JP2013227372A - Adhesive tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive tape capable of exhibiting balanced properties such as good rewinding property, good rewinding property after stored for a given period, good adhesive force, good adhesive force after stored for a given period, and low contamination property after peeled.SOLUTION: An adhesive tape comprises a base material layer and an adhesive layer. The base material layer includes a back face layer as an outermost layer opposite to the adhesive layer, the base material layer contains a saturated fatty acid bisamide having 19 or more carbon atoms in a terminal alkyl chain, and the back face layer contains the saturated fatty acid bisamide by a content percentage of 5 wt.% or less. The adhesive layer contains a styrene elastomer or an olefin elastomer.

Description

  The present invention relates to an adhesive tape. In more detail, it is related with the adhesive tape containing a base material layer and an adhesive layer.

  The pressure-sensitive adhesive tape is generally provided with a pressure-sensitive adhesive layer on one side of the base material layer. This base material layer is usually provided with a release layer as the outermost layer opposite to the pressure-sensitive adhesive layer in order to ensure good rewinding property (peelability) when the pressure-sensitive adhesive tape is rewound from the roll body. ing.

  As performance required for such an adhesive tape, in addition to the above-mentioned good rewinding property, for example, good rewinding property after storage over time, good adhesive force, good adhesive force after storage over time, For example, low contamination after peeling.

  The low contamination after peeling is a particularly important performance when, for example, it is desired to avoid contamination of the adherend, for example, when the adherend is an optical member or an electronic member. Conventionally, the release layer provided on the pressure-sensitive adhesive tape is formed by applying and drying a back treatment agent or a release agent solution dissolved in an organic solvent on an appropriate base material. However, from the viewpoint of preventing the adherend from being contaminated and from the viewpoint of environmental conservation, there is a strong demand for an adhesive tape that does not use an organic solvent.

  As a pressure-sensitive adhesive tape not using an organic solvent, a pressure-sensitive adhesive tape formed by co-extrusion of a base material layer made of polyolefin resin and a pressure-sensitive adhesive layer made of a thermoplastic pressure-sensitive adhesive resin has been proposed (for example, see Patent Document 1). ). When the pressure-sensitive adhesive tape is formed by coextrusion, various performances of the pressure-sensitive adhesive tape obtained by improving the integrity of each layer can be expressed well, and the productivity is high and the cost is low.

  However, since the pressure-sensitive adhesive tape of Patent Document 1 comprises only a base material layer and a pressure-sensitive adhesive layer, when it is made into a roll body, the rewinding property at the time of rewinding the pressure-sensitive adhesive tape from the roll body is poor, and rewinding is impossible. There is a case.

  Thus, several release treatment methods have been proposed in recent years for adhesive tapes obtained by coextrusion.

  For example, a pressure-sensitive adhesive tape obtained by coextrusion and a pressure-sensitive adhesive tape obtained by subjecting the back surface of the base material layer to friction treatment with a roll, cloth or the like has been proposed (for example, see Patent Document 2). However, this pressure-sensitive adhesive tape has a problem in that it is difficult to obtain uniform releasability because it is difficult to perform uniform friction treatment, and it is impossible to obtain good rewinding properties. Moreover, there exists a problem that the mold release effect varies depending on the blending state of the base material layer. Furthermore, there is a problem that resin powder is generated during friction, which causes contamination and the like.

  In addition, a surface protective sheet in which a fatty acid amide-based additive is added to the pressure-sensitive adhesive layer has been proposed (see, for example, Patent Document 3). However, this surface protective sheet has a problem that the adherend after peeling is contaminated because it is necessary to add the additive to the adhesive.

  Furthermore, a surface protective film in which an etheramide-based additive is added to the base material layer has been proposed (see, for example, Patent Document 4). However, when this surface protective film is stored in a high temperature environment such as summer, the ether amide additive is deposited on the pressure-sensitive adhesive layer side with time, and the adherend after peeling is contaminated. There's a problem.

  Moreover, the surface protection film which added the fatty acid amide type additive in the intermediate | middle layer of the surface protection film is proposed (for example, refer patent document 5). However, in this case, since the effect of the fatty acid amide-based additive develops with time, there is a problem that the effect is not manifested immediately after production and the effect is difficult to manifest even after a certain period of time.

  In addition, an adhesive tape using a long-chain alkyl-based back treatment agent has been proposed (see, for example, Patent Document 6). By using a long-chain alkyl-based back surface treating agent, a decrease in adhesive force due to transfer to the pressure-sensitive adhesive layer side is improved. However, since the molecular weight of the long-chain alkyl-based back treatment agent is large, there is a problem that the surface precipitation effect is excessively poor and the mold release effect is difficult to be exhibited. Furthermore, such a pressure-sensitive adhesive tape has a problem that the pressure-sensitive adhesive layer and the like are contaminated because the long-chain alkyl-based back treatment agent is thermally deteriorated during coextrusion molding to produce a low molecular weight compound.

