JP2006183001A - Random copolymer and its production process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a random copolymer suitable for optical materials excellent in transparency, high refractivity and low birefringence, and a production process for the copolymer excellent in productivity. <P>SOLUTION: The random copolymer is obtained by the metathesis copolymerization of a monomer mixture composed of an alkyne having a substituent and a monomer having a norbornene ring, and the hydrogenation of a C=C double bond in the main chain of the resultant metathesis copolymer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a random copolymer and a method for producing the same. More specifically, the present invention relates to a random copolymer suitable for an optical material excellent in transparency, high refractive index, and low birefringence, and a method for producing the same.

  A polymer obtained by ring-opening polymerization of a monomer having a norbornene ring such as dicyclopentadiene and then hydrogenating (hereinafter referred to as “norbornene polymer hydride”) has heat resistance, transparency and low moisture absorption. It has excellent properties, low water absorption, mechanical toughness, high refractive index and low birefringence, and is widely used as an optical material. However, in recent years, with the advancement of functions of optical devices, optical materials having a higher refractive index and lower birefringence have been demanded.

  The norbornene-based polymer hydride generally has a positive intrinsic birefringence value. Therefore, it is conceivable to reduce birefringence by using a born hydride of a norbornene polymer and a polymer having a negative intrinsic birefringence value such as polystyrene. However, since the hydride of norbornene-based polymer and polystyrene are low in compatibility and easily phase-separated, the mixture obtained simply by mixing was low in transparency.

  Block copolymers and graft copolymers having a segment of norbornene polymer hydride and a segment of polystyrene have also been proposed (Patent Documents 1 and 2). However, even these copolymers have a microphase separation structure, and thus optical transparency may be insufficient. Moreover, there existed a problem that a process was complicated and productivity was low.

  A copolymer of substituted acetylene and norbornene is also known (Patent Documents 3 and 4). However, the polymers described in these documents have low heat resistance and weather resistance and are easily colored, and cannot be used as optical materials.

JP-A-8-92357 JP 2001-316432 A Japanese Patent Laid-Open No. 3-126715 JP-A-8-295725

  The objective of this invention is providing the random copolymer suitable for the optical material excellent in transparency, high refractive index property, and low birefringence, and its manufacturing method.

  As a result of intensive studies, the present inventors have found that a random copolymer having a specific repeating unit can solve the above-mentioned problems, and that a metathesis copolymer of a alkyne having a substituent and a monomer having a norbornene ring And it discovered that the said random copolymer could be efficiently manufactured by hydrogenating the obtained polymer, and came to complete this invention based on these knowledge.

  Thus, according to the first aspect of the present invention, the general formula (1)

(Wherein R ¹ and R ² are a hydrogen atom, a halogen atom, a silyl group, or a hydrocarbon having 1 to 20 carbon atoms which may have a substituent containing a halogen atom, a silicon atom, an oxygen atom or a nitrogen atom) Represents a group, and R ¹ and R ² are not simultaneously hydrogen atoms.)
1 to 99 mol% of the repeating unit (I) represented by the general formula (2)

(Wherein R ^{3 to} R ⁶ represent a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a group containing a halogen atom, a silicon atom, an oxygen atom or a nitrogen atom, which may be the same or different, And may be bonded to each other to form a ring, and m is an integer of 0 to 2.)
1 to 99 mol% of the repeating unit (II) represented by formula (3)

There is provided a random copolymer comprising 0 to 20 mol% of the repeating unit (III) represented by the formula (I) and the content of the repeating unit (I) being larger than the content of the repeating unit (III). The

At least one of R ¹ and R ² preferably has an aromatic ring. The repeating unit (II) preferably has an aromatic ring.

  According to a second aspect of the present invention, the general formula (4)

(Wherein R ¹ and R ² represent the same meaning as described above.)
And a monomer represented by the general formula (5)

(Wherein R ^{3 to} R ⁶ and m have the same meaning as described above.)
A step of obtaining a metathesis copolymer by copolymerizing a monomer mixture containing a monomer represented by formula (1) and hydrogenating a carbon-carbon double bond in the main chain of the obtained metathesis copolymer. And a process for producing the random copolymer.

  According to the third aspect of the present invention, there is provided an optical material formed by molding the above random copolymer.

  INDUSTRIAL APPLICABILITY According to the present invention, a random copolymer excellent in transparency, high refractive index, and low birefringence, usable for various molding materials, and particularly suitable for optical materials, and a method for producing the same are provided. . The optical material of the present invention is excellent in transparency, high refractive index, low birefringence, and low hygroscopicity, and has high mechanical strength. Therefore, an optical disk, an optical lens, an optical card, an optical fiber, an optical mirror, and a liquid crystal display element. It can be suitably used as a substrate, a light guide plate, a polarizing film, a retardation film or the like.

1) Random Copolymer The random copolymer of the present invention has a repeating unit (I) of 1 to 99 mol% represented by the following general formula (1) and a repeating unit (II) represented by the general formula (2). 1 to 99 mol% and 0 to 20 mol% of the repeating unit (III) represented by the formula (3), and the content of the repeating unit (I) is larger than the content of the repeating unit (III). Is a random copolymer.

In the above general formula (1), R ¹ and R ² may have a hydrogen atom, a halogen atom, a silyl group, or a substituent having a halogen atom, a silicon atom, an oxygen atom, or a nitrogen atom. 20 hydrocarbon groups are represented. However, R ¹ and R ² are not simultaneously hydrogen atoms.

