Resin composition, adhesive film, high-frequency substrate, millimeter wave radar substrate, printed wiring board, and semiconductor device

Abstract

To provide a resin composition capable of forming a cured product having excellent flame retardancy, small relative permittivity and dielectric loss tangent values at 25°C in a high frequency band, and small temperature dependence of the dielectric loss tangent. A resin composition contains a flame retardant containing a cyclic phosphazene compound having an oxaphospholine ring-containing structure represented by formula (A1), and a cured product of the resin composition has a relative permittivity of 3.5 or less at 10 GHz and 25°C, a dielectric loss tangent of 0.003 or less at 10 GHz and 25°C, and a dielectric loss tangent at 120°C which is 30% or less with respect to the dielectric loss tangent at 10 GHz and 25°C. [In formula (A1), n is an integer of 3-8; a and b are each an integer of 0-4; and R1 and R2 (i) are either an alkyl group or an alkoxy group, and an aryl group or an aryloxy group or (ii) have a structure formed therebetween by saturated or unsaturated cyclic structures.]

Description

Resin composition, adhesive film, high-frequency substrate, millimeter-wave radar substrate, printed wiring board, and semiconductor device

[0001] The present invention relates to a resin composition, an adhesive film, a high-frequency substrate, a millimeter-wave radar substrate, a printed wiring board, and a semiconductor device.

[0002] Various resin substrates (for example, high-frequency substrates, millimeter-wave radar substrates, printed wiring boards) used in high-frequency bands of several GHz or more may require flame retardancy. In such cases, a flame retardant is used in the production of the resin substrate. And in the resin substrate added with the flame retardant, in order to ensure flame retardancy and improve transmission loss and the like, techniques using a specific flame retardant or making dielectric properties such as relative permittivity within a predetermined range have been proposed (for example, Patent Documents 1 and 2).

[0003] Japanese Patent Application Laid-Open No. 2022-21767 International Publication No. 2020 / 116408

[0004] The present invention has been made in view of the above circumstances, and provides (i) a resin composition, (ii) an adhesive film using the same, (iii) a high-frequency substrate, a millimeter-wave radar substrate, and a printed wiring board using a cured product of the resin composition, and (iv) a semiconductor device including at least one of these three types of substrates, which can form a cured product having excellent flame retardancy, small values of relative permittivity and dielectric tangent at 25 ° C in the high-frequency band, and small temperature dependence of the dielectric tangent.

[0005] The above problems are achieved by the following present invention. That is, the resin composition of the present invention includes (A) a flame retardant containing a cyclic phosphazene compound having an oxaphospholine ring-containing structure represented by the following general formula (A1), and a resin component, and the measured value of the relative permittivity of the cured product at 10 GHz and 25 ° C is 3.5 or less, the measured value of the dielectric tangent of the cured product at 10 GHz and 25 ° C is 0.003 or less, and the change rate of the measured value at 120 ° C with respect to the measured value at 10 GHz and 25 ° C of the dielectric tangent of the cured product is within the range of ± 30%.

[0006]

[0007] [In the general formula (A1), n is an integer of 3 to 8, and R １ and R ２ are each independently (i) an alkyl group or an alkoxy group having 1 to 8 carbon atoms, or an aryl group or an aryloxy group having 6 to 20 carbon atoms, which may be substituted with at least one group selected from an alkyl group having 1 to 6 carbon atoms and an aryl group, or (ii) a saturated or unsaturated cyclic structure which may be substituted with an alkyl group having 1 to 6 carbon atoms or a carbonyl group, and a and b are each independently an integer of 0 to 4, and the types of the oxaphosphorin ring-containing structures of each repeating unit are independent. ]

[0008] One embodiment of the resin composition of the present invention preferably contains the resin component (B) a styrene-based elastomer.

[0009] Another embodiment of the resin composition of the present invention preferably contains the (B) styrene-based elastomer as a hydrogenated styrene-based elastomer.

[0010] Another embodiment of the resin composition of the present invention preferably contains the resin component (C) a crosslinkable compound having a biphenyl skeleton.

[0011] Another embodiment of the resin composition of the present invention preferably contains the resin component (D) a crosslinking agent.

[0012] Another embodiment of the resin composition of the present invention preferably contains the (D) crosslinking agent as an isocyanurate ring-containing diallyl compound.

[0013] Another embodiment of the resin composition of the present invention preferably contains 10 to 60 parts by mass of the flame retardant with respect to 100 parts by mass of the resin component.

[0014] Another embodiment of the resin composition of the present invention preferably contains an inorganic filler.

[0015] Another embodiment of the resin composition of the present invention preferably has a content of the inorganic filler of 80% by mass or less.

[0016] Other embodiments of the resin composition of the present invention are preferably for high-frequency substrates or printed circuit boards.

[0017] The adhesive film of the present invention comprises the resin composition of the present invention.

[0018] In one embodiment of the adhesive film of the present invention, a thickness of 5 to 300 μm is preferred.

[0019] The high-frequency substrate of the present invention includes a cured product of the resin composition of the present invention.

[0020] The millimeter-wave radar substrate of the present invention includes a cured product of the resin composition of the present invention.

[0021] The printed circuit board of the present invention includes a cured product of the resin composition of the present invention.

[0022] The semiconductor device of the present invention includes at least one substrate selected from the group consisting of the high-frequency substrate of the present invention, the millimeter-wave radar substrate of the present invention, and the printed wiring substrate of the present invention.

[0023] According to the present invention, it is possible to provide (i) a resin composition that can form a cured product that has excellent flame retardancy, low relative permittivity and dielectric loss tangent values ​​at 25°C in the high frequency band, and low temperature dependence of the dielectric loss tangent; (ii) an adhesive film using the same; (iii) a high frequency substrate, a millimeter-wave radar substrate, and a printed wiring substrate using the cured product of the resin composition; and (iv) a semiconductor device including at least one of these three types of substrates.

[0024] This is a schematic diagram illustrating the method for evaluating slitting properties. It is a schematic cross-sectional view showing an example of the cut surface of the adhesive film after cutting, used for evaluating slitting properties.

[0025] [Resin Composition] The resin composition of this embodiment comprises (A) a flame retardant containing a cyclic phosphazene compound having an oxaphosphorine ring-containing structure represented by the following general formula (A1) (hereinafter sometimes simply abbreviated as "cyclic phosphazene compound") and a resin component, characterized in that the relative permittivity of the cured product measured at 10 GHz and 25°C is 3.5 or less, the dielectric loss tangent of the cured product measured at 10 GHz and 25°C is 0.003 or less, and the rate of change of the dielectric loss tangent of the cured product measured at 120°C with respect to the measurement at 10 GHz and 25°C is within ±30%.

[0026]

[0027] Here, in the general formula (A1), n ​​is an integer from 3 to 8, and R １ and R ２ (i) each independently forms a saturated or unsaturated cyclic structure which may be substituted with either an alkyl or alkoxy group having 1 to 8 carbon atoms, which may be substituted with at least one group selected from alkyl and aryl groups having 1 to 6 carbon atoms, or an aryl or aryloxy group having 6 to 20 carbon atoms, which may be substituted with at least one group selected from alkyl and aryl groups having 1 to 6 carbon atoms, or (ii) a saturated or unsaturated cyclic structure which may be substituted with an alkyl or carbonyl group having 1 to 6 carbon atoms, where a and b are each independently integers from 0 to 4, and the type of oxaphosphorine ring-containing structure of each repeating unit is independent.

[0028] The resin composition of this embodiment described above can form a cured product that is excellent in flame retardancy, has small relative permittivity and dielectric loss tangent values ​​at 25°C in the high-frequency band, and also has low temperature dependence of the dielectric loss tangent.

[0029] Next, we will describe in detail each component incorporated into the resin composition of this embodiment.

[0030] <(A) Flame retardant> The resin composition of this embodiment contains a flame retardant comprising a cyclic phosphazene compound having an oxaphospholine ring-containing structure represented by the general formula (A1) above.

[0031] In general formula (A1), n ​​is an integer from 3 to 8. Therefore, the cyclic phosphazene compounds having an oxaphosphorine ring-containing structure represented by general formula (A1) are: a cyclic phosphazene compound having an oxaphosphorine ring-containing structure with n = 3 (trimer), a cyclic phosphazene compound having an oxaphosphorine ring-containing structure with n = 4 (tetramer), a cyclic phosphazene compound having an oxaphosphorine ring-containing structure with n = 5 (pentamer), a cyclic phosphazene compound having an oxaphosphorine ring-containing structure with n = 6 (hexamer), a cyclic phosphazene compound having an oxaphosphorine ring-containing structure with n = 7 (heptamer), or a cyclic phosphazene compound having an oxaphosphorine ring-containing structure with n = 8 (octamer).

