KR100942787B1 - Heat absorbing sheet and method for preparing thereof - Google Patents

Abstract

The present invention relates to a heat absorption sheet. More particularly, the present invention relates to a heat absorbing sheet for dispersing a phase change material or an inorganic material and a resin having endothermic properties with a stirrer, and then forming a sheet having a predetermined thickness to absorb heat generated from an electronic device. The present invention is a resin having heat resistance and heat absorption; A heat absorption layer formed by mixing one or two or more heat storage materials selected from inorganic phase change materials, organic phase change materials, and inorganic materials with the resin; And a pressure-sensitive adhesive layer formed by applying an adhesive to one side of the heat-absorbing layer, and providing a heat-absorbing sheet, which is molded in a sheet form. According to the present invention, it is possible to exhibit more excellent heat absorption performance than the case where only the organic phase change material is used.

Description

Heat Absorbing Sheet and Method for Preparing Honey}

The present invention relates to a heat absorbing sheet composition and a method for producing a heat absorbing sheet. More particularly, the present invention relates to a heat absorbing sheet for dispersing a phase change material or an inorganic material and a resin having endothermic properties with a stirrer, and then forming a sheet having a predetermined thickness to absorb heat generated from an electronic device.

Advances in high-capacity and high-integration of various electrical and electronic components due to high performance and high functionality have caused a large amount of heat generation problems, which is a major factor in deterioration of product performance and quality. For example, heat transmitted directly to the human body due to the heat generation of electrical / electronic devices that occurs during long-term use of electronic devices such as plasma display panels (PDPs), mobile phones, personal data assistants (PDAs), notebook computers, etc. It may affect the various elements of the circuit embedded in the electrical / electronic device, causing problems such as deterioration of the device quality, shortening the life of the product, and battery explosion which is directly connected to the safety of the human body. Therefore, the device for efficiently accumulating and dissipating heat generated from these components is closely related to the performance and quality of the product.

Conventionally, in order to solve such a problem, a fin fan cooling method, a thermoelectric cooling method, a water-jet cooling method, an immersion cooling method, a heat pipe cooling method, etc. Although the heat generated from the electrical / electronic device is removed by using a method, the cooling device also needs to be light and small in size as the electronic / electronic device is gradually slimmer and smaller.

In response to this request, it has recently developed a heat-absorbing sheet using the characteristics of a phase change material (PCM) or an inorganic material that has a freezing point and a melting point and thus dissipates heat at the freezing point and absorbs heat at the melting point. It is attached to electrical / electronic devices to remove heat generated from electrical / electronic devices.

Organic phase change materials have been generally used in such endothermic sheets, and the heat absorption capacity of the endothermic sheet or the thermal conductive sheet using the organic phase change materials has a limit in absorbing and releasing heat generated continuously in electric / electronic devices for a long time. There was a problem.

In order to solve the above problems, the present invention includes an oxide-based inorganic material and is attached to an electrical / electronic device to absorb heat generated by the electrical / electronic device, and then gradually release the heat generated by the electrical / electronic device. It is an object of the present invention to provide a heat absorption sheet to be removed.

In order to achieve the above object, the present invention is formed by mixing a resin having heat resistance and heat absorption with one or two or more heat storage materials selected from an inorganic phase change material, an organic phase change material, and an inorganic material. Heat absorption layer; And a pressure-sensitive adhesive layer formed by applying an adhesive to one side of the heat-absorbing layer, and providing a heat-absorbing sheet, which is molded in a sheet form.

The phase change material is an inorganic phase change material, MgCl ₂ · 6H ₂ O, Al ₂ (SO ₄ ) 3 · 10H ₂ O, NH ₄ Al (SO ₄ ) 2 · 12H ₂ O, KAl (SO ₄ ) 2 · 12H ₂ O, Mg (SO ₃ ) 2 · 6H ₂ O, SrBr ₂ · 8H ₂ O, Sr (OH) 2 · 8H ₂ O, Ba (OH) ₂ · 8H ₂ O, Al (NO ₃ ) 2 · 9H ₂ O, Fe (NO ₃ ) 2 · 6H ₂ O, NaCH ₂ S ₂ O ₂ · 5H ₂ O, Ni (NO ₃ ) 2 · 6H ₂ O, Na ₂ S ₂ O ₂ · 5H ₂ O, ZnSO _{4 2} O, CaBr ₂ · 6H ₂ O, Zn (NO ₃ ) 2 · 6H ₂ O, Na ₂ HPO ₄ · 12H ₂ O, Na ₂ CO ₃ · 10H ₂ O, Na ₂ SO ₄ · 10H ₂ O, LiNO ₂ 3H ₂ O, CaCl ₂ It may include a material of any one of 6H ₂ O.

