KR101956371B1 - A heat-radiation silicon sheet reinforced electrically insulative - Google Patents

Abstract

According to the present invention, a resin composition for an insulating heat-radiant sheet can effectively emit heat generated from electric and electronic products and can secure sufficient insulating properties at the same time without adjusting the thickness of a heat-radiant sheet or forming a complex structure by using aluminum oxide unlike a phase change material used for the existing heat-radiant sheet resin.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a heat-

The present invention relates to a heat-dissipating silicon sheet having enhanced insulation performance, and more particularly, to a heat-dissipating silicon sheet having improved insulation performance, which is a disadvantage of a heat- A heat storage silicone sheet having a heat storage composition containing a heat storage capsule containing a phase change material between a silicon sheet and a heat source is provided.

Since most of the electronic components generate heat during use, it is necessary to remove heat from the electronic components in order to properly function the electronic components. In particular, integrated circuit devices such as CPUs used in personal computers are increasing in heat generation due to increase in operating frequency, and countermeasures against heat radiation have become an important issue.

PDP TVs, notebook computers, and LCD TVs are representative of the products to which the display panel is applied. Among them, a PDP (Plasma Display Panel) having a large amount of heat is an apparatus for displaying an image using plasma generated by gas discharge, Since it uses glass, the screen is not bent like a cathode ray tube and there is no distortion. Using a flat glass can make a monitor having a thin thickness, thereby enabling a light wall TV. However, recently, a PDP display device has become large- The PDP display device has a thermally poor environment due to its narrow structure than that of the conventional CRT display device, and as a cooling device of the PDP display device, a fan It is widely used, but it is the largest thickness of the thickness of PDP display device In recent years, there has been a demand for a non-powered type cooling device in which a fan is not used in the above PDP display device, and thus heat generated in the PDP panel A heat sink made of an aluminum heat dissipating plate capable of uniformly diffusing and delivering heat to a low temperature portion is used.

Many methods have been proposed as means for removing this heat. Particularly, in an electronic component having a large amount of heat, a method of pushing heat through a thermally conductive compound such as an electronic component and a heat sink or a heat conductive material such as a thermally conductive sheet has been proposed.

As such a thermally conductive material, heat dissipating compounding is known in which silicon oxide is used as a base material and zinc oxide or alumina powder is blended. Further, in order to improve the thermal conductivity, it is preferable to use at least one material selected from a liquid organosilicon carrier, silica fiber, dendritic zinc oxide, flaky aluminum nitride and flaky boron nitride as the thermally conductive material using the aluminum nitride powder Thixotropic heat transfer materials are also known.

However, such a silicone thermally conductive material may increase the hardness of the silicone thermal conductive material depending on the protection of the product against the external impact and the kind of the heat source. If the hardness is increased, the product may be protected. However, There has been a problem that the contact area between the heat source and the silicon thermal conductive material is reduced and the heat dissipation property is greatly deteriorated.

As a prior art related to silicone thermal conduction, Japanese Unexamined Patent Publication (Kokai) No. 2007-177001 discloses a silicone composition obtained by blending spherical hexagonal aluminum nitride powder having a certain particle size range with a specific organopolysiloxane. This Japanese Laid-Open Patent Application discloses a heat conductive silicone composition comprising a combination of aluminum nitride powder having a fine grain size and aluminum nitride powder having a grain size of roughly equal to that of the aluminum nitride powder; A heat conductive silicone composition comprising a combination of aluminum nitride powder and zinc oxide powder; A thermally conductive compound composition using an aluminum nitride powder surface-treated with organosilane; And a thermally conductive silicone composition comprising a silicone resin, diamond, zinc oxide and a dispersant. The thermal conductivity of aluminum nitride is 70 to 270 W / (m 占 K), and the thermal conductivity of diamond is higher than 900 to 2,000 W / (mK).

Japanese Patent Application Laid-Open No. 2007-177001 (July 12, 2007)

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a heat-dissipating silicon sheet having improved insulation performance, A heat storage silicone sheet having a heat storage composition including a heat storage capsule containing a phase change material between a silicon sheet and a heat source is provided.

It is another object of the present invention to provide a heat-dissipating silicon sheet reinforced with an insulating property by further adding a dispersing aid and an ionomer to further improve the heat radiation characteristic of the phase change material.

The present invention relates to a heat-dissipating silicon sheet reinforced with an insulating property.

One embodiment of the present invention relates to a method for producing an organopolysiloxane composition comprising 100 parts by weight of an organopolysiloxane having a kinematic viscosity of 100 to 100,000 mm 2 / s at 25 ° C and a number average molecular weight of 5,000 to 100,000, 10 to 200 parts by weight of one or more fillers selected from aluminum nitride, metal powder, boron nitride, silicon nitride, diamond, graphite, carbon nanotube, metal silicon, iron oxide, carbon fiber, glass fiber, glass bead powder and fullerene A thermally conductive silicone sheet comprising; And a heat accumulating sheet stacked on one side of the silicon sheet and including a base resin and a heat accumulating capsule dispersed in the base resin and containing therein a phase change material, wherein the heat accumulating capsule comprises a filler containing a phase change material, And a coating layer for containing the filler. The present invention also relates to a heat-dissipating silicon sheet having enhanced insulation performance.

In the present invention, the organopolysiloxane is characterized by having a structure represented by the following formula (1).

