JP2014240457A - Double-sided adhesive tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double-sided adhesive tape excellent in terms not only of air permeability along a direction parallel to the tape surface but also of adhesiveness.SOLUTION: The double-sided adhesive tape of the present invention is a double-sided adhesive tape possessing tackifier layers on both surfaces of a substrate in a state where the substrate has a laminate structure obtained by laminating air-impermeable layers on both surfaces of an air-permeable layer. It is desirable for the air-permeable layer to be at least one layer selected from the group consisting of papers, non-woven fabrics, and porous films. It is desirable for the air-permeable layer to be a layer consisting of a non-woven fabric.

Description

  The present invention relates to a double-sided pressure-sensitive adhesive tape.

  Conventionally, pressure-sensitive adhesive tapes (breathable pressure-sensitive adhesive tapes) have been widely used for fixing medical and sanitary materials and for degassing in the industrial field. As such a breathable pressure-sensitive adhesive tape, there is a pressure-sensitive adhesive tape provided with a breathable pressure-sensitive adhesive layer formed by fiberizing a pressure-sensitive adhesive material on a breathable support (breathable base material) having adhesiveness in the thickness direction. It is known (patent documents 1 to 3).

JP-A-6-108018 JP-A-7-109443 JP 2000-218649 A

  However, there are cases where the air-permeable adhesive layer formed by fiberizing the adhesive substance is not sufficiently adhesive. In addition, increasing the amount of the adhesive substance to increase the adhesiveness may impregnate the adhesive substance and reduce the air permeability of the breathable support, or form a breathable adhesive layer with moderate air permeability. In some cases, it was difficult to achieve both air permeability and adhesiveness.

  By the way, in addition to the air permeability in the thickness direction, the air-permeable adhesive tape may require air permeability in a direction parallel to the tape surface. For example, the breathable pressure-sensitive adhesive tapes of Patent Documents 1 to 3 have breathability not only in the thickness direction but also in a direction parallel to the tape surface. However, at present, there is no known adhesive tape that achieves both air permeability and adhesiveness in the direction parallel to the tape surface.

  Accordingly, an object of the present invention is to provide an adhesive tape that is excellent in air permeability and adhesiveness in the direction parallel to the tape surface.

  Thus, as a result of intensive studies by the present inventors, it was found that by using a specific base material, an adhesive tape having excellent air permeability and adhesiveness in the direction parallel to the tape surface was obtained, and the present invention was completed. did.

  That is, the present invention is a double-sided pressure-sensitive adhesive tape having pressure-sensitive adhesive layers on both sides of a base material, wherein the base material has a laminated structure in which non-breathable layers are laminated on both side surfaces of a breathable layer. A double-sided pressure-sensitive adhesive tape is provided.

  The breathable layer is preferably one or more layers selected from the group consisting of paper, nonwoven fabric and porous film.

  The breathable layer is preferably a nonwoven fabric.

  The non-breathable layer is preferably a layer formed from a resin.

  The pressure-sensitive adhesive layer is preferably a pressure-sensitive adhesive layer formed from one or more pressure-sensitive adhesives selected from the group consisting of a rubber-based pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive, and a urethane-based pressure-sensitive adhesive.

  The double-sided pressure-sensitive adhesive tape of the present invention is excellent in air permeability in the direction parallel to the tape surface and adhesiveness.

FIG. 1 is a schematic view (plan view) showing a test piece used for measurement of air permeability in a direction parallel to the surface. FIG. 2 is a schematic diagram (XX cross-sectional view) showing a test piece used for measuring the air permeability in a direction parallel to the surface. FIG. 3 is a schematic view showing a part of the apparatus used for measuring the air permeability in the direction parallel to the surface.

The double-sided pressure-sensitive adhesive tape of the present invention is a double-sided pressure-sensitive adhesive tape having pressure-sensitive adhesive layers on both sides of a substrate. The double-sided pressure-sensitive adhesive tape of the present invention may have other layers (for example, an intermediate layer, a design layer, a printing layer, etc.) in addition to the base material and the pressure-sensitive adhesive layer as long as the effects of the present invention are not impaired.
In the present specification, “adhesive tape” includes the meaning of “adhesive sheet”. That is, the double-sided pressure-sensitive adhesive tape of the present invention may be a double-sided pressure-sensitive adhesive sheet having a sheet form.
Further, in this specification, “a direction parallel to the surface” means that each layer in a laminated structure in which a non-breathable layer is laminated on both surfaces of a breathable layer included in the double-sided pressure-sensitive adhesive tape of the present invention. The surface direction (surface direction parallel to the surface of a tape or a layer) which touches shall be said. Further, the “thickness direction” (the thickness direction of the tape or layer) means each layer in a laminated structure in which air-impermeable layers are laminated on both surfaces of the air-permeable layer included in the double-sided pressure-sensitive adhesive tape of the present invention. The direction perpendicular to the surface (a surface parallel to the surface of the tape or the layer) in contact with.

(Base material)
The base material has at least a laminated structure in which a non-breathable layer is laminated on both side surfaces of a breathable layer. That is, the base material has at least a laminated structure of an air-impermeable layer / an air-permeable layer / an air-impermeable layer. In addition to the laminated structure, the base material may have, for example, another layer having air permeability, another layer having no air permeability, and the like.
In this specification, air permeability refers to the property of passing a gas such as air, moisture (such as water vapor), and a minute substance. Specifically, for example, the Frazier air permeability (the air permeability in the thickness direction) measured in accordance with JIS L 1096 is 10 cc / cm ² / sec or more. The air permeability (air permeability in the direction parallel to the surface) measured by the method described in “The air permeability in the direction parallel to the surface” is 40000 sec / 100 cc or less.
Moreover, in this specification, non-breathable means the property which does not allow gas, such as air, to pass. Specifically, for example, fragile air permeability (thickness direction air permeability) cannot be measured in accordance with JIS L 1096, and “(2) air flow in a direction parallel to the surface” described later in (Evaluation). The air permeability (air permeability in the direction parallel to the surface) measured by the method described in “degree” cannot be measured (100 cc of air does not permeate even after 12 hours).
Further, in this specification, a layer having air permeability may be referred to as a “breathable layer” and a non-breathable layer may be referred to as a “non-breathable layer”.

