JP2008037756A - Cyclic olefin and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a 1,4-methano-1,4,4a,9a-tetrahydrofluorene composition producing a cyclic olefin polymer suitable for an optical use. <P>SOLUTION: This 1,4-methano-1,4,4a,9a-tetrahydrofluorene composition contains 100 to 5,000 ppm indene content. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene composition.

The α-olefin-cycloolefin copolymer obtained by copolymerization of α-olefin and cyclic olefin is excellent in transparency, heat resistance, moisture resistance, chemical resistance, solvent resistance, dielectric properties, and various mechanical properties. Synthetic resin and widely used in various fields. This cyclic olefin is polymerized using an organometallic complex catalyst. 1,4-Methanol 1,4,4a, 9a-tetrahydrofluorene has been conventionally synthesized as an addition reaction product of indene and cyclopentadiene, and the resulting 1,4-methanol 1,4,4a, 9a- As described above, methods using tetrahydrofluorene as a polymer raw material have been proposed in Patent Document 1 as metathesis polymerization and Patent Document 2 as addition polymerization.

  In Patent Document 3, in the Diels-Alder reaction between indene and cyclopentadiene, 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene as well as cyclopentadiene trimer and the like are by-produced. A method for controlling the body content within a certain range is disclosed.

By the way, according to the study by the present inventors, 1,4-methanone 1,4,4a, 9a-tetrahydrofluorene is decomposed during the purification by distillation, and indene is generated, thereby reducing the distillation yield. Inden found that there is a problem to be improved that causes deterioration of polymer quality.
JP-A-7-53680 JP-A-5-97719 JP 2000-26331 A

  The problem to be solved by the present invention is 1,4-methanol 1,4,4a, 9a-, which is useful as a raw material for resins requiring high purity such as optical applications and can be economically produced in high yield. It is to provide a tetrahydrofluorene composition.

As a result of intensive studies in view of the above prior art, the present inventors have completed the present invention. That is, the present invention
[1] 1,4-Methanol 1,4,4a, 9a-tetrahydrofluorene composition represented by the following formula (1), wherein the indene content is 100 to 5,000 ppm,

[2] The content of 1,4,5,11-dimethanone 1,1a, 4,4a, 5,5a, 9a, 10,10a-octahydrobenzofluorene represented by the following formula (2) is 10 ppm or less 1,4-Methanol 1,4,4a, 9a-tetrahydrofluorene composition of [1],

[3] 1,4-Methanol 1,4 according to [1], comprising mixing cyclopentadiene and / or dicyclopentadiene and indene, heating and reacting in the presence of a polymerization inhibitor, followed by separation and purification by distillation. , 4a, 9a-tetrahydrofluorene composition manufacturing method,
[4] A method for producing a 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene composition according to [3], wherein the bottom temperature of the distillation can is 150 ° C. or less,
[5] A cyclic olefin polymer using the 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene composition of [1] or [2] as a raw material monomer.

  When the 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene composition of the present invention is used as a raw material for polymerization, coloring can be suppressed and a polymer having excellent optical performance can be obtained.

Hereinafter, the present invention will be described in detail with specific examples.
The 1,4-methanone 1,4,4a, 9a-tetrahydrofluorene composition represented by the formula (1) according to the present invention is a Diels-Alder reaction type thermal addition of cyclopentadiene and / or dicyclopentadiene and indene. It can synthesize | combine by performing reaction. In addition to the target 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene represented by the formula (1), the reaction mixture thus obtained includes unreacted cyclopentadiene, dicyclopentadiene, indene, and further the formula 1,4,5,11-dimethanol 1,1a, 4,4a, 5,5a, 9a, 10,10a-octahydrobenzofluorene represented by (2), which is a reaction product of formula (1) and cyclopentadiene And cyclopentadiene trimer trimer represented by the following formulas (3) and (4).

