Note: Descriptions are shown in the official language in which they were submitted.
This invention relates to a vapor phase polymerization of ethylene
using a Ziegler-type catalyst of high activity. More particularly, it is con-
cerned with a catalytic process for preparing polyolefins~
It has heretofore been known that a catalyst system obtained by first
supporting a transition metal on a magnesium-containing solid carrier, e.g.
MgO, Mg(OH)2, MgC12, MgC03, or Mg(OH)Cl and then combining it with an organo~
metallic compound can serve as a catalyst of remarkably high activity for the
polymerization of olefins. It is also known that an organometallic compound
and the reaction product of an organomagnesium compound, e.g, RMgX, R2Mg,
RMg(OR) and a transition metal compo~nd can be an excellent high polymeriza-
tion catalyst for olefins (see for example Japanese Patent Publication No.
12105/64, Belgian Patent No. 742,112, and Japanese Patent Publications Nos.
13050~68 and 9548/70).
Olefin polymerization using such high-activity Ziegler-type catalysts
is in many cases carried out in the liquid phase in the presence of an inert
hydrocarbon, e.g. butane, pentane, hexane and heptane, as solvent. The steps
of separation, recovery, purification and re-use of the solvent used are so
troublesome that~ in order to simplify the process to a large extent, vapor
phase polymerization has been tried in which the olefin is polymerized in a
condition substantially free from the liquid phase, namely in the vapor phase.
More particularly, a catalyst is fed into a bed consisting of polymer par-
ticles which have been introduced in advance or of granular polymer particles
which have been produced as the polymerization proceeded, and it contacts the
starting gaseaus olefin to produce a polymer.
Such vapor phase polymerization is advantageous in that the use of a
high-activity catalyst can eliminate the recovery step for the polymeri~ation
solvent and can omit the catalyst separation and inactivation step, so that
the process as a whole can be simplified to a large extent. ~ecause of the
following technical problems, however, it is still difficult to practise such
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vapor phase polymeri ation industrially advantageously.
Although there is the possibility of such vapor phase polymeriza-
tion becoming a very simplified process as mentioned abo~e, in order to adapt
it to an industrially advantageous manner many technical problems must be
solved. ~or example, the following are important technical problems to be
solved: the catalyst to be used should be sufficiently high in activity to
the extent that the resldual catalyst removing step is not required; there
should be no significant adhesion of the resulting polymer particles to the
reactor walls, stirrer, etc,; there should occur no abnormal phenomenon which
would cause blocking of the polymér discharge port ~rom the reactor, transport
line, etc. effected by the production of coarse or aggregate polymer par-
ticles; the production of ultra-fine particles which scatter easily during
polymerization should be minimized; the particle properties, e.g. bulk density,
should be satisfactory.
The present invention~ now provides a vapor phase polymerization
process for ethylene which as a whole is very simplified because a vapor phase
polymerization reaction can be carried out under extremely stable conditions
and because the catalyst-removing step can be omitted. In more particular
terms, this invention provides a process for preparing polyolefins, whîch
process comprises: cantacting a catalyst consisting essentially of a solid
substance and an organometallic compound, the solid substance containing mag-
nesium and at least one titanium and vanadium, with an c~ -olefin in the
absence or presence of a liquid hydrocarbon; and thereafter contacting
ethylene or a mixture of ethylene and an oC -olefin in the gaseous phase with
the so-treated catalyst, whereby the homopolymerization of ethylene or the
copolymerization of ethylene and c~ -olefin is effected. According to the
process of a broad aspect of this invention, that is, by contacting a catalyst
consisting of a solid substance and an organometallic compound, such solid sub-
stance containing magnesium and at least one of titanium snd vanadium, with
:`
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o~ -olefin in the absence or presence of a liquid hydrocarbon and thereafter
carrying out a vapor phase polymerization of ethylene, it has become clear
that, as compared with the case where the catalyst is no~ contacted with an
G~ -olein, the catalyst becomes extremely high in activity, the production
of coarse and ultra-fine particles is decreased, the particle properties are
satisfactory, the adhesion of polymer particles to the reactor and the aggre-
gation thereo are minimized, and a vapor polymerization can be carried out
under extremely stable conditions. It is quite unexpected and surprising that
according to the process of aspects of this invention it has become possible
to carry out a vapor phase polymerization extremely smoothly even with respect
to ~hose systems whose stable operation has heretofore been difficult.
