JPH06157672A - Production of cycloolefin polymer - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide a method for producing a cyclic olefin polymer having excellent heat resistance and weather resistance. [Structure] A phenolic compound and a solvent are used when producing and purifying a cyclic olefin-based (co) polymer of a monomer represented by the following chemical formula 1 or a hydrogenated polymer of the (co) polymer. And / or a solvent containing a phosphite-based antioxidant is used (in the formula 1, R ^{1 to} R ¹² are each a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a halogen atom or a monovalent organic group). ). [Chemical 1]

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a cyclic olefin polymer.

[0002]

BACKGROUND OF THE INVENTION Cyclic olefin polymers are useful as resins having excellent optical properties, and various cyclic olefin polymers and their production methods have been proposed. In the cyclic olefin polymer used as an optical material, in order to obtain the above excellent optical properties, the cyclic olefin polymer needs to be colorless and transparent, and further, the heat resistance stability and the weather resistance stability are It must be secured. In general, a method of incorporating an antioxidant into the thermoplastic polymer is used as a means for improving the heat resistance and weather resistance of the thermoplastic polymer. The above-mentioned cyclic olefin polymer is no exception, for example, by preventing the deterioration by adding an antioxidant to the cyclic olefin polymer,
A method for improving heat resistance stability and weather resistance stability is disclosed in Japanese Patent Application Laid-Open No. Hei 2
No. 269760 is proposed.

[0003]

However, in the above-mentioned method, pellets and beads of the cycloolefin polymer are produced after the production step of the cycloolefin polymer is completed.
Although it has the effect of preventing oxidative deterioration in the so-called finishing process and improving heat resistance stability and weather stability, it prevents oxidative deterioration during the manufacturing process because an antioxidant is added after the manufacturing process is completed. It is not possible. Further, when the deterioration of the polymer starts during the production process, it is difficult to prevent the progress of the deterioration even if an antioxidant is added to the polymer thereafter. Deterioration of the polymer in the manufacturing process has been a serious problem in terms of quality of the finally obtained optical material and the like.

[0004]

In view of the present situation, the present inventors have conducted extensive studies to prevent deterioration of the cyclic olefin polymer, and as a result, the cause of the deterioration is that it is used in the production stage. It was found that the deterioration of the obtained polymer can be suppressed by paying attention to a solvent that contains the compound and adding an antioxidant to the solvent. The present inventors have completed the present invention based on such findings. The method for producing a cyclic olefin polymer according to the present invention is a method for producing a cyclic olefin polymer comprising a (co) polymer of a monomer represented by the following chemical formula 2 or a hydrogenated polymer of the (co) polymer. The method is characterized in that a solvent containing an antioxidant composed of a phenol compound and / or a phosphite compound is used.

[0005]

[Chemical 2] (In the formula 2, R ^{1 to} R ¹² are each a hydrogen atom and a carbon number 1 respectively.
10 to a hydrocarbon group, a halogen atom or a monovalent organic group, which may be the same or different. R ⁹ and R ¹⁰ or R ¹¹ and R ¹² may combine to form a divalent hydrocarbon group, and R ⁹ or R ¹⁰ and R ^9
11 or R ¹² may form a ring with each other. m is 0 or a positive integer, and when m is 2 or more, R ¹ to
R ⁴ may be the same or different. ) Further, it is preferable to purify the solvent used in the production step and / or purification step of the cyclic olefin polymer by distillation and / or adsorption.

The present invention will be specifically described below.
The cyclic olefin polymer to be produced in the present invention is a polymer of a monomer represented by the above chemical formula 2 (hereinafter referred to as "specific monomer"), a copolymerizable monomer with the specific monomer. It means either a copolymer with a monomer or a hydrogenated polymer of the above (co) polymer. Further, the solvent used in the present invention is a solvent used in producing a cyclic olefin-based polymer, specifically refers to the polymerization reaction solvent and hydrogenation reaction solvent used in the production process, Further, it also includes a solvent used in the step of purifying the cyclic olefin polymer.

