Cyclic olefin ring-opening copolymer, composition for insulating material, and insulating material

Abstract

The present invention provides a cyclic olefin ring-opening copolymer, which comprises a structural unit derived from a norbornene compound having a heteroelement-containing hydrocarbon group and a structural unit derived from a norbornene compound having a heteroelement-free hydrocarbon group. In the copolymer, the content ratio of the structural unit derived from the norbornene compound having a heteroelement-containing hydrocarbon group is 0.01 mol% or more and 15.00 mol% or less, based on the total structural units of the copolymer being 100 mol%.

Description

Technical Field

[0001] The present invention relates to a cyclic olefin ring-opening copolymer, a composition for an insulating material comprising the cyclic olefin ring-opening copolymer, and an insulating material comprising the composition for an insulating material. Background Art

[0002] It is known that polymers containing units having a norbornene skeleton (hereinafter sometimes referred to as "norbornene-based polymers") can exhibit various beneficial properties. By effectively utilizing these properties, norbornene-based polymers can be appropriately applied to a variety of uses. In addition, in recent years, attempts have been made to improve norbornene-based polymers in order to further improve their adaptability in various uses.

[0003] Specifically, for example, in Patent Document 1, a norbornene-based crosslinked polymer is disclosed, which contains 50% by mass or more of one or more selected from dicyclopentadiene-based monomer units, tetracyclododecene-based monomer units, and tricyclopentadiene-based monomer units, and has a glass transition temperature of 240° C. or more. In addition, for example, in Patent Document 2, an addition polymer containing a unit having a norbornene skeleton and a unit having a norbornene skeleton containing a maleimide group is disclosed. Furthermore, in Patent Document 3, for example, an addition polymer and a ring-opening polymer containing at least a unit having a norbornene skeleton containing a free radical are disclosed.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-104934;

[0007] Patent document 2: International Publication No. 2008 / 070774;

[0008] Patent document 3: Japanese Patent Application Publication No. 2012-197440. Summary of the invention

[0009] Problem that the invention aims to solve

[0010] In recent years, due to the high heat resistance as one of the characteristics of norbornene-based polymers, their use as insulating materials has attracted much attention. In order to be used as insulating materials, norbornene-based polymers need to be able to exhibit high insulation breakdown voltage. However, according to the composition of the above-mentioned existing norbornene-based polymers, the insulation breakdown voltage cannot be sufficiently increased.

[0011] Therefore, an object of the present invention is to provide a cyclic olefin ring-opening copolymer having a sufficiently high dielectric breakdown voltage.

[0012] Another object of the present invention is to provide a composition for an insulating material that can be advantageously used when forming an insulating material.

[0013] Furthermore, an object of the present invention is to provide an insulating material capable of exhibiting excellent performance.

[0014] Solutions for solving problems

[0015] The present inventors have conducted intensive studies for the purpose of solving the above problems. Then, the present inventors have newly found that in a cyclic olefin ring-opening copolymer comprising a structural unit derived from a norbornene compound having a heteroelement-containing hydrocarbon group and a structural unit derived from a norbornene compound having no heteroelement-containing hydrocarbon group, when the content ratio of the structural unit derived from the norbornene compound having a heteroelement-containing hydrocarbon group is 0.01 mol% or more and 15.00 mol% or less, the dielectric breakdown voltage can be sufficiently improved, thereby completing the present invention.

[0016] That is, the object of the present invention is to advantageously solve the above-mentioned problems, and the cyclic olefin ring-opening copolymer of the present invention is characterized in that it contains a structural unit derived from a norbornene compound having a heteroelement-containing hydrocarbon group and a structural unit derived from a norbornene compound having no heteroelement-containing hydrocarbon group, and the content ratio of the structural unit derived from the norbornene compound having a heteroelement-containing hydrocarbon group is 0.01 mol% or more and 15.00 mol% or less, based on the total structural units possessed by the cyclic olefin ring-opening copolymer as 100 mol%. As such, if the content ratio of the structural unit derived from the norbornene compound having a heteroelement-containing hydrocarbon group in the cyclic olefin ring-opening copolymer containing the prescribed structural unit is 0.01 mol% or more and 15.00 mol% or less, the dielectric breakdown voltage can be sufficiently improved.

