JP7568040B2 - Modified olefin copolymer, resin composition, laminated sheet, prepreg, cured product, substrate with cured product, and electronic device - Google Patents

Description

The present disclosure relates to a modified olefin-based copolymer, a resin composition, a laminate sheet, and a prepreg. It also relates to a cured product obtained from the resin composition, a substrate with the cured product including the cured product formed by curing the resin composition, and an electronic device equipped with the substrate with the cured product.

Resin compositions or cured products of resin compositions are used in various members of electronic components. For example, resin compositions or their cured products are used as interlayer insulating layers between conductor layers of multilayer printed wiring boards. Prepregs made by impregnating glass cloth or the like with resin compositions are used as insulating layers on conductor layers of printed wiring boards. Insulating resin compositions or their cured products are used as sealing resins in semiconductor packages.

As such a resin composition, for example, Patent Document 1 discloses a resin composition containing a maleimide compound (A) having two or more N-substituted maleimide groups, a polyphenylene ether (B), and a copolymer (C) having structural units derived from a styrene-based compound, structural units derived from maleic anhydride, and structural units derived from an N-substituted maleimide. Patent Document 2 discloses a thermosetting cyclic imide resin composition containing specific proportions of (A) a styrene-based elastomer, (B) a cyclic imide compound having a specific structure, (C) an epoxy resin, and (D) a reaction accelerator. Patent Document 3 discloses a thermoplastic elastomer having a side chain containing a hydrogen-bond crosslinking moiety having a specific structure and another side chain containing a covalent crosslinking moiety. Patent Document 4 discloses a thermoplastic elastomer composition that contains at least one elastomer component selected from the group consisting of an elastomeric polymer (A) having a side chain (a) containing a hydrogen-bond cross-linking moiety with a specific structure and having a Tg of 25°C or less, and an elastomeric polymer (B) having a hydrogen-bond cross-linking moiety and a covalent-bond cross-linking moiety in the side chain and having a Tg of 25°C or less, clay, and an α-olefin resin that does not have a chemically bonded cross-linking moiety in a specific ratio.

JP 2020-169276 A JP 2022-111423 A JP 2006-131663 A International Publication No. 2017/047274

As electronic devices become more functional, there is an increasing demand for reliability in the electronic components built into the devices. There is also a demand for resin compositions and their cured products that provide not only excellent heat resistance but also excellent crack resistance after heat cycle testing. In addition, there is a need for materials with low dielectric constants and low dielectric tangents that can handle gigahertz frequencies as the frequency band of signals used in printed wiring boards used in electronic devices, communication devices, etc. There is a demand in the market for resins and resin compositions that can improve crack resistance after heat cycle testing while satisfying both dielectric properties and heat resistance.

The present disclosure has been made in view of the above background, and aims to provide a modified olefin-based copolymer and resin composition that are excellent in dielectric properties and heat resistance, and further excellent in crack resistance after a heat cycle test, as well as a laminate sheet, a prepreg, a cured product, a substrate with the cured product, and an electronic device formed using the resin composition.

As a result of extensive investigations, the present inventors have found that the problems of the present disclosure can be solved in the following aspect, and have thus completed the present disclosure.
[1]: A modified olefin copolymer, the main chain of which contains a structural unit derived from a conjugated diene compound and/or a structural unit derived from an alicyclic or linear non-conjugated olefin compound,
having a monocyclic structure and/or a polycyclic structure in at least one of a side group, a side chain and a molecular chain end;
A modified olefin copolymer in which a ring of the monocyclic structure and/or any ring of the polycyclic structure is at least one of an alicyclic skeleton consisting of carbon atoms and an alicyclic skeleton consisting of carbon atoms and hetero atoms, and which satisfies at least one of the following (i) and (ii):
(i) The alicyclic skeleton has a radical-reactive non-conjugated carbon-carbon unsaturated bond.
(ii) A carbon atom constituting the alicyclic skeleton and a carbon atom not constituting the ring bonded to the carbon atom are bonded to each other through a radically reactive non-conjugated carbon-carbon unsaturated bond.
[2]: The modified olefin copolymer according to [1], wherein the main chain has substantially no unsaturated bonds except at the molecular chain terminals.
[3]: The modified olefin copolymer according to [1] or [2], wherein the main chain contains a structural unit derived from an aromatic vinyl compound.
[4]: The modified olefin copolymer according to any one of [1] to [3], which contains a block consisting of a structural unit derived from an aromatic vinyl compound and a block containing a structural unit derived from a conjugated diene compound.
[5]: The modified olefin copolymer according to [4], wherein the block containing a structural unit derived from a conjugated diene compound further contains a structural unit derived from an aromatic vinyl compound.
[6]: A hydrogenated styrene-based elastomer.
The modified olefin copolymer according to any one of [1] to [5], which is a modified product of any one of styrene-ethylene-butylene block copolymer (SEB), styrene-ethylene-propylene block copolymer (SEP), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-ethylene-butylene-styrene-styrene block copolymer (SEBSS), styrene-isobutylene-styrene block copolymer (SIBS), and styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS).
[7]: A resin composition comprising the modified olefin copolymer according to any one of [1] to [6].
[8]: The resin composition according to [7], further comprising a curable compound, the curable compound comprising at least one selected from the group consisting of an epoxy compound (b1), a cyanate ester compound (b2), a maleimide compound (b3), an allyl group-containing compound (b4), a vinyl group-containing compound (b5), a (meth)acrylate group-containing compound (b6), and a benzoxazine compound (b7).
[9]: The resin composition according to [7] or [8], further comprising an inorganic filler.
[10]: A laminate sheet comprising a substrate and a resin composition layer formed on the substrate using the resin composition according to any one of [7] to [9].
[11]: A prepreg obtained by impregnating a substrate with the resin composition according to any one of [7] to [9].
[12]: A cured product obtained from the resin composition according to any one of [7] to [9].
[13]: A substrate with a cured product, comprising a cured product formed by curing the resin composition according to any one of [7] to [9].
[14]: An electronic device equipped with a substrate with the cured product according to [13].

The present disclosure has the excellent effect of providing a modified olefin-based copolymer and resin composition that are excellent in dielectric properties and heat resistance, and further excellent in crack resistance after a heat cycle test, as well as a laminate sheet, a prepreg, a cured product, a substrate with a cured product, and an electronic device formed using the resin composition.

IR spectra of Resin R-5, Synthesis Example 5, and Comparative Synthesis Example 5.

The present disclosure will be described in detail below. Other embodiments are also included in the scope of the present disclosure as long as they are consistent with the spirit of the present disclosure. In addition, in this specification, a numerical range specified using "~" includes the numerical values written before and after "~" as the range of the lower and upper limits. In this specification, "film" and "sheet" are synonymous and are not distinguished by thickness. In addition, unless otherwise noted, the various components appearing in this specification may be used independently alone or in combination of two or more types. The numerical values described in this specification refer to values obtained by the method described in the Examples below.

1. Modified Olefin-Based Copolymer The modified olefin-based copolymer of the present disclosure (hereinafter also referred to as the present copolymer) has a main chain containing structural units derived from a conjugated diene compound and/or structural units derived from an alicyclic or linear non-conjugated olefin compound. From the viewpoint of further improving the dielectric properties and heat resistance, it is preferable that the main chain does not substantially contain unsaturated bonds except at the molecular chain end. In addition, "substantially does not contain" as used herein means that there are no unsaturated bonds except those that are inevitably contained. At least one of the side groups, side chains, and molecular chain ends of the present copolymer has a monocyclic structure and/or a polycyclic structure. And, either the ring of this monocyclic structure and/or the ring of the polycyclic structure is at least one of an alicyclic skeleton consisting of carbon atoms and an alicyclic skeleton consisting of carbon atoms and hetero atoms, and satisfies at least one of the following (i) and (ii). In addition, the skeleton refers to a structure formed by atoms that directly form a ring. For example, in the case of a cycloalkenyl group, the atoms that directly form the ring are carbon atoms, and do not contain hydrogen. In the case of a maleimide group, the atoms directly forming the ring are a carbon atom and a heteroatom (nitrogen atom).
(i) The alicyclic skeleton has a radical-reactive non-conjugated carbon-carbon unsaturated bond.
(ii) A carbon atom constituting the alicyclic skeleton and a carbon atom not constituting the ring bonded to the carbon atom are bonded to each other through a radically reactive non-conjugated carbon-carbon unsaturated bond.

The aforementioned "structural unit derived from an alicyclic or linear non-conjugated olefin compound" in the main chain refers to a structure in which the main chain is composed of an aliphatic hydrocarbon that does not have aromaticity (i.e., a π-electron conjugated system). The present copolymer having a structural unit derived from an alicyclic non-conjugated olefin compound has a ring structure in the main chain. The main chain is a linear molecular chain that serves as the backbone of the polymer that constitutes the resin, and refers to a chain of carbon atoms. The main chain may contain carbon atoms that constitute an alicyclic structure made of hydrocarbons. From the viewpoint of dielectric properties, it is preferable that the present copolymer does not contain a copolymer having a ring containing a heteroatom in the main chain (e.g., having a ring derived from a maleimide group). Also, from the viewpoint of crack resistance after a heat cycle test, the main chain skeleton of the present copolymer is preferably a linear structure rather than an alicyclic structure.

The "alicyclic skeleton" in the monocyclic structure and/or polycyclic structure of the side chain, side group, or molecular chain end refers to a ring structure such as a cyclic aliphatic hydrocarbon group that does not have aromaticity (i.e., a π-electron conjugated system), and the monocyclic structure and/or polycyclic structure may have a functional group and/or a substituent such as a maleimide group or a carbonyl group. The "monocyclic structure" refers to a structure having a monocyclic ring. It has one or more monocyclic rings. The "polycyclic structure" refers to a bridged structure (bridgehead structure), a condensed ring structure formed by two or more monocyclic rings sharing (condensing) only one side of each ring, or a structure combining these. It is sufficient to have a ring having an alicyclic skeleton, and an aromatic ring may be included as part of the monocyclic structure or part of the polycyclic structure. It is preferable that it does not contain a heterocycle.

The "radical-reactive non-conjugated carbon-carbon unsaturated bond" in (i) and (ii) refers to a bond that can be covalently bonded to other modified olefin copolymers and/or curable compounds by a radical reaction. The radical reaction is induced, for example, by heating, light irradiation, or electron beam irradiation.

The copolymer has the above-mentioned structure and is therefore excellent in heat resistance. The main reason for this is believed to be that the alicyclic skeleton is present in at least one of the side groups, side chains and molecular chain ends, and is bonded by radically reactive non-conjugated carbon-carbon unsaturated bonds, forming a crosslinked structure through the curing treatment and improving the curability. In particular, by having the alicyclic skeleton in the side chains and/or side groups, steric hindrance is suppressed, improving reactivity and enhancing the curability.

In addition, the cured product of the resin composition containing this copolymer has excellent dielectric properties. The main reason for this is believed to be that by having this alicyclic skeleton in at least one of the side groups, side chains, and molecular chain ends, and containing structural units derived from conjugated diene compounds and/or structural units derived from alicyclic or linear non-conjugated olefin compounds, the crosslinking sites are carbon-carbon bonds, which reduces polarization and suppresses dielectric relaxation compared to crosslinking via oxygen atoms or nitrogen atoms (for example, compared to curing using epoxy compounds). In addition, since the side chains and/or side groups have this alicyclic skeleton, there is little steric hindrance and it is highly reactive, so that the non-conjugated carbon-carbon unsaturated bonds remaining after the curing reaction can be reduced. As a result, it is possible to suppress the generation of hydroxyl groups due to oxidation and the associated deterioration of dielectric properties.

In addition, since the cured product of the resin composition containing this copolymer has the above-mentioned structure, it has excellent crack resistance after heat cycle testing. The main reason for this is thought to be that the main chain is made of structural units derived from a conjugated diene compound and/or an alicyclic or linear non-conjugated olefin skeleton, which increases flexibility, while a crosslinkable structure is constructed by carbon-carbon unsaturated bonds of this alicyclic skeleton at least in the side group, the side chain, and the molecular chain end. From the viewpoint of more effectively increasing flexibility, it is preferable to use structural units derived from a conjugated diene compound that does not substantially have unsaturated bonds in the main chain and/or an alicyclic or linear non-conjugated olefin skeleton as the main chain skeleton.

