KR20180020218A - Pressure-sensitive adhesive tape, heat-radiating sheet, electronic device, and manufacturing method of pressure-sensitive adhesive tape - Google Patents

Abstract

The present invention provides an adhesive tape having at least two adhesive portions (B) on at least one surface (a) side of a support (A), wherein no adhesive portion (B) is provided between the two or more adhesive portions Area is present, and the area is through the end of the adhesive tape. INDUSTRIAL APPLICABILITY The present invention is useful because it can provide a thin pressure-sensitive adhesive tape that prevents air bubbles from being quickly released from the interface with an adherend, thereby preventing air bubbles from remaining in the interface, and also having excellent adhesion.

Description

Pressure-sensitive adhesive tape, heat-radiating sheet, electronic device, and manufacturing method of pressure-sensitive adhesive tape

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin type adhesive tape usable in a manufacturing process of electronic equipment, for example.

Adhesive tapes are widely used in production scenes of electronic devices such as OA devices and home appliances because they have excellent workability and high adhesion reliability.

In recent years, there has been a demand for a high-performance, miniaturized and thinner electronic apparatus. In particular, portable electronic terminals such as PCs, digital video cameras, electronic notebooks, cellular phones, PHSs, smart phones, Thinning is required. In addition, the adhesive tape constituting the portable electronic terminal is also required to be thinned.

Examples of the thin adhesive tape include an acrylic ester copolymer having a weight average molecular weight of 700,000 or more and a content of butyl acrylate units of 90% by mass or more and a tackifier having a tackifier as a main component, Sensitive adhesive tape having a content of 40 to 60 mass% on both sides of a core material, wherein the total thickness of the core material and the pressure-sensitive adhesive layers on both sides thereof is 30 占 퐉 or less and the thickness of the pressure- Double-sided pressure-sensitive adhesive tapes each having a thickness of 2 to 10 mu m are known (see, for example, Patent Document 1).

However, while further thinning of the adhesive tape is required, bubbles are likely to remain at the interface between the thin adhesive tape and the adherend, and as a result, There was a case.

In addition, since the remaining bubbles have thermal resistance, when the thin adhesive tape is used for bonding with the heat radiating member and the heat generating member, there is a case where the heat radiating property is lowered.

In addition, while thinning of the pressure-sensitive adhesive layer has been studied to realize the thinning, a pressure-sensitive adhesive layer which is thin and simply provided with an outlet for the bubble may not be able to maintain sufficient adhesive force for practical use.

Japanese Patent Application Laid-Open No. 2007-169327

A problem to be solved by the present invention is to provide a pressure-sensitive adhesive tape which is capable of preventing air bubbles from being rapidly released from the interface with an adherend to thereby keep air bubbles from remaining at the interface, and also having excellent adhesion.

The inventors of the present invention have found that an adhesive tape having at least two adhesive portions B on at least one side a of a support A has an adhesive portion B between the two or more adhesive portions B, Wherein the area is present on the edge of the adhesive tape, and the area is present on the edge of the adhesive tape.

INDUSTRIAL APPLICABILITY The adhesive tape of the present invention is very thin and easily escapes bubbles from the interface with an adherend, bubbles do not easily remain at the interface, and the adhesive strength is excellent. Thus, for example, And a heat-generating member such as a rechargeable battery, and a heat-radiating member such as a graphite sheet.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a top view of a pressure-sensitive adhesive tape having a roughly rhombic adhesive portion as seen from its adhesive side. Fig.
Fig. 2 is a top view of an adhesive tape having a substantially circular adhesive portion as viewed from its adhesive portion side. Fig.
3 is a top view of an adhesive tape having a roughly hexagonal-shaped adhesive portion as viewed from its adhesive portion side.
4 is a top view of an adhesive tape having a roughly rectangular adhesive portion as viewed from its adhesive portion side.
5 is a side view of the graphite composite sheet.
6 is a top view of a surface having an adhesive portion of the adhesive tape obtained in Example 20. Fig.
7 is a top view of the surface of the adhesive tape obtained in Comparative Example 2 having the adhered portion.

The adhesive tape of the present invention is an adhesive tape having at least two adhesive portions (B) on at least one side (a) side of a support (A), wherein an adhesive portion (B) is interposed between the two or more adhesive portions (B) There is an area in which the area is not provided, and the area is through the end of the adhesive tape.

Specific examples of the adhesive tape of the present invention include an adhesive tape having at least two adhesive portions B directly on at least one side a of the support A, An adhesive tape having the above-mentioned adhesive portion (B) can be mentioned on one side (a) side with another layer interposed therebetween.

When the double-sided pressure-sensitive adhesive tape is used as the pressure-sensitive adhesive tape, it is preferable that two or more of the specific pressure-sensitive adhesive portions (B) are provided on both sides of the surface (a) Wherein the adhesive tape has a region having no region B and the region has an arrangement through an end portion of the adhesive tape or a double-sided adhesive tape having a region on one side (a) (B), wherein a region having no adhesive portion (B) is present between the two or more adhesive portions (B), the region having a configuration through the end portion of the adhesive tape, Sensitive adhesive tape having an adhesive layer on its entire surface can be used on the other surface side of the adhesive layer (A).

Between the two or more adhesive portions B, there is a region in which the components constituting the adhesive portion B do not exist or may exist in such a degree as not to exhibit adhesiveness. Therefore, when the pressure-sensitive adhesive tape of the present invention is observed from the side direction, it is observed that the adhered portion B forms a convex shape with respect to the surface (a) of the support (A).

The adhesive tape of the present invention has a constitution in which a region not having the adhesive portion B between the two or more adhesive portions B is disposed on a part of the end portion (outer edge portion) of the adhesive tape. By using the adhesive tape having the above-described structure, when the adhesive tape is attached to the adherend, the bubbles are discharged to the outside from the interface between the adhesive tape and the adherend through the area, Defects can be prevented, and excellent thermal conductivity and adhesive force can be maintained.

The adhesive tape of the present invention preferably has a total thickness of 50 탆 or less, particularly preferably 20 탆 or less, more preferably 2 탆 to 15 탆, more preferably 3 탆 to 10 탆 And it is particularly preferable to use those having a thickness of 3 to 6 占 퐉, for example, contributing to the thinness of a portable electronic terminal or the like. INDUSTRIAL APPLICABILITY As described above, the adhesive tape of the present invention maintains the excellent slipperiness of bubbles even though it is very thin, and also has excellent adhesive force and thermal conductivity. The total thickness of the pressure-sensitive adhesive tape indicates the thickness of the pressure-sensitive adhesive tape measured under the condition that the contact surface of the dial gauge is flat, the diameter is 5 mm and the load is 1.23 N in accordance with JIS K6783 using a dial gauge , And the thickness of the release liner. The thickness can be measured by, for example, a thickness tester TH-102 of a tester acidifier.

The adhesive tape of the present invention preferably has an adhesive force of 1 N / 20 mm to 12 N / 20 mm, more preferably an adhesive force of 1.5 N / 20 mm to 10 N / 20 mm, / 20 mm to 8 N / 20 mm is preferable because it is easy to remove bubbles from the interface between the adherend and the adhesive tape even if it is thin and to obtain an adhesive tape having excellent adhesive force. On the other hand, when further excellent adhesion is required, it is more preferable to use an adhesive tape having an adhesive strength of 4 N / 20 mm to 10 N / 20 mm, and more preferably a tape having an adhesive strength of 4.5 N / 20 mm to 8 N / It is more preferable to use one having an adhesive force.

Note that the adhesive force refers to a value measured in accordance with JIS Z0237. Specifically, the adhesive strength was measured by superimposing a clean and smooth stainless steel plate (BA plate) with a surface having an adhesive portion (B) of an adhesive tape back side waiting with a polyethylene terephthalate film having a thickness of 25 占 퐉, The test piece was left under the conditions of 23 ° C and 50% RH for 1 hour or 24 hours, and then peeled off from the adhesive tape at a rate of 0.3 m / min in the direction of 180 ° Respectively. The backside atmosphere is performed on the surface having no adhesive portion B and not on the surface having the adhesive portion B which is a constituent requirement of the present invention. In the case where the adhesive tape has the adhesive portion B on both sides, the side having the adhesive portion B on either side is waited on the back side.

As the adhesive tape of the present invention, even if it is thin, it is possible to prevent detachment with time and detachment of parts due to the repulsive force of the adherend or the support (A), and to prevent peeling or the like even when used under a relatively high temperature, It is preferable to use a material having an adhesive holding force of 2 mm or less, more preferably 0.5 mm or less, and more preferably 0.1 mm or less.

