Note: Descriptions are shown in the official language in which they were submitted.
3L;2~i~f~3
-- 1 --
23443-323
The present invention relates to low molecular weight
polyalkenamers produced by ring-opening polymerization of cyclo-
octadiene isomer mixtures and useful as binders of coating compo-
sitions.
Low-molecular weight polymers of 1,3-dienes, primarily
polybutadienes wherein the double bc,nds exhibit predominantly
cis-1,4-configuration are conventionally utilized as binders in
air- and oven-drying paints (German Patent 1,186,631 and German
Auslegeschrift (DAS) 1,494,417).
It is furthermore known from German Auslegeschrift (DAS)
1,174,071 to rearrange isolated double bonds in polybutadienes to
conjugated double bonds. As a result, starting with the rela-
tively inert polybutadienes with extensively isolated double
bonds, very reactive polybutadienes are obtained which can be used
in the low-molecular range, inter alia, for the preparation of
self-drying varnishes.
Besides isomerization of isolated double bonds to con-
jugated double bonds particularly in low-molecular polybutadienes
as disclosed, for example, in German Auslegeschrift (DAS~
1,174,071; German Patent 2,342,885; German Offenlegungsschrifts
(DOS) 2,924,548, 2,924,598, and 2,924,577; as well as Published
European Application (EP-A-0) 086 894, another conventional method
for the production of polymeric compounds with conjugated double
bonds is the copolymerization of 1,3-dienes with acetylene
[J. Furukawa et a:l., Journ. Polym. Sci., Polym. Chem. Ed. 14 :
1213-19 (1976)].
~2~6~93
However, all of these prior art products, when used as
binders in painting media, fail to attain air-drying properties of
the especially quickly drying China wood oil (tung oil).
Consequently, it was surprising to find that the low-
molecular weight polyalkenamers produced by ring-opening polymeri-
zation of cyclooctadiene isomer mixtures, especially after iso
merization from isolated double bonds to conjugated double bonds,
reach or even surpass the level of ~hina wood oil with respect to
dust drying and through drying when used as binders in painting
media.
According to an aspect of the present invention, there
is provided a low-molecular weight polyalkenamer having a number
average molecular weight (Mn) of 500 to 6,000, produced by ring-
opening polymerization of a cyclooctadiene isomer mixture con-
taining at most 20% by weight of cis,cis-1,3-cyclooctadiene,
10 - 99~ by weight of cis,cis-1,4-cyclooctadiene, and
substantially the balance of cis,cis-1,5-cyclooctadiene.
According to another aspect of the present invention,
there is provided a process for producing a low molecular weight
polyalkenamer having a number average molecular weight (Mn) of
500 to 6,000, which comprises: simultaneously ring-opening and
polymerizing a cyclooctadiene isomer mixture containing 0.01 to
20% by weight of cis,cis-1,3-cyclooctadiene, 10 to 99% by weight
of cis,cis-1,4-cyclooctadiene and 0.99 to 89,99~ by weight of
cis,cis-1,5-cyclooctadiene, using a ring-opening polymerization
catalyst containing (A) a metal belonging to Sub-Group 5 through 7
of the Periodic Table and (B) a metal belonging to Main Group 1
~Z~ 3
-- 3 --
through 4 of the Periodic Table, in a dry soLvent at a temperature
of -50 to 80~C.
According to a still further aspect of the present
invention, there is provided a coating composition comprising a
painting medium and, as a binder, a low-molecular weight poly-
alkenamer having a number average molecular weight (Mn) of 500
to 6,000, produced by ring-opening polymerization of a cycloocta-
diene isomer mixture containing at most 20% by weight of cis,cis-
1,3-cyclooctadiene, 10 - 99% by weight of cis,cis-1,4-cycloocta-
diene, and substantially the balance of cis,cis-1,5-cycloocta-
diene.
