Cycloolefin resin cured material

Abstract

Provided is a cycloolefin resin cured product obtained by bulk polymerization of a polymerizable composition containing a cycloolefin monomer and a metathesis polymerization catalyst, wherein the cycloolefin monomer comprises norbornene monomer (a1) and monocyclic cycloolefin (a2), and the breaking elongation of the cycloolefin resin cured product at 23℃ is 30% or greater.

Description

[Technical Field]

[0001] The present invention relates to a cured cycloolefin resin, and more particularly to a cured cycloolefin resin having excellent crack resistance, stretchability, and high-temperature durability. [Background technology]

[0002] Cycloolefin resins are known to have excellent mechanical strength, heat resistance, low moisture absorption, dielectric properties, and the like, and are used in a variety of applications.

[0003] For example, Patent Document 1 considers using such cycloolefin resins for sealing semiconductor elements. The technology of Patent Document 1 utilizes the properties of cycloolefin resins, specifically, the low viscosity of the monomer liquid, which allows for a high degree of freedom in molding, and allows for application and curing in a short period of time, to use the cycloolefin resin for sealing semiconductor elements.

[0004] On the other hand, it has been confirmed that molded products with complex structures or molded products combined with fillers or metal components can develop cracks and breakage due to the concentration of internal stress even at low or high temperature, or even at room temperature.In complex moldings that utilize high functionality and low viscosity through combination with other materials, there is a demand for resin materials that have excellent durability at room temperature, temperature cycle reliability in low and high temperature environments, and durability for long-term use. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-48295 Summary of the Invention [Problem to be solved by the invention]

[0006] The present inventors have investigated the use of cycloolefin-based resins as resin materials that take advantage of the properties of cycloolefin-based resins, namely, that the monomer liquid has a low viscosity, allowing for a high degree of freedom in molding, and that it can be applied and cured in a short period of time. However, they have found that the cured products obtained using cycloolefin-based resins tend to crack during molding or under the environment in which they are used, resulting in poor reliability and durability. This problem is more pronounced when a filler is contained in the cycloolefin-based resin. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a cycloolefin resin cured product that is excellent in crack resistance, stretchability, and high-temperature durability, and a polymerizable composition that is suitably used for forming the cured product. [Means for solving the problem]

[0007] The present inventors have conducted studies to achieve the above object, and have found that the above object can be achieved by using a norbornene-based monomer (a1) and a monocyclic cycloolefin (a2) as cycloolefin monomers for forming a cured cycloolefin resin, and by setting the breaking elongation of the cured cycloolefin resin at room temperature to 30% or more, thereby completing the present invention.

[0008] That is, according to the present invention, there is provided a cured cycloolefin resin obtained by bulk polymerization of a polymerizable composition containing a cycloolefin monomer and a metathesis polymerization catalyst, the cycloolefin monomer contains a norbornene-based monomer (a1) and a monocyclic cycloolefin (a2), A cured cycloolefin resin having a breaking elongation at 23°C of 30% or more is provided.

[0009] In the cycloolefin resin cured product of the present invention, the content of the monocyclic cycloolefin (a2) in the cycloolefin monomer is preferably 30 to 99 mass %. In the cycloolefin resin cured product of the present invention, the monocyclic cycloolefin (a2) is preferably 1,5-cyclooctadiene, cyclooctene, cyclohexene, 1,4-cyclohexadiene, or 1,4-p-menthadiene. In the cycloolefin resin cured product of the present invention, the polymerizable composition preferably contains a filler. According to the present invention, there is also provided a polymerizable composition comprising a cycloolefin monomer and a metathesis polymerization catalyst, The cycloolefin monomer contains a norbornene-based monomer (a1) and a monocyclic cycloolefin (a2). A polymerizable composition for forming a cured product of the cycloolefin resin is provided. The polymerizable composition of the present invention preferably comprises two or more pre-blended liquids that do not undergo a polymerization reaction by themselves, and the polymerizable composition can be formed by combining the pre-blended liquids. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a cured cycloolefin resin product that is excellent in crack resistance, stretchability, and high-temperature durability. DETAILED DESCRIPTION OF THE INVENTION

[0011] The cured cycloolefin resin of the present invention is a cured cycloolefin resin obtained by bulk polymerization of a polymerizable composition containing a cycloolefin monomer and a metathesis polymerization catalyst, wherein the cycloolefin monomer contains a norbornene monomer (a1) and a monocyclic cycloolefin (a2), and the cured cycloolefin resin has an elongation at break of 30% or more at 23°C.

[0012] <Polymerizable composition> First, the polymerizable composition used to produce the cured cycloolefin resin of the present invention will be described. The polymerizable composition used to produce the cured cycloolefin resin of the present invention contains a cycloolefin monomer and a metathesis polymerization catalyst.

[0013] A cycloolefin monomer is a compound that has a ring structure formed by carbon atoms and has a carbon-carbon double bond in the ring. In the present invention, at least a norbornene-based monomer (a1) and a monocyclic cycloolefin (a2) are used as the cycloolefin monomer.

[0014] The norbornene-based monomer (a1) may be any compound having a norbornene ring structure, and is not particularly limited thereto. Examples include bicyclic compounds such as norbornene, norbornadiene, and vinylnorbornene; tricyclic compounds such as dicyclopentadiene and dihydrodicyclopentadiene; tetracyclic compounds such as tetracyclododecene and ethylidenetetracyclododecene; pentacyclic compounds such as tricyclopentadiene; heptacyclic compounds such as tetracyclopentadiene; and derivatives thereof having alkenyl groups, alkynyl groups, alkylidene groups, epoxy groups, or (meth)acrylic substitutions (e.g., ethylidene substitutions). The norbornene-based monomer (a1) may be used alone or in combination of two or more. As the norbornene-based monomer (a1), tricyclic compounds are preferred, and dicyclopentadiene is particularly preferred, from the viewpoint of further enhancing the effects of the present invention. Furthermore, from the viewpoint of further enhancing the effects of the present invention, it is also preferable to use a tricyclic compound and a pentacyclic compound in combination, and the pentacyclic compound is preferably tricyclopentadiene. When a tricyclic compound and a pentacyclic compound are used in combination, the mass ratio of the tricyclic compound to the pentacyclic compound in the norbornene-based monomer (a1) is preferably 50:50 to 98:2, more preferably 65:35 to 95:5, and even more preferably 80:20 to 93:7.