In addition, the inorganic material may include at least one inorganic material selected from inorganic oxides, hydroxide metal compounds, carbides, nitrides, borides, and non-metal oxides.

In addition, the inorganic phase change material is characterized in that the porous phase change material including nano air-pores (nano air-pores).

In addition, graphite may be further mixed with the organic phase change material.

In addition, the resin may include any one of polyimide resin, melamine resin, silicone resin, urethane resin, epoxy resin, acrylic resin.

In addition, the organic phase change material is selected from the group consisting of organic compounds containing 11 to 36 carbon atoms saturated hydrocarbons, n- octanoic acid, n- octadecane, n- ecoic acid, acetic acid, lactic acid, chloroacetic acid Can be.

In addition, the inorganic phase change material or the organic phase change material is characterized in that the powder.

On the other hand, the present invention (a) mixing and stirring a resin having heat resistance and heat absorption in the heat storage material of at least one or two or more selected from an inorganic phase change material, an organic phase change material and an inorganic material; (b) removing the bubbles present in the stirred mixture; And (c) molding the mixture from which the bubbles are removed into a sheet form.

In addition, the step after the step c) may further comprise d) laminating an adhesive layer made of an adhesive on one side of the molded sheet.

According to the present invention, it is possible to exhibit more excellent heat absorption performance than the case where only the organic phase change material is used. In addition, by efficiently removing the heat generated from the electrical / electronic devices, it is possible to prevent the life of the electrical / electronic device due to heat, or to reduce the performance, and to be easily applied to small electrical / electronic devices It has the advantage that it can be manufactured in the form of a small thin film.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In addition, detailed description is abbreviate | omitted when it is judged that it may obscure the summary of this invention. In addition, preferred embodiments of the present invention will be described below, but the technical idea of the present invention may be implemented by those skilled in the art without being limited or limited thereto.

Figure 1 shows that the adhesive layer is laminated on the heat absorption sheet according to a preferred embodiment of the present invention.

Hereinafter, the heat absorption sheet 100 according to the preferred embodiment of the present invention will be described with reference to FIG. 1.

The heat absorption sheet 100 according to the present invention includes a heat absorption layer 110 and an adhesive layer 120.

The heat absorption layer 110 includes a phase change material or an inorganic material as a heat storage material having a resin and heat absorption performance.

The resin has heat absorption, heat resistance, and chemical resistance, and in particular, polyimide resin, melamine resin, silicone resin, urethane resin, epoxy resin, which are excellent in heat absorption. resin, acrylic resin, and the like. The resin can be used by mixing any one or two or more of the above-listed resins.

The resin is mixed with a phase change material, wherein the phase change material used is MgCl ₂ · 6H ₂ O, Al ₂ (SO ₄ ) 3 · 10H ₂ O, NH ₄ Al (SO ₄ ) 2 · 12H ₂ O, KAl _{(SO4) 2 · 12H 2 O} , Mg (SO 3) 2 · 6H 2 O, SrBr 2 · 8H 2 O, Sr (OH) 2 · 8H 2 O, Ba (OH) 2 · 8H 2 O, Al (NO ₃ ) 2.9H ₂ O, Fe (NO ₃ ) 2,6H ₂ O, NaCH ₂ S ₂ O ₂ · 5H ₂ O, Ni (NO ₃ ) 2,6H ₂ O, Na ₂ S ₂ O ₂ · 5H ₂ O, ZnSO ₄ · 7H ₂ O, CaBr ₂ · 6H ₂ O, Zn (NO ₃ ) 2 · 6H ₂ O, Na ₂ HPO ₄ · 12H ₂ O, Na ₂ CO ₃ · 10H ₂ O, Na ₂ SO ₄ 10H ₂ O, LiNO ₂ · preferably in the inorganic phase change material, such as _{3H 2 O, CaCl 2 · 6H} 2 O.

