JPH08198919A - Norbornene addition type copolymer - Google Patents

Abstract

(57) [Summary] [Structure] (A) Norbornene or a substituted norbornene having a hydrocarbon group having 3 or less carbon atoms (preferably norbornene) and (B) an alkyl substituted norbornene having an alkyl substituent having 5 or more carbon atoms (preferably Is 5-hexyl-2-norbornene) and is subjected to addition-type copolymerization without ring-opening to obtain 15-70% by weight of (a) addition-type repeating structural unit derived from monomer (A) and (b) monomer. An addition-type copolymer having an addition-type repeating structural unit derived from (B) of 85 to 30% by weight and having a number average molecular weight of 50,000 to 1,000,000 and a glass transition temperature of 140 to 210 ° C. is obtained. . [Effect] Excellent transparency, low birefringence, moisture resistance, water resistance, chemical resistance, electrical characteristics, low elution of impurities, and an appropriate glass transition temperature, so heat resistance and ease of melt molding are achieved. A novel thermoplastic norbornene-based resin having both is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a norbornene-based addition type copolymer, more specifically, a norbornene-based addition type copolymer composed of a plurality of repeating structural units derived from a norbornene-based monomer having excellent heat resistance and moldability. It relates to a copolymer.

[0002]

2. Description of the Related Art Thermoplastic norbornene resins have many excellent properties such as optical properties and electrical properties and are widely used in various fields. The main thermoplastic norbornene-based resins include those obtained by ring-opening polymerization of norbornene-based monomers and addition-polymerized norbornene-based monomers. Among them, the ring-opening polymer of norbornene-based monomer has a drawback that it is easily deteriorated by heat or the like because it has a double bond in the main chain. Therefore, it is usually necessary to substantially saturate the main chain by hydrogenation treatment or the like,
There is a problem that the manufacturing process becomes complicated.

On the other hand, in the addition type polymer of norbornene type monomer, the homopolymer has a high glass transition temperature,
Melt molding is often difficult. In the case of norbornene, which is the most typical norbornene-based monomer, the glass transition temperature of the addition-type homopolymer is 300 ° C. or higher. Depending on the type of the monomer, an addition type homopolymer having an appropriate glass transition temperature may be obtained, but such a monomer is generally difficult to synthesize.

Therefore, an addition type copolymer obtained by randomly copolymerizing an α-olefin such as ethylene and a norbornene-based monomer is usually used. However, since the reaction rates of the α-olefin and the norbornene-based monomer are different, it may be difficult to control the copolymerization ratio and the glass transition temperature. Further, as the amount of α-olefin increases, a polymer containing a large amount of α-olefin is produced as a by-product,
In some cases, the excellent properties as a thermoplastic norbornene-based resin are weakened, such as the transparency of the polymer not being compatible with the random addition-type copolymer and the transparency being lowered.

[0005]

DISCLOSURE OF THE INVENTION The present inventors have aimed to obtain an addition-type polymer having a glass transition temperature which is easily melt-molded by polymerizing substantially only a norbornene-based monomer. As a result of earnest studies, it was found that the intended addition-type polymer can be obtained by addition-type copolymerization of specific norbornene-based monomers, and the present invention has been completed.

[0006]

Thus, according to the present invention,
(A) Repeating structural unit 1 derived from norbornene or a substituted norbornene having a hydrocarbon group having 3 or less carbon atoms
5 to 70% by weight and (b) 85 to 30% by weight of a repeating structural unit derived from an alkyl-substituted norbornene having an alkyl substituent having 5 or more carbon atoms and having a number average molecular weight of 5
Addition-type copolymers that are between 10,000 and 1,000,000 are provided.

(Monomer) The norbornene-based addition type copolymer of the present invention comprises (A) norbornene or a substituted norbornene having a hydrocarbon group having 3 or less carbon atoms and (B) 5 carbon atoms.
It is a random addition type copolymerization of the above alkyl-substituted norbornene having an alkyl substituent without ring opening.