[0015] The derivative preferably has an epoxy group in order to improve the adhesion of the resulting cured product to the substrate (for example, to the semiconductor element when used as an encapsulating material for the semiconductor element). For example, 4,5-epoxytricyclo[5.2.1.0 2,6 ]deca-8-ene [also called dicyclopentadiene monoepoxide (2,3-DCPME). In this specification, it may be referred to simply as DCPME.], 4,5-epoxy-8-chlorotricyclo[5.2.1.0 2,6 ]dec-8-ene, 4,5-epoxy-8-methyltricyclo[5.2.1.0 2,6 ]dec-8-ene, 4,5-epoxy-8-trifluoromethyltricyclo[5.2.1.0 2,6 ]dec-8-ene, etc., and among these, DCPME is preferred. The content of the derivative having an epoxy group in the polymerizable composition used in the present invention is preferably 0.1 to 20 mass %, more preferably 0.5 to 10 mass %, and even more preferably 1 to 5 mass %.

[0016] The monocyclic cycloolefin (a2) is not particularly limited, and examples thereof include cyclobutene, cyclopentene, cyclohexene, cyclooctene, cyclododecene, cyclopentadiene, 1,4-cyclohexadiene, 1,5-cyclooctadiene, and derivatives thereof having alkyl, alkenyl, alkynyl, alkylidene, epoxy, or (meth)acrylic substituents (e.g., ethylidene substituents). For example, 1,4-p-menthadiene is a suitable derivative of 1,4-cyclohexadiene. From the viewpoint of further enhancing the effects of the present invention, the monocyclic cycloolefin (a2) is preferably a monocyclic cycloolefin having one or more metathesis-reactive unsaturated bonds in the molecule. Examples of such monocyclic cycloolefins include 1,5-cyclooctadiene and its derivatives. The monocyclic cycloolefin (a2) may be used alone or in combination of two or more.

[0017] The content of the monocyclic cycloolefin (a2) in the cycloolefin monomer used in the present invention is preferably 30 to 99 mass%, more preferably 30 to 80 mass%, even more preferably 30 to 60 mass%, and even more preferably 40 to 50 mass%, based on 100 mass% of the total cycloolefin monomer. By setting the content of the monocyclic cycloolefin (a2) within the above range, the cycloolefin resin cured product can be made to have better crack resistance and stretchability, and therefore, when used as an encapsulating material for semiconductor devices, etc., the temperature cycle reliability and durability can be further improved.

[0018] Furthermore, the content of the norbornene-based monomer (a1) in the cycloolefin monomer used in the present invention is preferably 1 to 70 mass%, more preferably 20 to 70 mass%, even more preferably 40 to 70 mass%, and even more preferably 50 to 60 mass%, based on 100 mass% of the total cycloolefin monomer. By setting the content of the norbornene-based monomer (a1) within the above range, the cycloolefin-based resin cured product can be made to have better crack resistance and stretchability, and therefore, when used as an encapsulating material for semiconductor devices, etc., the temperature cycle reliability and durability can be further improved.

[0019] The polymerizable composition used in the present invention may contain, in addition to the norbornene-based monomer (a1) and the monocyclic cycloolefin (a2), another cycloolefin monomer (a3).

[0020] The content of the other cycloolefin monomer (a3) ​​in the cycloolefin monomer used in the present invention is preferably 70% by mass or less, more preferably 50% by mass or less, based on 100% by mass of the total cycloolefin monomers.

[0021] The metathesis polymerization catalyst used in the present invention is not particularly limited as long as it can ring-opening polymerize a cycloolefin monomer, and known metathesis polymerization catalysts can be used.

[0022] The metathesis polymerization catalyst used in the present invention is a complex formed by bonding a plurality of ions, atoms, polyatomic ions, and / or compounds to a transition metal atom as a central atom. The transition metal atom is an atom of Groups 5, 6, and 8 (long-form periodic table, the same applies hereinafter). The atom of each group is not particularly limited, but an example of a Group 5 atom is tantalum, an example of a Group 6 atom is molybdenum or tungsten, and an example of a Group 8 atom is ruthenium or osmium. Among these transition metal atoms, ruthenium and osmium of Group 8 are preferred. That is, the metathesis polymerization catalyst used in the present invention is preferably a complex having ruthenium or osmium as a central atom, and more preferably a complex having ruthenium as a central atom. A ruthenium-carbene complex in which a carbene compound is coordinated to ruthenium is preferred as a complex having ruthenium as a central atom. Here, "carbene compound" is a general term for compounds containing a methylene free radical, and refers to a compound having an uncharged divalent carbon atom (carbene carbon) represented by (>C:). Ruthenium carbene complexes have excellent catalytic activity during bulk ring-opening polymerization, resulting in polymers with little odor from unreacted monomers, enabling high-quality polymers to be obtained with good productivity. Furthermore, they are relatively stable against oxygen and moisture in the air and are not easily deactivated, making them suitable for use in the atmosphere. Metathesis polymerization catalysts may be used alone or in combination.

[0023] Examples of the ruthenium carbene complex include those represented by the following general formula (1) or (2). [ka]

[0024] In the above general formulas (1) and (2), R 1 and R 2are each independently a hydrogen atom; a halogen atom; or an organic group having 1 to 20 carbon atoms which may contain a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, or a silicon atom; and these groups may have a substituent, and may be bonded to each other to form a ring. 1 and R 2 Examples of groups bonded to each other to form a ring include an indenylidene group which may have a substituent, such as a phenylindenylidene group.

[0025] Specific examples of the organic group having 1 to 20 carbon atoms which may contain a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom or a silicon atom include an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkenyloxy group having 2 to 20 carbon atoms, an alkynyloxy group having 2 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms, an alkyl group having 1 to 8 carbon atoms, an alkyl group having 1 to 8 carbon atoms, an alkyl group having 2 to 20 carbon atoms, an alkynyloxy group having 2 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an alkyl group having 1 to 8 carbon atoms, an alkyl group having 1 to 8 carbon atoms, an alkyl group having 2 to 20 ...2 to 20 carbon atoms, an alkyl group having 1 to 8 carbon atoms, an alkyl group having 2 to 20 carbon atoms, an alkyl group having 2 to Examples of the organic group include an alkylthio group, a carbonyloxy group, an alkoxycarbonyl group having 1 to 20 carbon atoms, an alkylsulfonyl group having 1 to 20 carbon atoms, an alkylsulfinyl group having 1 to 20 carbon atoms, an alkylsulfonic acid group having 1 to 20 carbon atoms, an arylsulfonic acid group having 6 to 20 carbon atoms, a phosphonic acid group, an arylphosphonic acid group having 6 to 20 carbon atoms, an alkylammonium group having 1 to 20 carbon atoms, and an arylammonium group having 6 to 20 carbon atoms. These organic groups having 1 to 20 carbon atoms, which may contain a halogen atom, oxygen atom, nitrogen atom, sulfur atom, phosphorus atom, or silicon atom, may have a substituent. Examples of the substituent include an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and an aryl group having 6 to 10 carbon atoms.