The adhesive holding force refers to a value measured in accordance with JIS Z0237. Specifically, the adhesive retaining force was obtained by superimposing a clean and smooth stainless steel plate (hair line) on a surface having an adhesive portion (B) of an adhesive tape back side waiting with an aluminum foil having a thickness of 50 탆, Pressed by one reciprocation using a roller was allowed to stand for one hour under the conditions of 23 ° C and 50% RH as a test piece. Next, the stainless steel plate constituting the test piece was fixed in the vertical direction under an environment of 100 占 폚 and left for 24 hours in a state where a load of 100 g was applied to the lower end of the adhesive tape constituting the test piece, Is a value obtained by measuring the displacement distance between the adhesive tape and the adhesive tape.

[Support (A)]

The support (A) constituting the adhesive tape of the present invention preferably has a thickness of 1 to 20 탆, more preferably 1 to 10 탆, more preferably 1 to 4 탆 It is preferable to use a material having a thickness of 1.5 mu m to 2.5 mu m to reduce the thickness of the pressure-sensitive adhesive tape, and furthermore, it is possible to reduce the thickness of the bubble from the interface between the surface having the adhered portion B and the adherend, As a result, deterioration in appearance due to expansion of the pressure-sensitive adhesive tape and deterioration in performance such as thermal conductivity and adhesive force can be more effectively prevented.

As the support (A), for example, a sheet obtained by using a resin can be used.

Examples of the resin that can be used for the production of the support (A) include polyesters such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN) and polybutylene terephthalate (PBT), polyamide (nylon) , Amide resins such as polyamides, polyamides, polyamides, polyamides, polyamides, and wholly aromatic polyamides (aramid), acrylic resins such as polybutyl acrylate, polyethyl acrylate and polymethylmethacrylate (PMMA), polystyrene, acrylonitrile- , Styrene resins such as acrylonitrile-butadiene-styrene copolymer (ABS resin), polyether ketones such as polyether ether ketone (PEEK) and polyether ketone ketone, polyether sulfone (PES) (PPS), polyimide (PI), polyamideimide, polyetherimide (PEI), polyesterimide, polycarbonate (PC), polyacetal, poly Tolylene ether (polyphenylene ether), polyphenylene renseol feed, the polyamic Relate, polyarylene, polyurethane, epoxy resin or the like, may be used either alone or in combination of two or more.

Among them, as the support (A), it is preferable to use a polyester film because it is less uneven in thickness, excellent in tensile strength and workability, and economical (cost), and it is more preferable to use a polyethylene terephthalate film Do. It is preferable to use the polyester film obtained by biaxially stretching because it can further increase the strength of the support (A) and the adhesive tape obtained using the same.

The support (A) can be produced by molding the resin into a sheet. When polyester is used as the resin, the support (A) can be produced, for example, by the following method.

First, a master batch containing dry or non-dried polyester chips and, if necessary, a colorant or a colorant at a high concentration is melt-kneaded using a kneading extruder or the like.

Next, the kneaded product is extruded from a die, and quenched and solidified on a rotary cooling drum to obtain an unstretched polyester film which is substantially in an amorphous state.

As a method for further improving the smoothness of the polyester film, for example, a method of shortening the retention time of the polyester in the extruder, a method of using a uniaxial extruder in which the water content is preferably 50 ppm or less, A method of using a raw material such as polyester dried to be not more than 30 ppm in the case of using a twin-screw extruder or a method of providing a vent hole in the case of using a twin-screw extruder is preferably not more than 40 hectopascals, more preferably not more than 30 hectopascals, Preferably in a reduced pressure environment of 20 hectopascals or less, a method of employing, for example, an electrostatic adhesion method or a liquid application adhesion method in order to improve the adhesion between the polyester film and the rotary cooling drum .

As a method for stretching the polyester film obtained by the above method, for example, the unstretched sheet is preferably stretched at 70 to 145 占 폚 in the longitudinal direction at 2 to 6 times, uniaxially stretched in the longitudinal direction, Stretching is performed at 90 to 160 占 폚 in the transverse direction to 2 to 6 times, and the process proceeds to the heat fixation step.

It is preferable that the polyester film is relaxed by 0.1% to 20% in the longitudinal direction and / or the transverse direction in the highest temperature zone of the heat treatment and / or the cooling zone of the heat treatment outlet. The stretched polyester film obtained by the above method may be subjected to stretching and stretching in succession, if necessary.

The support (A) obtained by the above method may be composed of a single layer or may be composed of multiple layers made of the same or different resins.

As the support (A), the adhesiveness to the adhesive portion (B) or other adhesive layer is further enhanced. For example, chromic acid treatment, ozone exposure treatment, flame exposure treatment , A high-pressure electric field exposure treatment, an ionizing radiation treatment, or the like, or a primer layer formed by using a coating agent or the like can be used.

[Adhesive Part (B)]

Next, the adhesive portion B constituting the adhesive tape of the present invention will be described.

As described above, the adhesive portion B is provided on one side or both sides of the support A directly or through another layer.

Between the two or more adhesive portions B, there is a region in which the components constituting the adhesive portion B do not exist or may exist in such a degree as not to exhibit adhesiveness.

An area not having the adhesive portion B between the two or more adhesive portions B has a configuration through a part of an end portion (outer edge portion) of the adhesive tape. By using the adhesive tape having the above-described configuration, it is possible to easily remove bubbles from the interface between the adhesive tape and the adherend when the adhesive tape is adhered to the adherend, thereby preventing defective appearance due to expansion of the adhesive tape, Thermal conductivity and adhesive force can be maintained.

The shape of the adhesive portion B is preferably a substantially rectangular shape, a substantially hexagonal shape or a substantially circular shape when the adhesive tape of the present invention is observed from one surface (a) side of the support (A) , And the substantially circular shape are preferable because air bubbles tend to be released from the interface with the adherend (air venting property) and good adhesion can be maintained.

The roughly circular shape is not particularly limited, but it is preferable that the ratio of the maximum diameter to the minimum diameter (maximum diameter / minimum diameter) of any one adhesive portion is 1 to 4. More preferably 1 to 2, and most preferably 1 to 1.5. As an example of a roughly circular shape, a shape as shown in Fig. 6 can be given. The adhesive portions of the above shape are basically independent of each other, but as shown in Fig. 6, there may be portions where two or more adhesive portions are partially connected.

The roughly rectangular shape may be a substantially square shape, a substantially rectangular shape, a substantially trapezoidal shape, a roughly rhombic shape or the like, and the roughly rhombic shape is more likely to cause air bubbles to escape from the interface with the adherend, Further, it is preferable since a good adhesive force can be maintained.

The " roughly " such as the substantially rectangular shape and the substantially hexagonal shape is obtained when, for example, a release liner or the like is attached to the surface of the adhesive portion B or when the adhesive tape is wound on a roll , And that the corner portion of the rectangular shape and the hexagonal shape is rounded or the shape of the straight line portion is a curved portion when the adhesive portion (B) is pressed.

The corner portion of the substantially rectangular shape preferably has a substantially rhombic shape with an angle of an edge portion facing the flow direction of the adhesive tape of less than 90 degrees and a range of 45 to 70 degrees is preferable because bubbles are likely to escape from the interface with the adherend (Air releasing property), and it is more preferable because good adhesion can be maintained.

It is preferable that any of the adhesive portion b1 and the adhesive portion b2 constituting the two or more adhesive portions B are not opposed to each other in the flow direction and the width direction of the adhesive tape.

In addition, the adhesive tape is often cut and used in an arbitrary shape in accordance with applications. At this time, when the adhesive tape (b1) and the adhesive tape (b2) are arranged so as not to face each other with respect to the flow direction and the width direction, when the adhesive tape is cut at an arbitrary position, The portion B is present, so that peeling of the adhesive tape can be suppressed.

It is preferable that a distance between an arbitrary sticking part b1 selected from the two or more sticking parts B and the other sticking part b2 nearest to the sticking part b1 is 0.5 mm or less More preferably 0.05 mm to 0.2 mm, more preferably 0.06 mm to 0.15 mm, and most preferably 0.08 mm to 0.13 mm, the bubbles tend to be released from the interface with the adherend (air dropout) It is particularly preferable because good adhesion can be maintained.

