WO2004108829A1

WO2004108829A1 - Composition and coating film excellent in heat dissipation and heat shielding

Info

Publication number: WO2004108829A1
Application number: PCT/JP2004/007702
Authority: WO
Inventors: Noriyoshi Kaneko
Original assignee: Ceramission Co., Ltd.
Priority date: 2003-06-04
Filing date: 2004-06-03
Publication date: 2004-12-16
Also published as: JP2004359811A

Abstract

A composition excellent in heat dissipation and heat shielding is composed of a mixture of an alkoxysilane solution, an aqueous dispersion of colloidal silica, a silicon oxide powder, an aluminum oxide powder and a kaolin powder. The alkoxysilane may contain at least one of dialkoxysilanes, trialkoxysilanes and tetraalkoxysilanes, and may also contain a titanium alkoxide and/or an aluminum alkoxide. The alkoxysilane solution, aqueous dispersion of colloidal silica, silicon oxide powder, aluminum oxide powder and kaolin powder are mixed right before use.

Description

Specification

Compositions and films with excellent heat dissipation and heat insulation

Technical field

The present invention relates to a composition and a film having excellent heat dissipation and heat shielding properties. More specifically, the present invention relates to a composition and a film which are applied to an object which easily accumulates heat, forms a film, and releases the accumulated heat. Also, the present invention relates to a composition and a film having excellent heat dissipation and heat shielding properties, which have an effect of suppressing a temperature rise of an object by shielding heat.

^ Scenic technology

[0002] Far-infrared radiation paints or far-infrared radiation compositions have been known for a long time. The composition for far-infrared radiation, such as a paint for far-infrared radiation, is a paint or composition for enhancing the thermal efficiency of a heating body such as a far-infrared heater. Many of these paints or compositions for far-infrared radiation contain a binder mixed with an oxide such as aluminum oxide, titanium, silicon, zirconium, iron, copper, cobalt, nickel, manganese, and chromium. As the binder, a silicone resin, a phosphate, a silicate, or the like is used. Such a far-infrared radiation composition or paint is used for a heating element and is used to enhance the heating effect of the heating element.

[0003] As a binder, a composition for far-infrared radiation using an alkoxysilane (organic silicate) is known. For example, Patent Document 1 describes a composition in which alumina powder or silica powder is added to an alkyl silicate or a mixture of an alkyl silicate and a metal alkoxide, and this composition is useful for forming a far-infrared radiation layer of a heater. Is described.

[0004] Patent Document 2 describes a coating composition for forming a highly durable electric insulating film comprising an organoalkoxysilane, manganese dioxide, and chromium trioxide. Further, Patent Document 3 describes a composition comprising a silicon alkoxide or a metal alkoxide and a mixture thereof and a far-infrared radiation pigment, and describes that this composition is applied to the surface of a protective substrate for a heater. . Patent Document 4 discloses that alkoxysilane and ceramic powder having excellent far-infrared radiation characteristics are dispersed in an alcohol solvent. The composition is described as being applied to the inner wall of a dryer to enhance the drying effect.

[0005] Alkoxysilane is hydrolyzed and condensed by the action of moisture, and finally forms a polymer. By utilizing this action as a binder, a mixture of alkoxysilane and various powders in a solvent can be applied to an object to form a film. However, when stored for a long time in the presence of water, the alkoxysilane gradually hydrolyzes and eventually becomes a polymer. When it becomes a polymer, it has no fluidity and can no longer be applied to objects. That is, there is a problem that alkoxysilane cannot be used stably as a binder.

[0006] The present invention uses an alkoxysilane as a binder stably, coats an object or the like to form a film, promotes the release of heat accumulated in the object, and releases the heat from a surrounding heating element. It is intended to suppress the temperature rise of the object by shielding the heat. Many electric-electronic devices generate heat during use. For example, there are various devices using a motor or a motor, various devices using a lamp or the like, various devices using a semiconductor, and the like. The equipment is composed of various parts. Some types of equipment and components generate heat by themselves and increase in temperature, while others do not generate heat by themselves but receive heat from a heating element that generates heat in the surroundings and increase in temperature.

