WO2017179454A1

WO2017179454A1 - Ceramic-particle-containing composition

Info

Publication number: WO2017179454A1
Application number: PCT/JP2017/013957
Authority: WO
Inventors: 博丸澤; 淳柳原; 直晃阿部; 池田　豊; 廣瀬　左京
Original assignee: 株式会社村田製作所
Priority date: 2016-04-12
Filing date: 2017-04-03
Publication date: 2017-10-19

Abstract

The present invention provides a composition comprising: a ceramic particle containing vanadium and absorbing heat by latent heat; an insulating ceramic particle; and an insulating resin.

Description

Ceramic particle-containing composition

The present invention relates to a ceramic particle-containing composition, and more particularly to a composition containing ceramic particles containing vanadium, insulating ceramic particles, and insulating resin.

In recent years, thin and light smartphones and tablet terminals have begun to spread widely due to the progress of small communication devices. In such devices as well as the personal computer, the performance has been improved, and the problem related to heat generation of the CPU and the like has become conspicuous accordingly. Therefore, it is required to control the internal temperature of the device to a higher degree. Conventionally, a cooling device combining a heat sink and a fan or a Peltier element is known for such problems (see Patent Document 1).

The cooling device combining the heat sink and the fan or the Peltier element as described above has a relatively complicated structure and increases the equipment. Therefore, such a cooling device is difficult to use especially for thin devices, and is disadvantageous from the viewpoint of downsizing the devices. Moreover, since power is consumed, it is also disadvantageous from the viewpoint of low power consumption (battery life). Furthermore, since such a cooling device has a specific shape, the installation location is limited according to the shape, and for example, it is difficult to install in a location where the surface is uneven.

As a cooling device that solves the above problem, there is known a cooling device formed from a composition for manufacturing a cooling device comprising particles of a ceramic material that absorbs heat by latent heat and an insulating resin (Patent Document 2). reference). Such a cooling device can be used without a power source and can be designed freely.

JP 2010-223497 A International Publication No. 2015/118783

The cooling device described in Patent Document 2 uses vanadium oxide particles as ceramic material particles that absorb heat by latent heat. However, vanadium oxide has a tendency to decrease in resistance after phase transition and absorption of heat, and in the cooling device, vanadium oxide particles are joined together to form a path, resulting in low insulation of the composition There is. Therefore, it is not suitable for installation in a place where current can flow.

Therefore, an object of the present invention is to provide a cooling device that can be used without a power source, can be freely designed in accordance with the shape of the installation location, and has high insulation properties.

As a result of intensive studies to solve the above problems, the present inventors include particles of ceramic material, insulating ceramic particles, and insulating resin that absorb heat by latent heat associated with crystal structure phase transition or magnetic phase transition. It has been found that the above problem can be solved by forming a cooling device using the composition comprising the present invention, and the present invention has been achieved.

The present invention provides a composition comprising ceramic particles containing vanadium that absorbs heat by latent heat, insulating ceramic particles, and an insulating resin.

According to the present invention, an arbitrary space can be obtained by using a composition comprising ceramic material particles, insulating ceramic particles, and insulating resin that absorb heat by latent heat accompanying a crystal structure phase transition or a magnetic phase transition. A cooling device can be installed. Moreover, since the cooling device obtained from the composition of this invention has insulation, it can be installed also in the location where an electric current can flow, such as on a circuit board.

FIG. 1 is a graph showing a difference in cooling effect depending on the presence or absence of a cooling device in the example. FIG. 2 is a graph showing the relationship between the change rate of the endothermic amount and the integral width in the example.

The composition of the present invention includes particles of a ceramic material that absorbs heat by latent heat, particularly a ceramic material containing vanadium. The heat absorption of the ceramic material is performed by absorbing heat by latent heat. Such a ceramic material can smooth the temporal temperature change by temporarily absorbing excess heat by latent heat, and has a high cooling effect compared with conventional cooling devices such as graphite sheets Can be obtained.

The ceramic material containing vanadium is preferably a ceramic material mainly composed of vanadium oxide. Here, the ceramic material mainly composed of vanadium oxide means a ceramic material containing V and O, and includes, for example, vanadium dioxide and vanadium dioxide doped with other atoms.

In one embodiment, the ceramic material containing vanadium is vanadium oxide containing V, Ti and M (wherein M is at least one selected from W, Ta, Mo and Nb), Examples include vanadium oxide in which the molar part of M is from 0 to 15 parts by mole, and the molar part of Ti is from 0 to 30 parts by mole when the total of Ti and M is 100 parts by mole. It is done. Note that Ti and M are not essential components, and the mole part of Ti and M may be 0 mole part, that is, not contained. For example, when the mole content of Ti and M is 0 mole part, the ceramic material containing vanadium is vanadium oxide; when only the mole content of Ti is 0 mole part, the ceramic material containing vanadium is M If the only M-containing mole part is 0 mole part, the ceramic material containing vanadium is Ti-doped vanadium oxide.