<Specific Monomer> Specific examples of the specific monomer represented by the above chemical formula ² include bicyclo [2.2.1] hept-2-ene and tetracyclo [4.4.0.1 ^{2]. , 5} . 1
^7,10 ] -3-Dodecene, hexacyclo [6.6.1.1]
^3,6 . 0 ^2,7 . 0 ^9,14] -4-heptadecene, tricyclo [5.2.1.0 ^{2, 6]-8-decene,} pentacyclo [6.5.1.1 ^{3, 6.} 0 ^2,7 . 0 ^9,13] -4-pentadecene, heptacyclo [8.7.0.1 ^2,9. 1 ^4,7 .
1 ^11,17 . 0 ^3,8 . 0 ^12,16 ] -5-icosene, tricyclo [4.4.0.1 ^2,5 ] -3-decene, 5-methoxycarbonylbicyclo [2.2.1] hept-2-ene, 5-methyl- 5-methoxycarbonyl-bicyclo [2.2.1] hept-2-ene, 5- Shianobishikuro [2.2.1] hept-2-ene, 8-methoxycarbonyltetracyclo [4.4.0.1 ^{2 , 5} . 1 ^7,10 ] -3
-Dodecene, 8-methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene, 9-methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-Dodecene, tricyclo [4.3.0.1 ^2,3 ] -3-decene, 8-ethylidene tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ]-
3-dodecene, 8-methyltetracyclo [4.4.0.
1 ^2,5 . 1 ^7,10 ] -3-Dodecene, 8-isopropylidenetetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-
Dodecene, 8-ethyltetracyclo [4.4.0.1
^2,5 . 1 ^7,10 ] -3-dodecene, 5,10-dimethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene, hexacyclo [6.6.1.1 ^3,6 . 1 ^16,13 .
0 ^2,7 . 0 ^9,14] -4-heptadecene, mention may be made of the other. The above-mentioned monomers do not necessarily have to be of the same type, and two or more types can be used for copolymerization.

<Copolymerizable Monomer> The cyclic olefin-based polymer may be one obtained by (co) polymerizing the above-mentioned specific monomer. It may be a copolymer with the body. Specific examples of the copolymerizable monomer used in this case include cycloolefins such as cyclobutene, cyclopentene, cycloheptene, cyclooctene, and tricyclo [5.2.1.0 ^2,6 ] -3-decene. be able to. Further polybutadiene,
In the presence of an unsaturated hydrocarbon-based polymer having a carbon-carbon double bond in the main chain such as polyisoprene, styrene-butadiene copolymer, ethylene-propylene-non-conjugated diene copolymer, polynorbornene, etc. The monomer may be polymerized. The hydrogenated polymer obtained by hydrogenating the (co) polymer obtained as described above is useful as a raw material for a resin having high impact resistance. It is also possible to use an unsaturated double bond-containing compound such as ethylene as a copolymerizable monomer, and the unsaturated double bond-containing compound and a specific monomer are subjected to a copolymerization reaction to obtain a saturated copolymer. The method of the present invention can be applied even when a coalescence is obtained.

