WO2015039590A1

WO2015039590A1 - Double-sided adhesive tape

Info

Publication number: WO2015039590A1
Application number: PCT/CN2014/086627
Authority: WO
Inventors: 丁军义; 吉田升; 尹浪飞; 佐藤正名
Original assignee: 日东电工（上海松江）有限公司; 日东电工株式会社
Priority date: 2013-09-17
Filing date: 2014-09-16
Publication date: 2015-03-26
Also published as: JP2016535151A; CN111019552B; KR20160055867A; KR102268365B1; JP6677644B2; CN111019552A; CN104449438A; CN105874024A; CN105874024B

Abstract

Provided is a double-sided adhesive tape capable of easily peeling off the release liner from either side. The double-sided adhesive tape has a substrate layer, adhesive layers separately and sequentially layered on the two sides of the substrate layer, and the release liners respectively and sequentially layered on the adhesive layers. The peeling force of the surfaces of the release liners contacting the surfaces of the adhesive layers is measured according to JIS Z0237 to be between 0.01 N/50mm and 0.30 N/50mm.

Description

double-sided tape

Technical field

The present invention relates to an adhesive tape, and more particularly to a double-sided tape which can be suitably applied to manufacture (assembly) of various office automation equipment, portable equipment, and electronic parts.

Background technique

In recent years, the miniaturization of portable devices such as mobile phones, digital cameras, and PDAs (personal digital assistants, also known as handheld computers) has continued to grow. Therefore, various electronic components to be mounted also require miniaturization and thinning. For example, as a representative example of a portable device, the main components used therein are all in a trend of thinning. Generally, the display portion of the portable device is mainly composed of an LCD module and a backlight unit, and various sheet-like members are laminated to perform functions such as light emission, reflection, light shielding, and light guiding. For this purpose, a double-sided tape for assembling (joining) these components is designed (see Patent Document 1).

As shown in Fig. 1, a representative double-sided tape is constructed such that an adhesive layer 12 is formed on one surface of the base material layer 11, and an adhesive layer 12' is formed on the other surface 12'. In the above double-sided tape 10, a common form is that the adhesive layer 12' is protected by a release liner (anti-adhesive film) 13, and so that the adhesive layer 12 and the other side surface of the release liner 13 (and the adhesive layer) The surface on the opposite side of the mixture layer 12' is wound into a roll shape.

Prior art literature

Patent Document Japanese Unexamined Patent Publication No. 2012-52099

Summary of the invention

The release liner 13 used in the double-sided tape is provided on the base layer 11 and the adhesive layers 12 and 12' formed on both side surfaces thereof based on the peeling workability of the release liner or the like. The peeling force between the release liner of one side surface of the body and the surface of one side of the adherend (the force required to peel the release liner from the adherend) and the peeling provided on the other side surface of the adherend The peel force between the liner and the other side surface of the bond is generally different.

When such a double-sided tape is used for the above-mentioned adherend such as an electric or electronic component, the release liner of the side of the double-sided tape having a small peeling force (light peeling side) is peeled off and attached to the film. On either part of the adherend, the release liner on the side where the peeling force is large (heavy peeling side) is peeled off and attached to the other member.

Therefore, when a conventional double-sided tape is used, it is necessary to peel off the peeling liner on the light peeling side first (the release liner on the specific gravity peeling side), so that when peeling off the release liner, it is necessary to confirm which one is first. The side is the light peeling side. In addition, when the difference between the peeling force on the heavy peeling side and the peeling force on the light peeling side (the peeling force on the heavy peeling side) - (the peeling force on the light peeling side) is too small, there is a problem in peeling workability and the like. And if the above When the difference in peeling force is too large, when the release liner on the heavy peeling side is first peeled off, there may be a "floating" at the interface between the release liner on the light peeling side and the surface of the pressure-sensitive adhesive layer (a void occurs). Phenomenon) and even peeling (so-called "unexpected peeling phenomenon"). Moreover, since it is necessary to peel off the release liner on the light peeling side first, when the member attached to the surface (adhesive side) of each adhesive layer in the double-sided tape is determined, the component is attached to both sides. The order on the tape is also determined from this, and the degree of freedom (selectivity) and operability when using the double-sided tape are low. On the other hand, in the case where a release liner (light release liner, heavy release liner) is provided on the surface of the double-sided tape in accordance with the order of the attached member, the degree of freedom in the production of the double-sided tape (optional) ) and operational decline.

Accordingly, it is an object of the present invention to provide a double-sided tape which is less likely to cause the above-described floating or undesired peeling phenomenon.

Another object of the present invention is to provide a double-sided tape which can be easily peeled off from the adhesive surface by peeling off the liner from either side.

In order to achieve the above object, the inventors conducted intensive studies and found that the contact faces of the two release liners in contact with the adhesive layer in the double-sided tape were all made light-peelable type, and the above-mentioned hard-to-float type can be produced. Double-sided tape that is undesirably peeled off. Further, it has been found that when the tape is used, the release liner can be easily peeled off regardless of which side of the release liner is peeled off first, and the degree of freedom and workability at the time of use can be improved. The present invention has been accomplished on the basis of the above findings.

That is, the present invention provides a double-sided tape having a base material layer, an adhesive layer sequentially laminated on both sides of the base material layer, and a release liner sequentially laminated on the adhesive layer, respectively, the release liner The contact surface of the contact surface with the adhesive layer surface measured by JIS Z0237 was 0.01 N/50 mm or more and less than 0.30 N/50 mm.

The release liner preferably has a release treatment layer formed on the surface of the film or sheet as the substrate. The release treatment layer is preferably a light release type release treatment layer, and typically has a release treatment layer having a peeling force from the surface of the pressure-sensitive adhesive layer of 0.01 N/50 mm or more and less than 0.30 N/50 mm.

The contact surface of the release liner which is in contact with the surface of the pressure-sensitive adhesive layer has a peeling force measured according to JIS Z0237 of preferably 0.05 N/50 mm or more, 0.28 N/50 mm or less, more preferably 0.07 N/50 mm or more and 0.25 N. /50mm or less.

The 180° peel adhesion of the pressure-sensitive adhesive layer measured in accordance with JIS Z0237 is preferably 2 to 20 N/20 mm.

