WO2018181336A1

WO2018181336A1 - Double-sided adhesive tape

Info

Publication number: WO2018181336A1
Application number: PCT/JP2018/012468
Authority: WO
Inventors: 友也川本; 繁季松木; 徳之内田; 智土居; 泰志石堂; 寛幸片岡
Original assignee: 積水化学工業株式会社
Priority date: 2017-03-29
Filing date: 2018-03-27
Publication date: 2018-10-04
Also published as: CN110023439B; TW201840771A; KR102561378B1; TWI802564B; CN110023439A; KR20190128620A; JPWO2018181336A1; JP7036715B2

Abstract

The purpose of the present invention is to provide a double-sided adhesive tape having excellent stress relaxation properties and impact resistance, as well as excellent reworkability on both adhesive surfaces. This double-sided adhesive tape includes a foam substrate, and a first adhesive layer and a second adhesive layer which are respectively provided to one side and the other side of the foam substrate, wherein a first resin layer and a second resin layer having a tensile breaking point stress of 4 MPa or greater are disposed between the foam substrate and the first adhesive layer and between the foam substrate and the second adhesive layer, respectively.

Description

Double-sided adhesive tape

The present invention relates to a double-sided pressure-sensitive adhesive tape having excellent stress relaxation properties and impact resistance and excellent reworkability on both pressure-sensitive adhesive surfaces.

Double-sided adhesive tape is used for assembly in portable electronic devices such as mobile phones and personal digital assistants (PDAs) (for example, Patent Documents 1 and 2). In addition, double-sided adhesive tape is also used for fixing an in-vehicle electronic device component such as an in-vehicle panel to a vehicle body.

JP 2009-242541 A JP 2009-258274 A

High adhesive strength is required for double-sided adhesive tapes used for fixing portable electronic device parts, in-vehicle electronic device parts, and the like. Furthermore, in recent years, portable electronic devices, in-vehicle electronic devices, and the like tend to become more complicated in shape with higher functionality, and therefore, a double-sided adhesive tape is affixed to steps, corners, non-planar parts, etc. There is. In such a case, since the double-sided adhesive tape is fixed in a deformed state, a force to return to the original shape, that is, a restoring force or a repulsive force works, and the double-sided adhesive tape may peel off over time. It was. In particular, when fixing a part in a deformed state, the part itself tries to return to its original shape, so that the double-sided adhesive tape is subjected to restoring force and repulsion, and the fixing is insufficient, Sometimes it peeled off. In order to prevent peeling due to such restoring force and repulsive force, the double-sided pressure-sensitive adhesive tape is required to have excellent stress relaxation properties. Further, the double-sided pressure-sensitive adhesive tape may be required to have impact resistance.

As a double-sided pressure-sensitive adhesive tape having excellent stress relaxation properties and excellent impact resistance, a double-sided pressure-sensitive adhesive tape using a foam base material is known. However, with a double-sided pressure-sensitive adhesive tape using a conventional foam base material, the foam base material is cracked at the time of peeling when it is used for temporary fixing or when it is desired to peel off after bonding for some reason. There was a problem that the residue may remain on the body and the reworkability is poor. In particular, in a double-sided pressure-sensitive adhesive tape, reworkability on both pressure-sensitive adhesive surfaces has been demanded.

An object of this invention is to provide the double-sided adhesive tape which has the outstanding stress relaxation property and impact resistance, and was excellent in the rework property in both adhesive surfaces.

This invention is a double-sided adhesive tape which has a 1st adhesive layer and a 2nd adhesive layer on both surfaces of a foam base material and the said foam base material, Comprising: The said foam base material and said 1st Both surfaces having a first resin layer and a second resin layer each having a tensile stress at break of 4 MPa or more between the pressure-sensitive adhesive layers and between the foam base material and the second pressure-sensitive adhesive layer It is an adhesive tape.
The present invention is described in detail below.

In the double-sided pressure-sensitive adhesive tape having the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer on both sides of the foam base material and the foam base material, the present inventors have provided the foam base material and the first pressure-sensitive adhesive. A first resin layer and a second resin layer having a tensile breaking point stress of a certain level or more were disposed between the layers and between the foam base material and the second pressure-sensitive adhesive layer. While adopting a foam base material that can exhibit excellent stress relaxation and impact resistance by disposing such a first resin layer and a second resin layer, the present inventors have provided both adhesive surfaces. The present invention was completed by discovering that excellent reworkability can be exhibited.

In FIG. 1, the schematic diagram which shows an example of the double-sided adhesive tape which concerns on one embodiment of this invention was shown. 1 has a first pressure-sensitive adhesive layer 31 and a second pressure-sensitive adhesive layer 32 on both surfaces of a foam substrate 2. The double-sided pressure-sensitive adhesive tape 1 according to an embodiment of the present invention shown in FIG. And the 1st resin layer 41 is arrange | positioned between the foam base material 2 and the 1st adhesive layer 31, and it is 2nd resin between the foam base material 2 and the 2nd adhesive layer 32. Layer 42 is disposed.

The double-sided pressure-sensitive adhesive tape according to one embodiment of the present invention has a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer on both sides of the foam base material and the foam base material, respectively.
By using the said foam base material, the double-sided adhesive tape which concerns on one embodiment of this invention can exhibit the outstanding stress relaxation property and impact resistance. The foam substrate may have an open cell structure or a closed cell structure, but preferably has an open cell structure. By using a foam base material having an open cell structure, more excellent stress relaxation properties and impact resistance can be exhibited. The foam substrate may have a single layer structure or a multilayer structure.

The said foam base material is not specifically limited, For example, a polyurethane foam, a polyolefin foam, a rubber-type resin foam, an acrylic foam etc. are mentioned. Among these, a polyurethane foam or a polyolefin foam is preferable because it can easily form an open-cell structure and can exhibit excellent stress relaxation and impact resistance.

Although the density of the said foam base material is not specifically limited, A preferable minimum is 0.03 g / cm < ³ > and a preferable upper limit is 0.8 g / cm < ³ >. By setting the density of the foam base in this range, it is possible to exhibit excellent stress relaxation properties and impact resistance while maintaining the strength of the double-sided pressure-sensitive adhesive tape. From the viewpoint of the strength, stress relaxation property and impact resistance of the double-sided pressure-sensitive adhesive tape, a more preferable lower limit of the substrate is 0.1 g / cm ³ , a more preferable upper limit is 0.7 g / cm ³ , and a more preferable lower limit is 0. 0.15 g / cm ³ , a more preferred upper limit is 0.5 g / cm ³ , a particularly preferred lower limit is 0.2 g / cm ³ , and a particularly preferred upper limit is 0.4 g / cm ³ .
The density can be measured using an electronic hydrometer (for example, “ED120T” manufactured by Mirage, Inc.) according to JIS K 6767.