(Breathable layer)
The said air permeable layer means the layer which has air permeability in the direction parallel to the thickness direction and the layer surface.

The air-permeable layer is not particularly limited, but is, for example, a paper-based substrate such as paper (Japanese paper, high-quality paper, etc.); a fiber-based substrate such as nonwoven fabric, woven fabric, net, cloth; Etc. Among these, paper, non-woven fabric, and porous film are preferable from the viewpoint of excellent air permeability in the horizontal direction with respect to the layer surface, and non-woven fabric is more preferable.
The breathable layer may be a single layer or a laminate (for example, a laminate base material of a nonwoven fabric and a porous film).

The nonwoven fabric is not particularly limited. For example, a polyamide nonwoven fabric (nylon nonwoven fabric, etc.), a polyester nonwoven fabric (polyethylene terephthalate nonwoven fabric, etc.), a polyolefin nonwoven fabric (polypropylene nonwoven fabric, polyethylene nonwoven fabric, polypropylene / polyethylene mixed nonwoven fabric). Etc.) and non-woven fabric made of rayon. Among these, a polyolefin-based nonwoven fabric is preferable from the viewpoint of being hardly affected by a permeating gas or the like (not easily melted or discolored).
The said nonwoven fabric may be comprised from 1 type of fiber, and may be comprised combining multiple types of fiber. The nonwoven fabric may have either a single layer or multiple layers.

  Although the manufacturing method of the said nonwoven fabric is not specifically limited, For example, a spun bond system, a spunlace system, etc. are mentioned. Among these, a nonwoven fabric (spunbond nonwoven fabric) manufactured by a spunbond method is preferable from the viewpoint of strength.

The basis weight of the nonwoven fabric is not particularly limited. For example, the basis weight is preferably 20 to 100 g / m ² , and more preferably ²⁰ to 80 g / m ² from the viewpoint of air permeability and cost. When the basis weight is 20 g / m ² or more, a non-breathable layer can be laminated on the breathable layer, thereby ensuring ventilation. When the basis weight is 100 g / m ² or less, it is difficult for liquid to pass through the breathable layer (liquid is difficult to penetrate), and only gas, water vapor, minute substances, etc. are selectively passed (vented). Can be made.

  In the nonwoven fabric, the fiber diameter (average fiber diameter), fiber length, and the like are not particularly limited, and can be appropriately selected as long as the effects of the present invention are not impaired.

  Commercially available products can be used as the non-woven fabric. For example, the product name “E5025” (manufactured by Asahi Kasei Fibers Co., Ltd.), the product name “P3035” (manufactured by Asahi Kasei Fibers Co., Ltd.), and the product name “P3040”. (Asahi Kasei Fibers Co., Ltd.).

  Although it does not specifically limit as said porous film, For example, the porous film etc. which are comprised (formed) from resin, such as polyolefin resin, polyester resin, and polystyrene resin, are mentioned. Among these, a porous film composed of a polyolefin resin is preferable from the viewpoint of cost. The resin which comprises the said porous film may be used independently, and 2 or more types may be mixed and used for it.

  The polyolefin-based resin is a monomer of at least an olefin component (such as ethylene, propylene, butene-1, pentene-1, hexene-1, 4-methyl-pentene-1, heptene-1, octene-1, etc. α-olefin). If it is resin made into a component, it will not specifically limit.

  Although it does not specifically limit as said polyolefin resin, For example, low density polyethylene, linear low density polyethylene (linear low density polyethylene), medium density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, ethylene- Ethylene resins such as α-olefin copolymers (for example, ethylene-propylene copolymers); propylene resins (polypropylene, propylene-α-olefin copolymers, etc.); polybutene resins (polybutene-1, etc.); Poly-4-methylpentene-1; ethylene-unsaturated carboxylic acid copolymer such as ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer; ionomer; ethylene-methyl acrylate copolymer, ethylene-acrylic Ethyl acid copolymer, ethylene-methyl methacrylate copolymer And ethylene- (meth) acrylic acid ester copolymers; ethylene-vinyl alcohol copolymers and the like. As the polyolefin-based resin, an ethylene-based resin is preferable, and among them, low-density polyethylene, linear low-density polyethylene (linear low-density polyethylene), and ethylene-α-olefin copolymer are preferable.

Although the said porous film is not specifically limited, For example, you may contain the inorganic particle. The inorganic particles play a role of making the film porous by generating voids (pores) around the inorganic particles by stretching. The inorganic particles can be appropriately selected from known or commonly used particles, and examples thereof include metal carbonates such as calcium carbonate and magnesium carbonate; and metal salts of sulfuric acid such as magnesium sulfate. The shape of the inorganic particles is not particularly limited, and a flat plate shape, a granular shape, or the like can be used.
The said inorganic particle may be used independently and may mix and use 2 or more types.

  The porous film may contain various additives such as a colorant, an antioxidant, an antioxidant, an ultraviolet absorber, a flame retardant, and a stabilizer.

  Although the said porous film is not specifically limited, For example, it can be manufactured by making porous by extending | stretching an unstretched film. The porous film can be produced by, for example, a melt film forming method (T-die method, inflation method). Specifically, for example, the resin, the inorganic particles and the like are mixed and dispersed with a biaxial kneader / extruder to produce raw material pellets, and then melt-extruded with a monoaxial extruder to produce an unstretched film. An unstretched film is produced by making it porous by stretching. When a porous film is used as a laminated film, a coextrusion method can be preferably used.

  From the viewpoint of improving the adhesion between the air-permeable layer and the non-air-permeable layer, at least one surface of the air-permeable layer is subjected to various treatments such as corona treatment, flame treatment, and plasma treatment. May be.

Although the fragile air permeability in the thickness direction of the air permeable layer is not particularly limited, for example, 30 cc / cm ² / sec or more is preferable, more preferably 50 to 800 cc / cm ² / sec, and still more preferably 100 to 400 cc / sec. cm ² / sec. In addition, in this specification, a fragile air permeability means what was measured based on JISL1096.

  The air permeability in the direction parallel to the surface of the air permeable layer is not particularly limited. For example, it is measured by the method described in “(2) Air permeability in the direction parallel to the surface” in (Evaluation) described later. The air permeability (air permeability in the direction parallel to the surface) is preferably 1000 to 40000 sec / 100 cc, more preferably 10000 to 30000 sec / 100 cc.