  1,4-Methanol 1,4,4a, 9a-tetrahydrofluorene of the formula (1) reduces the yield because the reverse reaction of Diels-Alder reaction occurs due to heat and decomposes into indene and cyclopentadiene as raw materials. Become. In addition, 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene and cyclopentadiene further react to produce 1,4,5,11-dimethanol 1,1a, 4,4a represented by the formula (2). 5,5a, 9a, 10,10a-octahydrobenzofluorene is formed. 1,4,5,11-dimethanol 1,1a, 4,4a, 5,5a, 9a, 10,10a-octahydrobenzofluorene is higher than 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene Although it has a boiling point and can be removed from the bottom of the can by distillation, 1,4,5,11-dimethanol 1,1a, 4,4a, 5,5a, 9a, 10,10a-octahydrobenzo When the fluorene increases, the bottom temperature of the can must be raised, and when the temperature is raised, the above-mentioned reverse Diels-Alder reaction occurs, and indene is mixed in the product. Therefore, the 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene composition of the present invention can be obtained by strictly controlling the reaction process and / or the purification process.

  As the raw material cyclopentadiene used in the present invention, dicyclopentadiene obtained by pyrolysis distillation can be used in advance. Alternatively, dicyclopentadiene is directly supplied to the reactor and is thermally decomposed into cyclopentadiene in the reactor. It can also be used. As such dicyclopentadiene, a commercially available product can be used, and its purity is desirably 90% or more. Impurities of dicyclopentadiene are mainly 5-methyl-3a, 4,7,7a-tetrahydro-1H-indene represented by the following formula (5), C5 to C6 chain or cyclic diolefin, and cyclopentadiene. When the amount of these impurities is large, heavy by-products such as cyclopentadiene trimer increase. Therefore, it is preferable to use a high-purity raw material.

The indene that can be used in the present invention preferably has a purity of 90% or more. Main impurities include benzonitrile, benzoindene, dialkylbenzene and the like.
The supply ratio of indene to cyclopentadiene is such that the molar ratio of indene / cyclopentadiene is 2 to 100, more preferably 2 to 20. When dicyclopentadiene is used as a raw material, the molar ratio is converted to cyclopentadiene. When the indene is less than the lower limit of this range, 1,4,5,11-dimethanol 1,1a, 4,4a, 5,5a, 9a, 10,10a-octahydrobenzofluorene represented by the formula (2) is formed. However, due to the high boiling point, the side reaction due to the rise in the bottom temperature during purification by distillation, that is, the reverse Diels-Alder reaction of 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene of formula (1) There is a problem that indene and cyclopentadiene are generated. Moreover, when there is much indene exceeding this range, the amount of indene distilled out of the system by distillation purification increases, which is not preferable.

  Indene is modified and / or polymerized by heat or light. Therefore, it is preferable to add a polymerization inhibitor when reacting cyclopentadiene and / or dicyclopentadiene with indene. As polymerization inhibitors, phenol compounds such as hydroquinone, 2,6-di-tert-butylphenol, 2,6-di-tert-butylcresol, 4-methoxyphenol, 4-tert-butylcatechol, N, N- Amine compounds such as dimethylhydroxylamine, N, N-diethylhydroxylamine, N-nitroso-N-phenylbenzoamine and phenothiazine are preferably added. The addition amount is preferably 10 to 10,000 ppm, more preferably 50 to 5,000 ppm with respect to the indene supplied into the reactor. Moreover, it can add to the 1, 4- methanol 1,4,4a, 9a-tetrahydrofluorene composition of this invention which is a product similarly as a storage stabilizer.

  1,4-Methanol 1,4,4a, 9a-tetrahydrofluorene is synthesized using these raw materials and a polymerization inhibitor.

  In the reaction, either using a solvent or no solvent may be used. However, if a solvent is used, an additional distillation facility for solvent distillation is required in the subsequent purification step. In mass production at the level of 1,000 t, the equipment load becomes large and it is not economical, and in that case, it is preferable to use no solvent.

  The production method can be any of batch type, semi-flow type, and flow type, but is preferably carried out by the flow type. As the reactor, a complete mixing type, a tube type, a loop reactor or the like can be used, and the reaction can be carried out even when the reactor is full of liquid or has a gas phase part. The reaction can be carried out in one stage or multiple stages including two or more stages, and the reactors can be used in series or in parallel.

