Laminate, wiring board, and cyclic olefin resin for metal-clad laminate

Abstract

This laminate comprises an insulating layer and a metal layer provided on one or both surfaces of the insulating layer. The insulating layer contains a cyclic olefin resin (A) which is a copolymer of monomers including a cyclic olefin compound (a1) and an α-olefin compound (a2) having three or more carbon atoms. The cyclic olefin resin (A) has three or more glass transition temperatures within the range between -50 °C and 350 °C as determined by solid viscoelasticity measurement.

Description

Cyclic olefin resin for laminates, wiring boards, and metal-clad laminates

[0001] The present invention relates to a cyclic olefin resin for laminates, wiring boards, and metal-clad laminates.

[0002] Metal-clad laminates, such as copper-clad laminates, are generally laminates containing an insulating layer made of resin, prepreg, etc., and a conductive layer made of metal. Various materials are used for the insulating and conductive layers, depending on the application of the metal-clad laminate. Examples of resins used for the insulating layer include polyimide resins, liquid crystalline resins, and cyclic olefin resins.

[0003] As an example of technology related to metal-clad laminates using cyclic olefin resins, Patent Document 1 describes a material in which the glass transition temperature is in the range of 250 to 310°C, the weight-average molecular weight is in the range of 5,000 to 300,000, the relative permittivity at 5 GHz is 2.3 or less, and the dielectric loss tangent is 4 × 10⁻⁶. －４ The following describes a metal-clad laminate using a cyclic olefin resin as the insulating layer.

[0004] Japanese Patent Publication No. 2016-37045

[0005] The main properties required of resins used in insulating layers include low dielectric properties, heat resistance, and adhesion to the conductive layer. Furthermore, if the metal-clad laminate is for flexible substrates, flexibility and bendability are also required. The cyclic olefin resin described in Patent Document 1 excels in heat resistance among these properties, but its adhesion to the conductive layer was particularly insufficient.

[0006] One of the objectives of this disclosure is to provide a cyclic olefin resin for laminates, wiring boards, and metal-clad laminates that exhibits excellent adhesion between the insulating layer and the metal layer, as well as superior heat resistance.

[0007] This disclosure includes the following embodiments. This disclosure is not limited to the following embodiments. One embodiment relates to a laminate comprising an insulating layer and a metal layer provided on one or both sides of the insulating layer, wherein the insulating layer comprises a cyclic olefin resin (A), which is a copolymer of monomers comprising a cyclic olefin compound (a1) and an α-olefin compound (a2) having three or more carbon atoms, and the cyclic olefin resin (A) has three or more glass transition temperatures determined by solid viscoelasticity measurement within the range of -50 to 350°C.

[0008] Another embodiment of the present disclosure relates to a cyclic olefin resin for metal-clad laminates, which is a monomer copolymer containing a cyclic olefin compound (a1) and an α-olefin compound (a2) having three or more carbon atoms, having a number-average molecular weight (Mn) in the range of 150,000 to 700,000, and having three or more glass transition temperatures determined by solid viscoelasticity measurement in the range of -50 to 350°C.

[0009] According to this disclosure, it is possible to provide a cyclic olefin resin for laminates, wiring boards, and metal-clad laminates that is excellent in both adhesion between the insulating layer and the metal layer and heat resistance.

[0010] Embodiments of the present disclosure will be described in detail below. The present disclosure is not limited to the following embodiments. One embodiment of the laminate is a laminate comprising an insulating layer and a metal layer provided on one or both sides of the insulating layer, wherein the insulating layer comprises a cyclic olefin resin (A), which is a copolymer of monomers comprising a cyclic olefin compound (a1) and an α-olefin compound (a2) having 3 or more carbon atoms, and the cyclic olefin resin (A) has three or more glass transition temperatures within the range of -50 to 350°C, as determined by solid viscoelasticity measurement. The application of the laminate is not particularly limited, but for example, it may be used as a metal-clad laminate.

[0011] In the laminate of one embodiment, when the cyclic olefin resin (A) has three or more glass transition temperatures within the range of -50°C to 350°C, an effect excellent in both adhesion between the insulating layer and the metal layer and heat resistance can be obtained. Although not bound by a particular theory, it is believed that this effect is obtained when the structural characteristic of being a copolymer of a monomer containing a cyclic olefin compound (a1) and an α-olefin compound (a2) having 3 or more carbon atoms is combined with the viscoelastic characteristic of having three or more glass transition temperatures.

[0012] The cyclic olefin resin (A) contained in the insulating layer may be one type or two or more types. The cyclic olefin resin (A) is a copolymer of a monomer containing a cyclic olefin compound (a1) and an α-olefin compound (a2). The specific structure of the cyclic olefin compound (a1) is not particularly limited as long as it is a compound having a carbon-carbon double bond in the cyclic structure, and a wide variety of compounds can be used. One type of cyclic olefin compound (a1) may be used alone, or two or more types may be used in combination. Specific examples of the cyclic olefin compound (a1) include compounds represented by the following general formula (1).

[0013]

[0014] [In general formula (1), R １ to R １２ are each independently a hydrogen atom, a halogen atom, or a hydrocarbon group. R ９ and R １０ , R １１ and R １２ may together form a divalent hydrocarbon group. Further, R ９ or R １０ and R １１ or R １２ may be bonded to each other to form a ring. n represents 0 or a positive integer. When n is 2 or more, a plurality of R ５ to R ８ may all be different, or some or all may be the same.]

[0015] In general formula (1), R １ to R１２ Each of these is independently either a hydrogen atom, a halogen atom, or a hydrocarbon group.

