Description CATALYST SYSTEM FOR POLYMERIZING CYCLIC OLEFIN HAVING POLAR FUNCTIONAL GROUP, POLYMERIZING METHOD USING THE CATALYST SYSTEM, OLEFEV POLYMER PRODUCED BY THE METHOD AND OPTICAL ANISOTROPIC FILM COMPRISING THE OLEFIN POLYMER Technical Field [1] The present invention relates to a catalyst for polymerizing a cyclic olefin having a polar functional group and a polymerization method, and more particularly, to a catalyst system for polymerizing a cyclic olefin having a polar functional group, a polymerization method using the same, an olefin polymer produced by the method, and an optical anisotropic film comprising the olefin polymer. Background Art [2] Among catalyst systems used in polymerization reactions, a homogeneous Ziegler-Natta catalyst system which generally has multiple active sites includes methylaluminoxane (MAO) as a cocatalyst to improve the reactivity of the catalyst. However, a large amount of the MAO should be used relative to the catalyst precursor, and thus an increase in production cost and the requirement of post-treatment arise. [3] With appearance of single active site catalysts such as metallocene catalysts, a perfluoroarylborate type non-coordination anion capable of providing single cation active species to a catalyst precursor, having low charge of-1 or -2 and easily achieving delocalization of charges has been used as a cocatalyst (Chem. Rev. 1988, Vol. 88, 1405-1421; Chem. Rev. 1993, Vol. 93, 927-942). [4] Such an anion is used in the form of a salt in combination with trityl causing an alkide or hydride removal reaction or dialkylammonium cation causing protonolysis. Exemplary borate cocatalyst compounds include [PhNMe2H][B(C6F5)4]. [5] In the polymerization reaction, the cation part of a cocatalyst reacts with a leaving group of a metal precursor to provide a cationic metal precursor and forms an ion pair with the anion part of the cocatalyst. The anion weakly coordinates to the metal and is easily exchanged with an olefin monomer, resulting in polymerization. [6] The ion pair acts as a catalyst active species, but is thermally and chemically unstable and sensitive to solvents, monomers, etc., and thus reduces the reactivity of a catalyst. In particular, in the case of a nitrogen containing cocatalyst compound, a neutral amine compound is produced during a catalyst active reaction and can strongly interact with a cationic organometallic catalyst, thereby resulting in a reduction of the catalytic activity. To avoid this problem, carbenium, oxonium and sulfonium cations can be used instead of the ammonium cation (EP Patent No. 0426,637). [7] Meanwhile, when cyclic olefins are polymerized using MAO or organoaluminium, in most cases, high polymerization activity is shown against a non-polar norbornene such as norbornene, alkylnorbornene and silylnorboraene, whereas significantly low polymerization activity is shown against a polar norbornene such as ester or acetyl norbornene (U.S. Paten Nos. 5,468,819, 5,569,730, 5,912,313, 6,031,058 and 6,455,650). [8] Norbornene polymers which are composed of cyclic olefin monomers such as norboraenes exhibit much better properties than conventional olefin polymers, such as high transparency, heat resistance and chemical resistance, and have low birefringence and moisture absorption. Thus, they have various applications, e.g., optical components such as CDs, DVDs and POFs (plastic optical fibers), information and electronic components such as capacitor films and low-dielectrics, and medical components such as low-absorbent syringes, blister packagings, etc. Adhesion of polymers to inorganic materials such as silicon, silicon oxide, silicon nitride, alumina, copper, aluminium, gold, silver, platinum, titanium, nickel, tantalium, and chromium is often a critical factor in the reliability of the polymer for use as an electronic material. The introduction of functional groups into norbornene monomers enables control of chemical and physical properties of a resultant norbornene polymer. However, in this case, a problem of reduction in reactivity occurs. [9] That is, although catalyst