  The reaction temperature is 100 to 300 ° C, preferably 150 to 250 ° C. In particular, when dicyclopentadiene is used, it is necessary to introduce dicyclopentadiene directly into the reactor without using cyclopentadiene previously pyrolyzed and distilled, and to thermally decompose in the reactor to produce cyclopentadiene. C. or higher, more preferably 150.degree. C. or higher. When the reaction temperature is higher than 250 ° C., 1,4,5,11-dimethanol 1,1a, 4,4a, 5,5a, 9a, 10,10a-octa represented by the above formula [2] Hydrobenzofluorene and / or a cyclopentadiene trimer represented by the above formula [3] or formula [4] is generated, which is not preferable.

  The reaction time in the batch method requires time for the temperature raising time, but is 0.5 to 10 hours, more preferably 1 to 5 hours, and further preferably 1 to 3 hours after reaching the above reaction temperature. The reaction pressure is normal pressure to 10 MPaG, more preferably normal pressure to 5 MPaG, and still more preferably normal pressure to 1 MPaG.

  In the case of the semi-circulation type, cyclopentadiene and / or dicyclopentadiene and indene can be continuously added to the raw material previously placed in the reactor, and the extraction can be carried out batchwise. The raw materials can be mixed separately or supplied separately. In the semi-circulation type, the raw material cyclopentadiene and / or the ratio of dicyclopentadiene and indene can be changed with the reaction time. The reaction temperature is 0.5 to 10 hours, preferably 1 to 5 hours, more preferably 1 to 3 hours after reaching the predetermined reaction temperature, as in the batch process. The reaction pressure is normal pressure to 10 MPaG, more preferably normal pressure to 5 MPaG, and still more preferably normal pressure to 1 MPaG.

  In the flow type, the raw materials cyclopentadiene and / or dicyclopentadiene and indene can be supplied separately or mixed in advance. The residence time of the flow reactor is 0.5 to 10 hours, more preferably 1 to 5 hours, still more preferably 1 to 3 hours. The reaction pressure is normal pressure to 10 MPaG, more preferably normal pressure to 5 MPaG, and still more preferably normal pressure to 1 MPaG.

  Subsequently, the reaction mixture withdrawn from the reactor is introduced into the purification step. The purification method is preferably distillation purification. The operation can be carried out either batchwise or continuously. In the batch system, since the residence time at the bottom of the can becomes long, the continuous system that can continuously supply and extract is more preferable. In the batch system, it is distilled from the top of the tower step by step from the light boiling part, and 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene is distilled off from the product. It will be extracted from the bottom of the can. At this time, the recovered cyclopentadiene, dicyclopentadiene, and indene can be used again as synthesis raw materials or after being rectified again. In batch distillation, it is preferable to perform reflux and change the reflux ratio stepwise with time. The reflux ratio is 0.01 to 50, and when changing with time, it is preferable to gradually increase the reflux ratio.

  When distillation is performed continuously, the distillation column is a multistage system with two or more columns. When the distillation is carried out in two stages, the light boiling portion is distilled off from 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene in the first stage, and 1,4-methanoyl is obtained from the top of the tower in the second stage. Methanol 1,4,4a, 9a-tetrahydrofluorene is extracted from the bottom of the can more heavily than 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene. When distillation is performed in three stages, light boiling components are distilled away from indene such as cyclopentadiene and dicyclopentadiene in the first stage, and indene and / or 1,4-methanol 1,4,4a in the second stage. , 9a-Tetrahydrofluorene is distilled off from the bottom, 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene is distilled off from the top of the column in the third stage, and heavy components are extracted from the bottom of the can. .