  Although the thickness of the said air permeable layer is not specifically limited, From a viewpoint of air permeability ensuring, for example, 30-500 micrometers is preferable, More preferably, it is 40-300 micrometers, More preferably, it is 50-200 micrometers.

(Non-breathable layer)
Although it does not specifically limit as said non-breathable layer, For example, the layer (For example, the film etc. which are formed from a non-breathable material) formed from a non-breathable material is mentioned. The non-breathable layer may be a single layer or a laminate.

The non-breathable material is not particularly limited. For example, polyolefin resin, polyester resin (polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, etc.), polyvinyl chloride Resin, vinyl acetate resin, polyamide resin, polyurethane resin, fluorine resin, acrylic resin, metal (gold, silver, aluminum, etc.), rubber (synthetic rubber, natural rubber, etc.), leather (synthetic) Leather, artificial leather, natural leather, etc.). Among these, resins are preferable, and polyolefin resins are particularly preferable from the viewpoint of cost.
That is, as the air-impermeable layer, for example, polyolefin resin, polyester resin (polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, etc.), polyvinyl chloride resin, vinyl acetate Formed from plastic resin, polyamide resin, polyurethane resin, fluorine resin, acrylic resin, etc., metal foil (gold foil, silver foil, aluminum foil, etc.), rubber (synthetic rubber, natural rubber, etc.) Film, leather (synthetic leather, artificial leather, natural leather, etc.). Among these, a film formed from a resin is preferable, and a film formed from a polyolefin resin is more preferable.

  The olefinic resin in the non-breathable material includes at least an olefin component (ethylene, propylene, butene-1, pentene-1, hexene-1, 4-methyl-pentene-1, heptene-1, octene-1, etc.) The α-olefin is not particularly limited as long as it has a monomer component.

  The olefin resin in the non-breathable material is not particularly limited, and examples thereof include low density polyethylene, linear low density polyethylene (linear low density polyethylene), medium density polyethylene, high density polyethylene, and ethylene-acetic acid. Ethylene resins such as vinyl copolymers and ethylene-α-olefin copolymers (for example, ethylene-propylene copolymers); Propylene resins (polypropylene, propylene-α-olefin copolymers, etc.); Polybutene resins (Such as polybutene-1); poly-4-methylpentene-1; ethylene-acrylic acid copolymer, ethylene-unsaturated carboxylic acid copolymer such as ethylene-methacrylic acid copolymer; ionomer; ethylene-methyl acrylate Copolymer, ethylene-ethyl acrylate copolymer, ethylene-meta Examples thereof include ethylene- (meth) acrylic acid ester copolymers such as methyl crylate copolymer; ethylene-vinyl alcohol copolymers. Among these, polyethylene resins are preferable from the viewpoints of flexibility and cost.

  The method for providing the non-breathable layer is not particularly limited. For example, a method of laminating a film formed from the non-breathable material (a dry laminating method, a method of thermocompression bonding the film, etc.) Examples thereof include a method of melting an extrudable material and extruding it into a film (extrusion laminating method), a method of evaporating the non-breathable material, and a method of coating the non-breathable material. Of these, the extrusion laminating method is preferable from the viewpoint of adhesion between the air-permeable layer and the non-air-permeable layer.

  If the breathable layer is made of a material that melts by heat, the surface of the breathable layer is made non-breathable by heating the surface of the breathable layer to melt the surface material and thereby eliminating the breathability of the surface. A porous layer (a portion that has lost its breathability by re-coagulation after part of the breathable layer has melted) may be provided. If the breathable layer is made of a material that cures with energy rays, the surface of the breathable layer is irradiated with energy rays to eliminate the breathability of the surface, thereby providing a non-breathable layer on the breathable surface. May be.

  The method of providing a non-breathable layer on both surfaces of the breathable layer may be the same on both sides of the breathable layer or may be different. The non-breathable layer is preferably provided on the entire surface of the breathable layer (preferably, the entire surface of both surfaces).

Since the non-breathable layer is not breathable, it is preferable that the fragile air permeability (the air permeability in the thickness direction) cannot be measured.
Also, the air permeability (air permeability in the direction parallel to the surface) measured by the method described in “(2) Air permeability in the direction parallel to the surface” in (Evaluation) described later cannot be measured (12 hours It is preferable that 100 cc of air does not permeate even after elapse.

  The thickness of the non-breathable layer is not particularly limited. For example, from the viewpoint of cost and stabilization of breathability, for example, 15 to 80 μm is preferable, more preferably 20 to 50 μm, and still more preferably 20 to 40 μm. is there. When the thickness of the air-impermeable layer is 15 μm or more, pinholes and the like are hardly formed.

  Since the base material has a non-breathable layer, it is not breathable in the thickness direction. Therefore, it is preferable that the permeability of the base material in the thickness direction cannot be measured by the Frazier permeability.

  Since the said base material has an air permeable layer, it has air permeability in the direction parallel to the surface. The air permeability in the direction parallel to the surface of the substrate is not particularly limited. For example, it is measured by the method described in “(2) Air permeability in the direction parallel to the surface” in (Evaluation) described later. The air permeability (air permeability in the direction parallel to the surface) is preferably 1000 to 40000 sec / 100 cc, more preferably 10000 to 30000 sec / 100 cc.

  Although the thickness of the said base material is not specifically limited, For example, 50-700 micrometers is preferable, More preferably, it is 100-400 micrometers.

  In the substrate, the ratio of the thickness of the breathable layer to the thickness of each of the non-breathable layers is not particularly limited. For example, from the viewpoint of ensuring breathability in the parallel direction, the thickness of the breathable layer : The thickness of the non-breathable layer is preferably 2: 1 to 20: 1, more preferably 3: 1 to 10: 1.

