JP5920353B2 - Boron nitride particles, epoxy resin composition, semi-cured resin composition, cured resin composition, resin sheet, exothermic electronic component, and method for producing boron nitride particles - Google Patents

Description

The present invention, boron particles nitride, epoxy resin compositions, semi-cured resin composition, the cured resin composition, a resin sheet, a method of manufacturing a heat-generating electronic component and inorganic nitride particles.

  In recent years, with the increase in energy density due to downsizing of electronic devices, the amount of heat generated per unit volume tends to increase, and insulating materials constituting the electronic devices are required to have high heat dissipation. In addition, epoxy resins are widely used as insulating materials because of their high withstand voltage and ease of molding. In general, a method of adding an insulating filler having high thermal conductivity is used to increase the thermal conductivity of an epoxy resin. Examples of the insulating filler having high thermal conductivity include inorganic nitride particles such as boron nitride particles and aluminum nitride particles. However, inorganic nitrides have poor wettability to epoxy resins. Therefore, there is a possibility that voids are generated inside the insulating material without being uniformly dispersed in the epoxy resin, and the thermal conductivity is lowered.

In order to uniformly disperse the inorganic nitride particles in the epoxy resin, a method of treating the surface of the inorganic nitride particles with an aliphatic hydrocarbon is known (see, for example, Japanese Patent Application Laid-Open No. 2004-115369). However, the method of surface-treating inorganic nitride particles with aliphatic hydrocarbons can be applied only to specific inorganic nitride particles having high surface chemical reactivity. In addition, if inorganic nitride particles are coated with aliphatic hydrocarbons, the heat conductivity of the coating layer may be low, and heat dissipation may be reduced.
As another method for uniformly dispersing inorganic nitride particles in an epoxy resin, a method using a dispersant together with inorganic nitride particles is known (see, for example, JP-A-2008-266406). However, since the thermal conductivity of the dispersant is low, the heat dissipation may be reduced.

  An object of the present invention is to add inorganic nitride particles having excellent dispersibility when added to an epoxy resin, a method for producing inorganic nitride particles, an epoxy resin composition using the inorganic nitride particles, a semi-cured resin composition, The object is to provide a cured resin composition, a resin sheet, and an exothermic electronic component.

The present invention is as follows.
<1> Inorganic nitride particles having a surface energy polarity term of 1 mN / m or more.

<2> Inorganic nitride particles having a contact angle with respect to 25 ° C. water of 90 ° or less and a contact angle with respect to 25 ° C. of n-hexadecane of 20 ° or less when measured at 25 ° C. and a humidity of 50%.

<3> In the above <1>, when measured at 25 ° C. and humidity 50%, the contact angle with respect to 25 ° C. water is 90 ° or less and the contact angle with respect to 25 ° C. n-hexadecane is 20 ° or less. The inorganic nitride particles described.

<4> The inorganic nitride particles according to any one of <1> to <3>, which are boron nitride particles.

<5> The inorganic nitride particles according to <4>, wherein an oxygen atom concentration on the surface of the boron nitride particles is 1.5 at% or more.

<6> The inorganic nitride particles according to any one of <1> to <3>, which are aluminum nitride particles.

<7> The inorganic nitride particles according to any one of <1> to <6>, wherein the volume average particle diameter is 0.01 μm to 1 mm.

<8> The inorganic nitride particles according to any one of <1> to <7>, which are formed by irradiating light containing ultraviolet rays having a wavelength of 150 nm to 400 nm at 100 mJ / cm ² or more.

<9> The inorganic nitride particles according to <8>, further heat-treated at 60 ° C. to 400 ° C. for 1 minute or more.

<10> An epoxy resin composition containing the inorganic nitride particles according to any one of <1> to <9>, an epoxy resin, and a curing agent.

<11> A semi-cured resin composition that is a semi-cured product of the epoxy resin composition according to <10>.

<12> A cured resin composition that is a cured product of the epoxy resin composition according to <10>.

<13> A resin sheet which is a sheet-like molded body of the epoxy resin composition according to <10>.

<14> An exothermic electronic component having the cured resin composition according to <12>.

<15> a step of preparing inorganic nitride particles having a surface energy polarity term of less than 1 mN / m;
Irradiating the inorganic nitride particles with light containing ultraviolet rays having a wavelength of 150 nm to 400 nm at 100 mJ / cm ² or more;
The manufacturing method of the inorganic nitride particle | grains as described in said <1> which has these.

<16> Furthermore, the manufacturing method of the inorganic nitride particle | grains as described in said <15> which has the process heat-processed for 1 minute or more at 60 to 400 degreeC.

<17> Boron nitride particles having a surface oxygen atom concentration of 1.5 at% or more.

  According to the present invention, when added to an epoxy resin, inorganic nitride particles having excellent dispersibility, a method for producing inorganic nitride particles, an epoxy resin composition using the inorganic nitride particles, a semi-cured resin composition, A cured resin composition, a resin sheet, and an exothermic electronic component can be provided.

It is a figure explaining the contact angle which concerns on this invention.

In this specification, the term “process” is not limited to an independent process, and is included in the term if the intended purpose of the process is achieved even when it cannot be clearly distinguished from other processes. .
In the present specification, numerical ranges indicated using “to” indicate ranges including the numerical values described before and after “to” as the minimum value and the maximum value, respectively.
Further, in this specification, the amount of each component in the composition is the sum of the plurality of substances present in the composition unless there is a specific indication when there are a plurality of substances corresponding to each component in the composition. Means quantity.

<Inorganic nitride particles>
The inorganic nitride particles of the present invention have a surface energy polarity term of 1 mN / m or more. The inorganic nitride particles of the present invention have a contact angle with respect to water at 25 ° C. of 90 ° or less and a contact angle with respect to n-hexadecane at 25 ° C. of 20 ° when measured at 25 ° C. and 50% humidity. It is as follows.
When the inorganic nitride particles of the present invention are added to the epoxy resin, the dispersibility is improved without lowering the thermal conductivity compared to the case of adding a low thermal conductivity dispersant together with the inorganic nitride particles to the epoxy resin. can do.

  In general, since the surface energy of inorganic nitride particles is small, the inorganic nitride particles tend not to have excellent dispersibility with respect to the epoxy resin. Therefore, the present inventors tried to increase the surface energy in order to improve the dispersibility of the inorganic nitride particles in the epoxy resin. In the process of earnest examination, when the polarity term of the surface energy of the inorganic nitride particles is increased, specifically, when the polarity term of the surface energy is 1 mN / m or more, the dispersibility of the inorganic nitride particles in the epoxy resin is improved. I derived that. This can be considered as follows.

