Method for evaluating compatibility of thermosetting resin composition, thermosetting resin composition, prepreg, resin film, laminated board, multilayer printed wiring board, and semiconductor package

Abstract

The present invention relates to a method for evaluating the compatibility of a thermosetting resin composition, which is a method for evaluating the compatibility of a thermosetting resin composition containing two or more kinds of resins and inorganic filler, comprising the following steps 1A and 2A. Step 1A: a step of obtaining a reflection electron image of a scanning electron microscope at an observation magnification of 50 to 250 times for a cross section of a cured product of the above thermosetting resin composition. Step 2A: a step of binarizing the above reflection electron image in such a manner that a resin region where phase separation has occurred is taken as a separation portion, and other regions are taken as non-separation portions, the above separation portion is taken as one value, and the above non-separation portions are taken as another value, and calculating the ratio of the area of the above non-separation portions of the above binarized image with respect to the entire area of the obtained binarized image (area of the non-separation portion x 100 / area of the entire binarized image) as the area ratio Rw of the above non-separation portions.

Description

Technical Field

[0001] This embodiment relates to a compatibility evaluation method for thermosetting resin compositions, thermosetting resin compositions, prepregs, resin films, laminates, multilayer printed circuit boards, and semiconductor packages. Background Technology

[0002] In mobile communication devices such as mobile phones, their base station equipment, network infrastructure equipment such as servers and routers, and electronic devices such as mainframe computers, the speed and capacity of signals used are advancing year by year. Along with this, the substrate materials of the printed circuit boards used in these electronic devices require dielectric properties [hereinafter sometimes referred to as "high-frequency characteristics"] that can reduce the transmission loss of high-frequency signals, namely, low relative permittivity and low dielectric loss tangent.

[0003] In recent years, in addition to the aforementioned electronic devices, the practical application or implementation plans for new systems that process high-frequency wireless signals have been advancing in the fields of ITS (Information Technology Systems) related to automobiles and transportation systems, as well as in indoor short-range communication. Therefore, it is expected that the need for substrate materials with excellent high-frequency characteristics for printed circuit boards used in these fields will increase in the future.

[0004] Traditionally, thermoplastic polymers with excellent high-frequency properties have been used in printed circuit boards (PCBs) requiring low transmission loss. As thermoplastic polymers, polymers without intramolecular polar groups, such as polyphenylene ether (PPE) and polybutadiene, are effective for achieving low dielectric loss tangents. However, these thermoplastic polymers have low compatibility with other resins containing polar groups, leading to problems such as separation from other resins during resin composition. This separation sometimes results in reduced workability, decreased homogeneity of the finished product, and consequently, reduced physical properties; therefore, it is desirable to suppress this separation.

[0005] Patent Document 1 discloses a curable resin composition containing a specific polyphenylene ether and a polyfunctional vinyl aromatic copolymer. In the technology of Patent Document 1, the polyfunctional vinyl aromatic copolymer, epoxy resin, and phenolic resin are dissolved in a solvent, and the transparency of the dissolved sample is visually confirmed, thereby evaluating the compatibility between the polyfunctional vinyl aromatic copolymer and the epoxy resin.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2018-168347 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] However, in the evaluation method described in Patent Document 1, transparency varies depending on factors such as the affinity between the resin and the solvent used as the dispersion medium. Therefore, it is impossible to determine the degree of compatibility between different resins in the final cured product. Furthermore, while it is possible to judge the quality of compatibility when differences exist at a level that can be visually discerned, it is impossible to judge the quality when differences exist at a level that cannot be visually discerned. In the process of developing resin compositions with further improved dielectric properties and heat resistance, the necessity for material design while more rigorously evaluating the compatibility between resins is increasing.

[0011] In view of this situation, the objective of this embodiment is to provide: a method for evaluating the compatibility of thermosetting resin compositions, thermosetting resin compositions with improved compatibility, and prepregs, resin films, laminates, multilayer printed circuit boards, and semiconductor packages using the thermosetting resin compositions.

[0012] Methods for solving problems

[0013] In order to solve the above-mentioned problem, the inventors conducted research and found that the problem can be solved by the following embodiment.

[0014] That is, this embodiment relates to the following [1] to [9].

[0015] [1] A method for evaluating the compatibility of a thermosetting resin composition, which is a method for evaluating the compatibility of a thermosetting resin composition containing two or more resins and inorganic fillers, comprising the following steps 1A and 2A.

[0016] Step 1A: A step of obtaining a reflected electron image of the cured section of the above-mentioned thermosetting resin composition using a scanning electron microscope at a magnification of 50 to 250 times.

[0017] Step 2A: In the above reflected electron image, the resin region where phase separation has occurred is designated as the separated region, and the other regions are designated as the non-separated region. Binarization is performed with the separated region as one value and the non-separated region as another value. The area ratio R of the non-separated region in the binarized image relative to the entire area of ​​the resulting binarized image is calculated as (area of ​​the non-separated region × 100 / area of ​​the entire binarized image). w process

[0018] [2] A method for evaluating the compatibility of a thermosetting resin composition, which is a method for evaluating the compatibility of a thermosetting resin composition containing two or more resins and inorganic fillers, comprising the following steps 1B and 2B.

[0019] Step 1B: A step of obtaining a reflected electron image of the cross-section of the cured product of the above thermosetting resin composition using a scanning electron microscope.

[0020] Step 2B: In the above reflected electron image, the resin region where phase separation has occurred is taken as the separation part, and the average structural domain size D of the separation part is obtained. L process

[0021] [3] According to the compatibility evaluation method of the thermosetting resin composition described in [2] above, the above step 1B is a step of obtaining a reflected electron image of a scanning electron microscope by observing the cross section of the cured thermosetting resin composition at a magnification of 50 to 200 times.

[0022] [4] A thermosetting resin composition comprising two or more resins and an inorganic filler.

[0023] In the compatibility evaluation method described above [1], the area ratio R of the non-separated portion obtained under the condition of observation magnification of the scanning electron microscope being 100x or 200x is... w It is over 50%, and,

[0024] In the compatibility evaluation method described above [2], under the condition that the magnification of the scanning electron microscope is 65x, the average structural domain size D of the separated part is... L The average structural domain size D of the separated part is below 120 μm. L The following method is used to obtain the average size of the structural domains of the aforementioned separated portion observed in at least three fields of view, starting from the structural domain with the largest size.

[0025] [5] A prepreg comprising the thermosetting resin composition described in [4] above.

[0026] [6] A resin film comprising the thermosetting resin composition described in [4] above.

[0027] [7] A laminate comprising the prepreg and metal foil described in [5] above.

[0028] [8] A multilayer printed circuit board comprising one or more of the prepreg described in [5] above, the resin film described in [6] above, and the laminate described in [7] above.

[0029] [9] A semiconductor package formed using the printed circuit board described in [8] above.

[0030] Invention Effects

[0031] According to this embodiment, a method for evaluating the compatibility of thermosetting resin compositions, a thermosetting resin composition with improved compatibility, and prepregs, resin films, laminates, multilayer printed circuit boards, and semiconductor packages using the thermosetting resin composition can be provided. Attached Figure Description

[0032] Figure 1 This is an example of a reflected electron image obtained in the compatibility evaluation method of this embodiment.

[0033] Figure 2 This is a schematic diagram illustrating the method for measuring the dimensions of the structural domain of the separation section.

[0034] Figure 3 This is another schematic diagram illustrating the method for measuring the length of the structural domain of the separation section. Detailed Implementation

[0035] In this specification, the numerical range indicated by “~” represents the range of minimum and maximum values ​​recorded before and after the “~”.

[0036] The lower and upper limits of the numerical ranges described in this specification can be arbitrarily combined with the lower or upper limits of other numerical ranges.

[0037] In the numerical range described in this specification, the upper or lower limit of the numerical range may be replaced with the values ​​shown in the embodiments.

[0038] Unless otherwise specified, each component and material illustrated in this instruction manual may be used individually or in combination of two or more.

[0039] In this specification, the content of each component in the thermosetting resin composition refers to the total amount of the various substances present in the thermosetting resin composition, unless otherwise specified, when multiple substances corresponding to each component are present in the thermosetting resin composition.

[0040] This embodiment also includes any combination of the items described in this specification.

[0041] The mechanism of action described in this specification is speculative and is not intended to limit the mechanism by which the thermosetting resin composition of this embodiment achieves its effect.

[0042] The term "compatibility" in this specification means that the resins are not necessarily compatible at the molecular level, but are mixed together at the nanometer, micrometer, or visual level.

[0043] The number-average molecular weight in this specification refers to the value determined by gel permeation chromatography (GPC) converted to polystyrene, specifically, it can be determined by the methods described in the examples.

[0044] In the following description, thermosetting resin compositions are sometimes simply referred to as "resin compositions".

[0045] [Compatibility Evaluation Method of Approach 1]

[0046] The compatibility evaluation method of the first embodiment is a method for evaluating the compatibility of a thermosetting resin composition containing two or more resins and inorganic fillers, and includes the following steps 1A and 2A.

[0047] Step 1A: A step of obtaining a reflected electron image of the cured section of the above-mentioned thermosetting resin composition using a scanning electron microscope at a magnification of 50 to 250 times.

[0048] Step 2A: In the above reflected electron image, the resin region where phase separation has occurred is designated as the separated region, and the other regions are designated as the non-separated region. Binarization is performed with the separated region as one value and the non-separated region as another value. The area ratio R of the non-separated region in the binarized image relative to the entire area of ​​the resulting binarized image is calculated as (area of ​​the non-separated region × 100 / area of ​​the entire binarized image). w process

[0049] According to the compatibility evaluation method of the first aspect of this embodiment, the compatibility of the resin composition can be quantified, and the compatibility can be evaluated more rigorously than conventional compatibility evaluation methods.

[0050] The following is a detailed description of each step of the compatibility evaluation method of the first embodiment.

[0051] <Process 1A>

[0052] Step 1A is a step of obtaining a reflected electron image of a scanning electron microscope (SEM) by observing the cross section of a cured thermosetting resin composition containing two or more resins and inorganic fillers at a magnification of 50 to 250 times.

[0053] The resin composition that is the test object of the compatibility evaluation method of this embodiment is not particularly limited as long as it contains two or more resins and inorganic fillers. For example, the resin composition of this embodiment described later can be used as the test object.

[0054] The curing conditions for the resin composition are not particularly limited; curing can be carried out under conditions suitable for the resin composition being tested. For example, if the resin composition of this embodiment described later is the test object, the conditions described in the examples can be used. Specifically, by heating and drying the resin composition at 170°C for 5 minutes to prepare it into a grade B state, and then heating and pressurizing it at a temperature of 230°C, a pressure of 2.0 MPa, and a time of 120 minutes, a cured product can be obtained.

[0055] There is no particular limitation on the method for forming the cross-section of the cured resin composition; conventionally known methods can be used, such as using a precision cutter, an ion milling apparatus, or an ultrasonic cutter. It should be noted that, from a processability point of view, the cured resin composition can be in a state of being embedded in the resin when forming the cross-section. Furthermore, after forming the cross-section, grinding or other treatments can be performed as needed.

[0056] After the solidified cross-section is formed, it is preferable to perform a platinum or similar vapor deposition treatment on the cross-section for better SEM observation.

[0057] The objects observed by SEM through the above procedures are called "test pieces".

[0058] Next, the cross-section of the obtained test piece was observed using SEM.

[0059] Regarding the SEM observation in the compatibility evaluation method of this embodiment, the reflectance electron mode is used in particular to improve the contrast between the inorganic filler material and the resin component.

[0060] The accelerating voltage during SEM observation can be adjusted appropriately according to the object being measured; for example, it can be adjusted within the range of 0.5 to 20 kV.

[0061] In step 1A, the SEM magnification is in the range of 50 to 250 times, preferably 60 to 230 times, and more preferably 80 to 210 times. By setting the magnification to the above range, measurement bias caused by the field of view can be suppressed, and the calculated area ratio R of the non-separated portion can be improved. w The reproducibility of the resin is excellent. In particular, the compatibility evaluation method of the first aspect of this embodiment can observe the resin region where phase separation has occurred and the region outside of it as structural domains with the same hue by observing at a lower magnification, thus making it easier to carry out the following step 2A.

[0062] Through process 1A, a reflected electron image of the test piece can be obtained.

[0063] <Process 2A>

[0064] Step 2A is as follows: In the aforementioned reflected electron image, the resin region where phase separation has occurred is designated as the separated region, and the remaining region is designated as the non-separated region. Binarization is performed with the separated region as one value and the non-separated region as another value. The area ratio R of the non-separated region in the binarized image relative to the entire area of ​​the resulting binarized image is calculated (area of ​​the non-separated region × 100 / area of ​​the entire binarized image). w .

[0065] exist Figure 1 An example of a reflected electron image obtained in process 1A is shown. For example... Figure 1 As shown, the reflected electron image obtained in step 1A includes a relatively bright region 1 and a relatively dark region 2. The relatively dark region is a phase rich in resin with low electron density, corresponding to a resin region where phase separation has occurred. On the other hand, the relatively bright region is a phase containing compatible resin and inorganic filler material with high electron density.

[0066] In this process, the resin region where phase separation occurred is defined as the "separation section," and the remaining region is defined as the "non-separation section." According to... Figure 1 It can be seen that the separation part can be clearly and easily identified by visual inspection in reflected electron images.

[0067] Next, the reflected electron image is binarized with the separated portion as one value and the non-separated portion as another value. The area ratio of the non-separated portion of the binarized image to the entire area of ​​the resulting binarized image is calculated as (area of ​​the non-separated portion × 100 / area of ​​the entire binarized image), and this ratio is used as the area ratio R of the non-separated portion. w .

[0068] The binarization process in this step is, for example, assigning a pixel value of "1 (white)" to pixels with a pixel value above a specified threshold, and assigning a pixel value of "0 (black)" to all other pixels.

[0069] Binarization can be performed using well-known methods, such as commercially available image processing software.

[0070] The binarization conditions can be appropriately adjusted based on the reflected electron image obtained in process 1A. Binarization can be performed under the condition that the separated parts have one value and the non-separated parts have another value. Specifically, for example, when using the image analysis and processing software (Image-Pro Analyzer 7.0J) manufactured by Roper Co., Ltd. of Japan for binarization, as a processing condition, binarization can be performed by appropriately adjusting the RGB threshold to the range of 40 to 100.

[0071] Next, the area ratio of the non-separated region of the binarized image to the entire region of the resulting binarized image is calculated (area of ​​the non-separated region × 100 / area of ​​the entire region of the binarized image), and this ratio is used as the area ratio R of the non-separated region. w The above area ratio R w For example, it can be calculated by counting the number of pixels in the entire region of the binarized image and the number of pixels representing the values ​​of the non-separated parts.

[0072] The first compatibility evaluation method can calculate the area ratio R of the non-separated portion for a single field of view. w However, from a reproducibility standpoint, it is preferable to calculate the area ratio R of the non-separated portion for multiple views. w Then, average them. There is no particular limit to the number of fields of view for averaging; for example, you can set it to 2, 3, 4, or more than 5 fields of view, depending on the required accuracy.

