JP2013040344A - Double-sided adhesive tape or sheet - Google Patents

Abstract

To provide a double-sided adhesive tape or sheet having excellent strength even when the thickness is small, and a method for producing the same.
The double-sided adhesive tape or sheet of the present invention is a double-sided adhesive tape or sheet having a pressure-sensitive adhesive layer on both sides of a support, wherein the thickness of the support is 0.002 mm or more. Is composed of an acrylic pressure-sensitive adhesive containing an acrylic polymer mainly composed of (meth) acrylic acid C _1-20 alkyl ester, and the thickness of each pressure-sensitive adhesive layer is 0.0005 to 0.0275 mm, The total thickness including the thickness of the support and the two pressure-sensitive adhesive layers formed on both sides of the support is 0.003 mm or more and less than 0.03 mm (provided that the support and A double-sided adhesive tape or sheet having a pressure-sensitive adhesive layer, a total thickness of 0.01 mm, and a support being a polyester substrate, and a support and a pressure-sensitive adhesive layer, with a total thickness of 0.020 mm Yes, and Excluding double-sided adhesive tape or sheet support is a polyester substrate having a thickness of 0.012 mm).
[Selection figure] None

Description

  The present invention relates to a double-sided adhesive tape or sheet, and more particularly, to a double-sided adhesive tape or sheet that is suitably used at a joint of a housing or a component when manufacturing (assembling) various OA equipment and electronic components.

  In recent years, so-called “computers” (personal computers), printers, so-called “mobile phones”, PDAs, so-called “digital cameras” (digital cameras), OA devices such as digital video cameras, and electronic components (particularly mobile devices) Along with popularization, the number of production has increased, and in parallel with higher functionality, downsizing and thinning have been achieved. For example, in a mobile phone, which is a representative device as a mobile device, each major component that is configured tends to be thinned in order to increase the display screen and improve portability. Usually, the display part is mainly composed of an LCD module and a backlight unit, and various sheet-like parts are used (laminated) in order to develop functions such as light emission, reflection, light shielding, and light guide. . In the assembly (joining) of these parts, a double-sided adhesive tape or sheet, a screw, an adhesive, or the like is usually used (see Patent Document 1).

Japanese Patent Laid-Open No. 2002-249741

  When assembling (joining) parts, for example, when a double-sided adhesive tape or sheet is used, a relatively thin double-sided adhesive tape or sheet, among commercially available double-sided adhesive tapes or sheets, due to restrictions on the thickness of products or parts, Sheets tend to be used. However, as a conventional thin double-sided adhesive tape or sheet, it is often a double-sided adhesive tape or sheet (so-called “baseless double-sided adhesive tape or sheet”) consisting only of an adhesive layer. The thinner it is, the lower the strength of the double-sided adhesive tape or sheet, and the double-sided adhesive tape or sheet breaks during the bonding operation, or it becomes practically difficult to peel the double-sided adhesive tape or sheet once attached. As a result, work efficiency was reduced.

  On the other hand, in parts where a further ultrathin layer structure is required, a conventional double-sided adhesive tape or sheet becomes difficult to use due to clearance restrictions, so a liquid adhesive is used instead of the double-sided adhesive tape or sheet. The purpose is achieved by applying.

  However, since the properties of the adhesive are liquid, it is difficult to make the coating thickness uniform, and since the fluidity is high, problems associated with adhesion to areas other than necessary are likely to occur. In addition, it usually takes time to cure, which is a factor that reduces the productivity of assembly work and is inferior in economic efficiency.

Accordingly, an object of the present invention is to provide a double-sided adhesive tape or sheet having excellent strength even when the thickness is small.
Another object of the present invention is to provide a double-sided adhesive tape or sheet that has the required thinness and that has good strength without being cut during or during use.
Yet another object of the present invention is that it can be stably manufactured in a long and wound form in spite of its very small thickness, and it is easy and has excellent workability. The object is to provide a double-sided adhesive tape or sheet that can be rewound.

  Another object of the present invention is to provide a double-sided adhesive tape that can be used even when the distance between the joining parts is a thin area that has not been conventionally used in a joining means using a double-sided adhesive tape or sheet. Or to provide a sheet.

  As a result of intensive studies to achieve the above object, the present inventors have found that a support having a very thin thickness that has not been conventionally used as a support (base material) for a double-sided adhesive tape or sheet ( Base material), the total thickness including the support and the adhesive layer is less than 0.030 mm, and the breaking strength is set to a specific size, so that even if the thickness is small, it has excellent strength. The present invention has been completed by finding that a double-sided adhesive tape or sheet can be obtained.

That is, the present invention is a double-sided adhesive tape or sheet having pressure-sensitive adhesive layers on both sides of a support, wherein the thickness of the support is 0.002 mm or more, and the pressure-sensitive adhesive layer is (meth) acrylic acid C _{1. -20} consisting of an acrylic pressure-sensitive adhesive containing an acrylic polymer mainly composed of an alkyl ester, the thickness of each pressure-sensitive adhesive layer is 0.0005 to 0.0275 mm, and the support and the support Double-sided adhesive tape or sheet characterized in that the total thickness including the thickness of the two pressure-sensitive adhesive layers formed on both sides of the body is 0.003 mm or more and less than 0.03 mm (however, the support and the pressure-sensitive adhesive layer) A double-sided adhesive tape or sheet in which the total thickness is 0.01 mm and the support is a polyester base, and a support and a pressure-sensitive adhesive layer, and the total thickness is 0.020 mm, and Branch Body providing excluding double-sided adhesive tape or sheet is a polyester substrate having a thickness of 0.012 mm).