The 25% compressive strength of the foam substrate is not particularly limited, but a preferred lower limit is 1 kPa and a preferred upper limit is 100 kPa. By setting the 25% compressive strength of the foam base material within this range, excellent stress relaxation properties and impact resistance can be exhibited while maintaining the strength of the double-sided pressure-sensitive adhesive tape. From the viewpoint of further improving the strength, stress relaxation and impact resistance of the double-sided pressure-sensitive adhesive tape, the lower limit of the 25% compression strength of the substrate is more preferably 3 kPa, more preferably 50 kPa, and still more preferably 5 kPa. A preferable upper limit is 40 kPa.
In addition, 25% compressive strength can be calculated | required by measuring based on JISK6254.

The shear storage elastic modulus of the foam base material is not particularly limited, but the frequency is 1.0 × 10 ⁻⁴ to 1.0 × 10 ⁻ in the master curve measured at a reference temperature of 23 ° C. measured by a dynamic viscoelasticity device. The maximum value of the shear storage elastic modulus in the ⁵ Hz region is preferably 1.0 × 10 ⁵ Pa or less. The frequency range is a frequency corresponding to a peeling stress at a low speed generated when a restoring force or a repulsive force is applied to the double-sided pressure-sensitive adhesive tape. If the maximum value of the shear storage modulus in the frequency region is 1.0 × 10 ⁵ Pa or less, the foam base material relaxes the stress when a restoring force or repulsive force is applied to the double-sided pressure-sensitive adhesive tape, Since it is difficult to transmit to the adhesive layer, the stress relaxation property and impact resistance of the double-sided adhesive tape can be improved.
The shear storage modulus is in the range of −60 ° C. to 250 ° C. using a dynamic viscoelasticity measuring device (for example, DVA-200 manufactured by IT Measurement Co., Ltd.) at a rate of temperature increase of 5 ° C./min. It can be measured. When measuring the shear storage elastic modulus, measurement is performed by applying an adhesive on both sides of the substrate in order to suppress the deviation of the sample during the measurement. Although such an adhesive is not specifically limited, it measures by adjusting so that the thickness of the adhesive apply | coated to the both sides of the said base material may be 15% or less of the thickness of the said base material. By setting the thickness of the pressure-sensitive adhesive to 15% or less of the thickness of the base material, the shear storage elastic modulus of the base material can be measured while eliminating the influence of the pressure-sensitive adhesive as much as possible.

Although the thickness of the said foam base material is not specifically limited, A preferable minimum is 0.2 mm and a preferable upper limit is 2.9 mm. By setting the thickness of the foam base material within this range, the double-sided pressure-sensitive adhesive tape according to an embodiment of the present invention can be suitably used for fixing portable electronic device parts, in-vehicle electronic device parts, and the like. From the viewpoint that it can be suitably used for fixing the parts and the like, a more preferable lower limit of the thickness of the foam substrate is 0.3 mm, and a more preferable upper limit is 2.5 mm.

The first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer (hereinafter also referred to simply as “pressure-sensitive adhesive layer”) may have the same composition or different compositions. The pressure-sensitive adhesive layer is not particularly limited, and examples thereof include an acrylic pressure-sensitive adhesive layer, a rubber-based pressure-sensitive adhesive layer, a urethane pressure-sensitive adhesive layer, and a silicone-based pressure-sensitive adhesive layer. Among them, an acrylic pressure-sensitive adhesive layer containing an acrylic copolymer is relatively stable against light, heat, moisture, and the like and can adhere to various adherends (low adherend selectivity). Is preferred.

The acrylic copolymer constituting the acrylic pressure-sensitive adhesive layer is preferably obtained by copolymerizing a monomer mixture containing butyl acrylate and 2-ethylhexyl acrylate. The preferable lower limit of the butyl acrylate content in the total monomer mixture is 40% by weight, and the preferable upper limit is 80% by weight. By setting the content of the butyl acrylate within this range, both high adhesive strength and tackiness can be achieved. The preferable lower limit of the content of 2-ethylhexyl acrylate in the total monomer mixture is 10% by weight, and the preferable upper limit is 40% by weight. By setting the content of 2-ethylhexyl acrylate within this range, high adhesive strength can be exhibited.

The monomer mixture may contain other copolymerizable monomers other than butyl acrylate and 2-ethylhexyl acrylate as necessary. Examples of the other polymerizable monomer that can be copolymerized include, for example, (meth) acrylic acid alkyl esters having an alkyl group having 1 to 3 carbon atoms, (meth) acrylic acid alkyl esters having an alkyl group having 13 to 18 carbon atoms, A functional monomer etc. are mentioned.
Examples of the (meth) acrylic acid alkyl ester having 1 to 3 carbon atoms in the alkyl group include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, and (meth) acrylic acid. And isopropyl. Examples of the (meth) acrylic acid alkyl ester having 13 to 18 carbon atoms in the alkyl group include tridecyl methacrylate and stearyl (meth) acrylate. Examples of the functional monomer include hydroxyalkyl (meth) acrylate, glycerin dimethacrylate, glycidyl (meth) acrylate, 2-methacryloyloxyethyl isocyanate, (meth) acrylic acid, itaconic acid, maleic anhydride, crotonic acid, Maleic acid, fumaric acid, etc. are mentioned.

In order to copolymerize the monomer mixture to obtain the acrylic copolymer, the monomer mixture may be radically reacted in the presence of a polymerization initiator. As a method of radical reaction of the monomer mixture, that is, a polymerization method, a conventionally known method is used, and examples thereof include solution polymerization (boiling point polymerization or constant temperature polymerization), emulsion polymerization, suspension polymerization, bulk polymerization and the like.

As for the weight average molecular weight (Mw) of the said acrylic copolymer, a preferable minimum is 400,000 and a preferable upper limit is 1.5 million. By setting the weight average molecular weight of the acrylic copolymer within this range, high adhesive force can be exhibited. The minimum with said more preferable weight average molecular weight is 500,000, and a more preferable upper limit is 1.4 million.
In addition, a weight average molecular weight (Mw) is a weight average molecular weight of standard polystyrene conversion by GPC (Gel Permeation Chromatography: gel permeation chromatography).

A preferable upper limit of the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the acrylic copolymer is 10.0. When Mw / Mn exceeds 10.0, the low molecular component increases, and the acrylic pressure-sensitive adhesive layer is softened at a high temperature, the bulk strength may be lowered, and the adhesive strength may be lowered. A more preferable upper limit of Mw / Mn is 3.0.

The pressure-sensitive adhesive layer may contain a tackifier resin.
Examples of the tackifier resins include rosin ester resins, hydrogenated rosin resins, terpene resins, terpene phenol resins, coumarone indene resins, alicyclic saturated hydrocarbon resins, C5 petroleum resins, and C9 resins. Examples include petroleum resins and C5-C9 copolymer petroleum resins. These tackifying resins may be used alone or in combination of two or more.

