Resin composition, prepreg, resin film, metal-clad laminate, printed wiring board, and semiconductor package

Abstract

A resin composition comprising: a polyfunctional vinyl benzyl compound (A) having two or more vinyl benzyl groups; and a styrene copolymer (B) having a weight average molecular weight of 20,000 or less and having a vinyl group. Also provided are a prepreg, a resin film, a metal-clad laminate, a printed wiring board, and a semiconductor package, each of which is formed using the resin composition.

Description

TECHNICAL FIELD

[0001] The present application relates to a resin composition, a prepreg, a resin film, a metal-clad laminate, a printed wiring board, and a semiconductor package. BACKGROUND

[0002] A metal-clad laminate typified by a copper-clad laminate, a prepreg that can be used for a metal-clad laminate, and a semiconductor package using a metal-clad laminate are used for various electronic devices such as portable communication devices such as smartphones, personal computers, industrial computers, servers, large servers, routers, and portable base stations. In addition, they are also used for electronic devices mounted on home appliances and automobiles. Among them, electronic communication devices have an increased demand for processing a large amount of data at high speed due to the popularization of 5G.

[0003] In electronic devices, when a large amount of data is processed at high speed, a substrate material with less transmission loss in a high frequency region is required. A substrate material using a resin with low dielectric constant and low dielectric loss tangent provides a substrate with low dielectric loss, but further development of a resin with low dielectric constant and low dielectric loss tangent is required due to the development of communication technology in recent years.

[0004] In Patent Literature 1, as a material for an electronic component used in a high frequency band, a thermosetting resin composition containing a vinylbenzyl-based compound and a polycarbodiimide compound is disclosed, and it is proposed that the resulting electronic component improves adhesion to a metal material while maintaining excellent dielectric properties.

[0005] PRIOR ART DOCUMENTS

[0006] PATENT LITERATURE

[0007] Patent Literature 1: Japanese Patent Application Laid-Open No. 2007-119531 SUMMARY

[0008] PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] In Patent Literature 1, a vinylbenzyl-based compound with excellent dielectric properties in a high frequency band is proposed, and in specific examples, a low dielectric constant and a low dielectric loss tangent are achieved in a cured product of a resin composition containing only a vinylbenzyl-based compound. However, a material design that exhibits more excellent dielectric properties is desired.

[0010] In addition, a metal-clad laminate can be obtained by forming a metal foil on the surface of a laminate of prepreg in which a resin is impregnated in a fiber base material, and curing the prepreg by pressure and heat. Due to its structure, the metal-clad laminate exhibits rigidity, and is also a substrate material excellent in warpage characteristics and flatness. In order to further reduce transmission loss, it is also required to improve the impregnability and coatability of the resin composition to the fiber base material, and more strictly control transmission loss caused by coating defects and the like. The same problem also exists in resin films.

[0011] An object of the present application is to provide a resin composition for providing a product high in reliability and excellent in dielectric characteristics, and a prepreg, resin film, metal-clad laminate, printed wiring board, and semiconductor package high in reliability and excellent in dielectric characteristics.

[0012] Means for solving the problem

[0013] The present application includes the following embodiments. The present application is not limited to the following embodiments.

[0014] One embodiment relates to a resin composition comprising: a multifunctional vinylbenzyl compound (A) having 2 or more vinylbenzyl groups; and a styrene copolymer (B) having a weight average molecular weight of 20,000 or less and a vinyl group.

[0015] Effects of the Invention

[0016] According to the present application, it is possible to provide a resin composition for providing a product high in reliability and excellent in dielectric characteristics, and a prepreg, resin film, metal-clad laminate, printed wiring board, and semiconductor package high in reliability and excellent in dielectric characteristics. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a pattern used in the examples. DETAILED DESCRIPTION

[0018] Hereinafter, the embodiments of the present application will be described in detail. The present application is not limited to the following embodiments.

[0019] In the present application, a numerical range indicated using "~" represents a range including the values recited before and after the "~" as the minimum value and the maximum value, respectively. In the present application, the upper limit value or the lower limit value of a certain numerical range can be replaced with the upper limit value or the lower limit value of another numerical range. In addition, the upper limit value or the lower limit value of the numerical range recited in the present application can be replaced with the value shown in the examples. In the present application, unless otherwise specified, one or two or more kinds of the corresponding substances can be contained in each component. In the present application, with respect to the content of each component in the resin composition, in the case where a plurality of substances corresponding to each component is present in the resin composition, unless otherwise specified, it refers to the total amount of the plurality of substances present in the resin composition.

[0020] In the present application, unless otherwise specified, the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polymer are the values measured according to the following measurement method.

[0021] The weight average molecular weight and the number average molecular weight of the polymer are measured using gel permeation chromatography (GPC) and converted according to a standard curve using standard polystyrene. The standard curve uses standard polystyrene: TSK standard POLYSTYRENE (Type; A-2500, A-5000, F-20, F-80) (manufactured by Tosoh Corporation, trade name), and is approximated by a 3-time formula. The measurement conditions of GPC are shown below.

[0022] Apparatus: High-speed GPC device "HLC-8320 GPC" (Tosoh Corporation, trade name)

[0023] Detector: Ultraviolet absorbance detector "UV-8320" (Tosoh Corporation, trade name)

[0024] Column: Guard column; TSKgel guard column Super (HZ)-M+, Column; TSKgel Super Multipore HZ-M (2 pieces), Reference column; TSKgel Super H-RC (2 pieces) (all of which are manufactured by Tosoh Corporation, trade name)

[0025] Column size: 4.6 x 20 mm (guard column), 4.6 x 150 mm (column), 6.0 x 150 mm (reference column)

[0026] Eluent: Tetrahydrofuran

[0027] Sample concentration: 10 mg / 1 mL

[0028] Injection amount: 20 μL or 2 μL

[0029] Flow rate: 0.35 mL / minute

[0030] Measurement temperature: 40°C

[0031] "Resin composition"

[0032] The resin composition of one embodiment includes: a multifunctional vinylbenzyl compound (A) having 2 or more vinylbenzyl groups; and a styrene copolymer (B) having a weight average molecular weight of 20,000 or less and having a vinyl group.

[0033] In the present application, the "multifunctional vinylbenzyl compound (A) having 2 or more vinylbenzyl groups" is also referred to as "multifunctional vinylbenzyl compound (A)". In addition, the "styrene copolymer (B) having a weight average molecular weight of 20,000 or less and having a vinyl group" is also referred to as "styrene copolymer (B)".

[0034] By using the resin composition, an article with high reliability and excellent dielectric properties can be provided. Without being bound by theory, as a reason therefor, by using the resin composition, stress in a coating film of the resin composition is moderated, and generation of fine cracks in the coating film state can be inhibited. A cured product of such a resin composition is excellent in resistance to electrical corrosion because fine defects are precisely controlled. An article including a cured product of such a resin composition is excellent in reliability.

[0035] By including the multifunctional vinylbenzyl compound (A) as a curable compound and the styrene copolymer (B) as an elastomer in the resin composition, a lower dielectric constant and a lower dielectric loss tangent can be achieved in a cured product of the resin composition compared to a case where the multifunctional vinylbenzyl compound (A) is used alone. In addition, in the case where the styrene copolymer (B) is used in combination with the multifunctional vinylbenzyl compound (A), as described above, the reliability of an article can be improved as a result. One of the reasons is that the weight average molecular weight of the styrene copolymer (B) is 20,000 or less, and thus sufficient softness is imparted to a coating film of the resin composition, and generation of fine cracks in the coating film state is inhibited.

[0036] The multifunctional vinylbenzyl compound (A) is a multifunctional compound having 2 or more vinylbenzyl groups. The multifunctional vinylbenzyl compound (A) can be cured by promoting the reaction of the vinylbenzyl groups within or between molecules using heat, pressure, a curing promoter, or the like, by virtue of having 2 or more vinylbenzyl groups within the molecule.

[0037] The multifunctional vinylbenzyl compound (A) can be any of a monomer, an oligomer, and a prepolymer, and two or more kinds thereof in combination can be included in the resin composition.

[0038] In the case where the polyfunctional vinylbenzyl compound (A) is a monomer, two or more vinylbenzyl groups can be introduced into the base compound. The oligomer can be an oligomerization degree compound in which two or more of the monomers are polymerized. The prepolymer can be a prepolymer in which two or more vinylbenzyl groups are introduced into the resin skeleton, or a polymer of a monomer, an oligomer, or a combination thereof, having two or more vinylbenzyl groups. The prepolymer contains, to some extent, unreacted vinylbenzyl groups, and is preferably in a state in which a curing reaction is initiated by heating or the like.

[0039] In the monomer of the polyfunctional vinylbenzyl compound (A), the number of vinylbenzyl groups can be two to four or two to three.

[0040] In the oligomer or the prepolymer in the polyfunctional vinylbenzyl compound (A), the number of vinylbenzyl groups in the molecule can be two or more, and preferably two or more vinylbenzyl groups are contained in the monomer structural unit, and the number of vinylbenzyl groups in the monomer structural unit can be two to four or two to three.

