TW202300579A - Inorganic oxide powder, resin composition, and compression-molded article - Google Patents

Abstract

To provide: an inorganic oxide powder by which it is possible to provide a resin composition in which the ratio between the viscosity at low shear and the viscosity at high shear is small; a resin composition containing said inorganic oxide powder; and a compression molded article obtained by molding said resin composition. The present invention pertains to an inorganic oxide powder, wherein: in a frequency particle size distribution based on volume, the value of the ratio of the cumulative frequency for a second region, where the particle size is located in the range of 0.001-20 [mu]m, to the cumulative frequency for a first region, where the particle size is located in the range of 0.001-10 [mu]m (cumulative frequency for the second region divided by cumulative frequency for the first region), is 1.2-1.4; the cumulative frequency where the particle size is 20-46 [mu]m is 15-45 vol%; and the viscosity of a resin composition comprising 20 mass% of a bisphenol F-type epoxy resin (an epoxy equivalent of 170, viscosity of 4 Pa.s) and 80 mass% of an inorganic oxide powder is 45-70 Pa.s as measured at a temperature of 30 DEG C and a rotation speed of 1 rpm by using an E-type viscometer.

Description

Inorganic oxide powder, resin composition and compression molded product

The present invention relates to inorganic oxide powder, resin composition and compression molded article.

In recent years, with the development of higher functions and higher speeds of ICs, the heat generation tends to increase, and the demand for high heat dissipation of resins used in electronic parts such as sealing materials is also increasing. In the past, in order to achieve high heat dissipation of resin, it has been implemented to fill the resin with a high content of inorganic powder with high thermal conductivity. Aluminum nitride, alumina, crystalline silica, etc. are known as an inorganic powder with high thermal conductivity. However, if a high degree of inorganic powder with high thermal conductivity is filled in the resin, the fluidity of the resin may decrease and the moldability may be poor. Patent Document 1 describes a highly thermally conductive inorganic powder, which contains, in a predetermined ratio: spherical alumina powder having a predetermined average particle size having at least two or more frequency maximum peaks within a predetermined range in the particle size distribution, and Spherical silica powder with predetermined average particle size and specific surface area. With this highly thermally conductive inorganic powder, it is difficult to increase the viscosity even if it is filled in the resin to a high degree, and it is possible to prepare a high thermally conductive resin composition with high fluidity and low burr characteristics. [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Unexamined Patent Publication No. 2004-244491

[Problem to be Solved by the Invention]

As a molding method for resin sealing of electronic parts, a transfer molding method and a compression molding (compression molding) method are known. The transfer mold method is a molding method in which a plate-shaped resin is put into the groove of a pre-heated mold, and the molten resin is filled into the mold groove by a mixer. The compression molding method is a method in which a powder or granular resin composition is supplied into a cavity, and a workpiece is pressed against the molten resin composition to perform compression molding. From the viewpoint of cost reduction, the compression mold method is desired. In order to improve the formability in the compression molding method, the resin composition used is required not only to have excellent fluidity at high shear, but also to have excellent fluidity at low shear. That is, there is a demand for an inorganic oxide powder capable of imparting a resin composition having a low ratio of low-shear viscosity to high-shear viscosity.

The subject of the present invention is to provide an inorganic oxide powder that can provide a resin composition having a low ratio of viscosity at low shear to viscosity at high shear; resin composition containing inorganic oxide powder, the resin composition Compression molded products obtained by molding. [Means to solve the problem]

The present invention has the following aspects. [1] Inorganic oxide powder, in the volume-based frequency particle size distribution, the cumulative frequency of the second region in the range of particle diameters ranging from 0.001 μm to 20 μm relative to the range of particle diameters ranging from 0.001 μm to 10 μm The value of the ratio of the cumulative frequency of the first region (the cumulative frequency of the second region/the cumulative frequency of the first region) is 1.2~1.4, and the cumulative frequency of the particle size range of 20μm to 46μm is 15~45 volume %, a resin composition consisting of 20% by mass of bisphenol F-type epoxy resin (epoxy equivalent 170, viscosity 4Pa･s) and 80% by mass of inorganic oxide powder was measured at a temperature of 30°C and The viscosity measured at 1rpm is 45~70Pa･s. [2] The inorganic oxide powder according to [1], wherein the cumulative frequency of the first region is 35 to 60% by volume. [3] The inorganic oxide powder according to [1] or [2], wherein the specific surface area determined by the BET method is 0.5 to 2.0 m ² /g. [4] A resin composition comprising the inorganic oxide powder according to any one of [1] to [3], and a resin. [5] The resin composition described in [4] is used in the manufacture of compression molded articles. [6] A compression molded article comprising the resin composition of [4] or [5]. [Effect of Invention]

According to the present invention, it is possible to provide: an inorganic oxide powder capable of imparting a resin composition having a low ratio of low-shear viscosity to high-shear viscosity; a resin composition containing inorganic oxide powder, and the resin composition Compression molded products obtained by molding.

Hereinafter, one embodiment of the present invention will be described in detail. This invention is not limited to the following embodiment, In the range which does not impair the effect of this invention, it can change suitably and implement. In this specification, the description of "X~Y" in the numerical range means that X is greater than Y and less than Y.