The size per one arbitrary adhesive portion (b1) selected in the adhesive portion (B) is preferably 0.001 mm 2 to 100 mm 2, more preferably 0.01 mm 2 to 25 mm 2, More preferably 0.02 mm < 2 > to 5 mm < 2 > because air bubbles tend to escape from the interface with the adherend (air leaks) and good adhesion can be maintained.

The number of the adhesive portions B is preferably 10 to 10000 in the range of the area of the adhesive tape of the present invention (5 cm in the flow direction and 5 cm in the width direction), more preferably 1000 to 50000 And more preferably from 5000 to 40000 are particularly preferable because bubbles tend to be released from the interface with the adherend (air leaking property) and good adhesion can be maintained.

Further, as the above-mentioned pressure-sensitive adhesive tape, air bubbles are likely to be released from the interface with the adherend during air blowing (air venting) and good adhesive force can be maintained. Even when the adherend such as a graphite sheet is further thinned, It is preferable to use an adhesive tape having 120 to 2000 adhesive portions in a range of a predetermined area (1 cm in the flow direction and a square of 1 cm in the width direction) of the adhesive tape from the viewpoint of effectively preventing the appearance defect caused by the shape, More preferably 280 to 1600 adhesive portions, and more preferably 520 to 1200 adhesive portions.

The number of the adhering portions can be measured by observing with an electron microscope an arbitrary range (a square of 1 cm in the flow direction and 1 cm in the width direction) or a square of 5 cm in the flow direction and 5 cm in the width direction, . ≪ / RTI >

The ratio of the region having the adhesive portion (B) to the area of the one surface (a) is preferably 10% to 99%. , More preferably 20% to 90%, still more preferably 30% to 80%, and most preferably 35% to 80%. As a result, it is possible to form a pressure-sensitive adhesive tape which is liable to release air bubbles from the interface with the adherend (air venting property) and which can maintain good adhesion, It is particularly preferable because it can be produced well. The ratio of the area is the area ratio of the adhesive portion B in the area of the square tape of 5 cm in the flow direction and 5 cm in the width direction.

The peak temperature of loss tangent based on the dynamic viscoelastic spectrum measured at a frequency of 1 Hz of the adhesive portion (B) is not particularly limited, but is preferably -30 ° C to 20 ° C, more preferably -20 ° C to 10 ° C More preferably from -10 DEG C to 5 DEG C, bubbles tend to be released from the interface with the adherend (air dropout), and good adhesive strength can be maintained. As a result, the pressure- Is more preferable because it can more effectively prevent poor appearance, deterioration in performance such as thermal conductivity, heat resistance and adhesion.

In the dynamic viscoelasticity measurement, a test piece was sandwiched between parallel discs, which were the measurement part of the same tester, using a viscoelasticity tester (Rheometrics Shahe, product name: Ares 2KSTD), and the storage elastic modulus (G ') and loss modulus The loss tangent is calculated by the equation expressed by tan? = (G ") / (G '). The peak temperature refers to the peak temperature determined in the spectrum of tan? Versus the measurement temperature range (-50 ° C to 150 ° C).

As the test piece, a pressure-sensitive adhesive layer having a thickness of 0.5 mm to 2.5 mm formed by using a pressure-sensitive adhesive used for forming the pressure-sensitive adhesive portion (B) can be used.

As the test piece, those having a total thickness of the pressure-sensitive adhesive layer of 0.5 mm to 2.5 mm among the multiple laminated adhesive tapes of the present invention can be used. When the test pieces having different structures are used, the value of tan? Changes, but when the total thickness of the pressure-sensitive adhesive layer (B) in the test piece is the same, the peak temperature does not substantially change. Therefore, in the measurement of the peak temperature, any test piece may be used.

The adhesive portion (B) preferably has a gel fraction of 10% by mass to 60% by mass, more preferably a gel fraction of 20% by mass to 55% by mass, more preferably 30% To 50% by mass is used, the surface shape of the adhered portion B is easily maintained even if it is thin. Therefore, it is easy to prevent a change over time, and the surface of the adhered portion (B) As a result, it is more preferable that the appearance defects due to the expansion of the pressure-sensitive adhesive tapes, etc., and deterioration in performance such as thermal conductivity, heat resistance and adhesive force can be prevented more effectively. The gel fraction refers to a value measured by the following method.

The gel fraction refers to a value measured by the following method.

The releasing treated surface of the release liner (C) was coated with the pressure-sensitive adhesive so that the thickness after drying was 50 占 퐉, dried for 3 minutes under an environment of 100 占 폚 and aged for 2 days under an environment of 40 占 폚, .

The pressure-sensitive adhesive layer was cut into a square having a length of 50 mm and a width of 50 mm as a test piece.

After the mass (G1) of the test piece was measured, the test piece was immersed in toluene for 24 hours under an environment of 23 占 폚.

After the immersion, the mixture of the test piece and toluene was filtered using a 300 mesh network to extract an insoluble component in toluene. The mass (G2) of the insoluble component dried at 110 DEG C for 1 hour was measured.

Based on the mass (G1) and mass (G2) and the following formula, the gel fraction was calculated.

Gel fraction (mass%) = (G2 / G1) x100

The adhesive portion B preferably has a thickness of 1 탆 to 6 탆 and the thickness of 2 탆 to 5 탆 is used to easily remove bubbles from the interface between the adherend and the adhesive portion B, As a result, it is more preferable because it can more effectively prevent poor appearance due to expansion of the pressure-sensitive adhesive tape and deterioration of performance such as thermal conductivity, heat resistance and adhesive force. The thickness of the adhered portion B was measured by a method using a dial gauge according to JIS K6783 in the same manner as in Example 1 except that the contact surface of the dial gauge had a flat surface with a diameter of 5 mm and a load of 1.23 N Thickness.

The adhesive portion (B) may be a pressure sensitive adhesive such as an acrylic pressure sensitive adhesive, a rubber pressure sensitive adhesive, a silicone pressure sensitive adhesive, a urethane pressure sensitive adhesive, a polyester pressure sensitive adhesive, a styrene - diene block copolymer pressure sensitive adhesive, a vinyl alkyl ether pressure sensitive adhesive, a polyamide pressure sensitive adhesive, A creep property improving type pressure-sensitive adhesive, a radiation-curing pressure-sensitive adhesive, and the like. Among them, it is preferable to use an adhesive portion obtained by using an acrylic pressure-sensitive adhesive as the adhesive portion (B) because it is excellent in adhesion reliability.

When the adhesive tape of the present invention has an adhesive portion or an adhesive layer on both sides of the support, the adhesive portion or the adhesive layer may have the same composition or gel fraction as the adhesive tape or adhesive layer of different composition or gel fraction May be used.

As the acrylic pressure-sensitive adhesive, those containing an acrylic polymer can be used.

As the acrylic polymer, those obtained by polymerizing a monomer component containing a (meth) acrylic monomer such as alkyl (meth) acrylate can be used.

Examples of the alkyl (meth) acrylate ester include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (Meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isobutyl (meth) acrylate, isobutyl (Meth) acrylate, isohexyl (meth) acrylate, nonyl acrylate, nonyl acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (Meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl Acrylic acid eicosyl, etc., alone or in combination of two or more Can. Among them, as the (meth) acrylic acid alkyl ester, it is preferable to use a (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group, and the (meth) acrylic acid alkyl ester having 4 to 18 carbon atoms in the alkyl group Is more preferable. The alkyl group includes a linear or branched alkyl group.

As the (meth) acrylic acid alkyl ester having 4 to 18 carbon atoms in the acrylic group, use of butyl (meth) acrylate is easy to maintain the surface shape of the pressure-sensitive adhesive layer (B) , It is preferable to obtain a pressure-sensitive adhesive tape in which air bubbles are easily released from the interface with the adherend (air-leaking property), and a good adhesive force can be maintained.

Examples of the (meth) acrylic monomer include monomers having a carboxyl group such as (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid and isocrotonic acid, or anhydrides thereof; Monomers having sulfonic acid groups such as sodium vinyl sulfonate; Monomers having a cyano group such as acrylonitrile; Monomers having an amide group such as acrylamide, methacrylamide, N-vinylpyrrolidone and N, N-dimethyl (meth) acrylamide; Monomers having a hydroxyl group such as (meth) acrylic acid hydroxyalkyl, glycerin dimethacrylate; Aminoethyl (meth) acrylate, and (meth) acryloylmorpholine; Monomers having an imide group such as cyclohexylmaleimide and isopropylmaleimide; Monomers having an epoxy group such as glycidyl (meth) acrylate and methylglycidyl (meth) acrylate; (Meth) acrylate, diethylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, tetraethylene glycol diester (meth) acrylate and the like; monomers having an isocyanate group such as 2-methacryloyloxyethyl isocyanate; (Meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (Meth) acrylate, divinylbenzene, etc. may be used alone or in combination of two or more.