[0007] Among various devices, particularly electronic devices have a strong demand for miniaturization. Removal of generated heat is a major problem in realizing miniaturization of equipment. The present invention is applied to a device or its parts by applying a coating to form a film and releasing the heat accumulated in the device or its components, and by shielding the heat received from surrounding heating elements. It is intended to suppress the rise in temperature. By minimizing the temperature rise of equipment and parts, it is possible to easily reduce the size of the equipment.

[0008] As described above, it is widely used to enhance the heating effect of a heating element by mixing a powder of a far-infrared radiation material such as ceramics with a binder and forming a film on a heating element such as a heater. Is being done. By mixing the powder of the far-infrared radioactive substance with the binder to form a film, the heat accumulated in the heating element is released or the heat of the heating element is shielded, and the temperature of the object rises. It is completely known that we try to curb Not in.

Patent Document 1: JP-A-63-207868

Patent Document 2: Japanese Patent Application Laid-Open No. 3-47883

Patent Document 3: Japanese Patent Application Laid-Open No. 1-259073

Patent Document 4: JP-A-11-223191

Disclosure of the invention

Problems the invention is trying to solve

[0009] The gist of the present invention is a composition having excellent heat dissipation and heat shielding properties, comprising a mixture of an alkoxysilane solution, an aqueous dispersion of colloidal silica, silicon oxide powder, aluminum oxide powder, and kaolin powder. The alkoxysilane power may contain at least one of dialkoxysilane, trialkoxysilane and tetraalkoxysilane, and the colloidal silica (solid content) is used at a weight of 0.011 with respect to the alkoxysilane 1. Preferably.

[0010] A titanium alkoxide and / or an aluminum alkoxide can be mixed. Titanium alkoxide and / or aluminum alkoxide may be used alone or as a solution. When used as a solution, titanium alkoxide and Z or aluminum alkoxide may be used in a solution state of an organic solvent, or a titanium alkoxide and / or aluminum alkoxide may be further mixed with an alkoxysilane solution. .

[0011] The titanium alkoxide and / or aluminum alkoxide is preferably added in a ratio of 0.01 to 0.5 with respect to silicon atoms of the alkoxysilane.

[0012] The amount of the silicon oxide powder and the aluminum oxide powder is preferably 0.5 to 70 by weight based on the alkoxysilane 1, and the amount of kaolin is preferably based on the anorecoxy silane 1. It is preferably 0.1 to 20 by weight.

[0013] Further, the present invention is a film formed from the composition having excellent heat dissipation and heat shielding properties. The thickness of this coating is preferably 10-100 / im.

[0014] The term "heat dissipation" as used in the present invention refers to a characteristic of releasing accumulated heat by radiation. An example For example, it refers to the characteristic of suppressing the temperature rise of a semiconductor by releasing heat generated during use to the atmosphere like a semiconductor. In addition, the heat-shielding property refers to the property of blocking the heat from the surroundings and suppressing the rise in temperature when the temperature rises due to heat from surrounding heating elements, but does not generate heat by itself.

[0015] The basis of the present invention is a composition having excellent heat dissipation and heat shielding properties comprising a mixture of an alkoxysilane solution, an aqueous dispersion of colloidal silica, silicon oxide powder, aluminum oxide powder and kaolin powder. In addition, it is a film formed from the composition and having excellent heat dissipation and heat shielding properties. The alkoxysilane solution, colloidal silica aqueous dispersion, silicon oxide powder, aluminum oxide powder, and kaolin powder, which are the components of the composition, are mixed immediately before use. Until use, especially the alkoxysilanes are stored in solution. This alkoxysilane solution does not substantially contain water. Keep the alkoxysilane in a solution state without water, and

Prevents hydrolysis and condensation of silane.