The inorganic phase change material has advantages of higher density and higher heat absorption performance than organic phase change material. In addition, the excellent corrosion resistance contributes to long product life. On the other hand, the organic phase change material has a latent heat capacity due to the micro-encapsulated nature, but the inorganic phase change material can be directly mixed with the resin, so the limitation of using the organic phase change material Will be able to overcome. The inorganic phase change material may be in the form of a powder in addition to the hydrate forms listed above.

In addition, the phase change material is preferably a porous phase change material including nano air-pores.

Here, nano air-pores refer to nano-scale air-pores, the diameter of the air-pores is in the range of 1 ~ 10nm.

The sheet formed of a phase change material including such nano air-pores has a large surface area per unit volume in contact with air, and particularly, in an open cell structure, gas is easily passed through pores connected to each other, thereby obtaining an improved endothermic efficiency. In addition, due to the large number of pores formed inside, it has a buffering property, and can not only reduce vibrations or shocks applied from the outside, but also reduce the noise generated in electric / electronic devices. have.

The porous phase change material may be formed by using a porogen (polymer pore generator) material. The porogen material may be selected from a group of cyclodextrin compounds, for example, a cyclodextrin (CD) compound applied as an intermediate of food and medicine.

On the other hand, the phase change material used in the heat absorption sheet 100 according to the preferred embodiment of the present invention is not limited to being inorganic, and may be used by mixing an organic phase change material with the inorganic phase change material. In other words, organic compounds including saturated hydrocarbons having 11 to 36 carbon atoms and the like, acids such as n-octanoic acid, n-octadecane, n-eicoic acid, acetic acid, lactic acid, chloroacetic acid, etc., alone or in combination. It is possible to add by. Alternatively, graphite having excellent thermal conductivity and an organic phase change material may be mixed and used. The organic phase change material is preferably in the form of a powder.

As the inorganic material, one or more inorganic materials selected from inorganic oxides, hydroxide metal compounds, carbides, nitrides, and borides may be used.

Inorganic oxides are ceramic powders having heat resistance, and serve to improve heat absorption and heat resistance of the heat absorption sheet 100. Such inorganic oxides may include one or more materials such as alumina, silica, titania, zirconia, zirconia, chromite, zircon oxide, magnesium oxide, and the like. .

Hydroxide metal compounds are flame retardant compounds that improve heat absorption and heat resistance of the heat absorption sheet 100. Such hydroxide metal compounds may be used magnesium hydroxide, aluminum hydroxide and the like.

In addition, carbides such as silicon carbide, titanium carbide, nitrides such as silicon nitride, aluminum nitride, etc., are a kind of ceramic, which has high insulation properties. As a material having heat resistance, insulation of the heat absorption sheet 100 is improved.

Further, borides such as boron nitride having heat resistance, and nonmetal oxides such as oxides such as ceria, alumina, and titania may be added.

The inorganic material is uniformly dispersed in a mixed state with the resin and the phase change material so that uniform properties are exhibited.

On the other hand, the base material mixed with the resin and the phase change material is mixed with an additive such as an antifoaming agent, a dispersant, an organic solvent to remove bubbles generated in the base material, and the phase change material is evenly distributed in the resin, the heat produced Allow the absorbent sheet 100 to be flexible.

In this case, the antifoaming agent contains silicon and xylene or butyl acetate is added as a solvent, so as to add 0.05 to 2% by weight of the total formulation. If the amount of the antifoaming agent is less than 0.05% by weight, bubbles cannot be efficiently removed. If the amount of the antifoaming agent is more than 2% by weight, the drying speed becomes slow, and the production process of the heat absorption sheet 100 becomes inefficient.

As a dispersant, it is preferable to use an acrylic copolymer having excellent solubility in water and various solvents in an amount of 0.2 to 3% of the total formulation. When the content of the acrylic copolymer is less than 0.2%, it is difficult to function as a dispersant, and when it exceeds 3%, bubbles are severely generated.

The stirred substrate is molded into a sheet having a predetermined thickness by using a method such as knife coating, roll coating, calender coating, cast coating or the like. Preferably in consideration of the trend of miniaturization of electrical / electronic devices to be produced in a thin film form of 100 ~ 500㎛.

One side of the heat-absorbing sheet 100 prepared as described above to form a pressure-sensitive adhesive layer 120 by applying a pressure-sensitive adhesive, to be easily attached to a portion that generates a lot of heat, such as a battery or display unit of electrical / electronic devices To help.

Figure 2 is a flow chart showing the manufacturing process of the heat absorption sheet according to a preferred embodiment of the present invention.

