CA1340147C - Process for producing cycloolefin random copolymers - Google Patents

Abstract

Disclosed herein is a process for the production of cycloolefin random copolymers by copolymerization of ethylene with a cycloolefin of the general formula [I]

Description

134~147 Title PROCESS FOR PRODUCING CYCLOOLEFIN
RANDOM COPOLYMERS
This is a divisional application of Canadian Patent Application Serial No. 610,411 filed September 6, 1989.
Field of the Invention The invention relates to a process for the production of cycloolefin random copolymers. More particularly, it relates to a process for the production of cycloolefin random copolymers which are excellent in heat resistance, heat aging property, chemical resistance, solvent resistance, dielectric property, rigidity as well as impact property.
The subject matter of this divisional application is directed to such a process in which a copolymerization is carried out in a hydrocarbon solvent in the presence of a catalyst in a polymerization reactor in which a gas phase is not substantially present, described more in detail hereinunder (fourth process). The subject ~atter of the parent application was restricted to the other processes disclosed in this specification. However, it should be understood that the expression "the invention" or the like encompasses the subject matter of both the parent and this divisional applications.
Background of the Invention It has been recently found that random copolymers of ethylene and specific bulky cycloolefins are excellent in transparency and have balanced heat resistance, heat ageing property, chemical resistance, solvent resistance, dielectric -- 13401'~7 characteristics and mechanical properties, and such random copolymers were proposed in U. S. Patent No. 4,614,778 and Japanese Patent Laid-open Publication No. 61-98,780 (1984).
While the random copolymers proposed have excellent properties as described above, they are likely to contain an amount of unreacted cycloolefin monomer, which impairs the quality of the products. Japanese Patent Laid-open Publication No. 62-215,611 discloses a process for removing the unreacted cyclo-olefin monomer from the ethylene-cycloolefin random copolymers.
By the process disclosed in Japanese Patent Laid-open Publication No. 62-215,611, there can be obtained cycloolefin la 2 13401i~7 random copolymers of higll quality wllich are suitable for use in optical materials, in particular optical memory discs. This process is, llowever, complicated, and is hardly productive of a purified product of a unifonn quality unless the starting copolymer have a molecular 5 weight within a certain limited range.

Because of their excellent properties ethylene-cycloolefin random copolymers find tlleir application in various other fields, alld thus, desired in the art is a process for removing unreacted 10 cycloolefin monomer from ethylene-cycloolefin random copolymers having a molecular weight within a wide range.

Further, the inventors have found some problems that upon continuous copolymerization of ethylene with a bulky cycloolefin in a 15 polymerization vessel equipped with a stirrer, although depending upon the reaction conditions, undesirable copolymers which have unduly high content of ethylene and are insoluble in a hydrocarbon solvent used in the polymerization reaction (referred to hereinafter as solvent-insoluble copolymers) are liable to be formed on the wall 2 0 of the polymerization vessel in the vicinity of the gas-liquid interface in the vessel, that the solvent-insoluble copolymers formed on the wall of the vessel in the vicinity of the gas-liquid interface invite changes in conditions of tlle gas-liquid interface with time and, when formed in large amounts, result in decrease of the effective area of 2 S the gas-liquid interface, that on that account the copolymerization of etllylene and the cycloolefin does not proceed sufficiently, ànd that the solvent-insoluble copolymers formed on the wall of the vessel 3 I3~014 7 fall off in the liquid phase in the vessel, withdrawn tllrough a pick up line together with the desired copolymer produced, and trapped by a filtering device installed in the pick up line to clog the filtering device and occasionally the pick up line in itself, thereby hindering a 5 continuous and stable running of a series of apparatus for the production of the ethylene-cycloolefin random copolymers including the filtering device.

Object of the Invention The invention intends to solve the above discussed problems, and an object of the invention is to provide a process for the production of cycloolefin random copolymers, which process comprises simple steps and is capable of economically producing cycloolefin random copolymers of high quality with any unreacted 15 cycloolefin monomer substantially removed and having excellent heat resistance, heat aging property, chemical resistance, solvent resistance, dielectric property, rigidity as well as impact property.

Another object of the invention is to provide a process for the 2 0 production of cycloolefin random copolymers by copolymerizing ethylene with a cycloolefin in a polymerization reactor, whicll process is capable of ensuring a smooth copolymerization of ethylene and the cycloolefin and maintaining a continuous and stable running of the apparatus for the production of ethylene-cycloolefin random 2 5 copolymers for a prolonged period of time, and which is productive of ethylene-cycloolefin random copolymers which have uniform 13~0147 quality and are excellent in heat resistance, heat aging property and various mechanical properties.
Summary of the invention A first process for the production of cycloolefin random copolymers according to tl1e invention comprises flash drying a solution of a cycloolefin random copolymer in a hydrocarbon solvent, the solution being obtained by a copolymerization of ethylene and a cyclool.efin of the yeneral formula [I]:
. ~3 ~ 1~

n1u Il~r, ~ ~10 11 ~ [I]

nt ~ n,n (wherein n is 0 or a positive integer, and R to R are the same or different, and each represent a hydrogen or halogen atom or a hydrocarbon group, or R (or R ) and R (or R ), when taken together with the carhon atoms to which they are attached, form a mono- or poly-cyclic ring) in the hydrocarbon solvent in the presence of a catalyst.
More specifically, the flash drying step may include:
pre-heating the solution of the cycloolefin random copolymer;
flash-dryiny the pre-heated solution using a double pipe flash drier equipped with heat source to remove substantially all unreacted cycloolefin and the hydrocarbon solvent; and passing the thus obtained cycloolefin random 134~1~7 copolymer through an extruder equipped with a vacuum vent.
The flash-drying step of second and third processes has the same meaning.
A second process for the production of cycloolefin random copolymers according to the invention comprises admixing a first solution of a first cycloolefin random copolymer [B] in a first hydrocarbon solvent and a second solution of a second random copolymer [C] in a second hydrocarbon solvent to provide a mixed solution in which from 5 to 100 parts by weight of the second cycloolefin random copolymer [C] is present based on 100 parts by weight of the first cycloolefin random copolymer [B] present therein, wherein the first solution is obtained by a copolymerization of ethylene and a cycloolefin of the general formula [I] mentioned above in the first hydrocarbon solvent in the presence of a catalyst, the first cycloolefin random copolymer [B] having an intrinsic viscosity [~] of from 0.05 to 10 dl/g as measured in decalin at 135 C. and a softening point (TMA) of at least 70~C., and the second solution is obtained by a copolymerization of ethylene, at least one a-olefin other than ethylene and a cycloolefin of the general formula [I] mentioned above in the second hydrocarbon solvent in the presence of a catalyst, the second cycloolefin random copolymer [C] having an intrinsic viscosity [~] of from 0.01 to 10 dl/g as measured in decalin at 135 C. and a softening point (TMA) of less than 70 C.;
and flash drying the mixed solution.
A third process for the production of cycloolefin random 13~0147 copolymers according to the invention comprises admixing a first solution of a first cycloolefin random copolymer [B] in a first hydrocarbon solvent and a third solution of a third random copolymer [D] in a third hydrocarbon solvent to provide a mixed solution in which from S to 100 parts by weight of the third cycloolefin random copolymer [D] is present based on 100 parts by weight of the first cycloolefin random copolymer [B] present therein, wherein the first solution is obtained by a copolymerization of ethylene and a cycloolefin of the general formula [I] mentioned above in the first hydrocarbon solvent in the presence of a catalyst, the first cycloolefin random copolymer [B] having an intrinsic viscosity [~] of from 0.05 to 10 dl/g as measure in decalin at 135 C. and a softening point (TMA) of at least 70~C., and the third solution is obtained by a copolymerization of ethylene, at least one of propylene and butene and a cycloolefin of the general formula [I] mentioned above in the third hydrocarbon solvent in the presence of a catalyst, the third cycloolefin random copolymer [C] having an intrinsic viscosity [~] of from 0.01 to 10 dl/g as measured in decalin at 135 C. and a softening point (TMA) of less than 70 C.; and flash-drying the mixed solution.
By the first, second and third processes according to the invention in which a solution of cycloolefin random copolymer(s) in a hydrocarbon is flash-dried, there can be economically and effectively produced cycloolefin random copolymer(s) of high quality having any unreacted cycloolefin 13~0147 monomer substantially removed with no need of any complicated process steps.
In a fourth process for the production of cycloolefin random copolymers according to the invention, the copolymerization of ethylene with a cycloolefin of the general formula [I] mentioned above in a hydrocarbon solvent in the presence of a catalyst is carried out in a polymerization reactor in which a gas phase is not substantially present.
The process in which ethylene is copolymerized with the cycloolefin in a polymerization reactor where substantially no gas phase is present, ensures a smooth copolymerization of ethylene and the cycloolefin and a continuous and stable running of the apparatus for the production of ethylene cycloolefin random copolymers, and makes possible to produce ethylene cycloolefin random copolymers which have a uniform quality and are excellent in heat resistance, heat aging property and various mechanical properties.
Detailed Description of tl-e Invention The process according to the invention will now be illustrated in detail.
First, the steps of the first process for the production of cycloolefin random copolymers according to the invention will be specifically described in sequence.
Cycloolefin monomers In the first process according to the invention, at least one cycloolefin of the following general formula [I] is 13401~7 copolymerized with ethylene.

