KR20220038544A - Adhesive tape and manufacturing method thereof - Google Patents

Abstract

The problem to be solved by the present invention is that the bubble escapes quickly from the interface with the adherend, and it is possible to prevent the bubbles from remaining at the interface, and it is also excellent in adhesiveness and cushioning property, and is a thin adhesive tape at low cost. is to provide This invention is an adhesive tape which has two or more adhesive parts (B) on the foam layer (A), a resin film layer (C), and a resin film (C) side, Comprising: An adhesive part is provided between the said two or more adhesive parts (B). (B) there is a region without the adhesive tape, wherein the region runs through the end of the adhesive tape.

Description

Adhesive tape and its manufacturing method TECHNICAL FIELD

The present invention relates to, for example, an adhesive tape having a foam layer that can be used in a manufacturing scene of an electronic device or the like.

Since the adhesive tape is excellent in workability|operativity and adhesive reliability is also high, it is widely used, for example in the manufacturing scene of electronic devices, such as an OA apparatus and a household appliance.

Recently, electronic devices, particularly PCs, digital video cameras, electronic notebooks, mobile phones, PHS, smart phones, game devices, and electronic books are required to be miniaturized and thinned. In addition, thickness reduction is calculated|required also from the adhesive tape etc. which comprise.

In general, in the display device as described above, an adhesive tape having a cushioning foam layer is attached to the back surface of the display in many cases for the purpose of preventing cracking or pulling of the display (the phenomenon of waving light and shade of liquid crystal) (patent). Literature 1).

However, since the adhesive tape with the said foaming layer was very flexible, at the time of attachment, it attracted air|bubble and wrinkles were produced in many cases. In particular, when laminating several minutes after aligning a position with a press machine at the time of attachment, the said subject was remarkably generate|occur|produced.

Japanese Patent Laid-Open No. 2004-309699

The problem to be solved by the present invention is that the air bubbles escape from the interface with the adherend quickly, and it is possible to prevent the air bubbles from remaining at the interface, and it has excellent adhesion and cushioning properties, and is a thin adhesive at low cost. tape is provided.

The present inventors are an adhesive tape which has two or more adhesive parts (B) on the foam layer (A), a resin film layer (C), and a resin film (C) side, Comprising: Between said two or more adhesive parts (B), an adhesive part The above-mentioned problem was solved by the adhesive tape characterized in that there exists a region which does not have (B), and the said area|region runs through the edge part of the said adhesive tape.

In the adhesive tape of the present invention, air bubbles escape quickly from the interface with the adherend, the air bubbles hardly remain at the interface, and the adhesive tape is thin and has excellent cushioning properties and adhesive force. Therefore, the adhesive tape of this invention can prevent the crack and pulling of a display, without reducing the productive efficiency of a final product or its components. Therefore, the adhesive tape of this invention can be used suitably for adhesion|attachment with respect to the non-display surface side of the display of a display apparatus, for example.

BRIEF DESCRIPTION OF THE DRAWINGS It is the top view which looked at the adhesive tape which has a substantially rhombus-shaped adhesive part from the adhesive part side.
Fig. 2 is a top view of an adhesive tape having a substantially circular adhesive part as viewed from the adhesive part side.
Fig. 3 is a top view of an adhesive tape having a substantially hexagonal adhesive portion viewed from the adhesive portion side.
Fig. 4 is a top view of an adhesive tape having a substantially rectangular adhesive portion as viewed from the adhesive portion side.
5 is a top view of the surface having an adhesive portion of the adhesive tape obtained in Example 20;
6 is a schematic diagram showing a method for producing a polyurethane foam laminate of the present invention.

(adhesive tape)

The adhesive tape of this invention is an adhesive tape which has two or more adhesive parts (B) on the foam layer (A), a resin film layer (C), and a resin film (C) side, Comprising: Between the said two or more adhesive parts (B) is characterized in that there is a region having no adhesive portion (B), said region passing through the end of the adhesive tape.

As a specific embodiment of the adhesive tape of this invention, the foam layer (A), the resin film layer (C), the single-sided adhesive tape which has two or more adhesive parts (B) on the resin film (C) side, and also a foam layer (A) The double-sided adhesive tape which has an adhesive layer also on the side is mentioned. Moreover, you may provide intermediate|middle layers, such as a metal foil layer, between a resin film layer and a foaming layer (A), or between a resin film (C) and an adhesion part (B).

Between the two or more adhesive portions (B), there is a region in which the component constituting the adhesive portion (B) does not exist or may exist to such an extent that adhesiveness is not exhibited. Therefore, when the adhesive tape of this invention is observed from the side direction, it is observed that the said adhesive part (B) forms convex shape with respect to the said resin film (C) surface.

Moreover, the adhesive tape of this invention has a structure in which the area|region which does not have the adhesive part (B) between the said two or more adhesive parts (B) passes through a part of the edge part (outer edge part) of an adhesive tape. By using the adhesive tape having the above configuration, when the adhesive tape is adhered to the adherend, air bubbles escape from the interface between the adhesive tape and the adherend through the region to the outside, so the appearance due to swelling of the adhesive tape, etc. Defects can be prevented, and excellent cushioning properties, adhesive strength, and the like can be maintained.

As the adhesive tape of the present invention, it is preferable to use a thing with a total thickness of 300 μm or less, more preferably to use a thing of 30 μm to 250 μm, still more preferably to use a thing of 50 μm to 200 μm, and to use a thing of 50 μm to 100 μm , for example, it is particularly preferable in contributing to the reduction in thickness of a portable electronic terminal or the like. In addition, the total thickness of the adhesive tape refers to the thickness of the adhesive tape measured by a method using a dial gauge according to JIS K6250, under the condition that the contact surface of the dial gauge is flat, the diameter is 8mm, and the load is 0.51N, It does not include the thickness of the release liner. The thickness can be measured, for example, with a thickness meter FFG-6 manufactured by Ozaki Corporation.

As the adhesive tape of the present invention, it is preferable to use a thing having an adhesive force of 1N/20mm to 12N/20mm, more preferably to use a thing having an adhesive force of 1.5N/20mm to 10N/20mm, 3N/20mm to 8N It is thin to use a thing having an adhesive force of /20 mm, and even if a hole or the like is not formed in a part, air bubbles are easily removed from the interface between the adherend and the adhesive tape, and the adhesive tape has excellent adhesive strength It is preferable to obtain On the other hand, when further excellent adhesiveness is required, as the adhesive tape, it is more preferable to use one having an adhesive force of 4N/20mm to 10N/20mm, and one having an adhesive force of 4.5N/20mm to 8N/20mm It is more preferable to use

In addition, the said adhesive force points out the value measured according to JISZ0237. Specifically, the adhesive force is, the surface having the adhesive portion (B) of the adhesive tape overlapped with a clean and smooth stainless steel plate (BA plate), and the upper surface of the adhesive tape is pressed by one reciprocating using a 2 kg roller, 23 It is a value measured by peeling off the said adhesive tape at a speed of 0.3 m/min in a 180 degree direction after leaving to stand for 1 hour under conditions of ℃ and 50%RH.

As the adhesive tape of the present invention, even if it is thin, it is possible to prevent peeling over time due to the repulsive force of the adherend or the foam layer (A) or dropping of parts, etc. Therefore, it is preferable to use a holding force of 2 mm or less, more preferably using a 0.5 mm or less thing, and more preferably using a 0.1 mm or less thing.

In addition, the said holding force points out the value measured according to JISZ0237. Specifically, the holding force is that the surface having the adhesive portion (B) of the adhesive tape is superimposed on a clean and smooth stainless steel plate (hairline), and the upper surface is pressed by reciprocating one by using a 2 kg roller, 23 Let it stand for 1 hour under the conditions of °C and 50%RH as a test piece. Next, under an environment of 100 ° C., the stainless plate constituting the test piece is fixed in the vertical direction, and a load of 100 g is applied to the lower end of the adhesive tape constituting the test piece and left for 24 hours. It is a value obtained by measuring the shift|offset|difference distance of an adhesive tape with a noggis.

(Adhesive part B)

First, the adhesive part (B) which comprises the adhesive tape of this invention is demonstrated.

The adhesive portion (B) is provided on the resin film (C) directly or through another layer. Between the two or more adhesive portions (B), there is a region in which the component constituting the adhesive portion (B) does not exist or may exist to such an extent that adhesiveness is not exhibited.

Although the thickness of the said adhesive part (B) is not specifically limited, 0.5-30 micrometers is preferable, More preferably, it is preferable that it is 1-10 micrometers, Most preferably, it is 2-5 micrometers.

Moreover, the area|region which does not have the adhesive part (B) between the said two or more adhesive parts (B) has a structure through which part of the edge part (outer edge part) of an adhesive tape passes. By using the adhesive tape having the above configuration, even when no holes or the like are formed in a part of the adhesive tape, when the adhesive tape is adhered to the adherend, air bubbles can be easily removed from the interface thereof. It prevents appearance defects caused by swelling, etc., and can also maintain excellent thermal conductivity (heat dissipation) and adhesion.

