JP2017014302A - Insulating resin composition and article provided with the same - Google Patents

Abstract

An insulating resin composition having high thermal conductivity and excellent adhesiveness is provided. An insulating resin composition according to the present invention includes a phase separation having a first resin phase formed of a first resin and a second resin phase different from the first resin phase and formed of a second resin. A structure is provided. The insulating resin composition further includes an inorganic filler that is dispersed inside the phase separation structure. And a phase-separation structure has a 1st resin or 2nd resin as a main component, and equips the surface with the contact bonding layer whose thickness is 0.1-5 micrometers. [Selection] Figure 1

Description

  The present invention relates to an insulating resin composition and an article provided with the same. Specifically, the present invention relates to a heat conductive component that cools an electronic component or the like, for example, an insulating resin composition used for a radiator and an article provided with the insulating resin composition.

  Semiconductors such as computers (central processing units: CPUs), transistors, and light emitting diodes (LEDs) generate heat during use, and the performance of electronic components may deteriorate due to the heat. Therefore, a heat radiator is usually attached to an electronic component that generates heat.

  Conventionally, metals having high thermal conductivity have been used for such heat radiators. However, in recent years, insulating resin compositions that have a high degree of freedom in shape selection and are easy to be reduced in weight and size are being used (for example, see Patent Document 1). In order to improve thermal conductivity, the insulating resin composition must contain a large amount of thermally conductive inorganic filler in the binder resin. Therefore, when the insulating resin composition is bonded to the base material, the resin component on the surface portion to be bonded to the base material is reduced, and the adhesive strength is reduced. As a result, problems such as peeling of the insulating resin composition occur during thermal shock such as reflow or heat cycle.

  Therefore, conventionally, it has been proposed to improve the adhesion to the substrate by providing an insulating adhesive layer made of a resin different from the resin sheet on one or both sides of the resin sheet having high thermal conductivity ( For example, see Patent Document 2).

JP 2008-13759 A JP 2011-251491 A

  However, when a separate adhesive layer is provided on the resin sheet as in Patent Document 2, it is necessary to increase the thickness of the adhesive layer in order to ensure sufficient adhesion. In this case, since the thermal conductivity of the adhesive layer is lowered, there is a possibility that the heat dissipation of the resin sheet becomes insufficient.

  The present invention has been made in view of such problems of the prior art. And the objective of this invention is providing the articles | goods provided with the insulating resin composition which was excellent in adhesiveness while having high heat conductivity, and the said insulating resin composition.

  The insulating resin composition according to the first aspect of the present invention has a first resin phase formed by the first resin and a second resin phase that is different from the first resin phase and formed by the second resin. A phase separation structure is provided. The insulating resin composition further includes an inorganic filler that is dispersed inside the phase separation structure. And a phase-separation structure equips the surface with the adhesive layer which has 1st resin or 2nd resin as a main component, and thickness is 0.1-5 micrometers.

  The insulating resin composition according to the second aspect of the present invention is the insulating resin composition according to the first aspect, wherein the adhesive layer contains an inorganic filler.

  The insulating resin composition according to the third aspect of the present invention is the insulating resin composition according to the first or second aspect, wherein the inorganic filler is unevenly distributed in the first resin phase, and the adhesive layer is mainly composed of the second resin. And

  The insulating resin composition according to the fourth aspect of the present invention is the insulating resin composition according to any one of the first to third aspects, wherein the first resin phase is a phase in which the first resin is three-dimensionally continuous. Yes, the inorganic filler is unevenly distributed in the first resin phase.

  An article according to a fifth aspect of the present invention includes the insulating resin composition according to any one of the first to fourth aspects.

  The insulating resin composition of the present invention includes an adhesive layer having a first resin or a second resin as a main component and a thickness of 0.1 to 5 μm on the surface of the phase separation structure. For this reason, it is not necessary to attach an adhesive layer after separately preparing it as in the prior art, and the manufacturing process can be simplified while ensuring a high adhesive force. Moreover, since the inorganic filler is dispersed inside the phase separation structure, high thermal conductivity can be obtained.

It is the schematic which shows the insulating resin composition which concerns on embodiment of this invention. It is the schematic for demonstrating a phase-separation structure, (a) shows a sea island structure, (b) shows a continuous spherical structure, (c) shows a composite dispersion structure, (d) shows a co-continuous structure. Show. 2 is a scanning electron micrograph showing a cross section of the insulating resin composition of Example 1. FIG.

  Hereinafter, the insulating resin composition according to the embodiment of the present invention will be described in detail. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio.

  As shown in FIG. 1, the insulating resin composition 10 according to the embodiment of the present invention is different from the first resin phase 2 formed by the first resin and the first resin phase 2, and is formed by the second resin. A phase separation structure 1 having a second resin phase 3. Furthermore, the insulating resin composition 10 includes an inorganic filler 4 dispersed inside the phase separation structure 1.

