KR101705229B1

KR101705229B1 - Heat-dissipation adhesive tape, heat-dissipation sheet and composition used in the preparation thereof

Info

Publication number: KR101705229B1
Application number: KR1020150181233A
Authority: KR
Inventors: 유광현; 서윤희; 편승용; 백형준
Original assignee: 에스케이씨 주식회사
Priority date: 2015-12-17
Filing date: 2015-12-17
Publication date: 2017-02-09
Also published as: KR20160084293A

Abstract

The heat-dissipating adhesive tape and the heat-radiating sheet include: (a) an acrylic copolymer resin having an acid value of 15 or more; (b) a thermosetting adhesive tape for heat dissipation; (b) a heat dissipating filler dispersed in the acrylic copolymer resin; And (c) a pressure-sensitive adhesive layer containing a dispersing agent, thereby realizing a thin film having excellent thermal conductivity.

Description

TECHNICAL FIELD [0001] The present invention relates to a heat-dissipating adhesive tape, a heat-dissipating sheet, and a composition used for the same. BACKGROUND ART [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-dissipation adhesive tape, a heat-radiating sheet, and a composition for use in the production thereof,

In recent years, electronic devices have become highly integrated with thinning and multi - functionalization, and heat generation is increasing, and countermeasures are demanded. Especially, releasing the heat generated in the electronic device is important because it is closely related to the reliability and lifetime of the device. Accordingly, various heat dissipation mechanisms such as a heat dissipation fan, a heat dissipation fin, and a heat pipe have been developed, and various heat dissipation materials such as a heat dissipation pad, a heat dissipation sheet, and a heat dissipation material have been developed.

For example, in a mobile device such as a mobile phone in which slimness is required, a graphite sheet having superior thermal conductivity in the lateral direction is utilized to lower the temperature of a chip through a function of spreading heat. However, since the graphite sheet itself has no adhesive force, it can not be attached to the electronic device through the adhesive tape. In the case of a general adhesive tape, the thermal conductivity is low and the heat resistance is high, which is a factor to deteriorate the heat radiation performance.

Therefore, a technique of increasing the thermal conductivity by adding a heat-radiating filler or the like to the adhesive tape has been studied. However, since the carbon-based filler having hydrophobicity has a very low dispersibility with the binder resin, it is difficult to fill the film with a high content, there was. In order to solve this problem, when a heat-radiating filler having a large particle size while thickening the adhesive tape is used, it is possible to fill a high content with a high density, but the thicker the thickness, the larger the thermal resistance becomes.

The inventors of the present invention have found that it is possible to provide an adhesive tape having a high thermal conductivity and a thin film thickness by controlling the binder resin used for the adhesive tape to improve the dispersibility of the heat radiation filler to enable high- And completed the present invention.

Korean Patent No. 10-1465580 (November 26, 2014)

Accordingly, an object of the present invention is to provide a heat-resisting adhesive tape, a heat-radiating sheet, and a composition for use in the production of the heat-sensitive adhesive tape, which can provide a thin film with excellent thermal conductivity.

According to the above object, the present invention provides an adhesive tape comprising a pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer comprises (a) an acrylic copolymer resin having an acid value of 15 or more; (b) a heat dissipating filler dispersed in the acrylic copolymer resin; And (c) a dispersing agent, wherein the heat-radiating filler comprises not less than 15% by weight based on the total weight of the acrylic copolymer resin and the heat-radiating filler.

According to another aspect of the present invention, there is provided a heat radiation sheet comprising a graphite sheet and an adhesive layer formed on one side of the graphite sheet, wherein the adhesive layer comprises: (a) an acrylic copolymer resin having an acid value of 15 or more; (b) a heat dissipating filler dispersed in the acrylic copolymer resin; And (c) a dispersing agent, wherein the heat-radiating filler comprises not less than 15% by weight based on the total weight of the acrylic copolymer resin and the heat-radiating filler.