Among the monomers (A), the substituted norbornene is
It has a hydrocarbon group having 3 or less, preferably 2 or less carbon atoms. If the carbon number is too large, the glass transition temperature of the addition-type copolymer of the present invention becomes too high. The substituent is preferably linear. Those having a branch or a cyclic substituent are generally difficult to produce a substituted norbornene. Further, the substituent is norbornene 5
Those having one bond at the position are preferred. It is generally difficult to produce a substituted norbornene having a substituent bonded to another position or a substituted norbornene having two bonded 5-positions.
Examples of the monomer (A) include norbornene and 5-methyl-2.
-Norbornene, 5-methylidene-2-norbornene,
5-ethyl-2-norbornene, 5-ethylidene-2-
Examples include norbornene and 5-propyl-2-norbornene, and most preferred is norbornene.

The monomer (B) has an alkyl substituent having 5 or more carbon atoms, preferably 6 or more carbon atoms, preferably 10 or less carbon atoms, and more preferably 8 or less carbon atoms. If the carbon number is too small, the glass transition temperature of the addition-type copolymer of the present invention will be too high, and if the carbon number is too large, it will be difficult to produce an alkyl-substituted norbornene. Also,
The alkyl substituent is preferably linear. It is generally difficult to produce an alkyl-substituted norbornene if it has a branch or has a cyclic substituent. Further, it is preferable that one alkyl substituent is bonded to the 5-position of norbornene. Alkyl-substituted norbornenes having substituents bonded at other positions and substituted norbornenes having two bonded 5-positions are also generally difficult to manufacture. Monomer (B)
Examples thereof include 5-hexyl-2-norbornene, 5-heptyl-2-norbornene, 5-octyl-2-norbornene and the like, and most preferred is 5-hexyl-2-norbornene.

The addition type copolymer of the present invention comprises (a) an addition type repeating structural unit derived from the monomer (A) of 15% by weight or more and 7% or more.
0% by weight or less and (b) 85% by weight or less and 30% by weight or more of the addition type repeating structural unit derived from the monomer (B).
The amount of the monomer actually used for the polymerization reaction needs to be adjusted according to the reactivity so that the ratio of the repeating structural units is as desired.

In addition to the monomer (A) and the monomer (B), a copolymerizable monomer may be used in combination so long as the effects of the present invention are not substantially impaired. The range that does not substantially impair the effects of the present invention means that the repeating structural unit other than the repeating structural unit (a) and the repeating structural unit (b) in the resulting addition-type copolymer is usually 30% by weight or less, preferably Is 20
The amount is not more than 10% by weight, more preferably not more than 10% by weight. The amount of the monomer actually used for the polymerization reaction needs to be adjusted according to the reactivity so that the ratio of the repeating structural units is as desired.

Monomers that can be copolymerized include monoolefins such as ethylene, propylene, isobutene, 2-methyl-1-butene, 2-methyl-1-pentene, vinylcyclohexane and isopropenylcyclohexane; cyclopentene, Cyclic olefins such as cyclohexene and cycloheptene; butadiene, cyclopentadiene, isoprene, 1,3-pentadiene, furan,
Dienes such as thiophene, 4-vinylcyclohexene and 4-isopropenylcyclohexene; these chlorines,
Substitutes in which a halogen group such as bromine or an ester group is introduced;
Cyclic ethers such as ethylene oxide, propylene oxide, trimethylene oxide, trioxane, dioxane, cyclohexene oxide, styrene oxide, epichlorohydrin and tetrahydrofuran;
Vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; styrene, α-methylstyrene,
Styrenes such as p-methylstyrene, o-methylstyrene, m-methylstyrene, α-vinylnaphthalene, β-vinylnaphthalene, p-methoxystyrene; d-limonene, l-limonene, dipentene (dl-limonene), etc. Terpenes; 5-methoxycarbonyl-2-norbornene, 5-cyano-2-norbornene, 5-methyl-
5-methoxycarbonyl-2-norbornene, 5-phenyl-2-norbornene, 5-phenyl-5-methyl-
Norbornenes other than 2-norbornene, 5-octadecyl-2-norbornene, and other monomers (A) and monomers (B); 1,4: 5,8-dimethano-1,2,3,4,4
a, 5,8,8a-2,3-cyclopentadienooctahydronaphthalene, 6-methyl-1,4: 5,8-dimethano-1,4,4a, 5,6,7,8,8a- Octahydronaphthalene, 1,4: 5,10: 6,9-trimethano-1,2,3,4,4a, 5,5a, 6,9,9a,
Monomers of norbornene such as 10,10a-dodecahydro-2,3-cyclopentadienoanthracene and one or more cyclopentadiene added thereto or substituted products thereof; dicyclopentadiene, 2,3-dihydrodicyclopentadiene and the like Monomers of polycyclic structure which are polymerized by Diels-Alder reaction of cyclopentadiene or substituted products thereof; 1,4-methano-1,4,4a, 4b, 5,8,
Cyclopentadiene such as 8a, 9a-octahydrofluorene, 5,8-methano-1,2,3,4,4a, 5,8,8a-octahydro-2,3-cyclopentadienonaphthalene and tetrahydroindene, etc. And the substitution products thereof; and the like.

