Note: Descriptions are shown in the official language in which they were submitted.
1~5'~94~
~ he pre~ent invention relates to a process of
producing homopolymers of conjugated dienes or copolymer~ of
conjugated dienes with other conjugated dienes or wlth vinyl
aromatic compounds.
From Britiæh patent No. 1,246,914, it i~ already
known to prepare in solution homopolymers of conjugated dienes
- or ¢opolymers of conjugated dienes with other conjugated dienes
or with vinyl aromatic compounds by means of organometallic
compounds of an alkaline earth metal of the formula M1 M2 R R2
R3 R4 in which M1 represents caloium, barium, or strontium, M2
represents zinc or cadmium, and R1, R2, R3, R4 represent a
hydrocarbon radical. ~he polymers obtained have a very low
intrin~ic viscosity of between 0.24 and 0.62.
It is known (Chemical Abstracts, Vol. 78; 85 514
~ (1973) and RAPRA No. 23 738 L (1974) to prepare in a hydrocarbon
i reaction medium homopolymers of conjugated dienes or copolymers
; of conjugated dienes with other conjugated dienes or with vinyl
'~ aromatic compounds by means of organometallic compounds of an
~ alkaline earth metal and aluminum. However, the polymers~ 20 obtained by this process, like the polymers mentioned above,
have a very low intrinsic viscosity and, therefore, do not have
elastomeric properties which are sufficient to permit their use
~; as the principal component of mixtures serving for the manufacture
of tires. ~urthermore, such a process of manufacture cannot be
applied industrially due to the very low homopolymerization or
copolymerization reaction velocity.
Finally, it is widely known that the organometallic
compounds of aluminum have an extremely low or even zero intrinsic
catalytic activity and that they are not considered initiators
for the homopolymerization of copolymerization of conjugated
dienes.
~ he applicant has discovered a new process which makes
- lOSZ948
it possible industrially to obtain within relatively short times
and with good yield ho~opolymers of conjugated dienes or copoly-
mers of conjugated dienes with other conjugated dienes or with
vinyl aromatic compounds having an elasticity similar to rubber
and which can be used in the manufacture of pneumatic tires.
Therefore, the object of the present invention is a
process for the homopolymerizat~on of conjugated dienes or the
copolymerization of conjugated dienes with other conjugated
dienes or with vinyl aromatic compounds whioh comprises reactingthe monomers at a temperature between 50C. and 120C. in the
presence of a catalyti¢ system formed of the reaction product
of
a) an organometallic compound of a metal of Group
~ IIIA of the Mendeleev periodic table of elements having one of
.~ the following formulas:
Me1 Me3 R1 R2 R3 R4
Me2(Me3R1R2 R3 R4
Me3R1 R2 R3
~' Me1 o Me3R1 R2 ~ ~,
in which Me1 represent~ an alkali metal, Me2 represents an :
. alkaline earth metal, Me3 represents a metal of Group IIIA,
Rl, R2 and R3 represent an alkyl or aralkyl radical and R4
represents an alkyl or aralkyl radical or a radical XB in which
.. X represent~ an oxygen, 2ulfur or nitrogen atom and B represents
an alkyl or aralkyl radical, or a radical Me3(R5R6) in which R5
and R6 represent an alkyl or aralkyl radical; with
b) at least one electron-donor compound containing at
least one hetero-atom selected from the group consisting of
aprotic polar compounds, protic polar compounds and compounds
formed of the reaction product of protic polar compounds with
an alkali metal or with an alkaline earth metal.
~he applicant has surprisingly found that the reaction
105'~948
product of compounds which, taken alone, are not initiators of
: the homopolymerization or of the copolymerization of conjugated
dienes with other conjugated dienes or with vinyl aromatic com-
pounds or which have only an e~tremely low intrin~ic initiating
activity constitutes an initiating catalytic system for the
homopolymerization of conjugated dienes or the copolymerization
of coniugated dienes with other oonjugated dienes or with vinyl
aromatic compounds which can be used industrially as elastomers.
.~ ~he organometallic compounds o~ a metal of Group IIIA
10 which are particularly suitable as a component of the catalytic
s~stem are those in which the alkali metal i~ lithium, sodium,
or potassium, those in which the alkaline earth metal is - -
magnesium, calcium, strontium or barium, and those in which the
metal of Group IIIA is boron, aluminum, gallium, indium or
thallium. By way of example, the following compounds can be
mentioned: Al(CH3)3, Al(C2H5)3, Al(i-C4Hg)3, ~ (C2H5)4_7,
a~ l (C2H5)4_7J K~ l(C2H5)4_7~ ~i ~ l(C2Hs)3 C2H5-7~
(C2H5)30 Al(C2H5)2_7~ Mg ~ l(C2H5)4-72' C2 5 g 2 5 4
a ~ l(C2H5)4_72~ Sr ~ l(C2H5)4_72, Ba ~ l(C2H5)4 72'
Ba r l(C2H5~30 C2H5_72- Ba ~ l-(iso C4Hg)4_72~ ~i 0 Al (C2H5)2,
(C2H5)2' ~ (CH3)3~ ~ (C2H5)3, ~i B(C2H5)
~i B (C2H5)3C4~9, Ga(C~Hs?3, In(C2H5)3~ ( 2 5 3
By way of.examples of aprotic polar compounds, there
: are especially suitable the ethers ænd particularly the cyclic
~ ethers, such as tetrahydro~uran and dioxane, as well as the .