The content of the tackifying resin is not particularly limited, but a preferable lower limit with respect to 100 parts by weight of a resin (for example, an acrylic copolymer) as a main component of the pressure-sensitive adhesive layer is 10 parts by weight, and a preferable upper limit is 60 parts by weight. . When the content of the tackifying resin is less than 10 parts by weight, the adhesive strength of the pressure-sensitive adhesive layer may be reduced. When content of the said tackifying resin exceeds 60 weight part, the said adhesive layer may become hard and adhesive force or tackiness may fall.

In the pressure-sensitive adhesive layer, a cross-linking structure is formed between main chains of a resin (for example, the acrylic copolymer, the tackifying resin, etc.) constituting the pressure-sensitive adhesive layer by adding a cross-linking agent. Is preferred. The said crosslinking agent is not specifically limited, For example, an isocyanate type crosslinking agent, an aziridine type crosslinking agent, an epoxy-type crosslinking agent, a metal chelate type crosslinking agent etc. are mentioned. Of these, isocyanate-based crosslinking agents are preferred. By adding an isocyanate-based crosslinking agent to the pressure-sensitive adhesive layer, an alcohol in a resin (for example, the acrylic copolymer, the tackifying resin, etc.) constituting the pressure-sensitive adhesive layer and the isocyanate group of the isocyanate-based crosslinking agent The reactive hydroxyl group reacts to loosen the pressure-sensitive adhesive layer. Therefore, the pressure-sensitive adhesive layer can disperse the intermittently applied peeling stress, and the adhesive strength of the double-sided pressure-sensitive adhesive tape is further improved.
The addition amount of the cross-linking agent is preferably 0.01 to 10 parts by weight, preferably 0.1 to 7 parts by weight with respect to 100 parts by weight of the resin (for example, the acrylic copolymer) as a main component of the pressure-sensitive adhesive layer. Is more preferable.

The pressure-sensitive adhesive layer may contain a silane coupling agent for the purpose of improving the adhesive strength. The silane coupling agent is not particularly limited, and examples thereof include epoxy silanes, acrylic silanes, methacryl silanes, amino silanes, and isocyanate silanes.

The pressure-sensitive adhesive layer may contain a colorant for the purpose of imparting light shielding properties. The colorant is not particularly limited, and examples thereof include carbon black, aniline black, and titanium oxide. Among these, carbon black is preferable because it is relatively inexpensive and chemically stable.

Although the thickness of the said adhesive layer is not specifically limited, The preferable minimum of the thickness of the adhesive layer of one side is 0.01 mm, and a preferable upper limit is 0.1 mm. By setting the thickness of the pressure-sensitive adhesive layer within this range, the double-sided pressure-sensitive adhesive tape according to one embodiment of the present invention can be suitably used for fixing portable electronic device parts, in-vehicle electronic device parts, and the like. From the viewpoint that it can be suitably used for fixing the parts and the like, a more preferable lower limit of the thickness of the pressure-sensitive adhesive layer is 0.015 mm, and a more preferable upper limit is 0.09 mm.

The double-sided pressure-sensitive adhesive tape according to one embodiment of the present invention includes a first resin between the foam base material and the first pressure-sensitive adhesive layer and between the foam base material and the second pressure-sensitive adhesive layer. Each having a layer and a second resin layer (hereinafter, both are also simply referred to as “resin layer”). By having the resin layer, the double-sided pressure-sensitive adhesive tape according to an embodiment of the present invention employs the foam base material that can exhibit excellent stress relaxation properties and impact resistance, and the foam base material at the time of peeling. Can be peeled off without leaving any residue on the adherend, and excellent reworkability can be exhibited on both adhesive surfaces.

The resin layer has a tensile stress at break of 4 MPa or more. By using a resin layer having a tensile stress at break of 4 MPa or more, excellent reworkability can be exhibited. From the viewpoint of further improving reworkability, the tensile break stress of the resin layer is preferably 5 MPa or more, and more preferably 15 MPa or more. Although the upper limit of the tensile breaking stress of the resin layer is not particularly limited, the upper limit is substantially about 200 MPa.

At least one of the first resin layer and the second resin layer preferably has a tensile elongation at break of 200% or more. By using a resin layer having a tensile elongation at break of 200% or more, more excellent reworkability can be exhibited. From the viewpoint of further improving the reworkability, the elongation at break of the resin layer is preferably 300% or more, and more preferably 450% or more. Although the upper limit of the tensile elongation at break of the resin layer is not particularly limited, the upper limit is substantially about 1500%.

It is preferable that at least one of the first resin layer and the second resin layer has a tensile modulus of 200 MPa or less. By making at least one of the first resin layer and the second resin layer a flexible resin layer having a tensile elastic modulus of 200 MPa or less, the flexibility of the entire double-sided adhesive tape is secured, and the double-sided adhesive tape is rolled. It becomes easy to wind up, and handling property improves markedly.

In this specification, the tensile stress at break, the tensile elongation at break and the tensile modulus of elasticity mean the mechanical properties of the resin layer and can be measured by a method according to JIS K 7161.
Specifically, for example, using a punching blade “tensile No. 1 type dumbbell shape” manufactured by Kobunshi Keiki Co., Ltd., the resin layer is punched on the dumbbell to prepare a test piece. The obtained test piece is measured at a tensile speed of 100 mm / min using, for example, “Autograph AGS-X” manufactured by Shimadzu Corporation, and the test piece is broken. The tensile breaking stress is calculated from the breaking strength per unit area when the test piece breaks. From the elongation when the test piece broke, the elongation at break at tensile break was calculated by “(distance between grips at break / distance between initial grippers) × 100”. The tensile modulus is calculated from the slope of the tensile strength between 1 to 3% strain.

The resin constituting the resin layer is not particularly limited. For example, polyester resin such as polyethylene terephthalate, acrylic resin, polyethylene resin, polypropylene resin, polyvinyl chloride, epoxy resin, silicone resin, phenol resin, polyimide, Examples thereof include polyester and polycarbonate. Of these, acrylic resins, polyethylene resins, polypropylene resins, and polyester resins are preferred because of their excellent flexibility. Among the polyester resins, polyethylene terephthalate is preferable.