1-1. Main Chain Skeleton The main chain of the present copolymer contains structural units derived from a conjugated diene compound and/or structural units derived from an alicyclic or linear non-conjugated olefin compound. From the viewpoint of further improving the dielectric properties and heat resistance, it is preferable that the main chain has substantially no unsaturated bonds, except at the molecular chain terminals. In this case, if unsaturated bonds remain in the main chain skeleton, a copolymer having substantially no unsaturated bonds can be obtained by a hydrogenation reaction (hydrogenation reaction).

The monomer for obtaining the structural unit derived from the conjugated diene compound that constitutes the main chain of the copolymer (hereinafter also referred to as monomer A) can be appropriately selected from known monomers. Suitable examples include butadiene, isoprene, 2,3-dimethyl-butadiene, 2-phenyl-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 1,3-octadiene, 1,3-cyclohexadiene, 2-methyl-1,3-octadiene, 1,3,7-octatriene, myrcene, farnesene, chloroprene, and mixtures thereof. Among these, butadiene and isoprene are more preferred.

The monomer for obtaining the structural unit derived from the alicyclic or linear non-conjugated olefin compound constituting the main chain of the present copolymer (hereinafter also referred to as monomer B) can be appropriately selected from known monomers. Suitable examples include α-olefins such as ethylene, propylene, 1-pentene, 1-hexene, 1-heptene, and 1-octene, heteroatom-substituted alkene compounds such as N-vinylpyrrolidone, bicyclic monomers such as norbornene and norbornadiene, tricyclic monomers such as dicyclopentadiene and dihydrodicyclopentadiene, tetracyclic monomers such as tetracyclododecene, pentacyclic monomers such as tricyclopentadiene, heptacyclic monomers such as tetracyclopentadiene, and derivatives thereof. Among these, ethylene and propylene are preferred, and ethylene is particularly preferred.

From the viewpoint of achieving excellent mechanical strength and heat resistance, it is preferable that the copolymer has structural units derived from aromatic vinyl compounds in the main chain. The monomer for obtaining the structural units derived from aromatic vinyl compounds constituting the main chain of the copolymer (hereinafter also referred to as monomer C) can be appropriately selected from known monomers. Suitable examples include methylstyrenes such as styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, and p-methylstyrene; 2,6-dimethylstyrene, 2,4-dimethylstyrene, α-methyl-o-methylstyrene, α-methyl-m-methylstyrene, α-methyl-p-methylstyrene, β-methyl-o-methylstyrene, β-methyl-m-methylstyrene, β-methyl-p-methylstyrene, 2,4,6-trimethylstyrene, α-methyl-2,6-dimethylstyrene, α-methyl-2,4-dimethylstyrene, β-methyl-2,6-dimethylstyrene, β-methyl-2,4-dimethylstyrene, o-t-butylstyrene, m-t-butylstyrene, p-t-butylstyrene, o-methoxystyrene, m-methoxystyrene, p-methoxystyrene, indene, vinylnaphthalene, and N-vinylcarbazole. From the viewpoint of the balance between production cost and physical properties, styrene, α-methylstyrene, p-methylstyrene, and mixtures thereof are preferred, and styrene is more preferred.

The copolymer may contain other monomers (hereinafter also referred to as monomer D) that are copolymerizable with the above-mentioned monomers A and B, within the scope of the present disclosure. From the viewpoint of maintaining good dielectric properties and good crack resistance after heat cycles, it is preferable that the alicyclic structure that forms the main chain skeleton does not contain a heterocycle. Specific examples of monomer D include aromatic vinyl compounds such as N-vinylcarbazole, vinylnaphthalene, and vinylanthracene, β-pinene, 8,9-p-menthene, and dipentene.

The copolymer may be any of random copolymers, block copolymers, and gradient copolymers, but block copolymers are preferred from the viewpoint of both heat resistance and stress relaxation. As a preferred example, from the viewpoint of both heat resistance and stress relaxation, a block copolymer containing a block consisting of structural units derived from an aromatic vinyl compound and a structural unit derived from a conjugated diene compound can be exemplified. From the viewpoint of both heat resistance and stress relaxation, the block copolymer more preferably contains structural units derived from an aromatic vinyl compound at both ends of the block containing structural units derived from a conjugated diene compound. Furthermore, it is preferred that the main chain of the copolymer contains structural units derived from styrene as the block consisting of structural units derived from an aromatic vinyl compound, and contains structural units derived from butadiene and isoprene as the block containing structural units derived from a conjugated diene compound. A-B-A type triblock copolymers and A-B type diblock copolymers are preferred, and A-B-A type triblock copolymers are more preferred. As a preferred example of block A, a monomer derived from a styrene system can be exemplified, and as block B, a monomer derived from butadiene and isoprene can be exemplified.

Suitable examples of this copolymer include modified products of the following hydrogenated styrene elastomers: styrene-ethylene-butylene block copolymer (SEB), styrene-ethylene-propylene block copolymer (SEP), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-ethylene-butylene-styrene-styrene block copolymer (SEBSS), styrene-isobutylene-styrene block copolymer (SIBS), and styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS).

Monomers A to D may be used independently, either alone or in combination of two or more. The total of the structural units derived from monomer A and the structural units derived from monomer B constituting the copolymer (including the case where only one of them is present) is preferably contained in 30 to 90 mass% of 100 mass% of the copolymer from the viewpoint of stress relaxation, more preferably 40 to 80 mass%, and even more preferably 55 to 75 mass%. The structural units derived from monomer C constituting the copolymer are preferably contained in 100 mass% of the copolymer from the viewpoint of heat resistance, more preferably 10 to 70 mass%, more preferably 15 to 60 mass%, even more preferably 20 to 45 mass%, and particularly preferably 25 to 45 mass%. The total of the structural units derived from monomers A to C constituting the copolymer is preferably contained in 90 mass% or more of 100 mass% of the copolymer, more preferably 95 mass% or more, and may be 100 mass%. The above range is the mass% of the olefin-based copolymer before modification.

1-2. Side groups, side chains and molecular chain ends At least one of the side groups, side chains and molecular chain ends of the copolymer has a monocyclic structure and/or a polycyclic structure (hereinafter also referred to as a non-conjugated C=C bond-containing ring) having an alicyclic skeleton that satisfies at least one of (i) and (ii). This makes it possible to impart crosslinking properties to the copolymer. By crosslinking the copolymer, it is possible to improve crack resistance after a heat cycle test in addition to excellent heat resistance.

An example of a monocyclic structure or polycyclic structure having an alicyclic skeleton that satisfies the above (i) is represented by the following chemical formula (1).
In the formula, R ¹ is a direct bond or a methylene group, and R ² is hydrogen or a methyl group. In the formula, * indicates a bonding site with the main chain or side chain of the modified olefin copolymer. The hydrogen atom bonded to the carbon of the ring may be substituted with a substituent. Examples of such a substituent include an alkyl group having 1 to 18 carbon atoms (methyl group, ethyl group, isopropyl group, t-butyl group, etc.), an alkoxy group having 1 to 18 carbon atoms (methoxy group, ethoxy group, propoxy group, etc.), an aryl group (phenyl group, naphthyl group, etc.), a heteroaromatic group (thienyl group, etc.), a haloaryl group (pentafluorophenyl group, 3-fluorophenyl group, 3,4,5-trifluorophenyl group, etc.), an alkenyl group such as a vinylidene group, an alkynyl group, an amide group, an acyl group, a haloalkyl group (perfluoroalkyl group, etc.), a hydroxy group, a nitro group, a cyano group, a carboxy group, and a halogen group (fluoro group, chloro group, bromo group, etc.).

A specific example of the above (ii) is a group represented by the following chemical formula (2).
R ¹ , R ² and * in the formula are as explained in chemical formula (1). In addition, the hydrogen atom bonded to the carbon of the ring may be substituted with a substituent, and suitable examples of such a substituent include the substituents exemplified in chemical formula (1).

From the viewpoint of dielectric properties, it is preferable that an alicyclic skeleton having a radically reactive non-conjugated carbon-carbon unsaturated bond that satisfies at least one of (i) and (ii) above does not contain a heteroatom such as a maleimide group. From the viewpoint of dielectric properties, suitable examples of an alicyclic skeleton having a non-conjugated carbon-carbon unsaturated bond include norbornene and terpenes (e.g., α-pinene and limonene). When a norbornene group is included, the alicyclic structure does not contain a heteroatom, and therefore the dielectric properties can be improved.

The molecular chain ends of the copolymer may be substantially all structures having the alicyclic skeleton. In addition, some of the molecular chain ends may contain functional groups other than the alicyclic skeleton. Furthermore, some of the molecular chain ends may be blocked ends having no functional groups. The molecular chain ends of the copolymer may not have the alicyclic skeleton, but the alicyclic skeleton may be present in the side chains and/or side groups of the copolymer. It is sufficient that the alicyclic skeleton is present in at least one of the molecular chain ends, the side chains, and the side groups.

1-3. Copolymerization type, weight average molecular weight, etc. From the viewpoint of heat resistance and crack resistance after a heat cycle test, the present copolymer is preferably a block copolymer. A suitable example is a block copolymer containing a block consisting of structural units derived from an aromatic vinyl compound and a block containing structural units derived from a conjugated diene compound. Also suitable is a modified block copolymer containing a structural unit derived from an aromatic vinyl compound in addition to a block containing structural units derived from a conjugated diene compound.

The weight average molecular weight (hereinafter also referred to as Mw) of the present copolymer is not particularly limited, but from the viewpoint of improving the crack resistance after a heat cycle test, Mw is preferably 20,000 or more, more preferably 50,000 or more, and even more preferably 70,000 or more. From the viewpoint of compatibility between the present copolymer and the curable compound, Mw of the present copolymer is preferably 400,000 or less, more preferably 300,000 or less, and even more preferably 200,000 or less.

The position of the non-conjugated C=C bond-containing ring of this copolymer may be any of a side group, a side chain, and a molecular chain end, but from the viewpoint of the manufacturing process, a side group or a side chain is preferable. The amount of the radically reactive non-conjugated carbon-carbon unsaturated bond of this copolymer is not particularly limited, but from the viewpoint of improving heat resistance, the radically reactive non-conjugated carbon-carbon unsaturated bond valence of (i) and (ii) is preferably 1 to 50 mgKOH/g, more preferably 2 to 35 mgKOH/g, and even more preferably 5 to 25 mgKOH/g.

From the viewpoint of heat resistance and crack resistance after a heat cycle test, the content of blocks consisting of structural units derived from aromatic vinyl compounds is preferably 10 to 70% by mass relative to 100% by mass of the copolymer. It is more preferably 20 to 60% by mass, and even more preferably 25 to 45% by mass.

1-4. Production method An example of a method for producing the copolymer will be described. As a method for producing the copolymer, for example, a monomer containing at least a conjugated diene compound and/or an alicyclic or linear non-conjugated olefin compound is polymerized to obtain a resin before modification (unmodified copolymer). The polymerization method may be any of radical polymerization, anionic polymerization, cationic polymerization, and living polymerization, and known methods can be applied. An unmodified block copolymer is obtained by sequentially adding monomers. In order to make the unmodified block copolymer substantially free of unsaturated double bonds in the main chain, a hydrogenation reaction may be carried out by a known method, such as reacting with pressurized hydrogen in the presence of a catalyst after polymerization.

A suitable method for introducing (modifying) a non-conjugated C=C bond-containing ring into at least one of a side chain, a side group, and a molecular chain end is a production method through a reaction step in which a compound capable of introducing a non-conjugated C=C bond-containing ring is reacted with an unmodified copolymer. In addition, when polymerizing an olefin copolymer, a monomer having this non-conjugated C=C bond-containing ring may be used in part to obtain a copolymer having a C=C bond-containing ring in the side group.