When the adhesive tape of this invention is observed from the one side (a) side of the said resin film (C), it is preferable that the shape of the said adhesive part (B) is a substantially rectangular shape, a substantially hexagonal shape, or a substantially circular shape etc. It is preferable to have a substantially circular shape because the bubbles can easily escape from the interface with the adherend (air escape property) and good adhesive force can be maintained.

Although the substantially circular shape is not specifically limited, It is preferable that the ratio [maximum diameter/minimum diameter] of the maximum diameter and minimum diameter of any one adhesive part is 1-4. More preferably, it is 1-2, Most preferably, it is 1-1.5. As an example of a substantially circular shape, the shape like FIG. 5 is mentioned. Although the adhesive parts of the said shape are each independent basically, there may exist a location where two or more adhesive parts are partially connected as shown in FIG.

Examples of the substantially rectangular shape include a shape such as a substantially square, a substantially rectangular, a substantially trapezoid, and a substantially rhombic shape, and a substantially rhombic shape allows air bubbles to easily escape from the interface with the adherend (air escape property), and It is preferable because good adhesion can be maintained.

In addition, when a release liner etc. are adhered to the surface of the adhesive part (B), or when an adhesive tape is wound on a roll, "approximately", such as the said substantially rectangular shape and a substantially hexagonal shape, said adhesive part By pressing (B), it shows that the rectangular and hexagonal corners include a rounded shape and a shape in which a straight line portion is a curved portion.

The substantially rectangular corner portion is preferably in a substantially rhombus shape in which the angle of the corner portion toward the flow direction of the adhesive tape is less than 90°, and in the range of 45° to 70°, air bubbles easily escape from the interface with the adherend. (Air leaking property) and since favorable adhesive force can be maintained, it is more preferable.

Moreover, it is preferable that the arbitrary adhesive parts (b1) and the adhesive part (b2) which comprise the said two or more adhesive parts (B) do not face in front with respect to the flow direction and the width direction of an adhesive tape.

Moreover, the said adhesive tape is cut into arbitrary shapes according to a use etc. and is used in many cases. At that time, since the adhesive portion (b1) and the adhesive portion (b2) are arranged not to face each other in the flow direction and the width direction, when the adhesive tape is cut at an arbitrary position, a part of the end portion Since the adhesive part (B) will exist, it becomes possible to suppress peeling of an adhesive tape.

In addition, the long diameter of the contact area r2 of the adhesive part b1 and the release liner attached to the surface of the adhesive part b1 with respect to the long diameter of the contact area r1 of the adhesive part (b1) and the support body measured by the above method It is preferable that the ratio [the long diameter of the contact region r2 / the long diameter of the contact region r1] x 100 is 97% to 110%, and when it is in the range of 97% to 105%, the bubbles are removed from the interface with the adherend. It is easy to come off, and it is more preferable in order to make compatible the further outstanding adhesiveness.

In the adhesive tape of the present invention, among all the adhesive parts provided on the surface of the support, the ratio of the adhesive part (b1) satisfying the requirement of the ratio [contact area (s2)/contact area (s1)] x 100 is It is preferable to use a thing of 50%-100%, it is more preferable to use a thing of 80%-100%, it is still more preferable to use a thing of 90%-100%, and using a thing of 95%-100% This is particularly preferable for maximizing the effects of the present invention.

The distance between the optional adhesive part (b1) selected from the two or more adhesive parts (B) and the adhesive part (b2) adjacent to the adhesive part (b1) is preferably 0.5 mm or less, more preferably 0.05 mm~ It is 0.2 mm, more preferably 0.06 mm to 0.15 mm, and 0.08 mm to 0.13 mm makes it easy for air bubbles to escape from the interface with the adherend even if a hole or the like is not formed in a part of the adhesive tape (air leakage). ), and it is particularly preferable because good adhesion can be maintained.

The size of one optional adhesive part (b1) selected from the adhesive part (B) is preferably 0.001 mm ² to 100 mm ² in area, more preferably 0.01 mm ² to 25 mm ² , and more preferably 0.015 mm ² to It is more preferable that it is 16 mm ² , and when it is 0.02 mm ² to 5 mm ² , bubbles easily escape from the interface with the adherend even when a hole or the like is not formed in a part of the adhesive tape (air escape property), and good It is especially preferable because adhesive force can be maintained.

The adhesive portion (B) of the present invention, in the range of the area (a square of 5 cm in the flow direction and 5 cm in the width direction) of the adhesive tape of the present invention, it is preferable to exist 10 to 100000 pieces, more preferably 1000 to 50000 pieces Preferably, if there are 5000 to 40,000 pieces, even if no holes are formed in a part of the adhesive tape, air bubbles easily escape from the interface with the adherend (air escape property), and good adhesion can be maintained. Therefore, it is particularly preferable.

In addition, in the above-mentioned adhesive tape, air bubbles easily escape from the interface with the adherend at the time of attachment (air-repellent property), good adhesive strength can be maintained, and even when an adherend such as a graphite sheet is further thinned, the adhesive portion From the viewpoint of effectively preventing the appearance defect due to the shape, it is preferable to use one having 120 to 2000 adhesive parts in the range of a predetermined area (a square of 1 cm in the flow direction and 1 cm in the width direction) of the adhesive tape, and 280 It is more preferable to use a thing having ~1600 adhesive parts, and it is still more preferable to use a thing having 520 to 1200 adhesive parts.

In addition, the number of said adhesive parts can all be calculated|required by observing and counting an arbitrary range (a square of flow direction 1 cm and width direction 1 cm) or (a square of flow direction 5 cm and width direction 5 cm) of an adhesive tape with an electron microscope. .

It is preferable that the ratio of the area|region which has the said adhesion part (B) to the area of the said one side (a) is 10 % - 99 %. More preferably, it is 20% to 90%, More preferably, it is 30% to 80%, Most preferably, it is 35% to 80%. Those within the above range can form a substantially circular adhesive portion to be described later, and as a result, air bubbles are easy to escape from the interface with the adherend even when no holes are formed in a part of the adhesive tape (air leaking property); Moreover, since it can produce efficiently the adhesive tape which can maintain good adhesive force, it is especially preferable. In addition, the ratio of the said area|region is the area ratio of the said adhesive part (B) in the area of the square tape of 5 cm in a flow direction and 5 cm in a width direction.

The peak temperature of the 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, and -20°C to 10°C It is more preferable that the temperature is -10°C to 5°C, so that air bubbles easily escape from the interface with the adherend (air leaking property), and good adhesion can be maintained, as a result, due to swelling of the adhesive tape It is more preferable because it is possible to more effectively prevent deterioration in appearance, thermal conductivity (heat dissipation), heat resistance, adhesive strength, and the like.

In the dynamic viscoelasticity measurement, a viscoelasticity tester (manufactured by Rheometrics, trade name: Ares 2KSTD) is used, and the test piece is sandwiched between parallel disks that are measurement parts of the tester, and the storage modulus (G') and loss modulus at a frequency of 1 Hz (G") is measured. The loss tangent is calculated by the expression tan ? = (G")/(G'). The peak temperature refers to the peak temperature confirmed by the spectrum of tanδ for the measurement temperature range (-50°C to 150°C).

As said test piece, the adhesive layer of thickness 0.5mm - 2.5mm formed using the adhesive used for formation of the said adhesive part (B) can be used.

Moreover, as said test piece, among those which laminated|stacked the adhesive tape of this invention in multiple, the thing whose total thickness of an adhesive layer is 0.5 mm - 2.5 mm can be used. When the test piece of the said different structure is used, the said tan-delta value changes, but when the total thickness of the said adhesive layer (B) occupied in the said test piece is the same, the said peak temperature does not change substantially. Therefore, in the measurement of the said peak temperature, you may use any test piece.

As said adhesive part (B), it is preferable to use what has a gel fraction of 10 mass % - 60 mass %, It is more preferable to use what has a gel fraction of 20 mass % - 55 mass %, 30 mass % Even if it is thin to use a gel having a gel fraction of ~50% by mass, the surface shape of the adhesive portion (B) is easily maintained, so it is easy to prevent changes over time, and the interface between the adherend and the adhesive portion (B) Air bubbles can be easily removed from the duct, and as a result, poor appearance due to swelling of the adhesive tape, thermal conductivity (heat dissipation), deterioration in performance such as heat resistance, and adhesive force can be more effectively prevented, which is more preferable. In addition, the said gel fraction points out the value measured by the following method.

In addition, the said gel fraction points out the value measured by the method shown below.

(1) The adhesive layer coated with the adhesive on the release-treated surface of the release liner (D) so that the thickness after drying becomes 50 μm, dried in an environment of 100° C. for 3 minutes, and then aged under an environment of 40° C. for 2 days. was formed.