(Polymerization catalyst) The polymerization catalyst used for addition-type polymerization of these monomers is not particularly limited, and examples thereof include known polymerization catalysts used for addition-type polymerization of norbornene-based monomers. Examples of such a polymerization catalyst include transition metal compounds, organometallic compounds of Groups I to IV of the periodic table, protonic acids, and the like, and two or more kinds of these may be combined.

The transition metals include IVb to V of the periodic table.
Examples of the transition metal selected from Group III include titanium, zirconium, vanadium, iron, cobalt, tungsten, nickel and palladium. Examples of the transition metal compound include bis (cyclopentadienyl) titanium dichloride, bis (cyclopentadienyl) titanium monochloride, titanium (III) chloride and titanium (I
V) Titanium compounds such as chloride, titanium (IV) boromide, bis (cyclopentadienyl) dimethyltitanium, (cyclopentadienyl) titanium trichloride, dichlorotitanium bis (acetylacetonate); bis (cyclopentadienyl) zirconium Dichloride,
Bis (cyclopentadienyl) zirconium monochloride, zirconium (III) chloride, zirconium (IV) chloride, zirconium (IV) boromide, bis (cyclopentadienyl) dimethylzirconium, (cyclopentadienyl) zirconium trichloride, dichloro Zirconium compounds such as zirconium bis (acetylacetonate); bis (cyclopentadienyl) vanadium dichloride, bis (cyclopentadienyl) vanadium monochloride, vanadium (I
II) chloride, vanadium (IV) chloride, vanadium (IV) boromide, bis (cyclopentadienyl) dimethylvanadium, (cyclopentadienyl)
Vanadium compounds such as vanadium trichloride and dichlorovanadium bis (acetylacetonate); ferrous chloride, ferric chloride, ferrous bromide, ferric bromide, ferric acetate, iron (III) acetylacetate Iron compounds such as nato and ferrocene; cobalt acetate, cobalt (II) acetylacetonate, cobalt (III) acetylacetonate, cobalt benzoate, cobalt chloride, cobalt bromide, cobalt (II) tetrafluoroborate, 4-
Cobalt compounds such as cobalt cyclohexylbutyrate and cobalt stearate; tungsten compounds such as tungsten hexachloride and tungsten tetrachloride; nickelocene, nickel acetate, nickel bromide, nickel chloride, nickel bisacetylacetonate, tetrakis (triphenylphosphine) nickel, Nickel compounds such as dicarbonylbis (triphenylphosphine) nickel, bis (allyl) nickel, dibromobis (triphenylphosphine) nickel, allyl nickel chloride, chloro (phenyl) bis (triphenylphosphine) nickel; palladium (II) acetate, Palladium bisacetylacetonate, palladium bromide, palladium chloride, palladium iodide, palladium oxide, monoacetonitri Tris (trifinylphosphine) palladium tetrafluoroborate, carbonyltris (triphenylphosphine) palladium, dichlorobis (acetonitrile) palladium, dichlorobis (benzonitrile) palladium, dichlorobis (triphenylphosphine) palladium, tetrakis (acetonitrile) palladium tetrafluoro Palladium compounds such as borate; and the like are exemplified.