[0073] The area ratio R of the non-separated portion obtained by the above method w It can be used as an indicator of compatibility. That is, it can be known that the area ratio R of the non-separated parts is... w The larger the value, the less resin undergoes phase separation, resulting in a resin composition with superior compatibility.

[0074] [Compatibility Evaluation Method of the Second Approach]

[0075] The compatibility evaluation method of the second aspect of this embodiment is a method for evaluating the compatibility of thermosetting resin compositions containing two or more resins and inorganic fillers. It is a compatibility evaluation method for thermosetting resin compositions including the following steps 1B and 2B.

[0076] Step 1B: A step of obtaining a reflected electron image of the cross-section of the cured product of the above thermosetting resin composition using a scanning electron microscope.

[0077] Step 2B: In the above reflected electron image, the resin region where phase separation has occurred is taken as the separation part, and the average structural domain size D of the separation part is obtained. L process

[0078] According to the compatibility evaluation method of the second aspect of this embodiment, the compatibility of the resin composition can be quantified, and the compatibility can be evaluated more rigorously than conventional compatibility evaluation methods.

[0079] The following is a detailed description of each step of the compatibility evaluation method of the second embodiment.

[0080] <Process 1B>

[0081] Step 1B is a step of obtaining a reflected electron image of a scanning electron microscope from the cross section of a cured thermosetting resin composition containing two or more resins and inorganic fillers.

[0082] The magnification of the scanning electron microscope in step 1B is not particularly limited, but from the viewpoint of workability and reproducibility, it is preferably 30 to 500 times, more preferably 40 to 200 times, even more preferably 50 to 200 times, and particularly preferably 50 to 100 times.

[0083] The description of process 1B, excluding the observation ratio, is the same as that of process 1A.

[0084] <Process 2B>

[0085] Step 2B involves identifying the resin region where phase separation has occurred in the aforementioned reflected electron image as the separation region, and obtaining the average structural domain size D of the separation region. L The process.

[0086] Here, the structural domain size in this process is defined as the diameter of the largest perfect circle that can be drawn within the structural domain of the separation section.

[0087] exist Figure 2 and Figure 3 The diagram shows a method for measuring the length of the structural domain representing the separation section.

[0088] For example, such as Figure 2 As shown in (a), when the domain is considered a perfect circle, its diameter is equivalent to the domain size. Additionally, for example, as... Figure 2 As shown in (b) or (c), when the structural domain is considered as an ellipse or amorphous shape, the diameter of the largest perfect circle that can be drawn within the ellipse or amorphous shape is equivalent to the size of the structural domain.

[0089] For example, such as Figure 3 As shown in (a) and (b), the structural domain of the separation section sometimes has a shape such as two or more structural domains connected together. In this case, if the diameter of the largest circle that can be drawn within the structural domain is set to s, and the diameter of the largest circle that can be drawn within the connecting portion is set to t, then when the diameter t is less than 1 / 3 of the diameter s, the structural domain is considered to be divided by the connecting portion. That is, Figure 3 The structural domain shown in (a) is considered to consist of two domains: a structural domain with diameter s and a structural domain with diameter u. On the other hand, in Figure 3 In the case of the structural domain shown in (b), since the diameter t exceeds 1 / 3 of the diameter s, the connection is not broken, and it becomes a structural domain with a structural domain size of diameter s.

[0090] The average structural domain size D of the separation section in process 2B L Preferably, the separation is obtained by averaging the sizes of the structural domains with the largest size from the structural domains of the separated portion. This eliminates the influence of large separated portions unexpectedly caused by factors other than compatibility during the manufacture of the resin composition, resulting in better reproducibility.

[0091] The number of structural domains used to calculate the average value after the second one is not particularly limited; it can be appropriately determined based on the object being measured. From the viewpoint of operability and reproducibility, the average structural domain size D of the separation section... L The structure domains are obtained by averaging the sizes of the structural domains from the second onwards, in descending order: structural domains with a size of 100 or less, preferably structural domains with a size of 50 or less, more preferably structural domains with a size of 10 or less, and even more preferably structural domains with sizes from the second to the sixth.

[0092] In the second compatibility evaluation method, the average structural domain size D can be obtained by performing the above process on only one field of view. L However, from a reproducibility standpoint, it is preferable to observe multiple fields of view and then obtain the average domain size D from all the domains contained in those multiple fields of view. L When observing multiple fields of view, the number is preferably 3 or more, more preferably 5 or more, and even more preferably 6 or more. There is no particular limit to the upper limit of the number of fields of view observed; for example, it can be 20 or less, 15 or less, or 10 or less.

[0093] The average structural domain size D of the separation section obtained by the above method L It can be used as an indicator of compatibility. That is, it can be known that the average structural domain size D of the separated part is... L The smaller the value, the better the compatibility of the resin composition.

[0094] [Thermosetting Resin Composition]

[0095] Next, the thermosetting resin composition of this embodiment will be described.

[0096] The thermosetting resin composition of this embodiment contains two or more resins and inorganic fillers.

[0097] In the compatibility evaluation method of the first approach described above, the area ratio R of the non-separated portion is obtained under the condition of observation magnification of 100x or 200x using a scanning electron microscope. w It is over 50%, and,

[0098] In the compatibility evaluation method of the second approach described above, under the condition of a scanning electron microscope with an observation magnification of 65x, the average structural domain size D of the separated part is... L The average structural domain size D of the separated part is below 120 μm. L The following method was used: Counting from the structural domains of the separated portion observed in at least three fields of view, the structural domain sizes of the second to sixth largest structural domains were averaged.

[0099] The area ratio R of the non-separable portion related to the thermosetting resin composition of this embodiment w and average structural domain size D L The value is determined according to the compatibility evaluation method of the first method and the compatibility evaluation method of the second method described above, and more specifically, the value is determined by the method described in the examples.

[0100] The area ratio R of the non-separable portion of the resin composition in this embodiment w There are no particular limitations, but it is preferably 52% or more, more preferably 54% or more, and even more preferably 56% or more. If the area ratio R of the non-separated portion... w If the value is above the lower limit mentioned above, there is a trend towards better dielectric properties and heat resistance.

[0101] The area ratio R of the non-separated part w There is no specific upper limit; it can be 100%, but from the perspective of ease of manufacturing, it can be below 98% or below 95%.

[0102] The average domain size D of the separation portion of the resin composition in this embodiment L There are no particular limitations, but it is preferably 100 μm or less, more preferably 90 μm or less, and even more preferably 85 μm or less. If the average structural domain size D of the separated portion... L Below the aforementioned upper limit, there is a trend towards better dielectric properties and heat resistance.

[0103] Average structural domain size D of the separation section LThere is no specific limit to the lower limit value; it can be 0 μm, or from the perspective of ease of manufacturing, it can be 10 μm or higher, or even 30 μm or higher. It should be noted that the average structural domain size D of the separation section... L A value of 0 μm means that the separation part is not actually observable, and the size of the structural domain cannot be measured.

[0104] The area ratio R of the non-separated part w and the average structural domain size D of the separation section L For example, the range can be appropriately adjusted by selecting the type of resin contained in the resin composition.

[0105] The resin composition of this embodiment contains two or more types of resin and inorganic filler.

[0106] The resin composition only needs to satisfy the above-mentioned area ratio R of the non-separated portion. w and the average structural domain size D of the separation section L There are no particular limitations, but it is preferred to contain at least two types: an elastomer and a thermosetting resin.

[0107] Examples of elastomers include polyether-based elastomers, styrene-based elastomers, conjugated diene-based elastomers, urethane-based elastomers, polyester-based elastomers, polyamide-based elastomers, acrylic elastomers, and silicone-based elastomers. One type of elastomer can be used alone, or two or more types can be used in combination. From the viewpoint of dielectric properties, polyether-based elastomers, styrene-based elastomers, and conjugated diene-based elastomers are preferred.

[0108] Examples of thermosetting resins include epoxy resins, cyanate ester compounds, maleimide compounds, dielyl nadicimide resins, benzoxazine compounds, and their derivatives. A single thermosetting resin can be used alone, or two or more can be used in combination. From the viewpoints of heat resistance, low thermal expansion, and mechanical properties, maleimide compounds or their derivatives are preferred thermosetting resins.

[0109] Of the resins described above, the resin composition of this embodiment preferably contains a polyether-based elastomer as the elastomer and a maleimide compound or its derivative as the thermosetting resin.

[0110] Furthermore, the resin composition of this embodiment is more preferably a polyphenylene ether derivative [hereinafter sometimes referred to as "polyphenylene ether derivative (A)" or "(A) component"] having a group having an olefinically unsaturated bond as an elastomer, and contains one or more maleimide compounds having two or more N-substituted maleimide groups and their derivatives [hereinafter sometimes referred to as "maleimide compound or its derivative (B)" or "(B) component"] as a thermosetting resin.

[0111] Furthermore, in addition to components (A) and (B), the resin composition of this embodiment preferably contains two or more elastomers selected from (C) a conjugated diene polymer or modified conjugated diene polymer [hereinafter sometimes referred to as "conjugated diene polymer or its modified form (C)" or "(C) component"] and (D) a styrene-based thermoplastic elastomer [hereinafter sometimes referred to as "styrene-based thermoplastic elastomer (D)" or "(D) component"].

[0112] Furthermore, the resin composition of this embodiment particularly preferably contains an (E) imidazole compound or a modified imidazole compound [hereinafter, sometimes referred to as "imidazole compound or its modified (E)" or "(E) component"] as a curing accelerator.

[0113] Hereinafter, each component preferably contained in the resin composition of this embodiment will be described in detail.

[0114] <Polyphenylene ether derivative (A)>

[0115] Component (A) has groups containing olefinic unsaturated bonds. That is, component (A) can also be described as a component in which groups containing olefinic unsaturated bonds have been introduced into polyphenylene ether.

[0116] It should be noted that, in this specification, "olefinic unsaturated bond" refers to a carbon-carbon double bond capable of undergoing addition reactions, excluding double bonds in aromatic rings. Furthermore, "group containing olefinic unsaturated bond" refers to a substituent containing the aforementioned olefinic unsaturated bond.

[0117] (A) One ingredient may be used alone, or two or more ingredients may be used in combination.

[0118] In component (A), the position of the group containing an olefinic unsaturated bond is not particularly limited; it can be at the end or at a position other than the end. Furthermore, if component (A) has a group containing an olefinic unsaturated bond at the end, the position of this group can be either single-terminal or double-terminal. It should be noted that the "end" of component (A) refers not only to the outermost atom of the molecule but also to the entire organic group containing an ether bond bonded to the outermost end of the polyphenylene ether chain from the outer end side. That is, a group containing an olefinic unsaturated bond at the end of component (A) is synonymous with an organic group containing an olefinic unsaturated bond bonded to the outermost end of the aforementioned polyphenylene ether chain from the outer end side.

[0119] As component (A), it may be a mixture of a polyphenylene ether derivative having a group containing an olefinic unsaturated bond at one end and a polyphenylene ether derivative having a group containing an olefinic unsaturated bond at both ends, preferably containing at least a polyphenylene ether derivative having a group containing an olefinic unsaturated bond at one end, more preferably the polyphenylene ether derivative itself having a group containing an olefinic unsaturated bond at one end.

[0120] When component (A) contains a polyphenylene ether derivative having a group containing an olefinic unsaturated bond at a single end, the content of the polyphenylene ether derivative having a group containing an olefinic unsaturated bond at a single end in component (A) is preferably 30% by mass or more, more preferably 45% by mass or more, further preferably 55% by mass or more, even more preferably 70% by mass or more, particularly preferably 90% by mass or more, and most preferably substantially 100% by mass.

[0121] Examples of unsaturated olefinic groups in component (A) include: unsaturated aliphatic hydrocarbon groups such as vinyl, isopropenyl, allyl, 1-methylallyl, and 3-butenyl; and substituents containing heteroatoms such as maleimide and (meth)acryloyl. From the viewpoint of dielectric properties, unsaturated aliphatic hydrocarbon groups and maleimide groups are preferred, allyl and maleimide groups are more preferred, and allyl is even more preferred.

[0122] It should be noted that, in this specification, the unsaturated aliphatic hydrocarbon groups described as groups containing olefinic unsaturated bonds do not contain heteroatoms.

[0123] Next, polyphenylene ether derivatives having unsaturated aliphatic hydrocarbon groups as groups containing olefinic unsaturated bonds will be described in more detail.

[0124] (A) The number of unsaturated aliphatic hydrocarbon groups in one molecule of the component is not particularly limited, but from the viewpoint of dielectric properties, it is preferable to have two or more, more preferably three or more, and even more preferably four or more. (A) There is no particular limit to the upper limit of the number of unsaturated aliphatic hydrocarbon groups in one molecule of the component, and it can be eight or less, seven or less, or six or less.

[0125] (A) The number of unsaturated aliphatic hydrocarbon groups at the single end of the component is not particularly limited, but from the viewpoint of dielectric properties, it is preferable to have 2 or more, more preferably 3 or more, and even more preferably 4 or more. (A) There is no particular limit to the upper limit of the number of unsaturated aliphatic hydrocarbon groups at the single end of the component, and it can be 8 or less, 7 or less, or 6 or less.

[0126] The optimal number of unsaturated aliphatic hydrocarbon groups in component (A) and the optimal number of unsaturated aliphatic hydrocarbon groups at a single end of component (A) are both 4.

[0127] From the viewpoint of dielectric properties, component (A) preferably contains the structure shown in the following general formula (a-1).

[0128] [Chemical Formula 1]

[0129]

[0130] (where R is in the formula) a1 It is an unsaturated aliphatic hydrocarbon group with 2 to 10 carbon atoms. n1 is 1 or 2, n2 is 0 or 1. * indicates the bonding position with other structures.

[0131] In the above general formula (a-1), R is... a1 The unsaturated aliphatic hydrocarbon group with 2 to 10 carbon atoms represented above, from the viewpoint of dielectric properties, is preferably an unsaturated aliphatic hydrocarbon group with 2 to 5 carbon atoms, more preferably vinyl, isopropenyl, allyl, 1-methylallyl, 3-butenyl, and even more preferably allyl.

[0132] When n1 is 2, multiple R a1 They can be the same or different.

[0133] From the viewpoint of dielectric properties, component (A) is also preferably in a manner that includes the structure shown in the following general formula (a-2).

[0134] [Chemical Formula 2]

[0135]

[0136] (where R is in the formula) a2 and Ra3 Each group is an unsaturated aliphatic hydrocarbon group with 2 to 10 carbon atoms. * indicates a bonding position with other structures.

[0137] Regarding R in the above general formula (a-2) a2 and R a3 The unsaturated aliphatic hydrocarbon groups with 2 to 10 carbon atoms represented can be exemplified by R in the above general formula (a-1). a1 The same unsaturated aliphatic hydrocarbon group is preferred, and the same unsaturated aliphatic hydrocarbon group is also preferred.

[0138] From the viewpoint of dielectric properties, component (A) more preferably includes the structure shown in any one of the following general formulas (a-3) to (a-5), and even more preferably includes the structure shown in the following general formula (a-5).

[0139] [Chemical Formula 3]

[0140]

[0141] (where R is in the formula) a4 It is an unsaturated aliphatic hydrocarbon group with 2 to 10 carbon atoms. * indicates the bonding position with other structures.