(2) What cut the said pressure-sensitive adhesive layer into a square having a length of 50 mm and a width of 50 mm was used as a test piece.

(3) After measuring the mass (G1) of the said test piece, the said test piece was immersed in toluene in 23 degreeC environment for 24 hours.

(4) After the said immersion, the mixture of the said test piece and toluene was filtered using a 300 mesh wire mesh, and the insoluble component with respect to toluene was extracted. The mass (G2) of what dried the said insoluble component in 110 degreeC environment for 1 hour was measured.

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

Gel fraction (% by mass)=(G2/G1)×100

As the adhesive portion (B), it is preferable to use a thing with a thickness of 1 μm to 6 μm, and to use a thing with a thickness of 2 μm to 5 μm, air bubbles can be easily removed from the interface between the adherend and the adhesive portion (B), As a result, it is more preferable because it is possible to more effectively prevent poor appearance due to swelling of the pressure-sensitive adhesive tape, and deterioration in performance such as thermal conductivity, heat resistance, and adhesive strength. In addition, the thickness of the adhesive part (B) is, according to JIS K6783, a method using a dial gauge. The thickness of the double-sided adhesive tape measured under the condition that the contact surface of the dial gauge is flat, the diameter is 5mm, and the load is 1.23N. points to

The adhesive part (B) is, for example, an acrylic adhesive, a rubber adhesive, a silicone adhesive, a urethane adhesive, a polyester adhesive, a styrene-diene block copolymer adhesive, a vinyl alkyl ether adhesive, a polyamide adhesive, a fluorine adhesive, It can be formed using well-known adhesives, such as a creep property improvement type adhesive and a radiation-curing type adhesive. Especially, as said adhesion part (B), since it is excellent in adhesive reliability, it is preferable to use the adhesion part obtained using an acrylic adhesive.

When using the adhesive tape of the present invention having an adhesive part or an adhesive layer on both sides of the foam layer, the adhesive part or the adhesive layer has a different composition or gel fraction even if the adhesive part or the adhesive layer has the same composition or gel fraction. may be used.

As said acrylic adhesive, the thing containing an acrylic polymer can be used.

As said acrylic polymer, what is obtained by superposing|polymerizing the monomer component containing (meth)acrylic monomers, such as (meth)acrylic-acid alkylester, can be used.

As said (meth)acrylic acid alkylester, (meth)acrylate methyl, (meth)acrylate, (meth)acrylic acid propyl, (meth)acrylate isopropyl, (meth)acrylate butyl, (meth)acrylate isobutyl, for example, , (meth) acrylate s-butyl, (meth) acrylate t-butyl, (meth) acrylate pentyl, (meth) acrylate hexyl, (meth) acrylate heptyl, (meth) acrylate octyl, (meth) acrylate 2-ethylhexyl, (meth) acrylate isooctyl, (meth) acrylate nonyl, (meth) acrylate isononyl, (meth) acrylate decyl, (meth) acrylate isodecyl, (meth) acrylate undecyl, (meth) acrylate dodecyl, (meth) ) Tridecyl acrylate, (meth)acrylic acid tetradecyl, (meth)acrylic acid pentadecyl, (meth)acrylic acid hexadecyl, (meth)acrylic acid heptadecyl, (meth)acrylic acid octadecyl, (meth)acrylic acid nonadecyl, (meth)acrylate Acrylic acid eicosyl, etc. can be used individually or in combination of 2 or more types. Among them, as the (meth)acrylic acid alkyl ester, it is preferable to use (meth)acrylic acid alkylester having 1 to 20 carbon atoms in the alkyl group, and (meth)acrylic acid alkyl ester having 4 to 18 carbon atoms in the alkyl group. It is more preferable to use A straight-chain or branched alkyl group is mentioned as said alkyl group.

As the (meth)acrylic acid alkylester having 4 to 18 carbon atoms in the acrylic group, using butyl (meth)acrylate is easy to maintain the surface shape of the pressure-sensitive adhesive layer (B), so it is easy to prevent changes with time In order to obtain an adhesive tape which is easy to escape from the interface with a to-be-adhered body (air leak property), and can also maintain favorable adhesive force, it is preferable.

As said (meth)acrylic monomer, the monomer which has carboxyl groups, such as (meth)acrylic acid, itaconic acid, a maleic acid, a fumaric acid, a crotonic acid, an isocrotonic acid, or its anhydride other than what was mentioned above; a monomer having a sulfonic acid group such as sodium vinylsulfonate; a monomer having a cyano group such as acrylonitrile; a monomer having an amide group, such as acrylamide, methacrylamide, N-vinylpyrrolidone, and N,N-dimethyl (meth)acrylamide; Monomers which have hydroxyl groups, such as (meth)acrylic-acid hydroxyalkyl and glycerol dimethacrylate; Monomers which have amino groups, such as (meth)acrylic-acid aminoethyl and (meth)acryloylmorpholine; Monomer which has imide groups, such as cyclohexyl maleimide and isopropyl maleimide; Monomer which has epoxy groups, such as (meth)acrylic-acid glycidyl and (meth)acrylic-acid methylglycidyl; Monomers having an isocyanate group such as 2-methacryloyloxyethyl isocyanate, triethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, tetraethylene glycol di ( Meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipenta Monomers, such as erythritol hexa (meth)acrylate and divinylbenzene, can be used individually or in combination of 2 or more types.

Moreover, as said monomer, besides the said (meth)acryl monomer, 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 can also be used.

The acrylic polymer can be produced by polymerizing the monomers by a method such as a solution polymerization method, a bulk polymerization method, a suspension polymerization method, an emulsion polymerization method, etc., and employing the solution polymerization method improves the production efficiency of the acrylic polymer It is preferable to do

Examples of the solution polymerization method include a method of radical polymerization by mixing and stirring the monomer, the polymerization initiator, and the organic solvent at a temperature of preferably 40°C to 90°C.

Examples of the polymerization initiator include peroxides such as benzoyl peroxide and lauryl peroxide, azo thermal polymerization initiators such as azobisisobutylnitrile, acetophenone-based photopolymerization initiators, benzoin ether-based photopolymerization initiators, benzylketal-based photopolymerization initiators, An acylphosphine oxide type photoinitiator, a benzoin type photoinitiator, a benzophenone type photoinitiator, etc. can be used.

The acrylic polymer obtained by the said method may be in the state melt|dissolved or disperse|distributed in the organic solvent, if it is a case where it manufactures by the solution polymerization method, for example.

As an acrylic polymer obtained by the said method, it is preferable to use what has a weight average molecular weight of 300,000-1,200,000, It is more preferable to use what has a weight average molecular weight of 400,000-1,100,000, and it is a weight average of 500,000-1 million. It is preferable to use what has molecular weight, even if it is thin, when obtaining the still more excellent adhesive force and the adhesive tape provided with the ease of removal of a bubble.

In addition, the said weight average molecular weight is measured by the gel permeation chromatography method (GPC method), and points out the value computed by standard polystyrene conversion. Specifically, the said weight average molecular weight can be measured on condition of the following using the Tosoh Corporation GPC apparatus (HLC-8329GPC).

Sample concentration: 0.5% by mass (tetrahydrofuran solution)

Sample injection volume: 100μl

Eluent: tetrahydrofuran

Flow rate: 1.0ml/min

Measuring temperature: 40℃

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 million (manufactured by Tosoh Corporation)

As an adhesive which can be used for formation of the said adhesive part (B), in forming the adhesive part provided with the more outstanding adhesive force, tensile strength, and tensile breaking strength, it is preferable to use the thing containing tackifying resin.

Examples of the tackifying 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-based tackifying resin, and disproportionated rosin ester-based tackifying resin. Petroleum resin-based tackifying resins, such as tackifying resin, hydrogenated rosin ester-type tackifying resin, terpene-type tackifying resin, terpene-phenol-type tackifying resin, and styrene-type tackifying resin, etc. can be used.

As said tackifying resin, when it is thin to use combining rosin-type tackifying resin and petroleum resin-type tackifying resin, it is preferable when obtaining the still more excellent adhesive force and the adhesive tape provided with bubble removal easiness. The rosin-based tackifying resin and the petroleum resin-based tackifying resin are particularly preferably used in combination with the acrylic polymer, and used in combination with an acrylic polymer obtained by polymerizing a monomer containing butyl (meth)acrylate is thin. It is preferable when obtaining the adhesive tape provided with the still more outstanding adhesive force and the ease of removal of a bubble even if it continues.

Moreover, as said tackifying resin, when improving further the initial stage adhesive force of the said adhesion part (B), it is preferable to use liquid tackifying resin at normal temperature. As a liquid tackifying resin at normal temperature, low molecular weight liquid rubbers, such as process oil, a polyester plasticizer, and polybutene, are mentioned, for example, A terpene phenol resin can be used, As a commercial item, YP made by Yasuhara Chemicals Co., Ltd. -90L etc. are mentioned.