corresponding thioethers, such as thiodiisobutyl; the tertiary
amines, such as N,N,N',N'-tetramethylethylenediamine (~MED); the
~ aromatic amines and in particular the pyridine derivatives,
`. such as 4-methylpyridine, and the corresponding oxide~; phospho- rou~ compounds, such as the phosphines and their oxides, the
phosphites, the phosphoramides and in particular hexamethyl-
phosphorotriamide (HMP~); the ketones and particularly acetone;
- 3 -
r
105~948
the nitriles and particularly acetonitrile; the aldehgde~; the
esters; the amides; the nitro-aliphatic or aromatic compounds;
the sulfoxides and particularly dimethyl sulfoxide; the sulfones;
and the sulfites.
As protic polar compounds there are suitable in
particular water; the alcohols and particularly methanol; the
primary or ~econdary amines; the phenol~; and the thiols.
As compounds formed of the reaction proauct of
protic polar compounds with an alkali metal or with an alkaline
earth metal there are particularly suited the alcoholates and
phenates of alkali metals or alkaline earth metals, such as
lithium isopropylate, barium nonylphenate ands~ium orp~assium t~
amy~ t~e~1~1i me~l or alkaline earth metal mercapto and thio-
phenates; as well as the ether-alcoholate~ and amine-alcoholates
of alkali metals or aIka~ne e~h meta~s, such a~the~ithium alooholate of
ethyl d~ycoland lithium N,N-diethylamino-2-ethanolate.
~he organometallic compound of a metal of Group IIIA
and the electron-donor compound or compounds can be introduced -~
into the reaction medium either individually in any order or
preformed. In accordance with the second variant, the catalytic
system i8 "preformed" by mixing the variou~ components and then
- bringing the mixture to a temperature of between 20C. and 100C.
for 5 to 60 minutes. ~-~
The two components of the catalytic system can be
used in variable proportions but it is preferable to use them
in proportions such that the molar ratio of the ele¢tron donor
compound or compounds to the organometallic compound of a metal
of Group IIIA i~ between 0.01:1 and 100:1. For a given concentra-
~`~ tion of organometallic compound of a metal of Group IIIA, a modi-
fi¢ation of the value of the molar ratio may modify both the in-
trin~ic viscosity and the micro-structure of the polymer formed
as well as the polymerization and copolymerization reaction
.
- 4 -
~05'~948
velocity. Among the organometallic compounds of a metal of
Group IIIA organo-aluminum compounds are preferred due both to
their advantageous method of manufacture and to their extensive
availability on the market.
In the case of catalytic systems formed of an
organometallic compound of aluminum having the formula
Me2~ 1 R1R2R3R4 72 ~ such as defined above, and one or more
polar compound~ of the class of aprotic polar compounds, for
a given concentration of an aluminum organometallic compound
when the value of the molar ratio of the aprotic polar sompound
or compounds to the organo-aluminum compound increase~, the
reaction velocity and the intrinsic vis¢oæity of the polymer
formed increa~e without the micro-structure of the polymer being
changed. Thi~ i9 all the more surpri~ing, since the addition of
polar compounds to organo-lithium initiators leads to a system
which does not change the intrinsi¢ ~iscosity of the polymer
but changes the mi¢ro-structure thereof.
In the case of catalytic systems formed of an
organometallic compound of aluminum having the formula
Me2(Me3R1 R2 R3 R4)2, as defined previously, and a polar compound
selected from among those having one of the formulas
R (0 CH2CH2)n 0 Me1, or (R) ~ CH2CH20 Me1 in which Me1 represents
an alkali metal, R represents an alkyl radical and n is a whole
number, copolymers having a very high content of trans-1,4
linkages (up to 92%)and a very low content of 1,2 or 3,4
linkages, that is to say less than 4~, and which retain an
elastomeric character can be obtained. The copoly~ers of
butadiene and styrene (SBR) thu~ obtained have a resistance to
elongation similar to that of natural rubber when in crude state
(nonvulcanized) and when filled in accordance with the customary
formulations used for the manufacture of automobile tires.
The homopolymerization or copolymerization reaction is
lQ5'~948
- carried out either in an inert hydrocarbon solvent wh1ch may,
for instance, be an aliphatic or alicyclic hydrocarbon, such
a3 pentane, hexane, heptane, iso-octane, cyclohexane, or an
aromatic hydrocarbon, such as benzene, toluene, xylene, or in
bulk polymerization.