Organometallic compounds include I to I of the periodic table.
Group V organometallic compounds such as trimethyl aluminum, triethyl aluminum, tri-n-propyl aluminum, triisopropyl aluminum, triisobutyl aluminum, trihexyl aluminum, trioctyl aluminum, triphenyl aluminum, tribenzyl aluminum, diethyl aluminum monochloride , Di-n-propyl aluminum monochloride, diisobutyl aluminum monochloride, di-n-butyl aluminum monochloride, diethyl aluminum monobromide, diethyl aluminum monoiodide, diethyl aluminum monohydride, di-n-propyl aluminum monohydride, diisobutyl Aluminum monohydride, methyl aluminum sesquichloride, ethyl aluminum sesqui Organic aluminum compounds such as lomid, isobutylaluminum sesquichloride, ethylaluminum dichloride, ethylaluminum dichloride, methylaluminoxane and ethylaluminoxane; tin compounds such as tin dichloride, tin tetrachloride, tin tetrabromide and triphenylmethyltin pentachloride. And the like, and trifluoroboron, trichloroboron, boron trifluoride diethyl etherate and the like can also be used.

As the protonic acid type polymerization catalyst, HCl,
HF, HBr, H₂SO_Four, H₃BO₃ , HClO, CH₃
COOH, Cl₃CCOOH, CF₃SO₃H is an example
Be done.

These catalysts may be used as a catalyst system containing a component for improving the polymerization activity. As such a polymerization catalyst system, titanium tetrachloride / 2-methoxy-2-phenylpropane, titanium tetrachloride / t
Examples include living cation catalyst systems such as butanol and titanium tetrachloride / 1,4-bis (2-methoxy-2-propyl) benzene.

(Polymerization Solvent) In the present invention, addition-type copolymerization can be carried out without using a solvent, but it is generally carried out in an inert organic solvent. As the organic solvent used, aromatic solvents such as benzene, toluene and xylene; pentane, hexane, heptane, octane, cyclopentane,
Hydrocarbon solvents such as cyclohexane, methylcyclohexane and decalin; methyl chloride, methylene chloride, 1,2
-Dichloroethane, 1,1,1-trichloroethane,
Examples include halogenated hydrocarbon solvents such as 1,1,2-trichloroethane and 1,1,2-trichloroethylene; polar solvents such as nitromethane; and the like, and two or more kinds may be mixed and used.

(Polymerization reaction conditions) The addition-type copolymerization in the present invention is carried out under the temperature condition of usually -150 ° C or higher, preferably -100 ° C or higher, usually 100 ° C or lower, preferably 80 ° C or lower, usually 0 to 50 kgf / cm. It is performed under the pressure condition of ² . In addition, since the degree of polymerization and the ratio of repeating structural units of the obtained copolymer are different depending on the polymerization conditions, time, etc., the polymerization conditions, time and the like are set in advance so that the desired degree of polymerization and the ratio of repeating structural units are obtained. Consider and decide.

(Recovery of Addition-Type Copolymer) The method of collecting the addition-type copolymer from the polymerization reaction solution is not particularly limited, and may be carried out according to a conventional method. For example, the polymerization reaction solution may be poured into a large amount of a poor solvent for the copolymer, for example, alcohols to cause precipitation, and may be recovered by filtration or centrifugation. Moreover, the removal of the catalyst is not particularly limited, and may be performed according to a conventional method.
For example, a method in which a compound that reacts with a catalyst to precipitate a catalyst component is added to a polymerization reaction liquid or a copolymer solution, and the precipitated catalyst component is removed by centrifugation, filtration, or the like A method of pouring a polymerization reaction solution or a copolymer solution into a poor solvent of coalescence to precipitate the copolymer and recovering it by filtration, a method of treating the polymerization reaction solution with an adsorbent that adsorbs a catalyst component, etc. is there. These methods may be repeated or combined.

(Additional Copolymer) The addition type copolymer of the present invention has a repeating structural unit (a) of 15% by weight or more, preferably 20% by weight or more, more preferably 25% by weight or more,
70% by weight or less, preferably 65% by weight or less, more preferably 60% by weight or less, and the repeating structural unit (b) 85.
It is composed of not more than 80% by weight, preferably not more than 80% by weight, more preferably not less than 75% by weight, not less than 30% by weight, preferably not more than 35% by weight, more preferably not more than 40% by weight. If the repeating structural unit (a) is too much or the repeating structural unit (b) is too small, the glass transition temperature becomes high,
Melt molding becomes difficult, and when the repeating structural unit (a) is too small or the repeating structural unit (b) is too large, the glass transition temperature becomes too low and problems such as heat resistance occur.