As the alkoxysilane, tetraalkoxysilane, trialkoxysilane (monoorganic group-substituted alkoxysilane), dialkoxysilane (diorganic group-substituted alkoxysilane) and the like can be used. These alkoxysilanes can also be used as an appropriate mixture. Alkoxysilanes (also called alkyl silicates) are kept in the absence of water, ie, in a water-free solution, until immediately before use. Use a solvent that dissolves in water as the solvent used for the solution.

[0017] Specific examples of the alkoxysilane include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, and methyltripropoxy. Silane, ethyltripropoxysilane, tinolexethoxysilane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, and the like. It may have a functional group such as a hydroxyl group. However, it is not limited to these.

[0018] The solvent used for the alkoxysilane solution is a water-soluble solvent that dissolves the alkoxysilane. Solvent. Since the alkoxysilane needs to be dissolved in water to be mixed with the aqueous dispersion of colloidal silica, a water-soluble solvent is used. Specifically, alcohols such as methyl alcohol and ethyl alcohol, ketones such as acetone and methyl ethyl ketone, cyclic ethers such as dioxane and tetrahydrofuran, N-methylpyrrolidone, dimethyl sulfoxide, dimethylformamide, dimethylacetamide , Methylformamide, methylacetamide and the like. Among them, cyclic ethers such as dioxane and tetrahydrofuran, and solvent powers such as N-methylpyrrolidone, dimethylformamide, dimethylacetamide, methylformamide, and methylacetamide. Can be suitably used. Needless to say, the water-soluble organic solvent can be used as a solvent for titanium alkoxide and Z or aluminum alkoxide.

[0019] Colloidal silica can be easily obtained by hydrolyzing tetraalkoxysilane (tetraalkyl silicate) based on a known technique. It is also commercially available. For example, tetraethyl silicate is dropped into a mixture of ethyl alcohol and water containing a catalyst such as hydrochloric acid, nitric acid, and ammonia, and hydrolyzed.After the hydrolysis, ethyl alcohol and the catalyst are removed, for example, under vacuum. Thereby, an aqueous dispersion of colloidal silica is obtained. The particle size of the colloidal silica is as small as on the order of microns or less. Colloidal silica has silanol groups on the surface. The amount of colloidal silica in the aqueous dispersion of colloidal silica is about 10 to 60% by weight. This amount can be appropriately adjusted based on the amount of water used at the time of hydrolysis. After hydrolysis of the silicate, it is prepared by adding water.

[0020] Immediately before use, the alkoxysilane solution is mixed with an aqueous dispersion of colloidal silica, a metal oxide powder, and the like. The mixing ratio of the alkoxysilane solution and the aqueous dispersion of colloidal silica is preferably such that colloidal silica (solid content) is 0.011 by weight with respect to alkoxysilane 1. The water in the aqueous colloidal silica dispersion contributes to the hydrolysis of the alkoxysilane. At the same time, the alkoxysilane can react with the silanol groups of the colloidal silica during the hydrolysis process to form a film in a form that embraces the colloidal silica. Colloidal silica contributes to film shape, film retention, heat dissipation, and heat shielding. You.

[0021] The composition may further contain a titanium alkoxide and / or an aluminum alkoxide. By adding titanium alkoxide and / or aluminum alkoxide, the reaction rate of hydrolysis and condensation of alkoxysilane can be adjusted. The higher the amount of titanium alkoxide and the amount of Z or aluminum alkoxide added, the faster the hydrolysis reaction rate, and the lower the amount, the lower the reaction rate. From this viewpoint, it is preferable that the titanium alkoxide and / or the aluminum alkoxide be added in a ratio of 0.01 to 0.5 with respect to the silicon atom of the alkoxysilane.

[0022] Titanium alkoxide and Z or aluminum alkoxide are used alone or in the form of a solution when they are mixed with a solution of alkoxysilane, an aqueous dispersion of colloidal silica, silicon oxide powder, aluminum oxide powder and kaolin powder. can do. It may be added to the solution of the alkoxysilane in advance and mixed with the alkoxysilane. In any case, the titanium alkoxide and / or the aluminum alkoxide can be co-hydrolyzed with water and the alkoxysilane to form a polymer containing titanium and / or aluminum in the main chain and form a film.