In a preferred embodiment, the vanadium oxide is a vanadium oxide doped with Ti. That is, the content mole part of Ti in the vanadium oxide may be greater than 0 and 30 mole parts or less. Doping Ti improves the moisture resistance of vanadium oxide.

In the above-described vanadium oxide doped with Ti, the content mole part of Ti is preferably 2 mole parts or more and 30 mole parts or less, more preferably 5 mole parts or more and 10 mole parts or less. By making the content mole part of Ti within this range, the moisture resistance is further improved.

In the above aspect, when M is W, the molar content of M with respect to the total of 100 molar parts of V, Ti, and M is preferably larger than 0 molar part and 5 molar parts or less.

In the above embodiment, when M is Ta, Mo or Nb, the molar part of M contained with respect to the total of 100 parts by mole of V, Ti and M is preferably larger than 0 part by mole and 15 parts by mole or less.

In one embodiment, the ceramic material comprising vanadium has the formula:
V _1-xy M _x Ti _y O ₂
[Where:
M is W, Ta, Mo or Nb,
x is 0 or more and 0.15 or less,
y is 0 or more and 0.30 or less. ]
The vanadium oxide represented by these is mentioned.

In a preferred embodiment, x in the above formula is greater than 0. That is, the ceramic material containing vanadium is vanadium oxide doped with Ti. Doping Ti improves the moisture resistance of vanadium oxide.

X in the above formula is preferably 0.02 or more and 0.30 or less, and more preferably 0.05 or more and 0.10 or less. By setting it as such a range, moisture resistance further improves.

In the above embodiment, when M is W, y is preferably larger than 0 and not larger than 0.05.

In the above embodiment, when M is Ta, Mo or Nb, y is preferably greater than 0 and 0.15 or less.

The temperature at which the ceramic material containing vanadium undergoes phase transition is appropriately selected according to the object to be cooled, the purpose of cooling, and the like. For example, when the object to be cooled is a CPU, the temperature is 20 to 100 ° C., preferably 40 to 70. It is preferable that the phase transition occurs at ° C. The temperature at which the ceramic material containing vanadium of the present invention undergoes a phase transition, that is, the temperature at which the ceramic material containing vanadium exhibits latent heat is controlled by adding (doping) other atoms and adjusting the amount of the atoms added. Can be adjusted.

In the present invention, the ceramic material containing vanadium is used as particles (including powder). The average particle diameter D99 of the ceramic particles containing vanadium used in the present invention (the particle diameter at the point where the cumulative value is 99% in the cumulative curve where the particle size distribution is obtained on a volume basis and the total volume is 100%) is, in particular, Although it is not limited, Preferably they are 30 micrometers or more and 120 micrometers or less, More preferably, they are 50 micrometers or more and 110 micrometers or less, More preferably, they are 60 micrometers or more and 100 micrometers or less. The average particle size can be measured using an image analysis type particle size distribution measuring apparatus. By making the average particle diameter D99 to be 120 μm or less, the supply of the composition of the present invention with a dispenser is facilitated without problems such as filler sedimentation and nozzle clogging, and the surface of the cooling device obtained from the composition of the present invention Becomes flat. Further, when the average particle diameter D99 is 30 μm or more, the handling of the particles becomes easy, the fluidity of the composition of the present invention can be maintained, and the surface of the obtained cooling device becomes flat.

Therefore, the present invention also provides ceramic particles containing vanadium having an average particle diameter D99 of 30 μm or more and 120 μm or less, preferably 50 μm or more and 120 μm or less.

For the ceramic particles containing vanadium, for example, powders of oxides of V, Ti and M as raw materials are prepared, and then the powders are mixed at a predetermined ratio and heat-treated in a nitrogen / hydrogen / water atmosphere. Can be manufactured. The ceramic particles containing vanadium thus obtained may have an average particle size larger than the preferable average particle size. In such a case, a step for obtaining particles having an average particle diameter in the above range from the obtained particles may be included.

As a step for obtaining particles having an average particle size in the above range from the obtained particles, a step of selecting particles having a desired particle size from the obtained particles by classification, mesh pass, or the like. The particles are pulverized by a jet mill or the like to obtain a smaller average particle size. When the pulverization is performed, the crystal structure of the particles is partly destroyed and the moisture resistance may be reduced. Therefore, a method of obtaining particles having an average particle diameter in the above range from the obtained particles is a method that does not require pulverization, For example, classification and mesh pass are preferable.

Particles selected by classification, mesh pass, etc. can maintain high crystallinity without changing crystallinity before and after selection. For example, the change rate of the integral width in the powder X-ray diffraction analysis may be preferably 8% or less, more preferably 4% or less before and after selection. Specifically, the selected particles may have an integral width in a powder X-ray diffraction analysis of 0.230 ° or less, preferably 0.220 ° or less. Ceramic particles containing vanadium having such an integral width have high moisture resistance.