It is preferable to use the tackifying resin in the range of 20 parts by mass to 60 parts by mass, and use in the range of 30 parts by mass to 55 parts by mass, with respect to 100 parts by mass of the acrylic polymer, which has even more excellent adhesion. In obtaining an adhesive tape, it is more preferable.

Moreover, as an adhesive which comprises the said adhesive part (B), the thing containing a softener, a plasticizer, a filler, an antioxidant, a coloring agent, etc. other than the said acrylic polymer etc. as needed can be used.

Among them, the use of a crosslinking agent can adjust the gel fraction of the adhesive part (B) to a suitable range, and as a result, it is easy to maintain the shape of the adhesive part (B), so it is easy to prevent changes with time , it is preferable because it is possible to easily remove air bubbles from the interface between the adherend and the pressure-sensitive adhesive layer (B) and to obtain an adhesive tape having excellent adhesive strength.

As said crosslinking agent, it is preferable to use an isocyanate crosslinking agent or an epoxy crosslinking agent, for example.

As the isocyanate crosslinking agent, for example, tolylene diisocyanate, naphthylene-1,5-diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, trimethylolpropane modified tolylene diisocyanate, etc. can be used. In addition, it is preferable to use toluene diisocyanate adducts such as tolylene diisocyanate and trimethylolpropane modified tolylene diisocyanate. The said toluene diisocyanate adduct has a structure derived from toluene diisocyanate in a molecule|numerator, and speaking of a commercial item, for example, Coronate L (made by Nippon Polyurethane Industry Co., Ltd.) etc. are mentioned.

When using the said isocyanate crosslinking agent, it is preferable to use the acrylic polymer which has a hydroxyl group as said acrylic polymer. The acrylic polymer having a hydroxyl group is a monomer used in the production thereof, for example, 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylic acid, etc. It can be used, and it is more preferable to use 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate.

As the epoxy crosslinking agent, for example, Tetrad X or Tetrad C manufactured by Mitsubishi Gas Chemical Co., Ltd., or E-05X manufactured by Soken Chemical Co., Ltd. can be used.

When using the said epoxy crosslinking agent, it is preferable to use the acrylic polymer which has an acidic radical as said acrylic polymer. For the acrylic polymer having an acid group, it is preferable to use, for example, (meth)acrylic acid, acrylic acid dimer, itaconic acid, crotonic acid, maleic acid, maleic anhydride, etc. as a monomer used for the production thereof, (meth) It is more preferable to use acrylic acid.

As an adhesive which can be used for formation of the said adhesive part (B), it is preferable to use what contains a solvent as needed. As said adhesive, it is preferable to use the thing whose viscosity was adjusted in the range of 0.1 mPa*s - 1000 mPa*s, It is more preferable to use the thing adjusted in the range of 1 mPa*s - 200 mPa*s, 10 mPa* It is more preferable to use the thing adjusted to the range of s - 100 mPa*s, since it is easy to form the adhesive part (B) of a predetermined shape.

(resin film layer (C))

Next, the resin film layer (C) which comprises the adhesive tape of this invention is demonstrated.

As a resin film layer (C), a polyester film, a polyimide film, a polyolefin film, a polyamide film, a polyurethane film, etc. can be used. Among them, a polyethylene terephthalate film having excellent heat resistance and strength and low cost is most preferred.

As thickness of a resin film layer (C), it is preferable that it is 1-100 micrometers. More preferably, it is 1.5-50 micrometers, and since it is thin and does not reduce cushioning property that it is 1.5-6 micrometers, it is preferable.

(Releasable Liner (D))

The adhesive tape of this invention may have a peeling liner (D) on the surface in contact with the said adhesive part (B).

The release liner (D) is a resin film coated with a release agent. As a resin film, a polyester film, a polyimide film, a polyolefin film, etc. can be used. Especially, since a polyethylene terephthalate film has favorable heat resistance and intensity|strength and low cost, it is preferable. Although the thickness of a resin film is not specifically limited, 25 micrometers - 100 micrometers are preferable, More preferably, they are 50 micrometers - 100 micrometers. When it exists in the said range, when forming a foam layer (A), since it is hard to generate|occur|produce nonuniformity of a foam layer, it is preferable.

Although a release agent is not specifically limited, Since it is easy to adjust peeling force, it is preferable that it is silicone type.

(foam layer (A))

The thickness of the foam layer (A) constituting the adhesive tape of the present invention is not particularly limited, but preferably 250 μm or less, more preferably 30 μm to 200 μm, still more preferably 50 μm to 100 μm. there is. By using the foam layer (A) which has the thickness of the said range, an adhesive tape can be made thin. Moreover, even when a hole or the like is not formed in a part of the adhesive tape, air bubbles can be easily removed from the interface between the surface having the adhesive portion (B) and the adherend, as a result of which the adhesive tape swells. It is more preferable because it is possible to more effectively prevent deterioration in appearance, such as poor appearance and cushioning properties and adhesive strength.

As said foam layer (A), it is preferable to use the thing of 0.003 MPa - 1 MPa by 50% compressive strength, It is more preferable to use the thing of 0.01 MPa - 0.5 MPa, It is more preferable to use the thing of 0.02 MPa - 0.4 MPa desirable. It is especially preferable to use the thing of the said range in obtaining the adhesive tape provided with cushioning property and suitable followability|trackability with respect to a to-be-adhered body.

As the foam layer (A), for example, a sheet-like thing made of a foamed resin can be used, and a resin film (C) coated with a foam layer (A) can also be used, and the resin film (C) and adhesion What coated the foam layer (A) on the thing in which the part (B) and the release liner (D) were integrated can also be used. Among them, it is particularly preferable to use one in which the foam layer (A) is coated on the one in which the resin film (C), the pressure-sensitive adhesive portion (B) and the release liner (D) are integrated, as it is easy to form a thin and flexible foam layer. Do.

Examples of the foam layer (A) include polyolefin-based foams, polyurethane-based foams, acrylic rubbers and other elastomers containing polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, etc. A rubber-based foam or the like can be used. Especially, as said foam layer (A), the thing of the polyurethane type which is thin and easy to form a flexible foam layer is especially preferable.

The polyurethane foam layer is formed by mixing a raw material containing polyisocyanate and polyol and a gas to form a gas-liquid mixture, supplying the obtained gas-liquid mixture on a resin film, and then heating the gas-liquid mixture to react the raw material is obtained

As a raw material of a polyurethane foam layer, it is a composition containing polyisocyanate and a polyol, and the following other component is included as needed.

The polyisocyanate is not particularly limited, and a polyisocyanate conventionally used for producing a polyurethane foam may be used. As this polyisocyanate, 4,4'- diphenylmethane diisocyanate, tolylene diisocyanate, etc. are used normally. In addition to these, 1,6-hexamethylene diisocyanate, 1,5-naphthalene diisocyanate, paraphenylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, hexa Aromatic or aliphatic polyisocyanates, such as methylene diisocyanate and isophorone diisocyanate, polyisocyanate of a prepolymer type, etc. can also be used. The said polyisocyanate may use together 2 or more types, and may use individually by 1 type.

Polyisocyanate is mix|blended so that an isocyanate index becomes like this. Preferably it is 0.8-1.2, Especially preferably, it becomes 0.9-1.1.

The polyol is not particularly limited, and a polyol conventionally used in the production of a polyurethane foam may be used. Specifically, polyether polyol, polyester polyol, polyether ester polyol which is a copolymer of polyether polyol and polyester polyol, etc. can be used. Moreover, in order to improve tensile strength, a polymer polyol can also be used together. As this polymer polyol, for example, ethylenically unsaturated compounds, such as acrylonitrile, styrene, and methyl methacrylate, to polyether polyol, in conversion of solid content, Preferably it is 5-40 mass %, More preferably, it is 10-30 mass %. It is a polyol which carried out mass %, kraft polymerization.

The average molecular weight of the polyol is preferably 300 to 6000, more preferably 900 to 4000. One type may be used for the said polyol, and may use 2 or more types together.

As a raw material of the polyurethane foam layer other than the above, a catalyst, a foam stabilizer, a crosslinking agent, etc. are contained.

Examples of the catalyst include organotin compounds such as stannus octoate, dibutyltin diacetate and dibutyltin dilaurate, organozinc compounds such as zinc octylate, organic nickel compounds such as nickel acetylacetonate and nickel diacetylacetonate, iron Organic iron compounds such as acetylacetonate, alkali metal or alkaline earth metal alkoxides such as sodium acetate, and metal catalysts such as phenoxide, triethylamine, triethylenediamine, N-methylmorpholinedimethylaminomethylphenol, imidazole Tertiary amine catalysts, such as organic acid salt, etc. are mentioned. Among these, an organotin compound is especially preferable. One type of the said catalyst may be used and may use 2 or more types together. As content of the said catalyst, when a polyol is 100 mass parts, Preferably it is 0.03-3 mass parts. Especially preferably, it is 0.05-2.0 mass parts.