  The thickness of the support is preferably 0.002 to 0.012 mm. As the support, a plastic film is preferable, and a polyethylene terephthalate film is particularly preferable.

  The double-sided adhesive tape or sheet of the present invention has a length of 5 m or more and may be wound into a roll.

  The double-sided adhesive tape or sheet of the present invention may have a release liner on the pressure-sensitive adhesive surface opposite to the support-bonding surface of at least one pressure-sensitive adhesive layer.

  In the double-sided adhesive tape or sheet of the present invention, the thickness of the two pressure-sensitive adhesive layers formed on both sides of the support may be the same or different.

  According to the double-sided adhesive tape or sheet of the present invention, it has excellent strength even when the thickness is small. Moreover, it is the required thinness, and does not generate a cut during use or during use, and maintains good strength. Furthermore, although it is very thin, it can be stably produced in a long and wound form, and can be easily rewound with excellent workability. . Therefore, the double-sided adhesive tape or sheet of the present invention can be provided in a state of being long and wound in a roll shape, and thus, productivity when performing continuous punching processing or automatic sticking. Also excellent.

  Therefore, the double-sided adhesive tape or sheet of the present invention can be used even if the interval between the joining parts is a thin area that has not been conventionally adopted by the joining means using the double-sided adhesive tape or sheet. it can.

It is the schematic which shows an example of the double-sided adhesive tape or sheet | seat of this invention. It is a schematic process drawing which shows an example of the method of manufacturing the double-sided adhesive tape or sheet | seat of this invention.

[Double-sided adhesive tape or sheet]
As shown in FIG. 1, the double-sided adhesive tape or sheet of the present invention is a double-sided adhesive tape or sheet with a base material having a pressure-sensitive adhesive layer on both sides of the support, and is formed on both sides of the support and the support. The total thickness including the thickness of the two adhesive layers thus formed is 0.003 mm or more and less than 0.03 mm, and the breaking strength is 2 to 26 MPa / 10 mm width. Thus, although the double-sided adhesive tape or sheet of the present invention is a double-sided adhesive tape or sheet with a substrate having a support, its thickness is as thin as less than 30 μm, and its breaking strength is 2 to 26 MPa. And is excellent. Therefore, it has the required thinness, and does not cause cutting during use or during use, and maintains good strength. Therefore, the double-sided adhesive tape or sheet of the present invention can be stably produced in a long and wound form in spite of its very thin thickness, and is easy and excellent. It can be rewound with workability. Therefore, it is excellent in productivity when continuously punching or automatically sticking.

  On the other hand, conventionally, the thickness of a double-sided adhesive tape or sheet with a substrate (double-sided adhesive tape or sheet with a support) is substantially 80 to 300 μm, and a double-sided adhesive tape or sheet with no substrate (non-supported double-sided adhesive tape) Or in the case of a sheet), it was substantially 30 to 60 μm. Thus, conventionally, the thickness of the double-sided adhesive tape or sheet with a substrate is substantially thick, and a thickness of less than 30 μm has not been provided.

  Therefore, when the double-sided adhesive tape or sheet of the present invention is used, conventionally, the thickness of the joining portion (clearance between joining parts) is not adopted in the joining means using the double-sided adhesive tape or sheet (for example, (When the clearance allowed for the adhesive member is less than 0.03 mm), it is possible to perform a uniform bonding operation using a double-sided adhesive tape or sheet. That is, even if the interval between the joining parts is thin in a region that has not been conventionally adopted in the joining means using the double-sided adhesive tape or sheet, by using the double-sided adhesive tape or sheet of the present invention, A joining means by uniform joining using an adhesive tape or a sheet becomes possible.

  FIG. 1 is a schematic view showing an example of the double-sided adhesive tape or sheet of the present invention. In FIG. 1, 1 is a double-sided adhesive tape or sheet, 1a is a support, 1b is an adhesive layer (first adhesive layer), 1c is an adhesive layer (second adhesive layer), and 1d is a release liner. is there. The double-sided adhesive tape or sheet 1 has a configuration in which an adhesive layer 1b is formed on one surface of a support 1a and an adhesive layer 1c is formed on the other surface, and the adhesive layer 1b is It is protected by the release liner 1d, and is further overlapped so that the pressure-sensitive adhesive layer 1c and the other surface of the release liner 1d (surface opposite to the pressure-sensitive adhesive layer 1b) are in contact with each other and wound in a roll shape. It has become a form.

  The total thickness (tape thickness) of the double-sided adhesive tape or sheet of the present invention is not particularly limited as long as it is 0.003 mm or more and less than 0.03 mm, for example, 0.003 to 0.029 mm (preferably 0.003). ˜0.026 mm, more preferably 0.003 to 0.02, particularly 0.003 to 0.015 mm).

  In addition, the total thickness (tape thickness) of a double-sided adhesive tape or a sheet means the thickness of the part utilized in the case of sticking. That is, the total thickness of the double-sided adhesive tape or sheet means the thickness (total thickness) from one adhesive surface to the other adhesive surface. Specifically, since the double-sided adhesive tape or sheet of the present invention is a double-sided adhesive tape or sheet with a substrate, the total thickness of the double-sided adhesive tape or sheet is formed on the support and both sides of the support. In addition, the thickness includes the thickness of the two adhesive layers, and does not include the thickness of the release liner (separator) for protecting the adhesive surface.