  Specifically, the insulating resin composition 10 of the present embodiment has a first resin phase 2 and a second resin phase 3, and further has a structure in which these resin phases are mixed and phase-separated. . Furthermore, the inorganic fillers 4 dispersed in the phase separation structure 1 are in continuous contact. For this reason, since the heat conduction path formed by contacting the inorganic fillers 4 is formed inside the phase separation structure 1, the heat conductivity of the insulating resin composition 10 can be improved.

  In the insulating resin composition 10, the phase separation structure 1 includes an adhesive layer 5 mainly composed of the first resin that forms the first resin phase 2 or the second resin that forms the second resin phase 3. Yes. Thus, since the adhesive layer 5 containing the resin constituting the phase separation structure 1 is provided, a high adhesive force can be obtained. That is, the adhesive layer 5 is mainly composed of the first resin or the second resin, and the content of the inorganic filler 4 is relatively small. Therefore, since the inorganic filler 4 at the interface between the insulating resin composition 10 and the base material to which the insulating resin composition 10 is bonded decreases and the first resin or the second resin constituting the adhesive layer 5 increases, the adhesive strength with the base material is increased. It becomes possible to improve.

  Here, unlike the insulating adhesive layer of Patent Document 2, the adhesive layer 5 is not separately attached to the phase-separated structure 1 after being separately manufactured, but the phase separation between the first resin phase 2 and the second resin phase 3 is performed. It is a layer formed on the surface of the phase separation structure 1 together with the structure. That is, the adhesive layer 5 is a layer formed integrally with the first resin phase 2 and the second resin phase 3 on the surface of the phase separation structure 1. Thus, since the adhesive layer 5 is formed together with the phase separation structure of the first resin phase 2 and the second resin phase 3, it is possible to simplify the manufacturing process.

  The mechanism by which the adhesive layer 5 is formed on the surface of the phase separation structure 1 is considered as follows. As will be described later, the insulating resin composition 10 of the present embodiment first adds the first resin constituting the first resin phase 2, the second resin constituting the second resin phase 3, an inorganic filler, and a curing agent. And kneading to prepare an uncured resin composition. And the insulating resin composition 10 can be obtained by making it harden | cure after making an uncured resin composition contact a base material. At this time, among the plurality of resins forming the phase separation structure, a resin having a high affinity with the contacting base material forms the adhesive layer. For example, when an epoxy resin and polyethersulfone are used as the phase separation resin and aluminum is used as the base material, the epoxy resin forms an adhesive layer. That is, since the surface of aluminum has a hydroxyl group and has high affinity with the epoxy resin, the epoxy resin self-assembles to form an adhesive layer when forming the phase separation structure. Thus, by selecting these materials in consideration of the affinity between the resin and the substrate, it is possible to form the adhesive layer 5 made of a desired resin on the surface of the phase separation structure 1. However, even if the adhesive layer 5 of the present invention is formed by another mechanism, the technical scope of the present invention is not affected at all.

  As shown in FIG. 1, the thickness t of the adhesive layer 5 is preferably 0.1 μm to 5 μm. When the thickness t of the adhesive layer 5 is 0.1 μm or more, it is possible to increase the adhesive force with the base material. Moreover, when the thickness t of the adhesive layer 5 is 5 μm or less, a decrease in thermal conductivity due to the presence of the adhesive layer 5 can be suppressed. The thickness t of the adhesive layer 5 is more preferably 0.3 μm to 4 μm. By being in this range, it is possible to achieve both high adhesive strength and thermal conductivity. The thickness t of the adhesive layer 5 can be measured by observing the cross section of the insulating resin composition 10 with a scanning electron microscope.

  As described above, the adhesive layer 5 is mainly composed of the first resin or the second resin. Therefore, the content of the first resin or the second resin in the adhesive layer 5 needs to be 50 mol% or more, preferably 80 mol% or more, more preferably 95 mol% or more, and particularly preferably 99 mol% or more. The adhesive layer 5 may contain not only the resin component but also the inorganic filler 4. Since the thermal conductivity of the adhesive layer 5 is improved by containing the inorganic filler 4, the thermal conductivity of the insulating resin composition 10 as a whole can be further improved. However, when the inorganic filler 4 is contained, the amount of the resin component of the adhesive layer 5 is decreased, and the adhesive strength with the base material is decreased. Therefore, it is preferable that the content of the inorganic filler 4 is small.

  As described above, the insulating resin composition 10 has the first resin phase 2 and the second resin phase 3, and further has a structure in which these resin phases are mixed and phase separated. The inorganic filler 4 is dispersed inside the phase separation structure 1. However, the inorganic filler 4 is preferably unevenly distributed in the first resin phase 2 inside the phase separation structure 1. In this case, since it becomes easy to form a heat conduction path formed by the inorganic fillers 4 in contact with each other inside the first resin phase 2, the heat conductivity of the insulating resin composition 10 can be further improved. . Even when the inorganic filler 4 is unevenly distributed in the first resin phase 2, it is not necessary that all of the inorganic filler 4 is disposed inside the first resin phase 2, and a part thereof is in the second resin phase 3. It does not matter if it exists.

