KR101884944B1 - Double-sided adhesive tape and display device having touch panel - Google Patents

Abstract

An object of the present invention is to provide a portable information terminal which is excellent in bonding suitability to steps, adhesive property and water resistance, and which is suitable for fixing members in mobile products such as cellular phones and touch panels, Sensitive adhesive tape for use as a double-sided pressure-sensitive adhesive tape.
According to the present invention, there is provided a double-faced pressure-sensitive adhesive tape comprising a laminate having a core and a pressure-sensitive adhesive layer formed on both sides thereof, wherein the core has a 5% tensile stress of 3 to 100 N, (B) the two pressure-sensitive adhesive layers each contain 1 to 60 parts by mass of a tackifier resin with respect to 100 parts by mass of the (meth) acrylic acid ester copolymer and the copolymer, respectively And a pressure-sensitive adhesive composition comprising a crosslinking agent is thermally crosslinked.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a double-sided pressure-sensitive adhesive tape,

The present invention relates to a double-sided adhesive tape and a display device with a touch panel. More specifically, the present invention relates to a laminate comprising a pressure-sensitive adhesive layer having a specific property on both surfaces of a core material having a specific property, and for example, in a mobile product such as a cellular phone or a touch panel And is excellent in adhesion suitability to steps, adhesive property, and water resistance, and is suitable as a waterproof or the like for a portable information terminal having a small frame margin formed around the display screen. The present invention relates to a touch panel mounted display device using a double-sided adhesive tape and a double-sided adhesive tape.

BACKGROUND ART In a portable information terminal such as a mobile phone, a PHS (Personal Handiphone System), and a music player, a double-sided adhesive tape is used for fixing various parts such as an information display part, a housing, a camera periphery, and a keypad. 2. Description of the Related Art In recent years, portable information terminal devices having various functions have been developed, and waterproof performance has been demanded as one of them.

As a double-sided tape having a waterproof performance, for example, a double-sided pressure-sensitive adhesive tape having a foam substrate and a pressure-sensitive adhesive layer is disclosed (for example, see Patent Documents 1 and 2).

The double-sided adhesive tape for waterproofing disclosed in Patent Documents 1 and 2 has a polyolefin-based foam substrate and an acrylic pressure-sensitive adhesive. Since the base material is foamed, the base material and the pressure-sensitive adhesive bond strongly at the interface. In addition, since the foam substrate described above has the independent foam structure, even if one side of the double-sided adhesive tape is wet with water, it does not penetrate to the other side, and waterproof property is exhibited. Further, the foam base material is excellent in irregularity followability.

However, in the case of a tape width of a very narrow width of about 1 mm, there is a possibility that the bubble wall of the independent bubble for controlling the infiltration of water can not be sufficiently secured in the width direction in the waterproof double-sided tape using the foam, Do not. Moreover, the size of the foamed shape is limited, and it is difficult to finely control the size of the foamed shape.

[0002] In recent mobile phones, the number of large display screens has been increased due to demands for designability and function, and is designed to be as narrow as possible to the peripheral edge portion of the display screen. The double-sided tape used for these is assumed to be used in the form of a narrow frame having a width of 2 mm or less. However, the double-sided tape for waterproofing has a narrow width in the form of a framed frame from the reason of the above- Which is difficult to apply to a cellular phone with a large display screen. Further, it is necessary to firmly fix the member even in a narrow framed frame specification. However, since the base material is foamed, the strength of the base material is low and the adhesive property is difficult to be exerted.

JP 2009-108314 A JP 2009-242541 A

The present invention has been made under such circumstances, and it is a laminated body in which a pressure-sensitive adhesive layer is provided on both sides of a core material. The laminated body is suitable for fixing members in mobile products such as mobile phones and touch panels, It is an object of the present invention to provide a double-sided pressure-sensitive adhesive tape which is excellent in bonding suitability, adhesiveness and water resistance, and has irregularity following property, which is used as a waterproofing or the like, in a portable information terminal having a frame-

The inventors of the present invention have conducted intensive studies in order to achieve the above object, and as a result, the following findings were obtained.

As the core material, a film formed of a synthetic resin film having a specific property, preferably an ethylene-methacrylic acid copolymer or an olefinic polymer such as an ethylene-vinyl acetate copolymer, is used. The present inventors have found that a double-sided adhesive tape, which is a laminate formed by forming an acrylic pressure-sensitive adhesive layer, can achieve the object.

The present invention has been completed on the basis of such findings.