The resin constituting at least one of the first resin layer and the second resin layer is preferably made of a thermoplastic elastomer from the viewpoint of further enhancing stress relaxation, impact resistance, and reworkability.
The thermoplastic elastomer includes styrene (co) polymer, olefin (co) polymer, vinyl chloride (co) polymer, polyetherester triblock (co) polymer, polyester (co) heavy. It may be a coalescence, urethane (co) polymer, amide (co) polymer or acrylic (co) polymer. Among them, it can exhibit strength, elongation, flexibility, and self-adhesiveness as an elastic body, and it can improve the adhesion between the resin layer and the foam base material while exhibiting excellent reworkability. From the viewpoint that the thermoplastic elastomer can be used, the thermoplastic elastomer is preferably an acrylic (co) polymer, a styrene (co) polymer, or an olefin (co) polymer. Furthermore, an acrylic (co) polymer or a styrene (co) polymer is more preferable, and an acrylic (co) polymer is more preferable.
The ratio of the thermoplastic elastomer in the resin constituting at least one of the first resin layer and the second resin layer is preferably 70% by weight or more, more preferably 80% by weight or more, still more preferably 90% by weight or more, particularly Preferably it is 95 weight% or more, and 100 weight% may be sufficient.

In a preferred embodiment of the present invention, the thermoplastic elastomer is preferably composed of a block copolymer having a hard segment and a soft segment from the viewpoint of further enhancing stress relaxation, impact resistance, and reworkability. The thermoplastic elastomer described above is a block copolymer having a hard segment and a soft segment.
In a further preferred embodiment of the present invention, the thermoplastic elastomer is more preferably composed of a triblock copolymer having a hard segment and a soft segment. That is, the resin constituting at least one of the first resin layer and the second resin layer is made of a triblock copolymer having a hard segment and a soft segment, or a triblock having a hard segment and a soft segment. More preferably, it is a copolymer. By using such a triblock copolymer, it is possible to exhibit strength, elongation, flexibility, and self-adhesiveness as an elastic body, and while exhibiting excellent reworkability, a resin layer and a foam base material Can be further improved.

Examples of the triblock copolymer include an acrylic triblock copolymer, a styrene triblock copolymer, a polyetherester triblock copolymer, a urethane copolymer, and a vinyl chloride copolymer. And amide copolymers.

The ratio of the hard segment in the block copolymer or the triblock copolymer is preferably 10% by weight or more and 70% by weight or less, more preferably 12% by weight or more and 65% by weight or less, It is more preferable that it is 14 to 60 weight%, and it is especially preferable that it is 55 weight% or less. By setting the ratio of the hard segment within this range, the adhesion of the resin layer to the foam base material, particularly a foam base material made of polyurethane foam or polyolefin foam, is improved.
Especially, from the viewpoint of improving the adhesion of the resin layer to the foam base material, particularly a foam base material made of polyurethane foam or polyolefin foam, the proportion of the hard segment is 10% by weight or more and 60% by weight or less. An acrylic triblock copolymer is more preferred. If an acrylic triblock copolymer with excellent adhesion is used, it is not necessary to use an adhesive or the like to bring the resin layer and the foam base material into close contact, and the thickness of the resulting double-sided adhesive tape can be reduced. it can.

Further, the thermoplastic elastomer is composed of a triblock copolymer and a diblock copolymer from the viewpoint of further improving stress relaxation, impact resistance and reworkability (triblock copolymer and diblock copolymer). It is also preferred that it comprises a mixture of
In a preferred embodiment of the present invention, the proportion of the triblock copolymer in the thermoplastic elastomer is preferably 70% by weight or more, more preferably 80% by weight or more, still more preferably 90% by weight or more, particularly preferably. It is 95% by weight or more and may be 100% by weight.

The component constituting the hard segment of the acrylic triblock copolymer is not particularly limited, but methyl methacrylate, ethyl methacrylate, methacrylate-n-butyl, methacrylate-2-ethylhexyl, lauryl methacrylate, methacrylic acid Examples thereof include alkyl and tridecyl methacrylate.
The component constituting the soft segment of the acrylic triblock copolymer is not particularly limited, and examples thereof include n-butyl acrylate, methyl acrylate, ethyl acrylate, and 2-ethylhexyl acrylate.
Among these, an acrylic triblock copolymer having a hard segment derived from methyl methacrylate and a soft segment derived from n-butyl acrylate is preferable.

When the acrylic triblock copolymer is an acrylic triblock copolymer having a hard segment derived from methyl methacrylate and a soft segment derived from n-butyl acrylate, in the triblock copolymer The minimum with the preferable ratio of the hard segment derived from methyl methacrylate is 22 weight%. Moreover, a preferable upper limit is 50 weight%. Furthermore, the more preferable lower limit of the ratio of the hard segment derived from methyl methacrylate is 24% by weight, and the more preferable upper limit is 48% by weight. When the ratio of the hard segment derived from the methyl methacrylate is within this range, particularly excellent adhesion to the foam base material can be exhibited, and it floats between the foam base material and the resin layer. And the like can be prevented. In addition, it can exhibit excellent heat resistance and heat shrinkage. For example, even when heat treatment is performed at 100 to 200 ° C. for about 10 to 30 minutes, it may melt or wrinkle. Absent. Furthermore, when it tries to expand | deploy after making it into a roll-shaped body, it will not become impossible to expand | deploy by blocking.

When the acrylic triblock copolymer is an acrylic triblock copolymer having a hard segment derived from methyl methacrylate and a soft segment derived from n-butyl acrylate, the weight of the triblock copolymer The average molecular weight is preferably 30,000 or more. When the weight average molecular weight of the triblock copolymer is 30,000 or more, particularly excellent adhesion to the foam base material can be exhibited, and reworkability of the double-sided pressure-sensitive adhesive tape can be exhibited. it can. The weight average molecular weight of the triblock copolymer is more preferably 50,000 or more. The upper limit of the weight average molecular weight of the triblock copolymer is not particularly limited, but about 200,000 is the upper limit in consideration of handleability and the like.

The resin layer may be colored. By coloring the resin layer, light-shielding properties can be imparted to the double-sided pressure-sensitive adhesive tape.
The method for coloring the resin layer is not particularly limited. For example, a method of kneading particles such as carbon black or titanium oxide or fine bubbles in the resin constituting the resin layer, or applying ink to the surface of the resin layer. Methods and the like.

The resin layer may contain conventionally known additives such as an ultraviolet absorber, an antioxidant, an organic filler, and an inorganic filler, if necessary. Moreover, when resin which comprises at least one of the said 1st resin layer and the 2nd resin layer consists of thermoplastic elastomers, you may contain resin other than the said thermoplastic elastomer as resin.

Although the thickness of the said resin layer is not specifically limited, A preferable minimum is 5 micrometers and a preferable upper limit is 100 micrometers. By setting the thickness of the resin layer within this range, the double-sided pressure-sensitive adhesive tape according to one embodiment of the present invention can exhibit more excellent reworkability. From the viewpoint of further improving reworkability, a more preferable lower limit of the thickness of the resin layer is 10 μm, and a more preferable upper limit is 70 μm.

The double-sided pressure-sensitive adhesive tape according to an embodiment of the present invention may have a layer other than the foam base material, the pressure-sensitive adhesive layer, and the resin layer as necessary.