The addition type copolymer of the present invention has a temperature of 35 ° C.
The number average molecular weight in terms of polystyrene measured by gel permeation chromatography as a toluene solution of is 50,000 or more, preferably 80,000.
Or more, more preferably 100,000 or more, 1.00
It is 50,000 or less, preferably 500,000 or less, more preferably 300,000 or less. If the molecular weight is too small, sufficient strength cannot be obtained, and if it is too large, melt viscosity becomes high and sufficient moldability cannot be obtained.

The glass transition temperature of the addition-type copolymer of the present invention is 140 ° C. or higher, preferably 145 ° C. or higher, more preferably 150 ° C. or higher and 210 ° C. or lower, preferably 20.
It is 0 ° C or lower, and more preferably 190 ° C or lower. If the glass transition temperature is too high, melt molding becomes difficult, for example,
When an optical material is melt-molded, stress may remain inside the optical material depending on the molding method, and problems such as increased birefringence may occur. Further, if the glass transition temperature is too low, there is a problem that the heat resistance of the molded product deteriorates.

(Molding Method) The addition type copolymer of the present invention is
Molding can be performed by known molding methods such as injection molding, extrusion molding, inflation molding, blow molding, injection blow molding, press molding, rotational molding, cutting molding, vacuum molding, rolling molding, calendering, and cast molding.

In addition, the addition-type copolymer of the present invention has a good moldability, chargeability, melt flowability, mechanical strength, flexibility, impact resistance, coating agent adhesion, weather resistance,
Light-shielding property, flame retardancy, creep resistance, surface hardness, thermal expansion,
Addition of phenolic and phosphorus antioxidants, antistatic agents, lubricants, plasticizers, UV absorbers, light stabilizers, dyes, pigments, flame retardants, slipping agents, etc. for the purpose of improving physical properties such as elasticity. Agents: Fine particles of silica, alumina, talc, aluminum hydroxide, carbon, amorphous carbon, graphite, calcium carbonate, etc .; glass fiber,
Carbon fiber, boron fiber, silicon carbide fiber, vapor grown carbon fiber, asbestos fiber, potassium titanate crystal fine fiber, quartz fiber, metal fiber, carbon fibril,
Polyamide fiber, polyester fiber, fluororesin fiber,
Fibrous fillers such as cotton fibers, cellulose fibers and silicon fibers;
Etc. may be blended.

(Use) The addition-type copolymer of the present invention is useful in various fields such as optical materials and various molded articles. For example, optical disc, information disc, magnetic disc, hard disc, optical card, optical lens,
Glasses lens, prism, optical mirror, optical fiber,
Optical components such as beam splitter, liquid crystal display element substrate, light guide plate, polarizing film, retardation film, OHP film, light diffusing plate, light emitting element enclosing light diffusing plate, liquid crystal backlight, fluorescent lamp tube material, etc. , Vials, ampoules, prefilled syringes, infusion bags, solid drug containers, eye drop containers, imaging agent containers, liquid or solid drug containers such as press-through packages, blood test sampling containers, test cells, blood collection tubes, Sample containers such as specimen containers, syringes, sterilization containers for medical equipment, beakers, petri dishes, flasks, test tubes, centrifuge tubes, contact lens cases, infusion tubes, piping, joints, valves and other medical equipment, denture bases, artificial hearts , Medical devices such as check valves, check valves, artificial organs such as artificial dental roots and their parts; wafer carriers, tanks, Disc carrier, the carrier for the information disc substrate, carrier liquid crystal substrate, a magnetic disk carrier, IC trays, IC carrier tapes, separation films, Shippers, pipes for ultra-pure water, pipes, tubes, valves, flow meters, filters, pumps,
Equipment for processing electronic parts such as sampling containers, resist containers, inner bags for resist containers; electric wire coating materials, OA equipment parts for electronic devices, copying machines, computers, printers, etc.,
General insulators for instruments, radars, antennas, lamp shades for lighting equipment, etc .; printed circuit boards, flexible printed circuit boards, multilayer printed circuit boards, high-frequency circuit boards, and other electrical parts; transparent conductive film base materials; transistors.
Sealing materials for ICs, LSIs, LEDs, LEDs integrally molded with a light diffusion plate or lens; sealing materials for electric / electronic parts such as motors, capacitors, switches, and sensors; housing materials for TVs, video cameras, cameras, etc. Interior mirrors, door mirrors, head lamp covers, tail lamp covers, optical parts for head-up displays, window materials, parts for automobiles, aircraft and ships such as sunroofs; Show window materials, show window cases, sun roof materials, window materials, Building members such as sewage pipes, water pipes, pipes, wall materials, floor materials, and ceiling materials; and the like.