<Polymerization Catalyst> The polymerization reaction is carried out in the presence of a catalyst composed of a platinum group compound such as ruthenium, rhodium, palladium, iridium and platinum. Also, (a)
At least one selected from compounds of W, Mo and Re
Seeds and (b) Deming's Periodic Table Group IA elements (eg L
i, Na, K, etc.), Group IIA elements (eg, Mg, Ca, etc.), Group IIB elements (eg, Zn, Cd, Hg, etc.), I
A compound of a group IIA element (for example, B, Al, etc.), a group IVA element (for example, Si, Sn, Pb, etc.) or a group IVB element (for example, Ti, Zr, etc.), wherein at least one element-carbon bond or It may be a catalyst composed of a combination with at least one selected from those having an element-hydrogen bond, and in this case, the additive (c) described below is added to enhance the activity of the catalyst. May be Suitable W, Mo or R as component (a)
As typical examples of the compound of e, WCl ₆ , MoCl ₅ ,
Examples thereof include ReOCl ₃ and the compounds described in Japanese Patent Application No. 1-240517. (B) Specific examples of the _{component, n-C 4 H 9 Li} , (C 2 H 5) 3 Al, (C
₂ H ₅ ) ₂ AlCl, LiH, etc. Japanese Patent Application No. 1-24051
The compounds described in JP-A-7 can be mentioned. As typical examples of the component (c) which is an additive, alcohols, aldehydes, ketones, amines and the like can be preferably used, and further, the compounds shown in Japanese Patent Application No. 1-240517 are used. can do. The ratio of the component (a) to the component (b) is such that the metal atom ratio (a) :( b) is in the range of 1: 1 to 1:20, preferably 1: 2 to 1:10. The molar ratio of the component (a) to the component (c) is such that (c) :( a) is in the range of 0.005: 1 to 10: 1, preferably 0.05: 1 to 2: 1. It

<Molecular Weight of Cyclic Olefin Polymer> In the present invention, the polymer to be subjected to the hydrogenation reaction described below has a size such that the intrinsic viscosity (η _inh ) is in the range of 0.2 to 5.0. Those having a molecular weight of 10 are preferable. In general, it tends to be difficult to obtain a high hydrogenation rate as the molecular weight increases, so the above range is preferable. The molecular weight of the cyclic olefin-based polymer can be adjusted by the polymerization temperature, the type of catalyst and the type of solvent, but 1-butene, 1-pentene, 1-hexene,
It is preferable that α-olefins such as 1-octene are allowed to coexist in the reaction system and the amount thereof is changed to adjust.

<Hydrogenation catalyst> The hydrogenation catalyst used in the hydrogenation reaction of the polymer includes organic acid salts such as titanium, cobalt and nickel or acetylacetone salts and organic metal compounds such as lithium, magnesium, aluminum and tin. Combined with,
So-called Ziegler type homogeneous catalysts, supported noble metal catalysts in which precious metals such as palladium, platinum, ruthenium, rhodium, etc. are supported on a carrier such as carbon, alumina, silica alumina, silica magnesia, diatomaceous earth, rhodium, rhenium, ruthenium etc. Examples thereof include noble metal complex catalysts. Among the Ziegler type homogeneous catalysts, the catalyst composed of a nickel compound and a cobalt compound has high hydrogenation activity. Examples of such nickel compounds include nickel naphthenate, nickel carboxylates such as nickel octoate, nickel acetylacetonate, nickel chloride, nickel carbonyl, nickelocene, and the like, and examples of the cobalt compound include cobalt naphthenate and cobalt. Acetylacetonate, cobalt chloride,
Cobalt carbonyl etc. can be illustrated. Among the supported noble metal-based catalysts, the catalyst in which palladium is supported on the silica-alumina carrier or the silica-magnesia carrier has high hydrogenation activity. After the completion of the hydrogenation reaction, the supported precious metal-based catalyst is easily separated from the reaction solution by a known means such as filtration, sedimentation separation, and centrifugation. Among the noble metal complex catalysts, the catalyst composed of a ruthenium complex has high hydrogenation activity, and the ruthenium complex includes RuHCl (CO) [P (C ₆ H ₅ ) ₃ ] ₃ , R
uCl ₂ [P (C ₆ H ₅ ) ₃ ] ₃ , RuH ₂ (CO)
[P (C ₆ H ₅ ) ₃ ] ₃ , Ru (CO) ₃ [P (C ₆ H
₅ ) ₃ ] _{2 and the} like.