~, R12 ~ ~ [1]

n'l ~ 1-, n In the general formula [I~, n ls 0 or a positlve integer, and R to R are the same or different, and each represents a hydrogen or halogen atom or a hydrocarbon group, or R (or R10) and Rll (or R12), when taken together with the carbon atoms to which they are attached, may form a mono- or poly-cyclic ring.
The symbol n is preferably 1 or 2. The hydrocarbon group as R to R12 preferably has 1 to 4 carbon atoms and the cyclic ring formed by R9 and Rll or R10 and R12 together with the carbon atoms to which they are attached is preferably a 5- or 6-membered monocyclic ring.
The cycloolefins represented by the general formula [I]
can be easily prepared by condensation of cyclopentadienes with appropriate olefins by Diels-Alder reaction.
Examples of the cycloolefins represented by the general formula [I] include such compounds as exemplified in Table 1, and in addition to 1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene, such octahydronaphthalenes as 2-methyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene, 2-ethyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene, 2-propyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene, 2-hexyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene, 2-stearyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene, 2,3-dimethyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene, 2-methyl-3-ethyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene, 2-chloro-1,4,5,8-dimethano-13401~ 7 I ,2,3,4,4a,5,8,8a-octallydronapllthalene, 2-bromo- 1 ,4,5,8-dimetllano-1,2,3,4,4a,5,8,8a-octahydronaphthalene, 2-fluoro-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octallydrollaplltllalene, 2,3-dichloro-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene, 2-cyclohexyl-S I ,4,5,8-dimethano- 1 ,2,3,4,4a,5 ,8,8a-octahydronaphtllalcne, 2-n-butyl- 1 ,4,5,8-dimethano- 1 ,2,3,4,4a,5,8,8a-octahydronaphthalene and 2-isobutyl- 1 ,4,5,8-dimethano- 1,2,3 ,4,4a,5,8,8a-octahydronaphtllalene.

I, 13401~7 ChCllliCRI fOrlnUI~l CO~ OUI1~1 nalnC

I~ icyclo[2,~, 1 ] 11Cpt-2-CIlo --C H ~
6-Methylbicyclo[2,2, 1 ]llept-ene ¢~L 5,6-I~imctllylbicyclo[2,2,1]11cpl-2-cllc C 1-1, ~a 1 -Met~lylbicyclo[2,2, r ] 1lepl-2-e,le ¢~3 C 2 H ~

6-Etllylbicyclo[2,2, 1 ]11ept-2-ene C i H 1, 6 -B u tylbicyclo[2,2, 1 ] hept-2-ell e i C ~ H 9 ~ 6-Isobutylbicyclo[2,2,1]11ep~-2-ene . .

13101~7 ~ C H . 7 -Metllylbicyclo[2,2, 1 ] 11ept-2-cnc ¢~ Ietracyclo[4,4,0,12 5,17-l~]-3-(lo(lcccllc 8-Methyltetracyclo[4,4,~), C H, 12-5,17 10]-3-dodeceno 8-Ethyltetracyclo~4,4,0, C :~ H ~ 12-5,17-10~ _3 -dodeccne 8-Propyltetracycîo[4,4,~, 12-5,1 7-lOJ-3 -dodecellc ¢~ 8-Hexyltettacyclo[4,4,0, C. ~ ~, . 12 5,17-l0]-3-dodecene ¢~ 8-Stcaryl~etracycl~[4,4,~, C, ~ H, ~ 12-5, 17 l0] -3 -dodecene 13401~7 ¢~X C H ~ 8 ,9-Dime(llyltclr:lcyclo[4,4,(), C ~ ~ 12 5,17-1~]-3-~o~ccc~lc ~C H, 8-Metllyl-9-etllyltctracyclo[4,~1,(), C 2 H ~ 12-5,17-l0]-3-dodeccnc 8 -Cllloro tctr:lcyc lo [4 ,~1 ,U, ~C I 12-5,17-l0~-3-dodeccne ¢~1 8-I~romolctracyclo[4 4 () ~3 r 12-5,1 7-l0~ 3 -dodecetlc ' 8-~luorotelracyclo[4,4,(), 12-5,17-10~-3-dodeccne 1 4 134~ 147 ~C I 8,9-Diclllorolclr~cyclo[4,4,().
~C 1 . 1 2-5,17-l0~-3-dodccelle [~ 8-Cyclollcxyltctr~cyclo[4,4,(), ~ 12 5,17-l~~-3-,dodeccllc C H 2 C H 8-Isol)utyltotr~cyclo~4,4,~), C H ~ 1 2-s, 1 7-lO] -3 -dodccene ¢~ 8-Butyllctr~cyclo[4~4 C " H D 12-5,17-l0]-3-dodecene 8-13tllylidelletelr~cyclol4,4,0, ~V--C ~I C ~} ~ 12-5,17 1~]-3-dodecene ~CII " 8-Elllylidelle-9-1nctllyltettacyclo ~LCIIC~ 4,4,0,12-5,17-1~]-3-dodccene 13101~ ~

C211 0 8-Etllyli(Jcnc-9-ctllyllctr;lcyclo ~V--C11 Cll " ~4,4,~),12-S, 17 10~ -3-doclecclle CH ~ C~l ~ ) 2 ~=CH CH, 8 -Ethylidcnc-9-isor)ror~yl tetr~cycl o ~4 ,4 ,0,12-5,17-1~]-3 -dodcccnc ~L~C, H D 8-Et11ylidct~c-9-butyllctr~lcyclo ' [4,4,0,12-5,17-l0]-3-dodecclle 8-n-Propylidelletctr~cyclo ~CH CH 2 CH J
[4,4,0,12 5,17-l0]-3-dodcccne ~ J 8-n-Propylidclle-9-1nclllyllclr;lcyclo ~CHCH~CH~ 14,4,o,12.5,l7.10J 3-dodccenc ,HO 8-n-Propylidene-9-etllyltelr~cyclo CHCH~CHJ 14.4Ø12 5,17-l~]-3-dodeccne 1 6 l3~ol t 7 CH(CH;,)~ 8-1l-Propylidcl~e-9-rr~ isoprc7pyllclr~cyclo[4~4~o~ 12-5,17 I()J -3 -~LCH CH 2 C H ~
d odeccllc ~C ~ H 0 8 -Il-I'ropylidcllc-9-l7utyllctr.lcyclc7 [4,4,0,12-5,17-1~]-3-dodcccllc ¢~=C-CH " 8-lsoprol7ylidcllclclr~cyclo CH " [~1,4,0,12 5,17-l0]-3-dodcccnc CH ~

¢~=C . CH ~ 8-Iso~ropyliclclle-9-1llclllylîelr~cyclo CH~ [4 4 0 l2-5 l7-l0J-3-dodcccllc G~C2H o 8-Isopropylidellc-9-elllyltclr~cyclo CH, [4,4,0,125,17 ~~J-3-dodccene - 17 l~4olq7 l;H ( ~;H J ) i 8-lsopropyli~lcl~c-9-~¦)=(;-CH~ isol~ro~yltctr~cyclo[~ ,(),12-5,17-10]_3_ CH~ dodecellc ~-~-CH 8-Isopro~yli~lcllc-9-l~utyltctr:lcyclo C~l~ [,1 4 ~ l2.s 17.10]-3-(lo(lcccllc C H "

5,10-Ditt~ctllyltctt~cyclo C H, [4,4,~,12-5,17 l0J-3-dodcccllc C ~1, C H~
2,10-Dimctllyltctr;lcyclo-~4,4,0,12-5,17-10l-3-dodecelle C ~1, C H

2-Dil11cll~yl(clr;1Cyclo-[4,4,~),12-5,17-10] -3 -dodecellc C HJ

¢~ 2~7~9-Tr~ clllyltctr:lcyclo-C H . 14,4,(),12 5,17- 10] 3 -dodccenc . .

1~ 13401~7 C H J
C 2 H O 9-Etl1YI-2~7-~l;mCll1YIlClraCYC1O-C HJ [4,4,0,12 5,17 ~0]-3-dOdCCCIIC
C H ~ C H ~
C 1-1 2 C H 9-Isol7utyl-2,7-dimctllyllclracyclo-C ~1 J ~4 ,4,0,12 5 ,17 10] -3 -dodcccllc CHJ C~J
¢~--C H J 9,1 1~12-1'r;1~Cll~Y1lClr~lCYCIO-[4,4,0,125,17 10]-3-dodcccllc C H J C H J
¢~ ~C 2 H O 9-Et11yl-l 1,12-dimetliyllelr~cyclo-[4,4,0,12 5,17 1 ~] -3 -d odeccnc Cll, CH~ CH~
¢~CHs,CH 9-Isobutyl-1 1~l2-dimelhyllelr~
CH ~ [4,4,0,12 5,17 10J-3-dodecelle C }IJ
--C H :~ 5~8~9~1O-TetraInetI1YItelraCYCI
~C HJ [4,4,(),125,17 l0]-3-dOdCCel1e C HJ

I ~ l3~ol47 cxacyclo(6,6,1,l3-6,11t~-l3 ()2.7 (~9.1~J-c~)t;l~lcccllc C ~
12-Mc~hylllex~cyclo[6,6,1,13 6, ~GJ 1 lo. 1 3 ,o2.7 ,o9- 1 4] -4 -11 ept ~d ece n e C 2 H ~
I 2-Ethyll~exflcyclo[6,6, 1,13 6, 1t~ 13 o27,09-l4]-4-llept~dccelle C ~1, [~-C ~1 2 C H 1 2-Isol)utylllcx~cyclor6,6, 1 ,13 6, C ~1 J 1 10.13 (~2.7~o9.l4]-4-llcpt~()ccclle C H, C H" 1~6~lo-Trimclllyl-l2-isol~ut C H 2 C H lle~c~cyclo[G,6, 1,13-6,1 10.13,o2-7,o9-C H J C ~ C H ~ 4-hept;ldeccl~e ~ OCt~Cyclo[8~8~o~l2.9tl4.7~l~ll.l8 '~/Y'\/~/~ 1 13.16,o3.8,()12.17] 5-docoscll ~v 1340147 Cl~' ¢~/ 15-Metllyloct~cyclo[8,8,0,12-9,14-7, 1 11.18, ll3.l6~u3.8~ol2 l7~-5-d C2~
(~ 15-Etllyloct;lcyclo[8,8,0,12-9,14-7, 1 11.18, 1l3.lc~o3.8~ 2-l7]-5-d I'cllt~cyclo[6,6,1,13 G ()2 7 (19-11J ~1 llcx;ldcccllc C ~1. C H ~