~he reaction is generally carried out at a temperature
of between 50C. and 120C. and preferably between 80C. and
100~C., under a pressure which corresponds to the vapor
pressure of the reagents. The process of the invention can be
carried out batch-wi~e or continuously.
~he process not only makes it possible to obtain high
yields of macromolecular compounds per unit of weight of the
catalytic system but it al~o makes it possible to regulate to
the desired extent the molecular weight of the homopolymers or
copolymers prepared.
The process furthermore makes it possible to obtain
homopolymers or copolymers which during the reactio~ can give
rise to grafting reactions with all reagents capable of reacting ;t ~,~
with living polymers.
As representative examples of conjugated dienes which
are suitable for the homopolymerization and copolymerization
mention may be made of 1,3-butadiene, isoprene, 2,3-dimethyl-1,
3-butadiene, 1,3-pentadiene and 2-ethyl butadiene.
As representative examples of suitable vinyl aromatic
compounds mention may be made of styrene; ortho-, meta-, and
para-methyl styrene; di- and polymethylstyrene; para-tert-
butylstyrene, the vinyl naphthalenes; the methoxystyrenes;
the halostyrenes; and divinylbenzene.
~he products obtained by the process of preparation
employing the catalytio system in accordance with the invention
furthermore have a broad molecular weight distribution and a
high intrinsic viscosity, that is to say sufficient 90 that the
-- 6 --
105'~948
product~ can be used as the principal component of mixes 9¢rving
for the manufacture of pneumatic tires, and a micro-structure
which may vary extremely. As a matter of fact, the content of
trans-1,4 linkages may be between 20~ and 90% and the content
of 1,2-linkages may be between 1% and 60%. Furthermore, the~e
products are very well suited for mechanical working on tools.
The invention will be fully underatood from the
following examples which, by way of illustration, describe
~pecial manners for carrying it out. In all the examples the
intrinsic viscosities were determined at 25C. in solution of
1 g. per liter in toluene, the concentrations of catalysts are
expressed in micromols per 100 g. of monomers and the homo-
polymerization or copolymerization reactions were stopped when
the rate of conversion reached 80~ (except in Examples 19, 23
and 27), by addition of methanol in suitable quantities (1%).
The percentages of trans-1,4 linkaees and 1,2 linXages are
expressed with reference to the polybutadiene portion while the
percentage of styrene is expre~sed with reference to the total
amount of polymer obtained.
Example 1
Two liters of heptane were introduced as sol~ent into
a reactor under the pressure of rectified nitrogen whereupon
205 g. of butadiene and 69 g of styrene were introduced and
- the temperature was increased to 80C. ~he catalytic system
formed of Ba ~ l(C2H5)4_72 and of tetrahydrofuran (~HF) in
variable ~uantities was then introduced in succession in four
tests. ~en the rate of conversion wa~ reached, the reaction
was stopped and the copolymer recovered.
The results of the four tests are set forth in the
following table:
-- 7 --
~o5~948
TABLE I
Catalytic System Reaction SBR Copolymers
Time .
~est Ba~ l(C2Hs)4_72 THF Intrinsic Steric
No. . Vi8c osity Conf gur~ ~tion
% tr. % % Sty.
1,4 1,2 Incorp.
T 1820 0 40 hr. 0.8 85 3 15
1 1100 1100 8 hr. 1,6 81 3 15
30 min.
2 1100 2200 6 hr. 2.1 80 3 16
3 1100 4400 4 hr. 2.45 30 4 16
It was found that the reaotion time is 5 to 10 times
less (lest ~ versus Tests 1-3) and that when the value of the
molar ratio 6f ~HF to Ba~ l(C2~5)4 72 increases, the reaction
velocity and the intrinsic viscosity of the SBR copolymer
increase while the microstructure of the SBR copolymer remains
unchanged.
Example 2 -
Four tests were carried out repeating the procedure
of Example 1 with different catalytic systems. ~he results
J
ere aet forth in ~able II below:
-- 8 --
~05'~948
' _
~ O O N ~O U~
O O ~ .
h~
6q C~ _ .
h ~r-- ~-- 0 ~
rPI~ _ _ _
Pl o,~ . _ . _ .
U~ .
, H U~ h o ~ N
` ~1 a
.~, ., . .. ~ , .
O X ~ X
t ~ N N "~ t~ N . -
O CO~ :-
. ~_ ~ ~ N
. . ~
~ O O O O
~ ~ O O 0
O N ~J N ~
~1 1~
0 U~
. $ ~ N N P
~ O C~ 1
Cg h ~ .`
~ o c~ v~ m m
a o _
o 2 _ N t~ ~ .
_ 9 _
~05'~948
ExamPle 3
Three te~tq were carried out. Into a 250 ml. Steinie
bottle under pressure of rectified nitrogen there were introduced
100 ml. of heptane as solvent and 13.6 g. butadiene. The
catalytic system formed of Ba~ l(C2H5)4 72 and methanol was then
introduced. The bottle was placed in a thermostatically controlled
- tank at 80C. in which it was agitated.