[0041] In the polyfunctional vinylbenzyl compound (A), the vinylbenzyl group can be any of an ortho-vinylbenzyl group, a meta-vinylbenzyl group, and a para-vinylbenzyl group. In one molecule of the polyfunctional vinylbenzyl compound (A), two or more vinylbenzyl groups can be the same isomer or different isomers. From the viewpoint of dielectric properties, it is preferable that at least one vinylbenzyl group in one molecule of the polyfunctional vinylbenzyl compound (A) be a para-vinylbenzyl group.

[0042] By including a para-vinylbenzyl group in the polyfunctional vinylbenzyl compound (A), a cured product having further improved dielectric properties, or even a lower dielectric loss tangent, can be provided. From this viewpoint, in one molecule of the polyfunctional vinylbenzyl compound (A), the para-vinylbenzyl group can be 10 to 100% by mass, 20 to 80% by mass, 30 to 70% by mass, or 40 to 60% by mass, relative to the total mass of all the vinylbenzyl groups.

[0043] In the polyfunctional vinylbenzyl compound (A), the vinylbenzyl group can be unsubstituted or can have a substituent. In the case of having a substituent, the substituent can be, for example, an aliphatic hydrocarbon group having 1 to 20, 1 to 8, or 1 to 4 carbon atoms, or an alkyl group having these numbers of carbon atoms. In addition, the substituent can have a halogen atom, for example, a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. In the vinylbenzyl group, at least one of 1 to 4 hydrogen atoms bonded to the benzene ring can be substituted, and in the case of having two or more substituents, the substituents can be the same as or different from each other. In the polyfunctional vinylbenzyl compound (A), the presence or absence of a substituent, the number of substituents, and the kind of substituents can be the same as or different from each other between two or more vinylbenzyl groups. From the viewpoint of dielectric properties, the polyfunctional vinylbenzyl compound (A) preferably has at least one unsubstituted vinylbenzyl group, and all of the vinylbenzyl groups can be unsubstituted.

[0044] The polyfunctional vinylbenzyl compound (A) is preferably a hydrocarbon compound, and the structure other than the vinylbenzyl group can be any of a chain hydrocarbon structure, an alicyclic hydrocarbon structure, and an aromatic hydrocarbon structure, and from the viewpoint of thermal properties, the aromatic hydrocarbon structure is preferred. As the aromatic hydrocarbon structure, a monocyclic or polycyclic aromatic ring, a fused ring of two or more aromatic rings, a fused ring of an aromatic ring and a non-aromatic ring, or the like can be mentioned.

[0045] As the aromatic hydrocarbon structure, an indene ring, an indane ring, a phenanthrene ring, an acenaphthene ring, a fluorene ring, or the like can be mentioned. From the viewpoint of dielectric properties, an indene ring and a fluorene ring are preferred. More preferably, the polyfunctional vinylbenzyl compound (A) is a compound having an indene ring. In addition, it is preferred that the vinylbenzyl group be directly bonded to a carbon atom of the ring of the aromatic hydrocarbon structure.

[0046] In the case where the polyfunctional vinylbenzyl compound (A) includes an aromatic hydrocarbon structure, the indene ring, the indane ring, the phenanthrene ring, the acenaphthene ring, the fluorene ring, or the like can be unsubstituted or can have a substituent. Among them, the bonding site to the vinylbenzyl group is excluded. As the substituent, for example, the substituents described above for the vinylbenzyl group can be mentioned. For example, in the case where the polyfunctional vinylbenzyl compound (A) includes an indene ring, at least one of a plurality of hydrogen atoms bonded to the indene ring can be substituted, and in the case of having two or more substituents, the substituents can be the same as or different from each other. In the case where the polyfunctional vinylbenzyl compound (A) includes an aromatic hydrocarbon structure, from the viewpoint of dielectric properties, the indene ring, the indane ring, the phenanthrene ring, the acenaphthene ring, the fluorene ring, or the like can be unsubstituted except for the bonding site to the vinylbenzyl group.

[0047] Hereinafter, a monomer of the polyfunctional vinylbenzyl compound (A) will be described.

[0048] The polyfunctional vinylbenzyl compound (A) as a monomer is preferably a hydrocarbon compound, preferably a compound having an indene ring, an indane ring, a phenanthrene ring, an acenaphthene ring, a fluorene ring, or the like, or a combination thereof, more preferably a compound having an indene ring, a fluorene ring, or a combination thereof, further preferably a compound having an indene ring. For example, the polyfunctional vinylbenzyl compound (A) can be a monomer having two or more vinylbenzyl groups in one molecule and having one indene ring.

[0049] One example of the polyfunctional vinylbenzyl compound (A) is a monomer having an indene ring and having two or more vinylbenzyl groups bonded to any of positions 1, 2, and 3 of the indene ring.

[0050] Specific examples of the polyfunctional vinylbenzyl compound (A) are monomers represented by the following formula (1).

[0051] [Chemical Formula 1]

[0052]

[0053] In formula (1), n is 2 or 3. Note that a mixture of monomers represented by formula (1) can include a plurality of monomers having different n. In this case, n is preferably 2 to 3 on average, more preferably 2.0 to 2.5. In addition, the resin composition can further include a vinylbenzyl compound having n of 1 in formula (1). In this case, in a mixture of vinylbenzyl compounds having n of 1 to 3 in formula (1), n is preferably 2 or more on average, more preferably 2 to 3, further preferably 2.0 to 2.5.

[0054] In formula (1), the vinylbenzyl group is directly bonded to any of the carbon atoms of positions 1, 2, and 3 of the indene ring, but is preferably position 1, or a combination of position 1 and position 3. One or two vinylbenzyl groups can be bonded to each position. For example, the vinylbenzyl group can be bonded to a combination of positions 1, 1', and 3 of the indene ring, or a combination of positions 1 and 1' of the indene ring.

[0055] In formula (1), the methylene group of the vinylbenzyl group can be any of the ortho, meta, and para positions, and is preferably the meta or para position. In formula (1), two or three vinylbenzyl groups in one molecule can be any of the ortho, meta, and para isomers, or a combination thereof, and is preferably a combination including the para isomer, and can be only the para isomer, or a combination of the meta and para isomers. In the case where two or more monomers represented by formula (1) are included in the resin composition, the positions of the methylene groups of the vinylbenzyl groups in the two or more monomers can be the same as or different from each other. In the case where two or more monomers represented by formula (1) are included in the resin composition, in the mixture of the two or more monomers, the vinylbenzyl groups can be one or a combination of two or more of the ortho, meta, and para isomers, and is preferably a combination including the para isomer, and can be only the para isomer, or a combination of the meta and para isomers. In this case, the mass ratio of the meta isomer to the para isomer in the resin composition or the cured product thereof is preferably 40:60 to 60:40.

[0056] Next, a method for synthesizing the monomer in the multifunctional vinylbenzyl compound (A) will be described. Note that the multifunctional vinylbenzyl compound (A) is a compound specific to the molecular structure thereof, which is not dependent on the following synthesis method.

[0057] As a method for synthesizing the monomer in the multifunctional vinylbenzyl compound (A), for example, a method in which a base compound having a desired structure such as indene or fluorene is reacted with a styrene having a halomethyl group in the presence of an alkaline compound can be given. As the styrene having a halomethyl group, for example, o-chloromethylstyrene, m-chloromethylstyrene, p-chloromethylstyrene, or the like can be given, which can be one or a mixture of two or more. As the alkaline compound, an alkali metal hydroxide, an alkali metal alcoholate, or the like can be given.

[0058] A phase transfer catalyst can be used in the above reaction. As the phase transfer catalyst, for example, tetra-n-butylammonium bromide or the like can be given. The reaction can be performed by solution polymerization. The reaction can be performed, for example, with heating and stirring. A polymerization inhibitor can be added to the reaction system. The obtained product can be purified as needed by a known method such as concentration, reprecipitation, washing, or the like.

[0059] The resulting monomer can be a single compound or a monomer mixture of two or more compounds. For example, in the case where the base compound is indene, a compound in which a vinylbenzyl group is directly bonded to at least one carbon atom of positions 1, 2, and 3 of the indene ring can be synthesized, and a polyfunctional vinylbenzyl compound in which the bonding site is different can be included in the monomer mixture. In addition, depending on the synthesis conditions, a compound in which a vinylbenzyl group is directly bonded to at least two carbon atoms of positions 1, 2, and 3 of the indene ring, respectively, can be obtained. In this case, a polyfunctional vinylbenzyl compound in which the number of bonding of the vinylbenzyl group to the indene ring and the bonding site are different can be included in the monomer mixture.

[0060] Hereinafter, the prepolymer in the polyfunctional vinylbenzyl compound (A) will be described.

[0061] The polyfunctional vinylbenzyl compound (A) as the prepolymer is preferably a hydrocarbon compound, and among the hydrocarbon compounds, a compound having an indene ring, an indane ring, a phenanthrene ring, an acenaphthene ring, a fluorene ring, or the like, or a combination thereof is preferred, a compound having an indene ring, a fluorene ring, or the like, or a combination thereof is more preferred, and a compound having an indene ring is further preferred. For example, the polyfunctional vinylbenzyl compound (A) can be a prepolymer including a structural unit having two or more vinylbenzyl groups and having one indene ring. That is, the polyfunctional vinylbenzyl compound (A) can include a monomer having an indene ring and having two or more vinylbenzyl groups bonded to any of positions 1, 2, and 3 of the indene ring, a polymer of the monomer, or a combination thereof.