The introduction of a non-conjugated C=C bond-containing ring to the molecular chain end can be achieved by polymerizing an unmodified olefin copolymer, optionally carrying out a hydrogenation reaction, and reacting a compound having a non-conjugated C=C bond-containing ring. A compound having a functional group may be introduced to the molecular chain end of an unmodified olefin copolymer, and the functional group may be reacted with a compound having a non-conjugated C=C bond-containing ring. For example, acrylic acid is introduced to the molecular chain end. Then, a compound having a monocyclic structure and/or a polycyclic structure having an alicyclic skeleton that satisfies at least one of (i) and (ii) and has a functional group (e.g., an amino group, an epoxy group, a hydroxyl group) that reacts with a carboxy group can be reacted to introduce a non-conjugated C=C bond-containing ring to the molecular chain end.

The introduction of a non-conjugated C=C bond-containing ring into a side chain can be produced by, for example, adding a radical initiator to an unmodified olefin copolymer under heating, and graft polymerizing an acid anhydride. Examples of compounds into which an acid anhydride group can be introduced include maleic anhydride, citraconic anhydride, and itaconic anhydride. Commercially available products into which these have been introduced may also be used.

After introducing an acid anhydride into an unmodified olefin copolymer, which is the precursor of this copolymer, the entirety or a part of this acid anhydride is reacted with a compound having a monocyclic structure and/or a polycyclic structure with an alicyclic skeleton that satisfies at least one of (i) and (ii), to obtain the present copolymer having a non-conjugated C=C bond-containing ring in the side chain.

Examples of compounds having a monocyclic structure and/or a polycyclic structure with an alicyclic skeleton that satisfies at least one of (i) and (ii) include the following compounds having a functional group that reacts with a carboxylic acid as a substituent. That is, an indene ring having a functional group (amino group, epoxy group, hydroxyl group, etc.) that reacts with a carboxylic acid as a substituent; a cycloalkene ring such as cyclohexene; an alkyl-substituted ring such as 5-methyl-bicyclo[2.2.1]hept-2-ene, 5-ethyl-bicyclo[2.2.1]hept-2-ene, 5-butyl-bicyclo[2.2.1]hept-2-ene, 5-hexyl-bicyclo[2.2.1]hept-2-ene, 5-decyl-bicyclo[2.2.1]hept-2-ene, 5-cyclohexyl-bicyclo[2.2.1]hept-2-ene, or 5-cyclopentyl-bicyclo[2.2.1]hept-2-ene; 5-ethylidene-bicyclo[2.2.1]hept-2-ene (5-ethylidene-2-norbornene), 5-vinyl-bicyclo[2.2.1]hept alkenyl-substituted 5-phenyl-bicyclo[2.2.1]hept-2-ene (5-phenyl-2-norbornene), bicyclo[2.2.1]hept-2-ene, 5-propenyl-bicyclo[2.2.1]hept-2-ene, 5-cyclohexenyl-bicyclo[2.2.1]hept-2-ene, 5-cyclopentenyl-bicyclo[2.2.1]hept-2-ene, etc. Examples of such rings include norbornene-containing rings such as tricyclo[4.3.0.12,5]deca-3,7-diene, methyldicyclopentadiene, dimethyldicyclopentadiene, tetracyclo[9.2.1.02,10.03,8]tetradeca-3,5,7,12-tetraene, and tetracyclo[10.2.1.02,11.04,9]pentadeca-4,6,8,13-tetraene. Further examples include unsubstituted or alkyl tetracyclododecenes such as tetracyclododecene, 8-methyltetracyclododecene, 8-ethyltetracyclododecene, 8-cyclohexyltetracyclododecene, and 8-cyclopentyltetracyclododecene; tetracyclododecenes having a double bond outside the ring such as 8-methylidenetetracyclododecene, 8-ethylidenetetracyclododecene, 8-vinyltetracyclododecene, 8-propenyltetracyclododecene, 8-cyclohexenyltetracyclododecene, and 8-cyclopentenyltetracyclododecene; and tetracyclododecenes having an aromatic ring such as 8-phenyltetracyclododecene. Other examples include tetracyclododecenes having a substituent containing an oxygen atom, such as 8-methoxycarbonyltetracyclododecene, 8-methyl-8-methoxycarbonyltetracyclododecene, 8-hydroxymethyltetracyclododecene, 8-carboxytetracyclododecene, tetracyclododecene-8,9-dicarboxylic acid, and tetracyclododecene-8,9-dicarboxylic anhydride, which have a functional group (amino group, epoxy group, hydroxy group, etc.) that reacts with carboxylic acid as a substituent.

An example of a compound having a monocyclic structure and/or a polycyclic structure with an alicyclic skeleton having an amino group and satisfying at least one of (i) and (ii) is compound (3) below.
In the formula, R ¹ and R ² are as explained in chemical formula (1). R ³ is a direct bond or an alkyl group having 1 to 20 carbon atoms. ^{R 3} is preferably a direct bond or an alkyl group having 1 to 6 carbon atoms, and R ³ is more preferably a direct bond or an alkyl group having 1 to 4 carbon atoms. In addition, the hydrogen atom bonded to the carbon of the ring may be substituted with a substituent. Examples of such a substituent include the substituents exemplified in the explanation of chemical formula (1). A particularly preferred compound is 5-norbornene-2 - methylamine.

After introducing an acid anhydride into an unmodified olefin copolymer, all or part of the acid anhydride is reacted with a compound having a monocyclic structure and/or a polycyclic structure having an alicyclic skeleton that satisfies at least one of (i) and (ii) having an amino group to form an imide bond. This imide bond improves the compatibility of the curable compound with the maleimide compound (b3) described later, thereby improving crosslinking and improving the heat resistance of the cured product. In other words, from the viewpoint of the heat resistance of the cured product, a resin composition in which an imide bond is introduced into any of the side chains, side groups, or molecular chain ends of this copolymer and a maleimide compound (b3) is combined as a curable compound is preferable.

The temperature in the reaction for introducing an acid anhydride group into an unmodified olefin copolymer is preferably 50 to 200° C., more preferably 100 to 180° C. The temperature in the reaction for reacting the acid anhydride with a compound having a monocyclic structure and/or a polycyclic structure with an alicyclic skeleton after the introduction of the acid anhydride is preferably 80 to 250° C., more preferably 100 to 200° C.
The time for the reaction for introducing an acid anhydride group into an unmodified olefin copolymer is preferably 1 to 240 minutes, more preferably 10 to 180 minutes. After the introduction of the acid anhydride, the time for the reaction with the compound having a monocyclic structure and/or a polycyclic structure with an alicyclic skeleton is preferably 30 to 240 minutes, more preferably 60 to 180 minutes.

It is preferable to add an antioxidant when introducing an acid anhydride group and introducing the alicyclic skeleton into a side chain and/or a side group. As the antioxidant, for example, a known antioxidant can be used. Specific examples of the antioxidant include phenothiazine-based compounds such as phenothiazine, bis-(1-dimethylbenzyl)phenothiazine, and 3,7-dioctylphenothiazine; bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionic acid][ethylenebis(oxyethylene)]2,4-bis[(laurylthio)methyl]-o-cresol, 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl), 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl), and 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-1,3,5-triazine. and pentaerythritol tetrakis 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate; phenoxazine compounds such as phenoxazine; nitroso compounds or salts thereof such as 4-nitrosophenol, N-nitrosodiphenylamine, N-nitrosocyclohexylhydroxylamine, and N-nitrosophenylhydroxylamine; quinone compounds such as methylhydroquinone, t-butylhydroquinone, 2,5-di-t-butylhydroquinone, and 4-benzoquinone; and phenol compounds such as 4-methoxyphenol, 4-methoxy-1-naphthol, and t-butylcatechol.
Among these, in terms of obtaining superior effects of the present disclosure, the antioxidant is preferably at least one selected from the group consisting of phenothiazine-based compounds, hindered phenol-based compounds, and phenoxazine-based compounds.

Examples of catalysts include aliphatic tertiary amines such as triethylamine, aromatic tertiary amines such as dimethylaniline, and heterocyclic tertiary amines such as pyridine, picoline, and isoquinoline. Examples of dehydrating agents include aliphatic acid anhydrides such as acetic anhydride, and aromatic acid anhydrides such as benzoic anhydride. Suitable examples of radical initiators include the compounds described below.

Examples of organic solvents used in the polymerization include N-methyl-2-pyrrolidone (NMP), 2-butanone, dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N,N-diethylacetamide, hexamethylphosphoramide, N-methylcaprolactam, dimethyl sulfate, cyclohexanone, dioxane, tetrahydrofuran, diglyme, triglyme, and cresol. Solvents may be used alone or in combination of two or more. Aromatic hydrocarbons such as xylene and toluene may also be used in combination.

2. Resin Composition The resin composition according to this embodiment (hereinafter also referred to as the present composition) contains at least the present copolymer. According to the present composition, the non-conjugated C=C bond-containing rings between the molecules of the present copolymer can be crosslinked with a radical initiator. The present composition may further contain a curable compound. By containing the curable compound, crosslinking between the non-conjugated C=C bond-containing rings of the present copolymer and the curable compound can be formed. By containing the curable compound, it becomes easy to control the crosslink density of the cured product.

Since the composition has the above-mentioned structure, the cured product has excellent heat resistance. The main reason is that a crosslinking structure can be constructed starting from a non-conjugated carbon-carbon unsaturated bond of an alicyclic skeleton having a relatively mild and moderate reactivity in at least one of the side groups, side chains, and molecular chain ends, or a non-conjugated carbon-carbon unsaturated bond directly connected to the alicyclic skeleton, and that the relatively flexible and tough chain-like hydrocarbon skeleton in the main chain suppresses the decrease in mobility of the copolymer after curing treatment, improving stress relaxation and dispersibility. In addition, by combining the main chain chain-like hydrocarbon skeleton and the copolymer having a relatively low reactivity "radical-reactive non-conjugated carbon-carbon unsaturated bond derived from an alicyclic structure" with a curable compound, it is easy to create a contrast between the sparse and dense parts of the crosslinking structure, and it is thought that the heat resistance can be improved. From the viewpoint of further improving heat resistance, it is preferable that the chain-like hydrocarbon skeleton of the main chain is a saturated hydrocarbon skeleton.

In addition, since the composition has the above-mentioned structure, it is possible to provide a resin composition with excellent dielectric properties. By using the present copolymer having the present alicyclic skeleton in at least one of the side groups, side chains, and molecular chain ends, and having a chain-like hydrocarbon skeleton in the main chain, the presence of the present alicyclic skeleton in the side chains and/or side groups results in less steric hindrance and high reactivity, which makes it possible to reduce the non-conjugated carbon-carbon unsaturated bonds remaining after the curing reaction. As a result, it is possible to suppress the generation of hydroxyl groups due to oxidation and the associated decrease in dielectric properties, which is believed to result in excellent dielectric properties. Below, the components of the present composition and the manufacturing method are described in detail.

2-1. Curable Compound The curable compound is a compound that crosslinks and cures by heating, light irradiation, electron beam irradiation, etc., and the type is not particularly limited. The curable compound may be used alone or in combination of two or more types, regardless of whether they are the same or different.

Suitable examples of the curable compound include epoxy compounds (b1), cyanate ester compounds (b2), maleimide compounds (b3), allyl group-containing compounds (b4), vinyl group-containing compounds (b5), (meth)acrylate group-containing compounds (b6), and benzoxazine compounds (b7) (hereinafter also referred to as components (b1) to (b7)). It is preferable to have one or more types selected from the group consisting of components (b1) to (b7) as the curable compound.

The curable compound preferably contains a curable compound (B1) having a radically reactive non-conjugated carbon-carbon unsaturated bond (hereinafter also simply referred to as curable compound (B1)). The radically reactive non-conjugated carbon-carbon unsaturated bond refers to a bond that can react with other curable compounds to form a crosslinked structure and/or can react with the radically reactive non-conjugated carbon-carbon unsaturated bond of the copolymer to form a bond. Suitable examples of the curable compound (B1) bonded by a radically reactive non-conjugated carbon-carbon unsaturated bond include maleimide compounds (b3), allyl group-containing compounds (b4), vinyl group-containing compounds (b5), and (meth)acrylate group-containing compounds (b6).