  Inorganic nitride particles originally have a high affinity for nonpolar liquids and are hydrophobic, but have a low affinity for polar liquids and poor hydrophilicity. Here, since the epoxy group of the epoxy resin is a hydrophilic group, it is considered that the inorganic nitride particles need to be appropriately made hydrophilic in order to improve dispersibility. On the other hand, since the skeleton of the epoxy resin is hydrophobic, it is considered that the inorganic nitride particles need to balance hydrophilicity and hydrophobicity. From the viewpoint of balancing such hydrophilicity and hydrophobicity, it is presumed that it is effective to set the polar term of the surface energy to 1 mN / m or more.

  Further, from the viewpoint of dispersibility with respect to the polar group of the epoxy resin, the polar term of the surface energy of the inorganic nitride particles is preferably 10 mN / m or more. From the viewpoint of further improving dispersibility in the epoxy resin, the polarity term of the surface energy of the inorganic nitride particles is preferably 1 mN / m to 50 mN / m, and preferably 10 mN / m to 50 mN / m. More preferred.

The method for obtaining the polarity term of the surface energy of the inorganic nitride particles is as follows.
In the present invention, the surface energy (γ _s ) of the inorganic nitride particles is represented by the sum of the surface energy dispersion term (γ ^d _s ) and the surface energy polarity term (γ ^p _s ) as shown in the following formula 1. The

(Formula 1)

As for the polar term (γ ^p _s ) of the surface energy of the inorganic nitride, both the dispersion term (γ ^d _L ) and the polar term (γ ^p _L ) of the surface energy (γ _L ) of the liquid are known 2 It can obtain | require by the following formula 2 and the following formula 3 with the contact angle of the liquid and inorganic nitride more than a kind.

(Formula 2)

(Formula 3)
Here, θ is a contact angle between the inorganic nitride and the liquid.

The polar term of the surface energy in the present invention is calculated as follows when, for example, water and n-hexadecane are used as the liquid having a known surface energy. When the dispersion term (γ ^d _L ) of the surface energy of water is 29.3 mN / m and the polar term (γ ^P _L ) of the surface energy is 43.5 mN / m,

(Formula 4)

It becomes. Here, cos θ (water) is a contact angle between water and inorganic nitride. Further, when the dispersion term (γ ^d _L ) of n-hexadecane is 27.6 mN / m, the polarity term of surface energy (γ ^P _L ) is 0 mN / m, and is substituted into the equation 3,

(Formula 5)

It becomes. Therefore, by measuring the contact angle between n-hexadecane and inorganic nitride and substituting it into Equation 5, the dispersion term of surface energy (γ ^d _s ) is obtained, and the contact angle between water and inorganic nitride is further measured, By substituting into Equation 4, the surface energy polarity term (γ ^p _s ) is obtained.

As the two or more kinds of liquids used for determining the polar term of the surface energy of the inorganic nitride particles, both the dispersion term (γ ^d _L ) and the polar term (γ ^p _L ) are known. Any of them may be used, but it is preferable to use at least two kinds of polar liquid and nonpolar liquid from the viewpoint of reducing measurement errors.

  Examples of the polar liquid include water, diiodomethane, tetrabromoethane, tetrachloroethane, glycerin, formamide, thiodiglycol, and the like, and it is more preferable to use water from the viewpoint of the high value of the polar term of the surface energy. Examples of the nonpolar liquid include n-hexadecane, n-tetradecane, n-dodecane, n-undecane, n-decane, n-nonane, and n-octane, which have a high surface energy dispersion term value. From this viewpoint, it is more preferable to use n-hexadecane.

  Improve the wettability of the inorganic nitride particles with respect to polar and nonpolar liquids (amphiphilicity), increase the surface energy polarity term to 1 mN / m or more, and increase the dispersibility of the inorganic nitride particles in the epoxy resin. From the viewpoint, the inorganic nitride particles have a contact angle with water at 25 ° C. of 90 ° or less and a contact angle with n-hexadecane at 25 ° C. of 90 ° when measured at 25 ° C. and 50% humidity. It is preferable that the angle is not more than °. Furthermore, from the viewpoint of enhancing dispersibility in the epoxy resin, the inorganic nitride particles have a contact angle with water at 25 ° C. of 90 ° or less when measured at 25 ° C. and a humidity of 50%, and 25 The contact angle with n-hexadecane at 25 ° C. is more preferably 20 ° or less, the contact angle with water at 25 ° C. is 70 ° or less, and the contact angle with n-hexadecane at 25 ° C. is 20 More preferably, it is not more than 0 °. Further, from the viewpoint of enhancing dispersibility in the epoxy resin, the inorganic nitride particles have a contact angle with water at 25 ° C. of 45 ° or less when measured at 25 ° C. and a humidity of 50%, and 25 It is particularly preferable that the contact angle of n-hexadecane at 10 ° C. is 10 ° or less.

The contact angle referred to here is, as shown in FIG. 1, formed by the tangent of the droplet at the end point of the interface between the droplet 10 and the green compact 12 of the inorganic nitride particles and the surface of the green compact 12. The angle θ. The green compact 12 is filled with inorganic nitride particles in a 20 mmφ mold, and this is pressed at a pressure of 600 kgf / cm ² (5880 N / cm ² ) by a pressed product having an average surface roughness (Ra) of 0.1 μm and 19 mmφ. Get by pressing. Specifically, the contact angle can be measured by a method described in Examples described later.
Further, in the absence of the above-described apparatus, a metal mold having a diameter of 10 mmφ or more is filled with inorganic nitride particles, and this is pressed with an average surface roughness (Ra) of 0.5 μm or less and smaller than the mold diameter. Can be obtained by pressing at a pressure of 500 kgf / cm ² or more.

  Examples of the inorganic nitride particles that can be used in the present invention include boron nitride, aluminum nitride, silicon nitride, titanium nitride, zirconium nitride, tantalum nitride, and niobium nitride. These may be used individually by 1 type, or may use 2 or more types together. From the viewpoint of heat conduction, as an application to the filler contained in the heat dissipation material, at least one selected from boron nitride, aluminum nitride and silicon nitride is preferably used, and at least one selected from boron nitride and aluminum nitride is more preferable. preferable.