That is,

[1] A double-sided pressure-sensitive adhesive tape comprising a laminate having a core and a pressure-sensitive adhesive layer formed on both sides thereof,

(a) the core has a 5% tensile stress of 3 to 100 N and a stiffness of 0.2 mN or less (Gareth method)

(b) the two pressure sensitive adhesive layers each comprise 1 to 60 parts by mass of a (meth) acrylic acid ester copolymer and 100 parts by mass of the copolymer, and a pressure-sensitive adhesive composition comprising a crosslinking agent, Made up

A double-sided pressure-sensitive adhesive tape;

[2] The double-faced pressure-sensitive adhesive tape according to the above [1], wherein the core is a film formed by using an olefin-based polymer containing 60 to 100% by mass of an olefin-based monomer unit;

[3] The double-faced pressure-sensitive adhesive tape according to the above [2], wherein the olefinic polymer is an ethylene-methacrylic acid copolymer and / or an ethylene-vinyl acetate copolymer;

[4] The double-faced pressure-sensitive adhesive tape according to any one of the items [1] to [3], wherein the thickness of the core material is 2 to 400 탆 and the thicknesses of the two pressure-sensitive adhesive layers are respectively 2 to 80 탆.

[5] The double-faced pressure-sensitive adhesive tape according to any one of [1] to [4], having a shape obtained by punching in the form of a frame having a width of 0.1 to 2 mm.

[6] A double-faced pressure-sensitive adhesive tape as described in any one of [1] to [5] above, which is used for fixation in a portable information terminal machine.

[7] The double-faced pressure-sensitive adhesive tape according to any one of the above-mentioned [1] to [6], which is used for waterproofing. And

[8] A touch panel-equipped display device, comprising a housing body fixed by a double-faced adhesive tape according to any one of [1] to [7]

.

According to the present invention, it is possible to provide a laminate having a pressure-sensitive adhesive layer formed on both sides of a core material, and which is suitable for fixing members in mobile products such as cellular phones and touch panels, It is possible to provide a display device with a touch panel using a double-sided pressure-sensitive adhesive tape excellent in water resistance and having a concavo-convex following property which is used as waterproofing or the like in a portable information terminal with a narrow frame-

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a plan view of a sample for measurement used in a water resistance evaluation test of a double-faced pressure-sensitive adhesive tape;
FIG. 2 is a cross-sectional view taken along line AA in FIG. 1; FIG.
3 is a sectional view taken along the line BB in Fig. 1; Fig.
4 is an explanatory view showing a method of measuring a surface bonding force.

First, the double-faced pressure-sensitive adhesive tape of the present invention will be described.

[Double-sided adhesive tape]

The double-faced pressure-sensitive adhesive tape of the present invention is a laminate having a core material and a pressure-sensitive adhesive layer formed on both surfaces thereof,

(a) the core has a 5% tensile stress of 3 to 100 N and a lubrication index (grating method) of 0.2 mN or less,

(b) the two pressure sensitive adhesive layers each comprise 1 to 60 parts by mass of a (meth) acrylic acid ester copolymer and 100 parts by mass of the copolymer, and a pressure-sensitive adhesive composition comprising a crosslinking agent, .

(Core material)

In the double-faced pressure-sensitive adhesive tape of the present invention, the core material constituting the laminate must have a 5% tensile stress in the range of 3 to 100 N and a lubrication degree (grating method) of 0.2 mN or less.

By setting the 5% tensile stress of the core material to 3 to 100 N, a high surface bonding force can be obtained, and it has excellent flexibility while maintaining excellent processability and narrow frame formability. The tensile stress is preferably 4 to 80 N, particularly preferably 5 to 50 N.

On the other hand, by setting the laminating degree (grating method) of the core material to 0.2 mN or less, since it has appropriate flexibility, it has excellent irregularity followability.

The thickness of the core material is not particularly limited, but is preferably 2 to 400 占 퐉, more preferably 10 to 200 占 퐉, and particularly preferably 50 to 150 占 퐉, from the viewpoints of workability and thinness. By setting the thickness to 2 mu m or more, the core material itself can be processed, the double-sided tape can be cut, and punching suitability and strength can be ensured. By setting the thickness to 400 mu m or less, flexibility can be ensured.

The above 5% tensile stress and lubrication (gauze) are values measured by the following methods.

<Method of measuring tensile stress at 5% core material>

The core material was cut to a width of 15 mm and a length of 50 mm to prepare a sample for measurement. Ten mm of both ends of the sample for measurement were set using a tensile compression tester and the measurement point of 15 mm in width and 30 mm in length was measured at a tensile rate The stress at 5% increase at 200 mm / min is measured.

<Measurement method of core material lecture (kara method)>

A core sample is cut to a length of 38 mm and a width of 25 mm to prepare a sample for measurement, and a lapping degree is measured in accordance with "JIS L1085 (1998) 6.10.3 Gareth Law" using a Gareth type liner tester.