[0027]

The addition-type copolymer of the present invention is excellent in transparency, low birefringence, moisture resistance, water resistance, chemical resistance, electrical characteristics and low elution of impurities, and has an appropriate glass transition temperature. Therefore, it has both heat resistance and ease of melt molding.

[0028]

EXAMPLES The present invention will be specifically described below with reference to Reference Examples, Examples and Comparative Examples. The number average molecular weight is 35 ° C.
As a polystyrene conversion value by gel permeation chromatography using toluene as a solvent, the glass transition temperature is measured by the DSC method, the light transmittance is measured by a spectrophotometer at a wavelength of 700 nm, and the retardation value is measured by a double pass method at a wavelength of 630 nm. It was measured.

Example 1 In a reactor purged with nitrogen, 50 parts by weight of norbornene, 50 parts by weight of 5-hexyl-2-norbornene, and 1 nitromethane.
40 parts by weight and 180 parts by weight of toluene were charged, the temperature was kept at 20 ° C., and [Pd (CH ₃ C
A solution prepared by dissolving 0.3 part by weight of N) ₄ ] (BF ₃ ) _{2 in} 60 parts by weight of toluene was added and reacted for 1 hour. After the reaction, 5 parts by weight of the reaction solution was sampled and the rest was 1000
Copolymers precipitated by adding parts by weight of methanol were collected by filtration. After washing with a mixed solution of 300 parts by weight of methanol and 40 parts by weight of concentrated hydrochloric acid, it was washed twice with 150 parts by weight of methanol and dried at a temperature of 100 ° C. and a pressure of 1 mmHg for 48 hours to obtain 78 parts by weight of a copolymer.

This copolymer has a number average molecular weight of 1.12 ×
10 ⁵ , glass transition temperature is 179 ° C., ¹ H-NMR
^{1 to} 2.5p in the spectrum (in chloroform-d ¹ )
Only the peak of the proton bonded to the saturated carbon was observed in pm, and it was found to be an addition type polymer. Moreover, as a result of analyzing the reaction liquid after the sampled reaction by gas chromatography, 7 parts by weight of norbornene and 5-
It was confirmed that 8 parts by weight of hexyl-2-norbornene remained unreacted, and the obtained copolymer had about 50.6% by weight of repeating structural units derived from norbornene, and 5-hexyl-2- It was confirmed that the repeating structural unit derived from norbornene was composed of about 49.4% by weight.

This copolymer was formed into a plate having a thickness of 1.2 mm and a diameter of 65 mm by hot pressing at 250 ° C. This plate was excellent in transparency with a light transmittance of 90.2%, and had a small birefringence with a retardation value of 35 nm or less.

Example 2 Reaction, recovery, washing and drying were carried out in the same manner as in Example 1 except that 30 parts by weight of norbornene and 70 parts by weight of 5-hexyl-2-norbornene were used to obtain 85 parts by weight of a copolymer. It was

This copolymer has a number average molecular weight of 1.58 ×
10 ^5, a glass transition temperature of 152 ℃, ¹ H-NMR
^{1 to} 2.5p in the spectrum (in chloroform-d ¹ )
Only the peak of the proton bonded to the saturated carbon was observed in pm, and it was found to be an addition type polymer. Further, as a result of analysis in the same manner as in Example 1, it was confirmed that 3 parts by weight of norbornene and 8 parts by weight of 5-hexyl-2-norbornene remained unreacted, and the obtained copolymer was norbornene. It was confirmed that the repeating structural unit derived from this was about 30.3% by weight and the repeating structural unit derived from 5-hexyl-2-norbornene was about 69.7% by weight.