[0032] When a cyclic phosphazene compound has a small n value, it is easier to achieve a resin composition with superior dielectric properties. Therefore, the cyclic phosphazene compound included in component (A) is preferably one in which n is 3 or 4 (trimer or tetramer) in general formula (A1), and is particularly preferably one in which n is 3 (trimer). Furthermore, when the cyclic phosphazene compound included in component (A) is a mixture of two or more compounds with different n values, it is easier to achieve a resin composition with superior dielectric properties as the proportion of cyclic phosphazene compounds with a small n value increases. Therefore, when the cyclic phosphazene compound included in component (A) is a mixture of two or more compounds with different n values, a mixture containing 95% or more by mass ratio of cyclic phosphazene compounds with n value 3 and / or 4 is preferred, and a mixture containing 95% or more by mass ratio of cyclic phosphazene compounds with n value 3 is particularly preferred.

[0033] R in general formula (A1) １ and R ２ Each of these independently represents R-1, R-2, or R-3 below. Also, in general formula (A1), substituent R １ and R ２ The values ​​a and b, which represent the numbers, are each independent integers between 0 and 4.

[0034] R-1: A C1-C8 alkyl or alkoxy group, which may be substituted with at least one group selected from C1-C6 alkyl groups and aryl groups.

[0035] Examples of the relevant alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, 2-ethylhexyl, benzyl, and 2-phenylethyl. Examples of the relevant alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy, n-hexyloxy, n-heptyloxy, n-octyloxy, n-nonyloxy, 2-ethylhexyloxy, benzyloxy, and 2-phenylethyloxy.

[0036] R-1 is preferably a methyl group, an ethyl group, an n-propyl group, a benzyl group, or a methoxy group, with a methyl group or an ethyl group being particularly preferred.

[0037] R-2: A C6-C20 aryl group or aryloxy group, which may be substituted with at least one group selected from C1-C6 alkyl groups and aryl groups.

[0038] Examples of the corresponding aryl groups include a phenyl group, a methylphenyl group, a dimethylphenyl group, an ethylphenyl group, an ethylmethylphenyl group, a diethylphenyl group, an n-propylphenyl group, an isopropylphenyl group, an isopropylmethylphenyl group, an isopropylethylphenyl group, a diisopropylphenyl group, an n-butylphenyl group, a sec-butylphenyl group, a tert-butylphenyl group, an n-pentylphenyl group, an n-hexylphenyl group, a phenylphenyl group, a naphthyl group, an anthryl group, and a phenanthryl group. Examples of the corresponding aryloxy groups include a phenyloxy group, a methylphenyloxy group, a dimethylphenyloxy group, an ethylphenyloxy group, an ethylmethylphenyloxy group, a diethylphenyloxy group, an n-propylphenyloxy group, an isopropylphenyloxy group, an isopropylmethylphenyloxy group, an isopropylethylphenyloxy group, a diisopropylphenyloxy group, an n-butylphenyloxy group, a sec-butylphenyloxy group, a tert-butylphenyloxy group, an n-pentylphenyloxy group, an n-hexylphenyloxy group, a phenylphenyloxy group, a naphthyloxy group, an anthryloxy group, and a phenanthryloxy group.

[0039] R-2 is preferably a phenyl group, a methylphenyl group, a dimethylphenyl group, a diethylphenyl group, a phenylphenyl group, a naphthyl group or a phenyloxy group, and particularly preferably a phenyl group or a methylphenyl group.

[0040] R-3: A saturated or unsaturated cyclic structure formed between R １ and R ２ which may be substituted by an alkyl group or a carbonyl group having 1 to 6 carbon atoms.

[0041] Examples of the repeating unit of the general formula (A1) having an oxaphosphorin ring-containing structure having the corresponding saturated cyclic structure include those represented by the following structural formula (A2) and the following structural formula (A3).

[0042]

[0043] Furthermore, an example of a repeating unit of general formula (A1) having an oxaphosphorine ring-containing structure with the corresponding unsaturated cyclic structure is the one represented by the following structural formula (A4).

[0044]

[0045] In cyclic phosphazene compounds, the type of oxaphosphorine ring-containing structure in each repeating unit is independent. Therefore, a cyclic phosphazene compound may have all oxaphosphorine ring-containing structures being the same, or it may have two or more types of oxaphosphorine ring-containing structures.

[0046] Specific examples of cyclic phosphazene compounds include any of the following: a cyclotriphosphazene compound having an oxaphosphorine ring-containing structure where n in general formula (A1) is 3; a cyclotetraphosphazene compound having an oxaphosphorine ring-containing structure where n in general formula (A1) is 4; a cyclopentaphosphazene compound having an oxaphosphorine ring-containing structure where n in general formula (A1) is 5; a cyclohexaphosphazene compound having an oxaphosphorine ring-containing structure where n in general formula (A1) is 6; a cycloheptaphosphazene compound having an oxaphosphorine ring-containing structure where n in general formula (A1) is 7; or a cyclooctaphosphazene compound having an oxaphosphorine ring-containing structure where n in general formula (A1) is 8, where a, b, R １ and R ２ Examples of combinations include those shown in Table 1 below. The cyclic phosphazene compound may be used alone or in combination of two or more types.

[0047]

[0048] Of the above examples, a cyclotriphosphazene compound in which n in general formula (A1) is 3 or a cyclotetraphosphazene compound in which n in general formula (A1) is 4, and combination examples 1, 2, or 3 are preferred, with a cyclotriphosphazene compound in which n in general formula (A1) is 3, and combination example 1 or 2 being particularly preferred.

[0049] Among the above examples, the cyclotriphosphazene compound in general formula (A1) where n is 3, and which is in combination example 1, has a structure represented by the following structural formula (A5).

[0050]

[0051] A cyclic phosphazene compound having an oxaphosphorine ring-containing structure represented by structural formula (A5) can be obtained as a mixture of diastereomers by, for example, the method described in Japanese Patent Application Publication No. 2022-021767. That is, a cyclic phosphazene compound having an oxaphosphorine ring-containing structure represented by structural formula (A5) can be obtained as a mixture of a cis-cis-cis type compound represented by the following structural formula (A6) (hereinafter referred to as the "cis type compound") and a trans-cis-trans type compound represented by the following structural formula (A7) (hereinafter referred to as the "trans type compound") in terms of the stereoconfiguration of adjacent oxaphosphorine ring-containing structures.

[0052]

[0053]

[0054] Such a mixture of diastereomers can be used as is, but the cis-type compound and the trans-type compound can also be isolated and used as single compounds of each type. Isolation methods include, for example, a combination of separation using solubility in a solvent such as toluene and filtration, solvent extraction, recrystallization, or column chromatography.

[0055] The cyclic phosphazene compound is preferably a mixture of two or more compounds having different molecular structures represented by general formula (A1). An example of such a mixture is a mixture containing two or more of the compounds listed above as specific examples of cyclic phosphazene compounds. Furthermore, when the resin composition of this embodiment is used as a material for manufacturing resin molded articles for electrical and electronic components, the cyclic phosphazene compound contained in component (A) is preferably a mixture of a cyclotriphosphazene compound in which n in general formula (A1) is 3 and a cyclotetraphosphazene compound in which n in general formula (A1) is 4, in any combination selected from the groups of combination examples 1, 2, and 3.

[0056] The cyclic phosphazene compound may also be a mixture of isomers, such as a mixture of diastereomers of the cyclotriphosphazene compound described above. When a cyclic phosphazene compound of general formula (A1) has 4 or more n, it is usually produced by the manufacturing method described below and obtained as a mixture of stereoisomers having many diastereomers and enantiomers.

[0057] The cyclic phosphazene compound represented by general formula (A1) can be produced, for example, by the method described in Japanese Patent Application Publication No. 2022-021767. The resin composition of this embodiment may include by-products generated during the production of the cyclic phosphazene compound contained in component (A).

[0058] In the resin composition of this embodiment, which contains a flame retardant comprising a cyclic phosphazene compound having an oxaphosphorine ring-containing structure represented by general formula (A1), the cured product has, in the high-frequency band, (i) excellent flame retardancy, (ii) a small relative permittivity at room temperature (25°C), (iii) a small dielectric loss tangent (tanδ) at room temperature (25°C), and (iv) a small temperature dependence of the dielectric loss tangent (tanδ) (i.e., the rate of change of the measured value of tanδ at 120°C relative to the measured value of tanδ at 25°C). The reason why the cured product has not only the properties shown in (i) and (ii) but also the properties shown in (iii) and (iv) is unknown, but the inventors speculate as follows. First, the cyclic phosphazene compound represented by general formula (A1) has a molecular structure in which benzene rings are less likely to move due to the bonding of adjacent benzene rings. Therefore, compared to the molecular structure of conventional phosphazene-based flame retardants in which adjacent benzene rings are not bonded, molecular motion is suppressed in the cyclic phosphazene compound represented by general formula (A1). As a result, the dielectric loss tangent (tanδ) at room temperature (25°C) is small, and it is presumed that even at higher temperatures, when thermal energy is applied to the cyclic phosphazene compound molecule, molecular motion does not become more active, thus reducing the temperature dependence of the dielectric loss tangent (tanδ).