[Chemical Formula 1]

(C 1 -C 20) alkyl, (C 1 -C 20) alkoxy, (C 2 -C 20) alkenyl, (C 1 -C 20) acyl or (C 6 -C 20) aryl, ≪ / RTI >

In the present invention, the phase change material may be Fe ₂ O _{3 .4} SO ₃ .9H ₂ O, NaNH ₄ SO ₄ .2H ₂ O, NaNH ₄ HPO ₄ .4H ₂ O, FeCl ₃ .2H ₂ O, Na ₃ PO _{4 · 12H 2 O, Na 2 SiO} 3 · 5H 2 O, Ca (NO 3) 2 · 3H 2 O, K 2 HPO 4 · 3H 2 O, Na 2 SiO 3 · 9H 2 O, Fe (NO 3) 3 · 9H ₂ O, inorganic material such as _{K 3 PO 4 · 7H 2 O} , NaHPO 4 · 12H 2 O, CaCl 2 · 6H 2 O, Na 2 SO 4 · 10H 2 O, and _{Na (CH 3 COO) · 3H} 2 O But are not limited to, paraffin wax, n-octanoic acid, n-octadecane, n-triacotan, hexadecane, nonadecane, eicosane, hexenoic acid, docosane, tricoic acid, tetracholic acid, pentacosanoic acid, polyethylene glycol It may be any one or a plurality of organic substances selected from organic acids such as acetic acid, citric acid, citric acid, citric acid, tartaric acid, citric acid, citric acid,

Wherein the base resin is selected from the group consisting of polydimethylsiloxane resin, epoxy resin, acrylate resin, organopolysiloxane resin, polyimide resin, fluorocarbon resin, benzocyclobutene resin, fluorinated polyallyl ether resin, polyamide resin, An ester resin, a phenol resol resin, an aromatic polyester resin, a polyphenylene ether resin, a bismaleimide triazine resin, and a fluororesin.

The composition may further comprise one or more fillers selected from carbon nanotubes, graphene, graphite, fullerene, aluminum oxide, copper oxide, silver oxide, gold oxide, palladium oxide, platinum oxide, nickel oxide, And more particularly, aluminum oxide and acid whiten are mixed in a ratio of 60 to 80: 20 to 40 by weight.

The composition may further comprise a polyallyl amine derivative as a dispersion aid, and the phase change material may further comprise aluminum oxide nanoparticles.

Since the heat storage composition containing the phase change material is disposed between the heat source and the silicon sheet, the resin composition for an insulation sheet for heat insulation according to the present invention can maximize the thermal conductivity by the phase change material in which the phase change occurs according to the heat, Since it is not affected by the hardness, the composition of the silicone sheet can be freely made, and the product can be protected by increasing the hardness while maintaining the heat radiation characteristic.

In addition, the phase change material included in the composition is different from a phase change material used in a conventional resin for an insulation sheet, so that the thickness of the heat radiation sheet can be adjusted by using aluminum oxide, It is possible to effectively release heat generated from the electronic product and at the same time ensure sufficient insulation.

FIG. 1 is a cross-sectional view showing a state in which an insulating silicone heat-radiating sheet manufactured according to an embodiment of the present invention is applied to a heat-generating body.

Hereinafter, a heat-dissipating silicon sheet having enhanced insulation performance according to the present invention will be described in detail with reference to specific examples. The following specific embodiments are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention.

Therefore, the present invention is not limited to the embodiments shown below, but may be embodied in other forms. The embodiments shown below are only for clarifying the spirit of the present invention, and the present invention is not limited thereto.

Here, unless otherwise defined, technical terms and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. In the following description, the gist of the present invention is unnecessarily blurred And a description of the known function and configuration will be omitted.

In addition, the following drawings are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. Therefore, the present invention is not limited to the following drawings, but may be embodied in other forms, and the drawings presented below may be exaggerated in order to clarify the spirit of the present invention. Also, throughout the specification, like reference numerals designate like elements.

Also, the singular forms as used in the specification and the appended claims are intended to include the plural forms as well, unless the context clearly indicates otherwise.

In describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected to or connected to the other component, It should be understood that an element may be "connected," "coupled," or "connected."

The heat-dissipating silicon sheet having improved insulation performance according to the present invention has a structure in which a heat-conductive silicone sheet and a heat-accumulating sheet including heat-accumulating capsules are laminated on one surface of the heat-conductive silicone sheet.

The insulating silicone heat-radiating sheet according to the present invention may be composed of a silicon sheet 100 and a heat-accumulating sheet 200 as shown in the upper part of FIG. The silicon sheet is a kind of base material and carrier that accommodates a heat accumulating sheet, and the heat accumulating sheet is a layer in direct contact with the heat source 300.

As shown in FIG. 1, when the silicon heat-dissipating sheet is brought into contact with a heat source and a force is applied in a heat source direction as shown in the lower part of FIG. 1, the heat- To be completely contacted. Therefore, it is possible to make contact with all areas even in a rough heat source with a surface roughness, which is advantageous in that more reliable heat transfer is possible.

The thermally conductive silicone sheet according to the present invention may comprise an organopolysiloxane and a filler.

In the present invention, the organopolysiloxane is used for uniformly dispersing the filler, while maintaining high hardness even at the time of curing. The organopolysiloxane has a kinematic viscosity of 100 to 100,000 mm 2 / s at 25 ° C, And an average molecular weight of 5,000 to 100,000. If the kinematic viscosity is less than the above range, oil bleeding tends to occur from the composition. If the kinematic viscosity is higher than the above range, the fluidity and processability of the composition tend to become insufficient. The organopolysiloxane may be used singly or in combination of two or more.

The organopolysiloxane may be more specifically an organopolysiloxane having a structure represented by the following formula (1).

[Chemical Formula 1]

In the above formula (1), each R may independently and independently be (C1-C20) alkyl, (C1-C20) alkoxy, (C2-C20) alkenyl, (C1-C20) acyl or (C6-C20) aryl.