A characterizing feature of the polyalkenes of this
invention with a number average molecular weight ~n) f 500 ~
6,000 is the composition of the cyclooctadiene isomer mixture
used as a raw material of the ring-opening polymerization ~for
details see monograph "Olefin Metathesis" by K.J. Ivin, ~cademic
Press (1983)], which mixture contains, besides cis,cis-1,5-cyclo-
octadiene, at most 20% by weight of cis,cis-1,3-cyclooctadiene and
10 - 99% by weight of cis,cis-1,4-cyclooctadiene.
In general, mixtures of cyclooctadiene isomers are
employed as the starting material which contain 0.01 - 20% by
weight of cis,cis-1,3-cyclooctadiene, 10 - 99% by weight of
cis,cis-1,4-cyclooctadiene, and 0.99 - 89.99~ by weight of
cis,cis-1,5-cyclooctadiene. Preferred are isomer mixtures with
0.1 - 10~ by weight of cis,cis-1,3-cyclooctadiene, 20 - 99% by
weight of cis,cis-1,4-cyclooctadiene, and 0.9 - 79.9% by weight of
cis,cis-1,5-cyclooctadiene. Especially preferred are isomer mix-
3L~63~3
~ 4 ~ 23443 ~23
tures with 30 - 60~ by weight of cis,cis-l,~-cyclooctadiene and up
to 10~ by weight of cis,cis-1,3-cyclooctadiene.
The number average molecular weight of the polyalkenamer is
preferably from about 1,000 to 3,000. Preferably, the polyalkenamer
contains a substantial amount (e.g., 10 to 70 molar ~) of conju-
gated (i.e., 1,3-) double bonds. The polyalkenarner may have an
iodine number of 200 to 500. In the polyalkenamer, -the majority of
the double bonds (i.e., more than 50 molar ~) is usually trans.
As is Xnown, cis,cis~l,5-cyclooctadiene can be obtained
according to various methods with high selectivity and in high
yields by dimerization of 1,3-butadiene (German Patents 1,140,569;
1,144,268; 1,244,172; 1,79~,718; and 1,804,017).
It is then possible, according to the process of German
Offenlegungsschrift (DOS) 3,325,268, to produce, from cis,cis-1,5-
cyclooctadiene, a mixture of isomers with up to 97% by weight o~
cis,cis-1,3-cyclooctadiene and up to almost 30% by weight of
cis,cis-1,4-cyclooctadiene; from this mixture, by distillatory
separation, it is also possible to obtain cis,cis-1,4-cyclo-
octadiene, heretofore accessible only with difficulties, with a
degree of purity of up to 99% by weight.
As for ring-opening polymerization of the individual
cyclooctadiene isomers serving as the starting material for the
polyalkenamers according to this invention, this reaction has been
Xnown for a long time for cis,cis-1,5-cyclooctadiene. As for
cis,cis~l,3-cyclooctadiene, though, the only known aspect was that
it can be reacted to a rapidly crosslinking polymer with a
catalyst based on tungsten hexachloride/diethylaluminum chloride/
~'.
~Zi~9~
-- 5 --
epichlorohydrin in a 40 - 50% yield; this polymer, on aeeounk of
its strong erosslinking property, eannot be characterized in any
more detail [Y.V. Korshak, J. Mol. Catal. 15 : 207 (1982)].
Finally, the above-cited monograph "Olefin Metathesis" by K.J.
Ivin mentions with respect to cis,cis-1,4-cyclooctadiene that it
has thus far been impossihle to polymerize this monomer in a ring-
opening mode [A.J. Amass et al., Eur. Pol. J. 12 : 93 (1976)].
It has furthermore been known that polymerization of
eis,cis-1,5-cyclodecadiene, though initially yielding an expected
alternating copolymer of eyelobutene (or butadiene) and cyclo-
hexene, then progresses to decomposition into polybutene (= 1,4-
polybutadiene) and cyclohexene [Hocks et al., J. Pol. Sci. Pol.
Lett. 13 : 391 (1975)].