Although the thickness of the double-sided adhesive tape which concerns on one embodiment of this invention is not specifically limited, A preferable minimum is 0.3 mm and a preferable upper limit is 3 mm. By making the thickness of the double-sided pressure-sensitive adhesive tape according to one embodiment of the present invention within this range, the double-sided pressure-sensitive adhesive tape is prevented from peeling off without being able to withstand a restoring force and a repulsive force, while realizing sufficient adhesion and fixation. Excellent reworkability can be demonstrated. From the standpoint of suppressing the peeling of the double-sided tape and further improving the reworkability, the more preferable lower limit of the thickness of the double-sided pressure-sensitive adhesive tape according to one embodiment of the present invention is 0.4 mm, and the more preferable upper limit is 2.8 mm.

As a manufacturing method of the double-sided adhesive tape which concerns on one embodiment of this invention, the following methods are mentioned, for example. First, a laminate of the foam base material and the first resin layer is manufactured, a second resin layer is laminated on the laminate, and the first resin layer / foam base material / second resin layer is used. A laminated body is formed.
Here, in order to laminate the resin layer and the foam base material, the resin layer preferably has self-adhesiveness (tackiness). Moreover, adhesiveness can also be improved by crimping | bonding a resin layer and a foam base material with the warmed laminator. Moreover, adhesiveness can be improved more by inserting a resin layer at the time of foaming a base material and obtaining a foam base material. Moreover, the surface of the resin sheet used as the resin layer or the surface treatment (for example, plasma treatment or corona treatment) on the foam base material can also improve the adhesion between the resin layer and the foam base material. Can do. Furthermore, when the resin layer is not self-adhesive, an adhesive layer may be provided between the foam substrate and the resin layer and laminated. By modifying the polymer chain of the resin layer with a hydroxyl group or acid group as a reaction point, the adhesion between the resin layer and the foam substrate can be improved.
Next, a pressure-sensitive adhesive solution for forming the pressure-sensitive adhesive layer is prepared, the pressure-sensitive adhesive solution is applied to the release treatment surface of the release film, and the solvent in the solution is completely removed by drying to obtain the first pressure-sensitive adhesive. Form a layer. The first pressure-sensitive adhesive layer is formed on the surface of the first resin layer side of the laminate composed of the first resin layer / foam base / second resin layer, and the first pressure-sensitive adhesive layer is the first pressure-sensitive adhesive layer. Overlay in a state facing the resin layer side. On the other hand, a release film different from the above release film is prepared, a pressure-sensitive adhesive solution is applied to the release treatment surface of the release film, and the solvent in the solution is completely removed by drying, thereby releasing the release film. A laminated film having a second pressure-sensitive adhesive layer formed on the surface is prepared. The second pressure-sensitive adhesive layer is the second resin layer on the surface of the laminate made of the first resin layer / foam substrate / second resin layer on the second resin layer side. The laminate composed of the first pressure-sensitive adhesive layer / first resin layer / foam substrate / second resin layer / second pressure-sensitive adhesive layer is obtained by superimposing the layers facing each other. And by pressing the obtained laminate with a rubber roller or the like, it has a first adhesive layer / first resin layer / foam substrate / second resin layer / second adhesive layer, And the double-sided adhesive tape in which the surface of both adhesive layers was covered with the release film can be obtained. Moreover, when winding up to a roll, the release film which touches a 2nd adhesive layer can be peeled off, and a 2nd adhesive layer can be wound inside. At this time, the release film in contact with the first pressure-sensitive adhesive layer needs to be subjected to double-sided release treatment.

The use of the double-sided pressure-sensitive adhesive tape according to one embodiment of the present invention is not particularly limited, and for example, it is used for fixing portable electronic device parts, in-vehicle electronic device parts, and the like. The shape of the double-sided pressure-sensitive adhesive tape according to one embodiment of the present invention in these applications is not particularly limited, and examples thereof include a rectangle, a frame shape, a circle, an ellipse, and a donut shape.

The double-sided pressure-sensitive adhesive tape according to an embodiment of the present invention is excellent in adhesion reliability in a state where a peeling stress at a low speed such as a restoring force and a repulsive force is applied, and is thus applied to a step, a corner, a non-planar part, etc. It is preferable to be attached or used to fix the parts in a deformed state. On the other hand, since it is excellent in reworkability, it can be suitably used for temporary fixing. Furthermore, even if it is desired to peel after bonding for some reason, the foam base material does not break at the time of peeling and a residue does not remain on the adherend.

Examples of articles in which the double-sided adhesive tape according to one embodiment of the present invention is used include, for example, flat panel displays used in TVs, monitors, portable electronic devices, camera modules for portable electronic devices, internal members of portable electronic devices, vehicles Interior and exterior of home appliances (for example, TV, air conditioner, refrigerator, etc.). Examples of the adherend of the double-sided pressure-sensitive adhesive tape according to one embodiment of the present invention include a side panel, a back panel, various nameplates, a decorative film, and a decorative film of a portable electronic device.

ADVANTAGE OF THE INVENTION According to this invention, it can provide the double-sided adhesive tape which has the outstanding stress relaxation property and impact resistance, and was excellent in the rework property in both adhesive surfaces.

It is a schematic diagram which shows an example of the double-sided adhesive tape which concerns on one embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

Example 1
(1) Preparation of first resin layer As the first resin layer, a polyethylene terephthalate (PET) sheet (X30, manufactured by Toray Industries, Inc.) having a thickness of 50 μm was prepared. When measured by a method according to JIS K 7161, the PET sheet had a tensile breaking stress of 180 MPa, a tensile breaking elongation of 138%, and a tensile modulus of 4360 MPa.

(2) Production of polyurethane (PU) foam substrate Polyol (polyether polyol, weight average molecular weight 6000, hydroxyl number 3, hydroxyl value 48 mgKOH / g) 100 parts by weight of amine catalyst (Dabco LV33, Sankyo Air Products Co., Ltd.) 0.7 parts by weight and 1 part by weight of a foam stabilizer (SZ5740M, manufactured by Toray Dow Corning) were added and stirred. Polyisocyanate (Cosmonate TM-20, manufactured by Mitsui Chemicals Co., Ltd.) was adjusted and added so as to have an isocyanate index of 80. Then, it mixed and stirred with nitrogen gas so that it might be set to 0.2 g / cm < ³ >, and the solution in which the fine bubble was mixed was obtained. The solution was applied to a predetermined thickness using an applicator on a 50 μm thick polyethylene terephthalate (PET) sheet (X30, Toray Industries, Inc.) as the first resin layer, the foam raw material was reacted, and the thickness of 450 μm was reacted. A laminate comprising a polyurethane (PU) foam base material and a first resin layer was obtained.
The density of the obtained PU foam substrate was measured using an electronic hydrometer (Mirage, “ED120T”) in accordance with JISK-6767. As a result, it was 0.3 g / cm ³ . Furthermore, as a result of calculating | requiring 25% compressive strength of the obtained PU foam base material based on JISK6254, it was 15 kPa.