  When the inorganic filler 4 is unevenly distributed in the first resin phase 2 inside the phase separation structure 1, the adhesive layer 5 preferably contains the second resin constituting the second resin phase 3 as a main component. When the inorganic filler 4 is unevenly distributed in the first resin phase 2 and the content in the second resin phase 3 is decreased, the content of the inorganic filler 4 in the adhesive layer 5 is also decreased. Can be improved.

  In the present embodiment, the first resin phase 2 is preferably three-dimensionally continuous inside the phase separation structure 1. Furthermore, it is preferable that the inorganic filler 4 is unevenly distributed in the first resin phase 2 that is three-dimensionally continuous. Thereby, since a three-dimensional heat conduction path can be formed inside the phase separation structure 1, it is possible to improve the heat conductivity of the entire insulating resin composition even when the content of the inorganic filler 4 is small. It becomes.

  Here, the phase separation structure in the present embodiment refers to any of a sea-island structure, a continuous spherical structure, a composite dispersion structure, and a bicontinuous structure. As shown in FIG. 2 (a), the sea-island structure is a structure in which a small volume of dispersed phase 3A is dispersed in continuous phase 2A, and a structure in which fine particles or spherical dispersed phase 3A is scattered in continuous phase 2A. It is. As shown in FIG. 2B, the continuous spherical structure is a structure in which approximately spherical dispersed phases 3A are connected and dispersed in the continuous phase 2A. As shown in FIG. 2C, the composite dispersed structure is a structure in which the dispersed phase 3A is dispersed in the continuous phase 2A, and the resin constituting the continuous phase is further dispersed in the dispersed phase 3A. As shown in FIG. 2D, the co-continuous structure is a structure in which the continuous phase 2A and the dispersed phase 3A form a complicated three-dimensional network.

  And when the phase-separation structure in the phase-separation structure 1 is the said sea-island structure, a continuous spherical structure, and a composite dispersion structure, it is preferable that the continuous phase 2A is the 1st resin phase 2. However, in the case of the co-continuous structure, since both the continuous phase 2A and the dispersed phase 3A are three-dimensionally continuous, one of them may constitute the first resin phase 2. In addition, the phase separation structure such as the sea-island structure, continuous spherical structure, composite dispersion structure, and co-continuous structure is achieved by controlling the curing conditions such as the curing speed and reaction temperature of the resin composition, the compatibility of the resin, and the blending ratio. Can be obtained.

  In the present embodiment, the first resin phase 2 is preferably formed of one of a thermosetting resin and a thermoplastic resin, and the second resin phase 3 is preferably formed of the other of the thermosetting resin and the thermoplastic resin. . That is, when the first resin phase 2 is made of a thermosetting resin, the second resin phase 3 is preferably made of a thermoplastic resin. When the first resin phase 2 is made of a thermoplastic resin, the second resin phase 3 is preferably made of a thermosetting resin. Thereby, it becomes easy to form the phase separation structure. In this case, the adhesive layer 5 is mainly composed of the thermosetting resin or the thermoplastic resin.

  Examples of thermosetting resins include epoxy resins, unsaturated polyester resins, vinyl ester resins, phenol resins, urethane resins, urea resins, melamine resins, maleimide resins, cyanate ester resins, alkyd resins, and addition curable polyimide resins. It is done. One of these thermosetting resins may be used alone, or two or more may be used in combination. Among these, an epoxy resin is preferable because it is excellent in heat resistance, electrical insulation, and mechanical properties.

  When using an epoxy resin as a thermosetting resin, a well-known thing can be used. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin, naphthalenediol type epoxy resin, phenol novolac type epoxy resin can be used. Further, a cresol novolac type epoxy resin, a bisphenol A novolac type epoxy resin, a cyclic aliphatic epoxy resin, a heterocyclic epoxy resin (triglycidyl isocyanurate, diglycidyl hydantoin, etc.) can also be used. Furthermore, modified epoxy resins obtained by modifying these epoxy resins with various materials can also be used. Moreover, halides such as bromides and chlorides of these epoxy resins can also be used. One of these epoxy resins may be used alone, or two or more of them may be used in combination.

  As a curing agent for curing the epoxy resin, any compound can be used as long as it has an active group capable of reacting with an epoxy group. Known epoxy curing agents can be used as appropriate, but compounds having an amino group, an acid anhydride group, or a hydroxyphenyl group are particularly suitable. For example, dicyandiamide and its derivatives, organic acid hydrazine, amine imide, aliphatic amine, aromatic amine, tertiary amine, polyamine salt, microcapsule type curing agent, imidazole type curing agent, acid anhydride, phenol novolac, etc. . A hardening | curing agent may be used individually by 1 type of these, and may be used in combination of 2 or more type.