  The inorganic nitride may be formed by any manufacturing method such as a direct nitridation method, a reduction nitridation method, or a gas phase reaction method.

  The inorganic nitride particles include inorganic nitride single crystal particles, inorganic nitride single crystal aggregate particles, particles obtained by sintering a large number of inorganic nitride crystals, particles obtained by sintering a large number of inorganic nitride crystals. Any of these aggregated particles may be used.

  The shape of the inorganic nitride particles may be any of a spherical shape, a flat shape, a plate shape, a scale shape, and the like. From the viewpoint of high particle packing, spherical or flat particles are preferably used.

  The volume average particle diameter of the inorganic nitride particles of the present invention is preferably 0.01 μm to 1 mm from the viewpoint of use as a filler of the heat dissipation material, and 0.1 μm to 100 μm for high particle filling. More preferably.

  The oxygen atom concentration on the surface of the boron nitride particles according to the present invention is preferably 1.5 at% or more. By setting the oxygen atom concentration on the surface of the boron nitride particles within the above range, the surface can be made amphiphilic. From the viewpoint of enhancing hydrophilicity, it is more preferably 2.0 at% or more. More preferably, it is 2.0 at% to 10 at%, more preferably 2 at% to 5 at% from the viewpoint of amphiphilicity.

The oxygen atom concentration is defined by the method described in the examples described later.
The surface in the present invention is a region having a depth of 5 nm or less from the pole surface. In particular, in the present invention, the surface is a range within the depth limit detected under the aforementioned XPS measurement conditions.

<Method for producing inorganic nitride particles>
The inorganic nitride particles of the present invention have a contact angle with respect to water at 25 ° C. of 90 ° or less when the polarity term of the surface energy is 1 mN / m or more, or when measured at 25 ° C. and a humidity of 50%. And if the contact angle with respect to n-hexadecane of 25 degreeC is 20 degrees or less, the manufacturing method will not be restrict | limited in particular. The inorganic nitride particles of the present invention are amphiphilic inorganic nitride particles having affinity for both polar and nonpolar liquids. In the case of amphiphilic inorganic nitride particles, both hydrophobic and hydrophilic sites are distributed on the surface. Therefore, the surface of the inorganic nitride particles that are hydrophobic is partially made hydrophilic so that the surface of the particles Desirably amphiphilic.

Generally, the polar term of the surface energy of inorganic nitride particles is less than 1 mN / m. Therefore, as a method of improving the polarity term of the surface energy of the inorganic nitride particles, for example, a method of irradiating the inorganic nitride particles with ultraviolet rays, a method of ozone treatment, a method of O ₂ plasma treatment, a method of atmospheric pressure plasma treatment And a chromic acid treatment method. In particular, the hydrophilic portion can be efficiently formed on the surface of the inorganic nitride by the method of irradiating with ultraviolet rays, and the affinity for polar liquid can be improved. Furthermore, by partially forming a hydrophilic portion, both affinity for polar liquid and affinity for nonpolar liquid can be achieved. By these methods, when measured at 25 ° C. and 50% humidity, the contact angle with respect to water at 25 ° C. can be 90 ° or less, and the contact angle with respect to n-hexadecane at 25 ° C. can be made 20 ° or less. .

  As described above, by irradiating the inorganic nitride particles with ultraviolet rays, a part of the hydrophobic surface becomes hydrophilic, and the polarity term of the surface energy can be effectively set to 1 mN / m or more. The reason for this is not clear, but is considered as follows.

  When the inorganic nitride particles are irradiated with ultraviolet rays, hydroxyl groups are generated on the surface of the inorganic nitride, the surface of the inorganic nitride is polarized, and the affinity with the polar liquid molecules increases, so the polarity term of the surface energy Is considered to be 1 mN / m or more.

Note that inorganic oxides such as SiO ₂ and Al ₂ O ₃ are not amphiphilic even when irradiated with ultraviolet rays, whereas inorganic nitrides are amphiphilized when irradiated with ultraviolet rays. This is because when the inorganic metal oxide is irradiated with ultraviolet rays, the amount of hydroxyl groups on the surface of the inorganic metal oxide increases and the surface becomes hydrophilic and the contact angle with the polar liquid becomes very small. The contact angle is considered to be increased. Thus, it is considered that the effect of amphiphilization by ultraviolet irradiation cannot be obtained with inorganic metal oxides. On the other hand, when the inorganic nitride is irradiated with ultraviolet rays, it is considered that a part of the surface of the inorganic nitride particles becomes hydrophilic and the remaining part maintains hydrophobicity, and thus is amphiphilic.

  Examples of the method of irradiating the inorganic nitride particles with ultraviolet rays include the following methods. When irradiating the inorganic nitride particles with ultraviolet rays, an ultraviolet irradiation treatment technique and an ultraviolet irradiation apparatus that are used in manufacturing techniques for various chemical products can be used. Examples of the ultraviolet irradiation device include a high pressure mercury lamp, a low pressure mercury lamp, a deuterium lamp, a metal halide lamp, a xenon lamp, and a halogen lamp.

  As the ultraviolet irradiation treatment conditions, it is preferable to include light including an ultraviolet region having a wavelength of 150 nm to 400 nm, and other wavelengths may be included. From the viewpoint of decomposition of organic impurities on the surface of the inorganic nitride particles, it is more preferable to include light having a wavelength of 150 nm to 400 nm. From the viewpoint of activation of the surface of the inorganic nitride particles, light having a wavelength of 150 nm to 300 nm is preferably included. It is particularly preferable that it is included.

As the ultraviolet irradiation condition, the irradiation intensity is preferably 0.5 mW / cm ² or more. If it is this irradiation intensity, the target effect will fully be exhibited. Moreover, it is preferable that it is 100 mW / cm < ² > or less. With this irradiation intensity, damage to the inorganic nitride particles due to ultraviolet irradiation can be suppressed. A preferred range of the irradiation intensity was ^{0.5mW / cm 2 ~100mW / cm 2} , more preferably ^{a 1mW / cm 2 ~20mW / cm 2} .

  The irradiation time is preferably 10 seconds or longer in order to sufficiently exhibit the intended effect. Moreover, it is preferable to set it as 30 minutes or less from a viewpoint of suppressing the damage of the inorganic nitride particle | grains by ultraviolet irradiation. A suitable range of irradiation time is 10 seconds to 30 minutes.