  The breaking strength of the double-sided adhesive tape or sheet of the present invention is not particularly limited as long as it is 2 to 26 MPa / 10 mm wide, preferably 2 to 14 MPa / 10 mm wide, more preferably 4 to 10 MPa / 10 mm wide. It is. By setting the breaking strength of the double-sided adhesive tape or sheet within the above range, the double-sided adhesive tape or sheet can be stretched like a substrateless double-sided adhesive tape or sheet during processing, pasting operation, or handling. Various members (joint parts and the like) can be bonded to each other with a stable dimensional shape without being cut. In the present invention, the breaking strength of the double-sided adhesive tape or sheet is a value measured by the following method. That is, a double-sided adhesive tape or sheet is cut to a width of 10 mm, and a test piece (10 mm width) is prepared by attaching marks on the surface at intervals of 50 mm, using a tensile tester, at room temperature (23 ° C.) and 65 Under the condition of% RH, when the test piece is pulled and the test piece is broken (at the time when a crack is generated at least partially) under the conditions of 50 mm of the test piece holding distance (chuck distance) and a pulling speed of 200 mm / min. A load (stress) is measured, and the load is defined as a breaking strength (MPa).

(Support)
As the support, the total thickness of the double-sided adhesive tape or sheet can be 0.003 mm or more and less than 0.03 mm, and the breaking strength of the double-sided adhesive tape or sheet can be 2 to 26 MPa / 10 mm width. If possible, the material and thickness thereof are not particularly limited. Examples of the material of the support include plastic materials, paper materials, fiber materials (woven fabric, nonwoven fabric, etc.), metal materials, and the like. A plastic material is suitable as the material of the support. That is, a plastic film can be suitably used as the support.

  As such a plastic material (material of the plastic film), various engineer plastic materials can be suitably used. Specifically, as a plastic material, for example, polyester [polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), etc.], olefin resin [polyethylene (PE), polypropylene (PP), Olefin resins containing α-olefin as monomer component such as ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA)], polyethersulfone (PES) (polyethersulfone), polysulfone, polychlorinated Vinyl (PVC), polyphenylene sulfide (PPS), amide resins [polyamide (nylon), wholly aromatic polyamide (aramid), etc.], polyimide (PI), polyamideimide, polyetherimide (PEI), polyesterimide, methacrylate Rate resins [polymethyl methacrylate (PMMA), etc.], styrene resins [polystyrene, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), etc.], polycarbonate (PC), Polyacetal, polyarylene ether (such as polyphenylene ether), polyphenylene sulfide, polyarylate, polyaryl, polyurethanes, polyether ketones [polyether ether ketone (PEEK), polyether ketone ketone, etc.], polyacrylic acid esters (polyacrylic) Acid butyl, polyethyl acrylate, etc.) and epoxy resins. These materials (plastic materials) can be used alone or in combination of two or more.

  As the plastic material, polyester (in particular, polyethylene terephthalate) can be preferably used from the viewpoints of thickness accuracy, economy (cost), tensile strength, workability, and the like. That is, a polyester film (in particular, a polyethylene terephthalate film) can be suitably used as the support.

  The support may have any form of a single layer or a laminate, and is not subject to structural restrictions.

  As the thickness of the support, the total thickness of the double-sided adhesive tape or sheet can be 0.003 mm or more and less than 0.03 mm, and the breaking strength of the double-sided adhesive tape or sheet is 2 to 26 MPa / 10 mm width. Is selected as long as possible, but for example, it is selected from the range of 0.002 to 0.012 mm (preferably 0.002 to 0.009 mm, more preferably 0.002 to 0.004 mm). it can. A support in such a thickness range (for example, 0.002 to 0.012 mm) (especially when the support is a plastic film) is conventionally a support in a double-sided adhesive tape or sheet (in particular, the support is In the case of a plastic film, it is a support having a thickness range in a region that was not substantially employed.

  The surface of the support (particularly, a support made of a plastic material) has a conventional surface treatment, for example, chromic acid treatment, ozone exposure, etc., in order to enhance the adhesion with the pressure-sensitive adhesive layer formed on the support. Oxidation treatment by a chemical or physical method such as flame exposure, high-voltage impact exposure, ionizing radiation treatment, or the like may be performed, or a coating treatment with a primer may be performed.

(Adhesive layer)
Examples of the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer include acrylic pressure-sensitive adhesives, rubber-based pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, urethane-based pressure-sensitive adhesives, polyester-based pressure-sensitive adhesives, styrene-diene block copolymer-based pressure-sensitive adhesives, and vinyl alkyl. It can be appropriately selected from known pressure-sensitive adhesives such as ether-based pressure-sensitive adhesives, polyamide-based pressure-sensitive adhesives, fluorine-based pressure-sensitive adhesives, creep property improving pressure-sensitive adhesives, and radiation curable pressure-sensitive adhesives. An adhesive can be used individually or in combination of 2 or more types.

In the present invention, an acrylic pressure-sensitive adhesive is particularly used as the pressure-sensitive adhesive from the viewpoint of reliability of adhesion. The acrylic pressure-sensitive adhesive comprises an acrylic polymer as a pressure-sensitive adhesive component (base polymer) or main ingredient, and a crosslinking agent, a tackifier, a softener, a plasticizer, a filler, an anti-aging agent, and a colorant as necessary. Appropriate additives such as are included. The acrylic polymer is composed of a monomer (copolymerizable monomer) that has (meth) acrylic acid alkyl ester as a main monomer component and can be copolymerized with the (meth) alkyl ester as necessary. Body). Examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, (meth ) Isobutyl 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, (meth) acrylic acid Undecyl, dodecyl (meth) acrylate, tridecyl (meth) acrylate, Such as tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, eicosyl (meth) acrylate ( And (meth) acrylic acid C _1-20 alkyl ester [preferably (meth) acrylic acid C _4-18 alkyl (straight or branched alkyl) ester]. The (meth) acrylic acid alkyl ester can be appropriately selected according to the intended tackiness and the like. The (meth) acrylic acid alkyl ester can be used alone or in combination of two or more.