[0016] Of these, R １ ~R ８ Each of these may independently be hydrogen, a halogen atom, or an alkyl group having 1 to 20 carbon atoms. Specific examples of halogen atoms include fluorine, chlorine, and bromine atoms. The alkyl group having 1 to 20 carbon atoms may be linear or branched. Specific examples of alkyl groups having 1 to 20 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, decyl, lauryl, myristyl, palmityl, stearyl, and arachidyl groups. The alkyl group may have 1 to 4 carbon atoms. When n in general formula (1) is a positive integer of 2 or more, there may be multiple R groups in the molecular structure. ５ ~R ８ They may all be different, or some or all of them may be the same.

[0017] Also, R ９ ~R １２ Each of these may independently be a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group. Specific examples of halogen atoms include those mentioned above. Specific examples of alkyl groups include, for example, the alkyl groups with 1 to 4 carbon atoms mentioned above, as well as alkyl groups with 5 to 20 carbon atoms such as pentyl, hexyl, octyl, decyl, lauryl, myristyl, palmityl, stearyl, and arachidyl groups. Specific examples of cycloalkyl groups include, for example, the cyclohexyl group. Specific examples of aryl groups include, for example, aryl groups without substituents on the aromatic ring, such as phenyl, naphthyl, and anthryl groups, as well as aryl groups with substituents on the aromatic ring, such as tolyl, xylyl, ethylphenyl, and isopropylphenyl groups. Specific examples of aralkyl groups include, for example, benzyl and phenethyl groups, as well as structural sites in which an aryl group is substituted on an alkyl group with 1 to 4 carbon atoms.

[0018] R in general formula (1) ９ and R １０ , R １１ and R １２ These may integrate to form a divalent hydrocarbon group. Specific examples of divalent hydrocarbon groups in this case include alkylidene groups such as ethylidene, propyridene, and isopropylidene.

[0019] R in general formula (1) ９ or R １０ And, R １１ or R １２ These elements may be bonded to each other to form a ring. The formed ring may be monocyclic or polycyclic. It may also be a ring having a bridging site, or a ring having a double bond. Furthermore, it may be a ring consisting of a combination of these rings. Substituents may be present on the carbon atoms forming the ring structure, and examples of substituents include alkyl groups having 1 to 4 carbon atoms.

[0020] Specific examples of cyclic olefin compounds (a1) represented by general formula (1) include, for example, bicyclo[2.2.1]hepta-2-ene (common name: norbornene), 5-methyl-bicyclo[2.2.1]hepta-2-ene, 5,5-dimethyl-bicyclo[2.2.1]hepta-2-ene, 5-ethyl-bicyclo[2.2.1]hepta-2-ene, 5-butyl-bicyclo[2.2.1]hepta-2-ene, and 5-ethylidene-bicyclo Bicyclic olefin compounds such as [2.2.1]hepta-2-ene, 5-hexyl-bicyclo[2.2.1]hepta-2-ene, 5-octyl-bicyclo[2.2.1]hepta-2-ene, 5-octadecyl-bicyclo[2.2.1]hepta-2-ene, 5-methylidene-bicyclo[2.2.1]hepta-2-ene, 5-vinyl-bicyclo[2.2.1]hepta-2-ene, and 5-propenyl-bicyclo[2.2.1]hepta-2-ene;

[0021] Tricyclo[4.3.0.1 ２，５ Deca-3,7-diene (common name: dicyclopentadiene), tricyclo[4.3.0.1 ２，５ Deca-3-ene; tricyclo[4.4.0.1２，５ ]Undeca-3,7-diene or tricyclo[4.4.0.12,5]Undeca-3,8-diene or partially hydrogenated versions thereof (or adducts of cyclopentadiene and cyclohexene) are tricyclo[4.4.0.1 ２，５ ]undeca-3-ene; tricyclic olefin compounds such as 5-cyclopentyl-bicyclo[2.2.1]hepta-2-ene, 5-cyclohexyl-bicyclo[2.2.1]hepta-2-ene, 5-cyclohexenylbicyclo[2.2.1]hepta-2-ene, and 5-phenyl-bicyclo[2.2.1]hepta-2-ene;

[0022] Tetracyclo[4.4.0.1 ２，５ 1. ７，１０ ] Dodeca-3-ene (also simply called tetracyclododecene), 8-methyltetracyclo[4.4.0.1 ２，５ 1. ７，１０ ] Dodeca-3-ene, 8-ethyltetracyclo[4.4.0.1 ２，５ 1. ７，１０ ] Dodeca-3-ene, 8-methylidenetetracyclo[4.4.0.1 ２，５ 1. ７，１０ ] Dodeca-3-ene, 8-ethylidenetetracyclo[4.4.0.1 ２，５ 1. ７，１０ ] Dodeca-3-ene, 8-vinyltetracyclo[4,4.0.1 ２，５ 1. ７，１０ ] Dodeca-3-ene, 8-propenyl-tetracyclo[4.4.0.1 ２，５ 1. ７，１０ ] Tetracyclic olefin compounds such as dodeca-3-ene;