[0017] Here, the "structural unit" in the copolymer refers to a unit that can form a copolymer by repeating. In addition, the "content ratio of the structural unit" can be expressed as 1 H-NMR, 13 C-NMR and other nuclear magnetic resonance (NMR) methods.

[0018] Here, in the cyclic olefin ring-opening copolymer of the present invention, the content ratio of the structural unit derived from the norbornene compound having a hydrocarbon group containing no heteroelement is preferably 85.00 mol% or more and 99.99 mol% or less, based on 100 mol% of all the structural units possessed by the cyclic olefin ring-opening copolymer. If the content ratio of the structural unit derived from the norbornene compound having a hydrocarbon group containing no heteroelement in the cyclic olefin ring-opening copolymer containing the prescribed structural unit is 85.00 mol% or more and 99.99 mol% or less, the dielectric breakdown voltage of the cyclic olefin ring-opening copolymer can be further increased.

[0019] In addition, the cyclic olefin ring-opening copolymer of the present invention preferably has a cyclic structure in which the heteroelement-containing hydrocarbon group has a cyclic structure. If the heteroelement-containing hydrocarbon group of the structural unit derived from the norbornene compound having the heteroelement-containing hydrocarbon group has a cyclic structure, the dielectric breakdown voltage of the cyclic olefin ring-opening copolymer can be further increased.

[0020] In addition, in the cyclic olefin ring-opening copolymer of the present invention, it is preferred that the structural unit derived from the norbornene compound having a hydrocarbon group containing no heteroelement includes a structural unit derived from the norbornene compound having an aromatic ring and having no heteroelement hydrocarbon group. If the structural unit derived from the norbornene compound having a hydrocarbon group containing no heteroelement includes a structural unit derived from the norbornene compound having an aromatic ring and having no heteroelement hydrocarbon group, the dielectric breakdown voltage of the cyclic olefin ring-opening copolymer can be further increased.

[0021] The present invention aims to solve the above problems, and the insulating material composition of the present invention is characterized by comprising any one of the above cyclic olefin ring-opening copolymers. The insulating material composition containing the above cyclic olefin ring-opening copolymer can be advantageously used when forming an insulating material.

[0022] Furthermore, the present invention aims to advantageously solve the above-mentioned problems, and the insulating material of the present invention is characterized in that it is formed using the above-mentioned insulating material composition. The insulating material formed using the above-mentioned insulating material composition can exhibit excellent performance.

[0023] Effects of the Invention

[0024] According to the present invention, a cyclic olefin ring-opening copolymer having a sufficiently high breakdown voltage can be provided.

[0025] Furthermore, according to the present invention, it is possible to provide a composition for an insulating material that can be advantageously used when forming an insulating material.

[0026] Furthermore, according to the present invention, it is possible to provide an insulating material that can exhibit excellent performance. DETAILED DESCRIPTION

[0027] Hereinafter, embodiments of the present invention will be described in detail.

[0028] Here, the cyclic olefin ring-opening copolymer of the present invention has a sufficiently high dielectric breakdown voltage and can therefore be suitably used when forming an insulating material.

[0029] (Cyclic olefin ring-opening copolymer)

[0030] The cyclic olefin ring-opening copolymer can be obtained by, for example, ring-opening polymerization of a monomer composition containing a norbornene compound having a heteroelement-containing hydrocarbon group and a norbornene compound having a non-heteroelement-containing hydrocarbon group in the presence of a polymerization catalyst. Furthermore, the cyclic olefin ring-opening copolymer of the present invention contains a structural unit derived from a norbornene compound having a non-heteroelement-containing hydrocarbon group, and the content ratio of the structural unit derived from the norbornene compound having a heteroelement-containing hydrocarbon group is 0.01 mol% or more and 15.00 mol% or less.

[0031] <Structural unit derived from a norbornene compound having a heteroelement-containing hydrocarbon group>

[0032] Examples of the norbornene compound that can form a structural unit derived from a norbornene compound having a heteroelement-containing hydrocarbon group (hereinafter sometimes referred to as a "heteroelement-containing norbornene compound") include norbornene compounds represented by the following formula (1).