[0062] The prepolymer can be obtained by polymerizing a monomer. The vinylbenzyl group can be introduced from the monomer. For example, a monomer having one or two or more vinylbenzyl groups can be used, and a monomer having two or more vinylbenzyl groups is preferably used. The polymerization can not be completely completed, but can be stopped in a state in which the vinylbenzyl group from the monomer remains to some extent. For example, in order to obtain the prepolymer in a liquid state, the polymerization can be stopped in a state in which the viscosity of the polymerization reaction system of the prepolymer reaches a certain degree. In the polymerization of the prepolymer, an oligomer can be used together with the monomer, or an oligomer can be used instead of the monomer. For example, a monomer of the polyfunctional vinylbenzyl compound (A) described above can be used in the polymerization of the prepolymer, and an oligomer of the monomer can also be used.

[0063] In the case where the polyfunctional vinylbenzyl compound (A) is a prepolymer, the weight average molecular weight (Mw) can be 5,000 to 50,000, or 10,000 to 30,000, from the viewpoint of the flowability of the resin composition.

[0064] Next, a method of polymerizing the vinylbenzyl compound to obtain the multifunctional vinylbenzyl compound (A) as a prepolymer will be described. The polymerization of the vinylbenzyl compound is preferably performed by radical polymerization in a manner that no polar component is generated in the reaction product. The radical polymerization can be performed using a radical polymerization initiator. The polymerization can be performed by solution polymerization, and the polymerization solvent is not particularly limited. For example, one or two or more kinds in combination can be used as the polymerization solvent from the organic solvents described later that are used in the resin composition.

[0065] As the radical polymerization initiator, a thermal radical polymerization initiator or a photo radical polymerization initiator can be used, and a thermal radical polymerization initiator is preferred. The radical polymerization initiator is not particularly limited, and examples include azo-based polymerization initiators, organic peroxide-based polymerization initiators, and the like. Specifically, one can be appropriately selected from the azo-based polymerization initiators, organic peroxide-based polymerization initiators, and the like exemplified as the curing catalyst described later.

[0066] The multifunctional vinylbenzyl compound (A) as a prepolymer can be a homopolymer of the vinylbenzyl compound, or can be a copolymer. The copolymer can be a copolymer of two or more kinds of vinylbenzyl compounds, or can be a copolymer of a vinylbenzyl compound and another monomer. In the case of a copolymer, it can be a random polymer, a block copolymer, or the like.

[0067] As the oligomer in the multifunctional vinylbenzyl compound (A), a polymer of the above monomer having a low degree of polymerization can be used.

[0068] Hereinafter, a styrene copolymer (B) having a weight average molecular weight of 20,000 or less and having a vinyl group will be described. The styrene copolymer (B) is a copolymer different from the multifunctional vinylbenzyl compound (A).

[0069] By making the weight average molecular weight of the styrene copolymer (B) 20,000 or less, the reliability of an article using a cured product of the resin composition can be improved. As a reason therefor, the stress in the coating film of the resin composition is relaxed, and the generation of fine cracks in the coating film state can be suppressed. The cured product of such a resin composition is excellent in the electrocorrosion resistance. The article including the cured product of such a resin composition is excellent in the reliability.

[0070] From this viewpoint, the weight average molecular weight of the styrene copolymer (B) is preferably 20,000 or less, more preferably 15,000 or less, and further preferably 10,000 or less. From the viewpoint of imparting flexibility to the cured product of the resin composition moderately, the weight average molecular weight of the styrene copolymer (B) can be 1,000 or more, 3,000 or more, or 5,000 or more. For example, the weight average molecular weight of the styrene copolymer (B) can be 1,000 to 20,000, 3,000 to 15,000, or 5,000 to 10,000.

[0071] The styrene copolymer (B) preferably does not contain an oxygen atom in the molecule. Thereby, it is possible to reduce the amount of polar groups in the obtained cured product, and it is possible to further reduce the relative dielectric constant and the dielectric loss tangent. In addition, the styrene copolymer (B) has a benzene ring derived from styrene in the molecule, and thus has good compatibility with the multifunctional vinylbenzyl compound (A) in the resin composition, and it is possible to further improve the moldability in the obtained cured product.

[0072] The styrene copolymer (B) can improve the heat resistance of the cured product of the resin composition by having a vinyl group. The vinyl group in the styrene copolymer (B) can be introduced, for example, by using a polyvinyl compound as a compound to be copolymerized with styrene, or can be introduced by reacting a vinyl compound having a halogenated alkyl group after obtaining a copolymer having styrene as a necessary monomer, or the like.

[0073] In the styrene copolymer (B), as the other compound to be copolymerized with styrene, for example, an α-olefin compound, a cyclic olefin compound, an aromatic vinyl compound other than styrene, a polyvinyl compound, or the like can be given. The compound to be copolymerized with styrene can be used alone or in combination with two or more.

[0074] The above-described α-olefin compound can be, for example, an α-olefin compound having 2 to 20 carbon atoms such as ethylene, propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 4-methyl-1-pentene, 3,5,5,-trimethyl-1-hexene, or the like.

[0075] The above-described cyclic olefin compound can be, for example, norbornene, cyclopentene, or the like.

[0076] The above-described aromatic vinyl compound can be, for example, methylstyrene, an alkylstyrene such as isobutylstyrene, vinyl naphthalene, vinyl anthracene, or the like.

[0077] The above-described polyvinyl compound can be, for example, divinylbenzene, divinyl naphthalene, divinyl anthracene, divinyl biphenyl, an alkylene divinylstyrene such as ethylene divinylstyrene, or the like.

[0078] Among them, from the viewpoint of the balance between the properties as an elastomer and the heat resistance of the cured product of the resin composition, it is preferable to use the above-described α-olefin compound and the above-described polyvinyl compound. That is, the styrene copolymer (B) is preferably a styrene-α-olefin compound-polyvinyl compound copolymer. As the above-described α-olefin compound, an α-olefin compound having 1 to 8 carbon atoms is preferable, and ethylene is particularly preferable. In addition, as the above-described polyvinyl compound, divinylbenzene is preferable. By using divinylbenzene, the amount of polar groups in the obtained cured product can be further reduced, and the relative dielectric constant and the dielectric loss tangent can be further reduced. In addition, the compatibility with the multifunctional vinylbenzyl compound (A) in the resin composition becomes better, and the moldability in the obtained cured product can be further improved.

[0079] The proportion of styrene with respect to the total mass of the copolymerization components is preferably 5 to 80 mass%, more preferably 15 to 75 mass%, further preferably 25 to 70 mass%, and more further preferably 30 to 60 mass%. If within these ranges, the viscoelasticity of the styrene copolymer (B) also becomes moderate, and the adhesion of the resin composition to the material to be coated can be further improved. From the viewpoint of the balance between the properties as an elastomer and the heat resistance of the cured product of the resin composition, the proportion of the above-described α-olefin compound with respect to the total mass of the copolymerization components is preferably in the range of 10 to 70 mass%, and more preferably in the range of 30 to 55 mass%. From the viewpoint of the balance between the properties as an elastomer and the heat resistance of the cured product of the resin composition, the proportion of the above-described polyvinyl compound with respect to the total mass of the copolymerization components is preferably in the range of 0.05 to 10 mass%, and preferably in the range of 0.1 to 3 mass%.

[0080] In the case of using a vinyl compound having a halogenated alkyl group as a vinyl group introducing agent to the above-described styrene copolymer (B), as one example of the compound, a styrene having a halogenated methyl group used in the synthesis of the above-described multifunctional vinylbenzyl compound (A) or the like can be given.

[0081] The above-described styrene copolymer (B) can be manufactured, for example, by a method in which styrene and the above-described polyvinyl compound are polymerized as essential raw materials (Method 1), a method in which styrene is copolymerized with other compounds, and then, as necessary, a vinyl group introducing agent such as the above-described vinyl compound having a halogenated alkyl group is reacted (Method 2). Among them, from the aspect that the above-described styrene copolymer (B) can be more easily manufactured, the above-described Method 1 is preferable.

[0082] In the above-described method 1, as an example of a method in which styrene and a polyvinyl compound are polymerized as essential raw materials, a method using a single-site coordination polymerization catalyst such as dimethylmethylenebis(4,5-benzo-l-indenyl)zirconium dichloride, dimethylmethylenebis(l-indenyl)zirconium dichloride, or the like as a polymerization catalyst can be given. At this time, an aluminoxane such as methylaluminoxane or a boron compound can be used as a cocatalyst, and in addition to the above-described aluminoxane or boron compound, an alkylaluminum such as triethylaluminum, triisobutylaluminum, or the like can be used in combination. The reaction can be performed under solvent-free conditions, or in a solvent such as hexane, cyclohexane, toluene, or the like. The reaction temperature is preferably about 30 to 160°C, and the reaction can be performed under pressurized conditions.