[0142] [Chemical Formula 4]

[0143]

[0144] (where R is in the formula) a5 and R a6 Each is an unsaturated aliphatic hydrocarbon group with 2 to 10 carbon atoms. X a1 It is a divalent aliphatic hydrocarbon group with 1 to 6 carbon atoms. * indicates the bonding position with other structures.

[0145] [Chemical Formula 5]

[0146]

[0147] (where R is in the formula) a7 ~R a10 Each is an unsaturated aliphatic hydrocarbon group with 2 to 10 carbon atoms. X a2 It is a divalent organic group. * indicates a bonding position with other structures.

[0148] R in the above general formulas (a-3) to (a-5) a4 ~R a10 The unsaturated aliphatic hydrocarbon groups with 2 to 10 carbon atoms represented can be exemplified by R in the above general formula (a-1). a1 The same unsaturated aliphatic hydrocarbon groups are used, and the preferred unsaturated aliphatic hydrocarbon groups are also the same.

[0149] As X in the above general formula (a-4) a1 Examples of divalent aliphatic hydrocarbon groups with 1 to 6 carbon atoms include: methylene, ethylene, propylene, and other alkylene groups with 1 to 6 carbon atoms; and isopropylidene groups with 2 to 6 carbon atoms. Among these, methylene and isopropylidene are preferred, and isopropylidene is more preferred.

[0150] As X in the above general formula (a-5) a2 Examples of divalent organic groups include: aliphatic hydrocarbon groups that may contain heteroatoms in part, alicyclic hydrocarbon groups that may contain heteroatoms in part, aromatic hydrocarbon groups that may contain heteroatoms in part, and groups comprising any combination of these groups.

[0151] Examples of heteroatoms mentioned above include oxygen atoms, nitrogen atoms, and sulfur atoms.

[0152] As X a2 The divalent organic group represented is preferably a group that does not contain heteroatoms, more preferably an aliphatic hydrocarbon group or an alicyclic hydrocarbon group that does not contain heteroatoms, and even more preferably a group comprising a combination of an aliphatic hydrocarbon group and an alicyclic hydrocarbon group that does not contain heteroatoms.

[0153] From the viewpoint of dielectric properties, the structures shown in the above general formula (a-3), the above general formula (a-4), or the above general formula (a-5) are preferably the structures shown in the following formula (a-3'), the following formula (a-4'), or the following general formula (a-5').

[0154] From the viewpoint of dielectric properties, the structure shown in formula (a-4') or general formula (a-5') is more preferred, and the structure shown in general formula (a-5') is even more preferred.

[0155] [Chemical Formula 6]

[0156]

[0157] (where X) a2 X in the above general formula (a-5) a2 Same. * indicates a bonding location with other structures.

[0158] (A) is a polyphenylene ether derivative, and therefore also has phenylene ether bonds, preferably having the structural unit shown in the following general formula (a-10).

[0159] [Chemical Formula 7]

[0160]

[0161] (where R is in the formula)a11 It consists of an aliphatic hydrocarbon group or a halogen atom with 1 to 5 carbon atoms. n3 is an integer from 0 to 4.

[0162] R in the above general formula (a-10) a11 Examples of aliphatic hydrocarbon groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, and n-pentyl. Preferably, the aliphatic hydrocarbon group has 1 to 3 carbon atoms; more preferably, it has alkyl groups with 1 to 3 carbon atoms; and even more preferably, it has methyl.

[0163] As R a11 The halogen atoms represented can be, for example, fluorine, chlorine, bromine, iodine, etc.

[0164] Of the above, as R a11 Preferably, the aliphatic hydrocarbon group has 1 to 5 carbon atoms.

[0165] In the above general formula (a-10), n3 is an integer from 0 to 4, preferably an integer of 1 or 2, and more preferably 2. When n3 is 1 or 2, based on the substitution position of the oxygen atom, R... a11 The preferred substitution position is adjacent. Furthermore, when n3 is 2 or more, multiple R... a11 They can be the same or different.

[0166] As the structural unit shown in the above general formula (a-10), more specifically, the structural unit shown in the following general formula (a-10') is preferred.

[0167] [Chemical Formula 8]

[0168]

[0169] (A) The component preferably contains a polyphenylene ether derivative represented by any one of the following general formulas (a-6) to (a-8), more preferably contains a polyphenylene ether derivative represented by the following general formulas (a-7) or (a-8), and even more preferably contains a polyphenylene ether derivative represented by the following general formula (a-8).

[0170] [Chemical Formula 9]

[0171]

[0172] (where X) a2 X in the above general formula (a-5) a2 Same. n4 to n6 are each an independent integer from 1 to 200.

[0173] In the above general formulas (a-6) to (a-8), n4 to n6 are each independently an integer from 1 to 200. From the viewpoint of dielectric properties and compatibility with other resins, it is preferred to be an integer from 1 to 150, more preferably an integer from 1 to 120, and even more preferably an integer from 1 to 100.

[0174] In any of the above general formulas (a-6) to (a-8), it can also be a mixture of polyphenylene ether derivatives with different values ​​of n4 to n6.

[0175] [(A) Number-average molecular weight (Mn) of component]

[0176] (A) The number average molecular weight of the component is not particularly limited, but is preferably 1,000 to 25,000, more preferably 2,000 to 20,000, even more preferably 3,000 to 10,000, and particularly preferably 4,000 to 6,000.

[0177] If the number average molecular weight of component (A) is above the lower limit mentioned above, the dielectric properties tend to improve. Furthermore, if the number average molecular weight of component (A) is below the upper limit mentioned above, the compatibility of the resin composition becomes good, and there is a tendency for it to remain relatively stable even after prolonged storage.

[0178] [(A) Manufacturing method of component]

[0179] The following describes one method of manufacturing component (A), but is not specifically limited to the following description.

[0180] (A) The component can be manufactured, for example, by redistributing a phenolic compound containing the structure shown in any of the above general formulas (a-1) to (a-5) with polyphenylene ether in an organic solvent.

[0181] It should be noted that, in the following description, phenolic compounds containing structures shown in any of the above general formulas (a-1) to (a-5) are sometimes referred to as "phenolic compounds containing unsaturated aliphatic hydrocarbon groups (1)". In addition, polyphenylene ether used as a raw material for the redistribution reaction is sometimes referred to as "raw material polyphenylene ether". The number average molecular weight of the raw material polyphenylene ether is not particularly limited, but is preferably 3,000 to 30,000.

[0182] The aforementioned redistribution reaction is as follows: the oxygen free radical of the phenolic compound (1) containing an unsaturated aliphatic hydrocarbon group attacks the carbon atom bonded to the oxygen atom in the raw material polyphenylene ether, thereby breaking the OC bond and reducing the molecular weight. At this point, the attacked oxygen free radical of the phenolic compound (1) containing the unsaturated aliphatic hydrocarbon group bonds with the carbon atom whose bond has been broken and is incorporated into the structure of the polyphenylene ether. This redistribution reaction can be performed using known methods.

[0183] The molecular weight of component (A) can be controlled by the amount of phenolic compound (1) containing unsaturated aliphatic hydrocarbon groups used. The more phenolic compound (1) containing unsaturated aliphatic hydrocarbon groups is used, the lower the molecular weight of component (A) becomes. That is, by appropriately adjusting the amount of phenolic compound (1) containing unsaturated aliphatic hydrocarbon groups used, the number average molecular weight of the final manufactured component (A) can be within a suitable range.

[0184] There is no particular limitation on the amount of phenolic compound (1) containing unsaturated aliphatic hydrocarbon groups used, and it can be determined, for example, based on the number average molecular weight of the raw material polyphenylene ether that reacts with the phenolic compound (1) containing unsaturated aliphatic hydrocarbon groups.

[0185] For example, if the number average molecular weight of the raw material polyphenylene ether is 3,000 to 30,000, then the amount of hydroxyl groups of the phenolic compound (1) containing unsaturated aliphatic hydrocarbon groups is preferably 1 to 10 moles, more preferably 1 to 8 moles, and even more preferably 2 to 6 moles, relative to 1 mole of the raw material polyphenylene ether. If the amount of the phenolic compound (1) containing unsaturated aliphatic hydrocarbon groups used is within the above range, then component (A) with a number average molecular weight within the above preferred range can be obtained.

[0186] Organic solvents used in the manufacturing process of component (A) include, for example: alcohol solvents such as methanol, ethanol, butanol, butyl cellosolve, ethylene glycol monomethyl ether, and propylene glycol monomethyl ether; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; aromatic hydrocarbon solvents such as toluene, xylene, and mesitylene; ester solvents such as methoxyethyl acetate, ethoxyethyl acetate, butoxyethyl acetate, and ethyl acetate; and nitrogen-containing solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone.

[0187] Organic solvents can be used alone or in combination of two or more.

[0188] In the manufacturing process of component (A), as described above, a reaction catalyst may be used as needed.

[0189] As a reaction catalyst, for example, from the viewpoint of obtaining a (A) component with good reproducibility and stable number-average molecular weight, it is preferable to use a combination of organic peroxides such as tert-butyl peroxyisopropyl monocarbonate and carboxylic acid metal salts such as manganese naphthenate and manganese octanoate.

[0190] When using organic peroxide and metal carboxylate salt in combination, there is no particular limitation on the amount of both used. Preferably, the amount of organic peroxide used is 0.5 to 5 parts by mass and the amount of metal carboxylate salt used is 0.05 to 0.5 parts by mass relative to 100 parts by mass of the raw material polyphenylene ether. If the content of organic peroxide and metal carboxylate salt is within the above range, there is a tendency for the reaction rate and gelation inhibition during the manufacture of component (A) to become better.

[0191] A phenolic compound (1) containing unsaturated aliphatic hydrocarbon groups, raw material polyphenylene ether, organic solvent and reaction catalyst as needed are added to a reactor and reacted while being heated, kept warm and stirred as needed, thereby obtaining component (A).

[0192] The preferred reaction temperature for the above-mentioned redistribution reaction is 70–110°C. Furthermore, the preferred reaction time for the above-mentioned redistribution reaction is 1–8 hours. If the reaction temperature and reaction time are within the above ranges, workability and gelation inhibition are excellent, and there is a tendency to easily produce component (A) having the above-mentioned number-average molecular weight. The reaction conditions are not limited to the above conditions and can be appropriately adjusted according to the type of raw materials, etc. In addition, known reaction conditions related to the redistribution reaction can also be used.

[0193] (A) The concentration of solid components in the reaction during the manufacturing process of the component [hereinafter sometimes referred to as "reaction concentration"] is not particularly limited, but is preferably 10 to 60% by mass, more preferably 15 to 55% by mass, and even more preferably 20 to 50% by mass. If the reaction concentration is above the lower limit mentioned above, there is a tendency to obtain a good reaction rate and improve productivity. In addition, if the reaction concentration is below the upper limit mentioned above, there is a tendency to obtain better solubility, improve stirring efficiency, and further suppress gelation.

[0194] The solution of polyphenylene ether derivative (A) prepared by the above method can be diluted by adding organic solvent to remove part of the organic solvent as needed.

[0195] Compared with resin compositions containing polyphenylene ether as a substitute for component (A), the resin composition of this embodiment tends to have superior dielectric properties.

[0196] When the resin composition of this embodiment contains component (A), its content is not particularly limited. From the viewpoint of dielectric properties, it is preferably 0.1 to 20 parts by mass relative to 100 parts by mass of the total resin components in the resin composition, more preferably 0.5 to 10 parts by mass, further preferably 0.7 to 5 parts by mass, and particularly preferably 1 to 3 parts by mass.

[0197] In this specification, "resin component" refers to, for example, component (A), component (B), component (C), component (D), etc., and if other resins are contained, those other resins are also included in the resin component.

[0198] <Maleimide compounds or their derivatives (B)>

[0199] (B) The component is selected from one or more maleimide compounds having two or more N-substituted maleimide groups and their derivatives.

[0200] Examples of the above-mentioned "derivatives of maleimide compounds having two or more N-substituted maleimide groups" include, for example, the addition reaction products of the above-mentioned maleimide compounds having two or more N-substituted maleimide groups and diamine compound (b2).

[0201] (B) Components can be used alone or in combination of two or more.

[0202] As component (B), from the viewpoint of compatibility with other resins, adhesion to conductors and dielectric properties, it is preferred to select one or more compounds from (i) and (ii) below.

[0203] (i) Maleimide compound (b1) having two or more N-substituted maleimide groups [hereinafter sometimes referred to as "maleimide compound (b1)" or "(b1) component"].

[0204] (ii) An aminomaleimide compound having structural units derived from maleimide compound (b1) and structural units derived from diamine compound (b2) [hereinafter sometimes referred to as "aminomaleimide compound (B1)" or "(B1) component"].

[0205] (maleimide compounds having two or more N-substituted maleimide groups (b1))

[0206] (b1) There are no particular restrictions on the composition as long as it is a maleimide compound having two or more N-substituted maleimide groups.

[0207] (b1) One ingredient may be used alone, or two or more ingredients may be used in combination.

[0208] Examples of components (b1) include, for example: bis(4-maleimidephenyl)methane, bis(4-maleimidephenyl) ether, bis(4-maleimidephenyl) sulfone, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, m-phenylene bismaleimide, 2,2-bis[4-(4-maleimidephenyloxy)phenyl] Aromatic maleimide compounds with two N-substituted maleimide groups in the molecule, such as propane; aromatic polymaleimide compounds with three or more N-substituted maleimide groups in the molecule, such as polyphenylmethane maleimide and biphenyl aralkyl maleimide; aliphatic maleimide compounds such as 1,6-bismaleimide-(2,2,4-trimethyl)hexane and pyrophosphate binder-type long-chain alkyl bismaleimide. From the viewpoints of compatibility with other resins, adhesion to conductors, heat resistance, low thermal expansion, and mechanical properties, aromatic maleimide compounds having two N-substituted maleimide groups in the molecule, aromatic polymaleimide compounds having three or more N-substituted maleimide groups in the molecule, and more preferably 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide and biphenyl aralkyl maleimide.

[0209] As component (b1), the compound represented by the following general formula (b1-1) is preferred.

[0210] [Chemical Formula 10]

[0211]

[0212] (where X) b1 It is a divalent organic group.

[0213] In the above general formula (b1-1), X b1 It is a divalent organic group, which is equivalent to the divalent group obtained by removing two N-substituted maleimide groups from component (b1).

[0214] As X b1 Examples of divalent organic groups represented include those shown in general formula (b1-2), general formula (b1-3), general formula (b1-4), general formula (b1-5), and general formula (b1-6).

[0215] [Chemical Formula 11]

[0216]

[0217] (where R is in the formula) b1It consists of an aliphatic hydrocarbon group or halogen atom with 1 to 5 carbon atoms. p1 is an integer from 0 to 4. * indicates the bonding position with other structures.

[0218] As R b1 Examples of aliphatic hydrocarbon groups with 1 to 5 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, and n-pentyl. Preferably, the aliphatic hydrocarbon group has 1 to 3 carbon atoms; more preferably, it has alkyl groups with 1 to 3 carbon atoms; and even more preferably, it has methyl.

[0219] Examples of halogen atoms include fluorine, chlorine, bromine, and iodine.