In view of this state of the art, it eould not be
expeeted that mixtures of eyclooctadiene isomers containing,
besiaes eis,eis-1,5-eyelooetadiene, up to 20% by weight of
eis,eis-1,3-eyelooetadiene and 10 - 99% by weight of cis,eis-1,4-
eyelooetadiene ean be polymerized with ring opening without the
oeeurrenee of the aforementioned complieations (minimum yields,
six-membered ring eleavages).
It is especially surprising to note that the polymers
formed from cis,cis-1,4-eyelooetadiene do not split off their
=CH-CH2-CH= units as 1,4-cyelohexadiene although this reaetion was
expeeted from the behavior of the linolic and linolenic aeid
esters under metathesis eonditions (C. Boelhouver and E.
Verkuijlen, Chem. Comm. 1974 : 793).
ii64~33
- 6 - 23443-323
It is furthermore remarkable that the ring-opening poly-
merization of cis,cis-1,4-cyclooctadiene and cis,cis-1,5-cyclo-
octadiene is by far not so strongly inhibited as, for example,
that of cyclooctene by the presence of the 1,3-isomer.
The polyalkenamers of this invention can be produced
according to any processes of the prior art which concern the
ring-opening polymerization of cyclic olefins having at least one
unsubstituted double bond (~erman Offenlegungsschrifts 1,570,940;
1,645,038; 1,720,798; 1,720,820; 1,770,143; and 1,805,158; German
Auslegeschrift 1,299,868; British Patents 1,124,456; 1,194,013;
and 1,182,975). The catalysts utilized for this ring-opening
polymerization contain, as is known, compounds of metals of Sub-
groups 5 through 7 of the Periodic System of the Elements (PSE),
primarily those of niobium, tantalum, molybdenum, tungsten,and
rhenium, as well as metals of Main Groups 1 through 4 of the PSE,
such as aluminum or their alkyls or hydrides derivatives,
optionally with additional ligands, such as, for example, halogen,
alkoxy or carboxylate, or Lewis acids in their place. Besides,
these catalyst systems, also called metathetic catalysts, can
contain further activating additives, such as, for example,
alcohols, epoxides, hydroperoxides, vinyl ethers and esters, and
allyl ethers and esters, vinyl halides, and aromatic nitro
compounds.
Particularly preferred catalysts contain tungsten
compounds, for example, tungsten halides (e.g. WC16) and aluminum
compounds, for example, alXyl aluminum halides (e.g. EtAlC12 and
iBuAlC12). These preferred catalysts may further contain
~. .
~L2~i~493
-- 7
activating additives, such as, lower alCohols ~methanol, ethanol,
etc.) and allyl ethers (allyl tribromophenyl ether, etc.).
The reaction can be conducted in any inert solvents
known to be suitable in polymerization with the aid of Ziegler-
Natta catalysts. Suitable are aliphatic, alicyclic, aromatic, and
halogenated hydrocarbons, and particularly suitable are the
following: pentane, hexane, heptane, n- and isooctane, isononane
(hydrogenated trimer propene), n-decane, isododecane (hydrogenated
tetramer propene), cyclopentane, cyclohexane, methylcyclopentane,
methylcyclohexane, ethylcyclohexane, isopropylcyclohexane, cyclo-
octane, decahydronaphthalene, hydrogenated terpenes, such as
pinane and camphane, cyclohex~ne and its substitution products,
benzene, toluene, o-, m-, p-xylene, ethylbenzene, o-, m-, p-di-
ethylbenzene, n-propylbenzene, isopropylben~ene and other mono- to
polyalkylbenzenes, tetrahydronaphthalene, methylene chloride,
chloroform, carbon tetrachloride, 1,2-dichloroethylene, trichloro-
ethylene, tetrachloroethylene, chlorobenzene, o-dichlorobenzene,
trichlorobenzene (mixture of isomers), bromobenzene, fluoro-
benzene, 1,2-dichloroethane.