~0 1 ,3-I)inlctllyl~clltacyc~o[6,6, 1, 1 3-6,02-7,0s-~4] -4-llcx~deccnc C ~

1 ,6-Dimetllylpelltacyclo[6,6, 1, Y~ 1 3-6,o2-7,og ~4l -4-llcx~dccenc C Ha C H~ C H~
~f~ 15,16-Dilnclllylpelltacyclo[6,6,1, ''~,b~ 1 3-6,o2-7,og-1'l] -4-1lcx~(1cccl~c ~l 13401~7 I'elllacyclo[6,5,1,13 6, o2-7,09 l3~-4-pen~adecenc C 1-1 ~
,'~\ ' .
l ,3 -Dimethylpen~acyclo[6,5, 1, I 3 6, ' ~ ~ 02 7,09-l3]-4-pelltadcccllc C II J

~ 1 ,6-Dimelllyl~clltacyclo[6,5, 1, l 3 6, C 11 J o2 7 og-l 3J-4-l~cllt:ldcccllc C 1-1~ C 1-1~

I 4,1 5-Dimctllylpelltac'yclo[6~5~ 1, l 3 6, 02-7,09-l3]-4-pentadcccllc [~J IIep~acyclo[8,7,0,12 9, l'~ 7,1 1 1.17 ~3.8,ol2.16] -5-iCc7selle ~'1 IIC~ cycl(7~8~8~ 2~9~ .7~l 11.18 ,J 03-8,~12-l7l-5-icosellc 2~ 13~014 PCIlt~Cyclo[6,5, 1, 13.6, o2 1,09-l3]-4,iO-pentadccadicllc 'l'ricyclo[~1 ,3,0, 12-5] 3 -(Icccl~c C 11.

¢a~, . 2-Mclllyl-tricyclol~3~o~l2 5]-3-(lcccllc ~1 c 11, 5-Metllyl-tricyclo[4,3,(),12-5J-3-dccellc [~ Tricyclo[4,4,0,12-5)-3-ulldccctlc C ~
/~ 1 O-Metllyl-tricyclo[4,4,0, 12-5 ~J 3-undecenc Pel~t~cyclo[4,7,(), 1 2.5,()8.l3, 1 9-l2J 3 pentadecellc .. .. ..

23 13~101~7 I I a ~1~ Mctllyl-substitutcd l~cnl~cyclo ~//J~ [~ 7 o 12~s,o8.13,19.12]_3_pCllt~dCCCllc IIcl?t~cyclo(7,8,0, 13 6,02-7,1 10 17, O l 1-16,112-15] -~1 -icosenc Ç 1-1. C 11:, Dilnclhyl-sul)slilutc(l l~cpt~cyclo [7,8,0,i3-6,02-7,11o.l7,0ll.l6,ll2.ls]
icosene ~9,10,l,l4-7,03-8~o2-lo 012.21 3.20,ol4.19,1 1s.l8~-5-pe~ cosene C 1~ Trimetllyl-substituled nc?llacyclo [9, 10, ~ -7,~3-8,o2-1 0,() 1 2.21, l 1 3.2o 014-l9,1 IS-I8]-5-pentacoselle ~ C 1-1, In the process accor(lillg to the invelltioll, ethylelle is copolymerized with at least one cycloolefin of the general formula [I~.
In addilion to said two essential components, llowever, there may be optionally copolymerized other copolymerizable unsaturated 5 monomers in such a range th;lt they do not mar tlle object of the invention. Examples of the unsaturated monomers wllicll may optionally be copolymerized ethylene and at least one cycloolefin of the general formula [I], include a-olefins llaving from 3 to 20 carbon atoms, such as propylene, 1 -butene, 4-methyl- 1 -pentene, 1 -hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene and l-icosene, in such a proportion that the resulting cycloolefin random copolymer may contain units derived therefrom in an amount less than an equimolar amount of units derived from ethylene; cycloolefins, such as cyclopentene, cyclohexene, 3-l S methylcyclollexene, cyclooctene and 3a, 5, 6, 7a-tetrahydro-4, 7-methano- 1 H-indene of tlle formula ~J''II

2 0 in such a proportion that the resulting cycloolefin random copolymer may contain units derived therefrom in an amount less than an equimolar amount of units derived from the cycloolefin of the general formula [I]; non-conjugated dienes, such as 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene. 1,7-octadiene, 2 5 dicyclopentadiene, S-ethylydene-2-norbornene and 5~vinyl-2-norbornene, in such a proportion that the resulting cycloolefin random copolymer may contain UllitS derived therefrom in an 2s 1340147 amount less tllan an equimolar amount of units derived from the cycloolefin of the general formula [I]; and norbornene compounds, such as norbornene-2, 5-methylnorbornene-2, 5-ethylnorbornene-2, 5-isopropylnorbornene-2, 5-n-butylnorbornene-2, 5-i-5 butylnorbornene-2, 5,6-dimethylnorbornene-2, 5-chloronorbornene-2, 2-fluoronorbornene-2 and 5,6-dichloronorbornene-2, in such a proportion that tlle resulting cycloolefin random copolymer may contain units derived therefrom in an amount less than an equimolar amount of units derived from the cycloolefin of the general formula 1 0 [1].

Solvents In the process according to the invention, ethylene is copolymerized with at least one cycloolefin of the general formula [I]
15 in a hydrocarbon solvent. Tlle hydrocarbon solvents herein include aliphatic hydrocarbons SUCIl as hexane, heptane, octane, and kerosene; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; aromatic hydrocarbons such as benzene, toluene and xylene; and the above-illustrated cycloolefins of the general 2 0 formula [I], alone or in combination.

Catalysts In the process according to the invention, ethylene is copolymerized with at least one cycloolefin of the general formula [I]
2 5 in the presence of a catalyst. Suitable catalysts which can be used herein comprise a vanadium compound which is soluble in the particular hydrocarbon solvent used and an organoaluminum compound.
The vanadium compounds as one component of the catalyst, include compounds of the general formula VO(OR)aXb or V(OR)CXd wherein R is a hydrocarbon group, preferably having 1 to 4 carbon atoms, X is a halogen atom and a, b, c and d are each a number satisfying O < a c 3,0c b c 3,2< a + b < 3,0< c < 4,0< d c 4, and 3< c + d < 4; and their adducts with an electron donor. Examples of the vanadium compound include, for example, VO(C13), VO(OC2H5)C12, VO(OC2H5)2Cl, VO(O-iso-C3H7)C12, VO(O-n-C4Hg)C12, VO(OC2H5)3, VC14, VOC12, VOBr2 and V0(0-n-C4Hg)3; and an example of the electron donor adduct is VC13-20C8H17OH.
Electron donors which can be used for the preparation of the vanadium component of tlle catalyst may be oxygen-containing electron donors such as alcohols, phenols, ketones, aldehydes, carboxylic acids, esters of organic and inorganic acids, ethers, acid amides, acid anhydrides and alkoxysilanes; or nitrogen-containing electron donors such as ammonia, amines, nitriles andisocyanates. Examples of suitable electron donors include, for example, alcohols having from 1 to 18 carbon atoms, such as methanol, ethanol, propanol, isopropanol, pentanol, hexanol, octanol, dodecanol, octadecyl alcohol, oleyl alcohol, benzyl alcohol, phenylethyl alcohol, isopropylbenzyl alcohol and cumyl alcohol; phenols having from 6 to 20 carbon atoms which may include a lower alkyl group or groups attached to the aromatic 26a ring, such as phenol, cresols, xylenols, ethylphenols, propylphenols, nonylphenols, cumylphenols and naphthols; ketones having from 3 to 15 carbon atoms, such as acetone, methyl ethyl ketone, methyl isobutyl ketone, acetopllenone, benzophenone and benzoquinone; aldehydes having from 2 to 15 carbon atoms, such as acetaldehyde, propionaldehyde, octylaldehyde, benzaldehyde, tolualdehydes and naphthoaldehydes; organic acid S esters having from 2 to 30 carbon ato-ns, SUCIl as methyl formate, methyl acetate, ethyl acetate, vinyl acetate, propyl acetate, octyl acetate, cyclohexyl acetate, ethyl propionate, methyl butyrate, etllyl valerate, methyl chloroacetate, ethyl dichloroacetate, methyl methacrylate, ethyl crotonate, ethyl cyclohexanecarboxylate, metllyl 10 benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl bcnzoate, cyclol-exyl benzoate, phenyl benzoate, benzyl benzoatc, mcthyl toluyla~es, ethyl toluylatcs, amyl toluylates, cthyl ethylbenzoates, methyl anisates, n-butyl maleate, diisobutyl methyl malonate, di-n-hexyl cyclohexenecarboxylate, diethyl nadate, 15 diisopropyl tetrahydropl-thalate, diethyl phtllalate, diisobutyl phthalate, di-n-butyl phthalate, di-2-ethylhexyl phthalate, ~-butyrolactone, ~-valerolactone, coumarin, phthalide and ethylene carbonate; acid halides having from 2 to 15 carbon atoms, such as acetyl chloride, benzoyl chloride, toluyl chloride and anisic acid 2 0 chloride; ethers having from 2 to 20 carbon atoms, such as methyl ether, ethyl ether, isopropyl etller, butyl ether, amyl ether, tetrahydrofuran ,anisole and diphenyl ether; acid amides such as acetamide, benzamide and toluamides; amines such as methyl amine, ethyl amine, diethyl amine, tributyl amine, piperidine, tribenzyl 2 5 amine, aniline, pyridine, picolines and tetramethylenediamine;
nitriles such as acetonitrile, benzonitrile and tolunitriles; and 28 13~01 17 alkoxysilanes such as ethyl silicate and diphenylmethoxysilane. The illustrated electron donors may be used alone or in combination.

As the organoaluminum compound of the other component of 5 the catalyst, compounds having at least one Al-C bond in the molecule can be used. One group of such organoalbminum compounds may be represented by the general formula (i) RlmAl(OR2)nHpXq (;) wherein Rl and R2 are the same or different, and each represents a l 0 hydrocarbon group having normally from 1 to 15, preferably from 1 to 4 carbon atoms, X is halogen and m, n, p and q are numbers satisfying 0 ~ m < 3; 0 ~ n < 3; 0 ~ p < 3; 0 ~ q < 3; and m +
n + p + q = 3. Another group of SUCI1 compounds are complex compounds of aluminum and a metal of Group I represented by the l 5 general formula (ii) MIAlR14 (;;) wherein Ml is Li, Na or K, and Rl is as defined above.