<Hydrogenation reaction> The temperature of the hydrogenation reaction is
It is usually from 0 to 200 ° C, preferably from 50 to 180 ° C. If the temperature is too low, a large reaction rate cannot be obtained, while if the temperature is too high, the catalyst may be deactivated, which is not preferable. The pressure of the reaction system is usually 1-2.
00 kg / cm ² , preferably ² to 150 kg /
cm ² , more preferably 5 to 120 kg / cm ² . When the pressure is low, a high reaction rate cannot be obtained, while when the pressure is high, a high reaction rate can be obtained, but it is not economical because an expensive pressure resistant device is required. The time required for the reaction is related to the concentration of the polymer and the pressure,
Usually, it is selected in the range of 30 minutes to 100 hours, preferably in the range of 1 hour to 30 hours.

The solvent used in the present invention refers to all solvents which come into direct contact with the cyclic olefin-based polymer produced in the production process, such as a polymerization reaction solvent and a hydrogenation reaction solvent which will be described later. It also includes a solvent used in the purification step of the cycloolefin polymer such as removal.

<Polymerization Reaction Solvent> As the solvent for the polymerization reaction using the above-mentioned polymerization catalyst, the following solvent A or solvent B or a mixture thereof is preferably used. Solvent A
Is a mixture of the solvent component (1) and the solvent component (2). The solvent component (1) has 10 carbon atoms.
The following, preferably 5 to 8 alicyclic saturated hydrocarbons and /
Alternatively, an aliphatic saturated hydrocarbon is used. Here, specific examples of the alicyclic saturated hydrocarbon include cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, ethylcyclohexane, cycloheptane, decalin, and the like, and saturated aliphatic hydrocarbons. Specific examples of n-pentane, isopentane, n-hexane, n-heptane,
Examples thereof include n-octane. A dialkyl glycol ether is used as the solvent component (2). Specific examples thereof include ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, and triethylene glycol dimethyl ether. The mixing ratio of the solvent component (1) and the solvent component (2) in the solvent A is usually 95: 5 to 30: 7 by weight.
It is set to 0, preferably 90:10 to 40:60. If the proportion of the solvent component (1) is too large, the solubility of the solvent A in the produced polymer will be insufficient, while if it is too small, the reaction activity of the polymerization reaction will be low and high polymerization will occur. It is not possible to obtain a degree of polymer.

As the solvent B, for example, benzene, toluene, xylene, ethylbenzene and the like having 6 to 10 carbon atoms.
Aromatic hydrocarbons or alkanes such as pentane, hexane, heptane, nonane, decane, cyclohexane, cycloheptane, cyclooctane, decalin, cycloalkanes such as norbornane, chlorbutane, bromohexane, dichloroethane, hexamethylene dibromide, Examples thereof include halogenated alkanes such as chlorobenzene, compounds such as aryl, and saturated carboxylic acid esters such as ethyl acetate and methyl propionate. These solvents may be used alone or in combination of two or more. In the polymerization reaction carried out with the above solvent, the monomer concentration is usually 10 to 50% by weight.

<Hydrogenation Reaction Solvent> The hydrogenation reaction solvent is not particularly limited as long as it is a good solvent for the polymer to be hydrogenated and is not itself hydrogenated. Specifically, the same solvent as the above-mentioned polymerization reaction solvent can be mentioned. The concentration of the polymer in the polymer solution used for the hydrogenation reaction is usually 1 to 50% by weight, preferably 3 to 40% by weight, more preferably 5 to 30% by weight. If the concentration of the polymer is too high, a large reaction rate cannot be obtained, while if it is too low, it is economically disadvantageous.

<Solvent Used in Polymer Purifying Step> For example, as shown in Japanese Patent Application No. 3-53636, methanol is used in the purifying step of removing a metal compound from a polymer.
So-called poor solvents such as lower methanol such as ethanol and ketones such as acetone and methyl ethyl ketone may be used, and it is also necessary to add an antioxidant to these solvents.