  Examples of the copolymerizable monomer include (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid and other carboxyl group-containing monomers or anhydrides thereof; vinyl sulfonic acid Sulfonic acid group-containing monomers such as sodium; aromatic vinyl compounds such as styrene and substituted styrene; cyano group-containing monomers such as acrylonitrile; olefins such as ethylene, propylene and butadiene; vinyl esters such as vinyl acetate; Amide group-containing monomers such as vinyl chloride; acrylamide, methacrylamide, N-vinylpyrrolidone, N, N-dimethyl (meth) acrylamide; Hydroxyl group-containing monomers such as hydroxyalkyl (meth) acrylate and glycerol dimethacrylate Aminoethyl (meth) acrylate, (meth ) Amino group-containing monomers such as acryloylmorpholine; Imido group-containing monomers such as cyclohexylmaleimide and isopropylmaleimide; Epoxy group-containing monomers such as glycidyl (meth) acrylate and methyl glycidyl (meth) acrylate; 2 -In addition to isocyanate group-containing monomers such as methacryloyloxyethyl isocyanate, triethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, neo Pentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate Dipentaerythritol hexa (meth) acrylate, a polyfunctional copolymerizable monomer (polyfunctional monomer) such as divinylbenzene, and the like. A copolymerizable monomer can be used individually or in combination of 2 or more types. As the copolymerizable monomer, a modifying monomer having a functional group such as a carboxyl group can be suitably used.

  The acrylic polymer can be prepared by a conventional polymerization method such as a solution polymerization method, an emulsion polymerization method, or an ultraviolet irradiation polymerization method.

  The thickness of each pressure-sensitive adhesive layer can be appropriately selected in consideration of the pressure-sensitive adhesive properties and the total thickness of the double-sided adhesive tape or sheet. In the present invention, the thickness of each pressure-sensitive adhesive layer is selected from the range of 0.0005 to 0.0275 mm (preferably 0.004 to 0.014 mm, more preferably 0.004 to 0.01 mm). In the two pressure-sensitive adhesive layers formed on both sides of the support, the thickness of each pressure-sensitive adhesive layer (the front-side pressure-sensitive adhesive layer and the back-side pressure-sensitive adhesive layer) is not particularly defined and depends on the application. Can be selected as appropriate. Moreover, although the thickness of the two adhesive layers formed on both surfaces of the support may be the same or different, the same or almost the same thickness is often selected.

(Release liner)
In the double-sided adhesive tape or sheet of the present invention, a release liner for protecting the adhesive surface of the adhesive layer can be provided until use. Such a release liner is not particularly defined and can be appropriately selected from known release liners. Specifically, as the release liner, for example, a plastic film having high releasability itself [for example, ethylene such as polyethylene (low density polyethylene, linear low density polyethylene, etc.), polypropylene, ethylene-propylene copolymer, etc. -Alpha-olefin copolymer (block copolymer or random copolymer), polyolefin film made of a polyolefin resin made of a mixture thereof; a release liner made of Teflon (registered trademark) film, etc.] However, a release liner having a configuration in which a release treatment layer is formed on the surface (one side or both sides) of various supports (base materials) can be suitably used.

  As a base material of the release liner, a plastic film is preferably used, but a composite base material (for example, paper (for example, Japanese paper, western paper, glassine paper, etc.), non-woven fabric or cloth, foam, metal foil, various base materials (for example, It may be a metal-deposited plastic film or the like. Although the thickness of a base material can be suitably selected according to the objective, generally it is about 10-500 micrometers. In addition, as a raw material of the plastic film of the base material of the release liner, polyester such as polyethylene terephthalate; polyolefin such as polypropylene, polyethylene and ethylene-propylene copolymer; polyvinyl chloride; polyimide; thermoplastic resin such as polycarbonate, etc. Can be mentioned. The plastic film may be either an unstretched film or a stretched (uniaxially stretched or biaxially stretched) film.

  The release treatment layer is a known or commonly used release treatment agent for forming the release treatment layer in the release liner (for example, a silicone release agent, a fluorine release agent, a long-chain alkyl release agent, etc.). Can be formed. The release treatment layer is a polyolefin film made of a polyolefin resin such as an ethylene-α-olefin copolymer such as polyethylene, polypropylene, or an ethylene-propylene copolymer; a Teflon (registered trademark) film is formed on the support. Further, it may be formed by laminating or coating. In the release liner, the release treatment layer can be provided on one side or both sides of the substrate as described above.

  As the release liner, by adjusting the peeling force to the pressure-sensitive adhesive layer to be 1 N / 50 mm or less, it is possible to suppress or prevent the deformation of the double-sided adhesive tape or sheet at the time of bonding work (peeling of the release liner). And workability can be improved. The release liner and its release force can be appropriately selected or adjusted according to the application and the like, and are not particularly limited.

  The double-sided adhesive tape or sheet of the present invention may have a form of a laminated body in which sheet-like ones are laminated, or may have a form of a wound body wound in a roll shape. . For example, as the release liner, one long strip-shaped release liner whose both surfaces are release treatment surfaces, one release treatment surface of the release liner is attached to one of the long strip-like double-sided adhesive tape or sheet. The adhesive layer of the pressure-sensitive adhesive layer is overlapped and laminated, and the other release treatment surface of the release liner is overlapped with the pressure-sensitive adhesive surface of the other pressure-sensitive adhesive layer and wound into a roll shape to be wound into a roll shape. A double-sided adhesive tape or sheet having a formed form can be produced. In addition, as the release liner, two long strip-shaped release liners whose only one surface is a release treatment surface are used, and one of the pressure-sensitive adhesive layers of the long-band double-sided adhesive tape or sheet is formed by one release liner. A double-sided adhesive tape or sheet having a form wound in a roll shape by protecting the pressure-sensitive adhesive surface and winding it in a roll shape with the other release liner protecting the pressure-sensitive adhesive surface of the other pressure-sensitive adhesive layer Can be produced.