systems for polymerizing cyclic olefins having polar functional groups can be prepared using various cocatalysts, the resulting catalysts are sensitive to monomers and deactivated or not used at high temperatures due to poor thermal stability. Thus, the polymerization yield, the molecular weight of the resulting polymers, and the amount of catalyst used are not at practical desired levels, as in the case of general olefins having polar functional groups. When an excess of catalyst is used, the resulting polymer is colored or its transparency is deteriorated. [10] Therefore, there is a demand for a novel catalyst system capable of producing a cyclic olefin polymer having polar functional groups from a small amount of catalyst which has thermal and chemical stability to solvents, monomers, moisture and oxygen by simultaneously and properly controlling a cocatalyst structure and a procatalyst structure. Disclosure of invention Technical Solution [11] The present invention provides a catalyst system capable of producing a cyclic olefin polymer having polar functional groups and a high molecular weight in a high yield. The catalyst system has good thermal and chemical stability, and thus is not deactivated due to polar functional groups. [ 12] The present invention also provides a method for producing a cyclic olefin polymer having polar functional groups and a high molecular weight in a high yield by using the catalyst system. [13] The present invention also provides a cyclic olefin polymer with polar functional groups that has a high glass transition temperature, desirable thermal and oxidative stability, desirable chemical resistance and adhesion to metal. [14] The present invention also provides an optical anisotropic film made from a cyclic olefin polymer having polar functional groups. [15] According to an aspect of the present invention, there is provided a catalyst system for producing cyclic olefin polymers having polar functional groups, which comprises: [16] i) a procatalyst represented by formula (1) containing a group 10 metal and a ligand containing hetero atoms bonded to the metal; [17] ii) a cocatalyst represented by formula (2) including a salt compound which is capable of providing a phosphonium cation and an anion weakly coordinating to the metal of the procatalyst [19] where X is a hetero atom selected from S, O and N; [20] R, is -CH=CHR20, -OR20, -SR20, -N(R20)2, -N=NR20, -P(R20)2, -C(O)R20, -C(R20)=NR20, -C(O)OR20, -OC(O)OR20, -OC(O)R20, -C(R20)=CHC(O)R20, -R21C(O)R20, -R21C(0)OR20 or -R21OC(O)R20, where R20 is a hydrogen, a halogen, a linear or branched Q.s alkyl, a linear or branched Ci.5 haloalkyl, a linear or branched C5.]0 cycloalkyl, a lin.ear or branched C2.5 alkenyl, a linear or branched C2.s haloalkenyl, or an optionally substituted C? aralkyl, and R21 is a Ci.2o hydrocarbylene; [21] R2 is a linear or branched Q.M alkyl, alkenyl or vinyl, a Cs.i2 cycloalkyl optionally substituted by a hydrocarbon, a do aryl optionally substituted by a hydrocarbon, a €7.15 aralkyl optionally substituted by a hydrocarbon, or C3.2o alkynyl; [22] M is a group 10 metal; and [23] p is an integer from 0 to 2, and [24] [(R3)-P(R4)a(R4.)b[Z(R5)d]o][Ani] (2) [25] where each of a, b and c is an integer from 0 to 3, and a+b+c = 3; [26] ZtsO, S, SiorN; [27] d is 1 when Z is O or S, d is 2 when Z is N, and d is 3 when Z is Si; [28] R3 is a hydrogen, an alkyl, or an aryl; [29] each of Rt, R4- and R5 is a hydrogen; a linear or branched C|.20 alkyl, alkoxy, allyl, alkenyl or vinyl; a C3.|2 cycloalkyl optionally substituted by a hydrocarbon; a Co aryl optionally substituted by a hydrocarbon; a C?.i5 aralkyl optionally substituted by a hydrocarbon; a C3.20 alkynyl; a tri(linear or branched CMO alkyl)silyl; a tri(linear or branched C|.IO alkoxy)silyl; a tri(optionally substituted C3.12 cycloalkyl)silyl; a tri(optionally substituted C aryl)silyl; a tri(optionally substituted Ce-w aryloxy)silyl; a tri(linear or branched d.