(Adhesive layer)
The pressure-sensitive adhesive constituting (forming) the pressure-sensitive adhesive layer is not particularly limited. For example, rubber pressure-sensitive adhesive (synthetic rubber pressure-sensitive adhesive, natural rubber pressure-sensitive adhesive, etc.), urethane pressure-sensitive adhesive (acrylic urethane pressure-sensitive adhesive) ), Polyolefin adhesives (ethylene-vinyl acetate copolymer (EVA), ethylene-methyl acrylate copolymer (EMA), etc.), acrylic adhesives, polyester adhesives, polyamide adhesives, epoxy adhesives Agents, vinyl alkyl ether adhesives, fluorine adhesives and the like. Among these, from the viewpoint of price and adhesiveness, a rubber-based pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive, and a urethane-based pressure-sensitive adhesive are preferable, and a rubber-based pressure-sensitive adhesive is more preferable.
The said adhesive can be used individually or in combination of 2 or more types.

  From the viewpoint of cost, a silicone-based pressure-sensitive adhesive is often not used for the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer.

Examples of the rubber-based pressure-sensitive adhesive include rubber-based pressure-sensitive adhesives using natural rubber and various synthetic rubbers as a base polymer. Examples of the synthetic rubber include styrene-butadiene (SB) rubber, styrene-isoprene (SI) rubber, styrene-isoprene-styrene block copolymer (SIS) rubber, and styrene-butadiene-styrene block copolymer (SBS). Rubber, styrene-ethylene-butylene-styrene block copolymer (SEBS) rubber, styrene-ethylene-propylene-styrene block copolymer (SEPS) rubber, styrene-isoprene-propylene-styrene block copolymer (SIPS) rubber, Examples thereof include styrene rubbers (also referred to as styrene elastomers) such as styrene-ethylene-propylene block copolymer (SEP) rubber, polyisoprene rubber, recycled rubber, butyl rubber, polyisobutylene, and modified products thereof. Among these, styrene rubber (styrene elastomer) is preferable, and SIS block copolymer rubber and SBS block copolymer rubber are more preferable.
The base polymer of the rubber-based pressure-sensitive adhesive may be used alone or in combination of two or more.

The SIS block copolymer is not particularly limited. For example, a block copolymer comprising a styrene polymer block of a styrene compound such as styrene or methylstyrene and an isoprene polymer block of an isoprene compound such as isoprene. A polymer etc. are mentioned. The SIS block copolymer may contain a polymer block other than the styrene polymer block and the isoprene polymer block as necessary.
The styrene polymer block contained in the SIS block copolymer may be one type or two or more types. 1 type may be sufficient as the said isoprene-type polymer block contained in the said SIS block copolymer, and 2 or more types may be sufficient as it.

  The SIS block copolymer is not particularly limited, but from the viewpoint that the pressure-sensitive adhesive does not flow easily even when a high temperature or pressure is applied, the amount of SI diblock is a monomer constituting the SIS block copolymer. It is preferable that it is 10-35 weight% with respect to the component whole quantity (100 weight%).

  The content of styrene in the monomer component constituting the styrene rubber is not particularly limited. For example, it is preferably 5 to 40% by weight with respect to the total amount of monomer components (100% by weight) constituting the styrene rubber. More preferably, it is 10-30 weight%, More preferably, it is 15-25 weight%. In other words, the content of the structural unit (structural unit) derived from styrene in the styrene rubber (100% by weight) is not particularly limited. For example, the total amount of monomer components constituting the styrene rubber (100% by weight) %) Is preferably 5 to 40% by weight, more preferably 10 to 30% by weight, still more preferably 20 to 30% by weight. By setting the content of styrene to 5% by weight or more, the cohesive force of the pressure-sensitive adhesive layer becomes high, and the pressure-sensitive adhesive layer becomes difficult to flow even when a high temperature or high pressure is applied. By setting the styrene content to 40% by weight or less, sufficient adhesion (tackiness) can be obtained.

  Although content of the said synthetic rubber in the said adhesive is not specifically limited, For example, 10-80 weight% is preferable with respect to the said adhesive whole quantity (100 weight%), More preferably, 20-70 weight%, More preferably, it is 30 to 60% by weight. By setting the content of the synthetic rubber to 10% by weight or more, the cohesive force of the pressure-sensitive adhesive can be maintained. By making the content of the synthetic rubber 80% by weight or less, the coating property is excellent.

  The weight average molecular weight (Mw) of the synthetic rubber is not particularly limited, but from the viewpoint that the coating property of the pressure-sensitive adhesive increases, the applied pressure-sensitive adhesive becomes difficult to flow, and the strength of the formed pressure-sensitive adhesive layer is improved. For example, 100,000 to 300,000 is preferable. The weight average molecular weight of the synthetic rubber can be controlled by the monomer concentration and the like in addition to the temperature and time during the polymerization.

  A commercially available product can be used as the rubber-based pressure-sensitive adhesive. For example, from the viewpoint of low melt viscosity and high cohesive force, a trade name “Quintac 3280” (manufactured by Nippon Zeon Co., Ltd.) and the like can be mentioned. It is done.

  As the urethane-based pressure-sensitive adhesive, known and commonly used urethane-based pressure-sensitive adhesives having a urethane-based polymer as a base polymer can be used, and are not particularly limited. For example, Japanese Patent No. 3860880 and Japanese Patent Application Laid-Open No. 2006-288690 are available. Urethane adhesives and the like exemplified in the publication can be suitably used. Among these, a urethane-based adhesive composed of isocyanate and polyol is preferable. The acrylic urethane-based pressure-sensitive adhesive may be a foam-type pressure-sensitive adhesive having bubbles. Such a foaming type pressure-sensitive adhesive can be produced by, for example, a method of adding a known and usual foaming agent to the pressure-sensitive adhesive.

  As said acrylic adhesive, the well-known acrylic adhesive which uses an acrylic polymer as a base polymer can be used. The said acrylic polymer can be used individually or in combination of 2 or more types.

Although the said adhesive is not specifically limited, The tackifier may be further contained from a viewpoint that adhesiveness improves and a melt viscosity can be made low. The tackifier is not particularly limited, and examples thereof include terpene tackifier resins, phenol tackifier resins, rosin tackifier resins, petroleum tackifier resins, petroleum oils such as paraffin oil, process oils, and naphthenes. Examples thereof include organic acid esters such as oil, castor oil, linseed oil, soybean oil, di-2-ethylhexyl phthalate (DOP), dibutyl phthalate (DBP), phosphate ester, higher fatty acid ester, and alkyl sulfonate ester. Among these, terpene tackifier resins, phenol tackifier resins, rosin tackifier resins, and petroleum tackifier resins are preferred. In particular, when a SIS block copolymer is used as the base polymer, a terpene-based tackifying resin is preferable from the viewpoint of excellent compatibility with the SIS block copolymer.
The said tackifier can be used individually or in combination of 2 or more types.