<Solvent Purification Treatment> The above-mentioned solvent can be purified in advance, and the treatment method in that case is not particularly limited as long as impurities in the solvent can be substantially removed.
By performing operations such as distillation, extraction and adsorption, the solvent can be efficiently purified.

<Antioxidant> In the present invention, in order to prevent oxidative deterioration of the cyclic olefin polymer at the stage of the production step and / or the purification step, a specific antioxidant is added to the solvent used in each step. It is characterized in that the agent is added. As a result, a cyclic olefin polymer having good optical properties and the like can be finally obtained. As the antioxidant, a phenol compound and / or a phosphite compound are used from the viewpoints that they can suppress the activation of the solvent itself, which causes deterioration of the polymer, and that they have no contamination. Specific examples of the phenolic compound used in the method for producing a cyclic olefin polymer of the present invention include 2,6-di-t-butyl-p-cresol, 2,6-diphenyl-4-octadecyloxyphenol, Stearyl (3,5-di-t-butyl-4-hydroxyphenyl) propionate, distearyl (3,5
5-di-t-butyl-4-hydroxybenzyl) phosphonate, thiodiethylene glycol bis [(3,5-di-t-butyl-4-hydroxyphenyl) propionate], 4,4′-thiobis (6-t-butyl) -M-cresol), 2-octylthio-4,6-di (3,5-di-t-butyl-4-hydroxyphenoxy) -s-triazine, 2,2'-methylenebis (4-methyl-6-t).
-Butylphenol), 2,2'-methylenebis (4-
Ethyl-6-t-butylphenol), bis [3,3-
Bis (4-hydroxy-3-t-butylphenyl) butyric acid] glycol ester, 4,4′-butylidene bis (6-t-butyl-m-cresol), 2,
2'-ethylidene bis (4,6-di-t-butylphenol), 2,2'-ethylidene bis (4-s-butyl-)
6-t-butylphenol), 1,1,3-tris (2
-Methyl-4-hydroxy-5-t-butylphenyl)
Butane, bis [2-t-butyl-4-methyl-6- (2
-Hydroxy-3-t-butyl-5-methylbenzyl)
Phenyl] terephthalate, 1,3,5-tris (2,
6-dimethyl-3-hydroxy-4-t-butylbenzyl) isocyanurate, 1,3,5-tris (3,5-
Di-t-butyl-4-hydroxybenzyl) -2,4
6-trimethylbenzene, 1,3,5-tris [(3,
5-di-t-butyl-4-hydroxyphenyl) propionyloxyethyl] isocyanurate, tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane, 2-t- Butyl-4-methyl-6- (2-acryloyloxy-3
-T-butyl-5-methylbenzyl) phenol, 3,
9-bis (1,1-dimethyl-2-hydroxyethyl)
-2,4-8,10-Tetraoxaspiro [5.5] undecane-bis [β- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate], triethylene glycol bis [β- ( 3-t-butyl-4-hydroxy-5-methylphenyl) propionate] and the like.

Specific examples of phosphite compounds include trisnonylphenylphosphite, tris (2,4-di-t-butylphenyl) phosphite, tridecylphosphite, di (tridecyl) pentaerythritoldiphosphite. Phyto, distearyl pentaerythritol diphosphite, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite Fight, tetra (tridecyl) isopropylidene diphenol diphosphite, tetra (tridecyl) -4,4'-n-butylidene bis (2-t-butyl-5-methylphenol) diphosphite, hexa (tridecyl) -1,1, 3-Tris (3
-T-butyl-4-hydroxy-5-methylphenyl)
Butanetriphosphite, 2,2'-methylenebis (4,6-di-t-butylphenyl) octylphosphite, 2,2'-methylenebis (4,6-di-t-butylphenyl) octadecylphosphite, 2, 2'-methylenebis (4,6-di-t-butylphenyl) fluorophosphite, tetrakis (2,4-di-t-butylphenyl) biphenylene diphosphite and the like can be mentioned.