The organoaluminum compounds of the general formula (i) 2 0 include those of the general formula R I mAI(OR2)3 -m wherein Rl and R2 are as defined above, and m is a number preferably satisfying 1.5 ~ m < 3; those of the general formula RlmAlX3-m 25 wherein Rl and X are as defined above, and m is a number preferably satisfying 0 < m < 3; those of the general formula R I mAIH3 -m wherein Rl is as defined above, and m is a number preferably satisfying 2 ~ m < 3; and those of the general formula RlmAl(OR2)n Xq wherein Rl~ R2 and X are as defined above, and m, n and q are S numbers satisfying O < m < 3, 0~ n<3, 0~ q<3 andm+n+q=3.

Examples of the organoaluminum compound of the general formula (i) include, for example, trialkylaluminums such as triethylaluminum, triisopropylaluminum and tributylaluminum;
10 partly alkoxylated alkylaluminums including, in addition to dialkylaluminum alkoxides such as diethylaluminum ethoxide and dibutylaluminum butoxide, alkylaluminum sesquialkoxides such as ethylaluminum sesquiethoxide and butylaluminum sesquibutoxide, and those having such an average composition as, for example, 15 R 12.sAI(OR2)o.s; partly halogenated alkylaluminum halides including dialkylaluminum halides such as diethylaluminum chloride, dibutylaluminum chloride and diethylaluminum bromide, alkylaluminum sesquihalides such as ethylaluminum sesquichloride, butylaluminum sesquichloride and ethylaluminum sesquibromide, 2 0 and alkylaluminum dihalides such as ethylaluminum dichloride, propylaluminum dichloride and butylaluminum dibromide; partly hydrogenated alkylaluminums including dialkylaluminum hydrides such as diethylaluminum hydride and dibutylaluminum hydride and alkylaluminum dihydrides such as ethylaluminum dihydride and 2 5 propylaluminum dihydride; and partly alkoxylated and halogenated alkylaluminums such as ethylaluminum ethoxychloride, butylaluminum butoxychloride and ethylaluminum ethoxybromide.

Furthermore, organoaluminum compounds in which two aluminum atoms are attached to one and the same oxygen or nitrogen atom, such as (C2~1s)2AI O Al(C2l~s)2, S (C4~-Ig)2Al O Al(C4~Ig)2 and (C2~Ts)2Al ~ /~I(C2~15)2 may also be used as the organoaluminum component of the catalyst.

Examples of the organoaluminum compound of the general formula (ii) include, for example, LiAl(C2Hs)4 and LiAl(C7HIs)4.

Particularly preferred organoaluminum compounds which can be used herein as the organoaluminum component of the catalyst, are dialkylaluminum halides and alkylaluminum dihalides and mixtures thereof.

In the process according to the invention, the copolymerization is carried out continuously as hereinafter described in detail, and 2 0 both the catalyst components are normally respectively diluted with the hydrocarbon solvent described above and fed to the polymerization vessel. A concentration of the vanadium compound fed to the reaction system is normally not higher than 10 times, preferably from 1 to 7 times, more preferably from 1 to 5 times tlle 2 S concentration of the vanadium compound present in the reaction system. Whereas a concentration of the organoaluminum compound fed to the reaction system may be not higher than 50 times the concentration of the vanadium compound present in the reaction system.

The concentration of the vanadium compound present in the 5 reaction system is normally from 0.01 to 5 gram atom of V/liter, preferably from 0.05 to 3 gram atom of V/liter, and the atomic ratio of the aluminum atom to the vanadium atom (Al/V) in the reaction system is normally at least 2, preferably from 2 to 50, in particular from 3 to 20.

Polymerization In first process according to the invention, the cycloolefin random copolymer is prepared by copolymerization of ethylene with a cycloolefin represented by the aforementioned general formula [I]
15 in the above-mentioned hydrocarbon solvent in the presence of tlle catalyst as aforesaid at a temperature of usually from -50 to 100 ~C
and a pressure of from 0 to 50 kg/cm2 G.

The polymerization may be carried out using a polymerization 2 0 reactor such as a loop-shaped reactor having a function to perform forced circulation of a reaction liquid by means of a pump or a polymerization vessel equipped with a stirrer.

The optimum conditions under which the polymerization is 2 5 carried out are illùstrated below in detail.

13401~7 In the first process according to the invention, it is desirable tl-at the cycloofefin random copolymers are prepared by copolymerization of ethylel-e and the above-mentioned cycloolefins under such conditions tl-~t substantially no gas pllase portion is 5 present in the polymerization reactor even when either of the above-mentioned reactors is used.

By carryin~ out the above-mentioned polymerization reaction using a reactor in which substantially no vapor phase portion is 10 present, it becomes possible that solvent-insoluble copolymers which are high in the ethylene content and which are insoluble in the hydrocarbon solvent used in carrying out lhe polymerization reaction are difficult to form in tlle reactor.

When the cycloolefin random copolymers are prepared using tlle polymerization vessel equipped with a stirrer, various measures may be adopted in order that substantially no gas phase portion is present in said polymerization vessel. For example, it is desirable to design that a nozzle to pick up the copolymer solution from the 2 0 polymerization vessel is fitted to the uppermost portion of said polymerization vessel and the gas portion formed, if any, can be discharged promptly from the polymerization vessel. The amount of the resulting cycloolefin random copolymer to be picked up is preferably controlled automatically by means of a pressure control 25 valve and not by means of a liquid surface control valve as used hitherto.

In order to prevent leakage of the cycloolefin random copolymer from a shaft sealing portion of the stirrer, said leakage being caused by permeation of said copolymer into the shaft sealing portion, for example, a sealing surfsce of a mechanical seal or the 5 like, it is preferable to take a measure, for example, by flowing a flashing liquid over said shaft sealing portion or the like.

Wllen the cycloolefin random copolymers are prepared using the loop-sllaped reactor, a so-called cavitation takes place if the gas 10 phase portion in excess of a certain degree is present around a pump for forced circulation of said copolymer solution and consequently the forced circulation of said copolymer solution becomes difficult, and hence, it is possible to confirm whether or not the interior of said reactor is substantially filled with said copolymer solution by 15 observing a flow rate of said copolymer solution within the reactor.
The resulting cycloolefin random copolymers are preferably picked up from the reactor, while automatically controlling the pressure inside tlle reactor by a pressure control valve.

2 0 Even in the case where either the above-mentioned polymerization vessel equipped with a stirrer or loop-shaped reactor is used, variations of the pressure in said polymerization reactor which is automatically controlled by means of the pressure control valve become large as the amount of the gas phase portion in tlle 2 5 reactor decreases. Then, it is readily confirmed that substantially no gas phase portion is present in the reactor when a large variation in 1340i~1 ~

pressure as aforesaid is recorded in a pressure record provide(l in said reac~or.

I~rom Illc sl3lldpoilll of m;llcrial t)alancc, Il-orcovcr, sucll a sli~lc wherein substanlially no gas pl-ase porlion is present call also be sel by seleclion of such polymerization lemperalure and prcssure lll;~l a producl of an armount of ll~e llydrocarbon solvent fed per unil of lime lo lhe reaclor and a solubilily in said hydroc;lrbon solvenl of clllylcnc becomc~ largcr lh;lll Illc amount of unre3cled cll~ylcnc pcr 10 ullil lime. In nclunl prucllcc~ llowover, ll is pre~crable lO c;-rry OUl lhe polymerizalion reaclion while confirniing lhal substantially no g;lS phase porlion is presenl in lhe reaclor by cllecking lhe variation width of pressure in tlle reactor or lhe electric current consumplion of lhe pump in lhe loop-sllnped reaclor.

The copolymerizalioll of elllylene and lhe cycloolefin in Ille reaclor wllere subslanlially no gas phase is presenl, is carried OUl al a lcmpcralure Or norlnally îrom - SO ~ lo 100 ~C., prcrcrnt)ly rronl -30 ~ lo 80 ~C., more preferably from - 20 ~ to 60 ~C.
The copolymerization of ethylene and the cycloolerin is norl~ lly carried out continuously. In lllis case, lhe monolllcrs inclllding elllylene, llle cycloolefin of tlle general formula 11] and oplionally one or more olher copolymerizablc monomers; lhe calalys componenls, îhal is, lhc soluble Yanadium compound and lhe organoalulllinum compound, nnd the hydroc~rbon solvenl, are conlinuously fed lo the polymerization syslem, while lhc polymerization reaction mixlure is continuously dr~wn out from the polymerization systetn.

The average residence time of the polymerization mixture in S the polymerization system may be normally from S minutes to 5 hours, preferably from 10 minutes to 3 hours, although depending upon kinds of the monomers, tl-e concentration of the catalyst and the polymerization temperature. The pressure of the polymerization system is positive and may be normally up to 50 kg/cm2, preferably 10 up to 20 kg/cm2.

The molar ratio of ethylene to the cycloolefin used in the copolymerization may be from 99/1 to 1/99, preferably from 98/2 to 2/98, more preferably from 90/10 to 10/90.

By the copolymerization described above, there is obtained a solution of the cycloolefin random copolymer in the hydrocarbon solvent.

2 0 In the cycloolefin random copolymer obtained by copolymerization of ethylene and cycloolefin, said cycloolefin exhibits a structure as represented by the general formula [II].

3 6 I340I ~ 7 General formula [II]

~ 117 ~, ~1~
[II]
n'~ , rl wherein n and Rl to Rl2 are as defined above.

The cycloolefin random copolymer thus obtained comprises normally from 1 to 99 mol %, prcfcrably from 40 to 85 mol % and more preferably from 50 to 75 mol % of recurring units (a) derived from ethylene and normally from 1 to 99 mol %, preferably from 15 15 to 60 mol % and more preferably from 25 to 50 mol % of recurring units (b) derived from the cycloolefin. In the cycloolefin random copolymer, the recurring units (a) derived from ethylene and the recurring units (b) derived from tlle cycloolefin are arranged substantially at random. That this cycloolefin copolymer is 2 0 substantially linear and has no gel-forming crosslinked structure can be confirmed by the fact that the copolymer completely dissolves in decalin at 135 ~C.