[0023] 8-Cyclopentyl-Tetracyclo[4.4.0.1 ２，５ 1. ７，１０ ] Dodeca-3-ene, 8-cyclohexyl-tetracyclo[4.4.0.1 ２，５ 1. ７，１０ ] Dodeca-3-ene, 8-cyclohexenyl-tetracyclo[4.4.0.1 ２，５ 1. ７，１０ ] Dodeca-3-ene, 8-phenyl-cyclopentyl-tetracyclo[4.4.0.1 ２，５ 1. ７，１０] Dodeca-3-ene; Tetracyclo[7.4.1 ３，６ . 0 １，９ . 0 ２，７ ] Tetradeca-4,9,11,13-tetraene (also known as 1,4-methano-1,4,4a,9a-tetrahydrofluorene), tetracyclo[8.4.1 ４，７ . 0 １，１０ . 0 ３，８ ] Pentadeca-5,10,12,14-tetraene (also known as 1,4-methano-1,4,4a,5,10,10a-hexahydroanthracene); pentacyclo[6.6.1.1 ３，６ . 0 ２，７ . 0 ９，１４ ]-4-Hexadecene, Pentacyclo[6.5.1.1 ３，６ . 0 ２，７ . 0 ９，１３ ]-4-Pentadecene, Pentacyclo[7.4.0.0 ２，７ 1. ３，６ 1. １０，１３ ]-4-pentadecene; heptacyclo[8.7.0.1 ２，９ 1. ４，７ 1. １１，１７ . 0 ３，８ . 0 １２，１６ ]-5-Eicosene, heptacyclo[8.7.0.1 ２，９ . 0 ３，８ 1. ４，７ . 0 １２，１７ 1. １３，ｌ６ Examples include polycyclic cyclic olefin compounds such as tetramers of 14-eicosene and cyclopentadiene.

[0024] Among these, bicyclic olefin compounds are preferred, and bicyclo[2.2.1]hepta-2-ene (common name: norbornene) and 5-ethylidene-bicyclo[2.2.1]hepta-2-ene are more preferred. The proportion of bicyclic olefin compounds in cyclic olefin compound (a1) may be 70 mol% or more, 80 mol% or more, 90 mol% or more, or 100 mol%.

[0025] The α-olefin compound (a2) may be any α-olefin compound having 3 or more carbon atoms, and its specific structure is not particularly limited. One type of α-olefin compound (a2) may be used alone, or two or more types may be used in combination. The number of carbon atoms in the α-olefin compound (a2) may be 4 or more, or 6 or more, in order to form an insulating layer with superior adhesion to the metal layer and heat resistance. Furthermore, in order to form an insulating layer with an excellent balance of low dielectric properties, heat resistance, and adhesion to the metal layer, the number of carbon atoms may be 20 or less, 12 or less, or 10 or less. The number of carbon atoms in the α-olefin compound (a2) may be in the range of 3 to 20. In a particularly preferred configuration, the proportion of compounds with a number of carbon atoms in the α-olefin compound (a2) that are in the range of 6 to 10 may be 70 mol% or more, 80 mol% or more, 90 mol% or more, or 100 mol%.

[0026] Specific examples of α-olefin compounds (a2) having 3 to 20 carbon atoms include, for example, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, and compounds in which one or more hydrogen atoms in these compounds are substituted with halogen atoms or the like.

[0027] The ratio of the total number of moles of the cyclic olefin compound (a1) and the α-olefin compound (a2) to the total number of moles of monomers constituting the cyclic olefin resin (A) may be 70 mol% or more, 80 mol% or more, 90 mol% or more, or 100 mol%.

[0028] The ratio of the cyclic olefin compound (a1) to the total number of moles of monomers constituting the cyclic olefin resin (A) may be 10 mol% or more, 30 mol% or more, or 40 mol% or more. It may also be 95 mol% or less, 90 mol% or less, or 80 mol% or less. The ratio of the cyclic olefin compound (a1) to the total number of moles of monomers constituting the cyclic olefin resin (A) may be in the range of 10 to 95 mol%.

[0029] The ratio of the α-olefin compound (a2) to the total number of moles of monomers constituting the cyclic olefin resin (A) may be 5 mol% or more, 10 mol% or more, or 20 mol% or more. It may also be 90 mol% or less, 70 mol% or less, or 60 mol% or less. The ratio of the α-olefin compound (a2) to the total number of moles of monomers constituting the cyclic olefin resin (A) may be in the range of 10 to 90 mol%.

[0030] The ratio of cyclic olefin compound (a1) to the total number of moles of cyclic olefin compound (a1) and α-olefin compound (a2) may be 10 mol% or more, 30 mol% or more, or 40 mol% or more. It may also be 95 mol% or less, 90 mol% or less, or 80 mol% or less. The ratio of cyclic olefin compound (a1) to the total number of moles of cyclic olefin compound (a1) and α-olefin compound (a2) may be in the range of 10 to 95 mol%.

[0031] The cyclic olefin resin (A) has three or more glass transition temperatures within the range of -50 to 350°C, which can be determined by solid viscoelasticity measurement. In this disclosure, the glass transition temperature of the cyclic olefin resin (A) is a value measured under the following conditions.

[0032] (Measurement conditions for glass transition temperature) A cyclic olefin resin (A) film with a thickness of 50 μm is used, and the glass transition temperature of the cyclic olefin resin (A) is measured by observing its viscoelastic behavior using a solid rheometer (for example, "RSA-G2 solids analyzer" manufactured by TA Instruments). The observation temperature range is -100 to 350°C. In the temperature range above 120°C and below 350°C, the temperature at the peak of the tanδ chart obtained by measurement is taken as the glass transition temperature. In the temperature range between -100°C and below 0°C and in the temperature range between 0 and 120°C, in the chart of the numerical value obtained by measurement by differentiating the value of the loss modulus with respect to temperature, the point where the numerical value changes from positive to negative as the temperature increases, i.e., the maximum point of the loss modulus, is considered as the peak, and the temperature at which the peak occurs is taken as the glass transition temperature. In the temperature range of -100°C to less than 0°C and the temperature range of 0 to 120°C, if the chart of the derivative of the loss modulus with respect to temperature does not have a point where the value changes from positive to negative as the temperature increases, that is, if the chart of the loss modulus substantially does not have a maximum point, then it is assumed that there is no glass transition temperature in that temperature range.

[0033] The specific measurement conditions for the glass transition temperature are as follows: Sample: Cyclic olefin resin (A) molded into a 50 μm thick film. Measurement mode: Temperature lamp. Measurement temperature range: -100 to 350°C. Measurement frequency: 10 Hz. Heating rate: 4°C / min. Load: 1 to 100 g.

