan and Leslie Seed, Northwich, Cheshire (UK),

have been named as inventors

CH ₃ CO COCH ₃

ClC ₆ H ₄ -N = NNNN = N- C ₆ H ₄ Cl 1,6-di- (p-chlorophenyl) -3,4-diacetyl-1,5-hexazdiene,

C ₆ H ₅ -N = NNN = NNN = N-C ₆ H ₅

C ₈ H ₅ C ₆ H ₅

1,3,6,8-tetraphenyl-1,4,7-octaztriene,

contain 1,5-hexazdienes and those that make up the group

-N = N-N-N = N-N-N = N-

contain 1,4,7-octaztrienes. Examples such connections are:

CH,

C ₆ H ₅

N = NNN = NC ₆ H ₅

1, S-diphenyl-3-methyl-1,4-pentazdiene, CH ₃ -C ₆ H ₄ -N = N -NN = NC ₆ H ₄ -CH ₃ 1,5-di (p-tolyl) -1 , 4-pentazdiene,

CH ₃ • C ₆ H ₄ -N = NNN = N- C ₆ H ₄ • CH ₃

C ₄ H ₉
1,5-di- (p-tolyl) -3-butyl-1,4-pentazdiene.

Compared with the tetrazene, the polyazapolyenes to be used according to the invention show their catalytic activity at lower temperatures; the useful range for tetrazenes is approximately between 150 and 250 ⁰ C, the Polyazapolyene whereas according to the present invention, even at a temperature as low as 120 ⁰ C, to give good yields. Reaction pressures above

009 630/441

500 atmospheres are suitable; preferred pressures are between 1000 and 1500 atmospheres. Preferred reaction temperatures are between about 120 and 22O ⁰ C. Higher temperatures may, if very high polymerization rates are desired, be applied.

A suitable admixture ratio of the catalyst is between 50 and 100 parts by weight per Mülion des Ethylene.

The polymerization according to the invention can be carried out in the presence or in the absence of an added inert liquid medium; this can happen in batches or happen continuously. Chain transfer agents, e.g. B. hydrogen, carbon tetrachloride and chloroform, can be added to the reaction mixture, if desired, and also antioxidants and other polymer soluble additives. The invention is illustrated in more detail by the following examples.

example 1

In a stainless steel vessel equipped with a stirrer, benzene was added to 0.5 ecm 0.05 g of 1,6-di- (p-chlorophenyl) -3,4-diacetyl-1,5-hexazdiene

CH ₃ CO

COCH,

= N - N - N - N = N <

that according to the description by J. P. Horwitz and V. A. Grakauskas (J. Amer. Chem. Soc, 79, p. 1249 [1957]) was added. The jar was closed and filled with ethylene except for a pressure brought from 20 atmospheres and then released the pressure to atmospheric pressure. The rinsing process was repeated twice. Ethylene was then poured in up to a pressure of 500 atmospheres, the stirrer turned on and the vessel heated to 140 ° C for 25 minutes. After this time the pressure had risen to 1000 atmospheres. As indicated by the pressure drop, a Reaction is observed, whereupon the pressure is increased by adding more after each pressure drop of 25 atmospheres

ίο Ethylene was restored. After 2 hours it was a total pressure drop of 100 atmospheres has been indicated. The pressure was up on quickly 500 atmospheres reduced and the vessel cooled to temperature by a blower wind. The rest of the pressure was drained and the vessel opened. 8.2 g of a white ethylene polymer were obtained.

The polymer was dissolved in hot xylene and after the solution was filtered it became Polymers from it precipitated by turning it into a large one

Excess of methanol was added. The precipitated polymer was recovered by filtration and dried in vacuo. According to this, the polymer had a melt index of 1.0, a density of 0.934 g / ccm and a tensile strength of 140 kg / cm ² .

