JPH05132546A - Production of polymer - Google Patents

Abstract

PURPOSE:To obtain a ring-opening polymer having good flowability, low birefingence and a narrow molecular weight distribution by performing the ring-opening polymerization of a specified monomer in the presence of a specified molecular weight modifier while continuously or intermittently adding the monomer to the reactional system. CONSTITUTION:A process for producing a polymer comprising the step of performing the metathetic ring-opening polymerization of a monomer comprising a norbornene derivative of formula I (wherein A and B are each H or a 1-10C hydrocarbon group; X and Y are each H, halogen or a monovalent organic group; and (m) is 0 or 1) (e.g. a compound of formula II) in the presence of a metathesis catalyst and a molecular weight modifier, wherein at least one member (e.g. styrene or methyl acrylate) selected from the group consisting of an aromatic vinyl compound and an acrylic ester is used as the molecular weight modifier, and the ring-opening polymerization is performed while continuously or intermittently adding the monomer to the reactional system. The obtained ring-opening polymer has a narrow molecular weight distribution, good flowability and low birefringence.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a polymer, and more particularly to a method for producing a metathesis ring-opening polymer having a narrow molecular weight distribution.

[0002]

2. Description of the Related Art Conventionally, transparent resins have been used as materials for molded articles requiring ordinary transparency such as automobile parts, lighting equipment, and electric parts, and more recently, as an optical material in which optical properties are important. Is being applied to. As a transparent resin preferably used for such an application, a ring-opening polymer obtained by metathesis ring-opening polymerization of a monomer composed of a norbornene derivative in the presence of a metathesis catalyst and hydrogenated products thereof are known, These ring-opening polymers and hydrogenated products have transparency, low water absorption, low birefringence, and heat resistance.

However, among these ring-opening polymers, those having a large molecular weight have insufficient fluidity, are difficult to process, and are prone to form birefringence. In such a case, it is known to control the molecular weight by carrying out a metathesis ring-opening polymerization reaction in the presence of a molecular weight regulator composed of an olefin compound.

[0004]

However, the molecular weight of the ring-opening polymer cannot be sufficiently controlled only by performing the metathesis ring-opening polymerization reaction in the presence of the molecular weight regulator. That is, (1) the molecular weight modifier composed of an olefin compound has a low activity with respect to a monomer composed of a norbornene derivative, and when the ratio of the molecular weight modifier to the monomer is too small, The ring-opening polymer thus obtained has a large molecular weight. A ring-opening polymer having a large molecular weight does not have sufficient fluidity and low birefringence, and a gel is generated during injection molding of a hydrogenated product of such a ring-opening polymer. (2) If the ratio of the molecular weight regulator to the monomer is too large, the molecular weight of the ring-opening polymer obtained due to the excess molecular weight regulator becomes too small, and the hydrogen of such a ring-opening polymer becomes too small. Silver streaks may occur during injection molding of the additive, and stickiness may occur on the surface of the molded product. (3) The monomer composed of the norbornene derivative is dissolved in a solvent together with the metathesis catalyst and the molecular weight modifier,
Usually, they are all put together in a reaction vessel and subjected to a ring-opening polymerization reaction. Therefore, at the start of the ring-opening polymerization reaction, even if the ratio of the molecular weight modifier to the monomer is appropriate, the ratio of the molecular weight modifier to the monomer gradually increases as the ring-opening polymerization reaction progresses. Then, the ring-opening polymer obtained in the latter stage of the reaction causes the same problem as in the above (2). this is,
Since the rate of decrease of the monomer due to the ring-opening polymerization reaction is higher than the rate of decrease of the olefin compound which is the molecular weight modifier, the ratio of the molecular weight modifier to the monomer changes (increases) with time. is there. Further, when the ratio of the molecular weight regulator to the monomer is too small in the early stage of the reaction and this ratio increases over time and becomes too large in the latter stage of the reaction, the molecular weight distribution becomes considerably wide, and The ring-opening polymer thus obtained has both the problems (1) and (2).

As described above, it is difficult to control the molecular weight by simply adding a molecular weight regulator composed of an olefin compound to the reaction system, and a metathesis ring-opening polymer having a suitable molecular weight distribution cannot be obtained. .. The present invention has been made based on the above circumstances, and an object thereof is to exhibit good fluidity and low birefringence, and moreover, in injection molding a hydrogenated product of a ring-opening polymer. An object of the present invention is to provide a production method for producing a polymer that does not generate silver streaks or gels.