In addition to the above (meth) acrylic monomers, aromatic vinyl compounds such as styrene and substituted styrene; Olefins such as ethylene, propylene and butadiene; Vinyl esters such as vinyl acetate; Vinyl chloride or the like may be used.

The acrylic polymer can be produced by polymerizing the monomer by a solution polymerization method, a bulk polymerization method, a suspension polymerization method, an emulsion polymerization method or the like, and employing a solution polymerization method is an acrylic polymer It is preferable to improve the production efficiency of the polymer.

Examples of the solution polymerization method include a method in which the monomer, the polymerization initiator, and the organic solvent are mixed preferably at a temperature of 40 to 90 캜 and stirred to perform radical polymerization.

Examples of the polymerization initiator include peroxides such as benzoyl peroxide and lauryl peroxide, azo type thermal polymerization initiators such as azobisisobutyl nitrile, acetophenone type photopolymerization initiators, benzoin ether type photopolymerization initiators, benzylketal type photopolymerization initiators, An acylphosphine oxide-based photopolymerization initiator, a benzoin-based photopolymerization initiator, and a benzophenone-based photopolymerization initiator.

The acrylic polymer obtained by the above method may be dissolved or dispersed in an organic solvent as long as it is produced by, for example, solution polymerization.

The acrylic polymer obtained by the above method preferably has a weight average molecular weight of 300,000 to 1,200,000, more preferably a weight average molecular weight of 400,000 to 1,100,000, more preferably a weight average of 500,000 to 1,000,000 Use of a material having a molecular weight is preferable for obtaining a pressure-sensitive adhesive tape having even more excellent adhesive force and easy removal of air bubbles even though it is thin.

The weight average molecular weight refers to a value measured by gel permeation chromatography (GPC) and calculated in terms of standard polystyrene. Specifically, the weight average molecular weight can be measured by using a GPC apparatus (HLC-8329GPC) manufactured by TOSOH CORPORATION under the following conditions.

Sample concentration: 0.5% by mass (tetrahydrofuran solution)

Sample injection amount: 100 μl

Eluent: tetrahydrofuran

Flow rate: 1.0 ml / min

Measuring temperature: 40 ° C

This column: 2 TSKgel GMHHR-H (20)

Guard column: TSKgel HXL-H

Detector: differential refractometer

Weight average molecular weight of standard polystyrene: 10,000 to 20,000 (manufactured by TOSOH CORPORATION)

As the pressure-sensitive adhesive which can be used for forming the pressure-sensitive adhesive portion (B), it is preferable to use a pressure-sensitive adhesive containing a pressure-sensitive adhesive resin in order to form a pressure-sensitive adhesive portion having further excellent adhesive force, tensile strength and tensile break strength.

Examples of the tackifier resin include rosin-based tackifying resin, polymerized rosin-based tackifying resin, polymerized rosin ester-based tackifying resin, rosin phenol-based tackifying resin, stabilized rosin ester tackifying resin, disproportionated rosin ester- Tackifier resin, tackifier resin, tackifier resin, hydrogenated rosin ester tackifier resin, terpene tackifier resin, terpene phenol tackifier resin, and styrene tackifier resin.

As the tackifier resin, it is preferable to use a combination of a rosin-based tackifier resin and a petroleum resin-based tackifier resin in order to obtain a pressure-sensitive adhesive tape having even better adhesion and ease of removing bubbles. The rosin-based tackifier resin and the petroleum resin-based tackifier resin are particularly preferably used in combination with the acrylic polymer, and it is preferable to use the acrylic resin in combination with an acrylic polymer obtained by polymerizing a It is preferable to obtain a pressure-sensitive adhesive tape having further excellent adhesive force and easy removal of air bubbles.

As the tackifier resin, it is preferable to use a tackifier resin in liquid form at room temperature to further improve the initial adhesion of the tackifier (B). Examples of the tackifier resin in a liquid state at room temperature include low molecular weight liquid rubbers such as process oil, polyester plasticizer and polybutene, and terpene phenol resins can be used. Commercially available products include Yasuhara Chemical Co., Ltd. YP -90 L and the like.

The tackifier resin is preferably used in a range of 20 parts by mass to 60 parts by mass, more preferably in a range of 30 parts by mass to 55 parts by mass, with respect to 100 parts by mass of the acrylic polymer, It is more preferable to obtain an adhesive tape.

As the pressure-sensitive adhesive constituting the pressure-sensitive adhesive portion (B), those containing a softening agent, a plasticizer, a filler, an antioxidant, a colorant and the like may be used, if necessary, in addition to the acrylic polymer and the like.

Among them, use of a cross-linking agent makes it possible to adjust the gel fraction of the adhesive portion (B) to a favorable range, and as a result, it is easy to maintain the shape of the adhesive portion (B) Bubbles can be easily removed easily from the interface between the adherend and the pressure-sensitive adhesive layer (B), and an adhesive tape having excellent adhesion can be obtained.

As the crosslinking agent, for example, an isocyanate crosslinking agent or an epoxy crosslinking agent is preferably used.

As the isocyanate crosslinking agent, for example, tolylene diisocyanate, naphthylene-1,5-diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, trimethylolpropane-modified tolylene diisocyanate and the like can be used , Tolylene diisocyanate, trimethylolpropane-modified tolylene diisocyanate, and the like. The toluene diisocyanate adduct has a structure derived from toluene diisocyanate in the molecule, and commercially available products include, for example, Coronate L (manufactured by Nippon Polyurethane Industry Co., Ltd.).

When the isocyanate crosslinking agent is used, it is preferable to use an acrylic polymer having a hydroxyl group as the acrylic polymer. Examples of the acrylic polymer having a hydroxyl group include monomers such as 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl And it is more preferable to use 2-hydroxyethyl (meth) acrylate or 4-hydroxybutyl (meth) acrylate.

As the epoxy cross-linking agent, for example, Tetrad X or Tetrad C of Mitsubishi Gas Kagaku Co., Ltd. or E-05X of Soken Kagaku KK can be used.

When the epoxy crosslinking agent is used, it is preferable to use an acrylic polymer having an acid group as the acrylic polymer. (Meth) acrylic acid, acrylic acid dimer, itaconic acid, crotonic acid, maleic acid, maleic anhydride and the like are preferably used as the monomer used in the production of the acrylic polymer having the acid group, It is more preferable to use acrylic acid.

As the pressure-sensitive adhesive usable for forming the pressure-sensitive adhesive portion (B), it is preferable to use a pressure-sensitive adhesive containing a solvent if necessary. The pressure-sensitive adhesive preferably has a viscosity adjusted to a range of 0.1 mPa · s to 1000 mPa · s, more preferably a viscosity of 1 mPa · s to 200 mPa · s, s to 100 mPa · s is more preferable because it is easy to form the adhesive portion B having a predetermined shape.

[Production method of adhesive tape]

The adhesive tape of the present invention can be produced, for example, by coating the adhesive on at least one surface (a) side of the support (A) with an intermittent phase and drying it to form an adhesive portion (B) .

The adhesive tape may be produced by coating the pressure-sensitive adhesive on both sides of the support (A) in an intermittent pattern and drying the pressure-sensitive adhesive.

The pressure-sensitive adhesive is preferably applied to at least one surface (a) of the support (A) in an intermittent phase by a coating method such as a gravure coating method or a slot die coating method, and is preferably applied by a direct gravure coating method It is preferable to apply it.

The pressure-sensitive adhesive tape may be obtained by forming the pressure-sensitive adhesive portion B by applying the pressure-sensitive adhesive on the surface of the release liner and drying the pressure-sensitive adhesive tape to form the pressure-sensitive adhesive portion B on at least one side (a) side.

The adhesive tape of the present invention may be produced by using, for example, a release liner as described above, and then peeling the release liner as necessary and attaching another release liner.

INDUSTRIAL APPLICABILITY Since the adhesive tape of the present invention has an excellent adhesive force even though it is very thin, it can be suitably used in a production view of an electronic device such as a portable electronic terminal which is required to be thin. Particularly, even if the clearance between the adherends (adhesive portion of the adhesive tape) is in a very narrow range of 20 mu m or less in width, the adherend can be strongly adhered.