According to another aspect of the present invention, there is provided an acrylic resin composition comprising: (a) an acrylic copolymer resin having an acid value of 15 or more; (b) a heat dissipating filler dispersed in the acrylic copolymer resin; And (c) a dispersing agent, wherein the heat-radiating filler comprises at least 15% by weight based on the total weight of the acrylic copolymer resin and the heat-radiating filler.

The heat-dissipating adhesive tape includes a heat-radiating filler, and improves the dispersibility of the heat-radiating filler by increasing the polarity of the binder resin used in the adhesive layer. As a result, a high content of heat-radiating filler can be filled in the pressure-sensitive adhesive layer, so that it is possible to realize a thin film having a thickness of 5 탆 or less while having excellent thermal conductivity. Accordingly, the heat-radiating sheet manufactured using the adhesive tape can adhere to the surface of a heat-generating article such as an electronic device and exhibit excellent heat-radiating performance.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional view of a heat-conducting adhesive tape according to the present invention. Fig.
2 is a sectional view of a heat-radiating sheet according to the present invention.

Hereinafter, the present invention will be described more specifically with reference to the drawings. In the accompanying drawings, sizes, intervals, and the like may be exaggerated for clarity of understanding, and the contents obvious to those skilled in the art may be omitted.

(A) an acrylic copolymer resin having an acid value of 15 or more; (b) a heat dissipating filler dispersed in the acrylic copolymer resin; And (c) a dispersant.

Hereinafter, each component will be described in detail.

The acrylic copolymer resin has an acid value of 15 or more. When the acid value of the acrylic copolymer resin is 15 or more, even when a non-polar heat-radiating filler such as a carbon-based filler is dispersed in the acrylic copolymer resin, the polarity difference between the filler and the resin becomes large, thereby increasing the formation of micelle and improving dispersibility .

Preferably, the acid value of the acrylic copolymer resin may range from 15 to 25. When the acid value is 15 or more, the adhesive layer is advantageous in preventing the adhesion strength from being lowered even when the adhesive layer is formed as a thin film having a thickness of 5 탆 or less, and is advantageous in preventing the elasticity degradation due to an excessive increase in the glass transition temperature (Tg)

The acrylic copolymer resin preferably contains at least one acrylate unit having an alkyl group having 8 to 10 carbon atoms as a monomer unit. The acrylate unit having an alkyl group having 8 to 10 carbon atoms can improve the elasticity by effectively lowering the glass transition temperature (Tg) of the acrylic copolymer resin. The at least one acrylate unit having an alkyl group of 8 to 10 carbon atoms is contained in the acrylic copolymer resin in an amount of 50 to 80% by weight, 60 to 80% by weight, 65 to 80% by weight, or 60 to 70% Based on the weight of the resin).

More preferably, the acrylic copolymer resin may include at least one acrylate unit having an alkyl group having 9 to 10 carbon atoms as a monomer unit.

The at least one acrylate monomer unit having an alkyl group having 9 to 10 carbon atoms is contained in the acrylic copolymer resin in an amount of 15 to 45 wt%, 25 to 45 wt%, 30 to 45 wt%, or 30 to 40 wt% Based on the weight of the copolymer resin).

(Meth) acryl-based resin has a glass transition temperature (Tg) that varies depending on the number of carbon atoms of the (meth) acrylate unit constituting the (meth) acrylate resin, and an acrylate monomer having an alkyl group having 2 to 10 carbon atoms or a methacrylate monomer having an alkyl group having 8 to 12 carbon atoms Since the Tg of the resin obtained from the cryol-based monomer is the lowest, the effect of decreasing the Tg of these monomers is great. In particular, the Tg reduction effect of an acrylate unit having an alkyl group of 4 to 10 carbon atoms is most excellent.

In addition, in order to increase the acid value of the acrylic copolymer resin, it is preferable that the acrylate unit having a long chain alkyl group has a skeleton so that many acrylic acid units are bonded to the side chain thereof. The acrylic acid unit decreases the elasticity by increasing the Tg of the resin From this point of view, an acrylate unit having an alkyl group of 8 to 10 carbon atoms, particularly an alkyl acrylate unit having an alkyl group of 9 to 10 carbon atoms, has a long chain alkyl group and can bind to a large number of acrylic acid units, Since the effect of suppressing the increase is large.