  The length of the double-sided adhesive tape or sheet having a form wound in such a roll shape is not particularly limited as long as it is a long strip shape, but is usually 5 m or more (preferably 10 m or more, more preferably Is 20 m or more).

  In the present invention, the thickness of the double-sided adhesive tape or sheet is very thin as less than 0.03 mm, and since a thin support of a level not conventionally employed is used, when winding in a roll shape, The double-sided adhesive tape or sheet or the support is easy to wrinkle, but as shown below, by adjusting the tension of the support at the time of manufacture (tensile tension, etc.) In a good state, a double-sided adhesive tape or sheet wound in a roll can be stably produced.

  The double-sided adhesive tape or sheet may be used after being cut (pre-processed) into a part shape in advance. Examples of such pre-processing include sealing processing and press processing. Therefore, from the viewpoint of workability and economy, the form of the double-sided adhesive tape or sheet before pre-processing is preferably a wound body shape and a long product. Therefore, the double-sided adhesive tape or sheet of the present invention has a tensile strength necessary for processing and affixing work despite the fact that the total thickness or the thickness of the support is thin, and is long in the wound body. Therefore, various pre-processing can be performed easily and continuously, and excellent workability and economy can be exhibited.

  Of course, as a double-sided adhesive tape or sheet, even when pre-processed, it may have a single-plate (sheet-like) form. In this case, the pre-processing is not a continuous type but a batch type. Therefore, it is not preferable economically (in terms of cost).

  Therefore, the double-sided adhesive tape or sheet of the present invention uses a double-sided adhesive tape or sheet that has been conventionally used for a joining member that is required to be thinned. Supplying a joining member that is required to be thin such that the area that has not been adopted by the joining means is thin (for example, the area where the clearance allowed for the adhesive member is less than 0.03 mm). It can be used suitably for doing. Such a joining member is not particularly limited as long as it is a joining member that requires a thin layer. For example, a personal computer (a desktop personal computer, a notebook personal computer, etc.), a printer, a mobile phone, a PDA, a digital camera, a digital Members that make up OA equipment such as video cameras and electronic components (especially mobile devices such as notebook computers, mobile phones and PDAs) (for example, LCD modules, backlight units, as well as light emission, reflection, light shielding, light guide) And sheet-like parts that express various functions such as).

(Production method)
The method for producing the double-sided adhesive tape or sheet of the present invention is not particularly limited, and can be appropriately selected from known production methods. For example, a first adhesive is applied to one surface of the support, A double-sided adhesive tape comprising a step of forming a second pressure-sensitive adhesive layer after forming the pressure-sensitive adhesive layer or simultaneously with the formation of the first pressure-sensitive adhesive layer, by applying a pressure-sensitive adhesive to the other surface of the support. Or the manufacturing method of a sheet | seat, the manufacturing method of the double-sided adhesive tape or sheet | seat which comprises the following process (A)-(C), etc. are mentioned.
Step (A): Step of forming a pressure-sensitive adhesive layer on the release liner by applying a pressure-sensitive adhesive to the release treatment surface of the release liner. Step (B): Forming on the release liner on one surface of the support. Step of forming the first pressure-sensitive adhesive layer on the support by pasting together the pressure-sensitive adhesive layers Step (C): Applying the pressure-sensitive adhesive to the other surface of the support, Step of forming an adhesive layer

In particular, in the present invention, in the step (B), when the pressure-sensitive adhesive layer formed on the release liner is bonded to one surface of the support, the tension applied to the support is preferably less than 2N. . That is, the step (B) is preferably the following step (B1).
Step (B1): In a state where the tension applied to the support is less than 2N, the pressure-sensitive adhesive layer formed on the release liner is bonded to one surface of the support, and the first pressure-sensitive adhesive is formed on the support. Step of forming a layer

  Thus, when the pressure-sensitive adhesive layer formed on the release liner is bonded to one side of the support to form the first pressure-sensitive adhesive layer on the support, the tension applied to the support becomes as low as possible. By adjusting in this way, even if the thickness of the support is very thin, it is possible to produce a double-sided adhesive tape or sheet in a good state without causing wrinkles and the like.

  Therefore, as shown in FIG. 2, the double-sided adhesive tape or sheet of the present invention can be suitably produced by a production method comprising the step (A), the step (B1) and the step (C). In particular, when producing a double-sided adhesive tape or sheet wound in the form of a roll as a double-sided adhesive tape or sheet, a production method comprising the steps (A), (B1) and (C). By using it, it is possible to produce a double-sided adhesive tape or sheet that is stably wound in a roll shape without causing wrinkles or the like.