It has firstly been found that if a catalyst is contacted with a
gaseous c~ -olefin and then a vapor phase polymerization is carried out using
the so-treated catalyst, improvements are attained in activity and in the
properties of the resulting polymer particles. Secondly it has been found
that further advantages accur, i.e. if a catalyst is contacted with an c< -ole-
fin in the presence of a liquid hydrocarbon and then a vapor phase polymeri-
zation is carried out using the so-treated catalyst, in addition to the above-
mentioned advantages, it becomes possible to introduce the catalyst treated
with the c~ -olefin in the state of slurry into the reaction vessel so the
operation is made easier, and the latent heat of vaporization caused by the
introduction of a liquid hydrocarbon into the reaction vessel facilitates the
removal of the reaction heat.
By one variant of this invention, the catalyst is contacted with a
gaseous c~ -olefin; and then the homopolymerization of ethylene or the copoly-
merization of ethylene and ~ -olefin is effected. -~
By another variant, the catalyst is contacted with an C~ -olefin in
thed presence of a liquid hydrocarbon; and then the homopolymerization of
ethylene or the copolymerization of ethylene and ~>~ -olefin is effected.
. ~ . , . , ; . : ,~ ,,
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39~
By stlll another variant, the catalyst is contacted with l g. to
50,000 g., per gram of the solid sybstance, of an ot -olefin at a pressure in
the range of from -1 to 100 kg.cm2 G; and then the homopolymerization of
ethylene or the copolymerization of ethylene and ~ -olefin is effected.
By a further variant, the liquid hydrocarbon is selected from the
group consisting of C3 to C12 n~paraffins, iso-paraffins, aromatic hydrocar-
bons and ~ -olefins.
~ y yet another variant, the liquid hydrocarbon is used in an amount
of 1 g. to lO0 g. per gram of the solid substance.
By a further variant, the homopolymerization of ethylene or the co-
polymeri~ation of ethylene and c~ -olefin is carried out in the presence of
hydrogen at a temperature in the range of from 20 to 110C and at a pressure
in the range of from atmospheri_ to 70 kg/cm G.
The catalyst used in aspects of this invention is the combination
of a solid substance and an organometallic compound, the solid substance con-
taining magnesium and at least one titanium and vanadium. The solid substance
is obtained by supporting at least one of a titanium compound and a vanadium
compound on an inorganic solid carrier in known manner. Examples of such in-
organic solid carrier are magnesium metal, magnesium hydroKide, magnesium
carbonate, magnesium oxide and magnesium chloride; double salts, double oxides,
carbonates, chlorides and hydroxides containing magnesium atom and a metal
selected from the group consisting of magnesium, silicon, aluminum and cal-
cium. Furthermore, it may be these inorganic solid carriers after treatment
or reaction with an oxygen-containing compound, a sulfur-contalning compound,
a hydrocarbon or a halogen-containing substance.
As the titanium compound and the vanadium compound referred to here-
in, mention may be made of halides, alkoxy halides, oxides and halide oxides
of titanium and vanadium. Examples are tetravalent titanium compounds, e.g.
titanium tetrachloride, titanium tetrabromide, titanium tetraiodide,
. .. .. . .
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. . ,; , ~ ; . : . .
monoethoxytrichlorotitanium, diethoxydichlorotitanium, triethoxymonochloro-
titanium, tetraethoxytitani~9 monoisopropoxytrichlorotitanium, diisopropoxy-
cidhlorotitaniu~, and tetraisopropoxytitanium; various ti'tanium trihalides
obtained by reducing titanium ~etrahalides with hydrogen, aluminum, titanium
or an organometallic compound; trivalent titanium compounds, e.g. compounds
obtained by reducing tetravalent alkoxytitanium halides with an organometallic
compound; tetravalent vanadium compounds, e.g. vanadium tetrachloride; penta-
valent vanadium compounds, e.g. vanadium oxytrichloride and orthoalkyl vana-
date; and trivalent vanadium compounds, e.g. vanadium trichloride and vanadium
triethoxide.