[0006]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have used a specific compound as a molecular weight regulator coexisting in a reaction system together with a metathesis catalyst. By allowing the ring-opening polymerization reaction to proceed continuously or intermittently while adding to the reaction system, a low molecular weight substance causing silver streak and a high molecular weight substance causing gel formation are contained. It was found that a ring-opening polymer having a narrow molecular weight distribution can be obtained, and the present invention was completed based on such findings.

That is, in the method for producing a polymer of the present invention, a monomer comprising at least one norbornene derivative represented by the following chemical formula 2 (hereinafter also referred to as "specific monomer") is used.
A method for producing a polymer, which comprises a ring-opening polymerization step of performing metathesis ring-opening polymerization in the presence of a metathesis catalyst and a molecular weight modifier, wherein the aromatic vinyl compound and acrylic acid ester are used as the molecular weight modifier in the ring-opening polymerization step. It is characterized in that at least one selected from the group consisting of the following is used, and the ring-opening polymerization reaction is allowed to proceed while a monomer comprising a norbornene derivative is continuously or intermittently added to the reaction system.

[Chemical 2] [In Chemical Formula 2, A and B are a hydrogen atom or a C1-C10.
Wherein X and Y represent a hydrogen atom, a halogen atom or a monovalent organic group, and m is 0 or 1. ]

The present invention will be specifically described below.
The specific monomer used in the production method of the present invention is a compound having a norbornene structure represented by Chemical Formula 2 above. Among the specific monomers, X or Y in the above Chemical Formula 2 is a polar group,
In particular, the specific monomer which is a carboxylic acid ester group represented by the formula — (CH ₂ ) _n COOR ¹ is such that the hydrogenated product of the resulting ring-opening polymer has high glass transition temperature and low hygroscopicity. Is preferred. In the above formula, R ¹ is a hydrocarbon group having 1 to 12 carbon atoms. Further, the smaller the value of n is, the higher the glass transition temperature of the obtained ring-opening polymer is, which is preferable. Further, the specific monomer in which n is 0 is easy to synthesize and It is preferable in that the ring-opening polymer obtained has a high glass transition temperature. Further, A and B in the above chemical formula 2 are alkyl groups,
It is particularly preferably a methyl group, and particularly preferably, this alkyl group is bonded to the same carbon atom as that to which the above-mentioned carboxylic acid ester group is bonded.
Further, the specific monomer in which m is 1 in the above chemical formula 2 is more preferable than the one in which m is 0 in that a ring-opening polymer having a high glass transition point is obtained.

Specific examples of the specific monomer represented by the above chemical formula 2 include bicyclo [2.2.1] hept-2-ene,
Tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene, tricyclo [5.2.1.0 ^2,6 ] -8-decene, pentacyclo [6.5.1.1 ^3,6 . 0 ^2,7 . 0
^9,13 ] -4-Pentadecene, tricyclo [4.4.0.
1 ^2,5 ] -3-undecene, 5-carboxymethylbicyclo [2.2.1] hept-2-ene, 5-methyl-5
-Carboxymethylbicyclo [2.2.1] hept-2
-Ene, 5-cyanobicyclo [2.2.1] hept-2
-Ene, 8-carboxymethyltetracyclo [4.4.
0.1 ^2,5 . 1 ^7,10 ] -3-Dodecene, 8-carboxyethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ]-
3-dodecene, 8-carboxy n-propyl tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene, 8
-Carboxy isopropyl tetracyclo [4.4.0.
1 ^2,5 . 1 ^7,10 ] -3-dodecene, 8-carboxy n-
Butyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ]-
3-dodecene, 8-methyl-8-carboxymethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-Dodecene, 8-methyl-8-carboxyethyltetracyclo [4.4.0.1 ^2,5 . ^1,7,10 ] -3-Dodecene, 8-
Methyl-8-carboxy n-propyl tetracyclo [4.4.0.1 ^2,5 . ^1,7,10 ] -3-Dodecene, 8-
Methyl-8-carboxyisopropyltetracyclo [4.4.0.1 ^2,5 . ^1,7,10 ] -3-Dodecene, 8-
Methyl-8-carboxy n-butyl tetracyclo [4.
4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene, 9-methyl-8-carboxymethyltetracyclo [4.4.0.1
^2,5 . 1 ^7,10 ] -3-dodecene, norbornene, dimethanooctahydronaphthalene, ethyltetracyclododecene, trimethanooctahydronaphthalene and the like can be mentioned. Of these, 8-methyl-8-carboxymethyltetracyclo [4.4.0.1 ^2,5 .
[ ^17,10 ] -3-Dodecene is preferable because it has a high glass transition temperature and a small water absorption. The above-mentioned specific monomers are not necessarily used alone, and the ring-opening copolymerization reaction can be carried out using two or more kinds.