More specifically, R is an unsubstituted or substituted monovalent hydrocarbon group of (C1-C12) independently, and examples thereof include a straight chain alkyl group, a branched chain alkyl group, a cyclic alkyl group, an alkenyl group, Halogenated alkyl groups and the like. Examples of the straight chain alkyl group include a methyl group, an ethyl group, a propyl group, a hexyl group, an octyl group, a decyl group and a dodecyl group. Examples of the branched alkyl group include an isopropyl group, an isobutyl group, a tert-butyl group and a 2-ethylhexyl group.

Examples of the cyclic alkyl group include a cyclopentyl group and a cyclohexyl group. Examples of the alkenyl group include a vinyl group and an allyl group. Examples of the aryl group include a phenyl group and a tolyl group. Examples of the aralkyl group include a 2-phenylethyl group and a 2-methyl-2-phenylethyl group. Examples of the halogenated alkyl group include a 3,3,3-trifluoropropyl group, a 2- (nonafluorobutyl) ethyl group and a 2- (heptadecafluorooctyl) ethyl group. Examples of the (C1-C20) alkoxy include a methoxyethyl group and a methoxypropyl group. Examples of the (C1-C20) acyl group include an acetyl group and an octanoyl group. The R group is most preferably a methyl group or an ethyl group or a phenyl group.

In the above formula (1), n is an integer of 1 to 100, preferably an integer of 10 to 30.

The thermally conductive silicone sheet may include one or more fillers to enhance the heat radiation effect. Specific examples of the filler include aluminum, silver, copper, nickel, zinc oxide, alumina, magnesium oxide, aluminum nitride, metal powder, boron nitride, silicon nitride, diamond, graphite, carbon nanotube, metal silicon, iron oxide, Fiber, glass bead powder, and fullerene, which may be used alone or in combination of two or more.

In the present invention, the filler is not limited in size, but may preferably have an average particle diameter of 0.1 to 100 mu m, more preferably 1 to 20 mu m. When the filler has an average particle size in the range as described above, the filler can have a high bulk density but a small specific surface area, thereby increasing the uniform mixing and mixing ratio of the filler. The shape of the filler is not limited, and examples thereof include a spherical shape, a multi-faceted shape, a film object, a needle shape, a circular shape, and an irregular shape.

In the present invention, the content of the filler may be 10 to 200 parts by weight based on 100 parts by weight of the organopolysiloxane. If the amount of the filler added is less than 10 parts by weight, the heat radiation properties of the thermally conductive silicone sheet may be deteriorated. If the filler is added in an amount exceeding 200 parts by weight, the processability may be greatly decreased due to the viscosity increase of the composition.

In the present invention, the production method of the thermally conductive silicone sheet is not limited. For example, the organopolysiloxane and the filler are mixed using a mixing device such as a dough mixer (kneader), a gate mixer, a stream line mixer, and a planetary mixer, and then mixed with a gravure roll coater, a reverse roll coater, a kiss roll coater, A roll coater, a bar coater, a knife coater, a spray coater, a comma coater, a direct coater, and the like, and curing the coating.

The heat storage composition may include a base resin and a heat storage capsule dispersed in the base resin, the heat storage silicone resin being coated on one surface of the silicone sheet to be positioned between the heat conductive silicone sheet and the heat source.

The heat storage composition is intended to fill the void space between the heat conductive silicone sheet and the heat source according to the uneven illuminance of the heat source, and it is required to have a certain level of adhesion force, moldability, heat conduction characteristics and the like.

In the present invention, the base resin is a resin or emulsion, such as a pressure-sensitive adhesive, to provide EMI shielding and to improve the thermal performance of a device to which the composition is applied.

The composition may also function as an endothermic film, such as a transfer tape format, so that it can be applied at any location on the apparatus requiring cooling. The application position may act as a heat spreader on or between the substrates.

The composition may be used with a power source, such as a battery module, to dissipate the heat generated by the power source during operation. The operating temperature is not limited in the present invention, but may be as high as about 40 占 폚. In this embodiment, a housing comprising at least one substrate having an inner surface and an outer surface is provided on or against the product and on its inwardly facing surface, and the spreading of the generated heat, A composition comprising a plurality of encapsulated phase change material storage capsule particles dispersed in a matrix disposed on a substrate capable of providing a thermal conductivity to facilitate is disposed on at least a portion of the inner surface of the at least one substrate. In one aspect, the encapsulated phase change material particles may have a layer of conductive material disposed on at least a portion of a surface of the particle. The conductive coating should be a metal such as Ag, Cu or Ni to provide an EMI shielding effect.

In the present invention, the base resin is a receptacle for receiving a heat accumulation capsule therein, and is a substrate directly contacting with a heat source.

In the present invention, the base resin has ductility and is easily adhered to a heat source, has excellent workability, and is excellent in heat resistance, so that even if the continuous heat is supplied, deformation does not occur in the resin, It is preferable to use a substance having

Examples of the base resin in the present invention include polydimethylsiloxane resin, epoxy resin, acrylate resin, organopolysiloxane resin, polyimide resin, fluorocarbon resin, benzocyclobutene resin, fluorinated polyallyl ether resin, polyamide resin, Amide resins, cyanate ester resins, phenol resole resins, aromatic polyester resins, polyphenylene ether resins, bismaleimide triazine resins, fluororesins, or mixtures thereof. The polymer can be thermoplastic or thermoset and can be selected according to the desired final properties (e.g., viscosity, modulus and elasticity). Suitable examples of curable thermosetting matrices include, but are not limited to, acrylate resins, epoxy resins and polydimethylsiloxane resins, as well as free radical polymerization, atom transfer, radical polymerization ring opening polymerization, ring opening metathesis polymerization, anionic polymerization, cationic polymerization, Other organic functional polysiloxane resins that can form crosslinked networks through other methods of the invention. In the case of a non-curable polymer, the resulting thermal interface material may be formulated as a gel, grease, or phase change material that can maintain heat transfer during operation while holding the components together during manufacture.