Further, in the double-sided tape of the present invention, the holding strength of the pressure-sensitive adhesive layer to the adherend measured in accordance with JIS Z0237 is preferably 5.0 mm/hr or less.

In a preferred embodiment of the double-sided tape disclosed herein, the peeling force of the two release liners on both sides of the substrate layer is substantially the same as the surface of the adhesive layer.

Further, in another preferred embodiment of the double-sided tape disclosed herein, the peeling forces of the two release liners provided on both sides of the base material layer and the surface of the pressure-sensitive adhesive layer are different from each other. That is, the release liner has different peeling forces from the surfaces of the pressure-sensitive adhesive layers provided on both surfaces of the base material layer. In the above embodiment, the peeling force of the larger one is not more than 200% of the peeling force of the smaller one.

The release liner is preferably a polyester film or sheet as a substrate.

Further, the release treatment layer is preferably formed of a silicone release treatment agent.

In the double-sided tape of the present invention, since the surface (peeling surface) of the release liner which is bonded to both surfaces of the pressure-sensitive adhesive layer is a lightly peelable surface, no stickiness occurs when the release liner is peeled off. The mixture layer floats or undesirably peels off. Further, when the double-sided tape of the present invention is produced, it is not necessary to attach to the corresponding peeling surface in accordance with the order of the attached members, and therefore, the release liner can be attached to any one of the surfaces of any of the peeling faces. Thus, the degree of freedom (selectivity) and operability in manufacturing the double-sided tape are greatly improved.

DRAWINGS

Fig. 1 is a schematic cross-sectional view showing an example of a double-sided tape.

Fig. 2 is a schematic cross-sectional view showing an example of a double-sided tape of the present invention.

Description of the reference numerals

10 double-sided tape

11 substrate layer

12,12' adhesive layer

13 release liner

20 double-sided tape

21 substrate layer

22,22' adhesive layer

23,23' release liner

detailed description

Hereinafter, preferred embodiments of the present invention will be described. It should be noted that matters required for the implementation of the present invention in matters other than those specifically mentioned in the present specification can be grasped as design matters of those skilled in the art based on the prior art in the field. The present invention can be implemented in accordance with the contents disclosed in the present specification and the technical common knowledge in the field.

The double-sided tape of the present invention is characterized in that it has a base material layer and an adhesive layer which is sequentially laminated on both sides of the base material layer, and a release liner which is sequentially laminated on the pressure-sensitive adhesive layer, respectively, and the release liner The contact faces of the surfaces of the two adhesive layers are all lightly peelable surfaces.

Thus, in the double-sided tape of the present invention, since the surface of the release liner which is in contact with the surface of the adhesive layer is a lightly peelable surface, when the release liner is peeled off from the surface of one adhesive layer, The interface between the surface of the adhesive layer on one side and the release liner is less likely to cause so-called "floating" (a gap is formed between the release liner) or "undesired peeling phenomenon" (it is not peelable at a predetermined interface) However, in another interface, peeling occurs.)

In the present specification, the "light peeling type" release liner refers to a force required for peeling off the release liner from the adhesive surface of the double-sided tape, that is, the 180° peel strength of the release liner measured in accordance with JIS Z0237, which will be described later. (also referred to as "peeling force") is 0.01 N/50 mm or more and less than 0.30 N/50 mm, preferably 0.05 N/50 mm or more and 0.28 N/50 mm or less, more preferably 0.07 N/50 mm or more and 0.25 N/50 mm or less.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings and drawings.

In each of the following embodiments, a double-sided tape having a pressure-sensitive adhesive layer on both surfaces of a base material layer as a support will be described as an example. However, the double-sided tape of the present invention also includes a sheet-like product, that is, a double-sided adhesive sheet.

(base material layer)

The double-sided tape of the present invention may have a substrate as a support or may have no substrate. However, it is preferred to have a substrate. The substrate is not particularly limited, but a plastic substrate can be suitably used from the viewpoints of strength, thickness precision, and thinness. Examples of materials or materials for plastic substrates are polyester (polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate) Ester, etc., polyolefin (polyethylene, polypropylene, ethylene-propylene copolymer, etc.), polyvinyl alcohol, polyvinylidene chloride, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyamide Polyimide, cellulose, fluorine resin, polyether, polystyrene resin (polystyrene, etc.), polycarbonate, polyethersulfone, and the like. Among them, a polyester film or a polyolefin film is preferable from the viewpoint of price and rigidity, and a polyethylene terephthalate (PET) film is particularly preferable. The plastic film substrate may be a single layer or a multilayer.

The thickness of the base material layer can be appropriately selected depending on the strength, flexibility, and purpose of use of the double-sided tape required for the double-sided tape. In the present invention, the thickness and the unevenness compliance of the release liner-free pressure-sensitive adhesive body of the double-sided tape (also referred to as "concavity and convexity absorbability" means that it is easy to conform to the characteristics of the uneven shape of the adherend when the tape is attached). The thickness of the base material layer is preferably 40 μm or less, and more preferably 25 μm or less. For example, in the double-sided tape having a thickness of the base material layer of 15 μm or less (and further 13 μm or less, for example, 12 μm or less), the meaning of applying the technique disclosed herein can be effectively exerted. The lower limit of the thickness of the base material layer is not particularly limited, and is usually 2 μm or more from the viewpoint of handleability and the like, and is preferably 4 μm or more. In a preferred embodiment, the thickness of the substrate layer can be set to 4 to 12 μm. .

(adhesive layer)

The pressure-sensitive adhesive layer (hereinafter referred to as "adhesive composition") is not particularly limited, and may be, for example, a polyurethane-based pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive, a rubber pressure-sensitive adhesive, or a silicone resin. A known binder such as a binder, a polyester binder, a polyamide binder, an epoxy binder, a vinyl alkyl ether binder, or a fluorine binder. The binder may be used singly or in combination of two or more. The binder may be in any form, and may be, for example, an emulsion type binder, a solvent type binder, a hot melt type binder, or the like.