At the end of the reaction, the polybutadiene was
recovered in ordinary manner. The results are set forth in
Table III below.
TABLE III
, ~ ~ .
~ Catalytic System Time Polybutadiene
`. i
Test Ba~ l(C H ) 72 Methanol IntrinsicSteric
~` ~o.2 ~ ~- _ _ v~ I ~ tr. ¦ %
i 11100 74 7 hr. 1.64 86 3
21100 222 6 nr. 1.59 84 3
31100 444 5 hr. 1.50 81 ¦ 3
Example 4
A test was carried out repeating the procedure of
Example 3 and using similar conditions except that a catalytic
system formed of ~a~ l(C2H5)4_72 and water was employed. ~he
results are set forth in Table IV below.
TAB~E IV
Catalytic System Reaction Polybutadiene
Time
.
Test Ba~ l(C2Hs)4_72 H20 Intrinsic Steric
No. Viscosity Configuration
r _ ~,4r 1 1~2
L _ 1100 440 17 hr. 1.55 87 ¦ 2
_ 10 --
- 105'~948
ExamPle 5
~ hree tests were conducted, the reaction being carried
out in a reactor under pressure of rectified nitrogen. ~wo
liters of heptane were introduced as solvent followed by 191 g.
of butadiene a~d 82 g. of styrene. lhe temperature was increased
to 80C. and the catalytic system formed of Ba/~l(C2H5)4_72 and
of lithium isopropylate was added. At the end of the reaction,
the copolymer was recovered in a customary manner. ~he results
are set forth in ~able V below.
~AB~E V
'~
_ ~ ,
~ Catalytic System Reaction SBR Copolymers
_
~e~t Ba~Al(c2Hs)~ 2 ~ithium Intrinsic Steric
No. Isopro- Viscosity Configuration
pylate
% tr. % % Sty.
1,4 1,2 I~orp.
1 340 2400 4 hr. 3 83 4 21
2 380 2600 4 hr. 2.6 83 3 20
3 1 550 1380 4 hr. 1.7 at 4 23
.,
ExamPle 6
~wo tests were carried out. Two liters of solvent
(heptane) followed by 205 g. of butadiene and 69 g. of styrene
were introduced into a reactor under the pressure of rectified
nitrogen. Ihe temperature was brought to 80~C. and then the
components of the catalytic system, i.e., N,N,N',N'-tetramethyl-
ethylenediamine (~MED) and ~a~ l(C2H5)4 72' were introduced one
} after the other. The results are set forth in ~able VI below.
.: ' ' .
105~ 948
TABLE VI
Catalytic System Reaction SBR Copolymers
~ime
Iest Ba ~Al(C2Hs)4~ 2 ~MED Intrinsic Steric
No. Viscosity Configuration
% tr. ~ ~ Sty
1,4 1,2 Incorp.
1 2440 1220 45 mhirn. 0.8 84 4 15
2 2440 l2440 ~ hr. 1.5 81 4 16
Example 7
~ wo liter~ of heptane, 205 g. of butadiene and 69 g.
of styrene were introduced into a reactor under pressure of
rectified nitrogen whereupon the temperature was increased to -
- 80C. and 4-methylpyridine or r-picoline and Ba~l(C2H5)4 72
were added one after the other. ~he results are set forth in
Table VII below.
~A~E VII
Catalytic System Reaction SBR Copolylaers
_ _ Iime
Ba [Al(C2Hs)4~ 2 r-picoline Intrinsic Steric
Viscosity Configuration
tr. % % Sty.
1,4 1,2 Incorp.
1100 1100 1 hr.1.30 607 18
40 min.
ii
Example 8
~wo tests were carried out repeating the procedure of
`~ Example 3 using the catalytic system of 13a~1(C2H5)4 72 and
acetonitrile. ~he results are set forth in Table VIII below.
j .
- 12 -
~5'~94~3
TAB~E VIII
`
.
Catalytic Sy3tem Reaction Polybutadiene
Time
Test Ba[Al(C2Hs)4~2 Acetonitrile Intrinsic Steric
No. Viscosity Configuration
; lF-F~- ~,2
1 1100 74 3 hr. 1.6 77 3
45 min.
2 1100 222 3 hr. 1.7 75 5
15 min.
,
Example 9
Three tests were carried out repeating the procedure
of Example 3 and using similar conditions except that acetone
and Ba~ l(C2H5)4_72 were used as the catalytic ~y~tem. The
results are set forth in Table IX below.
;~ ~AB~E IX
Catalytlc System Reaction Polybutadiene
, .
i Test BatAl(C2H5)J 2 AcetoneIntrin~ic Steric
No. Viscosity Configuration
1 1100 74 7 hr. ~ % tr.
2 1100 222 30 mhirn. 1.8 78 3
3 1100 444 5 hr. 2.0 75 4
30 min.
i~ . I . l .