[0034] Since the cyclic olefin resin (A) provides an insulating layer with superior adhesion to the metal layer and heat resistance, it is preferable that it has at least one glass transition temperature in the range of -50°C or higher and less than 0°C, in the range of 0°C to 120°C, and in the range of 120°C or higher and 350°C or lower.

[0035] Glass transition temperatures in the range of -50°C or higher but below 0°C may also be in the range of -40°C to -10°C. Glass transition temperatures in the range of 0°C to 120°C may also be in the range of 30°C to 100°C or in the range of 50°C to 90°C. Glass transition temperatures in the range of above 120°C but below 350°C may also be in the range of 130°C to 330°C or in the range of 150°C to 320°C.

[0036] The molecular weight of the cyclic olefin resin (A) is not particularly limited and can be adjusted as appropriate depending on the desired application of the laminate. The number average molecular weight (Mn) of the cyclic olefin resin (A), measured by gel permeation chromatography (GPC) on a polystyrene basis, may be 150,000 or more, 180,000 or more, or 200,000 or more. It may also be 700,000 or less, 600,000 or less, or 500,000 or less. The number average molecular weight (Mn) of the cyclic olefin resin (A) may be in the range of 150,000 to 700,000.

[0037] The weight-average molecular weight (Mw) of the cyclic olefin resin (A) may be, for example, 200,000 or more, 250,000 or more, or 300,000 or more. It may also be 800,000 or less, 700,000 or less, or 750,000 or less. The weight-average molecular weight (Mw) of the cyclic olefin resin (A) may be in the range of 200,000 to 800,000.

[0038] The dispersion ratio (Mw / Mn) of the cyclic olefin resin (A) may be 1.2 or higher, or 1.3 or higher. It may also be 5 or lower, or 3 or lower. The dispersion ratio (Mw / Mn) of the cyclic olefin resin (A) may be in the range of 1.2 to 5.

[0039] In this disclosure, the number-average molecular weight (Mn) and weight-average molecular weight (Mw) of the resin are values ​​measured by gel permeation chromatography (GPC) under the following conditions: Apparatus: Malvern Panatorial "Viscotech TDA302" + Pump autosampler apparatus Detector: RI Solvent: Toluene Column: Tosoh Corporation "TSKgel GMHHR-M" (300 mm × 7.8 mmφ) Flow rate: 1 mL / min Temperature: 75°C Sample concentration: 2.5 mg / mL Injection volume: 100 μL Standard sample: Monodisperse polystyrene

[0040] A cyclic olefin resin (A), that is, a copolymer of monomers containing a cyclic olefin compound (a1) and an α-olefin compound (a2), having three or more glass transition temperatures within the range of -50 to 350°C as determined by solid viscoelasticity measurement, can be produced, for example, by a method that includes addition polymerization of monomers containing a cyclic olefin compound (a1) and an α-olefin compound (a2) having three or more carbon atoms in the presence of a titanocene catalyst represented by the following general formula (2) and a co-catalyst. The resin produced by this method will contain portions in which structural sites derived from the α-olefin compound (a2) are continuous or portions in which the density of structural sites derived from the α-olefin compound (a2) is high, thereby resulting in a resin having three or more glass transition temperatures within the range of -50 to 350°C.

[0041]

[0042] [In general formula (2), R １３ ~R １５ Each of these is independently an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms. １６ and R １７ Each of these is independently one of the following: an alkyl group having 1 to 12 carbon atoms, an alkyl halide having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a halogen atom. １８ ~R ２５each independently represents any one of a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, and a silyl group which may have a monovalent hydrocarbon group having 1 to 12 carbon atoms as a substituent.]]

[0043] One titanocene catalyst may be used alone, or two or more titanocene catalysts may be used in combination. In general formula (2), R １３ to R １５ each independently represent an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, a pentyl group, a hexyl group, a cyclopentyl group, a cyclohexyl group, and the like. Examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, a naphthyl group, a biphenyl group, and those having one or two or more alkyl groups on their aromatic rings, and the like.

[0044] R １６ and R １７ each independently represent any one of an alkyl group having 1 to 12 carbon atoms, a halogenated alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like. Examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a cyclopentyl group, a cyclohexyl group, and the like. Examples of the halogenated alkyl group having 1 to 12 carbon atoms include those obtained by substituting one or two or more hydrogen atoms in an alkyl group having 1 to 12 carbon atoms with halogen atoms. Examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, a naphthyl group, a biphenyl group, and those having one or two or more of one or more types selected from the group consisting of alkyl groups and halogen atoms on their aromatic rings, and the like.

[0045] R １８ to R ２５Each of these is independently a silyl group which may have a hydrogen atom, a C1-C12 alkyl group, a C6-C12 aryl group, or a C1-C12 monovalent hydrocarbon group as a substituent. Examples of C1-C12 alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, hexyl, heptyl, octyl, cyclopentyl, and cyclohexyl groups. Examples of C6-C12 aryl groups include phenyl, naphthyl, biphenyl, and those having one or more alkyl groups on their aromatic rings. In a silyl group having a monovalent hydrocarbon group having 1 to 12 carbon atoms as a substituent, examples of the hydrocarbon group having 1 to 12 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, hexyl, heptyl, octyl, cyclopentyl, and cyclohexyl groups.

[0046] Among the titanocene catalysts represented by general formula (2), the titanium complex represented by the following general formula (3) [(t-BuNSiMe ２ Flu) Time ２ ] is preferred. The compound can be easily synthesized, for example, based on the description in "Macromolecules, Vol. 31, p. 3184, 1998".

[0047]

[0048] [In structural formula (3), Me represents a methyl group, and t-Bu represents a tert-butyl group.]