  In addition, a surface protective film for a prism sheet using bisstearic acid amide having 17 or less carbon atoms as a release agent has been proposed (see, for example, Patent Document 7). However, this release agent tends to contaminate the pressure-sensitive adhesive layer. For this reason, there exists a problem that it cannot apply except to the to-be-adhered body which adhesive force does not fall easily even if a mold release agent adheres to an adhesive layer like a prism sheet.

  On the other hand, a fatty acid bisamide composition having 19 or more carbon atoms has recently been proposed as a release agent capable of obtaining stable release characteristics because it does not become compatible with the silicone pressure sensitive adhesive over time ( For example, see Patent Document 8). Since the release agent of Patent Document 8 has a feature that it does not become compatible with the silicone pressure sensitive adhesive over time, its release property is evaluated as a release property with the silicone pressure sensitive adhesive. Therefore, it can be said that the mold release agent of patent document 8 was developed on the assumption of a combination with a silicone-based pressure-sensitive adhesive. However, in pressure-sensitive adhesive tapes that apply a silicone-based pressure-sensitive adhesive to the pressure-sensitive adhesive layer, good unwinding properties, good unwinding properties after storage over time, good adhesive strength, good adhesive strength after storage over time, after peeling It is difficult to express the low-contamination property in a well balanced manner. Moreover, the adhesive tape which applies a silicone type adhesive to an adhesive layer cannot be manufactured by coextrusion.

  As mentioned above, the pressure-sensitive adhesive tape that can express a good rewinding property, a good rewinding property after storage over time, a good adhesive strength, a good adhesive strength after storage over time, low contamination after peeling, etc. in a well-balanced manner. It has not been developed yet.

JP-A-61-103975 JP-A-2-252777 Japanese Patent Laid-Open No. 10-176147 Japanese Patent Laid-Open No. 10-309781 Japanese Patent Laid-Open No. 9-217046 JP 11-43655 A Japanese Patent No. 4565058 JP 2009-161482 A

  An object of the present invention is to provide a pressure-sensitive adhesive tape capable of expressing in a well-balanced state a good rewinding property, a good rewinding property after storage over time, a good adhesive strength, a good adhesive strength after storage over time, a low contamination property after peeling, and the like. Is to provide.

The adhesive tape of the present invention is
An adhesive tape comprising a base material layer and an adhesive layer,
The base material layer has a back layer as an outermost layer opposite to the pressure-sensitive adhesive layer,
The base material layer contains a saturated fatty acid bisamide having 19 or more carbon atoms in the terminal alkyl chain,
In the back layer, the saturated fatty acid bisamide is contained at a content of 5% by weight or less,
The pressure-sensitive adhesive layer contains a styrene elastomer or an olefin elastomer.

  In a preferred embodiment, the pressure-sensitive adhesive tape of the present invention is integrally formed by coextrusion molding.

  In preferable embodiment, the said base material layer contains an olefin resin.

  In a preferred embodiment, the back layer contains a resin having an MFR of 1 g / 10 min to 100 g / 10 min.

  In a preferred embodiment, the back layer includes a polypropylene resin.

In preferable embodiment, content per unit area of the said back surface layer of the said saturated fatty acid bisamide is 0.15 g / m < ² > or less.

  In a preferred embodiment, the pressure-sensitive adhesive tape of the present invention has an unwinding force of 23 ° C., a humidity of 50% RH, a peeling angle of 90 °, and a tensile speed of 10 m / min. Any of the unwinding force after storage for days is 0.01 N / 20 mm to 2.0 N / 20 mm.

  In a preferred embodiment, the adhesive tape of the present invention has a haze of 60% or less.

  According to the present invention, a pressure-sensitive adhesive tape that can exhibit good unwinding properties, good unwinding properties after storage over time, good adhesive strength, good adhesive strength after storage over time, low contamination after peeling, and the like in a well-balanced manner. Can be provided.

It is a schematic sectional drawing of the adhesive tape by preferable embodiment of this invention.

≪ << A. Adhesive tape >>>>
The pressure-sensitive adhesive tape of the present invention includes a base material layer and a pressure-sensitive adhesive layer. The pressure-sensitive adhesive tape of the present invention may be a laminate formed only of a base material layer and a pressure-sensitive adhesive layer, or a laminate formed of a base material layer, a pressure-sensitive adhesive layer and any other at least one layer. There may be.

  The base material layer has a back layer as the outermost layer on the side opposite to the pressure-sensitive adhesive layer. If the base material layer has such a back layer, it may be a single layer or a laminate of two or more layers.

  The pressure-sensitive adhesive layer may be a single layer or a laminate of two or more layers.

  FIG. 1 is a schematic cross-sectional view of an adhesive tape according to a preferred embodiment of the present invention. In FIG. 1, an adhesive tape 100 includes a base material layer 10 and an adhesive layer 20, and the base material layer 10 includes a back layer 30 and an intermediate layer 40.