Further, since the pressure-sensitive adhesive tape is easily detached from the interface between the adherend and the adhering portion (B), the pressure-sensitive adhesive tape can be used for fixing the heat-radiating sheet or for fixing the magnetic sheet, Can be used.

(Use in fixing heat sink sheet)

BACKGROUND ART [0002] Electronic devices such as portable electronic terminals are often equipped with members that emit heat by use. Examples of the heat generating member include a rechargeable battery and a circuit board.

It is preferable to avoid locally high temperature of a part of the electronic apparatus due to the heat generated by the member in order to prevent malfunction of the electronic apparatus. Therefore, for the purpose of diffusing the heat, the heat generating member or a member adjacent to the heat generating member (for example, a metal member such as a frame member used for imparting rigidity to an electronic apparatus) There are many cases where it is pasted.

As the heat dissipating member, for example, a graphite sheet or a graphene sheet is preferably used.

Examples of the graphite sheet include an artificial graphite sheet and a natural graphite sheet.

As the artificial graphite sheet, for example, a pyrolytic graphite sheet obtained by thermally decomposing an organic film such as a polyimide film in an inert gas atmosphere at a high temperature can be given.

The natural graphite sheet can be obtained, for example, by subjecting natural graphite to acid treatment and then heating and expanding the graphite powder to form a sheet.

As the graphite sheet, it is preferable to use a sheet having a small number of wrinkles so as to exhibit more excellent heat radiation property, and it is more preferable to use an artificial graphite sheet with less wrinkles.

The thickness of the graphite sheet is preferably 10 탆 to 100 탆, and the thickness of 15 탆 to 50 탆 is preferable for contributing to the thinning of electronic devices such as portable electronic terminals.

On the other hand, since the graphite sheet is relatively fragile, it is generally used in a state of a graphite composite sheet in which an adhesive tape is attached to one side or both sides thereof.

As the graphite composite sheet, for example, as shown in Fig. 5, it is preferable to use a graphite composite sheet having a constitution in which the graphite composite sheet is sealed with a single-sided adhesive tape and a double-sided adhesive tape to improve the strength and insulating properties of the graphite sheet. It is preferable for compatibility.

As the graphite composite sheet, it is possible to prevent occurrence of interlayer fracture or powder drop of the graphite sheet by using an encapsulation (pouch) with an adhesive tape having an area larger than that of the graphite sheet, thereby realizing a desired processability It is preferable because it becomes easy to do.

The adhesive tape of the present invention can be used suitably when pouching the graphite sheet. At this time, it is preferable that the adhesive tape is used in a state in which the surface having the adhesive portion B faces outside (in the direction other than the graphite sheet side). This makes it possible to effectively prevent air bubbles from remaining on the interface between the graphite composite sheet and a heating member such as a rechargeable battery or a member adjacent thereto.

The graphite composite sheet and the member are adhered to each other by, for example, a step of placing the graphite composite sheet on the surface of the member and gently pressing them to bond them, And then pressing them using a roller or the like to firmly adhere them. In the adhesion step, bubbles usually exist at the interface between the member and the graphite composite sheet. However, when the pressure-sensitive adhesive tape of the present invention is used to press the graphite composite sheet with the roller or the like, the bubbles are quickly removed from the interface.

In addition, the graphite composite sheet is often pasted with a surface protective film for the purpose of preventing the surface of the graphite composite sheet from being scratched or the like. The surface protective film is usually removed after the graphite composite sheet and the member are pasted.

Since the adhesive tape of the present invention can firmly adhere to an adherend such as a member after the air bubbles are removed, when the surface protective film is removed from the graphite composite sheet, And it is difficult to cause peeling.

As described above, the graphite composite sheet obtained by using the pressure-sensitive adhesive tape of the present invention can prevent bubbles from remaining at the interface with an adherend such as a member. Therefore, the heat resistance value As a result, the thermal conductivity in the thickness direction of the adhesive tape can be improved.

(Use in magnetic sheet fixing applications)

The magnetic sheet is intended to prevent leakage of electromagnetic waves generated from members constituting the electronic apparatus to the outside or to prevent electromagnetic waves generated from the outside from affecting the electronic apparatus, There are many cases.

Examples of the magnetic sheet include a Ni ferrite magnetic powder, a Mg ferrite magnetic powder, a Mn ferrite magnetic powder, a Ba ferrite magnetic powder, a Sr ferrite magnetic powder, an Fe-Si alloy powder, A sheet obtained by using an Fe-Co alloy powder, an Fe-Si-Al alloy powder, an Fe-Si-Cr alloy powder, an iron powder, an Fe amorphous, a Co-based amorphous or Fe-based nanocrystal.

As the magnetic sheet, generally, a relatively thick one is preferably used to impart good electromagnetic shielding properties.

Since the adhesive tape of the present invention is extremely thin as described above, it is possible to use a magnetic sheet having the largest thickness as the magnetic sheet.

The magnetic sheet is preferably used in the form of a magnetic composite sheet in which an adhesive tape is attached to one surface or both surfaces of the magnetic sheet for the purpose of imparting good insulating properties and high strength.

(Example)

Hereinafter, embodiments of the present invention will be described and more specifically described.

(Preparation Example 1) Pressure-sensitive adhesive a

97.98 parts by mass of n-butyl acrylate, 2 parts by mass of acrylic acid, 0.02 parts by mass of 4-hydroxybutyl acrylate and 0.2 parts by mass of azobisisobutyronitrile as a polymerization initiator in an ethyl acetate solution at 80 DEG C for 8 hours By solution polymerization, an acrylic polymer having a weight average molecular weight of 900,000 was obtained.

5 parts by mass of "D-135" (polymerized rosin ester, manufactured by Arakawa Chemical Industries, Ltd.) and 100 parts by mass of "KE-100" (manufactured by Arakawa Chemical Industries, , And 25 parts by mass of " FTR6100 " (manufactured by Mitsui Chemicals, Inc., petroleum resin) were mixed and ethyl acetate was further added to adjust the pressure-sensitive adhesive solution to a solid content of 40 mass% .

The pressure-sensitive adhesive solution and 2.0 parts by mass of "NC40" (Isocyanate Crosslinking Agent, manufactured by DIC Corporation) were mixed and stirred to obtain a pressure-sensitive adhesive a.

The peak temperature of tan? Of the pressure-sensitive adhesive layer obtained using the pressure-sensitive adhesive a was 0 占 폚, and the gel fraction thereof was 40 mass%.

(Preparation Example 2) The pressure-sensitive adhesive b

97.98 parts by mass of n-butyl acrylate, 2 parts by mass of acrylic acid, 0.02 parts by mass of 4-hydroxybutyl acrylate and 0.3 part by mass of azobisisobutyronitrile as a polymerization initiator in an ethyl acetate solution at 90 DEG C for 6 hours By solution polymerization, an acrylic polymer having a weight average molecular weight of 500,000 was obtained.

5 parts by mass of "D-135" (polymerized rosin ester, manufactured by Arakawa Chemical Industries, Ltd.) and "KE-100" (manufactured by Arakawa Chemical Industries, Ltd.) were added to 100 parts by mass of the acrylic polymer ) And 25 parts by mass of " FTR6100 " (manufactured by Mitsui Chemicals, Inc., petroleum resin) were mixed and ethyl acetate was further added to obtain a pressure-sensitive adhesive solution adjusted to a solid content of 40% by mass .

The above pressure-sensitive adhesive solution and 0.6 parts by mass of " NC40 " (Isocyanate Crosslinking Agent, manufactured by DIC Corporation) were mixed and stirred to obtain a pressure-sensitive adhesive b.

The peak temperature of tan? Of the pressure-sensitive adhesive layer obtained using the pressure-sensitive adhesive b was 0 占 폚, and the gel fraction thereof was 10 mass%.

(Preparation Example 3) Adhesive c

97.98 parts by mass of n-butyl acrylate, 2 parts by mass of acrylic acid, 0.02 parts by mass of 4-hydroxybutyl acrylate and 0.3 part by mass of azobisisobutyronitrile as a polymerization initiator in an ethyl acetate solution at 90 DEG C for 6 hours By solution polymerization, an acrylic polymer having a weight average molecular weight of 500,000 was obtained.

5 parts by mass of "D-135" (polymerized rosin ester, manufactured by Arakawa Chemical Industries, Ltd.) and 100 parts by mass of "KE-100" (manufactured by Arakawa Chemical Industries, , And 25 parts by mass of " FTR6100 " (manufactured by Mitsui Chemicals, Inc., petroleum resin) were mixed and ethyl acetate was further added to adjust the pressure-sensitive adhesive solution to a solid content of 40 mass% .