A plate formed by hot pressing this copolymer at 220 ° C. in the same manner as in Example 1 had a light transmittance of 90.2.
%, The transparency was excellent, and the retardation value was 30 nm or less, and the birefringence was small.

Example 3 The reaction, recovery, washing and drying were carried out in the same manner as in Example 1 except that 65 parts by weight of norbornene and 35 parts by weight of 5-hexyl-2-norbornene were used to obtain 81 parts by weight of a copolymer. It was

This copolymer has a number average molecular weight of 2.20 ×
10 ^5, a glass transition temperature of 201 ℃, ¹ H-NMR
^{1 to} 2.5p in the spectrum (in chloroform-d ¹ )
Only the peak of the proton bonded to the saturated carbon was observed in pm, and it was found to be an addition type polymer. Also, as a result of analysis in the same manner as in Example 1, it was confirmed that 7 parts by weight of norbornene and 5 parts by weight of 5-hexyl-2-norbornene remained unreacted, and the obtained copolymer was norbornene. It was confirmed that the repeating structural unit derived from this was about 65.9% by weight and the repeating structural unit derived from 5-hexyl-2-norbornene was about 34.1% by weight.

A plate formed by hot pressing this copolymer at 270 ° C. in the same manner as in Example 1 had a light transmittance of 89.9.
%, The transparency was excellent, and the retardation value was 40 nm or less, and the birefringence was small.

Comparative Example 1 5-Hexyl-2-using 100 parts by weight of norbornene
Reaction similar to that of Example 1 except that norbornene was not used,
It was recovered, washed and dried to obtain 72 parts by weight of polymer.

This polymer has a number average molecular weight of 1.86 × 1.
0 ^5, the glass transition temperature was 300 ° C. or higher. This polymer had low solubility, ¹ H-NMR spectrum could not be measured, and it could not be molded by hot pressing.

Comparative Example 2 Using 100 parts by weight of 5-hexyl-2-norbornene,
Reaction similar to that of Example 1 except that norbornene was not used,
It was recovered, washed and dried to obtain 84 parts by weight of copolymer.

This copolymer has a number average molecular weight of 9.2 × 1.
0 ^4, a glass transition temperature of 130 ° C., was that there is a problem in heat resistance. ^{In the 1} H-NMR spectrum (in chloroform-d ¹ ), only the peak of the proton bonded to the saturated carbon was observed at ^{1 to} 2.5 ppm, and it was found to be an addition type polymer.

A plate formed by hot pressing this copolymer at 200 ° C. in the same manner as in Example 1 had a light transmittance of 90.2.
%, The transparency was excellent, and the retardation value was 40 nm or less, and the birefringence was small.

Comparative Example 3 Reaction, recovery, washing, and washing were conducted in the same manner as in Example 1 except that 5-hexyl-2-norbornene and norbornene were not used, and 100 parts by weight of 5-butyl-2-norbornene was used instead.
It was dried to obtain 74 parts by weight of a copolymer.

This copolymer has a number average molecular weight of 1.25 ×
The glass transition temperature was 10 ⁵ and the glass transition temperature was 221 ° C. ¹ H-NM
1 to 2.5 in R spectrum (in chloroform-d ¹ )
Only the peak of the proton bonded to the saturated carbon was observed in ppm, and it was found to be an addition type polymer.

A plate formed by hot pressing this copolymer at 290 ° C. in the same manner as in Example 1 had a light transmittance of 88.5.
%, The transparency was excellent, but the retardation value was 60.
It was less than nm, and a molded product having a small birefringence could not be obtained.

Claims (1)

[Claims] 1. 15 to 70% by weight of a repeating structural unit derived from (a) norbornene or a substituted norbornene having a hydrocarbon group having 3 or less carbon atoms, and (b) an alkyl-substituted norbornene having an alkyl substituent having 5 or more carbon atoms. An addition-type copolymer comprising 85 to 30% by weight of a repeating structural unit derived from the above and having a number average molecular weight of 50,000 to 1,000,000.