[0059] The resin composition of this embodiment may contain only a cyclic phosphazene compound represented by general formula (A1) as (A) a flame retardant, or it may contain a cyclic phosphazene compound represented by general formula (A1) and other flame retardants other than the cyclic phosphazene compound represented by general formula (A1). Suitable other flame retardants include those whose cured product has a small relative permittivity (ε) at room temperature (25°C), a small dielectric loss tangent (tanδ) at room temperature (25°C), and a small temperature dependence of the dielectric loss tangent (tanδ). Specific examples of suitable other flame retardants include phosphinate metal salts such as aluminum diethylphosphinate (aluminum phosphinate salt), biphenol bis-dixylenyl phosphate, 10-(2,5-dihydroxyphenyl)-10-H-9-oxa-10-phosphaphenanthrene-10-oxide, and the like.

[0060] Furthermore, from the viewpoint of easily obtaining the effects shown in (i) to (iv) above, the content of other flame retardants is preferably 0 to 50 parts by mass, more preferably 0 to 30 parts by mass, and even more preferably 0 to 10 parts by mass per 100 parts by mass of flame retardant (A), and it is particularly preferable that flame retardant (A) consists only of a cyclic phosphazene compound represented by general formula (A1).

[0061] <Resin Components (Components (B) to (D), etc.)> The resin composition of this embodiment contains resin components in addition to (A) the flame retardant. Specific examples of resin components include (B) a styrene elastomer, (C) a crosslinkable compound having a biphenyl skeleton, and (D) a crosslinking agent. Other examples include polymers, elastomers, polymerizable monomers, and non-volatile low-molecular-weight organic components other than components (B) to (D). The resin components to be incorporated into the resin composition of this embodiment are not particularly limited as long as the cured product of the resin composition exhibits excellent flame retardancy and satisfies the three physical properties shown in (a) to (c) below. However, it is preferable to include at least one of (B) a styrene elastomer and (C) a crosslinkable compound having a biphenyl skeleton. Furthermore, when using (C) a crosslinkable compound having a biphenyl skeleton as the resin component, the resin component may further contain (D) a crosslinking agent. (a) The relative permittivity of the cured material measured at 10 GHz and 25°C is 3.5 or less. (b) The dielectric loss tangent of the cured material measured at 10 GHz and 25°C is 0.003 or less. (c) The rate of change of the dielectric loss tangent of the cured material measured at 120°C relative to the measured value at 10 GHz and 25°C is within ±30%.

[0062] <(B) Styrene-based elastomer> Styrene-based elastomers contribute to the film properties when the resin composition is formed into a film, as well as the heat resistance of the cured product. They also impart excellent electrical properties, low dielectric constant, and low dielectric loss tangent to the cured product in the high-frequency band. Furthermore, styrene-based elastomers have a moderate degree of flexibility that allows them to relieve externally applied stress on the cured product. For this reason, they can relieve stress generated in various substrates, such as high-frequency substrates, made using the resin composition of this embodiment.

[0063] Examples of styrene-based elastomers include hydrogenated styrene-based elastomers and non-hydrogenated styrene-based elastomers. Specifically, examples include styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene / butylene-styrene block copolymer (SEBS), styrene-butadiene / butylene-styrene block copolymer (SBBS), styrene-ethylene / propylene-styrene block copolymer (SEPS), and styrene-(ethylene-ethylene / propylene)-styrene block copolymer (SEEPS). Among these, hydrogenated styrene-based elastomers such as styrene-ethylene / butylene-styrene block copolymer (SEBS), styrene-butadiene / butylene-styrene block copolymer (SBBS), and styrene-(ethylene-ethylene / propylene)-styrene block copolymer (SEEPS) are preferred from the viewpoint of reducing the temperature dependence of tanδ, and styrene-ethylene / butylene-styrene block copolymer (SEBS) is more preferred from the viewpoint of heat resistance. The weight-average molecular weight of the styrene-based elastomer is preferably 30,000 to 200,000. The weight-average molecular weight is determined by gel permeation chromatography (GPC) using a calibration curve based on standard polystyrene. Furthermore, from the viewpoint of embedding ability into uneven surfaces caused by wiring etc. formed on the surface of various substrates, styrene-butadiene-styrene block copolymer (SBS) is preferred, and from the viewpoint of low volatility, styrene-butadiene-styrene block copolymer (SBS) having a 1,2-vinyl structure is more preferred. The weight-average molecular weight of styrene-butadiene-styrene block copolymer (SBS) having a 1,2-vinyl structure is preferably 1,000 to 10,000. The styrene-based elastomer may be used alone or in combination of two or more types.

[0064] <(C) Crosslinkable Compounds Having a Biphenyl Skeleton> Crosslinkable compounds having a biphenyl skeleton can increase the glass transition temperature (Tg) of the cured product and reduce the time-dependent changes in the cured resin composition, thus contributing to the maintenance of long-term reliability of various substrates such as high-frequency substrates made using the resin composition of this embodiment. Furthermore, crosslinkable compounds having a biphenyl skeleton also contribute to reducing the temperature dependence of the cured product's tanδ. Examples of crosslinkable compounds having a biphenyl skeleton include compounds having a biphenyl skeleton and having two or more reactive groups at the end of the molecule. Here, examples of reactive groups include vinyl groups, (meth)acryloyl groups and other groups containing reactive double bonds, and epoxy groups, and the number of reactive groups in the molecule is preferably two to four, and more preferably two. Examples of compounds having a biphenyl skeleton and having two or more reactive groups at the end of the molecule include polyphenylene ether compounds (hereinafter sometimes referred to as "modified PPE") having phenyl groups bonded to vinyl groups or (meth)acryloyl groups at both ends of the molecule, and epoxy resins having a biphenyl skeleton. Modified PPE and epoxy resins with a biphenyl skeleton have fewer hydrophilic groups in their molecules, thus reducing the hygroscopicity of the cured product and improving its moisture resistance. Furthermore, cured products of resin compositions containing crosslinkable compounds with a biphenyl skeleton have excellent insulating properties, allowing for the maintenance of substrate reliability even when the thickness of the substrate formed from the resin composition is reduced.

[0065] Examples of polyphenylene ether compounds having vinyl-bonded phenyl groups at both ends include compounds represented by the following general formula (C1) (vinyl-modified PPE).

[0066]

[0067] Here, in the general formula (C1), R １ , R ２ , R ３ , R ４ , R ５ , R ６ , R ７R may be the same or different, and is a hydrogen atom, a halogen atom, an alkyl group, an alkyl halide, or a phenyl group, where -(O-X-O)- is represented by the following general formula (C2), where R ８ , R ９ , R １０ , R １４ , R １５ R may be the same or different, and is a halogen atom, an alkyl group having 6 or fewer carbon atoms, or a phenyl group. １１ , R １２ , R １３ R may be the same or different, and is a hydrogen atom, a halogen atom, or an alkyl group or phenyl group having 6 or fewer carbon atoms, and -(Y-O)- is one type of structure represented by the following general formula (C3), or two or more types of structures represented by the general formula (C3) arranged randomly, where R １６ , R １７ R may be the same or different, and is a halogen atom, an alkyl group having 6 or fewer carbon atoms, or a phenyl group. １８ , R １９ , which may be the same or different, are a hydrogen atom, a halogen atom, or an alkyl group or phenyl group having 6 or fewer carbon atoms; Z is an organic group having 1 or more carbon atoms, which may optionally include an oxygen atom, a nitrogen atom, a sulfur atom, or a halogen atom; a and b represent integers from 0 to 300, with at least one of them being non-zero; and c and d represent integers of 0 or 1.

[0068]

[0069] In general formula (C2) which represents -(O-X-O)- in general formula (C1), R ８ , R ９ , R １０ , R １４ , R １５ Preferably, R is an alkyl group having 3 or fewer carbon atoms. １１ , R １２ , R １３ Preferably, this is a hydrogen atom or an alkyl group having 3 or fewer carbon atoms. That is, a preferred form of -(O-X-O)- is the following structural formula (C4).

[0070]

[0071] In general formula (C3) which shows -(Y-O)- in general formula (C1), R １６ , R １７ Preferably, R is an alkyl group having 3 or fewer carbon atoms. １８ , R １９ Preferably, this is a hydrogen atom or an alkyl group having 3 or fewer carbon atoms. That is, preferred forms of -(Y-O)- include the following structural formula (C5) or the following structural formula (C6).

[0072]

[0073] In the general formula (C1), Z can be any alkylene group having three or fewer carbon atoms, specifically a methylene group.

[0074] In general formula (C1), a and b represent integers from 0 to 300, preferably from 0 to 30, with at least one of them being non-zero.

[0075] The number average molecular weight of vinyl group-modified PPE represented by general formula (C1) is preferably 1,000 to 4,500, more preferably 1,000 to 3,000, and even more preferably 1,000 to 2,500. One type of vinyl group-modified PPE may be used alone, or two or more types may be used in combination.

[0076] Furthermore, examples of polyphenylene ether compounds having (meth)acryloyl groups at both ends include modified polyphenylene ethers ((meth)acryloyl group-modified PPE) having a group represented by the following general formula (C7) at one end.