As a preferable example of the binder in the technique disclosed herein, an acrylic binder and a rubber-based binder can be suitably used. Among them, an acrylic pressure-sensitive adhesive is preferred from the viewpoint of excellent heat resistance and weather resistance and design freedom. The acrylic adhesive contains an acrylic polymer as a main component or a base polymer. Further, as the base polymer (the essential component of the binder), it is preferred to use an alkyl (meth)acrylate having an alkyl group having 4 to 12 carbon atoms (generally referred to as an alkyl acrylate or an alkyl methacrylate). The meaning of the ester is a polymer of a main component of a monomer (C4-12 alkyl acrylate polymer). The (meth)acrylic acid C _4-12 alkyl ester polymer may be used singly or in combination of two or more.

The (meth)acrylic acid alkyl ester [C _4-12 alkyl (meth)acrylate) having 4 to 12 carbon atoms in the alkyl group, as long as the alkyl group has 4 to 12 carbon atoms. The alkyl (meth)acrylate is not particularly limited, and examples thereof include butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, and tert-butyl (meth)acrylate. Ester, amyl (meth)acrylate, isoamyl (meth)acrylate, neopentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, (meth)acrylic acid 2 -ethylhexyl ester, octyl (meth)acrylate, isooctyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, decyl (meth)acrylate, (A) Isodecyl acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, and the like. The C _4-12 alkyl (meth)acrylate may be used singly or in combination of two or more.

The C _4-12 alkyl (meth)acrylate is used as a main component of the monomer, and may be 50% by weight or more (preferably 70% by weight or more, and more preferably 85% by weight or more) based on the total amount of the monomer components. If the proportion of the C _4-12 alkyl (meth)acrylate in the total amount of the monomer components is less than 50% by weight, the adhesion and retention may be lowered, and it may be difficult to obtain an adhesive tape or a PSA sheet. Good adhesion and retention.

The upper limit of the C _4-12 alkyl (meth)acrylate in the total amount of the monomer components is not particularly limited, and is, for example, preferably 98% by weight or less, preferably 98% by weight or less (for example, 97% by weight or less). .

When the acrylic base polymer is used, the weight average molecular weight is not particularly limited, but is usually 300,000 or more and 2,000,000 or less (preferably 60 to 1.5 million, more preferably 70 to 1.3 million). When the weight average molecular weight of the acrylic base polymer is less than 300,000, the adhesive strength required for the binder may not be exhibited, and if it is more than 2,000,000, the viscosity of the binder may increase, which may cause problems such as poor coatability. .

Further, in order to increase the cohesive force or the like, a crosslinking agent may be added to the acrylic pressure-sensitive adhesive. Specifically, an isocyanate compound, a polyfunctional melamine compound, a polyfunctional epoxy compound, or the like can be used. Among them, an isocyanate compound is preferred from the viewpoint of easily obtaining a balance between adhesion and cohesive force. The isocyanate compound is not particularly limited as long as it has at least two isocyanate groups in one molecule. Examples of the isocyanate compound include aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, and aromatic aliphatic polyisocyanates.

The crosslinking agent may be used singly or in combination of two or more.

Further, a crosslinking assistant may be added to introduce a cross-linking point of the crosslinking agent or the like. As the crosslinking assistant, a polyhydroxy compound having two or more hydroxyl groups in one molecule can be used, and as such a polyhydroxy compound, for example There are aliphatic polyols, alicyclic polyols, aromatic polyols, polyether polyols, polyester polyols, polycarbonate polyols, polycaprolactone polyols, acrylic polyols, polyurethane polyols and the like.

The crosslinking assistant may be used singly or in combination of two or more.

Further, since the acrylic polymer has a large polarity and is difficult to adhere to a low-polar adherend such as polyolefin, a tackifier may be added to the binder as needed.

The tackifier is not particularly limited, and may be, for example, various tackifier resins such as rosins, terpenes, hydrocarbons, epoxies, polyamides, elastomers, phenols, and ketones. Such tackifying resins may be used singly or in combination of two or more.

Specifically, examples of the rosin-based tackifying resin include unmodified rosin (raw rosin) such as gum rosin, wood rosin, and tall oil rosin; and these unmodified rosins are modified by hydrogenation, disproportionation, polymerization, and the like. Rosin (hydrogenated rosin, disproportionated rosin, polymerized rosin, other chemically modified rosin, etc.); various other rosin derivatives; The rosin derivative is, for example, a product obtained by esterifying an unmodified rosin with an alcohol (that is, an esterified product of rosin), and a modified rosin (hydrogenated rosin, disproportionated rosin, polymerized rosin, etc.) is esterified with an alcohol. Rosin esters such as modified products (ie, esterified esters of modified rosin, etc.); unsaturated unmodified rosins or modified rosins (hydrogenated rosin, disproportionated rosin, polymerized rosin, etc.) modified with unsaturated fatty acids Fatty acid-modified rosin; unsaturated fatty acid-modified rosin ester modified with rosin esters with unsaturated fatty acids; unmodified rosin, modified rosin (hydrogenated rosin, disproportionated rosin, polymerized rosin, etc.), Rosin alcohol obtained by reduction treatment of a carboxyl group in a saturated fatty acid-modified rosin or unsaturated fatty acid-modified rosin ester; rosin (especially rosin ester) such as unmodified rosin, modified rosin, and various rosin derivatives a metal salt of the type; a rosin phenol resin obtained by thermally polymerizing phenol on an rosin (unmodified rosin, modified rosin, various rosin derivatives, etc.) with an acid catalyst;

Examples of the terpene tackifying resin are terpene resins such as α-pinene polymer, β-pinene polymer, and diterpene polymer; these terpene resins are modified (phenol modified, aromatic modified) Modified terpene resin such as hydrogenation modification, hydrocarbon modification, etc.; Examples of the modified terpene resin include a terpene-phenol resin, a styrene-modified terpene resin, an aromatic modified terpene resin, and a hydrogenated terpene resin.