  Various curing accelerators can be used in combination with the above-described curing agent. For example, when an epoxy resin is used as the thermosetting resin, the tertiary accelerator is a tertiary amine curing accelerator, a urea derivative curing accelerator, an imidazole curing accelerator, or a diazabicycloundecene (DBU) curing. Accelerators can be mentioned. Also, organophosphorus curing accelerators (for example, phosphine curing accelerators), onium salt curing accelerators (for example, phosphonium salt curing accelerators, sulfonium salt curing accelerators, ammonium salt curing accelerators, etc.) Can be mentioned. Furthermore, a metal chelate type | system | group hardening accelerator, an acid, and a metal salt type hardening accelerator etc. can be mentioned.

  The thermoplastic resin generally has at least one bond selected from the group consisting of a carbon-carbon bond, an amide bond, an imide bond, an ester bond, and an ether bond in the main chain. Further, the thermoplastic resin may have at least one bond selected from the group consisting of a carbonate bond, a urethane bond, a urea bond, a thioether bond, a sulfone bond, an imidazole bond, and a carbonyl bond in the main chain.

  Examples of the thermoplastic resin include polyolefin resins, polyamide resins, elastomeric (styrene, olefin, polyvinyl chloride (PVC), urethane, ester, amide) resins, polyester resins, and the like. It is done. Further, engineering plastics, polyethylene, polypropylene, nylon resin, acrylonitrile-butadiene-styrene (ABS) resin, acrylic resin, ethylene acrylate resin, ethylene vinyl acetate resin, and polystyrene resin can be used. Furthermore, polyphenylene sulfide resin, polycarbonate resin, polyester elastomer resin, polyamide elastomer resin, liquid crystal polymer, polybutylene terephthalate resin, and the like are also included. A thermoplastic resin may be used individually by 1 type, and may be used in combination of 2 or more type.

  Among these, from the viewpoint of heat resistance, engineering plastics such as polyethersulfone, polysulfone, polyimide, and polyetherimide are preferable as the thermoplastic resin. Furthermore, it is preferable to polyethersulfone which is excellent in various points such as mechanical properties, insulating properties and solubility in a solvent.

  Furthermore, these thermoplastic resins may have a functional group capable of reacting with an epoxy resin. Examples of such functional groups include amino groups, hydroxyl groups, chlorine atoms, and alkoxy groups.

  In addition, in the insulating resin composition 10, the following are mentioned as a combination of the thermosetting resin and thermoplastic resin which form a phase-separation structure. For example, when an epoxy resin is used as the thermosetting resin, polyethersulfone or polyetherimide can be used as the thermoplastic resin. Further, when an unsaturated polyester resin is used as the thermosetting resin, polystyrene can be used as the thermoplastic resin.

  In the insulating resin composition 10, the inorganic filler 4 preferably has an average particle size of 0.1 μm to 15 μm. When the average particle diameter of the inorganic filler 4 is 0.1 μm to 15 μm, it is easy to disperse inside the phase-separated structure 1, and an insulating resin composition with good workability and moldability can be obtained. That is, when the average particle size is 0.1 μm or more, the viscosity of the resin can be prevented from becoming excessively high, and the fluidity of the resin is ensured, so that workability and moldability are improved. Moreover, since it becomes easy to disperse | distribute the inorganic filler 4 in the inside of the phase-separation structure 1 because an average particle diameter is 15 micrometers or less, a heat conduction path can be formed and high heat conduction is attained. In addition, More preferably, the average particle diameter of the inorganic filler 4 is 3-10 micrometers.

  In the present specification, “average particle diameter” means a median diameter. The median diameter means a particle diameter (d50) at which an integrated (cumulative) weight percentage is 50%. The median diameter can be measured using, for example, a laser diffraction particle size distribution measuring apparatus “SALD2000” (manufactured by Shimadzu Corporation). The average particle diameter of the inorganic filler 4 contained in the insulating resin composition 10 can be measured by baking the insulating resin composition 10 and isolating the inorganic filler 4.

  Moreover, as for the ratio of the inorganic filler 4 in the insulating resin composition 10, it is more preferable that it is 15-70 volume%, and it is especially preferable that it is 30-60 volume%. By being in such a range, it becomes possible to achieve both high thermal conductivity and moldability.

  Here, the insulating resin composition 10 of this embodiment can provide the resin composition which has electrical insulation by using the material which shows electrical insulation. In the insulating resin composition 10, the constituent material of the inorganic filler 4 is preferably an inorganic compound that has both thermal conductivity and electrical insulation.

As the inorganic compound having thermal conductivity, for example, an inorganic compound having a thermal conductivity of 1 W / m · K or more can be used. The thermal conductivity of an inorganic compound having thermal conductivity is preferably 10 W / m · K or more, more preferably 30 W / m · K or more. In addition, as the inorganic compound having electrical insulation, an inorganic compound having a volume resistivity of 10 Ω · cm or more at room temperature (25 ° C.) can be used. The volume resistivity of the inorganic compound having electrical insulation is preferably 10 ⁵ Ω · cm or more, more preferably 10 ⁸ Ω · cm or more, and particularly preferably 10 ¹³ Ω · cm or more.