Hereinafter, a manufacturing process of the heat absorption sheet 100 will be described with reference to FIG. 2.

First, a mixture of a resin such as polyimide resin, melamine resin, silicone resin, urethane resin, epoxy resin, acrylic resin and a phase change material is mixed and stirred (S200). At this time, additives such as a dispersant, an antifoaming agent, and an organic solvent are added to make the stirring work more smoothly.

Then, by removing the air bubbles contained in the stirred substrate through a slow milling operation for about 6 hours (S210), the substrate from which the bubbles are removed is formed into a sheet through a method such as knife coating, roll coating, calender coating, cast coating, or the like. (S220).

Preferably, at one side of the heat absorption sheet 100 formed in the shape of the sheet to form an adhesive layer 120 made of an adhesive (S230).

Table 1 shows the content ratios for the compositions of the various embodiments of the heat absorption sheet 100. Hereinafter, the present invention will be described in detail through examples.

Example 1

31.5% by weight of urethane resin, 13.5% by weight of epoxy resin, 35% by weight of magnesium hydroxide as an inorganic substance in powder form, and 18.2% by weight of butyl acetate as a solvent were mixed and stirred for 1 hour to prepare a mixture. 0.3 weight% of xylene as an antifoaming agent and 1.5 weight% of the acrylic copolymer as a dispersant were added thereto, followed by post stirring for 1 hour. Then, after performing a slow milling operation for 6 hours to remove the bubbles contained in the mixture, using a knife coating to prepare a heat absorption sheet 100 of 200㎛ thickness. Then, an adhesive was attached to one side of the sheet.

[Examples 2-3]

Prepared in the same manner as in Example 1, but the content ratio of each composition was the same as described in Example 2 of Table 1 above.

In order to examine the heat absorption characteristics of each heat absorption sheet manufactured by the above [Examples 1 to 3], the heat absorption sheet of [Examples 1 to 3] was attached to a heat capacity measuring apparatus, and 43 kcal / m ³ hr The time required for the temperature to rise from the initial temperature of 22 ° C to 40 ° C by applying heat was measured for each sheet.

As a result, the temperature rise time of the heat absorption sheet 100 manufactured by [Example 1] was found to be the latest, and it was confirmed that the heat absorption capacity was the largest. In the case of [Example 2], the content of the phase change material is low so that the heat absorption ability is lowered. In the case of [Example 3], the content of the phase change material in the anhydrous state is high, so that a lot of bubbles are generated and workability is poor. Appeared.

Example 4

In the same manner as in [Example 1], a heat absorption sheet was manufactured by replacing magnesium hydroxide, which is an inorganic material, with n-octadecane, which is an organic phase change material. Then, the heat absorption sheet of [Example 4] was attached to the heat capacity measuring device in the same manner as the above measuring method, and it was required to increase the temperature from the initial temperature of 22 ° C. to 40 ° C. by applying 43 kcal / m ³ hr of heat. The time was measured. As a result, in the heat absorption sheet 100 manufactured in the same content ratio, the temperature rise time of the heat absorption sheet according to [Example 1] containing magnesium hydroxide according to [Example 4] containing n-octadecane It took longer than the heat absorption sheet, and it was confirmed that the heat absorption performance was excellent.

Example 5

Prepared in the same manner as in [Example 1], by replacing the magnesium hydroxide of the inorganic material with magnesium chloride of the inorganic phase change material to prepare a heat absorption sheet, the temperature rise time before and after applying the heat absorption sheet to the heat capacity measuring device Was measured. At this time, the added heat was 43 kcal / m ³ hr and the initial temperature was 22 ° C. As a result, it was confirmed that the temperature rise time is delayed than the application of the heat absorption sheet as shown in FIG. 4. Therefore, it can be seen that the heat absorption capacity of the heat absorption sheet including the inorganic phase change material is excellent.

The above description is merely illustrative of the technical idea of the present invention, and various modifications, changes, and substitutions may be made by those skilled in the art without departing from the essential characteristics of the present invention. will be. Accordingly, the embodiments disclosed in the present invention and the accompanying drawings are not intended to limit the technical spirit of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by the embodiments and the accompanying drawings. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

Figure 1 shows that the adhesive layer is laminated on the heat absorption sheet according to a preferred embodiment of the present invention.