In ~spects of this invention the catalyst used is the combination of
a solid substance, which is obtained by supporting at least one of a titanium
compound and a vanadium compound on a solid carrier which has previously been
exemplified, and an organometallic compound.
Examples of preferred catalyst systems are the combination
of an organometallic compound with solid substances of the following
systems (in which R represents an organic radical): MgO-RX-TiC14
Csee Japanese Patent Publication No.3514/76), Mg-SiCl4-ROH-TiC14
(see Japanese Patent Publication No.23864/75), MgC12-Al~OR)3-TiC14
~see Japanese Patent Publications Nos.152/76 and 15111/77),
MgClz-SiC14-ROH-TiC14 ~see Japanese Patent Public Disclosure No.
106581/74), Mg(OOCR)z-Al(OR)3-TiC14 (see Japanese Patent Publication
No.11710/77), Mg-POC13-TiC14 (see Japanese Patent Publication
No.153/76), MgClz-AlOCl-TiC14 {see Japanese Patent Public Disclosure
No.133386/76).
l8~3~
Another example of a catalyst system which may be suitably used in
aspects of this lnvention is the conbination of, as the solid substance, the
reaction product of an organomagnesium compound, e.g. a G~ignard compound and
a transition metal compound, and an organometallic compound. As an organomag-
nesium compound there may be used, for example, those represented by the gener-
al fo~mulae RMgX, R2Mg, and RMg(OR) wherein R is an organic radical and X is
halogen, ether complex thereof, and further these organomagnesium compounds
after modiflcation by adding other organometallic compounds, e.g. organosod-
ium, organolithium, organopotassium, organoboron, organocalcium and organozinc.
Examples of these catalyst systems are the combination
of solid substances of for example the following systems, RMgX-TiC14
(see Japanese Patent Publication No.39470/75), RMgX- Cl ~ 0~ -TiCl4
(see Japanese Patent Public Dlsclosure No.119977/74) and
RMgX- ~ 0~ -TiCl4 ~see Japanese Patent Public Disclosure No.
119982/74~, and an or~anometallic compound.
In aspects of this invention, the catalyst systems exemplified
above are first contacted with an d-olefin in the presence or
absence of a liquid hydrocarbon and then used in a vapor phase
`polymerization. In this case there may be used various ~-olefins,
but preferably those having 3 to 12 carbon atoms and more preferably
those having 3 to 8 carbon atoms; for example, propylene, butene-l,
pentene-l, 4-methylpentene-1, heptene-l, hexene-l, octene-l, and
mixtures thereof. The contact temperature and time of catalyst
and ~-olefin may be selected in wide range, for example, l minute
to 24 hours at 0 to 200C, preferably 0 to 110C.
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~ liquld hydrocarbon which may be used in one preferred embodiment
of this invention is a hydrocarbon which is liquid under the contact-treatment
conditions, for example, C3 to C12 and preferably C3 to ~8 n- and iso-paraf-
fins and aromatic hydrocarbons) e.g. propane, n-butane, iso-butane, n-pentane,
iso-pentane, n-hexane, n-heptane, n-octane, iso-octane, benzene, toluene and
~ylene.
The c~ -olefins previously exemplified are also employable as a
liquid hydrocarbon in other aspects of this invention.
Refarding the amount of a liquid hydrocarbon used in aspects of this
invention, too great an amount would make it difficult to carry out a stable
vapor-phase reaction in the reaction vessel, while too small an amount would
make it difficult to introduce the catalyst after contact with an -olefin
into the reaction vessel. Usually it is desirable to use a liquid hydrocarbon
in an amount ranging from 1 g. to 1000 g., preferably 5 g. to 500 g. and more
preferably 10 g. to 300 g., per gram of tha solid substance.