[0083] The content ratio of the styrene structural unit of the above-described styrene copolymer (B) is preferably 5 to 80% by mass, more preferably 15 to 75% by mass, further preferably 25 to 70% by mass, and more further preferably 30 to 60% by mass. If within these ranges, the viscoelasticity of the styrene copolymer (B) also becomes moderate, and the adhesion of the resin composition to a coated material can be further improved. In addition, as the structural unit other than styrene, from the viewpoint of the balance between the properties as an elastomer and the heat resistance of the cured product of the resin composition, the content ratio of the above-described a-olefin compound structural unit is preferably in the range of 10 to 70% by mass, and more preferably in the range of 30 to 55% by mass. The content ratio of the above-described polyvinyl compound structural unit is preferably in the range of 0.05 to 10% by mass, and more preferably in the range of 0.1 to 3% by mass.

[0084] In addition to the prepolymers (A) of the multifunctional vinylbenzyl compound and the styrene copolymers (B), other resins can also be included in the resin composition. Among these, as the elastomer, in order to suppress the generation of fine cracks in the cured product of the resin composition, it is preferable to use the styrene copolymers (B) in an amount of 50% by mass or more with respect to the total amount of the elastomers, and can be 60% by mass, 80% by mass, or 90% by mass or more, and further more preferably, one kind of styrene copolymer (B) is used alone. In addition, as the thermosetting resin, from the viewpoint of the dielectric properties, it is preferable to use the multifunctional vinylbenzyl compound (A) in an amount of 50% by mass or more with respect to the total amount of the thermosetting resins, and can be 60% by mass or 80% by mass.

[0085] From the viewpoint of improving the heat resistance of the cured product of the resin composition, a resin having a high glass transition temperature (Tg) can be included in the resin composition. For example, the resin composition can further include a vinyl compound (C) having a glass transition temperature of 150°C or higher. The vinyl compound (C) is a different compound from the multifunctional vinylbenzyl compound (A) and the styrene copolymer (B). From the viewpoint of the heat resistance of the cured product of the resin composition, the glass transition temperature (Tg) of the vinyl compound (C) is preferably 150°C or higher, more preferably 170°C or higher, and further preferably 200°C or higher. The upper limit of the glass transition temperature (Tg) of the resin is not particularly limited, and for example, can be 300°C or lower.

[0086] In the present application, unless otherwise specified, the glass transition temperature (Tg) of a polymer is a value measured according to the following measurement method. The glass transition temperature of a polymer is measured by a differential scanning calorimeter (DSC). The measurement device can be, for example, "DSC Q200" (trade name) by TA Instruments Japan, Inc.

[0087] As a specific procedure, first, a polymer is dried, then cooled, and a test sample for measurement is prepared. 10 mg of the test sample for measurement is warmed at a temperature range of 25°C to 400°C at 10°C / minute under a nitrogen (N2) atmosphere in a differential scanning calorimeter, and then cooled to 25°C. When the temperature is again warmed under the same conditions, the temperature at which the baseline is shifted is defined as the glass transition temperature.

[0088] The vinyl compound (C) can be a high molecular compound having a vinyl group. The vinyl compound (C) is preferably a high molecular compound having a plurality of structural units. The vinyl compound (C) can be a homopolymer, or can be a copolymer. The vinyl compound (C) can be, for example, a random copolymer, a block copolymer, or the like.

[0089] The vinyl compound (C) can include, for example, one or two or more structural units having a vinyl group. The vinyl compound (C) can include, for example, one or two or more structural units having a vinyl group and one or two or more structural units not having a vinyl group.

[0090] The vinyl compound (C) can be, for example, a homopolymer of a monomer having a vinyl group, or can be a copolymer of two or more monomers including a monomer having a vinyl group. The vinyl compound (C) can be, for example, a copolymer of one or two or more monomers having a vinyl group and one or two or more monomers not having a vinyl group.

[0091] The vinyl compound (C) can have, for example, a long chain. As the long chain, for example, an alkyl chain or the like can be given.

[0092] From the viewpoint of the adhesive strength to the metal foil, the weight average molecular weight (Mw) of the vinyl compound (C) is preferably 6,500 or more, more preferably 10,000 or more, further preferably 25,000 or more, particularly preferably 30,000 or more. The weight average molecular weight of the vinyl compound (C) may be, for example, 50,000 or more. The weight average molecular weight of the vinyl compound (C) may be, for example, 100,000 or less, or 50,000 or less. The weight average molecular weight of the vinyl compound (C) may be, for example, 30,000 or less. The weight average molecular weight of the vinyl compound (C) may be, for example, 6,500 to 100,000, 10,000 to 100,000, 25,000 to 100,000, or 30,000 to 50,000. The weight average molecular weight of the vinyl compound (C) may be, for example, 6,500 to 30,000, 25,000 to 50,000, 30,000 to 50,000, or 50,000 to 100,000. In addition, from the viewpoint of the viscosity, the weight average molecular weight of the vinyl compound (C) is preferably 25,000 or more, more preferably 30,000 or more.

[0093] From the viewpoint of the adhesive strength to the metal foil, the number average molecular weight (Mn) of the vinyl compound (C) is preferably 2,000 or more, more preferably 3,000 or more, further preferably 4,000 or more. The number average molecular weight of the vinyl compound (C) may be, for example, 10,000 or more. The number average molecular weight of the vinyl compound (C) may be, for example, 20,000 or less, or 10,000 or less. The number average molecular weight of the vinyl compound (C) may be, for example, 4,000 or less. The number average molecular weight of the vinyl compound (C) may be, for example, 2,000 to 20,000, 3,000 to 10,000, or 4,000 to 10,000. The number average molecular weight of the vinyl compound (C) may be, for example, 2,000 to 4,000, 4,000 to 10,000, or 10,000 to 20,000.

[0094] The vinyl equivalent of the vinyl compound (C) is preferably 150 g / eq or more, more preferably 200 g / eq or more, and further preferably 250 g / eq or more, from the viewpoint of the adhesive strength to the metal foil and the dielectric properties. The vinyl equivalent of the vinyl compound (C) may be, for example, 500 g / eq or more. The vinyl equivalent of the vinyl compound (C) may be, for example, 2,300 g / eq or less, 2,100 g / eq or less, 1,000 g / eq or less, or 500 g / eq or less. The vinyl equivalent of the vinyl compound (C) may be, for example, 150 g / eq to 2,300 g / eq, 150 g / eq to 2,100 g / eq, 200 g / eq to 1,000 g / eq, or 250 g / eq to 500 g / eq. The vinyl equivalent of the vinyl compound (C) may be, for example, 150 g / eq to 250 g / eq, 250 g / eq to 500 g / eq, or 500 g / eq to 1,000 g / eq.

[0095] The content of each of the monomer, the oligomer, and the polymer in the resin composition is not particularly limited. Here, the total amount of the monomer, the oligomer, and the polymer in the resin composition is collectively referred to as the resin total amount PT. The resin total amount PT includes the content of the multifunctional vinylbenzyl compound (A) and the styrene copolymer (B), and optionally includes the content of the vinyl compound (C) having a glass transition temperature of 150°C or higher, and further optionally includes the content of other monomers, oligomers, and polymers. Note that the resin total amount PT also optionally includes the content of an elastomer.

[0096] The multifunctional vinylbenzyl compound (A) is preferably 30 to 80% by mass, more preferably 40 to 75% by mass, and further preferably 50 to 70% by mass, based on the resin total amount PT. If within these ranges, a cured product having more excellent electrocorrosion resistance can be obtained. In addition, the flowability of the resin composition can be controlled, and the moldability of the metal-clad laminate becomes excellent.

[0097] The styrene copolymer (B) is preferably 5 to 50% by mass, more preferably 10 to 40% by mass, and further preferably 20 to 30% by mass, based on the resin total amount PT. If within these ranges, the dielectric properties and the electrocorrosion resistance of the metal-clad laminate become excellent.

[0098] The vinyl compound (C) having a glass transition temperature of 150°C or higher is preferably 5 to 50% by mass, more preferably 10 to 40% by mass, and further preferably 20 to 30% by mass, based on the resin total amount PT. If within these ranges, a cured product having excellent electrocorrosion resistance can be obtained. In addition, the tackiness of uncured or semi-cured products such as prepregs and resin films becomes excellent.

[0099] As one of the preferable examples, the resin composition contains 40 to 60 mass% of the multifunctional vinylbenzyl compound (A), 20 to 30 mass% of the styrene copolymer (B), and 20 to 30 mass% of the vinyl compound (C) having a glass transition temperature of 150°C or higher, with respect to the total amount PT of the resin.

[0100] The total content of the multifunctional vinylbenzyl compound (A) and the styrene copolymer (B) is preferably 20 to 100 mass%, more preferably 40 to 90 mass%, and further preferably 60 to 80 mass%, with respect to the total amount PT of the resin. If within these ranges, the flowability of the resin composition can be controlled, the generation of fine cracks in the cured product of the resin composition can be suppressed, and a metal-clad laminate having good dielectric properties and electric corrosion resistance can be produced.

[0101] In order to promote the curing of the multifunctional vinylbenzyl compound (A), a curing catalyst can be further contained in the resin composition.