Examples of the hydrocarbon tackifier resin include aliphatic hydrocarbon resins, aromatic hydrocarbon resins, aliphatic cyclic hydrocarbon resins, aliphatic/aromatic petroleum resins (styrene-olefin copolymers, etc.), aliphatic/fat Various hydrocarbon resins such as a cycloh petroleum resin, a hydrogenated hydrocarbon resin, a coumarone resin, and a coumarone-indene resin. The aliphatic hydrocarbon resin may, for example, be a polymer of an aliphatic hydrocarbon selected from one or more of an olefin having 4 to 5 carbon atoms and a diene. Examples of the olefin include 1-butene, isobutylene, 1-pentene and the like. Examples of the diene include butadiene, 1,3-pentadiene, and isoprene. The aromatic hydrocarbon resin is, for example, a polymerization of a vinyl-containing aromatic hydrocarbon (styrene, vinyl toluene, α-methylstyrene, anthracene, methylhydrazine, etc.) having a carbon number of about 8 to 10. Things and so on. Examples of the aliphatic cyclic hydrocarbon resin include an alicyclic hydrocarbon resin obtained by cyclizing and dimerizing a so-called "C4 petroleum fraction" and a "C5 petroleum fraction"; a polymer of a compound (cyclopentadiene, dicyclopentadiene, ethylidene norbornene, diterpene, etc.) or a hydride thereof; an aromatic hydrocarbon resin or an aromatic ring of an aliphatic/aromatic petroleum resin An alicyclic hydrocarbon resin obtained by hydrogenation; and the like.

If necessary, a filler, a flame retardant, an anti-aging agent, an antistatic agent, a softener, an ultraviolet absorber, an antioxidant, a plasticizer, a surfactant, a colorant (dye, etc.) may be added to the above binder. A known additive such as a pigment or the like, a light stabilizer, or the like.

Since the double-sided tape of the present invention has excellent initial cohesive force after coating, it can be bonded with an excellent holding force. In addition, the double-sided tape can also be adhered to various adherends with excellent adhesion.

In the present invention, the 180° peel adhesion of the pressure-sensitive adhesive layer is preferably 2 to 20 N/20 mm, and more preferably 4 to 12 N/20 mm. Here, the 180° peeling adhesive force is a 180 measured by a stainless steel (SUS304) plate as an adherend according to JIS Z0237, and pressed at a tensile speed of 300 mm/min 30 minutes after being pressed against the adherend. ° Peel adhesion. The double-sided tape disclosed herein preferably has one of the adhesive faces (one side) and the other adhesive side (two faces) of the adherend other than the release liner exhibiting the above-described 180° peel adhesion.

Further, the holding power of the pressure-sensitive adhesive layer of the double-sided tape disclosed herein is preferably 5.0 mm/hr or less, more preferably 2.0 mm/hr or less. Here, the above-mentioned holding force means that the electric board is used as an adherend according to JIS Z0237, and a double-sided tape is pressed against the adherend after being bonded to the adherend by a bonding area of 20 mm × 20 mm, and a load of 500 g is applied and left for 1 hour. Then, the offset distance of the double-sided tape from the initial pasting position was measured, thereby obtaining the holding force. It is preferable that both of the one side and the two sides of the adherend (double-sided tape other than the release liner) exhibit the above-described holding force.

Further, with respect to the double-sided tape disclosed herein, the adhesive layer surface (adhesive surface) of the double-sided tape preferably has a holding force against the adhered adherend measured in accordance with JIS Z0237 of 5.0 mm/hr or less. It is preferably 2.0 mm/hr or less. It is preferable that both of the one side and the two sides of the adherend exhibit the above-described holding force.

The thickness of the pressure-sensitive adhesive layer (the thickness of the pressure-sensitive adhesive layer on one side of the pressure-sensitive adhesive body) is not particularly limited, and the adhesion property, the total thickness of the base material layer and the pressure-sensitive adhesive layer formed on both surfaces thereof, or the unevenness can be considered. Appropriate selection is made for sex and operability. It is preferably 1 to 30 μm, more preferably 10 to 25 μm, and particularly preferably 13 to 20 μm. When the thickness of the pressure-sensitive adhesive layer is less than 1 μm, it is difficult to obtain good adhesion. When the thickness is more than 30 μm, the thickness of the double-sided tape is large, and it may be produced by fixing a flexible printed circuit board or the like. Thinning and miniaturization of the product are disadvantageous. The adhesive layer may be a single layer or a plurality of layers. Further, the thicknesses of the two adhesive layers formed on both sides of the substrate layer may be substantially the same or different, but in many cases, the thicknesses of both are substantially the same.

In the present invention, the total thickness of the base material layer and the pressure-sensitive adhesive layer formed on both surfaces thereof (that is, the thickness of the pressure-sensitive adhesive body other than the release liner) may be in the range of 3 to 80 μm, preferably 10 to 10 60 μm, more preferably 25 to 50 μm, particularly preferably 30 to 45 μm. When the thickness of the adherend is more than 80 μm, it is disadvantageous for thinning and miniaturization of a product (for example, a hard disk drive or the like) produced by the double-sided tape of the present invention. On the other hand, when it is less than 3 μm and is too thin, the workability, workability, and adhesiveness of the double-sided tape may be lowered.

The thickness of the pressure-sensitive adhesive layer formed on both surfaces of the base material layer may be the same or different. It is generally preferred that the thickness of the pressure-sensitive adhesive layer formed on both surfaces of the base material layer be substantially the same level. For example, the thickness of the pressure-sensitive adhesive layer formed on one surface of the base material layer can be 0.8 to 1.2 times (preferably 0.9 times) with respect to the thickness of the pressure-sensitive adhesive layer formed on one surface of the base material layer. 1.1 times, more preferably 0.95 times to 1.05 times, and typically 1.0 times).

Although not particularly limited, the double-sided tape disclosed herein may suitably have a total thickness of the adhesive layer formed on both sides (one side and two sides) of the base material layer with respect to the thickness of the base material layer by more than 2 times. The way to implement. The total thickness of the pressure-sensitive adhesive layers formed on both surfaces of the base material layer is preferably 3 times or more, and more preferably 4 times or more (for example, 5 times or more) with respect to the thickness of the base material layer. Thereby, by increasing the ratio of the total thickness of the pressure-sensitive adhesive layer to the thickness of the base material layer, the unevenness conformability and the adhesion to the adherend (for example, 180° peel adhesion) can be achieved at a high level. In the embodiment in which the thickness of the base material layer is 15 μm or less (for example, 13 μm or less), it is particularly preferable to use the above-described “ratio of the total thickness of the pressure-sensitive adhesive layer to the thickness of the base material layer”. When the thickness of the pressure-sensitive adhesive layer is increased, the peeling force of the release liner and the surface of the pressure-sensitive adhesive layer tends to be high. Therefore, it is particularly meaningful to apply the technique disclosed herein to define the peeling force.