[0220] p1 is an integer from 0 to 4. From the viewpoint of ease of acquisition, it is preferably an integer from 0 to 2, more preferably 0 or 1, and even more preferably 0. When p1 is an integer of 2 or more, multiple R b1 They can be the same or different.

[0221] [Chemical Formula 12]

[0222]

[0223] (where R is in the formula) b2 and R b3 Each is independently an aliphatic hydrocarbon group or halogen atom with 1 to 5 carbon atoms. X b2 It can be an alkylene group with 1 to 5 carbon atoms, an alkylidene group with 2 to 5 carbon atoms, an ether group, a thioether group, a sulfonyl group, a carbonyl group, a ketone group, a single bond, or a divalent group as shown in the general formula (b1-3-1) below. p2 and p3 are each independently integers from 0 to 4. * indicates the bonding position with other structures.

[0224] As R b2 and R b3 The aliphatic hydrocarbon groups and halogen atoms with 1 to 5 carbon atoms represented can be exemplified by R. b1 The same group is used. As this aliphatic hydrocarbon group, an aliphatic hydrocarbon group with 1 to 3 carbon atoms is preferred, methyl or ethyl is more preferred, and ethyl is even more preferred.

[0225] As X b2 Examples of alkyl groups with 1 to 5 carbon atoms include methylene, 1,2-ethylene, 1,3-propylene, 1,4-butylene, and 1,5-pentaneene. From the viewpoints of compatibility with other resins, adhesion to conductors, heat resistance, low thermal expansion, and mechanical properties, alkyl groups with 1 to 3 carbon atoms are preferred, alkyl groups with 1 or 2 carbon atoms are more preferred, and methylene is even more preferred.

[0226] As X b2Examples of alkylidene groups with 2 to 5 carbon atoms include ethoxylide, propionyl, isopropylidene, butylidene, isobutylidene, pentylidene, and isopentylidene. Among these, isopropylidene is preferred from the viewpoints of compatibility with other resins, adhesion to conductors, heat resistance, low thermal expansion, and mechanical properties.

[0227] p2 and p3 are each independently an integer from 0 to 4. From the viewpoint of ease of acquisition, both are preferably integers from 0 to 3, more preferably integers from 0 to 2, and even more preferably 0 or 2. When p2 or p3 is an integer greater than 2, multiple R... b2 Each other or R b3 They can be the same or different.

[0228] X b2 The divalent group represented by the general formula (b1-3-1) is as follows.

[0229] [Chemical Formula 13]

[0230]

[0231] (where R is in the formula) b4 and R b5 Each is independently an aliphatic hydrocarbon group or halogen atom with 1 to 5 carbon atoms. X b3 It can be an alkyl group with 1 to 5 carbon atoms, an alkylidene group with 2 to 5 carbon atoms, an ether group, a thioether group, a sulfonyl group, a carbonyl group, a ketone group, or a single bond. p4 and p5 are each independent integers from 0 to 4. * indicates the bonding position with other structures.

[0232] As R b4 and R b5 The aliphatic hydrocarbon groups and halogen atoms with 1 to 5 carbon atoms represented are related to R. b1 The same explanation applies to the other cases.

[0233] As X b3 The alkylene groups with 1 to 5 carbon atoms and the alkylidene groups with 2 to 5 carbon atoms represented can be exemplified by X. b2 The groups represented are the same as the alkylene groups with 1 to 5 carbon atoms and the alkylidene groups with 2 to 5 carbon atoms.

[0234] As X b3 Among the above options, alkylidene groups with 2 to 5 carbon atoms are preferred, alkylidene groups with 2 to 4 carbon atoms are more preferred, and isopropylidene groups are even more preferred.

[0235] p4 and p5 are each independently an integer from 0 to 4. From the viewpoint of ease of acquisition, they are preferably integers from 0 to 2, more preferably 0 or 1, and even more preferably 0. When p4 or p5 is an integer greater than 2, multiple R... b4Each other or R b5 They can be the same or different.

[0236] [Chemical Formula 14]

[0237]

[0238] (In the formula, p6 is an integer from 0 to 10. * indicates the bonding position with other structures.)

[0239] From the viewpoint of ease of acquisition, p6 is preferably an integer from 0 to 5, more preferably an integer from 0 to 4, and even more preferably an integer from 0 to 3.

[0240] [Chemical Formula 15]

[0241]

[0242] (In the formula, p7 is a number from 0 to 5. * indicates the bonding position with other structures.)

[0243] [Chemical Formula 16]

[0244]

[0245] (where R is in the formula) b6 and R b7 Each group consists independently of a hydrogen atom or an aliphatic hydrocarbon group with 1 to 5 carbon atoms. p8 is an integer from 1 to 8. * indicates the bonding position with other structures.

[0246] As R b6 and R b7 The aliphatic hydrocarbon groups representing 1 to 5 carbon atoms, and R b1 The same explanation applies to the other cases.

[0247] p8 is an integer from 1 to 8, preferably an integer from 1 to 5, more preferably an integer from 1 to 3, and even more preferably 1.

[0248] When p8 is an integer greater than 2, multiple R b6 Each other or R b7 They can be the same or different.

[0249] (Aminomaleimide compound (B1))

[0250] (B1) is an aminomaleimide compound having structural units derived from maleimide compound (b1) and structural units derived from diamine compound (b2).

[0251] (B1) Components can be used alone or in combination of two or more.

[0252] [Structural units derived from maleimide compound (b1)]

[0253] As a structural unit derived from component (b1), for example, a structural unit formed by the Michael addition reaction of at least one N-substituted maleimide group of component (b1) with an amino group of diamine compound (b2).

[0254] The structural units derived from component (b1) contained in component (B1) can be a single type or two or more types.

[0255] As structural units derived from component (b1), examples include groups represented by general formulas (b1-7) and (b1-8).

[0256] [Chemical Formula 17]

[0257]

[0258] (where X) b1 (This is a divalent organic group; * indicates a bonding position with other structures.)

[0259] Regarding X in the above general formulas (b1-7) and (b1-8) b1 The explanation and regarding X in the above general formula (b1-1) b1 The explanation is the same.

[0260] The content of structural units derived from component (b1) in the aminomaleimide compound (B1) is not particularly limited, but is preferably 5 to 95% by mass, more preferably 30 to 93% by mass, even more preferably 60 to 90% by mass, and particularly preferably 75 to 90% by mass. If the content of structural units derived from component (b1) is within the above range, there is a tendency for the dielectric properties and film processability to become better.

[0261] [Derived from the structural unit of the diamine compound (b2)]

[0262] As a structural unit derived from component (b2), for example, one or both of the two amino groups of component (b2) undergo a Michael addition reaction with the N-substituted maleimide group of maleimide compound (b1).

[0263] The structural units contained in component (B1) derived from component (b2) can be a single type or two or more types.

[0264] (b2) The amino group of the component is preferably a primary amino group.

[0265] As structural units derived from component (b2), examples include groups represented by the following general formula (b2-1) and groups represented by the following general formula (b2-2).

[0266] [Chemical Formula 18]

[0267]

[0268] (where X) b4 (This is a divalent organic group; * indicates a bonding position with other structures.)

[0269] In the above general formulas (b2-1) and (b2-2), X b4 It is a divalent organic group, which is equivalent to the divalent group obtained by removing two amino groups from component (b2).

[0270] In the above general formulas (b2-1) and (b2-2), X b4 Preferably, it is a divalent group as shown in the following general formula (b2-3).

[0271] [Chemical Formula 19]

[0272]

[0273] (where R is in the formula) b11 and R b12 Each is independently an aliphatic hydrocarbon group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a hydroxyl group, or a halogen atom. X b5 It can be an alkylene group with 1 to 5 carbon atoms, an alkylidene group with 2 to 5 carbon atoms, an ether group, a thioether group, a sulfonyl group, a carbonyl group, a ketone group, a fluorene group, a single bond, or a divalent group as shown in the following general formula (b2-3-1) or (b2-3-2). p9 and p10 are each independently integers from 0 to 4. * indicates the bonding position with other structures.

[0274] [Chemical Formula 20]

[0275]

[0276] (where R is in the formula) b13 and R b14 Each is independently an aliphatic hydrocarbon group or halogen atom with 1 to 5 carbon atoms. X b6 It can be an alkyl group with 1 to 5 carbon atoms, an alkylidene group with 2 to 5 carbon atoms, a m-phenylene diisopropylidene group, a p-phenylene diisopropylidene group, an ether group, a thioether group, a sulfonyl group, a carbonyl group, a ketone group, or a single bond. p11 and p12 are each independent integers from 0 to 4. * indicates the bonding position with other structures.

[0277] [Chemical Formula 21]

[0278]

[0279] (where R is in the formula) b15 It consists of an aliphatic hydrocarbon group or a halogen atom with 1 to 5 carbon atoms. X b7 and X b8 Each group can be independently an alkyl group (1–5 carbon atoms), an alkylidene group (2–5 carbon atoms), an ether group, a thioether group, a sulfonyl group, a carbonyl group, a ketone group, or a single bond. p13 is an integer from 0 to 4. * indicates the bonding position with other structures.

[0280] R in the above general formulas (b2-3), (b2-3-1), and (b2-3-2) b11 R b12 R b13 R b14 and R b15 The aliphatic hydrocarbon group or halogen atom representing 1 to 5 carbon atoms can be exemplified by R in the above general formula (b1-2). b1 Same group. As this aliphatic hydrocarbon group, an aliphatic hydrocarbon group with 1 to 3 carbon atoms is preferred, an alkyl group with 1 to 3 carbon atoms is more preferred, and methyl or ethyl is even more preferred.

[0281] As X in the above general formula (b2-3) b5 X in the above general formula (b2-3-1) b6 And X in the above general formula (b2-3-2) b7 and X b8 The alkylene groups with 1 to 5 carbon atoms and the alkylidene groups with 2 to 5 carbon atoms represented are the same as X in the above general formula (b1-3). b2 The same explanation applies to the other cases.

[0282] In the above general formula (b2-3), p9 and p10 are each an integer from 0 to 4. From the viewpoint of ease of acquisition, they are preferably integers from 0 to 3, more preferably integers from 0 to 2, and even more preferably 0 or 2.

[0283] When p9 and p10 are integers greater than 2, multiple R b11 Each other or R b12 They can be the same or different.

[0284] In the above general formula (b2-3-1), p11 and p12 are each independently an integer from 0 to 4. From the viewpoint of ease of obtaining, they are preferably integers from 0 to 2, more preferably 0 or 1, and even more preferably 0.

[0285] When p11 and p12 are integers greater than 2, multiple R b13 Each other or Rb14 They can be the same or different.

[0286] In the above general formula (b2-3-2), p13 is an integer from 0 to 4. From the viewpoint of ease of acquisition, it is preferably an integer from 0 to 2, more preferably 0 or 1, and even more preferably 0.

[0287] Examples of components (b2) include: 4,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ketone, 4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, 2,2-bis(3-amino-4-hydroxyphenyl)propane, 3,3'-dimethyl-5,5'-diethyl-4,4'-diaminodiphenylmethane, 2,2-bis(4-aminophenyl)propane, 2,2-bis[4-(4-aminophenoxy)] [Phenylacetyl]propane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 1,3-bis[1-[4-(4-aminophenoxy)phenyl]-1-methylethyl]benzene, 1,4-bis[1-[4-(4-aminophenoxy)phenyl]-1-methylethyl]benzene, 4,4'-[1,3-phenylenebis(1-methylethoxy)]bisaniline, 4,4'-[1,4-phenylenebis(1-methylethoxy)]bisaniline, 3,3'-[1,3-phenylenebis(1-methylethoxy)]bisaniline, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, 9,9-bis(4-aminophenyl)fluorene, etc.

[0288] Of which, as component (b2), from the viewpoint of excellent solubility in organic solvents, reactivity with maleimide compound (b1), and heat resistance, 4,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 4,4'-[1,3-phenylenebis(1-methylethoxy)]bisaniline, and 4,4'-[1,4-phenylenebis(1-methylethoxy)]bisaniline are preferred. Furthermore, from the viewpoint of excellent dielectric properties and low water absorption, component (b2) is preferably 3,3'-dimethyl-5,5'-diethyl-4,4'-diaminodiphenylmethane. Furthermore, from the viewpoint of excellent mechanical properties such as high adhesion to conductors, elongation, and tensile strength, component (b2) is preferably 2,2-bis[4-(4-aminophenoxy)phenyl]propane. Moreover, from the viewpoint of excellent solubility in organic solvents, reactivity during synthesis, heat resistance, excellent high adhesion to conductors, and excellent dielectric properties and low hygroscopicity, component (b2) is preferably 4,4'-[1,3-phenylenebis(1-methylethoxy)]bisaniline or 4,4'-[1,4-phenylenebis(1-methylethoxy)]bisaniline.

[0289] The content of structural units derived from component (b2) in the aminomaleimide compound (B1) is not particularly limited, but is preferably 5 to 95% by mass, more preferably 7 to 70% by mass, even more preferably 10 to 40% by mass, and particularly preferably 10 to 25% by mass. If the content of structural units derived from component (b2) is within the above range, there is a tendency for the dielectric properties, heat resistance, flame retardancy, and glass transition temperature to become better.

[0290] The equivalence ratio (Tb2 / Tb1) of the total equivalent amount (Tb2) of the -NH2 group (including -NH2) from the diamine compound (b2) in the aminomaleimide compound (B1) to the total equivalent amount (Tb1) of the N-substituted maleimide group (including N-substituted maleimide) from the maleimide compound (b1) is not particularly limited, but is preferably 0.05 to 10, more preferably 0.5 to 7, and even more preferably 1 to 5. If the equivalence ratio (Tb2 / Tb1) is within the above range, there is a tendency for improved dielectric properties, heat resistance, flame retardancy, and glass transition temperature.

[0291] The number-average molecular weight of the aminomaleimide compound (B1) is not particularly limited, but is preferably 400 to 10,000, more preferably 500 to 5,000, even more preferably 600 to 2,000, and particularly preferably 700 to 1,500.

[0292] From the viewpoints of dielectric properties, solubility in organic solvents, high adhesion to conductors, and formability of resin films, aminomaleimide compounds (B1) preferably contain aminomaleimide compounds represented by the following general formulas (b2-4).

[0293] [Chemical Formula 22]

[0294]

[0295] (where X) b1 and X b4 As explained above.

[0296] (Method for manufacturing aminomaleimide compound (B1))

[0297] (B 1) Component can be manufactured, for example, by reacting a maleimide compound (b1) with a diamine compound (b2) in an organic solvent.

[0298] By reacting maleimide compound (b1) with diamine compound (b2), an aminomaleimide compound (B1) can be obtained by Michael addition reaction of maleimide compound (b1) and diamine compound (b2).

[0299] When reacting maleimide compound (b1) with diamine compound (b2), a reaction catalyst may be used as needed.

[0300] Examples of reaction catalysts include: acidic catalysts such as p-toluenesulfonic acid; amines such as triethylamine, pyridine, and tributylamine; imidazoles such as methylimidazolium and phenylimidazolium; and phosphorus-based catalysts such as triphenylphosphine.

[0301] The reaction catalyst can be used alone or in combination of two or more.

[0302] In addition, there is no particular limitation on the amount of reaction catalyst used. For example, 0.01 to 5 parts by mass can be used relative to 100 parts by mass of maleimide compound (b1) and diamine compound (b2).