The ring-opening polymer may be a ring-opening polymerized product of the above-mentioned specific monomer alone, but it may be a ring-opening copolymerized product of the specific monomer and a copolymerizable monomer. It may be Specific examples of the copolymerizable monomer used in this case include cyclobutene, cyclopentene, cycloheptene, cyclooctene, tricyclo [5.2.1.
Cycloolefins such as 0 ^2,6 ] -3-decene can be mentioned. Furthermore, polybutadiene, polyisoprene,
Styrene-butadiene copolymer, ethylene-propylene-non-conjugated diene copolymer, polynorbornene and the like in the presence of unsaturated hydrocarbon-based polymer containing a carbon-carbon double bond in the main chain, etc. Ring-opening polymerization may be performed.
The hydrogenated product of the ring-opening copolymer obtained in this case is useful as a raw material for a resin having high impact resistance.

In the present invention, the ring-opening polymerization reaction is carried out in the presence of a metathesis catalyst. This metathesis catalyst
(A) at least one selected from compounds of W, Mo and Re, and (b) an element of Group IA (eg, Li, Na, K) of the periodic table of Deming, an element of Group IIA (eg, Mg,
Ca, etc., IIB group elements (eg Zn, Cd, Hg etc.), IIIA group elements (eg B, Al etc.), IVA group elements (eg Si, Sn, Pb etc.) or IVB group elements (eg Ti, Zr). Etc.) and a catalyst comprising a combination with at least one selected from those having at least one element-carbon bond or element-hydrogen bond. Further, in this case, an additive (c) described later may be added to enhance the activity of the catalyst. Suitable W, Mo or R as component (a)
As typical examples of the compound of e, WCl ₆ , MoCl ₅ ,
The compounds described in JP-A-1-240517 such as ReOCl ₃ can be mentioned. (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.
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 JP-A-1-240517 are used. be able to.

The amount of the metathesis catalyst to be used is such that the component (a): specific monomer is usually 1: 500 to 1: 50000 in molar ratio of the component (a) and the specific monomer. A range, preferably a range of 1: 1000 to 1: 10000. The ratio between the component (a) and the component (b) is
The metal atomic ratio of (a) :( b) is in the range of 1: 1 to 1:40, preferably 1: 2 to 1:20. The molar ratio of the components (a) and (c) is such that (c) :( a) is 0.
005: 1 to 15: 1, preferably 0.05: 1 to 7:
The range is 1.

Examples of the solvent used in the ring-opening polymerization reaction include alkanes such as pentane, hexane, heptane, octane, nonane and decane, cyclohexane, cycloheptane, cyclooctane, decalin, norbornane and the like, benzene. , Toluene, xylene, ethylbenzene, aromatic hydrocarbons such as cumene, chlorobutane, bromhexane, methylene chloride, dichloroethane, hexamethylene dibromide, halogenated alkanes such as chlorobenzene, chloroform, tetrachloroethylene, compounds such as aryl, ethyl acetate, acetic acid Saturated carboxylic acid esters such as n-butyl, iso-butyl acetate, methyl propionate and dimethoxyethane, dibutyl ether, tetrahydrofuran, dimethoxyethane and the like And the like ethers. Of these, aromatic hydrocarbons are preferred.

The molecular weight of the ring-opening polymer can be controlled by the polymerization temperature, the type of catalyst and the type of solvent.
In the present invention, the molecular weight modifier is adjusted by coexisting in the reaction system.