  The terpene-based tackifier resin in the tackifier is not particularly limited. For example, terpene resins such as α-pinene polymer, β-pinene polymer, and dipentene polymer, and these terpene resins are modified. Modified terpene resins (for example, phenol modified, aromatic modified, hydrogenated modified, hydrocarbon modified, etc.) (for example, phenol modified terpene resin, aromatic modified terpene resin, hydrogenated modified terpene resin, hydrocarbon modified terpene resin) Resin, etc.). Of these, hydrogenated modified terpene resins and aromatic modified terpene resins are preferred from the viewpoints that they are less susceptible to thermal degradation even in a high temperature atmosphere, can adjust the viscosity to an appropriate range, and are excellent in low temperature adhesion. In addition, the hydrogenated terpene resin and the aromatic modified terpene resin are excellent in compatibility with the SIS block copolymer.

  Examples of the phenolic tackifier resin in the tackifier include condensates of various phenols (eg, phenol, m-cresol, 3,5-xylenol, p-alkylphenol, resorcin, etc.) and formaldehyde (eg, alkylphenol type). Resin, xylene formaldehyde resin, etc.), resole obtained by addition reaction of the above phenols and formaldehyde with an alkali catalyst, novolak obtained by condensation reaction of the above phenols with formaldehyde with an acid catalyst, and rosins (not yet used). Examples thereof include rosin-modified phenolic resins obtained by adding phenol to an acid catalyst and heat-polymerizing it with modified rosin, modified rosin, and various rosin derivatives.

  Examples of the rosin-based tackifier resin in the tackifier include unmodified rosin (raw rosin) such as gum rosin, wood rosin, tall oil rosin, and hydrogenation, disproportionation, polymerization, etc. of these unmodified rosins. In addition to modified rosin modified by the above (hydrogenated rosin, disproportionated rosin, polymerized rosin, and other chemically modified rosins), various rosin derivatives and the like can be mentioned.

  Examples of the petroleum-based tackifier resin in the tackifier include aromatic petroleum resins, aliphatic petroleum resins, alicyclic petroleum resins (aliphatic cyclic petroleum resins), and aliphatic / aromatic petroleum resins. And petroleum resins such as aliphatic / alicyclic petroleum resins, hydrogenated petroleum resins, coumarone resins, coumarone indene resins, and the like.

  Although the softening temperature (softening point) of the said tackifier is not specifically limited, For example, 90-130 degreeC is preferable, More preferably, it is 100-120 degreeC. When the softening temperature is 90 ° C. or higher, the adhesive property at high temperature is improved. When the softening temperature is 130 ° C. or lower, the coating property is improved. In addition, the said softening temperature means the Vicat softening point measured based on JISK7206.

  The content of the tackifier in the pressure-sensitive adhesive is preferably 20 to 90% by weight, more preferably 30 to 80% by weight, and still more preferably 40 to 70% by weight with respect to 100% by weight of the total pressure-sensitive adhesive. is there. By setting the content to 20% by weight or more, the adhesive properties are improved. By setting the content to 90% by weight or less, adhesive properties at low temperatures are improved.

  Commercially available products can be used as the tackifier, for example, from the viewpoint of compatibility and melt viscosity, the trade name “Quinton S-195” (manufactured by Nippon Zeon Co., Ltd., aliphatic aromatic resin). Trade name “YS Resin TO-L” (Yasuhara Chemical Co., Ltd., aromatic modified terpene resin), trade name “Clearon M105” (Yasuhara Chemical Co., Ltd., aromatic modified terpene resin), and the like.

The pressure-sensitive adhesive may further contain an antioxidant. When an antioxidant is contained in the pressure-sensitive adhesive, the thermal stability of the pressure-sensitive adhesive is improved. The antioxidant is not particularly limited. For example, 4-[[4,6-bis (octylthio) -1,3,5-triazin-2-yl] amino] -2,6-di-tert- Hindered phenol antioxidants having a 2,6-alkylphenol skeleton such as butylphenol (Irganox 565) and phosphite compounds such as tris (2,4-di-t-butylphenyl) phosphite (Irgaphos 168) And a mixture thereof. Among them, from the viewpoint of preventing primary aging and secondary aging, hindered phenolic antioxidants having a 2,6-alkylphenol skeleton such as Irganox B612 (a mixture of Irganox 565 and Irgaphos 168) and phosphite compounds Is preferred.
The said antioxidant can be used individually or in combination of 2 or more types.

  Although content of the said antioxidant in the said adhesive is not specifically limited, For example, 0.5-10 weight% is preferable with respect to 100 weight% of said adhesive whole quantity, More preferably, it is 1-5 weight% More preferably, it is 1 to 3% by weight. Thermal stability improves by making the said content into 0.5 weight% or more. By setting the content to 10% by weight or less, bleeding of low molecular weight compounds in the pressure-sensitive adhesive layer can be suppressed.

  The pressure-sensitive adhesive is not particularly limited. For example, a crosslinking agent, a polymerization initiator, a crosslinking accelerator, an anti-aging agent, a filler, a colorant, an ultraviolet absorber, a chain transfer agent, a plasticizer, a surfactant, a charge Additives such as inhibitors may be included.

  The pressure-sensitive adhesive can be prepared by, for example, mixing a base polymer, the tackifier, the antioxidant, the additive, and the like as necessary.

  The pressure-sensitive adhesive may be any pressure-sensitive adhesive, such as an emulsion-type pressure-sensitive adhesive, a solvent-type pressure-sensitive adhesive, an ultraviolet curable (UV-curable) pressure-sensitive adhesive, a thermosetting pressure-sensitive adhesive, Examples thereof include an electron beam curable adhesive (EB curable adhesive) and a hot melt adhesive (hot melt adhesive). Among these, a hot-melt adhesive (hot melt adhesive) is preferable from the viewpoint that it can be directly applied without using a solvent to form an adhesive layer and is excellent in safety. In addition, a crosslinking agent or a polymerization initiator for exhibiting curability is appropriately used for the ultraviolet curable pressure sensitive adhesive, the thermosetting pressure sensitive adhesive, and the electron beam curable pressure sensitive adhesive.