The amount of an ~ -olefin to be contacted may also be selected
within wide ranges, but usually it is 1 g. to 50,000 g. and preferably 5 g. to
30,000 g. per gram of the solid substance, and it is desirable that 1 g. to
500 g. per gram of the solid substance of an G~ -olefin be reacted. The con-
tact pressure may be selected optionally, but it is desired to be in therange of from -1 to 100 kg/cm2 G.
In aspects of this invention, an organometallic compound to be used
may be combined in its total amount with the solid subs~ance and then con-
tacted with an o~ -olefin; or alternatively, a part of the organometallic co
pound may be combined with the solid substance, then contacted with an C~-ole-
fin and thereafter the remaining organometallic compound may be separately
added in the vapor phase polymerization of ethylene. In the contact of cata-
lyst with the ~ -olefin, moreover, a gaseous hydrogen, or other inert gases,
e.g. nitrogen, argon and helium, may be present.
As set forth hereinbefore, the polymerization of ethylene is carried
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39~6~
out using the foregoing catalyst after contact with an ~ -olefin, but the co-
polymerization of ethylene and other ~ -olefln then ethylene may also be con-
ducted in according to other aspects of this invention;'that is, ehtylene or
a mixture of ethylene and other ~ -olefin is polymerized in vapor phase.
Known reactors such as a fluidized bed and an agitation vessel may be used.
The polymerization reaction is carried out at a temperature usually
in the range of from 20 to 110C, preferably from 50 to 100C, and at a pres-
sure in the range of from atmospheric to 70 kg/cm G, preferably from 2 to
60 kg/cm G. Adjustment of the molecular weight can be made by changing the
polymerization temperature, the molar ratio of catalyst, the amount of co-
monomer, etc., but the addition of hydrogen into the polymerization system is
more effective for this purpose. Of course, two or more stage polymerization
reactions with different polymerization conditions, e.g. different hydrogen
and co-monomer concentrations and different polymerization temperatures can be
carried out without any trouble using the process of aspects of this invention.
As an organometallic compound used in aspects of this invention
there may be employed organometallic compounds of Groups I - IV of the Period-
ic Table which are knwon to be one component of Ziegler catalyst, among which
organoaluminum compounds and organo~inc compounds are specially preferred;
for example, organoaluminum compounds of the general formulae R3Al, R2AlX,
RAlX2, R2AlOR, RAl(OR)X, and R3A12X3 wherein R is Cl to C20 alkyl or aryl and
may be same or different, and X is halogenl and organozinc compounds of the
general formula R2Z wherein R is Cl to C20 alkyl and both Rs may be same or
different, e.g. triethylaluminum, triisobutylaluminum, trihexylaluminum, tri-
octylaluminum, diethylaluminum chloride, ethylaluminum sesquichloride, di-
ethylzinc, and mixtures thereof.
The amount of an organometallic compound to be used in this inven- ;
tion is not specially limited, but usually it is 0.1 to 1000 mols per mol of a `
transition metal compound.
The process of aspects of this invention is applicable to the homo-
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8946
polymerization of ethylene and also to the copolymerization of ethylene and
other ~ -olefin than ethylene, but the ~ -oleflns used herein may be the
same as or different from the the ~ -olefins which have been contacted with
the foregoing catalyst system. Examples of these ~ -olefins are propylene,
butene-l, pentene-l, hexene-l, 4-methylpentene-1, octene-l, decene-l, dodecene-
1, and mixtures thereof~ Various dienes as co-monomer, e.g. butadiene, 1,4-
hexadiene and ehtylideneorbornene may be further added to ethylene or mixtures
of ethylene and the above ~ -olefin to carry out polymerization.
The following are working ~xamples of aspects of this invention, but
it is to be understood that these examples are for purpose of illustration to
work the invention.