  The thickness of the pressure-sensitive adhesive tape of the present invention can be set to any appropriate thickness depending on the application. The thickness of the pressure-sensitive adhesive tape of the present invention is preferably 10 μm to 200 μm, more preferably 10 μm to 150 μm, still more preferably 20 μm to 120 μm, and particularly preferably 20 μm to 100 μm.

  The pressure-sensitive adhesive tape of the present invention is preferably integrally formed by coextrusion molding. That is, the pressure-sensitive adhesive tape of the present invention preferably coextrudes a forming material composition containing a base layer forming material (for example, a back layer forming material and an intermediate layer forming material) and an adhesive layer forming material. To be integrated.

  The pressure-sensitive adhesive tape of the present invention has an unwinding force under conditions of a temperature of 23 ° C., a humidity of 50% RH, a peeling angle of 90 °, and a tensile speed of 10 m / min. Any of the return forces is preferably 0.01 N / 20 mm to 2.0 N / 20 mm, and more preferably 0.01 N / 20 mm to 1.5 N / 20 mm. Thus, the pressure-sensitive adhesive tape of the present invention is very excellent in rewinding property (peeling property) when rewinding from a roll body. Details of the method for measuring the unwinding force will be described later.

  The pressure-sensitive adhesive tape of the present invention preferably has an initial pressure-sensitive adhesive strength of the pressure-sensitive adhesive layer to the SUS plate under the conditions of a temperature of 23 ° C., a humidity of 50% RH, a peeling angle of 180 °, and a peeling speed of 10 m / min. To 5.0 N / 20 mm, more preferably 1.0 N / 20 mm to 4.5 N / 20 mm, still more preferably 1.2 N / 20 mm to 4.0 N / 20 mm, and particularly preferably 1.5 N / 20 mm. 20 mm to 3.6 N / 20 mm. As described above, the adhesive tape of the present invention has an appropriate level of initial adhesive strength with respect to the SUS plate of the adhesive layer. Therefore, it is easy to perform both sufficient adhesion and easy peeling for various applications. It can be widely deployed. Details of the method for measuring the initial adhesive strength will be described later.

  The adhesive tape of the present invention has a haze of preferably 60% or less, more preferably 50% or less, further preferably 40% or less, particularly preferably 30% or less, and most preferably 20%. It is as follows. When the haze of the pressure-sensitive adhesive tape of the present invention falls within such a range, good transparency can be expressed. Details of the haze measurement method will be described later.

<< A-1. Base material layer >>
The base material layer has a back layer as the outermost layer on the side opposite to the pressure-sensitive adhesive layer. That is, the base material layer may be composed of only the back layer, or may be composed of the back layer and an intermediate layer composed of at least one layer.

  The base material layer contains a saturated fatty acid bisamide having 19 or more carbon atoms in the terminal alkyl chain. This saturated fatty acid bisamide having 19 or more carbon atoms in the terminal alkyl chain can act as a release agent. The content ratio of the saturated fatty acid bisamide in the base material layer is preferably 5% by weight or less, more preferably 4.5% by weight or less as the content ratio in the back layer. If the content ratio of the saturated fatty acid bisamide in the substrate layer is within the above range, the pressure-sensitive adhesive tape of the present invention has good unwinding property, good unwinding property after storage over time, and low contamination after peeling. It can be expressed in a balanced manner. The lower limit of the content ratio of the saturated fatty acid bisamide in the base material layer is preferably 0.001% by weight or more, more preferably 0.01%, because there is a possibility that the above effect cannot be sufficiently exhibited if it is too small. % By weight or more, more preferably 0.1% by weight or more, and particularly preferably 1% by weight or more.

The saturated fatty acid bisamide having 19 or more carbon atoms in the terminal alkyl chain is represented by R—CONH— (CH 2) _n —NHCO—R, wherein R is a linear aliphatic group having 19 or more carbon atoms, and n is It is an integer of 1-6. R is preferably a linear aliphatic group having 19 to 23 carbon atoms.

Specific examples of the saturated fatty acid bisamide as described above include, for example, ethylene bisarachidic acid amide, ethylene bisbehenic acid amide, ethylene bislignoceric acid amide, ethylene biscerotic acid amide, ethylene bismontanoic acid amide, And ethylene bismelicinamide. Among these, ethylene bisbehenate amide (C ₂₁ H ₄₃ —CONH—CH ₂ —CH ₂ —NHCO—C ₂₁ H ₄₃ ) is preferable from the viewpoint of the effect of precipitation on the surface and the drop-off from the surface. It is.

  The base material layer preferably contains an olefin resin. The content ratio of the olefin resin in the base material layer is preferably 50% by weight to 99.999% by weight, more preferably 70% by weight to 99.99% by weight, and still more preferably 90% by weight to 99% by weight. 0.9 wt%, particularly preferably 95 wt% to 99 wt%. When the base material layer contains the olefin resin in the above content ratio, the pressure-sensitive adhesive tape of the present invention further balances good unwinding properties, good unwinding properties after storage over time, and low contamination after peeling. Can express well.