The acrylic copolymer resin may further include an acrylic acid (AA) unit. The acrylic acid unit enhances the acid value of the acrylic copolymer resin and improves the adhesion. Preferably, the acrylic acid unit is contained in an acrylic copolymer resin in an amount of 12 to 17% by weight (based on the weight of the acrylic copolymer resin). When the content of the acrylic acid unit is 12% by weight or more, the acid value of the acrylic copolymer resin is increased to improve the dispersibility of the heat radiation filler and the adhesion of the adhesive layer. When the acrylic acid unit content is 17% by weight or less, It is advantageous to prevent the deterioration of elasticity in accordance with the present invention.

The acrylic copolymer resin may further include a butyl acrylate (BA) unit. The butyl acrylate unit can increase the distribution of functional groups (-COOH, etc.) on the surface of the adhesive layer because the steric effect is small while lowering the glass transition temperature of the acrylic copolymer resin. Preferably, the butyl acrylate unit may be contained in the acrylic copolymer resin in an amount of 5 to 40% by weight, more preferably 10 to 30% by weight (based on the weight of the acrylic copolymer resin).

The acrylic copolymer resin may have a glass transition temperature (Tg) of -40 ° C to -15 ° C. Preferably, the acrylic copolymer resin may have a Tg of -30 ° C to -15 ° C, more preferably -25 ° C to -20 ° C.

The acrylic copolymer resin may have a weight average molecular weight (Mw) of about 150,000 to 250,000 g / mol. If the molecular weight is less than 150,000 g / mol, the elasticity may decrease after the filler dispersion, so that the formation of the adhesive layer may be difficult. If the molecular weight is more than 250,000 g / mol, the tack may decrease after the filler dispersion.

The heat-radiating filler may be a carbon-based filler. Specifically, the heat-radiating filler may be at least one filler selected from the group consisting of diamond, carbon nanotube (CNT), graphene, graphite, carbon black, carbon fiber, and fullerene

In order to increase the thermal conductivity of the composition in which the filler is dispersed in the resin, a method may be employed in which the thermal conductivity of the resin is improved, the filling rate (density) of the filler is improved, or the thermal conductivity of the filler is improved. As can be seen from the formula (effective medium equation), improving the filling factor of the filler can further improve the thermal conductivity of the composition rather than improving the thermal conductivity of the filler.

[Equation 1]

And wherein, λ c, λ m and λ p is the thermal conductivity coefficient of each composition, the resin and filler, V p is the volume fraction of the filler.

However, in general heat-resisting fillers such as carbon-based fillers, the apparent density is low and the filling rate is limited. Thus, the apparent density can be improved by controlling the specific surface area of the filler. For example, a filler having a BET specific surface area of 300 m < 2 > / g or less can be used. However, when the BET specific surface area of the filler is less than 80 m < 2 > / g, protrusions may occur when the filler solution is coated to a thickness of 5 mu m or less. Therefore, it is preferable that the filler has a BET specific surface area in the range of 80 to 300 m < 2 > / g.

The heat-radiating filler is contained in the adhesive layer in an amount of 15 wt% or more, and preferably 20 wt% or more, based on the total weight of the acrylic copolymer resin and the heat-radiating filler. For example, the heat-radiating filler may be added to the adhesive composition in an amount of 15 to 50% by weight, 15 to 40% by weight, 15 to 30% by weight, 20 to 50% by weight based on the total weight of the acrylic copolymer resin and the heat- 20 to 40% by weight, 20 to 30% by weight, and the like. Generally, it is difficult to increase the packing ratio of the heat-radiating filler to 15 wt% or more in a thin-film adhesive layer (for example, a thickness of 3 to 15 mu m). However, as described above, the heat-

The dispersing agent may be a nonionic surfactant.

Specifically, the dispersing agent may be a nonionic surfactant containing units derived from oleic acid. More specifically, the dispersing agent may be a surfactant containing a unit derived from oleic acid as a polysorbate-based compound.