[0033] [Chemical formula 1]

[0034]

[0035] In the above formula (1), p is an integer from 0 to 4, R 1 ~R 4 are each independently a hydrogen atom, a single bond, a hydrocarbon group containing no heteroelements, or a hydrocarbon group containing heteroelements, R 1 ~R 4 At least one of them is a heteroelement-containing hydrocarbon group, and further, R 1 ~R 4 Two or more of them may bond to each other to form a single ring or multiple rings.

[0036] More specifically, as can be R 1 ~R 4 The heteroelement-containing hydrocarbon group may include substituted or unsubstituted imido groups, substituted or unsubstituted maleimide groups, substituted or unsubstituted carbonyl groups, and substituted or unsubstituted epoxy groups. In addition, in this specification, "substituted or unsubstituted" means having one or more substituents or having no substituents.

[0037] As can be R 1 ~R 4 Examples of the heteroelement-free hydrocarbon group include a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms and a substituted or unsubstituted aryl group having 1 to 40 carbon atoms.

[0038] When the above-mentioned various groups have a substituent, the substituent is not particularly limited, and examples thereof include a linear or branched alkyl group having 1 to 20 carbon atoms and an aryl group having 6 to 40 carbon atoms.

[0039] In formula (1), preferably: p is 0, R 1 ~R 4 One of the following is a substituted or unsubstituted imide group, and the imide group forms a ring structure with one of the other three, and the ring structure forms a condensed ring structure together with the norbornene ring. In this case, R 1 ~R 4 The other two atoms in the norbornene compound are hydrogen atoms. The norbornene compound containing a heteroelement is a maleimide-modified norbornene compound satisfying the following formula (2).

[0040] [Chemical formula 2]

[0041]

[0042] In the above formula, R is hydrogen or a linear or branched alkyl group having 1 to 10 carbon atoms. R is particularly preferably a linear or branched alkyl group having 1 to 6 carbon atoms such as methyl, ethyl, n-butyl, tert-butyl, n-propyl, isopropyl, and R is particularly preferably n-butyl, tert-butyl, or isopropyl.

[0043] The above-mentioned heteroelement-containing norbornene compounds may be used alone or in combination of two or more.

[0044] Moreover, among all the structural units (100 mol%) of the cyclic olefin ring-opening copolymer, the content ratio of the structural unit derived from the norbornene compound having a heteroelement hydrocarbon group is preferably 0.10 mol% or more and 10.00 mol% or less, and more preferably 0.50 mol% or more and 5.00 mol% or less. When the copolymer has the structural unit derived from the norbornene compound having a heteroelement hydrocarbon group within this range, the insulation breakdown voltage can be further improved.

[0045] <Structural unit derived from a norbornene compound having a hydrocarbon group containing no heteroelement>

[0046] Examples of the norbornene compound that can form a structural unit derived from a norbornene compound having a hydrocarbon group containing no hetero element (hereinafter sometimes referred to as a "norbornene compound containing no hetero element") include a norbornene compound represented by the following formula (3).

[0047] [Chemical formula 3]

[0048]

[0049] In the above formula (3), q is an integer from 0 to 4, R 5 ~R 8 is a hydrogen atom or a substituted or unsubstituted hydrocarbon group. 5 ~R 8When the hydrocarbon group has a substituent, the substituent is also a group containing no hetero element.

[0050] As the norbornene compound not containing heteroelements, it is particularly preferred to use at least a norbornene compound not containing heteroelements having an aromatic ring. Furthermore, as the norbornene compound not containing heteroelements, it is more preferred to use a norbornene compound not containing heteroelements having an aromatic ring and a norbornene compound not containing heteroelements having no aromatic ring in combination. In other words, the structural unit derived from the norbornene compound having a hydrocarbon group not containing heteroelements preferably contains at least a structural unit derived from a norbornene compound not containing heteroelements having an aromatic ring, and more preferably contains a structural unit derived from a norbornene compound not containing heteroelements having an aromatic ring and a structural unit derived from a norbornene compound not containing heteroelements having no aromatic ring.