Specific examples of R ¹ and R ² include hydrogen atom; halogen atom such as fluorine atom, chlorine atom, bromine atom, and iodine atom; trimethylsilyl group, triethylsilyl group, trimethoxysilyl group, triethoxysilyl group, and trichloro. Silyl groups such as silyl groups; alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, and octyl groups; aromatic rings such as phenyl, benzyl, and naphthyl groups The hydrocarbon group which has is mentioned. Furthermore, the hydrocarbon group having an alkyl group or an aromatic ring includes a halogen atom; a silyl group; a group containing an oxygen atom such as an alkoxyl group, an aryloxy group, a carbonyl group, a carboxyl group, and a hydroxyl group; an amino group, an amide group, And a group containing a nitrogen atom such as a nitrile group;
Among them, a hydrocarbon group having an aromatic ring; and an alkyl group having a group containing a halogen atom, a silicon atom, an oxygen atom or a nitrogen atom as a substituent or a hydrocarbon group having an aromatic ring; are preferred. A hydrogen group is most preferred.

In the general formula (2), R ^{3 to} R ⁶ represent a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a group containing a halogen atom, a silicon atom, an oxygen atom, or a nitrogen atom, and they are the same or different. They may be bonded to each other to form a ring.

Examples of the hydrocarbon group having 1 to 20 carbon atoms of R ^{3 to} R ⁶ include an alkyl group having 1 to 20 carbon atoms such as a methyl group, an ethyl group, and a propyl group; a vinyl group, a propenyl group, an isopropenyl group, and a crotyl group. Alkenyl groups having 2 to 20 carbon atoms such as: alkynyl groups having 2 to 20 carbon atoms such as ethynyl group and propargyl group; hydrocarbon groups having an aromatic ring having 6 to 20 carbon atoms such as phenyl group, benzyl group and naphthyl group And the like.

Examples of the group containing a halogen atom include halogen atoms such as fluorine atom and chlorine atom; haloalkyl groups such as trifluoromethyl group, 2,2,2-trifluoroethyl group and pentafluoroethyl group;
Examples of the group containing a silicon atom include silyl groups such as trimethylsilyl group, triethylsilyl group, t-butyldimethylsilyl group, and triphenyl group; alkyl groups substituted with silyl groups such as trimethylsilylmethyl group and 2-trimethylsilylethyl group; Etc.

Examples of the group containing an oxygen atom include an alkoxyl group such as a methoxy group, an ethoxy group, a propoxy group and an isopropoxy group; an alkoxycarbonyl group such as a methoxycarbonyl group, an ethoxycarbonyl group and a t-butoxycarbonyl group;
Examples of the group containing a nitrogen atom include: an amino group; a monosubstituted amino group such as a methylamino group; a disubstituted amino group such as a dimethylamino group; an amide group; a monosubstituted amide group such as an N-methylamide group; A disubstituted amide group such as an amide group;

R ^{3 to} R ⁶ may be bonded to each other to form a ring. Such a ring may be composed of only carbon atoms, or may be a ring containing oxygen atoms and / or nitrogen atoms.

The repeating unit (II) preferably has an aromatic ring. That is, it is preferable that at least one of R ^{3 to} R ⁶ is a hydrocarbon group having an aromatic ring, or R ^{3 to} R ⁶ are bonded to each other to form an aromatic ring.

  m is an integer of 0 to 2, and 0 or 1 is preferable.

  In the random copolymer of the present invention, the content of the repeating unit (I) is 1 to 99 mol%, preferably 1 to 90 mol%, more preferably 2 to 80 mol%, still more preferably 3 to 70 mol%. Most preferably, it is 5 to 60 mol%. When the content of the repeating unit (I) is within this range, the low birefringence is particularly excellent.

  The content of the repeating unit (II) is 1 to 99 mol%, preferably 10 to 99 mol%, more preferably 20 to 98 mol%, still more preferably 30 to 97 mol%, most preferably 40 to 95. Mol%. When the content of the repeating unit (II) is within this range, the balance between low birefringence and heat resistance is excellent.

  In the random copolymer of the present invention, the repeating unit (III) is an optional component, and the content thereof is 0 to 20 mol%, preferably 0 to 15 mol%, more preferably 0 to 10 mol%. Further, the content of the repeating unit (I) is larger than the content of the repeating unit (III). If the content of the repeating unit (III) is too large, there are problems such as a decrease in heat resistance and an increase in birefringence.

  The weight average molecular weight (Mw) of the random copolymer of the present invention is a polystyrene conversion value measured by gel permeation chromatography, and is usually 10,000 to 1,000,000, preferably 15,000 to 800. 20,000, more preferably 20,000 to 600,000. If the molecular weight is too low, the mechanical strength as an optical material is inferior, and if the molecular weight is too high, the solution viscosity and the melt viscosity are too high, making handling difficult.

  The glass transition temperature (Tg) of the random copolymer of the present invention is preferably 50 to 250 ° C, more preferably 80 to 200 ° C. When Tg is within this range, the moldability as an optical material and the heat resistance during use are excellent.

  The random copolymer of the present invention is a copolymer in which at least repeating unit (I) and repeating unit (II) are bonded at random. Random bonding can be confirmed by observing signals derived from bonds adjacent to the repeating unit (I) and the repeating unit (II) by performing two-dimensional NMR spectrum analysis of the copolymer. . Further, when the glass transition temperature (Tg) of the copolymer is measured, it can be confirmed that one Tg by random copolymerization is observed.