[Inorganic oxide powder] The inorganic oxide powder of this embodiment is: In the frequency granularity distribution of the volume basis, The value of the ratio of the cumulative frequency of the second region within the particle diameter range of 0.001 μm to 20 μm to the cumulative frequency of the first region within the particle diameter range of 0.001 μm to 10 μm (cumulative frequency of the second region frequency/cumulative frequency of the first area) is 1.2~1.4, And the cumulative frequency in the range of particle size between 20 μm and 46 μm is 15~45% by volume, In addition, a resin composition composed of 20% by mass of bisphenol F-type epoxy resin (epoxy equivalent 170, viscosity 4Pa･s) and 80% by mass of inorganic oxide powder was measured at a temperature of 30°C, The viscosity measured at 1rpm is 45~70Pa･s. Such an inorganic oxide powder is designed to provide a resin composition having a low ratio of viscosity at low shear to viscosity at high shear. The resin composition whose ratio of the viscosity at low shear to the viscosity at high shear is small maintains a low viscosity from the beginning to the end of pushing the workpiece against the resin in the compression mold method, so the formability excellent. In addition, such an inorganic oxide powder is designed to provide a resin composition having excellent fluidity during melting. As a result, formability can be further improved in the compression molding method.

"Volume-based frequency particle size distribution" is measured by the laser diffraction scattering method (refractive index: 1.68). The horizontal axis is the particle size (μm), and the vertical axis is the distribution curve of the volume-based frequency (%). express. "Particle size" is a numerical value expressed on the horizontal axis of the frequency particle size distribution on a volume basis. "Peak" refers to the distribution curve with a maximum value in the volume-based frequency particle size distribution. "Shoulder" means an incomplete peak that is not completely separated from the peak (that is, a portion of the slope of the distribution curve that constitutes the peak with a height difference that forms a bulge) with or without a maximum value The meaning of the distribution curve. "Maximum value" means the critical point at which the slope of the curve in the frequency particle size distribution of the volume basis changes from positive to negative.

"Region" in this specification refers to a distribution curve within a range having a predetermined particle diameter regardless of the presence or absence of a maximum value and the numerical value in the volume-based frequency particle size distribution. The "first region" means a region of the distribution curve within the range of particle diameters from 0.001 to 10 μm in the volume-based frequency particle size distribution. The "second region" means a region of the distribution curve within the range of particle diameters of 0.001 to 20 μm in the volume-based frequency particle size distribution. In addition, the first area is included in the second area. "Cumulative frequency" means the cumulative value of the frequency (%) in the predetermined particle size range of the volume-based frequency particle size distribution. "Viscosity at low shear" refers to a resin composition composed of 20% by mass of bisphenol F-type epoxy resin (epoxy equivalent 170, viscosity 4Pa･s) and 80% by mass of inorganic oxide powder. The meaning of the viscosity measured by the E-type viscometer at a temperature of 30°C and a rotation speed of 1 rpm. "Viscosity at high shear" refers to a resin composition composed of 20% by mass of bisphenol F-type epoxy resin (epoxy equivalent 170, viscosity 4Pa･s) and 80% by mass of inorganic oxide powder. The meaning of the viscosity measured by the E-type viscometer at a temperature of 30°C and a rotational speed of 10rpm. In addition, the viscosity of the bisphenol F type epoxy resin uses the manufacturer's nominal value.

(Cumulative frequency of the 2nd area/Cumulative frequency of the 1st area) Inorganic oxide powder is in the volume-based frequency particle size distribution, the cumulative frequency of the second area in the range of particle size 0.001~20μm relative to the cumulative frequency of the first area in the range of particle size 0.001~10μm The ratio value (cumulative frequency in the second area/accumulative frequency in the first area) is 1.2 to 1.4. When the ratio of the cumulative frequency of the second region to the cumulative frequency of the first region is 1.2 to 1.4, a resin composition having a low ratio of viscosity at low shear to viscosity at high shear can be provided.

In the past, there have been attempts to blend a variety of inorganic oxide powders with different particle sizes, such as small, medium, and large particles, by filling the gaps between the medium and/or large particles with small particles. A resin composition with excellent fluidity to form a densely packed structure. The inorganic oxide powder of this embodiment can provide a resin composition with excellent fluidity and low viscosity at low shear. Although the reason for this is not clear at this stage, it is presumed that by setting the ratio of the cumulative frequency of the second region to the cumulative frequency of the first region to be 1.2 to 1.4, small-diameter particles (fine particles with a particle size of 10 μm or less) The aggregation is suppressed, improving the ease of particle movement at low shear.

The value of the ratio of the cumulative frequency in the second region to the cumulative frequency in the first region (cumulative frequency in the second region/cumulative frequency in the first region) may be 1.2 to 1.3 or 1.3 to 1.4.

The accumulation frequency of the first region of the inorganic oxide powder system is preferably 35-60%, more preferably 40-60%, and further preferably 45-55%. In one embodiment, the cumulative frequency of the first region may be 42-58%. With the accumulative frequency of the first zone being 35~60%, the viscosity at low shear can be easily adjusted to a predetermined range. In addition, the fluidity of the resin composition can be improved.

Inorganic oxide powder system, considering fluidity, the accumulation frequency of the second region is preferably 40-80%, more preferably 45-75%, and still more preferably 50-70%. In one embodiment, the cumulative frequency of the second region may be 54-75%.