Examples of inorganic compounds having both heat dissipation and electrical insulation include borides, carbides, nitrides, oxides, silicides, hydroxides, carbonates, and the like. Specific examples include magnesium oxide (MgO), aluminum oxide (Al ₂ O ₃ ), boron nitride (BN), aluminum nitride (AlN), and aluminum hydroxide (Al (OH) ₃ ). Moreover, silicon dioxide (SiO ₂ ), magnesium carbonate (MgCO ₃ ), magnesium hydroxide (Mg (OH) ₂ ), calcium carbonate (CaCO ₃ ), clay, talc, mica, titanium oxide (TiO ₂ ), zinc oxide ( ZnO). From the viewpoint of thermal conductivity and ease of filling, the inorganic filler 4 preferably contains at least one selected from the group consisting of MgO, Al ₂ O ₃ , BN, and AlN.

  In order to improve the compatibility with the resin, the inorganic filler 4 may be improved in dispersibility in the insulating resin composition 10 by performing a surface treatment such as a coupling treatment or adding a dispersant. . Moreover, the inorganic filler 4 can be effectively unevenly distributed in the phase separation structure by appropriately selecting the surface treatment agent.

  For the surface treatment, organic surface treatment agents such as fatty acids, fatty acid esters, higher alcohols, and hardened oils can be used. In addition, an inorganic surface treatment agent such as a silicone oil, a silane coupling agent, an alkoxysilane compound, or a silylated material can also be used for the surface treatment. By using these surface treatment agents, water resistance may be improved, and dispersibility in the resin may be further improved. Although it does not specifically limit as a processing method, There exist (1) dry method, (2) wet method, (3) integral blend method etc.

(1) Dry method The dry method is a method in which a surface treatment agent is dropped onto a surface treatment agent while stirring the inorganic filler by mechanical stirring such as a Henschel mixer, a Nauter mixer, or a vibration mill. . When silane is used as the surface treatment agent, a solution obtained by diluting silane with an alcohol solvent, a solution obtained by diluting silane with an alcohol solvent, further adding water, diluting silane with an alcohol solvent, and further adding water and an acid. Can be used. Although the preparation method of a surface treating agent is described in the catalog of the manufacturer of a silane coupling agent, etc., a preparation method is suitably determined according to the hydrolysis rate of silane and the kind of inorganic filler.

(2) Wet method The wet method is a method in which an inorganic filler is directly immersed in a surface treatment agent. The surface treatment agent that can be used is the same as in the dry method. The method for preparing the surface treatment agent is the same as the dry method.

(3) Integral blend method The integral blend method is a method of diluting a surface treatment agent with a stock solution or alcohol, etc., and directly adding it into a mixer when stirring the resin and filler. The preparation method of the surface treatment agent is the same as that of the dry method and wet method, but the amount of the surface treatment agent in the case of the integral blend method is generally larger than that of the dry method and wet method.

  In the dry method and the wet method, the surface treatment agent is dried as necessary. When a surface treatment agent using alcohol or the like is added, it is necessary to volatilize the alcohol. If alcohol eventually remains in the formulation, the alcohol is generated as a gas that adversely affects the polymer content. Therefore, it is preferable that the drying temperature be equal to or higher than the boiling point of the solvent used. Furthermore, when silane is used as the surface treatment agent, heating is performed at a high temperature (for example, 100 ° C. to 150 ° C.) using an apparatus in order to quickly remove silane that has not reacted with the inorganic filler. Is preferred. However, considering the heat resistance of the silane, it is preferable to keep the temperature below the decomposition point of the silane. The treatment temperature is preferably about 80 to 150 ° C., and the treatment time is preferably 0.5 to 4 hours. By appropriately selecting the drying temperature and time depending on the amount of treatment, it is possible to remove the solvent and unreacted silane.

When silane is used as the surface treatment agent, the amount of silane required to treat the surface of the inorganic filler can be calculated by the following equation.
[Silane amount (g)] = [Amount of inorganic filler (g)] × [Specific surface area of inorganic filler (m ² / g)] / [Minimum coverage area of silane (m ² / g)]

The “minimum coverage area of silane” can be obtained by the following calculation formula.
[Minimum coverage area of silane (m ² /g)]=(6.02×10 ²³ ) × (13 × 10 ⁻²⁰ (m ² )) / [Molecular weight of silane]
In the formula, “6.02 × 10 ²³ ” is an Avogadro constant, and “13 × 10 ⁻²⁰ ” is an area (0.13 nm ² ) covered by one molecule of silane.

  The necessary silane amount is preferably 0.5 times or more and less than 1.0 times the silane amount calculated by this calculation formula. Even if the amount of silane is 1.0 times or more, the effect of the present invention can be exhibited. However, when the amount of silane is 1.0 times or more, an unreacted component remains, which may cause deterioration of physical properties such as deterioration of mechanical properties and water resistance. Therefore, the upper limit is preferably less than 1.0 times. Moreover, the reason why the lower limit value is set to 0.5 times the amount calculated by the above formula is that even this amount is sufficiently effective in improving the filler filling property into the resin.