  Further, by the production method of the present invention, which will be described later, a monomer mixture containing the monomer represented by the general formula (4) and the monomer represented by the general formula (5) is subjected to metathesis copolymerization. When a polymer is obtained and then the obtained metathesis copolymer is hydrogenated to obtain the random copolymer of the present invention, it may be confirmed that the metathesis copolymer is randomly copolymerized. . When the metathesis copolymer obtained by random copolymerization of the monomer represented by the general formula (4) and the monomer represented by the general formula (5) is hydrogenated, the resulting hydride is converted into the random copolymer of the present invention. It becomes a polymer.

  Specifically, it can be confirmed by the method described in Polymer, 34, 1490-1495, 1993. That is, about a metathesis copolymer, it can confirm that it has copolymerized at random by performing a two-dimensional NMR spectrum measurement like the above. It can also be confirmed that the absorption in the ultraviolet-visible region is shifted to the lower wavelength side as compared with the homopolymer of the monomer represented by the general formula (4). The shift of the absorption wavelength in the ultraviolet-visible region can be measured by ultraviolet spectroscopy. Further, depending on the type of the metathesis copolymer, it may be confirmed by visual color change. For example, when phenylacetylene is homopolymerized using tungsten hexachloride as a catalyst, the resulting polymer is red, but when phenylacetylene and the monomer represented by the general formula (5) are randomly copolymerized, yellow Or it turns orange. When such a metathesis copolymer is hydrogenated, a colorless random copolymer of the present invention is obtained.

2) Method for Producing Random Copolymer The production method of the present invention involves metathesis of a monomer mixture containing the monomer represented by the following general formula (4) and the monomer represented by the general formula (5). Production of the random copolymer of the present invention having a step of copolymerizing to obtain a metathesis copolymer and a step of hydrogenating a carbon-carbon double bond in the main chain of the obtained metathesis copolymer Is the method.

In the general formula (4), R ¹ and R ² represent the same meaning as described above. In the general formula ^(5), R 3 ~R ⁶ and m are as defined above.

  Specific examples of the monomer represented by the general formula (4) include linear or branched such as propyne, 1-butyne, 2-butyne, 1-hexyne, 1-octyne, and t-butylacetylene. Chain alkynes; Alkynes having aromatic rings such as phenylacetylene, diphenylacetylene, and (methylphenyl) acetylene; Alkynes having silyl groups such as trimethylsilylacetylene and trimethylsilylpropyne; Halogens such as chloropropyne and chlorohexyne And alkynes having an atom. Among them, alkynes having an aromatic ring are preferable, and phenylacetylene is particularly preferable.

  As the monomer represented by the general formula (5), norbornenes in which m is 0 in the general formula (5), tetracyclododecenes in which m is 1, and hexacycloheptadecene in which m is 2 Kind.

  Specific examples of norbornenes in which m is 0 include norbornenes having an unsubstituted or alkyl group such as norbornene, 5-methylnorbornene, 5-ethylnorbornene, 5-cyclohexylnorbornene, and 5-cyclopentylnorbornene; 5-methylidene; Norbornenes having an alkenyl group such as norbornene, 5-ethylidenenorbornene, 5-vinylnorbornene, 5-cyclohexenylnorbornene, 5-cyclopentenylnorbornene; norbornenes having an aromatic ring such as 5-phenylnorbornene;

  5-methoxycarbonylnorbornene, 5-ethoxycarbonylnorbornene, 5-methyl-5-methoxycarbonylnorbornene, norbornenyl-2-methylpropionate, norbornene-5,6-dicarboxylic anhydride, 5-hydroxymethylnorbornene, 5, Norbornenes having a group containing an oxygen atom such as 6-di (hydroxymethyl) norbornene, 5,5-di (hydroxymethyl) norbornene, 5,6-dicarboxynorbornene, 5-methoxycarbonyl-6-carboxynorbornene; 5 -Norbornenes having a group containing a nitrogen atom such as cyanonorbornene, norbornene-5,6-dicarboxylic imide;

Dicyclopentadiene, tricyclo [4.3.1 ^2,5 . 0] Dec-3-ene or the like, a monomer in which R ⁴ and R ⁶ are bonded to each other to form a five-membered ring in the general formula (5); tetracyclo [6.5.1, ^{2, 5} . 0 ^1,6 . 0 ^8,13] trideca -3,8,10,12- tetraene (1,4-methano -1,4,4a, also referred 9a- tetrahydrofluorene), tetracyclo ^{[6.6.1 2,5.} 0 ^1,6 . 0 ^8,13] tetradeca -3,8,10,12- tetraene (1,4-methano -1,4,4a, 5,10,10a also called hexa hydro anthracene) such, in the general formula (5) A monomer in which R ^{3 to} R ⁶ are bonded to each other to form an aromatic ring; and the like.