Therefore, the present invention also provides ceramic particles containing vanadium having an integral width of 0.230 ° or less in powder X-ray diffraction analysis.

Here, in this specification, the width of the rectangle when the plane index 011 peak as the main peak is converted into a rectangle having the same area as the peak area and the same height as the peak intensity is expressed as follows. Set to "Integral width". The larger the integration width, the greater the variation in the lattice spacing of the crystal and the lower the crystallinity.

In a preferred embodiment, the surface of the ceramic particle containing vanadium is covered with an insulating layer. In other words, the ceramic particles containing vanadium are coated with an insulating material. Thus, by covering the ceramic particles containing vanadium with an insulating material, the insulating properties are further improved, and when completely covered, the moisture resistance is improved.

The insulating material constituting the insulating layer is not particularly limited as long as it is an insulating material, and may be a resin material or an inorganic material. A preferred insulating material is an inorganic material. By using an inorganic material, the moisture resistance is further improved.

Examples of the resin used as the insulating material include a fluorine resin, a silicone resin, and a silica resin.

Examples of the inorganic substance used as the insulating substance include silicon compounds such as SiO _x (x is 1.5 to 2.5, typically SiO ₂ ), TiO ₂ , Al ₂ O ₃ , and Cr oxidation. And SiO _x is preferably used.

In the composition of the present invention, the content of the ceramic particles containing vanadium is preferably 30 vol% or more, more preferably 35 vol% or more, and further preferably 40 vol% or more. By setting the content of the ceramic particles containing vanadium to 30 vol% or more, a high latent heat amount can be secured. The content of the ceramic particles containing vanadium is preferably 60 vol% or less, more preferably 50 vol% or less, and further preferably 45 vol% or less. By setting the content of the ceramic particles containing vanadium to 60 vol% or less, an appropriate viscosity of the composition can be ensured.

The composition of the present invention further comprises insulating ceramic particles. The ceramic particles containing vanadium tend to decrease in resistance after absorbing heat and undergoing phase transition. In the composition, when the ceramic particles containing vanadium are connected to form a path, Insulation can be reduced. In particular, in a paste filled with ceramic particles containing vanadium (particles having an average particle size D99 of 30 μm or more and 120 μm or less, preferably 50 μm or more and 120 μm or less), the particles are selected during the time until curing after the paste is applied. Therefore, the path is formed on the bottom surface contacting the substrate mounting surface, which may cause a problem of deterioration in insulation. However, when the insulating ceramic particles are included in the composition, the presence of the insulating ceramic particles between the ceramic particles containing vanadium suppresses the formation of a path of the ceramic particles containing vanadium. As a result, the insulating property of the composition, and thus the insulating property of the cooling device formed from this composition is improved. Therefore, the composition of the present invention can be applied directly to a location where current can flow, such as on a circuit board.

The insulating ceramic material constituting the insulating ceramic particles is not particularly limited as long as it is insulative, and examples thereof include glass, metal oxide, metal nitride, and metal carbide.

The insulating ceramic material has a resistivity at 25 ° C. of preferably 1 × 10 ⁶ Ω · cm or more, more preferably 1 × 10 ⁸ Ω · cm or more, and further preferably 1 × 10 ¹⁰ Ω · cm or more. .

In a preferred embodiment, the insulating ceramic material has thermal conductivity. The insulating ceramic material having such thermal conductivity is preferably 1.0 W / (m · K) or more, preferably 10 W / (m · K) or more, more preferably 30 W / (m · K) or more. Has thermal conductivity.

In a preferred embodiment, the insulating ceramic material has heat dissipation. By using the insulating ceramic material having heat dissipation, the cooling characteristics of the cooling device formed from the composition of the present invention are improved.

In a preferred embodiment, the insulating ceramic material includes alumina (Al ₂ O ₃ ) and silica (SiO ₂ ).

In a preferred embodiment, the insulating ceramic particles composed of the insulating ceramic material preferably have an average particle diameter (D99) of 50 μm to 120 μm, more preferably 60 μm to 100 μm. The average particle size of the insulating ceramic particles is preferably about the same as the ceramic particles containing vanadium.

Insulating ceramic particles may be used alone or in combination of two or more.

In one embodiment, the content of the insulating ceramic particles in the composition of the present invention is preferably 10 vol% or more, more preferably 15 vol% or more. By setting the content of the insulating ceramic particles to 10 vol% or more, high insulating properties can be ensured. Further, the content of the insulating ceramic particles is preferably 25 vol% or less, more preferably 20 vol% or less, and still more preferably 18 vol% or less. By setting the content of the insulating ceramic particles to 25 vol% or less, an appropriate viscosity of the composition can be ensured.