[0077]

[0078] In general formula (C7), R １ R represents a hydrogen atom or an alkyl group. １ The alkyl group is not particularly limited, but for example, alkyl groups having 1 to 18 carbon atoms are preferred, and alkyl groups having 1 to 10 carbon atoms are more preferred. Specifically, examples include methyl groups, ethyl groups, propyl groups, hexyl groups, and decyl groups.

[0079] Furthermore, examples of groups represented by the general formula (C7) include the acryloyl group and the methacryloyl group.

[0080] Furthermore, modified polyphenylene ethers having the group represented by general formula (C7) preferably have a polyphenylene ether chain in their molecule, and for example, preferably have repeating units represented by the following general formula (C8) in their molecule.

[0081]

[0082] In the above general formula (C8), m represents an integer from 1 to 50. Also, R ２２ ~R ２５ These elements are independent of each other and may be identical or different from each other. ２２ ~R ２５ This represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, or an alkynylcarbonyl group. Among these, hydrogen atoms and alkyl groups are preferred.

[0083] R ２２ ~R ２５ Specifically, the functional groups mentioned include the following:

[0084] R ２２ ~R ２５ The alkyl group in is not particularly limited, but for example, alkyl groups having 1 to 18 carbon atoms are preferred, and alkyl groups having 1 to 10 carbon atoms are more preferred. Specifically, examples include methyl groups, ethyl groups, propyl groups, hexyl groups, and decyl groups.

[0085] R ２２ ~R ２５ The alkenyl group in is not particularly limited, but for example, an alkenyl group having 2 to 18 carbon atoms is preferred, and an alkenyl group having 2 to 10 carbon atoms is more preferred. Specifically, examples include a vinyl group, an allyl group, and a 3-butenyl group.

[0086] R ２２ ~R ２５The alkynyl group in is not particularly limited, but for example, an alkynyl group having 2 to 18 carbon atoms is preferred, and an alkynyl group having 2 to 10 carbon atoms is more preferred. Specifically, examples include the ethynyl group and the propa-2-in-1-yl group (propargyl group).

[0087] R ２２ ~R ２５ The alkylcarbonyl group in is not particularly limited as long as it is a carbonyl group substituted with an alkyl group, but for example, an alkylcarbonyl group having 2 to 18 carbon atoms is preferred, and an alkylcarbonyl group having 2 to 10 carbon atoms is more preferred. Specifically, examples include acetyl group, propionyl group, butyryl group, isobutyryl group, pivaloyl group, hexanoyl group, octanoyl group, and cyclohexylcarbonyl group.

[0088] R ２２ ~R ２５ The alkenylcarbonyl group in is not particularly limited as long as it is a carbonyl group substituted with an alkenyl group, but for example, an alkenylcarbonyl group having 3 to 18 carbon atoms is preferred, and an alkenylcarbonyl group having 3 to 10 carbon atoms is more preferred. Specifically, examples include acryloyl groups, methacryloyl groups, and crotonoyl groups.

[0089] R ２２ ~R ２５ The alkynylcarbonyl group in is not particularly limited as long as it is a carbonyl group substituted with an alkynyl group, but for example, an alkynylcarbonyl group having 3 to 18 carbon atoms is preferred, and an alkynylcarbonyl group having 3 to 10 carbon atoms is more preferred. Specifically, for example, a propioloyl group can be mentioned.

[0090] Examples of (meth)acryloyl group-modified PPE include modified polyphenylene ethers having a group represented by the above general formula (C7) at the terminus of a polyphenylene ether represented by the following general formula (C9) or general formula (C10), i.e., modified polyphenylene ethers represented by the following general formula (C11) or general formula (C12).

[0091]

[0092]

[0093]

[0094]

[0095] In general formulas (C9) to (C12), it is preferable that the sum of s and t is an integer between 1 and 30. It is also preferable that s is an integer between 0 and 20, and t is an integer between 0 and 20. That is, it is preferable that s represents an integer between 0 and 20, t represents an integer between 0 and 20, and the sum of s and t represents an integer between 1 and 30. Furthermore, in general formulas (C9) to (C12), Y represents an alkylene group having 1 to 3 carbon atoms or a direct bond, and examples of this alkylene group include the dimethylmethylene group. Furthermore, in general formulas (C11) and (C12), R １ R in the above general formula (C7) １ It is similar to the above and represents a hydrogen atom or an alkyl group. Furthermore, the alkyl group is not particularly limited, for example, alkyl groups having 1 to 18 carbon atoms are preferred, and alkyl groups having 1 to 10 carbon atoms are more preferred. Specifically, examples include methyl group, ethyl group, propyl group, hexyl group, and decyl group.

[0096] The number-average molecular weight (Mn) of (meth)acryloyl-modified PPE is not particularly limited, but is preferably 500 to 5000, more preferably 800 to 4000, and even more preferably 1000 to 3000. Here, the number-average molecular weight refers to the value measured using gel permeation chromatography (GPC). Furthermore, if the (meth)acryloyl-modified PPE has repeating units represented by general formula (C8) in its molecule, it is preferable that m is a value such that the number-average molecular weight of the modified polyphenylene ether falls within the above range. Specifically, it is preferable that m is an integer from 1 to 50.

[0097] When the number-average molecular weight of (meth)acryloyl group-modified PPE is within the numerical range described above, it can possess excellent dielectric properties derived from polyphenylene ether, while also exhibiting excellent heat resistance in the cured product, and furthermore, the moldability of the resin composition can be improved. For example, in conventional polyphenylene ether, when its number-average molecular weight is within the numerical range described above, it tends to have a relatively low molecular weight, resulting in a decrease in the heat resistance of the cured product. On the other hand, (meth)acryloyl group-modified PPE has a group represented by formula (C7) at its terminal end even when its number-average molecular weight is within the numerical range described above, thus improving the heat resistance of the cured product. In addition, since the number-average molecular weight of (meth)acryloyl group-modified PPE can be made relatively low, it also exhibits excellent moldability. Therefore, when (meth)acryloyl group-modified PPE, which has a number-average molecular weight within the numerical range described above and has a group represented by formula (C7) at its terminal end, is used as component (C), a resin composition with superior heat resistance and superior moldability can be obtained.

[0098] Furthermore, in (meth)acryloyl group-modified PPE, the average number of groups represented by the general formula (C7) at the molecular ends of one molecule of (meth)acryloyl group-modified PPE (number of terminal functional groups) is not particularly limited, but is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1.5 to 3. If the number of terminal functional groups is too small, it tends to be difficult to obtain sufficient heat resistance in the cured product. Also, if the number of terminal functional groups is too large, the reactivity becomes too high, which may cause problems such as a decrease in the shelf life of the resin composition or a decrease (insufficiency) in the fluidity of the resin composition. If insufficient fluidity of the resin composition occurs, for example, when multilayer molding using the resin composition, the embedding of circuit patterns on the substrate becomes poor, resulting in molding defects such as void formation, which may make it difficult to obtain a highly reliable printed circuit board. However, in (meth)acryloyl group-modified PPE with the number of terminal functional groups within the above range, it becomes easy to achieve both heat resistance of the cured product and shelf life and fluidity of the resin composition.

[0099] The number of terminal functional groups in (meth)acryloyl group-modified PPE can be expressed as a numerical value representing the average number of groups represented by the general formula (C7) per molecule of (meth)acryloyl group-modified PPE present in one mole of (meth)acryloyl group-modified PPE. This number of terminal functional groups can be measured, for example, by measuring the number of hydroxyl groups remaining in the obtained (meth)acryloyl group-modified PPE and calculating the decrease from the number of hydroxyl groups in the polyphenylene ether before modification. This decrease from the number of hydroxyl groups in the polyphenylene ether before modification is the number of terminal functional groups. The number of hydroxyl groups remaining in (meth)acryloyl group-modified PPE can be measured by adding a quaternary ammonium salt (tetraethylammonium hydroxide) that associates with hydroxyl groups to a solution of (meth)acryloyl group-modified PPE and measuring the UV absorbance of the mixed solution.

[0100] Furthermore, the method for synthesizing (meth)acryloyl group-modified PPE is not particularly limited, as long as it allows for the synthesis of modified PPE having the group represented by the general formula (C7) at its terminus.

[0101] (Meth)acryloyl group-modified PPE may be used alone or in combination of two or more types.

[0102] A commercially available example of (meth)acryloyl group-modified PPE is "Noryl SA9000" from SABIC Japan.

[0103] Epoxy resins having a biphenyl skeleton are preferred from the viewpoint of improving the adhesive strength of the resin composition and reducing the temperature dependence of tanδ compared to epoxy resins having other skeleton structures. Furthermore, it is preferable that the epoxy resin having a biphenyl skeleton has an epoxy equivalent of 150 to 300 and does not contain hydroxyl groups in its molecule. However, the epoxy resin having a biphenyl skeleton does not necessarily have to be included in the resin composition of this embodiment.