In one embodiment, the inorganic oxide powder is, in the volume-based frequency particle size distribution, the cumulative frequency of the 2a region with a particle diameter in the range of 0.01 to 20 μm relative to the 1a region with a particle diameter in the range of 0.01 to 10 μm The value of the ratio of the cumulative frequency (cumulative frequency in the 2a region/cumulative frequency in the 1a region) is 1.2 to 1.4. The value of the ratio of the cumulative frequency of the 2a region to the cumulative frequency of the 1a region (cumulative frequency of the 2a region/cumulative frequency of the 1a region) may also be 1.2~1.3 or 1.3~1.4. Inorganic oxide powder, considering fluidity, the accumulation frequency in the 1a region is preferably 30-70%, more preferably 35-70%, and further preferably 40-65%. In one embodiment, the cumulative frequency of the region 1a may be 42-58%. Inorganic oxide powder, considering fluidity, the cumulative frequency in the 2a region is preferably 40-80%, more preferably 45-75%, and further preferably 50-70%. In one embodiment, the cumulative frequency of the 2a region may be 54-75%.

In one embodiment, the inorganic oxide powder is, in the volume-based frequency particle size distribution, the cumulative frequency of the 2b region with a particle diameter in the range of 0.1 to 20 μm relative to the 1b region with a particle diameter in the range of 0.1 to 10 μm The value of the cumulative frequency ratio (cumulative frequency in the 2b region/cumulative frequency in the 1b region) was 1.2 to 1.4. The value of the ratio of the cumulative frequency of the 2b region to the cumulative frequency of the 1b region (cumulative frequency of the 2b region/cumulative frequency of the 1b region) may also be 1.2~1.3 or 1.3~1.4. Inorganic oxide powder, considering fluidity, the accumulation frequency of the 1b region is preferably 30-70%, more preferably 35-70%, and further preferably 40-65%. In one embodiment, the cumulative frequency of the region 1b may be 42-58%. Inorganic oxide powder, considering fluidity, the cumulative frequency of the 2b region is preferably 40-80%, more preferably 45-75%, and further preferably 50-70%. In one embodiment, the cumulative frequency of the 2b region may be 54-75%.

As for the method of adjusting the ratio of the cumulative frequency of the second region (0.001~20μm) to the cumulative frequency of the first region (particle size: 0.001~10μm) to 1.2~1.4, for example, the first While adjusting the cumulative frequency of the second area to the above-mentioned ideal range, there are methods of adjusting the maximum frequency of the first peak, second peak, and third peak described later to the ideal range described later. In addition, the accumulative frequency can be adjusted by adjusting the blending amount of the raw material powder whose particle size has been adjusted, or by sieving, classifying, and the like.

(Cumulative frequency in the range of particle size between 20 μm and 46 μm) In the frequency particle size distribution of the inorganic oxide powder based on the volume, the cumulative frequency of the particle size in the range of 20 μm to 46 μm is 15 to 45% by volume. Since the cumulative frequency of particle diameters in the range of 20 μm to 46 μm is 15 to 45% by volume, it is possible to provide a resin composition having a low ratio of viscosity at low shear to viscosity at high shear. The cumulative frequency in the range of particle diameters from 20 μm to 46 μm is preferably 17 to 45% by volume, more preferably 18 to 43% by volume. In one embodiment, the cumulative frequency of particle diameters in the range of not less than 20 μm and not more than 46 μm may be 19 to 41% by volume. In addition, the accumulative frequency can be adjusted by adjusting the blending amount of the raw material powder whose particle size has been adjusted, or by sieving, classifying, and the like.

(Viscosity at low shear) Inorganic oxide powder system, a resin composition composed of bisphenol F-type epoxy resin (epoxy equivalent 170, viscosity 4Pa･s) 20% by mass and inorganic oxide powder 80% by mass is used with an E-type viscometer. The viscosity (viscosity at low shear) measured at a temperature of 30°C and a rotational speed of 1 rpm is 45~70Pa･s. Since the viscosity at low shear is 45~70Pa･s, in the compression molding (compression molding) method, the viscosity is maintained at the stage where the work piece is pressed against the resin composition, so there is little influence on linear deformation and molding Good sex. In addition, since the viscosity at low shear is 45 to 70 Pa･s, it is possible to provide a resin composition with a low ratio of viscosity at low shear to viscosity at high shear. As a result, in the compression molding method, when the workpiece is pressed against the resin composition, the viscosity is kept low from the beginning to the end, so the formability is excellent. The viscosity at low shear should be 45~65Pa･s. In one embodiment, the viscosity at low shear is 49 to 69 Pa･s. The viscosity adjustment at low shear can be adjusted by adjusting the ratio of the cumulative frequency in the second region/the cumulative frequency in the first region, the cumulative frequency in the range from 20 μm to 46 μm, and the cumulative frequency in the first region within the above-mentioned predetermined range to become a predetermined range. For example, in terms of increasing the viscosity at low shear, the value of the ratio of the cumulative frequency of the second region/the cumulative frequency of the first region becomes a relatively small value within the above-mentioned predetermined range (that is, by having a particle diameter of A smaller range makes more particles exist), or the cumulative frequency of the range of 20 μm to 46 μm becomes a relatively small value within the above predetermined range.

(Inorganic Oxide Powder) Examples of the inorganic oxide powder include metal oxide powder. Examples of metal oxide powders include inorganic powders such as silicon dioxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), titanium dioxide (TiO ₂ ), magnesium oxide (MgO), and calcium oxide (CaO). The inorganic powder preferably contains one or more metal oxide powders selected from these, more preferably contains alumina, and is still more preferably alumina. Considering the high filling of the resin, it is preferable to contain spherical alumina. "Spherical" refers to a particle shape that is round or spherical when observed with a scanning electron microscope at 100 magnifications. In one embodiment, the inorganic oxide powder contains alumina in an amount of 90% by mass or more, or 92% by mass or more. In one embodiment, the inorganic oxide powder contains spherical amorphous alumina in an amount of 90% by mass or more, or 92% by mass or more.