It is extremely desirable to use solvents, completely or
substantially freed of water and other ~-acidic compounds as well
as compounds having donor functions (Lewis bases), by means of
suitable purification. Except for very small amounts optionally
added to obtain specific effects, such impurities generally impair
catalyst activity.
The process of this invention is usually performed at
temperatures of between -50 and +80C. The reaction temperature
~i64~3
- 7a - 23443-323
herein is limited in the upward direction by the thermal stability
of the catalyst and in the downward direction by an excessively
reduced reaction velocity. The process is advantageo-lsly con-
ducted at temperatures of between -30 and +60C, but preferably
in a range between 0 and ~50C that can be realized with special
ease.
The polyalkenamers of this invention, on account of
their molecular weight, are readily fluid to highly viscous
liquids. In order to obtain them, it is usually necessary to add
to the polymerization charge, so-called molecular weight modifiers
which are optionally substituted open-chain olefins of 2 - 30
carbon atoms (German Offenlegungsschrift 2,922,335 and German
Patents 1,919,047; 1,945,35S3; 2,027,905; 2,028,716; 2,028,935,
2,105,161; and 2,157,405). The amount of the modifier to be added
depends on the desired molecular weight of the polyalkenamer and
generally is 1 - 20, preferably 3 - 12 mole percent, based on the
total cyclooctadiene isomer raw material.
In general, the procedure in preparing the polyalkenamers
of the invention involves putting the cyclooctadiene isomers
together with the modifier into the solvent, adding the individual
catalyst components, and performing the polymerization under
agitation and optionally with removal of heat of reaction. The
polymerization can, of course, also be conducted in partial steps,
i.e. monomers, modifiers and catalyst components can be repeatedly
introduced subsequently in metered amounts. Once the desired or
attainable conversion has been achieved, the catalyst is
deactivated by addition of an alcohol, such as, for example,
~2~i6493
- 7b - 23443-323
methanol, or other H-acidic compounds, optionally in admixture
with alkaline compounds, such as sodium hydroxide. Then the
polymer-containing phase is washed with an aqueous, aqueous-
alcoholic or alcoholic solution of agents having a dissolving
effect on the catalyst residues which latter are present initially
as alcoholates or compounds of the H-acidic materials. Such
dissolution-promoting materials are, for example, acids, alkaline
solutions, or complex-forming agents, such as citric or tartaric
acid, methanolic potassium hydroxide solution, acetylace~one,
ethylenediaminetetraacetic acid, and nitrilotriacetic acid.
Thereafter the polymers are separated by precipitation, for
example by pouring into a precipitant, such as, for instance,
methanol or isopropanol, or by removing the solvent by distilla-
tion, e.g. by blowing in steam or by passing the polymer solution
throuyh nozzles into hot water.
In order to protect the resulting polyalkenamers against
oxidation, gelling and other aging phenomena, stabilizers, for
example, aromatic amines or sterically hindered phenols, can be
admixed to the polyalkenamers of this invention in various pro-
cessing stages. It is likewise possible, if necessary, to effectfurther purification of the polymers by reprecipitation. After
these operations, the polymers are dried as is conventional, for
example in a vacuum drying cabinet or by means of a rotary evapor-
ator.
The polyalkenamers of this invention are well suitable,
as mentioned hereinabove, as binders in paint media, especially
after previous isomerization, for example according to the method
, . ~
- 7c -
of DOS 3,003,894. They can be intermixed, within the scope of
their compatibility, with other binders, e.g. the isomerized,
low-molecular polybutadienes obtained according to the process of
EP-A 0 086 894, to such an extent that the good properties in
connection with varnishing technology are brought out.
'
~,, ' ,
12~i6~93
- 8 -
The present invention is described in
greater detail by the examples below. In the latter,
the following terms are written as the abbreviations
appearing below:
cis,cis-Cyclooctadiene = COD
Ethyl = Et
Isobutyl = isu
Allyltribromophenyl ether = ATBPE
Double bond(s) = DB
Iodine number [g iodine/100 g compound] =
IN
Number-average molecular weight
(determined by vapor pressure
osmosis) = Mn
Infrared = IR
Ultraviolet = UV
Nuclear magnetic resonance = NMR
~266493
.