In another embodiment, the content of the insulating ceramic particles in the composition of the present invention is preferably 20 vol% or more, more preferably 25 vol% or more. By setting the content of the insulating ceramic particles to 20 vol% or more, higher thermal conductivity can be ensured. The content of the insulating ceramic particles is preferably 40 vol% or less, more preferably 35 vol% or less. By setting the content of the insulating ceramic particles to 40 vol% or less, the viscosity of the composition can be reduced.

In a preferred embodiment, the content of the ceramic particles containing vanadium is 30 vol% or more, preferably 30 vol% or more and 50 vol% or less, and the content of the insulating ceramic particles is 10 vol% or more, preferably 10 vol% or more and 20 vol% or less. It is.

In another preferred embodiment, the content of the ceramic particles containing vanadium is 30 vol% or more, preferably 30 vol% or more and 50 vol% or less, and the content of the insulating ceramic particles is 20 vol% or more and 40 vol% or less.

The total content of the ceramic particles containing vanadium and the insulating ceramic particles is preferably 40 vol% or more and 90 vol% or less, more preferably 50 vol% or more and 70 vol% or less.

The composition of the present invention further comprises an insulating resin. This insulating resin has fluidity and may be in a liquid or paste form. When it does not have fluidity at room temperature, it may be fluidized, for example, by heating or by adding a solvent. A cooling device can be obtained by providing the composition of the present invention to a predetermined part of an electronic component or an electronic device, where it is cured and / or solidified. When the composition of the present invention is provided to a predetermined part of an electronic component or electronic device, the composition of the present invention has a shape corresponding to the part provided by its fluidity, and is substantially cured or solidified in that shape. And become a cooling device. Therefore, by using the composition of the present invention, it is possible to install a cooling device at a location having a fine and complicated shape.

The insulating resin is not particularly limited, and for example, various thermosetting resins and thermoplastic resins can be used.

The thermosetting resin is not particularly limited, and examples thereof include urethane resin, epoxy resin, polyimide resin, silicone resin, fluorine resin, liquid crystal polymer resin, and polyphenyl sulfide resin. These may be used alone or in admixture of two or more.

When a thermosetting resin is used as the insulating resin, the cooling device manufacturing composition may contain a curing agent, if desired. Such a curing agent is not particularly limited, and examples thereof include phenol resins, polyamines, and imidazoles.

The thermoplastic resin is not particularly limited, and examples thereof include polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinyl acetate, acrylic resin, nylon, and polyester. These may be used alone or in admixture of two or more.

The insulating resin is preferably a low adhesion resin. By using the low-adhesion resin, it becomes easy to remove after installing as a cooling device.

The insulating resin to be used can be appropriately selected according to the type and application of the electronic device in which the cooling device is installed using the composition of the present invention. For example, when used for general electronic equipment, an epoxy resin or polyimide resin having solder heat resistance and high versatility is preferable. When used for equipment requiring heat resistance, a glass such as a phenol novolac type epoxy resin or polyimide resin is used. A resin having a transition temperature of 150 ° C. or higher is preferred. In order to increase the thermal conductivity of the cooling device, it is preferable to use a liquid crystal polymer resin having a mesogenic group.

The composition of the present invention may further contain a solvent.

The solvent can be appropriately selected from general-purpose solvents according to various factors such as the type and amount of the insulating resin used and the properties required for the composition. For example, dipropylene methyl ether acetate, toluene, methyl ethyl ketone Etc. are used.

The composition of the present invention may further contain additives such as a dispersant, a curing accelerator, and an antifoaming agent. A dispersing agent, a hardening accelerator, an antifoaming agent, etc. can be suitably selected as needed from what is used in a general polymer composition.

The composition of the present invention is not particularly limited. For example, the ceramic particles containing vanadium, the insulating ceramic particles, and the insulating resin, and optionally a curing agent, a solvent, an additive, and the like are mixed with a commercially available mixer or the like. Can be manufactured.

The viscosity of the composition of the present invention can be selected according to the method of providing the composition to electronic equipment, the shape of the cooling device to be obtained, etc., but preferably 0.5 Pa · s to 120 Pa · s, more It may be preferably 1.0 Pa · s or more and 80 Pa · s or less, and more preferably 5 Pa · s or more and 50 Pa · s or less (E-type viscosity, shear rate 10 s ⁻¹ ).

The viscosity of the composition of the present invention can be adjusted by various methods. For example, adjusting the amount and particle size of ceramic particles to be used, adjusting the type, combination and amount of insulating resin to be used, chemically modifying the insulating resin, adding additives, adding solvents, etc. be able to.

The composition of the present invention is provided in a place where it comes into contact with a heat source of an electronic component or an electronic device, or in the vicinity of the heat source, for example, a place affected by heat from the heat source. Since the composition of the present invention can have fluidity as described above, it can be provided on a surface and / or space having a fine and complicated shape. In addition, since the insulating property is high, it can also be provided on a circuit board or the like where current can flow. Therefore, it can also be provided in places that have conventionally been dead spaces.