The pressure-sensitive adhesive solution and 3.3 parts by mass of "NC40" (Isocyanate Crosslinking Agent, manufactured by DIC Corporation) were mixed and stirred to obtain a pressure-sensitive adhesive c.

The peak temperature of tan? Of the pressure-sensitive adhesive layer obtained using the pressure-sensitive adhesive c was 0 占 폚, and the gel fraction thereof was 46 mass%.

(Preparation Example 4) The pressure-sensitive adhesive d

97.98 parts by mass of n-butyl acrylate, 2 parts by mass of acrylic acid, 0.02 parts by mass of 4-hydroxybutyl acrylate and 0.3 part by mass of azobisisobutyronitrile as a polymerization initiator in an ethyl acetate solution at 90 DEG C for 6 hours By solution polymerization, an acrylic polymer having a weight average molecular weight of 500,000 was obtained.

5 parts by mass of "D-135" (polymerized rosin ester, manufactured by Arakawa Chemical Industries, Ltd.) and 100 parts by mass of "KE-100" (manufactured by Arakawa Chemical Industries, , And 25 parts by mass of " FTR6100 " (manufactured by Mitsui Chemicals, Inc., petroleum resin) were mixed and ethyl acetate was further added to adjust the pressure-sensitive adhesive solution to a solid content of 40 mass% .

The pressure-sensitive adhesive solution and 1.2 parts by mass of " NC40 " (manufactured by DIC Corporation, isocyanate crosslinking agent) were mixed and stirred to obtain a pressure-sensitive adhesive d.

The peak temperature of tan? Of the pressure-sensitive adhesive layer obtained using the pressure-sensitive adhesive d was 0 占 폚, and the gel fraction thereof was 20 mass%.

(Preparation Example 5) Pressure-sensitive adhesive e

96.4 parts by mass of n-butyl acrylate, 3.5 parts by mass of acrylic acid, and 0.1 part by mass of 4-hydroxy-ethyl acrylate were mixed with 0.2 part by mass of azobisisobutyronitrile as a polymerization initiator in an ethyl acetate solution at 80 占 폚 Hour solution polymerization to obtain an acrylic polymer having a weight average molecular weight of 800,000.

10 parts by mass of "D-135" (polymerized rosin ester, manufactured by Arakawa Chemical Industries, Ltd.) and 100 parts by mass of "A100" (disproportionated rosin ester, Arakawa Chemical Industries, Ltd., Ltd.) and 10 parts by mass of ethyl acetate was further added thereto to obtain a pressure-sensitive adhesive solution adjusted to a solid content of 40% by mass.

The pressure-sensitive adhesive solution and 1.3 parts by mass of "NC40" (Isocyanate Crosslinking Agent, manufactured by DIC Corporation) were mixed and stirred to obtain a pressure-sensitive adhesive "e".

The peak temperature of tan? Of the pressure-sensitive adhesive layer obtained using the pressure-sensitive adhesive e was -15 占 폚, and the gel fraction thereof was 40 mass%.

(Preparation Example 6) The pressure-sensitive adhesive f

44.9 parts by mass of n-butyl acrylate, 50 parts by mass of 2-ethylhexyl acrylate, 3 parts by mass of vinyl acetate, 2 parts by mass of acrylic acid and 0.1 part by mass of 4-hydroxybutyl acrylate were mixed with azobisisobutylo And 0.1 part by mass of nitrile as a polymerization initiator were subjected to solution polymerization at 70 DEG C for 10 hours in an ethyl acetate solution to obtain an acrylic polymer having a weight average molecular weight of 800,000.

10 parts by mass of "D-135" (polymerized rosin ester, manufactured by Arakawa Chemical Industries, Ltd.) was mixed with 100 parts by mass of the acrylic polymer, and ethyl acetate was further added thereto to adjust the solid content to 40% by mass To obtain a pressure sensitive adhesive solution.

The pressure-sensitive adhesive solution and 1.3 parts by mass of " NC40 " (Isocyanate Crosslinking Agent, manufactured by DIC Corporation) were mixed and stirred to obtain a pressure-sensitive adhesive f.

The peak temperature of tan? Of the pressure-sensitive adhesive layer obtained using the pressure-sensitive adhesive f was -25 占 폚, and the gel fraction thereof was 40 mass%.

(Example 1)

The pressure-sensitive adhesive "a" was applied to a release liner having a silicone-based release surface on the surface of a PET-flattened PET film made by Nippon Kayaku Co., Ltd., using a roll coater, and then dried at 100 ° C. for 1 minute A pressure-sensitive adhesive layer having a thickness of 1 m was produced.

Next, the pressure-sensitive adhesive layer was transferred to one surface of a support chain " K100-2.0W " (manufactured by Mitsubishi Jushi Kabushiki Kaisha, polyester film, thickness: 2 m) to obtain a single-sided tape.

Next, the pressure-sensitive adhesive (a) was dot-printed on the other surface of the support constituting the single-sided tape using a gravure coater and dried at 100 DEG C for 1 minute to obtain a substantially rhombic Thereby obtaining a pressure-sensitive adhesive tape having a thickness of 3 m and a total thickness of 6 m. In addition, among the above adhesive portions, the distance between any adhesive portion and the adhesive portion in the vicinity of the adhesive portion was 0.1 mm.

PET 25 x 1 J0L "(a release liner having a silicone-based release surface on the surface of a smooth PET film made by Nippon Kayaku Co., Ltd.) was superimposed on the surface of the adhesive tape obtained above with the adhered portion, Mm.

(Examples 2 to 12)

An adhesive tape was produced in the same manner as in Example 1 except that the shape and area of the adhesive portion (B) and the thickness of the adhesive portion (B) were changed to those shown in Tables 1 to 3.

(Example 13)

The above pressure-sensitive adhesive a was dot-printed on a PET-lacquer coater to "PET25 x 1J0L" (a release liner having a silicone-based release surface on the surface of a smooth PET film made by Nippon K.K.) By drying, a tacky portion having a roughly rhombic shape as shown in Fig. 1 (having an angle of the corner toward the flow direction of the adhesive tape of 60 deg.) Of 3 mu m in thickness was formed. In addition, among the above adhesive portions, the distance between any adhesive portion and the adhesive portion in the vicinity of the adhesive portion was 0.1 mm.

Next, the adhesive portion was transferred to one side of a support chain " K100-2.0W " (manufactured by Mitsubishi Jushi Kabushiki Kaisha, polyester film, thickness: 2 m) to obtain a one-sided tape.

Next, the pressure-sensitive adhesive (a) was dot-printed on the other surface of the support constituting the single-sided tape using a gravure coater and dried at 100 DEG C for 1 minute to obtain a substantially rhombic shape And an angle of the corner portion facing the flow direction of the tape was 60 DEG). In addition, among the above adhesive portions, the distance between any adhesive portion and the adhesive portion in the vicinity of the adhesive portion was 0.1 mm.

Adhesive tapes having a total thickness of 8 占 퐉 and having roughly rhombic-shaped adhesive portions of 3 占 퐉 in thickness shown in Fig. 1 were obtained on both surfaces of the support by the above method.

(Example 14)

An adhesive tape was obtained in the same manner as in Example 1 except that the adhesive agent b was used in place of the adhesive agent a.

(Example 15)

An adhesive tape was obtained in the same manner as in Example 1 except that the adhesive agent c was used in place of the adhesive agent a.

(Example 16)

An adhesive tape was obtained in the same manner as in Example 1 except that the adhesive agent d was used in place of the adhesive agent a.

(Example 17)

An adhesive tape was obtained in the same manner as in Example 1 except that the adhesive agent e was used instead of the adhesive agent a.

(Example 18)

An adhesive tape was obtained in the same manner as in Example 1 except that the adhesive agent f was used in place of the adhesive agent a.

(Examples 19 to 25)

An adhesive tape was prepared in the same manner as in Example 1 except that the shape and area of the adhesive portion (B) and the thickness of the adhesive portion (B) were changed to those shown in Tables 4 and 5. Further, the surface of the adhesive tape obtained in Example 20 having a substantially circular adhered portion was observed with an optical microscope at a magnification of 200 times (Fig. 6).