The first feature of the production method of the present invention is that a specific compound, that is, at least one selected from the group consisting of an aromatic vinyl compound and an acrylate ester is used as a molecular weight regulator. Among the above-mentioned specific compounds used as the molecular weight regulator, specific examples of the aromatic vinyl compound include styrene, p-methylstyrene, α-methylstyrene, divinylbenzene, and the like, and specific examples of the acrylic ester. as,
Methyl acrylate, ethyl acrylate, butyl acrylate, etc. can be mentioned. These can be used alone or in combination of two or more. The amount of the molecular weight modifier added is 0.5 to 40 mol%, preferably 3 to 30 mol%, based on the specific monomer used in the ring-opening polymerization reaction.
It is said that.

The second feature of the production method of the present invention is that the ring-opening polymerization reaction proceeds while the specific monomer is continuously or intermittently added to the reaction system. The rate of addition of the specific monomer is such that the ratio of the molecular weight modifier to the specific monomer in the reaction system is always constant from the start of the reaction, for example, 10%.
The rate is preferably about 35 mol% or so. The time required for adding the specific monomer varies depending on the reaction conditions such as the amount of the metathesis catalyst present in the reaction system and the reaction temperature, but is, for example, 30 minutes to 3 hours, preferably 1 minute.
~ 2 hours.

In order to achieve the object of the present invention, it is necessary to have both the above-mentioned first and second characteristic points, and only one of them has a ring-opening weight with a narrow molecular weight distribution. A coalescence cannot be obtained, and silver streaks and gels are generated during the injection molding of the hydrogenated product of such a ring-opening polymer.

The intrinsic viscosity (η _inh ) of the ring-opening polymer obtained by the ring-opening polymerization reaction is preferably in the range of 0.2 to 5.0.

As the polystyrene-reduced average molecular weight (solvent: tetrahydrofuran) of the ring-opening polymer measured by GPC, the number average molecular weight (M _n ) is usually 0.8 ×.
10 ⁴ to 10 × 10 ⁴ , preferably 1.5 × 10 ⁴ to 8
× 10 ⁴ , more preferably 2.0 × 10 ^{4 to} 6.0 × 1
0 ⁴ , and the weight average molecular weight (M _w ) is usually 2.5 ×
10 ⁴ to 30 × 10 ⁴ , preferably 3.0 × 10 ⁴ to 2
5 × 10 ⁴ , more preferably 4.0 × 10 ^{4 to} 20 × 1
It is 0 ⁴ . The molecular weight distribution (M _w / M _n ) is usually 1.5 to 4.5, preferably 1.5 to 4.0, more preferably 1.5 to 3.5. If the molecular weight is too large, the resulting ring-opening polymer and its hydrogenated product do not have sufficient fluidity, and birefringence is likely to occur. On the other hand, if the molecular weight is too small,
When the hydrogenated product of the ring-opening polymer is injection-molded, silver streak occurs, and the surface of the molded product tends to be sticky.

The ring-opening polymer obtained as described above is
It can be hydrogenated using a hydrogenation catalyst. The hydrogenation reaction is carried out by a conventional method, that is, a hydrogenation catalyst is added to the solution of the ring-opening polymer, and hydrogen gas at atmospheric pressure to 300 atm, preferably 3 to 200 atm is added at 0 to 200 ° C., preferably It is carried out by operating at 20 to 180 ° C. As the hydrogenation catalyst, those used in the hydrogenation reaction of ordinary olefinic compounds can be used. As this hydrogenation catalyst, a heterogeneous catalyst and a homogeneous catalyst are known. Heterogeneous catalysts include palladium,
Examples of the solid catalyst include a noble metal catalyst substance such as platinum, nickel, rhodium, and ruthenium supported on a carrier such as carbon, silica, alumina, and titania. Further, as a homogeneous catalyst, nickel naphthenate / triethyl aluminum, nickel acetylacetonate / triethyl aluminum, cobalt octenoate / n-butyl lithium, titanocene dichloride / diethyl aluminum monochloride, rhodium acetate, chlorotris (triphenylphosphine) rhodium. And so on. The catalyst may be in the form of powder or particles. These hydrogenation catalysts are "ring-opening polymer: hydrogenation catalyst (weight ratio)".
Is used in a ratio of 1: 1 × 10 ⁻⁴ to 1: 2.
As described above, by hydrogenation, the hydrogenated polymer obtained has excellent thermal stability, and its characteristics are not deteriorated by heating during molding or use as a product. Here, the hydrogenation rate is usually 50.
% Or more, preferably 70% or more, more preferably 90% or more.