(Release liner)
The pressure-sensitive adhesive layer in the double-sided pressure-sensitive adhesive tape of the present invention may be protected by a release liner (separator) until use. The release liner is used as a protective material for the pressure-sensitive adhesive layer, and is peeled off when the pressure-sensitive adhesive tape of the present invention is applied to an adherend. Note that the release liner is not necessarily provided.

  As the release liner, a conventional release paper or the like can be used, and is not particularly limited. For example, a substrate having a release agent layer, a low adhesive substrate made of a fluorine-based polymer, or a low adhesive group made of a nonpolar polymer. Materials. Examples of the substrate having the release agent layer include a plastic film or paper surface-treated with a release agent such as a silicone release agent, a long-chain alkyl release agent, a fluorine release agent, and a molybdenum sulfide release agent. Can be mentioned. Examples of the fluorine polymer include polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, chlorofluoroethylene-vinylidene fluoride copolymer, and the like. Is mentioned. Moreover, as said nonpolar polymer, polyolefin resin (for example, polyethylene, a polypropylene, etc.) etc. are mentioned, for example. The release liner can be formed by a known or common method. Further, the thickness of the release liner is not particularly limited.

  The pressure-sensitive adhesive tape of the present invention has a pressure-sensitive adhesive layer on both surfaces of a base material having a laminated structure in which air-impermeable layers are laminated on both surfaces of a gas-permeable layer. Is difficult to soak into the base material, and the adhesive layer after formation is difficult to soak into the base material.

  The method for producing the pressure-sensitive adhesive tape of the present invention is not particularly limited. For example, the method for producing the pressure-sensitive adhesive by applying the pressure-sensitive adhesive to the surface of the substrate, or the pressure-sensitive adhesive layer by applying the pressure-sensitive adhesive to the surface of the release liner. And a method in which the pressure-sensitive adhesive layer is bonded to the substrate to produce the same, and combinations thereof. In the said manufacturing method, you may perform heating, drying, active energy ray irradiation (for example, ultraviolet irradiation etc.), etc. for the adhesive layer after application | coating as needed.

Although the application quantity of the said adhesive is not specifically limited, For example, 20-150 g / m < ² > is preferable, More preferably, it is 30-100 g / m < ² >. By setting the coating amount to 20 g / m ² or more, coating unevenness is reduced and the adhesiveness is excellent. By making the coating amount 150 g / m ² or less, it is advantageous in terms of cost.

  As a method of applying (coating) the pressure-sensitive adhesive to the surface of the base material, a known coating method can be adopted, and is not particularly limited. For example, roll coating, kiss roll coating, gravure coating, reverse coating, Examples include roll brushing, spray coating, dip roll coating, bar coating, knife coating, air knife coating, curtain coating, lip coating, and extrusion coating using a die coater.

In the double-sided pressure-sensitive adhesive tape of the present invention, the pressure-sensitive adhesive layer may be coated on the entire surface of the substrate without any gap (so-called “solid coating”), or may be coated in a fibrous form on a part or the entire surface of the substrate. It may be crafted. That is, the pressure-sensitive adhesive layer may be a film-like pressure-sensitive adhesive layer (a non-porous layer-like pressure-sensitive adhesive layer, a pressure-sensitive adhesive layer coated on the substrate without any gap), or a fibrous pressure-sensitive adhesive layer and a film-like shape. A combination with the pressure-sensitive adhesive layer may be used, or a fibrous pressure-sensitive adhesive layer may be used. Among these, a film-like pressure-sensitive adhesive layer is preferable from the viewpoint that the adhesiveness is further improved.
The pressure-sensitive adhesive layers provided on both sides of the base material may have the same or different coating methods. Especially, it is preferable to have a film-like adhesive layer on both surfaces of a base material.

  Although the thickness of the said adhesive layer is not specifically limited, For example, 5-200 micrometers is preferable from an adhesive viewpoint, More preferably, it is 10-150 micrometers, More preferably, it is 15-100 micrometers.

Although the adhesive force of the double-sided adhesive tape of this invention is not specifically limited, For example, 11-40 N / 25mm is preferable, More preferably, it is 13-20 N / 25mm.
The above adhesive strength was obtained by applying the double-sided adhesive tape of the present invention to a stainless steel plate (SUS304BA plate), leaving it for 30 minutes, and then measuring 180 ° peel adhesive strength using a tensile tester (temperature 23 ° C., humidity 50%). , Peeling angle 180 °, tensile speed 300 mm / min) (N / 25 mm). More specifically, it can be measured by the method described in “(1) Adhesive strength” in (Evaluation) described later.

  The double-sided pressure-sensitive adhesive tape of the present invention is not breathable in the thickness direction. That is, the air permeability in the thickness direction of the double-sided pressure-sensitive adhesive tape of the present invention is preferably such that the Frazier air permeability cannot be measured. Due to the lack of air permeability in the thickness direction, the adhesive does not penetrate into the air permeable layer when the adhesive is applied, and the air permeability in the direction parallel to the surface is excellent.

The double-sided pressure-sensitive adhesive tape of the present invention has air permeability in a direction parallel to the surface.
The air permeability in the direction parallel to the surface of the double-sided pressure-sensitive adhesive tape of the present invention is not particularly limited, but is preferably, for example, 30 to 80000 sec / 100 cc, more preferably 50 to 50000 sec / 100 cc, and still more preferably 1000 to 30000 sec / 100 cc. It is. When the air permeability is 80000 sec / 100 cc or less, the air permeability in the direction parallel to the surface is excellent.
The air permeability in the direction parallel to the surface refers to the air permeability measured by the method described in “(2) Air permeability in the direction parallel to the surface” described later in (Evaluation).

The double-sided pressure-sensitive adhesive tape of the present invention can ventilate (pass) a gas such as air, moisture (such as water vapor), or a minute substance in a direction parallel to the surface.
That is, since the double-sided pressure-sensitive adhesive tape of the present invention does not allow liquids or solids to pass through in a direction parallel to the surface except for fine substances, gas and minute substances can be selectively vented (passed). .