(release liner)

The release liner is not particularly limited and can be appropriately selected from known release liners. As the release liner, a liner in which a release coating layer is formed on at least one surface of a substrate (base material for release liner) can be suitably used. The base material of the release liner may be, for example, a plastic film, a paper, a foam, a metal foil or the like, but generally the plastic film can be used satisfactorily. The material of the plastic film as the release liner substrate may be a polyester such as polyethylene terephthalate, a polyolefin such as polypropylene or an ethylene-propylene copolymer, or a thermoplastic resin such as polyvinyl chloride. The release liner substrate may, for example, be a polyolefin film composed of a polyolefin resin and a polyester film composed of a polyester resin, because the polyolefin film and the polyester film are bonded to each other. Since it has excellent adhesion and affinity, and has excellent flexibility, even if it is warped in various processes, it does not float, and it can maintain the state adhered to the adhesive surface favorably. Further, the substrate of the release liner may be a single layer or a plurality of layers.

As the polyolefin-based resin, polyethylene, polypropylene, and ethylene-α-olefin copolymer are suitable, and among them, polyethylene (especially linear low-density polyethylene, low-density polyethylene) can be suitably used. Therefore, as the polyolefin-based release liner, a polyethylene-based film or sheet (especially a linear low-density polyethylene film or sheet, a low-density polyethylene film or sheet) can be suitably used.

Examples of the polyester resin include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), and polynaphthalene. Butylene formate and the like. Especially preferred PET. Therefore, a PET-based release liner of a PET film can be suitably used.

The thickness of the base material of the release liner is not particularly limited, and may be appropriately selected, for example, in the range of 5 to 75 μm (preferably 8 to 50 μm, more preferably 12 to 40 μm). When the thickness is too large, the rigidity is large, and the compliance with the side surface of the pressure-sensitive adhesive layer is lowered, and the floating of the release liner may easily occur. In addition, when the strip is elongated, the diameter of the reel becomes large, and the volume sometimes becomes large. On the other hand, when the thickness is less than 5 μm, the workability at the time of peeling off the release liner may be inferior. When the double-sided tape of the present invention has two release liners, the thickness of the two release liners may be substantially the same or different.

The double-sided tape disclosed herein may preferably be implemented in such a manner that the thicknesses of the two release liners described above are different. By making the thickness of one of the two release liners larger than the other one, it is possible to improve the workability (for example, the punchability) of the double-sided tape before peeling off the release liner. In addition, it is possible to suppress the total thickness of the double-sided tape (including the thickness of the adherend and the two release liners) as compared with the case where the thickness of both of the release liners is increased, and it is also possible to suppress the float of the release liner. Start. In addition, it is preferable that the thickness of the one-side release liner is thicker than the other side, and it is excellent in workability, and it is also easy to produce a starting point of peeling (pickup property is good). When the thickness of the base material layer is 15 μm or less (for example, 13 μm or less), it is particularly meaningful to achieve the workability and other characteristics by making the thickness of the release liner different as described above.

The difference between the thicknesses of the two release liners is usually less than 50 μm, and from the viewpoint of better suppressing the floating of the release liner, it is preferably 40 μm or less, and more preferably 30 μm or less. In a preferred embodiment, the difference in thickness of the release liner may be 20 μm or less, or may be 15 μm or less. In addition, the lower limit of the difference in the thickness of the two release liners may be greater than 0. However, from the viewpoint of better exerting the effect of different thicknesses, it is appropriate to set the difference in thickness to 3 μm or more, and preferably 5 μm or more. More preferably, it is 10 micrometer or more. The difference in thickness of the two release liners can be suitably employed, for example, in a double-sided tape having a thickness of the base material layer of 15 μm or less (for example, 13 μm or less).

In the above release liner, it is preferred to provide a release treatment layer on the surface of the substrate with a release treatment agent. The release treatment agent constituting the release treatment layer is not particularly limited, and for example, a silicone release treatment agent, a fluorine release treatment agent, a long-chain alkyl release treatment agent, or the like can be used. The release treatment agents may be used singly or in combination of two or more.

As the release treatment agent, a silicone release treatment agent is suitable from the viewpoints of peelability, cost, and the like. The silicone-based release treatment agent can be appropriately selected from a known polysiloxane-based release treatment agent (silicone-based release treatment agent) containing a polysiloxane-based polymer as a main component. In the silicone release treatment agent, an addition reaction type polysiloxane release treatment agent can be suitably used. The addition reaction type polysiloxane release treatment agent can be cured by an addition reaction type crosslinking (curing reaction) to form a release film, and exhibits useful release characteristics. For example, a silicone-based release treatment agent exemplified in, for example, JP-A-2004-346303, and the like.

As an addition reaction type polysiloxane type release treatment agent, it can be peeled from the well-known addition reaction type polysiloxane type. Appropriate selection and use from the treatment agent. Such a polysiloxane-based release treatment agent is, for example, commercially available under the trade name "TPR6600" (product of GE Toshiba Silicone Co., Ltd.), trade name "KS-778" (product of Shin-Etsu Chemical Co., Ltd.), and trade name "KS-837". Commercial products of Shin-Etsu Chemical Co., Ltd. products.

The release treatment layer can be formed by applying a release treatment agent to a predetermined surface of the base material for a release liner, followed by a heating step for drying, a curing reaction, or the like. A known or conventional heating method (for example, a method using a hot air dryer) can be used in the heating step for drying, curing reaction, and the like. Further, it is important that the coating amount of the release treatment agent is appropriate. When the coating amount of the release treatment agent is too small, the peeling force is large, and there is a problem in practical use. If the amount is too large, the cost increases and it is economically disadvantageous. The suitable coating amount (solid content) of the release treatment agent can be appropriately selected depending on the type of the binder to be used, and the like, and may be, for example, 0.01 to 5 g/m ² , preferably 0.05 to 3 g/m ² , and more preferably 0.2 to 1 g. /m ² .