The core material constituting the laminate of the double-sided pressure-sensitive adhesive tape of the present invention is not particularly limited and may be appropriately selected from conventionally known synthetic resin films as long as it satisfies the above-described properties.

As the synthetic resin film having the above-described properties and constituting the core material, for example, the olefinic monomer unit may be contained in an amount of about 60 to 100 mass%, preferably 70 to 97 mass%, more preferably 80 to 94 mass% % Of an olefin-based polymer can be suitably used.

Specific examples of such olefinic polymers include ethylene-methacrylic acid copolymer and ethylene-vinyl acetate copolymer. These olefin-based polymers may be used singly or in combination of two or more kinds.

The synthetic resin film constituting the core material may be surface-treated or primer-treated on both sides by an oxidation method, an irregularization method or the like, if necessary, for the purpose of improving adhesion with the pressure-sensitive adhesive layer provided on both sides thereof. Examples of the oxidation method include a corona discharge treatment, a plasma discharge treatment, a chromic acid treatment (wet type), a hot air treatment, an ozone / ultraviolet ray irradiation treatment and the like. Examples of the irregularity method include a sandblast blast method, and solvent treatment method. These surface treatment methods are appropriately selected depending on the kind of the synthetic resin film, but generally, the corona discharge treatment method is preferably used in terms of effect and operability.

The color of the core material is not particularly limited and may be colorless or may be colored with an appropriate color.

Further, it is preferable that the core material is not a foam structure. In the double-sided tape for waterproofing using the core material having the foam structure, the bubble wall of the independent bubble for controlling the infiltration of water can not be sufficiently secured in the width direction.

(Pressure-sensitive adhesive layer)

In the double-sided tape of the present invention, the two pressure-sensitive adhesive layers formed on both sides of the synthetic resin film constituting the above-mentioned core material are composed of (meth) acrylic acid ester copolymer and 100 parts by mass of the copolymer 1 to 60 parts by mass of a resin, and the acrylic pressure-sensitive adhesive composition containing a crosslinking agent is thermally crosslinked.

In the double-sided pressure-sensitive adhesive tape of the present invention, the two pressure-sensitive adhesive layers may have the same composition and properties, or may have different compositions and properties, provided that the respective properties satisfy the requirements described above. However, It is preferable that they have the same composition and properties.

&Lt; (Meth) acrylic acid ester copolymer >

In the acrylic pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer, the (meth) acrylic acid ester copolymer contained as the main component is not particularly limited, and any of the (meth) acrylic acid ester copolymers conventionally used as a main component of the acrylic pressure- You can select and use it appropriately. Examples of such a (meth) acrylic acid ester copolymer include a (meth) acrylic acid ester in which the alkyl moiety of the ester moiety has 1 to 20 carbon atoms, a monomer having a functional group having active hydrogen, and other monomers Are preferably used. Further, the (meth) acrylic acid ester means methacrylic acid ester and / or acrylic acid ester.

Examples of the (meth) acrylic acid ester in which the alkyl group of the ester moiety has 1 to 20 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) (Meth) acrylate, isobutyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (Meth) acrylate, isopropyl (meth) acrylate, isooctyl (meth) acrylate, decyl (meth) acrylate, dodecyl And the like. These may be used alone or in combination of two or more.

On the other hand, examples of the monomer having a functional group having an active hydrogen include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) Hydroxyalkyl (meth) acrylates such as butyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate; (Meth) acrylates such as monomethylaminoethyl (meth) acrylate, monoethylaminoethyl (meth) acrylate, monomethylaminopropyl (meth) acrylate and monoethylaminopropyl (meth) ; And ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid and citraconic acid. These monomers may be used alone or in combination of two or more.

Examples of other monomers to be optionally used include vinyl esters such as vinyl acetate and vinyl propionate; Olefins such as ethylene, propylene and isobutylene; Halogenated olefins such as vinyl chloride and vinylidene chloride; Styrene monomers such as styrene and? -Methyl styrene; Diene-based monomers such as butadiene, isoprene, and chloroprene; Nitrile monomers such as acrylonitrile and methacrylonitrile; And acrylamides such as acrylamide, N-methylacrylamide and N, N-dimethyl acrylamide. These may be used alone or in combination of two or more.

In the acrylic pressure-sensitive adhesive composition, the (meth) acrylic acid ester copolymer used as the main component is not particularly limited in its copolymerization form and may be a random, block or graft copolymer. The molecular weight is preferably 300,000 or more in terms of weight average molecular weight, and more preferably 500,000 to 250,000. If the weight average molecular weight is less than 300,000, there is a possibility that the adhesion with the adherend and the endurance adhesion are insufficient. In view of adhesion and endurance adhesion, the weight average molecular weight is preferably from 600,000 to 1,800,000.