The amount of irradiation ultraviolet rays is defined by irradiation intensity (mW / cm ² ) × irradiation time (seconds). If the amount is too small, the intended effect cannot be sufficiently exhibited. Therefore, the amount is preferably 100 mJ / cm ² or more. , more preferably a polar liquid, and from the viewpoint of improved affinity for nonpolar liquids 1000 mJ / cm ² or more, still more preferably 5000 mJ / cm ² or more, still be at 10000 mJ / cm ² or more preferable. Moreover, it is preferable that it is 50000 mJ / cm < ² > or less from a viewpoint of suppressing the damage of the inorganic nitride particle | grains by ultraviolet irradiation. A preferred range of the irradiation amount of ultraviolet rays is less than ^{100mJ / cm 2 ~50000mJ / cm 2} , more preferably not more than ^{1000mJ / cm 2 ~50000mJ / cm 2} , more preferably 5000mJ ^/ cm 2 ~50000mJ ^/ cm ² or less, even more preferably less ^{10000mJ / cm 2 ~50000mJ / cm 2} .
In addition, ultraviolet irradiation intensity | strength is prescribed | regulated by the method described in the Example mentioned later.

The ultraviolet irradiation treatment is preferably performed as follows, for example. The inorganic nitride particles are irradiated with light containing ultraviolet rays having a wavelength of 150 nm to 400 nm at 100 mJ / cm ² or more. Thereby, the inorganic nitride particle | grains whose polarity term of surface energy is 1 mN / m or more can be obtained.

  When irradiating the inorganic nitride particles with ultraviolet rays, it is preferable to uniformly irradiate the entire inorganic nitride particles with ultraviolet rays. Examples of the uniform irradiation method include a method of uniformly irradiating ultraviolet rays while stirring the inorganic nitride particles. For the stirring of the inorganic nitride particles during the ultraviolet irradiation, for example, a stirring device such as a method of stirring with a stirring rod, a spatula, a spoon, etc., or a method of vibrating the container containing the inorganic nitride particles is used. Any of the above-described methods and a method using a stirring device such as a vibration mixer, a ribbon mixer, and a paddle mixer can be applied at the time of ultraviolet irradiation. From the viewpoint of uniform mixing, it is preferable to use a stirrer, and specifically, a stirrer such as a paddle type mixer is suitable.

  Moreover, it is preferable to heat-process inorganic nitride particle | grains at 60 to 400 degreeC from a viewpoint of the ultraviolet irradiation effect to inorganic nitride, and 100 to 400 degreeC is more preferable from a viewpoint of removing a water | moisture content. Furthermore, 200 to 400 degreeC is especially preferable from a viewpoint of the removal of the organic deposit | attachment on the surface of an inorganic nitride particle. By removing extraneous deposits such as moisture and organic deposits on the surface of the inorganic nitride particles as described above, it is possible to expect an improvement in the effect on the inorganic nitride particles by ultraviolet irradiation.

  The heat treatment time is preferably 1 minute or more from the viewpoint of improving the effect of ultraviolet irradiation on the inorganic nitride, more preferably 5 minutes or more and 120 minutes or less from the viewpoint of moisture removal, and removal of organic deposits. From the viewpoint of the above, it is particularly preferably from 10 minutes to 120 minutes.

  The heat treatment of the inorganic nitride particles can be performed by a general method. For the heat treatment, a general heating apparatus that is used in the manufacturing technology of various chemical products such as a hot plate, a constant temperature bath, an electric furnace, and a baking furnace can be used.

The heat treatment may be performed simultaneously with the ultraviolet irradiation or sequentially. When performing sequentially, it is preferable to irradiate ultraviolet rays after the heat treatment from the viewpoint of improving the polarity term of the surface energy of the inorganic nitride particles. For example, it is preferably performed as follows. The inorganic nitride particles are heat-treated at 60 ° C. to 400 ° C. for 1 minute or longer, and then the inorganic nitride particles are irradiated with light containing ultraviolet rays having a wavelength of 150 nm to 400 nm for 100 mJ / cm ² or more. Thereby, inorganic nitride particles having a sufficiently high surface energy polarity term can be obtained.

  In the ultraviolet irradiation process, the temperature inside the processing apparatus may increase. For example, when processing is started at room temperature, the maximum temperature may be close to 60 ° C. However, even if the mixture of inorganic nitride particles is simply heated to 60 ° C., the effect of improving wettability does not appear. Therefore, it is considered that the effect of ultraviolet irradiation is not due to temperature rise.

  Since the inorganic nitride particles having a surface energy polarity term of 1 mN / m according to the present invention have improved wettability of the hydrophilic liquid while maintaining the wettability of the hydrophobic liquid, the affinity with the epoxy resin is improved. As a result, the dispersibility in the epoxy resin is excellent.

  Further, by using the inorganic nitride particles having a surface energy polarity term of 1 mN / m according to the present invention, the affinity with the epoxy resin is improved, and the resin composition when the inorganic nitride particles are contained in the resin. The viscosity of the product can be lowered.

  Further, the inorganic nitride particles having a surface energy polarity term of 1 mN / m according to the present invention are suitable for heat dissipation materials of heat-generating electronic components (for example, IC chips and printed wiring boards) of various electric and electronic devices. Can be used.

<Epoxy resin composition>
The epoxy resin composition of the present invention contains the inorganic nitride particles, the epoxy resin, and a curing agent.

  As the epoxy resin (hereinafter also referred to as “epoxy resin monomer”), a commonly used general epoxy resin can be used without particular limitation. Specific examples of general epoxy resins include glycidyl ethers such as bisphenol A type, F type, S type, and AD type, hydrogenated bisphenol A type glycidyl ether, phenol novolac type glycidyl ether, and cresol novolac type. Examples thereof include glycidyl ether, bisphenol A type novolak type glycidyl ether, naphthalene type glycidyl ether, biphenol type glycidyl ether, and dihydroxypentadiene type glycidyl ether.

  The epoxy resin monomer in the present invention preferably contains a bifunctional or higher functional epoxy group in one molecule as a molecular skeleton, and has a high thermal conductivity in addition to heat resistance and adhesiveness when a resin cured product is formed. It is preferable that it has. Among these, an epoxy resin monomer having a mesogenic skeleton is preferable from the viewpoint of a resin having high thermal conductivity.