Specific examples of titanium alkoxides include tetramethoxytitanium, tetraethoxytitanium, tetrapropoxytitanium, tetrabutoxytitanium, and specific examples of aluminum alkoxides include aluminum triisopropoxide, aluminum triethoxide. You can use force S etc. However, it is not limited to these. A solution containing a titanium alkoxide and / or an aluminum alkoxide or an alkoxysilane solution can be stably stored in the absence of water.

[0024] A mixture of an alkoxysilane solution, an aqueous dispersion of colloidal sily force, and a metal oxide is applied to an object such as a heating element to form a film. Immediately before application to an object, a solution of an alkoxysilane and an aqueous dispersion of colloidal silica are first mixed, and a metal oxide powder is added to the mixture to obtain a suspension. At the same time, an alkoxysilane solution, an aqueous dispersion of colloidal silica, a metal oxide and the like may be mixed. These mixtures become suspensions. This suspension is applied to an object such as a heating element to form a film. Metal oxides and the like to be added are aluminum oxide, silicon oxide and kaolin. Add another metal oxide You can also. Specifically, zirconium oxide, titanium oxide, tin oxide, copper oxide, iron oxide, cobalt oxide, magnesium oxide, manganese oxide, zinc oxide, germanium oxide, antimony oxide, boron oxide, barium oxide, bismuth oxide, calcium oxide, It can contain at least one metal oxide such as strontium oxide. In addition to metal oxides, nitrides such as boron nitride, aluminum nitride, zirconium nitride, tin nitride, strontium nitride, titanium nitride, and barium nitride-silicon nitride can be contained.

[0025] The aluminum oxide, silicon oxide, kaolin, and other metal oxides and nitrides used should preferably have a particle size of 15 zm lOOnm. More preferably, those having a particle size of 10 zm 80 nm are used. The use of particles with this particle size makes the surface of the film smooth and clean and increases the efficiency of heat dissipation and heat shielding.

[0026] Metal oxide powders such as silicon oxide powder and aluminum oxide powder are preferably mixed with alkoxysilane 1 and added with a weight of 0.570, and added with kaolin. Is preferably 0.1 to 20 parts by weight, based on the alkoxysilane 1. This is to maintain high heat dissipation performance and heat shielding performance while maintaining film forming properties.

At the time of film formation, an alkoxysilane solution, an aqueous dispersion of colloidal silica, a metal oxide, and the like are mixed to obtain a suspension. If the viscosity of the suspension is high, adjust the viscosity by adding a solvent or water as needed. By applying the suspension thus obtained to an object, a film can be obtained. The suspension is applied to the object by brushing, spraying, roller, printing, etc., dried at room temperature or warming, and then, if necessary, heat-treated at 80 ° C to 300 ° C. A film having a high degree of adhesion to the surface can be obtained. The suspension can be applied to quartz glass or spot welds between metals. The object that forms the film is a heating element that accumulates heat. Its target is mainly electrical and electronic equipment and its components.

[0028] Unless the film thickness of the present film is a certain level, the heat radiation effect is not sufficiently exhibited. Conversely, if the film thickness is too large, a heat storage effect occurs in the film, and the heat radiation effect becomes insufficient. According to the experiment of the present invention, the film thickness is preferably 100 zm or less, more preferably 10 100 zm, and particularly preferably 3080 x m.

[0029] The composition of the present invention may be used as a coating material, an adhesive, a binder, etc. , Vehicles, cooking utensils, building materials, etc. Further, as a substrate to be coated, metals such as iron, iron, stainless steel, aluminum, copper, nickel, molybdenum, and inconel, resins, plastics, wood, stones, glass, and ceramics are preferably used.

[0030] The composition and film of the present invention have excellent properties such as heat shock resistance, heat resistance, heat dissipation, and heat shielding. In addition, it has a high ability to emit stored energy as far-infrared rays into the air (having a high emissivity of 0.95) and has the property of shielding heat from surrounding heating elements. The heat stored inside is converted into far-infrared electromagnetic waves, which are radiated efficiently, thereby suppressing the temperature rise of objects. In addition, it is considered that the heat of the heat source can be shielded by far-infrared radiation.