In addition, the weight average molecular weight is a value in terms of standard polystyrene measured by gel permeation chromatography (GPC).

In the (meth) acrylic acid ester copolymer, the content of the monomer unit having a functional group having active hydrogen is preferably in the range of 0.01 to 10% by mass. If the content is less than 0.01% by mass, the crosslinking point becomes too small, the crosslinking becomes insufficient, and the pressure-sensitive adhesive layer may cause cohesive failure. When the content exceeds 10% by mass, the potability may deteriorate due to an increase in viscosity. A more preferable content of the monomer unit having a functional group having active hydrogen is from 0.05 to 6.0% by mass, particularly preferably from 0.2 to 5.0% by mass.

&Lt; Adhesion-imparting resin &

In the double-sided pressure-sensitive adhesive tape of the present invention, as the pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer, it is necessary to use a pressure-sensitive adhesive resin in order to improve adhesion with an adherend in view of obtaining sufficient irregularity, adhesion and processing suitability. The tackifier resin is not particularly limited and may be suitably selected from those conventionally used as a tackifier resin in the tackifier. Examples of the tackifier resin include rosin resins (such as rosin rosin, hydrogenated rosin, polymerized rosin and rosin ester type), xylene resins, terpene-phenol resins, petroleum resins, coumaroneindene resins, terpene resins, .

Specific examples of commercially available products include Pine Crystal KE-359 (product of Arakawa Chemical Industries, Ltd.), Super Ester A-75 [product of Arakawa Kakuko Co., Ltd.], Super Ester A-100 [product of Arakawa Chemical Industries, Ltd. , Rosin esters such as Super Aster A-125 [product of Arakawa Kagaku Kogyo Co., Ltd.], PENCEL D125 [product of Arakawa Kagaku Kochi], PENCEL D160 [product of Arakawa Kakuko Co., Ltd.], RIKATAK PCJ Manufactured by Mitsubishi Kagaku Kogyo Co., Ltd.], Nylonol HP-100 [manufactured by Mitsubishi Gas Chemical Company], Nikanol HP-150 [manufactured by Mitsubishi Gas Chemical Company] Phenol resin such as Tter-phenol resin such as T-115 [manufactured by Yasuhara Chemical Co., Ltd. and Mightech G125 (manufactured by Yasuhara Chemical Co., Ltd.), FTR-6120 [manufactured by Mitsui Chemicals], and FTR-6100 [manufactured by Mitsui Chemicals] Resin and the like.

These tackifying resins may be used singly or in combination of two or more kinds. Among them, rosin ester is preferable from the viewpoint of tackiness.

In the above pressure-sensitive adhesive composition, the tackifier resin is required to be 1 to 60 parts by mass with respect to 100 parts by mass of the (meth) acrylic acid ester copolymer described above, preferably 3 to 50 parts by mass, more preferably 5 to 40 parts by mass It is more desirable to be negative. When the tackifier resin is contained in the above range, adhesion with an adherend becomes good.

<Cross-linking agent>

In the acrylic pressure-sensitive adhesive composition, the crosslinking agent to be contained is not particularly limited, and any of those conventionally used as a crosslinking agent in the acrylic pressure-sensitive adhesive composition may be appropriately selected and used. Examples of such a crosslinking agent include polyisocyanate compounds, epoxy resins, melamine resins, urea resins, dialdehydes, methylol polymers, aziridine compounds, metal chelate compounds, metal alkoxides and metal salts, A polyisocyanate compound is preferably used.

Examples of the polyisocyanate compound include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate and xylylene diisocyanate, and aromatic polyisocyanates such as hexamethylene diisocyanate Alicyclic polyisocyanates such as aliphatic polyisocyanates such as isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate, and their alicyclic polyisocyanates such as buret resin, isocyanurate resin And adducts which are reacted with low-molecular active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylol propane, castor oil and the like.

In the present invention, these crosslinking agents may be used singly or in combination of two or more kinds. The amount of the crosslinking agent to be used depends on the kind of the crosslinking agent, but is usually selected in the range of 0.01 to 20 parts by mass, preferably 0.1 to 10 parts by mass, based on 100 parts by mass of the solid content of the (meth) acrylic acid ester copolymer.

The pressure-sensitive adhesive composition may contain various additives such as a silane coupling agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a softening agent, a filler, a colorant, and the like in a range that does not impair the object of the present invention have.

In the double-sided tape of the present invention, the thickness of the two pressure-sensitive adhesive layers formed using the acrylic pressure-sensitive adhesive composition is not particularly limited, but is preferably 2 to 80 占 퐉, and particularly preferably 5 to 60 占 퐉. By setting the thickness to be not less than 2 mu m, it is excellent in irregularity followability and adhesion to an adherend, and when it is 80 mu m or less, workability is excellent.