(3) Preparation of second resin layer As the second resin layer, a sheet made of acrylic triblock copolymer a (acrylic TPE-a) having a thickness of 50 μm (LA2250, manufactured by Kuraray Co., Ltd.) was prepared.
The acrylic TPE-a has a proportion of hard segments derived from polymethyl methacrylate resin of 30% by weight, a proportion of soft segments derived from polybutyl acrylate resin of 70% by weight, and a weight average molecular weight of 59000.
When measured by a method according to JIS K 7161, the sheet made of acrylic TPE-a had a tensile stress at break of 8.0 MPa, an elongation at tensile break of 493%, and a tensile modulus of 10.1 MPa.

(4) Preparation of pressure-sensitive adhesive solution 52 parts by weight of ethyl acetate was placed in a reactor equipped with a thermometer, a stirrer, and a cooling tube, and after replacing with nitrogen, the reactor was heated to start refluxing. 30 minutes after ethyl acetate boiled, 0.08 parts by weight of azobisisobutyronitrile was added as a polymerization initiator. A monomer mixture consisting of 70 parts by weight of butyl acrylate, 27 parts by weight of 2-ethylhexyl acrylate, 3 parts by weight of acrylic acid and 0.2 parts by weight of 2-hydroxyethyl acrylate was added dropwise uniformly and gradually over 1 hour 30 minutes. Reacted. 30 minutes after completion of the dropping, 0.1 part by weight of azobisisobutyronitrile was added, and the polymerization reaction was further performed for 5 hours. Ethyl acetate was added to the reactor and cooled while diluting to obtain a solid content of 40% by weight. An acrylic copolymer solution was obtained.
When the weight average molecular weight of the obtained acrylic copolymer was measured by a GPC method using “2690 Separations Model” manufactured by Water as a column, it was 710,000. The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) was 5.5.
15 parts by weight of polymerized rosin ester having a softening point of 150 ° C., 10 parts by weight of terpene phenol having a softening point of 145 ° C., and 10 parts by weight of rosin ester having a softening point of 70 ° C. with respect to 100 parts by weight of the solid content of the obtained acrylic copolymer Was added. Furthermore, 30 parts by weight of ethyl acetate (produced by Fuji Chemical Co., Ltd.) and 3.0 parts by weight of an isocyanate-based crosslinking agent (trade name “Coronate L45” produced by Nippon Polyurethane Co., Ltd.) were added and stirred to obtain an adhesive solution. It was.

(5) Production of double-sided pressure-sensitive adhesive tape From acrylic triblock copolymer a as the second resin layer to the PU foam substrate side of the laminate comprising the obtained PU foam substrate and the first resin layer The resulting sheet was laminated and thermally laminated at 80 ° C. to form a laminate composed of the first resin layer / foam substrate / second resin layer.
By applying the pressure-sensitive adhesive solution to a release treatment surface of a release liner composed of polyethylene (PE) / fine paper / polyethylene (PE) having been subjected to a release treatment with a thickness of 100 μm, and drying at 100 ° C. for 5 minutes, A first pressure-sensitive adhesive layer having a thickness of 50 μm was formed.

On the other hand, the pressure-sensitive adhesive solution is applied to a release treatment surface of a release liner composed of polyethylene (PE) / quality paper / polyethylene (PE) subjected to a release treatment with a thickness of 100 μm and dried at 100 ° C. for 5 minutes. Thus, a second pressure-sensitive adhesive layer having a thickness of 50 μm was formed.
A release liner having a second pressure-sensitive adhesive layer formed thereon is formed on the second resin layer side surface of the laminate composed of the first resin layer / foam substrate / second resin layer. From the first pressure-sensitive adhesive layer / first resin layer / foam substrate / second resin layer / second pressure-sensitive adhesive layer in a state where the pressure-sensitive adhesive layer faces the second resin layer. The resulting laminate was obtained. And by pressing the obtained laminate with a rubber roller, it has a first pressure-sensitive adhesive layer / first resin layer / foam base / second resin layer / second pressure-sensitive adhesive layer, and A double-sided pressure-sensitive adhesive tape in which the surface of each pressure-sensitive adhesive layer was covered with a release liner was obtained.

(Example 2)
A double-sided pressure-sensitive adhesive tape was prepared in the same manner as in Example 1 except that a sheet made of acrylic triblock copolymer b (acrylic TPE-b) having a thickness of 50 μm (LA2140e, manufactured by Kuraray Co., Ltd.) was used as the second resin layer. Manufactured.
The acrylic TPE-b has a proportion of hard segments derived from polymethyl methacrylate resin of 21% by weight, a proportion of soft segments derived from polybutyl acrylate resin of 79% by weight, and a weight average molecular weight of 73,000.
When measured by a method according to JIS K 7161, the sheet made of acrylic TPE-b had a tensile stress at break of 5.0 MPa, an elongation at break of 602%, and a tensile modulus of 1.0 MPa.

(Example 3)
A double-sided pressure-sensitive adhesive tape was prepared in the same manner as in Example 1 except that a sheet (made by Kuraray, LA2330) made of an acrylic triblock copolymer c (acrylic TPE-c) having a thickness of 50 μm was used as the second resin layer. Manufactured.
The acrylic TPE-c has a proportion of hard segments derived from polymethyl methacrylate resin of 23% by weight, a proportion of soft segments derived from polybutyl acrylate resin of 77% by weight, and a weight average molecular weight of 112,000.
When measured by a method according to JIS K 7161, the sheet made of acrylic TPE-c had a tensile stress at break of 4.6 MPa, an elongation at tensile break of 550%, and a tensile modulus of elasticity of 0.6 MPa.

Example 4
A double-sided pressure-sensitive adhesive tape was prepared in the same manner as in Example 1 except that a sheet (made by Kuraray Co., Ltd., LA4285) made of an acrylic triblock copolymer d (acrylic TPE-d) having a thickness of 50 μm was used as the second resin layer. Manufactured.
The acrylic TPE-d has a proportion of hard segments derived from polymethyl methacrylate resin of 55% by weight, a proportion of soft segments derived from polybutyl acrylate resin of 45% by weight, and a weight average molecular weight of 60000.
When measured by a method according to JIS K 7161, the sheet made of acrylic TPE-d had a tensile breaking stress of 18.1 MPa, a tensile breaking elongation of 232%, and a tensile modulus of 275.1 MPa.

(Example 5)
A double-sided pressure-sensitive adhesive tape was prepared in the same manner as in Example 1 except that a sheet (made by Kuraray, LA2270) made of an acrylic triblock copolymer e (acrylic TPE-e) having a thickness of 50 μm was used as the second resin layer. Manufactured.
The acrylic TPE-e has a proportion of hard segments derived from polymethyl methacrylate resin of 40% by weight, a proportion of soft segments derived from polybutyl acrylate resin of 60% by weight, and a weight average molecular weight of 60000.
When measured by a method according to JIS K 7161, the sheet made of acrylic TPE-e had a tensile breaking stress of 11.4 MPa, a tensile breaking elongation of 434%, and a tensile modulus of 51.8 MPa.