The specific surface area of the inorganic oxide powder based on the BET method is preferably 0.5~2.0m ² /g, more preferably 0.8~1.8m ² /g, further preferably 1.0~1.5m ² /g, especially 1.1~1.5m 2 /g ² /g. The specific surface area obtained by the BET method is 0.5~2.0m ² /g, and the viscosity can be adjusted to a predetermined range. The specific surface area by the BET method can be measured, for example, using a specific surface area measuring machine such as "Macsorb HM model-1208" (manufactured by MACSORB). The method of adjusting the specific surface area can be carried out by changing the particle size and ratio of the inorganic oxide powder to be blended.

For inorganic oxide powders, in the volume-based frequency particle size distribution, the cumulative frequency in the range of particle diameters from 0.01 μm to 70 μm is preferably at least 90%, more preferably at least 95%, and even more preferably at least 98%. . In one embodiment, the inorganic oxide powder may have a particle diameter of 0.01 μm to 70 μm and a cumulative frequency of 100%. Inorganic oxide powders, in the volume-based frequency particle size distribution, the cumulative frequency in the particle size range of 0.01 μm to 60 μm is preferably 90% or more, more preferably 95% or more, and still more preferably 98% or more . In one embodiment, the inorganic oxide powder may have a particle diameter of 0.01 μm to 60 μm and a cumulative frequency of 100%. Inorganic oxide powders, in the volume-based frequency particle size distribution, the cumulative frequency in the particle size range of 1 μm to 50 μm is preferably 90% or more, more preferably 95% or more, and still more preferably 98% or more. In one embodiment, the inorganic oxide powder may have a particle diameter in the range of 1 to 50 μm and a cumulative frequency of 100%.

For inorganic oxide powders, considering the fluidity and viscosity of the resin composition, the volume-based cumulative 50% diameter D ₅₀ is preferably 5-20 μm, more preferably 5-15 μm. The volume-based cumulative 50% diameter D ₅₀ is the particle size corresponding to the cumulative value of 50% in the volume-based cumulative particle size distribution measured by the laser diffraction scattering method (refractive index: 1.68).

Inorganic oxide powder is because it is easy to adjust the ratio of the cumulative frequency of the second region to the cumulative frequency of the first region (cumulative frequency of the second region/cumulative frequency of the first region), and/or, it is easy to adjust 20 μm or more Because of the cumulative frequency in the range below 46 μm, there may be more than one peak with a maximum value in the predetermined particle size region.

(1st peak) Inorganic oxide powder, in the volume-based frequency particle size distribution, the particle size (particle size) is at least in the range of 1 μm to 7 μm, preferably in the range of 2 μm to 7 μm, and more preferably in the range of 2 μm to 6 μm. Have the maximum value of the peak and/or shoulder (more preferably the maximum value of the peak). In addition, in this specification, the peak part and/or the shoulder peak which have a maximum value in the range whose particle diameter is 1 micrometer or more and 7 micrometers or less are also called "the 1st peak part." Inorganic oxide powders having maximum peaks and/or shoulder peaks in the range of 1 μm to 7 μm in particle size, it is easy to design the value of the ratio of the cumulative frequency of the second region to the cumulative frequency of the first region as A predetermined range can more easily give a resin composition having a smaller ratio of viscosity at low shear to viscosity at high shear. In addition, if the powder with peaks and/or shoulders in the range of 1 μm to 7 μm in particle size is also a fine powder, by mixing it with a powder with a large particle size, it can give a fluidity to form a densely packed structure. Excellent resin composition.

The maximum frequency (the frequency at the maximum value) of the first peak is preferably 1 to 7%, more preferably 1 to 6%, and still more preferably 2 to 6%. Since the maximum frequency of the first peak is 1 to 7%, the value of the ratio of the cumulative frequency of the second region to the cumulative frequency of the first region, which will be described later, can be easily adjusted to a predetermined range. In addition, desired fluidity can be imparted to inorganic oxide powders. In addition, the maximum frequency of each peak can be adjusted by adjusting the blending amount of the raw material powder whose particle size has been adjusted, or by sieving, classifying, and the like.

(2nd peak) For inorganic oxide powders, in the volume-based frequency particle size distribution, the particle size is preferably in the range of more than 7 μm to 15 μm, more preferably in the range of 8 to 14 μm, and even more preferably in the range of 9 to 12 μm , may also have the maximum value of the peak and/or shoulder. In addition, in this specification, the peak part and/or the shoulder peak which have a maximum value in the range of particle diameter exceeding 7 micrometers and 15 micrometers or less are also called "the 2nd peak part." By having the second peak, the value of the ratio of the cumulative frequency of the second region to the cumulative frequency of the first region (cumulative frequency of the second region/cumulative frequency of the first region) can be easily adjusted to 1.2~ 1.4.

In one embodiment, the second peak is a shoulder that is not completely separated from the first peak. In other embodiments, the second peak is a peak that is completely separated from the first peak.

In one embodiment, the second peak is from the minimum point between the first peak to the minimum point between the third peak (the point where the distribution curve converges when there is no third peak) The cumulative frequency (hereinafter also referred to as "the cumulative frequency of the second peak") is preferably 40-80%, more preferably 45-75%, and further preferably 50-70%. By setting the cumulative frequency of the second peak It becomes 40~80%, which can give high fluidity to the resin composition.