At least one or more antioxidants composed of these compounds are contained in the solvent. The content should not be an amount that inhibits the polymerization reaction and / or the hydrogenation reaction. Specifically, the weight ratio to the solvent is in the range of 0.1 ppm to 1000 ppm, preferably 0.5 ppm to 500 ppm, more preferably 1 ppm.
~ 100 ppm. Further, it is preferable to use the phenol compound and the phosphite compound together in a molar ratio of phenol compound / phosphite compound = 1 / 0.5 to 1/1.

[0022]

EXAMPLES Examples of the present invention will be described below.
The present invention is not limited to these. Example 1 (1) Purification Treatment of Solvent and Addition of Antioxidant to Solvent In the polymer production process, xylene used as a polymerization reaction solvent and a hydrogenation reaction solvent, and methanol used in the purification process are preliminarily distilled. Purified. For each of purified xylene and methanol, 50 p of stearyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate was added as an antioxidant.
Tris (2,4-di-t-butylphenyl) phosphite was added at 50 ppm so as to obtain pm. (2) Polymerization reaction Xylene 7040k purified by the above operation
g and 8-methyl-8 represented by the following chemical formula 3 as a monomer
-Carboxymethyltetracyclo [4.4.0.
1 ^2,5 . 1 ^7,10 ] -3-Dodecene 1760 kg and 1-hexene 130 kg as a molecular weight regulator were charged into a reaction vessel purged with nitrogen gas, and a chlorobenzene solution of WCl ₆ as a polymerization catalyst (concentration 0 0.05 mol /
30 liters and paraaldehyde 1,2-
Dichloroethane solution (concentration 0.1 mol / l) 15
Liter and 47 liters of an n-hexane solution of diethylaluminum chloride (concentration 0.8 mol / liter) were added to prepare a monomer mixed solution. This monomer mixed solution was polymerized at 60 ° C. for 5 hours to obtain a polymer.

[0023]

[Chemical 3] (3) Hydrogenation reaction In the polymer solution containing the polymer obtained by the above operation,
RuHCl (CO) [P (C
₆ H ₅ ) ₃ ] ₃ 1650 g was added, and the hydrogen gas pressure was 100 k.
The mixture was stirred under the conditions of g / cm ² and a reaction temperature of 165 ° C. for 4 hours to carry out a hydrogenation reaction to obtain a hydrogenated polymer. (4) Polymer Purification Step 10 kg of lactic acid was added to the obtained hydrogenated polymer solution containing the hydrogenated polymer, and the mixture was stirred at 60 ° C. afterwards,
After adding 4570 kg of the purified methanol described above and performing contact treatment for 1 hour, the mixture was allowed to stand at room temperature for separation to separate into a methanol phase and a hydrogenated polymer-containing phase, and then the methanol phase was removed. After this, again, methanol (purified) having the same amount and composition as the removed methanol phase and containing no metal species was added to the hydrogenated polymer solution after the above-mentioned stationary separation, and contact treatment was carried out for 1 hour. It was This contact treatment was repeated twice more to purify the hydrogenated polymer.

<Example 2> The antioxidant added to xylene and methanol was replaced with tridecyl phosphite, and 20 pp was added for each weight of the above xylene and methanol.
Example 1 except that the addition amount was changed to be m.
A polymer and a hydrogenated polymer were obtained by the same method as above, and further purified in the same manner as in Example 1.

Comparative Example 1 When a polymer / hydrogenated polymer was obtained by the same operation as in Example 1, the polymerization reaction solvent and the xylene used as the hydrogenation reaction solvent were not subjected to purification treatment and further oxidation prevention. Used without addition of agent.
After that, when the obtained hydrogenated polymer was purified by the same operation as in Example 1, methanol was used without purification treatment and without adding an antioxidant.