From the viewpoint of further improving heat resistance, it is preferable to include a maleimide compound (b3) as a curable compound. The maleimide compound (b3) may be used alone, or may be used in combination with one or more of the components (b1), (b2), (b4) to (b7). Suitable combinations include a combination of the cyanate ester compound (b2) and the maleimide compound (b3), and a combination of the maleimide compound (b3) and at least one of the components (b4) to (b7). Among these, a combination of the maleimide compound (b3) and the allyl group-containing compound (b4) is more suitable. In addition, when the maleimide compound (b3) and the benzoxazine compound (b7) are crosslinked by heating, the reactivity of the maleimide is improved and the dielectric properties are also excellent, which is particularly preferable.

From the viewpoint of forming stronger crosslinks by the reaction between carbon-carbon unsaturated bonds, combinations of maleimide compound (b3) and allyl group-containing compound (b4), maleimide compound (b3) and vinyl group-containing compound (b5), and maleimide compound (b3) and (meth)acrylate group-containing compound (b6) are preferred.

From the viewpoint of improving toughness, it is preferable to use a curable compound having a polyphenylene ether structure in (b1) to (b7), and more preferably, in the allyl group-containing compound (b4), the vinyl group-containing compound (b5), the (meth)acrylate group-containing compound (b6), and the benzoxazine compound (b7), a polyphenylene ether compound having the following general formula (4) as a part of its structure.
Examples of R ¹¹ , R ¹² , R ¹³ and R ¹⁴ each independently represent a hydrogen atom, a halogen atom (such as a fluorine atom, a chlorine atom or a bromine atom), an alkyl group which may have a substituent (a linear or branched alkyl group having 1 to 6 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group or a heptyl group, and a cycloalkyl group such as a cyclohexyl group), an alkoxy group which may have a substituent (an alkoxy group having 1 to 6 carbon atoms, such as a methoxy group, an ethoxy group, a butoxy group or a propoxy group), an aryl group which may have a substituent (such as a phenyl group or a naphthyl group), an amino group which may have a substituent, a carboxy group, a nitro group or a cyano group.

From the viewpoint of heat resistance, particularly long-term heat resistance, the average number of curable functional groups in the polyphenylene ether compound is preferably 1 to 10, and more preferably 2 or more.

The Mw of the components (b4) to (b7) having a polyphenylene ether structure is not particularly limited, but from the viewpoint of improving crack resistance after a heat cycle test, it is preferably 200 or more, and more preferably 500 or more. The upper limit of Mw is not particularly limited, but taking into consideration ease of availability, etc., it is 10,000 or less.

Of the 100% by mass of the components in the composition excluding the filler and solvent, it is preferable to use 10 to 98% by mass of the curable compound, more preferably 30 to 90% by mass, and even more preferably 45 to 85% by mass.

From the viewpoint of heat resistance, a preferred embodiment includes a curable compound (B1) having a molecular weight of 100 or more and less than 10,000, and bonded by a radically reactive non-conjugated carbon-carbon unsaturated bond. In addition to the above embodiment, the heat resistance is further improved by setting the content of the present copolymer to 5 to 40% by mass relative to 100% by mass of the total of the present copolymer and the curable compound (B1).

The molecular weight of a curable compound refers to the molecular weight of a low molecular weight compound, and refers to the number average molecular weight in the case of a compound obtained by polymerizing a monomer. When two or more curable compounds are used, the molecular weight of the curable compound refers to the sum of the molecular weight of each curable compound x the content (mass %) of that curable compound.

Epoxy compound (b1) refers to a curable compound having an epoxy group. It is preferable to use epoxy compound (b1) in combination with an active ester compound. An active ester compound refers to a compound that has one or more ester groups in one molecule that react with epoxy groups and cures epoxy resins. Examples of commercially available active ester compounds include "HPC-8000-65T", "EXB9416-70BK" and "EXB8100-65T" manufactured by DIC Corporation.

By using an active ester compound, an ester group is generated by the reaction between the epoxy compound (b1) and the active ester compound. This makes it possible to reduce polarity compared to when a phenol-based curing agent is used. As a result, it is possible to more effectively improve the dielectric properties.

Specific examples of epoxy compounds (b1) include glycidyl ether type epoxy resins; glycidyl amine type epoxy resins such as tetraglycidyl diaminodiphenylmethane, triglycidyl para-aminophenol, triglycidyl meta-aminophenol, tetraglycidyl meta-xylylenediamine, and sorbitol polyglycidyl ether; glycidyl ester type epoxy resins such as diglycidyl phthalate, diglycidyl hexahydrophthalate, and diglycidyl tetrahydrophthalate; cyclic aliphatic (alicyclic) epoxy resins such as epoxycyclohexylmethyl-epoxycyclohexanecarboxylate and bis(epoxycyclohexyl)adipate; bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, and bisphenol AD type epoxy resins. Other examples include cresol novolac epoxy resins, phenol novolac epoxy resins, α-naphthol novolac epoxy resins, bisphenol A novolac epoxy resins, dicyclopentadiene epoxy resins, tetrabromobisphenol A epoxy resins, and brominated phenol novolac epoxy resins.

Cyanate ester compound (b2) refers to a curable resin having a cyanate group. Examples of cyanate ester compound (b2) include bisphenol A type cyanate ester resin, bisphenol A type cyanate ester, bisphenol F type cyanate ester resin, bisphenol E type cyanate ester resin, bisphenol S type cyanate ester resin, bisphenol sulfide type cyanate ester resin, phenylene ether type cyanate ester resin, naphthylene ether type cyanate ester resin, biphenyl type cyanate ester resin, tetramethylbiphenyl type cyanate ester resin, polyhydroxynaphthalene type cyanate ester resin, phenol novolac type cyanate ester resin, cresol novolac type cyanate ester resin, Examples of such cyanate ester resins include triphenylmethane type cyanate ester resins, tetraphenylethane type cyanate ester resins, dicyclopentadiene-phenol addition reaction type cyanate ester resins, phenol aralkyl type cyanate ester resins, naphthol novolac type cyanate ester resins, naphthol aralkyl type cyanate ester resins, naphthol-phenol co-condensed novolac type cyanate ester resins, naphthol-cresol co-condensed novolac type cyanate ester resins, aromatic hydrocarbon formaldehyde resin modified phenol resin type cyanate ester resins, biphenyl modified novolac type cyanate ester resins, and anthracene type cyanate ester resins.

Commercially available cyanate ester compounds (b2), such as phenol novolac type cyanate ester resins (PT-30 and PT-60 manufactured by Lonza Japan), and trimerized prepolymers of bisphenol type cyanate ester resins (BA-230S, BA-3000S, BTP-1000S, and BTP-6020S manufactured by Lonza Japan), may also be used.

From the viewpoint of improving heat resistance and crack resistance after a heat cycle test, it is preferable to include a maleimide compound (b3) having a molecular weight of 100 or more and less than 10,000. By combining such a maleimide compound (b3) having a relatively low molecular weight and high reactivity with the present copolymer having a relatively high molecular weight and relatively low reactivity, which is bonded by a radically reactive non-conjugated carbon-carbon unsaturated bond derived from an alicyclic structure, it is believed that sparse and dense parts of the crosslinked structure are easily generated, effectively improving heat resistance and crack resistance after a heat cycle test.

An example of the maleimide compound (b3) is a polyfunctional maleimide obtained by reacting a polyfunctional amine with maleic anhydride. Examples of polyfunctional amines include isophorone diamine, dicyclohexylmethane-4,4'-diamine, and Huntsman Corporation's Jeffamine D-230, HK-511, D-400, XTJ-582, D-2000, XTJ-578, XTJ-509, XTJ-510, T-403, and T-5000, which have an aminated polypropylene glycol backbone, and XTJ-500, XTJ-501, XTJ-502, XTJ-504, XTJ-511, XTJ-512, and XTJ-590, which have an aminated ethylene glycol backbone, and XTJ-542, XTJ-533, XTJ-536, XTJ-548, and XTJ-559, which have an aminated polytetramethylene glycol backbone.

As the maleimide compound (b3), 4,4'-diphenylmethane bismaleimide, m-phenylene bismaleimide, p-phenylene bismaleimide, 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane, bis-(3-ethyl-5-methyl-4-maleimidophenyl)methane, 4-methyl-1,3-phenylene bismaleimide, N,N'-ethylene dimaleimide, N,N'-hexamethylene dimaleimide, bis( Resins having two maleimide groups in the molecule, such as bis(4-maleimidophenyl) ether, bis(4-maleimidophenyl) sulfone, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, bisphenol A diphenyl ether bismaleimide, etc., biphenyl aralkyl type maleimide, polyphenylmethane maleimide (CASNO: 67784-74-1, polymers consisting of formaldehyde and aniline and maleic anhydride), N,N'-(toluene-2,6-diyl)bismaleimide), 4,4'-diphenylether bismaleimide, 4,4'-diphenylsulfone bismaleimide, 1,3-bis(3-maleimidophenoxy)benzene, 1,3-bis(4-maleimidophenoxy)benzene, N,N'-ethylene bismaleimide, N,N'-trimethylene bismaleimide, N,N'-propylene bismaleimide, N, N'-tetramethylene bismaleimide, N,N'-pentamethylene bismaleimide, N,N'-(1,3-pentanediyl)bis(maleimide), N,N'-hexamethylene bismaleimide, N,N'-(1,7-heptanediyl)bismaleimide, N,N'-(1,8-octanediyl)bismaleimide, N,N'-(1,9-notanediyl)bismaleimide, N,N'-(1,10-decanediyl)bismaleimide, N,N '-(1,11-undecanediyl)bismaleimide, N,N'-(1,12-dodecanediyl)bismaleimide, N,N'-[(1,4-phenylene)bismethylene]bismaleimide, N,N'-[(1,2-phenylene)bismethylene]bismaleimide, N,N'-[(1,3-phenylene)bismethylene]bismaleimide, 1,6'-bismaleimido-(2,2,4-trimethyl)hexane, N,N'-[(methylimino) N,N'-(2-hydroxypropane-1,3-diylbisiminobiscarbonylbisethylene)bismaleimide, N,N'-(dithiobisethylene)bismaleimide, N,N'-[hexamethylenebis(iminocarbonylmethylene)]bismaleimide, N,N'-carbonylbis(1,4-phenylene)bismaleimide, N,N',N''-[nitrilotris(ethylene)]tris Maleimide, N,N',N''-[nitrilotris(4,1-phenylene)]trismaleimide, N,N'-[p-phenylenebis(oxy-p-phenylene)]bismaleimide, N,N'-[methylenebis(oxy)bis(2-methyl-1,4-phenylene)]bismaleimide, N,N'-[methylenebis(oxy-p-phenylene)]bis(maleimide)N,N'-[dimethylsilylenebis[(4,1-phenylene)(1 ,3,4,-oxadiazole-5,2-diyl)(4,1-phenylene) bismaleimide, N,N'-[(1,3-phenylene)bisoxybis(3,1-phenylene)] bismaleimide, 1,1'-[3'-oxospiro[9H-xanthene-9,1'(3'H)-isobenzofuran]-3,6-diyl]bis(1H-pyrrole-2,5-dione), N,N'-(3,3'-dichlorobiphenyl-4,4'-diyl)bismaleimide biphenyl-4,4'-diyl)bismaleimide, N,N'-(3,3'-dimethylbiphenyl-4,4'-diyl)bismaleimide, N,N'-(3,3'-dimethoxybiphenyl-4,4'-diyl)bismaleimide, N,N'-[methylenebis(2-ethyl-4,1-phenylene)]bismaleimide, N,N'-[methylenebis(2,6-diethyl-4,1-phenylene)]bismaleimide, N,N'-[methylenebis(2-bromo-6-ethyl-4,1-phenylene)]bismaleimide, N,N'-[methylenebis(2-methyl-4,1-phenylene)]bismaleimide, N,N'-[ethylenebis(oxyethylene)]bismaleimide, N,N'-[sulfonylbis(4,1-phenylene)bis(oxy)bis(4,1-phenylene)]bismaleimide, N,N'-[naphthalene-2,7-diylbis(oxy)bis(4,1-phenylene)]bismaleimide, N,N'-[p-phenylene bis(oxy-p-phenylene)]bismaleimide, N,N'-[(1,3-phenylene)bisoxybis(3,1-phenylene)]bismaleimide, N,N'-(3,6,9-trioxaundecane-1,11-diyl)bismaleimide, N,N'-[isopropylidenebis[p-phenyleneoxycarbonyl(m-phenylene)]]bismaleimide, N,N'-[isopropylidenebis[p-phenyleneoxycarbonyl(p -phenylene)] bismaleimide, N,N'-[isopropylidenebis[(2,6-dichlorobenzene-4,1-diyl)oxycarbonyl(p-phenylene)]] bismaleimide, N,N'-[(phenylimino)bis(4,1-phenylene)] bismaleimide, N,N'-[azobis(4,1-phenylene)] bismaleimide, N,N'-[1,3,4-oxadiazole-2,5-diylbis(4,1-phenylene)] bis Maleimide, 2,6-bis[4-(maleimido-N-yl)phenoxy]benzonitrile, N,N'-[1,3,4-oxadiazole-2,5-diylbis(3,1-phenylene)]bismaleimide, N,N'-[bis[9-oxo-9H-9-phospha(V)-10-oxaphenanthren-9-yl]methylenebis(p-phenylene)]bismaleimide, N,N'-[hexafluoroisopropylidenebis[p-phenylene N,N'-[carbonylbis[(4,1-phenylene)thio(4,1-phenylene)]]bismaleimide, N,N'-carbonylbis(p-phenyleneoxyp-phenylene)bismaleimide, N,N'-[5-tert-butyl-1,3-phenylenebis[(1,3,4-oxadiazole-5,2-diyl)(4,1-phenylene)]]bismaleimide, N,N' -[cyclohexylidenebis(4,1-phenylene)]bismaleimide, N,N'-[methylenebis(oxy)bis(2-methyl-1,4-phenylene)]bismaleimide, N,N'-[5-[2-[5-(dimethylamino)-1-naphthylsulfonylamino]ethylcarbamoyl]-1,3-phenylene]bismaleimide, N,N'-(oxybisethylene)bismaleimide, N,N'-[dithiobis(m-phenylene)]bismaleimide Examples of polyfunctional maleimides include N,N'-(3,6,9-trioxaundecane-1,11-diyl)bismaleimide, N,N'-(ethylenebis-p-phenylene)bismaleimide, BMI-689, BMI-1500, BMI-1700, BMI-3000, BMI-5000, and BMI-9000 manufactured by Designer Molecules, and ODA-BMI and BAFBMI manufactured by JFE Chemical Corporation.