  The distillation is preferably performed under reduced pressure conditions. Distilling at a lower temperature is possible by carrying out under reduced pressure. This is because the desired 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene undergoes a reverse Diels-Alder reaction by heat, and the raw materials cyclopentadiene and indene are produced to produce 1,4-methanol 1,4,4a. , 9a-tetrahydrofluorene is intended to suppress the decrease in yield. The distillation pressure is 0.01 to 100 kPa, more preferably 0.1 to 50 kPa, and still more preferably 0.1 to 20 kPa.

The distillation is performed at a bottom temperature of 30 to 150 ° C, preferably 95 to 150 ° C. When the temperature is higher than 150 ° C., cyclopentadiene and indene are produced by the above-mentioned reverse Diels-Alder reaction during distillation, and the raw material is mixed into the desired 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene. The purity will be lowered. On the other hand, when the temperature is lower than 95 ° C., a high degree of vacuum is required, and the equipment load increases, so there is a slight difficulty in mass production of several hundred to several thousand tons. As the distillation column, a packed column, a plate column, or the like can be used, but a packed column is more preferable.
The 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene composition of the present invention produced as described above contains 100 to 5,000 ppm of indene, and is represented by the formula (2) described above. The content of 4,5,11-dimethanol 1,1a, 4,4a, 5,5a, 9a, 10,10a-octahydrobenzofluorene is 10 ppm or less.

  The 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene composition of the present invention can be subjected to metathesis polymerization or olefin moiety addition polymerization by a conventionally known method. Metathesis polymerization can be carried out by methods disclosed in, for example, JP-A-9-183832, JP-A-8-151435, JP-A-5-043663, JP-A-1-172422, and the like.

  In addition polymerization, the olefin part can be copolymerized alone or with a lower α-olefin. A Ziegler catalyst or a metallocene catalyst is used as a catalyst for addition polymerization. Examples of the production method using a Ziegler catalyst include vanadium soluble in a hydrocarbon solvent as described in JP-A-9-176396, JP-A-62-252406, and JP-A-62-2252407. A copolymer of an α-olefin such as ethylene and a cyclic olefin can be synthesized by a method using a catalyst formed from a compound and an organoaluminum compound.

  In recent years, as a new catalyst, for example, a transition metal compound having a salicylaldoimine ligand as shown in JP-A-11-315109 is used as a catalyst. For example, as shown in JP-A-2004-331966, an α-olefin such as ethylene is used. And a cyclic olefin copolymer can be synthesized.

  The polymer solution thus obtained is deashed from the catalyst residue and then sent to the monomer solvent separation step, where it is heated by a rotary desolvator such as a multitubular heat exchanger, a hopper or a thin film evaporator, By flashing and sucking under reduced pressure, the solvent and unreacted monomers are removed by drying, and the olefin polymer is recovered. In the polymerization solution, unreacted monomers coexist with the polymerization solvent. Therefore, when it separates from a polymer by heating, the thermal stability of a monomer is needed. The cyclic olefin monomer 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene composition in the present invention contains 100 to 5,000 ppm of indene and is represented by 1,4,5,11 represented by the above formula (2). The content of dimethanone 1,1a, 4,4a, 5,5a, 9a, 10,10a-octahydrobenzofluorene is 10 ppm or less. If the indene content exceeds this range, the separation from the polymer becomes insufficient, and the indene-modified product colored yellow due to overheating remains in the polymer and causes the resin to turn yellow. A malfunction occurs. Further, 1,4,5,11-dimethanone 1,1a, 4,4a, 5,5a, 9a, 10,10a-octahydrobenzofluorene represented by the above formula (2) exceeds this range. If it is contained in a large amount, it is a high-boiling compound, so that it is difficult to remove it from the polymer in the above-described drying step, resulting in a problem of deteriorating the quality of the resin. The 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene composition of the present invention contains 100 to 5,000 ppm of indene and is 1,4,5,11-dimethanol 1 represented by the above formula (2). , 1a, 4,4a, 5,5a, 9a, 10,10a-Octahydrobenzofluorene content of 10 ppm or less, the resin raw material exhibiting excellent performance as an optical application without causing such problems Useful.