[0031] Efficiently radiating far-infrared rays means converting heat accumulated inside into far-infrared electromagnetic waves and radiating heat efficiently, resulting in an effect of suppressing a temperature rise. This results in efficient heat dissipation without using air convection. Looking at the far-infrared radiation characteristics of substances that are conventionally considered to have high far-infrared radiation capabilities (eg, zeolite, cordierite, apatite, dolomite, etc.) The emissivity differs depending on the wavelength that does not have the above radiation characteristics. In many cases, the emissivity tends to decrease in the region around the 9-micron wavelength. On the other hand, the composition provided by the present invention emits far-infrared rays at an emissivity of 0.9 or more over the entire wavelength range from 4 microns to 14 microns, and has extremely high radiation efficiency. Has become.

[0032] In the composition of the present invention, for example, when applied to a metal, even when heated at a high temperature of about 500 ° C, the film is not broken (crack, peeling phenomenon, discoloration, etc.) and has excellent heat resistance. Have. In addition, even if it is dropped into chilled water from a high temperature such as 500 ° C or more and quenched, it does not suffer from film breakage phenomena such as cracking or peeling, and has excellent heat shock resistance.

[0033] It is known that components used in electric and electronic devices deteriorate due to heat accumulation. For example, the life of a light bulb can be extended by the deterioration and cutting of a light-emitting wire, and in a fluorescent lamp, the discharge part blackens due to heat and at the same time, the amount of light decreases, thereby extending the life. In addition, in an electrolytic capacitor as an electronic component, the electrolytic solution present therein evaporates due to heating, and the performance as an electrolytic capacitor cannot be exhibited. This However, if the composition of the present invention is applied to the periphery of a component to form a film having excellent heat dissipation and heat shielding properties, the internal heat generated by the component is sequentially radiated to the surroundings as far-infrared rays. As a result, the internal energy is reduced, and the heat history applied to the component can be reduced, which leads to a longer life of the component.

[0034] Furthermore, the composition of the present invention can damage or peel off a coating on a bending curved surface or a cut cross section even when a physical external force such as bending or pressing is applied to the applied metal. There is no. Utilizing such performance, the composition of the present invention was applied to a metal to form a film, and then the metal was processed.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail based on examples.

Example 1

[0036] A solution prepared by dissolving 300 parts by weight of methyltrimethoxysilane, 170 parts by weight of dimethyldimethoxysilane, 30 parts by weight of glycidoxypropyltrimethoxysilane, and 15 parts by weight of tetrabutoxytitanium in 485 parts by weight of N-methylpyrrolidone, silica solids Was mixed with 1000 parts by weight of an aqueous dispersion of 20% by weight of acidic colloidal silica. Take 700 parts by weight of this mixture, 110 parts by weight of kaolin, 435 parts by weight of silicon oxide powder, 190 parts by weight of aluminum oxide powder and 120 parts by weight of dinoreconium oxide powder, and stir and mix. Obtained.

[0037] The above suspension was applied to an aluminum L-shaped plate to form a film. After application of the suspension, it was air-dried in air. The film thickness was 48 / im. Subsequently, it was dried at 95 ° C for 30 minutes, and further heat-treated at 100 ° C for 60 minutes. This L-shaped heat sink was mounted on a power module. In this case, the L-shaped heat sink simultaneously serves as a support for the power module and also serves as a heat sink. The operating temperature of the power module was measured at six locations on the power module body. The average value was 55.8 ° C. On the other hand, the temperature during operation of the power module equipped with the same L-shaped heat sink except that it did not have a coating was measured at six locations on the main body in the same way, and the average value was 62.5 ° C. Was. The heat accumulated in the power module body is transmitted to the heat sink by heat conduction and is radiated from the heat sink. As a result, the heat of the power module body is released, and the temperature rise of the power module body is suppressed. At this time, the power module is attached by attaching the heat sink with the film formed. It was confirmed that the temperature of the main body was kept low.