More specifically, when producing a double-sided adhesive tape or sheet wound in a roll shape, as a support, a long support wound in a roll shape is used. The support used in (B) or step (B1) is a long support wound in a roll shape, and the long support wound in a roll shape is fed out and supported. When the pressure-sensitive adhesive layer formed on the release liner is bonded to one surface of the body, the tension applied to the support is preferably less than 2N. That is, the step (B) or the step (B1) is preferably the following step (B2).
Step (B2): In a state where the tension applied to the support is less than 2N, the long support wound in the form of a roll was unwound and formed on one surface of the support on the release liner. A process of bonding the pressure-sensitive adhesive layer to form a first pressure-sensitive adhesive layer on the support

In addition, when manufacturing the double-sided adhesive tape or sheet | seat of the form wound by roll shape, as FIG. 2 shows, while having the said process (A), a process (B2), and a process (C) Furthermore, it is important that the following step (D) is provided.
Step (D): A double-sided adhesive tape or sheet wound in a roll shape is wound so that the second pressure-sensitive adhesive layer and the release treatment surface of the other surface of the release liner are overlapped. Obtaining process

  FIG. 2 is a schematic process diagram showing an example of a method for producing the double-sided adhesive tape or sheet of the present invention. In FIG. 2, 2 is a release liner, 3 is an adhesive coating device, 4 is a drying or ultraviolet irradiation zone, 5 is a support, 6 is a bonding site, 7 is an adhesive coating device, and 8 is drying or ultraviolet irradiation. Zone 9 is a double-sided adhesive tape or sheet. The double-sided adhesive tape or sheet 9 has a form wound in a roll shape. The release liner 2 has a form in which both surfaces are release-treated surfaces and wound in a roll shape. The support 5 has a form wound in a roll shape. The pressure-sensitive adhesive coating device 3 is a coating device for applying a pressure-sensitive adhesive for forming the first pressure-sensitive adhesive layer, and the pressure-sensitive adhesive coating device 7 forms a second pressure-sensitive adhesive layer. It is the coating device for apply | coating the adhesive for doing.

  In the process diagram of the production method shown in FIG. 2, in the step (A), the release liner 2 in a form wound in a roll shape is unwound, and the adhesive liner 3 is applied to one surface of the release liner 2. The pressure-sensitive adhesive is applied, and the pressure-sensitive adhesive is dried by drying or ultraviolet irradiation zone 4 to form a pressure-sensitive adhesive layer as a first pressure-sensitive adhesive layer on one surface of the release liner.

  Further, in step (B1) [or step (B2)], the support 5 in the form of a roll is unwound in a state where the tension (feeding tension) is less than 2N and little or no tension is applied. The adhesive layer formed on the release liner 2 is bonded to one surface (the lower surface in FIG. 2) of the support 5 at the bonding site 6, and the first on the support 5. The pressure-sensitive adhesive layer is formed.

  Furthermore, in the step (C), an adhesive is applied to the other surface of the support (upper surface in FIG. 2) by the adhesive application device 7, and the adhesive is applied by drying or ultraviolet irradiation zone 8. It was made to dry and the 2nd adhesive layer was formed on the support body.

  In step (D), the second pressure-sensitive adhesive layer and the release treatment surface of the other surface of the release liner 2 are wound into a roll shape so as to overlap each other, thereby being wound into a roll shape. An adhesive tape or sheet 9 is obtained.

  In addition, when manufacturing the double-sided adhesive tape or sheet | seat of the form wound by the roll shape, as FIG. 2 shows, it can manufacture with the same manufacturing line. Of course, the step (A), the step (B1) [or the step (B2)], the step (C) and the step (D) may be performed partially using the same production line, and they are all differently manufactured. It may be performed using a line.

  In the manufacturing method, the tension applied to the support (particularly, the supply tension applied to the support when the support wound in a roll shape is supplied) is applied to the support by a tension detector. The tension can be adjusted by detecting the tension and controlling the torque of the powder brake so that the tension will be described later through an automatic tension control device.

  As described above, when the first pressure-sensitive adhesive layer is formed on the support by laminating the pressure-sensitive adhesive layer formed on the release liner on one side of the support, tension such as tensile tension applied to the support. By adjusting the tension (especially when feeding a long support wound in a roll shape) to be as low as possible, the roll can be wound in a clean state without causing wrinkles. It is possible to stably manufacture a double-sided adhesive tape that is wound into a roll. The tension applied to such a support is not particularly limited as long as it is less than 2N. For example, it can be selected from the range of 0 to 1.9N, preferably 1N or less (for example, 0 to 1N), Preferably it is 0.5N or less (for example, 0-0.5), and it is especially suitable for it to be 0.3N or less (for example, 0-0.3N).

  Of course, after the step (B) [including the step (B1) and the step (B2)], the support has a form in which the first pressure-sensitive adhesive layer and the release liner are laminated in this order on one surface. The support is usually not at all or hardly in tension and is not stretched, but after step (B) [including step (B1) and step (B2)]. The tension applied to the support may be less than 2N or 2N or more.

  In the production of an adhesive tape or sheet, an adhesive formed on a release liner on one side of the support (particularly, a long support wound in a roll shape is fed out to one side of the support). When the adhesive layer is bonded to form the pressure-sensitive adhesive layer on the support, usually a tension of about 2 to 10 N (particularly, a feeding tension) is applied to the support. Therefore, in such a case, when the thickness of the support is thin, the support is stretched by the tension, and when the tension applied to the support is removed in the subsequent process, the support is stretched. This shrinks (shrinks) from the damaged state to the original state, and wrinkles or the like occur in the adhesive tape or sheet.

  Examples of the present invention will be described below in more detail. In the following, “part” means part by weight, and “%” means weight%.