<Release sheet>

In the double-sided pressure-sensitive adhesive tape of the present invention, it is preferable that the release sheet is laminated on the basis of convenience in transportation and use. The double-faced pressure-sensitive adhesive tape of the present invention may be inserted between two peeling sheets, or may be laminated with a single peeling sheet having releasability on both sides and rolled.

As the release sheet for use in the double-sided pressure-sensitive adhesive tape of the present invention, various release sheets can be used, but they are typically composed of a release sheet base having a releasability on the surface. Examples of the base material for the release sheet include polyethylene terephthalate, polyethylene, polypropylene, polybutene, polybutadiene, polymethylpentene, polyvinyl chloride, vinyl chloride copolymer, polybutylene terephthalate, polyurethane, ethylene- (Meth) acrylic acid copolymer, polystyrene, polycarbonate, fluorine resin, low density polyethylene, linear low density polyethylene, and triacetyl cellulose, or a resin film such as a thermoplastic film, a coated paper, a glossy paper, And the like. Of these, a polyethylene terephthalate film which is inexpensive and elastic is preferable. The thickness of the base material for the release sheet is preferably 5 탆 to 300 탆, more preferably 10 탆 to 200 탆.

In order to have releasability on the surface of the release sheet substrate, it is formed by applying a releasing agent such as a silicone resin, a fluorine resin, or a long chain alkyl mechanical resin to the surface. Of these, a silicone-based resin capable of obtaining an inexpensive and stable performance is preferable. The thickness of the release agent layer is preferably 0.05 탆 to 2.0 탆, more preferably 0.1 탆 to 1.5 탆.

When producing the double-sided pressure-sensitive adhesive tape of the present invention, it is desirable to make a difference in the peeling force of each release sheet. When the peeling force is different, it is possible to prevent the pressure-sensitive adhesive layer from being deformed due to elongation of the pressure-sensitive adhesive layer when trying to follow both release sheets, because the pressure-sensitive adhesive layer may come from the heavy- Even in the case of a double-sided pressure-sensitive adhesive tape in which a single release sheet having releasability on both sides and a double-sided pressure-sensitive adhesive tape laminated on the both sides are left as they are, the same effect can be obtained by making a difference in peeling force from the front and back sides of the release sheet.

(Production of double-faced adhesive tape)

Next, a method for producing the double-faced pressure sensitive adhesive tape of the present invention will be described.

First, a solvent is added to the above-described pressure-sensitive adhesive composition, if necessary, and adjusted to a viscosity suitable for coating to prepare a coating liquid.

Next, on the release treatment surface of the light-exfoliation sheet (or the heavy-weight recycled sheet), the coating liquid is applied onto the surface of the light-exfoliation sheet (or the heavy-weighted sheet) so that the thickness after drying is 2 to 80 탆, preferably 5 to 60 탆, Such as a roll coating method, a reverse roll coating method, a knife coating method, a roll knife coating method, a gravure coating method, an air doctor coat method, a doctor blade coating method and the like, at a temperature of about 80 to 120 DEG C for several tens of seconds For a few minutes. After heat-crosslinking the adhesive composition layer, the core material is bonded to the adhesive layer to produce a single-sided pressure-sensitive adhesive film.

Next, on the release treatment surface of the heavy-weight recycled sheet (or light-release sheet), the coating solution is coated and heated in the same manner as described above so that the film thickness after drying is 2 to 80 탆, preferably 5 to 60 탆 Dried, thermally crosslinked, and then bonded to the core surface of the single-sided pressure-sensitive adhesive film to obtain the double-sided pressure-sensitive adhesive tape of the present invention.

The surface bonding strength of the double-faced pressure-sensitive adhesive tape of the present invention thus obtained is preferably 120 N or more, more preferably 170 N or more, as measured by the measurement conditions described later. When it is 120 N or more, excellent adhesion can be obtained for fixation of members.

Next, the use of the double-faced pressure-sensitive adhesive tape of the present invention will be described.

[Use of double-sided adhesive tape]

The double-faced pressure-sensitive adhesive tape of the present invention is a laminate in which a pressure-sensitive adhesive layer having a specific property is formed on both sides of a core film having a specific property and is used for fixing a member in a mobile product such as a cellular phone or a touch panel Adhesive property and water resistance, and is used as a waterproof double-faced tape on a portable information terminal of a narrow framed frame specification.