  The insulating resin composition 10 may have a colorant, a flame retardant, a flame retardant aid, a fiber reinforcement, a viscosity reducing agent for viscosity adjustment in production, a toner (coloring) as long as the effect of the present invention is not impaired. Dispersion modifiers, mold release agents, and the like for improving the dispersibility of the agent) may be included. These may be known ones, and examples thereof include the following.

  As the colorant, for example, an inorganic pigment such as titanium oxide, an organic pigment, or a toner containing them as a main component can be used. These may be used individually by 1 type and may be used in combination of 2 or more types.

  Examples of the flame retardant include organic flame retardants, inorganic flame retardants, and reactive flame retardants. These may be used individually by 1 type and may be used in combination of 2 or more types. In addition, when making the insulating resin composition 10 contain a flame retardant, it is preferable to use a flame retardant aid together. Examples of the flame retardant aid include antimony trioxide, antimony tetroxide, antimony pentoxide, sodium antimonate, antimony compounds such as antimony tartrate, zinc borate, and barium metaborate. Moreover, hydrated alumina, zirconium oxide, ammonium polyphosphate, tin oxide, iron oxide, and the like are also included. These may be used individually by 1 type and may be used in combination of 2 or more types.

  The thermal conductivity of the insulating resin composition 10 of the present embodiment is preferably 3 W / m · K or more. Even if the thermal conductivity is less than 3 W / m · K, the effect of the present invention can be exhibited. However, with such a thermal conductivity, when the insulating resin composition 10 is used as a heat radiator for an electronic component, the electronic component can be efficiently cooled even if the size is reduced.

  Next, the manufacturing method of the insulating resin composition of this embodiment is demonstrated. First, a first resin, a second resin, an inorganic filler, and a curing agent are added and kneaded to produce an uncured resin composition. The kneading of each component may be performed in one step, or each component may be added sequentially or in multiple steps. When adding each component sequentially, it can add in arbitrary orders.

  As a method of kneading and adding each component, for example, first, a part or all of the second resin is kneaded with the first resin to adjust the viscosity. Next, it knead | mixes, adding the remaining 2nd resin, an inorganic filler, and a hardening | curing agent sequentially. The order of addition is not particularly limited, but the curing agent is preferably added last from the viewpoint of the storage stability of the resin composition.

  As described above, additives such as a colorant, a flame retardant, a flame retardant aid, a fiber reinforcement, a viscosity reducer, a dispersion regulator, and a release agent are added to the resin composition as necessary. May be. Also, the order of addition of these additives is not particularly limited and can be added at an arbitrary stage. However, as described above, the curing agent is preferably added last.

  A conventionally well-known thing can be used as a kneading machine apparatus used for manufacture of a resin composition. Specific examples include a roll mill, a planetary mixer, a kneader, an extruder, a Banbury mixer, a mixing vessel provided with a stirring blade, and a horizontal mixing vessel.

  The kneading temperature at the time of producing the resin composition is not particularly limited as long as it can be kneaded, but for example, a range of 10 to 150 ° C is preferable. When it exceeds 150 degreeC, a partial hardening reaction will start and the storage stability of the resin composition obtained may fall. If it is lower than 10 ° C., the viscosity of the resin composition is high, and it may be difficult to knead substantially. Preferably it is 20-120 degreeC, More preferably, it is the range of 30-100 degreeC.

  Next, the resin composition is cured while the uncured resin composition is in contact with the substrate. As the curing method, a method such as heating, light irradiation, or electron beam irradiation can be used depending on the type of the curing agent. And as above-mentioned, since it is thought that resin with high affinity with a base material among several resin which forms a phase-separation structure comprises an adhesive layer, an uncured resin composition is made to contact a base material. The adhesive layer can be formed by performing the curing process in the state. The uncured resin composition can be formed into an arbitrary shape. The molding method can be any method, and for example, various means such as compression molding (direct pressure molding), transfer molding, injection molding, extrusion molding, and screen printing can be used.

  The material of the substrate is not particularly limited, but may be basically anything such as ceramic, metal, glass, plastic, decorative plywood or a composite thereof. The shape of the substrate is not particularly limited. For example, it may be a simple or complex shape such as a plate-like object, a spherical object, a columnar object, a cylindrical object, a rod-like object, a prismatic object, or a hollow prismatic object. Good.