The dispersant may have a molecular weight, for example, a weight average molecular weight of about 500 to 3000 g / mol.

Such a dispersant improves the dispersibility of the composition, forms a rigid micro-shell to improve dispersion stability, and prevents re-aggregation from occurring after dispersion.

The dispersant may be used in an amount of 0.05 to 5 parts by weight, more preferably 0.1 to 3 parts by weight based on 100 parts by weight of the total weight of the acrylic copolymer resin and the heat-radiating filler.

The heat-dissipating adhesive tape may have a single-layer structure of a non-substrate type composed of the adhesive layer.

As another example, the heat-radiation adhesive tape may be a base-type tape further comprising a base layer formed on one side of the adhesive layer. Alternatively, the heat-sensitive adhesive tape may be a double-sided adhesive tape having the adhesive layer formed on both surfaces of the base layer.

As another example, referring to FIG. 1, the heat radiation adhesive tape may further include a release film on one side or both sides of the adhesive layer 110. For example, the first release film 121 may be provided on one side of the adhesive layer 110 and the second release film 122 may be provided on the other side.

The release film may comprise conventional silicon based release materials.

The first release film 121 and the second release film 122 may have different peeling forces. For example, the first release film 121 and the second release film 122 may be respectively a heavy-weight recoil film and a light-releasing film.

The heat-sensitive adhesive tape may have a thickness of 3 to 15 탆, more specifically 3 to 12 탆, more specifically 4 to 10 탆. As described above, the heat-sensitive adhesive tape can be realized as a thin film as described above even though the heat-radiating filler is filled with a high content.

The adhesive layer may have a thermal conductivity of 0.6 W / mK, 0.6-0.8 W / mK, or 0.6-0.7 W / mK, for example, 0.6 W / mK or more, . In addition, the adhesive layer may have a thermal conductivity of 6 times or more than that of a general acrylic adhesive tape.

The adhesive layer may have a density (based on the dry film) of 1.19 g / cc or more, for example, 1.19 to 1.35 g / cc. The adhesive layer may have a density (based on the dry film) of 1.25 g / cc or more, for example, 1.25 to 1.35 g / cc.

The adhesive layer may have an adhesive strength of 0.3 to 0.7 kgf / in. For example, when the thickness of the adhesive layer is 5 m, the adhesive layer may have the adhesive strength. The heat-resistant adhesive tape may have heat resistance that minimizes deterioration of initial adhesion even when left at 85 캜 for one month or more.

The heat-dissipating adhesive tape can adhere to the surface of an IC chip or the like to lower the temperature. For example, the temperature-sensitive adhesive tape can lower the temperature of the surface to be attached by 2 DEG C or more.

Therefore, the adhesive tape can be used as a material of a heat-radiating sheet of an electronic device such as an IC chip. The adhesive tape can be utilized as an adhesive layer of a heat-radiating sheet using a heat-radiating material such as a graphite sheet.

2, the present invention also relates to a heat-radiating sheet comprising a graphite sheet 130 and an adhesive layer 110 formed on one surface of the graphite sheet 130, wherein the adhesive layer 110 comprises (a) 15 An acrylic copolymer resin having an acid value of at least 10; (b) a heat dissipating filler dispersed in the acrylic copolymer resin; And (c) a dispersing agent, wherein the heat-radiating filler comprises not less than 15% by weight based on the total weight of the acrylic copolymer resin and the heat-radiating filler.

The heat-radiating sheet may be attached to the surface of a heat-generating article such as an electronic device via the adhesive layer. At this time, since the adhesive layer has a good thermal conductivity, it is possible to effectively transmit the surface heat of the heat generating article to the graphite sheet effectively, and also the heat dissipation performance can be exhibited by the adhesive layer itself. Further, since the adhesive layer can be formed as a thin film, the overall thickness of the heat radiation sheet may not be increased. In addition, since the adhesive layer has excellent adhesive force, the adhesive force of the heat-radiating sheet to the product can be well maintained even in a harsh environment.

The graphite sheet may be an artificial graphite sheet or a natural graphite sheet. The graphite sheet may have a thickness ranging from 17 to 500 mu m.