  Specific examples of tetracyclododecenes in which m is 1 include tetracyclododecenes having an unsubstituted or alkyl group such as tetracyclododecene, 8-methyltetracyclododecene, and 8-cyclohexyltetracyclododecene. Tetracyclododecenes having an alkenyl group such as 8-methylidenetetracyclododecene, 8-ethylidenetetracyclododecene, 8-vinyltetracyclododecene, 8-cyclohexenyltetracyclododecene, etc .; 8-phenyltetra Tetracyclododecenes having an aromatic ring such as cyclododecene;

  8-methoxycarbonyltetracyclododecene, 8-methyl-8-methoxycarbonyltetracyclododecene, 8-carboxytetracyclododecene, tetracyclododecene-8,9-dicarboxylic acid, tetracyclododecene-8,9 -Tetracyclododecenes having a group containing an oxygen atom such as dicarboxylic acid anhydride; Tetra having a group containing a nitrogen atom such as 8-cyanotetracyclododecene, tetracyclododecene-8,9-dicarboxylic imide Cyclododecenes; tetracyclododecenes having a group containing a halogen atom such as 8-chlorotetracyclododecene; and the like.

  As the hexacycloheptadecenes where m is 2, any Diels-Alder adduct of the above-mentioned tetracyclododecenes and cyclopentadiene can be used.

Among these, norbornenes having an aromatic ring; monomers in which R ^{3 to} R ⁶ are bonded to each other to form an aromatic ring in the general formula (5); and tetracyclododecenes having an aromatic ring are preferable. .

  In addition to the monomer represented by the general formula (4) and the monomer represented by the general formula (5), the monomer mixture used in the present invention is a monomer that can be copolymerized with these. The monomer may be copolymerized. Such monomers include acetylene, cyclic monoolefins and cyclic diolefins.

  Specific examples of the cyclic monoolefin include cyclobutene, cyclopentene, cyclohexene, phenylcyclohexene, cycloheptene, cyclooctene, phenylcyclooctene and the like. Specific examples of the cyclic diolefin include cyclohexadiene, methylcyclohexadiene, cyclooctadiene, phenylcyclooctadiene and the like.

  The ratio of the amount of each monomer used in the production method of the present invention is such that the content (composition ratio) of the repeating units (I) to (III) in the obtained random copolymer is in the above range. It is selected appropriately. That is, in the case where only the monomer represented by the general formula (4), the monomer represented by the general formula (5) and acetylene are used as the monomer mixture, and the polymerization conversion rate in the metathesis copolymerization is In the case of 100%, the ratio of the amounts of these monomers used is the same as the composition ratio in the desired random copolymer. Also, when the polymerization conversion is less than 100%, the correlation between the ratio of the amount of monomer used and the composition ratio of the resulting copolymer is obtained to match the composition ratio of the desired random copolymer. You can decide how much to use.

  The monomer unit obtained by ring-opening metathesis polymerization of a cyclic monoolefin or cyclic diolefin and hydrogenating has a linear structure, and has a structure in which the repeating unit (III) and the repeating unit (I) are combined. . For example, when cyclooctene is subjected to ring-opening metathesis polymerization and hydrogenated, 4 moles of repeating units (III) are produced per mole of cyclooctene. When phenylcyclooctene is used instead of cyclooctene, 3 moles of repeating unit (III) and 1 mole of repeating unit (I) are produced per mole of phenylcyclooctene. Therefore, when the monomer mixture further contains a cyclic monoolefin or a cyclic diolefin, the amount of each monomer used depends on the repeating units (III) and (I) generated from these monomers. It is determined in consideration of the amount.

  The production method of the present invention includes a step of copolymerizing the monomer mixture in the presence of a metathesis polymerization catalyst. The metathesis polymerization catalyst may be any compound as long as it is a compound of a transition metal of Group 4 to 8 of the periodic table and can metathesis copolymerize the monomer mixture.

  Examples of the metathesis polymerization catalyst include (i) metathesis polymerization by a combination of a transition metal compound as a main catalyst and an alkylating agent or a Lewis acid functioning as a cocatalyst (hereinafter sometimes simply referred to as “cocatalyst”). A catalyst, (ii) a carbene complex catalyst of Group 4-8 transition metal of the periodic table, and (iii) a metallacyclobutane complex catalyst. These metathesis reaction catalysts can be used alone or in admixture of two or more. Among these, (i) a metathesis polymerization catalyst comprising a combination of a transition metal compound as a main catalyst and a cocatalyst is preferable because of its high activity.

The transition metal compound used as the main catalyst in the above (i) is preferably a molybdenum or tungsten compound. Further, as the transition metal compound, a compound having a halogen group, an imide group, an alkoxyl group, an allyloxy group or a carbonyl group as a ligand is preferable, and a compound having a halogen group is more preferable. Specifically, molybdenum compounds having a halogen group such as MoBr ₂ , MoBr ₃ , MoBr ₄ , MoCl ₄ , MoCl ₅ , MoF ₄ , MoOCl ₄ , MoOF ₄ ; WBr ₂ , WCl ₂ , WBr ₄ , WCl ₄ , WCl ₅ , tungsten compounds having a halogen group such as WCl ₆ , WF ₄ , WI ₂ , WOBr ₄ , WOCl ₄ , WOF ₄ , WCl ₄ (OC ₆ H ₄ Cl ₂ ) ₂ .

  Examples of the alkylating agent or Lewis acid that functions as a cocatalyst include compounds of Group 1, Group 2, Group 12, Group 13, and Group 14 organometallic compounds of the periodic table. Among these, organic lithium, organic magnesium, organic zinc, organic aluminum, and organic tin are preferable, and organic lithium, organic aluminum, and organic tin are particularly preferable.