[0026] X 1 and X 2 each independently represents an anionic ligand. The anionic ligand is a ligand that has a negative charge when separated from the central metal atom, and examples thereof include a halogen atom, a diketonate group, a substituted cyclopentadienyl group, an alkoxyl group, an aryloxy group, and a carboxyl group.

[0027] L 1 and L 2 represents a heteroatom-containing carbene compound or a neutral electron donor compound other than a heteroatom-containing carbene compound. Heteroatom-containing carbene compounds and neutral electron donor compounds other than a heteroatom-containing carbene compound are compounds that have a neutral charge when separated from a central metal. From the viewpoint of improving catalytic activity, heteroatom-containing carbene compounds are preferred. The heteroatom refers to an atom of Groups 15 and 16 of the periodic table, and specific examples include a nitrogen atom, an oxygen atom, a phosphorus atom, a sulfur atom, an arsenic atom, and a selenium atom. Among these, from the viewpoint of obtaining a stable carbene compound, a nitrogen atom, an oxygen atom, a phosphorus atom, and a sulfur atom are preferred, and a nitrogen atom is more preferred.

[0028] The heteroatom-containing carbene compound is preferably a compound represented by the following general formula (3) or (4), and from the viewpoint of improving catalytic activity, a compound represented by the following general formula (3) is more preferred. [ka]

[0029] In the above general formulas (3) and (4), R 3 , R 4 , R 5 and R 6 each independently represents a hydrogen atom, a halogen atom, or an organic group having 1 to 20 carbon atoms which may contain a halogen atom, oxygen atom, nitrogen atom, sulfur atom, phosphorus atom, or silicon atom. Specific examples of the organic group having 1 to 20 carbon atoms which may contain a halogen atom, oxygen atom, nitrogen atom, sulfur atom, phosphorus atom, or silicon atom are the same as those in the general formulae (1) and (2) above. Also, R 3 , R 4 , R 5 and R 6 may be bonded to each other in any combination to form a ring.

[0030] In addition, since the effect of the present invention becomes more remarkable, R 5 and R 6 is preferably a hydrogen atom. 3 and R 4 is preferably an aryl group which may have a substituent, more preferably a phenyl group having an alkyl group of 1 to 10 carbon atoms as a substituent, and even more preferably a mesityl group.

[0031] Examples of the neutral electron donor compound include oxygen atoms, water, carbonyls, ethers, nitriles, esters, phosphines, phosphinites, phosphites, sulfoxides, thioethers, amides, imines, aromatic compounds, cyclic diolefins, olefins, isocyanides, and thiocyanates.

[0032] In the above general formulas (1) and (2), R 1 , R 2 , X 1 , X 2 , L 1 and L 2 may be linked together in any combination to form a multidentate chelating ligand.

[0033] Furthermore, as the ruthenium carbene complex used in the present invention, among the compounds represented by the above general formula (1) or (2), the compound represented by the above general formula (1) is preferred because the effects of the present invention are more pronounced, and among these, the compound represented by the following general formula (5) or general formula (6) is more preferred.

[0034] General formula (5) is shown below. [ka]

[0035] In the general formula (5), Z is an oxygen atom, a sulfur atom, a selenium atom, or NR 12 , PR 12 or AsR 12 and R 12represents a hydrogen atom; a halogen atom; or an organic group having 1 to 20 carbon atoms which may contain a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, or a silicon atom; however, an oxygen atom is preferred as Z, as this makes the effects of the present invention more pronounced.

[0036] In addition, R 1 , R 2 , X 1 and L 1 are the same as those in the above general formulas (1) and (2), and may be bonded to each other alone or in any combination to form a multidentate chelating ligand, but X 1 and L 1 does not form a multidentate chelating ligand, and R 1 and R 2 are preferably bonded to each other to form a ring, are more preferably an indenylidene group which may have a substituent, and are further preferably a phenylindenylidene group. Specific examples of the organic group having 1 to 20 carbon atoms which may contain a halogen atom, oxygen atom, nitrogen atom, sulfur atom, phosphorus atom or silicon atom are the same as those in the general formulae (1) and (2) above.

[0037] In the above general formula (5), R 7 and R 8 are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or a heteroaryl group having 6 to 20 carbon atoms, and these groups may have a substituent or may be bonded to each other to form a ring. Examples of the substituent include an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms. When a ring is formed, the ring may be an aromatic ring, an alicyclic ring, or a heterocyclic ring, but preferably an aromatic ring, more preferably an aromatic ring having 6 to 20 carbon atoms, and even more preferably an aromatic ring having 6 to 10 carbon atoms.

[0038] In the above general formula (5), R 9 , R 10 and R 11are each independently a hydrogen atom, a halogen atom, or an organic group having 1 to 20 carbon atoms which may contain a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, or a silicon atom, and these groups may have a substituent or may be bonded to each other to form a ring. Specific examples of the organic group having 1 to 20 carbon atoms which may contain a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, or a silicon atom are the same as those in the general formulas (1) and (2) above.

[0039] R 9 , R 10 and R 11 is preferably a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

[0040] Specific examples of the compound represented by the general formula (5) and the method for producing the same include those described in International Publication No. 03 / 062253 (JP 2005-515260).

[0041] General formula (6) is shown below. [ka]

[0042] In the above general formula (6), m is 0 or 1. m is preferably 1, in which case Q is an oxygen atom, a nitrogen atom, a sulfur atom, a methylene group, an ethylene group or a carbonyl group, and preferably a methylene group.

[0043] In the above general formula (6), [ka] is a single bond or a double bond, preferably a single bond.

[0044] R 1 , X 1 , X 2 and L 1are the same as those in the above general formulas (1) and (2), and may be bonded to each other alone or in any combination to form a multidentate chelating ligand, but X 1 , X 2 and L 1 does not form a multidentate chelating ligand, and R 1 is preferably a hydrogen atom.

[0045] R 13 ~R 21 is a hydrogen atom, a halogen atom, or an organic group having 1 to 20 carbon atoms which may contain a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, or a silicon atom; these groups may have a substituent and may be bonded to each other to form a ring. Specific examples of the organic group having 1 to 20 carbon atoms which may contain a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, or a silicon atom are the same as those in the above general formulas (1) and (2).