[Example]
Hereinafter, the contents of the present invention will be described more specifically with reference to examples, but the present invention is not limited to these. In the examples, “parts” means “parts by weight” unless otherwise specified.

(Monomer synthesis process)
Indene (purity 96.8% by weight) 2,369 parts, dicyclopentadiene (purity 95.0%) 652 parts (indene / dicyclopentadiene molar ratio = 4) as a polymerization inhibitor N-nitroso-N-phenylbenzo Each 2.3 parts of amine was charged into a 5 m ³ autoclave. The reaction was carried out batchwise. After replacing the gas phase with nitrogen, the temperature was raised to 180 ° C. over 3 hours. The system pressure after the temperature increase was 0.1 MPaG. The reaction was completed by heating and stirring at 180 ° C. for 3 hours. The liquid composition after completion of the reaction was indene / 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene / 1,4,5,11-dimethanol 1,1a, 4,4a, 5,5a, 9a, 10, 10a-octahydrobenzofluorene = 42/49/3.

  The resulting reaction solution was purified by distillation. Distillation was carried out batchwise. First, the first distillation was distilled off at a temperature of 60 ° C. to 110 ° C., a pressure of 0.02 to 0.03 kPa, and a reflux ratio of 1. The temperature was raised as it was, and a fraction containing the desired 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene was collected. At that time, the temperature was 110 to 140 ° C., the pressure was 0.015 to 0.03 kPa, and the reflux ratio was 1 to 2.5. Thereafter, the bottom liquid was extracted, and the 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene fraction collected at the first time was distilled again. Distillation was performed at 120 to 122 ° C., a pressure of 0.015 to 0.05 kPa, and a reflux ratio of 2 to 3. The resulting 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene composition has impurities of 2,400 ppm indene, 1,4,5,11-dimethanol 1,1a, 4,4a, 5,5a, 9a. , 10,10a-octahydrobenzofluorene was 10 ppm or less.

(Monomer synthesis process)
Indene (purity 96.8% by weight) 884 parts, dicyclopentadiene (purity 95.0%) 201 parts (indene / dicyclopentadiene molar ratio = 5) N-nitroso-N-phenylbenzoamine 0 as a polymerization inhibitor A mixed solution of 9 parts was prepared and continuously fed into a 2 m ³ autoclave. The residence time in the reactor was controlled to be 3 hours. The reaction temperature was 180 ° C. and the pressure was 0.5 MPa. The liquid composition at the outlet of the reactor was indene / 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene / 1,4,5,11-dimethanol 1,1a, 4,4a, 5,5a, 9a, 10, 10a-octahydrobenzofluorene = 47/50/2.

  The obtained reaction liquid was introduced into the distillation column as it was. The distillation operation was performed by two-stage continuous distillation. The first stage operating conditions were a can bottom temperature of 130 ° C. and a tower top pressure of 2 kPa, and the second stage operating conditions were a can bottom temperature of 143 ° C. and a tower top pressure of 1 kPa. The resulting 1,4-methanone 1,4,4a, 9a-tetrahydrofluorene composition has 2,000 ppm indene as impurities, 1,4,5,11-dimethanone 1,1a, 4,4a, 5,5a, 9a. , 10,10a-octahydrobenzofluorene was 10 ppm or less.

(Polymerization process)
The 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene composition obtained as in Example 2 was copolymerized with ethylene. Dehydrated and purified cyclohexane 130L per hour, ethylaluminum sesquichloride hexane solution (80 mmol / L) 27 mmol / h, vanadium catalyst VO (OEt) Cl ₂ hexane solution (30 mmol / L) in a continuous polymerization reactor with a volume of 300 L The molar ratio of vanadium to aluminum is Al / V = 14, ethylene 0.81 kg per hour, 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene composition 9.2 kg per hour, hydrogen 3.6 NL per hour The polymerization was conducted at a temperature of 20 ° C. and a total pressure of 0.3 MPa. From the polymerization tank, a mixture of polymer, unreacted monomer and solvent was extracted as a polymerization solution. This polymerization solution was then introduced into the decalcification process.