The polymers produced by the production method of the present invention include known antioxidants such as 2,6-di-t-butyl-4-methylphenol, 2,2'-dioxy-3,
3'-di-t-butyl-5,5'-dimethyldiphenylmethane, tetrakis [methylene-3- (3,5-di-t
-Butyl-4-hydroxyphenyl) propionate]
Methane; UV absorbers such as 2,4-dihydroxybenzophenone and 2-hydroxy-4-methoxybenzophenone can be added for stabilization. Further, additives such as lubricants may be added for the purpose of improving processability.

The polymer produced by the production method of the present invention and the hydrogenated polymer thereof can be used to produce molded articles by using known molding means such as injection molding, compression molding and extrusion molding.

On the surface of the produced molded article, an inorganic compound, an organic silicon compound such as a silane coupling agent, an acrylic resin, a vinyl resin, a melamine resin, an epoxy resin, a fluorine resin, a silicone resin, or the like is used. A hard coat layer can be formed. Examples of means for forming the hard coat layer include known methods such as a heat curing method, an ultraviolet curing method, a vacuum deposition method, a sputtering method, and an ion plating method.
It is possible to improve the heat resistance, optical characteristics, chemical resistance, abrasion resistance and moisture permeability of the molded product.

[0024]

EXAMPLES Examples of the present invention will be described below.
The present invention is not limited to these. In the following examples and comparative examples, "part" means "part by weight".

Example 1 Ring-Opening Polymerization Step 8-methyl-8 represented by the following chemical formula 3 as a specific monomer
-Carboxymethyltetracyclo [4.4.0.
1 ^2,5 . The ring-opening polymerization reaction of the specific monomer was carried out as follows using ^1,7,10 ] -3-dodecene.

[0026]

[Chemical 3]

The inside of a reaction vessel having a jacket was replaced with nitrogen gas, and 75 parts of toluene was added to the reaction vessel.
0.6 parts of styrene, which is a molecular weight regulator, and a toluene solution of diethylaluminum chloride (concentration: 1.20 mol /
1) 0.6 part was charged and heated to 80 ° C. with stirring, and 0.7 part of a solution of tungsten hexachloride in dimethoxyethane (concentration 0.05 mol / l) was added. Then, the reaction temperature was maintained at 80 ° C., and 37 parts of a toluene solution of the specific monomer (specific monomer: toluene = 25 parts: 12 parts)
Was continuously added over 1 hour to carry out the ring-opening polymerization reaction. After the total amount of the specific monomer was added, the ring-opening polymerization reaction was further performed for 2 hours while maintaining the reaction temperature at 80 ° C. The ring-opening polymerization reaction was stopped, the solution of the reaction system was added to a large amount of methanol to precipitate a ring-opening polymer, which was separated by filtration and dried to obtain a white powdery ring-opening polymer A-1.

The ring-opening polymer A-obtained as described above
The yield of 1 is 99.1% and the intrinsic viscosity (η _inh ) is 0.52.
dl / g (in chloroform, 30 ° C., concentration 0.5 g / d
1), and the polystyrene-reduced average molecular weight (developing solvent: tetrahydrofuran) measured by GPC is number average molecular weight M _n = 2.0 × 10 ⁴ , weight average molecular weight M _w = 6.
It was 2 × 10 ⁴ (M _w / M _n = 3.1).

Hydrogenation Step 100 parts of the ring-opening polymer A-1 was mixed with 20 parts of tetrahydrofuran.
A polymer solution was prepared by dissolving in 100 parts. To this polymer solution, 10 parts of a palladium catalyst (activated carbon-supported catalyst: palladium concentration = 5% by weight) was added as a hydrogenation catalyst, and hydrogen gas pressure was 150 kg / cm ^{2 at} a temperature of 1 in an autoclave.
The hydrogenation reaction was performed by heating at 50 ° C. for 4 hours. After completion of the reaction, the reaction system was cooled and the pressure of hydrogen gas was released, the hydrogenation catalyst was filtered off, and the filtrate was poured into methanol to coagulate the hydrogenated polymer. The hydrogenation rate of this hydrogenated polymer was substantially 100%. Also,
When the number average molecular weight M _n was measured in the same manner as above,
It was 2.0 × 10 ⁴ , which was the same as before hydrogenation.