" .
~ ExamPle 10
:~
The procedure of Example 3 was repeated using similar
conditions except that thiodii~obutyl and Ba~ l(C2H5)4_72 were
used as the catalytic system. ~he results are set forth in
~able X below.
- 13 -
.. .. . . : ~ : -
- . ~ . ~. . . .
. . ~ , .
.. . . . . .
.
~,o5~ 948
~ABLE X
Catalytic System Reaction Polybutadiene
Time
,
Ba~Al(c2H ) ~ Thiodi- Intrinsic Steric
S 4 2 ¦i~obutyl l l ¦ 1,4
1100 222 22 hr. 1.50 85 2
Example 11
Three tests were carried out repeating the procedure
of Example 3 and using similar conditions except that hexamethyl-
pho9phorotriamide (HMP~) and Ba~ l(C2H5)4_72 were used a~ the
catalytic system. ~he reYults are set forth in ~able XI below.
~ABIæ XI
., .
,~ Catalytic System Reaction Polybutadiene
Test BaCAl(c2Hs)4~2 HMP~ Intrinsic Steric
No. VisGosity Configuration
. % tr. 1,2
1 1100 2223 hr. 1.55 82 2
2 1100 444152 hirn. 1.68 80 3
3 1100 8882 hr. 2.48 78 3
Example 12
s ~wo tests were carried out repeating the procedure
of Example 3 and using similar conditions except that a catalytic
system formed of BarAl(C2H5)30R 72~ OR being the nonylphenate
radical, and lithium isopropylate were used. The results are
set forth in ~able XII below.
- 14 -
~(~5~948
TABLE XII
Catalytic System Reaotlon Polybutadiene
~est Ba~Al(c2Hs)30R~2 ~ithium Intrinsic Steric
No. Isopropylate Viscosity Configuration
~ tr. 1,2
1 1450 2900 18 hr.1 15 76 4
2 1450 5800 17 hr.1.33 78 4
Under the same conditions the use of Ba~ l(C2H5)30R 72
by itself did not lead to any trace of polymer, even after 48
hours of reaction.
Example 13
~` Two tests were carried out repeating the procedure
of Example 3 and using similar conditions exoept that ~i Al(C2H5)4
and lithium isopropylate were used as the catalytic system. ~he
results are set forth in ~able XIII below. -
_ B~E XIII
Catalytic System Reaction Polybutadiene
Time
.
Test ~i Al(C2X ) ~ithium ~so- Intrinsic Steric
No. 5 4 propylate Viscosity Configuration
tr. 1,2
1 1450 750 3 hr. 1 22 60 8
30 m~n.
2 1450 1450 3 hr. 1.24 60 8
30 min.
s . I .,
Under the same conditions, the use either of
~i Al(C2H5)4 alone or of lithium isopropylate alone did not lead
to any trace of polymer even after 48 hours of reaction.
.
~o52948
Example 14
A test was carried out repeating the procedure of
Example 3 and using ~i Al(C2H5)4, lithium isopropylate and
barium nonylphenate as components of the catalytic system. The
reæults are set forth in ~able XIV below.
TABLE XIV
Catalytic System naction Polybutadiene
, . . . .
~i Al(C2H5)4 ~arium ~ithium Intrinsic Steric
Nonyl- Iso- Viscoæity Configuration
phenate propylate
; ~,4r' ¦ 1~2
1450 725 2900 1 hr.
30 =i~. 2,3 79 4
~; :
As compared with the preceding example 13, the
addition of the barium nonylphenate had the effect of orienting
the micro~tructure. ~-
Example t5 -
A test was carried out repeating the procedure of
Example 3 using a catalytic sy~tem conæisting of ~i Al(C2H5)4,
- and sodium tert-amylate. The reæults are set forth in ~able XV
below.
TA~E XV
Catalytic System Reaction Polybutadiene
~i Al(C2H5)4 Sodium Tert- Intrinsic Steric
_ amylate Viscosity Configu ration
~L ¦ 2900 ~ 4 ¦ 1~2 ¦
- 16 -
~o5~,2948
Example 16
- Two tests were carried out repeating the procedure
of Example 3 except that a catalytic system formed of
Na Al(C2H5)4 and potassium tert-amylate (ROK) wa~ used. ~he
re3ults are set forth in Table XVI below.
TABLE XVI
Catalye~c ~y~t~- - R ~ e~n Polybutadiene
~est Na Al(C2H ) ROE Intrinsic Steric
No. 5 4 Viscosity Configuration
.
%,4r' 1,2
1 1450 725 5 hr. 3.12 37 38
2 1450 1450 5 hr. 2.55 40 36
~ - .
Under the same conditions the use of Na Al(C2H5)4
by itself did not lead to any trace of polymer, e~en after 48
hours of reaction.
I Example 17 -~,
Two te~ts were carried out repeating the procedure
of Example 3 except that a catalytic system formed of K AltC2H5)
and potassium tert-~mylate (ROE) was used. ~he results are set
, forth in ~able XVII below.