As the foam stabilizer, a silicone-based foam stabilizer is used. As this silicone-based foam stabilizer, a dimethylsiloxane-based compound, a polyetherdimethylsiloxane-based compound, a phenylmethylsiloxane-based compound, or the like can be used. One type of the said foam stabilizer may be used and may use 2 or more types together.

As content of the said foam stabilizer, when a polyol is 100 mass parts, Preferably it is 1-20 mass parts. Especially preferably, it is 2-10 mass parts.

Examples of the crosslinking agent include ester-based oligomers chain-extended with ε-caprolactone using ethylene glycol, trimethylolpropane, etc. as an initiator, a crosslinking agent with a high molecular weight such as trifunctional polyether polyol having a molecular weight of about 300 to 700, ethylene glycol, and short-chain diol-based crosslinking agents such as diethylene glycol, glycerin, and trimethylolpropane. By using a high molecular weight crosslinking agent, a more flexible foam layer can be obtained. One type of crosslinking agent may be used and may use 2 or more types together.

Although content of the crosslinking agent contained in the raw material of the said polyurethane-type foam layer depends on the type, when the polyol is 100 mass parts, Preferably it is 1-10 mass parts, Especially preferably, it is 2-5 mass parts.

Additives, such as a ultraviolet absorber, antioxidant, organic and inorganic filler, and a coloring agent, can be mix|blended with the said foam raw material as needed.

(Method for producing polyurethane foam layer)

The raw material for manufacturing a polyurethane foam layer is a gas-liquid mixture containing the foam raw material and base|substrate which have the said structure, and a resin film layer (C). The gas to be mixed with the foam raw material is not particularly limited, and nitrogen gas, inert gas, dry air, and the like may be used. Among these, nitrogen gas is preferable. Hereinafter, the manufacturing method of a polyurethane foam laminated body is demonstrated concretely using FIG.

The said foam raw material and gas are stirred using the mixer 11, and let it be the gas-liquid mixture 21a. Then, this gas-liquid mixture 21a is supplied so that it may be apply|coated on the resin film layer (C) 20, and then, on the surface of the gas-liquid mixture 21a to be cast, from the upper side, the release paper (or the resin film to which the process for release was made) 7 is supplied. And the thickness of the non-hardened layer 21b which consists of the gas-liquid mixture 21a is adjusted by passing the roll coater 12 etc. with this laminated|stacked state. In addition, although the release paper 7 is used regardless of whether or not the release paper 7 is used, it is easy to adjust the thickness of the uncured layer 21b, and the surface of the foam layer obtained after heat treatment (release paper 7 side) ) to form a skin layer. By these steps, a three-layer laminate in which the resin film C is provided on one surface side (lower surface) of the uncured layer 21b and the release paper 7 is laminated on the other surface side (upper surface) is obtained.

Thereafter, the laminate is heated by a heat treatment apparatus. Thereby, the foam raw material is made to react, the non-hardened layer 21b is hardened, and the polyurethane foam laminated body 30 in which the foam layer (A) was formed can be obtained. By this manufacturing method, the polyurethane foam layer (A) and the resin film layer (C) are firmly joined. The obtained laminated body 30 is a state of a three-layer structure, and may be wound on a paper tube or the like and made into a roll body. You can do it with a sieve. Moreover, it can also be cut into a predetermined size on a manufacturing line, and it can also be set as a sheet|seat. Next, these sheets may be stacked on top of each other and packed. Also in this case, the three layers may be superimposed on each other, or they may be superimposed as a two-layer laminate.

As described above, the raw materials for production of the polyurethane foam laminate are the gas-liquid mixture 21a obtained using the foam raw material and the base, and the resin film (C).

The method for preparing the foam raw material is not particularly limited, but preferably, polyisocyanate and a mixture that does not contain polyisocyanate and contains a polyol, a flame retardant, a catalyst, etc. (hereinafter referred to as “first mixture”). way to mix In addition, the additive mix|blended as needed is contained in 1st mixture normally.

The method for preparing the gas-liquid mixture 21a is not particularly limited, and when the volume ratio of the foam raw material and the gas is 100% by volume in total, preferably 5 to 30% by volume and 70 to 95% by volume, respectively. %, more preferably 8 to 25% by volume and 75 to 92% by volume, the foam raw material and the gas are mixed. By this mixing ratio, the gas-liquid mixture 21a suitable for formation of the foam layer which has the said specific density can be prepared. Moreover, although the mixer 11 used for mixing of a foam raw material and gas is not specifically limited, Preferably, an Ox mixer, a Hobart mixer, etc. are used. With these mixers 11, the foam raw material and the gas can be uniformly mixed, the control of the bubble formation is easy, and the bubbled gas-liquid mixture 21a can be produced as a more homogeneous thing.

The method of mixing the foam raw material and the gas is preferably a method of blowing gas into the foam raw material previously accommodated in a mixing chamber or the like, and a method of simultaneously supplying the foam raw material and the gas to this chamber. In these cases, the foam raw material may separately supply polyisocyanate and the first mixture to this chamber.

The foam layer using the gas-liquid mixture is preferably formed by a mechanical cross method. According to this method, the volume of the gas-liquid mixture to be used and the volume of the polyurethane foam obtained can be made substantially the same. Therefore, the density of the polyurethane foam can be adjusted by the composition of the gas-liquid mixture, that is, the amount of gas introduced into the raw material for the foam.

The gas-liquid mixture 21a is supplied to the surface of the resin film layer (C) 20, and then a release paper 7 is supplied to the surface of the flexible gas-liquid mixture 21a from the upper side, to be laminated. Next, the three-layer laminate is heated by a heat treatment device 13 set at a predetermined temperature to react the foam raw material contained in the uncured layer 21b to form a foam layer (A). .

The heating method of the three-layer laminate is not particularly limited, and is appropriately selected depending on the type of the heat treatment apparatus 13 and the like.

The heating temperature is appropriately selected according to the types of polyol and polyisocyanate, etc. in order to harden the foam raw material contained in the uncured layer 21b. This heating temperature becomes like this. Preferably it is 120 degreeC - 200 degreeC, Preferably it is 140 degreeC - 180 degreeC, Especially preferably, it is 150 degreeC - 170 degreeC.

Moreover, a heating time becomes like this. Preferably it is for 1 to 10 minutes, More preferably, it is for 1 to 5 minutes.

As the said heat processing apparatus 13, a heating furnace, a far-infrared irradiation apparatus, etc. are mentioned. In the case of using a heating furnace, heat treatment can be performed while the three-layer laminate is stopped or moved using a heat source fixed in the apparatus. At this time, you may supply hot air. Moreover, when manufacturing a polyurethane foam laminated body continuously, it is preferable to heat while moving a three-layer type laminated body in a heating furnace.

The heating of the three-layer laminate can be performed on either one side of the resin film side and the release paper side, or both sides. In the present invention, in order to uniformly heat the whole and efficiently form a more homogeneous foam layer, it is preferable to heat from both sides of the three-layer laminate.

When the manufacturing method of the polyurethane foam laminate is set to the manufacturing system shown in FIG. 6, preparation of the gas-liquid mixture 21a, supply of the gas-liquid mixture 21a onto the resin film (C) 20, and The polyurethane foam laminate can be continuously manufactured by continuously supplying a release paper or the like to the upper surface of the cured layer 21b, adjusting the thickness by the roll coater 12 or the like, and heating the three-layer laminate. That is, the gas-liquid mixture 21a prepared by the mixer 11 is continuously fed out and continuously supplied on the moving resin film (C) 20 at a predetermined feed rate, and the gas-liquid mixture 21a is flexible. The release paper 7 is supplied to the surface of the resin film (C) at the same speed as the 20 , and the thickness is adjusted by the roll coater 12 . Thereafter, the three-layer laminate is introduced into a heat treatment apparatus 13 disposed close to the roll coater 12 , for example, a heating furnace. In the case of using a heating furnace, normally, the three-layer laminate is introduced from one of the openings, and the inside of the heating furnace is moved at the same or close to that of the resin film (C) 20 at the same or close to the opening of the other opening. should be derived from Accordingly, the polyurethane foam laminate 30 having the release paper 7 is produced. Thereafter, if necessary, the release paper 7 can be removed to obtain a polyurethane foam laminate comprising the foam layer (A) and the resin film layer (C).

A polyurethane foam laminated body can be manufactured by the mechanical cross method which does not mix|blend water and a foaming agent with foam raw material as mentioned above. Moreover, it can also manufacture by the so-called chemical cross method, which mix|blends water and/or a foaming agent with foam raw material. In this case, as water, ion-exchange water, tap water, distilled water, etc. can be used. Although the usage-amount of water is not specifically limited, When a polyol is 100 mass parts, it is 0.1-0.5 mass part normally, Especially preferably, it is 0.2-0.4 mass part. In addition, the blowing agent is not particularly limited, and hydrocarbons, alternative Freon gas, and the like may be used. The usage-amount of this foaming agent is also not specifically limited also. In this way, instead of the mechanical cross method, even in the case of a chemical cross method using a foam raw material blended with water and/or a foaming agent, the bubble state of the gas-liquid mixture is stably maintained and cell non-uniformity is not generated. , it is possible to easily form a foam layer having a desired density and thickness. As a result, it can be set as the polyurethane foam laminated body provided with the foam layer provided with the outstanding physical property.