(Decalcification process)
A boiler water at 80 ° C. and an aqueous sodium hydroxide solution having a concentration of 25% by weight as a pH adjuster were added to stop the polymerization reaction and remove (deash) the catalyst residue remaining in the polymerization solution.

(Solvent and monomer separation process)
The deashed polymerization solution is sent to a solvent and monomer separation step. The double tube heater was supplied at a rate of 30 kg per hour and heated to a temperature of 205 ° C. The heated polymerization solution was released to normal pressure with a flash valve, passed through a double tube heater heated to 260 ° C., and led to a hopper to heat and evaporate the solvent and the monomer to separate from the polymer. The polymer was obtained at 3 kg per hour. The obtained polymer was kneaded by using an extruder with a vacuum vent (screw diameter: 30 mm, meshing twin screw extruder, L / D = 30) at a barrel temperature of 260 ° C. and a vacuum vent pressure of 0.7 kPa. The pellet was recovered by cooling and cutting. The remaining unreacted monomer was reduced by a vacuum vent in the extruder.

The intrinsic viscosity [η] measured in decalin at 135 ° C., which is an index of the molecular weight of the obtained polymer, is 0.50 dl / g, from 30 ° C. using a differential scanning calorimeter (DSC-7 manufactured by Perkin Elmer). The temperature was increased at 10 ° C./min, and the endothermic peak temperature observed at the glass transition point was 145 ° C.
The b value of the sample measured from the reflected light using a color meter SQ-300H manufactured by Nippon Denshoku Industries Co., Ltd. was 4.8.

[Comparative Example 1]
Indene (purity 96.8% by weight) 1,895 parts, dicyclopentadiene (purity 95.0%) 1,135 parts (indene / dicyclopentadiene molar ratio = 2) as a polymerization inhibitor N-nitroso-N- The reaction was conducted in the same manner as in Example 1 except that 1.8 parts of phenylbenzoamine was used. The liquid composition after completion of the reaction was indene / 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene / 1,4,5,11-dimethanol 1,1a, 4,4a, 5,5a, 9a, 10, 10a-octahydrobenzofluorene = 10/84/6.

  The obtained reaction solution was purified by distillation in the same manner as in Example 1. However, the can bottom temperature rose to a maximum of 168 ° C. The resulting 1,4-methanone 1,4,4a, 9a-tetrahydrofluorene composition has 21,000 ppm of indene as impurities, 1,4,5,11-dimethanol 1,1a, 4,4a, 5,5a, 9a , 10,10a-octahydrobenzofluorene was 100 ppm. During the distillation, 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene was decomposed to produce indene, and the purity could not be increased.

Next, a polymerization reaction was carried out in the same manner as in Example 3. The physical properties of the obtained polymer were as follows.
The intrinsic viscosity [η] was 0.38 dl / g, the glass transition point was 141 ° C., and the b value was 18.0.

  The polymer using the 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene composition of the present invention can produce a cyclic olefin polymer suitable for optical use in which coloring is suppressed.

Claims (5)

1,4-Methanol 1,4,4a, 9a-tetrahydrofluorene composition represented by the following formula (1), wherein the indene content is 100 to 5,000 ppm

The content of 1,4,5,11-dimethanol 1,1a, 4,4a, 5,5a, 9a, 10,10a-octahydrobenzofluorene represented by the following formula (2) is 10 ppm or less The 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene composition according to claim 1

2. 1,4-Methanol 1,4 according to claim 1, wherein cyclopentadiene and / or dicyclopentadiene and indene are mixed, heated and reacted in the presence of a polymerization inhibitor, and then separated and purified by distillation. Process for producing 4a, 9a-tetrahydrofluorene composition The method for producing a 1,4-methanone 1,4,4a, 9a-tetrahydrofluorene composition according to claim 3, wherein the bottom temperature of the distillation can is 150 ° C or lower. A cyclic olefin polymer using the 1,4-methanol 1,4,4a, 9a-tetrahydrofluorene composition according to claim 1 or 2 as a raw material monomer.