[0051] <<Structural unit derived from a norbornene compound having an aromatic ring and containing no hetero element>>

[0052] Examples of the norbornene compound having an aromatic ring and containing no hetero element that can be used to form the structural unit derived from the norbornene compound having an aromatic ring and containing no hetero element include compounds having an aromatic ring and a norbornene ring in the molecule.

[0053] The aromatic ring and the norbornene ring may each exist as a single ring or may form a condensed ring. From the viewpoint of further improving the dielectric breakdown voltage, it is particularly preferred that the aromatic ring and the norbornene ring form a condensed ring.

[0054] Here, the aromatic ring is not particularly limited, and examples thereof include aromatic hydrocarbon rings such as a benzene ring, a naphthalene ring, and an anthracene ring.

[0055] In addition, the compound having an aromatic ring and a norbornene ring in the molecule (norbornene compound having an aromatic ring and not containing a heteroelement) is not particularly limited, and examples thereof include phenyl norbornenes such as 5-phenyl-2-norbornene, 5-methyl-5-phenyl-bicyclo[2.2.1]hept-2-ene, 5-benzyl-bicyclo[2.2.1]hept-2-ene, 5-tolyl-bicyclo[2.2.1]hept-2-ene (i.e., 5-(4-methylphenyl)-2-norbornene), 5-(ethylphenyl)-bicyclo[2.2.1]hept-2-ene, 5-(isopropylphenyl)-bicyclo[2.2.1]hept-2-ene, 8-phenyl-tetracyclo[4.4.0.1 2,5 .1 7,10 ]-3-dodecene, 8-methyl-8-phenyl-tetracyclo[4.4.0.1 2,5 .1 7,10 ]-3-dodecene, 8-benzyl-tetracyclo[4.4.0.1 2,5 .1 7,10]-3-dodecene, 8-methylphenyl-tetracyclo[4.4.0.1 2,5 .1 7,10 ]-3-dodecene, 8-(ethylphenyl)-tetracyclo[4.4.0.1 2,5 .1 7,10 ]-3-dodecene, 8-(isopropylphenyl)-tetracyclo[4.4.0.1 2,5 .1 7,10 ]-3-dodecene, 8,9-diphenyl-tetracyclo[4.4.0.1 2,5 .1 7,10 ]-3-dodecene, 8-(biphenyl)-tetracyclo[4.4.0.1 2,5 .1 7,10 ]-3-dodecene, 8-(β-naphthyl)-tetracyclo[4.4.0.1 2,5 .1 7,10 ]-3-dodecene, 8-(α-naphthyl)-tetracyclo[4.4.0.1 2,5 .1 7,10 ]-3-dodecene, 8-(anthracenyl)-tetracyclo[4.4.0.1 2,5 .1 7,10 ]-3-dodecene, 11-phenyl-hexacyclo[6.6.1.1 3,6 .1 10,13 .0 2, 7 .0 9,14 ]-4-heptadecene, 6-(α-naphthyl)-bicyclo[2.2.1]-hept-2-ene, 5-(anthracenyl)-bicyclo[2.2.1]-hept-2-ene, 5-(biphenyl)-bicyclo[2.2.1]-hept-2-ene, 5-(β-naphthyl)-bicyclo[2.2.1]-hept-2-ene, 5,6-diphenyl-bicyclo[2.2.1]-hept-2-ene, 1,4-methano-1,4,4a,4b,5,8,8a,9a-octahydrofluorene, 1,4-methano-1,4 ,4a,9a-tetrahydrofluorene, 1,4-methano-8-methyl-1,4,4a,9a-tetrahydrofluorene, 1,4-methano-1,4,4a,9a-tetrahydrodibenzofuran, 1,4-methano-1,4,4a,5,10,10a-hexahydroanthracene, 7,10-methano-6b,7,10,10a-tetrahydrofluoranthene, cyclopentadiene-acenaphthylene adduct, a compound obtained by further adding cyclopentadiene to cyclopentadiene-acenaphthylene adduct, 11,12-benzo-pentacyclic [6.5.1.1 3,6 .0 2,7 .0 9,13 ]-4-pentadecene, 11,12-benzo-pentacyclo[6.6.1.1 3,6 .0 2,7 .0 9,14]-4-hexadecene, 14,15-benzo-heptacyclo[8.7.0.1 2,9 .1 4,7 .1 11,17 .0 3,8 .0 12,16 ]-5-eicosene, etc. In addition, the above-mentioned norbornene compounds having an aromatic ring and containing no hetero element may be used alone or in combination of two or more.