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Example 1
- ~ 2 liter stainless steel autoclave equipped with an induction
stirrer was purged with nltrogen, in which were then placed 50 g. of a
dried polyethylene powder and 500 ml of hexane. Further added were 10 mg
of a solid substance (titanium content 67 mgtg-solid substance), which was
obtained by sub~ecting 10 g. anhydrous magnesium chloride, 0.5 g. dichloro-
ethane and 3.3 g. titanium trichloride - aluminum chloride eutectic mixture
to a ball milling for 16 hours at room temperature under a nitrogen atmos~
phere, and 5 millimols of triisobutylaluminum. ~he hexane was distilled off
10 under reduced pressure with stirring to give a catalyst. The reaction tem-
perature was raised to 70C, then propylene gas was introduced up to 7 kg/
cm2.G and the catalyst was treated with propylene for 10 minutes, during which
period 3 g. of propylene was consumed. Then, propylene within the autoclave
was purged and the purging was further repeated several times with nitrogen
gas. After the reaction temperature had been raised to 80C, hydrogen was
introduced up to 5 kg/cm2.G, then introduced ethylene up to a total pressure
of 10 kg/cm2.G and a polymerization was started, which was continued for 2
hours at 85C while ethylene was continuously introduced so as to maintain
the total pressure at 10 kg/cm2.G, to yield 185 g. of a white polyethylene,
20 from which the weight of the polyethylene powder initially fed to the auto-
` clave was deducted to find that the amount of polyethylene newly produced
by the vapor phase polymerization was 135 g,
The catalyst activity was 225,000 g.po~l~yethylene/g.Ti, which is
much higher than in Comparative Example 1 where the catalyst was not treated
with propylene. There was neither aggregation nor adhesion of polymer with-
in the autoclave and the results obtained
.
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were very satisfactory as compared with Comparative Example 1
in which the catalyst used was not treated with propy'lene. Besides,
the bulk density of the resulting polyethylene particles was high
with only a small production of coarse and ultra-fine particles,
and the particle properties were very good.
Comparative Example 1
Polymerization was carried out in the same manner as
in Example 1 except that the solid substance was used 30 mg and
the catalyst was not treated with propylene gas, to yield 132 g.
of a white polyethylene as the product of ~he vapor phase ;~
polymerization. The ca~alyst activity was 73,000 g.polyethylene/g.Ti
and thus it was lower than in Example 1. On the autoclave flange
surface and the upper portion of the reactor wall was adhered
130 g. of polyethylene and thus the adhesion of polymer was conspicuous-
Example 2
lO mg of the catalyst obtained in Example 1 was treated ;~
with propylene for 1 minute at 70C and at a propylene pressure
of 7 kg/cm2 G, which treatment consumed 0.5 g. of propylene.
Then propylene was purged and the purging was further repeated
several times with nitrogen gas, thereafter the polymerization -
of ethylene was conducted for 2 hours at 10 kg/cm2-G in the same
manner as in Example 1 to yield 130 g. of a white polyethylene
as the product of the vapor phase polymerization. The catalyst
activity, 217,000 g.polyethylene/g.Ti, was much higher than ill
Comparative Example 1, and ~here was found no adhesion of polymer
~ithin the autoclave.
Example 3
10 mg of the catalyst obtained in Example 1 was treated
with butene~l for 30 minutes at 70C and at 2 kg/cm2oG, which
treatment consumed 1.5 g. of butene-l. Then butene-l was purged
-- 11 --
. . . : ,
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~8~
and the purging was further repeated several times with nitrogen
gas, thereafter the polymerization of ethylene was conducted for
2 hours at 10 kg/cm2 G in ~he same manner as in Example 1 to yield
128 g, of a whlte polyethylene as the product of the vapor phase
polymerization. The catalyst activity, 213,000 g.polyethylene/g.Ti,
was much higher than in Comparative Example 1, and within the
autoclave there was only a small amount, about 3 grams, of polymer
adhesion on the upper portion of the flange, which was much smaller
than in Comparative Example 1.
Example 4
A 2 liter stainless steel autoclave equipped with an
induction stirrer was purged with nitrogen, in whlch were then
placed 50 g. of a dried polyethylene powder and 500 ml of hexane.