When the maleimide compound (b3) is crosslinked by radicals, a radical polymerization initiator may be added. Specific examples include azo compounds and organic peroxides. The polymerization initiator may be used alone or in combination of two or more.
Examples of azo compounds include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2'-azobis(2-methylpropionate), 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(2-hydroxymethylpropionitrile), and 2,2'-azobis[2-(2-imidazolin-2-yl)propane].
Examples of organic peroxides include benzoyl peroxide, t-butyl perbenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di(2-ethoxyethyl)peroxydicarbonate, t-butyl peroxy 2-ethylhexanoate, t-butyl peroxy neodecanoate, t-butyl peroxypivalate, (3,5,5-trimethylhexanoyl)peroxide, dipropionyl peroxide, and diacetyl peroxide.

The allyl group-containing compound (b4) may be either monofunctional or polyfunctional. An example of a monofunctional allyl compound is (meth)allyl alcohol. An example of a polyfunctional allyl compound is triallyl isocyanurate, trimethylolpropane diallyl ether, trimethylolpropane triallyl ether, pentaerythritol diallyl ether, pentaerythritol triallyl ether, tetraallyloxyethane, polyallyl saccharose, di(meth)allyl phthalate, tri(meth)allyl isocyanurate, and tri(meth)allyl cyanurate. In addition, the following compounds can be mentioned.

The vinyl group-containing compound (b5) may be monofunctional or polyfunctional. Examples of monofunctional vinyl compounds include styrene, vinyl toluene, N-vinyl pyrrolidone, N-vinyl caprolactam, vinyl imidazole, and vinyl pyridine. Examples of polyfunctional vinyl compounds include vinyl ethers such as hexanediol dinorbornene carboxylate, vinylbenzyl-modified polyphenylene ether, pentaerythritol tetranorbornene carboxylate, triethylene glycol divinyl ether, cyclohexane dimethanol divinyl ether, and cyclohexane diol divinyl ether, and divinyl benzene. Among these, vinyl group-containing polyphenylene ether is particularly preferred.

The (meth)acrylate group-containing compound (b6) may be monofunctional or polyfunctional. Examples include monofunctional (meth)acrylamide compounds, polyfunctional (meth)acrylamide compounds, monofunctional (meth)acrylates, and polyfunctional (meth)acrylates.

Examples of monofunctional (meth)acrylamide compounds include diacetone (meth)acrylamide, isobutoxymethyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, t-octyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, (meth)acryloylmorpholine, acrylamido-2-methylpropanesulfonic acid, and N-isopropyl (meth)acrylamide.
Examples of polyfunctional (meth)acrylamide compounds include N,N'-diacryloyl-4,7,10-trioxa-1,13-tridecanediamine, N,N',N''-triacryloyldiethylenetriamine, N,N',N'',N''-tetraacryloyltriethylenetetramine, and N,N'-{[2-acrylamido-2-[(3-acrylamidopropoxy)methyl]propane-1,3-diyl)bis(oxy)]bis(propane-1,3-diyl)}diacrylamide.

Examples of monofunctional (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, cyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentenyloxyethyl. (meth)acrylate, benzyl (meth)acrylate, (meth)acrylate of phenol alkylene oxide adduct, (meth)acrylate of p-cumylphenol alkylene oxide adduct, (meth)acrylate of o-phenylphenol alkylene oxide adduct, (meth)acrylate of nonylphenol alkylene oxide adduct, 2-methoxyethyl (meth)acrylate, ethoxyethoxyethyl (meth)acrylate, (meth)acrylate of alkylene oxide adduct of 2-ethylhexyl alcohol, tetrahydrofurfuryl (meth)acrylate, caprolactone modified tetrahydrofuran Lofurfuryl (meth)acrylate, (2-ethyl-2-methyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, (2-isobutyl-2-methyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, (1,4-dioxaspiro[4,5]decan-2-yl)methyl (meth)acrylate, glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, (3-ethyloxetan-3-yl)methyl (meth)acrylate, 2-(meth)acryloyloxyethyl isocyanate, allyl (meth)acrylate, N-(meth)acryloyloxyethyl Examples of the acryloyloxyethyl ester include hexahydrophthalimide, N-(meth)acryloyloxyethyl tetrahydrophthalimide, 2-(meth)acryloyloxyethyl hexahydrophthalic acid, 2-(meth)acryloyloxyethyl succinic acid, ω-carboxy-polycaprolactone mono(meth)acrylate, 2-(meth)acryloyloxyethyl acid phosphate, 3-(meth)acryloyloxypropyl trimethoxysilane, 3-(meth)acryloyloxypropyl dimethoxymethylsilane, 3-(meth)acryloyloxypropyl triethoxysilane, and 2-(meth)acryloyloxyethyl acid phosphate.
In the alkylene oxide adduct, examples of the alkylene oxide include ethylene oxide and propylene oxide.

Polyfunctional (meth)acrylates include methacrylate group-containing polyphenylene ether, di(meth)acrylates of aliphatic diols such as ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 2-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, and 1,9-nonanediol di(meth)acrylate;
Di(meth)acrylates of alicyclic diols such as cyclohexanedimethylol di(meth)acrylate and tricyclodecanedimethylol di(meth)acrylate;
Alkylene glycol di(meth)acrylates such as diethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, and tripropylene glycol di(meth)acrylate;
Esterification reaction product of neopentyl glycol, hydroxypivalic acid, and (meth)acrylic acid (hereinafter referred to as "hydroxypivalic acid neopentyl glycol di(meth)acrylate"), caprolactone-modified hydroxypivalic acid neopentyl glycol di(meth)acrylate;
Di(meth)acrylates of alkylene oxide adducts of bisphenol-based compounds, such as di(meth)acrylates of alkylene oxide adducts of bisphenol A;
di(meth)acrylates of hydrogenated bisphenol compounds, such as di(meth)acrylate of hydrogenated bisphenol A;
poly(meth)acrylates of isocyanuric acid alkylene oxide adducts, such as di(meth)acrylates of isocyanuric acid alkylene oxide adducts, tri(meth)acrylates of isocyanuric acid alkylene oxide adducts, di(meth)acrylates of caprolactone-modified isocyanuric acid alkylene oxide adducts, and tri(meth)acrylates of caprolactone-modified isocyanuric acid alkylene oxide adducts;
Polyol poly(meth)acrylates such as trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tri- or tetra(meth)acrylate, and dipentaerythritol penta- or hexa(meth)acrylate;
Poly(meth)acrylates of polyol alkylene oxide adducts such as tri(meth)acrylate of trimethylolpropane alkylene oxide adduct, tetra(meth)acrylate of ditrimethylolpropane alkylene oxide adduct, tri- or tetra(meth)acrylate of pentaerythritol alkylene oxide adduct, penta- or hexa(meth)acrylate of dipentaerythritol alkylene oxide adduct:
Examples include urethane (meth)acrylates; epoxy (meth)acrylates; and polyester (meth)acrylates.
In the alkylene oxide adduct, examples of the alkylene oxide include ethylene oxide and propylene oxide.

Benzoxazine compound (b7) is a compound having a benzoxazine skeleton, specifically, o-cresolaniline type benzoxazine resin, m-cresolaniline type benzoxazine resin, p-cresolaniline type benzoxazine resin, phenol-aniline type benzoxazine resin, phenol-methylamine type benzoxazine resin, phenol-cyclohexylamine type benzoxazine resin, phenol-m-toluidine type benzoxazine resin, phenol-3,5-dimethylaniline type benzoxazine resin, bisphenol A-aniline type benzoxazine resin, bisphenol A-amine type benzoxazine resin , bisphenol F-aniline type benzoxazine resin, bisphenol S-aniline type benzoxazine resin, dihydroxydiphenylsulfone-aniline type benzoxazine resin, dihydroxydiphenylether-aniline type benzoxazine resin, benzophenone type benzoxazine resin, biphenyl type benzoxazine resin, bisphenol AF-aniline type benzoxazine resin, bisphenol A-methylaniline type benzoxazine resin, phenol-diaminodiphenylmethane type benzoxazine resin, triphenylmethane type benzoxazine resin, and phenolphthalein type benzoxazine resin.

As curable compounds other than components (b1) to (b7), phenolic resins and compounds containing isocyanate groups may be used.

2-2. Other Components The present composition may further contain other compounds within the scope of the present disclosure. For example, a copolymer other than the present copolymer may be used. Any thermoplastic resin may be used. A radical polymerization initiator may be added for the purpose of promoting the crosslinking reaction of radically reactive non-conjugated carbon-carbon unsaturated bonds. The curing process can be efficiently promoted by using a catalyst. Suitable examples of such catalysts include imidazole-based, amine-based, and phosphorus-based catalysts.

Known compounds can be used as radical polymerization initiators. Examples of peroxides include benzoyl peroxide, cumene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, di-t-butyl peroxide, t-butylcumyl peroxide, α,α'-bis(t-butylperoxy-m-isopropyl)benzene, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, dicumyl peroxide, di-t-butylperoxyisophthalate, t-butylperoxybenzoate, 2,2-bis(t-butylperoxy)butane, 2,2-bis(t-butylperoxy)octane, di-t-amyl peroxide, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, di(trimethylsilyl)peroxide, trimethylsilyltriphenylsilylperoxide, and diisopropylbenzene hydroperoxide. 2,3-dimethyl-2,3-diphenylbutane is also suitable as a radical polymerization initiator.