[0056] From the viewpoint of further improving the dielectric breakdown voltage, 1,4-methano-1,4,4a,9a-tetrahydrofluorene is particularly preferred.

[0057] <<Structural unit derived from a norbornene compound having no aromatic ring and containing no hetero element>>

[0058] The norbornene compound (norbornene compound not containing hetero elements but not containing aromatic ring) capable of forming a structural unit derived from a norbornene compound not containing hetero elements but not containing aromatic ring is not particularly limited, and examples thereof include norbornene; norbornenes having an alkyl group such as 5-methyl norbornene, 5-ethyl norbornene, 5-butyl norbornene, 5-hexyl norbornene, 5-decyl norbornene, 5-cyclohexyl norbornene, and 5-cyclopentyl norbornene; norbornenes having an alkenyl group such as 5-ethylidene norbornene, 5-vinyl norbornene, 5-propenyl norbornene, 5-cyclohexenyl norbornene, and 5-cyclopentenyl norbornene; dicyclopentadiene, tricyclo[4.3.0.1 2,5 ]dec-3-ene, tricyclo[4.4.1 2,5 .0] undec-3-ene and other dicyclopentadienes; tetracyclododecene (tetracyclo[6.2.1.1 3,6 .0 2,7] dodeca-4-ene); tetracyclododecenes having an alkyl group, such as 8-methyltetracyclododecene, 8-ethyltetracyclododecene, 8-cyclohexyltetracyclododecene, and 8-cyclopentyltetracyclododecene; tetracyclododecenes having a double bond outside the ring, such as 8-methylenetetracyclododecene, 8-ethylenetetracyclododecene, 8-vinyltetracyclododecene, 8-propenyltetracyclododecene, 8-cyclohexenyltetracyclododecene, and 8-cyclopentenyltetracyclododecene; hexacycloheptacyclododecene; Carbene; 12-methyl hexacycloheptadecene, 12-ethyl hexacycloheptadecene, 12-cyclohexyl hexacycloheptadecene, 12-cyclopentyl hexacycloheptadecene and other hexacycloheptadecenes having an alkyl group; 12-methylene hexacycloheptadecene, 12-ethylene hexacycloheptadecene, 12-vinyl hexacycloheptadecene, 12-propenyl hexacycloheptadecene, 12-cyclohexenyl hexacycloheptadecene, 12-cyclopentenyl hexacycloheptadecene and other hexacycloheptadecenes having double bonds outside the ring. In addition, these can be used alone or in combination of two or more.

[0059] From the viewpoint of further improving the dielectric breakdown voltage, dicyclopentadiene and tetracyclododecene (tetracyclo[6.2.1.1 3,6 .0 2,7 ] dodeca-4-ene).

[0060] Moreover, among all the structural units (100 mol%) of the cyclic olefin ring-opening copolymer, the proportion of the structural units derived from the norbornene compound having no heteroelement hydrocarbon group needs to be 99.99 mol% or less, preferably 85.00 mol% or more, and more preferably 99.50 mol% or less. If the proportion of the structural units derived from the norbornene compound having no heteroelement hydrocarbon group is within the above range, the insulation breakdown voltage can be further improved.

[0061] Furthermore, when the structural units derived from the norbornene compound having a hydrocarbon group containing no heteroelement is 100 mol%, the proportion of the units having an aromatic ring is preferably 10 mol% or more, more preferably 25 mol% or more, preferably 90 mol% or less, more preferably 75 mol% or less. If the proportion of the units having an aromatic ring when the structural units derived from the norbornene compound having a hydrocarbon group containing no heteroelement is 100 mol% is within the above range, the dielectric breakdown voltage can be further increased.