  As the olefin resin, preferably, a polyolefin resin is used. Examples of the polyolefin resin include a polyethylene resin, a polypropylene resin, and a copolymer of ethylene and a polar monomer. More specifically, as the polyolefin-based resin, for example, low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, homopolypropylene, block polypropylene, random polypropylene, poly-1-butene, poly- 4-methyl-1-pentene, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene / 1- Examples include octene copolymer, ethylene-methyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl alcohol copolymer. .

  When the base material layer contains an olefin resin, the olefin resin may be only one kind or two or more kinds.

  The thickness of the base material layer can be set to any appropriate thickness depending on the application. The thickness of the base material layer is preferably 10 μm to 200 μm, more preferably 10 μm to 150 μm, still more preferably 20 μm to 100 μm, and particularly preferably 20 μm to 80 μm.

<< A-1-1. Back layer >>
The back layer preferably includes a resin having an MFR of 1 g / 10 min to 100 g / 10 min. The content ratio of such a resin in the back layer is preferably 50% by weight to 99.999% by weight, more preferably 70% by weight to 99.99% by weight, and further preferably 90% by weight to 99% by weight. 0.9 wt%, particularly preferably 95 wt% to 99 wt%. When the back layer contains the resin in the above content ratio, the pressure-sensitive adhesive tape of the present invention expresses better rewinding property, better rewinding property after storage over time, and low contamination after peeling in a more balanced manner. it can.

  The MFR of the resin that can be contained in the back layer is preferably 2 g / 10 min to 50 g / 10 min, more preferably 2 g / 10 min to 30 g / 10 min, in that the above effect can be further exhibited. It is.

  The back layer preferably contains a polyolefin resin. The content ratio of the polyolefin resin in the back layer is preferably 50% by weight to 99.999% by weight, more preferably 70% by weight to 99.99% by weight, and further preferably 90% by weight to 99.99% by weight. 9% by weight, particularly preferably 95% by weight to 99% by weight. When the back layer contains the polyolefin resin at the above-mentioned content ratio, the pressure-sensitive adhesive tape of the present invention has a better balance of good unwinding property, good unwinding property after storage over time, and low contamination after peeling. It can be expressed.

  Examples of the polyolefin resin include a polyethylene resin, a polypropylene resin, and a copolymer of ethylene and a polar monomer. More specifically, as the polyolefin-based resin, for example, low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, homopolypropylene, block polypropylene, random polypropylene, poly-1-butene, poly- 4-methyl-1-pentene, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene / 1- Examples include octene copolymer, ethylene-methyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl alcohol copolymer. . Of these, polyethylene resins and polypropylene resins are preferable, and polypropylene resins are more preferable. When the back layer contains a polypropylene-based resin, the pressure-sensitive adhesive tape of the present invention can exhibit better unwinding properties, good unwinding properties after storage over time, and low contamination after peeling, in a more balanced manner.

  When the back surface layer contains a polyolefin resin, the polyolefin resin may be only one type or two or more types.

  The back layer contains a saturated fatty acid bisamide having 19 or more carbon atoms in the terminal alkyl chain. The content ratio of the saturated fatty acid bisamide in the back layer is preferably 5% by weight or less, more preferably 4.5% by weight or less. If the content of the saturated fatty acid bisamide in the back layer falls within the above range, the pressure-sensitive adhesive tape of the present invention balances good unwinding properties, good unwinding properties after storage over time, and low contamination after peeling. Can express well. The lower limit of the content ratio of the saturated fatty acid bisamide in the back layer is preferably 0.001% by weight or more, more preferably 0.01% by weight, because if the amount is too small, the above effect may not be sufficiently exhibited. % Or more, more preferably 0.1% by weight or more, and particularly preferably 1% by weight or more.

The content of the saturated fatty acid bisamide per unit area of the back layer is preferably 0.15 g / m ² or less, more preferably 0.14 g / m ² or less, and further preferably 0.13 g / m ^2. It is as follows. If the content of the saturated fatty acid bisamide per unit area of the back layer is within the above range, the pressure-sensitive adhesive tape of the present invention has good unwinding property, good unwinding property after storage over time, and low contamination after peeling. Sex can be expressed in a well-balanced manner. The lower limit of the content of the saturated fatty acid bisamide per unit area of the back layer is preferably 0.001 g / m ² or more, more preferably because the above effect may not be sufficiently exhibited if it is too small. 0.05 g / m ² or more.

  The thickness of the back layer is preferably 1 μm to 10 μm, more preferably 2 μm to 8 μm, and further preferably 2 μm to 5 μm. When the thickness of the back layer is within the above range, the pressure-sensitive adhesive tape of the present invention can exhibit better unwinding properties, good unwinding properties after storage over time, and low contamination after peeling in a more balanced manner. .

  The back layer may contain any other suitable additive. Examples of such additives include fillers, pigments, ultraviolet absorbers, antioxidants, heat stabilizers, lubricants, antiblocking agents and the like.