Production of optical disk plate To 100 parts of the obtained hydrogenated polymer, 0.2 part of antioxidant "Irganox 1010" (manufactured by Ciba-Geigy) was added, and pelletized by an extruder (extrusion temperature 290 ° C). It was made. The produced pellets are processed by injection molding machine "DISK
5 ”(manufactured by Sumitomo Heavy Industries, Ltd .: molding temperature 300 ° C.) was used for injection molding to manufacture an optical disk plate. When the appearance of this optical disk plate was visually inspected, generation of silver streaks and gel was not observed. The birefringence value was less than 15, which was good.

Example 2 The ring-opening polymerization reaction was carried out in the same manner as in Example 1 except that the charged amount of styrene as a molecular weight modifier was changed to 0.8 part, and a white powdery ring-opening polymer was obtained. A-2 was obtained. Ring-opening polymer A obtained as described above
-2 yield 97.8%, intrinsic viscosity (η _inh ) 0.5
The average molecular weight in terms of polystyrene by GPC measurement is 0 dl / g, and the number average molecular weight is M _n = 1.7 × 10 ⁴ ,
Weight average molecular weight M _w = 5.2 × 10 ⁴ (M _w / M _n =
It was 3.1). A hydrogenation step was performed in the same manner as in Example 1 except that the ring-opening polymer A-2 was used in place of the ring-opening polymer A-1, and the obtained hydrogenated polymer was used in Examples. An optical disc was manufactured in the same manner as in 1. When the appearance of this optical disk plate was visually inspected, generation of silver streaks and gel was not observed. The birefringence value was less than 10, which was good.

Example 3 The ring-opening polymerization reaction was carried out in the same manner as in Example 1 except that 0.55 parts of ethyl acrylate was used as the molecular weight regulator instead of styrene, and a white powdery ring-opening ring-opening reaction was carried out. Polymer A-3 was obtained. The yield of the ring-opening polymer A-3 obtained as described above is 97.5%, the intrinsic viscosity (η _inh ) is 0.55 dl / g, and the polystyrene-converted average molecular weight by GPC measurement is several Average molecular weight M _n
= 2.2 × 10 ⁴ , weight average molecular weight M _w = 6.5 × 10
⁴ (M _w / M _n = 3.0). Ring-opening polymer A-1
Instead of the ring-opening polymer A-3, a hydrogenation step was carried out in the same manner as in Example 1, and the obtained hydrogenated polymer was used in the same manner as in Example 1 to prepare an optical disc. Manufactured. When the appearance of this optical disk plate was visually inspected, generation of silver streaks and gel was not observed. The birefringence value was less than 20, which was good.

Comparative Example 1 As a specific monomer, Example 1 was used.
8-Methyl-8-carboxymethyltetracyclo [4.4.0.1 ^2,5 . The ring-opening polymerization reaction of the specific monomer was carried out as follows using ^1,7,10 ] -3-dodecene. The inside of the reaction vessel having the jacket was replaced with nitrogen gas, and 75 parts of toluene was added to the reaction vessel.
25 parts of the specific monomer, 2.5 parts of styrene, and 0.6 parts of a toluene solution of diethylaluminum chloride (concentration 1.20 mol / l) were charged and heated to 80 ° C. while stirring. Next, 0.7 part of a solution of tungsten hexachloride in dimethoxyethane (concentration: 0.05 mol / l) was added to start the ring-opening polymerization reaction. The ring-opening polymerization reaction is performed at a reaction temperature of 80.
It was carried out for 3 hours while keeping at ℃. The ring-opening polymerization reaction was stopped, the solution of the reaction system was added to a large amount of methanol to precipitate a ring-opening polymer, which was separated by filtration and dried to obtain a white powdery ring-opening polymer a-4. The yield of the ring-opening polymer a-4 obtained as described above was 94.7%, the intrinsic viscosity (η _inh ) was 0.54 dl / g, and the average molecular weight in terms of polystyrene by GPC measurement was several Average molecular weight M _n = 1.1 × 1
0 ⁴ , weight average molecular weight M _w = 6.9 × 10 ⁴ (M _w / M _n
= 6.3). A hydrogenation step was carried out in the same manner as in Example 1 except that the ring-opening polymer a-4 was used in place of the ring-opening polymer A-1, and the obtained hydrogenated polymer was used in Examples. An optical disc was manufactured in the same manner as in 1. When the appearance of this optical disk plate was visually inspected, the occurrence of silver streaks was recognized. The birefringence value was 60 or more.