[0062] In addition, the cyclic olefin ring-opening copolymer may arbitrarily have a ring-opening polymerization unit derived from a cyclic olefin monomer having no norbornene structure as a unit having no norbornene structure, and the ratio of the unit having no norbornene structure in all structural units (100 mol %) possessed by the cyclic olefin ring-opening copolymer is preferably 10% or less, more preferably 5% or less, and even more preferably 0%.

[0063] As a cyclic olefin monomer without a norbornene structure that can be used to introduce a unit without a norbornene structure into a cyclic olefin ring-opening copolymer, a monocyclic cyclic olefin monomer can be cited. As a monocyclic cyclic olefin, a cyclic monoolefin or a cyclic diene having a carbon number of usually 4 to 20, preferably 4 to 10 can be cited. As specific examples of cyclic monoolefins, cyclobutene, cyclopentene, methylcyclopentene, cyclohexene, methylcyclohexene, cycloheptene, cyclooctene, etc. can be cited. As specific examples of cyclic dienes, cyclohexadiene, methylcyclohexadiene, cyclooctadiene, methylcyclooctadiene, phenylcyclooctadiene, etc. can be cited. These can be used alone or in combination.

[0064] <Method for producing cyclic olefin ring-opening copolymer>

[0065] The cyclic olefin ring-opening copolymer of the present invention can be produced by using a known ring-opening polymerization method such as ring-opening polymerization using a metathesis polymerization catalyst.

[0066] Here, as a metathesis polymerization catalyst and an additive that can be used arbitrarily, there is no particular limitation, and known reagents such as ruthenium carbene complexes can be used (see, for example, Japanese Patent Publication No. 2019-104934 and Japanese Patent No. 6104263). The amount of the catalyst and additive used can be appropriately selected according to the polymerization conditions.

[0067] The polymerization reaction can be carried out by bulk polymerization, and polymerization conditions such as polymerization temperature, polymerization pressure, and polymerization time can be appropriately adjusted.

[0068] (Insulating material composition)

[0069] The insulating material composition of the present invention comprises the cyclic olefin ring-opening copolymer of the present invention described above, and optionally further contains various additives.

[0070] Furthermore, since the insulating material composition of the present invention contains a copolymer having a high dielectric breakdown voltage, it can be used particularly advantageously when forming an insulating material.

[0071] Here, the additive that can be contained in the insulating material composition is not particularly limited, and examples thereof include fillers described in Japanese Patent Application Laid-Open No. 2019-104934. In addition, the addition ratio of the additive can be appropriately adjusted according to the application as long as the effect of improving the dielectric breakdown voltage is not impaired.

[0072] (Insulation material)

[0073] The insulating material of the present invention is formed using the insulating material composition of the present invention and contains the cyclic olefin ring-opening copolymer of the present invention, and therefore can exhibit excellent performance.

[0074] Here, the molding method for obtaining the insulating material is not particularly limited, and examples thereof include RIM (Reaction Injection Molding) molding method, RTM (Resin Transfer Molding) method, casting sealing method, (solid, liquid) transfer molding method, compression molding method, printing molding method, vacuum molding method, etc. In particular, the insulating material of the present invention can be preferably manufactured by RIM molding method in which a norbornene compound having a heteroelement-containing hydrocarbon group, a norbornene compound having no heteroelement-containing hydrocarbon group, and a complex containing a metathesis polymerization catalyst are subjected to bulk ring-opening polymerization in a molding die.

[0075] Example

[0076] Next, the present invention will be described in further detail by way of examples, but the present invention is not limited to these examples.

[0077] In addition, the measurement and evaluation in each example were performed by the following method. In addition, in the following description, unless otherwise specified, "part" and "%" indicating the amount are based on mass.

[0078] (Determination of insulation breakdown voltage)

[0079] According to JIS-C2110-1 (2010), the test samples obtained in the examples and comparative examples were sandwiched between two spherical electrodes in an electronic fluoride liquid (Fluorinert) as an insulating liquid and fixed. After the voltage was increased to 10 kV, the voltage was applied to the test sample by a step-by-step voltage increase method of increasing the voltage by 1 kV each time within 10 seconds. The voltage of the test sample in the previous stage before the short circuit (Short) was recorded as the insulation breakdown voltage (Break Down Voltage) of the test sample.