Examples 2 to 7

A number of further experiments were carried out in which!, O-Di ^ p-chlorophenyQ-S ^ -diacetyl-l.S-hexazdiene was used as a catalyst. The general procedure was as described in Example 1, but the pressure, reaction time, amount of catalyst and temperature were changed. The results are compiled in the following table:

example Maximum
Ethylene pressure temperature Reaction
duration Kata
lyser yield Melting
indßX density train
strength atü ⁰ C hours G G g / ccm kg / cm * 2 1000 180 0.5 18th > 10 0.932 128 3 1000 180 V ₂ 0.05 7.5 4th 0.930 139 4th 1000 120 9V ₂ 0.05 6.8 1 0.934 158 5 1000 150 1 0.05 7.2 4th 0.934 135 6th 1000 160 1 0.05 7.8 5 0.929 155 7th 1200 140 IV ₂ 0.05 4.6 0.02 0.934 211

Example 8

The experiment described in Example 1 was repeated using instead of 1,6-di- (p-chlorophenyl) -3,4-diacetyl-1,5-hexazdiene 0.05 g of 1,5-diphenyl-3-methyl-1,4-pentazdiene

CH,

V-N = N-N-N = N

was used, which according to H. v. Pechmann and L. Frobenius (Ber., 27, p. 703 [1894]). 5.6 g of the polymer with the melt index 3 were obtained in 45 minutes.

Examples 9-13

A number of other experiments were carried out in which 1,5-diphenyl-3-methyl-1,4-pentazdiene as Catalyst was applied. The test procedure was generally, as described in the earlier tests, but the pressure, reaction time, amount of catalyst and temperature were changed. The results are compiled in the following table:

Maximum temperature Reaction Kata yield Enamel example Ethylene pressure ⁰ C duration lyser G index atü 150 hours G 5.5 of the product 9 1000 130 ¹ U 0.1 6.3 > 10 10 1000 120 IVa 0.05 5.1 0.4 11 1000 120 2V * 0.05 5.8 0.6 12th 1200 120 0.05 5.0 3 13th 1400 IV ₂ 0.05 0.005

Example 14

The experiment described in Example 1 was repeated with 1,6-di- (p-chlorophenyl) -3,4-diacetyl-1,5-hexazdiene instead of 0.05 g approximately 0.2 g of 1,3,6,8-tetraphenyl-1,4,7-octaztriene

V-N = N-N-N = N-N-N = N-

(Bp 40 to 60 ⁰ C.) Was added to accommodate the entire solid material, and the solution was separated and stored at -78 ° C. A reaction similar to that described in Example 1 was carried out with 2 ecm of this solution instead of 0.05 g of 6-di- (p-chlorophenyl) -3,4-diacetyl-1,5-hexazdiene and 0 , 5 ecm benzene. The maximum pressure was 1265 atmospheres and the temperature 160 ° C. After 105 minutes, 4 g of polyethylene were obtained.

which was produced according to A.Wohl and H. Schiff (Ber., 33, p. 3341 [1900]). After 4.5 hours were 1.8 g of the polymer were obtained.

Example 15

The experiment was repeated as described in Example 14 by adding 1,8-di-p-tolyl-3,6-diphenyl-1,4,7-octaztriene, which was prepared according to A. Wohl and H. Schiff (Ber., 33, p. 3341 [1900]), instead of 1,3,6,8-tetraphenyl-1,4,7-octaztriene was used. After 2 hours, 2 g of the polymer were obtained.

Example 16

Isopropyl bicarbamate was prepared from hydrazine hydrate and isopropyl chloroformate by the method described by A. W. Dox (J. Am. Chem. Soc, 48, p. 1954 [1926]) was used for the preparation of butyl bicarbamate, manufactured. This was then reacted with benzene diazonium chloride in 6% strength aqueous sodium carbonate solution according to the regulations published by J. P. Horwitz and V. A. Grakauskas (J. Am. Chem. Soc, 79, p. 1249 [1957]) for the preparation of 1,6-diaryl-3,4-diacyl-1,5-hexazdiene was given. The expected product 1,6-diphenyl-3,4-di (carboisopropoxy) -1,5-hexazdiene from the formula

(CH ₃ J ₂ CHOOC COOCH (CH ₃ ) ₂

= N-N-N-N = N- was not isolated. A sufficient amount of petroleum ether

40

Example 17

An experiment similar to that described in Example 16 was carried out with 2 ecm of the same solution carried out. A pressure of 1000 atmospheres and a temperature of 140 ° C were used. Man allowed the reaction to proceed for 67 hours at the end of which time 2.6 grams of polyethylene was obtained.