The method for providing the composition of the present invention is not particularly limited, and examples thereof include dispenser application, dispenser injection, screen printing, electrostatic application, inkjet printing, spray spraying, dipping, die coating, blade coating, and the like.

The composition provided as described above forms a cooling device by curing or solidifying there. Accordingly, the present invention also provides a cooling device manufactured using the composition of the present invention.

As described above, since the composition of the present invention has fluidity, the cooling device of the present invention obtained by curing or solidifying the composition can have any shape and size.

Since the cooling device of the present invention contains an insulating ceramic, it exhibits high insulating properties.

The cooling device of the present invention has a dielectric breakdown voltage of 2 mm, preferably 0.1 kV or more, more preferably 0.5 kV or more, still more preferably 1.0 kV or more, and even more preferably 1.5 kV or more.

The surface resistance of the cooling device of the present invention is preferably 10 GΩ or more, more preferably 100 GΩ or more, and even more preferably 1000 GΩ or more.

The present invention also provides an electronic component and an electronic apparatus having the cooling device of the present invention.

The electronic component is not particularly limited, but for example, an integrated circuit (IC) such as a central processing unit (CPU), a power management IC (PMIC), a power amplifier (PA), a transceiver IC, and a voltage regulator (VR). Light emitting diodes (LEDs), incandescent bulbs, semiconductor lasers and other light emitting elements, field effect transistors (FETs) and other components that can be heat sources, and other components such as substrates, heat sinks, housings, etc. Examples of parts that are commonly used.

The electronic device is not particularly limited, and examples thereof include a mobile phone, a smartphone, a personal computer (PC), and a tablet terminal.

Preparation starting material of the ceramic particles comprising a synthetic example vanadium, vanadium trioxide _(V _{2 O} 3), vanadium pentoxide _(V _{2 O} 5), tungsten oxide _(WO 3), and titanium oxide (TiO ₂₎ using These were weighed so that V: W: T: O = 0.895: 0.005: 0.1: 2 (molar ratio), and dry-mixed. Thereafter, heat treatment was performed at 1000 ° C. for 4 hours in a nitrogen / hydrogen / water atmosphere, and a powder of V _0.895 W _0.005 Ti _0.1 O ₂ (hereinafter, also referred to as “VWTi powder” in the examples) as a ceramic material. Got.

-Preparation of paste composition 1
The above-obtained V _0.895 W _0.005 Ti _0.1 O ₂ powder, Al ₂ O ₂ powder, and silicone resin were blended in the proportions shown in Table 1 below, and a planetary mixer Were mixed for about 2 hours to obtain paste compositions of the present invention (samples 1 to 8). Thereafter, a cured resin cured at 120 ° C. for 1 hour was prepared, and endothermic and heat dissipation characteristics were evaluated.

Evaluation / Endotherm, Evaluation of Heat Dissipation Characteristics About the cured resin obtained above, by DSC (Differential Scanning Calorimetry) method, the heating rate is 10 K / min, from 0 ° C. to 100 ° C., and then to 0 ° C. in a nitrogen atmosphere By sweeping, the amount of heat absorbed during temperature rise and the amount of heat released during temperature drop were measured. Table 1 shows the peak heat absorption per unit volume and unit mass. A peak was present at about 58 ° C. during endotherm and at about 55 ° C. during heat release.

Viscosity measurement The viscosity of the paste composition obtained above was measured with an E-type viscometer (shear rate 20 s ^-1 for sample number 5 and shear rate 10 s ^-1 for sample numbers 6 to 8). The results are shown in Table 1.

From the above results, Samples 4 to 8 having a V _0.895 W _0.005 Ti _0.1 O ₂ powder content of 30 vol% or more show an endotherm of 50 J / cm ² or more, and are useful as a cooling device. It was confirmed that it could be. Further, from the viscosity of the paste compositions of sample numbers 5 to 8, the sample numbers 5 and 6 in which the content of Al ₂ O ₃ powder is 20.0 vol% have a viscosity of 50 Pa · s or less, and the substrate It was confirmed that it was preferable in view of the applicability to etc.

・ Measurement of surface resistance value and dielectric strength voltage Two electrodes were provided on a mounting substrate with a width of 0.2 mm, the paste composition of Samples 4 to 8 was applied so as to straddle the electrodes, and cured at 120 ° C. for 1 hour. . The surface resistance value was measured with an insulation resistance meter YHP4329A (measurement voltage 10 V, number of samples n = 5), and the withstand voltage was measured with an insulation voltage meter KIKUUSUI TOS8650 (number of samples n = 5). Moreover, the measurement of the surface resistance value and the withstand voltage was also measured when the paste was not applied and when only the resin not containing ceramic particles was applied. The results are shown in Table 2 and Table 3, respectively.