[0046] R 13 is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and R 14 ~R 17 is preferably a hydrogen atom, and R 18 ~R 21 is preferably a hydrogen atom or a halogen atom.

[0047] Specific examples of the compound represented by the general formula (6) and the method for producing the same include those described in International Publication No. 2011 / 079799 (JP 2013-516392 A).

[0048] The content of the metathesis polymerization catalyst is preferably 0.005 mmol or more, more preferably 0.01 to 50 mmol, and even more preferably 0.015 to 20 mmol, per mole of all cycloolefin monomers used in the reaction.

[0049] Furthermore, the polymerizable composition used in the present invention may contain a radical generator, a diisocyanate compound, a polyfunctional (meth)acrylate compound, and other optional components, if necessary.

[0050] The radical generator generates radicals when heated, which induces a crosslinking reaction in the cycloolefin polymer formed by bulk polymerization. The sites where the radical generator induces the crosslinking reaction are mainly the carbon-carbon double bonds of the cycloolefin monomer, but crosslinking can also occur at saturated bonds.

[0051] The radical generator includes organic peroxides, diazo compounds and non-polar radical generators. Examples of organic peroxides include hydroperoxides such as t-butyl hydroperoxide, p-menthane hydroperoxide, and cumene hydroperoxide; dialkyl peroxides such as di-t-butyl peroxide, dicumyl peroxide, and t-butylcumyl peroxide; diacyl peroxides such as dipropionyl peroxide and benzoyl peroxide; peroxyketals such as 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexyne, and 1,3-di(t-butylperoxyisopropyl)benzene; peroxyesters such as t-butylperoxyacetate and t-butylperoxybenzoate; peroxycarbonates such as t-butylperoxyisopropylcarbonate and di(isopropylperoxy)dicarbonate; and alkylsilyl peroxamides such as t-butyltrimethylsilyl peroxide. Among these, dialkyl peroxides are preferred because they cause less interference with the metathesis polymerization reaction in bulk polymerization.

[0052] Examples of diazo compounds include 4,4'-bisazidobenzal(4-methyl)cyclohexanone, 4,4'-diazidochalcone, 2,6-bis(4'-azidobenzal)cyclohexanone, 2,6-bis(4'-azidobenzal)-4-methylcyclohexanone, 4,4'-diazidodiphenylsulfone, 4,4'-diazidodiphenylmethane, and 2,2'-diazidostilbene.

[0053] Examples of non-polar radical generators include 2,3-dimethyl-2,3-diphenylbutane, 2,3-diphenylbutane, 1,4-diphenylbutane, 3,4-dimethyl-3,4-diphenylhexane, 1,1,2,2-tetraphenylethane, 2,2,3,3-tetraphenylbutane, 3,3,4,4-tetraphenylhexane, 1,1,2-triphenylpropane, 1,1,2-triphenylethane, triphenylmethane, 1,1,1-triphenylethane, 1,1,1-triphenylpropane, 1,1,1-triphenylbutane, 1,1,1-triphenylpentane, 1,1,1-triphenyl-2-propene, 1,1,1-triphenyl-4-pentene, and 1,1,1-triphenyl-2-phenylethane.

[0054] The amount of the radical generator in the polymerizable composition used in the present invention is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, based on 100 parts by mass of all cycloolefin monomers used.

[0055] Examples of diisocyanate compounds include 4,4'-methylenediphenyl diisocyanate (MDI), toluene-2,4-diisocyanate, 4-methoxy-1,3-phenylene diisocyanate, 4-isopropyl-1,3-phenylene diisocyanate, 4-chloro-1,3-phenylene diisocyanate, 4-butoxy-1,3-phenylene diisocyanate, 2,4-diisocyanate diphenyl ether, 1,4-phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate (XDI), 1,5-naphthalene diisocyanate, benzidine diisocyanate, o-nitrobenzidine diisocyanate, and 4,4'-diisocyanate dibenzidine. Examples of suitable diisocyanate compounds include aromatic diisocyanate compounds such as benzoyl; aliphatic diisocyanate compounds such as methylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, and 1,10-decamethylene diisocyanate; alicyclic diisocyanate compounds such as 4-cyclohexylene diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), 1,5-tetrahydronaphthalene diisocyanate, isophorone diisocyanate, hydrogenated MDI, and hydrogenated XDI; and polyurethane prepolymers obtained by reacting these diisocyanate compounds with low-molecular-weight polyols or polyamines to form isocyanate groups at the terminals. Furthermore, conventionally known compounds having polyfunctional isocyanate groups, such as isocyanurates, biurets, adducts, or polymers, can be used without particular limitation. Examples of such compounds include a dimer of 2,4-toluylene diisocyanate, triphenylmethane triisocyanate, tris-(p-isocyanatophenyl)thiophosphite, polyfunctional aromatic isocyanate compounds, polyfunctional aromatic aliphatic isocyanate compounds, polyfunctional aliphatic isocyanate compounds, fatty acid-modified polyfunctional aliphatic isocyanate compounds, polyfunctional blocked isocyanate compounds such as blocked polyfunctional aliphatic isocyanate compounds, and polyisocyanate prepolymers.Among these, polyfunctional unblocked isocyanate compounds, such as aromatic diisocyanate compounds, aliphatic diisocyanate compounds, and alicyclic diisocyanate compounds, are preferably used because of their easy availability and ease of handling. These compounds can be used either alone or in combination of two or more.

[0056] A polyfunctional blocked isocyanate compound is one in which at least two isocyanate groups in the molecule are reacted with an active hydrogen-containing compound, rendering the compound inactive at room temperature. The isocyanate compound generally has a structure in which the isocyanate groups are masked with a blocking agent such as alcohols, phenols, ε-caprolactam, oximes, and active methylene compounds. Polyfunctional blocked isocyanate compounds generally do not react at room temperature, and therefore have excellent storage stability. However, heating at temperatures typically between 140 and 200°C regenerates the isocyanate groups, enabling them to exhibit excellent reactivity.

[0057] When a diisocyanate compound is used in combination with a polyfunctional (meth)acrylate compound, the active hydrogen reactive group in the molecule forms a chemical bond with a hydroxyl group present in the polyfunctional (meth)acrylate compound, and as a result, it is thought to play a role in improving the adhesion between the cycloolefin monomer and the substrate (for example, the semiconductor element when used as an encapsulating material for a semiconductor element).