[0049] The amount of titanocene catalyst used is not particularly limited, but one preferred condition is that a higher molecular weight cyclic olefin resin (A) can be obtained, so the total mass of monomers per 1 part by mass of titanocene catalyst may be in the range of 1,200 to 1,600 parts by mass.

[0050] The co-catalyst used with the titanocene catalyst may be one or more selected from the group consisting of borate compounds and hindered phenol compounds. Both borate compounds and hindered phenol compounds may be used as co-catalysts.

[0051] A single borate compound may be used alone, or two or more may be used in combination. Specific examples of borate compounds include triphenylmethylium tetrakis(pentafluorophenyl) borate, dimethylphenylammonium tetrakis(pentafluorophenyl) borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl) borate, and N-methyldinormaldecylammonium tetrakis(pentafluorophenyl) borate. Among these, triphenylmethylium tetrakis(pentafluorophenyl) borate is preferred. The amount of borate compound used is not particularly limited and may be in the range of 0.1 to 10 parts by mass per 100 parts by mass of the total monomers.

[0052] Hindered phenol compounds may be used individually or in combination of two or more. Specific examples of hindered phenol compounds include, for example, 2,6-di-tert-butyl-4-hydroxytoluene (BHT), 2,6-di-tert-butylphenol, 2-tert-butylphenol, 2-tert-butyl-p-cresol, 3,3',5,5'-tetra-tert-butyl-4,4'-dihydroxybiphenyl, 3,3',5,5'-tetra-tert-butyl-2,2'-dihydroxybiphenyl, 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), and 2,2'-methylenebis(6 Examples include tris(6-tert-butyl-m-cresol), 4,4',4''-(1-methylpropanyl-3-ylidene), 1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenylmethyl), 2,4,6-trimethylbenzene, etc. Among these, 2,6-di-tert-butyl-4-hydroxytoluene is preferred. The amount of hindered phenol compound used is not particularly limited and may be in the range of 0.01 to 10 parts by mass per 100 parts by mass of the total monomers.

[0053] When a hindered phenol compound is used as a co-catalyst, an alkylaluminum compound may be used as a condition that can further improve the yield of the cyclic olefin resin (A). One type of alkylaluminum compound may be used alone, or two or more types may be used in combination. Specific examples of alkylaluminum compounds include, for example, trialkylaluminum such as trimethylaluminum, triethylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, trisec-butylaluminum, and tri-n-octylaluminum; dialkylaluminum halides such as dimethylaluminum chloride and diisobutylaluminum chloride; dialkylaluminum hydrides such as diisobutylaluminum hydride; and dialkylaluminum alkoxides such as dimethylaluminum methoxide. The amount of alkylaluminum compound used is not particularly limited and may be in the range of 0.01 to 5 parts by mass per 100 parts by mass of the total monomers.

[0054] The reaction conditions for addition polymerization of monomers containing a cyclic olefin compound (a1) and an α-olefin compound (a2) having three or more carbon atoms are not particularly limited and can be appropriately adjusted according to the desired molecular weight and other physical properties of the cyclic olefin resin (A). As an example of reaction conditions, the reaction may be carried out in a solvent. The type of solvent is not particularly limited and can be appropriately selected according to the reaction temperature, etc., but examples include various hydrocarbon compounds and halogenated hydrocarbon compounds. The amount used is not particularly limited but may be in the range of 0.5% to 1,000% by mass relative to the total mass of monomers.

[0055] The reaction temperature is not particularly limited, but may be in the range of -20 to 200°C, for example. The reaction may be carried out under an inert gas atmosphere such as nitrogen gas or helium gas, as desired. The monomer may be charged into the reaction vessel all at once or in stages.

[0056] The insulating layer may contain components other than the cyclic olefin resin (A). Examples of these other components include resins other than the cyclic olefin resin (A); fiber reinforcing agents such as glass fibers and polytetrafluoroethylene fibers; fillers such as silica; and additives such as antioxidants, antistatic agents, plasticizers, adhesion aids, and copper damage inhibitors.

[0057] Other resins include, for example, cyclic olefin resins other than cyclic olefin resin (A), polyphenylene ether resins, polyimide resins, and the like. The proportion of cyclic olefin resin (A) to the total resin components in the insulating layer may be 60% by mass or more, 80% by mass or more, 90% by mass or more, or 100% by mass or more.

[0058] When the laminate is for a flexible substrate, the insulating layer generally does not contain a fiber reinforcing agent. In this case, the proportion of cyclic olefin resin (A) in the insulating layer may be 60% by mass or more, 80% by mass or more, 90% by mass or more, or 100% by mass or more.

[0059] When the laminate is used in rigid substrates, etc., the insulating layer may contain a fiber reinforcing agent. In this case, the ratio of the total mass of the fiber reinforcing agent and the cyclic olefin resin (A) to the total mass of the insulating layer may be 60% by mass or more, 80% by mass or more, 90% by mass or more, or 100% by mass or more. Furthermore, the proportion of the fiber reinforcing agent in the insulating layer may be in the range of 20 to 80% by mass.

[0060] The type of metal in the metal layer contained in the laminate is not particularly limited and may be any type of metal commonly used in metal-clad laminates. Specifically, examples include copper, aluminum, gold, silver, nickel, etc.

[0061] In the laminate, the thicknesses of the insulating layer and the metal layer are not particularly limited and may be equivalent to those of a typical metal-clad laminate. For example, the thickness of the insulating layer may be in the range of 50 to 200 μm, and the thickness of the metal layer may be in the range of 1 to 50 μm.

[0062] The laminate includes an insulating layer and a metal layer provided on one or both sides of the insulating layer. The metal layer may be provided over the entire surface of the insulating layer or on only a part of the insulating layer.