(Example 6)
As the second resin layer, an acrylic triblock copolymer e (acrylic TPE-e) (Kuraray, LA2270) having a thickness of 50 μm and an acrylic diblock copolymer f (acrylic TPE-f) (made by Kuraray) , LA1114) A double-sided pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that a sheet having a weight ratio of 85/15 was used.
The acrylic TPE-e has a proportion of hard segments derived from polymethyl methacrylate resin of 40% by weight, a proportion of soft segments derived from polybutyl acrylate resin of 60% by weight, and a weight average molecular weight of 60000.
When measured by a method according to JIS K 7161, the sheet made of acrylic TPE-e and acrylic TPE-f has a tensile breaking stress of 4.3 MPa, a tensile breaking elongation of 660%, and a tensile modulus of 0.8 MPa. Met.

(Example 7)
A double-sided pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that a sheet made of styrene / acrylic triblock copolymer (styrene / acrylic TPE) having a thickness of 50 μm was used as the second resin layer.
The styrene / acrylic TPE has a proportion of hard segments derived from polystyrene resin of 17% by weight, a proportion of soft segments derived from polybutyl acrylate resin of 83% by weight, and a weight average molecular weight of 240000.
When measured by a method according to JIS K 7161, the sheet made of styrene / acrylic TPE had a tensile stress at break of 7.6 MPa, an elongation at break of 650%, and a tensile modulus of 1.9 MPa.

(Example 8)
Double-sided pressure-sensitive adhesive adhesive layer was used in the same manner as in Example 1 except that a sheet (made by Nippon Zeon Co., Ltd., # 3620) made of styrene triblock copolymer a (styrene TPE-a) having a thickness of 50 μm was used as the second resin layer. Tape was manufactured.
In the styrene TPE-a, the proportion of hard segments derived from styrene is 14% by weight, and the proportion of soft segments derived from isoprene is 86% by weight. Moreover, the diblock component of the same composition is included 12% by GPC area ratio.
When measured by a method according to JIS K 7161, the sheet made of styrene TPE-a had a tensile breaking point stress of 24.0 MPa, a tensile breaking point elongation of 1200%, and a tensile elastic modulus of 40.0 MPa.

Example 9
Double-sided pressure-sensitive adhesive layer was prepared in the same manner as in Example 1 except that a sheet (made by Nippon Zeon Co., Ltd., # 3421) made of styrene triblock copolymer b (styrene TPE-b) having a thickness of 50 μm was used as the second resin layer. Tape was manufactured.
In the styrene TPE-b, the proportion of hard segments derived from styrene is 14% by weight, and the proportion of soft segments derived from isoprene is 86% by weight. Moreover, the diblock component of the same composition is contained 26% by GPC area ratio.
When measured by a method according to JIS K 7161, the sheet made of styrene TPE-b had a tensile stress at break of 19.0 MPa, an elongation at break of 1300%, and a tensile modulus of 38.0 MPa.

(Example 10)
The same as Example 1 except that a sheet made of polyether ester block copolymer a (polyether ester TPE-a) (manufactured by Toray DuPont, # 5557) having a thickness of 50 μm was used as the second resin layer. Thus, a double-sided adhesive tape was produced.
The polyether ester TPE-a has a hard segment derived from PBT and a soft segment derived from polyether.
When measured by a method according to JIS K 7161, the sheet composed of the polyether ester TPE-a had a tensile stress at break of 31.4 MPa, an elongation at tensile break of 390%, and a tensile modulus of 137.0 MPa. .

(Example 11)
As in Example 1, except that a sheet made of a polyether ester block copolymer b (polyether ester TPE-b) (manufactured by Toray DuPont, # 7247) having a thickness of 50 μm was used as the second resin layer. Thus, a double-sided adhesive tape was produced.
The polyether ester TPE-b has a hard segment derived from PBT and a soft segment derived from polyether.
When measured by a method according to JIS K 7161, the sheet made of the polyether ester TPE-b had a tensile breaking stress of 36.3 MPa, a tensile breaking elongation of 260%, and a tensile modulus of 422.0 MPa. .

(Example 12)
A double-sided pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that a sheet (BASF, 1198ATR) made of a urethane block copolymer (urethane TPE) having a thickness of 60 μm was used as the second resin layer.
When measured by a method according to JIS K 7161, the sheet made of urethane TPE had a tensile stress at break of 57.1 MPa, an elongation at tensile break of 406%, and a tensile modulus of elasticity of 108.0 MPa.

(Example 13)
A sheet made of biaxially oriented polypropylene (OPP) having a thickness of 60 μm (Toyobo Co., Ltd., # 60) was used as the second resin layer, and an adhesive layer was used for laminating the second resin layer and the foam substrate. A double-sided pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that they were laminated.
When measured by a method according to JIS K 7161, the OPP sheet had a tensile breaking stress of 140.0 MPa, a tensile breaking elongation of 210%, and a tensile modulus of 2100.0 MPa.

(Example 14)
A sheet made of polyethylene terephthalate (PET) having a thickness of 25 μm (Toyobo Co., Ltd., # 25) was used as the second resin layer, and the second resin layer and the foam base material were laminated via an adhesive layer. A double-sided pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that the layers were laminated.
When measured by a method according to JIS K 7161, the PET sheet had a tensile stress at break of 177.0 MPa, an elongation at tensile break of 132%, and a tensile modulus of 2376.0 MPa.

(Comparative Example 1)
A pulp nonwoven fabric sheet (manufactured by Ritsuto Shosha Co., Ltd., SPC) having a thickness of 50 μm was used as the second resin layer, and the second resin layer and the foam base material were laminated via an adhesive layer. Produced a double-sided pressure-sensitive adhesive tape in the same manner as in Example 1.
When measured by a method according to JIS K 7161, the pulp nonwoven fabric sheet had a tensile stress at break of 3.7 MPa, an elongation at break of 102%, and a tensile modulus of 160.0 MPa.