Examples of the organic lithium include n-butyllithium, methyllithium, phenyllithium, neopentyllithium, and neophyllithium.
Examples of the organic magnesium include butylethylmagnesium, butyloctylmagnesium, dihexylmagnesium, ethylmagnesium chloride, n-butylmagnesium chloride, allylmagnesium bromide, neopentylmagnesium chloride, neophyllmagnesium chloride and the like.

Examples of the organic zinc include dimethyl zinc, diethyl zinc, and diphenyl zinc.
Examples of the organoaluminum include organoaluminum compounds such as trimethylaluminum, triethylaluminum, triisobutylaluminum, diethylaluminum chloride, ethylaluminum sesquichloride, ethylaluminum dichloride, diethylaluminum ethoxide, and ethylaluminum diethoxide. Furthermore, the conventionally well-known aluminoxane obtained by reaction of said organoaluminum and water can be mentioned.
Examples of the organic tin include tetramethyltin, tetra (n-butyl) tin, and tetraphenyltin.

  In the metathesis copolymerization, the ratio of the polymerization catalyst to the monomer mixture is usually 1: 100 to 1: 2,000,000, preferably 1: 200 in terms of molar ratio of transition metal: monomer in the main catalyst. To 1,000,000, more preferably 1: 500 to 1: 500,000. If the amount of catalyst is too large, catalyst removal becomes difficult, and if it is too small, sufficient polymerization activity may not be obtained.

  The amount of the cocatalyst used varies depending on the compound used, but is preferably 0.1 to 10,000 times, more preferably 0.2 to 5,000 times in terms of molar ratio to the transition metal in the main catalyst. It is particularly preferably 5 to 2,000 times. When the amount used is 0.1 times or less, the polymerization activity is not improved, and when it is 10,000 times or more, side reactions tend to occur.

  The polymerization reaction is initiated by mixing the monomer mixture and the metathesis polymerization catalyst. The polymerization reaction temperature is not particularly limited, but is generally −30 ° C. to + 200 ° C., preferably 0 ° C. to + 180 ° C. The polymerization reaction time is 1 minute to 100 hours and is not particularly limited.

  In the present invention, the polymerization reaction is usually carried out in an organic solvent. The organic solvent used in the present invention is not particularly limited as long as the obtained metathesis copolymer and its hydride are dissolved or dispersed under predetermined conditions and do not affect the polymerization, but industrially general-purpose ones are preferable. .

  Specific examples of such organic solvents include aliphatic hydrocarbons such as pentane, hexane, heptane; cyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, ethylcyclohexane, diethylcyclohexane, decahydronaphthalene, bicycloheptane, Alicyclic hydrocarbons such as tricyclodecane, hexahydroindene and cyclooctane; aromatic hydrocarbons such as benzene, toluene and xylene; halogen-containing aliphatic solvents such as dichloromethane, chloroform and 1,2-dichloroethane; chlorobenzene and di Halogen-containing aromatic solvents such as chlorobenzene; nitrogen-containing solvents such as nitromethane, nitrobenzene, and acetonitrile; aliphatic ethers such as diethyl ether and tetrahydrofuran Aromatic ethers such as anisole and phenetole; among these solvents, among these solvents, industrially versatile aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons, aliphatic ethers, aromatics Ethers are preferred.

  When the polymerization reaction is carried out in a solvent, the concentration of the monomer mixture is preferably 1 to 50% by weight, more preferably 2 to 45% by weight, more preferably 3 to 40% based on the total amount of the solvent and the monomer mixture. Weight percent is particularly preferred. When the concentration of the monomer mixture is 1% by weight or less, the productivity is poor, and when it is 50% by weight or more, the solution viscosity after polymerization is too high, and the subsequent hydrogenation reaction may be difficult.

  In the polymerization reaction, a molecular weight modifier can be added to adjust the molecular weight of the metathesis copolymer. Examples of molecular weight modifiers include α-olefins such as 1-butene, 1-pentene, 1-hexene and 1-octene; aromatic vinyl compounds such as styrene and vinyltoluene; ethyl vinyl ether, isobutyl vinyl ether, allyl glycidyl ether, acetic acid Oxygen-containing vinyl compounds such as allyl, allyl alcohol and glycidyl methacrylate; halogen-containing vinyl compounds such as allyl chloride; nitrogen-containing vinyl compounds such as acrylamide; 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1 , 6-heptadiene, 2-methyl-1,4-pentadiene, 2,5-dimethyl-1,5-hexadiene and other non-conjugated dienes; 1,3-butadiene, 2-methyl-1,3-butadiene, 2, 3-dimethyl-1,3-butadiene, 1,3- Ntajien, a conjugated diene such as 1,3-hexadiene; can be mentioned. The amount of the molecular weight modifier to be added can be arbitrarily selected from 0.1 to 10 mol% based on the monomer mixture depending on the desired molecular weight.

  The production method of the present invention includes a step of hydrogenating a carbon-carbon double bond in the main chain of the metathesis copolymer obtained above. The hydrogenation reaction is performed by adding hydrogen to the metathesis copolymer in the presence of a hydrogenation catalyst.

  In the production method of the present invention, the hydrogenation rate of the carbon-carbon double bond in the main chain of the metathesis copolymer is preferably 80% or more, more preferably 90% or more, and still more preferably 95% or more. When the hydrogenation rate is low, the resulting hydride, that is, the random copolymer of the present invention may have poor heat resistance.