The heat-radiating sheet may further include an additional functional layer on the other surface of the graphite sheet 130. For example, the heat-radiating sheet may further include a general adhesive layer 140, a printing layer 150, and / or a base film layer 160, which are not provided on the other surface of the graphite sheet 130 . Further, a release film 121 may be further provided on at least one of both outer surfaces.

The release film 121 may include a commonly used release material such as a silicon based material and may have a thickness ranging from 10 to 30 mu m.

The general adhesive layer 140 may include a polymer resin, typically used in an adhesive layer, and may include, for example, an acrylic resin. Preferably, the adhesive layer may include a thermosetting polymer resin and / or a UV curable polymer resin.

The printing layer 150 refers to a layer on which a color, a pattern, a pattern or the like is printed or deposited for a decoration function. The printing layer may be formed by printing or vapor deposition. Alternatively, a black PET film may be used as the printing layer.

The base film layer 160 may be a commonly used polyester film or the like, and may be a transparent film layer including a polymer resin such as polyethylene terephthalate. The base film layer may have a thickness ranging from 10 to 30 mu m.

The adhesive tape can be produced by molding an adhesive layer using a pressure-sensitive adhesive composition. For example, the adhesive layer is formed by applying a pressure-sensitive adhesive composition onto a release film and drying the pressure-sensitive adhesive tape, whereby the pressure-sensitive adhesive tape can be made into an inorganic material type. Alternatively, the adhesive layer is formed by applying a pressure-sensitive adhesive composition on a substrate layer and drying the pressure-sensitive adhesive layer, whereby the pressure-sensitive adhesive tape can be manufactured into a base type. The coating method of the adhesive layer may be a micro gravure coating method or the like.

The pressure-sensitive adhesive composition used in the production of the heat-dissipating adhesive tape and the heat-radiating sheet includes (a) an acrylic copolymer resin having an acid value of 15 or more; (b) a heat dissipating filler dispersed in the acrylic copolymer resin; And (c) a dispersing agent, wherein the heat-radiating filler is contained in an amount of 15 wt% or more based on the total weight of the acrylic copolymer resin and the heat-radiating filler.

Specific descriptions of the components (a) to (c) constituting the adhesive composition are as described above.

The adhesive composition may further comprise a solvent. Specific examples of the solvent include ethyl acetate (EA), methyl ethyl ketone (MEK), toluene, and isopropyl alcohol (IPA). Two or more of these solvents may be used in combination. The solvent may be contained such that the solid content of the adhesive composition is 25 to 50% by weight, more preferably 20 to 40% by weight.

The pressure-sensitive adhesive composition may have a viscosity of 1000 to 3000 cps based on 40% by weight of the solid content.

The pressure-sensitive adhesive composition can be used as a heat-dissipating material in various fields and applications, such as heat-dissipating paints, in addition to the production of heat-resisting adhesive tape.

Hereinafter, the present invention will be described more specifically by way of examples. The following examples are for illustrative purposes only, and the scope of the present invention is not limited to these examples.

Production Example: Production of acrylic copolymer resin

The monomers were charged and mixed in the reactor as shown in Table 1 below. Then, 0.07 part by weight of AIBN (2,2'-azobis (isobutyronitrile)) as an initiator was added to the reactor in an amount of 14 parts by weight based on 100 parts by weight of the monomer mixture, and 14% . The reactor temperature was adjusted to 80 ° C and the copolymerization reaction was carried out for 4 hours.