Example 18

The experiment, which was described in Example 1, was carried out with 0.25 gl, 5-di- (p-tolyl) -3-butyl-l, 4-pentazdiene as a catalyst instead of l, 6-di- (p- chlorophenyl) -3,4-diacetyl-1,5-hexazdiene repeated. After 1 hour, 6.9 g of the polymer were obtained. The 1,5-di- (p-tolyl) -3-butyH, 4-pentazdiene was obtained by adding a p-methylphenyldiazonium chloride solution, which was prepared from 37.3 g of p-toluidine, to a solution of 11.5 g of n -butylamine prepared ° / ₀ aqueous sodium carbonate solution in 31 ice-cold. 6 A semi-solid mass separated out after 25 minutes. This became solid after some time and recrystallized from petroleum ether (boiling point 40 to 60 ° C.).

Examples 19-23

A number of further experiments were carried out in which 0.05 g of 1,5-di- (p-tolyl) -3-butyl-1,4-pentazdiene were used as a catalyst. The procedure was as described in the previous experiment, but the pressure, reaction time and temperature were changed. The results are in the table below summarized:

example Maximum
Ethylene pressure temperature Reaction
duration 4th Kata
lyser yield Enamel
index density atü ° C hours 4th S. G of the product g / ccm 19th 1000 120 7th I74 0.05 3.4 0.010 0.944 20th 1000 120 1 0.05 5.6 0.014 0.940 21 1000 130 0.05 5.8 0.035 0.940 22nd 1000 140 0.05 4.3 0.24 0.939 23 1200 120 0.05 6.3 0.015 0.931

Examples 24 and 25

Two experiments were carried out in which 1,5-di- (p-tolyl) -l, 4-pentazdiene was used as a catalyst became. The experimental procedure was generally as described in Example 1, but the The reaction time and temperature were changed. The results are summarized in the table below:

example Maximum
Ethylene pressure
atü temperature
⁰ C Reaction
duration
hours Kata
lyser
G yield
G 24
25th 1000
1000 150
180 5 0.05
0.05 2.9
4.6

The 1,5-di- (p-tolyl) -l, 4-pentazdiene was prepared by means of which 7 g of p-toluidine was added to a concentration of 15 ecm of p-Methylphenyldiazoniumchlorid, which from 70 trated ammonia solution (density 0.880) in 500 ecm

6% aqueous sodium carbonate solution prepared. The Pentazdien which had separated out was filtered and stored at -60 ^0C.

Claims (4)

Patent claims: 1. A process for the polymerization of ethylene at a pressure above 500 atmospheres and a temperature of at least 120 ⁰ C, characterized in that a polyazapolyene is used as a catalyst which contains more than 4 nitrogen atoms in the nitrogen chain. 2. The method according to claim 1, characterized in that at pressures between 1000 and 1500 atmospheres and at a temperature between 120 and 220 ⁰ C is worked. 3. The method according to claim 1 or 2, characterized in that a chain-transferring agent is used in the polymerization. 4. The method according to any one of the preceding claims, characterized in that as a catalyst 1,5-Diphenyl-3-methyl-1,4-pentazdiene, 1,5-di- (p-tolyl) -4-butyl-1,4-pentazdiene, 1,5-di- (p-tolyl) 1 , 4-pentazdiene, 1,6-di- (p-chlorophenyl) -3,4-diacetyl-1,5-hexazdiene, 1,6-Diphenyl-3,4-di- (carboisopropoxy) -1,5-hexazdiene, 1,3,6,8-tetraphenyl-l, 4,7-octaztriene, 1,8-di-p-tolyl-3,6-diphenyl-1,4,7-octaztriene is used. ι 009 630/441 10.60