Further added were 20 mg of a solid substance (titanium content
40 mg/g.solid substance~, which was obtained by subjecting 10 g.
anhydrous magnesium chloride, 0.5 g. dichloroethane and lo 7 g.
titanium tetrachloride to a ball milling for 16 hours at room
temperature under a nitrogen atmosphere, and 5 millimols of
triisobutylaiuminum. The hexane was distilled off under reduced
pressure with stirring to give a catalyst. The reaction temperature
was raised to 80C, then 2 g. of he~ene-l was added and the catalyst
was treated with hexene-l for 10 hours at 80C. After the lnterior
of the autoclave was purged several times with nitrogen gas, the
reaction eemperature was raised to 85C, then hydrogen was introduced
` up to 5 kg/cm2 G, thereafter introduced ethylene up to a total :
pressure of 10 kg/cm2-G and a polymerization was startedl which was
continued for 2 hours at 85C while ethylene was continuously
introduced so as to maintain the total pressure at 10 kg/cm2-G,
to yield 91 g. of a white polyethylene. The catalyst activity,
`j 30 114,000 g.polyethylene/g.Ti, was much higher than in Comparative
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63~16
Example 2, and within the autoclave there was only about 1 gram
of polymer adhesion on the flange surface, which was much less
than in Comparative Example 2.
Comparative Example 2
Polymerization was carried out in the same manner
as in Example 4 except that the solid substance was used 30 mg and
the catalyst was not treated with hexene-l, to yield 96 g. of
a white polyethylene as the product of the vapor phase polymerization.
The cataly~t activity, 80,000 g.polyethylene/g.Ti, was lower than
in Example 4. On the autoclave flange surface and the upper portion
of the inside wall was adhered 50 g. of polyethylene and thus
the adhesion of polymer was conspicuou~.
Example 5
Polymerization was carried out in the same manner as
in Example 4 except that as the solid substance there was used
20 mg of a solid substance (titanium content 40 mg/g.solid substance)
obtained by sub~ecting 8.3 g. anhydrous magnesium chloride, 1.2 g.
anthracene and 1.7 g. titanium tetrachloride to a ball milling
for 16 hours at room temperature under a nitrogen atmosphere,
~0 and there was used 4-methylpentene-1 in place of hexene-l, to
yleld 88 g. of a white polyethylene as the product of the vapor
phase polymerization. The catalyst activity, 110,000 g.polyethylene/g.Ti,
was much higher than in Comparative ~xample 3 where the catalyst
was not treated with 4-methylpentene-1. Within the autoclave there
was found no adhesion of polymer.
Comparative Example 3
Polymerization was carried out in the same manner as
in Example 5 except that the solid substance was used 30 mg and
the catalyst wa~ not treated with 4-methylpentene-1, to yield
92 g. of a white polyethylene as the product of the vapor phase
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39~6
polymerization. The catalyst activity was low, 77,000 g~polyethylene/g.Ti.
T~e adhesion of polymer was con~picuous; there was found 30 g. of
polymer ad~esion on the autoclave flange surface and inside wall.
Example 6
In the same manner a6 in Example 1, except that there
was used 10 mg of a golid substance (titanium content 39 mg/g.solid
substance~ obtained by sub;ectlng 9.5 g. of the product resulting
from heat reaction for 4 hours at 300C of 40 g. magneslum oxide
and 133 g. aluminum chloride, and 1.7 g. of titanium tetrachloride,
to a ball milling for 16 hours at room temperature under a nitrogen
atmosphere, the catalyst wag treated with propylene at 50C and
at a propylene pressure of 7 kgtcm2-G. In 30 minutes, 1.5 g. of
propylene was consumed. Then propylene was purged and the purging
wa3 further repeated several times w~th nitrogen gas. Hydrogen
was then introduced up to 5 kg/cm2~Gl thereafter introduced ethylene
containing 2 mol% of butene-l up to a total pressure of 10 kg/cm2-&
and a polymerization was conducted for 2 hours at 85C to yield
85 g. of a white polyethylene as the product of the vapor phase
polymerization. The catalyst activity was very high, 218,000 g.