[0303] From the viewpoints of workability such as reaction rate and suppression of gelation during the reaction, the reaction temperature of the above reaction is preferably 50–160°C. Furthermore, from the same viewpoint, the reaction time of the above reaction is preferably 1–10 hours.

[0304] Furthermore, by adding or concentrating the organic solvent in this process, the solid content concentration and solution viscosity of the reactants can be adjusted. The solid content concentration of the reactants is not particularly limited, but is preferably 10–90% by mass, more preferably 15–85% by mass, and even more preferably 20–80% by mass. If the solid content concentration of the reactants is above the lower limit mentioned above, a good reaction rate is obtained, and productivity tends to improve. Conversely, if the solid content concentration of the reactants is below the upper limit mentioned above, better solubility is obtained, stirring efficiency is improved, and the tendency to further suppress gelation is achieved.

[0305] When the resin composition of this embodiment contains component (B), its content is not particularly limited. From the viewpoint of heat resistance and dielectric properties, it is preferably 10 to 90 parts by mass relative to 100 parts by mass of the total resin components in the resin composition, more preferably 20 to 80 parts by mass, further preferably 30 to 70 parts by mass, and particularly preferably 40 to 60 parts by mass.

[0306] <Conjugated diene polymers or modified conjugated diene polymers (C)>

[0307] As for component (C), there are no particular limitations, but the preferred option is:

[0308] (c1) Conjugated diene polymers with vinyl side chains [hereinafter, sometimes referred to as "(c1) component"]., or,

[0309] A modified conjugated diene polymer (C1) is prepared by modifying a conjugated diene polymer with a vinyl side chain (C1) with a maleimide compound having two or more N-substituted maleimide groups (C2) [hereinafter sometimes referred to as "(C2) component"].

[0310] (C) Components can be used alone or in combination of two or more.

[0311] ((c1) Conjugated diene polymers with vinyl side chains)

[0312] (c1) There are no particular restrictions on the composition as long as it is a conjugated diene polymer with vinyl side chains.

[0313] (c1) Components can be used alone or in combination of two or more.

[0314] (c1) is preferably a conjugated diene polymer having a plurality of vinyl groups in its side chains. The number of vinyl groups in one molecule of (c1) is not particularly limited, but from the viewpoint of dielectric properties and heat resistance, it is preferably three or more, more preferably five or more, and even more preferably ten or more.

[0315] In this specification, conjugated diene polymers refer to polymers of conjugated diene compounds.

[0316] Examples of conjugated diene compounds include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, 2-phenyl-1,3-butadiene, and 1,3-hexadiene.

[0317] Conjugated diene polymers can be polymers of one conjugated diene compound or copolymers of two or more conjugated diene compounds.

[0318] In addition, the conjugated diene polymer can be a copolymer of one or more conjugated diene compounds and one or more monomers other than conjugated diene compounds. The polymerization method is not particularly limited in this case and can be any of random polymerization, block polymerization, or graft polymerization.

[0319] Specific examples of component (c1) include: polybutadiene having 1,2-vinyl groups, butadiene-styrene copolymers having 1,2-vinyl groups, and polyisoprene having 1,2-vinyl groups. From the viewpoint of dielectric properties and heat resistance, polybutadiene having 1,2-vinyl groups and butadiene-styrene copolymers having 1,2-vinyl groups are preferred, and polybutadiene having 1,2-vinyl groups is more preferred. Furthermore, as polybutadiene having 1,2-vinyl groups, polybutadiene homopolymers having 1,2-vinyl groups are preferred.

[0320] The 1,2-vinyl group derived from butadiene in component (c1) refers to the vinyl group contained in the structural unit of butadiene as shown in formula (c1-1).

[0321] [Chemical Formula 23]

[0322]

[0323] When component (c1) is polybutadiene having 1,2-vinyl groups, the content of the 1,2-vinyl structural units [hereinafter sometimes referred to as "vinyl content"] relative to all structural units derived from butadiene constituting the polybutadiene is not particularly limited. From the viewpoint of compatibility with other resins, dielectric properties, low thermal expansion, and heat resistance, it is preferably 50 mol% or more, more preferably 60 mol% or more, further preferably 70 mol% or more, particularly preferably 80 mol% or more, and most preferably 85 mol% or more. Furthermore, there is no particular upper limit to the vinyl content; it can be 100 mol% or less, 95 mol% or less, or even 90 mol% or less. The 1,2-vinyl structural units are preferably derived from the butadiene shown in formula (c1-1) above.

[0324] From the same point of view, polybutadiene having 1,2-vinyl groups is preferably 1,2-polybutadiene homopolymers.

[0325] (c1) The number average molecular weight of the component is not particularly limited, but from the viewpoint of compatibility with other resins, dielectric properties, low thermal expansion and heat resistance, it is preferably 400 to 2500, more preferably 500 to 2000, further preferably 600 to 1800, and particularly preferably 700 to 1500.

[0326] (Modified conjugated diene polymer (C1))

[0327] The (C1) component is a modified conjugated diene polymer obtained by modifying a (C1) conjugated diene polymer with vinyl side chains with a maleimide compound having two or more N-substituted maleimide groups in (C2).

[0328] [(c2) Maleimide compounds having two or more N-substituted maleimide groups]

[0329] (c2) Any maleimide compound having two or more N-substituted maleimide groups may be used, and the substances listed as maleimide compounds or their derivatives (B) may be used.

[0330] (c2) Components can be used alone or in combination of two or more.

[0331] Among them, as component (c2), from the viewpoints of solubility in organic solvents, inhibition of gelation in the reaction, compatibility of component (C1) with other resins, dielectric properties, low thermal expansion and heat resistance, it is preferred to be an aromatic bismaleimide compound substituted with an aliphatic hydrocarbon group, and more preferably a compound represented by the following general formula (c2-1).

[0332] [Chemical Formula 24]

[0333]

[0334] (where R is in the formula) c1 and R c2 Each is an aliphatic hydrocarbon group with 1 to 5 carbon atoms. X c1 It can be an alkyl group with 1 to 5 carbon atoms, an alkylidene group with 2 to 5 carbon atoms, an ether group, a thioether group, a sulfonyl group, a carbonyl group, a ketone group, a single bond, or a divalent group represented by the following general formula (c2-1-1). q1 and q2 are each independently integers from 0 to 4, and q1+q2 is an integer greater than or equal to 1.

[0335] As R c1 and R c2 Examples of aliphatic hydrocarbon groups with 1 to 5 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, and n-pentyl. From the viewpoint of compatibility with other resins and inhibition of gelation in the reaction, aliphatic hydrocarbon groups with 1 to 3 carbon atoms are preferred, alkyl groups with 1 to 3 carbon atoms are more preferred, and methyl and ethyl groups are even more preferred.

[0336] As X c1 Examples of alkyl groups with 1 to 5 carbon atoms include methylene, 1,2-ethylene, 1,3-propylene, 1,4-butylene, and 1,5-pentaneene. Preferably, the alkyl group has 1 to 3 carbon atoms; more preferably, it has 1 or 2 carbon atoms; and even more preferably, it has methylene.

[0337] As X c1 Examples of alkylidenes with 2 to 5 carbon atoms include ethoxyl, propionyl, isopropionyl, butylidene, isobutylidene, pentylidene, and isopentylidene.

[0338] q1 and q2 are each independently an integer from 0 to 4. From the viewpoint of ease of acquisition, compatibility with other resins and inhibition of gelation in the reaction, they are preferably integers from 1 to 3, more preferably 1 or 2, and even more preferably 2.

[0339] From the same point of view, q1+q2 is preferably an integer from 1 to 8, more preferably an integer from 2 to 6, and even more preferably 4.

[0340] When q1 or q2 is an integer greater than 2, multiple R c1 Each other or R c2 They can be the same or different.

[0341] X c1 The divalent group represented by the general formula (c2-1-1) is as follows.

[0342] [Chemical Formula 25]

[0343]

[0344] (where R is in the formula) c3 and R c4 Each is independently an aliphatic hydrocarbon group or halogen atom with 1 to 5 carbon atoms. X c2 It can be an alkyl group with 1 to 5 carbon atoms, an alkylidene group with 2 to 5 carbon atoms, an ether group, a thioether group, a sulfonyl group, a carbonyl group, a ketone group, or a single bond. q3 and q4 are each independently integers from 0 to 4.

[0345] As R c3 and R c4 The aliphatic hydrocarbon groups and halogen atoms with 1 to 5 carbon atoms represented are related to R. c1 The same explanation applies to the other cases.

[0346] As X c2 The alkylene groups with 1 to 5 carbon atoms and the alkylidene groups with 2 to 5 carbon atoms represented can be exemplified by X. c1 The groups represented are the same as the alkylene groups with 1 to 5 carbon atoms and the alkylidene groups with 2 to 5 carbon atoms.

[0347] q3 and q4 are each independently an integer from 0 to 4. From the viewpoint of ease of acquisition, both are preferably integers from 0 to 2, more preferably 0 or 1, and even more preferably 0. When q3 or q4 is an integer of 2 or more, multiple R... c3 Each other or R c4 They can be the same or different.

[0348] As for the compound represented by the above general formula (c2-1), from the viewpoints of solubility in organic solvents and inhibition of gelation in the reaction, as well as the compatibility, dielectric properties, low thermal expansion and heat resistance of the obtained (C1) component with other resins, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide is preferred.

[0349] The modified conjugated diene polymer (C1) preferably has a substituent in its side chain formed by the reaction of the vinyl group of the conjugated diene polymer (C1) with the N-substituted maleimide group of the maleimide compound (C2) [hereinafter, sometimes referred to as "substituent (x)"].

[0350] Regarding the substituent (x), from the viewpoint of compatibility with other resins, dielectric properties, low thermal expansion and heat resistance, as a structure derived from maleimide compound (c2), it is preferred to include a group containing the structure shown in the following general formula (C-11) or (C-12).

[0351] [Chemical Formula 26]

[0352]

[0353] (where X) C1 It is a divalent organic group,* C1 The site where the material bonds to the carbon atoms of the vinyl group in the side chain of the conjugated diene polymer (c1). C2 (This refers to the site where the atoms bond with each other.)

[0354] Regarding X in the above general formulas (C-11) and (C-12) C1 The explanation and the X in the above general formula (b1-1) b1 The explanation is the same.

[0355] From the viewpoints of compatibility with other resins, dielectric properties, low thermal expansion and heat resistance, the substituent (x) more preferably includes one or more structures selected from the structures shown in the following general formula (C-21) and the following general formula (C-22), and is a structure derived from maleimide compound (c2).

[0356] [Chemical Formula 27]

[0357]

[0358] (where R is an example) c1 R c2 X c1 The explanations for q1 and q2 are as described in the general formula (c2-1) above. Regarding * C1 and* C2 The explanation is as described in the general formulas (C-11) and (C-12) above.

[0359] The modified conjugated diene polymer (C1) preferably has substituents (x) and vinyl groups (y) on its side chains.

[0360] In modified conjugated diene polymers (C1), the extent to which substituents (x) are present can be indicated by the extent to which the vinyl group of component (C1) is modified by component (C2) [hereinafter sometimes referred to as "vinyl modification rate"].

[0361] The vinyl modification rate is not particularly limited, but from the viewpoint of compatibility with other resins, dielectric properties, low thermal expansion and heat resistance, it is preferably 20-70%, more preferably 30-60%, and even more preferably 35-50%. Here, the vinyl modification rate is a value obtained by the method described in the examples.

[0362] Vinyl (y) is preferably derived from the 1,2-vinyl group of the structural unit of butadiene.

[0363] (Method for manufacturing modified conjugated diene polymer (C1))

[0364] The (C1) component can be manufactured by reacting a conjugated diene polymer (C1) with a maleimide compound (C2).

[0365] There are no particular limitations on the method for reacting the conjugated diene polymer (C1) with the maleimide compound (C2). For example, the (C1) component can be obtained by adding the conjugated diene polymer (C1), the maleimide compound (C2), a reaction catalyst, and an organic solvent into a reaction vessel and reacting it while heating, maintaining the temperature, stirring, etc., as needed.

[0366] From the viewpoint of workability and inhibition of gelation in the reaction, the reaction temperature of the above reaction is preferably 70 to 120°C, more preferably 80 to 110°C, and even more preferably 85 to 105°C.

[0367] From the same point of view, the reaction time of the above reaction is preferably 0.5 to 15 hours, more preferably 1 to 10 hours, and even more preferably 3 to 7 hours.

[0368] These reaction conditions can be adjusted appropriately depending on the type of raw materials used, and there are no particular limitations.

[0369] Examples of organic solvents used in the above reactions include: alcohol solvents such as methanol, ethanol, butanol, butyl cellosolve, ethylene glycol monomethyl ether, and propylene glycol monomethyl ether; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; aromatic hydrocarbon solvents such as toluene, xylene, and mesitylene; ester solvents such as methoxyethyl acetate, ethoxyethyl acetate, butoxyethyl acetate, and ethyl acetate; and nitrogen-containing solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone.

[0370] One organic solvent can be used alone, or two or more can be used in combination. From the viewpoint of resin solubility, toluene is preferred.

[0371] When the above reaction is carried out in an organic solvent, the total content of the conjugated diene polymer (c1) and maleimide compound (c2) in the reaction solution is not particularly limited, but is preferably 10-70% by mass, more preferably 15-60% by mass, and even more preferably 20-50% by mass. If the total content of the conjugated diene polymer (c1) and maleimide compound (c2) is above the lower limit mentioned above, there is a tendency to obtain a good reaction rate and improve productivity. In addition, if the total content of the conjugated diene polymer (c1) and maleimide compound (c2) is below the upper limit mentioned above, there is a tendency to obtain better solubility, improve stirring efficiency, and further suppress gelation.

[0372] From the viewpoint of suppressing gelation in the reaction and obtaining sufficient reactivity, organic peroxides are preferred as reaction catalysts, and α,α'-bis(tert-butylperoxide)diisopropylbenzene is more preferred.

[0373] The reaction catalyst can be used alone or in combination of two or more.

[0374] The amount of reaction catalyst used is not particularly limited, but is preferably 0.01 to 1.2 parts by mass relative to 100 parts by mass of the total amount of conjugated diene polymer (c1) and maleimide compound (c2), more preferably 0.03 to 1.0 parts by mass, and even more preferably 0.05 to 0.8 parts by mass.

[0375] When the above reaction is carried out, the molar number (M) of N-substituted maleimide groups in the maleimide compound (c2) is... m The molar number (M) of side chain vinyl groups relative to the conjugated diene polymer (c1) v The ratio of (M) m / M v There are no particular limitations, but from the viewpoint of the compatibility of the obtained (C1) component with other resins and the inhibition of gelation in the reaction, it is preferably 0.001 to 0.5, more preferably 0.005 to 0.1, and even more preferably 0.008 to 0.05.

[0376] (C) The number average molecular weight of the component is not particularly limited, but from the viewpoint of compatibility with other resins, dielectric properties, low thermal expansion and heat resistance, it is preferably 700 to 6000, more preferably 800 to 5000, further preferably 900 to 4500, and particularly preferably 1000 to 4000.