The thickness of the release-treated layer is not particularly limited, and can be appropriately selected, for example, in the range of 0.03 to 10 μm (preferably 0.1 to 5 μm, more preferably 0.3 to 2 μm).

In the double-sided tape of the present invention, the peeling force of the release liner on the surface (adhesive surface) of the pressure-sensitive adhesive layer in the 180° peel test is 0.01 N/50 mm or more, less than 0.30 N/50 mm, preferably 0.05. N/50 mm or more and 0.28 N/50 mm or less, more preferably 0.07 N/50 mm or more and 0.25 N/50 mm or less. When the peeling force is 0.30 N/50 mm or more, the structure of the double-light peeling release liner of the present invention may make it difficult to obtain an effect of preventing floating when the release liner is peeled off. On the other hand, when the peeling force is less than 0.01 N/50 mm, the protective property is inferior and the floating of the release liner may easily occur. The peeling force of each release liner may be the same or different. Further, if both are less than 0.30 N/50 mm, either one of the release liners may be relatively large or small. However, it is preferable that the peeling force of the larger one is not more than 200% of the peeling force of the smaller one. For example, the peeling force of the larger one is preferably 150% or less of the peeling force of the smaller one, and more preferably 125% or less.

Although not particularly limited, in the embodiment in which two release liners having different thicknesses are provided as described above, the release liner (F1) [N/50 mm] of the release liner having a large thickness is higher than the peeling having a small thickness. The peeling force (F2) [N/50 mm] of the liner is advantageous. As described above, when the thickness of the release liner is increased, the lifting of the release liner may easily occur. Therefore, by configuring F2 < F1, it is possible to effectively suppress the floating of any of the release liners having different thicknesses. For example, F1/F2 may be made larger than 1.0 and 1.5 or less, preferably 1.05 or more and 1.25 or less. The above-described configuration can be preferably used, for example, in a double-sided tape having a difference in thickness of the release liner of 5 μm or more and 40 μm or less (more preferably 10 μm or more and 30 μm or less).

When the surface of the base material of the release liner has a release treatment layer, it can be produced, for example, by applying a release treatment agent to at least one surface (especially one surface) of the base material, drying or solidifying as necessary, and forming a release treatment layer.

(double-sided tape products)

The adhesive layer surface (adhesive side) of the double-sided tape of the present invention can be protected by a release liner before use. As shown in FIG. 1, each of the adhesive faces of the double-sided tape can be protected from being curled into a roll shape by a release liner having a double-faced peeling surface. However, in general, in order to improve the workability, As shown in FIG. 2, in the double-sided tape 20 including the base material layer 21, the adhesive faces of the two adhesive layers (22, 22') are respectively protected by two release liners (23, 23'). The release liner is used as a protective material for the adhesive layer, and is peeled off after the double-sided tape is adhered to the adherend.

Further, in the present invention, the total thickness of the pressure-sensitive adhesive and the release liner is not particularly limited, but is preferably 180 μm or less. If the total thickness is too large, the overall rigidity of the double-sided tape protected by the release liner is too large, and may float at the interface between the adhesive face and the release liner. In addition, the diameter of the reel becomes large and the volume becomes large at the time of the sliver, and the total thickness is preferably 150 μm or less, more preferably 130 μm or less (for example, 125 μm or less, and further 120 μm or less). The lower limit of the total thickness is not particularly limited, and may be, for example, 60 μm or more.

The double-sided tape may be in the form of a laminate of sheets, or may be in a form of being rolled into a roll shape. Further, in the present invention, the double-sided tape may be protected from the outer surface of the release liner by a surface protection material such as the "SPV-V" series manufactured by Nitto Denko Corporation before use.

It should be noted that the matters disclosed in the present specification include the following technical solutions.

(1) A double-sided tape in which a base material layer, each of the pressure-sensitive adhesive layers on both surfaces of the base material layer, and each release liner are laminated in this order, and the release liner is adhered to the above-mentioned The surface in contact with the surface of the mixture layer was a lightly peelable surface having a peeling force of 0.01 N/50 mm or more and less than 0.30 N/50 mm as measured by JIS Z0237.

(2) The double-sided tape according to (1), wherein the release liner has a light-peelable release treatment layer formed on a surface of a film or a sheet of a substrate.

The double-sided tape according to the above aspect (1), wherein the release liner has a peeling force from the surface of the pressure-sensitive adhesive layer of 0.05 N/50 mm or more and 0.28 N/50 mm or less. .

(4) The double-sided tape according to the above (1) or (2), wherein a peeling force of the release liner to the surface of the pressure-sensitive adhesive layer is 0.07 N/50 mm or more and 0.25 N/50 mm or less. .

(5) The double-sided tape according to the above (1) or (2), wherein the pressure-sensitive adhesive layer has a 180° peel adhesion measured according to JIS Z0237 of 2 to 20 N/20 mm.

(6) The double-sided tape according to the above (1) or (2), wherein the pressure-sensitive adhesive layer has a holding force against the adherend measured in accordance with JIS Z0237 of 5.0 mm/hr or less.

(7) The double-sided tape according to the above aspect (1), wherein the total thickness of the base material layer and the pressure-sensitive adhesive layer formed on both surfaces of the double-sided tape is 3 to 80 μm.

(8) The double-sided tape according to the above (1) or (2), wherein the two release liners provided on both surfaces of the base material layer have the same peeling force as the surface of the pressure-sensitive adhesive layer.

(9) The double-sided tape according to the above (1) or (2), wherein the two release liners provided on both surfaces of the base material layer are different from the peeling force of the surface of the pressure-sensitive adhesive layer, The peeling force of the larger side is not more than 200% of the peeling force of the smaller one.

(10) The double-sided tape according to the above (1) or (2), wherein the release liner has a polyester film or a sheet as a substrate.

The double-sided tape according to the above (1) or (2), wherein the pressure-sensitive adhesive layer is formed of an acrylic pressure-sensitive adhesive.

(12) The double-sided tape according to the above (2), wherein the release-treated layer of the release liner is formed of a silicone release treatment agent.

The invention will now be described in more detail with reference to the examples, but the invention is not limited to these examples.

In the following description, "parts" means "parts by weight" unless otherwise specified.