(Adhesive Preparation Example 1)
N-butyl acrylate: 97 parts, acrylic acid: 3 parts, 2-hydroxyethyl acrylate: 0.1 part, azobisisobutyronitrile: 0.2 part as a polymerization initiator, toluene and ethyl acetate In a mixed solution of [Toluene / ethyl acetate (weight ratio) = 1/1], solution polymerization was performed for 6 hours to obtain an acrylic polymer having a weight average molecular weight of 500,000. The acrylic polymer: 100 parts, a terpene-phenol resin (trade name “YS Polystar T 130” manufactured by Yasuhara Chemical Co., Ltd .; softening point: 130 ° C.): 30 parts and an isocyanate cross-linking agent (trade name “Coronate L” Japan) Polyurethane Kogyo Co., Ltd.): 2 parts was added, and the mixture was stirred and mixed uniformly to prepare a pressure-sensitive adhesive (pressure-sensitive adhesive composition; sometimes referred to as “pressure-sensitive adhesive A”). .

Example 1
As a support, a pressure-sensitive adhesive having a thickness of 0.004 mm using the pressure-sensitive adhesive A on both sides of a polyester film (trade name “C660-2.0W” manufactured by Mitsubishi Chemical Polyester; thickness: 0.002 mm). A layer was formed, wound into a roll, and a double-sided adhesive tape (total thickness: 0.010 mm, winding length: 50 m) wound into a roll was produced. Specifically, in accordance with the manufacturing process as shown in FIG. 2, it was manufactured on the same manufacturing line as follows.

  First, after releasing the release liner that has both surfaces of the release treatment surface and wound in a roll shape, the adhesive A is applied to the release treatment surface on one side of the release liner by a roll coater, It dried at 100 degreeC and formed the adhesive layer (it is an adhesive layer used as a 1st adhesive layer) with a thickness of 0.004 mm.

  Next, a polyester film (trade name “C660-2.0W” manufactured by Mitsubishi Chemical Polyester Co., Ltd .; thickness: 0.002 mm) wound in a roll shape as a support is fed at a feeding tension of 0.1 N. The adhesive layer formed on the release liner is bonded to one surface of the polyester film, and the first pressure-sensitive adhesive is bonded to one surface of the polyester film as a support. An agent layer was formed.

  Subsequently, the pressure-sensitive adhesive A is applied to the other surface of the polyester film (the surface opposite to the surface on which the first pressure-sensitive adhesive layer is formed) with a roll coater, and then dried at 100 ° C. Thus, a second pressure-sensitive adhesive layer (thickness: 0.004 mm) was formed.

  Further, the second pressure-sensitive adhesive layer and the other surface of the release liner (the surface opposite to the surface on which the first pressure-sensitive adhesive layer is formed) are wound up in a roll shape. A double-sided adhesive tape wound in a roll shape (total thickness: 0.010 mm, winding length: 50 m) was produced. In addition, the tension | tensile_strength in the winding-up part at the time of winding up a double-sided adhesive tape was 40N.

(Example 2)
While using a polyester film (trade name “K880-4.5W” manufactured by Mitsubishi Chemical Polyester; thickness: 0.004 mm) as a support, the thickness of each adhesive layer formed on both sides of the support is 0.010 mm, and a double-sided adhesive tape (total thickness: 0.024 mm) was produced in the same manner as in Example 1 except that the winding length of the double-sided adhesive tape was 200 m. Therefore, the feeding tension at the time of feeding the support is 0.1 N, as in the first embodiment. Further, the tension at the winding portion when winding the double-sided adhesive tape is 40 N as in the first embodiment.

(Example 3)
A polyester film (trade name “K230-6E” manufactured by Mitsubishi Chemical Polyester; thickness: 0.006 mm) is used as a support, and the thickness of each pressure-sensitive adhesive layer formed on both sides of the support is 0. A double-sided adhesive tape (total thickness: 0.026 mm) was produced in the same manner as in Example 1 except that the length was 0.010 mm and the winding length of the double-sided adhesive tape was 200 m. Therefore, the feeding tension at the time of feeding the support is 0.1 N, as in the first embodiment. Further, the tension at the winding portion when winding the double-sided adhesive tape is 40 N as in the first embodiment.

(Comparative Example 1)
A release liner having both surfaces formed as a release treatment surface and wound in a roll is drawn out, and the pressure-sensitive adhesive A is applied to the release treatment surface on one side of the release liner by a roll coater. To form a pressure-sensitive adhesive layer having a thickness of 0.010 mm, and then the pressure-sensitive adhesive layer and the other surface of the release liner (the surface opposite to the surface on which the pressure-sensitive adhesive layer is formed) The double-sided adhesive tape (total thickness: 0.010 mm, winding length: 200 m) wound into a roll shape and wound into a roll shape was prepared so that and contact with each other. The double-sided adhesive tape is a base material-less type double-sided adhesive tape.

(Comparative Example 2)
As a support, a polyester film (trade name “Lumirror # 12” manufactured by Toray Industries, Inc .; thickness: 0.012 mm) is fed at a feeding tension of 50 N, and the adhesive A is rolled on both sides of the support. After applying with a coater and drying at 100 ° C. to form a pressure-sensitive adhesive layer (thickness of each pressure-sensitive adhesive layer: 0.009 mm), peeling is performed on both sides of the pressure-sensitive adhesive layer. Double-sided adhesive that is rolled up in a roll shape so that one release treatment surface of the liner is overlapped, and the other adhesive layer and the other surface of the release liner are in contact with each other A tape (total thickness: 0.030 mm, winding length: 200 m) was produced. In addition, the tension | tensile_strength in the winding-up part at the time of winding up a double-sided adhesive tape was 40N.

(Evaluation)
About the double-sided adhesive tapes according to Examples 1 to 3 and Comparative Examples 1 to 2, whether or not to produce a wound body, suitability for clearance, adhesive strength, breaking strength, and workability were measured by the following measurement method or evaluation method, respectively. Measured or evaluated. The evaluation results are shown in Table 1.

