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Патент USA US3070599

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tates Patent 0 Nice
Unite
.
3,070,589
Patented Dec. 25, 1962
2
1
active catalysts or catalyst components which initiate the
polymerization of the monomers.
3,070,589
In spite of the above, it is not always necessary to have
CATALYST REMOVAL FROM POLYOLEFIN
catalyst combinations and in some catalytic polymeriza
POLYMER SOLUTIONS
tions, a single ?nely divided metal or metallic compound
is employed as catalyst, including such metals and metal
lic compounds as the ?nely dispersed alkali metals, alumi
num trihalides, boron halides, vanadium halides, titanium
and zirconium halides, metallic hydrides, alkali metal
_
William Kirch, Cincinnati, and Ragnar S. Solvilr, Wyo
ming, Ohio, assignors to National Distillers and Chem
' icai Corporation, New York, N.Y., a corporation of
Virginia
‘No Drawing. Filed Oct. 30, 1958, Ser. No. 770,594
5 Claims. (Cl. 2604-943)
10
alkylsand aryls, chromium and molybdenum oxides, and
the like.
This invention ‘is broadly concerned with a novel
.
In some of these polymerizations, the reaction is carried
method for recovery and puri?cation of polymers and
out as a homogeneous reaction in a diluent and/ or solvent
more speci?cally, with a method for handling and removal
in which the reactants and the ?nal polymer are essentially
"of metallic catalyst residues from polymerization reaction
mixtures.
It is an object of this invention to provide a method for
effective deactivation of metallic polymerization catalysts
soluble. For example, in the polymerization of ethylene
under conditions of moderate temperatures and low pres
'sures, reaction conditions can be selected such that the
polymer product is in solution in the solvent and a homo
and efficient removal thereof from polymer solutions.
geneous reaction mixture is obtained.
It is another object of this invention to provide a
In many cases, the catalyst is essentially not soluble,
20
method for deactivation and agglomeration to metallic
however, and is present at the end of the polymerization
cycle in very ?nely divided form. This metallic catalyst
residues in polymer solutions and removal thereof.
It is a further object to remove ash-forming metallic
residue must be deactivated and removed from the ?n
residues from polymer solutions by deactivation and
‘ ished "polymer solution.‘ Both the deactivation and re
moval must be as complete as possible. If deactivation 18
25
Other objectives of the process of this invention will be
not effective and complete, other undesirable side-reac
agglomeration thereof.
tions take place such as after-polymerization reactions
apparent from the detailed description below.
There are a relatively large number of processes known
in which ole?nic reactants including alpha ole?ns, such as
and catalytic degradation-of the polymer.
In other cases, the'polymerization reaction may be
ethylene, propylene and the like are subjected to polymeri ‘30 carried out at relatively low temperatures and pressures
zation using either the monomer singly or in combina
tion with various metallic compounds. A great number
of these metal bearing polymerization catalysts are well
known and are frequently combination catalysts consist
'
so that the polymer product is not in solution and a
heterogeneous reaction mixture results. In these cases,
the unsoluble catalyst'residues must be deactivated and
converted to a form that can be separated from the poly
ing of more than one metal-containing compound. In
'
35 mer suspension.
many instances, it has been shown that at‘least two di?er
It‘ the catalyst removal is not complete, then metallic,
ent materials, both metal-containing compounds, are re
lash-forming and color-forming residues will inevitably
quired to form active polymerization catalysts. These are
be present in the ?nal polymer. Although one of the
generally classed as: (1) the cocatalyst, or the reducing ‘
most economical and ef?cient methods for removal of
agent, and (2) the catalyst, or a metallic compound in a 40 such residues would be by ?ltration or other gravity
multivalent state. The cocatalyst or reducing agent may
separations, this is not always feasible or e?ective since
be, for example, metal alkyls or aryls, metal hydrides.
by the very nature of the material and its use, these
Grignard reagents, and alkali metals or alkaline earth
metals. Some of the more successfully used cocatalysts
are triethylaluminum, tetrabutyltin, amylsodium, diethyl
magnesium, sodium, sodium hydride, etc. The catalyst
or metallic compund may be, for instance, a titanium or
zirconium halide such as the tetrachloride or the tetra
metallic catalytic materials are generally in very ?nely
divided and well dispersed form and are not removable
directly by ?ltration.