Such cycloolefin random copolymers as mentioned above 25 usually have an intrinsic viscosity [11] of from 0.05 to 10 dl/g as measured at 135 ~C in decalin, a softening point (TMA) of from 70 to 250 ~C as measured by a thermal mechanical analyzer, a glass r3nsilioll lcnlperalure (Tg) of from 50 lo 230 ~C. and a cryslallillily il)dex of from 0 lo 10 % as measured by X-ray diffractolnelry.

A~ll r~lllovnl 'I llc cycloolefin random copolymer solulion is subjccled, if Icsircd, lo ;Ish rcll~oval slcp. 11l lhis nsll rcl)~ov;ll slcp, nn alkali solulioll~ for exalllple an a(lllcous sodiuln llydroxidc solulion l~avin~, a concelllralion of frolll 10 to 50 % by wci~,llt, is a~ldc(l lo lllc cycloolcfin rnndolll copolylller solulion lo slop llle polymcriz;ll re~ction, alld llle callllysl residue whicll remains in lhis polymcr solution is removed (deaslled) thercfrom.

Subsequently, the lhus deaslled polymer solulioll is transferred, in aclual praclice, once lo a conlailler equipped wilh a stirrer ~nd stirred for a certain period of time, thougll the poly~er solution may be subjecled~ immedialely afler the deasllirlg step, to flasll drying slep.

PRE-HEAT ING
2 0 The cycloolefin ralldom copolymer solulion subjecled lo deasllillg slep in llle manner menlioned above is lhell llcaled usually by using a healer~ for cxalllple, a double-pipc llcalcr~ plale -lypc heal exchanger and so on.

In healing tlle cycloolefin random copolymcr solulion by usills Illis hcaler, a concenlrsllion of lhe copolymer in ~h'e solution is preferal)ly adjusled usually lo from I lo 70 % by weighl Tlle llcalillg lcmpcraluro cmployed slloùld be a lcmpcralure sufficicnl IO

13~l0lq7 lllorougllly volatillize ttle solvent in the copolymer solution in tlle subsequent flash drying step, and is usu~lly from 150 to 280 ~C, prcfcr;ll~ly from 180 to 250 ~C.

I; Insh drylng Afler complelion of lhe ~bove~ enliolled healing step, lhe cycloolefin random copolymer solution is f 1 a s~l d r i e d, wllereby unreacted cycloolefin monomer is removed lllerefrom. I'llis flastl drying slep may be carried out, for example, by using a doublc-10 pipe flasll drier.

In flash drying the cycloolefin random copolymer solution using the double-pipe flasll drier, it is preferable to give the solution sucll ~ pressure distribulion and quan~ily of heal that lhc temperature as preset in ttle drier becomes a tempcrature at wtlicl no solidification of the copolymer in the cycloolefin random copolymer solution will take pl3ce. In that case, it is preferable to fecd llle cycloolefin random copolymer solution lo the drier al a rille of at least 0.3 mlsec or lllereabouts in order to inl~ibit staining of a 2 0 heat transfer surface of the drier.

I~y carrying out lhc flash drying of the cycloolefin randonI
copolymer solulion under lhe above-menlioned condilions, Illerc are oblail-ed cycloolefin random copolymers from wllictl unreacle cycloolefin monomer and tlle solvent remaining llave been substan~i311y removed. The cycloolefin random copolymers Illus obtained are excellent in such propcrlies as heat resistance, he;ll aging property, chemical resistance, solvent resistance, dielectric properties, rigidity and impact property.

As mentioned above, the cycloolefin random copolymers S subjected to flash drying step contain practically no unreacted cycloolefin monomer. I-lowever, these copolymers which contain, if any, small amounts of unreacted cycloolefin monomer may also be treated with the following extruder, and thereby to remove the unreacted monomer therefrom.

By passing the above-mentioned flash dried cycloolefin randoln copolymer through a twin-screw extruder equipped with atmospheric and vacuum vents, the unreacted cycloolefin monomer present in such small amounts in said copolymer can be removed 1 5 therefrom.

The atmospheric vent is necessary for preventing the cycloolefin random copolymer from its foaming in the vacuum vent.
The temperature of the extruder should be higher than a boiling 2 0 point of the unreacted cycloolefin monomer in the atmosphere, and is usually from 210 to 280 ~C., preferably from 230 to 260 ~C.

The second process for the production of cycloolefin random copolymers according to the invention will now be described in 2 5 detail.

1~40 147 In the second process for the production of cycloolefin random copolymers according to the invention, a first solution of a first cycloolefin random copolymer [B] in a first hydrocarbon solvent obtained by copolymerization of ethylene and a cycloolefin of the general formula in the first hydrocarbon solvent in the presence of a catalyst, the first cycloolefin random copolymer [B] having an intrinsic viscosity [~] of from 0.05 to 10 dl/g measured in decalin at 135~C. and a softening point (TMA) of at least 70~C., and a second solution of a second random copolymer [C] in a second hydrocarbon solvent obtained by copolymerization of ethylene, at least one a-olefin other than ethylene and a cycloolefin of the general formula [I] in the second hydrocarbon solvent in the presence of a catalyst, the second cycloolefin random copolymer [C] having an intrinsic viscosity [~] of from 0.01 to 10 dl/g measured in decalin at 135~C. and a softening point (TMA) of less than 70 C., are mixed to form a mixed solution in which from 5 to 100 parts by weight of the second cycloolefin random copolymer [C] is present based on 100 parts by weight of the first cycloolefin random copolymer [B] present therein;
the mixed solution is pre-heated to a temperature in the range of from 150 to 280~C., the pre-heated solution is flash-dried using a double pipe flash-drier equipped with heat source, and the thus-obtained cycloolefin random copolymer is passed through an extruder equipped with a vacuum vent.

40a 134014 7 The first solution of a first cycloolefin random copolymer [B] in a first hydrocarbon is obtained by copolymerization of ethylene and a cycloolefin of the general formula [I] in a hydrocarbon as described herein above with respect to the first process according to the invention in the presence of a catalyst as described herein above with respect to the first process according to the invention normally 13~0147 4 l at a temperature of from - 50 ~ to 100 ~C. under a pressure of above 0 and not higher than 50 kg/cm2 G. In the production of the first cycloolefin random copolymer [Bl, a minor amount of a-olefin having from 3 to 20 carbon atoms may be copolymerized with the ethylene 5 and cycloolefin provided that tlle resulting copolymer [B~ has properties prescribed herein The copolymerization may be carried out using either a loop-sllaped reactor or a polymerization vessel equipped with a stirrcr.

The cycloolefin random copolymer [B] thus obtained comprises from 40 to 85 mol % and preferably from 50 to 75 mol % of recurring units (a) derived from ethylene and from 15 to 60 mol % and preferably from 25 to 50 mol % of recurring units (b) derived from 15 the cycloolefin. In the cycloolefin random copolymer [B], the recurring units (a) derived from ethylene and tlle recurring units (b) derived from the cycloolefin are arranged substantially linear and at random. That this cycloolefin copolymer [B] is substantially linear and has no gel-forming crosslinked structure can be confirmed by 20 the fact that the copolymer completely dissolves in decalin at 135 ~C.

The cycloolefin random copolymer [B] has an intrinsic viscosity ltl] of from 0.05 to 10 dl/g, preferably from 0.08 to 5 dl/g as measured at 135 ~C in decalin, a softening point (TMA) of at least 70 25 ~C., preferably from 90 ~ to 250 ~C., ad more preferably from 100 ~ to 200 ~C., as measured by a thermal mechanical analyzer, a glass transition temperature (Tg) of usually from 50 to 230 ~C., preferably 42 13~ol~7 from 70 to 210 ~C. and a crystallinity index of from 0 to 10 %, preferably from 0 to 7 %, and more preferably from 0 to S %, as measured by X-ray diffractometry.

S The second solution of a second cycloolefin random copolymcr[C] in a second hydrocarbon can be obtained by the same process as described hereinabove with respect to the production of the first solution of the first cycloolefin random copolymer [C] in the first hydrocarbon except that at least one ~-olefin other than ethylene is necessarily copolymerized with ethylene and the cycloolefin of the general formula [I] and that conditions are suitably selected so tllat the resulting second cycloolefin random copolymer may have the properties prescribed herein. Thus, the catalyst, hydrocarbon solvent and apparatus used in the preparation of the second solution can be l S tlle same as those used in the preparation of the first solution.

The cycloolefin random copolymer [C] thus obtained comprises from 40 to 98 mol %, preferably from 75 to 98 mol % of recurring units (a) derived from ethylene, from 1 to 40 mol %, preferably from 1 to 15 mol % of recurring units (b) derived from the cycloolefin and from 1 to 45 mol %, preferably from 1 to 35 mol % of recurring units (c) derived from at least one a-olefin other than ethylene . In the cycloolefin random copolymer [C], the recurring units (a) derived from ethylene, tlle recurring units (b) derived from tlle cycloolefin 2 S and the recurring units derived from at least one a-olefin other lhan ethylene are arranged substantially linear and at random. That this cycloolefin copolymer [C] is substantially linear and has no gel-forming crosslinked structure can be confirmed by the fact that the copolymer completely dissolves in decalin at 135 ~C.

The cycloolefin random copolymer [C] has an intrinsic viscosity S [rl] of from 0.01 to 10 dl/g, preferably from 0.08 to 5 dl/g as measured at 135 ~C in decalin, a softening point (TMA) of less than 70 ~C., preferably from - 40 ~ to 60 ~C., and more preferably from - 30 ~ to 30 ~C., as measured by a thermal mcc~lanical analyzer wllicl is desirably lower th~n the softening point of tlle copolymer [B] by from 30 to 250 ~C., preferably by from 50 ~ to 250 ~C., and more preferably by from 200 ~ to 240 ~C., a glass transition temperature (Tg) of usually from - 60 ~ to 40 ~C., preferably from - 50 ~ to 10 ~C.which is desirably lower than that of the copolymer [B] by from 30 to 250 ~C., preferably by from 100 ~ to 240 ~C., and a crystallinity l S index of from 0 to 10 %, preferably from 0 to 7 %, and more preferably from 0 to 5 %, as measured by X-ray diffractometry.