[0080] Furthermore, the insulation breakdown voltage value V of each test sample recorded is i The dielectric breakdown voltage V of the test specimen obtained using the same basic monomer mixture as recorded o By comparison, we can get the improvement rate (%) = V i / V o ×100-100.

[0081] (Example 1)

[0082] <Preparation of Catalyst Liquid>

[0083] 0.6 parts of a ruthenium catalyst (Zhan 1N) represented by the following formula as a metathesis polymerization catalyst and 15 parts of 2,6-di-tert-butyl-p-cresol (BHT) as an antioxidant were dissolved in 82 parts of cyclopentanone to obtain a catalyst liquid.

[0084] [Chemical formula 4]

[0085]

[0086] In the above formula, Mes represents mesitylene.

[0087] <Molding of sample plates>

[0088] 6.43 g (about 0.04 mol) of tetracyclic [6.2.1.1] as a norbornene compound having no aromatic ring and no hetero element were weighed and 3,6 .0 2,7 ] Dodec-4-ene (hereinafter sometimes abbreviated as "TCD", molecular weight: 160.85g / mol) and 7.32g (about 0.04mol) of 1,4-methyl-1,4,4a,9a-tetrahydrofluorene (hereinafter sometimes abbreviated as "MTF", molecular weight: 182.95g / mol) as a norbornene compound having an aromatic ring and not containing heteroelements are mixed to obtain a basic monomer mixture. At room temperature, 0.41g (about 0.002mol) of a maleimide-modified norbornene monomer as a norbornene compound having a heteroelement hydrocarbon group represented by the following formula is dissolved in the basic monomer mixture to obtain a resin liquid. 0.41g of the above-prepared catalyst liquid is added to the obtained resin liquid, and the mixture is mixed by stirring to obtain a polymerizable composition.

[0089] [Chemical formula 5]

[0090]

[0091] In the above formula, R represents an isopropyl group.

[0092] As a mold, a stainless steel positive mold with a space of 100 mm wide × 100 mm long × 0.15 mm thick is prepared, and the polymerizable composition obtained above is injected into the space, and while being careful not to introduce voids, another flat and smooth stainless steel plate is covered on it, and a press molding machine is used to heat at a temperature of 80°C and a pressure of 10 MPa for 10 minutes, and then heated at 120°C and a pressure of 10 MPa for 10 minutes, thereby conducting a bulk ring-opening polymerization reaction to obtain a sample plate.

[0093] A 40 mm×40 mm slice was cut out from the obtained sample plate to prepare a test sample, and the dielectric breakdown voltage at 23° C. was measured according to the above method. The results are shown in Table 1.

[0094] (Example 2)

[0095] A sample plate was formed in the same manner as in Example 1, and the dielectric breakdown voltage was measured. The results are shown in Table 1.

[0096] (Example 3)

[0097] A sample plate was formed in the same manner as in Example 1, and the dielectric breakdown voltage was measured. The results are shown in Table 1.

[0098] (Example 4)

[0099] When preparing the basic monomer mixture, 2.78 g (about 0.02 mol) of dicyclopentadiene (hereinafter sometimes abbreviated as "DCP", molecular weight: 132.2 g / mol), which is a norbornene compound without an aromatic ring and does not contain heteroelements, and 9.65 g (about 0.06 mol) of TCD are weighed and mixed to obtain a basic monomer mixture. 0.12 g (about 0.0006 mol) of maleimide-modified norbornene monomer is added to the obtained basic monomer mixture and dissolved at room temperature. Using the obtained resin solution, a sample plate is molded in the same manner as in Example 1, and the insulation breakdown voltage is measured. The results are shown in Table 1.

[0100] (Example 5)

[0101] 0.62 g (about 0.003 mol) of maleimide-modified norbornene monomer was added to the same basic monomer mixture as in Example 4 and dissolved at room temperature. Using the obtained resin solution, a sample plate was molded in the same manner as in Example 1, and the dielectric breakdown voltage was measured. The results are shown in Table 1.