In a series of comparative studies for developing suit
able deactivating and agglomerating agents for the active
catalyst to’ render it ?lterable, it has been found that
organic peroxides are very e?icient agents. Typical or
tetrahalide, hexavalent chromium compounds, and the 50 -ganic peroxides which can be used for this purpose include
like( Examples of known satisfactory coordination cata
t-butyl hydroperoxide, di-t-butyl peroxide, t-butyl peroxy
bromide, vanadium tetrachloride, hafnium or thorium
lyst systems include titanium tetrachloride-aluminum tri
ethyl, titanium tetrachloride-ethyl magnesium bromide,
acetate,‘ t-butyl peroxy pivalents, cumene hydroperoxide,
cyclohexyl hydroperoxide, di-benzoyl peroxide, di-acetyl
and titanium tetrachloride-lithium aluminum tetrabutyl, _
peroxide, di-cetyl peroxide, t-butyl perbenzoate, per
and there are many others known in the art.
55 acetic acid and persuccinic acid. This list it not, however,
, Some of the most active catalyst complexes are formed
‘intended to be limitive in nature and the invention is not
from liquid or organosoluble metallic catalysts and co
to be considered as limited thereto.
.
catalysts, since more centers are provided for the forma
In general, these compounds apparently serve to de
tion of the active catalyst. Generally, however, the active
activate the metal-containing catalyst and also to change
catalyst formed by the reduction (co-catalytic) of the 60 vthe physical structure or the metallic residues so that the
catalyst is a ?nely dispersed solid. It is believed but not
‘solid particles agglomera'te and form larger, ?lterable
necessarily proved that coordination complexes are
solids which give substantially faster settling rate and
formed in the polymerization mixture or in the catalyst
vare thus separable from a polymer solution.
The use of the organic peroxide is critical and its eifects
cocatalyst mixture. While the chemical nature of these 7 _
complexes is not known, it is believed that they are the
8,070,589
4
on agglomeration and ?ltration of the polymer solution
are surprising and totally unexpected. This is particu
larly true in view of the many similar and related com
such as diatornaceous earth, fuller’s earth, wood-pulp,
activated carbon or asbestos pulp.
pounds and materials which were tested and found to be
Following deactivation, agglomeration, and removal of
substantially or totally useless. For example, many sur
factants of varying classes of organic compounds were
the metallic residues, the polymer solutions are handled
by the well-known methods and in any convenient man~
tried. These included sorbitan trioleate (Span), poly
oxyethylene stearate (Myrj) and polyoxyethylene sorbi
ner to separate and recover the polymer and the solvent.
tan monooleate (Tween). None of these had any sub
stantial effect on ?ltration rate. A number of the polyols,
including 1,2,6-hexanetriol, 2-ethyl-L3-hexanediol, mono
The invention will be further described and illustrated
by the following speci?c examples, but it is intended in
no way to limit the invention thereto.
10
EXAMPLE 1
pentaerythritol, and various derivatives thereof, were also
tried without substantial effect on agglomeration and
In the process used in the following described examples
of catalyst removal, puri?ed ethylene, puri?ed solvent
?ltration rate. Also the synthetic flocculant aids were
and dilute solutions of catalyst and cocatalyst were in
tested with no effect. Both triethyl and tributyl citrate
gave-colored precipitates which did not ?lter satisfactorily. 15 jected into a continuous, stirred reactor operating at about
240° C. and 2500-3500 lbs. per square inch pressure
vIt is particularly surprising that surfactants and ?occu
(p.s.i.g.). The residence time in the reactor, required to
lating agents such as the above were of little or no effect
convert the ethylene to polyethylene was 10-20 minutes.
in the deactivation and agglomeration of these metallic
residues.