In the second process according to the invention, the first solution and the second solution are admixed together in such 2 0 proportions that the resulting mixed solution may contain from S to 100 parts, preferably from 7 to 80 parts, and more preferably from 10 to 70 parts by weight of the second cycloolefin random copolymer [C] based on 100 parts by weight of the first cycloolefin random copolymer [B] present therein. With less tllan 5 parts by weigllt, based on 100 parts by wight of the copolymer [B], of the copolymer [C], tlle final product tends not to have satisfactory impact property, although it has excellent rigidity. Whereas with the copolymer [C] in 13401~7 excess of 100 parts by weight based on 100 parts by weight of the copolymer [B], the final product tends to have unsatisfactory rigidity, although the impact property is excellent.
The mixed solution of the first cycloolefin random copolymer [B] and the second cycloolefin random copolymer [C] is then optionally subjected to ash removal and heating steps and thereafter flash-dried in the manner as described hereinabove with respect to the first process according to the invention.
In the third process for the production of cycloolefln random copolymers according to the invention, a first solution of a first cycloolefin random copolymer [B] in a first hydrocarbon solvent described hereinabove with respect to the second process accordlng to the invention, and a third solution of a third random copolymer [D] in a third hydrocarbon solvent obtained by copolymerization of ethylene, at least one of propylene and butene, and a cycloolefin of the general formula [I] in the third hydrocarbon solvent in the presence of a catalyst, the third cycloolefin random copolymer [C]
having an intrinsic viscosity [~] of from 0.01 to 10 dl~g measured in decalin at 135 C. and a softening point (TMA) of less than 70~C
are mixed to form a mixed solution in which from 5 to 100 parts by weight of the second cycloolefin random copolymer [D] is present based on 100 parts by weight of the first cycloolefin random copolymer [B] present therein;
the mixed solution is pre-heated to a temperature in the range of from 150 to 280~C., 44a the pre-heated solution is flash-dried using a ~ouble pipe flash-drier equipped with heat source, and the thus obtained cycloolefin random copolymer is passed through an extruder equipped with a vacuum vent.

The third solution of a third cycloolefin random copolymer LDl in a third hydrocarbon can be obtained by the same process as described hereinabove with respect to the production of the second solution of tlle second cycloolefin random copolymer lC] in tlle second 5 hydrocarbon except that at least one specific a-olefin, that is propylene and/or butene is copolymerized with the ethylene and cycloolefin to produce tl-e third solution of the tllird copolymer [D].
Thus. the third hydrocarbon nay be the same as the second and first hydrocarbons .

The cycloolefin random copolymer [D] comprises from 40 to 98 mol %, preferably from 75 to 98 mol % of recurring unils (a) derived from ethylene, from 1 to 40 mol %, preferably from 1 to 15 mol % of recurring units (b) derived from the cycloolefin and from 1 to 45 mol 15 %, preferably from 1 to 35 mol % of recurring units (c) derived from propylene and/or butene . In the cycloolefin random copolymer [D], the recurring units (a) derived from ethylene, the recurring units (b) derived from the cycloolefin and the recurring units derived from propylene and/or butene are arranged substantially linear and at 2 0 ~andom. That this cycloolefin copolymer [D] is substantially linear and has no gel-forming crosslinked structure can be confirmed by the fact that the copolymer completely dissolves in decalin at 135 ~C.

The cycloolefin random copolymer [D] has an intrinsic viscosity 25 [11] of from 0.01 to 10 dl/g, preferably from 0.08 to 5 dl/g as measured at 135 ~C in decalin, a softening point (TMA) of less than 70 ~C., preferably from - 40 ~ to 60 ~C., and more preferably from - 30 ~ to 30 ~C., as measured by a thermal mechanical analyzer which is desirably lower than the softening point of the copolymer [B] by from 30 to 250 ~C., preferably by from 50 ~ to 250 ~C., and more preferably by from 200 ~ to 240 ~C., a glass transition temperature (Tg) of usually from - 60 ~ to 40 ~C., preferably from - 50 ~ to 10 ~C.which is desirably lower than that of the copolymer [B] by from 30 to 250 ~C., preferably by from 100 ~ to 240 ~C., and a crystallinity index of from 0 to 10 %, preferably from 0 to 7 %, and more preferably from 0 to 5 %, as measured by X-ray diffractometry.

In the third process according to the invention, the first solution and the third solution are admixed together in such proportions that the resulting mixed solution may contain from 5 to 100 parts, preferably from 7 to 80 parts, and more preferably from 10 to 70 parts by weight of the third cycloolefin random copolymer [D] based on 100 parts by weight of the first cycloolefin random copolymer [B] present therein. Or otherwise undesirable tendencies appear as is the case with the second process according to the invention .
The mixed solution of the first cycloolefin random copolymer [B] and the third cycloolefin random copolymer [D] is then oplionally subjected to asll removal and heating steps and thereafter flash dried in the manner as described hereinabove with respect to tlle 2 5 first and second processes according to the invention.

By the first, second and third processes according to the invention in which a solution of cylcoolefin random copolymer(s) in a hydrocarbon is flash dried, there can be economically and effectively produced cycloolefin random copolymer(s) of high quality having 5 any unreacted cycloolefin monomer substantially removed with no need of any complicated process steps.

The fourth process for the production of cycloolefin random copolymers according to the invention comprises copolymerization of 10 ethylene with a cycloolefin of the general formula lI] noted in a hydrocarbon in the presence of a catalyst wherein said copolymerization is carried out in a polymerization reactor where a gas phase is not substantially present.

The fourth process for the production of cycloolefin random copolymers according to the invention, in which ethylene is copolymerized with the cycloolefin in a polymerization reactor where a gas phase is not substantially present, ensures a smooth copolymerization of ethylene and tlle cycloolefin and a continuous 2 0 and stable running of the apparatus for the production of ethylene-cycloolefin random copolymers, and is productive of ethylene-cycloolefin random copolymers which have a uniform quality and are excellent in heat resistance, heat aging property and varioùs mechanical properties.
The cycloolefin random copolymers produced by the processes according to the invention have excellent properties as mentioned 48 13~01~7 above and are relatively inexpensive, and therefore, they find application in wide industrial fields, including as engineering plastics.

The process for the production of cycloolefin random 5 copolymers according to the invention will now be described in detail below with refercnce to the following exal~ les, to whicll thc inven~ion is in no way limited.

Properties of cycloolefin random copolymers were determined 1 0 as follows.
M~R w~s measured at 260 ~C under ~ load of 2160 g.
Intrinsic viscosity [Tl] was measured in decalin at 135 ~C. using an Atlantic viscometer.
Copolymer composition [mol %] was determined by infrared 15 spectroscopy. From the height of the peak of the absorption band (1026 cm-l) based on the cycloolefin component, the content of cycloolefin was determined. The remainder was regarded as the content of ethylene.
Various ash contents [V, Al and Cl] were determined by X-ray 2 0 diffractometry.
Volatile materials [VM] was determined from the weigllt change measured at 300 ~C, 1 Torr, for 1 hour, and expressed in wt.%.
Unreacted cycloolefin content was determined by gas chromatography on a solution of the cycloolefin random copolymer in 2 5 cyclohexane 13lol~7 Softening point [TMA] was determined by Penetration test using a thermomechanical analyzer supplied by Du pont with a rate of temperature rise of 5 ~C/minute .
Molecular-weight distribution [Mw/Mn] was determilled by S GPC.

Example 1 (Flash drying) ~Catalyst preparation]
VO(OC2lls)CI was diluted with cyclohexane to prepare a 10 vanadium catalyst of whicll vanadium concentration was 6.7 mmol/l-cyclohexane. On the other hand, ethyl aluminum sesquichloride (Al(C2TIs)l .sCI 1 .5) was diluted with cyclohexane to prepare an organic aluminum catalyst of which aluminum concentration was 107 mmol/l-cyclohexane.
[Polymerization]
Cycloolefin random copolymer [B] was continuously prepared by carrying out copolymerization reaction between ethylene and tetracyclo[4,4,0,12-5,17-l0]-3-dodecene] (sometimes called merely 2 0 tetracyclododecene hereinafter) which was cycloolefin by using a polymerization reactor equipped with a stirrer (500 mm in inner diameter, 100 liter in reaction capacity). To perform the copolymerization reaction, the vanadium catalyst prepared in the method stated above was fed into the reactor at such a rate that the 2 5 concentration of vanadium in cyclohexane, which was a polymerization solvent used, might be maintained at 0.6 mmoltl in the reactor. Just before the feeding of the vanadium catalyst to the 13~0147 reactor, the vanadium catalyst was further diluted with cyclohexane to a V concentration of two times that in the polymerization reactor.

The organoaluminum catalyst prepared above was supplied to 5 the reactor at a rate so that tlle Al/V of 8.0 might be maintained in the reactor. The aforementioned copolymerization reaction was carried out continuously at a temperature of 11 ~C and under a pressure of 1.8 kg/cm2 G.

Cycloolefin copolymer [C] was produced by executing the co-polymerization reaction by using a loop-shaped reactor (internal tube diameter:4B, external tube diameter 6B, length: 32 m, vertical type), under a pressure of 4 kg/ cm2 G, witll ethylene, tetracyclododecene as cycloolefin, and propylene as a-olefin.

[Ash removal]
The solutions of cycloolefin random copolymer [B] and cycloolefin type random copolymer [C] drawn from the respective reactors were sent into a pipe where they were premixed, and boiler 20 water and a 25 wt.% NaOH aqueous solution as a pH modifier were added to the mixed solution, thereby stopping the above polymerization reaction. The so formed catalyst residue was then removed (deashed) from the mixed solution. The mixed solution being rid of its ash was once mixed for an hour in a stirring bath 25 having an effective capacity of 1.0 m3 before it is sent to the subsequent step.