[0377] When the resin composition of this embodiment contains component (C), its content is not particularly limited. From the viewpoint of compatibility with other resins, dielectric properties, low thermal expansion and heat resistance, it is preferably 1 to 50 parts by mass relative to 100 parts by mass of the total resin components in the resin composition, more preferably 5 to 40 parts by mass, further preferably 10 to 30 parts by mass, and particularly preferably 15 to 25 parts by mass.

[0378] <Styrene-based thermoplastic elastomers (D)>

[0379] As for component (D), there are no particular restrictions as long as it is a thermoplastic elastomer with structural units derived from styrene compounds.

[0380] (D) Components can be used alone or in combination of two or more.

[0381] As component (D), it is preferred to have the structural unit shown in the following general formula (d-1).

[0382] [Chemical Formula 28]

[0383]

[0384] (where R is in the formula) d1 R is an alkyl group having 1 to 5 carbon atoms or hydrogen atoms. d2 It is an alkyl group with 1 to 5 carbon atoms. k is an integer from 0 to 5.

[0385] As R d1 and R d2 The alkyl group represented by carbon atoms, having 1 to 5 carbon atoms, can be exemplified by methyl, ethyl, n-propyl, etc. Among these, alkyl groups having 1 to 3 carbon atoms are preferred, alkyl groups having 1 or 2 carbon atoms are more preferred, and methyl is even more preferred.

[0386] k is preferably an integer from 0 to 2, more preferably 0 or 1, and even more preferably 0.

[0387] The structural units that (D) has are not derived from styrene compounds, such as structural units derived from butadiene, structural units derived from isoprene, structural units derived from maleic acid, structural units derived from maleic anhydride, etc.

[0388] The structural units derived from butadiene and isoprene described above can be hydrogenated. Upon hydrogenation, the structural units derived from butadiene become structural units composed of a mixture of ethylene and butene units, and the structural units derived from isoprene become structural units composed of a mixture of ethylene and propylene units.

[0389] As component (D), from the viewpoints of dielectric properties, adhesion to conductors, heat resistance, glass transition temperature, and low thermal expansion, it is preferably selected from one or more of styrene-butadiene-styrene block copolymers (SEBS, SBBS), styrene-isoprene-styrene block copolymers (SEPS), and styrene-maleic anhydride copolymers (SMA), more preferably from one or more of styrene-butadiene-styrene block copolymers (SEBS) and styrene-isoprene-styrene block copolymers (SEPS), and even more preferably from styrene-butadiene-styrene block copolymers (SEBS).

[0390] In the aforementioned SEBS, the content of structural units derived from styrene [hereinafter, sometimes referred to as "styrene content"] is not particularly limited, but from the viewpoints of dielectric properties, adhesion to conductors, heat resistance, glass transition temperature, and low thermal expansion, it is preferably 5 to 80% by mass, more preferably 10 to 75% by mass, even more preferably 15 to 70% by mass, and particularly preferably 20 to 50% by mass.

[0391] The melt flow rate (MFR) of SEBS is not particularly limited, but under the test conditions of 230°C and a load of 2.16 kgf (21.2 N), it is preferably 0.1 to 20 g / 10 min, more preferably 0.3 to 17 g / 10 min, and even more preferably 0.5 to 15 g / 10 min.

[0392] Examples of SEBS' commercially available products include: TUFTEC (registered trademark) H series and M series manufactured by Asahi Kasei Corporation; SEPTON (registered trademark) series manufactured by KURARAY Corporation; and KRATON (registered trademark) G polymer series manufactured by KRATON POLYMER JAPAN Corporation.

[0393] (D) The weight-average molecular weight (Mw) of component (D) is not particularly limited, but is preferably 12,000 to 1,000,000, more preferably 30,000 to 500,000, even more preferably 50,000 to 120,000, and particularly preferably 70,000 to 100,000. Weight-average molecular weight (Mw) refers to the value determined by gel permeation chromatography (GPC) using polystyrene.

[0394] When the resin composition of this embodiment contains component (D), its content is not particularly limited. From the viewpoint of dielectric properties, heat resistance, formability and compatibility, it is preferably 10 to 60 parts by mass relative to 100 parts by mass of the total resin components in the resin composition, more preferably 15 to 50 parts by mass, further preferably 20 to 40 parts by mass, and particularly preferably 25 to 30 parts by mass.

[0395] <Imidazole compounds or their modified forms (E)>

[0396] The resin composition of this embodiment, by containing component (E), tends to not only have better heat resistance, but also exhibit excellent dielectric properties.

[0397] (E) Components can be used alone or in combination of two or more.

[0398] Examples of components (E) include: 2-methylimidazole, 2-ethylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1,2-dimethylimidazole, 2-ethyl-1-methylimidazole, 1,2-diethylimidazole, 1-ethyl-2-methylimidazole, 2-ethyl-4-methylimidazole, 4-ethyl-2-methylimidazole, 1-isobutyl-2-methylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxyimidazole. 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 2,4-diamino-6-[2'-methylimidazolyl-(1')]ethyl-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]ethyl-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-( 1')] Imidazole compounds such as ethyl-triazine; isocyanate-masked imidazole, epoxy-masked imidazole, salts of the above imidazole compounds with trimellitic acid, salts of the above imidazole compounds with isocyanuric acid, salts of the above imidazole compounds with hydrobromic acid, and other modified imidazole compounds.

[0399] As a modifier of imidazole compounds, the modified imidazole compounds shown in the following general formula (e-1) or the following general formula (e-2) are preferred.

[0400] [Chemical Formula 29]

[0401]

[0402] (where R is in the formula) e1 R e2 R e3 and R e4 Each is independently composed of a hydrogen atom, an aliphatic hydrocarbon group or a phenyl group having 1 to 20 carbon atoms, X e1 It can be an alkyl group or a divalent aromatic hydrocarbon group.

[0403] [Chemical Formula 30]

[0404]

[0405] (where R is in the formula) e5 R e6 R e7 and R e8 Each is independently composed of a hydrogen atom, an aliphatic hydrocarbon group or a phenyl group having 1 to 20 carbon atoms, X e2 It can be an alkylene group, alkylidene group, ether group, or sulfonyl group.

[0406] The resin composition of this embodiment further enhances the compatibility of the resin components by containing a modified imidazole compound represented by the above-described general formula (e-1) or (e-2). The reason for this is not yet certain, but it is speculated as follows: The modified imidazole compound has an imidazole group as a highly polar group and possesses the "-CH2-X" in the above-described general formula (e-1). e1 -CH2-” and "-Ph-X" in the above general formula (e-2) e2 The hydrocarbon group indicated by "-Ph-" is a low-polarity group. Therefore, it is speculated that the above-mentioned modified imidazole compound functions as a compatibilizer for the high-polarity (B) component and the low-polarity elastomer.

[0407] Resin compositions containing the modified imidazole compound shown in general formula (e-1) tend to become resin compositions with good heat resistance and particularly excellent dielectric properties. Furthermore, resin compositions containing the modified imidazole compound shown in general formula (e-2) tend to become resin compositions with improved dielectric properties and particularly excellent heat resistance.

[0408] In the above general formula (e-1), R e1 R e2 R e3 and R e4 The aliphatic hydrocarbon group represented has 1 to 20 carbon atoms, preferably 1 to 10, more preferably 1 to 5, and even more preferably 1 or 2.

[0409] As R e1 R e2 R e3 and R e4 Examples of aliphatic hydrocarbon groups include: methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecanyl, stearyl, and other alkyl groups; alkenyl groups; and alkynyl groups. These aliphatic hydrocarbon groups can be either straight-chain or branched. Methyl and ethyl groups are preferred.

[0410] In the above general formula (e-1), Xe1 The alkyl group represented preferably has 1 to 10 carbon atoms, more preferably 2 to 8, and even more preferably 3 to 5.

[0411] As X e1 Examples of alkyl groups represented include methylene, ethylene, 1,3-propylene, 1,4-butylene, 1,5-pentylene, and 1,6-hexylene. 1,4-butylene is preferred.

[0412] X e1 The number of carbon atoms in the divalent aromatic hydrocarbon group is preferably 6 to 20, more preferably 6 to 15, and even more preferably 6 to 12.

[0413] As X e1 Examples of divalent aromatic hydrocarbon groups include phenylene, biphenylene, terphenylene, naphthylene, and anthraceneylene.

[0414] In the above general formula (e-2), R e5 R e6 R e7 and R e8 The aliphatic hydrocarbon group represented has 1 to 20 carbon atoms, preferably 1 to 10, more preferably 1 to 5, and even more preferably 1 or 2.

[0415] As R e5 R e6 R e7 and R e8 Examples of aliphatic hydrocarbon groups include: methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptyl, stearyl, and other alkyl groups; alkenyl groups; and alkynyl groups. These aliphatic hydrocarbon groups can be either straight-chain or branched.

[0416] R e5 R e6 R e7 and R e8 In the atoms or groups represented, R e5 and R e6 Preferably, hydrogen atoms, R e7 and R e8 Phenyl is preferred.

[0417] In the above general formula (e-2), X e2 The alkyl group represented preferably has 1 to 10 carbon atoms, more preferably 2 to 8, and even more preferably 3 to 5.

[0418] As X e2Examples of alkyl groups that can be represented include methylene, ethylene, 1,3-propylene, 1,4-butylene, 1,5-pentylene, and 1,6-hexylene.

[0419] X e2 The carbon number of the represented alkylidene group is preferably 3 to 10, more preferably 3 to 8, and even more preferably 3 to 5.

[0420] As X e2 Examples of alkylidene groups include ethoxyl, propionyl, isopropionyl, butylidene, isobutylidene, pentylidene, and isopentylidene. Propyleneide is preferred.

[0421] When the resin composition of this embodiment contains component (E), its content is not particularly limited. From the viewpoint of compatibility, dielectric properties and heat resistance, it is preferably 0.01 to 10 parts by mass relative to 100 parts by mass of the total resin components in the resin composition, more preferably 0.1 to 6 parts by mass, further preferably 0.5 to 4 parts by mass, and particularly preferably 0.8 to 2 parts by mass.

[0422] <Inorganic filler material (F)>

[0423] By including inorganic filler material (F) [hereinafter sometimes referred to as "(F) component"] in the resin composition of this embodiment, there is a tendency for further improvement in the coefficient of thermal expansion, elastic modulus, heat resistance and flame retardancy.

[0424] Inorganic filler material (F) can be used alone or in combination of two or more types.

[0425] As for component (F), there are no particular limitations, and examples include silicon dioxide, aluminum oxide, titanium oxide, mica, beryllium oxide, barium titanate, potassium titanate, strontium titanate, calcium titanate, aluminum carbonate, magnesium hydroxide, aluminum hydroxide, aluminum silicate, calcium carbonate, calcium silicate, magnesium silicate, silicon nitride, boron nitride, clay, talc, aluminum borate, and silicon carbide. Among these, from the viewpoints of coefficient of thermal expansion, elastic modulus, heat resistance, and flame retardancy, silicon dioxide, aluminum oxide, mica, and talc are preferred, silicon dioxide and aluminum oxide are more preferred, and silicon dioxide is even more preferred.

[0426] Examples of silica include: precipitated silica with high water content produced by wet processing, and dry silica produced by dry processing that contains almost no bound water. Furthermore, dry silica can be further categorized into, depending on the manufacturing method, crushed silica, fumed silica, and molten silica.

[0427] The particle size of the inorganic filler material (F) is not particularly limited, but is preferably 0.01 to 20 μm, more preferably 0.1 to 10 μm, even more preferably 0.2 to 1 μm, and particularly preferably 0.3 to 0.8 μm. Here, the particle size of the inorganic filler material (F) refers to the average particle size, which is the particle size at a point corresponding to 50% of the volume when the total volume of the particles is set to 100% and a cumulative frequency distribution curve based on particle size is obtained. The particle size of the inorganic filler material (F) can be measured using a particle size distribution measuring device employing laser diffraction scattering.

[0428] Examples of the shapes of inorganic filler material (F) include spherical and fragmented shapes, with spherical shapes being preferred.

[0429] When the resin composition of this embodiment contains inorganic filler (F), the content of inorganic filler (F) in the resin composition is not particularly limited. From the viewpoints of low thermal expansion, elastic modulus, heat resistance and flame retardancy, it is preferably 10 to 70% by mass, more preferably 20 to 65% by mass, further preferably 30 to 60% by mass, and particularly preferably 40 to 55% by mass, relative to the total solid content (100% by mass) of the resin composition.

[0430] In the case where the resin composition of this embodiment contains inorganic filler (F), coupling agents may be used as needed to improve the dispersibility of inorganic filler (F) and its compatibility with organic components.

[0431] <Flame retardant (G)>

[0432] The resin composition of this embodiment tends to have further improved flame retardancy by containing a flame retardant (G).

[0433] Flame retardant (G) can be used alone or in combination of two or more. In addition, flame retardant additives may be included as needed.

[0434] Examples of flame retardants (G) include phosphorus-based flame retardants, metal hydrates, and halogen-based flame retardants. From an environmental perspective, phosphorus-based flame retardants and metal hydrates are preferred.

[0435] -Phosphorus-based flame retardants-

[0436] Phosphorus-based flame retardants can be used without special restrictions as long as they are substances commonly used as flame retardants that contain phosphorus atoms. From an environmental perspective, phosphorus-based flame retardants that do not contain halogen atoms are preferred.

[0437] Phosphorus-based flame retardants can be inorganic, but organic phosphorus-based flame retardants are preferred from the perspectives of dielectric properties, adhesion to conductors, heat resistance, glass transition temperature, low thermal expansion, and flame retardancy.

[0438] Examples of inorganic phosphorus-based flame retardants include: red phosphorus; ammonium phosphates such as monoammonium phosphate, diammonium phosphate, triammonium phosphate, and ammonium polyphosphate; inorganic nitrogen- and phosphorus-containing compounds such as phosphoric acid amide; phosphoric acid; and phosphine oxide.

[0439] Examples of organic phosphorus-based flame retardants include: aromatic phosphates, monosubstituted phosphonate diesters, disubstituted hypophosphonates, metal salts of disubstituted hypophosphonic acids, organic nitrogen- and phosphorus-containing compounds, cyclic organophosphorus compounds, and phosphine oxide compounds. Among these, aromatic phosphates, metal salts of disubstituted hypophosphonic acids, and phosphine oxide compounds are preferred. Examples of metal salts of disubstituted hypophosphonic acids include lithium salts, sodium salts, potassium salts, calcium salts, magnesium salts, aluminum salts, titanium salts, and zinc salts. Among these, aluminum salts are preferred.

[0440] Examples of aromatic phosphate esters include: triphenyl phosphate, tricresyl phosphate, tri(xyl) phosphate, toluene diphenyl phosphate, toluene di-2,6-dimethyl phosphate, resorcinol bis(diphenyl phosphate), 1,3-phenylene bis(di-2,6-dimethyl phosphate), bisphenol A-bis(diphenyl phosphate), and 1,3-phenylene bis(diphenyl phosphate).

[0441] Examples of monosubstituted phosphonic acid diesters include diethylene phenylphosphonate, diallyl phenylphosphonate, and bis(1-butenyl) phenylphosphonate.