[0038] The far-infrared emissivity of the film formed from the above composition was measured. The measurement was performed based on the laser flash method. That is, a film is formed on the surface of the metal plate, the surface on which the film is not formed is heated using a gas parner, and the amount of far-infrared radiation per unit area emitted from the film-formed surface is measured with an emissivity meter. Things. The emissivity is determined by the amount of heat energy emitted as far-infrared rays when heated at a constant temperature. Since the amount of radiated far-infrared rays per unit area when 100% of the energy is emitted as far-infrared rays when a certain amount of heat energy is given is determined, the amount of far-infrared rays actually emitted per unit area is measured. By doing so, the emissivity can be obtained.

In this measurement, a test piece was prepared by forming a 70 μm thick film from the composition obtained in Example 1 on a 0.8 mm thick SU4 plate (150 mm × 40 mm). Using a far-infrared radiometer (600 L, manufactured by Inframetrics), measurement was performed over a wavelength range of 1.5 / i to 25 / i. The measurement temperatures were three points: 50 ° C, 100 ° C and 150 ° C. The far-infrared emissivity curves at each temperature are shown in Figs.

[0040] As is apparent from Figs. 13 to 13, an emissivity of 95% or more was measured on average over the wavelength range of 5 / i-25 / i. The emissivity tends to increase as the measurement temperature increases. The far-infrared emissivity described in the cited documents and the like has a high emissivity near 5 /, but as the wavelength increases, the emissivity tends to decrease particularly at wavelengths of 9 µ or more. On the other hand, it can be seen that the film of the present invention still maintains a high emissivity even when the wavelength is long.

Example 2

270 parts by weight of ethyltriethoxysilane, 150 parts by weight of acetylethylethoxysilane, 30 parts by weight of tetraethoxysilane, and 15 parts by weight of titanium tetrabutoxide were dissolved in 535 parts by weight of methylpyrrolidone. This solution was mixed with 1000 parts by weight of an aqueous dispersion of an acidic colloidal silica having a silica solid content of 20% by weight. To 550 parts by weight of the mixture, 70 parts by weight of kaolin, 310 parts by weight of silicon oxide powder, 135 parts by weight of aluminum oxide powder, and 85 parts by weight of zirconium oxide powder were added and stirred to obtain a suspension. . [0042] The suspension was applied to a motor portion of a fan motor to form a film. The film thickness was 40 / im. A heat gun was placed 10 mm in front of the fan motor, a temperature detection end was attached to the motor shaft on the back of the motor part of the fan motor, the heat gun was turned on without moving the fan motor, and the temperature rise of the motor shaft was measured. The room temperature at the time of measurement was 25.1 ° C. The temperature of the motor shaft reached an equilibrium state in about 30 minutes. The temperature of the motor shaft in the equilibrium state was 64.2 ° C. On the other hand, the temperature of the motor shaft of the fan motor without the coating was 75.4 ° C. Thus, by forming the film of the present invention, it was possible to suppress a rise in temperature of the fan motor, particularly at the motor portion. This indicates that the coating has a thermal barrier effect.

Example 3

270 parts by weight of ethyltriethoxysilane, 200 parts by weight of acetylethylethoxysilane and 30 parts by weight of tetraethoxysilane were dissolved in 500 parts by weight of N-methylpyrrolidone. To this solution, 500 parts by weight of an aqueous dispersion of acidic colloidal silica having a silica solid content of 15% by weight was mixed. To 500 parts by weight of the mixed solution, 70 parts by weight of kaolin, 305 parts by weight of silicon oxide powder, 130 parts by weight of aluminum oxide powder and 80 parts by weight of zirconium oxide powder were mixed, stirred and mixed to obtain a suspension. .