From the above results, the samples 5-8 containing Al ₂ O ₃ powder, as compared to Sample 4 containing no Al ₂ O ₃ powder, it was confirmed that a high withstand voltage and surface resistance.

Evaluation of Cooling Effect The paste composition of Sample 5 was applied at a coating thickness of about 0.2 mm around a fixed resistance heater assuming a heat generating component using a dispenser (nozzle inner diameter 250 μm). Then, it was cured at 120 ° C. for 1 hour to form a cooling device. The fixed resistance heater was operated and the temperature of the fixed resistance surface was measured with a thermocouple to obtain a temperature profile. As a target, a temperature profile was obtained when no cooling device was installed. The results are shown in FIG.

From the above results, it was confirmed that an increase in the temperature of the surface of the fixed resistance can be suppressed by installing a cooling device obtained from the paste composition of the present invention.

-Preparation of paste composition 2
Paste compositions (Samples 9 to 12) of the present invention were obtained in the same manner as Samples 5 to 8, except that SiO ₂ powder was used in the ratio shown in Table 4 instead of Al ₂ O ₂ powder.

Evaluation The withstand voltage of the paste compositions of Samples 9 to 12 was evaluated in the same manner as described above. The results are shown in Table 3.

・ Measurement of thermal conductivity About paste compositions of Samples 5 to 12,
A paste was printed with a bar coater and cured at 120 ° C. for 1 hour, and then a test piece processed into a disk shape having a diameter of 10 mmφ and a thickness of about 1 mm was produced. The density, specific gravity, and thermal diffusion coefficient of the obtained test piece were measured, and the thermal conductivity was measured. A Xe flash apparatus was used for the thermal diffusion coefficient. The results are shown in Table 4.

From the above results, it was confirmed that the paste compositions of Samples 5 to 8 containing Al ₂ O ₃ powder had higher thermal conductivity than the paste compositions of Samples 9 to 12 containing SiO ₂ powder.

・ Granularity adjustment 1
The powder of V _0.895 W _0.005 Ti _0.1 O ₂ obtained in the above synthesis example was pulverized by a jet mill (air pressure: 0.25, 0.35 and 0.45 MPa, respectively), and the particle size Of smaller powders (Samples 13-15).

・ Granularity adjustment 2
The powders of V _0.895 W _0.005 Ti _0.1 O ₂ obtained in the above synthesis example were selected by a mesh pass (100 μm and 40 μm, respectively) to obtain powders with smaller particle sizes (Samples 16 to 17).

・ Granularity adjustment 3
The V _0.895 W _0.005 Ti _0.1 O ₂ powder obtained in the above synthesis example was controlled by adjusting the classification point by adjusting the classification rotor rotation speed, air flow rate, and raw material supply amount of the classifier. Classification was performed to obtain two kinds of powders having different particle sizes (Samples 18 to 19).

Measurement of particle size The powder obtained in the synthesis example and the powders of Samples 13 to 19 were measured by a dry method using an image analysis type particle size distribution measuring apparatus (QICPIC, manufactured by Nippon Laser), and D10, D50, D90 and D99 were obtained. The results are shown in Table 5.

Evaluation of surface characteristics The paste composition of sample 1 and the paste composition using the powders of samples 13 to 19 were applied on a substrate at a thickness of 1 mm and cured at 120 ° C. for 1 hour. The case where the surface was smooth by visual observation was evaluated as ◯, and the surface having irregularities was evaluated as ×. The results are shown in Table 5.

・ Measurement of integral width The powder obtained in the synthesis example and the powders of samples 13 to 19 were subjected to powder X-ray diffraction (XRD) analysis using the following apparatus and conditions, and the main peak (surface index 011) was measured. The integral width was measured. The results are shown in Table 5.
XRD analysis:
Measuring device: Rigaku powder X-ray diffractometer Measuring conditions: Optical system Concentration method optical system 2θ 20 ° -80 °
Step width 0.02 °
Scanning speed 10 ° / min
Analysis method: Rigaku integrated intensity calculation software is used

-Humidity resistance evaluation The DSC peak endotherm was measured as an initial value for the powder obtained in the synthesis example and the powders of Samples 13 to 19. Next, the powder was allowed to stand for 500 hours in an environment of 85 ° C. and a relative humidity of 85%, and the DSC peak endotherm was measured again to determine the rate of change from the initial value. The results are shown in Table 5. The relationship with the integration width is shown in FIG.

From the above results, the V _0.895 W _0.005 Ti _0.1 O ₂ powder has a D99 having a D99 of 120 μm or more, and a D99 having a D99 of 30 μm or less has good flatness. There wasn't. When D99 is 120 μm or more, the particle size is too large and the surface becomes rough, and when D99 is 30 μm or less, the specific surface area becomes large and the fluidity of the paste composition is lowered, so that the surface is considered rough.