In one embodiment, the value of the cumulative frequency of the second peak relative to the ratio of the cumulative frequency of the first peak to the sum of the cumulative frequency of the second peak [cumulative frequency of the second peak/(first peak The cumulative frequency of + the cumulative frequency of the second peak)] is 1.2~1.4. "Cumulative frequency of peak" refers to the cumulative frequency from the rising point of the curve constituting each peak to the part where the curve converges (the frequency becomes zero or becomes a minimum value). Since the ratio of the cumulative frequency of the second peak to the sum of the cumulative frequency of the first peak and the cumulative frequency of the second peak is 1.2 to 1.4, the cumulative frequency of the second region can be easily compared to the cumulative frequency of the second peak. The value of the ratio of the accumulation frequency in the first area (the accumulation frequency in the second area/the accumulation frequency in the first area) is 1.2 to 1.4.

The maximum frequency (the frequency at the maximum value) of the second peak is preferably 1 to 4%, more preferably 2 to 4%, and still more preferably 2 to 3%. Since the maximum frequency of the second peak is 1 to 4%, it is possible to provide ease of particle movement at low shear.

(3rd peak) In the frequency particle size distribution of the inorganic oxide powder based on the volume, it is preferably in the range of more than 15 μm and less than 30 μm, more preferably in the range of 20 to 30 μm in particle size, and further preferably in the range of 20 to 25 μm in particle size It may have the maximum value of the peak and/or the shoulder (more preferably the maximum value of the peak). In addition, in this specification, the peak part and/or the shoulder peak which have a maximum value in the range of particle diameter exceeding 15 micrometers and 30 micrometers or less is also called "the 3rd peak part." In one embodiment, the inorganic oxide powder has a peak maximum value in the range of 18 to 29 μm in the volume-based frequency particle size distribution. By having the third peak, the value of the ratio of the cumulative frequency of the second region to the cumulative frequency of the first region and the value of the ratio of the cumulative frequency of the third region to the cumulative frequency of the first region can be easily calculated Adjust to within the predetermined range.

In one embodiment, the third peak is from the rising starting point of the curve (the minimum point between the second peak) to the minimum point between the fourth peak (if there is no fourth peak, the frequency becomes The cumulative frequency up to zero or the point where the distribution curve converges) (hereinafter also referred to as "the cumulative frequency of the third peak") is preferably 65-95%, more preferably 70-95%, and further preferably 75-95% . Since the cumulative frequency of the third peak is 75-90%, the resin composition can be highly fluidized.

The maximum frequency (the frequency at the maximum value) of the third peak is preferably 2 to 8%, more preferably 3 to 7%, and further preferably 4 to 6%. By making the maximum frequency of the third peak part 2~8%, high fluidity can be imparted to the resin composition.

(4th peak) Inorganic oxide powder is preferably in the range of more than 30 μm and less than 50 μm in the frequency particle size distribution based on volume, more preferably in the range of 35-50 μm in particle size, and further preferably in the range of 40-46 μm in particle size It may have the maximum value of the peak and/or the shoulder (more preferably the maximum value of the peak). In addition, in this specification, the peak part and/or the shoulder peak which has a maximum value in the range of particle diameter exceeding 30 micrometers and 50 micrometers or less is also called "the 4th peak part." By having the fourth peak, high fluidity can be imparted to the resin composition.

The maximum frequency (the frequency at the maximum value) of the fourth peak is preferably 2 to 8%, more preferably 3 to 7%, and further preferably 4 to 6%. By setting the maximum frequency of the fourth peak to 2~8%, high fluidity can be imparted to the resin composition.

(Cumulative frequency of the 3rd area/Cumulative frequency of the 1st area) In the volume-based frequency particle size distribution of inorganic oxide powder, the cumulative frequency of the third area within the particle size range of 0.001 to 35 μm is relative to the cumulative frequency of the first area within the particle size range of 0.001 to 10 μm The value of the ratio (cumulative frequency in the third area/accumulative frequency in the first area) is preferably 1.4~2.2, more preferably 1.5~2.0. When the value of the ratio of the cumulative frequency of the third region to the cumulative frequency of the first region is 1.4 to 2.2, a resin composition with high fluidity can be provided. The "third region" means a region of the distribution curve within the range of particle diameters from 0.001 to 35 μm in the volume-based frequency particle size distribution. Regarding the "first area", it is the same as above. In addition, the first area and the second area are also included in the third area.

Inorganic oxide powder, considering the fluidity of the resin composition, the cumulative frequency of the third region is 70-95%, preferably 75-95%, more preferably 75-90%. The cumulative frequency for the first area is the same as above. In one embodiment, the cumulative frequency of the third region may be 77-94%.

For the method of adjusting the ratio of the cumulative frequency of the third region (particle size: 0.001~35μm) to the cumulative frequency of the first region (particle size: 0.001~10μm) to 1.4~2.2, for example, While adjusting the cumulative frequency of the 1st to 3rd areas and/or the maximum frequency of the 1st peak to the above ideal range, the 2nd peak, the 3rd peak and the 4th peak are available according to the demand, and the maximum frequency is adjusted Methods of adjusting to the above ideal range, etc. In addition, the accumulative frequency and the maximum frequency can be adjusted by adjusting the blending amount of the raw material powder whose particle size has been adjusted, or by sieving, classifying, and the like.