Following polymerization, the deactivation-agglomera
20
tion agents (sometimes ?lter aid also) were injected into
It is an additional and further feature of this invention
the el?uent from the reactor and after su?'icient time
to add to the polymer solution containing metallic residue
was allowed for the deactivating reaction to take place,
an amount of hydrogen peroxide in the range of 1-100
the combined stream was sent to a battery of sintered
weight percent based on weight of total catalyst with a
preferred range of 2-5 %. It has been found for instance, 25 metal ?lters. ‘The polymer-solvent stream was then re
duced in pressure to _20 p,s.i.g. into a separator which
that such addition of hydrogen peroxide causes forma~
tion of larger agglomerates which are readily ?lterable.
It is contemplated that the organic peroxide should be
.used in the amount required to effectively deactivate and
permitted the solvent to vaporize. The solvent-free poly
mer was collected from the bottom of the separator and
subjected to analytical characterization.
data on four runs are shown in Table I.
Experimental
Table 1
Buns
_
-__
_.
_ Ethylene feed rate, lbs/hr
1
2.0.-
‘Solvent feed rate, lbs/hr-.-
-. 40.0-.
Catalyst type ____________________________________ __
Cocatalyst type _____________________ --_
TiCh _____ ..
Cat. feed rate, lbs/hr. of a 1% cone _____ _.
0 Bl
Cocat. feed rate, lbs/hr. of a 1.1%7 cone...
2
3
2.0.-
3.2-.
40.0"
30.0 _______ __
TiCh _____ ._
TiClt _____ __
82
4
20
0
72
Cocat/eat. wt. ratio _______________________ ._
Percent conversion of monomer to polymer.
Reactor pressure (p.s.i.g.)
Reactor temperature (° 0.)
Deactivator (I) type ..... ._
Deaetivator (II) type
Deaetivator (I) feed rate, lbs./hr. of 2.0% cone .... ._
,Deactivator (II) feed rate, lbs/hr. of .04% conc__-_
Wt. ratio 01 deaetivator (I) to total catalyst ______ ._
Wt. ratio of deactivator (II) to total catalyst--. __
Ratio of ?lter aid to total cataly
__
Percent total catalyst in polymers ________________
before ?ltration- _
Percent total catalyst in polymer alter
?ltration_._
Polymer melt index
Polymer density-._::::::: _________________
“
Polymer as}:o content, p.p.m._..
Polymer co r _________________________________ -I:
1 taButylhydroperoxlde.
agglomerate the metallic catalysts. Thus, it is somewhat
EXAMPLE 2
dif?cult to de?ne exact limits of concentrations necessary 6
but generally, ‘these amounts are from 100 to 500 wt.
Table II shows comparative results obtained by various
percent based on weight of total catalyst.
methods for deactivation and agglomeration of a TiCl4
Too little of the organic peroxide obviously will not
AlEt3 catalyst in a Decalin solution. The relative effec
have the desired effect and too great an amount will be
tiveness of the catalyst was measured in each instance
uneconomical and may have undesirable effects such as 65 by the sediment height in milliliters for a 40 milliliter
oxidationand degradation of the polymer.
sample after varying and increasing periods of time as
It is a further feature of this invention to include with
indicated after treatment with the stated deactivator
agglomerator combinations. The ?rst four experiments
the deactivated polymer solution a mechanical ?ltration
are typical examples of the invention showing the sur
aid, ‘in the event that a ?ltration step is carried out sub
sequently. This is, of course, unnecessary if the ?nal 70 prising eifectiveness of the organic peroxide and hydro
gen peroxide either with or without ?ltering aid and the
separation of the agglomerated catalyst residues is done
poor results obtained in their absence. The results ob
by gravity settling or by centrifugation. However, if
tained when the organic peroxide or hydrogen peroxide
?ltration is done, as is preferred for commercial opera
is used alone with the ?lter aids and when the ?lter aid
tions, then it is highly desirable to add ?ltration aids 75 is
used alone are shown.