Specifically, the polymer matrix may be a polysiloxane resin such as an addition curable silicone rubber composition. Such compositions may include one or more organopolysiloxane components (e. G., An organopolysiloxane containing an average of at least two silicon-bonded alkenyl groups per molecule), one or more organohydrogenpolysiloxanes that serve as crosslinkers (e. G., Two or more silicon- (For example, ruthenium, rhodium, platinum or palladium complex), and optionally at least one catalyst inhibitor (used to modify the curing profile and improve shelf life) and 1 Or more adhesion promoters.

The polymer matrix may further comprise various additives to achieve the desired overall properties of the thermal interface material. For example, when combined with a filler, a reactive organic diluent may be added to reduce the viscosity of the polymer matrix. Non-reactive diluents may also be added to reduce the viscosity of the formulation. It may also comprise one or more pigments or pigments mixed with a carrier liquid. In the case of epoxy resins, various known hardeners, hardeners and / or other optional reagents may be used with the curing catalyst.

For example, a dispersant such as fatty acid, fish oil, polydiallyldimethylammonium chloride, polyacrylic acid, and polystyrene sulfonate may be further added to disperse the filler or the fibrous heat conductor, and polyvinyl alcohol, polyvinyl butyral, A binder such as wax may be mixed.

In the present invention, the base resin is preferably added in an amount of 60 to 85% by weight based on 100% by weight of the total composition. If less than 60% by weight is added, the content of the substrate is small and it is difficult to adhere well to the heat source. If the content exceeds 85% by weight, the content of the other components may be decreased and the thermal conductivity may be greatly decreased.

In the present invention, the heat storage capsules comprise a filler containing a phase change material and a coating layer containing the filler. The filler contained in the coating layer, more specifically, absorbs or emits a large amount of heat generated from the heat source by the phase change material. Thereby maintaining the temperature uniformly.

The heat storage capsule may be formed in various shapes such as spherical and elliptical shapes, and the coating layer may be formed to have a predetermined thickness and surround the filler. For example, the coating layer may be formed to a thickness of about 10 to 200 nm, but it is not limited thereto and may have various thicknesses depending on the shape of the heat storage capsule, the kind of the component forming the coating layer, .

In the present invention, the coating layer protects the filler containing the phase change material from external impact, and blocks the mixing with other components due to the phase change material in which the phase change occurs depending on the temperature, It plays a role.

In the present invention, the component constituting the coating layer is not particularly limited as long as it is a polymer capable of providing excellent mechanical strength. Examples of the polymer include polyurea, polyurethane, polyester, polyamide, melamine resin, gelatin, And one or more of these may be used in combination.

As the material for forming the coating layer, more specifically, a monomer capable of causing condensation polymerization, preferably a compound containing two or more isocyanate groups is preferable.

The compound containing two or more isocyanate groups may be selected from the group consisting of toluene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, octamethylene diisocyanate, etc., Two or more species can be used.

In the present invention, the filler may include a phase change material. The phase change material may be an organic or inorganic material. Examples of the organic phase change material include paraffin wax, n-eicosane, n-octadecane, n-triacontane, hexadecane, But are not limited to, hexadecane, nonadecane, eicosane, heneicosane, docosane, tricosane, tetracosane, pentacosane, polyethylene glycol, But are not limited to, lauric acid, propyl palmitate, capric acid, isopropyl stearate, butyl stearate, palmitic acid, Petrolatum, myristic acid, vinyl stearic acid, and the like.

Examples of the inorganic phase change material include Fe ₂ O _{3 .4} SO ₃ .9H ₂ O, NaNH ₄ SO ₄ .2H ₂ O, NaNH ₄ HPO ₄ .4H ₂ O, FeCl ₃ .2H ₂ O, Na ₃ PO _{4 · 12H 2 O, Na 2} SiO 3 · 5H 2 O, Ca (NO 3) 2 · 3H 2 O, K 2 HPO 4 · 3H 2 O, Na 2 SiO 3 · 9H 2 O, Fe (NO 3) 3 , and the like _{9H 2 O, K 3 PO 4} · 7H 2 O, NaHPO 4 · 12H 2 O, CaCl 2 · 6H 2 O, Na 2 SO 4 · 10H 2 O, and _{Na (CH 3 COO) · 3H} 2 O .

These phase change materials may be used singly or in combination of two or more kinds depending on the use, and organic and inorganic systems may be mixed. At this time, the blending ratio can be freely carried out within a range that does not impair the object of the present invention. For example, when paraffin and petrolatum are mixed, it is preferable to mix them in a weight ratio of 1 to 3: 1 to satisfy softness and shrinkage.

The phase change material and the polymer monomer constituting the coating layer are preferably mixed in a weight ratio of 1: 5: 1. The physical strength of the heat storage capsule can be firmly manufactured within the above content range.

The heat storage capsule does not limit the production method. For example, the emulsion may be prepared by mixing the phase change material and the coating layer polymer, homogenizing the mixture to a nanometer size, mixing the homogenized mixture with an emulsifier, and emulsifying the mixture by forced emulsification.

The step of homogenizing the composition may be performed by using a physical device such as a homogenizer to crush the droplet to a nanometer size. Any separation method commonly used in the art may be used for this purpose. Do.