<< A-1-2. Middle layer >>
The intermediate layer preferably contains a polyolefin resin. The content ratio of the polyolefin resin in the intermediate layer is preferably 50% by weight to 100% by weight, more preferably 70% by weight to 100% by weight, still more preferably 90% by weight to 100% by weight, Particularly preferred is 95% to 100% by weight, and most preferred is substantially 100% by weight. When the intermediate layer contains the polyolefin resin in the above content ratio, the pressure-sensitive adhesive tape of the present invention has a better balance of good rewinding property, good rewinding property after storage over time, and low contamination after peeling. It can be expressed.

  Examples of the polyolefin resin include a polyethylene resin, a polypropylene resin, and a copolymer of ethylene and a polar monomer. More specifically, as the polyolefin-based resin, for example, low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, homopolypropylene, block polypropylene, random polypropylene, poly-1-butene, poly- 4-methyl-1-pentene, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene / 1- Examples include octene copolymer, ethylene-methyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl alcohol copolymer. . Of these, polyethylene resins and polypropylene resins are preferable, and polyethylene resins are more preferable. When the intermediate layer contains a polyethylene-based resin, the pressure-sensitive adhesive tape of the present invention can exhibit a good rewinding property, a good rewinding property after storage with time, and a low contamination property after peeling in a more balanced manner.

  When the intermediate layer contains a polyolefin-based resin, the polyolefin-based resin may be one type or two or more types.

  The intermediate layer may be a single layer or a laminate of two or more layers. In the case where the intermediate layer is a laminate of two or more layers, it is preferable that these layers are bonded to each other by melt coextrusion.

  The intermediate layer can contain any appropriate additive. Examples of such additives include fillers, pigments, ultraviolet absorbers, antioxidants, heat stabilizers, lubricants, antiblocking agents and the like.

  The thickness of the intermediate layer is preferably 10 μm to 200 μm, more preferably 10 μm to 150 μm, still more preferably 20 μm to 100 μm, and particularly preferably 20 μm to 80 μm. When the thickness of the intermediate layer is within the above range, the pressure-sensitive adhesive tape of the present invention can exhibit better unwinding properties, good unwinding properties after storage over time, and low contamination after peeling in a more balanced manner. . Moreover, if the thickness of the intermediate layer is too small, the base material layer may be torn or torn during peeling. If the thickness of the intermediate layer is too large, the stiffness of the base material layer becomes too large, and there is a possibility that floating or the like is likely to occur after sticking.

<< A-2. Adhesive layer >>
The pressure-sensitive adhesive layer contains a styrene-based elastomer or an olefin-based elastomer. The content ratio of these resins in the pressure-sensitive adhesive layer is preferably 50% by weight or more, more preferably 60% by weight or more, still more preferably 70% by weight or more, and particularly preferably 80% by weight or more. Most preferably, it is 90% by weight or more. When the pressure-sensitive adhesive layer contains the styrene-based elastomer or the olefin-based elastomer in the above content ratio, the pressure-sensitive adhesive tape of the present invention has a good rewinding property, a good rewinding property after storage over time, a good adhesive force, and storage over time. Good adhesive strength later, low contamination after peeling, etc. can be expressed in a well-balanced manner.

  Preferred examples of the styrene elastomer include a styrene / butadiene copolymer or a hydrogenated product thereof, and a styrene block copolymer or a hydrogenated product thereof. Specific examples of the styrene / butadiene copolymer or hydrogenated product thereof include hydrogenated styrene / butadiene rubber (HSBR) (for example, JSR, Dynalon 1320P, 1321P, 2324P, etc.). Specific examples of the styrenic block copolymer or hydrogenated product thereof include, for example, styrene / ethylene-butylene copolymer / styrene copolymer (SEBS) (for example, JSR, Dynalon 8601P, 9901P, etc.). Can be mentioned.

  Examples of styrene block copolymers include styrene ABA block copolymers (triblock copolymers) such as styrene / butadiene / styrene copolymers (SBS) and styrene / isoprene / styrene copolymers (SIS). ); Styrenic ABAB type block copolymer (tetrablock copolymer) such as styrene / butadiene / styrene / butadiene copolymer (SBSB), styrene / isoprene / styrene / isoprene copolymer (SISI); styrene / butadiene・ Styrene-based ABABA block copolymer (pentablock copolymer) such as styrene / butadiene / styrene copolymer (SBSBS), styrene / isoprene / styrene / isoprene / styrene copolymer (SISIS); Styrene group having repeating units Click copolymers; and the like.

  Examples of hydrogenated styrenic block copolymers include styrene / ethylene-butylene copolymer / styrene copolymer (SEBS), styrene / ethylene-propylene copolymer / styrene copolymer (SEPS), and styrene. -Ethylene-butylene copolymer-Styrene-ethylene-butylene copolymer copolymer (SEBSEB);

  Only one type of styrene elastomer may be used, or two or more types may be used.