[0442] Examples of 2-substituted phosphonates include phenyl diphenylphosphonate and methyl diphenylphosphonate.

[0443] Examples of metal salts of dialkylphosphinic acid include metal salts of dialkylphosphinic acid, diallylphosphinic acid, divinylphosphinic acid, and diarylphosphinic acid. Aluminum salts are preferred among these metal salts.

[0444] Examples of organic nitrogen- and phosphorus-containing compounds include: bis(2-allylphenoxy)phosphazene, xylylphosphazene and other phosphazene compounds; melamine phosphate; melamine pyrophosphate; melamine polyphosphate; melamine polyphosphate, etc.

[0445] Examples of cyclic organophosphorus compounds include 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0446] Examples of phosphine oxide compounds include p-xylylbis(diphenyl)phosphine oxide, p-phenylenebis(diphenyl)phosphine oxide, ethylenebis(diphenyl)phosphine oxide, biphenylenebis(diphenyl)phosphine oxide, and naphthylbis(diphenyl)phosphine oxide.

[0447] Among the above-mentioned organic phosphorus-based flame retardants, aromatic phosphate esters, metal salts of 2-substituted phosphonates, and phosphine oxide compounds are preferred, and 1,3-phenylenebis(di-2,6-dimethyl phosphate), aluminum salts of dialkyl phosphonates, and p-xylenebisdiphenylphosphine oxide are more preferred.

[0448] -Metal hydrates-

[0449] Examples of metal hydrates include aluminum hydroxide hydrate and magnesium hydroxide hydrate.

[0450] -Halogen-based flame retardants-

[0451] Examples of halogen-based flame retardants include chlorine-based and brominated flame retardants. Examples of chlorine-based flame retardants include chlorinated paraffins.

[0452] When the resin composition of this embodiment contains a phosphorus-based flame retardant as component (G), the content of the phosphorus-based flame retardant in the resin composition is not particularly limited. From the viewpoint of flame retardancy, formability and heat resistance, the content is preferably 0.2 to 10 parts by mass relative to 100 parts by mass of the total resin components in the resin composition, more preferably 0.3 to 7 parts by mass, further preferably 0.5 to 5 parts by mass, and particularly preferably 1 to 3 parts by mass.

[0453] <Other components (H)>

[0454] The resin composition of this embodiment may also contain other components (H) besides those described above [hereinafter, sometimes referred to as "(H) components"]. Examples of other components (H) include thermosetting resins, thermoplastic polymers, curing accelerators, flame retardants, additives, organic solvents, etc., other than those described above.

[0455] (H) Components can be used individually or in combination of two or more.

[0456] Examples of curing accelerators used as (H) components include: acidic catalysts such as p-toluenesulfonic acid; amine compounds such as triethylamine, pyridine, and tributylamine; tertiary amine compounds; quaternary ammonium compounds; phosphorus compounds such as triphenylphosphine; organic peroxides such as dicumyl peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxide)hexyn-3, 2,5-dimethyl-2,5-bis(tert-butylperoxide)hexane, tert-butylperoxide isopropyl monocarbonate, and α,α'-bis(tert-butylperoxide)diisopropylbenzene; and carboxylates of manganese, cobalt, zinc, etc.

[0457] Examples of additives that are components of (H) include antioxidants, heat stabilizers, antistatic agents, ultraviolet absorbers, pigments, colorants, and lubricants.

[0458] There is no particular limitation on the amount of component (H), which can be used as long as it does not impede the effect of the present invention.

[0459] (Organic solvents)

[0460] The resin composition of this embodiment may contain an organic solvent. By diluting with an organic solvent, the processability of the resin composition of this embodiment and the ease of manufacturing the prepreg described later tend to improve. Resin compositions containing organic solvents are often referred to as resin varnishes or varnishes.

[0461] Examples of organic solvents include: alcohol solvents such as ethanol, propanol, butanol, methyl cellosolve, butyl cellosolve, and propylene glycol monomethyl ether; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ether solvents such as tetrahydrofuran; aromatic hydrocarbon solvents such as toluene, xylene, and mesitylene; nitrogen-containing solvents such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone; sulfur-containing solvents such as dimethyl sulfoxide; and ester solvents such as γ-butyrolactone.

[0462] From the viewpoint of solubility, alcohol solvents, ketone solvents, nitrogen-containing solvents, and aromatic hydrocarbon solvents are preferred, aromatic hydrocarbon solvents are more preferred, and toluene is even more preferred.

[0463] In the case where the resin composition of this embodiment contains an organic solvent, the concentration of the solids content of the resin composition is not particularly limited, but is preferably 30 to 90% by mass, more preferably 35 to 80% by mass, and even more preferably 40 to 60% by mass. If the concentration of the solids content of the resin composition is within the above range, the processability of the resin composition becomes easier, and the impregnation of the substrate and the appearance of the manufactured prepreg tend to be better. Furthermore, the adjustment of the solids content of the resin in the prepreg, as described later, becomes easier, and the manufacture of prepregs with the desired thickness becomes more convenient.

[0464] <Method for manufacturing resin composition>

[0465] The resin composition of this embodiment can be manufactured by mixing the above-mentioned components using a known method. At this time, the components can be dissolved or dispersed while stirring. The mixing order, temperature, time, and other conditions are not particularly limited and can be arbitrarily set according to the type of raw materials.

[0466] <Physical Properties of Resin Compositions>

[0467] (Dielectric properties)

[0468] The dielectric constant (Dk) of the cured resin composition of this embodiment at 10 GHz is not particularly limited, but is preferably 3.0 or less, more preferably 2.9 or less, and even more preferably 2.8 or less. A lower dielectric constant (Dk) is preferred, and its lower limit is not particularly limited; considering the balance with other properties, it can be 2.3 or more, 2.4 or more, or 2.5 or more. The dielectric constant (Dk) is a value obtained according to the cavity resonator perturbation method, and more specifically, a value measured by the method described in the examples. Furthermore, in this specification, when simply referred to as dielectric constant, it refers to the relative dielectric constant.

[0469] The dielectric loss tangent (Df) of the cured resin composition of this embodiment at 10 GHz is not particularly limited, but is preferably 0.0050 or less, more preferably 0.0040 or less, further preferably 0.0030 or less, particularly preferably 0.0025 or less, and most preferably 0.0022 or less. A smaller dielectric loss tangent (Df) is preferred, and its lower limit is not particularly limited. Considering the balance with other properties, it can be, for example, 0.0010 or more, 0.0013 or more, or 0.0015 or more. The dielectric loss tangent (Df) is a value obtained based on the cavity resonator perturbation method, and more specifically, a value measured by the method described in the examples.

[0470] (Glass transition temperature)

[0471] The resin composition in this embodiment is not particularly limited. The glass transition temperature measured using the method described in the examples is preferably 190°C or higher, more preferably 200°C or higher, and even more preferably 210°C or higher. A higher glass transition temperature is preferred. From the viewpoint of ease of manufacture, it can be 300°C or lower, 270°C or lower, or 250°C or lower.

[0472] [Prepreg]

[0473] The prepreg in this embodiment is a prepreg containing the resin composition of this embodiment.

[0474] As the sheet fiber reinforced substrate contained in the prepreg of this embodiment, known sheet fiber reinforced substrates used in various electrical insulation material laminates can be used.

[0475] Materials used as sheet fiber reinforced substrates include, for example, inorganic fibers such as E-glass, D-glass, S-glass, and Q-glass; organic fibers such as polyimide, polyester, and tetrafluoroethylene; and mixtures thereof. These sheet fiber reinforced substrates can take the form of fabrics, nonwovens, rovings, chopped strand mats, and surface mats.

[0476] The thickness of the sheet fiber reinforced substrate is not particularly limited, for example, it is 0.02 to 0.5 mm.

[0477] From the perspective of the impregnation properties of the resin composition, the heat resistance, moisture resistance and processability when the laminate is made, the sheet fiber reinforced substrate can be a sheet fiber reinforced substrate that has been surface treated with coupling agents or the like, or a sheet fiber reinforced substrate that has undergone mechanical fiber opening treatment.

[0478] The prepreg of this embodiment can be manufactured, for example, by impregnating or coating the resin composition of this embodiment onto a sheet fiber reinforced substrate and then drying it as needed.

[0479] Methods for impregnating or coating a resin composition onto a sheet fiber reinforced substrate include, for example, hot melt methods and solvent methods.

[0480] The hot-melt method is a method of impregnating or coating a resin composition that does not contain organic solvents onto a sheet fiber reinforced substrate. One example of the hot-melt method is to temporarily coat the resin composition onto a peelable coated paper and then laminate the coated resin composition onto the sheet fiber reinforced substrate. Another example of the hot-melt method is to directly coat the resin composition onto the sheet fiber reinforced substrate using a die-coating machine.

[0481] The solvent method is a method of impregnating or coating a resin composition containing an organic solvent onto a sheet fiber reinforced substrate. Specifically, examples include: a method of impregnating a sheet fiber reinforced substrate in a resin composition containing an organic solvent and then drying it.

[0482] As for the drying conditions in the solvent method, for example, heating at 80–200°C for 1–30 minutes can be set. By drying, the organic solvent is removed, and the resin composition is semi-cured (acetylated), thus obtaining the prepreg of this embodiment.

[0483] The concentration of solid components from the resin composition in the prepreg of this embodiment is not particularly limited, but is preferably 30 to 90% by mass. If the concentration of solid components from the resin composition in the prepreg is within the above range, there is a tendency to obtain better formability when making laminates.

[0484] [Resin film]

[0485] The resin film of this embodiment is a resin film containing the resin composition of this embodiment.

[0486] The resin film of this embodiment can be manufactured, for example, by coating a support with a resin composition containing an organic solvent, i.e., a resin varnish, and then heating and drying it.

[0487] Examples of supporting materials include: films of polyolefins such as polyethylene, polypropylene, and polyvinyl chloride; films of polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate; various plastic films such as polycarbonate films and polyimide films; metal foils such as copper foil and aluminum foil; and release paper.

[0488] The support can be a support that has undergone surface treatments such as matte finish or corona treatment. Alternatively, the support can also be a support that has undergone release treatment using silicone resin-based release agents, alkyd resin-based release agents, fluoropolymer-based release agents, etc.

[0489] The thickness of the support is not particularly limited, but is preferably 10 to 150 μm, more preferably 20 to 100 μm, and even more preferably 25 to 50 μm.

[0490] As a coating apparatus for applying resin varnishes, one can use, for example, a comma coater, a bar coater, a coincidence coater, a roller coater, a gravure coater, a die coater, or other coating apparatus known to those skilled in the art. These coating apparatuses can be selected appropriately based on the desired film thickness.

[0491] The drying conditions after coating the resin composition can be appropriately determined based on the content and boiling point of the organic solvent, and there are no particular limitations. For example, in the case of a resin varnish containing 40-60% by mass of an aromatic hydrocarbon solvent, a resin film can be appropriately formed by drying at 50-200°C for about 3-10 minutes.

[0492] [Laminated Board]

[0493] The laminate in this embodiment is a laminate containing the prepreg and metal foil of this embodiment. It should be noted that a laminate with metal foil is sometimes also referred to as a metal-clad laminate.

[0494] The metal used for the foil is not particularly limited as long as it is used in electrical insulation materials. From the viewpoint of conductivity, copper, gold, silver, nickel, platinum, molybdenum, ruthenium, aluminum, tungsten, iron, titanium, chromium, and alloys containing one or more of these metal elements are preferred, copper and aluminum are more preferred, and copper is even more preferred.

[0495] The laminated board of this embodiment can be manufactured, for example, by heating and pressing after metal foil is applied to one or both sides of the prepreg of this embodiment. In this case, only one sheet of prepreg can be used, or two or more sheets can be laminated.

[0496] There are no particular limitations on the conditions for heat-pressurization molding. For example, the temperature can be set to 100–300°C, the pressure to 0.2–10 MPa, and the time to 0.1–5 hours. Alternatively, heat-pressurization molding can also be performed by using vacuum pressing or other methods to maintain a vacuum state for 0.5–5 hours.

[0497] Multilayer printed circuit board

[0498] The multilayer printed circuit board of this embodiment is composed of one or more selected from the prepreg, resin film and laminate of this embodiment.

[0499] That is, the multilayer printed circuit board of this embodiment includes at least a multilayer structure and a conductor circuit layer, wherein the multilayer structure contains a cured prepreg of this embodiment, a cured resin film of this embodiment, or a laminate of this embodiment.

[0500] The multilayer printed circuit board of this embodiment can be manufactured by performing conductor circuit formation and multilayer bonding processing on one or more of the prepreg, resin film and laminate selected from this embodiment using known methods. The conductor circuit can be formed, for example, by appropriately performing hole processing, metal plating processing, etching of metal foil, etc.

[0501] [Semiconductor Package]

[0502] The semiconductor package in this embodiment is a semiconductor package formed using a multilayer printed circuit board of this embodiment.

[0503] The semiconductor package of this embodiment is formed by mounting semiconductors on a multilayer printed circuit board of this embodiment. The semiconductor package of this embodiment can be manufactured, for example, by mounting semiconductor chips, memory, etc., on a multilayer printed circuit board of this embodiment using known methods.

[0504] The embodiments described above are merely illustrative examples of the invention and are not intended to limit the scope of the invention to these embodiments. The invention can be implemented in various ways different from the embodiments described above without departing from its spirit.

[0505] Example

[0506] The following examples illustrate this implementation method in detail. However, this implementation method is not limited to the following examples.

[0507] It should be noted that, in each case, the number-average molecular weight was determined according to the following steps.

[0508] (Methods for determining number-average molecular weight)

[0509] Number-average molecular weight was calculated by gel permeation chromatography (GPC) based on a standard curve using standard polystyrene. The standard curve used standard polystyrene: TSKstandard POLYSTYRENE (Type: A-2500, A-5000, F-1, F-2, F-4, F-10, F-20, F-40) [manufactured by Tosoh Corporation, trade name], approximated by a cubic formula. The determination conditions for GPC are shown below.

[0510] Device: High-speed GPC device HLC-8320GPC

[0511] Detector: UV-8320 ultraviolet absorbance detector [manufactured by Tosoh Corporation]

[0512] Column: Protective column; TSK Guardcolumn SuperHZ-L+ Column: TSKgel SuperHZM-N+ TSKgel SuperHZM-M+ TSKgel SuperH-RC (All manufactured by Tosoh Corporation, product names)

[0513] Column dimensions: 4.6×20mm (protective column), 4.6×150mm (column), 6.0×150mm (reference column)

[0514] • Eluent: Tetrahydrofuran

[0515] • Sample concentration: 10 mg / 5 mL

[0516] Injection volume: 25μL

[0517] • Flow rate: 1.00 mL / min

[0518] • Measurement temperature: 40℃

[0519] (Determination of vinyl modification rate)

[0520] In Manufacturing Example 2 described later, GPC was measured using the above method for both the solution containing components (c1) and (c2) before the reaction and the solution after the reaction, thereby determining the peak area from component (c2) before and after the reaction. Next, the vinyl modification rate of component (c2) was calculated using the following formula. It should be noted that the vinyl modification rate corresponds to the rate of decrease in the peak area from component (c2) caused by the reaction.