[0102] As the curing catalyst, a radical polymerization initiator can be used. As the radical polymerization initiator, a thermal radical polymerization initiator or a photo radical polymerization initiator can be used, and a thermal radical polymerization initiator is preferable. The radical polymerization initiator is not particularly limited, and examples include azo-based polymerization initiators, organic peroxide-based polymerization initiators, and the like.

[0103] As the azo-based polymerization initiator, for example, 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylpropanenitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), dimethyl 2,2'-azobis(2-methylpropanoate), 1,1'-azobis(cyclohexylmethanol), 2,2'-azobis[N-(2-propenyl)-2-methylpropanamide], 2,2'-azobis(N-butyl-2-methylpropanamide), 4,4'-azobis(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl 4-cyanopentanoate), 1,1'-azobis(cyclohexane-1-carbonitrile), and the like can be given.

[0104] As the organic peroxide-based polymerization initiator, for example, dicumyl peroxide, dibenzoyl peroxide, 2-butanone peroxide, t-butyl peroxybenzoate, di-t-butyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, bis(t-butylperoxyisopropyl)benzene, t-butyl hydroperoxide, and the like can be given.

[0105] In order to prevent the mixing of a polar component into the resin composition, the generation of a by-product that exhibits polarity in the polymerization system can be reduced. From such a viewpoint, in the radical polymerization initiator, a compound having a small amount of oxygen atoms can be used. As such a compound, an azo-based polymerization initiator is preferable. Among them, a compound that does not contain a hetero atom other than the two nitrogen atoms (N) of the azo group is preferable. For example, a compound represented by the following formula (2) can be mentioned.

[0106] As the azo-based polymerization initiator, a compound represented by the following formula (2) can be used.

[0107] R 1 -N=N-R 2 (2)

[0108] In formula (2), R 1 and R 2 are each independently a hydrogen atom or a monovalent group, and at least one of R 1 and R 2 is a monovalent group. R 1 and R 2 may be the same as or different from each other. The monovalent group is preferably a hydrocarbon group, and can be a saturated hydrocarbon group or an unsaturated hydrocarbon group, or an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The monovalent group is preferably a saturated or unsaturated aliphatic hydrocarbon group, and is preferably an alkyl group.

[0109] As the alkyl group, any of a chain alkyl group and a cyclic alkyl group can be used. The chain alkyl group can be a straight chain alkyl group or a branched chain alkyl group. The cyclic alkyl group can have a substituent bonded to a carbon atom on the ring.

[0110] The alkyl group can be, for example, an alkyl group having 1 to 10 carbon atoms, an alkyl group having 3 to 8 carbon atoms, or an alkyl group having 4 to 8 carbon atoms. As the alkyl group, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, an n-hexyl group, an isohexyl group, a cyclohexyl group, a methylcyclohexyl group, a cyclohexylmethyl group, a heptyl group, an octyl group, an isooctyl group, a 2-ethylhexyl group, a nonyl group, a decyl group, a 1,1',3,3'-tetramethylbutyl group, a 2,2',4,4'-tetramethylbutyl group, or the like can be mentioned.

[0111] As a specific example of the compound represented by formula (2), 2,2'-azobis(2,4,4-trimethylpentane), 2,2'-azobis(2,4-dimethylvaleronitrile), or the like can be mentioned.

[0112] The amount of the curing catalyst used is appropriately adjusted, and can be, for example, 0.01 to 5 parts by mass, 0.1 to 4 parts by mass, or 0.5 to 2 parts by mass, with respect to 100 parts by mass of the content of the multifunctional vinyl benzyl compound (A).

[0113] The resin composition can contain an inorganic filler as an optional component. As the inorganic filler, for example, there can be mentioned silica (Si02), alumina (AI2O3), titanium oxide, barium titanate, strontium titanate, potassium titanate, calcium titanate, aluminum carbonate, magnesium hydroxide, aluminum hydroxide, aluminum silicate, calcium carbonate, calcium silicate, magnesium silicate, silicon nitride, boron nitride, aluminum borate, silicon carbide, mica, beryllium oxide, clay, talc, and the like. From the viewpoint of dielectric properties, silica is preferred.

[0114] The shape and size of the inorganic filler are not particularly limited. The average particle diameter of the inorganic filler can be, for example, 0.01 to 20 μm, or 0.1 to 10 μm. Here, the average particle diameter of the inorganic filler is the particle diameter at the point corresponding to the cumulative value of 50% in the particle distribution on a volume basis based on the laser diffraction scattering method.

[0115] The inorganic filler can be used alone or in combination of two or more kinds.

[0116] The inorganic filler can be 10 to 500 parts by mass, or 50 to 400 parts by mass, 100 to 350 parts by mass, or 150 to 300 parts by mass, relative to 100 parts by mass of the solid components of the resin composition. Here, the mass of the solid components of the resin composition is the total mass of the components other than the solvent.

[0117] In the case where the polyfunctional vinylbenzyl compound (A) is a polymer such as a prepolymer, the resin composition can contain a radical polymerization initiator or a by-product thereof from the polymerization of the prepolymer. In this case, the radical polymerization initiator uses a compound having a small oxygen atomic weight or a compound not containing an oxygen atom, and in the resin composition, the prepolymer can be made to have a small oxygen atomic weight or not contain an oxygen atom.

[0118] If the polyfunctional vinylbenzyl compound (A) alone, or the combination of the polyfunctional vinylbenzyl compound (A) and other resin components is in a liquid state, the resin composition can be a resin composition containing the polyfunctional vinylbenzyl compound (A) and free of a solvent. Alternatively, the resin composition can contain the polyfunctional vinylbenzyl compound (A) and a solvent. The solvent is capable of adjusting the viscosity of the resin composition, and further improving the coatability. As the solvent, an organic solvent is preferred.

[0119] As the organic solvent, for example, alcohol-based solvents such as ethanol, propanol, butanol, methyl cellosolve, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, and the like; ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and the like; ether-based solvents such as tetrahydrofuran and the like; aromatic hydrocarbon-based solvents such as toluene, xylene, mesitylene, and the like; solvents containing a nitrogen atom such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and the like; solvents containing a sulfur atom such as dimethyl sulfoxide and the like; ester-based solvents such as γ-butyrolactone and the like can be given. The organic solvent can be used alone or in combination of two or more.

[0120] In the case where the resin composition contains a solvent, the amount of the solid component other than the solvent with respect to the total mass of the resin composition can be 10 to 90% by mass, 30 to 80% by mass, or 50 to 75% by mass.

[0121] The resin composition can further contain an additive other than the above-mentioned components within a range not impairing the effects of the present application. As the additive, for example, a flame retardant, a curing accelerator, an antioxidant, a heat stabilizer, an antistatic agent, an ultraviolet absorber, a pigment, a colorant, a lubricant, and the like can be given.

[0122] The production method of the resin composition is not particularly limited. The resin composition of one embodiment is not limited by the production method, and is characterized as described in the present application. As one example of the production method of the resin composition, the resin composition can be obtained by mixing the polyfunctional vinylbenzyl compound (A) and the styrene copolymer (B) with optional components as needed. In more detail, the polyfunctional vinylbenzyl compound (A) and the styrene copolymer (B) can be dissolved or dispersed in a solvent, and a vinyl compound (C), an inorganic filler, an additive other than these, and the like can be added as needed and mixed, whereby the resin composition can be obtained. The order of mixing of the components, the temperature, the time, and the like are not particularly limited, and can be appropriately adjusted depending on the kind of the raw material, the production scale, the production apparatus, and the like.

[0123] "Cured product"

[0124] According to one embodiment, a cured product of a resin composition can be provided. Details of the resin composition are as described above. Since the amount of the polar group containing an oxygen atom is small in the polyfunctional vinylbenzyl compound (A) and the styrene copolymer (B), the amount of the polar group in the cured product can be reduced, and a low dielectric constant and a low dielectric loss tangent can be achieved in the cured product. In addition, the resin composition has good compatibility, and the generation of agglomerates is also small, and thus a cured product is provided by using the resin composition, and the generation of fine cracks and the like in the cured product can be inhibited, the resistance to electrical corrosion can be improved, and the reliability of the product can be improved.

[0125] The cured product of the resin composition preferably has a relative dielectric constant (Dk) of 4.0 or less, more preferably 3.5 or less, and further preferably 3.3 or less at 25°C and 10 GHz. More specifically, the cured product of the resin composition can have a relative dielectric constant (Dk) of 3.30 or less, 3.25 or less, or 3.23 or less at 25°C and 10 GHz. The relative dielectric constant (Dk) of the cured product of the resin composition is more preferably smaller, and the lower limit thereof is not particularly limited, and can be, for example, 2.3 or more or 2.4 or more in consideration of the balance with other physical properties.

[0126] For example, the cured product of the resin composition can have a relative dielectric constant (Dk) of 2.3 to 4.0, 2.3 to 3.3, 2.3 to 3.25, or 2.4 to 3.23 at 25°C and 10 GHz.

[0127] The cured product of the resin composition preferably has a dielectric loss tangent (Df) of 0.0020 or less, more preferably 0.0012 or less, and further preferably 0.0010 or less at 25°C and 10 GHz. More specifically, the cured product of the resin composition can have a dielectric loss tangent (Df) of 0.00100 or less or 0.00099 or less at 25°C and 10 GHz. The dielectric loss tangent (Df) of the cured product of the resin composition is more preferably smaller, and the lower limit thereof is not particularly limited, and can be, for example, 0.0001 or more or 0.00050 or more in consideration of the balance with other physical properties.