The mesogen skeleton here is not particularly limited as long as it can form a higher order structure derived from the mesogen skeleton in the cured resin when the epoxy resin monomer forms a cured resin together with a curing agent. Absent.
The higher order structure here means a state in which molecules are aligned after the resin composition is cured. For example, a crystal structure or a liquid crystal structure exists in the cured resin. The presence of such a crystal structure or liquid crystal structure can be directly confirmed by, for example, observation with a polarizing microscope under crossed Nicols or X-ray scattering. In addition, the presence of the elastic modulus of storage can be confirmed indirectly by a small change in temperature.

  Specific examples of the mesogenic skeleton include a biphenyl group, a terphenyl group, a terphenyl analog, an anthracene group, and a group in which these are connected by an azomethine group or an ester group.

  In the present invention, a high thermal conductivity can be achieved by using an epoxy resin monomer having a mesogenic skeleton as an epoxy resin monomer and forming a cured resin together with a curing agent. For example, this can be considered as follows. That is, an epoxy resin monomer having a mesogen skeleton in the molecule forms a cured resin together with a curing agent, so that a highly ordered higher order structure derived from a mesogenic group can be formed in the cured resin. For this reason, it is thought that scattering of the phonon which is a heat conductive medium in the insulating resin can be suppressed, and thereby high heat conductivity can be achieved.

  As described above, an epoxy resin having a mesogen skeleton forms a highly ordered high-order structure, and therefore, the dispersibility of the filler generally tends to decrease. However, when the inorganic nitride particles of the present invention having a surface energy polarity term of 1 mN / m are used as fillers, excellent dispersibility is exhibited in the epoxy resin. As a result, the filler can be dispersed without using a dispersant for dispersing the filler, and high thermal conductivity can be maintained.

  Specific examples of the epoxy resin monomer having a mesogenic skeleton include 4,4′-biphenol glycidyl ether, 1-{(3-methyl-4-oxiranylmethoxy) phenyl} -4- (4-oxira). Nylmethoxyphenyl) -1-cyclohexene, 4- (oxiranylmethoxy) benzoic acid-1,8-octanediylbis (oxy-1,4-phenylene) ester, 2,6-bis [4- [4- [ 2- (oxiranylmethoxy) ethoxy] phenyl] phenoxy] pyridine and the like.

  Although there is no restriction | limiting in particular as a content rate of the epoxy resin in the said epoxy resin composition, From a heat conductivity and adhesive viewpoint, it is 3 mass%-30 mass% in the total solid which comprises an epoxy resin composition. It is preferable to be 5% by mass to 25% by mass from the viewpoint of thermal conductivity.

  Examples of the curing agent include amine curing agents, acid anhydride curing agents, phenol curing agents, polymercaptan curing agents, polyaminoamide curing agents, isocyanate curing agents, and block isocyanate curing agents. It is done.

The blending amount of the curing agent may be appropriately set in consideration of the type of curing agent to be blended and the physical properties of the epoxy resin. Specifically, the blending amount of the curing agent is preferably 0.005 to 5 equivalents, more preferably 0.01 to 3 equivalents, most preferably 0.5 to 1 chemical equivalent of the curing agent with respect to 1 mol of the epoxy group. Equivalent to 1.5 equivalents. When the blending amount is 0.005 equivalent or more with respect to 1 mol of the epoxy group, the curing rate of the epoxy resin is excellent. Moreover, when it is 5 equivalents or less, the curing reaction can be appropriately suppressed.
Here, the chemical equivalent represents, for example, the number of moles of active hydrogen of an amine with respect to 1 mole of an epoxy group when an amine curing agent is used as the curing agent.

  Although there is no restriction | limiting in particular as content rate of the inorganic nitride particle | grains of this invention in the epoxy resin composition of this invention, From a viewpoint of viscosity adjustment, in the total solid which comprises an epoxy resin composition, 10 volume%-80 volume %, Preferably from 30% by volume to 80% by volume from the viewpoint of thermal conductivity.

The epoxy resin composition of the present invention may contain a solvent in order to dissolve the epoxy resin or the curing agent when it is solid, and to reduce the viscosity when it is liquid.
Examples of the solvent include acetone, isobutyl alcohol, isopropyl alcohol, isopentyl alcohol, ethyl ether, ethylene glycol monoethyl ether, xylene, cresol, chlorobenzene, isobutyl acetate, isopropyl acetate, isopentyl acetate, ethyl acetate, methyl acetate, cyclohexanol, cyclohexanone, 1,4-dioxane, dichloromethane, styrene, tetrachlorethylene, Tetorahido b furan, toluene, n-hexane, 1-butanol, 2-butanol, methanol, methyl isobutyl ketone, methyl ethyl ketone, methyl cyclohexanol, methyl cyclohexanone , Chloroform, carbon tetrachloride, 1,2-dichloroethane, methylene chloride, etc. Can be used organic solvents are.

  In addition, when the epoxy resin composition of the present invention is cured to obtain a cured product, the contact angle of inorganic nitride particles contained in the cured product with water and the contact angle with n-hexadecane, and the surface of boron nitride particles The oxygen atom concentration of can be measured as follows.

The cured product etches the surface to expose the inorganic nitride particles contained therein. In this state, the contact angle for water and the contact angle for n-hexadecane are measured by the method described above.
Note that the contact angle measured from the cured product after etching, which is an object of contact angle measurement, may be affected by the surface roughness. However, by calculating in advance a relational expression between the surface roughness of the measurement object and the contact angle, it can be converted into a contact angle measured under a certain condition.

  In addition, when a metal foil is attached to the surface of the cured product, etching can be performed from the metal foil side to remove the surface of the metal foil and the cured product to expose the inorganic nitride particles. Thus, the contact angle with water and the contact angle with n-hexadecane of the inorganic nitride particles contained in the cured product can be measured.

  Further, the cured product is heated at 600 ° C. for 0.5 hours in an air atmosphere to burn off an epoxy resin and the like, and boron nitride particles are taken out. Can be measured.

<Resin sheet>
The resin sheet of the present invention is a sheet-like molded body of the epoxy resin composition. The resin sheet is formed, for example, by applying and drying the epoxy resin composition on a release film.

Specifically, for example, a resin sheet can be obtained by applying and drying a varnish-like epoxy resin composition to which a solvent such as methyl ethyl ketone or cyclohexanenon is added on a release film such as a PET film.
Application | coating can be implemented by a well-known method. Specific examples of the coating method include comma coating, die coating, lip coating, and gravure coating. As a coating method for forming a resin sheet with a predetermined thickness, a comma coating method in which an object to be coated is passed between gaps, a die coating method in which a varnish-like epoxy resin composition with a flow rate adjusted from a nozzle is applied, and the like. Can be applied. For example, when the thickness of the resin sheet before drying is 50 μm to 500 μm, it is preferable to use a comma coating method.