[0063] The method for manufacturing the laminate is not particularly limited and can be manufactured using the same methods as for general metal-clad laminates. Specifically, it can be manufactured using lamination, casting, sputtering, plating, and printing techniques for manufacturing electronic circuits (printed electronics).

[0064] The lamination method is a method for manufacturing a laminate by preparing an insulating layer and a metal layer separately and bonding them together. Bonding can be performed, for example, by pressing using a press machine. Pressing may also be performed under heated conditions.

[0065] The insulating layer can be manufactured, for example, by applying a solvent solution containing a cyclic olefin resin (A) and other optional components to a releaseable substrate and drying it. Drying may be carried out under heating conditions, reduced pressure conditions, or heated-reduced-pressure conditions. Specific examples of solvents include aliphatic hydrocarbon solvents such as cyclohexane, methylcyclohexane, ethylcyclohexane, dimethylcyclohexane, p-menthane, and decahydronaphthalene; aromatic hydrocarbon solvents such as toluene and xylene; and halogenated hydrocarbon solvents such as dichloromethane, chloroform, and carbon tetrachloride. The insulating layer may be surface-treated with ultraviolet light or the like to further improve its adhesion to the metal layer.

[0066] The metal layer may be a metal foil. The insulating layer and the metal layer may be adjacent to each other, or they may be laminated with other layers such as an adhesive layer in between. Since the insulating layer containing the cyclic olefin resin (A) has excellent adhesion to the metal layer, the laminate of one embodiment may not have an adhesive layer, and the insulating layer and the metal layer may be adjacent to each other.

[0067] The casting method involves applying a solvent solution containing a cyclic olefin resin (A) and other optional components onto a pre-prepared metal layer, and then drying the solution to produce a laminate. The metal layer may be a metal foil. Drying may be carried out under heating conditions, reduced pressure conditions, or heated-reduced-pressure conditions.

[0068] Sputtering is a method of forming a metal layer by sputtering metal onto a pre-prepared insulating layer. The insulating layer can be manufactured in the same way as the lamination method. Sputtering can be carried out under general conditions.

[0069] Plating is a method of forming a metal layer by plating a metal onto a pre-prepared insulating layer. The insulating layer can be manufactured in the same way as the lamination method. Metal plating can be carried out under general conditions.

[0070] Printed electronics is a method of forming a metal layer by applying an ink containing metals with an average primary particle size of several nanometers to several tens of nanometers to a pre-prepared insulating layer using various printing methods such as screen printing, inkjet, offset, and gravure, and then firing the applied ink. Examples of metals that can be used include gold, silver, copper, platinum, palladium, nickel, and aluminum. Among these, gold, silver, and platinum are preferred in terms of conductivity and oxidation resistance, and silver is more preferred in terms of cost and low-temperature sinterability. Copper, nickel, and aluminum are also preferred. The insulating layer can be manufactured in the same manner as the lamination method. Various printing methods can be carried out under general conditions.

[0071] The laminate of one embodiment can be used for various wiring board applications, similar to general metal-clad laminates. The wiring board may be a multilayer board or a flexible board. Furthermore, since the insulating layer containing the cyclic olefin resin (A) has excellent low dielectric properties, heat resistance, and adhesion to the metal layer, it can also be preferably used for high-frequency wiring board applications.

[0072] High-frequency wiring boards are special wiring boards used in electronic devices that primarily handle high-frequency signals (generally in the range of several hundred MHz to GHz and even THz). Specific examples of high-frequency wiring boards include, but are not limited to, rigid high-frequency boards (PCBs), flexible high-frequency boards (FPCs), rigid-flex high-frequency boards, and metal-based high-frequency boards (with heat dissipation capabilities). The laminate of one embodiment can be preferably used in flexible high-frequency boards. Flexible high-frequency boards are used in applications where bending and mobility of the board are required while handling high-frequency signals. Specific examples of such applications include antenna circuits in smartphones and tablets, and connection parts in millimeter-wave and terahertz-wave compatible devices.

[0073] Examples of embodiments of the present disclosure are given below. The present disclosure is not limited to the following embodiments. <1> A laminate comprising an insulating layer and a metal layer provided on one or both sides of the insulating layer, wherein the insulating layer comprises a cyclic olefin resin (A), which is a copolymer of monomers comprising a cyclic olefin compound (a1) and an α-olefin compound (a2) having 3 or more carbon atoms, and the cyclic olefin resin (A) has three or more glass transition temperatures determined by solid viscoelasticity measurement within the range of -50 to 350°C.

[0074] <2> The laminate according to <1>, wherein the cyclic olefin resin (A) has at least one glass transition temperature in the range of -50°C or more and less than 0°C, in the range of 0°C to 120°C, and in the range of 120°C or more and 350°C or less.

[0075] <3> The laminate according to <1> or <2>, wherein the number of carbon atoms of the α-olefin compound (a2) is in the range of 3 to 20.

[0076] <4> The laminate according to any one of <1> to <3>, wherein the ratio of the cyclic olefin compound (a1) to the total number of moles of monomers constituting the cyclic olefin resin (A) is in the range of 10 to 90 mol%.

[0077] <5> The laminate according to any one of <1> to <4>, wherein the number average molecular weight (Mn) of the cyclic olefin resin (A) is in the range of 150,000 to 700,000.

[0078] A wiring board using a laminate described in any one of the following: <6>, <1>, to <5>.

[0079] A high-frequency wiring board using a laminate described in any one of the following: <7>, <1>, to <5>.

[0080] <8> A copolymer of monomers containing a cyclic olefin compound (a1) and an α-olefin compound (a2) having 3 or more carbon atoms, having a number-average molecular weight (Mn) in the range of 150,000 to 700,000, and having three or more glass transition temperatures determined by solid viscoelasticity measurement within the range of -50 to 350°C, a cyclic olefin resin for metal-clad laminates.