The acid value and the glass transition temperature (Tg) of the copolymer resin obtained after completion of the reaction were measured and are summarized in Table 1 below.

division Monomer component (% by weight) Properties 2-EHMA 2-EHA M BA AA Acid value Tg (占 폚) Resin 1 31 0 42 15 12 15 -12 Resin 2 0 38 42 15 5 6 -29 Resin 3 0 38 35 15 12 15 -23 Resin 4 0 33 35 15 17 23 -15 Resin 5 0 30 38 15 17 23 -17 Resin 6 0 27 38 15 20 27 -11 Comparative group 0 15 0 80 5 6 -33

2-EHMA: 2-ethylhexyl methacrylate

2-EHA: 2-ethylhexyl acrylate

M: acrylate having an alkyl group having 9 to 10 carbon atoms

BA: butyl acrylate

AA: Acrylic acid

Experimental Example 1: Evaluation of acrylic copolymer resin

A carbon composition filler (graphene flake) was dispersed in an amount of 30% by weight (based on the total weight of the resin to which the filler had been added) to each of the acrylic copolymer resins prepared above to make a coating composition and tape cast. Then, the dispersion and agglomeration state of the carbon-based filler was observed, and the presence or absence of formation of a tape and the evaluation of adhesion were summarized in Table 2 below.

(1) Dispersion: During the dispersion of the carbon-based filler in the acrylic copolymer resin, it was confirmed by using a particle size analyzer (FOG gauge) that particles having a particle diameter of 3 탆 or more were generated.

- O: Particles with particle size of 3 μm or more are not observed and dispersibility is excellent.

- X: Particles with particle diameters of 3 탆 or more were observed, resulting in poor dispersibility.

(2) Filler aggregation: After dispersing the carbon-based filler in the acrylic copolymer resin, it was confirmed by using a particle size analyzer (FOG gauge) that particles having a particle diameter of 3 탆 or more were generated.

(3) Tape formation: Acrylic copolymer resin was coated on the substrate to observe the formation of the coating film.

- O: No problem in tape formation.

- X: Tape formation is not easy.

(4) Adhesive strength: A 38 탆 thick PET substrate was coated with an acrylic copolymer resin and held for 1 hour, then attached to a glass plate, and the 180 占 peel strength was measured using a TA machine.

Dispersion Filler aggregation Tape formation Adhesion (kgf / in) Resin 1 O radish X - Resin 2 O Flocculation O - Resin 3 O radish O 0.37 Resin 4 O radish X - Resin 5 O radish O 0.31 Resin 6 O radish X - Comparative group X Flocculation X -

As shown in Table 2, resin 3 and resin 5 were excellent in dispersion, and the carbon-based filler was not aggregated and could be formed of a tape having excellent adhesive strength. On the other hand, other resins were not dispersed so that the carbon-based filler could not be formed into a tape due to aggregation or low elasticity. In particular, in the case of the comparative group containing no acrylate (M) having an alkyl group having 9 to 10 carbon atoms, dispersion was very low and a tape could not be formed.

Examples 1-1 to 1-6 and Comparative Example 1: Production of adhesive composition

An acrylic copolymer resin (resin 5) was added to the filler solution in a solvent (ethyl acetate) in a weight ratio shown in the following Table 3, and the mixture was stirred for 2 hours. Then, the solid content concentration Was added in an amount of 30% by weight and stirred for 2 hours to prepare a filler solution. The fillers were dispersed through a basket mill or a Dyno mill to prepare respective compositions.

Experimental Example 2: Evaluation of adhesive composition

The pressure-sensitive adhesive compositions prepared in Examples 1-1 to 1-6 were evaluated in the following manner and summarized in Table 3.

(1) Adhesive strength: A 38 탆 thick PET substrate was coated with an acrylic copolymer resin and held for 1 hour, then attached to a glass plate, and the 180 占 peel strength was measured using a TA machine.

(2) Thermal conductivity: Thermal conductivity was measured by NETZCH LFA467 model according to laser scintillation method (LFA).

(3) Formation of a 5 탆 coating film: An epoxy curing agent was added to the pressure-sensitive adhesive composition and stirred for 1 hour, followed by casting to determine whether a heat-sensitive adhesive tape having a dry thickness of 5 탆 could be formed.

(4) Particle re-agglomeration: Using a particle size analyzer (FOG gauge), it was confirmed whether particles having a particle diameter of 3 μm or more were generated.