In the hydrogenation reaction, when R ^{1 to} R ⁶ which are substituents of the monomer mixture have a carbon-carbon unsaturated bond, the unsaturated bond may be hydrogenated. When the unsaturated bond is a carbon-carbon double bond, the hydrogenation rate is preferably 80% or more, more preferably 90% or more, and further preferably 95% or more. The higher the hydrogenation rate of the carbon-carbon double bond, the higher the heat resistance of the resulting hydride. When the unsaturated bond is an aromatic ring, the hydrogenation rate of the aromatic ring is preferably 50% or less, more preferably 30% or less, and still more preferably 10% or less. When the hydrogenation rate of the aromatic ring is low, the random copolymer of the present invention obtained has an aromatic ring in the molecule, so that it can be a random copolymer having a high refractive index.

  Any hydrogenation catalyst can be used as long as it is generally used in the hydrogenation of olefin compounds, and is not particularly limited. Examples thereof include the following.

  As the homogeneous catalyst, a catalyst system comprising a combination of a transition metal compound and an alkali metal compound, such as cobalt acetate / triethylaluminum, nickel acetylacetonate / triisobutylaluminum, titanocene dichloride / n-butyllithium, zirconocene dichloride / sec- Examples include butyl lithium, tetrabutoxy titanate / dimethyl magnesium, and the like. Further examples include noble metal complex catalysts such as dichlorobis (triphenylphosphine) palladium, chlorohydridocarbonyltris (triphenylphosphine) ruthenium, chlorotris (triphenylphosphine) rhodium.

  As the heterogeneous catalyst, nickel, palladium, platinum, rhodium, ruthenium, or a solid catalyst in which these metals are supported on a support such as carbon, silica, diatomaceous earth, alumina, titanium oxide, for example, nickel / silica, nickel / Examples of the catalyst system include diatomaceous earth, nickel / alumina, palladium / carbon, palladium / silica, palladium / diatomaceous earth, and palladium / alumina.

The hydrogenation reaction is usually carried out in an inert organic solvent. Examples of such inert organic solvents include aromatic hydrocarbons such as benzene and toluene; aliphatic hydrocarbons such as pentane and hexane; alicyclic hydrocarbons such as cyclohexane and decahydronaphthalene; tetrahydrofuran, ethylene glycol dimethyl ether, and the like. Ethers; and the like.
The inert organic solvent is usually the same as the solvent used for the polymerization reaction, and the reaction is carried out by adding the above hydrogenation catalyst to the polymerization reaction solution without isolating the metathesis copolymer obtained by the polymerization reaction. You can do it.

  The conditions for the hydrogenation reaction vary depending on the hydrogenation catalyst used, but the reaction temperature is usually -20 ° C to + 250 ° C, preferably -10 ° C to + 220 ° C, more preferably 0 ° C to + 200 ° C. If the reaction temperature is too low, the reaction rate is slow, and if it is too high, side reactions may occur. The hydrogen pressure is usually 0.01 to 20 MPa, preferably 0.05 to 15 MPa, and more preferably 0.1 to 10 MPa. If the hydrogen pressure is too low, the hydrogenation rate is slow, and if it is too high, a high pressure reactor is required. Although reaction time will not be specifically limited if it can be set as the desired hydrogenation rate, Usually, it is 0.1 to 10 hours.

  When the metathesis copolymer has an aromatic ring, it is preferable to use a heterogeneous catalyst containing palladium or ruthenium or a noble metal complex catalyst as a catalyst. By using these catalysts, a carbon-carbon double bond can be selectively hydrogenated without hydrogenating an aromatic ring. Even when other catalysts are used, the carbon-carbon double bond can be selectively hydrogenated by setting the upper limit of the hydrogenation reaction temperature to 150 ° C., preferably 120 ° C.

3) Optical material The random copolymer of the present invention can be used as various molding materials, but is preferably used as an optical material. The optical material of the present invention is obtained by molding the random copolymer of the present invention. As the molding method, any known thermoplastic resin molding method can be employed. Specific examples include injection molding, extrusion molding, blow molding, vacuum molding, rotational molding, press molding, roll molding, and the like.

  The optical material of the present invention may contain various additives. Additives include: antioxidants; UV absorbers; weathering stabilizers; antistatic agents; light stabilizers; near infrared absorbers; colorants such as dyes and pigments; lubricants; plasticizers; antiblocking agents; Deodorant; Filler; Cross-linking agent; Vulcanizing agent; Other synthetic resins and rubbery polymers; These additives can be contained in the optical material of the present invention by mixing with the random copolymer of the present invention and molding.

  The optical material of the present invention is excellent in transparency, high refractive index, low birefringence, and low hygroscopicity, and has high mechanical strength. Therefore, an optical disk, an optical lens, an optical card, an optical fiber, an optical mirror, and a liquid crystal display element. It can be suitably used as a substrate, a light guide plate, a polarizing film, a retardation film or the like.

  EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the following, “part” and “%” are based on weight unless otherwise specified.