  The thickness of the resin sheet can be appropriately selected depending on the purpose, and can be, for example, 50 μm or more and 200 μm or less. From the viewpoint of thermal conductivity, electrical insulation, and sheet flexibility, 60 μm or more and 150 μm or less. It is preferable that

<Semi-cured resin composition>
The semi-cured resin composition of the present invention is a semi-cured product of the epoxy resin composition, and includes a so-called B stage sheet. The B stage sheet can be manufactured by a manufacturing method including, for example, a process of heat-treating the resin sheet to a B stage state.
By being formed by heat-treating the epoxy resin composition, it is excellent in thermal conductivity and electrical insulation, and excellent in flexibility and usable time as a B stage sheet.
The semi-cured resin composition of the present invention has a resin sheet viscosity of 10 ⁴ Pa · s to 10 ⁵ Pa · s at room temperature (25 ° C.), whereas 10 ² Pa · s at 100 ° C. The viscosity decreases to 10 ³ Pa · s. Moreover, the cured resin layer after curing described later is not melted even by heating. The viscosity can be measured by dynamic viscoelasticity measurement (frequency 1 Hz, load 40 g, temperature increase rate 3 ° C./min).

Since the resin sheet after coating hardly undergoes a curing reaction, the resin sheet has flexibility, but has low flexibility as a sheet, and in a state where the PET film as a support is removed, the sheet is not self-supporting. , Difficult to handle. Therefore, in the present invention, it is preferable that the epoxy resin composition is semi-cured by a heat treatment described later to be B-staged.
In the present invention, the conditions for heat-treating the obtained resin sheet are not particularly limited as long as the epoxy resin composition can be semi-cured to the B stage state, and should be appropriately selected according to the configuration of the epoxy resin composition. Can do. In the present invention, for the heat treatment, a heat treatment method selected from hot vacuum press, hot roll laminating and the like is preferred for the purpose of eliminating voids in the resin layer generated during coating. Thereby, a flat B stage sheet | seat can be manufactured efficiently.
Specifically, for example, the epoxy resin composition can be semi-cured into a B-stage state by heat-pressing at a heating temperature of 80 ° C. to 130 ° C. for 1 to 30 seconds under vacuum (for example, 1 MPa). .

  The thickness of the B stage sheet can be appropriately selected according to the purpose, and can be, for example, 50 μm or more and 200 μm or less. From the viewpoint of thermal conductivity, electrical insulation, and sheet flexibility, 60 μm or more and 150 μm. The following is preferable. It can also be produced by hot pressing while laminating two or more resin sheets.

<Curing resin composition>
The cured resin composition of the present invention is a cured product of the epoxy resin composition, and is formed by, for example, heat and pressure treatment and heat curing. Since it is a cured body of the epoxy resin composition, it has excellent thermal conductivity.
The conditions of the heat and pressure treatment for curing the epoxy resin composition are not particularly limited as long as the epoxy resin composition can be cured, and can be appropriately selected according to the configuration of the epoxy resin composition. For example, it can be 10 to 300 minutes at a temperature of 120 to 180 ° C. and a pressure of 0.5 to 20 MPa.

<Heat-generating electronic parts>
The exothermic electronic component of this invention has the said epoxy resin composition. The epoxy resin composition of the present invention can be suitably used as a heat dissipation material for heat-generating electronic components (for example, IC chips and printed wiring boards) of various electric and electronic devices. Specific examples of the heat dissipation material include a resin sheet composed of an epoxy resin composition, a prepreg using the epoxy resin composition, a laminated board using the resin sheet or prepreg, or a printed wiring board.

The entire disclosure of Japanese application 2011-211078 is incorporated herein by reference.
All documents, patent applications, and technical standards mentioned in this specification are to the same extent as if each individual document, patent application, and technical standard were specifically and individually described to be incorporated by reference, Incorporated herein by reference.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, “part” and “%” are based on mass.

Example 1
Using a tabletop optical surface treatment device (Sen Special Light Source Co., Ltd. device name: Photo Surface Processor PL21-200) on boron nitride powder (Mizushima Alloy Iron Co., Ltd., trade name: HP-40) having a volume average particle diameter of 40 μmφ The mixture was irradiated with ultraviolet rays for 10 minutes while stirring with a 200 W low-pressure mercury lamp. The volume average particle size of the boron nitride powder was determined by using a Microtrac particle size analyzer (manufactured by Nikkiso Co., Ltd .: Microtrac FRA) as the volume average particle size of 50% particle size (D50%) of the particle size distribution.

  The irradiation intensity was measured with an ultraviolet integrated light meter (USHIO UIT-150) to obtain an average irradiation intensity. More specifically, the ultraviolet intensity meter was put in the surface treatment apparatus, the irradiation intensity was measured, and the value displayed on the meter was recorded every 10 seconds. Thereafter, the sum of the recorded values was divided by the ultraviolet irradiation time to obtain the average irradiation intensity.

The powder subjected to the ultraviolet irradiation treatment was placed in an adapter female die 20 mmφ for hand press, and pressed at a pressure of 600 kgf / cm ² (5880 N / cm ² ) using an adapter male die 19 mmφ for hand press to obtain a green compact. Remove adapter male type for hand press and put into adapter female type for hand press, contact angle measuring device for contact angle of green compact and water, green compact and n-hexadecane (Kyowa Interface Science Co., Ltd.) (Device name: FACE CONTACT ANGLE METER CA-D) and measured at 25 ° C. and humidity 50%.

From the measured value of the contact angle, the polarity term of the surface energy was determined using the above formulas 1 to 3. More specifically, when the water surface energy dispersion term (γ ^d _L ) is 29.3 mN / m and the surface energy polarity term (γ ^p _L ) is 43.5 mN / m,

(Formula 4)

It becomes. Here, cos θ (water) is a contact angle between water and inorganic nitride. Further, when the hexadecane dispersion term (γ ^d _L ) is 27.6 mN / m, the surface energy polarity term (γ ^p _L ) is 0 mN / m,

(Formula 5)

It becomes. Therefore, the contact angle between hexadecane and the inorganic nitride is measured and substituted into the above equation 5 to obtain the surface energy dispersion term (γ ^d _S ), and further the contact angle between water and the inorganic nitride is measured. By substituting into 4, the surface energy polarity term (γ ^p _S ) was determined.