  The insulating resin composition 10 of the present embodiment is a phase having a first resin phase 2 formed of a first resin and a second resin phase 3 different from the first resin phase 2 and formed of a second resin. A separation structure 1 is provided. Furthermore, the insulating resin composition 10 includes an inorganic filler 4 dispersed inside the phase separation structure 1. And the phase-separation structure 1 equips the surface with the adhesive layer 5 which has 1st resin or 2nd resin as a main component, and thickness is 0.1-5 micrometers. Therefore, it is not necessary to attach the adhesive layer after forming it separately as in the prior art, and it is possible to simplify the manufacturing process while ensuring a high adhesive force. Moreover, since the inorganic filler 4 is disperse | distributing the inside of the phase-separation structure 1, the insulating resin composition 10 can ensure high thermal conductivity. Furthermore, since the insulating resin composition 10 is made of a material having electrical insulation as described above, even the entire resin composition can have high electrical insulation.

  Since the insulating resin composition 10 of this embodiment has high thermal conductivity while ensuring electrical insulation as described above, it can be used as a thermal conductive component that cools electronic components and the like. Specifically, it can be used for an article such as a sealing material, which is one of materials constituting a semiconductor package. Moreover, it can also be used for articles such as metal / resin hybrid products such as light emitting diode lighting (LED lighting), electronic substrates, IC chips, motor sealing materials, and power devices that require heat dissipation.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited to these Examples.

[Example 1]
First, 22.3 parts by mass of polyethersulfone (PES) pulverized so as to have an average particle diameter of 5 μm was added to 100 parts by mass of bisphenol A type epoxy resin. Furthermore, this mixture was stirred in an oil bath heated to 120 ° C. to completely dissolve the polyethersulfone in the epoxy resin, thereby obtaining an epoxy resin solution.

  Next, 125 parts by mass of an alumina filler was kneaded with the above-described epoxy resin solution heated to 80 ° C. using a rotation / revolution mixer. Further, 26 parts by mass of 4,4'-methylenedianiline was kneaded into the kneaded epoxy resin solution. Then, the obtained kneaded material was put into a vacuum dryer set at 120 ° C., and degassed under reduced pressure for 5 minutes to obtain a resin composition.

  Then, a copper foil having a thickness of 18 μm was put into a mold set at 150 ° C., a resin composition was further introduced, and heat pressing was performed for 120 minutes under the condition of a pressure of 3 MPa. Thereby, the test piece of the present Example whose thickness is 1 mm was obtained. In addition, Mitsubishi Chemical Corporation "jER (trademark) 828" was used for the epoxy resin. As the polyethersulfone, “Sumika Excel (registered trademark) 5003P” manufactured by Sumitomo Chemical Co., Ltd. was used. For 4,4'-methylenedianiline, a reagent manufactured by Wako Pure Chemical Industries, Ltd. was used. As the alumina filler, “AO-502” manufactured by Admatechs Co., Ltd. having an average particle diameter of 0.7 μm was used.

[Example 2]
A test piece of this example was obtained in the same manner as in Example 1 except that the blending amount of the alumina filler was changed as shown in Table 1.

[Comparative Example 1]
First, 5 parts by mass of dicyandiamide and 90 parts by mass of alumina filler were kneaded with 100 parts by mass of bisphenol A type epoxy resin. Further, 12 parts by mass of methyl ethyl ketone was added as a solvent and kneaded with a planetary mixer. The obtained slurry was applied to an organic film, dried by heating at 120 to 140 ° C. for 5 to 10 minutes, the solvent was removed, and the resin component was semi-cured (B-stage) to prepare a B-stage resin sheet. .

  And the said resin sheet and copper foil with a thickness of 18 micrometers were overlap | superposed, and it heat-press-molded for 90 minutes on the conditions of temperature 170 degreeC and pressure 3MPa, and obtained the test piece of this comparative example of thickness 1mm. The epoxy resin used was “EPICLON (registered trademark) 840S” manufactured by DIC Corporation. As the alumina filler, “AO-502” manufactured by Admatechs Co., Ltd. having an average particle diameter of 0.7 μm was used. As the organic film, “Lumirror (registered trademark) S10” manufactured by Toray Industries, Inc. was used.

[Comparative Example 2]
100 parts by mass of a bisphenol A type epoxy resin was kneaded with 5 parts by mass of dicyandiamide, 1000 parts by mass of a first alumina filler having an average particle diameter of 20 μm, and 430 parts by mass of a second alumina filler having an average particle diameter of 5 μm. . Further, 230 parts by mass of methyl ethyl ketone was added as a solvent and kneaded with a planetary mixer.

  And the B-stage-shaped resin sheet was produced similarly to the comparative example 1 using the obtained slurry. Furthermore, the test piece of this comparative example was obtained by heat-press-molding a resin sheet and copper foil similarly to the comparative example 1. FIG. In addition, Showa Denko Co., Ltd. "CB-A20S" was used for the 1st alumina filler. As the second alumina filler, “CB-A05S” manufactured by Showa Denko KK was used. Table 1 shows the amounts of the thermosetting resin, thermoplastic resin, curing agent, and inorganic filler in each example.