|0 alkyl)siloxy; a tri(optionally substituted C3.i2 cycloalkyl)siloxy; or a tri(optionally substituted Cnz, Re values of all cyclic olefin films increased, which indicates that Rt|, of a cyclic olefin film is 34 produced due to a negative birefringence (ny>nz) in a direction through the film thickness. Industrial Applicability [245] The present invention provides a catalyst system capable of producing a cyclic olefin polymer having polar functional groups and a high molecular weight in a high yield. The catalyst system has good thermal and chemical stability, and thus is not deactivated due to functional groups. Claims [1] A catalyst system for producing cyclic olefm polymers having polar functional groups, the catalyst system comprising: i) a procatalyst represented by formula (1) containing a group 10 metal and a ligand containing hetero atoms bonded to the metal; ii) a cocatalyst represented by formula (2) including a salt compound which is capable of providing a phosphonium cation and an anion weakly coordinating to the metal of the procatalyst: (Figure Removed) where X is a hetero atom selected from S, O and N; R, is -CH=CHR20, -OR20, -SR20, -NflR20),, -N=NR20, -P(R20)2, -C(O)R20, -C(R20)=NR20, -C(O)OR20, -OC(O)OR20, -OC(O)R20, -C(R20)=CHC(O)R20, -RZ1C(O)R20, -R21C(O)OR20 or -R21OC(O)R20, where R20 is a hydrogen, a halogen, a linear or branched Q.s alkyl, a linear or branched Ci.s haloalkyl, a linear or branched CS-io cycloalkyl, a linear or branched C2-s alkenyl, a linear or branched C2.s haloalkenyl, or an optionally substituted C7.24 aralkyl, and R21 is a Ci.20 hydrocarbylene; R2 is a linear or branched Ci.20 alkyl, alkenyl or vinyl; a C5.i2 cycloalkyl optionally substituted by a hydrocarbon; a C\aryl optionally substituted by a hydrocarbon; a C7.i5 aralkyl optionally substituted by a hydrocarbon; or C3.2o alkynyl;M is a group 10 metal; and p is an integer from 0 to 2, and [(R3)-P(R4)a(R40b[Z(R5)d]c][Ani] (2) where each of a, b and c is an integer from 0 to 3, and a+b+c = 3; ZisO, S, SiorN; d is 1 when Z is O or S, d is 2 when Z is N, and d is 3 when Z is Si; R) is a hydrogen, an alkyl, or an aryl; each of R4, Rr and R5 is a hydrogen; a linear or branched Ci.2o alkyl, alkoxy, allyl, alkenyl or vinyl; a C3.(2 cycloalkyl optionally substituted by a hydrocarbon; a CMC (Figure Removed) aryl optionally substituted by a hydrocarbon; a C7.i5 aralkyl optionally substituted by a hydrocarbon; a C3.2o alkynyl; a tri(linear or branched CMO alkyl)silyl; a tri(linear or branched CMo alkoxy)silyl; a tri(optionally substituted C3.i2 cycloalkyl)silyl; a tri(optionally substituted Co aryl)silyl; a tri(optionally substituted Cgo aryloxy)silyl; a tri(linear or branched C|_i0 alkyl)siloxy; a tri(optionally substituted C3.i2 cycloalkyl)siloxy; or a tri(optionally substituted CMO aryl)siloxy, in which each substituent is a halogen or Ci.2o haloalkyl; and [Ani] is an anion capable of weakly coordinating to the metal M of the procatalyst represented by formula (1) and is selected from the group consisting of borate, aluminate, [SbF6]-, [PF6]-, [AsF6]-, perfluoroacetate([CF3CO2]-), perfluoropropionate([C2F5CO2]-),perfluorobutyrate([CF3CF2CF2CO2]-), perchlorate([C!O4]-), p-toluenesulfonate([p-CH3C6H4SO3]-), [SO3CF3]-, boratabenzene, and carborane optionally substituted with a halogen. The catalyst system of claim 1, wherein the borate or aluminate of formula (2) is an anion represented by formula (2a) or (2b): RS is a halogen, a linear or branched Ci_2o alkyl or alkenyl optionally substituted by a halogen, a C3.j2 cycloalkyl optionally substituted by a halogen, a Cfi.40 aryl optionally substituted by a hydrocarbon, a C6.4o aryl optionally substituted by a linear or branched C3.2o trialkylsiloxy or a linear or branched Ci8u»8 triarylsiloxy, or a C7.is aralkyl optionally substituted by a halogen. The catalyst system of claim 1, wherein the procatalyst represented by formula (1) and the cocatalyst represented by formula (2) are a group 10 metal containing compound represented by formula (3) and a phosphonium compound represented by formula (4), respectively; each of R|', R2', R2" and R2'" is a linear or branched C|.2o alkyl, alkenyl or vinyl; a C$.\2 cycloalkyl optionally substituted by a hydrocarbon; a C