~AB~E X~
, . ~- "
Catalytic System Reaction Polybutadiene . . , ,:
~ ~est Intrinsic Steric
~ ~0 ~ ~
1 1450 360 4 hr. 1.37 50 26
30 min.
17
.
' ' ' '' ' ' ~ ' .
`'''` 105~'Z948
Under the same conditlons the use of KAl(C2H5)4 by
itself did not lead to any trace of polymer, e~en after 48 hours
of reaction.
Example 18
A test was carried out repeating the procedure of
Example 3 using a catalytic ~ystem consisting of
CH
; ~i Al(C2H5)3 0 C ~CH3 and barium nonylphenate.
~he results are set forth in ~able XVIII below.
~AB~E XVIII
~,
. 10
Catalytic System Reaction Polybutadiene
Time
~i Al(C2H5)3 - CH ~ 3 Barium Intrinæic Steric
\CH3 Nonyl- Viscosity Configuration
phenate
725 ~ '4
Under the same condltion~, the use of
Li Al(C2H5)30-CH ~ 3 by itself did not -lead to any trace of
polymer, even after ~8 hours of reaction.
Example 19
A test was carried out repeating the procedure of
Example 3 employing a catalytic ~ystem consisting of
~iOAl(C2H5)2 and barium nonylphenate. The polymerization
reaction was stopped when the conversion rate reached 60%
instead oi~ 80%. ~he re~ults sro ~et i'orth in ~able XIX below.
, .
- 18 -
, .
:lOSZ948
TAB~E XIX
.
Catalytic System Reactlon Polybutadiene
Time
lil O Al(C H )z Barium Nonyl- IntrinRic I Steric
2 5 phenate Viscosity Configuration
~, 4r~ 2
2960 740 5 hr. 1 . 9 63 ¦ 6
, .
Under the same conditions the use of LiOAl(C2H5)2
by itself did not lead to any trace of polymer, even after 48
- hours of reaction.
, Example 20
Two tests were carried out repeating the procedure `~ ~ -
of Example 3 using a catalytic system consisting of
(C2H5)3 Al(C2H5)2_7 and lithium isopropylate. The
results are set forth in Table XX below. - - -
TABI E XX
., . ...... _ . . . . ~ - -
Catalytic System Reac ti on
Time Polybutadlene
. ., :,
Test Li[Al(C2H5)30 Al(C2H5)21 ~ithium Intrinsic Steric
No. ~ Iso- Viscosity Configuraki on
propylate
~y _ . _ . ~ ~
. 1 1100 370 30 mhirn. 1.78 58 9
2 1100 1 I 00 30 mlll. 1, 95 59 9
Under the same oonditions the use of
30 ~i~l(C2H5)30 Al(C2H5)2_7 by itself did not lead to any trace
of polymer, even after 48 hours of reaction.
.
- 19
.. . . . .
.
~5"~94~
ExamPle 21
Two tests were carried out repeating the procedure
of Example 3 using a catalytic system consistine of Al(C2H5)3,
lithium isopropylate, and barium nonylphenate. The results are
set forth in Table XXI below.
TAB~E XXI
. . _
Catalytic System Reaction Polybutadiene
Time
Test Al(C H ) Lithium Barium Intrinsic Steric
No. 2 5 3 Iso- Nonyl- V1scosity Can~guration
propylate phenate
.
tr 1,2
1 2900 3600 360 5 hr. 1.7 88 3
1 2900 3600 720 5 hr. 1.35 85 3
.,
;~ Under the same conditions the use of Al(C2H5)3 by
itself did not lead to any trace of polymer, even after 48 hours
of reaction. ~-
Example 22
A test was carried out repeating the procedure of
Example 3 except that a catalytic system consisting of
~i B(C2H5)3C4Hg and barium nonylphenate was used. The results
are ~et forth in Table XXII below.
?AB~E XXII
., .. .
Catalytic System Reaction Polybutadiene
Test ~i B(C2Hs)3C4Hg Barium Intrinsic Steric
No. phenate Viscosity Configuration
. ..
%,4r 1,2
S900 100 4 hr. 1.6 83 3
- 20 -
' ~
5,~2948
Under the same conditions the u~e of
~i ~(C2H5)3C4Hg by itself did not lead to any trace of polymer
even after 48 hours of reaction.
Example 23
A mi~ture of heptane, butadiene and styrene having
a weight ratio of monomers to solvent of 1:5 and of butadiene
to styrene of 3:1 was introduced continously into a reactor.
Ba~ l(C2H5)4 72 and lithium isopropylate were also introduced
continuously in a molar ratio of 1:10 with such a speed that
there was 960 ~ mols of Ba~ l(C2H5)4 72 in the reactor for
100 g. of monomers and that there was an average time of ~tay
in the reactor of 1 1/2 hours. ~he copolymerization was ~ -
effected at sooa. and the reaction wai~ stopped when the percentage
conversion reached was 60% rather than 80%. The copolymer was
recovered at the outlet of the reactor. It contained 16%
styrene and had an intrinsic viscosity of 1.64, a trans-1,4
linkage content of 81% and a 1,2 linkage content of 3%.