(5) 4 weeks storage stability: After the adhesive composition was stored at room temperature for 4 weeks, it was observed whether or not a cake was formed at the bottom.

division Example
1-1 Example
1-2 Example
1-3 Example
1-4 Example
1-5 Example
1-6 Comparative Example
One Filler content (parts by weight) 15 20 25 30 35 40 30 Resin content (parts by weight) 85 80 75 70 65 60 70 Dispersant apply apply apply apply apply apply Unapplied Adhesion (kgf / in) 0.66 0.55 0.41 0.3 - - 0.3 Thermal conductivity (W / mK) 0.4 0.45 0.6 0.7 0.85 One 0.7 5㎛ coating film formation possible possible possible possible difficulty difficulty possible Particle re-agglomeration X X X X X X O 4 weeks storage O O O O O O X

Example 2: Production of heat-resistant adhesive tape

An epoxy curing agent was added to the pressure-sensitive adhesive composition of Example 1-2 and stirred for 1 hour, followed by casting to prepare a heat-sensitive adhesive tape having a dry thickness of 5 占 퐉.

Comparative Example 2

As a comparative example, a general insulating tape (DC05S, SKC) having a thickness of 5 mu m was used.

Experimental Example 3: Thermal performance test

An adhesive tape was laminated on one surface of the graphite sheet to prepare a heat-radiating sheet, which was attached to the surface of the test chip via the adhesive tape. The heat-sensitive adhesive tape of Example 2 or the general insulating tape of Comparative Example 2 was used as the adhesive tape. As the graphite sheet, an artificial graphite sheet having a thickness of 25 mu m or a natural graphite sheet having a thickness of 25 mu m was used.

Specifically, a heat-radiating sheet was fabricated as shown in Table 4, attached to the surface of the test chip, and placed in a sealed space at 25.6 캜 in an atmosphere with less influence of outside air. After power was connected to the chip to generate heat, the surface temperature was measured with a thermal camera 10 minutes after reaching the heat saturation state.

At this time, since the surface of the chip and the surface of the graphite of the heat-radiating sheet are highly reflective, it is difficult to measure the temperature with the thermal imaging camera, so that a black PET single-sided adhesive tape having a thickness of 5 탆 was attached to the surface of the heat- Also, for comparison under the same conditions, each test was performed under the same output condition using the same chip.

The composition of each heat-radiating sheet and the temperature measurement results are summarized in Table 4 below.

division Sample # 0 Sample # 1 Sample # 2 Sample # 3 Sample # 4 Graphite
Sheet Unattached synthetic
Graphite natural
Graphite synthetic
Graphite natural
Graphite Adhesive layer Unattached Insulating tape Insulating tape Heat-radiating tape Heat-radiating tape Temperature 70.6 ° C 55.7 DEG C 56.8 ° C 53.7 DEG C 54.8 ° C

As shown in Table 4, it was confirmed that the surface temperature of the samples # 1 to # 4 to which the heat-radiating sheet was applied was significantly lower than that of the chip (sample # 0) without the heat-radiating sheet.

The heat radiation performance of the artificial graphite sheet and the heat release tape according to the present invention was found to be the best in the sample # 3. Specifically, the heat radiation performance was evaluated in the order of sample # 3> sample # 4> sample # 1> .

When the samples using the same kind of graphite sheet were compared with each other, it was confirmed that the surface temperature in the case of introducing the heat radiation tape of the present invention was lowered by about 2 占 폚 than that in the case where the general insulation tape was introduced.

In particular, in the case of the sample # 4 in which the heat radiation tape according to the present invention was introduced, the heat radiation performance was superior to that of the sample # 1 using the artificial graphite sheet even though the natural graphite sheet was used.

110: heat-dissipating adhesive layer,
121: first release film layer,
122: second release film layer,
130: graphite sheet,
140: general adhesive layer,
150: printing layer,
160: Base film layer.