[0128] For example, the cured product of the resin composition can have a dielectric loss tangent (Df) of 0.0001 to 0.0020, 0.00050 to 0.00100, or 0.00050 to 0.00099 at 25°C and 10 GHz.

[0129] In the present application, the relative dielectric constant (Dk) and the dielectric loss tangent (Df) at 25°C and 10 GHz are measured in a 10 GHz band at 25°C according to the SPDR method (split post dielectric resonator). The measuring device can use "PNA Network Analyzer N5222B" (trade name) of Agilent Technologies, Inc.

[0130] The sample for measurement of the relative dielectric constant (Dk) and the dielectric loss tangent (Df) of the cured product of the resin composition is obtained by using the resin composition to obtain a cured product and molding it into a sample sheet having a thickness of 130 μm and a size of 5 cm x 10 cm.

[0131] In addition, a test piece that is a measurement target of relative dielectric constant (Dk) and dielectric loss tangent (Df) of a cured product of the resin composition is a test piece that is cured to be in a state of C-stage in JIS K 6800 (1985).

[0132] "Prepreg"

[0133] According to one embodiment, a prepreg containing a resin composition or a semi-cured product of the resin composition can be provided. Details of the resin composition are as described above.

[0134] The prepreg refers to an article in a state in which the resin composition is impregnated in a fiber base material. In the prepreg, the resin composition can be in an uncured state, or in a partially or completely semi-cured state. For example, the prepreg is used to assemble a molded product such as a laminate, and is cured by heat treatment or the like, whereby a cured product can be obtained.

[0135] The prepreg can be obtained, for example, by applying the resin composition to a fiber base material and drying. In another method, the prepreg can be obtained by impregnation coating the resin composition to a fiber base material, and drying the fiber base material impregnated with the resin composition. The drying is preferably performed at a temperature at which a volatile component such as a solvent contained in the resin composition is removed, and can be performed at a temperature at which the resin composition is semi-cured, according to the use. In addition, the drying can be adjusted so that the resin composition is not completely cured. From such a viewpoint, the drying temperature can be 80 to 200°C, and the drying time can be 1 to 30 minutes, according to the drying temperature and the drying device, the scale thereof, and the like.

[0136] In the present application, in the case where the semi-cured product of the resin composition is mentioned, it means a state in which a part of the vinylbenzyl group and the vinyl group contained in the resin composition contributes to the curing reaction, and the remaining vinylbenzyl group and the vinyl group remain. The semi-cured product becomes a state in which the curing reaction can be further performed by further performing heat treatment or the like. In the present application, as one index of the semi-cured product, a state of B-stage in JIS K 6800 (1985) can be cited.

[0137] The fiber base material can be any of a woven fabric, a knitted fabric, and a nonwoven fabric. The fiber base material can be provided in the shape of a chopped strand mat, a roving, or the like. As a material of the fiber, any of an inorganic fiber and an organic fiber can be used. As the inorganic fiber, a glass fiber, a carbon fiber, or the like can be cited. As the glass fiber, an E glass, an NE glass, a D glass, an S glass, a Q glass, or the like can be cited. As the organic fiber, a polyimide, a polyester, a tetrafluoroethylene, or the like can be cited. The fiber base material can be a single fiber among them, or a blended fiber of two or more kinds among them. From the viewpoints of dielectric properties and heat resistance, the fiber base material is preferably an inorganic fiber, and more preferably a glass fiber.

[0138] The fiber base material is appropriately selected according to the use of the prepreg, and a sheet-like fiber base material is preferred. As the sheet-like fiber base material, for example, various sheet-like fiber base materials used in the known laminated boards for electric insulating materials can be used. The thickness of the sheet-like fiber base material is not particularly limited, and for example, 0.02 to 0.5 mm is preferred. Here, the thickness is the thickness of 5 points measured at the entire surface of the sheet-like fiber base material at equal intervals, and is set as the arithmetic average of the 5 points.

[0139] In the prepreg, the total mass of the resin composition can be 20 to 90 mass% or 30 to 80 mass% with respect to the total mass of the prepreg. If within these ranges, the impregnation coating of the resin to the fiber base material can be performed more easily in the prepreg. In addition, the process of assembling the prepreg into a molded product and curing can be performed more easily.

[0140] "Resin film"

[0141] According to one embodiment, a resin film containing a resin composition or a semi-cured product of a resin composition can be provided. Details of the resin composition are as described above.

[0142] The resin film refers to an article in which the resin composition is shaped into a film-like state. In the resin film, the resin composition can be in an uncured state, or in a partially or completely semi-cured state. By curing the resin film using heat treatment or the like, a cured product can be obtained.

[0143] The resin film can be obtained, for example, by applying the resin composition to an application material and drying it. The drying can be performed, for example, in the same manner as the manufacturing method of the prepreg described above. The product can also be provided in the form of a combination of the resin film and the application material after drying the resin film on the application material. In this method, the resin film can be provided in order to form an insulating layer or the like on the application material in electronic devices and the like. In other methods, the resin film can also be provided as a product after peeling the resin film from the application material after drying the resin film on the application material.

[0144] As the application material, any of inorganic base materials and organic base materials can be used, and the fiber base materials described above in the prepreg, such as glass base materials, metal base materials such as metal foils, metal plates, plastic base materials such as plastic plates, plastic films, and paper base materials, can be used. In order to provide the resin film by peeling it from the application material, an application material having a release layer formed on the surface can be used.

[0145] "Metal-clad laminated board"

[0146] According to one embodiment, a metal-clad laminate sheet including a cured product of a resin composition and a metal foil can be provided. The cured product of the resin composition can be a cured product of the resin composition or a cured product of a prepreg. Details of the resin composition and the prepreg are as described above.

[0147] The metal-clad laminate sheet preferably includes a resin cured product layer including a resin cured product and a metal foil formed on at least one face of the resin cured product layer. The resin cured product layer includes a cured product of the resin composition, but can also be a cured product of the prepreg described above. As a more useful use, a metal foil is formed on at least one face of a cured product of the prepreg, and more preferably, a metal foil is formed on both faces of a cured product of the prepreg. The metal-clad laminate sheet can be manufactured by forming a metal foil on at least one face of one sheet of a prepreg, or can be manufactured by laminating two or more sheets of a prepreg and forming a metal foil on at least one face of the outermost surface of the laminate. As a more useful use, the metal-clad laminate sheet is manufactured by laminating two or more sheets of a prepreg and forming a metal foil on both faces of the laminate.

[0148] Hereinafter, as a specific example of a method of manufacturing a metal-clad laminate sheet, a method of forming a metal foil on a laminate of two or more sheets of a prepreg will be described.

[0149] First, two or more sheets of a prepreg are combined to obtain a laminate. In the laminate, the two or more sheets of a prepreg can be the same as each other, or can be partially or entirely different. In the laminate, at least one sheet of a prepreg among the two or more sheets of a prepreg can be obtained using the resin composition of one embodiment. Next, a metal foil is formed on at least one face of the laminate. For example, by previously preparing a shaped product of a metal foil, the metal foil can be attached to the laminate to form a metal foil on the laminate.

[0150] Next, the metal-clad laminate sheet can be manufactured by performing heat and pressure on the laminate on which the metal foil is formed. Thereby, a curing reaction of the prepreg proceeds, and a cured product of the prepreg can be obtained. In addition, the sheets of a prepreg adjacent to each other can be fixed. The heat and pressure conditions are not particularly limited, and for example, can be set to a temperature of 100 to 300°C, a time of 10 to 300 minutes, and a pressure of 1.5 to 5 MPa. In addition, after the pressure, in order to further perform curing of the prepreg, reheating can be performed. The reheating temperature at this time can be 100 to 300°C. As a pressure method, for example, an autoclave molding machine, a multistage press machine, a multistage vacuum press machine, a continuous molding machine, or the like can be used.

[0151] The dielectric properties of the resin cured product in the state in which the metal foil is removed from the assembled metal-clad laminate sheet (also simply referred to as the dielectric properties of the metal-clad laminate sheet) are preferably as follows.

[0152] The relative dielectric constant (Dk) of the metal-clad laminate at 25°C, 10 GHz is 4.0 or less, more preferably 3.5 or less, and further preferably 3.3 or less. More specifically, the relative dielectric constant (Dk) of the metal-clad laminate at 25°C, 10 GHz can be 3.30 or less, 3.25 or less, or 3.23 or less. The smaller the relative dielectric constant (Dk) of the metal-clad laminate at 25°C, 10 GHz, the more preferable it is, and the lower limit thereof is not particularly limited, and in view of the balance with other physical properties, it can be 2.3 or more, or 2.4 or more, for example.

[0153] For example, the relative dielectric constant (Dk) of the metal-clad laminate at 25°C, 10 GHz can be 2.3 to 4.0, preferably 2.3 to 3.3, 2.3 to 3.25, or 2.4 to 3.23.