The amount of radical polymerization initiator to be added is in the range of 0.01 to 10 parts by mass, preferably 0.1 to 8 parts by mass, per 100 parts by mass of the copolymer. Within this range, the reaction proceeds smoothly without inhibiting the curing reaction.

Further examples include inorganic fillers, heat stabilizers, dyes, pigments (e.g., carbon black), polymerization inhibitors, defoamers, leveling agents, ion collectors, moisturizers, viscosity adjusters, preservatives, antibacterial agents, antistatic agents, antiblocking agents, ultraviolet absorbers, infrared absorbers, and electromagnetic wave shielding agents.

The composition may be solvent-free or may contain a solvent. Examples of solvents include toluene, xylene, methyl ethyl ketone, N,N-dimethylformamide, methyl isobutyl ketone, N-methyl-pyrrolidone, acetone, methanol, ethanol, butanol, 2-propanol, 2-methoxyethanol, 2-ethoxyethanol, 1-methoxy-2-propanol, 2-acetoxy-1-methoxypropane, n-hexane, cyclohexane, cyclohexanone, and mixtures thereof.

From the viewpoint of effectively achieving low dielectric constant, it is preferable to use a fluorine-based filler. Examples of the fluorine-based filler include PTFE, PVDF (vinylidene fluoride polymer having a linear structure in which _CF2 and _CH2 are alternately bonded), NEOFLON FEP (tetrafluoroethylene-hexafluoropropylene copolymer: tetrafluoroethylene-hexafluoropropylene copolymer resin), PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer: perfluoroalkoxy resin), NEOFLON ETFE (tetrafluoroethylene and ethylene copolymer), and ECTFE (polychlorotrifluoroethylene: trifluorochloroethylene resin).

The type of inorganic filler is not particularly limited. By using an inorganic filler, crack resistance after a heat cycle test is improved.

Specific examples of inorganic fillers include alumina, aluminum hydroxide, zirconium hydroxide, barium hydroxide, calcium hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, zinc carbonate, barium carbonate, magnesium sulfate, titanium oxide, tin oxide, magnesium oxide, zirconium oxide, calcium oxide, magnesium oxide, zinc oxide, molybdenum oxide, antimony oxide, nickel oxide, calcium silicate, beryllia, calcium titanate, silicon carbide, silicon nitride, aluminum nitride, boron nitride, titanium white, and zinc borate. Examples include metal compounds such as lead and aluminum borate; talc; clay; mica; metal oxides and metal nitrides such as glass fiber, kaolin, hydrotalcite, wollastonite, xonotlite, calcium hydrogen phosphate, calcium phosphate, glass flakes, hydrated glass, and sepiolite; hydrated metal compounds; silica-based fillers such as fused crushed silica, fused spherical silica, crystalline silica, non-crystalline silica, secondary agglomerated silica, fine silica, hollow silica, and porous silica; and nitride-based and carbon-based fillers such as silicon carbide, silicon nitride, titanium carbide, and diamond.
Among these, silica-based, alumina, aluminum nitride, and boron nitride are more preferable, and silica-based, alumina, and boron nitride are particularly preferable from the viewpoint of effectively increasing crack resistance.

2-3. Properties of the resin composition and the cured product The cured product is obtained by curing the present composition. Here, the cured product refers to a state in which a three-dimensional crosslinked structure is formed by the curing treatment and cured, and the cured product is cured to such an extent that the curing reaction does not proceed substantially even if the curing treatment is further performed. The curing treatment may crosslink the curable compounds with each other, crosslink the curable compound with the present copolymer, crosslink the curable compound with other components, or any combination of these. The curing treatment is performed by a radical reaction or the like. Heating may be performed as necessary. Note that when the present composition is molded into a desired shape such as a sheet, a part of the composition may undergo a curing reaction, but a state in which the composition can be cured by further curing treatment is not included in the cured product referred to here. At the stage of the resin composition, the component may be in a semi-cured B-stage state.

3. Manufacturing method of resin composition The present composition is obtained by blending each blending component. In blending, a solvent can be used as appropriate. The solid content concentration is, for example, 20 to 60 mass%. The present composition is, for example, in a powder form, a film form, a sheet form, a plate form, a pellet form, a paste form, or a liquid form. A liquid or paste-like resin composition can be easily obtained by adjusting the viscosity using a solvent. In addition, a film-like, sheet-like, or plate-like resin composition can be formed, for example, by coating and drying a liquid or paste-like resin composition. In addition, a powder-like or pellet-like resin composition can be obtained, for example, by pulverizing or cutting the film-like or other resin composition into a desired size.

4. Resin composition layer, laminated sheet and prepreg The present composition can be suitably used as a resin composition layer. The present composition can also be suitably used for laminated sheet applications including a substrate and a resin composition layer formed of the present composition on the substrate. The resin composition layer exhibits excellent adhesion after curing treatment, and is therefore suitable for bonding with various materials (resin layer, metal layer, inorganic layer such as ITO, composite layer, etc.). For example, it is suitable for use as an adhesive sheet for copper clad laminate (CCL), and as a bonding material between components such as electronic circuit boards and electronic components.

For example, a coating liquid (varnish) of the present composition containing a solvent is applied to one side of a release film, and the liquid medium such as an organic solvent is removed and dried at, for example, 40 to 150°C to obtain a laminated sheet having a resin composition layer (adhesive sheet). A laminated sheet that is an adhesive sheet with double-sided release films is obtained by laminating another release film on the surface of the obtained adhesive sheet. By laminating both sides with release films, surface contamination of the adhesive sheet can be prevented. The adhesive sheet can be isolated by peeling off the release film. The two release films can be of the same type or different types. By using release films with different release properties, the peeling force can be adjusted to different strengths, making it easier to peel them off in order. A laminated sheet having an adhesive sheet (resin composition layer) can also be obtained by applying the coating liquid to a substrate other than a release substrate.

Examples of substrates include resin materials such as polyimide film, polyethylene film, polycarbonate, polyethylene, liquid crystal polymer, phenolic resin, and aramid resin; metal materials such as copper, aluminum, and stainless steel; inorganic materials such as ITO, glass, silicon, and silicon carbide, and composite materials that are any combination of these. The composition not only has excellent heat resistance to various substrates, but also has excellent moldability by using the copolymer that has the alicyclic structure in at least one of the side chain, side group, and molecular chain end and has a non-conjugated C=C bond-containing ring.

The coating method may be any known method, such as comma coating, knife coating, die coating, lip coating, roll coating, curtain coating, bar coating, gravure printing, flexographic printing, screen printing, dip coating, spray coating, spin coating, etc. In order to ensure sufficient adhesion and from the standpoint of ease of handling, the thickness of the adhesive sheet after drying is preferably 5 to 500 μm, and more preferably 10 to 100 μm.

This composition can be suitably used as a material for forming a prepreg obtained by impregnating a substrate with this composition. The prepreg can be produced, for example, by impregnating a fiber substrate with this composition, and then heating and drying the resin composition to semi-cure (B-stage). The solid content of the resin composition attached to the fiber substrate is preferably 20 to 90% by mass after drying relative to the prepreg. More preferably, it is 30 to 80% by mass, and even more preferably, it is 40 to 70% by mass. For example, the composition can be impregnated or coated on a fiber substrate so that the solid content of the resin composition in the prepreg is 20 to 90% by mass, and then the prepreg can be semi-cured (B-staged) by heating and drying at a temperature of, for example, 40 to 250°C for 1 to 30 minutes.

As the fiber substrate, any known material can be used without restriction, and examples thereof include organic fibers, inorganic fibers, and glass fibers. Examples of organic fibers include polyimide, polyester, tetrafluoroethylene, and fully aromatic polyamide. Examples of inorganic fibers include carbon fibers. Examples of glass fibers include E-glass cloth, D-glass cloth, S-glass cloth, Q-glass cloth, NE-glass cloth, L-glass cloth, T-glass cloth, spherical glass cloth, and low-dielectric glass cloth. Among these, from the viewpoint of low thermal expansion coefficient, E-glass cloth, T-glass cloth, S-glass cloth, Q-glass cloth, and organic fibers are preferable. The fiber substrate may be used alone or in combination of two or more types.

The shape of the fiber substrate can be appropriately selected depending on the intended use and performance. Specific examples include woven fabric, nonwoven fabric, roving, chopped strand mat, and surfacing mat. Examples of the weaving method of the woven fabric include plain weave, sash weave, and twill weave. It can be freely selected and designed depending on the desired characteristics. The thickness of the fiber substrate is, for example, in the range of about 0.01 to 1.0 mm. From the viewpoint of thinning, 500 μm or less is preferable, and 300 μm or less is more preferable.

If necessary, the fiber substrate may be surface-treated with a silane coupling agent or mechanically opened to bring out the desired properties. Corona treatment or plasma treatment may also be performed. Surface treatments using silane coupling agents include amino silane coupling treatment, vinyl silane coupling treatment, cationic silane coupling treatment, and epoxy silane coupling treatment.

The method of impregnating the fiber substrate with the resin composition is not particularly limited, but examples include a method of preparing a varnish-like resin composition using an organic solvent such as alcohols, ethers, acetals, ketones, esters, alcohol esters, ketone alcohols, ether alcohols, ketone ethers, ketone esters, or ester ethers, and immersing the fiber substrate in the varnish, a method of coating or spraying the varnish onto the fiber substrate, and a method of laminating both sides of the fiber substrate with a film made of the resin composition.

Furthermore, the resin composition layer formed from this composition and its cured product layer are suitable for use as an insulating layer for semiconductor chip packages, underfill materials, adhesives, etc. They are also suitable as compositions for copper-clad laminates, bonding sheets for forming wiring boards, and cover coats for flexible substrates.

5. Manufacturing method of the cured product The cured product is obtained by curing the present composition. When a thermosetting compound is contained, it is cured by a heat curing process, and when a photocurable compound is contained, it is cured by a light irradiation process. For example, a method of molding the resin composition into a desired shape such as a sheet and curing it can be exemplified. A resin composition containing a solvent can be applied and dried to easily obtain a molded body such as a sheet of the resin composition, and the cured product can be formed by curing. The timing of curing may be before, during, or after molding. The sheet-shaped cured product is also called a cured layer.

The temperature for heat curing may be appropriately selected depending on the type of curable compound. For example, a method of heat treatment at a temperature of 150 to 300°C for 30 to 180 minutes can be exemplified. For photocuring, active light may be irradiated at a strength sufficient for curing. During curing, pressure may be applied (e.g., 2 MPa) as necessary for thermocompression. A crosslinked structure is formed in the composition by the curing treatment, and a three-dimensionally crosslinked cured product is obtained.

6. Cured Products and Substrates with Cured Products The cured products obtained from the present composition have excellent heat resistance, as well as excellent crack resistance after heat cycle tests, and are also excellent in suitability for substrate processing during the manufacturing process, and are therefore suitable as cured products for various parts such as metal-clad laminates and printed wiring boards, or as substrates with cured products containing this cured product.

A metal-clad laminate can be obtained, for example, by forming an insulating layer using the composition, and then laminating the insulating layer and a metal layer. For this insulating layer, an adhesive sheet or prepreg formed from the composition is preferably used. For example, a metal layer and a prepreg formed using the composition are laminated, and then a curing process is performed by hot pressing to obtain a metal-clad laminate. The hot pressing process can be performed by a known method. For example, it is performed by hot pressing at a temperature of 120 to 250°C and a pressure of 0.5 to 10 MPa for 0.5 to 5 hours.

Examples of the laminate structure of the metal-clad laminate include a two-layer laminate of a metal layer/hardened layer, a laminate consisting of multiple layers of a metal layer/hardened layer/metal layer, or a metal-clad laminate having a multi-layer structure in which metal layer/hardened layer/metal layer/hardened layer/metal layer are alternately laminated. The laminate may also include an insulating layer other than the hardened layer formed from the present composition. In addition, multiple sheets of prepreg or the like may be stacked and hardened to adjust the thickness of the hardened layer. Also, a conductive layer other than the metal layer may be laminated.