(Comparative Example 1)

The pressure-sensitive adhesive "a" was applied to a "PET25 × 1 J0L" (a release liner having a silicone-based release surface on the surface of a smooth PET film made by Nippon Kayaku Co., Ltd.) using a roll coater, And dried to produce a pressure-sensitive adhesive layer having a thickness of 1 m.

Next, the pressure-sensitive adhesive layer was transferred to one surface of a support chain " K100-2.0W " (manufactured by Mitsubishi Jushi Kabushiki Kaisha, polyester film, thickness: 2 m) to obtain a single-sided tape.

Next, the pressure-sensitive adhesive a was coated on the other surface of the support constituting the single-sided tape using a roll coater and dried at 100 DEG C for 1 minute to prepare a pressure-sensitive adhesive layer having a thickness of 3 mu m.

PET 25 x 1 J0L "(a release liner having a silicone-based release surface on the surface of a smooth PET film made by Nippon Kayaku Co., Ltd.) was superimposed on the surface of the adhesive tape obtained above with the adhered portion, Mm.

(Comparative Example 2)

The pressure-sensitive adhesive "a" was applied to a "PET25 × 1 J0L" (a release liner having a silicone-based release surface on the surface of a smooth PET film made by Nippon Kayaku Co., Ltd.) using a roll coater, And dried to produce a pressure-sensitive adhesive layer having a thickness of 2 m.

Next, the pressure-sensitive adhesive layer was transferred to one side of a support chain " K100-2.0W " (manufactured by Mitsubishi Jushi Kabushiki Kaisha, polyester film, thickness: 2 m) to obtain a single-sided tape.

The pressure-sensitive adhesive a was coated on a support of a single-sided tape using a roll coater and then dried at 100 ° C for 1 minute to prepare a pressure-sensitive adhesive layer having a thickness of 2 μm. The pressure of the laminator used for transferring the pressure-sensitive adhesive layer to the support was set at a linear pressure of 3 N / mm.

Thereafter, a peeling paper subjected to a lattice-shaped embossing treatment was applied to the pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer was cured at 40 占 폚 for 2 days to form an adhesive tape having a pressure-sensitive adhesive layer as shown in Fig. 7 on the surface of the pressure- . Fig. 7 shows the surface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape obtained in Comparative Example 2 at a magnification of 100 times using an optical microscope.

(Comparative Example 3)

The pressure-sensitive adhesive "a" was applied to a "PET25 × 1 J0L" (a release liner having a silicone-based release surface on the surface of a smooth PET film made by Nippon Kayaku Co., Ltd.) using a roll coater, And dried to produce a pressure-sensitive adhesive layer having a thickness of 2 m.

Next, the pressure-sensitive adhesive layer was transferred to one surface of a support chain " K100-2.0W " (manufactured by Mitsubishi Jushi Kabushiki Kaisha, polyester film, thickness: 2 m) to obtain a single-sided tape.

Next, the PSM100GS (release liner having a silicone-based peeled surface on the surface of a sand mat-treated PET film, manufactured by LINTEC CORPORATION, centerline average surface roughness Ra = 0.36 mu m) a, and dried at 100 DEG C for 1 minute to prepare a pressure-sensitive adhesive layer having a thickness of 2 mu m. Next, the pressure-sensitive adhesive layer was transferred to the other surface of the support to obtain a pressure-sensitive adhesive tape having a total thickness of 6 m. The pressure of the laminator used for transferring the pressure-sensitive adhesive layer to the support was set at a linear pressure of 3 N / mm.

(Method of measuring gel fraction of adhesive portion)

Each of the pressure-sensitive adhesives a to f was coated with the pressure-sensitive adhesive so that the thickness after drying was 50 占 퐉 on the releasing treatment surface of the release liner, dried at 100 占 폚 for 3 minutes and then aged for 2 days under an environment of 40 占 폚 To form a pressure-sensitive adhesive layer. The pressure-sensitive adhesive layer was cut into a square having a length of 50 mm and a width of 50 mm as a test piece.

After the mass (G1) of the test piece was measured, the test piece was immersed in toluene for 24 hours under an environment of 23 占 폚. After the immersion, the mixture of the test piece and toluene was filtered using a 300 mesh network to extract an insoluble component in toluene. The mass (G2) of the insoluble component dried at 110 DEG C for 1 hour was measured.

Based on the mass (G1) and mass (G2) and the following formula, the gel fraction was calculated.

Gel fraction (mass%) = (G2 / G1) x100

(Measurement of dynamic viscoelasticity)

Each of the pressure-sensitive adhesives a to f was coated on the surface of the release liner to a dry thickness of 50 占 퐉 and dried to form a pressure-sensitive adhesive layer, which was cured for 2 days under an environment of 40 占 폚. The cured adhesive layer was superimposed on the test piece until the total thickness became 2 mm.

Next, using the viscoelasticity tester (Rheometrics GmbH, product name: Ares 2KSTD), the above test piece was put into a parallel disc measuring part having a diameter of 7.9 mm, and a test piece of -50 (G ') and a loss elastic modulus (G' ') from 0 to 150 ° C. The loss tangent tan δ was calculated from the following calculation formula.

Loss tangent tan? = G "/ G '

(Production of graphite composite sheet)

Side adhesive tape " IL-05G " (manufactured by DIC Corporation) having a size of 104 mm in length x 104 mm in width x 5 m in thickness was laminated on one side of a graphite sheet of 100 mm in length x 100 mm in width x 25 mm in thickness And the pressure-sensitive adhesive tapes obtained in Examples and Comparative Examples were cut to a size of 104 mm in length and 104 mm in width on the other surface of the graphite sheet.

At that time, of the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive tape, the pressure-sensitive adhesive layer having a smooth surface was brought into contact with the graphite sheet.

Next, a 62 μm thick unfixed single-sided single-sided tape "CPF50 (25) -SP" (manufactured by Nippon Kayaku Co., Ltd.) was stuck to the surface of the single-sided pressure-sensitive adhesive tape "IL-05G" .

(Adhesion (1 hour after application))

The pressure-sensitive adhesive tapes obtained in Examples and Comparative Examples were cut to a width of 20 mm, and the pressure-sensitive adhesive layer on one side thereof was placed on a back side with a polyethylene terephthalate film having a thickness of 25 탆. The backside atmosphere was performed on the surface of the pressure-sensitive adhesive layer having a smooth surface, and the pressure-sensitive adhesive layer corresponding to the pressure-sensitive adhesive portion (B), which is a constituent requirement of the present invention, was not performed.

The test piece was attached to the surface of a clean and smooth stainless steel plate and pressed by a reciprocating 2 kg roller on the upper surface of the test piece was left under the conditions of 23 캜 and 50% RH for 1 hour in accordance with JIS Z-0237 (Peeling direction: 180 deg., Tensile speed: 0.3 m / min) was measured using a tensile tensile tester under an atmosphere of 23 DEG C and 50% RH. The measurement results are shown in the column of " Adhesion (1 hour after application) " in the table.

(Adhesion (24 hours after application))

The pressure-sensitive adhesive tapes obtained in Examples and Comparative Examples were cut to a width of 20 mm, and the pressure-sensitive adhesive layer on one side thereof was placed on a back side with a polyethylene terephthalate film having a thickness of 25 탆. The backside atmosphere was performed on the surface of the pressure-sensitive adhesive layer having a smooth surface, and the pressure-sensitive adhesive layer corresponding to the pressure-sensitive adhesive portion (B), which is a constituent requirement of the present invention, was not performed.

The test piece was attached to the surface of a clean and smooth stainless steel plate and pressured by reciprocating one round using a 2 kg roller on the top surface thereof under conditions of 23 ° C and 50% RH for 24 hours in accordance with JIS Z-0237 The peel adhesion (peeling direction: 180 deg., Tensile rate: 0.3 m / min) was measured using a tensile tensile tester in an atmosphere of 23 deg. C and 50% RH. The measurement results are shown in the column "Adhesion (24 hours after application)" in the table.

(retention)

The pressure-sensitive adhesive tapes obtained in Examples and Comparative Examples were cut to a width of 20 mm, and a pressure-sensitive adhesive layer on one side thereof was waited on the back surface with an aluminum foil having a thickness of 50 탆. The backside atmosphere was performed on the surface of the pressure-sensitive adhesive layer having a smooth surface, and the pressure-sensitive adhesive layer corresponding to the pressure-sensitive adhesive portion (B), which is a constituent requirement of the present invention, was not performed.