  When the styrenic elastomer is a styrenic block copolymer or a hydrogenated product thereof, the styrene block content in the styrenic elastomer is preferably 5 wt% to 40 wt%, more preferably 7 wt% to 30 wt%. %, More preferably 9% by weight to 20% by weight. When the styrene block content is reduced, adhesive residue due to insufficient cohesive force of the adhesive layer may be easily generated. When the styrene block content is increased, the pressure-sensitive adhesive layer becomes hard, and there is a possibility that good adhesion to a rough surface cannot be obtained.

  As the styrene-based elastomer, a hydrogenated product of a styrene-based block copolymer having a repeating structure (ABA type, ABAB type, ABABA type, etc.) of a triblock copolymer or more composed of styrene (A) and butadiene (B) ( SEBS, SEBSEB, SEBSEBS, etc.) are preferred. By adopting such a styrene-based elastomer, the adhesive force in the state of being applied to the adherend can be made reasonably sufficiently high, while the adhesive force when peeling off after being attached to the adherend is more appropriate. Therefore, it can be more easily peeled off from the adherend with a slight force, and the increase in adhesive strength when exposed to an environmental load for long-term storage at a relatively high temperature can be further suppressed. .

  Hydrogenated styrene block copolymer (SEBS) in which the styrenic elastomer has a repeating structure (ABA type, ABAB type, ABABA type, etc.) more than a triblock copolymer composed of styrene (A) and butadiene (B) , SEBSEB, SEBSEBS, etc.), the proportion of the butylene structure in the ethylene-butylene copolymer block is preferably 60% by weight or more, more preferably 70% by weight or more, and further preferably 75% by weight. That's it. When the proportion of the butylene structure in the ethylene-butylene copolymer block is within the above range, the adhesive force in the state of being applied to the adherend can be made reasonably high, while being attached to the adherend. Adhesive strength at the time of peeling later is a more appropriate level, and therefore, it can be peeled off from the adherend more easily with a slight force, and further exposed to the environmental load of long-term storage at relatively high temperatures. In this case, the increase in adhesive strength can be further suppressed. The proportion of the butylene structure in the ethylene-butylene copolymer block is preferably 90% by weight or less.

  Other styrene elastomers include styrene block copolymers other than those described above; styrene / butadiene copolymers (SB), styrene / isoprene copolymers (SI), and copolymers of styrene / ethylene-butylene copolymers. (SEB), AB block polymers such as styrene / ethylene-propylene copolymer (SEP); Styrene random copolymers such as styrene / butadiene rubber (SBR); Styrene / ethylene-butylene copolymer -ABC type styrene-olefin crystal type block polymers such as olefin crystal copolymer (SEBC); hydrogenated products thereof; and the like.

  The olefin elastomer is preferably an amorphous polyolefin elastomer.

  Examples of the amorphous polyolefin-based elastomer include ethylene propylene rubber, an elastomer composed of ethylene and α-olefin, and an amorphous polypropylene-based resin (such as atactic polypropylene) that exhibits adhesiveness. Preferably, an amorphous polypropylene resin is used. As the amorphous polypropylene resin, any appropriate amorphous polypropylene resin can be adopted as long as it has rubber elasticity in the operating temperature range.

  Here, the amorphous polyolefin-based elastomer has an amorphous property having no crystal structure. Examples of a method for confirming that the material has an amorphous property include a solubility test in n-heptane. Specifically, an amorphous polyolefin-based elastomer is dissolved in n-heptane at a concentration of 10% by weight, and the solubility is measured. In this case, the solubility is substantially 100%. Those having 90% or more shall be amorphous.

  Examples of the amorphous polypropylene-based resin include a propylene-α-olefin copolymer and a propylene-ethylene-α-olefin copolymer.

  Examples of the α-olefin include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4-methyl-1-pentene, 4-methyl-1-hexene and the like. Among these, 1-butene, 1-hexene, 1-octene and 4-methyl-1-pentene are preferable. Only 1 type may be sufficient as an alpha olefin, and 2 or more types may be sufficient as it.

  As an amorphous polypropylene-type resin, Preferably, an amorphous propylene- (1-butene) copolymer is mentioned. The amorphous propylene- (1-butene) copolymer can be preferably obtained by copolymerizing propylene and 1-butene using a metallocene catalyst. The amorphous propylene- (1-butene) copolymer obtained by copolymerization using a metallocene catalyst exhibits a narrow molecular weight distribution (for example, 2 or less). If an amorphous propylene- (1-butene) copolymer having such a narrow molecular weight distribution is used, bleeding of low molecular weight components can be prevented.

  The content ratio of the structural unit derived from propylene in the amorphous propylene- (1-butene) copolymer is preferably 80 mol% to 99 mol%, more preferably 85 mol% to 99 mol%, Preferably it is 90 mol%-99 mol%. If the content ratio of the structural unit derived from propylene in the amorphous propylene- (1-butene) copolymer is in such a range, an adhesive layer excellent in balance between toughness and flexibility can be obtained, The effect of the present invention can be expressed more effectively.