[0104] When component (C) is incorporated into the resin composition of this embodiment, it is preferable to also incorporate an initiator and / or curing agent together with component (C). Examples of initiators for modified PPE include organic peroxides, and examples of curing agents for epoxy resins having a biphenyl skeleton include phenolic curing agents, amine curing agents, imidazole curing agents, acid anhydride curing agents, etc. From the viewpoint of reducing the curability, adhesion, and temperature dependence of tanδ for epoxy resins having a biphenyl skeleton, it is particularly preferable to use an imidazole curing agent. Component (C) may be used alone or in combination of two or more. In this specification, the term "curing agent" includes not only curing agents in the narrow sense, but also compounds called curing catalysts and curing accelerators.

[0105] <D>Crosslinking agent (D) Examples of crosslinking agents include allyl crosslinking agents, acrylamide crosslinking agents, vinyl sulfone crosslinking agents, and among these, allyl crosslinking agents are preferred. Furthermore, as allyl crosslinking agents, compounds containing an isocyanuryl ring structure and two or more allyl groups in the molecule are preferred (for example, (i) triallyl isocyanurate (TAIC) or (ii) a compound having an isocyanuryl ring structure and two allyl groups in one molecule and being liquid at 25°C (isocyanuryl ring-containing diallyl compound)), and compounds containing an isocyanuryl ring structure and two allyl groups in the molecule are more preferred (for example, (ii) a compound having an isocyanuryl ring structure and two allyl groups in one molecule and being liquid at 25°C (isocyanuryl ring-containing diallyl compound)). In particular, since isocyanuryl ring-containing diallyl compounds are liquid at 25°C, using them as crosslinking agents can lower the melt viscosity of resin compositions, thereby improving their ability to embed into uneven surfaces caused by wiring and other features formed on the surface of various substrates. Furthermore, because isocyanuryl ring-containing diallyl compounds have two allyl groups in their molecule, they can achieve extremely good low dielectric properties. For example, if a compound having an isocyanuryl ring structure and three allyl groups in one molecule is used as a crosslinking agent instead of an isocyanuryl ring-containing diallyl compound, sufficient low dielectric properties cannot be obtained. The details of this reason are not clear, but it is presumed that when a compound with three allyl groups in its molecule is used, a three-dimensional crosslinked structure is formed during the curing of the resin composition, resulting in insufficient dielectric properties of the cured product. On the other hand, when an isocyanuryl ring-containing diallyl compound is used as a crosslinking agent, a linear crosslinked structure is formed during the curing of the resin composition, and the dipole moment, a measure of molecular polarization, becomes smaller, thus it is presumed that low dielectric properties can be obtained. In addition, when an isocyanuryl ring-containing diallyl compound is used as a crosslinking agent, an improvement in the heat resistance of the cured product can also be expected. Although the exact reasons for this are unclear, it is presumed that the isocyanuric ring structure contributes to improved heat resistance.

[0106] Specific examples of isocyanuryl ring-containing diallyl compounds include diallyl isocyanurate, in which the hydrogen atoms constituting the isocyanuryl ring are substituted with two allyl groups, and monoalkyldiallyl isocyanurate, in which the hydrogen atoms constituting the isocyanuryl ring are substituted with two allyl groups and one alkyl group. However, when an isocyanuryl ring-containing diallyl compound is used as a crosslinking agent, sufficient heat resistance may not be obtained depending on the type of flame retardant. On the other hand, when a flame retardant containing a cyclic phosphazene compound having an oxaphosphorine ring-containing structure is combined with an isocyanuryl ring-containing diallyl compound, excellent flame retardancy and heat resistance can be achieved simultaneously. Furthermore, using an isocyanuryl ring-containing diallyl compound as a crosslinking agent can improve the slitting properties (slitting properties in the B-stage state) when the material is formed into a film.

[0107] (D) The molecular weight of the crosslinking agent is preferably 300 to 400, and more preferably 320 to 400. Having a molecular weight within the above range results in excellent dielectric properties of the cured product and fluidity of the resin composition.

[0108] (D) The crosslinking agent is preferably a monoalkyldiallyl isocyanurate represented by the following general formula (D1).

[0109]

[0110] Here, in the general formula (D1), R ２５ R represents an alkyl group with 4 to 14 carbon atoms. ２５ It is preferably an alkyl group having 8 to 14 carbon atoms, and particularly preferably an alkyl group having 10 to 12 carbon atoms.

[0111] An example of a monoalkyldiallyl isocyanurate represented by the general formula (D1) is "L-DAIC," a product manufactured by Shikoku Chemicals, Inc.

[0112] <E> Other Resin Components In the resin composition of this embodiment, it is preferable to use one or more of the above-mentioned components (B) to (D) as resin components, but other resin components <E> other than components (B) to (D) may also be used as needed. Examples of other resin components include epoxy resins (except epoxy resins having a biphenyl skeleton, which is one of the components (C)), polyimide compounds, nitrogen-containing poly(arylene ether) polymers, benzoxazine compounds, maleimide-containing compounds, etc. When using the above-mentioned other resin components as resin components, it is more preferable to use resin components other than (i) nitrogen-containing poly(arylene ether) polymers, (ii) benzoxazine compounds, and / or (iii) maleimide-containing compounds. Furthermore, components (i) to (iii) above may not be used. Furthermore, when other resin components are used as resin components, the content of other resin components in the total resin components is preferably greater than 0% by mass and 20% by mass or less, more preferably greater than 0% by mass and 10% by mass or less, and even more preferably greater than 0% by mass and 5% by mass or less.

[0113] <Other Components> The resin composition of this embodiment only needs to contain at least component (A) and the resin component, but may also contain other components other than component (A) and the resin component as needed. Other components include, in addition to the initiators and curing agents described above, various additives such as inorganic fillers, silane coupling agents, defoamers, dispersion aids, antioxidants, leveling agents, thixotropes, blooming inhibitors, and organic solvents.

[0114] As an inorganic filler, a general inorganic filler can be used from the viewpoint of improving the physical properties of the cured product. Furthermore, as a suitable inorganic filler, SiO is preferred from the viewpoint of reducing the thermal expansion coefficient of the cured product. ２ These include talc, kaolin, and BaSO4, which are easily obtained with the desired properties of the cured product. ４ CaCO ３ MgO, Al ２ O ３ SiO ２Examples include AlN, BN, diamond filler, ZnO, and SiC. Furthermore, the inorganic filler may be surface-treated with a surface treatment agent such as a silane coupling agent.

[0115] The average particle size of the inorganic filler (or its average maximum diameter if the inorganic filler is not granular) is not particularly limited, but it is preferably 0.05 to 20 μm from the viewpoint of preventing a decrease in the moisture resistance of the cured product due to moisture absorption on the surface of the filler particles and from the viewpoint of easily obtaining a coating film of the desired thickness when forming a coating film of the resin composition. If the average particle size of the inorganic filler is less than 0.05 μm, the amount of moisture absorbed to the inorganic filler surface increases due to the large specific surface area, which may worsen the moisture resistance of the cured product. Also, if the average particle size of the inorganic filler is greater than 20 μm, large particles that exist as part of the particle size distribution will be exposed on the coating film surface relative to the required coating film thickness, which may impair the surface smoothness of the coating film and make it impossible to obtain a film thickness of the desired thickness. Furthermore, when applying the resin composition to various substrates with fine patterns formed on their surfaces, or when laminating a resin composition formed in film form, even if the coating is applied thickly enough to obtain smoothness, or a thick film is formed, the particle size of the inorganic filler may become too large relative to the horizontal dimensions of the fine patterns. In this case, on the fine pattern, large inorganic filler particles and components other than the inorganic filler in the resin composition become localized as materials with different dielectric properties. As a result, differences in the dielectric properties of the cured material in contact with the fine pattern occur depending on the position, which may lead to an increase in the transmission loss of the substrate. The average particle size of the inorganic filler is more preferably 1 to 10 μm, and further preferably the maximum particle size is 10 μm or less. By setting the maximum particle size to 10 μm or less, it becomes easier to prevent an increase in the transmission loss of the substrate in the high-frequency band. Here, the average particle size and maximum particle size of the inorganic filler refer to values ​​measured by a laser scattering diffraction particle size distribution analyzer. The inorganic filler may be used alone or in combination of two or more types.

[0116] Examples of organic solvents include (i) aromatic solvents such as toluene and xylene, (ii) ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, (iii) methylcyclohexane, (iv) butyl acetate, (v) cyclohexanone, dimethylformamide, and 1-methyl-2-pyrrolidone. Organic solvents may be used individually or in combination of two or more. Organic solvents are usually incorporated into resin compositions when the resin composition is used as a coating liquid. In this case, the amount of organic solvent in the resin composition (coating liquid) is not particularly limited, but can be appropriately selected to obtain a coating liquid with a suitable viscosity depending on the application method of the coating liquid. For example, it can be selected so that the solid content in the coating liquid is 20 to 80% by mass.

[0117] <Content of main components> The content of component (A) is preferably 10 to 60 parts by mass, more preferably 15 to 55 parts by mass, and even more preferably 20 to 50 parts by mass, per 100 parts by mass of resin components contained in the resin composition, from the viewpoint of imparting excellent flame retardancy and high-frequency characteristics to the cured product.