Claims

As an adhesive tape comprising a pressure-sensitive adhesive layer,
The adhesive layer
(a) an acrylic copolymer resin having an acid value of from 15 to 25 and a glass transition temperature of from -25 DEG C to -17 DEG C;
(b) a heat dissipating filler dispersed in the acrylic copolymer resin; And
(c) a dispersant,
Wherein the heat radiation filler is contained in an amount of 15 to 30% by weight based on the total weight of the acrylic copolymer resin and the heat radiation filler,
Wherein the acrylic copolymer resin contains at least one acrylate unit having an alkyl group of 8 to 10 carbon atoms as a monomer unit in a total amount of 50 to 80% by weight based on the weight of the acrylic copolymer resin, and an alkyl group having 9 to 10 carbon atoms Wherein the total content of the acrylate units is 25 to 45 wt% based on the weight of the acrylic copolymer resin.

delete

The method according to claim 1,
The acrylic copolymer resin
Further comprising 12 to 17% by weight of an acrylic acid (AA) unit as a monomer unit based on the weight of the acrylic copolymer resin.

5. The method of claim 4,
Wherein the acrylic copolymer resin further comprises a butyl acrylate unit as a monomer unit.

delete

The method according to claim 1,
Wherein the adhesive layer comprises 20 to 30% by weight of the heat radiation filler based on the total weight of the acrylic copolymer resin and the heat radiation filler.

8. The method of claim 7,
Wherein the heat-radiating filler is a carbon-based filler having a BET specific surface area of 80 to 300 m < 2 > / g.

The method according to claim 1,
Wherein the dispersant comprises a nonionic surfactant comprising units derived from oleic acid.

10. The method of claim 9,
Wherein the dispersant is a surfactant containing units derived from oleic acid as a polysorbate-based compound and has a weight average molecular weight of 500 to 3000 g / mol.

The method according to claim 1,
Wherein the adhesive layer has a thickness of 3 to 15 탆, a thermal conductivity of 0.6 W / mK or more, an adhesive force of 0.3 to 0.7 kgf / in, and a density of 1.19 g / cc or more.

Graphite sheet, and
And a pressure-sensitive adhesive layer formed on one surface of the graphite sheet,
The adhesive layer
(a) an acrylic copolymer resin having an acid value of from 15 to 25 and a glass transition temperature of from -25 DEG C to -17 DEG C;
(b) a heat dissipating filler dispersed in the acrylic copolymer resin; And
(c) a dispersant,
Wherein the heat radiation filler is contained in an amount of 15 to 30% by weight based on the total weight of the acrylic copolymer resin and the heat radiation filler,
Wherein the acrylic copolymer resin contains at least one acrylate unit having an alkyl group having 8 to 10 carbon atoms as a monomer unit in a total amount of 50 to 80% by weight based on the weight of the acrylic copolymer resin, and an alkyl group having 9 to 10 carbon atoms And the total amount of the acrylate units is 25 to 45 wt% based on the weight of the acrylic copolymer resin.

(a) an acrylic copolymer resin having an acid value of from 15 to 25 and a glass transition temperature of from -25 DEG C to -17 DEG C;
(b) a heat dissipating filler dispersed in the acrylic copolymer resin; And
(c) a dispersant,
Wherein the heat radiation filler is contained in an amount of 15 to 30% by weight based on the total weight of the acrylic copolymer resin and the heat radiation filler,
Wherein the acrylic copolymer resin contains at least one acrylate unit having an alkyl group having 8 to 10 carbon atoms as a monomer unit in a total amount of 50 to 80% by weight based on the weight of the acrylic copolymer resin, and an alkyl group having 9 to 10 carbon atoms Acrylate units in a total amount of 25 to 45% by weight based on the weight of the acrylic copolymer resin.

(a) an acrylic copolymer resin having an acid value of from 15 to 25 and a glass transition temperature of from -25 DEG C to -17 DEG C;
(b) a heat dissipating filler dispersed in the acrylic copolymer resin; And
(c) a dispersant,
Wherein the heat radiation filler is contained in an amount of 15 to 30% by weight based on the total weight of the acrylic copolymer resin and the heat radiation filler,
Wherein the acrylic copolymer resin contains at least one acrylate unit having an alkyl group having 8 to 10 carbon atoms as a monomer unit in a total amount of 50 to 80% by weight based on the weight of the acrylic copolymer resin, and an alkyl group having 9 to 10 carbon atoms And a total of 25 to 45% by weight based on the weight of the acrylic copolymer resin.