Each characteristic in an Example and a comparative example was measured as follows.
(1) Molecular weight The number average molecular weight (Mn) and the weight average molecular weight (Mw) of the polymer were measured by gel permeation chromatography (GPC) using tetrahydrofuran or chloroform as a developing solvent, and were determined as polystyrene equivalent values.
(2) Repeating unit composition ratio and hydrogenation rate of copolymer The repeating unit composition ratio and hydrogenation rate (%) of the copolymer were determined by ¹ H-NMR spectrum analysis.
(3) Birefringence value The polymer was hot-pressed to form an optical disk substrate having a thickness of 1.2 mm and a diameter of 85 mm. The birefringence value at a radius of 25 mm from the center of the substrate was measured using a polarizing microscope (546 nm Senalmon Compensator, manufactured by Nikon Corporation). The closer the birefringence value is to 0, the lower the birefringence.
(4) Refractive index The refractive index of the disk substrate produced in the above (4) was measured.
(5) Glass transition temperature The glass transition temperature (Tg) of the polymer was measured by raising the temperature at 10 ° C. per minute by differential scanning calorimetry (DSC).

[Example 1] Production of hydrogenated phenylacetylene / dicyclopentadiene copolymer In a glass reactor equipped with a stirrer, a solution prepared by dissolving 0.09 part of tungsten hexachloride in 1 part of toluene, 0.16 part of tetrabutyltin, Was added and stirred for 15 minutes. To this was added 27 parts of cyclohexane as a solvent, 2.7 parts of phenylacetylene and 4.8 parts of dicyclopentadiene as a monomer mixture, 0.15 part of 1-hexene as a molecular weight regulator, and heated to 80 ° C. A polymerization reaction was performed. After the polymerization reaction started, the viscosity of the solution gradually increased. After the reaction for 3 hours, a large amount of isopropyl alcohol was poured into the obtained polymerization reaction solution to aggregate the precipitate, this precipitate was filtered and washed, and dried under reduced pressure at 40 ° C. for 24 hours to obtain a copolymer a. . The yield of copolymer a was 3 parts, Mn was 16,000, and Mw was 56,000. The composition ratio of copolymer a was 39:61 in terms of a molar ratio of phenylacetylene units: dicyclopentadiene units. Copolymer a was yellow-orange and one Tg was observed at 115 ° C., confirming random copolymerization.

Next, 3 parts of the copolymer a obtained above and 47 parts of cyclohexane were supplied to an autoclave equipped with a stirrer. Then, a hydrogenation catalyst solution in which 0.0187 part of bis (tricyclohexylphosphine) benzilidineruthenium (IV) dichloride and 0.45 part of ethyl vinyl ether were dissolved in 10 ml of cyclohexane was added, and the hydrogen pressure was 0.8 MPa at 160 ° C. for 8 hours. A hydrogenation reaction was performed. The obtained hydrogenation reaction solution is poured into a large amount of isopropyl alcohol to completely precipitate the polymer, washed by filtration, and dried under reduced pressure at 40 ° C. for 24 hours to obtain a copolymer A which is a hydride of copolymer a. 3 parts were obtained. In the ¹ H-NMR measurement of copolymer A, no peak derived from the carbon-carbon double bond of the side chain of the copolymer main chain and dicyclopentadiene unit was observed, and the hydrogenation rate of the main chain and side chain Was 99% or more. The hydrogenation rate of the aromatic ring was 1% or less. One Tg was observed at 100 ° C.

As described above, the copolymer A has a repeating unit of 39 mol% in which R ¹ is a hydrogen atom and R ² is a phenyl group in the general formula (1), and R ³ and R ⁵ are hydrogen in the general formula (2). It was an atom, and R ⁴ and R ⁶ were bonded to each other to form a five-membered ring, and it was confirmed to be a random copolymer having 61 mol% of repeating units in which m is 0.
The optical disk substrate obtained by hot pressing the copolymer A was transparent, had a birefringence value of 6 nm, and a refractive index of 1.56.

[Example 2] Preparation of hydrogenated phenylacetylene / 1,4-methano-1,4,4a, 9a-tetrahydrofluorene copolymer As a monomer mixture, 2.7 parts of phenylacetylene and 4.8 of dicyclopentadiene were used. The copolymer b was prepared in the same manner as in Example 1 except that 4.8 parts of phenylacetylene and 4.8 parts of 1,4-methano-1,4,4a, 9a-tetrahydrofluorene were used instead of the parts. Obtained. The yield of copolymer b was 3 parts, Mn was 15,000, and Mw was 48,000. The composition ratio of copolymer b was 64:36 in terms of a molar ratio of phenylacetylene units: 1,4-methano-1,4,4a, 9a-tetrahydrofluorene units. Moreover, since it was yellowish orange, it has confirmed that it copolymerized at random.

Subsequently, a hydrogenation reaction was carried out in the same manner as in Example 1 except that 3 parts of copolymer b was used instead of 3 parts of copolymer a to obtain 3 parts of copolymer B which is a hydride of copolymer b. It was. In ¹ H-NMR measurement of copolymer B, no peak derived from the carbon-carbon double bond of the copolymer main chain was observed, and the hydrogenation rate of the main chain was 99% or more. The hydrogenation rate of the aromatic ring was 1% or less. Since one Tg was observed at 120 ° C., it was confirmed to be a random copolymer. From the above, the copolymer B has a repeating unit of 64 mol% in which R ¹ is a hydrogen atom and R ² is a phenyl group in the general formula (1), and R ^{3 to} R ⁶ in the general formula (2) are It was confirmed that it was a random copolymer having 36 mol% of repeating units bonded to form an aromatic ring and m = 0.
The optical disk substrate obtained by hot pressing the copolymer B was transparent, had a birefringence value of 8 nm, and a refractive index of 1.59.