The homogenization can be carried out by stirring at 5,000 to 20,000 rpm for 5 to 30 minutes, but it is not particularly limited.

The emulsion can be prepared by mixing a mixed solution of a phase transition material and a polymer monomer crushed to a nanometer size, a dispersing solution of an emulsifier and a polymer.

The emulsifier can be used for the polymerization reaction with the monomer, emulsify the phase transition material to produce stable liquid droplets of small size, and for the chemical bonding with the reactor of the polymer monomer for the polymerization reaction.

The emulsifier can be used without limitation as long as it is a reactive group having reactivity with a reactor of a polymer monomer, preferably a compound having a hydroxy group. For example, a poly (styrene sulfonic acid comoleic acid) or a styrene-maleic anhydride copolymer may be used alone or in combination of two or more.

The emulsifier is preferably contained in an amount of 0.2 to 1 part by weight based on 100 parts by weight of the emulsion. When the content is within the above range, the produced nanocomposite capsules have the highest dispersion stability.

The emulsion may have a nanocapsule structure in which a polymer shell encapsulates the phase change material through condensation polymerization at 60 to 80 ° C for 3 to 12 hours in combination with a chain extender.

Examples of the compound include ethylenediamine, propanediamine, hexanediamine, phenylenediamine, and the like. Examples of the compound having two or more amine groups at the terminal thereof include ethylenediamine, propanediamine, hexanediamine, Or polyoxyethylene bisamine may be used alone or in combination of two or more.

The chain extender may be included in an amount of 1 to 10 parts by weight based on 100 parts by weight of the emulsion. When the content is within the above range, the physical strength of the polymer coating layer is maintained.

Preferably, the heat storage capsules are added in an amount of 15 to 40% by weight based on 100% by weight of the total composition. When it is added in an amount of less than 15% by weight, the thermal conductivity may be considerably lowered. When it is added in an amount of more than 40% by weight, the content of the substrate may be too small.

The composition may further include one or more fillers to further improve mechanical properties such as heat resistance, adhesiveness, durability and the like.

The filler is added to improve the thermal conductivity or the chargeability in addition to the mechanical properties as described above. The filler has high thermal conductivity and can easily receive heat from the heat source and release it to the graphite sheet layer or the outside Any material that can be used can be used regardless of the type.

The filler is generally composed of a metal oxide having excellent thermal conductivity such as aluminum oxide, copper oxide, silver oxide, palladium oxide, platinum oxide, nickel oxide and acid whitanium, carbon nanotubes, graphene, graphite, Fullerene, and the like. In addition to the above materials, ceramic nanoparticles such as dry silica, fused silica, quartz powder, amorphous silica, aluminum nitride (AlN) or boron nitride (BN) may be added.

In the present invention, as the filler, more specifically, it is preferable to use a mixture of aluminum oxide and whitening acid. The aluminum oxide has high thermal conductivity, electrical resistance and mechanical strength, and is used as a heat-radiating material due to its low dielectric constant, which is further amplified when mixed with acid whiten.

In the present invention, the mixing ratio of the aluminum oxide to the acid whitanium is preferably 60 to 80: 20 to 40 by weight. In particular, when the acid whiten is added in an amount exceeding the above range, the heat radiation characteristic of the adhesive layer due to the thermal conductivity drop of the aluminum oxide may be deteriorated.

In the present invention, the filler is preferably added in an amount of 5 to 30 parts by weight based on 100 parts by weight of the total composition. If it is added in an amount of less than 5 parts by weight, the effect of improving thermal conductivity and mechanical properties is insufficient. If it is added in an amount of more than 30 parts by weight, the insulating property of the composition is deteriorated due to excessive addition of a metallic material.

The filler may further include aluminum oxide nanoparticles to further increase the insulating property.

The aluminum oxide (Al ₂ O ₃ ) has a high thermal conductivity and mechanical strength and exhibits excellent insulation characteristics, but is inexpensive and is widely used as a typical ceramic substrate material. The filler according to the present invention is characterized by satisfying the insulating property by further adding aluminum oxide to the composition.

The aluminum oxide does not limit the production method. For example, water can be prepared by reacting aluminum nitrate (Al (NO ₃ ) ₃ ) with ammonium hydroxide (NH ₄ OH) in the presence of laponite as a reaction medium and a dispersing agent.

The aluminum oxide is not limited in size and shape but may be spherical particles having a diameter of 1 to 50 nm in order to satisfy heat radiation characteristics and insulation characteristics of the composition. The addition amount is not limited, but the addition of 0.1 to 5 parts by weight based on 100 parts by weight of the total composition may satisfy excellent heat and insulation properties without impairing the mechanical properties of the composition.

The composition according to the present invention may further include a dispersing aid to further increase the dispersibility of the inorganic material such as a filler and the heat dissipation property.

In the present invention, the dispersion aid is intended to further increase the dispersibility of the filler in the composition, And a polyallylamine derivative as a main component.

In the present invention, the polyallylamine derivative can be obtained by first polymerizing allylamine in the presence of an initiator and a chain transfer catalyst to prepare a polyallylamine, and then reacting the polyester, the polyamide and the polyester amide. The polyallylamine derivative prepared by the above method may have an acidity of 2.5 to 50 mg and a weight average molecular weight of 2,000 to 100,000.

In the present invention, the dispersion aid is preferably added in an amount of 1 to 10 parts by weight based on 100 parts by weight of the total composition. If it is less than 1 part by weight, the fibrous heat conductor may not migrate sufficiently during charging, and the thermal conductivity may be greatly deteriorated. If it is added in an amount exceeding 10 parts by weight, moldability may be deteriorated due to an increase in flowability of the adhesive layer composition.