[0081] The embodiment will be described in more detail below with reference to examples, but this embodiment is not limited to the following examples.

[0082] [Measurement of Glass Transition Temperature and Storage Modulus of Resin] The glass transition temperature and storage modulus of a resin were measured by observing its viscoelastic behavior using a 50 μm thick resin film with a solid rheometer (RSA-G2 solids analyzer manufactured by TA Instruments). The observed temperature range was -100 to 350°C. In the temperature range above 120°C and below 350°C, the temperature at the peak of the tanδ chart obtained by measurement was defined as the glass transition temperature. In the temperature range between -100°C and below 0°C and in the temperature range between 0 and 120°C, the point at which the value of the loss modulus obtained by measurement, obtained by differentiation with respect to temperature, changes from positive to negative as the temperature increases, i.e., the maximum point of the loss modulus, was considered the peak, and the temperature at which this peak occurred was defined as the glass transition temperature. In the temperature range of -100°C to less than 0°C and the temperature range of 0 to 120°C, if the value does not have a point where it changes from positive to negative as the temperature increases, that is, if the chart of the loss modulus does not have a maximum point, then it was determined that there is no glass transition temperature in that temperature range.

[0083] The specific measurement conditions for the glass transition temperature are as follows: Sample: Resin molded into a 50 μm thick film; Measurement mode: Temperature lamp; Measurement temperature range: -100 to 350°C; Measurement frequency: 10 Hz; Heating rate: 4°C / min; Load: 1 to 100 g

[0084] A 50 μm thick film sample was prepared under the following conditions: 1. A mold with a depth of 50 μm was prepared using "Kapton® film" (size: 10 cm x 10 cm x 50 μm). 2. Resin was filled into the mold and vacuum pressed at a pressure of 15 MPa, a temperature of 320-340°C, and a time of 15 minutes. 3. The film obtained by vacuum pressing was sandwiched between metal plates at room temperature and rapidly cooled to obtain a 50 μm thick film sample.

[0085] [Measurement of Resin Molecular Weight] The number-average molecular weight (Mn) and weight-average molecular weight (Mw) of the resin were measured by gel permeation chromatography (GPC) under the following conditions: Apparatus: Malvern Panatorial "Viscotech TDA302" + Pump autosampler apparatus Detector: RI Solvent: Toluene Column: Tosoh Corporation "TSKgel GMHHR-M" (300 mm x 7.8 mmφ) Flow rate: 1 mL / min Temperature: 75°C Sample concentration: 2.5 mg / mL Injection volume: 100 μL Standard sample: Monodisperse polystyrene

[0086] [Preparation of cyclic olefin resin (A1)] 13.82 mmol of 2-norbornene, 3.46 mmol of 1-octene, 0.0032 mmol of triisobutylaluminum, and 0.0064 mmol of 2,6-di-tert-butyl-4-hydroxytoluene were added to a 50 mL Schlenk flask under a nitrogen atmosphere. Decalin was then added as a solvent to adjust the volume of the flask contents to 18.6 mL. After cooling the contents of the flask to 0°C, 0.1 mL of a toluene solution of titanocene catalyst (*1) (concentration 0.032 mmol / mL) was added. Next, 0.4 mL of a toluene solution of triphenylmethylium tetrakis (pentafluorophenyl) borate (concentration 0.008 mmol / mL) was added. The contents of the flask were stirred with a magnetic stirrer at 0°C for 30 minutes to allow the addition polymerization reaction to proceed. After 30 minutes, a small amount of 2-propanol was added to the flask to stop the addition polymerization reaction. Hydrochloric acid was added to the reaction mixture and stirred for 10 minutes. The mixture was then separated into an aqueous layer and an organic layer, and the organic layer was washed with deionized water. The washing of the organic layer with deionized water was repeated until the pH of the water after washing the organic layer became neutral, at which point the washing was terminated. The organic layer was added dropwise to a large amount of acetone, and the precipitate was collected. The precipitate was washed with methanol and acetone alternately a total of four times, and then dried under reduced pressure at 110°C for 16 hours to obtain cyclic olefin resin (A1). The glass transition temperatures of cyclic olefin resin (A1) were -30°C, 60°C, and 252°C. The number-average molecular weight (Mn) of cyclic olefin resin (A1) was 201,000, and the weight-average molecular weight (Mw) was 342,000.

[0087] Titanocene catalyst (*1): the titanium complex "(t-BuNSiMe ２ Flu)TiMe ２

[0088] [Production of cyclic olefin resin (A'1)] In a 500 mL eggplant-shaped flask purged with a nitrogen atmosphere, 95.1 mmol of 2-norbornene, 23.7 mmol of 1-octene, and a 6.5 mass% MMAO-3A toluene solution (calculated as Al atom content) [[(CH ３ ) ０．７ (iso-C ４ H ９ ) ０．３ AlO] ｎA solution of methylisobutylaluminoxane, represented by , manufactured by Tosoh Finechem Co., Ltd., containing 6 mol% trimethylaluminum relative to total Al, was added in a quantity of 0.97 mmol, and a 9.0% by mass (as Al atom content) TMAO-211 toluene solution (a solution of methylaluminoxane, manufactured by Tosoh Finechem Co., Ltd., containing 26 mol% trimethylaluminum relative to total Al), was added in a quantity of 0.68 mmol. Toluene was further added as a solvent to adjust the volume of the flask contents to 258 mL. After heating the contents of the flask to 40°C, a toluene solution of titanocene catalyst (*1) (concentration 0.04 mmol / L) was added so that the amount of titanocene catalyst was 0.22 mmol. The contents of the flask were stirred with a magnetic stirrer at 40°C for 4 hours to allow the addition polymerization reaction to proceed. After 4 hours, a small amount of 2-propanol was added to the flask to stop the addition polymerization reaction. Hydrochloric acid was added to the reaction mixture and stirred for 10 minutes. The mixture was then separated into an aqueous layer and an organic layer, and the organic layer was washed with deionized water. The washing of the organic layer with deionized water was repeated until the pH of the water after washing the organic layer became neutral, at which point the washing was terminated. The organic layer was added dropwise to a large amount of acetone, and the precipitate was collected. The precipitate was washed with methanol and acetone alternately a total of four times, and then dried under reduced pressure at 110°C for 16 hours to obtain a cyclic olefin resin (A'1). The glass transition temperatures of the cyclic olefin resin (A'1) were -20°C and 264°C. The number-average molecular weight (Mn) of the cyclic olefin resin (A'1) was 73,000, and the weight-average molecular weight (Mw) was 127,000.