(Evaluation method of availability of winding body production)
In Examples 1 to 3 and Comparative Examples 1 and 2, it is judged whether or not a double-sided adhesive tape wound in a good shape can be produced in a roll shape, and what can be produced is “O”, Those that could not be produced were evaluated as “×”. The evaluation results are shown in the column “Possibility of production of wound body” in Table 1.

(Evaluation method of clearance suitability)
It is determined whether the double-sided adhesive tapes obtained in Examples 1 to 3 and Comparative Examples 1 and 2 can be applied to a portion where the clearance between parts is 0.03 mm or less and can be adapted to the clearance. Evaluation was made with “○” for those that could be matched and “×” for those that could not be matched. The evaluation results are shown in the “clearance suitability” column of Table 1.

(Measurement method of adhesive strength)
The double-sided adhesive tapes obtained in Examples 1 to 3 and Comparative Examples 1 and 2 were cut to a width of 20 mm to prepare test pieces. The test pieces (20 mm width) were subjected to Tensilon tensile according to JIS Z-0237. Using a testing machine, peel adhesive strength (peeling angle: 180 °, tensile speed: 300 mm / min, 23 ° C. × 65% RH, adherend: stainless steel plate) was measured. The measurement results are shown in the column of “Adhesive strength (N / 20 mm)” in Table 1.

(Measurement method of breaking strength)
The double-sided adhesive tapes obtained in Examples 1 to 3 and Comparative Examples 1 to 2 were cut to a width of 10 mm, and test pieces (10 mm width) were prepared by attaching marks on the surface thereof at intervals of 50 mm. When the test piece was pulled at a room temperature (23 ° C.) and 65% RH and the test piece was gripped (chuck distance) was 50 mm and the tensile speed was 200 mm / min, and the test piece was broken ( The load (stress) at the time when a crack is generated from at least a part) is measured, and the load is defined as the breaking strength (MPa). The measurement results are shown in the column of “breaking strength (MPa)” in Table 1.

  In addition, since the double-sided adhesive tape which concerns on the comparative example 1 is a base material-less type, its breaking strength was very small, and it was a value so small that it could not be measured substantially.

(Processability)
About the double-sided adhesive tapes obtained in Examples 1 to 3 and Comparative Examples 1 and 2, the specified dimensions are sealed, and the peeling workability and the blocking property after the processing are excellent in the peeling workability during the processing. In addition, the case where the cut cross section did not adhere was evaluated as “◯”, and the case where the peeling workability was poor at the time of processing or the case where the cut cross section adhered was evaluated as “x”. The evaluation results are shown in the column of “workability” in Table 1.

  From Table 1, the double-sided adhesive tape according to the example can be wound in a good state to be a wound body even though the total thickness is extremely thin as less than 0.03 mm, and the clearance between parts is 0. It can be adapted to the part which becomes 0.03 mm or less. Moreover, the adhesive strength and breaking strength are also good, and the processability is excellent. Therefore, when the double-sided adhesive tape according to the embodiment is used, it is possible to meet the demand for ultra-thin layering of the joint portion by the double-sided adhesive tape, and to achieve both workability and economical efficiency (cost performance) at an excellent level. It was confirmed that the special effect of being able to

1 Double-sided adhesive tape or sheet 1a Support 1b Adhesive layer (first adhesive layer)
1c pressure-sensitive adhesive layer (second pressure-sensitive adhesive layer)
DESCRIPTION OF SYMBOLS 1d Release liner 2 Release liner 3 Adhesive coating apparatus 4 Drying or ultraviolet irradiation zone 5 Support body 6 Bonding part 7 Adhesive coating apparatus 8 Drying or ultraviolet irradiation zone 9 Double-sided adhesive tape or sheet

Claims (8)

A double-sided adhesive tape or sheet having an adhesive layer on both sides of the support,
The support has a thickness of 0.002 mm or more;
The pressure-sensitive adhesive layer is made of an acrylic pressure-sensitive adhesive containing an acrylic polymer mainly composed of (meth) acrylic acid C _1-20 alkyl ester,
The thickness of each pressure-sensitive adhesive layer is 0.0005 to 0.0275 mm, and the total thickness including the thickness of the support and the two pressure-sensitive adhesive layers formed on both sides of the support is 0.003 mm or more and Double-sided adhesive tape or sheet characterized by being less than 0.03 mm (however, the double-sided adhesive tape having a support and a pressure-sensitive adhesive layer, a total thickness of 0.01 mm, and the support being a polyester substrate) Or a double-sided adhesive tape or sheet having a sheet, and a support and a pressure-sensitive adhesive layer, a total thickness of 0.020 mm, and the support being a polyester substrate having a thickness of 0.012 mm).   The double-sided adhesive tape or sheet according to claim 1, wherein the support has a thickness of 0.002 to 0.012 mm.   The double-sided adhesive tape or sheet according to claim 1 or 2, wherein the support is a plastic film.   The double-sided adhesive tape or sheet according to claim 3, wherein the support is a polyethylene terephthalate film.   The double-sided adhesive tape or sheet according to any one of claims 1 to 4, wherein the double-sided adhesive tape or sheet has a length of 5 m or more and is wound in a roll shape.   The double-sided adhesive tape or sheet according to any one of claims 1 to 5, which has a release liner on the pressure-sensitive adhesive surface opposite to the support-bonding surface of at least one pressure-sensitive adhesive layer.   The double-sided adhesive tape or sheet according to any one of claims 1 to 6, wherein the two pressure-sensitive adhesive layers formed on both sides of the support have the same thickness.   The double-sided adhesive tape or sheet according to any one of claims 1 to 6, wherein the two pressure-sensitive adhesive layers formed on both sides of the support have different thicknesses.

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