The test piece was attached to the surface of a clean and smooth stainless steel plate so as to have an adhesive surface area of 20 mm x 20 mm and pressed on the top surface of the stainless steel plate by one reciprocation using a 2 kg roller. Deg.] C and 50% RH for 1 hour, a load of 100 g was applied in the direction of shearing in an atmosphere of 100 deg. C, and a displacement distance of the tape after 24 hours was measured. The measurement results are shown in the column of " holding power " in the table.

[Method for evaluating ease of removal of bubbles 1 (ease of removal)] [

The release liner of the graphite composite sheet was peeled off, and an aluminum plate having a length of 200 mm and a width of 200 mm was placed on the surface of the adhesive portion at 23 캜 and 50% RH atmosphere. I got the hangover by neglecting.

Next, after the adherend was reversed, a 2 kg roller was reciprocated from the side of the graphite composite sheet side by pressing them, thereby obtaining a laminate.

Ten sheets of the laminate were prepared by the above-mentioned method. The presence or absence of air bubbles between the pressure-sensitive adhesive layer of the graphite composite sheet constituting the laminate and the aluminum plate was confirmed by observing the bubbles of the graphite sheet. On the basis of the number of the laminated bodies in which the presence of bubbles could not be confirmed by the above-mentioned method, the ease of the bubbles to fall out was evaluated.

[Evaluation method of ease of bubbles 2 (easy to remove)] [

PET25X1J0L " (a release liner having a smooth release surface, Ra = 0.03 mu m, made by Nippon Kayaku Co., Ltd.) was stuck to the surface of the adherend shown by peeling off the release liner of the graphite composite sheet, After pressurizing under the condition of 3 N / mm, it was allowed to stand for one day under an environment of 23 캜.

Thereafter, the above-mentioned " PET25X1J0L " was peeled off, and an aluminum plate having a length of 200 mm and a width of 200 mm was placed on the surface of the adhesive portion exposed by peeling at 23 DEG C and 50% RH, And allowed to stand for 5 seconds in one state.

Next, after the adherend was reversed, a 2 kg roller was reciprocated from the side of the graphite composite sheet side by pressing them, thereby obtaining a laminate.

Ten sheets of the laminate were prepared by the above-mentioned method. Whether or not air bubbles exist between the adhered portion of the graphite composite sheet constituting the laminate and the aluminum plate was confirmed by observing the bump of the graphite sheet with a visual observation. On the basis of the number of the laminated bodies in which the presence of bubbles could not be confirmed by the above-mentioned method, the ease of the bubbles to fall out was evaluated.

(Presence or absence of lifting of the graphite composite sheet when the non-adhesive film was peeled off)

(One having a silicone-based unfixed layer on one side of a PET film having a thickness of 75 占 퐉: adhesive strength = 0.05 (one side) was laminated on the surface of a single-sided pressure-sensitive adhesive tape "IL-05G" (manufactured by DIC Co.) constituting the graphite composite sheet N / 20 mm) was placed on an aluminum plate, and the surface thereof was reciprocated by a 2 kg roller to fix them.

The unfixed film was peeled at a rate of 5 m / min against the surface of the graphite composite sheet in the direction of 180 after 1 minute from the attachment, and then whether or not the graphite composite sheet was released from the surface of the aluminum plate It was evaluated as a mosque. Ten stacked articles were prepared for each of the graphite composite sheets obtained in Examples and Comparative Examples, and the above test was conducted. The number of laminated articles which could not confirm lifting of the graphite composite sheet from the surface of the aluminum plate by the above test is shown in the following table.

(Appearance evaluation method)

The graphite composite sheet was attached to an aluminum plate, and the shape of the adhesive portion (the substantially rhombic shape, the substantially annular shape, and the like) was visually observed when the graphite composite sheet was observed from a position of 30 cm from the top surface of the graphite composite sheet under a fluorescent lamp . &Quot; good ", " good ", " good ", " good ", and " good " In addition, as shown in Comparative Example 1, in the case where a pressure-sensitive adhesive was applied to the entire surface of a support to form a pressure-sensitive adhesive layer, the pressure-sensitive adhesive portion did not have a predetermined shape, - ".

[Number of adhesive portions]

The number of the adhesive portions was determined by observing with an electron microscope a range of an arbitrary range of the adhesive tape (a square of 5 cm in the flow direction and 5 cm in width) or a square of 1 cm in the flow direction and 1 cm in the width direction.

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

[Table 6]

In the table, " roughly rhombic pattern 1 " indicates a rhombic adhesive portion having an angle of the corner portion oriented toward the flow direction of the adhesive tape of 60 占 (the angle of the corner portion facing the width direction is 120) (Fig. 1) Model 2 "indicates a rhombic adhesive portion having an angle of 30 ° toward the flow direction of the adhesive tape (the angle of the corner portion facing the width direction is 150 °), and the" substantially square shape " Refers to a tacky portion on a square surface having an angle of 90 占 toward the widthwise direction (the angle of the edge portion facing the width direction is 90 占), and the term " substantially circular shape " refers to a tacky portion of the shape shown in Fig. Quot; indicates an adhered portion having a shape shown in Fig. 3, and " substantially rectangular (diagonal) " indicates an adhered portion having a shape shown in Fig.

Since the pressure-sensitive adhesive tapes of the examples each have a plurality of independent pressure-sensitive adhesive layers on one side thereof, the pressure-sensitive adhesive tapes are excellent in ease of bubble drop. On the other hand, in the pressure-sensitive adhesive tape of Comparative Example 1, since the pressure-sensitive adhesive layer is smooth, there is no way out of bubbles and the ease of bubbling is significantly worse. In the pressure-sensitive adhesive tapes of Comparative Example 2 and Comparative Example 3, since the pressure-sensitive adhesive layer has irregularities, the bubbles tend to fall off at the beginning, but the bubbles tend to fall off after a lapse of time.

1: Support 2: Adhesive
3: adhesive tape 4: graphite sheet
5: single-sided adhesive tape 6: double-sided adhesive tape

Claims (12)

An adhesive tape having at least two adhesive portions (B) on at least one side (a) side of a support (A), wherein a region not having the adhesive portion (B) is present between the two or more adhesive portions , And the area is through the end of the adhesive tape. The method according to claim 1,
Wherein the shape of the adhered portion (B) when the adhered portion (B) is observed from the side (a) of one side of the support (A) is a substantially circular shape, a substantially rectangular shape or a substantially hexagonal shape. 3. The method according to claim 1 or 2,
Wherein a distance between an arbitrary adhesive portion (b1) selected from the two or more adhesive portions (B) and an adhesive portion (b2) adjacent to the adhesive portion (b1) is 0.5 mm or less. 4. The method according to any one of claims 1 to 3,
Wherein a ratio of a region occupying the area of one surface (a) of the support (A) and having the adhesive portion (B) is 10% to 99%. 5. The method according to any one of claims 1 to 4,
Wherein the number of the adhesive portions (B) is 120 to 2000 in a range of 1 cm in the flow direction of the adhesive tape and 1 cm in the width direction. 6. The method according to any one of claims 1 to 5,
Adhesive tape having a total thickness of 20 탆 or less. 7. The method according to any one of claims 1 to 6,
A smooth stainless steel plate was placed on the surface having the adhesive portion B and subjected to one round trip using a 2 kg roller so that they were pressed and allowed to stand for 1 hour under the conditions of 23 캜 and 50% Wherein the 180 [deg.] Peel adhesive force measured by using the adhesive tape is in a range of 2N / 20 mm to 12 N / 20 mm. 8. The method according to any one of claims 1 to 7,
A pressure-sensitive adhesive tape used for bonding between a heat generating member and a heat dissipating member, or for bonding a metal member in contact with a heat generating member to a heat dissipating member. 9. The method of claim 8,
Wherein the heat radiation member is a graphite sheet or a graphen sheet. The heat radiation sheet according to any one of claims 1 to 8, wherein an arbitrary single-sided adhesive tape is pasted on one surface of the heat radiation member and the other surface of the heat radiation member is pasted to the adhesive tape. The electronic device according to claim 10, wherein the heat-radiating sheet is attached to a heating member or a metal member in contact with the heat-generating member, wherein the surface of the heat-radiating sheet having the adhesive portion (B) Wherein the electronic device is attached to a metal member. Characterized in that at least two adhesive portions (B) having a substantially circular shape, a substantially rectangular shape or a substantially hexagonal shape are formed on at least one surface (a) of the support by applying a pressure-sensitive adhesive by a gravure coating method or a slot die coating method Wherein the pressure-sensitive adhesive tape has a thickness of 10 mm.

Images