(Manufacturing method) Inorganic oxide powders can be produced by mixing commercially available inorganic oxide powders with a predetermined particle size distribution, or by existing spray technology. From the point of view of productivity and production cost, it should be manufactured by spraying technology. Existing spray technology, for example, based on the "Steelmaking Research No. 310 of 1982 on the spray collection technology for steel furnaces", for fuel gases such as hydrogen, natural gas, acetylene gas, propane gas, butane, etc. Put the raw material powder into the formed high temperature flame to make it melt and spheroidize. An example of a manufacturing device is basically composed of a spheroidizing furnace and a collecting device connected to the furnace. The spherical inorganic oxide powder produced by the spheroidizing furnace is transported by air such as a blower and recovered by a collection device. The spherical inorganic oxide powder can be classified as required before and/or after being collected by the collecting device. The main body of the spheroidizing furnace and the delivery piping should be water-cooled by means of a water-cooling jacket. As a collection device, a cyclone, gravity settling, louver type, bag filter, etc. can be used. The collection temperature is determined by the calorific value caused by the amount of combustible gas and the suction capacity of the blower. This adjustment can be made by the amount of cooling water, the suction volume of the external air installed in the pipeline, etc. As raw materials for producing spherical alumina powder, aluminum hydroxide, alumina, metallic aluminum, etc. are used. It is desirable to adjust the particle size of the raw material powder to the product particle size (same particle size as the target inorganic oxide powder) in advance, and the particle size can also be adjusted by classifying after the spheroidization treatment. In addition, the spherical inorganic powder with the same composition can also be obtained by melting and spheroidizing various raw materials with different particle diameters, and then mixing and adjusting them. The mixing can be performed, for example, under normal temperature conditions using known equipment such as a blender and mixer.

The surface treatment of inorganic oxide powder with silane coupling agent can further reduce the water absorption rate of the powder, increase the strength of the resin composition, and reduce the boundary resistance between the resin and the powder, further improving the Thermal conductivity. As far as the silane coupling agent is concerned, vinyltrichlorosilane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-methacrylpropyltrimethoxysilane, β(3,4 -epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N-β(aminoethyl base) γ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N- Phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, etc. For other surface treatment agents, Zr chelate, Titanate coupling agent, aluminum coupling agent, etc.

(use) Inorganic oxide powder can be suitably used in the manufacture of semiconductor sealing materials, adhesives, heat sinks, etc. for electronic equipment. In particular, since it can provide a resin composition having a low ratio of viscosity at low shear to viscosity at high shear, it can be suitably used in the manufacture of compression molded articles.

[Resin composition] The resin composition of this embodiment contains the above-mentioned inorganic oxide powder and resin. Regarding the inorganic oxide powder, it is the same as above. The content of the inorganic oxide powder is preferably 80-95% by mass, more preferably 85-95% by mass, and still more preferably 90-95% by mass in the resin composition in consideration of heat resistance and mechanical strength. In one embodiment, the content of the inorganic oxide powder may exceed 80% by mass and not more than 95% by mass in the resin composition.

Examples of resins include epoxy resins, silicone resins, phenolic resins, melamine resins, urea-formaldehyde resins, unsaturated polyesters, fluororesins, polyimides, polyamideimides, and polyetherimides. Polyamide, polybutylene terephthalate, polyethylene terephthalate and other polyesters, polyphenylene ether, polyphenylene sulfide, wholly aromatic polyester, polyethylene, liquid crystal polymer , polyether resin, polycarbonate, maleimide modified resin, ABS resin, AAS (acrylonitrile-acrylic rubber・styrene) resin, AES (acrylonitrile・ethylene・propylene・diene rubber-styrene) The resin and the like preferably contain one or more selected from these.

When the resin composition is a molding material for sealing, epoxy resin is preferably used as the resin. Any epoxy resin can be used as long as it has two or more epoxy groups in one molecule. Specific examples include phenol novolak type epoxy resin, o-cresol novolak type epoxy resin, those obtained by epoxidizing novolac resins of phenols and aldehydes, bisphenol A, bisphenol F and bisphenol Glycidyl ethers such as phenol S, glycidyl ester acid epoxy resins obtained by reacting polybasic acids such as phthalic acid and dimer acids with epichlorohydrin, linear aliphatic epoxy resins, Cycloaliphatic epoxy resins, heterocyclic epoxy resins, alkyl-modified polyfunctional epoxy resins, β-naphthol novolac epoxy resins, 1,6-dihydroxynaphthalene epoxy resins, 2,7 - Dihydroxynaphthalene epoxy resins, biphenyl epoxy resins, bishydroxybiphenyl epoxy resins, epoxy resins in which halogens such as bromine have been introduced to impart flame retardancy, etc.

The content of the resin is preferably 5 to 20% by mass, more preferably 5 to 15% by mass, further preferably 5 to 10% by mass.

In terms of hardeners containing epoxy resins, for example, phenol aralkyl resins; Phenol novolac resin obtained by reacting one or more mixtures of one or more of the group consisting of , isopropylphenol, octylphenol, etc., with formaldehyde, paraformaldehyde or p-xylene under an oxidation catalyst ; poly-p-hydroxystyrene resin; bisphenol compounds such as bisphenol A and bisphenol S; trifunctional phenols such as pyrogallol or phloroglucinol; maleic anhydride, phthalic anhydride, pyromellitic anhydride and other acid anhydrides; aromatic amines such as m-phenylenediamine, diaminodiphenylmethane, diaminodiphenylmethane, etc. A hardening accelerator may be blended to accelerate the reaction with the hardening agent. Examples of the hardening accelerator include 1,8-diazabicyclo(5,4,0)undecene-7, triphenylphosphine, benzyldimethylamine, 2-methylimidazole, and the like.