  The oxygen atom concentration on the surface of the powder irradiated with ultraviolet rays was measured with an X-ray photoelectron spectrometer (manufactured by Shimadzu / KRATOS: AXIS-HS) at a scanning speed of 20 eV / min (0.1 eV step). As detailed measurement conditions, monochrome Al (tube voltage: 15 kV, tube current: 15 mA) was used as the X-ray source, the lens conditions were HYBRID (analysis area: 600 × 1000 μm), and the resolution was Pass Energy 40. did.

  An epoxy resin (prepared by Mitsubishi Chemical (former Japan Epoxy Resin): jER828) and a curing agent (manufactured by Nippon Kayaku: amine-based curing agent, Kayahard AA) was added to the powder irradiated with ultraviolet rays to prepare an epoxy resin composition (epoxy resin) And the curing agent were adjusted so that the molar ratio of the active hydrogen of the amine of the curing agent to the epoxy group of the epoxy resin was 1: 1, and the boron nitride content in the cured resin was 30% by volume. An epoxy resin composition was prepared. The viscosity of the prepared epoxy resin composition was measured at room temperature with a rotational viscometer (manufactured by HAAKE: Rheo Stress RS600).

(Example 2)
In Example 1, the powder was similarly treated except that the ultraviolet irradiation time was 20 minutes. Pressing was performed in the same manner as in Example 1 to determine the contact angle of water and green compact, n-hexadecane and green compact, and the polarity term of surface energy. The viscosity of the epoxy resin composition was determined in the same manner as in Example 1 using the treated boron nitride powder.

(Example 3)
In Example 1, the powder was similarly processed except that the ultraviolet irradiation time was 30 minutes. Pressing was performed in the same manner as in Example 1 to determine the contact angle of water and green compact, n-hexadecane and green compact, and the polarity term of surface energy. The viscosity of the epoxy resin composition was determined in the same manner as in Example 1 using the treated boron nitride powder.

Example 4
In Example 3, as a pretreatment for the ultraviolet irradiation treatment, the powder was similarly treated except that it was heat-treated in a thermostatic bath at 150 ° C. for 10 minutes. Pressing was performed in the same manner as in Example 1 to determine the contact angle of water and green compact, n-hexadecane and green compact, and the polarity term of surface energy. The viscosity of the epoxy resin composition was determined in the same manner as in Example 1 using the treated boron nitride powder.

(Example 5)
In Example 4, the powder was treated in the same manner except that the heat treatment temperature was 250 ° C. Pressing was performed in the same manner as in Example 1 to determine the contact angle of water and green compact, n-hexadecane and green compact, and the polarity term of surface energy. The viscosity of the epoxy resin composition was determined in the same manner as in Example 1 using the treated boron nitride powder.

(Example 6)
In Example 5, the powder was similarly treated except that the heat treatment time was 30 minutes. Pressing was performed in the same manner as in Example 1 to determine the contact angle of water and green compact, n-hexadecane and green compact, and the polarity term of surface energy. The viscosity of the epoxy resin composition was determined in the same manner as in Example 1 using the treated boron nitride powder.

(Example 7)
Instead of the boron nitride powder used in Example 1, aluminum nitride sintered particles (Furukawa Electronics Co., Ltd., trade name: ALN filler FAN-f30-TY) having a volume average particle diameter of 30 μmφ were used in the same manner. The powder was processed. Pressing was performed in the same manner as in Example 1 to determine the contact angle of water and green compact, n-hexadecane and green compact, and the polarity term of surface energy. The viscosity of the epoxy resin composition was determined in the same manner as in Example 1 using the treated boron nitride powder.

(Example 8)
In Example 7, the powder was treated in the same manner except that the ultraviolet irradiation time was 20 minutes. Pressing was performed in the same manner as in Example 1 to determine the contact angle of water and green compact, n-hexadecane and green compact, and the polarity term of surface energy. The viscosity of the epoxy resin composition was determined in the same manner as in Example 1 using the treated boron nitride powder.

Example 9
In Example 7, the powder was similarly treated except that the ultraviolet irradiation time was 30 minutes. Pressing was performed in the same manner as in Example 1 to determine the contact angle of water and green compact, n-hexadecane and green compact, and the polarity term of surface energy. The viscosity of the epoxy resin composition was determined in the same manner as in Example 1 using the treated boron nitride powder.

(Example 10)
Instead of the boron nitride powder used in Example 4, aluminum nitride sintered particles (Furukawa Electronics Co., Ltd., trade name: ALN filler FAN-f30-TY) having a volume average particle diameter of 30 μmφ were used in the same manner. The powder was processed. Pressing was performed in the same manner as in Example 1 to determine the contact angle of water and green compact, n-hexadecane and green compact, and the polarity term of surface energy. The viscosity of the epoxy resin composition was determined in the same manner as in Example 1 using the treated boron nitride powder.

(Example 11)
In Example 10, the powder was treated in the same manner except that the heat treatment temperature was 250 ° C. Pressing was performed in the same manner as in Example 1 to determine the contact angle of water and green compact, n-hexadecane and green compact, and the polarity term of surface energy. The viscosity of the epoxy resin composition was determined in the same manner as in Example 1 using the treated boron nitride powder.

(Example 12)
In Example 11, the powder was similarly treated except that the heat treatment time was 30 minutes. Pressing was performed in the same manner as in Example 1 to determine the contact angle of water and green compact, n-hexadecane and green compact, and the polarity term of surface energy. The viscosity of the epoxy resin composition was determined in the same manner as in Example 1 using the treated boron nitride powder.

(Example 13)
In Example 1, the powder was similarly treated except that the time of ultraviolet irradiation was set to 15 seconds. Pressing was performed in the same manner as in Example 1 to determine the contact angle of water and green compact, n-hexadecane and green compact, and the polarity term of surface energy. The viscosity of the epoxy resin composition was determined in the same manner as in Example 1 using the treated boron nitride powder.

(Comparative Example 1)
Without treating the boron nitride powder, pressing was performed in the same manner as in Example 1 to determine the contact angle of water and green compact, n-hexadecane and green compact, and the polar term of surface energy. The viscosity of the epoxy resin composition was determined in the same manner as in Example 1 using the non-treated boron nitride particles.