polyethylene/g.Ti, and there was found no polymer adhesion within
the autoclave. ~ `
Example 7
(1) Pre-treatment with Propylene
In a 200 ml stainle~s steel autoclave equipped with
an induction stirrer were placed 200 mg of a solid ~ubstance obtained
by sub~ecting 10 g. anhydrous magnesium chloride, 0.5 g. dichloroethane
and 3.3 g. titanium trichloride-aluminum trichloride eutetic mixture
to a ball milling for 16 hours at room temperature under a nitrogen
atmosphere, 20 milllmols of triisobutylaluminum and 100 ml of hexane,
and a reactlon was allowed to take place for 10 minutes at 70C.
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Then 3 g. of propylene was added and reacted for 10 minutes,
then the temperature was brought down to room temperat'ure to glve
a catalyst filurry pre-treated wlth propylene.
C2) Vapor Phase Polymerization
A 2 liter stainless 6teel autoclave equipped with
an induction stirrer was purged ~ith nitrogen, in which were placed
50 g. of a dried polyethylene powder and then 5 ml of the catalyst
slurry pre-treated with propylene obtained in the above (1).
After the temperature had been raised to 80C, hydrogen was introduced
up to 5 kg/cm2 G, then introduced ethylene up to a total pressure
of 10 kg/cm2 G and a polymerization was started, which was continued
for 2 hours at 85C while ethylene was continuously introduced
so as to maintaln the total pressure at 10 kg/cm2-G, to yield
193 g~ of a white polyethylene, from which ~he weight of the polyethylene
powder initially fed to the autoclave was deducted to find that the
amount of polyethylene newly produced by the vapor phase polymerization
was 143 g. The catalyst activity was 255,400 g.polyethylene/g.Ti,
which is much higher than in Comparative Example 4 where the catalyst
was not pre~treated with propylene. There was neither aggregation
nor adhesion of polymer within the autoclave and the results o~tained
were very satisfactory as compared with Comparative E~ample 4 in
which the catalyst used was not treated with propylene. Besides,
the bulk density of the resulting polyethylene particles was high
with only a small production of coarse and ultra-fine particles~
and the particle properties were very good.
Comparative Example 4
Polymerlzation was carried out ln the same manner as
in Example 7 except that the hexane slurry of catalyst was not treated
with propylene, to yield 45 g. of a white polyethylene as the product
of the vapor phase polymerization. The catalyst activity was
- 15 -
, . ,
... .. . .. .
80,400 g.polyethylene/g.Ti and thu~ it was lower than in Example
7. On the autoclave flange surface and the upper portio,n of the
reactor wall was adhered 41 g. of polyethylene and thus the adhesion
of polymer was conspicuous.
Example 8
Pre-treatment and vapor phase polymerization were conducted
in the same manner as in Example 7 except that there was used lg.,
in place of 3 g., of propylene in the stage of pre-treatment with
propylene, to yield 131 g. of a white polyethylene as the product
of the vapor phase polymerization. The catalyst activity, 234,000 g.
polyethylene/g.Ti, was much higher than in Comparative Example 4,
and there was found no adhesion of polymer within the autoclave.
Example 9
Pre-treatment with ~-olefin and vapor phase polymerization
were conducted in the same manner as in Example 7 except that the
pre-treatment applied was with butene-l in place of propylene and
the amount of butene-l added was 2 grams, to yield 125 g. oE a
white polyethylene as the produot of the vapor phase polymerization.
The catalyst activity, 223,200 g.polyethylene/g~Ti, was much higher
than in Comparative Example 4, and there was found no adhesion
of polymer within the autoclave.
Rxample 10
Pre-treatment with propylene and vapor phase polymerization
were conducted in the same manner as in Example 7 except that there
was used 100 ml of n-butane in place of hexane in the stage of
pre-treatment with propylene, to yield 151 g. of a white polyethylene
as the product of the vapor phase polymerization. The catalyst
activity, 269,600 g.polyethylene/g.Ti, was much higher than in
Comparative Example 5 There was found no adhesion of polymer
within the autoclave, and the particle properties were satisfactory.