(Comparative Example 2)
A double-sided pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that an acrylic pressure-sensitive adhesive having a thickness of 50 μm was used as the second resin layer.
When measured by a method according to JIS K 7161, the layer made of the acrylic pressure-sensitive adhesive had a tensile stress at break of 0.5 MPa, an elongation at break of 825%, and a tensile modulus of 0.2 MPa.
The acrylic adhesive was prepared by the following method.
After putting 52 parts by weight of ethyl acetate into a reactor equipped with a thermometer, a stirrer, and a cooling tube and replacing with nitrogen, the reactor was heated to start refluxing. 30 minutes after ethyl acetate boiled, 0.08 parts by weight of azobisisobutyronitrile was added as a polymerization initiator. Here, a monomer mixture (60 parts by weight of butyl acrylate (BA), 36.9 parts by weight of 2-ethylhexyl acrylate (2EHA), 3 parts by weight of acrylic acid (AAc), and 2-hydroxyethyl acrylate (2HEA) ) 0.1 parts by weight) was added dropwise uniformly and gradually over 1 hour 30 minutes. 30 minutes after the completion of the dropping, 0.1 part by weight of azobisisobutyronitrile is added, the polymerization reaction is further performed for 5 hours, and ethyl acetate is added to the reactor and cooled while diluting to thereby prepare an acrylic copolymer-containing solution. Got.
Ethyl acetate was added to 100 parts by weight of the nonvolatile content of the resulting acrylic copolymer-containing solution and stirred, and the total amount of tackifying resin was 30 parts by weight (10 parts hydrogenated rosin resin, 10 parts rosin ester resin, 10 parts of terpene phenol resin) was added and stirred to obtain an adhesive having a nonvolatile content of 30% by weight.

(Comparative Example 3)
A double-sided adhesive tape was prepared in the same manner as in Example 1 except that a sheet made of an acrylic diblock copolymer f (acrylic TPE-f) (Kuraray, LA1114) having a thickness of 50 μm was used as the second resin layer. Manufactured.
When measured by a method according to JIS K 7161, the sheet made of acrylic TPE-f had a tensile stress at break of 1.2 MPa, an elongation at tensile break of 990%, and a tensile modulus of elasticity of 0.3 MPa.

(Evaluation)
The following evaluation was performed about the double-sided adhesive tape obtained by the Example and the comparative example. The results are shown in Table 1.

(1) Evaluation of flexibility Double-sided pressure-sensitive adhesive tape (release liner / first pressure-sensitive adhesive layer / first resin layer / foam substrate / second resin layer / second pressure-sensitive adhesive layer) obtained A roll-shaped body was obtained by winding a paper core having a diameter of 3 inches so that the second pressure-sensitive adhesive layer side was inside.
The side surface and surface layer of the obtained roll-shaped body were observed visually. Furthermore, after pulling out the double-sided pressure-sensitive adhesive tape from the roll-shaped body, it was visually observed from the second pressure-sensitive adhesive layer side and evaluated according to the following criteria.
○: Wrinkles and folds were not observed in all the confirmed locations.
Δ: Wrinkles and creases were observed in some of the confirmed locations.
X: Wrinkles and creases were observed in all confirmed locations.

(2) Evaluation of reworkability The obtained double-sided pressure-sensitive adhesive tape was cut into a size of 5 mm wide × 100 mm long and 10 mm wide × 100 mm long to prepare a 5 mm wide sample and a 10 mm wide sample.
The release liner on the first pressure-sensitive adhesive layer side of each sample obtained is peeled off, and the first pressure-sensitive adhesive layer side is bonded to a glass plate (width 50 mm, length 125 mm) having a thickness of 2 mm, on a double-sided pressure-sensitive adhesive tape. A 2 kg rubber roller was reciprocated once at a speed of 300 mm / min, and then left for 24 hours in an environment of 23 ° C. and 50% relative humidity. Next, the portion of the double-sided pressure-sensitive adhesive tape is left after the interlayer of the foam-based material is torn and the second pressure-sensitive adhesive layer, the second resin layer, and a part of the foam base material are removed from the double-sided pressure-sensitive adhesive tape. Was pulled at a speed of 300 mm / min in an angle direction of 30 ° from the horizontal direction, and the remaining part of the double-sided adhesive tape was peeled off from the glass plate. The reworkability on the first pressure-sensitive adhesive layer side was evaluated according to the following criteria. The same evaluation was performed on the second pressure-sensitive adhesive layer side.
○: The remaining part of the double-sided adhesive tape could be removed.
Δ: A part of the double-sided pressure-sensitive adhesive tape was broken during the peeling, but could be removed.
X: The remaining part of the double-sided pressure-sensitive adhesive tape could not be removed.

DESCRIPTION OF SYMBOLS 1 Double-sided adhesive tape 2 Foam base material 31 1st adhesive layer 32 2nd adhesive layer 41 1st resin layer 42 2nd resin layer

Claims

A double-sided pressure-sensitive adhesive tape having a foam base material and a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer on both sides of the foam base material,
A first resin layer having a tensile stress at break of 4 MPa or more between the foam base material and the first pressure-sensitive adhesive layer and between the foam base material and the second pressure-sensitive adhesive layer; A double-sided pressure-sensitive adhesive tape comprising a second resin layer.
The double-sided pressure-sensitive adhesive tape according to claim 1, wherein at least one of the first resin layer and the second resin layer has an elongation at break of 200% or more.
The double-sided pressure-sensitive adhesive tape according to claim 1 or 2, wherein at least one of the first resin layer and the second resin layer has a tensile elastic modulus of 200 MPa or less.
The double-sided pressure-sensitive adhesive tape according to claim 1, 2 or 3, wherein at least one of the first resin layer and the second resin layer is made of a thermoplastic elastomer.
The double-sided pressure-sensitive adhesive tape according to claim 4, wherein the thermoplastic elastomer comprises a block copolymer having a hard segment and a soft segment.
The double-sided pressure-sensitive adhesive tape according to claim 4, wherein the thermoplastic elastomer comprises a triblock copolymer having a hard segment and a soft segment.
The double-sided pressure-sensitive adhesive tape according to claim 5 or 6, wherein the ratio of the hard segment in the block copolymer or the triblock copolymer is 10 wt% or more and 70 wt% or less.
The double-sided pressure-sensitive adhesive tape according to claim 4, 5, 6, or 7, wherein the thermoplastic elastomer has a triblock copolymer ratio of 70% by weight or more.
The double-sided pressure-sensitive adhesive tape according to claim 4, 5, 6, 7 or 8, wherein the thermoplastic elastomer comprises a triblock copolymer and a diblock copolymer.
The double-sided pressure-sensitive adhesive tape according to claim 4, wherein the thermoplastic elastomer is made of an acrylic copolymer.
The triblock copolymer is an acrylic triblock copolymer, and the acrylic triblock copolymer has a hard segment derived from methyl methacrylate and a soft segment derived from n-butyl acrylate, The ratio of the hard segment derived from the methyl methacrylate in the acrylic triblock copolymer is 22% by weight or more and 50% by weight or less, and the weight average molecular weight of the acrylic triblock copolymer is 3 The double-sided pressure-sensitive adhesive tape according to claim 6, 7, 8, 9 or 10, wherein the pressure-sensitive adhesive tape is 10,000 or more.
The double-sided pressure-sensitive adhesive tape according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11, wherein the foam substrate is made of polyurethane foam or polyolefin foam.