<Evaluation> Regarding the hydrogenated polymers obtained by the methods shown in Examples 1 and 2 and Comparative Example 1 above,
In order to evaluate heat resistance stability and weather resistance stability, measurement samples were prepared and measured.

(1) Addition of Antioxidant For each hydrogenated polymer contained in the hydrogenated polymer solutions of Examples 1 and 2 and Comparative Example 1, stearyl (3,5-dithird) was used as an antioxidant. Butyl-4-hydroxyphenyl) propionate was added to 5000 ppm.

(2) Pelletization Each of the hydrogenated polymer solutions added with the above antioxidant was concentrated at 180 ° C. under atmospheric pressure to obtain a concentrated polymer solution having a hydrogenated polymer concentration of 50% by weight. Obtained. This concentrated polymer solution was added to a plate fin type heat exchanger (width: 270 m).
m, height 200 mm, depth 255 mm, heat transfer area 4.
It was supplied at a rate of 40 kg per hour into a demolition apparatus equipped with 3 m ² ) and the solvent was removed under the conditions of a temperature of 280 ° C. and a pressure of 10 Torr. The solvent evaporated in the demolition apparatus was sucked from the exhaust port with a vacuum pump, condensed with a heat exchanger, and collected. After removing the solvent, the molten hydrogenated polymer remaining in the demelting device is continuously extruded at a rate of 20 kg per hour by a gear pump to form a strand, which is passed through a water tank and then cut by a pelletizer to add hydrogen to the pellet. A polymer was obtained. Here, the hydrogenated polymer pellets obtained in Example 1 are polymer pellets A, the hydrogenated polymer pellets obtained in Example 2 are polymer pellets B, and the hydrogenated polymer pellets obtained in Comparative Example 1 are Let polymer pellets be polymer pellets C.

(3) Test method Each of the above-mentioned polymer pellets A, B and C was heated at 120 ° C.
After vacuum-drying in, a 3.2 mm thick molded plate was produced using an injection molding machine (PS-40E; made by NISSEI RESIN). This molded plate was put in a gear oven at 150 ° C., and a color difference meter (S
The color change of the molded plate was measured using an M5 color computer (manufactured by Suga Test Instruments Co., Ltd.). YE obtained by measurement
The change in LLOW INDEX (YI) is regarded as the change in the color of the molding plate, and the change in YI is measured over time to obtain YI.
The time T at which the change of 10 or more was measured. Table 1 shows the initial value of YI and the time T for each molded plate.

[0030]

[Table 1]

[0031]

As described above, according to the present invention,
In the step of producing and purifying the cyclic olefin-based polymer by adding an antioxidant composed of a phenol-based compound and / or a phosphite-based compound to a solvent used in the production and purification steps of the cyclic olefin-based polymer Oxidative deterioration of the cyclic olefin polymer can be prevented. Therefore, it becomes possible to obtain a cyclic olefin polymer having excellent heat resistance and weather resistance.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Akira Iio 2-11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd.

Claims (1)

[Claims] 1. A method for producing a cyclic olefin-based polymer comprising a (co) polymer of a monomer represented by the following chemical formula 1 or a hydrogenated polymer of the (co) polymer, A method for producing a cyclic olefin polymer, characterized in that a solvent containing an antioxidant composed of a phenol compound and / or a phosphite compound is used in the production step and / or purification step of the combined product. [Chemical 1] (In Chemical formula 1, R ^{1 to} R ¹² are a hydrogen atom and a carbon number of 1, respectively.
10 to a hydrocarbon group, a halogen atom or a monovalent organic group, which may be the same or different. R ⁹ and R ¹⁰ or R ¹¹ and R ¹² may combine to form a divalent hydrocarbon group, and R ⁹ or R ¹⁰ and R ^9
11 or R ¹² may form a ring with each other. m is 0 or a positive integer, and when m is 2 or more, R ¹ to
R ⁴ may be the same or different. )