[0058] The diisocyanate compounds may be used alone or in combination of two or more. The amount of the diisocyanate compound in the polymerizable composition used in the present invention is preferably 0.5 to 20 parts by mass, more preferably 1 to 15 parts by mass, and even more preferably 2 to 10 parts by mass, relative to 100 parts by mass of all cycloolefin monomers. This range is preferable because it can improve the strength and heat resistance of the resulting cycloolefin-based resin cured product while also improving the adhesion of the cycloolefin-based resin cured product.

[0059] A polyfunctional (meth)acrylate compound may be used to further enhance adhesion to a substrate (for example, a semiconductor element when used as an encapsulating material for a semiconductor element). It is presumed that the use of such a compound together with a diisocyanate compound synergistically enhances the function of the diisocyanate compound as an adhesion improver or adhesion imparter. Preferred examples of the polyfunctional (meth)acrylate compound include ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and neopentyl glycol dimethacrylate.

[0060] The polyfunctional (meth)acrylate compounds may be used alone or in combination of two or more. The amount of the polyfunctional (meth)acrylate compound is preferably 0.5 to 20 parts by mass, more preferably 1 to 15 parts by mass, and even more preferably 2 to 10 parts by mass, relative to 100 parts by mass of all cycloolefin monomers used. This range is preferable because it synergistically enhances the function of the diisocyanate compound as an adhesion improver or adhesion imparter, thereby further improving the adhesion of the cycloolefin resin cured product.

[0061] Other optional ingredients include activators, activity regulators, elastomers, antioxidants, and the like.

[0062] The activator is a compound that acts as a cocatalyst for the metathesis polymerization catalyst described above and improves the polymerization activity of the catalyst. Examples of activators that can be used include alkylaluminum halides such as ethylaluminum dichloride and diethylaluminum chloride; alkoxyalkylaluminum halides in which some of the alkyl groups in these alkylaluminum halides are substituted with alkoxy groups; and organotin compounds. The amount of activator used is not particularly limited, but is preferably 0.1 to 100 mol, more preferably 1 to 10 mol, per mol of the total metathesis polymerization catalysts used in the polymerizable composition.

[0063] The activity regulator is used to prevent polymerization from starting during the injection process when a polymerizable composition is prepared by mixing two or more reaction stock solutions as described below and then injected into a mold to initiate polymerization.

[0064] When a compound of a transition metal of Group 5 or 6 of the periodic table is used as the metathesis polymerization catalyst, examples of the activity modifier include compounds that have the effect of reducing the metathesis polymerization catalyst, such as alcohols, haloalcohols, esters, ethers, nitriles, etc. Among these, alcohols and haloalcohols are preferred, and haloalcohols are more preferred.

[0065] Specific examples of alcohols include n-propanol, n-butanol, n-hexanol, 2-butanol, isobutyl alcohol, isopropyl alcohol, t-butyl alcohol, etc. Specific examples of haloalcohols include 1,3-dichloro-2-propanol, 2-chloroethanol, 1-chlorobutanol, etc.

[0066] Examples of activity regulators, particularly when using a ruthenium carbene complex as a metathesis polymerization catalyst, include Lewis base compounds. Examples of Lewis base compounds include phosphorus-containing Lewis base compounds such as tricyclopentylphosphine, tricyclohexylphosphine, triphenylphosphine, triphenylphosphite, and n-butylphosphine; and nitrogen-containing Lewis base compounds such as n-butylamine, pyridine, 4-vinylpyridine, acetonitrile, ethylenediamine, N-benzylidenemethylamine, pyrazine, piperidine, and imidazole. Furthermore, norbornenes substituted with alkenyl groups, such as vinylnorbornene, propenylnorbornene, and isopropenylnorbornene, function not only as cycloolefin monomers but also as activity regulators. The amount of these activity regulators used can be adjusted appropriately depending on the compound used.

[0067] Examples of elastomers include natural rubber, polybutadiene, polyisoprene, styrene-butadiene copolymer (SBR), styrene-butadiene-styrene copolymer (SBS), styrene-isoprene-styrene copolymer (SIS), ethylene-propylene-diene terpolymer (EPDM), ethylene-vinyl acetate copolymer (EVA), and hydrogenated versions of these. Dissolving an elastomer in the polymerizable composition allows for adjustment of its viscosity. Adding an elastomer also improves the impact resistance of the resulting composite molded article. The amount of elastomer used is preferably 0.5 to 20 parts by mass, more preferably 2 to 10 parts by mass, per 100 parts by mass of all cycloolefin monomers in the polymerizable composition.

[0068] Antioxidants include various types of antioxidants for plastics and rubber, such as phenolic, phosphorus, and amine antioxidants.

[0069] The polymerizable composition used in the present invention may contain a filler as an optional component. Various fillers can be used as the filler, and although there are no particular limitations, it is preferable to use a particulate inorganic filler.

[0070] The particulate inorganic filler preferably has an aspect ratio of 1 to 2, more preferably 1 to 1.5. The 50% cumulative volume diameter of the particulate inorganic filler is preferably 0.1 to 50 μm, more preferably 1 to 30 μm, and particularly preferably 1 to 10 μm. Here, the aspect ratio refers to the ratio of the average major axis diameter of the filler to the 50% cumulative volume diameter. The average major axis diameter is the number-average major axis diameter calculated as the arithmetic mean value of the major axis diameters of 100 fillers randomly selected from an optical microscope photograph. The 50% cumulative volume diameter is a value determined by measuring the particle size distribution using an X-ray transmission method.

[0071] Specific examples of particulate inorganic fillers include calcium carbonate, calcium hydroxide, calcium silicate, calcium sulfate, aluminum hydroxide, magnesium hydroxide, titanium oxide, zinc oxide, barium titanate, silica, alumina, carbon black, graphite, antimony oxide, red phosphorus, various metal powders, clay, various ferrites, hydrotalcite, etc. Among these, magnesium hydroxide, aluminum hydroxide, silica, and alumina are preferred, and aluminum hydroxide and silica are particularly preferred.

[0072] The particulate inorganic filler may have its surface hydrophobized. The use of a hydrophobized particulate inorganic filler can prevent aggregation and sedimentation of the particulate inorganic filler in the polymerizable composition and can ensure uniform dispersion of the particulate inorganic filler in the resulting cured cycloolefin resin. Consequently, the elasticity of the cured cycloolefin resin can be improved. Examples of treating agents used for the hydrophobization include silane coupling agents such as vinyl silane, titanate coupling agents, aluminum coupling agents, fatty acids such as stearic acid, oils and fats, surfactants, waxes, etc.