[0102] (Comparative Example 1)

[0103] The same basic monomer mixture as in Example 4 was prepared without adding maleimide-modified norbornene to prepare a resin solution containing only the basic monomer mixture. Using the obtained resin solution, a sample plate was molded in the same manner as in Example 1, and the dielectric breakdown voltage was measured. The results are shown in Table 1.

[0104] (Comparative Example 2)

[0105] When preparing the basic monomer mixture, 8.33 g (about 0.06 mol) of DCP and 3.66 g (about 0.02 mol) of MTF were mixed, and no maleimide-modified norbornene monomer was added to prepare a resin solution containing only the basic monomer mixture. Using the obtained resin solution, a sample plate was molded in the same manner as in Example 1, and the dielectric breakdown voltage was measured. The results are shown in Table 1.

[0106] (Comparative Example 3)

[0107] The same basic monomer mixture as in Example 1 was prepared without adding maleimide-modified norbornene to prepare a resin solution containing only the basic monomer mixture. Using the obtained resin solution, a sample plate was molded in the same manner as in Example 1, and the dielectric breakdown voltage was measured. The results are shown in Table 1.

[0108] (Comparative Example 4)

[0109] At room temperature, 3.36 g (about 0.016 mol) of maleimide-modified norbornene monomer was dissolved in the same basic monomer mixture as in Example 1 to obtain a resin solution. Using the obtained resin solution, a sample plate was molded in the same manner as in Example 1, and the dielectric breakdown voltage was measured. The results are shown in Table 1.

[0110] In addition, in Table 1,

[0111] "NB" represents a norbornene compound,

[0112] "TCD" means tetracyclic [6.2.1.1 3,6 .0 2,7 ] dodec-4-ene,

[0113] "MTF" stands for 1,4-methano-1,4,4a,9a-tetrahydrofluorene.

[0114] "DCP" means dicyclopentadiene,

[0115] "NBNiPr" represents an isopropyl-substituted maleimide-modified norbornene compound.

[0116] [Table 1]

[0117]

[0118] As shown in Table 1, the cyclic olefin ring-opening copolymers obtained in Examples 1 to 5 having the maleimide-modified norbornene monomer added in a predetermined range (0.01 mol % or more and 15.00 mol % or less) have improved dielectric breakdown voltages compared to copolymers obtained using the same base monomers.

[0119] Furthermore, as can be seen from Comparative Example 4 in Table 1, when the amount of the maleimide-modified norbornene monomer added is greater than 15.00 mol %, the effect of improving the breakdown voltage cannot be obtained.

[0120] Industrial Applicability

[0121] According to the present invention, a cyclic olefin ring-opening copolymer having a sufficiently high breakdown voltage can be provided.

[0122] Furthermore, according to the present invention, it is possible to provide a composition for an insulating material that can be advantageously used when forming an insulating material.

[0123] Furthermore, according to the present invention, it is possible to provide an insulating material that can exhibit excellent performance.

Claims

1. A cyclic olefin ring-opening copolymer comprising a structural unit derived from a norbornene compound having a heteroelement-containing hydrocarbon group and a structural unit derived from a norbornene compound having a heteroelement-free hydrocarbon group, The structural unit derived from the norbornene compound having a hydrocarbon group containing no heteroelement comprises a structural unit derived from a norbornene compound containing no heteroelement having an aromatic ring and a structural unit derived from a norbornene compound containing no heteroelement having no aromatic ring, The content ratio of the structural unit derived from the norbornene compound having a heteroelement-containing hydrocarbon group is 2.4 mol% to 3.6 mol% based on 100 mol% of all structural units of the cyclic olefin ring-opening copolymer.

2. The cyclic olefin ring-opening copolymer according to claim 1, wherein With all structural units of the cyclic olefin ring-opening copolymer being 100 mol %, the content ratio of the structural unit derived from the norbornene compound having a hydrocarbon group containing no heteroelement is 85.00 mol % or more and 99.99 mol % or less.

3. The cyclic olefin ring-opening copolymer according to claim 1 or 2, wherein The heteroelement-containing hydrocarbon group has a cyclic structure. 4 . A composition for an insulating material, comprising the cyclic olefin ring-opening copolymer according to claim 1 . 5 . An insulating material comprising the insulating material composition according to claim 4 .

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