(Comparative Example 2)
In Example 1, the powder was treated in the same manner except that the ultraviolet irradiation time was 6 seconds. The treated boron nitride powder was pressed in the same manner as in Example 1 to determine the contact angle of water and green compact, n-hexadecane and green compact, and the polarity term of surface energy. The viscosity of the epoxy resin composition was determined in the same manner as in Example 1 using the treated boron nitride powder.

(Comparative Example 3)
The boron nitride powder was heat-treated in a constant temperature bath at 150 ° C. for 10 minutes. The treated boron nitride powder was pressed in the same manner as in Example 1 to determine the contact angle of water and green compact, n-hexadecane and green compact, and the polarity term of surface energy. The viscosity of the epoxy resin composition was determined in the same manner as in Example 1 using the treated boron nitride powder.

(Comparative Example 4)
Instead of the boron nitride powder used in Comparative Example 1, aluminum nitride sintered particles (Furukawa Electronics Co., Ltd., trade name: ALN filler FAN-f30-TY) having a volume average particle diameter of 30 μmφ were used in the same manner. For the powder, the contact angle of water and green compact, n-hexadecane and green compact, the polar term of surface energy, and the viscosity of the epoxy resin composition were determined.

(Comparative Example 5)
Instead of the boron nitride powder used in Comparative Example 2, aluminum nitride sintered particles (Furukawa Electronics Co., Ltd., trade name: ALN filler FAN-f30-TY) having a volume average particle diameter of 30 μmφ were used in the same manner. For the powder, the contact angle of water and green compact, n-hexadecane and green compact, the polar term of surface energy, and the viscosity of the epoxy resin composition were determined.

(Comparative Example 6)
Instead of the boron nitride powder used in Comparative Example 3, aluminum nitride sintered particles (Furukawa Electronics Co., Ltd., trade name: ALN filler FAN-f30-TY) having a volume average particle diameter of 30 μmφ were used in the same manner. For the powder, the contact angle of water and green compact, n-hexadecane and green compact, the polar term of surface energy, and the viscosity of the epoxy resin composition were determined.

  When Examples 1 to 3 and 13 are compared with Comparative Example 1, each Example has a smaller water contact angle than Comparative Example 1 and a large surface energy polarity term. Moreover, the viscosity of an epoxy resin composition is small. Therefore, sufficient ultraviolet irradiation is effective in reducing the contact angle and the viscosity of the epoxy resin composition. In addition, since the viscosity of an epoxy resin composition is fully reduced, it turns out that the dispersibility of the boron nitride powder in an epoxy resin is improving.

  When Examples 1 to 3 and Comparative Example 2 are compared, each Example has a smaller water contact angle than Comparative Example 2 and a large surface energy polarity term. Moreover, the viscosity of an epoxy resin composition is small. Therefore, when the ultraviolet irradiation time is too short, the polarity term of the surface energy is less than 1 mN / m, which is not very effective for reducing the contact angle and the viscosity of the epoxy resin composition.

  When Examples 4 to 6 and Comparative Example 3 are compared, each Example has a smaller water contact angle than Comparative Example 3 and a large surface energy polarity term. Moreover, the viscosity of an epoxy resin composition is small. Accordingly, the heat energy alone has a surface energy polarity term of less than 1 mN / m, which is insufficient for reducing the contact angle and the viscosity of the epoxy resin composition.

  When Examples 7 to 9 and Comparative Example 4 are compared, each Example has a smaller water contact angle than Comparative Example 4 and a large surface energy polarity term. Moreover, the viscosity of an epoxy resin composition is small. Therefore, sufficient ultraviolet irradiation is effective in reducing the contact angle and the viscosity of the epoxy resin composition. In addition, since the viscosity of an epoxy resin composition is fully reduced, it turns out that the dispersibility of the aluminum nitride sintered particle in an epoxy resin is improving.

  When Examples 7 to 9 and Comparative Example 5 are compared, each Example has a smaller water contact angle than Comparative Example 5 and a large surface energy polarity term. Moreover, the viscosity of an epoxy resin composition is small. Therefore, when the ultraviolet irradiation time is too short, the polarity term of the surface energy is less than 1 mN / m, which is not very effective for reducing the contact angle and the viscosity of the epoxy resin composition.

  Comparing Examples 10 to 12 and Comparative Example 6, all Examples have a smaller water contact angle than Comparative Example 6 and a large surface energy polarity term. Moreover, the viscosity of an epoxy resin composition is small. Accordingly, the heat energy alone has a surface energy polarity term of less than 1 mN / m, which is insufficient for reducing the contact angle and the viscosity of the epoxy resin composition.

10 Droplet 12 Green compact of inorganic nitride particles

Claims (12)

Polarity term of surface energy Ri der least 1 mN / m, the surface of the oxygen atom concentration is 5at% or less der Ru boron nitride particles. 25 ° C., as measured in 50% humidity, no more than the contact angle of 90 ° for 25 ° C. water, and Ri der contact angle 20 ° or less with respect to 25 ° C. of n- hexadecane, an oxygen atom concentration in the surface 5at% or less der Ru boron nitride particles. 2. The boron nitride according to claim 1, wherein the contact angle with respect to water at 25 ° C. is 90 ° or less and the contact angle with respect to n-hexadecane at 25 ° C. is 20 ° or less when measured at 25 ° C. and a humidity of 50%. particle. Boron nitride particles according to any one of claims 1 to 3 oxygen atom concentration on the front surface is not less than 1.5 at%. Boron nitride particles according to any one of claims 1 to 4 volume-average particle diameter of 0.01Myuemu～1mm. Wherein the boron nitride particles according to any one of claims 1 to 5, epoxy resin composition containing an epoxy resin, a curing agent, a. The semi-hardened resin composition which is a semi-hardened body of the epoxy resin composition of Claim 6 . The cured resin composition which is a hardening body of the epoxy resin composition of Claim 6 . The resin sheet which is a sheet-like molded object of the epoxy resin composition of Claim 6 . An exothermic electronic component comprising the cured resin composition according to claim 8 . A step of the polarity term to prepare boron nitride particles of less than 1 mN / m surface energy,
The boron nitride particles, and irradiating light including ultraviolet rays having a wavelength of 150 nm to 400 nm 100 mJ / cm ² or more,
Method for producing a boron nitride particles according to any one of claims 1 to 5 having. Furthermore, the manufacturing method of the boron nitride particles according to claim 11 comprising a step of heat treatment for more than one minute at 60 ° C. to 400 ° C..