[Evaluation]
The thickness of the adhesive layer, the volume ratio of the inorganic filler, the thermal conductivity, and the copper foil adhesive strength in each test piece of Examples and Comparative Examples were measured and evaluated by the following methods. The measurement / evaluation results are shown in Table 1. Furthermore, the cross section of the test piece of Example 1 was observed by the following method.

(Adhesive layer thickness)
The cross section of the test piece of each example was observed with a scanning electron microscope (SEM), and the thickness of the resin adhesive layer in which almost no filler was present was measured. That is, since the filler is observed in white in the reflected electron image, the resin adhesive layer and the layer containing the filler can be distinguished.

(Volume ratio of inorganic filler)
First, the volume of the test piece of each example was calculated by an underwater substitution method. Next, each test piece was baked at 625 degreeC using the muffle furnace, and the ash weight was measured. And since ash was an inorganic filler, the volume ratio of the filler in a test piece was measured from the density of the inorganic filler, the said ash content weight, and the volume of the test piece. In addition, the density of the alumina which is an inorganic filler was 3.9 g / cm ³ .

(Thermal conductivity)
The thermal diffusivity was measured by the xenon flash method (z-axis direction), and the thermal conductivity was calculated from the following formula. In addition, specific heat calculated the specific heat of each substance comprised from the composite law, and the density was measured by the underwater substitution method.
Thermal conductivity (W / m · K) = thermal diffusivity (m ² / s) × specific heat (J / kg · K) × density (kg / m ³ )

(Copper foil adhesion)
The adhesive force between the copper foil and the resin composition was evaluated according to JIS C6481 (Test method for copper-clad laminate for printed wiring board). Those having a copper foil adhesive strength of 1.5 kN / m or more by a peel test were evaluated as “◯”, and those less than 1.5 kN / m were evaluated as “x”.

(Cross section observation)
First, the test piece of Example 1 was immersed in a mixed solution of 95% by mass of methylene chloride and 5% by mass of methanol at room temperature for 48 hours to dissolve the polyethersulfone. Then, after wash | cleaning and drying the test piece, the cross section was observed with the scanning electron microscope (SEM). In FIG. 3, the result of having observed the cross section of the said test piece is shown. In FIG. 3, reference numeral 2B is a resin phase in which polyethersulfone was present. And what is contained in the phase of the code | symbol 2B is the ball | bowl of the epoxy resin which was contained in the inorganic filler 4 and the polyether sulfone phase, and did not melt | dissolve. As described above, since the inorganic filler 4 is observed in white in the reflected electron image, the inorganic filler 4 and the epoxy resin sphere can be distinguished.

  As shown in Table 1, Examples 1 and 2 resulted in achieving both high thermal conductivity and adhesive strength as compared with Comparative Examples 1 and 2, respectively. Specifically, Example 1 and Comparative Example 1 contained the same volume of inorganic filler, and because the amount of resin was large, both had good adhesion. Moreover, as shown in FIG. 3, since the resin composition of Example 1 had a heat conduction path, the heat conductivity was good. However, since Comparative Example 1 did not contain a thermoplastic resin and the heat conduction path was not sufficiently formed, the thermal conductivity was lower than that of Example 1.

  Furthermore, the comparative example 2 increases the amount of fillers so that it may become the thermal conductivity equivalent to Example 2. FIG. However, since Comparative Example 2 had a large filler content, the amount of resin was insufficient, and the adhesive strength was lower than that of Example 2.

  As a result of observing the cross section of the test piece of each example with a scanning electron microscope, a clear adhesive layer having almost no filler was observed on the surface of the test piece of Example 1. Further, even in the test piece of Example 2, a clear adhesive layer with almost no filler was observed. On the other hand, in the test pieces of Comparative Examples 1 and 2, a clear adhesive layer was not observed. As shown in FIG. 3, the test piece of Example 1 has a co-continuous phase separation structure, and it can be confirmed that the inorganic filler is unevenly distributed on one side of the resin layer.

  Although the present invention has been described with reference to the examples and comparative examples, the present invention is not limited to these, and various modifications can be made within the scope of the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Phase separation structure 2 1st resin phase 3 2nd resin phase 4 Inorganic filler 5 Adhesive layer 10 Insulating resin composition

Claims (5)

A phase separation structure having a first resin phase formed of a first resin and a second resin phase different from the first resin phase and formed of a second resin;
An inorganic filler dispersed inside the phase separation structure;
With
The said phase-separation structure has the said 1st resin or 2nd resin as a main component, and equips the surface with the contact bonding layer whose thickness is 0.1-5 micrometers, The insulating resin composition characterized by the above-mentioned.   The insulating resin composition according to claim 1, wherein the adhesive layer includes the inorganic filler.   The insulating resin composition according to claim 1 or 2, wherein the inorganic filler is unevenly distributed in the first resin phase, and the adhesive layer contains the second resin as a main component.   The first resin phase is a phase in which the first resin is three-dimensionally continuous, and the inorganic filler is unevenly distributed in the first resin phase. Insulating resin composition.   An article comprising the insulating resin composition according to any one of claims 1 to 4.