[Comparative Example 2] A ring-opening polymerization reaction was carried out in the same manner as in Example 1 except that 0.36 parts of 1-hexene was used as the molecular weight modifier in place of styrene, and a white powdery ring-opening compound was obtained. Polymer a-5 was obtained. The yield of the ring-opening polymer a-5 obtained as described above was 56%. The intrinsic viscosity (η _inh ) of this ring-opening polymer a-5 is 0.71 dl / g.
The average molecular weight in terms of polystyrene measured by GPC is number average molecular weight M _n = 1.1 × 10 ⁴ , weight average molecular weight M _w = 4.5 × 10 ⁴ (M _w / M _n = 4.1). there were. A hydrogenation step was performed in the same manner as in Example 1 except that the ring-opening polymer a-5 was used in place of the ring-opening polymer A-1, and the obtained hydrogenated polymer was used in the examples. An optical disc was manufactured in the same manner as in 1. When the appearance of this optical disk plate was visually inspected, the occurrence of silver streaks was recognized. The birefringence value was less than 30.

[Comparative Example 3] A ring-opening polymerization reaction was carried out in the same manner as in Comparative Example 1 except that 1.50 parts of 1-hexene was used in place of styrene as a molecular weight regulator, and a white powdery ring-opening compound was obtained. Polymer a-6 was obtained. The yield of the ring-opening polymer a-6 obtained as described above was 94.7%, and the intrinsic viscosity (η
_inh ) is 0.51 dl / g, and the polystyrene-reduced average molecular weight by GPC measurement is number average molecular weight M _n =
1.1 × 10 ⁴ , weight average molecular weight M _w = 6.1 × 10 ^4.
(M _w / M _n = 5.6). Example 1 except that the ring-opening polymer a-6 was used instead of the ring-opening polymer A-1.
A hydrogenation step was carried out in the same manner as in, and an optical disk was produced in the same manner as in Example 1 using the obtained hydrogenated polymer. When visually inspecting the appearance of this optical disk plate,
Occurrence of silver streak was observed. The birefringence value was 50 or more.

As shown above, in the hydrogenated products of the ring-opening polymers obtained by the production methods of Examples 1 to 3, neither silver streaks nor gels were observed and the birefringence was small. Met. On the other hand, Comparative Example 1 (example in which specific monomers were charged all at once), Comparative Example 2 (example in which 1-hexene was used as a molecular weight modifier) and Comparative Example 3 (inclusive of specific monomers) And as a molecular weight regulator 1-
The hydrogenated products of the ring-opening polymer obtained by the production method of Example using hexene were all found to have silver streaks and had large birefringence.

[0037]

According to the process of the present invention, a specific compound is used as a molecular weight regulator, and a specific monomer is continuously or intermittently added to the reaction system to allow the ring-opening polymerization reaction to proceed. A ring-opening polymer having a narrow molecular weight distribution can be obtained. The obtained ring-opening polymer exhibits good fluidity and low birefringence, and silver streak and gel do not occur during injection molding of a hydrogenated product of the ring-opening polymer.

The use of the polymer produced by the production method of the present invention is not particularly limited, and it can be used in a wide range, and it can be used for general camera lenses, video camera lenses, telescope lenses, laser beams. It can be particularly suitably used as an optical material such as lenses such as lenses, optical video disks, audio disks, document file disks, optical disks such as memory disks.

Claims (1)

[Claims] 1. A method for producing a polymer, which comprises a ring-opening polymerization step in which a monomer comprising at least one norbornene derivative represented by the following chemical formula 1 is subjected to metathesis ring-opening polymerization in the presence of a metathesis catalyst and a molecular weight modifier. In the ring-opening polymerization step, at least one selected from the group consisting of aromatic vinyl compounds and acrylates is used as a molecular weight regulator, and a monomer comprising a norbornene derivative is continuously or intermittently added. A process for producing a polymer, which comprises allowing the ring-opening polymerization reaction to proceed while being added to the reaction system. [Chemical 1] [In Chemical Formula 1, A and B are a hydrogen atom or C1-C10.
Wherein X and Y represent a hydrogen atom, a halogen atom or a monovalent organic group, and m is 0 or 1. ]