For example, a circuit board having a circuit pattern layer can be obtained by forming a circuit pattern on the metal layer of a metal-clad laminate having a layer structure of metal layer/hardened layer/metal layer. Through holes or vias may be formed in the hardened layer by a laser or the like. A core board may be multi-layered by overlaying an insulating hardened layer on it by a build-up process to form vias. A circuit board can be obtained, for example, by forming the metal layer of a metal-clad laminate into the desired circuit pattern by a subtractive method, or by forming the desired circuit pattern on one or both sides of an insulating layer by an additive method.

Copper foil or the like is used as the metal layer. In the production of copper-clad laminates, electrolytic copper plating is performed on the copper foil surface, and after removing the resist layer, etching is performed with an alkaline or other plating solution. This composition has excellent substrate processing suitability, such as plating solution resistance, and is therefore suitable for use in copper-clad laminates. Furthermore, this cured product has excellent crack resistance and heat resistance after heat cycle testing, so that substrates with the cured product formed by curing this composition can be used for a wide range of applications under a variety of environments.

A printed wiring board can be manufactured, for example, by processing the copper foil in a copper-clad laminate by etching or the like, forming a signal circuit or the like, bonding the resulting substrate and cover film via an adhesive sheet, and then carrying out a curing process or the like. Alternatively, a flexible printed wiring board can be manufactured, for example, by forming a conductor pattern on an insulating flexible film, forming a protective film on top of the conductor pattern via the adhesive sheet, and carrying out a process of thermocompression bonding. Examples of the flexible film include polyester, polyimide, liquid crystal polymer, and PTFE film. Examples of the conductor pattern include a method of forming the conductor pattern using a printing technique, or a method using sputtering and plating.

Openings may be provided in the cured layer of the composition formed on one or both sides of a printed wiring board by drilling or laser processing, and a conductive agent may be filled to form vias. A circuit layer may also be formed on the cured layer of the composition. The cured product of the composition has excellent plating solution resistance and is therefore suitable for the manufacture of multilayer printed wiring boards. Printed wiring boards formed using the composition have excellent processability and excellent heat resistance and crack resistance after heat cycle testing, making them suitable for various electronic devices such as smartphones and tablet terminals.

Since this copolymer has excellent electrical insulation, by further using an insulating curable compound in this composition, a cured product with excellent insulation can be provided. For example, it is suitable for use as an insulating layer forming material on a circuit board (including a coverlay layer of a printed wiring board, an interlayer insulating layer of a built-up board, etc., a bonding sheet, etc.). In addition, by using a conductive material in a filler such as a thermally conductive filler, it can also be used as a conductive member of an electronic component. Examples of electronic components include power modules such as power semiconductor devices, LEDs, and inverter devices.

Furthermore, by blending an inorganic filler, such as a thermally conductive filler, with the cured product of this composition, it can be applied to all applications requiring heat dissipation. For example, by utilizing the moldability of the resin composition, it can be suitably used as a heat dissipation part of a desired shape. In particular, it is useful as a heat dissipation adhesive or heat dissipation sheet for electronic devices (smartphones, tablet terminals, etc.) that cannot be equipped with fans or heat sinks due to their small size and light weight. In addition, the cured product of this composition is suitable as an adhesive layer between a heating element and a heat sink, or as a heat spreader. It can also be used as a heat dissipation layer that covers one or more electronic components mounted on a substrate.

The amount of the copolymer to be blended is arbitrary, but in order to improve the heat resistance of the cured product and to improve crack resistance after a heat cycle test, it is preferable that the copolymer be included in an amount of 1 to 50% by mass relative to 100% by mass of the non-volatile content (solid content) of the composition. The range is more preferably 4 to 44% by mass, and even more preferably 6 to 38% by mass.

The present disclosure will be explained in more detail below with reference to examples. The present disclosure is not limited to the following examples. Unless otherwise specified, "%" and "parts" are based on mass.

7. Measurement method 7-1. Measurement of acid anhydride value Approximately 1 g of sample (resin of each synthesis example) was precisely weighed and placed in a stoppered Erlenmeyer flask, and 100 mL of 1,4-dioxane solvent was added to dissolve it. 10 mL of a mixed solution of octylamine, 1,4-dioxane, and water (mixing ratio by mass: 1.49/800/80) was added, which was greater than the amount of acid anhydride groups in the sample, and the mixture was stirred for 15 minutes to react with the acid anhydride groups. The excess octylamine was then titrated with a mixed solution of 0.02 M perchloric acid and 1,4-dioxane. In addition, a blank measurement was also performed using 10 mL of a mixed solution of octylamine, 1,4-dioxane, and water (mixing ratio by mass: 1.49/800/80) to which no sample was added. The acid anhydride value was calculated using the following formula (unit: mgKOH/g):
Acid anhydride value (mg KOH/g) = 0.02 x (B - A) x F x 56.11/S
B: Blank titer (mL)
A: titer of sample (mL)
S: Amount of sample collected (g)
F: Potency of 0.02 mol/L perchloric acid

7-2. Measurement of amine value Approximately 1 g of sample (resin of each synthesis example) was precisely weighed and placed in a stoppered Erlenmeyer flask, and dissolved in 100 mL of cyclohexanone solvent. A few drops of indicator, which was prepared by mixing 0.20 g of Methyl Orange dissolved in 50 mL of distilled water and 0.28 g of Xylene Cyanol FF dissolved in 50 mL of methanol, were added and held for 30 seconds. After that, the solution was titrated with 0.1 N alcoholic hydrochloric acid solution until it turned blue-gray. The amine value was calculated by the following formula.
Amine value (mgKOH/g)=(5.611×a×F)/S
however,
S: Amount of sample collected (g)
a: consumption of 0.1N alcoholic hydrochloric acid solution (mL)
F: Potency of 0.1N alcoholic hydrochloric acid solution

7-3. Measurement of weight average molecular weight (Mw) Mw was measured using Showa Denko K.K.'s GPC (gel permeation chromatography) "GPC-101". THF (tetrahydrofuran) was used as the solvent, and two "KF-805L" (Showa Denko K.K.: GPC column: 8 mm ID x 300 mm size) connected in series were used as the column. The conditions were a sample concentration of 1 mass%, a flow rate of 1.0 mL/min, a pressure of 3.8 MPa, and a column temperature of 40°C, and Mw was determined in terms of polystyrene. Data analysis was performed using the manufacturer's built-in software to calculate the calibration curve, molecular weight, and peak area, and Mw was determined for the range of retention times of 17.9 to 30.0 minutes.

7-4. Valence of radically reactive non-conjugated carbon-carbon unsaturated bonds of (i) and (ii) The valence of radically reactive non-conjugated carbon-carbon unsaturated bonds of (i) and (ii) was obtained from the design values of the raw materials used for polymerizing the present copolymer. That is, it was calculated from the charge amount of the compound bonded by the radically reactive non-conjugated carbon-carbon unsaturated bonds of (i) and (ii) relative to the charge amount of the raw materials used for synthesizing the present copolymer.

7-5. Calculation of total functional group value The total functional group value was determined as the sum (mg KOH/g) of the acid anhydride group value, the amine value, and the radical-reactive non-conjugated carbon-carbon unsaturated bond values of (i) to (ii).

8. Synthesis of the present copolymer [Synthesis Example 1]
48 parts of LICOCENE PP 1602 (polypropylene polyethylene copolymer, (Clariant), Mw 57000, St 0%) was dissolved in 50 parts of xylene, and 20 parts of maleic anhydride as an acid anhydride and 1.7 parts of Luperox DTA (di-t-amyl peroxide, Arkema Yoshitomi) as a radical initiator were added, followed by stirring for 2 hours under reflux at 140°C. The end point of the reaction was confirmed by FT-IR based on the generation of a peak (near 1711 cm ^-1 ) derived from a carboxy group, and a maleic anhydride -modified polyethylene polypropylene copolymer was obtained. Thereafter, 0.5 parts of K-NOX 1010 (pentaerythritol tetrakis 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, manufactured by Kuo Ching Chemical Co., Ltd.) was added, the temperature was raised to 100°C, 2.8 parts of 5-norbornene-2 - methylamine and 0.08 parts of dimethylbenzylamine as a catalyst were added, and the mixture was stirred at 100°C for 2 hours, and then imidization was performed by stirring at 170°C for 2 hours while azeotroping xylene and water generated by the reaction. The end point of the reaction was confirmed by FT-IR, where the peak derived from the carboxyl group (near 1711 cm ^-1 ) shifted to the peak derived from the imide group (near 1704 cm ^-1 ) and the peak derived from the alkane (near 1397 cm ^-1 ). Then, 200 parts of toluene was added to dilute the mixture, and 225 parts of methanol were added to obtain a precipitate. The precipitate was collected by filtration, 200 parts of toluene was added again to dissolve the precipitate, and 225 parts of methanol was added to obtain a precipitate. The precipitate was collected by filtration and dried in a vacuum oven at 100° C. for 2 hours to obtain a resin having a non-conjugated carbon-carbon unsaturated bond in the side chain. The radical-reactive carbon-carbon unsaturated bond valence was 10 mgKOH/g.

[Synthesis Examples 2 to 8]
Copolymers Synthesis Examples 2 to 8 were obtained in the same manner as in Synthesis Example 1, except that the monomers and their amounts were changed to those shown in Table 1.

[Comparative Synthesis Example 1]
48 parts of LICOCENE PP 1602 was dissolved in 50 parts of xylene, 20 parts of maleic anhydride was added as an acid anhydride, and 1.7 parts of Luperox DTA was added as a radical initiator, and the mixture was stirred for 2 hours under reflux at 140 ° C. Then, 200 parts of toluene was added to dilute the mixture, and 225 parts of methanol was added to obtain a precipitate. The precipitate was collected by filtration, and 200 parts of toluene was added again to the precipitate to dissolve it, and 225 parts of methanol was added to obtain a precipitate. The precipitate was collected by filtration, and dried in a vacuum oven at 100 ° C. for 2 hours to obtain a resin having an acid anhydride in the side chain. The acid anhydride value was 10 mg KOH / g.

[Comparative Synthesis Examples 2 to 7]
Copolymers of Comparative Synthesis Examples 2 to 7 were obtained in the same manner as in Comparative Synthesis Example 1, except that the monomers and their amounts were changed to those shown in Table 1.

The abbreviations in Table 1 are as follows:
(Resin before modification)
R-1: Polypropylene (LICOCENE PP 1602, Mw 57,000, St 0%)
R-2: Hydrogenated styrene-butadiene rubber (Dynaron 2324P, Mw 170,000, St 16%)
R-3: SEP (G1702, Mw150,000, St28%)
R-4: SEBS (G1652, Mw72,000, St30%)
R-5: SEBSS (A1536, Mw130,000, St40%)
(Non-conjugated carbon-carbon unsaturated bond-containing compounds)
T-1: 5-norbornene-2 - methylamine T-2: N-(4-aminophenyl)maleimide

1 shows IR spectrum diagrams of Resin R-5 before modification, Comparative Synthesis Example 5, and Synthesis Example 5. As shown in the figure, a peak derived from a carboxy group (near 1711 cm ^-1 ) was confirmed in Comparative Synthesis Example 5. On the other hand, in Synthesis Example 5, it was confirmed that the peak derived from C=O of the carboxylic acid (near 1711 cm ^-1 ) shifted to the peak derived from C=O of the imide group (near 1704 cm ^-1 ). In addition, a peak derived from an alkane (near 1397 cm ^-1 ) was confirmed.

9. Preparation of resin composition (varnish) [Example 1]
A vessel was charged with 100 parts of the present copolymer (P1) of Synthesis Example 1 calculated as solid content, and 1 part of (C)-1 as an initiator, and a mixed solvent (toluene:MEK=1:1 (mass ratio)) was added so that the non-volatile content concentration became 25%, and the mixture was stirred with a disper for 10 minutes to prepare a varnish according to Example 1.