[0154] The dielectric loss tangent (Df) of the metal-clad laminate at 25°C, 10 GHz is preferably 0.0020 or less, more preferably 0.0012 or less, and further preferably 0.0010 or less. More specifically, the dielectric loss tangent (Df) of the metal-clad laminate at 25°C, 10 GHz can be 0.00100 or less, or 0.00099 or less. The smaller the dielectric loss tangent (Df) of the metal-clad laminate at 25°C, 10 GHz, the more preferable it is, and the lower limit thereof is not particularly limited, and in view of the balance with other physical properties, it can be 0.0001 or more, or 0.00050 or more, for example.

[0155] For example, the dielectric loss tangent (Df) of the metal-clad laminate at 25°C, 10 GHz can be 0.0001 to 0.0020, preferably 0.00050 to 0.00100, or 0.00050 to 0.00099.

[0156] The measurement of the relative dielectric constant (Dk) and the dielectric loss tangent (Df) of the metal-clad laminate can be performed according to the measurement of the relative dielectric constant (Dk) and the dielectric loss tangent (Df) of the cured product of the resin composition described above.

[0157] The sample for the measurement of the relative dielectric constant (Dk) and the dielectric loss tangent (Df) of the metal-clad laminate is a sample in which a copper foil is removed from the resin cured product by immersing the metal-clad laminate in an etching solution, and a 130-μm-thick, 5-cm- by-10-cm evaluation substrate is cut out from the sample from which the copper foil has been removed. In the case of a copper-clad laminate, an ammonium persulfate 10% by mass solution is used as the etching solution.

[0158] "Printed wiring board"

[0159] According to one embodiment, a printed wiring board including a cured product of a resin composition can be provided. Details of the resin composition are as described above.

[0160] In the printed wiring board, the cured product of the resin composition can be produced by using the resin composition, prepreg, resin film, metal-clad laminate, or a combination thereof. For example, the printed wiring board can be provided by forming an insulating layer by applying the resin composition to the surface of a substrate of the printed wiring board and curing it. In another example, the printed wiring board can be provided by using a metal-clad laminate as a substrate of the printed wiring board. The printed wiring board can also be a combination of these examples. Details of the prepreg, resin film, and metal-clad laminate are as described above.

[0161] The printed wiring board can be any of a single-layer printed wiring board and a multi-layer printed wiring board. In the case of a multi-layer printed wiring board, the prepreg, resin film, metal-clad laminate, or a combination thereof can be used to make it multi-layered.

[0162] "Semiconductor package"

[0163] According to one embodiment, a semiconductor package including a printed wiring board including a cured product of a resin composition and a semiconductor element can be provided. Details of the resin composition are as described above. Details of the cured product of the resin composition and the printed wiring board are also as described above. The semiconductor package can be produced, for example, by mounting a semiconductor element, memory, or the like on the printed wiring board using a known method. As an insulating material, sealing material, or the like of the semiconductor package, the cured product of the resin can be used.

[0164] Examples of embodiments of the present application are described below. The present application is not limited to the following embodiments.

[0165] <1> A resin composition including: a multifunctional vinylbenzyl compound (A) having two or more vinylbenzyl groups; and a styrene copolymer (B) having a weight average molecular weight of 20,000 or less and having a vinyl group.

[0166] <2> The resin composition described in the above <1>, wherein the multifunctional vinylbenzyl compound (A) includes a compound having an indene ring.

[0167] <3> The resin composition described in the above <1> or <2>, wherein the multifunctional vinylbenzyl compound (A) includes a monomer having an indene ring and having two or more vinylbenzyl groups bonded to any of positions 1, 2, and 3 of the indene ring, a polymer of the monomer, or a combination thereof.

[0168] The resin composition according to any one of the above <1> to <3>, further comprising a vinyl compound (C) having a glass transition temperature of 150°C or higher, the above vinyl compound (C) being a different compound from the above multifunctional vinylbenzyl compound (A) and the above styrene copolymer (B).

[0169] The resin composition according to the above <4>, wherein the weight average molecular weight of the above vinyl compound (C) is 25,000 or more.

[0170] The resin composition according to any one of the above <1> to <5>, wherein a cured product of the resin composition shows a relative dielectric constant of 2.3 to 3.3 at a measurement temperature of 25°C and a frequency of 10 GHz.

[0171] The resin composition according to any one of the above <1> to <6>, wherein a cured product of the resin composition shows a dielectric loss tangent of 0.00050 to 0.00100 at a measurement temperature of 25°C and a frequency of 10 GHz.

[0172] A prepreg containing the resin composition according to any one of the above <1> to <7> or a semi-cured product of the above resin composition.

[0173] A metal-clad laminate containing a cured product of the resin composition according to any one of the above <1> to <7> and a metal foil.

[0174] A resin film containing the resin composition according to any one of the above <1> to <7> or a semi-cured product of the above resin composition.

[0175] A printed wiring board containing a cured product of the resin composition according to any one of the above <1> to <7>.

[0176] A semiconductor package containing the printed wiring board according to the above <11> and a semiconductor element.

[0177] Examples

[0178] The present application is more specifically described below by way of examples, but the present application is not limited to the following examples.

[0179] "Manufacture of vinylbenzyl compound"

[0180] Into a 500 mL volume reaction vessel equipped with a stirring device, a thermometer, a reflux tube, and a nitrogen inlet, were charged indene 35.6 parts by mass, the following chloromethylstyrene 101.2 parts by mass, tetra-n-butylammonium bromide (manufactured by KANTO CHEMICAL CO., INC.) 7.1 parts by mass as a phase transfer catalyst, phenothiazine 0.1 part by mass as a polymerization inhibitor, toluene 77.6 parts by mass as a solvent, and nitrogen was blown at a flow rate of 50 mL / min while heating and stirring at 40°C.

[0181] Chloromethylstyrene "CMS-P": AGC SEIMI CHEMICAL CO., LTD., mixture of meta- and para- isomers, 50 mass% of the meta-isomer and 50 mass% of the para-isomer.

[0182] Next, an aqueous solution of the following basic compound 46.5 parts by mass was added dropwise over 20 minutes, and further stirred at 60°C for 9 hours. Note that nitrogen was continuously blown during the reaction. After cooling to room temperature (25°C) and neutralization with 10% aqueous hydrochloric acid, washed with pure water twice, and after distilling off toluene under reduced pressure, the obtained viscous liquid was washed with methanol, and vacuum dried, whereby a vinylbenzyl compound was obtained.

[0183] Aqueous solution of basic compound: aqueous solution of sodium hydroxide at a concentration of 48 mass%, KANTO CHEMICAL CO., INC.

[0184] By 1 H-NMR analysis confirmed that the obtained vinylbenzyl compound had a structure in which a vinylbenzyl group was directly bonded to a carbon atom at position 1, position 3, or a combination thereof of the indene represented by the following formula (3). In addition, according to GPC analysis, the vinylbenzyl compound was a mixture of a compound into which two vinylbenzyl groups were introduced and a compound into which three vinylbenzyl groups were introduced. In the case where three vinylbenzyl groups were introduced into the vinylbenzyl compound, two vinylbenzyl groups directly bonded to the carbon atom at position 1 of the indene ring and one vinylbenzyl group directly bonded to the carbon atom at position 3 were confirmed. The weight average molecular weight (Mw) of the vinylbenzyl compound was 500. The weight average molecular weight was measured by the following method.

[0185] [Chemical Formula 2]

[0186]

[0187] "Method for measuring weight average molecular weight (Mw)"

[0188] The weight average molecular weight was converted according to a standard curve using a standard polystyrene by gel permeation chromatography (GPC). The standard curve was approximated by a 3-time formula using a standard polystyrene: TSK standard POLYSTYRENE (type; A-2500, A-5000, F-20, F-80) (manufactured by Tosoh Corporation, trade name), and the measurement conditions of GPC are shown below.

[0189] Apparatus: High-speed GPC device HLC-8320GPC (Tosoh Corporation, trade name)

[0190] Detector: Ultraviolet absorbance detector UV-8320 (Tosoh Corporation, trade name)

[0191] Column: Guard column; TSKgel guard column Super (HZ)-M+, Column; TSKgel Super Multipore HZ-M (2 pieces), Reference column; TSKgel Super H-RC (2 pieces) (all of which are manufactured by Tosoh Corporation, trade name)

[0192] Column size: 4.6 x 20 mm (guard column), 4.6 x 150 mm (column), 6.0 x 150 mm (reference column)

[0193] Eluent: Tetrahydrofuran

[0194] Sample concentration: 10 mg / 1 mL

[0195] Injection amount: 20 μL or 2 μL

[0196] Flow rate: 0.35 mL / minute

[0197] Measurement temperature: 40°C

[0198] "Preparation of Resin Composition"

[0199] Each component shown in Table 1 was combined with toluene at the content shown in the table, and stirred and mixed at 25°C to prepare a resin composition having a solid component concentration of about 75 mass%. In the table, the combined amount of each component is in units of mass parts, and in the case of a solution, refers to mass parts converted to solid components.

[0200] The components used were as follows.

[0201] Polyfunctional vinylbenzyl compound (A): The compound prepared above was used.

[0202] Styrene copolymer (B): Styrene copolymer having a vinyl group (styrene ratio 51 mass%, ethylene ratio 48 mass%, divinylbenzene ratio 1 mass%, weight average molecular weight (Mw): 9,000).