Example 1
In a 6-liter glass reactor with face ground
lid, equipped with agitator, thermal probe, dropping
funnel, as well as feed and discharge conduits for
protective gas, 3 1 of hexane and the partial amount
of 250 g of a mixture of 376 g of 1,4-COD (49.2% by
weight), 376 g of 1,5-COD (49.2~ by weight), 12 g of
1,3-C~D (1.6% by weight), and 59 g of l-octene were
combined under dry argon with 10 mmol of WC16 (in the
form of a 0.1-molar solution in chloroben~ene),
10 mmol of EtOH (in the form of a 0.1-molar solution
in chlorobenzene), 10 mmol of ATBPE (in the form of a
0.1-molar solution in chlorobenzene), and 70 mmol of
EtAlC12 (in the fo~m of a l-molar solution in chloro-
benzene), and, with e~ternal cooling, the remaindero~ the monomer/modifier mi~ture was added to the
reaction mi~tu~e through the dropping funnel within
10 minutes, the temperature rising from 20 C to 46 C.
Thereafter, once more the same amount of catalyst was
added to the reaction mixture, the latter polymerized
for 15 minutes, and the reaction stopped with a solu-
tion of 30 g o~ potassium hydroxide in 300 ml of
methanol. The polymer was precipitated into 6 1 of
methanol, washed twice with respectively 4 1 of
methanol, dissolved in 2 1 of toluene, insoluble
proportions were filtered off, precipitated into
4 1 of methanol, washed with 2 1 of methanol, and
dried under vacuum at 70 C.
The result was 522 g of an oil having the
following characteristic data:
DB Configuration [~ trans/vinyl/cis] as
per IR analysis: 67/4~29.
DB Positioning [~ 1,4-/1,5- and more remote/
vinyl] by NMR analysis: 54/42/4.
3S IN: 392
~n: 2,050
- .
~266493
-- 10 -- ,
Example 2
In a 2-liter glass reactor, equipped like
the 6-liter glass reactor descxibed in Example 1,
54 g of 1,4-COD (45.5% by weight), 54 g of 1,5-COD
(45.5% by weight), 10.8 g of 1,3-COD (9~ by weight),
and 11.2 g of l-octene in 500 ml of hexane were
combined with 3 mmol of WC16 lin the form of a 0.1-
molar solution in chlorobenzene), 3 mmol of EtOH (in
the form of a 0.1-molar solution in chlorobenzene),
3 mmol of ATBPE (in the form of a 0.1-molar solution
in chlorobenzene), and 21 mmol of EtAlC12 (in the form
of a l-molar solution in chlorobenzene~, and the
- mixture was polyme~ized under agitation for 15 min-
utes, the temperature rising during this step from
21 ~ to 40 C. Thereafter polymerization was
stopped by adding a solution of 4 ~ o~ potassium
hydroxide in 100 ml o~ methanol. The polymer was
precipitated into 1 liter o~ methanol, washed with
1 liter of methanol, dissolved in 50~ ml of toluene,
a small amount o~ insoluble material was removed by
filtration, and th~ product was reprecipitated as
described above and washed under agitation. A~ter
removal of the volatile proportions under vacuum on
a rotary evaporator at 70 C, 78 g o~ an oil was
obtained having the following characteristics:
DB Configuration [% trans/vinyl/cis] deter-
mined by IR analysis: 64/4/32.
DB Positioning [% 1,4-/1,5- and more
remote/1,3-/vinyl] determined by NMR analysis:
56/35/5/4.