Since the double-faced pressure-sensitive adhesive tape of the present invention uses a synthetic resin film having a specific property as a core material, it does not have pores and is excellent in water resistance and has a width of 0.1 to 2 mm and a width of 0.2 to 1 mm And is used for waterproofing. That is, the present invention can be applied to a portable information terminal with a narrow frame specification as a waterproof double-sided tape.

As the form of the double-faced pressure-sensitive adhesive tape of the present invention, it is possible to adopt a form of framed sheet formation in which a release sheet is adhered to both sides.

Further, in the double-sided pressure-sensitive adhesive tape of the present invention, either or both of the core layer and the pressure-sensitive adhesive layer can be made black. Particularly, when the double-faced pressure-sensitive adhesive tape is in the form of a framed body, it is preferably black.

The blackening of the core or the pressure-sensitive adhesive layer can be performed by incorporating carbon black, black pigment, dye or the like.

The present invention also provides a display device with a touch panel, characterized in that the housing body is fixed by the double-sided adhesive tape of the present invention described above.

Example

EXAMPLES Next, the present invention will be described in further detail with reference to Examples, but the present invention is not limited to these Examples.

Various properties of the double-faced pressure-sensitive adhesive tape obtained in each example were obtained by the following methods.

(1) Thickness of core and pressure-sensitive adhesive layer

The thicknesses of the core material and the pressure-sensitive adhesive layer obtained in the respective examples were measured according to JIS K7130 using a static pressure thickness gauge [product name: "PG-02" manufactured by Tecrock Co., Ltd.].

(2) 5% tensile stress of core

The core material obtained in each example was cut to a width of 15 mm and a length of 50 mm to prepare a sample for measurement. Subsequently, 10 mm of both ends of the sample for measurement was set using a tensile tester (product number: Shimazu Seisakusho Co., Ltd., model number "AG-IS") at a temperature of 23 ° C. and a width of 15 mm and a length of 30 mm Was measured at a stretching speed of 200 mm / min by 5%.

(3) Lecture of core material (karate method)

The core material was cut into a length of 38 mm and a width of 25 mm to prepare a sample for measurement. The sample was measured using Jare L1085 (1998) 6.10 (manufactured by Toyo Seiki Seisaku- . &Lt; 3 &gt;

(4) Waterproofness test

&Quot; Test for the second characteristic number 7 in the temporary diving state of JIS C0920 (2003) 14.2.7 depth 0.15 to 1m &quot;. Fig. 1 is a plan view of a sample for measurement, Fig. 2 is a sectional view taken along the line A-A in the plan view, and Fig. 3 is a sectional view taken along the line B-B in the plan view. Two transparent acrylic plates 1a and 1b each having a length of 70 mm, a width of 50 mm and a thickness of 2 mm were stacked on a frame-shaped laminated member 1 having an outer size of 60 mm x width 40 mm and a width of 1 mm (2) were prepared. On one acrylic plate 1a of the measurement sample, there was used a smooth acrylic plate 1b having a height of 10 占 퐉 and a width of 5 mm in cross-shaped black printing (3) and no step on the other side ( 1 to 3). After 24 hours from the measurement sample, the sample for measurement was immersed in a depth of 1 m and allowed to stand for 30 minutes. Then, the presence or absence of water intrusion into the test piece was visually observed, and water resistance was evaluated according to the following criteria.

○: No penetration of water into the specimen (pass).

X: Intrusion of water into the specimen (rejection).

(5) Surface adhesion force

Acrylic plate (product name: "Acrylite L001", 70 × 50 × 2 mm, manufactured by Mitsubishi Rayon Co., Ltd.) was prepared, and a UV curable ink [manufactured by Teikoku Ink Co., 911 ink &quot;]. Subsequently, a hole having a diameter of 2 cm was passed through a center of a stainless steel plate (product name: SUS304 # 600, 150 × 70 × 0.5 mm, single side # 600 polishing, manufactured by Paltech Co.).

Next, the ink layer of the acrylic plate and the # 600 polished surface of the stainless plate were bonded to each other with a double-sided pressure-sensitive adhesive tape having an outer size of 60 mm × 40 mm and a width of 2 mm. Thereafter, the portion where the hole is opened and the acrylic plate ink application surface is exposed with a universal tensile compression tester (manufactured by Instron, product name "Instron 5581 type") at a speed of 10 mm / min is measured using a universal tensile tester A jig fixed on the measuring part (a cube made of a polycarbonate resin having a side length of 10 mm is fixed to the bottom surface of the measuring part with an adhesive tape, a contact part between the measuring part and the acrylic plate is square with a size of 10 mm x 10 mm) , The stress (peak value of load) when the double-sided adhesive tape was peeled off was measured.