[0118] Furthermore, from the same viewpoint as above, if component <ia>(A) consists only of a cyclic phosphazene compound represented by general formula (A1), and component <ii>(resin) contains at least components (B), (C), and (D), then the content of component (A) (in other words, the content of a cyclic phosphazene compound having an oxaphosphorine ring structure represented by general formula (A1)) is preferably 10 to 60 parts by mass, more preferably 15 to 55 parts by mass, and even more preferably 20 to 50 parts by mass, based on 100 parts by mass of the total of components (B), (C), and (D).

[0119] Furthermore, from the same viewpoint as above, if component <ib>(A) contains a cyclic phosphazene compound represented by general formula (1) and other flame retardants, and component <ii>resin contains at least components (B), (C), and (D), then it is preferable that the total content of component (A) is 10 to 60 parts by mass per 100 parts by mass of the total of components (B), (C), and (D), the content of the cyclic phosphazene compound represented by general formula (A1) is 10 parts by mass or more and less than 60 parts by mass, and the content of the other flame retardants is more than 0 parts by mass and 25 parts by mass. In addition, if the above conditions to <III> are met, improved heat resistance of the cured product and improved adhesion of the resin composition can also be expected.

[0120] Furthermore, if component (A) consists only of a cyclic phosphazene compound represented by general formula (A1), and the resin component contains at least components (B) and (C), the content of component (A) (in other words, the content of a cyclic phosphazene compound having an oxaphosphorine ring structure represented by general formula (A1)) is preferably 10 to 60 parts by mass, more preferably 15 to 55 parts by mass, and even more preferably 20 to 50 parts by mass, based on 100 parts by mass of the total of components (A), (B), and (C).

[0121] Furthermore, if component (A) contains a cyclic phosphazene compound represented by general formula (1) and other flame retardants, and the resin component contains at least component (B) and component (C), then it is preferable that, per 100 parts by mass of the total of components (A), (B), and (C), the total content of component (A) is 10 to 60 parts by mass, the content of the cyclic phosphazene compound represented by general formula (A1) is 10 parts by mass or more and less than 60 parts by mass, and the content of other flame retardants is greater than 0 parts by mass and less than 25 parts by mass. More preferably, the content of other flame retardants is greater than 0 parts by mass and less than or equal to 3 parts by mass, and even more preferably greater than 0 parts by mass and less than or equal to 1.5 parts by mass. Here, the content of other flame retardants refers to the total amount of all types of other flame retardants used when two or more types of other flame retardants are used in combination.

[0122] The content of component (B) is preferably 30 to 80 parts by mass, and more preferably 40 to 70 parts by mass, based on 100 parts by mass of the total of components (B), (C), and (D). When the content of component (B) is within the above range, the peel strength of the resin composition tends to increase, and the heat resistance reliability of the dielectric properties (for example, 1000 hours or more at 125°C) tends to improve. If the amount of component (B) is too low, the dried film and cured product tend to become too hard and brittle, making it difficult to form a film, and the physical properties tend to deteriorate, such as a decrease in peel strength after curing. Also, if the amount of component (B) is too high, curing becomes insufficient, which again tends to decrease the peel strength and heat resistance.

[0123] The content of component (C) is preferably 60 parts by mass or less, more preferably 55 parts by mass or less, and even more preferably 50 parts by mass or less, per 100 parts by mass of the resin component. If the content of component (C) exceeds 60 parts by mass, the dried film and cured product become too hard and brittle, making it difficult to form a film, and problems such as a decrease in peel strength and cracking after curing, and increased warping in various substrates such as high-frequency substrates, millimeter-wave radar substrates and printed wiring substrates made using the resin composition of this embodiment are likely to occur. The lower limit of the content of component (C) is not particularly limited, but in practical terms, it is preferably 15 parts by mass or more, and more preferably 20 parts by mass or more.

[0124] (D) The amount of crosslinking agent is preferably 0 to 40 parts by mass, more preferably 0 to 30 parts by mass, and even more preferably 0 to 25 parts by mass, based on 100 parts by mass of the total of components (B), (C), and (D).

[0125] Furthermore, inorganic fillers may be added to the resin composition of this embodiment as needed. In this case, the amount of inorganic filler contained in the resin composition is not particularly limited, but from the viewpoint of improving physical properties such as the coefficient of thermal expansion of the cured product, 30% by mass or more is preferred, 40% by mass or more is more preferred, 50% by mass or more is even more preferred, and 60% by mass or more is particularly preferred. Also, from the viewpoint of practicality such as the viscosity and handling of the resin composition, the upper limit of the inorganic filler content is preferably 80% by mass or less, more preferably 77% by mass or less, and even more preferably 75% by mass or less.

[0126] <Method for Manufacturing and Use of Resin Composition> The resin composition of this embodiment can be obtained by dissolving or dispersing raw materials containing at least component (A) and a resin component, and further blending other components excluding the organic solvent as needed, in an organic solvent. The apparatus for dissolving or dispersing these raw materials is not particularly limited, but a stirrer equipped with a heating device, a desolver, a raika, a three-roll mill, a ball mill, a planetary mixer, a bead mill, a wet atomizer, etc. can be used. These apparatuses may also be used in appropriate combinations. When the resin composition of this embodiment is used as a film-like component such as an adhesive film, the resin composition prepared with the organic solvent can be further dried to remove the organic solvent and form a film.

[0127] The resin composition of this embodiment can be formed into a film and used as an adhesive film. Furthermore, the resin composition can be used for forming adhesive layers and coverlays on printed circuit boards, as well as for forming high-frequency substrates, millimeter-wave radar substrates, and the substrate portion of printed circuit boards themselves.

[0128] <Resin Composition and Cured Product Properties> The curing conditions for obtaining a cured product by curing the resin composition of this embodiment are not particularly limited and can be appropriately selected according to the manufacturing process of various substrates and devices made using the resin composition of this embodiment. For example, it can be heat-cured at 130 to 220°C for 30 to 180 minutes. The viscosity when the resin composition is used as a coating liquid can be appropriately selected according to the coating method. For example, the viscosity measured using an E-type viscometer at 10 rpm and 25°C can be in the range of 0.1 to 100 Pa·s.

[0129] Furthermore, the dielectric properties of the cured resin composition of this embodiment satisfy the following conditions (a) to (c): (a) The relative permittivity of the cured product measured at 10 GHz and 25°C is 3.5 or less. (b) The dielectric loss tangent (tanδ) of the cured product measured at 10 GHz and 25°C is 0.003 or less. (c) The rate of change of the dielectric loss tangent (tanδ) of the cured product measured at 120°C relative to the measurement at 10 GHz and 25°C is within ±30%.

[0130] By simultaneously satisfying (a) to (c), when various substrates and devices manufactured using the resin composition of this embodiment are used in the high-frequency band, the relative permittivity and dielectric loss tangent can be reduced, and the temperature dependence of the dielectric loss tangent can also be reduced even when there is a large temperature change from room temperature to high temperature.

[0131] (a) The measured value of the relative permittivity of the cured product at 10 GHz and 25°C is preferably 3.4 or less, and more preferably 3.3 or less. The lower limit of the relative permittivity is not particularly limited, but in practice it is preferably 1.5 or more. (b) The measured value of the dielectric loss tangent of the cured product at 10 GHz and 25°C is preferably 0.0028 or less, and more preferably 0.0025 or less. The lower limit of the dielectric loss tangent is not particularly limited, but in practice it is preferably 0.0005 or more. (c) The rate of change of the measured value of the dielectric loss tangent (tanδ) of the cured product at 120°C relative to the measured value at 10 GHz and 25°C is preferably within the range of ±25%, more preferably within the range of ±20%, and the closer to 0%, the better. The rate of change is a value calculated based on the following formula (1). • Equation (1) Rate of change = 100 × {tanδ(120) - tanδ(25)} / tanδ(25) Here, in equation (1), tanδ(120) represents the measured value of the dielectric loss tangent of the cured material at 10 GHz and 120°C, and tanδ(25) represents the measured value of the dielectric loss tangent of the cured material at 10 GHz and 25°C.

[0132] [Adhesive Film] The adhesive film of this embodiment is a component made of the resin composition of this embodiment (solid component that does not contain organic solvents) in the form of a film. The adhesive film of this embodiment is made by applying the resin composition of this embodiment (a coating liquid resin composition containing organic solvents) to a desired support and then drying it. The support is not particularly limited and includes metal foils such as copper and aluminum, and organic films such as polyester resin, polyethylene resin, and polyethylene terephthalate resin. The support may be released with a silicone compound or the like. The adhesive film is usually provided to the user as an adhesive film with a support, and is peeled off from the support and used when manufacturing products that use adhesive films, such as various substrates such as printed circuit boards. The adhesive film with a support only needs to include a support and an adhesive film, and may further include other layers as needed. Examples of other layers include a protective film provided on the side of the adhesive film opposite to the side on which the support is provided.

[0133] The method for applying the resin composition to the support is not particularly limited, but from the viewpoint of thinning and controlling the thickness of the adhesive film formed on the support, the microgravure method, slot die method, and doctor blade method are preferred. For example, using the slot die method, an adhesive film made of the resin composition with a thickness of 5 to 300 μm after drying can be obtained.