(Method for producing adhesive tape)

The adhesive tape of the present invention, for example, (I) the foam layer (A) and the resin film (C) are integrally applied to the surface side of the resin film (C), the adhesive is applied intermittently and dried a method for producing the pressure-sensitive adhesive portion (B) by applying the pressure-sensitive adhesive (II) to the release liner (D), intermittently applying the pressure-sensitive adhesive to the release liner (D) and drying to form the pressure-sensitive adhesive portion (B), and the foam layer (A) and a method of bonding the resin film (C) integrally, (III) applying the pressure-sensitive adhesive to the release liner (D) in an intermittent fashion and drying to form the pressure-sensitive adhesive portion (B), followed by a resin film ( After bonding with C), a method of forming a foam layer (A) on a resin film (C), (IV) applying the adhesive to the resin film (C) intermittently and drying the adhesive portion (B) After forming and bonding with a release liner (D) next, the method of forming a foam layer (A) in a resin film (C) is mentioned. Especially, since the method of (III) and (IV) can make a resin film relatively thin and it is excellent in productivity, it is preferable. In particular, the method of (IV) is most preferable.

The pressure-sensitive adhesive is, for example, by a coating method such as a gravure coating method or a slot die coating method, is preferably applied to at least one surface (a) of the foam base material (A) in an intermittent fashion, direct gravure It is preferable to apply|coat by a coating method.

The adhesive tape of the present invention has excellent adhesive force, cushioning properties, and adhesion workability (bubble release property) even when it is very thin. there is. In particular, by using it for the back surface of a display, cracking and pulling of a display device can be prevented, and also it can contribute to thickness reduction.

In addition, in the adhesive tape, even when no holes or the like are formed in a part of the adhesive tape, air bubbles easily escape from the interface between the adherend and the adhesive portion (B), and there is no need for puncturing to improve adhesion. It can be used suitably on the back side of a display where there is concern about the degradation of the performance resulting from the residual bubble.

[Example]

Hereinafter, Examples of the present invention will be described in more detail.

(Preparation Example 1) 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 polymerization initiators, in ethyl acetate solution at 80°C for 8 hours By carrying out solution polymerization, the acrylic polymer with a weight average molecular weight of 900,000 was obtained.

With respect to 100 parts by mass of the acrylic polymer, 5 parts by mass of "D-135" (manufactured by Arakawa Chemical Industries, Ltd., polymerized rosin ester) and 20 parts by mass of "KE-100" (manufactured by Arakawa Chemical Industries, Ltd., disproportionated rosin ester) , 25 mass parts of "FTR6100" (the Mitsui Chemicals Co., Ltd. make, petroleum resin) were mixed, and the adhesive solution adjusted to 40 mass % of solid content was obtained by adding ethyl acetate further.

The adhesive a was obtained by mixing and stirring the said adhesive solution and 2.0 mass parts of "NC40" (the DIC Corporation make, an isocyanate crosslinking agent).

The peak temperature of tan-delta of the adhesive layer obtained using the said adhesive a was 0 degreeC, and the gel fraction was 40 mass %.

(Preparation Example 2) 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 parts by mass of azobisisobutyronitrile as polymerization initiators, in ethyl acetate solution at 90° C. for 6 hours By carrying out solution polymerization, the acrylic polymer with a weight average molecular weight of 500,000 was obtained.

With respect to 100 parts by mass of the acrylic polymer, 5 parts by mass of "D-135" (manufactured by Arakawa Chemical Industries, Ltd., polymerized rosin ester) and 20 parts by mass of "KE-100" (manufactured by Arakawa Chemical Industries, Ltd., disproportionated rosin ester) 25 mass parts of "FTR6100" (the Mitsui Chemicals Co., Ltd. make, petroleum resin) was mixed, and the adhesive solution adjusted to 40 mass % of solid content was obtained by adding ethyl acetate further.

The adhesive b was obtained by mixing and stirring the said adhesive solution and 0.6 mass parts of "NC40" (the DIC Corporation make, an isocyanate crosslinking agent).

The peak temperature of tan-delta of the adhesive layer obtained using the said adhesive b was 0 degreeC, and the gel fraction 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 parts by mass of azobisisobutyronitrile as polymerization initiators, in ethyl acetate solution at 90° C. for 6 hours By carrying out solution polymerization, the acrylic polymer with a weight average molecular weight of 500,000 was obtained.

With respect to 100 parts by mass of the acrylic polymer, 5 parts by mass of "D-135" (manufactured by Arakawa Chemical Industry Co., Ltd., polymerized rosin ester) and 20 parts by mass of "KE-100" (manufactured by Arakawa Chemical Industry Co., Ltd., disproportionated rosin ester) And 25 mass parts of "FTR6100" (the Mitsui Chemical Co., Ltd. make, petroleum resin) were mixed, and the adhesive solution adjusted to 40 mass % of solid content was obtained by adding ethyl acetate further.

The adhesive c was obtained by mixing and stirring the said adhesive solution and 3.3 mass parts of "NC40" (the DIC Corporation make, an isocyanate crosslinking agent).

The peak temperature of tan-delta of the adhesive layer obtained using the said adhesive c was 0 degreeC, and the gel fraction was 46 mass %.

(Preparation Example 4) 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 parts by mass of azobisisobutyronitrile as polymerization initiators, in ethyl acetate solution at 90° C. for 6 hours By carrying out solution polymerization, the acrylic polymer with a weight average molecular weight of 500,000 was obtained.

Based on 100 parts by mass of the acrylic polymer, 5 parts by mass of "D-135" (manufactured by Arakawa Chemical Industries, Ltd., polymerized rosin ester) and 20 parts by mass of "KE-100" (manufactured by Arakawa Chemical Industries, Ltd., disproportionated rosin ester) And 25 mass parts of "FTR6100" (the Mitsui Chemicals Co., Ltd. make, petroleum resin) were mixed, and the adhesive solution adjusted to 40 mass % of solid content was obtained by adding ethyl acetate further.

The adhesive d was obtained by mixing and stirring the said adhesive solution and 1.2 mass parts of "NC40" (the DIC Corporation make, an isocyanate type crosslinking agent).

The peak temperature of tan-delta of the adhesive layer obtained using the said adhesive d was 0 degreeC, and the gel fraction was 20 mass %.

(Preparation Example 5) Adhesive e

96.4 parts by mass of n-butyl acrylate, 3.5 parts by mass of acrylic acid, 0.1 parts by mass of 4-hydroxy-ethyl acrylate, and 0.2 parts by mass of azobisisobutyronitrile as polymerization initiators, in an ethyl acetate solution at 80° C. at 8 By carrying out time solution polymerization, the acrylic polymer with a weight average molecular weight of 800,000 was obtained.

With respect to 100 parts by mass of the acrylic polymer, 10 parts by mass of "D-135" (manufactured by Arakawa Chemical Industry Co., Ltd., polymerized rosin ester) and 10 parts by mass of "A100" (disproportionated rosin ester, manufactured by Arakawa Chemical Industry Co., Ltd.) are mixed, The adhesive solution adjusted to 40 mass % of solid content was obtained by adding ethyl acetate further.

The adhesive e was obtained by mixing and stirring the said adhesive solution and 1.3 mass parts of "NC40" (the DIC Corporation make, an isocyanate crosslinking agent).

The peak temperature of tan-delta of the adhesive layer obtained using the said adhesive e was -15 degreeC, and the gel fraction was 40 mass %.

(Preparation Example 6) 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 parts by mass of 4-hydroxybutyl acrylate, azobisisobutyro The acrylic polymer with a weight average molecular weight of 800,000 was obtained by carrying out solution polymerization of 0.1 mass parts of nitriles as a polymerization initiator at 70 degreeC in ethyl acetate solution for 10 hours.

With respect to 100 mass parts of the said acrylic polymer, 10 mass parts of "D-135" (Arakawa Chemical Industry Co., Ltd. make, polymerization rosin ester) was mixed, and the adhesive solution adjusted to 40 mass % of solid content was obtained by adding ethyl acetate further.

The adhesive f was obtained by mixing and stirring the said adhesive solution and 1.3 mass parts of "NC40" (the DIC Corporation make, an isocyanate crosslinking agent).

The peak temperature of tan-delta of the adhesive layer obtained using the said adhesive f was -25 degreeC, and the gel fraction was 40 mass %.