Example 24
Two liters of heptane, 191 g. of butadiene ar~d 82 g.
of styrene were introduced into a reactor under the pressure of
rectified nitrogen and the temperature was increased to 80C.
~here was then added in succession the catalytic system formed
of 460 tu mols of Ba~ l(C2H5)4 72 per 100 g. of monomers and
1380 ~ mols per 100 g. of monomers of lithium isopropylate.
When the rate of conversion reaohed 80~o (2 hours), 50 cc. of
copolymer were recovered in customary manner and the reaction
~topped by the addit-ion of methanol. An amount of diphenyl
i carbonate (CDP) was then added to the reactor such that the ratio
i
7 of CDP Ba~ l(C2H5)4_72 wa~ equal to 0.5:1.
< 30 ~he copolymer obtained was recovered by a conventional
method. ~he microstructure of the copolymer obtained before
- grafting and of the grafted copolymer was: 81% trans-1,4 linkages,
- 21 -
~5~948
4~ of 1,2 linkages and 24% incorporated styrene.
The intrinsic viscosity of the ungrafted copolymer
was 1.7 and that of the grafted copolymer was 2.6.
Example 25
1) PreParation of the CoPolymer: Two liter~ of
heptane, 191 g. of butadiene and 82 g. of styrene were introduced
into a reactor under the pressure of rectified nitrogen whereupon
the temperature was increased to 80C. The catalytic system
formed of Ba~ l(C2H5)4_72 and lithium isopropylate waq then
gradually added. When a rate of conversion of 80~ had been
reached, the reaction was stopped and the copolymer recovered
in customary manner. ~he elastomer obtained was then diluted
with 37,5 parts of aromatic oil (Exarol MX 140, marketed by
Compagnie Française de Raffinage) per 100 parts of dry elastomer.
lhe results are set forth in Table XXV A
lAB~E XXV A
_
Catalytic System Reaction SBR Steric Configuration
Time ~ ~-
BatAl(C2H ~d 2 ~ithium Intrinsic ~ tr % ~ Styr.
Iso- Viscosity 1,4 1,2 Incorp.
Propylate Before After
Dilution
With the Oil
1000 7100 5 hr. 2.67 ¦ 1.96 84 4 22
30 min. l _ _
2) Rubber Making Mix:
~he elastomer described abo~e was used to form a
mixture ha~ing the following formula in parts by weight:
100 - Elastomer diluted with 37.5 parts of aromatic
oil
2 - Stearic acid
3 - ZnO
1 -Antioxidant (Santoflex 13: N-(dimethyl 1,3-butyl
N'-phenyl-p-phenylene diamine)
- 22 -
,~ ~o5~948
- HAF Black (Philblack O)
- Aromatic oil (Sundex 8125, PM 380, density 0.995
marketed by Sun Oil)
- Santocure (~-cyclohexyl-mercaptobenzothiazole
; sulfenamide)
~; 1.8 - Sulfur
~ he same mixture was prepared with a butadiene/styrene
copolymer (SBR 1712) available on the market as a control. The
two mixtures were then vulcanized for 60 minutes at 144C.
The mechanical propertie~ obtained are set forth
in ~able XXV B below.
TAB~E XXV 13
Control
Pro~erties (SBR 1712) Test SBR
Modulus at 100% elongation 16 14.9
( kg/cm2 )
Modulus at 300% elongation 67.5 58
(kg/cm2) ~ ,
steresis loss at 60C. 29 24.6
Index of coefficient of
friction at 20C. (SRT) 100 84
20Scott rupture index
- elongation at rupture (%) 570 540
- rupture force (kg/cm2) 231 222
- Shore A hardness 62 60
SBR 1712 is a butadiene/styrene copolymer ¢omprising
23.5% styrene, 15-16% of 1,2 linkage~, 60% of tra~s-1,4 linkages
and 37.5 parts of aromatic oil.
It was found that the elastomer in accordance with
the in~ention ha~ properties substantially equal to those of the
above conventional copolymer. It can be u~ed as the principal
30 component of a mlx for the manufacture of pneumatic tires.
.~
-- 23 --
,;
~., .
.... . . .
-........ ~ ,
''"` ' ' ~ : :
105,'~948
Example 26
This example relate~ to the preparation of
butadiene/styrene copolymers; six tests were carried out.
The copolymerization was effected in a reactor in
an inert atmosphere (rectified nitrogen) at 80C. in the presence
of heptane as solvent. The weight ratio of monomers to sol~ent
was 1:5. The reaction was stopped when the rate of conversion
reached 80%. The conditions of the tests and the results obtained
are set forth in Table XXVI.