[0073] The treating agent is preferably a silane coupling agent having at least one hydrocarbon group with a norbornene structure, because even when a filler is blended into the polymerizable composition, the viscosity is low, thixotropy (viscosity at rest) is not likely to increase, and adhesion to the substrate (for example, the semiconductor element when used as an encapsulating material for a semiconductor element) can be improved. While the silane coupling agent can also function as a monomer, it is treated as a silane coupling agent in the present invention. Specific examples of such silane coupling agents include bicycloheptenylethyltrimethoxysilane, bicycloheptenylethyltriethoxysilane, bicycloheptenylhexyltrimethoxysilane, and bicycloheptenylhexyltriethoxysilane, with bicycloheptenylethyltriethoxysilane and bicycloheptenylhexyltrimethoxysilane being preferred. The content of the silane coupling agent having at least one hydrocarbon group with a norbornene structure in the polymerizable composition used in the present invention is preferably 0.1 to 5 mass %, more preferably 0.3 to 2 mass %, and even more preferably 0.5 to 1 mass %.

[0074] The amount of the particulate inorganic filler blended in the polymerizable composition used in the present invention is preferably 10 to 1000 parts by mass, more preferably 100 to 500 parts by mass, per 100 parts by mass of the cycloolefin monomer.

[0075] Furthermore, the polymerizable composition used in the present invention may contain a fibrous inorganic filler in addition to the particulate inorganic filler. The fibrous inorganic filler preferably has an aspect ratio of 5 to 100, more preferably 10 to 50. The 50% cumulative volume diameter of the fibrous inorganic filler is preferably 0.1 to 50 μm, more preferably 1 to 30 μm.

[0076] Specific examples of fibrous inorganic fillers include glass fiber, wollastonite, potassium titanate, zonolite, basic magnesium sulfate, aluminum borate, tetrapod-type zinc oxide, gypsum fiber, phosphate fiber, alumina fiber, whisker-like calcium carbonate, and whisker-like boehmite. Among these, wollastonite and whisker-like calcium carbonate are preferred. Furthermore, the fibrous inorganic filler may have its surface hydrophobized, similar to the particulate inorganic filler described above.

[0077] The polymerizable composition used in the present invention is prepared by appropriately mixing the above-mentioned components according to a known method. The polymerizable composition used in the present invention may also be prepared by preparing two or more premixed liquids and mixing the two or more premixed liquids using a mixing device or the like immediately before forming a cycloolefin resin cured product. Although one premixed liquid alone will not undergo bulk polymerization, the above-mentioned components are prepared by dividing them into two or more liquids so that mixing all the liquids will result in a polymerizable composition containing each component in a predetermined ratio. Such combinations of two or more reaction stock liquids include the following two types (a) and (b), depending on the type of metathesis polymerization catalyst used.

[0078] (a): The metathesis polymerization catalyst may be one that does not have polymerization activity by itself but exhibits polymerization activity when used in combination with an activator. In this case, a premixed liquid (Liquid A) containing a cycloolefin monomer and an activator and a premixed liquid (Liquid B) containing a cycloolefin monomer and a metathesis polymerization catalyst are used and mixed to obtain a polymerizable composition. Furthermore, a premixed liquid (Liquid C) containing a cycloolefin monomer but not a metathesis polymerization catalyst or an activator may also be used in combination.

[0079] (b): When a metathesis polymerization catalyst having polymerization activity by itself is used, a polymerizable composition can be obtained by mixing a premix (i) containing a cycloolefin monomer with a premix (ii) containing a metathesis polymerization catalyst. In this case, the premix (ii) is typically prepared by dissolving or dispersing the metathesis polymerization catalyst in a small amount of an inert solvent. Examples of such solvents include aromatic hydrocarbons such as toluene, xylene, ethylbenzene, and trimethylbenzene; ketones such as methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, and 4-hydroxy-4-methyl-2-pentanone; cyclic ethers such as tetrahydrofuran; diethyl ether, dichloromethane, dimethyl sulfoxide, and ethyl acetate. Among these, aromatic hydrocarbons are preferred, and toluene is more preferred.

[0080] Optional components such as a radical generator, a diisocyanate compound, and a polyfunctional (meth)acrylate compound may be contained in any of the pre-mixed liquids, or may be added in the form of a mixed liquid other than the pre-mixed liquid.

[0081] Examples of the mixing device used for mixing the pre-mixed liquid include an impingement mixer that is generally used in reaction injection molding, as well as low-pressure mixers such as a dynamic mixer and a static mixer.

[0082] <Cured cycloolefin resin> The cured cycloolefin resin of the present invention is obtained by bulk polymerization of the polymerizable composition described above, and has an elongation at break at 23° C. of 30% or more.

[0083] Examples of methods for producing the cycloolefin-based resin cured product of the present invention include a method in which the two or more pre-blended liquids described above are separately introduced into an impingement mixer, instantaneously mixed using a mixing head, and then bulk polymerized in a mold or on a substrate.

[0084] For example, when the cured cycloolefin resin of the present invention is used as an encapsulating material for encapsulating semiconductor elements such as power semiconductor elements, the above-mentioned two or more pre-blended liquids are introduced separately into an impingement mixer and instantaneously mixed with a mixing head, and the mixed liquid is supplied from the mixing head so as to cover the surface of the semiconductor element, thereby obtaining a semiconductor device in which the semiconductor element is encapsulated with the cured cycloolefin resin of the present invention.

[0085] Furthermore, the cured cycloolefin resin of the present invention has an elongation at break at 23°C of 30% or more, more preferably 50% or more, and even more preferably 100% or more. The upper limit of the elongation at break is not particularly limited, but is, for example, 1000% or less. The elongation at break of the cured cycloolefin resin can be measured by forming the cured cycloolefin resin into an A1 dumbbell shape conforming to JIS K7161, conducting a tensile test on the dumbbell-shaped test piece conforming to JIS K7161 under the following conditions: chuck distance: 110 mm, tensile speed: 50 mm / s, gauge length: 75 mm, and temperature: 23°C, and measuring the elongation at break.

[0086] The cycloolefin resin cured product of the present invention may have a breaking elongation at 23°C within the above range, but the breaking elongation at -25°C is preferably 7% or more, more preferably 30% or more, even more preferably 50% or more, and even more preferably 100% or more. The upper limit of the breaking elongation at -25°C is not particularly limited, but is, for example, 1000% or less. The breaking elongation at -25°C can be measured in the same manner as the breaking elongation at 23°C described above, except that the temperature condition is -25°C. Furthermore, the cured cycloolefin resin of the present invention preferably has a breaking elongation at 23°C after storage at 155°C for 1000 hours of 7% or more, more preferably 20% or more, even more preferably 28% or more, and even more preferably 50% or more, with no particular upper limit, for example, being 500% or less. The breaking elongation at 23°C after storage at 155°C for 1000 hours can be measured by storing the cured cycloolefin resin at 155°C for 1000 hours and then measuring the breaking elongation at 23°C by the method described above.