In addition, the composition may further include one or more ionomers to further increase the insulating properties and adhesion properties with the heat source.

The ionomer means an ion conductive polymer having a fixed ion attached to a polymer chain or a side chain by a covalent bond. In order to further increase the insulating property, the ionomer is an alkyl group of at least one monomer constituting a general aliphatic hydrocarbon or aromatic hydrocarbon, , A partially fluorinated ionomer in which a part of the hydrogen of the aromatic group is substituted with a fluorine atom is preferably used.

In the present invention, the partially fluorinated ionomer is a sulfonated poly (arylene ether sulfone-co-vinylidene fluoride), a sulfonated tri-fluoro styrene-graft-poly (tetrafluoroethylene) (PTFE- , Copolymers containing fluorinated or partially fluorinated monomers such as styrene-grafted sulfonated polyvinylidene fluoride (PVDFg-PSSA), dicarfluorobiphenyl or hexafluorobenzene (eg HQSH-6F Block copolymers), and the like, and it is also possible to use one or a mixture thereof.

The ionomer is not limited in shape, but preferably has an average particle size of 0.01 nm to 600 nm, and its content is 0.1 to 5 parts by weight in 100 parts by weight of the total composition, .

In addition, the thermally conductive silicone sheet composition or the heat storage composition may further include at least one additive in preparing the composition within the range not impairing the object of the present invention. Examples of the additives include plasticizers, crosslinking agents, antioxidants, crosslinking aids, curing accelerators, scorch retarders, processing aids, coupling agents, ultraviolet stabilizers (including UV absorbers), antistatic agents, , Viscosity modifiers, tackifiers, antiblocking agents, surfactants, extender oils, antacids, flame retardants, adhesion promoters, and metal deactivators.

Examples of such plasticizers in the present invention include, but are not limited to, phthalic acid diesters (also known as "phthalates") such as di-isononyl phthalate (DINP), diallyl phthalate (DAP), di- ), Dioctyl phthalate (DOP) and diisodecyl phthalate (DIDP); Trimellitates such as trimethyltrimellitate, n-octyltrimellitate, and tri- (2-ethylhexyl) trimellitate; Adipate plasticizers such as bis (2-ethylhexyl) adipate, dimethyl adipate and dioctyl adipate; Sebacate plasticizers, such as dibutyl sebacate; Maleates such as dibutyl maleate; Benzoate; Sulfonamides such as N-ethyltoluenesulfonamide; Organophosphate; Polybutene; Glycols / polyethers such as triethylene glycol dihexanoate; Paraffinic process oils such as SUNPAR 2280 (Sunoco Corp.); Special hydrocarbon fluids, and polymer modifiers; And those derived from renewable sources such as epoxidized grains (e.g., soy, corn, etc.) oils (i.e., biochemical plasticizers).

Examples of the curing agent in the present invention include (1) a free radical initiator (for example, an organic peroxide or an azo compound), (2) a silane functional group generally activated by moisture (for example, a vinylalkoxysilane or a vinylalkoxy (3) a sulfur-containing curing agent to facilitate vulcanization, and / or (4) a polymeric material selected from the group consisting of electromagnetic radiation (e.g., infrared (IR), ultraviolet (UV), visible, gamma , Etc.) to accelerate crosslinking of the composition.

Examples of the scorch retarder in the present invention include 2,2,6,6-tetramethylpiperidinoxyl (TEMPO) and 4-hydroxy-2,2,6,6-tetramethylpiperidinoxyl Roxy TEMPO).

Examples of the ultraviolet stabilizer in the present invention include hindered amine light stabilizers (HALS) and ultraviolet absorber (UVA) additives. Representative UVA additives include benzotriazole type, such as Tinuvin 326 and Tinuvin 328, commercially available from Ciba, Inc. A blend of HAL and UVA additives is also effective. Examples of antioxidants include hindered phenols such as tetrakis [methylene (3,5-di-tert-butyl-4-hydroxyhydrocinnamate)] methane; (2-methyl-6-tert-butylphenol), 4,4'-thiobis (4-hydroxybenzyl) , 4'-thiobis (2-tert-butyl-5-methylphenol), 2,2'-thiobis -tert-butyl-4-hydroxy) -hydrocinnamate; Phosphites and phosphonites such as tris (2,4-di-tert-butylphenyl) phosphite and di-tert-butylphenyl-phosphonite; Thio compounds such as dilauryl thiodipropionate, dimyristyl thiodipropionate, and distearyl thiodipropionate; Various siloxanes; Polymerized 2,2,4-trimethyl-1,2-dihydroquinoline, n, n'-bis (1,4-dimethylpentyl-p-phenylenediamine), alkylated diphenylamine, Bis (alpha, alpha-dimethylbenzyl) diphenylamine, diphenyl-p-phenylenediamine, mixed di-aryl-p-phenylenediamine, and other hindered amine anti-dispersants or stabilizers .

Examples of processing aids include, but are not limited to, metal salts of carboxylic acids, such as zinc stearate or calcium stearate; Fatty acids such as stearic acid, oleic acid, or erucic acid; Fatty amides such as stearamide, oleamide, erucamide, or N, N'-ethylene bis-stearamide; Polyethylene wax; Oxidized polyethylene wax; Polymers of ethylene oxide; Copolymers of ethylene oxide and propylene oxide; Vegetable wax; Petroleum wax; Non-ionic surfactants; Silicone fluids and polysiloxanes.