Usually, a breathable base material is often used in order to obtain a breathability in the thickness direction and an effect of flexibility. At that time, if a non-breathable layer is provided on both sides of the breathable substrate, the breathability and flexibility in the thickness direction will be reduced (or disappear). Was not done. Moreover, in order to obtain air permeability in the thickness direction, the pressure-sensitive adhesive layer on the air-permeable base material is often made into a fibrous form, and there are cases where sufficient adhesiveness cannot be obtained.
However, the double-sided pressure-sensitive adhesive tape of the present invention is provided with non-breathable layers on both surfaces of the breathable layer from the viewpoint of obtaining breathability only in the direction parallel to the surface. Therefore, the applied pressure-sensitive adhesive does not penetrate into the air permeable layer, and the air permeability in the direction parallel to the surface of the double-sided pressure-sensitive adhesive tape is excellent. In addition, since a liquid or a large substance does not pass, a phenomenon (liquid leakage) in which the liquid or solid leaks in a direction parallel to the surface hardly occurs. Furthermore, since the pressure-sensitive adhesive does not penetrate into the substrate, the pressure-sensitive adhesive is excellent, and since the pressure-sensitive adhesive layer can be made to have a constant thickness, the appearance is also excellent.
Especially, when the double-sided adhesive tape of this invention has a film-like adhesive layer on both surfaces of a base material, it is further excellent in adhesiveness.

  The double-sided pressure-sensitive adhesive tape of the present invention is not particularly limited. For example, it can be used for applications in which only a gas such as air or a minute substance is selectively allowed to pass in a direction parallel to the surface and no liquid is allowed to pass. . More specifically, for example, it can be used for filling a liquid in a sealed portion. For example, as shown in FIG. 3, a ring-shaped PET film 1 is sandwiched between the PET film 1 and the PET film 1. 3 is affixed via the double-sided tape 2 of the present invention, and the air flows from the air inlet 4 to the air outlet 5 through the air-permeable layer of the double-sided tape 2 of the present invention. By filling a liquid such as water from the inlet 4 and sucking it from the air outlet 5, the upper half of the container can be filled with the liquid.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

Example 1
As a base polymer, a SIS block copolymer [manufactured by Nippon Zeon Co., Ltd., trade name “Quintac 3280”, diblock ratio 17% (GPC (area ratio)), styrene content 25% (Abbe refractive index)] : 100 parts by weight, aliphatic aromatic copolymer resin (manufactured by Nippon Zeon Co., Ltd., trade name “Quinton S195”): 100 parts by weight, aromatic modified terpene resin [manufactured by Yasuhara Chemical Co., Ltd., product 30 parts by weight of the name “YS Resin TO-L” was added and mixed uniformly to obtain an adhesive.
Also, linear low-density polyethylene was extruded onto the surface of an olefin-based nonwoven fabric [manufactured by Asahi Kasei Fibers Co., Ltd., trade name “P3040”, basis weight 40 g / m ³ , air permeable layer] by extrusion lamination. Non-breathable layer (thickness 20 μm) made of linear low-density polyethylene is provided on both sides of an olefin nonwoven fabric, and a base material (olefin that has a non-breathable layer laminated on both sides of a breathable layer) A base material having a laminated structure in which a non-breathable layer made of linear low-density polyethylene was laminated on both surfaces of the non-woven fabric, and the total thickness of the base material was 120 μm).
On one surface of the release liner having a release layer on both sides [manufactured by Sumika Kogyo Co., Ltd., trade name “SLB-50WD”], the above-mentioned pressure-sensitive adhesive is applied to the entire surface at a coating amount of 30 g / m ^2. Coating (solid coating) was performed to form an adhesive layer A (film adhesive layer) having a thickness of 30 μm. Thereafter, the one non-breathable layer of the base material and the pressure-sensitive adhesive layer A are bonded together so that the release liner / pressure-sensitive adhesive layer A / base material (non-breathable layer / olefin-based nonwoven fabric / non-breathable layer). ) And rolled up.
Next, the wound member is unwound, and the pressure-sensitive adhesive is applied to the entire surface of the other non-breathable layer of the base material at a coating amount of 30 g / m ² (solid coating), and a pressure-sensitive adhesive having a thickness of 30 μm. A base material having a laminate structure of release liner / adhesive layer A / base material (non-breathable layer / olefin non-woven fabric / non-breathable layer) by forming and winding agent layer B (film-like pressure-sensitive adhesive layer) ) / A double-sided pressure-sensitive adhesive tape having the structure of pressure-sensitive adhesive layer B was obtained.

(Comparative Example 1)
On one side of the release liner of a release liner [manufactured by Sumika Kogyo Co., Ltd., trade name “SLB-50WD”] having a release layer on both sides, the pressure-sensitive adhesive is applied at an application temperature of 180 ° C. and an application amount of 30 g. / M ² was applied by spray coating to form a fibrous pressure-sensitive adhesive layer A having an average fiber diameter of 50 μm. Thereafter, a polyolefin film [trade name “FNA # 70”, non-breathable base material, manufactured by Phutamura Chemical Co., Ltd.] is bonded onto the fibrous pressure-sensitive adhesive layer A, and a release liner / fibrous pressure-sensitive adhesive layer A is bonded. / A member having the structure of a polyolefin film (non-breathable substrate) was wound up.
Next, the wound member is unwound, and the pressure-sensitive adhesive is applied on the other surface of the polyolefin film by spray coating at an application temperature of 180 ° C. and an application amount of 30 g / m ² , and the average fiber diameter is 50 μm. A double-sided pressure-sensitive adhesive tape having a configuration of release liner / fibrous pressure-sensitive adhesive layer A / polyolefin-based film (non-breathable base material) / fibrous pressure-sensitive adhesive layer B Got.
In addition, the adhesive similar to Example 1 was used for the adhesive.

(Comparative Example 2)
Release liner / adhesive layer A / polyethylene in the same manner as in Example 1 except that a polyethylene terephthalate non-woven fabric [Asahi Kasei Fibers Co., Ltd., trade name “E5025”] not subjected to polylamination treatment was used as the base material. A double-sided pressure-sensitive adhesive tape comprising a terephthalate nonwoven fabric / pressure-sensitive adhesive layer B was obtained.