4 is an explanatory view showing a method of measuring the surface bonding force. 4 is a cross-sectional view, (b) is a perspective view, 10 is a double-sided adhesive tape, 11 is stainless steel having holes, and 12 is an ink layer 14 on the double- Genie is the acrylic plate, (13) is the pushing direction.

(6) Thinning processability

When cutting was performed in the form of a width of 1 mm and a length of 50 mm using an NT cutter, it was confirmed by using a micro gauge that the sample width was 1 mm ± 0.2 mm, and if it was within the range of 1 mm ± 0.2 mm , And it was evaluated as x if it was out of the range.

Preparation Example 1 Preparation of a coating liquid 1 for forming a pressure-sensitive adhesive

(BA / 2EHA / AAc ratio by weight = 80/19/1, weight average molecular weight of 60,000, solid content (weight ratio of acrylic acid / acrylic acid copolymer) 5 parts by mass of a tackifier resin (product of Arakawa Chemical Industries, Ltd., product name: Fine Crystal KE-359) and 100 parts by mass of an isocyanate crosslinking agent [product name: BHS-8515 (Solid content: 37.5% by mass)] (2.45 parts by mass based on 100 parts by mass of the solid content of the acrylic acid ester copolymer) were mixed to prepare a coating liquid 1 for forming a pressure-

Preparation Example 2 Preparation of coating liquid 2 for forming pressure-sensitive adhesive

Acrylic acid ester copolymer (BA / AAc / HEA mass ratio = 98 / 1.5 / 0.5, weight average molecular weight: 600,000) having a monomer component of butyl acrylate (BA), acrylic acid (AAc) and 2-hydroxyethyl acrylate , 20 parts by mass of a tackifier resin (product of Arakawa Chemical Industries, Ltd., product name: Fine Crystal KE-359) and 100 parts by mass of an isocyanate crosslinking agent [product name: BHS -8515 &quot;, solid content 37.5% by mass] (0.94 parts by mass based on 100 parts by mass of the solid content of the acrylic acid ester copolymer) were mixed to prepare a pressure-sensitive adhesive coating liquid 2.

Preparation Example 3 Preparation of coating liquid 3 for forming pressure-sensitive adhesive

Acrylic acid ester copolymer [BA / MA / AAc mass ratio = 77/20/3, weight average molecular weight 80,000, copolymer of butyl acrylate (BA), methyl acrylate (MA) and acrylic acid (Product name &quot; BHS-8515 &quot;, solid content: 37.5% by mass)] was added to 100 parts by mass of an acrylic acid ester copolymer And 1.8 parts by mass of an aluminum chelate crosslinking agent (M-5A, solid content: 4.95% by mass, manufactured by Soken Kagaku Co., Ltd.) (0.32 parts by mass based on 100 parts by mass of the solid content of the acrylic acid ester copolymer) were mixed to prepare a pressure- 3 was prepared.

Preparation Example 4 Preparation of coating liquid 4 for forming a pressure-sensitive adhesive

(BA / MA / 4HBA, mass ratio = 79/20/1, weight average molecular weight (Mw / Mn)) of the acrylic acid ester copolymer having butyl acrylate (BA), methyl acrylate (MA) and 4-hydroxybutyl acrylate 0.05 part by mass (solid content 100 parts by mass of acrylic acid ester copolymer) of 100 parts by mass of an isocyanate-based crosslinking agent (product name: TD-75, solid content 75% 0.13 parts by mass based on the mass part) were mixed to prepare a coating liquid 4 for forming a pressure-sensitive adhesive.

Example  One

Ethylene-methacrylic acid copolymer [product name "NO903HC", product of Du Pont-Mitsui Polychemicals Co., Ltd., olefinic monomer unit: 91 mass%] was formed into a thickness of 100 μm and subjected to corona treatment on both sides to obtain a core film. Next, a coating liquid 1 for forming a pressure-sensitive adhesive was applied on the release-treated surface of a light-releasing sheet (trade name: SP-PET381031, manufactured by LINTEC CO., LTD.) Using a knife coater so that the thickness after drying became 50 m, And heat-dried at 100 DEG C for about 2 minutes to thermally crosslink. Thereafter, the core film described above was laminated on the pressure-sensitive adhesive layer to obtain a single-sided pressure-sensitive adhesive film.

Subsequently, a coating liquid 1 for forming a pressure-sensitive adhesive was applied on the release-treated surface of a heavy-duty recycled sheet (trade name: SP-PET3811, manufactured by LINTEC CO., LTD.) Using a knife coater so that the thickness after drying became 50 m, ° C for about 2 minutes to form a double-sided pressure-sensitive adhesive tape, which was then thermally crosslinked and then bonded to the core film surface of the single-sided pressure-sensitive adhesive film.