[0087] According to the present invention, by using a combination of the norbornene-based monomer (a1) and the monocyclic cycloolefin (a2) as the cycloolefin monomer and setting the breaking elongation at 23°C within the above range, it is possible to obtain a cured cycloolefin resin having sufficient crack resistance and excellent elasticity and high-temperature durability. As a result, when the cured cycloolefin resin of the present invention is used for electrical sealing, particularly as a sealing material for resin-sealed semiconductor devices, the semiconductor device obtained using the cured cycloolefin resin of the present invention can have excellent temperature cycle reliability and durability. In particular, since the semiconductor device obtained using the cured cycloolefin resin of the present invention as a sealing material has excellent temperature cycle reliability and durability, it can achieve sufficient reliability and durability even in an environment where a power semiconductor element (e.g., a power semiconductor element using a wide bandgap material such as SiC, GaN, Ga2O3, or diamond) is used. Therefore, it is particularly suitable as a semiconductor device equipped with a power semiconductor element. The cycloolefin-based resin cured product of the present invention is obtained using a cycloolefin monomer, and therefore has the properties of a cycloolefin-based resin, namely, a high degree of freedom in molding due to the low viscosity of the monomer liquid, and also has the properties of being able to be applied and cured in a short time.

[0088] Furthermore, because the cured cycloolefin resin of the present invention has excellent crack resistance, elasticity, and high-temperature durability, it can be used as an encapsulating material for resin-encapsulated semiconductor devices. It can also be used in metal composite molding applications, more specifically, for coating components having metal parts on their surfaces that are installed in environments with large temperature changes, such as coating applications for pipeline field joints (applications for coating welded fastening portions of pipeline field joints). In particular, for applications in coating pipeline field joints, where rapid curing is desired, the properties of cycloolefin resins, i.e., their ability to be applied and cured in a short period of time, can be fully utilized, making them suitable. Furthermore, in addition to these applications, the cured cycloolefin resin of the present invention, taking advantage of its excellent crack resistance, elasticity, and high-temperature durability, can also be used favorably for automotive applications such as bumpers and air deflectors, construction and industrial machinery applications such as wheel loaders and power shovels, leisure applications such as golf carts and game consoles, medical applications such as medical equipment, industrial applications such as large panels and chairs, and home appliance applications such as shower pans and washbasins. [Example]

[0089] The present invention will be described below based on examples, but the present invention is not limited to these examples. Note that "parts" and "%" are by mass unless otherwise specified. Tests and evaluations were conducted according to the following procedures.

[0090] <Elongation at break (room temperature)> Dumbbell-shaped test pieces were prepared by punching out the cured cycloolefin resin into an A1 dumbbell shape conforming to JIS K 7161. The resulting dumbbell-shaped test pieces were then subjected to a tensile test conforming to JIS K 7161 under the following conditions: chuck distance: 110 mm, tensile speed: 50 mm / s, gauge length: 75 mm, and temperature: 23°C. The elongation at break was measured, thereby determining the elongation at break at room temperature.

[0091] <Elongation at break (-25℃)> Dumbbell-shaped test pieces were prepared by punching out the cured cycloolefin resin into an A1 dumbbell shape conforming to JIS K 7161. The resulting dumbbell-shaped test pieces were then subjected to a tensile test conforming to JIS K 7161 under the following conditions: chuck distance: 110 mm, tensile speed: 50 mm / s, gauge length: 75 mm, and temperature: -25°C. The elongation at break was measured, thereby determining the elongation at break at -25°C.

[0092] <High temperature durability> A plurality of dumbbell-shaped test pieces were prepared by punching out the cured cycloolefin resin into an A1 dumbbell shape conforming to JIS K 7161. The prepared dumbbell-shaped test pieces were then stored at 125°C for 1000 hours, 155°C for 1000 hours, and 175°C for 1000 hours, respectively, and the elongation at break of each test piece after storage was measured under the same conditions as those for "elongation at break (room temperature)" described above.

[0093] Example 1 A preliminary blend solution (i) was obtained by mixing 70 parts of RIM monomer (manufactured by Zeon Corporation) and 30 parts of 1,5-cyclooctadiene. The RIM monomer contained 90 parts of dicyclopentadiene and 10 parts of tricyclopentadiene as norbornene-based monomers.

[0094] A preliminary blend solution (ii) was obtained by dissolving 0.3 parts of a ruthenium catalyst (Zhan1N) represented by formula (7) as a metathesis polymerization catalyst, 30 parts of 2,6-di-t-butyl-p-cresol (BHT, antioxidant), and 30 parts of triphenylphosphine in 39.7 parts of cyclopentanone. [ka] (In the formula, Mes represents a mesityl group.)

[0095] The mold used was a flat-plate reaction injection mold consisting of two stainless steel plates with an internal space measuring 245 mm long x 210 mm wide x 4 mm thick. This reaction injection mold had a structure in which one of the stainless steel plates had a reaction liquid injection hole at the bottom.

[0096] The pre-mixed liquid (i) and pre-mixed liquid (ii) prepared above were mixed in a ratio of (i):(ii) = 100:3.5 (mass ratio), degassed in a vacuum, and then injected into a reaction injection mold through the reaction liquid injection port. The mixture was heated in an oven preheated to 40°C for 30 minutes, and then heated at 175°C for 60 minutes to obtain a polymerized and cured cycloolefin resin. The resulting cured cycloolefin resin was then measured and evaluated for elongation at break (room temperature and -25°C) and high-temperature durability. The results are shown in Table 1.

[0097] <Example 2> A cured cycloolefin resin was obtained and evaluated in the same manner as in Example 1, except that the amount of RIM monomer and the amount of 1,5-cyclooctadiene were changed to 60 parts and 40 parts, respectively, when preparing pre-blended liquid (i). The results are shown in Table 1.

[0098] Example 3 A cured cycloolefin resin was obtained and evaluated in the same manner as in Example 1, except that the amount of RIM monomer and the amount of 1,5-cyclooctadiene were changed to 50 parts and 50 parts, respectively, when preparing pre-blended liquid (i). The results are shown in Table 1.

[0099] Example 4 A cured cycloolefin resin was obtained and evaluated in the same manner as in Example 1, except that the amount of RIM monomer and the amount of 1,5-cyclooctadiene were changed to 30 parts and 70 parts, respectively, when preparing pre-blended liquid (i). The results are shown in Table 1.