[Evaluation]
The following measurements were performed on the double-sided pressure-sensitive adhesive tapes obtained in Examples and Comparative Examples. The evaluation results are shown in Table 1.

(1) Adhesive strength From the double-sided adhesive tape obtained by the Example and the comparative example, the tape piece (100 mm x 25 mm tape piece) of length 100mm and width 25mm was cut out. One pressure-sensitive adhesive layer surface (adhesive layer A or fibrous pressure-sensitive adhesive layer A) of the tape piece is bonded to the surface of a stainless steel plate [SUS304BA plate], and a 2 kg roller at a temperature of 23 ° C. and a humidity of 50%. Was crimped by reciprocating once.
Then, it was left to stand at a temperature of 23 ° C. and a humidity of 50% for 0.5 hours, and a 180 ° peel adhesive force of the pressure-sensitive adhesive layer A or the fibrous pressure-sensitive adhesive layer A (temperature 23 ° C., humidity 50%, A peel angle of 180 ° and a tensile speed of 300 mm / min) were measured, and the obtained value was defined as “adhesive strength of adhesive layer A or fibrous adhesive layer A (N / 25 mm)”.
Also, another tape piece is prepared, and similarly, the adhesive layer B or the fibrous adhesive layer B has a 180 ° peel adhesive strength (temperature 23 ° C., humidity 50%, peeling angle 180 °, tensile speed 300 mm / min. ) Was measured, and the obtained value was defined as “adhesive strength of adhesive layer B or fibrous adhesive layer B (N / 25 mm)”.

(2) Air permeability parallel to the surface The double-sided pressure-sensitive adhesive tapes obtained in Examples and Comparative Examples were cut out to a length of 15 mm and a width of 15 mm, and the pressure-sensitive adhesive layer A or the fibrous pressure-sensitive adhesive layer A was formed into a polyethylene terephthalate film. (PET film) (Futamura Chemical Co., Ltd., trade name “FE2001”, length 50 mm, width 50 mm, thickness 38 mm, non-breathable film) bonded to the surface, under conditions of temperature 23 ° C. and humidity 50% Crimping was performed by reciprocating a 2 kg roller once. Thereafter, the sample was allowed to stand at a temperature of 23 ° C. and a humidity of 50% for 0.5 hour, and the center of the test piece was cut out into a circle having a diameter of 7 mm.
Subsequently, the pressure-sensitive adhesive layer B or the fibrous pressure-sensitive adhesive layer B of the double-sided pressure-sensitive adhesive tape was made into a polyethylene terephthalate film (PET film) (trade name “FE2001”, length 15 mm, width 15 mm, thickness 38 mm, manufactured by Phutamura Chemical Co., Ltd. , Non-breathable film), and a test piece having the structure of PET film / double-sided adhesive tape / PET film, which is pressure-bonded by reciprocating a 2 kg roller under the conditions of a temperature of 23 ° C. and a humidity of 50%. (FIGS. 1 and 2).
Obtained by measuring the time required to pass 100 cc of air through the test piece by placing the above test piece on a Gurley air permeability tester [manufactured by Kumagai Riki Kogyo Co., Ltd.] (Fig. 3). The value was defined as “air permeability in a direction parallel to the surface (sec / 100 cc)”. In addition, when 100 cc of air did not pass even after 12 hours had passed, it was determined as “−” that measurement was impossible.

1 and 2 are schematic views showing a test piece used for measuring the air permeability in the direction parallel to the surface. The test piece is laminated in the order of PET film 1, double-sided adhesive tape 2, and PET film 3. Among these, the PET film 1 and the double-sided pressure-sensitive adhesive tape 2 are provided with circular cutouts having a diameter of 7 mm (FIGS. 1 and 2).
FIG. 3 is a schematic view showing a part of the apparatus (test piece installation part) used for measuring the air permeability in the direction parallel to the surface. In the above apparatus, air is fed into the apparatus from the air inlet 4 under a constant pressure.
Since the PET film 1 and the PET film 3 do not have air permeability and do not allow air to pass therethrough, the air sent from the air inlet 4 into the apparatus does not pass through the double-sided pressure-sensitive adhesive tape 2. Is not discharged to the outside of the device.
In the above test, pressure is applied from the air inlet 4 and the time required to pass 100 cc of air through the test piece is measured.

As is clear from the results in Table 1, the double-sided pressure-sensitive adhesive tape of Example 1 was excellent in air permeability in the direction parallel to the surface. In addition, it was excellent in tackiness. In addition, the double-sided pressure-sensitive adhesive tape of Example 1 could not measure the fragile air permeability (the air permeability in the thickness direction).
On the other hand, the double-sided pressure-sensitive adhesive tape of Comparative Example 1 had low adhesiveness. Moreover, since the air permeability in the direction parallel to the surface is too good, liquid and large substances may also permeate (cause liquid leakage), and gas may not be selectively permeated. In the double-sided pressure-sensitive adhesive tape of Comparative Example 2, the pressure-sensitive adhesive penetrated the nonwoven fabric, and there was no air permeability in the direction parallel to the surface.

DESCRIPTION OF SYMBOLS 1 PET film 2 Double-sided adhesive tape 3 PET film 4 Air inlet 5 Air outlet

Claims (5)

  A double-sided pressure-sensitive adhesive tape comprising a double-sided pressure-sensitive adhesive tape having pressure-sensitive adhesive layers on both sides of a base material, wherein the base material has a laminated structure in which non-breathable layers are laminated on both side surfaces of a breathable layer. tape.   The double-sided pressure-sensitive adhesive tape according to claim 1, wherein the breathable layer is one or more layers selected from the group consisting of paper, nonwoven fabric and porous film.   The double-sided pressure-sensitive adhesive tape according to claim 1, wherein the air-permeable layer is a nonwoven fabric.   The double-sided pressure-sensitive adhesive tape according to any one of claims 1 to 3, wherein the air-impermeable layer is a layer formed from a resin.   The pressure-sensitive adhesive layer is a pressure-sensitive adhesive layer formed from one or more pressure-sensitive adhesives selected from the group consisting of a rubber-based pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive, and a urethane-based pressure-sensitive adhesive. Double-sided adhesive tape as described in 1.

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