(polymer)

The polymers synthesized as described below were used in the following examples and comparative examples.

68 parts of toluene, 70 parts of 2-ethylhexyl acrylate, 30 parts of butyl acrylate and 3 parts of acrylic acid were added to a reactor equipped with a thermometer, a stirrer, a nitrogen inlet tube and a reflux condenser with nitrogen (N ₂ ) Replacement for more than 1 hour. An azobisisobutyronitrile (product of Shanghai Test Sihewei Chemical Co., Ltd.) was charged as an initiator, and then the temperature of the inner bath was raised to 62 ° C, the temperature was maintained until the reaction was almost completed, and then, the reaction was terminated by cooling.

(tackifying resin)

A trade name "Pensel D-125" (product of Arakawa Chemical Co., Ltd.) of a polymerized rosin pentaerythritol ester was used as a tackifier resin.

(crosslinking agent)

A trade name "Coronate L" (product of Nippon Polyurethane Industry Co., Ltd.) of an isocyanate crosslinking agent was used as a crosslinking agent.

Example 1

A binder solution was prepared by adding 3 parts of a crosslinking agent to 100 parts of the above polymer, and then adding 30 parts of a tackifying resin.

A 25 μm-thick PET film (light peeling A#25) which had been subjected to a light peeling treatment A (which can be treated in the same manner as HY-S10 (product of Higashiyama Film Co., Ltd.)) was prepared. The above-mentioned binder solution was applied onto the release surface (one surface) of the PET film and dried to form a pressure-sensitive adhesive layer having a thickness of 4 μm at the time of drying. Thereby, the pressure-sensitive adhesive layer laminated on one surface of the base material layer is formed on the thin release surface (one surface) of the PET. Further, one surface of the 2 μm thick PET film of the substrate layer was laminated on the surface of the pressure-sensitive adhesive layer.

A 38 μm thick PET film (light peeling A#38) subjected to light peeling treatment A was prepared. The above-mentioned binder solution was applied onto the release surface (two surfaces) of the PET film and dried to form a pressure-sensitive adhesive layer having a thickness of 4 μm at the time of drying. Thus, the pressure-sensitive adhesive layer laminated on both surfaces of the base material layer was formed on the release surface (two surfaces) of the PET film. The pressure-sensitive adhesive layer on the two surfaces is laminated on the surface (two surfaces) of the side of the PET film on which the pressure-sensitive adhesive layer is not laminated, thereby laminating one surface and two surfaces of the base material layer, respectively. The adhesive layer was obtained as a double-sided tape having a thickness of 10 μm without a release liner.

Example 2

A double-sided tape was obtained in the same manner as in Example 1 except that the thickness of each of the two adhesive layers laminated on one side and two sides was 13 μm, and the thickness of the PET film of the base material layer was 4 μm. The thickness of the release liner was 30 μm.

Example 3

A double-sided tape was obtained in the same manner as in Example 1 except that the thickness of each of the two pressure-sensitive adhesive layers laminated on one side and two sides was 24 μm, and the thickness of the PET film of the base material layer was 12 μm. The thickness without the release liner was 60 μm.

Example 4

A double-sided tape was obtained in the same manner as in Example 1 except that the thickness of each of the two pressure-sensitive adhesive layers laminated on one side and two sides was 14 μm, and the thickness of the PET film of the substrate layer was 23 μm. The thickness without the release liner was 51 μm.

Example 5

A double-sided tape was obtained in the same manner as in Example 1 except that the thickness of each of the two pressure-sensitive adhesive layers laminated on one side and two sides was 21 μm, and the thickness of the PET film of the base material layer was 18 μm. The thickness without the release liner was 60 μm.

Example 6

A double-sided tape was obtained in the same manner as in Example 1 except that the thickness of each of the two pressure-sensitive adhesive layers laminated on one side and two sides was 19 μm, and the thickness of the PET film of the substrate layer was 12 μm. The thickness without the release liner was 50 μm.

Example 7

A double-sided tape was produced in the same manner as in Example 6 except that the two-side release treatment was changed to the light release treatment B (the same treatment as HY-US20 (product of Higashiyama Film Co., Ltd.)). The thickness of the liner was 50 μm. In this example, a PET film having a thickness of 38 μm (light peeling B#38) having a thickness of 38 μm subjected to the above-described light peeling treatment B is used as a release liner for forming a pressure-sensitive adhesive layer laminated on both surfaces of the base material layer. ) generation A PET film of A#38 was lightly peeled off.

Example 8

A double-sided tape was produced in the same manner as in Example 6 except that the thickness of the base material of the one-side release liner and the base of the two-side release liner was changed to 38 μm and 75 μm, respectively, and the release liner was not contained. The thickness of the mat was 50 μm. In this example, as a release liner for forming a pressure-sensitive adhesive layer laminated on one surface of a base material layer, a PET film of light-peeling A#38 is used as a two-side layer for forming a laminate layer. For the release liner of the pressure-sensitive adhesive layer, a PET film (light peeling A#75) having a thickness of 75 μm subjected to the above-described treatment of the light release treatment A was used.

Example 9

A double-sided tape was produced in the same manner as in Example 3 except that the release treatment on the two sides was changed to the light release treatment B (the same treatment as HY-US20 (product of Higashiyama Film Co., Ltd.)), and the release tape was not peeled off. The thickness of the liner was 60 μm. That is, in this example, a PET film of light peeling B#38 was used as a release liner for forming the adhesive layer laminated on the both surfaces of a base material layer.

Example 10

In the case of the first embodiment, the one-side and two-side release treatments were changed to the light release treatment B (the same treatment as HY-US20 (product of Higashiyama Film Co., Ltd.)). That is, in this example, as a release liner for forming the pressure-sensitive adhesive layer laminated on one surface of the base material layer, a PET film of light peeling B#38 was used. In addition, as a release liner for forming the two-layer pressure-sensitive adhesive layer laminated on the base material layer, a PET film (light peeling B#75) having a thickness of 75 μm subjected to the above-described light peeling treatment B treatment was used. Otherwise, in the same manner as in Example 8, a double-sided tape having a thickness of 50 μm without a release liner was obtained.