The resin composition for a heat-radiating sheet according to the present invention may be processed into a liquid form for maintaining moldability and then coated on the surface of the thermally conductive silicone sheet to be attached to a heat source. At this time, the sheet may be processed into a sheet shape before bonding to the thermally conductive silicone sheet so as to facilitate the adhesion of the composition, and may be laminated with the release film, followed by laminating with the thermally conductive silicone sheet. In addition, when attached to a heat source, the release film attached to the heat accumulating sheet is removed, and the exposed heat accumulating sheet can be attached to the heat source. The release film adhered to the heat accumulating sheet may be a polyolefin based base film commonly used in the art, in which a release coating layer composed of a silicone type, a long chain alkyl type, a fluorine type, or the like is coated.

In the present invention, the method of preparing the pressure sensitive adhesive sheet containing the composition is not particularly limited, but a method of applying the composition to a release film in a thickness of 10 to 500 탆 and irradiating ultraviolet rays to cure the adhesive sheet is cited. At this time, the irradiation dose of ultraviolet rays may vary depending on the type of resin constituting the composition, but it is preferably 500 to 5,000 mJ / cm 2.

Examples of the coater used when applying the composition include, but are not limited to, a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, a spray coater, a comma coater, .

The resin composition for a heat-radiating sheet of the present invention may be protected by a release film (separator) until it is laminated with the thermally conductive silicone sheet. Specifically, the resin composition for a heat-radiating sheet may be protected by being sandwiched between two release films or may be rolled up and protected by a single release film on both sides of the release film.

The heat-dissipating silicon sheet having the improved insulation performance according to the present invention can be attached to an LED light source and a heat radiation material (heat sink, graphite sheet, etc.) with the above-described characteristics, and can be used for electronic parts such as CPU and AP.

Hereinafter, a heat-dissipating silicon sheet having enhanced insulation performance according to the present invention will be described in detail with reference to Examples and Comparative Examples. However, the following examples and comparative examples are merely examples for explaining the present invention in more detail, and the present invention is not limited by the following examples and comparative examples.

The physical properties of the specimens prepared through the following examples and comparative examples were measured as follows.

(Electrical insulation)

Measurement was carried out in accordance with JIS-K-6911 using a resistivity meter (Hiresta UP MCP-HT450 type, manufactured by Mitsubishi Kagaku Kagaku Co., Ltd.) in an atmosphere of a temperature of 23 캜 and a humidity of 50% RH. The measured results were assigned to the following criteria.

Electrical Insulation ⊚: 1.0 × 10 ¹⁴ Ω / □ or more

Electrical Insulation ◯: 1.0 × 10 ¹² Ω / □ or more and 1.0 × 10 ¹⁴ Ω / □ or less

Electrical insulation?: 1.0 x 10 ⁹ ? /? Or more 1.0 x 10 ¹² ? /?

Electrical insulation x: Less than 1.0 x 10 ⁹ ? /?

(Thermal conductivity)

The thermal conductivity in the thickness direction was measured using a LFA 457 micro flash measuring instrument (NES cooking, Germany).

(Temperature falling width)

The specimen was attached to the heating element, and the temperature was measured with a non-contact thermometer. The temperature was measured with the same thermometer 30 minutes later.

(Adhesive property)

The prepared specimens were cut into a size of 100 mm long × 25 mm long and specimens were laminated on a test plate including SUS304. Then, the test piece and the rectangular sheet were attached to each other by making one round of a 2-kg rubber roller (width: about 50 mm), and the bonded test plates and the rectangular sheet were allowed to stand for 24 hours under conditions of 23 ° C and 50% RH. Thereafter, in accordance with JIS Z 0237, a tensile test in the direction of 180 占 was carried out at a peeling speed of 300 mm / min, and the adhesive force (N / 25 mm) of the rectangular sheet to the test plate was measured.

(Example 1)

First, an organopolysiloxane having a kinematic viscosity of 15,000 mm 2 / s and a number average molecular weight of 7,500 was prepared at 25 ° C to prepare a thermally conductive silicone sheet. Next, an aluminum powder having an average particle diameter of 5 μm was mixed with an organopolysiloxane. At this time, the mixing ratio was 80 parts by weight of aluminum relative to 100 parts by weight of the organopolysiloxane. After mixing, the mixture was mixed at 25 ° C for 3 hours, coated with a knife coater to a thickness of 2 cm, and cured to complete a thermally conductive silicone sheet.

Next, 3 g of a toluene diisocyanate [Sigma-Aldrich, USA] which can be polymerized as an encapsulating material by condensation polymerization to make a thermal storage capsule, a paraffin as a capsule core material [Sigma-Aldrich, 5 g of acetone (Duksan, Korea) was added to 80 g of water and stirred at 8000 rpm for about 10 minutes using a homogenizer (T25 basic ULTRA-TURAX, IKA, Germany) To prepare a first solution.

Then, a second solution obtained by dispersing 0.6 g of polystyrene sulfonic acid-co-maleic acid (Sigma-Aldrich, USA) in 60 g of water was stirred at 600 rpm, The first emulsified solution was mixed with the second stirring solution to prepare a third solution.

, 0.005 g of polystyrene sulfonic acid-co-maleic acid (poly (styrene sulfonic acid-co-maleic acid)), 5 g of ethyldiamine (Junsei Chemical, Japan) and 5 g of water was added to the third solution The mixture was gradually mixed and reacted for 4 hours at 60 ° C with stirring at 600 rpm to prepare a heat storage capsule (particle diameter: 100 to 600 nm, see FIGS. 2 to 4).

Separately, a composition was prepared by mixing 30 parts by weight of the heat-accumulating capsules prepared in 100 parts by weight of an acrylate resin (Vinil (registered trademark) PSA SV-6805 solid content 47 mass% by Showa Denko K.K.) as a base resin , A doctor blade on a peeled PET film (trade name: E7006, thickness: 25 mu m, manufactured by Toyo Boseki Co., Ltd.), and the solvent was dried to form an adhesive layer having a thickness of 10 mu m, . The properties of the prepared specimens were measured and are shown in Table 1 below.