This suspension was applied on a servomotor and air-dried in the air. The film thickness was 60 μm. The servo motor was driven at 100V voltage. The temperature of the outer wall of the servomotor in the driving state was measured. Approximately 60 minutes after driving, the temperature of the servomotor reached a steady state and reached 75.5 ° C. On the other hand, those without a film had a temperature of 99.5 ° C after 60 minutes, and the temperature tended to rise. This indicates that the film of the present invention has a heat radiation effect.

Example 4

[0045] 265 parts by weight of ethyltriethoxysilane, 150 parts by weight of acetylethylethoxysilane, 20 parts by weight of tetraethoxysilane, and 15 parts by weight of aluminum triisopropoxide were dissolved in 450 parts by weight of N-methylpyrrolidone. To this solution, 900 parts by weight of an aqueous dispersion of acidic colloidal silica having a silica solid content of 20% by weight was mixed. Take 550 parts by weight of the mixed solution, mix 80 parts by weight of kaolin, 335 parts by weight of silicon oxide powder, 145 parts by weight of aluminum oxide powder, and 80 parts by weight of dinoleconium oxide powder, stir and mix to obtain a coating material (suspension). Got. This suspension was applied to a casing of a motor and air-dried in the air. The film thickness was 55 μm. Similarly, after heat drying, heat treatment was performed. The motor was driven for 1 hour, during which time the motor casing temperature was measured. The temperature was measured at five places and the average was taken. One hour later, the temperature of the motor casing was 70.5 ° C. On the other hand, when the film was not formed, the temperature of the monitoring was 99.5 ° C. This indicates that the film of the present invention has heat dissipation.

[0047] As described above in detail in the specific examples, the film made of the composition of the present invention is free from deformation, crack, discoloration, peeling, cracking, etc., and is resistant to quenching heat shock. Heat shock resistance) and heat resistance. Furthermore, the film made of the composition of the present invention has excellent far-infrared radiation activity, releases stored heat, suppresses temperature rise of the heating element, and shields heat received from surrounding heating elements. This has the effect of suppressing the temperature rise of the object. A coating can be formed by applying the composition of the present invention to an object.

Industrial applicability

[0048] Since the composition and the film that work in the present invention are excellent in heat dissipation and heat shielding, when applied to various electronic devices, for example, they can contribute to miniaturization of the devices.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a graph showing far-infrared emissivity at 50 ° C. of a film according to the present invention.

FIG. 2 is a graph showing far-infrared emissivity at 100 ° C. of a film according to the present invention.

FIG. 3 is a graph showing far-infrared emissivity at 150 ° C. of a film according to the present invention.

Claims

The scope of the claims

[1] A composition excellent in heat dissipation and heat shielding properties comprising a mixture of an alkoxysilane solution, an aqueous dispersion of colloidal silica, silicon oxide powder, aluminum oxide powder and kaolin powder.

2. The composition according to claim 1, wherein the composition has at least one of dialkoxysilane, trialkoxysilane and tetraalkoxysilane.

[3] The heat dissipation property and heat insulation property according to claim 1 or 2, wherein the amount of the colloidal silica (solid content) is 0.01-1 in weight with respect to the alkoxysilane 1. Excellent composition.

4. The composition according to claim 1, further comprising a mixture of the titanium alkoxide and / or the aluminum alkoxide.

5. The titanium alkoxide and / or aluminum alkoxide has a titer of 0.01 to 0.5 with respect to silicon atoms of the alkoxysilane. Excellent heat radiation and heat shielding properties.

6. The method according to any one of claims 1 to 5, wherein the amount of the silicon oxide powder and the aluminum oxide powder is 0.570 by weight with respect to the alkoxysilane 1. Excellent heat radiation and heat shielding properties.

[7] The capacity of the kaolin The weight of the alkoxysilane 1 is 0.120, and the heat dissipation and heat shielding properties according to any one of claims 1 to 6, Excellent composition.

[8] A film formed from the composition excellent in heat dissipation and heat insulation according to any one of claims 1 to 7.

[9] The film formed from the composition having excellent heat dissipation and heat shielding properties according to claim 8, wherein the thickness of the film is 10 lOOxm.