TABLE XXVI
Catalytic System
Ba ~ l(C2H5)4_72 and Te~t Nos.
2H5(CH2CH2)2~i 1 2 3 4 5
, -
Molar ratio Li/Ba 1 1 1.5 1 5 2 2
Initial Styrene content 24 32 24 32 24 32
(% by weight)
~ Quantity of 730 600 910 750 400 1300
-~ Ba~ l(C2Hs) 4_72
Reaction time (in140 ` 200 190 270 270 33
minutes) -
Copolymers
-- .
Intrinsic Viscosity2~17 2.08 1 86 2.09 2.1 1.90
Content of trans-1,4(~) 85 85 87 87 90 90
1 Content of 1,2(~o) 3 3 3 3 3 3
i Content of incorporated 15 23 15 23 15 23
styrene (~ by weight)
On test pieces of the copolymer of Test 5 and of
natural rubber (~) filled in accordance with the formulation Of
Example 25 but not vulcanized, force-elongation measurements
(measurement of the green strength) were carried out at 25C.
The force elongation measurement were carried out on "dumb-
bell" test specimen~ of a thickness of 2. 5 mm. and effected with
the u~e of an "In~tron" electronic dynamometer 24 hours after
- 24 -
~05Z948
molding and with a rate of traction of 10 cm./minute. The
result~ obtained are set forth in the graph Or the drawing, the
~ . .
'~ ordinate of which represents the force exerted in g,/m~' and -'
the abscissa represents the elongation (in %). It wa~ found - ,
that the copolymer prepared by the improved method of the
invention had a resistance to elongation similar to that of
- natural rubber.
.~
Exam~le 27
A mixture of toluene, butadiene and styrene in` 1Q proportion~ such that the weight ratio of monomers to solvent
was equal to 1:5 and the ratio of butadiene to styrene was
equal to 3:1 was introduced continuously into a reactor.
Ba~ l(C2H5)4_72 and C2H5(0CH2CH2)20~i were also introduced
~ continuously in quantities such that their moltar ratio was
,~s 1:2. The rate of flow was such that there were 1000 micromols
of Ba~ l(C2H5)4~ 2 in the reactor per 100 g. of monomers and ''
that an average time of stay in the reactor of 1 hour was
~ obtained. ~he copolymerization was effected at 90C. and the
,1 reaction was stopped when,the percentage conversion reached was ~,- ,~ 20 65% rather than 80~. ~he copolymer formed was recovered ' ,
;l continuouæly at the outlet of the reactor. It contained 15~ by
! ' weight of styrene and had an intrinsic viscosity of 1.6. ~he
content of 1,2 linkages was 3% and that of tranæ-1,4 linkages
was 83%. ~ '
ExamPle 28
~he catalytic system of Ba~ l(C2H5)4 72 and
(C2H5)2NCH2CH20~i was used. 100 ml. of heptane as solvent and
13.6 g. of butadiene were introduced into a 250 ml. Steinie
bottle under the pressure of recti~ied nitrogen. The catalytic
system was then added whereupon the bottle wa~ placed in a tank
which was thermostatically controlled at 80C., in which it was
agitated.
- 25 -
,, , ' ' . ,
105;~948
At the end of the reaction, when the percent of
conversion reached 80%, the polybutadiene formed was recovered
by an ordinary method. ~he results are set forth in Table XXVIII.
TAB~E XXVIII
Catalytic System Reaction Polybutadiene
_ (in min.)
¦~9t~ ~Al( ~ )4]21' 2~S)2NC~2Cn2~ ¦ ¦ V~cooity ¦ 1~4 ¦l,Z ¦
~ 100 ¦ 200 60 1 . 75 85 4
Example 29
A test was carried out repeating the procedure of -
Example 28 and using similar conditions except that a catalytic
' ~ l(C2H5)4_72 and C2Hs(0CH2CH2)20Na was u~ed
$ ~he re3ults are ~et forth in Table XXIX below.
~, TAB~E XXIX
.
., .
Catalytic System Reaction Polybutadiene
~, 20 ~ !2~ ~2¦C2~(CC~2C~2)2C~a¦ ¦Intrin~ c ¦ % tr.¦
1 ¦ 100 ¦ 100 3 hr. 5 ¦ 88 ¦ 3 -
..
Example 30 ~:
A test was carried out repeating the procedure of
Example 29 and using similar conditions except that a catalytic
system formed of Ba~ l(C2H5)4_72 and C2H5~0CH2CH2)3Li was
employed. The results are set forth in Table XXX below.
~:
-
'
- 26 -
r`~
105Z948
~ABLE XXX
.~ Catalyti~ Sy~tem Reaction Polybutadiene
.~, (in mi~) .
.), . .
Na Ba ~(C2H5)~2 C2H5(oCH2CH2)3cai Viscosity ~,4tr. 1,2
. 1 100 100 60 2.8 80 4
.~ .
, ,
1~ ..
-- 27 --
. ., :