[0203] Reference styrene copolymer: styrene-ethylene-butadiene-styrene copolymer (styrene ratio: 20 mass%, weight average molecular weight (Mw): 78,000, no vinyl group within the copolymer molecule).

[0204] Bismaleimide compound: bismaleimide compound (Mn = 1300).

[0205] Vinyl compound (C): vinyl compound (Tg ≥ 150°C, vinyl equivalent: 265 g / eq, weight average molecular weight (Mw): 36,000, number average molecular weight (Mn): 3,300).

[0206] Silica filler: average particle diameter 2.4 μm.

[0207] The glass transition temperature of the vinyl compound (C) is a value measured by a differential scanning calorimeter (DSC). The measuring device used was "DSC Q200" (trade name) by TA Instruments Japan, Inc.

[0208] As a specific procedure, first, the vinyl compound (C) was dried and then cooled to prepare a measurement sample. 10 mg of the measurement sample was warmed at a rate of 10°C / minute in a nitrogen (N2) atmosphere in a differential scanning calorimeter in the temperature range of 25°C to 400°C, and then cooled to 25°C. When warmed again under the same conditions, the temperature at which the baseline was shifted was defined as the glass transition temperature.

[0209] "Production of prepreg"

[0210] The obtained resin composition was impregnation-coated on a Nippon Electric Glass Co., Ltd. NE glass fiber cloth having a thickness of 0.03 mm, and heated and dried at 130°C for 4 minutes to obtain a prepreg having a content of solid components from the resin composition of 80 mass%.

[0211] "Production of copper-clad laminate"

[0212] On both sides of the obtained prepreg, a low-profile copper foil (SI-VSP18, manufactured by Mitsui Mining Co., Ltd., "VSP" is a registered trademark) having a thickness of 18 μm was overlapped so that the rough surface was attached to the prepreg, and heating and pressurization was performed under vacuum press conditions of 230°C, 80 minutes, and 2 MPa, whereby a copper-clad laminate (CCL) was produced. The copper-clad laminate had a thickness of 130 μm and a size of 5 cm x 10 cm.

[0213] "Method of evaluation and measurement method"

[0214] The evaluation and measurement were carried out as follows, and the results are shown in the table.

[0215] (Dielectric properties of copper-clad laminates)

[0216] The copper-clad laminate fabricated as described above was immersed in a 10% by mass solution of ammonium persulfate (manufactured by MITSUBISHI GASCHEMICAL Co., Ltd.) as the copper etching solution to remove the copper foil from both sides of the prepreg. An evaluation substrate of 5cm × 10cm was then cut from the substrate with the copper foil removed. The thickness of the evaluation substrate was 130μm.

[0217] Using this evaluation substrate, the relative permittivity (Dk) and dielectric loss tangent (Df) were measured in the 10 GHz band at 25 °C according to the SPDR method (split dielectric resonator). The measurement apparatus used was an Agilent Technologies PNA Network Analyzer N5222B (trade name).

[0218] (Electro-erosion resistance (CAF) evaluation)

[0219] Following the same steps as the manufacturing method for the copper-clad laminate described above, a double-sided copper-clad laminate with a thickness of 0.8 mm and dimensions of 230 mm × 230 mm is fabricated. A... Figure 1 The pattern shown is illustrated. The drill conditions for pattern formation were as follows: drill diameter 0.4 mm, rotation speed 80,000 rpm, feed rate 1.2 m / min, hole spacing of 0.3 mm, and a total of 320 holes. A resist film was applied during pattern formation to prevent damage. After drilling, a copper plating layer of approximately 20 μm was applied inside the holes. The resulting sample was then subjected to a heat treatment process, maintaining the surface temperature above 260°C for 10 seconds and cooling to room temperature (approximately 25°C). This heat treatment process was repeated 6 times to obtain samples for CAF evaluation. The obtained samples were placed in a constant temperature bath at 85°C / 85%RH for 96 hours, and a DC voltage of 100V was applied within the bath. Regarding the evaluation criteria, a resistance value consistently above 1.0E+0.6 Ω for 500 hours from the start of the measurement was considered OK, while a resistance value below 1.0E+0.6 Ω was considered NG. In this test, evaluation was conducted for each test number, with N=5. Electrolytic corrosion resistance was evaluated according to the following criteria.

[0220] A: In N=5, the OK number is 4 or 5.

[0221] B: In N=5, the OK number is 1 to 3.

[0222] C: OK number in N=5 is 0.

[0223] (Dielectric properties of the cured product of the resin composition)

[0224] The resin composition obtained above was applied to a polyethylene terephthalate (PET) film (manufactured by Teijin Corporation, trade name: G2000) having a thickness of 38 μm, and heated and dried at 130°C for 10 minutes, thereby producing a resin film in a B-stage state. After the resin film was peeled from the PET film, it was pulverized to produce a resin powder.

[0225] Next, a Teflon (registered trademark) sheet punched to a size of a thickness of 0.3 mm x a length of 50 mm x a width of 40 mm was disposed on a copper foil, and the resin powder was dropped into the punched portion. Further, a copper foil was disposed thereon, thereby obtaining a laminate. Note that the copper foil was a low-profile copper foil (manufactured by Sumitomo Metal Mining Co., Ltd., trade name: SI-VSP) having a thickness of 18 μm, and was disposed in a state where the S face (glossy face) was in contact with the dropped resin powder. Subsequently, the laminate was subjected to vacuum heat-press molding at a temperature of 230°C, a pressure of 2 MPa, and a time of 90 minutes, thereby curing the resin composition. Then, the copper foil on both faces was peeled and removed, thereby obtaining a resin board.

[0226] Using this test piece, the relative dielectric constant (Dk) and the dielectric loss tangent (Df) were measured at a frequency band of 10 GHz and at 25°C according to the SPDR method (split post dielectric resonator). The measuring device used was "PNA Network Analyzer N5227A" (trade name) manufactured by Agilent Technologies, Inc.

[0227]

[0228] As shown in the table, the copper-clad laminate using the resin composition of Example 4 containing the multifunctional vinylbenzyl compound (A) and the styrene copolymer (B) exhibited a low dielectric constant and a low dielectric loss tangent, and exhibited excellent electric corrosion resistance. It was known that the reliability as a product was high because the electric corrosion resistance was excellent. In addition, the dielectric properties of the cured product of the resin composition of the resin composition of Example 4 were also excellent. In Examples 1 to 3, the electric corrosion resistance of the copper-clad laminate was reduced because the resin composition containing no styrene copolymer (B) was used.

[0229] Industrial applicability

[0230] The resin composition of some embodiments of the present application and the article formed using the same can be applied, for example, as a metal-clad laminate such as a copper-clad laminate, a substrate material of a printed wiring board, and the like, in electronic devices such as mobile communication devices typified by smartphones, network infrastructure devices such as base station apparatuses thereof, servers, routers, and the like, electronic devices in which high speed and large capacity of signals are expected such as large computers, and the like.

[0231] The present application is associated with the subject matter described in Japanese Patent Application No. 2023-181836 filed on October 23, 2023, the entire disclosure of which is hereby incorporated by reference. It should be noted that, in addition to the already described content, various modifications, changes, and the like can be applied to the above-described embodiments without departing from the novel and advantageous features of the present application. Therefore, all such modifications, changes, and the like are included in the appended technical solutions.

Claims

1. A resin composition comprising: Polyfunctional vinylbenzyl compounds (A) having two or more vinylbenzyl groups; and Styrene copolymers (B) with a weight average molecular weight of less than 20,000 and containing vinyl groups.

2. The resin composition according to claim 1, wherein, The polyfunctional vinyl benzyl compound (A) comprises a compound having an indene ring.

3. The resin composition according to claim 1, wherein, The polyfunctional vinylbenzyl compound (A) comprises a monomer having an indene ring and having two or more vinylbenzyl groups bonded to any of the 1, 2, and 3 positions of the indene ring, a polymer of the monomer, or a combination thereof.

4. The resin composition according to claim 1, further comprising a vinyl compound (C) having a glass transition temperature of 150°C or higher, said vinyl compound (C) being a compound different from said polyfunctional vinyl benzyl compound (A) and said styrene copolymer (B).

5. The resin composition according to claim 4, wherein, The vinyl compound (C) has a weight-average molecular weight of 25,000 or more.

6. The resin composition according to claim 1, wherein, The relative permittivity of the cured resin composition at a measurement temperature of 25°C and a frequency of 10 GHz was 2.3–3.

3.

7. The resin composition according to claim 1, wherein, The dielectric loss tangent of the cured resin composition at a measurement temperature of 25°C and a frequency of 10 GHz is 0.00050 to 0.00100.

8. A prepreg comprising the resin composition of any one of claims 1 to 7 or a semi-cured product of the resin composition.

9. A metal-clad laminate comprising a cured resin composition according to any one of claims 1 to 7 and a metal foil.

10. A resin film comprising the resin composition of any one of claims 1 to 7 or a semi-cured product of the resin composition.

11. A printed circuit board comprising a cured product of the resin composition according to any one of claims 1 to 7.

12. A semiconductor package comprising the printed circuit board and semiconductor element as described in claim 11.

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