[0089] Example 1, Comparative Example 1 and Comparative Example 2 [Preparation of Laminates] Using the previously obtained cyclic olefin resin (A1), cyclic olefin resin (A'1), or TOPAS® "6017S-04" (addition copolymer of 2-norbornene and ethylene, glass transition temperature at a single point of 178°C, number average molecular weight (Mn) 40,500, manufactured by Polyplastics Co., Ltd.), a resin film with a thickness of 50 μm was prepared in the same manner as the preparation of the glass transition temperature measurement sample of the resin described above. Copper foil (*2) cut to 110 mm x 110 mm was placed on both sides of the resin film, and a laminate was prepared using a vacuum press. The vacuum press conditions were as follows. Vacuum press: Manual hydraulic vacuum heating press "IMC-4813" (Imoto Seisakusho Co., Ltd.) Temperature conditions: Heat from room temperature to 310°C at 6°C / min, hold at 310°C for 5 minutes, then cool to room temperature at 6°C / min Pressure conditions: Pressurize to 4.5 MPa when heated to 220°C, and maintain the same pressure until cooled to room temperature after heating Vacuum conditions: Vacuum conditions are maintained from room temperature before heating begins until cooled to room temperature after heating.

[0090] Copper foil (*2): "CF-T4X-SV-18" manufactured by Fukuda Metal Foil & Powder Industry Co., Ltd., thickness 18 μm, Rz JIS 1 μm, corresponding to "VL" in the classification of "JIS C6515:1998 Copper foil for printed wiring boards".

[0091] [Evaluation of Adhesion Between Insulating Layer and Metal Layer] The obtained laminate was cut into 10 mm wide strips to obtain test pieces. The test pieces were then adhered to a 0.8 mm thick stainless steel plate using double-sided tape. A small portion of the copper foil on the test piece was lightly peeled off by hand to create a starting point, and the peeled copper foil was grasped with a jig at a 90° angle to perform a peel strength test. The tensile speed was 50 mm / min. A Shimadzu Autograph AGS-X peel tester was used. The following criteria were used to evaluate the measured values: A: Peel strength of 3 N / 10 mm or more B: Peel strength of less than 3 N / 10 mm

[0092] [Heat Resistance Evaluation] The storage modulus of the resin film obtained above was measured under the above conditions. The storage modulus at 260°C was 1.0 × 10⁻⁶. ５ If it is less than 1, use "1", 1.0 x 10 ５In the above cases, the evaluation was "2". The storage modulus at 260°C is 1.0 × 10⁻⁶. ５ If the above conditions are met, it can be said that the material has heat resistance for solder reflow.

[0093] [Evaluation of Bending Resistance] The resin film obtained above was subjected to a bending resistance test (MIT test) in accordance with JIS P 8115. Specifically, an MIT bending fatigue tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.) was used to measure the number of bending cycles until the film broke. The details of the MIT test conditions are as follows: Loading method: Spring load Load: 1 kgf Bending angle: 135° Bending speed: 175 cpm

[0094]

[0095] The disclosures of this application are related to the subject matter described in Japanese Patent Application No. 2025-049709, filed on 25 March 2025, the disclosures of which are incorporated herein by reference.

Claims

1. A laminate comprising an insulating layer and a metal layer provided on one or both sides of the insulating layer, wherein the insulating layer comprises a cyclic olefin resin (A), which is a copolymer of monomers comprising a cyclic olefin compound (a1) and an α-olefin compound (a2) having three or more carbon atoms, and the cyclic olefin resin (A) has three or more glass transition temperatures within the range of -50 to 350°C, as determined by solid viscoelasticity measurement.

2. The laminate according to claim 1, wherein the cyclic olefin resin (A) has at least one glass transition temperature in the range of -50°C or higher and less than 0°C, in the range of 0°C to 120°C, and in the range of 120°C or higher and 350°C or lower.

3. The laminate according to claim 1, wherein the number of carbon atoms of the α-olefin compound (a2) is in the range of 3 to 20.

4. The laminate according to claim 1, wherein the ratio of the cyclic olefin compound (a1) to the total number of moles of monomers constituting the cyclic olefin resin (A) is in the range of 10 to 90 mol%.

5. The laminate according to claim 1, wherein the number average molecular weight (Mn) of the cyclic olefin resin (A) is in the range of 150,000 to 700,000.

6. A wiring board using the laminate according to any one of claims 1 to 5.

7. A high-frequency wiring board using the laminate described in any one of claims 1 to 5.

8. A copolymer of monomers containing a cyclic olefin compound (a1) and an α-olefin compound (a2) having three or more carbon atoms, having a number-average molecular weight (Mn) in the range of 150,000 to 700,000, and possessing three or more glass transition temperatures determined by solid viscoelasticity measurement within the range of -50 to 350°C, a cyclic olefin resin for metal-clad laminates.

Images