Also, from Table 5 and FIG. 2, samples 13 to 15 obtained by physically pulverizing the V _0.895 W _0.005 Ti _0.1 O ₂ powder obtained by the heat treatment showed a large endothermic amount in the moisture resistance test. A significant decrease was confirmed. It was confirmed that these powders had an integral width larger than that before pulverization. On the other hand, samples 16 to 19 in which the powders having the optimum particle diameter were selected without pulverizing the V _0.895 W _0.005 Ti _0.1 O ₂ powder obtained by the heat treatment showed a slight decrease in the endothermic amount. The integration width was also slightly increased. FIG. 2 showing the relationship between the rate of change of the endothermic amount and the integral width in the moisture resistance test confirmed that the powder having a small integral width, that is, high crystallinity, can suppress a decrease in the endothermic amount even after the moisture resistance test. .

The present disclosure includes the following aspects.
Aspect 1.
A composition comprising ceramic particles containing vanadium that absorbs heat by latent heat, insulating ceramic particles, and insulating resin;
Aspect 2.
The vanadium-containing ceramic particles are vanadium oxide particles containing V, Ti, and M (where M is at least one selected from W, Ta, Mo, and Nb), and the sum of V, Ti, and M Aspect 1 is characterized in that the content mole part of M is from 0 to 15 mole parts, and the content mole part of Ti is from 0 to 30 mole parts, with 100 mole parts being 100 mole parts. A composition as described;
Aspect 3.
In the vanadium oxide particles, the content mole part of Ti when the sum of V, Ti, and M is 100 mole parts is 5 mole parts or more and 10 mole parts or less;
Aspect 4.
Ceramic particles containing vanadium have the formula:
V _1-xy M _x Ti _y O ₂
[Where:
M is W, Ta, Mo or Nb,
x is 0 or more and 0.15 or less,
y is 0 or more and 0.30 or less. ]
The composition according to aspect 1, wherein the composition is a particle of vanadium oxide represented by:
Aspect 5
The composition according to aspect 4, wherein x is 0.05 or more and 0.10 or less;
Aspect 6
The composition according to any one of aspects 1 to 5, wherein the ceramic particles containing vanadium have an average particle diameter D99 of 50 μm or more and 120 μm or less;
Aspect 7.
The composition according to any one of embodiments 1 to 6, wherein the integral width in the powder X-ray diffraction analysis of the ceramic particles containing vanadium is 0.230 ° or less;
Aspect 8
The composition according to any one of embodiments 1 to 7, wherein the ceramic particles containing vanadium are covered with an insulating layer;
Aspect 9.
The composition according to any one of embodiments 1 to 8, wherein the insulating ceramic particles have thermal conductivity;
Aspect 10
The composition according to any one of embodiments 1 to 9, wherein the insulating ceramic particles are silica particles or alumina particles;
Aspect 11
The composition according to any one of embodiments 1 to 10, wherein the content of the ceramic particles containing vanadium is 30 vol% or more and the content of the insulating ceramic particles is 10 vol% or more;
Aspect 12
The composition according to any one of embodiments 1 to 11, wherein the content of the ceramic particles containing vanadium is 30 vol% or more and 50 vol% or less;
Aspect 13
The composition according to any one of embodiments 1 to 12, wherein the content of the insulating ceramic particles is 10 vol% or more and 20 vol% or less;
Aspect 14.
The composition according to any one of embodiments 1 to 12, wherein the content of the insulating ceramic particles is 20 vol% or more and 40 vol% or less;
Aspect 15
Embodiments 1 to 14 characterized in that the insulating resin is one or more thermoplastic resins selected from polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinyl acetate, acrylic resin, nylon and polyester. A composition according to any of the above;
Aspect 16.
A cooling device formed from the composition according to any of embodiments 1-15;
Aspect 17
An electronic component having the cooling device according to aspect 16;
Aspect 18.
Vanadium oxide particles containing V, Ti and M (where M is at least one selected from W, Ta, Mo and Nb),
When the total amount of V, Ti and M is 100 mole parts, the mole content of M is 0 to 15 mole parts, and the mole content of Ti is 0 to 30 mole parts,
Vanadium oxide particles having a particle size D99 of 50 μm or more and 120 μm or less;
Aspect 19
formula:
V _1-xy M _x Ti _y O ₂
[Where:
M is W, Ta, Mo or Nb,
x is 0 or more and 0.15 or less,
y is 0 or more and 0.30 or less. ]
Vanadium oxide particles represented by the formula: Vanadium oxide particles having a particle diameter D99 of 50 μm or more and 120 μm or less;
Aspect 20
Vanadium oxide particles containing V, Ti and M (where M is at least one selected from W, Ta, Mo and Nb),
When the total amount of V, Ti and M is 100 mole parts, the mole content of M is 0 to 15 mole parts, and the mole content of Ti is 0 to 30 mole parts,
Vanadium oxide particles having an integral width in powder X-ray diffraction analysis of 0.230 ° or less;
Aspect 21.
formula:
V _1-xy M _x Ti _y O ₂
[Where:
M is W, Ta, Mo or Nb,
x is 0 or more and 0.15 or less,
y is 0 or more and 0.30 or less. ]
The vanadium oxide particle | grains which are the particle | grains represented by these, Comprising: The integral width in a powder X-ray-diffraction analysis is 0.230 degrees or less.