(Example 1)

“PET50×1J0” (manufactured by Nipa Corporation, a release liner having a silicone-based release-treated surface on the surface of a 50 μm polyester film), using a gravure coater, dot-print the adhesive a, and dry at 100° C. for 1 minute By doing so, an island-like adhesive portion having a substantially rhombic shape shown in FIG. 1 and having a thickness of 2 µm was obtained. In addition, the distance between an arbitrary adhesive part and the adhesive part adjacent thereto among the said adhesive parts was 0.1 mm. Next, a 2 μm polyester film (K100-2.0W manufactured by Mitsubishi Resin Co., Ltd.) was superimposed and attached with a laminator at a linear pressure of 3 N/mm. This was cured at 40°C for two days to obtain a dot adhesive film. Next, a foam layer was formed on the 2 μm polyester film of this dot adhesive film by the following method.

Sanyo Kasei Co., Ltd. polyether polyol "GP-3000" 90 parts by mass, Sanyo Kasei Co., Ltd. polyether polyol "GP-600" 10 parts by mass, Johoku Chemical Co., Ltd. catalyst "Stannus Octoate" 0.1 parts by mass, Foaming agent劑) 5 mass parts was mixed and stirred, and the mixture was adjusted. Thereafter, the mixture and MDI "Coronate 1130" manufactured by Nippon Polyurethane Co., Ltd. in a compounding amount at which the isocyanate index becomes 1 were put into a chamber arranged in an Ox mixer. And, at the same time, nitrogen gas was injected so that the density of the foam layer became 300 kg/m ³ .

Next, in the chamber, the above components were stirred to prepare a bubbled gas-liquid mixture. And this gas-liquid mixture is supplied on the 2 micrometers polyester film of the dot adhesive film sent out at a speed|rate of 5 m/min, and the release paper is supplied to the surface of the flexible gas-liquid mixture at the same speed as the dot adhesive film from the upper side. Then, the thickness was adjusted to 100 µm with a roll coater to form an uncured layer made of a gas-liquid mixture.

Then, the laminate which consists of a dot adhesive film, an uncured layer, and release paper was put into the superheating furnace of 160 degreeC with a far-infrared heater, and it was overheated for 1 minute. Next, the release paper was peeled from the laminated body, and the adhesive tape by which the dot adhesive film and the foam layer were bonded together was obtained.

(Examples 2-13)

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

(Example 14)

The adhesive tape was obtained by the method similar to Example 1 except having replaced the adhesive a and having used the adhesive b.

(Example 15)

The adhesive tape was obtained by the method similar to Example 1 except having used the adhesive c instead of the adhesive a.

(Example 16)

The adhesive tape was obtained by the method similar to Example 1 except having replaced the adhesive a and having used the adhesive d.

(Example 17)

The adhesive tape was obtained by the method similar to Example 1 except having used the adhesive e instead of the adhesive a.

(Example 18)

The adhesive tape was obtained by the method similar to Example 1 except having replaced the adhesive a and having used the adhesive f.

(Examples 19-25)

The adhesive tape was created by the method similar to Example 1 except having changed the shape and area of the adhesive part (B), and the thickness of the adhesive part (B) to what was described in Tables 4 and 5. Moreover, the surface which has the substantially circular adhesive part of the adhesive tape obtained in Example 20 was observed at 200 times magnification using the optical microscope (FIG. 5).

(Example 26)

An adhesive tape was obtained in the same manner as in Example 1 except that the thickness of the foam layer was changed from 100 µm to 50 µm.

(Example 27)

An adhesive tape was obtained in the same manner as in Example 1 except that the density of the foam layer was changed from 300 kg/m ³ to 200 kg/m ³ .

(Example 28)

The adhesive tape was obtained by the method similar to Example 1 except having changed the 2 micrometers polyester film into the 25 micrometers polyester film.

(Example 29)

Instead of "PET50 x 1J0" (manufactured by Nipa Corporation, a release liner having a silicone-based release treatment surface on the surface of a 50 µm polyester film), "PET25 x 1J0" (manufactured by Nipa Corporation, silicone-based on the surface of a 25 µm polyester film) An adhesive tape was obtained in the same manner as in Example 1 except that a release liner having a release treatment surface) was used.

(Example 30)

90 parts by mass of polyether polyol "GP-3000" manufactured by Sanyo Kasei Co., Ltd., 10 parts by mass of polyether polyol "GP-600" manufactured by Sanyo Kasei Co., Ltd. 0.1 parts by mass of catalyst "Stannus Octoate" manufactured by Johoku Chemical Co., Ltd., 5 parts by mass of foaming agent Mix and stir to adjust the mixture. Thereafter, the mixture and MDI "Coronate 1130" manufactured by Nippon Polyurethane Co., Ltd. in a compounding amount at which the isocyanate index becomes 1 were put into a chamber arranged in an Ox mixer. And, at the same time, nitrogen gas was injected so that the density of the foam layer became 300 kg/m ³ .

Next, in the chamber, the above components were stirred to prepare a bubbled gas-liquid mixture. Then, this gas-liquid mixture is supplied on a 25 μm polyester film made by Toray Co., Ltd. “S10-25” delivered at a speed of 5 m/min, and on the surface of the gas-liquid mixture to be cast, a polyester film of 25 μm from the upper side and A release paper was supplied at the same speed, and the thickness was adjusted to 100 µm with a roll coater to form an uncured layer made of a gas-liquid mixture.

Then, the laminated body which consists of a polyester film, an uncured layer, and a release paper was put into the superheating furnace of 160 degreeC with a far-infrared heater, and it was overheated for 1 minute. Next, the release paper was peeled from the laminate to obtain a polyester film and a foam layer bonded together.

Next, "PET50 x 1J0" (manufactured by Nipa Co., Ltd., a release liner having a silicone-based release-treated surface on the surface of a 50 µm polyester film), using a gravure coater, dot-print the adhesive a, and 1 at 100 ° C. By drying for minutes, an island-like adhesive portion having a substantially rhombic shape shown in FIG. 1 and having a thickness of 2 µm was obtained. In addition, the distance between an arbitrary adhesive part and the adhesive part adjacent thereto among the said adhesive parts was 0.1 mm. Next, the polyester film layer of the polyester film and the foam layer were laminated and attached with a laminator at a linear pressure of 3N/mm. This was cured at 40°C for two days to obtain a dot adhesive film.

(Comparative Example 1)

An adhesive tape was obtained in the same manner as in Example 30, except that the pressure-sensitive adhesive layer was formed in an island shape with a gravure coater, except that it was formed on the entire surface using a roll coater.

(Measurement of the gel fraction of the adhesive part)

The adhesives a to f were coated with the adhesive on the release-treated surface of the release liner so that the thickness after drying was 50 μm, dried under an environment of 100° C. for 3 minutes, and then aged under an environment of 40° C. for 2 days. layer was formed. The adhesive layer was cut into a square having a length of 50 mm and a width of 50 mm as a test piece.

After measuring the mass (G1) of the said test piece, the said test piece was immersed in toluene in 23 degreeC environment for 24 hours. After the said immersion, the mixture of the said test piece and toluene was filtered using a 300 mesh wire mesh, and the insoluble component with respect to toluene was extracted. The mass (G2) of what dried the said insoluble component in 110 degreeC environment for 1 hour was measured.

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

Gel fraction (% by mass)=(G2/G1)×100

(Measurement of dynamic viscoelasticity)

The pressure-sensitive adhesives a to f were respectively coated on the surface of the release liner so as to have a dry thickness of 50 µm and dried to form a pressure-sensitive adhesive layer and cured in an environment of 40°C for 2 days. What overlapped the adhesive layer after the said curing until the total thickness became 2 mm was used as a test piece.

Next, using a viscoelasticity tester (Rheometrics Co., Ltd., trade name: Ares 2KSTD), the test piece is inserted into a parallel disk-shaped measuring part with a diameter of 7.9 mm, and the frequency is 1 Hz, and the temperature rise time is -50 under the conditions of 1 ° C. / 1 minute. The storage modulus (G') and the loss modulus (G") from °C to 150 °C were measured. The loss tangent tan δ was calculated from the following formula.

Loss tangent tanδ=G"/G'

(Measurement of total thickness of adhesive tape)

The layer thickness of the adhesive tape from which the release liner was peeled off was measured using a thickness meter FFG-6 manufactured by Ozaki Corporation.

(Measurement of adhesive force (1 hour after attachment))

The adhesive tape obtained by the Example and the comparative example was cut|disconnected by 20 mm width, and what affixed the adhesive layer on one side with the polyethylene terephthalate film of thickness 25 micrometers was used as the test piece. Said affixing was performed with respect to the surface of the adhesive layer with a smooth surface, and it was made not to perform with respect to the adhesive layer corresponded to the adhesive part (B) which is a structural requirement of this invention.

The test piece was adhered to the clean and smooth surface of a stainless steel plate and pressed by reciprocating one 2 kg roller on the upper surface. Peel adhesion (peel direction: 90°, tensile speed: 0.3 m/min) was measured using a Tensilon tensile tester under an atmosphere of 23° C. and 50%RH. The measurement result is shown in the column of "Adhesive force (1 hour after adhesion)" of the table.