a
3,070 , 589
5
6
and in which the catalyst comprises at least two compo
nents, (l) a cocatalyst and (2) a catalyst, at least one
Table II
component of which produces metallic residues, and the
Catalyst deactivatorlagglomerator
1. t-butylhydroperoxide-l-?ror (t-BHP) .... ..
Settling
Sediment
height for
time,
hours
40 ml.
sample
of adding thereto an organic peroxide, as the sole deacti
vating and agglomerating agent, in an amount suf?cient
to e?ectively deactivate and agglomerate all metallic cata
3 25
4(8)
6
2. t-BHP+H1O¢+?lter aid (type 1)a ________ _-
0
(i. 25
40
3. t-BHP-l-HzOz-l-?lter aid (type 2)h ........ ...
00.25
1
6
18
40
12
l1
9. 5
9. 5
0.
0. 25
1
3
22
40
11. 5
11.5
10. 5
10. 5
00.25
1
40
11
10.5
5. HzO2+?lter aid (type 2) ..................
I _.
(13+)
2.5
10.5
6. HiO¢+?lter aid (type 1) .................. ..
00.50
1
3
40
(5+)
6
6
7. t-BHP+?lter aid-F5202 (% cone. of l.
above) (type 1).
0
0.25
1
40
11
10
3
22
00.25
1
8
40
17
12. 5
7.0
9. t-BHP+?lter aid (type 2) ................ ._
00.25
40
20
s1
a19
d.typ e n ........................ ..
16
11. blank (active catalyst exposed only to air).
10
lyst residues, and separating the deactivated, agglomerated
catalyst residues therefrom.
2. The method of claim 1 in which the organic per
oxide is a t-butyl hydroperoxide and it is added to said
polymer reaction mixture in an amount between 100
and 500 weight percent of total catalyst.
15
3. The method of claim 1 in which a mechanical ?lter
ing aid is added to the polymer solution prior to ?ltra
tion.
and in which the catalyst comprises at least two compo
nents, (1) a cocatalyst and (2) a catalyst, at least one
component of which produces metallic residues, and the
resulting polymerization reaction mixture contains poly
25 mer from at least one ole?nic reactant, which consists
of adding thereto an organic peroxide, in an amount
between 100 and 500 weight percent of total catalyst,
and hydrogen peroxide, in an amount between 2 and 5
weight percent of total catalyst, said peroxides being
30 the sole deactivating and agglomerating agents, and sepat
rating the deactivated, agglomerated catalyst residues
from the thus treated polymerization reaction mixture.
5. The method of claim 4 in which the organic per
9. 5
({ 5
2?)
17
20
1
4. A method for deactivation and agglomeration of
metallic catalyst residues from a polymerization reaction
20 mixture wherein the polymer is substantially in solution
9
7.5
8. t-BHP+?lter aid (type 1) ................ ..
10. ?lter at
mer from at least one ole?nic reactant, which consists
(mL)
1
4. t-BHP+HrOr+?1teI aid (type 2) ......... .-
resulting polymerization reaction mixture contains poly
35
oxide is t-butyl hydroperoxide.
References Cited in the ?le of this patent
UNITED STATES PATENTS
I Diatomaceous earth.
b Diatomaceous earth plus asbestos ?bers.
What is claimed is:
1. A method for deactivation and agglomeration of 40
metallic catalyst residues from a polymerization reaction
mixture wherein the polymer is substantially in solution
[m.,
2,827,445
2,845,414
2,849,429
Bartolomeo etal. ____ __ Mar. 18, 1958
Schultze _____________ -_ July 29, 1958
Cines ______________ .._ Aug. 26, 1958
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