Figure 2 is a flow chart showing the manufacturing process of the heat absorption sheet according to a preferred embodiment of the present invention.

3 shows a heat capacity measuring apparatus.

Figure 4 is a graph showing the results of measuring the heat absorption capacity before and after applying the heat absorption sheet according to Example 5.

<Explanation of symbols for the main parts of the drawings>

100: heat absorption sheet 110: heat absorption layer

120: adhesive layer

Claims (14)

Resin having heat resistance and heat absorption The resin includes alumina, silica, titania, zirconia, zirconia, chromite, zircon oxide, magnesium oxide, magnesium hydroxide, aluminum hydroxide carbide, At least one inorganic material selected from the group consisting of titanium carbide, silicon nitride, aluminum nitride boron nitride and ceria or MgCl 2 .6H 2 O, Al 2 (SO 4) 3 10H2O, NH4Al (SO4) 2, 12H2O, KAl (SO4) 2, 12H2O, Mg (SO3) 2, 6H2O, SrBr2, 8H2O, Sr (OH) 2, 8H2O, Ba (OH) 2, 8H2O, Al (NO3) 2,9H2O, Fe (NO3) 2,6H2O, NaCH2S2O2, 5H2O, Ni (NO3) 2, 6H2O, Na2S2O2, 5H2O, ZnSO4, 7H2O, CaBr2, 6H2O, Zn (NO3) 2, 6H2O, Na2HPO4 Na2HPO A heat absorption layer formed by mixing at least one inorganic phase change material selected from the group consisting of 10H 2 O, LiNO 2 · 3H 2 O and CaCl 2 · 6H 2 O; And And a pressure-sensitive adhesive layer formed by applying an adhesive to one side of the heat-absorbing layer, wherein the heat-absorbing sheet is formed in a sheet form. delete delete The method of claim 1, The inorganic phase change material is a heat-absorbing sheet, characterized in that it comprises a nano air-pore formed using a porogen material selected from the group of cyclotextine compounds. The method of claim 1, The heat absorption layer further comprises at least one or more of an antifoaming agent, a dispersant, an organic solvent. delete The method of claim 5, The antifoaming agent is a heat absorbing sheet, characterized in that 0.05 to 2% by weight of the total heat absorbing layer. The method of claim 1, The heat absorption layer is a heat absorption sheet, characterized in that to form a thin film using any one method of knife coating, roll coating, calendar coating, cast coating. (a) Alumina, Silica, Titania, Zirconia, Zirconia, Chromite, Zircon Oxide, Magnesium Oxide, Magnesium Hydroxide, Aluminum Hydroxide, At least one inorganic material selected from the group consisting of titanium carbide, silicon nitride, aluminum nitride boron nitride and ceria, or MgCl 2 .6H 2 O, Al 2 (SO 4) 3 10H2O, NH4Al (SO4) 2, 12H2O, KAl (SO4) 2, 12H2O, Mg (SO3) 2, 6H2O, SrBr2, 8H2O, Sr (OH) 2, 8H2O, Ba (OH) 2, 8H2O, Al (NO3) 2,9H2O, Fe (NO3) 2,6H2O, NaCH2S2O2, 5H2O, Ni (NO3) 2, 6H2O, Na2S2O2, 5H2O, ZnSO4, 7H2O, CaBr2, 6H2O, Zn (NO3) 2, 6H2O, Na2HPO4 Na2HPO A step of mixing and stirring at least one inorganic phase change material selected from the group consisting of 10H 2 O, LiNO 2 · 3H 2 O, and CaCl 2 · 6H 2 O and a resin having heat resistance and heat absorption .; (b) mixing at least one or more of an antifoaming agent, a dispersant, and an organic solvent to the stirred mixture produced in step (a) to remove bubbles present in the stirred mixture; And (c) forming the stirred mixture produced in the step (b) into a sheet form. delete The method of claim 9, After the step (c) the mixture is formed into a thin film using any one method of knife coating, roll coating, calendar coating, cast coating method of producing a heat absorption sheet. The method of claim 9, The inorganic phase change material is a method for producing a heat-absorbing sheet, characterized in that it comprises a nano air-pore formed using a porogen material selected from the group of cyclotextine compounds. delete The method of claim 9, To step after step c) d) Method of manufacturing a heat absorbing sheet, characterized in that it further comprises the step of laminating an adhesive layer containing an adhesive on one side of the molded sheet.

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