(Measurement of holding force)

The adhesive tape obtained by the Example and the comparative example was cut|disconnected by 20 mm width, and what the adhesive layer of the one side was affixed with 50-micrometer-thick aluminum foil was used as the test piece. Said affixing was performed with respect to the surface of the adhesive layer with a smooth surface, and it was made not to perform with respect to the adhesive layer corresponded to the adhesive part (B) which is a structural requirement of this invention.

According to JISZ-0237, according to JISZ-0237, according to JISZ-0237, the said test piece was attached so that the said test piece might become an adhesion area of 20 mm x 20 mm on the surface of a clean and smooth stainless steel plate, and it was pressurized by 1 reciprocating using a 2 kg roller on the upper surface. After leaving it to stand under the conditions of RH for 1 hour, a load of 100 g was applied in the shearing direction in 100 degreeC atmosphere, and the shift|offset|difference distance of the tape after 24 hours was measured. The measurement result was shown in the column of "holding force" of a table.

(Evaluation of ease of release of bubbles)

The adhesive tapes obtained in Examples and Comparative Examples were cut to 50 mm long × 100 mm wide, and the release liner was peeled off, and an aluminum plate of 70 mm length × 150 mm width was placed on the surface of the adhesive part under 23 ° C and 50% RH atmosphere, A temporary attachment was obtained by leaving it to stand for 5 seconds in the state which loaded 5N on the aluminum plate.

Next, after inverting the said temporary attachment, the laminated body was obtained by pressurizing them by reciprocating 1 2 kg roller from the surface by the side of an adhesive tape.

Ten pieces of the above-mentioned laminate were produced by the above method. Whether or not air bubbles were present between the adhesive tape and the aluminum plate was confirmed by visually observing the swelling (10 mm ² or more) of the adhesive tape. Based on the number of the laminates in which the presence of bubbles could not be confirmed by the above method, the ease of removal of the bubbles was evaluated.

(Evaluation of stains in the foam layer)

When the foamed layer of the obtained adhesive tape was observed from the position of 30 cm of upper surface of the said adhesive tape under a fluorescent lamp, whether or not there existed nonuniformity was evaluated.

◎: No stains

○: Slightly uneven

×: There is severe staining

(Evaluation of appearance)

When the adhesive tape is attached to an aluminum plate and observed from a position of 30 cm above the top surface of the adhesive tape under a fluorescent lamp, the shape of the adhesive part (the substantially rhombic shape, the substantially annular shape, etc.) can be visually recognized. did A thing in which the shape of the said adhesive part was not visually recognizable at all was evaluated as "(double-circle)", what was able to visually recognize a part of the said shape slightly was evaluated as "○", and what was able to visually recognize the said shape clearly was evaluated as "x". In addition, as shown in Comparative Example 1, in the case where the pressure-sensitive adhesive layer was formed by applying the pressure-sensitive adhesive to the entire surface of the foam substrate, the pressure-sensitive adhesive portion does not form a predetermined shape, and therefore the shape cannot be visually recognized by the above method. Instead, it was set to “-”.

(Number of adhesive parts)

The number of adhesive parts was calculated|required by observing and counting the range of arbitrary ranges (flow direction 5 cm and width 5 cm square) or (flow direction 1 cm and width direction 1 cm square) of the adhesive tape with an electron microscope.

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

[Table 6]

[Table 7]

"Approximately rhombus 1" in the table refers to a rhombus-shaped adhesive part in which the angle of the corner portion facing the flow direction of the adhesive tape is 60° (the angle of the corner portion facing the width direction is 120°) (FIG. 1), and "approximately rhombus 2" "" indicates a rhombus-shaped adhesive part in which the angle of the corner portion facing the flow direction of the adhesive tape is 30° (the angle of the corner portion facing the width direction is 150°), and "approximately square shape" is the adhesive tape facing the flow direction The angle of the corner is 90° (the angle of the corner facing the width direction is 90°) is a square-shaped adhesive part, "approximately circular" refers to the adhesive part of the shape shown in FIG. 2, and "approximately hexagon (slanted line)" is the The adhesive part of the shape shown in 3 is pointed out, and "approximately square (slanted line)" points out the adhesive part of the shape shown in FIG.

Since all the adhesive tapes of an Example have a plurality of independent adhesive layers on one surface, they are excellent in the ease of removal of a bubble. Moreover, the adhesive tape of Example is thin, and there is no unevenness of a foaming layer, and it is excellent also in adhesive force and holding power. On the other hand, in the adhesive tape of a comparative example, since the adhesive layer is formed on the whole surface instead of an island shape, there is no way for a bubble to escape, and the ease of removal of a bubble is remarkably bad.

1: foam layer
2: adhesive part
3: adhesive tape
4: Graphite Sheet
5: Single-sided adhesive tape
6: double-sided adhesive tape
7: Lee Hyungji
11: mixer for mixing foam raw material and gas
12: roll coater
13: heat treatment layer
20: Resin film (C)/or resin film (C), the adhesive portion (B), and the release liner (D) are integrated
21a: gas-liquid mixture
21b: uncured layer
30: laminate

Claims (15)

An adhesive tape having two or more adhesive portions (B) on the foam layer (A), the resin film layer (C), and the resin film (C) side,
A region not having the adhesive portion (B) exists between the two or more adhesive portions (B), and the region passes through the end of the adhesive tape,
The gel fraction of the adhesive portion (B) is 10% by mass to 60% by mass,
An adhesive tape, characterized in that the peak temperature of the loss tangent based on the dynamic viscoelasticity spectrum measured at a frequency of 1 Hz of the adhesive portion (B) is -30°C to 20°C. The method according to claim 1,
The adhesive tape of which the shape of the said adhesive part (B) when the said adhesive part (B) is observed from one side (a) side of the said foam layer (A) is a substantially circular shape, a substantially rectangular shape, or a substantially hexagonal shape. The method according to claim 1 or 2,
The adhesive tape, wherein the distance between the optional adhesive part (b1) selected from the two or more adhesive parts (B) and the adhesive part (b2) adjacent to the adhesive part (b1) is 0.5 mm or less. 4. The method according to any one of claims 1 to 3,
The size per one optional adhesive part (b1) selected from the adhesive part (B), the area is 0.001mm ² ~ 100mm ² , the adhesive tape. 5. The method according to any one of claims 1 to 4,
The adhesive tape whose ratio of the area|region which has the said adhesive part (B) to the area of one side (a) of the said foam layer (A) is 10 % - 99 %. 6. The method according to any one of claims 1 to 5,
The adhesive tape in which 10-1000000 said adhesive parts (B) exist in the range of 5 cm in the flow direction and 5 cm in the width direction of the said adhesive tape. 7. The method according to any one of claims 1 to 6,
The said foam layer (A) is a polyurethane-type foam layer or an acrylic foam layer, The adhesive tape. 8. The method according to any one of claims 1 to 7,
A test piece obtained by placing a smooth stainless steel plate on the surface having the adhesive portion (B), compressing them by one reciprocating using a 2 kg roller, and leaving it to stand under the conditions of 23° C. and 50% RH for 1 hour An adhesive tape having a 180° peel adhesion measured using the range of 2N/20mm to 12N/20mm. 9. The method according to any one of claims 1 to 8,
The adhesive tape which has a release liner (D) on the surface in contact with the said adhesive part (B). A resin film layer (C), a pressure-sensitive adhesive portion (B), and a release liner (D) are formed by coating a foam layer (A) on the resin film layer (C) of a laminate integrally formed. A method of manufacturing the tape. 11. The method of claim 10,
A step of intermittently applying an adhesive to the release liner (D) and drying it to form an adhesive portion (B), and bonding the resin film layer (C) to the adhesive portion (B); or
After intermittently applying an adhesive to the resin film layer (C) to form the adhesive portion (B), and bonding the release liner (D) to the adhesive portion (B), the foam layer (A) The manufacturing method of the adhesive tape including the process of forming in the said resin film layer (C). An adhesive tape characterized in that an adhesive portion (B) is formed by the following method 1 or method 2 on the surface side of the resin film (C) of the laminate in which the foam layer (A) and the resin film (C) are integrated. manufacturing method.
Method 1: An adhesive portion (B) is formed by intermittently applying an adhesive to the surface side of the resin film (C) of the laminate.
Method 2: A pressure-sensitive adhesive is intermittently applied to the release liner (D) to form a pressure-sensitive adhesive portion (B) and bonded to the surface of the resin film (C) of the laminate. 13. The method according to any one of claims 10 to 12,
The method for producing an adhesive tape, wherein the pressure-sensitive adhesive is applied intermittently by a gravure coating method or a slot die coating method. The electronic device using the adhesive tape in any one of Claims 1-9. A display device characterized in that the adhesive tape according to any one of claims 1 to 9 is provided on the non-display surface side of the display.

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