The composition of the present invention can be used, for example, to manufacture a cooling device for a small communication terminal in which the problem of countermeasures against heat has become prominent.

Claims

A composition comprising ceramic particles containing vanadium that absorbs heat by latent heat, insulating ceramic particles, and an insulating resin.
The vanadium-containing ceramic particles are vanadium oxide particles containing V, Ti, and M (where M is at least one selected from W, Ta, Mo, and Nb), and the sum of V, Ti, and M The content mole part of M is from 0 mole part to 15 mole parts, and the content mole part of Ti is from 0 mole part to 30 mole parts, when the content is 100 mole parts. A composition according to 1.
3. The composition according to claim 2, wherein in the vanadium oxide particles, the content mole part of Ti is 5 mole parts or more and 10 mole parts or less when the total of V, Ti, and M is 100 mole parts. .
Ceramic particles containing vanadium have the formula:
V 1-xy M x Ti y O 2
[Where:
M is W, Ta, Mo or Nb,
x is 0 or more and 0.15 or less,
y is 0 or more and 0.30 or less. ]
The composition according to claim 1, wherein the composition is vanadium oxide particles represented by the formula:
Y is 0.05 or more and 0.10 or less, The composition of Claim 4 characterized by the above-mentioned.
6. The composition according to claim 1, wherein the average particle diameter D99 of the ceramic particles containing vanadium is 30 μm or more and 120 μm or less.
The composition according to claim 6, wherein the average particle diameter D99 of the ceramic particles containing vanadium is 50 µm or more and 120 µm or less.
The composition according to any one of claims 1 to 7, wherein the integral width in the powder X-ray diffraction analysis of the ceramic particles containing vanadium is 0.230 ° or less.
The composition according to any one of claims 1 to 8, wherein the ceramic particles containing vanadium are coated with an insulating layer.
The composition according to any one of claims 1 to 9, wherein the insulating ceramic particles have thermal conductivity.
The composition according to any one of claims 1 to 10, wherein the insulating ceramic particles are silica particles or alumina particles.
The composition according to any one of claims 1 to 11, wherein the content of the ceramic particles containing vanadium is 30 vol% or more and the content of the insulating ceramic particles is 10 vol% or more.
The composition according to any one of claims 1 to 12, wherein the content of the ceramic particles containing vanadium is 30 vol% or more and 50 vol% or less.
The composition according to any one of claims 1 to 13, wherein the content of the insulating ceramic particles is 10 vol% or more and 20 vol% or less.
The composition according to any one of claims 1 to 13, wherein the content of the insulating ceramic particles is 20 vol% or more and 40 vol% or less.
The insulating resin is one or more thermoplastic resins selected from polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinyl acetate, acrylic resin, nylon and polyester, characterized in that 15. The composition according to any one of 15.
A cooling device formed from the composition according to any one of claims 1 to 16.
An electronic component having the cooling device according to claim 17.
Vanadium oxide particles containing V, Ti and M (where M is at least one selected from W, Ta, Mo and Nb),
When the total amount of V, Ti and M is 100 mole parts, the mole content of M is 0 to 15 mole parts, and the mole content of Ti is 0 to 30 mole parts,
Vanadium oxide particles having a particle size D99 of 30 μm or more and 120 μm or less.
formula:
V 1-xy M x Ti y O 2
[Where:
M is W, Ta, Mo or Nb,
x is 0 or more and 0.15 or less,
y is 0 or more and 0.30 or less. ]
Vanadium oxide particles represented by the formula (1), having a particle size D99 of 30 μm or more and 120 μm or less.
Vanadium oxide particles containing V, Ti and M (where M is at least one selected from W, Ta, Mo and Nb),
When the total amount of V, Ti and M is 100 mole parts, the mole content of M is 0 to 15 mole parts, and the mole content of Ti is 0 to 30 mole parts,
Vanadium oxide particles having an integral width of 0.230 ° or less in powder X-ray diffraction analysis.
formula:
V 1-xy M x Ti y O 2
[Where:
M is W, Ta, Mo or Nb,
x is 0 or more and 0.15 or less,
y is 0 or more and 0.30 or less. ]
The vanadium oxide particle | grains which are the particle | grains represented by these, Comprising: The integral width in a powder X-ray-diffraction analysis is 0.230 degrees or less.