Example  2

A double-faced pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that the coating liquid 2 for forming a pressure-sensitive adhesive was used in place of the coating liquid 1 for forming a pressure-sensitive adhesive.

Example  3

A double-faced pressure-sensitive adhesive tape was produced in the same manner as in Example 1, except that a corona treatment was applied to both surfaces of a polyethylene film (manufactured by Tama Polys, product name "A-1" Respectively.

Example  4

In Example 1, an ethylene-vinyl acetate copolymer (manufactured by Sumitomo Chemical Industries, Ltd., product name: "EVATATE D2045", olefin-based monomer unit: 95% by mass) , And corona treatment was applied to both sides, the same procedures as in Example 1 were carried out to produce a double-sided pressure-sensitive adhesive tape.

Comparative Example  One

A double-faced pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that the coating liquid 3 for forming a pressure-sensitive adhesive was used instead of the coating liquid 1 for forming a pressure-sensitive adhesive.

Comparative Example  2

A double-faced pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that the coating liquid 4 for forming a pressure-sensitive adhesive was used instead of the coating liquid 1 for forming a pressure-sensitive adhesive.

Comparative Example  3

The same procedure as in Example 1 was carried out except that a black polyolefin foam having a thickness of 100 占 퐉 (manufactured by Sekisui Chemical Co., Ltd., trade name "Vorala") was used as the core film in Example 1, A double-sided pressure-sensitive adhesive tape was produced.

Comparative Example  4

A double-faced pressure-sensitive adhesive tape was produced in the same manner as in Example 1, except that a polyethylene terephthalate (PET) film having a thickness of 100 탆 (product name: "Lumirra T-60"

Comparative Example  5

The coating liquid 1 for forming a pressure-sensitive adhesive was coated on the release-treated surface of a heavy-duty recycled sheet (trade name: SP-PET3811, manufactured by LINTEC CO., LTD.) So as to have a thickness of 50 mu m after drying using a knife coater, After heat-drying for about 2 minutes to thermally crosslink, a light-releasing sheet (trade name "SP-PET381031" manufactured by LINTEC CO., LTD.) Was bonded. Subsequently, three pieces of the obtained pressure-sensitive adhesives were bonded to each other to produce a double-sided pressure-sensitive adhesive tape. For the 5% tensile stress and the lubrication of Comparative Example 5, the middle layer of the three sheets was regarded as core material.

The evaluation results of various properties of the double-faced pressure-sensitive adhesive tapes produced in Examples 1 to 4 and Comparative Examples 1 to 5 are shown in Table 1 below.

The double-faced pressure-sensitive adhesive tape of the present invention is a laminate formed by forming a pressure-sensitive adhesive layer on both sides of a core material, and is preferably used as a member for fixing members in mobile products such as cellular phones and touch panels, , Adhesiveness and water resistance, and can be used as waterproofing or the like in a portable information terminal with a narrow frame-like width.

1a: transparent acrylic plate 1b: transparent acrylic plate
2: frame-shaped laminate member 3: cross-shaped black printing
10: Double-sided adhesive tape 11: Stainless steel plate having holes
12: An acrylic plate having an ink layer on the double-sided adhesive tape side
13: pushing direction 14: ink layer

Claims (9)

A double-sided pressure-sensitive adhesive tape comprising a laminate having a core material and two pressure-sensitive adhesive layers provided on both sides of the core material,
(a) the core has a 5% tensile stress of 3 to 100 N and a stiffness (gauze method) of more than 0 and less than 0.2 mN,
(b) the two pressure sensitive adhesive layers each comprise 1 to 60 parts by mass of a (meth) acrylic acid ester copolymer and 100 parts by mass of the copolymer, and a pressure-sensitive adhesive composition comprising a crosslinking agent, , And
And is formed by punching in the form of a frame having a width of 0.1 to 2 mm and is used for fixing in the portable information terminal machine
Sensitive adhesive tape The double-faced pressure-sensitive adhesive tape according to claim 1, wherein the core is a film formed by using an olefin-based polymer having 60 to 100 mass% of an olefin-based monomer unit. The double-faced pressure-sensitive adhesive tape according to claim 2, wherein the olefinic polymer is at least one of ethylene-methacrylic acid copolymer and ethylene-vinyl acetate copolymer. The double-faced pressure-sensitive adhesive tape according to any one of claims 1 to 3, wherein the core has a thickness of 2 to 400 탆 and the thickness of the two pressure-sensitive adhesive layers is 2 to 80 탆. delete delete delete The double-faced pressure-sensitive adhesive tape according to any one of claims 1 to 3, which is used for waterproofing. A touch-panel-equipped display device characterized in that a housing body is fixed by the double-faced pressure-sensitive adhesive tape according to any one of claims 1 to 3.

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