[0134] The drying conditions for the resin composition containing the organic solvent applied to the support can be appropriately set according to the type and amount of organic solvent used in the resin composition, the thickness of the application, etc. For example, it can be set to 50 to 150°C for about 1 to 30 minutes. The adhesive film of this embodiment obtained in this way has good storage stability.

[0135] When using an adhesive film with a support, the layers other than the adhesive film (such as the support) that make up the adhesive film with a support are peeled off from the adhesive film at an appropriate time, and the adhesive film is heat-cured. The heat-curing conditions are appropriately selected according to the manufacturing conditions of the various substrates made using the adhesive film, but for example, it can be heat-cured at 130 to 220°C for 30 to 180 minutes.

[0136] The thickness of the adhesive film is preferably 5 to 300 μm, and more preferably 10 to 200 μm. If the thickness of the adhesive film is less than 5 μm, the desired properties (e.g., insulation, strength, durability, etc.) may not be obtained in the cured adhesive film. If the thickness of the adhesive film exceeds 300 μm, the stress during curing will be large, and defects such as warping may occur in various substrates made using the adhesive film.

[0137] [High-frequency substrates, millimeter-wave radar substrates, printed circuit boards, and semiconductor devices] The high-frequency substrates, millimeter-wave radar substrates, and printed circuit boards of this embodiment include cured products of the resin composition of this embodiment. These various substrates are typically manufactured by transferring, attaching, or laminating the adhesive film of this embodiment onto the substrate body (a component that ultimately constitutes part of the substrate (finished product)), followed by a heat-curing process. Furthermore, in the manufacture of these various substrates, the transfer, attachment, or lamination process of the adhesive film may be repeated multiple times as needed. However, in the manufacture of these various substrates, the resin composition of this embodiment in liquid form may be directly applied to the substrate body to form a coating film, and the coating film may be dried and heat-cured to produce the various substrates. Furthermore, the semiconductor devices of this embodiment are manufactured using the high-frequency substrates, millimeter-wave radar substrates, and / or printed circuit boards of this embodiment.

[0138] The various substrates produced using the resin composition or adhesive film of this embodiment are preferably used in a high-frequency band of around 10 GHz (for example, several GHz to tens of GHz), but as long as the dielectric properties of the cured product satisfy the following (a)-(c), they may be used in a higher frequency band than around 10 GHz (for example, several tens of GHz to about 300 GHz) as needed. (a) The measured value of the relative permittivity of the cured product at 10 GHz and 25°C is 3.5 or less. (b) The measured value of the dielectric loss tangent (tanδ) of the cured product at 10 GHz and 25°C is 0.003 or less. (c) The rate of change of the measured value of the dielectric loss tangent (tanδ) of the cured product at 120°C relative to the measured value at 10 GHz and 25°C is within ±30%.

[0139] The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In the following description, parts and % refer to parts by mass and mass%, respectively, unless otherwise specified.

[0140] 1. Raw Materials The details of the raw materials used in the preparation of the resin compositions for each example and comparative example are shown below.

[0141] (A) Flame retardant FP-72TP: A cyclic phosphazene compound having an oxaphosphorine ring-containing structure, manufactured by Fushimi Pharmaceutical Co., Ltd., represented by structural formula (A5).

[0142] OP935: Aluminum diethylphosphinate (aluminum phosphinate salt) manufactured by Clariant Chemicals, represented by the following structural formula:

[0143]

[0144] HCA-HQ-HS: Sanko-made 10-(2,5-dihydroxyphenyl)-10-H-9-oxa-10-phosphaphenanthrene-10-oxide, represented by the following structural formula:

[0145]

[0146] FP-110T: Phenoxycyclophosphazene manufactured by Fushimi Pharmaceutical Co., Ltd., represented by the following structural formula:

[0147]

[0148] PX-200: Resorcinol bis-dixyl phosphate manufactured by Daihachi Chemical Industry Co., Ltd., represented by the following structural formula:

[0149]

[0150] PX-202: Biphenol bis-dixylenyl phosphate manufactured by Daihachi Chemical Industry Co., Ltd., represented by the following structural formula:

[0151]

[0152] TPP: Triphenyl phosphate manufactured by Daihachi Chemical Industry Co., Ltd., represented by the following structural formula:

[0153]

[0154] FP-600: ADEKA-manufactured bisphenol A bis-diphenyl phosphate, represented by the following structural formula:

[0155]

[0156] HCA: Sanko-made 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, represented by the following structural formula:

[0157]

[0158] (B) Styrene-based elastomers G1652MU: Hydrogenated styrene-based elastomer manufactured by Kraton Polymers SEBS Septon 8004: Hydrogenated styrene-based elastomer manufactured by Kuraray SEBS

[0159] (C) Crosslinkable compounds having a biphenyl skeleton OPE-2St 2200: Styrene-terminated PPE oligomer manufactured by Mitsubishi Gas Chemical (number average molecular weight Mn: 2200) OPE-2St 1200: Styrene-terminated PPE oligomer manufactured by Mitsubishi Gas Chemical (number average molecular weight Mn: 1200) SA-9000: Methacryloyl-terminated PPE oligomer manufactured by Sabic Innovative Plastics (number average molecular weight Mn: 1850-1950) YX4000HK: Biphenyl skeleton epoxy resin manufactured by Mitsubishi Chemical

[0160] (D) Crosslinking agent L-DAIC: Monoalkyldiallyl isocyanurate manufactured by Shikoku Chemicals Co., Ltd.

[0161] Other ingredients KBM-1083: Silane coupling agent manufactured by Shin-Etsu Chemical, 7-octenyltrimethoxysilane KBE-846: Silane coupling agent manufactured by Shin-Etsu Chemical, bis(triethoxysilylpropyl)tetrasulfide percamyl D: Organic peroxide dicumyl peroxide manufactured by Nippon Oil & Fats EH-2021: Modified imidazole manufactured by ADEKA FB-300MDX: Spherical silica filler manufactured by Denka (average particle size: 3.7 μm) FB-3SDX: Spherical silica filler manufactured by Denka (average particle size: 3.4 μm)

[0162] 2. Preparation of Resin Compositions and Adhesive Films After weighing each component according to the formulations (parts by mass) shown in Tables 2 to 4, components (B) and (C), or <ii>(B), (C), and (D) were further added to a heated stirrer into which a predetermined amount of toluene had been added. Dissolution and mixing were carried out for 2 hours at 70°C and atmospheric pressure, while rotating the stirring blades at a rotation speed of 35 rpm. After cooling to room temperature, components (A) and other components were added, and stirring was carried out for 1 hour while rotating the stirring blades at a rotation speed of 60 rpm to obtain a stirred product. Next, a predetermined amount of toluene was further added to this stirred product to obtain a diluted product, which was stirred to obtain a viscosity suitable for coating. Then, this diluted product was dispersed using a wet atomizing device (manufactured by Yoshida Machinery Industry Co., Ltd., model number: Nanomizer MN2-2000AR) to obtain the coating liquids (resin compositions) for each example and comparative example.

[0163] Next, the coating liquid was applied to one side of a support (a PET film with a release treatment applied to the surface on which the coating liquid was applied), and dried at 100°C to obtain an adhesive film with a support, comprising the support and an adhesive film (thickness: 100 μm) made of the solid components of the coating liquid formed on one side of the support.

[0164] 3. Evaluation Results and Evaluation Methods The adhesive films of each example and comparative example obtained were evaluated for flame retardancy, relative permittivity (ε), dielectric loss tangent (tanδ), temperature dependence of relative permittivity (ε), and temperature dependence of dielectric loss tangent (tanδ). The results are shown in Tables 2 to 4. In addition, various evaluation items were evaluated according to the procedure shown below. In Tables 2 and 3, the total resin component is the sum of parts by mass of components (B), (C), and (D), and is expressed as 100 parts by mass. The total resin component and flame retardant is the sum of parts by mass of the resin component and component (A). The total non-volatile content is the sum of parts by mass of the raw materials used other than toluene.

[0165] 3.1 Flame Retardancy Evaluation The flame retardancy was determined by testing in accordance with the UL94 VTM combustion test method. The obtained adhesive film with support was heat-cured at 200°C for 60 minutes under a pressure of 10 kgf. Next, the cured adhesive film was peeled off the support and cut to a size of 200 ± 5 mm in length and 50 ± 1 mm in width to obtain a test specimen. One of the two short sides (50 mm side) of the test specimen was used as the base, and a marking line was drawn with a pen perpendicular to the base and 125 mm from the base along the width direction (short side direction). A rod with a diameter of 12.7 ± 0.5 mm was placed parallel to the longitudinal direction of the test specimen, and the test specimen was wrapped around it. The portion above the marking line was then attached with pressure-sensitive tape, the rod was removed, and the upper end of the cylindrical test specimen was closed with pressure-sensitive tape to prevent the chimney effect from occurring, thereby obtaining a cylindrical test specimen. The upper end of the cylindrical test specimen was grasped with a clamp set on a stand, and the cylindrical test specimen was held vertically. A piece of absorbent cotton was placed 300 ± 10 mm below it.