Example 11

A double-sided tape having a thickness of 60 μm without a release liner was obtained in the same manner as in Example 8 except that the thickness of each of the two adhesive layers laminated on one side and two sides was 24 μm.

Example 12

A double-sided tape having a thickness of 50 μm without a release liner was obtained in the same manner as in Example 6, except that the thickness of the substrate of the one-side release liner was changed to 12 μm. In this example, a PET film having a thickness of 12 μm (light peeling A#12) having a thickness of 12 μm which has been subjected to the above-described light peeling treatment A is used as a release liner for forming a pressure-sensitive adhesive layer laminated on one surface of the base material layer. ).

Example 13

A double-sided tape having a thickness of 30 μm without a release liner was obtained in the same manner as in Example 3 except that the thickness of each of the two adhesive layers laminated on one side and two sides was 9 μm.

Comparative example 1

In addition to the case where the thickness of the base material having the two-sided release liner is 75 μm, and the release treatment on the two sides is changed to the heavy release treatment C (the treatment equivalent to HY-S30 (product of Higashiyama Film Co., Ltd.)), 2 In the same manner, a double-sided tape having a thickness of 30 μm without a release liner was obtained. In this example, as a release liner for forming the pressure-sensitive adhesive layer of the two surfaces of the base material layer, a PET film having a thickness of 75 μm subjected to the above-described treatment of the heavy separation treatment C (heavy peeling C#75) was used. ).

(Evaluation)

The peeling force and peeling property of each of the double-sided tape products obtained in the examples and the comparative examples were measured by the following methods.

The results are shown in Table 1.

(Method of measuring peeling force)

A tape piece having a width of 50 mm and a length of 150 mm was cut out from the double-sided tape product, and the release liner opposite to the release liner on which the peeling force was to be tested was peeled off, and then a PET film having a thickness of 25 μm was bonded to the pressure-sensitive adhesive surface. Have to test the sample.

The release liner was subjected to a 180° peel test in accordance with JIS Z 0237 using a tensile tester, and the 180° peel adhesion (N/50 mm) of the release liner was measured as the “peeling force of the release liner”. The measurement was carried out under the conditions of a peeling angle of 180° and a tensile speed of 300 mm/min in an environment of 23° C.±2° C. and 50%±5% RH. The number of tests (n number) was three times, and the average value was calculated.

(Method for evaluating peelability of release liner)

A double-sided tape of 50 mm × 300 mm size was prepared, and each of the release liners was peeled off at a speed of 0.3 to 50 m/min, and it was confirmed whether or not a "floating" phenomenon occurred. Specifically, when the one side release liner was peeled off, it was visually confirmed whether or not the interface between the release liner on the peeling side and the surface (adhesive surface) of the pressure-sensitive adhesive layer was reliably peeled off, and whether the peeling could be easily performed. Whether the release liner on the side is peeled off from the double-sided tape, and whether the release liner on the other side (the release liner on the unpeeled side) floats from the adhesive surface of the double-sided tape or the adhesive sheet, and whether or not The interface between the release liner on the peeling side and the adhesive face is not peeled off, and the interface between the release liner on the other side and the adhesive face is peeled off.

In addition, the peeling evaluation criteria of a release liner are as follows.

○: When the one side release liner was peeled off, the peeling was easy and the release liner on the other side did not float.

×: The peeling pad on the other side floats

Table 1

(result)

As shown in Table 1, in Examples 1 to 13, regardless of which side of the release liner was peeled off, the release liner and the adhesion were peeled off without causing a so-called "floating" phenomenon. The surface between the layers is peeled off, and the release liner to be peeled off is easily peeled off from the double-sided tape.

On the other hand, in Comparative Example 1, when the release liner on the side of the heavy peeling treatment was peeled off, a so-called "floating" phenomenon occurred on the release liner on the side of the light peeling treatment.

The specific examples of the present invention have been described in detail above, but these are merely illustrative and not limiting. The technology described in the claims includes various modifications and changes to the specific examples described above.

Claims

a double-sided tape having a substrate layer and an adhesive layer sequentially laminated on both sides of the substrate layer, and a release liner sequentially laminated on the adhesive layer, the release liner and the adhesive layer The surface contact surface was measured to have a peeling force of 0.01 N/50 mm or more and less than 0.30 N/50 mm as measured in accordance with JIS Z0237.
The double-sided tape according to claim 1, wherein the release liner has a release treatment layer formed on a surface of a film or sheet as a substrate.
The double-sided tape according to claim 1 or 2, wherein a peeling force of the release liner from the surface of the pressure-sensitive adhesive layer is 0.05 N/50 mm or more and 0.28 N/50 mm or less.
The double-sided tape according to any one of claims 1 to 3, wherein a peeling force of the release liner to the surface of the pressure-sensitive adhesive layer is 0.07 N/50 mm or more and 0.25 N/50 mm or less.
The double-sided tape according to any one of claims 1 to 4, wherein the pressure-sensitive adhesive layer has a 180° peel adhesion measured by JIS Z0237 of 2 to 20 N/20 mm.
The double-sided tape according to any one of claims 1 to 5, wherein the adhesive layer has a holding force against the electric board measured by JIS Z0237 of 5.0 mm/hr or less.
The double-sided tape according to any one of claims 1 to 6, wherein a total thickness of the base material layer and the pressure-sensitive adhesive layer formed on both surfaces of the double-sided tape is 3 to 80 μm.
The double-sided tape according to any one of claims 1 to 7, wherein the peeling force of the two release liners provided on both surfaces of the base material layer and the surface of the pressure-sensitive adhesive layer are the same.
The double-sided tape according to any one of claims 1 to 8, wherein the peeling force of the two release liners provided on both surfaces of the base material layer and the surface of the pressure-sensitive adhesive layer are different from each other. The peeling force is not more than 200% of the peeling force of the smaller one.
The double-sided tape according to any one of claims 1 to 9, wherein the release liner is made of a polyester film or a sheet.
The double-sided tape according to any one of claims 1 to 10, wherein the pressure-sensitive adhesive layer is formed of an acrylic pressure-sensitive adhesive.
The double-sided tape according to any one of claims 1 to 11, wherein the release liner has a release treatment layer formed of a silicone release treatment agent formed on a surface of a film or sheet as a substrate. .