(Example 2)

A specimen was prepared in the same manner as in Example 1, except that 15 parts by weight of a filler mixed with aluminum oxide and whitening acid in a weight ratio of 70:30 was added to 100 parts by weight of the base resin. The properties of the prepared specimens were measured and are shown in Table 1 below.

(Example 3)

A specimen was prepared in the same manner as in Example 1, except that 5 parts by weight of polyallylamine derivative (Mw: 10,000) was further mixed as a dispersing aid in the preparation of the composition. The properties of the prepared specimens were measured and are shown in Table 1 below.

(Example 4)

A specimen was prepared in the same manner as in Example 1, except that 1.0 g of aluminum oxide nanoparticles having an average particle size of 50 nm was added during the preparation of the second solution. The properties of the prepared specimens were measured and are shown in Table 1 below.

(Example 5)

A specimen was prepared in the same manner as in Example 1, except that 1 part by weight of poly (arylene ether sulfone-co-vinylidene fluoride) having an average particle diameter of 300 nm was added during the preparation of the composition. The properties of the prepared specimens were measured and are shown in Table 1 below.

(Comparative Example 1)

Only the silicon sheet was prepared without laminating the heat accumulating sheet in Example 1. The properties of the prepared specimens were measured and are shown in Table 1 below.

[Table 1]

As shown in Table 1, the heat-dissipating silicon sheet with improved insulation performance according to the present invention exhibits excellent thermal conductivity, temperature drop width, electrical insulation, and adhesive property. Particularly, Example 2 using a mixture of aluminum oxide and acid whiten with a filler exhibited a further excellent thermal diffusion effect. In Example 3 in which a dispersion auxiliary agent was further added, the thermal conductivity and the temperature lowering width were further improved. In Example 4 in which aluminum oxide nanoparticles were further added to the filler, the best electrical insulation, thermal conductivity, have. It can be seen that Example 5 in which an ionomer was further added showed improved adhesion properties while maintaining electrical insulation and thermal properties.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention as defined by the following claims. It will be understood that the invention may be modified and varied without departing from the scope of the invention.

100: Silicone sheet
200: Heat accumulation sheet
300: heat source

Claims (8)

Silver, copper, nickel, zinc oxide, alumina, magnesium oxide, aluminum nitride, metal powder, or the like is added to 100 parts by weight of an organopolysiloxane having a kinematic viscosity of 100 to 100,000 mm 2 / s and a number average molecular weight of 5,000 to 100,000 at 25 ° C Which comprises 10 to 200 parts by weight of one or more fillers selected from boron nitride, silicon nitride, diamond, graphite, carbon nanotubes, metal silicon, iron oxide, carbon fiber, glass fiber, glass bead powder and fullerene, Sheet; And
A heat accumulating capsule which is laminated on one side of the silicone sheet and dispersed in a base resin and in which a phase change material is contained, a filler in which aluminum oxide and acid whiten are mixed in a ratio of 60 to 80: 20 to 40, A dispersing aid comprising an amine derivative and an ionomer having an average particle diameter of 0.01 nm to 600 nm;
, Wherein the heat storage capsule
A heat-radiating silicone sheet reinforced with an insulation property, comprising a filler containing a phase change material and a coating layer containing the filler.
The method according to claim 1,
Wherein the organopolysiloxane has a structure represented by the following formula (1).
[Chemical Formula 1]

Wherein each R is independently (C1-C20) alkyl, (C1-C20) alkoxy, (C2-C20) alkenyl, (C1-C20) acyl or (C6-C20) aryl;
and n is an integer of 1 to 100.)
The method according to claim 1,
The phase change material is selected from the group consisting of Fe ₂ O _{3 .4} SO ₃ .9H ₂ O, NaNH ₄ SO ₄ .2H ₂ O, NaNH ₄ HPO ₄ .4H ₂ O, FeCl ₃ .2H ₂ O, Na ₃ PO ₄ .12H ₂ O _{, Na 2 SiO 3 · 5H 2} O, Ca (NO 3) 2 · 3H 2 O, K 2 HPO 4 · 3H 2 O, Na 2 SiO 3 · 9H 2 O, Fe (NO 3) 3 · 9H 2 O, K ₃ PO ₄揃 7H ₂ O, NaHPO ₄揃 12H ₂ O, CaCl ₂揃 6H ₂ O, Na ₂ SO ₄揃 10H ₂ O, Na (CH ₃ COO) 揃 3H ₂ O, paraffin wax, , n-octadecane, n-triacotane, hexadecane, nonadecane, eicosane, hexoic acid, docosane, tricoic acid, tetracosan, pentacosane, polyethylene glycol, lauric acid, propyl palmitate, Wherein the heat-resistant silicone sheet is one or more selected from the group consisting of stearic acid, isopropyl stearate, butyl stearate, palmitic acid, myristic acid and vinyl stearic acid.
The method according to claim 1,
Wherein the base resin is selected from the group consisting of polydimethylsiloxane resin, epoxy resin, acrylate resin, organopolysiloxane resin, polyimide resin, fluorocarbon resin, benzocyclobutene resin, fluorinated polyallyl ether resin, polyamide resin, Wherein the thermally conductive silicone sheet is one or more selected from the group consisting of an ester resin, a phenol resol resin, an aromatic polyester resin, a polyphenylene ether resin, a bismaleimide triazine resin, and a fluororesin.
delete delete delete The method according to claim 1,
Wherein the phase change material further comprises aluminum oxide nanoparticles.

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