[0166] Next, a Bunsen burner with an inner diameter of 9.5 ± 0.3 mm (0.374 ± 0.012 inches) was ignited, and the flame was adjusted to be a blue flame without yellow color and a height of 19 mm (3 / 4 inch). This flame was held over the center of the lower end of a cylindrical test piece so that the distance between the flame and the burner opening was 9.5 mm (3 / 8 inch). The first contact with the flame was performed for 3 ± 0.5 seconds, then removed, and the burning time until the flame on the cylindrical test piece went out was measured. As soon as the flame went out, a second contact with the flame was performed for 3 ± 0.5 seconds, then removed, and the burning time and ignition time were measured. This measurement was performed using five cylindrical test pieces for each example and comparative example.

[0167] The criteria for evaluating the flame retardancy (VTM-0) shown in Tables 2-4 are as follows: Pass: All of the following VTM-0 evaluation conditions (1)-(5) are met. Fail: One or more of the following VTM-0 evaluation conditions (1)-(5) are not met. <VTM-0 evaluation conditions> (1) The burning time after the first or second flame extinction of each test piece is 10 seconds or less. (2) The total burning time after the first and second flame extinction of the five test pieces is 50 seconds or less. (3) The total burning time and ignition time after the second flame extinction of each test piece is 30 seconds or less. (4) The combustion or ignition does not reach the threshold. (5) There is no ignition of the absorbent cotton by falling objects during combustion.

[0168] Furthermore, the criteria for evaluating the flame retardancy (burning time) shown in Tables 2 and 3 are as follows: A: The average burning time of five cylindrical test pieces after the first flame treatment is 5 seconds or less. B: The average burning time of five cylindrical test pieces after the first flame treatment exceeds 5 seconds.

[0169] 3.2 Evaluation of Relative Permittivity (ε) and Dielectric Loss Tangent (tanδ) A laminate of adhesive films was obtained by peeling the support from the adhesive film with a support and laminating the adhesive films to a thickness of approximately 1 mm. Next, this laminate was heated and cured at 200°C for 60 minutes under a pressure of 10 kgf to obtain a sheet-like cured material. Subsequently, this cured material was cut to a width of approximately 1 mm and a length of approximately 120 mm to obtain rod-shaped test pieces. The dimensions of these test pieces were measured, and the relative permittivity (ε) and dielectric loss tangent (tanδ) were measured at 10 GHz and 25°C using a cavity resonator in a precision constant temperature bath.

[0170] 3.3 Evaluation of Temperature Dependence (Temperature Characteristics) of Relative Permittivity (ε) and Dielectric Loss Tangent (tanδ) The test specimens prepared in [3.2 Evaluation of Relative Permittivity (ε) and Dielectric Loss Tangent (tanδ)] were measured at 10 GHz and 120°C using a cavity resonator in a precision constant temperature chamber heated to 120°C. The percentage change from the measured value at 25°C was calculated from these values.

[0171] 3.4 Evaluation of Slitting Properties The slitting properties of the adhesive films of Examples 1, 2, and 9 were evaluated using the following procedure. First, as shown in Figure 1, both ends of the adhesive film with a support 20 were fixed to a pair of block-shaped fixing devices 10 spaced apart on a stand (not shown) so that the entire surface of the adhesive film with a support 20 was perfectly parallel to the horizontal direction. At this time, the side of the adhesive film with a support 20 on which the support 30 is provided was set as the upper surface, and the side of the adhesive film with a support 20 on which the adhesive film 40 is provided was fixed so that it was in close contact with the upper surface of the fixing device 10. Next, a blade 50 (OLFA "MBB50K (blade thickness: 0.25 mm)") was inserted from the upper surface side of the adhesive film with a support 20 at one end (the left end in Figure 1), and then the blade 50 was moved from one end to the other end of the adhesive film with a support 20 at a cutting speed of 2.5 cm / second to form a cut of 10 cm in length.

[0172] Subsequently, the support 30 was peeled off the adhesive film 20 with the support attached, and the adhesive film 40 was removed from the fixing device 10. Then, the total area of ​​the chips that formed on the cut surface along the 10 cm long cut formed in the adhesive film 40 (the area of ​​the part that was lost due to chipping during cutting) was evaluated using an optical microscope.

[0173] Here, "chip" refers to a chip 46 that occurs along the lower surface 44 of the cut surface 42 of the adhesive film 40 during cutting, as shown in Figure 2. The area of ​​the chip 46, which is formed as a recess relative to the lower surface 44, is the region R enclosed by the reference line (dotted line in Figure 2) that is flush with the lower surface 44 and the cross-sectional contour line of the chip 46. The total area of ​​the chip 46 is the total area of ​​the region R enclosed by the cross-sectional contour line and the reference line of the chip 46 formed within the 10 cm cut. The evaluation criteria for the measured total area of ​​the chip 46 are as follows: A: The total area of ​​the chip 46 formed within the 10 cm cut length is 5 mm ２ Less than B: The total area of ​​46 chips formed within a cut length of 10 cm is 5 mm ２ That's all.

[0174] 3.5 Evaluation of Solder Heat Resistance Copper foil (CF-T9FZSV, manufactured by Fukuda Metal Foil & Powder Industry Co., Ltd., thickness: 18 μm) was bonded to both sides of an adhesive film peeled from a support, with the roughened side facing inward, and heated and cured at 200°C for 60 minutes under a pressure of 10 kgf. This was cut into 25 mm x 25 mm pieces to obtain test specimens. These test specimens were placed on the surface of a solder bath heated to 280°C, 290°C, and 300°C for 180 seconds each, and the presence or absence of blistering was observed. Five test specimens were prepared for each temperature. The criteria for judging the evaluation results of solder heat resistance shown in Table 5 are as follows: OK: No blistering occurred in any of the five test specimens. NG (No Good): Blistering occurred in at least one of the five test specimens.

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[0176]

[0177]

[0178]

[0179] 10 Fixing device 20 Adhesive film with support 30 Support 40 Adhesive film 42 Cut surface 44 Bottom surface 46 Chipped surface 50 Blade

Claims

1. A resin composition comprising (A) a flame retardant containing a cyclic phosphazene compound having an oxaphosphorine ring structure represented by the following general formula (A1), and a resin component, wherein the relative permittivity of the cured product measured at 10 GHz and 25°C is 3.5 or less, the dielectric loss tangent of the cured product measured at 10 GHz and 25°C is 0.003 or less, and the rate of change of the dielectric loss tangent of the cured product measured at 120°C with respect to the measurement at 10 GHz and 25°C is within ±30%. [In the above general formula (A1), n ​​is an integer from 3 to 8, and R １ and R ２ (i) each unit independently forms a saturated or unsaturated cyclic structure which may be substituted with either an alkyl or alkoxy group having 1 to 8 carbon atoms, which may be substituted with at least one group selected from alkyl and aryl groups having 1 to 6 carbon atoms, or an aryl or aryloxy group having 6 to 20 carbon atoms, which may be substituted with at least one group selected from alkyl and aryl groups having 1 to 6 carbon atoms, or (ii) an alkyl or carbonyl group having 1 to 6 carbon atoms, where a and b are each independently integers from 0 to 4, and the type of oxaphosphorine ring-containing structure of each repeating unit is independent.

2. The resin composition according to claim 1, wherein the resin component comprises (B) a styrene-based elastomer.

3. The resin composition according to claim 2, wherein the (B) styrene elastomer comprises a hydrogenated styrene elastomer.

4. The resin composition according to any one of claims 1 to 3, wherein the resin component comprises a crosslinkable compound having a biphenyl skeleton (C).

5. The resin composition according to any one of claims 1 to 4, wherein the resin component comprises (D) a crosslinking agent.

6. The resin composition according to claim 5, wherein the (D) crosslinking agent comprises an isocyanuric ring-containing diallyl compound.

7. The resin composition according to any one of claims 1 to 6, comprising 10 to 60 parts by mass of the flame retardant per 100 parts by mass of the resin component.

8. A resin composition according to any one of claims 1 to 7, comprising an inorganic filler.

9. The resin composition according to claim 8, wherein the inorganic filler content is 80% by mass or less.

10. The resin composition according to any one of claims 1 to 9, which is for high-frequency substrates or printed wiring substrates.

11. An adhesive film comprising the resin composition according to any one of claims 1 to 10.

12. The adhesive film according to claim 11, wherein the thickness is 5 to 300 μm.

13. A high-frequency substrate comprising a cured product of the resin composition according to any one of claims 1 to 10.

14. A millimeter-wave radar substrate comprising a cured product of the resin composition according to any one of claims 1 to 10.

15. A printed circuit board comprising a cured product of the resin composition according to any one of claims 1 to 10.

16. A semiconductor device comprising at least one substrate selected from the group consisting of the high-frequency substrate described in claim 13, the millimeter-wave radar substrate described in claim 14, and the printed wiring substrate described in claim 15.

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