Mn: 1,480
~Z66493
- 11 -
Example 3
In the 2-liter glass reactor of Example 2,
there were added to 100 ml of chlorobenzene first of all
0.5 mmol of WC16 (in the form of a 0.1-molar solution
in chlorobenzene),
O.5 mmol of EtOH (in the fo~m of a 0.l-molar solution
. in chlorobenzene),
O . 5 mmol of ATsPE (in the form of a 0.1-molar solution
in chlorobenzene), and
3.5 mmol of iBuAlC12 (in the form of a l-molar solution
in chlorobenzene),
then a mixture o~ 10.8 g of 1,4-~OD (20% by weight),
35.1 g o~ 1~5-~0~ ~65% by weight~, ~.1 g o~ 1,3-COD
(15~o by weight~, and 2. a g of l-octene. The batch was
polymerized un~e~ agitation fo~ 20 minute~, ths
temperature rising ~rom 2~ C t~ 42 ~ ~herea~ter
; 2 g o~ potassium hydroxi~e in 50 ml o~ methanol wa~
added, the polyme~ was pre~ipitated by ad~ing 1 llter
o~ methanol~ the precipitated produ~t was washed with
50Q ml o~ methanol, then ~issolved in 250 ml o~ he~ane,
a small amount o~ insoluble mate~ial wa~ filteEe~ ~r
an~ the he~ane wa~ removed on a rotary evaporatoE at
a~o ~ thus obtaining 31 9 o~ an oil having the
characteristic data set ~orth below:
DB ~on~iguration [~ trans/vinyl/cis] deter-
mined by IR analysis: 67~1/32.
D~ Positioning [~ 1~4~ 5- and more remote/
1,3-/vinyl] determined by NMR analysis: 36/53/9/2.
Mn: 1,870
'
6~ 3
- 12 -
Example 4
(a) Isomerization of a Po.lyalkenamer
According to Invention
._______________________________
. Under a protective gas atmosphere (nitro-
gen), a three- necked flask having a capacity of ~ liters
and equipped with reflux condenser and thermometer was
charged with 750 g of a pol~ner having the following
characteristic data and having been prepared from
equal parts of l,4-COD and 1,5-COD (49.2% by weight)
as well as 1.6~ by weight of 1r3-COD~in
750 g of dry toluene:
DB Configuration [% transtvinyl/cis] deter-
mined by IR analysi.s: 67/4/29.
DB Positioning [% 1,4-/1,5- and more remote~
15 vinyl] determined by NMR analysis: 58/38~4.
Conjugated DB [as % o~tadiene] determined by
UV analysis: 1.1.
IN: 377
Mn: 1,850
.
After heating to 80 C, isomerization was
performed with the catalyst according to ~xample 6 of
DOS 3,003,894 by agitating the batch for 30 minutes at
80 C. Since the reaction was slightly exothermic,
cooling had to provided at times. Subsequently the
- 25 mixture was rapidly cooled down to room temperature
(20 C) and the insoluble portions were separated by
filtration under pressure. After removing the solvents
: on a rotary evaporator in an oil pump vacuum, 675 g of
a viscous, brownish oil was obtained having the
following analytical data:
DB Configuration [% trans/vinyl/cis] deter-
mined by IR analysis: 69/3/28.
DB Positioning [% 1,3-/1,4-/1,5- and more
remote/vinyl] determined by NMR analysis: 44/-/53/3.
. .
- , . '
.
~L2~6~9~
~ 13 - ,
Conjugated DB [as % octadiene/-triene/-tetra-
ene] determined by UV analysis: 21/1.6/0.48.
IN: 337
Mn: 1,870
(b) Testing of AiI-Drying Properties
The specimens were applied to glass
plates in the coating thickness indicated in the
table by means of an applicator frame and stored
horizontally in a climate 23/50 according to DIN 50 014,
illumination: "Osram" daylight lamp. Siccative: 0.04% Co.
- The abbreviations in the table mean the following:
ST = dust drying time, drying stage 1,
DIN 53 150, in hours (h)
DT = complete drying time in hours ~h~,
measured according to DE~ 1053, method 8, load 2.27 kg.
.,
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