[0521] Vinyl modification rate = [(peak area of ​​(C2) component before reaction) - (peak area of ​​(C2) component after reaction)] × 100 / (peak area of ​​(C2) component before reaction)

[0522] [Manufacturing Example 1: Manufacturing of Polyphenylene Ether Derivatives]

[0523] In a 2L glass flask equipped with a thermometer, reflux condenser, and stirring device, toluene, 1 mol of polyphenylene ether "XYRON (registered trademark) S203A" (trade name, manufactured by Asahi Kasei Corporation, number average molecular weight = 12000, hereinafter also referred to as "raw material PPE"), and an amount of allyl-containing compound of the following general formula (1) with a hydroxyl equivalent of 6 relative to the raw material PPE, are added. The mixture is then stirred at 90–100°C to dissolve the components. It should be noted that the amount of toluene used is set to achieve a reaction concentration of 35% by mass.

[0524] [Chemical Formula 31]

[0525]

[0526] (where X) a2 It is a divalent organic group, and it is related to X in the above general formula (a-5). a2 The same explanation will be given.

[0527] After visually confirming the dissolution of the allyl-containing compound, 2 parts by mass of tert-butylperoxyisopropyl monocarbonate relative to 100 parts by mass of the raw material PPE and 1.11 parts by mass of manganese octanoate relative to 100 parts by mass of the raw material PPE were added. Then, a redistribution reaction was carried out at a solution temperature of 90–100°C for 6 hours, followed by cooling to 40°C, thereby obtaining a polyphenylene ether derivative with allyl groups at the molecular ends. A small amount of this reaction solution was taken and subjected to GPC analysis (polystyrene conversion, eluent: tetrahydrofuran). The results confirmed that the bimodal peaks from the allyl-containing compound became a single peak. Furthermore, the number-average molecular weight of the polyphenylene ether derivative was 4200.

[0528] [Manufacturing Example 2: Manufacturing of Modified Conjugated Diene Polymer]

[0529] 33.5 parts by mass of 1,2-polybutadiene homopolymer (number average molecular weight = 1200, vinyl content = ≥ 85%), 1.47 parts by mass of 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, a reaction catalyst, and an organic solvent were added to a 2L glass flask equipped with a thermometer, reflux condenser, and stirring device. Next, the mixture was stirred at 90–100°C for 5 hours under a nitrogen atmosphere to allow the (C1) and (C2) components to react, yielding a solution of a modified conjugated diene polymer with a solid content concentration of 35% by mass. The vinyl modification rate of the (C2) component was 40%, and the number average molecular weight of the obtained modified conjugated diene polymer was 3500.

[0530] [Preparation of the resin composition]

[0531] Examples 1-5, Comparative Example 1

[0532] After combining the components listed in Table 1 according to the proportions listed in Table 1, the mixture was stirred and mixed at room temperature or heated to 50–80°C, thereby preparing a resin composition with a solid component concentration of approximately 50% by mass. It should be noted that the proportions of each component in Table 1 are in parts by mass; in the case of a solution, they refer to the parts by mass converted from solid components. Furthermore, the values ​​in parentheses in Table 1 indicate the content of phosphorus atoms from each component in the resin composition.

[0533] [Manufacturing of resin film and resin board with copper foil on both sides]

[0534] The resin compositions obtained in each example were coated onto a 38 μm thick PET film (manufactured by Teijin Corporation, trade name: G2-38), and then heated and dried at 170°C for 5 minutes to produce a resin film in the ethyl phase. This resin film was then peeled off from the PET film and pulverized to produce ethyl phase resin powder, which was then fed into a Teflon (registered trademark) sheet cut to dimensions of 1 mm thickness × 50 mm length × 35 mm width. Next, 18 μm thick low-smoothness copper foil (manufactured by Mitsui Metals & Mining Co., Ltd., trade name: 3EC-VLP-18) was placed on top and bottom of the Teflon (registered trademark) sheet containing the resin powder, thus obtaining a laminate before heat-pressing molding. It should be noted that the low-smoothness copper foil was arranged with the resin powder side facing M. Next, the laminate was heated and pressurized at 230°C, 2.0 MPa, and for 120 minutes to form a resin plate from the resin powder, which was then cured to produce a resin plate with copper foil on both sides. The thickness of the resin plate portion of the resulting resin plate with copper foil on both sides was 1 mm.

[0535] [Evaluation Methods and Measurement Methods]

[0536] Using the resin plates with copper foil on both sides obtained in the above examples and comparative examples, various measurements and evaluations were performed according to the following methods. The results are shown in Table 1.

[0537] (1. Compatibility evaluation methods)

[0538] (1) Preparation of test pieces

[0539] The resin plates with copper foil on both sides obtained in each example were immersed in a 10% by mass solution of ammonium persulfate (manufactured by MITSUBISHI GAS CHEMICAL Co., Ltd.) as a copper etching solution, thereby removing the copper foil and obtaining the resin plate.

[0540] Next, the resin board was embedded in injection molding resin and cured at room temperature for 12 hours to obtain an injection-molded resin board. The obtained injection-molded part was cut using a precision cutting machine (Refine Tec Co., Ltd., trade name: Refine Saw Excel). This formed a cross-section of the resin board. The resulting injection-molded part, after undergoing platinum vapor deposition on this cross-section, was used as a test piece.

[0541] (2) Observation using a scanning electron microscope

[0542] The cross-section of the test piece obtained above was observed using a scanning electron microscope (SEM) (manufactured by Nippon Electron Ltd., trade name: JSM-6010PLUA / LA) under the conditions of accelerating voltage 15kV, no tilt, and reflected electron mode, thereby obtaining a reflected electron image.

[0543] It should be noted that the area ratio R used to calculate the non-separated portion is... w The images were obtained by taking pictures of any three fields of view at a magnification of 100x or 200x (100x for Examples 1, 3-5 and Comparative Example 1, and 200x for Example 2).

[0544] Additionally, the average structural domain size D of the separation section is used to calculate... L The images were obtained by taking pictures of any 6 fields of view at a magnification of 65x.

[0545] In Example 4, to investigate the effect of magnification, reflected electron images were also obtained at magnifications of 200x and 1000x.

[0546] (3) Observation using a scanning electron microscope

[0547] In the aforementioned reflected electron image, the relatively dark resin regions where phase separation has occurred are defined as "separated areas," and the remaining areas are defined as "non-separated areas." It should be noted that separated areas can, for example, be... Figure 1 As shown, it is clearly identified.

[0548] (4) Binarization processing of reflected electron images

[0549] Using image analysis and processing software (Roper Co., Ltd. of Japan, product name: Image-Pro Analyzer 7.0J), the RGB threshold is adjusted in the range of 40 to 100 as a condition for binarization processing. The obtained reflective electron image is binarized under the condition that the separated part is one value and the non-separated part is another value as determined in (3) above, thereby obtaining a binarized image.

[0550] (5) Area ratio R of the non-separated part w Calculated

[0551] Calculate the area ratio of the non-separated region of the binarized image relative to the entire region of the binarized image (area of ​​the non-separated region × 100 / area of ​​the entire region of the binarized image). The average of these area ratios across the three viewpoints is then used as the area ratio R of the non-separated region. w The calculated R w The larger the value, the better the compatibility.

[0552] (6) Average structural domain size D of the separation section L Calculated

[0553] In the structural domains of the separated region in the six field-of-view reflected electron images obtained above, counting from the structural domain with the largest size, the structural domain sizes of the second to sixth largest structural domains are averaged to calculate the average structural domain size D of the separated region. L The calculated average structural domain size D of the separation section L The smaller the value, the better the compatibility. It should be noted that the length of the structural domain is measured using the method described above.

[0554] (2. Methods for determining dielectric constant and dielectric loss tangent)

[0555] The resin plates with copper foil on both sides obtained in each example were immersed in a 10% by mass solution of ammonium persulfate (manufactured by MITSUBISHI GAS CHEMICAL Co., Ltd.) as a copper etching solution to remove the copper foil and prepare a 2 mm × 50 mm test piece. Next, the relative permittivity (Dk) and dielectric loss tangent (Df) of the test piece were measured in the 10 GHz band at an ambient temperature of 25 °C using the cavity resonator perturbation method.

[0556] (3. Methods for determining glass transition temperature)

[0557] The copper foil on both sides of the resin plate with copper foil on both sides obtained in each example was etched away to prepare a 5 mm square test piece. Next, the glass transition temperature of the test piece was measured using a thermomechanical measurement apparatus (TMA) [manufactured by TA Instruments Japan Co., Ltd., Q400 (model)] according to the IPC (The Institute for Interconnecting and Packaging Electronic Circuits) standard.

[0558] [Table 1]

[0559]

[0560] *In the table, the values ​​in parentheses refer to the content of phosphorus atoms from each component in the resin composition.

[0561] It should be noted that the details of each component recorded in Table 1 are as follows.

[0562] [(A) ingredient]

[0563] • Polyphenylene ether derivatives: Polyphenylene ether derivatives manufactured in Example 1

[0564] [(B) Component]

[0565] ·Maleimide compound (B-1): biphenyl aralkyl maleimide (manufactured by Nippon Kayaku Co., Ltd., trade name "MIR-3000")

[0566] • Maleimide compound (B-2): 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide

[0567] [(C) Component]

[0568] • Unmodified conjugated diene polymer: 1,2-polybutadiene homopolymer (number average molecular weight = 1200, vinyl content = 85% or higher)

[0569] • Modified conjugated diene polymer: The modified conjugated diene polymer manufactured in Example 2

[0570] [(D) component]

[0571] • Hydrogenated styrene-based thermoplastic elastomer: Styrene-ethylene-butene-styrene (SEBS) copolymer (manufactured by KRATONPOLYMER JAPAN Co., Ltd., trade name "KRATON (registered trademark) MD1653", melt flow rate 5.0 g / 10 min, styrene content 30%, hydrogenation rate 100%)

[0572] [(E) component]

[0573] • Modified imidazole compounds represented by general formula (e-1): R in the above general formula (e-1) e1 R e2 Methyl, R e3 R e4 Ethyl, X e1 Compounds that are 1,4-butylene

[0574] • Modified imidazole compounds represented by general formula (e-2): R in the above general formula (e-2) e5 R e6 For hydrogen atoms, Re7 and R e8 For phenyl, X e2 Compounds with propylene groups

[0575] 2-Ethyl-4-methylimidazolium

[0576] [(F)INGREDIENT]

[0577] • Silica: Spherical molten silica, average particle size = 0.5 μm

[0578] [(G) component]

[0579] · 1,3-phenylene bis(2,6-xylyl)phosphate (Japanese: 1,3-フェニレンビス(ジ2,6-キシレニルホスフェート)): Phosphorus content 9.0% by mass

[0580] • Phosphate metal salt: Dialkylphosphinic acid aluminum salt, a metal salt of 2-substituted phosphinic acid, with a phosphorus content of 23.5% by mass (manufactured by Clariant, trade name "OP-935").

[0581] ·P-xylylene bis(diphenylphosphine oxide) (Japanese: パラキシリレンビスジフェニルホスフィンオキサイド): phosphorus content 12.0% by mass

[0582] [(H) component]

[0583] ·α,α'-bis(tert-butylperoxide)diisopropylbenzene

[0584] As shown in Table 1, the area ratio R of the non-separated portion of the cured material obtained in Examples 1 to 5 of this embodiment is... w The average structural domain size D of the separated section is over 50%. L With a diameter below 120 μm, it exhibits excellent dielectric properties and heat resistance. On the other hand, the average structural domain size D of the separated portion... L The dielectric properties of the cured product of Comparative Example 1, which has a diameter exceeding 120 μm, are poor.

[0585] It should be noted that, for the cured material obtained in Example 4, the area ratio R of the non-separated portion was calculated for each of the three fields of view at a magnification of 200x. w The result was R in 3 fields of view w All values ​​fell within ±1% relative to the average. On the other hand, for the same test piece, the area ratio R of the non-separated portion was calculated for three fields of view at a magnification of 1000x. w The results showed that some test pieces had a maximum difference of 5.7% relative to the average value. Based on this result, it can be concluded that the compatibility evaluation method of the first embodiment of this invention can achieve excellent reproducibility by setting the observation magnification to 50-250 times.

[0586] Industrial availability

[0587] The compatibility evaluation method for thermosetting resin compositions of this embodiment can evaluate the compatibility that affects the physical properties of thermosetting resin compositions, such as dielectric properties and heat resistance. Therefore, it is useful for substrate materials used in printed circuit boards.

[0588] Explanation of reference numerals in the attached figures

[0589] 1. Non-separation section

[0590] 2 Separation section

Claims

1. A method for evaluating the compatibility of a thermosetting resin composition, which is a method for evaluating the compatibility of a thermosetting resin composition containing two or more kinds of resins and an inorganic filler, comprising the following procedures 1A and 2A, Procedure 1A: a procedure for obtaining a reflection electron image of a scanning electron microscope at an observation magnification of 50 to 250 times for a cross section of a cured product of the thermosetting resin composition, Process 2A: In the reflection electron image, the resin region in which phase separation has occurred is taken as a separation portion, and the region other than this is taken as a non-separation portion, binarization is performed in such a manner that the separation portion becomes one value and the non-separation portion becomes another value, and the area ratio of the non-separation portion region of the binarized image with respect to the entire region of the obtained binarized image, that is, the area of the non-separation portion region x 100 / the area of the entire region of the binarized image, is calculated as the area ratio R of the non-separation portion w Process.

2. A method for evaluating the compatibility of a thermosetting resin composition, which is a method for evaluating the compatibility of a thermosetting resin composition containing two or more kinds of resins and an inorganic filler, comprising the following procedures 1B and 2B, Procedure 1B: a procedure for obtaining a reflection electron image of a scanning electron microscope at an observation magnification of 50 to 200 times for a cross section of a cured product of the thermosetting resin composition, Process 2B: In the reflection electron image, a resin region in which phase separation has occurred is obtained as a separation portion, and an average domain size D of the separation portion is obtained L Process, The average domain size D of the separation section L Obtained by averaging the domain sizes of the domains having the 2nd or subsequent size, counting from the domain having the largest domain size among the domains of the separation section.

3. A thermosetting resin composition containing two or more kinds of resins and an inorganic filler. In the compatibility evaluation method according to claim 1, the area ratio R of the non-separated portion obtained under the observation magnification of 100x or 200x of the scanning electron microscope is 50% or more w is 50% or more, and In the compatibility evaluation method according to claim 2, the average domain size D of the separation portion is 120 μm or less at an observation magnification of 65 times in the scanning electron microscope L In the compatibility evaluation method according to claim 2, the average domain size D of the separation portion is 120 μm or less at an observation magnification of 65 times in the scanning electron microscope L is obtained by averaging the domain sizes of the domains having the 2nd to 6th sizes from the domain having the largest domain size among the domains of the separation portion observed in at least 3 fields.

4. A prepreg containing the thermosetting resin composition according to claim 3.

5. A resin film containing the thermosetting resin composition according to claim 3.

6. A laminate containing the prepreg according to claim 4 and a metal foil.

7. A multilayer printed wiring board containing one or more selected from the group consisting of the prepreg according to claim 4, the resin film according to claim 5, and the laminate according to claim 6.

8. A semiconductor package formed using the multilayer printed wiring board according to claim 7.

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