8~6
Comparative Example S
Polymerization was carried out in the same manner
as in Example 7 except that there wag ueed 100 ml of n-butane
in place of hexane and the pre treatment with propylene was not
applied, to yield 50 g. of a white polyethylene as the product
of the vapor phase polymPrization. The catalyst activity, 89,300 g.
polyethylenetg.Ti, was lower than in Example 10. On the autoclave
flange surface and the upper portion of the reactor wall there was
found a large amount of adhered polyethylene, and the polymer
particles were irregular.
Example 11
(1) Pre-treatment with Hexene-l
In a 200 ml stainless steel autoclave equipped with
an induction stirrer were placed 200 mg of a solid substance obtained
by subjecting 10 g. anhydrous magnesium chloride, 0.5 g. dichloroethane
and 1.7 g. titanium tetrachloride to a ball milling for 16 hours
at room temperature under a nitrogen atmosphereg 20 millimols of
triisobutylaluminum and 100 ml of hexane, and a reaction was allowed
to take place for 10 minutes at 80C. Then 5 g. of hexene-l was
added and reacted for 5 hours, then the temperature was brought
down to room temperature to give a catalyst slurry pre-treated
with hexene-l.
(2) Vapor Phase Polymerization
A 2 liter stainless steel autoclave equipped with an
induction stirrer was purged with nitrogen, in which were placed
50 g. of a dried polyethylene powder and then 5 ml of the catalyst
slurry pre-treated with he~ene-l obtained in the above ~1). After
the temperature had been raised to 85UC, hydrogen was lntroduced
up to 5 kg/cm2 G, then introduced ethylene up tO a total pressure
V 30 of 10 kg/cm2-G and a polymerization was started, which was continued
- 17 -
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.. .,. .:
,, ~ . : . , : :
for 2 hours at 85C while ethylene wa~ continuously introduced 90
as to maintain the total pressure at 10 kg/cm2-G, to yield 62 g.
of a white polyethylene as the product of the vapor phase polymerization.
The catalyst activity was 155,00~ g.polyethylene/g.Ti, which is
much higher than in Comparatlve ~xample 6 where the catalyst was
not treated with hexene-l. There was neither aggregation nor
adhesion of polymer within the autoclave and the results obtained
were very satisfactory as compared with Comparative Example 6 in
which the catalyst was not treated with hexene-l. Besides, the bulk
density of the resultlng polyethylene particles was high with only
a s~all produc~ion of coarse and ultra-fine particles, and the
partlcle properties were very good. "
Comparative Example 6
Vapor phase polymerization was carried out in the same
manner as in Example 11 except that the catalyst was not treated
with hexene-l, to yield 37 g. of a white polyethylene as the product
of the vapor phase polymerization. The catalygt activity, 92,500 g.
polyethylene/g.Ti, was lower than in Example 5. On the autoclave
flange surface and the upper portion of the inside wall there
waæ found a large amount of adhered polyethylene, and the polymer
particles were irregular.
Example 12
Pre-treatment with propylene was conducted in the same
manner as in Example 7 except that as the solid substance there
was used a solid substance obtained by subjecting 9.5 g. of the
product resulting from heat reaction for 4 hours at 300C of 40 g.
magnesium oxide and 133 g. aluminum chloride, and 1.7 g. of titanium
tetrachloride, to a ball milling for 16 hours at room temperature
under a nltrogen atmosphere. Thereafter, a vapor phase polymerization
was carried out in the same way as in Example 7 with the proviso -
,,, ., ... . ... --, 1,~ ,= . .. . ,.. ,,, ,, , . ~ .
that there was used ethylene containing 2 mol% of butene-l, to
newly afford 93 g. of a white polyethylene. The catalyst activity
was very high, 238,500 g.polyethylene/g.Ti, and there wa~ found no
adhecion of poly~er within the autoclave.
- 19 -
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`: ; ' ' " ;, : '