In the resin composition, other additives may be blended as needed. As other additives, in terms of stress reducing agents, rubber-like substances such as silicone rubber, polysulfide rubber, acrylic rubber, butadiene rubber, styrene-based block copolymers, and saturated elastomers, the above-mentioned resins Resin-like substances such as various thermoplastic resins and polysiloxane resins, and further modify part or all of epoxy resin or phenolic resin with amino polysiloxane, epoxy polysiloxane, alkoxy polysiloxane, etc. Resins derived from chemical properties, flame retardant additives include Sb ₂ O ₃ , Sb ₂ O ₄ , Sb ₂ O ₅ , etc., flame retardants include halogenated epoxy resins or phosphorus compounds etc., as the coloring agent, carbon black, iron oxide, dye, pigment, etc. are mentioned.

Since the ratio of the viscosity at low shear to the viscosity at high shear is small, the resin composition has excellent formability even in the case of compression molding, and can process materials (workpieces) such as semiconductor wafers without gaps. seal.

The resin composition is as above, and the viscosity at low shear is a resin composed of 20% by mass of bisphenol F-type epoxy resin (epoxy equivalent 170, viscosity 4Pa･s) and 80% by mass of inorganic oxide powder The viscosity of the composition measured with an E-type viscometer at a temperature of 30°C and a rotational speed of 1 rpm should be 45~70Pa･s, more preferably 45~65Pa･s. Since the viscosity at low shear is 45~70Pa･s, in the compression molding (compression molding) method, the viscosity is maintained at the stage where the work piece is pressed against the resin, so it has little influence on the linear deformation and the formability excellent.

The resin composition system, as the viscosity at high shear, will be a resin composition composed of 20% by mass of bisphenol F-type epoxy resin (epoxy equivalent 170, viscosity 4Pa･s) and 80% by mass of inorganic oxide powder , using an E-type viscometer, the viscosity measured at a temperature of 30°C and a rotational speed of 10rpm should be 35~55Pa･s, more preferably 40~55Pa･s. Since the viscosity at high shear is 35~55Pa･s, in compression molding (compression molding) method, low viscosity is maintained at high shear, so formability is excellent.

The value of the ratio of the viscosity at low shear to the viscosity at high shear (viscosity at low shear/viscosity at high shear) of the above-mentioned resin composition is preferably less than 1.5, more preferably less than 1.4, and further It should be below 1.3. Since the ratio of the viscosity at low shear to the viscosity at high shear is less than 1.5, in the compression molding (compression molding) method, the resin composition is kept low from the beginning to the end when the workpiece is pressed. Viscosity, so formability is excellent.

The production of the resin composition is carried out by stirring, dissolving, mixing, and dispersing predetermined amounts of the above-mentioned materials. As devices for mixing, stirring, and dispersing such a mixture, a crushing machine equipped with a stirring and heating device, a three-roll mill, a ball mill, a planetary mixer, etc. can be used. In addition, these devices may be used in combination as appropriate.

(use) The resin composition can be ideally used in the manufacture of semiconductor sealing materials, adhesives, heat sinks, etc. for electronic equipment. In particular, since the ratio of the viscosity at low shear to the viscosity at high shear is small, it can be ideally used in the manufacture of compression molded products.

[compression molded product] The compression molded product of this embodiment contains the above-mentioned resin composition. A known compression molding method can be used for the production method of the compression molded product. For example, it can be manufactured by compression-molding a resin composition by heating and curing it under conditions of a temperature of 180° C. and a pressure of 8 MPa using a compression molding machine.

Compression molded products contain a resin composition with a low ratio of low-shear viscosity to high-shear viscosity, so they have characteristics such as being able to seal workpieces such as semiconductor wafers with very little or no gaps. Therefore, the compression molded product can be ideally used as a semiconductor sealing material for electronic equipment, an adhesive member, a heat radiation sheet, and the like. [Example]

The following examples are shown to illustrate the present invention more specifically, but the explanation of the present invention is not limited by these examples.

[Examples 1-6, Comparative Examples 1-6] Put the alumina raw material powder with the maximum value in the range of average particle diameter (D ₅₀ ) in the range of 2-45 μm into LPG as fuel gas and oxygen as combustion support Inorganic oxide powder (spherical alumina powder) is produced by melting and spheroidizing in a high-temperature flame formed by gas. The cumulative frequency of each particle size region was adjusted to the value described in Table 1 by adjusting the blending amount of the raw material powder, or performing sieving and classification.

(Frequency Granularity Distribution) For the obtained inorganic oxide powder, use a particle size distribution measuring machine (manufactured by Beckman Coulter KK, "LS-13230"), with a refractive index of 1.68 and water as a measurement solvent, within 60 seconds, and an ultrasonic homogenizer of 200W. Under pre-treatment conditions, measure the frequency particle size distribution of the volume benchmark by the laser diffraction scattering method. From the obtained frequency particle size distribution, calculate the cumulative frequency in the first and second regions and the cumulative frequency in the particle size of 20~46μm, and calculate the value of the ratio of the cumulative frequency in the second region to the cumulative frequency in the first region . The results are shown in Table 1. In addition, in either of the Examples and the Comparative Examples, the cumulative frequency of the particle diameter in the range of 0.01 μm to 70 μm was 90% or more.