  The content of the structural unit derived from 1-butene in the amorphous propylene- (1-butene) copolymer is preferably 1 mol% to 15 mol%, more preferably 1 mol% to 10 mol%. . If the content ratio of the structural unit derived from 1-butene in the amorphous propylene- (1-butene) copolymer is in such a range, an adhesive layer excellent in balance between toughness and flexibility can be obtained. And the effects of the present invention can be expressed more effectively.

  Any appropriate copolymer structure can be adopted as the copolymer structure of the amorphous propylene- (1-butene) copolymer. Examples of such a copolymer structure include a block copolymer and a random copolymer.

  The weight average molecular weight (Mw) of the amorphous propylene- (1-butene) copolymer is preferably 200000 or more, more preferably 200000-500000, and further preferably 200000-300000. If the weight average molecular weight (Mw) of the amorphous propylene- (1-butene) copolymer is in such a range, a pressure-sensitive adhesive layer having an appropriate adhesive force can be obtained, and the effects of the present invention can be further improved. It can be expressed more effectively.

  When the pressure-sensitive adhesive layer contains an amorphous propylene- (1-butene) copolymer, the pressure-sensitive adhesive layer may further contain a crystalline polypropylene resin in order to adjust the pressure-sensitive adhesive force of the pressure-sensitive adhesive layer. When the pressure-sensitive adhesive layer contains a crystalline polypropylene resin, the adhesive strength of the pressure-sensitive adhesive layer can be appropriately reduced and the storage elastic modulus can be increased. When the pressure-sensitive adhesive layer further contains a crystalline polypropylene resin, the content of the crystalline polypropylene resin in the pressure-sensitive adhesive layer is set to any appropriate content depending on the desired adhesive force and storage elastic modulus. obtain. The content of such a crystalline polypropylene resin is preferably 0% by weight to the total weight of the amorphous propylene- (1-butene) copolymer and the crystalline polypropylene resin. It is 50% by weight, more preferably 0% by weight to 40% by weight, and still more preferably 0% by weight to 30% by weight.

  The pressure-sensitive adhesive layer may contain any appropriate other component as required. Other components include, for example, a tackifier; a softener; an anti-aging agent; an olefin resin; a silicone resin; a liquid acrylic copolymer; a polyethyleneimine; a fatty acid amide; a phosphate ester; and a hindered amine light stabilizer; UV absorbers; heat-resistant stabilizers; fillers or pigments such as calcium oxide, magnesium oxide, silica, zinc oxide, and titanium oxide; other additives; The kind, number, and amount of other components that can be contained in the pressure-sensitive adhesive layer can be appropriately set depending on the purpose.

  The tackifier is effective for improving the adhesive strength. When the pressure-sensitive adhesive layer contains a tackifier, the content ratio of the tackifier in the pressure-sensitive adhesive layer can be set to any appropriate content ratio in consideration of prevention of generation of adhesive residue due to a decrease in cohesive force. . The content of the tackifier in the pressure-sensitive adhesive layer is preferably 1% by weight to 60% by weight, more preferably 3% by weight to 50% by weight, and still more preferably with respect to the resin component of the pressure-sensitive adhesive layer. Is 4% to 45% by weight, particularly preferably 5% to 40% by weight.

  Examples of tackifiers include hydrocarbon tackifiers, terpene tackifiers, rosin tackifiers, phenol tackifiers, epoxy tackifiers, polyamide tackifiers, and elastomer tackifiers. And ketone-based tackifiers. Only one type of tackifier may be used in the pressure-sensitive adhesive layer, or two or more types may be used.

  Examples of the hydrocarbon tackifier include aliphatic hydrocarbon resins, aromatic hydrocarbon resins (for example, xylene resins), aliphatic cyclic hydrocarbon resins, aliphatic / aromatic petroleum resins (for example, Styrene-olefin copolymers, aliphatic / alicyclic petroleum resins, hydrogenated hydrocarbon resins, coumarone resins, coumarone-indene resins, and the like.

  Examples of the terpene tackifier include terpene resins such as α-pinene polymers and β-pinene polymers; modified terpenes obtained by modifying terpene resins (eg, phenol modification, aromatic modification, hydrogenation modification, etc.) Resin (for example, terpene-phenol resin, styrene-modified terpene resin, hydrogenated terpene resin, etc.);

  Examples of rosin-based tackifiers include unmodified rosins such as gum rosin and wood rosin (raw rosin); modified rosins modified by hydrogenation, disproportionation, polymerization, etc. (for example, hydrogenated rosin, non-modified rosin) Averaged rosin, polymerized rosin, other chemically modified rosins, etc.); various other rosin derivatives;

  Examples of the phenol tackifier include resol type or novolac type alkylphenols.

  The tackifier may be commercially available as a blend with an olefin resin or a thermoplastic elastomer.