[0100] <Example 5> A cured cycloolefin resin was obtained and evaluated in the same manner as in Example 1, except that the amount of RIM monomer was changed to 10 parts and the amount of 1,5-cyclooctadiene was changed to 90 parts when preparing pre-blended liquid (i). The results are shown in Table 1.

[0101] Example 6 A cured cycloolefin resin was obtained and evaluated in the same manner as in Example 1, except that 1,5-cyclooctadiene was not added, and the amount of RIM monomer was changed to 70 parts and the amount of cyclooctene was changed to 30 parts when preparing pre-blended liquid (i). The results are shown in Table 1.

[0102] Example 7 A cured cycloolefin resin was obtained and evaluated in the same manner as in Example 1, except that 1,5-cyclooctadiene was not added, and the amount of RIM monomer was changed to 50 parts, and the amount of cyclooctene was changed to 50 parts when preparing pre-blended liquid (i). The results are shown in Table 1.

[0103] Example 8 A cured cycloolefin resin was obtained and evaluated in the same manner as in Example 1, except that 1,5-cyclooctadiene was not added, and the amount of RIM monomer was changed to 50 parts, and the amount of cyclohexene was changed to 50 parts when preparing pre-blended liquid (i). The results are shown in Table 1.

[0104] Example 9 A cured cycloolefin resin was obtained and evaluated in the same manner as in Example 1, except that when preparing pre-blended liquid (i), 1,5-cyclooctadiene was not added, and the amount of RIM monomer was changed to 70 parts and the amount of 1,4-p-menthadiene was changed to 30 parts. The results are shown in Table 1.

[0105] Example 10 When preparing pre-mixture solution (i), the amounts of RIM monomer and 1,5-cyclooctadiene were changed to 14.5 parts and 14.5 parts, respectively, and 0.6 parts of dicyclopentadiene monoepoxide (DCPME) solution and 0.4 parts of bicycloheptenylethyltrimethoxysilane were mixed in. The DCPME solution used was a cyclopentanone solution (DCPME content: approximately 40%, by-product content: approximately 27%) containing 5,6-DCPME and DCPDE (dicyclopentadiene diepoxide) as by-products. This was further blended with 70 parts of aluminum hydroxide (aspect ratio: 1, 50% volume cumulative diameter: 3 μm) to obtain pre-blended liquid (i), and the prepared pre-blended liquid (i) and pre-blended liquid (ii) were mixed in a mass ratio of (i):(ii) = 100:1.1, except that a cured cycloolefin resin was obtained and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0106] <Comparative Example 1> A cured cycloolefin resin was obtained and evaluated in the same manner as in Example 1, except that the amount of RIM monomer was changed to 100 parts and 1,5-cyclooctadiene was not added when preparing the pre-blended solution (i). The results are shown in Table 1.

[0107] <Comparative Example 2> A cured cycloolefin resin was obtained and evaluated in the same manner as in Example 1, except that the amount of RIM monomer and the amount of 1,5-cyclooctadiene were changed to 90 parts and 10 parts, respectively, when preparing pre-blended liquid (i). The results are shown in Table 1.

[0108] <Comparative Example 3> A cured cycloolefin resin was obtained and evaluated in the same manner as in Example 1, except that the amount of RIM monomer and the amount of 1,5-cyclooctadiene were changed to 80 parts and 20 parts, respectively, when preparing pre-blended liquid (i). The results are shown in Table 1.

[0109] <Comparative Example 4> A cured cycloolefin resin was obtained and evaluated in the same manner as in Example 10, except that the amount of RIM monomer was changed to 29 parts and 1,5-cyclooctadiene was not added when preparing pre-blended liquid (i). The results are shown in Table 1.

[0110] [Table 1]

[0111] As shown in Table 1, the cured cycloolefin resins obtained using polymerizable compositions containing a norbornene monomer (a1) and a monocyclic cycloolefin (a2) as cycloolefin monomers and having a breaking elongation of 30% or more at 23°C (room temperature) had a large breaking elongation at -25°C in addition to the breaking elongation at room temperature, and also had sufficient breaking elongation after high-temperature storage, and were excellent in crack resistance, stretchability, and high-temperature durability. Therefore, when used as an encapsulating material for semiconductor devices, it can be said that excellent temperature cycle reliability and excellent high-temperature durability can be achieved (Examples 1 to 10). On the other hand, when a polymerizable composition not containing a monocyclic cycloolefin (a2) was used as the cycloolefin monomer, or when a polymerizable composition containing a monocyclic cycloolefin (a2) was used, if the breaking elongation at 23°C (room temperature) was less than 30%, the breaking elongation at -25°C and the breaking elongation after high-temperature storage were poor (Comparative Examples 1 to 4).

Claims

1. A cured cycloolefin resin obtained by bulk polymerization of a polymerizable composition containing a cycloolefin monomer and a metathesis polymerization catalyst, the cycloolefin monomer contains a norbornene-based monomer (a1) and a monocyclic cycloolefin (a2), The breaking elongation at 23°C is 30% or more, A cycloolefin resin cured product, wherein a tricyclic compound and a pentacyclic compound are used in combination as the norbornene-based monomer (a1), and the weight ratio of the tricyclic compound to the pentacyclic compound is 65:35 to 95:

5.

2. 2. The cycloolefin-based resin cured product according to claim 1, wherein the content of the monocyclic cycloolefin (a2) in the cycloolefin monomer is 30 to 99 mass %.

3. The cycloolefin resin cured product according to claim 1 or 2, wherein the monocyclic cycloolefin (a2) is at least one selected from the group consisting of 1,5-cyclooctadiene, cyclooctene, cyclohexene, 1,4-cyclohexadiene, and 1,4-p-menthadiene.

4. The cycloolefin resin cured product according to claim 3, wherein the monocyclic cycloolefin (a2) is 1,5-cyclooctadiene.

5. The cycloolefin resin cured product according to any one of claims 1 to 4, wherein the polymerizable composition contains a filler.

6. 1. A polymerizable composition comprising a cycloolefin monomer and a metathesis polymerization catalyst, The cycloolefin monomer contains a norbornene-based monomer (a1) and a monocyclic cycloolefin (a2). The polymerizable composition for forming a cured cycloolefin resin product according to claim 1 .

7. The polymerizable composition according to claim 6, which comprises two or more pre-mixed liquids that do not undergo polymerization reaction by themselves, and which can form the polymerizable composition by combining the pre-mixed liquids.

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