[Examples 2 to 31, Comparative Examples 1 to 22]
Varnishes according to Examples 2 to 31 and Comparative Examples 1 to 22 were prepared in the same manner as in Example 1, except that the ingredients and amounts were changed to those shown in Tables 2 to 3.

The materials used in the examples and comparative examples are shown below.
(Curable Compound)
(B)-1: Epoxy compound (b1), XD-1000 (manufactured by Nippon Kayaku Co., Ltd., dicyclopentadiene type epoxy, multifunctional, functional group equivalent 252 g/eq)
(B)-2: Cyanate ester compound (b2), BAD (manufactured by Mitsubishi Gas Chemical Company, Inc., bisphenol A type cyanate ester, bifunctional, functional group equivalent 139 g/eq, molecular weight 278)
(B)-3: Maleimide compound (b3), BMI-4000 manufactured by Daiwa Kasei Kogyo Co., Ltd., bisphenol A diphenyl ether bismaleimide, bifunctional, functional group equivalent weight 285.3 g/eq, molecular weight 570.6)
(B)-4: Allyl group-containing compound (b4), Taik (manufactured by Shinryo Corporation, triallyl isocyanurate, trifunctional, molecular weight 249.3)
(B)-5: vinyl group-containing compound (b5), OPE-2St 1200 (manufactured by Mitsubishi Gas Chemical Company, Inc., vinylbenzyl-modified polyphenylene ether, bifunctional, functional group equivalent: 590 g/eq, number average molecular weight: 1180)
(B)-6: (meth)acrylate group-containing compound (b6), Noryl SA9000 (SABIC, methacrylate group-containing polyphenylene ether, bifunctional, functional group equivalent: 850 g/eq, number average molecular weight 1700)
(B)-7: Benzoxazine compound (b7), 3,3'-(methylene-1,4-diphenylene)bis(3,4-dihydro-2H-1,3-benzoxazine) (manufactured by Shikoku Chemical Industry Co., Ltd., P-d type benzoxazine), bifunctional, oxazine equivalent 217)
(Initiator (C))
(C)-1: Radical initiator (c1), Parmicle D (manufactured by NOF Corporation, dicumyl peroxide, molecular weight 270.4)
(C)-2: Epoxy initiator (c2), TETRAD-X (manufactured by Mitsubishi Gas Chemical Company, Inc., multifunctional epoxy resin, molecular weight 360.5)
The epoxy initiator (c2) can be classified as an epoxy compound (b1) since it has an epoxy group. However, in this example, it is used as an initiator that mainly causes epoxy ring-opening by an amine structure, and therefore it is classified as an initiator (C).
(Filler (D))
(D)-1: SO-C2 (average particle size 0.4 to 0.6 μm, manufactured by Admatechs, silica)
(D)-2: AO-509 (average particle size 7 to 13 μm, manufactured by Admatechs Co., Ltd., alumina)
(D)-3: SP-2 (average particle size D50 4 μm, manufactured by Denka, boron nitride)
(D)-4: HF-01 (average particle size D50 1.1 μm, manufactured by Tokuyama Corporation, aluminum nitride)
(Olefin Polymer (E) Containing a Radical-Reactive Carbon-Carbon Unsaturated Bond in the Side Chain)
(E)-1: Styrene-butadiene-styrene resin (Tufprene 126S, manufactured by Asahi Kasei Corporation)
(E)-2: Polybutadiene resin (PB B-3000, manufactured by Nippon Soda Co., Ltd.)

10. Preparation of Evaluation Samples 10-1. Preparation of Adhesive Sheet The resin varnish of each example was uniformly coated on a 50 μm thick heavy release film (polyethylene terephthalate (PET) film coated with a heavy release agent) using a doctor blade so that the thickness after drying was 50 μm, and dried at 100 ° C for 2 minutes. After that, it was cooled to room temperature to obtain an adhesive sheet with a single-sided release film. Next, the adhesive sheet surface of the obtained adhesive sheet with a single-sided release film was superimposed on a 50 μm thick light release film (polyethylene terephthalate (PET) film coated with a light release agent), and an adhesive sheet with double-sided release films consisting of a heavy release film / adhesive sheet / light release film was obtained.

10-2. Manufacturing of copper-clad laminate The light release film was peeled off from the adhesive sheet with double-sided release film obtained by the above method, and the exposed adhesive sheet surface was temporarily bonded to the copper foil side of a single-sided copper-clad laminate consisting of a 50 μm polyimide film and a 12 μm copper foil laminated together using a vacuum laminator (Nichigo Morton Co., Ltd., small pressure vacuum laminator V-130). The vacuum lamination conditions were heating temperature 100°C, vacuum time 60 seconds, vacuum ultimate pressure 2 hPa, pressure 0.4 MPa, and pressure time 60 seconds.
Next, the heavy release film was peeled off, and the polyimide film side of a second single-sided copper-clad laminate was similarly temporarily adhered to the exposed adhesive sheet surface using a vacuum laminator, and then the adhesive sheet was thermally cured in a vacuum hot press at 200°C for 2 hours at 2 MPa to produce an evaluation sample with a laminate structure of polyimide film /copper foil/cured adhesive sheet/polyimide film/copper foil film.

11. Evaluation α. Heat resistance The copper-clad laminates prepared in each example were cut into a width of 10 mm and a length of 65 mm, and the test pieces were stored under various conditions. The copper foil surface was then brought into contact with molten solder at various temperatures and floated for 1 minute. The appearance of the test pieces was then visually observed, and the presence or absence of adhesion abnormalities such as foaming, lifting, and peeling of the adhesive layer after curing was evaluated. This test evaluates the thermal stability of the adhesive layer after curing when in contact with solder by its appearance. Those with good heat resistance did not change in appearance, whereas those with poor heat resistance foamed or peeled after soldering. These evaluation results were judged according to the following criteria.
AA: No change in appearance even after storage for 24 hours in an atmosphere of 85° C. and 85% relative humidity and then floating in molten solder at 300° C.
A: Does not satisfy the above AA. After storing for 24 hours in an atmosphere of 40°C and 90%, there was no change in appearance even when floated in molten solder at 300°C.
B: Does not satisfy the above A. When a test piece stored for 24 hours in an atmosphere of 40°C and 90% humidity was floated in molten solder at 280°C, there was no change in appearance.
C: The above conditions A and B are not satisfied. When a test piece stored for 24 hours in an atmosphere of 23° C. and 50% humidity was floated in molten solder at 280° C., there was no change in appearance.
D: Does not satisfy the above A to C. When a test piece stored for 24 hours in an atmosphere of 23°C and 50% humidity was floated in molten solder at 260°C, there was no change in appearance.
E: Does not satisfy the above A to D. When a test piece stored for 24 hours in an atmosphere of 23°C and 50% humidity was floated in molten solder at 240°C, there was no change in appearance.
F: When a test piece stored for 24 hours in an atmosphere of 23° C. and 50% humidity was floated in molten solder at 240° C., there was a change in appearance. Problematic in practical use.

β. Dielectric properties The adhesive sheet with double-sided release film was stored for 24 hours or more in an atmosphere of 23°C and 50% relative humidity, and then the release film was peeled off, and the dielectric loss tangent (Df) at a measurement frequency of 10 GHz was determined by the cavity resonator method using a dielectric constant measuring device manufactured by AET Corporation under the same temperature and humidity environment.
AA: Df is less than 0.0004 A: Df is 0.0004 or more and less than 0.0005 B: Df is 0.0005 or more and less than 0.0010 C: Df is 0.0010 or more and less than 0.0020 D: Df is 0.0020 or more and less than 0.0030 E: Df is 0.0030 or more and less than 0.0035 F: Df is 0.0035 or more. Problems in practical use.

γ. Evaluation of stress relaxation properties (crack resistance) A glass cloth-based epoxy resin copper-clad laminate with a circuit pattern having L/S=25 μm/25 μm and copper thicknesses of 25 μm and 50 μm was prepared as an inner layer circuit board. On both sides of the laminate, the resin sheets of each example prepared by the above method were vacuum hot-pressed under conditions of 200° C., 3.0 MPa, and 2 hours, and finally, copper foil was placed on the outermost layers on both sides to obtain a printed wiring board for evaluation.
The printed wiring board for evaluation was then placed in a thermal shock device ("TSE-11-A", manufactured by Espec Corporation) and alternately exposed a predetermined number of times under the following conditions: high temperature exposure: 125°C, 15 minutes; low temperature exposure: -50°C, 15 minutes. The printed wiring board for evaluation was cut, and the exposed cross section was observed for the presence or absence of cracks at a magnification of 5000 times using a scanning electron microscope (SEM). Note that a crack refers to a fissure of 0.1 μm or more in size. The evaluation criteria are as follows:
AA: No cracks were observed after 4,000 heat cycle tests. This is an extremely good result.
A: Does not satisfy the above AA criteria. No cracks were generated after 3,000 heat cycle tests. This is an extremely good result.
B: Does not satisfy the above A. No cracks were generated after 1000 heat cycle tests. This is a very good result.
C: Neither A nor B is satisfied. No cracks are generated after 200 heat cycle tests. Good results.
D: Does not satisfy the above A to C. No cracks were generated after 100 heat cycle tests. Problems remain in practical use.
E: Cracks occurred before 100 heat cycle tests were completed. Problems in practical use.

Claims (14)

A modified olefin copolymer, the main chain of which contains a structural unit derived from a conjugated diene compound and/or a structural unit derived from an alicyclic or linear non-conjugated olefin compound,
having a monocyclic structure and/or a polycyclic structure in at least one of a side group, a side chain and a molecular chain end;
A modified olefin copolymer in which a ring of the monocyclic structure and/or any ring of the polycyclic structure is at least one of an alicyclic skeleton consisting of carbon atoms and an alicyclic skeleton consisting of carbon atoms and hetero atoms, and which satisfies at least one of the following (i) and (ii):
(i) The alicyclic skeleton has a radical-reactive non-conjugated carbon-carbon unsaturated bond.
(ii) A carbon atom constituting the alicyclic skeleton and a carbon atom not constituting the ring bonded to the carbon atom are bonded to each other through a radically reactive non-conjugated carbon-carbon unsaturated bond. The modified olefin copolymer according to claim 1, wherein the main chain does not have an unsaturated bond except at the molecular chain terminals. The modified olefin copolymer according to claim 1, wherein the main chain contains structural units derived from an aromatic vinyl compound. The modified olefin copolymer according to claim 1, which contains a block consisting of structural units derived from an aromatic vinyl compound and a block containing structural units derived from a conjugated diene compound. The modified olefin copolymer according to claim 4 , wherein the block containing the structural unit derived from the conjugated diene compound further contains a structural unit derived from an aromatic vinyl compound. It is a hydrogenated styrene-based elastomer.
The modified olefin copolymer according to claim 1, which is any one of modified products of styrene-ethylene-butylene block copolymer (SEB), styrene-ethylene-propylene block copolymer (SEP), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-ethylene-butylene-styrene-styrene block copolymer (SEBSS), styrene-isobutylene-styrene block copolymer (SIBS), and styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS). A resin composition comprising the modified olefin copolymer according to claim 1. The resin composition according to claim 7, further comprising a curable compound, the curable compound comprising at least one selected from the group consisting of an epoxy compound (b1), a cyanate ester compound (b2), a maleimide compound (b3), an allyl group-containing compound (b4), a vinyl group-containing compound (b5) , a (meth)acrylate group-containing compound (b6), and a benzoxazine compound (b7). The resin composition according to claim 7, further comprising an inorganic filler. A laminate sheet comprising a substrate and a resin composition layer formed on the substrate using the resin composition according to any one of claims 7 to 9. A prepreg in which a substrate is impregnated with the resin composition described in any one of claims 7 to 9. A cured product obtained from the resin composition according to any one of claims 7 to 9. A substrate with a cured product, comprising a cured product formed by curing the resin composition according to any one of claims 7 to 9. An electronic device equipped with a substrate with the cured material according to claim 13.