(specific surface area) Weigh 1.0 g of the obtained inorganic oxide powder, put it into the tank for measurement, and measure the BET specific surface area value after pretreatment. The results are shown in Table 1. As a measuring machine, "Macsorb HM model-1208" manufactured by MACSORB was used. The preprocessing conditions are shown below. Degassing temperature: 300°C Degassing time: 18 minutes Cooldown: 4 minutes

Then, each of the obtained inorganic oxide powders was mixed with the following materials and the following blending amounts, using a Henschel mixer ("FM-20C/I" manufactured by NIPPON COKE & ENGINEERING CO., LTD.), The mixture was mixed under the conditions of normal temperature and rotation speed of 2000 rpm to obtain a resin composition. 90 parts by mass of the above-mentioned spherical alumina powder, 5.5 parts by mass of biphenyl epoxy resin (YX-4000HK manufactured by Japan Epoxy Resin Co., Ltd.), phenolic resin (phenol aralkyl resin, Meiwa Chemical Industry Co., Ltd. Co., Ltd. MEHC-7800S) 4.8 parts by mass, triphenylphosphine (manufactured by Hokko Chemical Co., Ltd.: TPP) 0.15 parts by mass, and N-phenyl-3-aminopropyltrimethoxysilane (Shin-Etsu Chemical Industry Co., Ltd.: KBM-573) 0.35 parts by mass were dry blended. Afterwards, heating and kneading is carried out in a two-axis extrusion kneading machine (screw diameter D=25mm, L/D=10.2, paddle speed 50~120rpm, discharge rate 3.0kg/Hr, kneading material temperature 98~100℃) in the same direction. , to obtain a resin composition.

(fluidity) The fluidity of each obtained resin composition was measured by the method shown below. The results are shown in Table 1. Use a spiral flow mold and follow EMMI-1-66 (Epoxy Molding Material Institute; Society of Plastic Industry). The mold temperature was set to 175° C., the molding pressure was set to 7.4 MPa, and the dwell time was set to 90 seconds. Those of 200 cm or more were evaluated as ◯ (excellent), and those of less than 200 cm were evaluated as poor (×).

(viscosity) Regarding the obtained inorganic oxide powder, the viscosity (at low shear and high shear) when blended with an epoxy resin was measured by the method shown below. Using the obtained value, the value of the ratio of the viscosity at low shear to the viscosity at high shear was calculated. The results are shown in Table 1. A resin composition consisting of 20% by mass of bisphenol F-type epoxy resin (manufactured by Mitsubishi Chemical Corporation: Epikote 807, epoxy equivalent 170, viscosity 4Pa･s) and 80% by mass of the above-mentioned spherical alumina powder Regarding the viscosity of the material at low shear, the viscosity of the resin composition was measured using an E-type viscometer (trade name "TVE-10" manufactured by Toki Sangyo Co., Ltd.) at a temperature of 30°C and a rotational speed of 1 rpm. Regarding the viscosity at high shear, the viscosity of the resin composition was measured using an E-type viscometer (trade name "TVE-10" manufactured by Toki Sangyo Co., Ltd.) at a temperature of 30°C and a rotation speed of 10 rpm.

[Table 1] Example comparative example 1 2 3 4 5 6 1 2 3 4 5 6 Cumulative value of frequency in the range of 0.001-20μm/cumulative value of frequency in the range of 0.001-10μm - 1.3 1.3 1.2 1.4 1.3 1.3 1.1 1.5 1.4 1.2 1.2 1.4 Cumulative frequency of the first area vol% 46 52 45 49 42 58 44 48 49 38 67 28 Cumulative value of frequency in the range of 20-46μm vol% 34 32 43 27 41 19 45 28 10 50 twenty two 40 BET specific surface area m ² /g 1.5 1.1 1.2 1.3 1.4 1.5 1.0 1.2 1.8 1.1 1.8 1.7 Mobility (spiral flow evaluation) cm ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ Viscosity at low shear/Viscosity at high shear - 1.2 1.3 1.2 1.2 1.4 1.4 1.6 1.6 1.7 1.8 1.6 1.8 Viscosity at low shear Pa･s 49 61 56 63 60 69 95 88 108 93 120 80 Viscosity at high shear Pa･s 40 47 46 53 43 51 59 57 65 53 74 44

As shown in Table 1, the ratio of the viscosity of the resin composition system containing the inorganic oxide powder (spherical alumina powder) obtained in the examples at low shear to that at high shear is less than 1.5, and at low shear The ratio of the viscosity to the viscosity at high shear is small. Therefore, low viscosity is maintained from the beginning to the end when the workpiece is pressed against the resin composition by the compression molding method. As a result, compression molded articles can be produced with excellent formability.

none

Claims (6)

An inorganic oxide powder, in the volume-based frequency particle size distribution, The value of the ratio of the cumulative frequency of the second region within the particle diameter range of 0.001 μm to 20 μm to the cumulative frequency of the first region within the particle diameter range of 0.001 μm to 10 μm (cumulative frequency of the second region frequency/cumulative frequency of the first area) is 1.2~1.4, And the cumulative frequency in the range of particle size between 20 μm and 46 μm is 15~45% by volume, A resin composition consisting of 20% by mass of epoxy resin with a bisphenol F-type epoxy equivalent of 170 and a viscosity of 4Pa･s and 80% by mass of inorganic oxide powder was measured using an E-type viscometer at a temperature of 30°C and a rotational speed of 1rpm. The obtained viscosity is 45~70Pa･s. The inorganic oxide powder according to claim 1, wherein the cumulative frequency of the first region is 35-60% by volume. The inorganic oxide powder according to claim 1 or 2, wherein the specific surface area obtained by the BET method is 0.5~2.0m ² /g. A resin composition, containing the inorganic oxide powder according to any one of claims 1 to 3, and resin. The resin composition as claimed in claim 4 is used in the manufacture of compression molded products. A compression molded product comprising the resin composition according to claim 4 or 5.