[Comparative Example 1] Preparation of hydride of phenylacetylene homopolymer In place of 2.7 parts of phenylacetylene and 4.8 parts of dicyclopentadiene as a monomer mixture, only 7.5 parts of phenylacetylene was used. In the same manner as in Example 1, 1.1 parts of polymer c was obtained. Polymer c was a homopolymer of phenylacetylene, Mn was 10,000, Mw was 23,000, and it was red.

  Subsequently, the obtained polymer c1 part and cyclohexane 15.7 parts were supplied to the autoclave with a stirrer. Next, a hydrogenation catalyst solution prepared by dissolving 0.0062 part of bis (tricyclohexylphosphine) benzilidine ruthenium (IV) dichloride and 0.15 part of ethyl vinyl ether in 3.3 ml of cyclohexane was added, and the hydrogen pressure was 0.8 MPa at 160 ° C. Hydrogenation reaction was performed for 8 hours. The obtained hydrogenation reaction solution is poured into a large amount of isopropyl alcohol to completely precipitate the polymer, washed by filtration, dried under reduced pressure at 40 ° C. for 24 hours, and polymer C which is a hydride of polymer c is 1 I got a part.

In the ¹ H-NMR measurement of polymer C, no peak derived from the carbon-carbon double bond of the polymer main chain was observed, and the hydrogenation rate of the main chain was 99% or more. The hydrogenation rate of the aromatic ring was 1% or less, and the polymer C had the same structure as polystyrene. Tg was 102 ° C.
The optical disk substrate obtained by hot pressing the polymer C was transparent, had a birefringence value of 54 nm and a refractive index of 1.59.

[Comparative Example 2] Preparation of dicyclopentadiene homopolymer hydride Instead of 2.7 parts of phenylacetylene and 4.8 parts of dicyclopentadiene, which are monomer mixtures, only 4.8 parts of dicyclopentadiene were used. In the same manner as in Example 1, 4.5 parts of polymer d was obtained. The polymer d was a homopolymer of dicyclopentadiene, Mn was 18,000, Mw was 64,000, and Tg was 125 ° C.
Subsequently, a hydrogenation reaction was carried out in the same manner as in Example 1 except that 3 parts of the polymer d was used instead of 3 parts of the copolymer a to obtain 3 parts of a polymer D which is a hydride of the polymer d. In the ¹ H-NMR measurement of polymer D, no peak derived from the carbon-carbon double bond in the side chain of the copolymer main chain and dicyclopentadiene unit was observed, and the hydrogenation rate of the main chain and side chain was It was 99% or more. Tg was 100 ° C.
The optical disk substrate obtained by hot pressing the polymer D was transparent, the birefringence value was 26 nm, and the refractive index was 1.54.

[Comparative Example 3] Mixture of polymer C and polymer D 1 part of polymer C and 1 part of polymer D were added to 10 parts of cyclohexane and heated to 80 ° C to dissolve. Subsequently, the obtained solution was poured into excess isopropyl alcohol to precipitate a polymer, filtered and dried to obtain 2 parts of a polymer mixture.
The optical disk substrate obtained by hot pressing the polymer mixture was cloudy.

  From the above, the random copolymer of the present invention in which the repeating unit represented by the general formula (1) and the repeating unit represented by the general formula (2) are randomly bonded is transparent and has a birefringence value. Since it is small and has a high refractive index, it can be seen that it is suitable as an optical material (Examples 1 and 2). On the other hand, the homopolymer of each repeating unit is transparent but has a large birefringence value (Comparative Examples 1 and 2). Moreover, since the mixture of these homopolymers became cloudy by phase separation, it was not suitable for an optical material (Comparative Example 3).

Claims (5)

General formula (1)

(Wherein R ¹ and R ² are a hydrogen atom, a halogen atom, a silyl group, or a hydrocarbon having 1 to 20 carbon atoms which may have a substituent containing a halogen atom, a silicon atom, an oxygen atom or a nitrogen atom) Represents a group, and R ¹ and R ² are not simultaneously hydrogen atoms.)
1 to 99 mol% of the repeating unit (I) represented by the general formula (2)

(Wherein R ^{3 to} R ⁶ represent a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a group containing a halogen atom, a silicon atom, an oxygen atom or a nitrogen atom, which may be the same or different, And may be bonded to each other to form a ring, and m is an integer of 0 to 2.)
1 to 99 mol% of the repeating unit (II) represented by formula (3)

A random copolymer comprising 0 to 20 mol% of the repeating unit (III) represented by the formula (I) and a larger content of the repeating unit (I) than that of the repeating unit (III). The random copolymer according to claim 1, wherein at least one of R ¹ and R ² has an aromatic ring. The random copolymer according to claim 1 or 2, wherein the repeating unit (II) has an aromatic ring. General formula (4)

(Wherein R ¹ and R ² represent the same meaning as described above.)
And a monomer represented by the general formula (5)

(Wherein R ^{3 to} R ⁶ and m have the same meaning as described above.)
A step of obtaining a metathesis copolymer by copolymerizing a monomer mixture containing a monomer represented by formula (1) and hydrogenating a carbon-carbon double bond in the main chain of the obtained metathesis copolymer. The method for producing a random copolymer according to any one of claims 1 to 3, comprising a step. The optical material formed by shape | molding the random copolymer in any one of Claims 1-3.