13401~7 e;~ g]
To a doul~le-lube l~ealer (exlern;ll tube dialneler: 2B, inleru~l llll)c ~ lmelcr: 3/4 l~, len~: 21 m) heale~J willl ste;lm Or 20 k~/cll~2G us u l~c;llillg source, lllc mixe~ solulion of wllicll lllc copolymer concelllration in llle mixcd so~ ioll was sel lo 5 w1.% was fe~l at a ra~e of 150 kg/ll, and Ille mixlure was he;lled lO 180 ~C.

sll dryingl l3y llSillg a double-tul)e rlnsll drier (exlerll;ll lubc ~lialllctcr: 213, inlern;ll lul)e diall)eler: 3/4 13, lenglh: 27 m) alld ;I naSI~ llopl)er (capacity: 200 liter), Illixed solulion from Ille lle~lillg slep w~s rlnsl~ drie~i ~o remove mosl of lllc unreaclcd lelracyclo(Jo(Jecellc together with the poly~erizatioh ~olYent. Ste~m of 25 kg/cm2a w;ls used as a llenllng sourcc for Ille doùble-lube flasl ~Irier.

[Kne;l(ling by venlcd exlruder]
'I'llc copolylner Irolll Ille nl~ovc rlnsll iryin~ slcp wns llcxl kne.llle(J by me.lns o~ a venled exlruder. Tlle kne;l~lir)g was excculc~l 2 0 llsillg a venle(J exlru(ler (screw ~ melcr 30 ~ mlll, lwin-screw rolnlill~ in lhe snme direclloll, L/D-42, nlr venl; 1, vncllt~ velll: 2), al n b;lrrel leml~er~lurc of 250 ~C nnd ~ vncllum dcgrec of vcnl o~ S
'I'orr. Unreacled lelracyclododecelle was again removed frol~ le copol ymer.

Typlcal physical properltes of lhc resulling copolymer are sllown in Table 2.

52 13~iO147 Example 2 (Flash drying) Example 1 was repeated except that methyltetracyclo[4~4!0,12 5,17 10]-3-dodecene] (sometimes called 5 merely methyltetracyclododecene hereinafter) was used as the cycloolefin monomer.

Typical physical properties of the resulting copolymer are shown in Table 2.

53 13~0147 Table 2 Example 1 Example 2 Polymer solution Polymer B
Ethylene content (mol %) 51 6 2 Polymer concentration (wt. %) 5 5 Polymer [rl] (d/g) 0.94 0.48 Polymer TMA (~C.) 170 154 Unreacted cycloolefin rate (kg/ll) 1 1 . 2 Feed rate (kg/h) 10 5 12 0 Polymer C
Ethylene content (mol %) 76 69 Propylene content (mol %)) 16 21 Polymer concentration (wt. %) 5 5 Polymer [rl~ (d/g) 0.98 1.44 Polymer TMA (~C.) - 8 - 4 Unreacted cycloolefin rate (kg/h) 0.05 0.3 2 0 Feed rate (kg/h) 4 5 3 0 ~leater outlet temperature (~C ) 1 8 1 1 8 0 Flash tube outlet temperature (~C ) 200 200 Properties of the product Unreacted cycloolefin content at 2 5 flash tube outlet (wt.%) 0.7 0.77 VM at flash tube outlet (wt.%) 3.79 3.81 Unreacted cycloolefin content at extruder outlet (wt.~o) 0.04 0.04 VM at extruder outlet (wt.%) 0.76 0.77 3 0 Example 3 (copolymerization in the state without gas phase) By using a loop-shaped reactor ( vertical double-tube having 4B of internal tube diameter, 6B of external tube diameter and 32 m 54 1~40147 of overall length) copolymerization reaction between ethylene and cycloolefin the formula: ¢~

that is, tetracyclo[4,4,0,12 5,17 10]-3-dodecene] (sometimes called S merely tetracyclododecene hereinafter). In this copolymerization, the vanadium catalyst (V-catalyst) prepared described in Example 1 was fed to the reactor at a rate so that the concentration of V-catalyst in cyclohexane, wllicll was a polymerization solvent used, might be maintained at 0.6 mmol/l in the reactor. Just before the 10 feeding of the V-catalyst to the reactor, the V-catalyst was further diluted with cyclohexane to a V concentration of two times that in the reactor.

The organoaluminum catalyst prepared as in Example 1 was 15 supplied to the polymerization vessel at a rate so that the Al/V of 8.0 might be maintained in the polymerization vessel. Cycloilexane which was used as a polymerization solvent was fed into the reactor at a rate of 250 kg/h. Moreover, 4,55 kg/h of ethylene, 5 Nl/h of hydrogen gas as a molecular weight regulator and 10.1 g/h of 2 0 tetracyclododecene were fed to the reactor. In this reaction, the polymerization temperature was controlled at 10 ~C. The polymerization temperature was controlled by circulating a 25 wt. %
aqueous methanol as a refrigerant through an annular path between the two tubes in the loop-shaped reactor. The rotation speed of the 2 5 circulating pump was controlled by an invertor so that the flow rale of the aqueous methanol in the path be S m/S.

The copolymer solulion of etllylene and the cycloolefin obtained under the above conditions was drawn out from tlle rcactor.
The copolymer solution was drawll out while controlling the pressure on the intake side of the circulating pump at 4 kg/cm2G by S a pressure control valve installed in a pick-up line of the reactor.
During the above reaction, variations in pressure was within ~1 kg/cm2, and no cavitation occurred around the pump.

~Ash removal]
To the solution of tlle ethylene-tetracyclododecene copolymer drawn out from the reactor were added boiler water and a 25 wt %
NaOH solution as a pH modifier, thereby stopping the copolymerization reaction and tl-e catalyst residue so formed (ash) was removed from the copolymer solution.

The copolymer solution being rid of the ash was once stored in a container with a stirrer having the inner diameter of 900 mm and the effective capacity of 1.0 m3 until the subsequent precipitation operation .
[Precipitation]
The copolymer solution from the ash removal step and a precipitating solvent (acetone, water content of 1.0 wt.%) were fed into a first precipitation drum at rates of 265 kg/h and 1060 kg/h 2 5 respectively. The first precipitation drum had an inner diameter of 450 mm and an effective capacity of 100 liter, and baffle plates and a stirrer were installed inside. The stirrer provided on the 56 1~01~7 precipitation drum was composed of six turbine blades, and rotatcd at a speed of 600 rpm during precipitatiom The liquid temperature in the precipitation was 30 ~to 35 ~C. The dispersion of precipitated copolymer was caused to overflow and fed once into a second 5 precipitation drum witll baffles plate and stirrer, 1.3 m of inner diameter and 2.7 m3 of effective capacity, where precipitation of the copolymer was further proceeded. The rotation speed of the stirrer installed in the second precipitation drum in this operation was 200 rpm .
~Filtration]
To a filtering machine manufactured by Schumacher Japan (model CF-26) comprising 13 ceramic filters, each having an outer diameter of 70 mm, an inner diameter of 50 mm and a length of 1 m, 15 the copolymer dispersion obtained in the second precipitation drum was fed, and filtered therein. The filtrate was sent to a distillation system, where it was fractionated into the unreacted monomer and the solvents, cyclohexane and acetone, and purified respectively, for re-use. Wet cakes of the copolymer of ethylene and cycloolefin 2 0 containing acetone, which adhered to the outer surface of the ceramic filters of the filtering machine during the above filtration, were dropped into an extraction bath disposed on a lower part of the filtering machine by intermittent back washing with acetone.
That is, acetone was blown out from an acetone holding drum 2 5 pressurized up to 4 to 5 kg/cm2 by nitrogen gas, into the cylindrical ceramic filters at a rate about 200 liter/once, thereby dropping down wet cakes adhering to the outer surface of the cylindrical ceramic 57 13~01~7 filters into the extraction bath. The above back washing was executed at an interval of about 30 minutes.

[Extraction]
An extraction vessel equipped with bafrle plates and a stirrer and having an intler diameter of 1850 mm and an effective capacity of 6 m3 was used as the extraction bath for receiving tlle wet cakes dropped from the filtering maclline and the acetone used for back washing. Using such an extraction vessel, the above fallitlg objects were heated for two llOUtS at a temperature of 78 ~C under pressure and stirring so tllat tetracyclododecene remaining in the wet cakes be extracted in acetone. 'l llis extraction was executed by using two extraction vessels A and B, that is, when the dispersion of the wet cakes in acetone was heated and the extraction of unreacted monomer was executed in the extraction vessel A, the polymer wet cakes and acetone dropped from the filtering machine were received in the other vessel B, and to the contrary, whell the copolymer dispersion was heated and unreacted monomer was extracted in tlle extraction vessel B, the wet cakes and acetone falling from the 2 0 filtering machine were received in the other vessel A. In tllis way, the extraction vessels A and B were used alternately.
[Centrifugal separation]
The copolymer dispersion on which extraction was carried out in the above way was separated into solid and liquid by using a 2 5 super-decanter produced by Tomoe Kogyo (model P-4400), thereby batching off the wet cakes of the copolymer.

58 13~0 [Dryingl The copolymer wet cakes processed through tlle above centrifugal separation was, at first, dried at normal pressure by using an atmospheric drier (produced by Nara Seiki, model NPD-3w-w).
During this atmospheric drying, steam at a temperature of 120 o C
was passed through a jacket and screw of the atmospheric dryer, and the copolymer wet cakes were thereby heated. The time for drying was determined based on a carrying speed of tlle wet cakes by means of the screw installed in the atmospheric drier, but it was practically from 20 to 30 minutes.

The copolymer wet cakes dried under normal pressure as stated above was, next, subjected to vacuum drying in a vacuum dryer (made by Tamagawa Machines, 2 m3 of capacity, vacuum stirring drier). During this vacuum drying, steam at a temperature of 140 ~C was passed througll a jacket and agitating element of the vacuum dryer, and the wet cakes of copolymer were thereby heated.
The time for vacuum drying was set at 2.5 hours. The final pressure in tlle vacuum drying was practically in the range of from 5 to 10 2 0 Torr. The copolymer powder obtained by drying wet cakes of copolymer in the above way once stored in a powder silo having a capacity of 2 m3.

[Pelletizing]
2 5 The copolymer powder was melt extruded using a twin-screw extruder (made by The Japan Steel Works, Ltd., TEX-44), and pelletized by means of a hot cut pelletizer . A filter having meshes of 13~01~7 5 ~,lm or 10 ~lm was mounted between the extruder and the pelletizer for the purpose of removing fine foreign matters in molten polymer.

The above described series of apparatus from the 5 polymerization reactor to tlle pelletizer were continuously operated for two months.to produce a cycloolefin random copolymer. Tlle reactor used in the above operation was disassembled thereafter and inspected, but not a specific grime was detec~ed in the reactor.

The polymerization conditions, used and typical properties of the obtained copolymer are shown in Table 3.

Example 4 Example 3 was repeated except that the tetracyclododecene ~5 was replaced with methyltetracyclododecene of the formula ¢~ C~13 and that the process was continued for 3 weeks under conditions indicated in Table 3. The reactor used in tlle above operation was disassembled thereafter and inspected, but not a specific grime was 2 0 detected in the reactor.

The polymerization conditions used and typical properties of the obtained copolymer are shown in Table 3.

2 S Comparative example 1 (copolymerization in reactor where a gas phase is present) 13~0 Example 3 was repeated except that the polymerization was carried out as noted below using a polymerization vessel in which a gas phase is present.

5 [Polymerization]
The copolymerization system used comprised a polymerization vessel equipped with stirrer and having an inner diameter of 700 mm, an overall capacity of 560 liter and an available reaction capacity of 280 liter, a vertical shell-and-fin heat exchanger having a 10 heat transfer area of 19.4 m2, a circulating line for drawing out the polymerization liquid from the bottom of the polymerization vessel, circulating the liquid through the heat exchanger and returning the liquid to the polymerization vessel, and a circulating pump installed in the circulating line.

Using such a polymerization system, ethylene was continuously copolymerized with tetracyclododecene.

The vanadium catalyst (V-catalyst) prepared as described in 2 0 Example 3 was fed to the polymerization vessel at a rate so that the concentration of V in cyclohexane, which was a polymerization solvent used, might be maintained at 0.6 mmol/l in the polymerization vessel. Just before the feeding of the V-catalyst to the polymerization vessel, the V-catalyst was further diluted with 2 5 cyclohexane to a V concentration of more than two times tllat in the polymerization vessel in its dilution rate.

.. . . ... . .

Tlle organoaluminum catalyst prepared above was supplicd to the polymerization vessel at a rate so that the Al/V of 8.0 might be maintained in the polymerization vessel. Cyclohexane which was used as a polymerization solvent was fed into tlle reactor at a rate of 200 kg/h. Moreover, 4.55 kg/h of ethylene, 0.2 Nl/h of hydrogen gas as a molecular weight regulator were introduced to the gas phase in the polymerization vessel, and 10.1 g/h of tetracyclododecene was to the liquid phase in the vessel.

Around the jacket installed outside the polymerizatioll vessel and the shell side of thc shell~ ld-fin heat cxchanger, 25 wt.%
aqueous mcthatlol was circul~tcd as a rcfrigcr~nt so as to control thc polymerization temperature to 10 ~C. The pressure was controlled by introducing nitrogen gas in the vessel so that the polymerization pressure be 1.0 kg/cm2G.

The copolymerization reaction between ethylene and tetracyclododecene was continuously performed under the above conditions to provide a solution of an ethylene-tetracyclododecene 2 0 copolymer in.cyclohexane.

The solution of the cycloolefin random copolymer so obtained was thereafter processed in the same manner as described in Example 3. Typical properties of the obtained copolymer are shown in Table 3.

1340l~7 /~flcr l11C tllrcc-wcck COlltillUOUS opcr;ltion, thc currcnt consulllptioll Or tllc circuP.ltillg pUIl~p bcc~mc unstablc. l'llc CirCUI;ltillg pUlllp was IhCn OpCnC(I to find tl~at it was cloggcd witll a copolyl-1cr insolublc in cyclollex~llc. By slor~r~ing thc above opcra~io S alld insl-cc(illg insi(Jc tllc rc;lctor, a copolynlcr insolublc in cyclol~cx;lnc a(lhcrillg ill ;1 I-clt S11;117C on tllC illSitlC CirCUn~rCrCIl~
surfacc of tllC polyl-lcriz;ltioll vCSSCI al a Icvcl in lllC vicinity of tl~c ~as liqlli(l intcrr;lcc in lllc polylllcrizatioll vcsscl was found.. As a consc(lucl~cc, tllc obstruction or tllc punlp was supposccl to ~c tllc I () col~olynlcr illsolul)lc ill cyclollcxal~c formc(l on tllc insi~lc cirCunlrcrcntial wall of tllc polyn~crization vcsscl at a Icvcl nc.lr tllc gas-liquid intcrface in tl~c vCSSCI, WhiCIl droppc(l down, flowcd out from lhe polymerizaliol- vessel and causcd clogging of tl~e circulating pump. Tlle compositioll of tllC copolylner insolublc ill cyclohcxanc 15 was analyzed to find tllat the content of ethylene was 90 %.

-Table 3 Exalnple 3 Examplc 4 Polymerizntion conditiolls V~nadium concentration [mmol/l] 0.6 0.6 Ratio Al/V lmol/mol] 8 8 Employed cycloolefin Tetracyclo- Methyl-dodecene tetracyclo dodecene 1 0 Feed rate of cycloolefin [kg/h] 10.1 10.5 Feed rate of hydrogen [Nl/h] 5 3 Feed rate of ethylene [kg/h] 4 . 5 5 4 . 5 5 Feed rate of CH,c [kglh] 250 250 Temperature [~C ] 10 10 Pressure [kg/cm2 G] 4 4 Product Ethylene content [mol%] 6 2 - 6 5 6 2 - 6 5 Remaining V [ppm] < 1 < I
Al [ppm] < 5 c 5 Cl [ppm] 10-35 10-35 MFR [g/10 min.] 30-35 30-35 VM[%] 01-03 0.1-0.3 Mw/Mn [-] 1 . 8 1 . 9 Table 3(continued) Comp.Ex. 1 Polymerization conditions V-concentration [mmol/l] 0.6 Ratio Al/V [mol/mol] 8 Employed cycloolefin Tetracyclo dodecene Feed rate of cycloolefin [kg/h] 10.1 Feed rate of hydrogen [Nl/h] 0 . 2 Feed rate of ethylene [kg/h] 4. 5 5 Feed rate of CH~ [kg/h] 200 Temperature [~C ] 10 Pressure [kg/cm2 Gl 1 5 Product Ethylene content [mol%] 6 2 - 6 5 Remaining V [ppm] c 1 Al [ppml < S
Cl [ppm] 10-35 MFR lg/10 min.] 30-35 VM[%] 0.1-0.3 Mw/Mn [-] 2.0

Claims (5)

1. A process for the production of cycloolefin random copolymers by copolymerization of ethylene with a cycloolefin of the general formula [I]

(wherein n is 0 or a positive integer, and R1 to R12 are the same or different, and each represents a hydrogen or halogen atom or a hydrocarbon group, or R9 (or R10) and R11 (or R12), when taken together, may form a mono- or poly-cyclic ring) in a hydrocarbon solvent in the presence of a catalyst, wherein the copolymerization is carried out in a polymerization reactor where substantially no gas phase is present.

2. The process according to claim 1, wherein:
in the formula [I], n is 1 or 2, R1 to R12 are each a hydrogen or halogen atom or a hydrocarbon group having 1 to 4 carbon atoms, or R9 and R11 together or R1 and R12 together with the carbon atoms to which they are attached form a 5- or 6-membered monocyclic ring; and the hydrocarbon solvent is a member selected from the group consisting of hexane, heptane, octane, kerosene, cyclohexane, methylcyclohexane, benzene, toluene, xylene and a mixture thereof.

3. The process according to claim 1 or 2, wherein:
the catalyst is a combination of (a) a vanadium compound which is soluble in the hydrocarbon solvent and has the formula:

VO(OR)a X b or V(OR)c X d [wherein R is a hydrocarbon group having 1 to 4 carbon atoms;
X is a halogen atom; and a, b, c and d are each a number satisfying 0~a~3, 0~b~3, 2~a+b~3, 0~c~4, 0~d~4 and 3~c+d~4]
or an adduct thereof with an electron donor and (b) an organoaluminum compound of the formula:

R1m Al (OR2)n H p X q (i) or M1AlR1 4 (ii) [wherein R1 and R2 are the same or different and are each a hydrocarbon group having 1 to 15 carbon atoms, X is a halogen atom, M1 is Li, Na or K, and m, n, p and q are each a number satisfying 0~m~3, 0~n~3, 0~p~3, 0~q~3 and m+n+p+q=3]; and the catalyst is removed, prior to a preheating step, by adding an aqueous alkali solution to the cycloolefin random copolymer solution and then removing resulting ash.

4. The process according to claim 1, 2 or 3, wherein the cycloolefin random copolymer contains 40 to 85 mol% of recurring units derived from ethylene and 60 to 15 mol% of recurring units derived from the cycloolefin [I], each linearly arranged, and has an intrinsic viscosity [n] of 0.05 to 10 dl/g as measured at 135°C in decalin, a softening point (TMA) of from 70 to 250°C, as measured by a thermal mechanical analyzer, a glass transition temperature (Tg) of from 50 to 230°C and a crystallinity index of from 0 to 10% as measured by X-ray diffractometry.

5. The process according to any one of claims 1 to 4, wherein the cycloolefin [I] is tetracyclo[4,4,0,1 2.5 ,1 7.10]-3-dodecene or methyltetracyclo[4,4,0,1 2.5,1 7.10]-3-dodecene.