  The softening agent is effective for improving the adhesive strength. When the pressure-sensitive adhesive layer contains a softening agent, any appropriate amount can be adopted as the content ratio of the softening agent in the pressure-sensitive adhesive layer. If the content of the softener in the pressure-sensitive adhesive layer becomes too large, the amount of adhesive residue at the time of high temperature or outdoor exposure tends to increase. Therefore, the content of the softener in the pressure-sensitive adhesive layer is preferably 40% by weight. % Or less, more preferably 20% by weight or less, and still more preferably 10% by weight or less.

  Examples of the softening agent include low molecular weight diene polymers, polyisobutylene, hydrogenated polyisoprene, hydrogenated polybutadiene, and derivatives thereof. Examples of the derivative include those having an OH group or a COOH group at one or both ends. Specific examples include hydrogenated polybutadiene diol, hydrogenated polybutadiene monool, hydrogenated polyisoprene diol, and hydrogenated polyisoprene monool. In order to further suppress the improvement in adhesive strength, hydrogenated products of diene polymers such as hydrogenated polybutadiene and hydrogenated polyisoprene, olefinic softeners, and the like are preferable. Specific examples include “Kuraprene LIR-200” manufactured by Kuraray Co., Ltd. Only one type of softening agent in the pressure-sensitive adhesive layer may be used, or two or more types may be used.

  The molecular weight of the softener can be set to any suitable amount. If the molecular weight of the softening agent is too small, it may cause contamination by bleeding from the pressure-sensitive adhesive layer. On the other hand, if the molecular weight of the softening agent is too large, the effect of improving the adhesion tends to be poor. Therefore, the number average molecular weight of the softening agent is preferably 5,000 to 100,000, more preferably 10,000 to 50,000.

  The thickness of the pressure-sensitive adhesive layer is preferably 1 to 50 μm, more preferably 2 to 40 μm, and further preferably 3 to 20 μm. When the thickness of the pressure-sensitive adhesive layer falls within the above range, the pressure-sensitive adhesive tape of the present invention has a good rewinding property, a good rewinding property after storage over time, a good adhesive force, and a good adhesive force after storage over time. Moreover, the low contamination after peeling can be expressed in a more balanced manner.

  For the surface of the adhesive layer, for example, corona discharge treatment, ultraviolet irradiation treatment, flame treatment, plasma treatment, sputter etching treatment, etc. It can also be applied.

  If necessary, the pressure-sensitive adhesive layer can be temporarily attached with a separator or the like until it is put to practical use.

≪≪B. Manufacturing method of adhesive tape >>>>
The pressure-sensitive adhesive tape of the present invention is preferably integrally formed by coextrusion molding. That is, the pressure-sensitive adhesive tape of the present invention preferably coextrudes a forming material composition containing a base layer forming material (for example, a back layer forming material and an intermediate layer forming material) and an adhesive layer forming material. By doing so, it can be integrated and manufactured.

  The method of coextrusion molding can be performed according to an inflation method, a T-die method, or the like, using an extruder and a co-extrusion die for each layer forming material. By this coextrusion molding, the layers derived from the respective forming materials are integrated into a laminate.

  The material for forming the back layer is preferably the above << A-1-1. The resin whose MFR is 1 g / 10 min to 100 g / 10 min described in the section of the back layer >> is included. The content of such a resin in the material for forming the back layer is preferably 50% by weight to 99.999% by weight, more preferably 70% by weight to 99.99% by weight, and still more preferably 90% by weight. % To 99.9% by weight, particularly preferably 95% to 99% by weight. When the forming material of the back layer contains the above resin in the above content ratio, the pressure-sensitive adhesive tape of the present invention has further excellent rewinding property, good rewinding property after storage over time, and low contamination after peeling. It can be expressed in a balanced manner.

  The material for forming the back layer is preferably the above << A-1-1. The polyolefin-based resin described in the section of the back layer >> is included. The content ratio of the polyolefin resin in the material for forming the back layer is preferably 50% by weight to 99.999% by weight, more preferably 70% by weight to 99.99% by weight, and still more preferably 90% by weight. ˜99.9% by weight, particularly preferably 95% by weight to 99% by weight. When the forming material of the back layer contains the polyolefin resin in the above content ratio, the pressure-sensitive adhesive tape of the present invention has better unwinding properties, good unwinding properties after storage over time, and low contamination after peeling. It can be expressed in a better balance.

  The material for forming the back layer is preferably the above << A-1-1. The saturated fatty acid bisamide having 19 or more carbon atoms in the terminal alkyl chain described in the section of the back layer is included. The content ratio of the saturated fatty acid bisamide in the material for forming the back layer is preferably 5% by weight or less, more preferably 4.5% by weight or less. If the content ratio of the saturated fatty acid bisamide in the back layer forming material is within the above range, the pressure-sensitive adhesive tape of the present invention has good unwinding property, good unwinding property after storage over time, and low contamination after peeling. Sex can be expressed in a well-balanced manner. The lower limit of the content ratio of the saturated fatty acid bisamide in the material for forming the back layer is preferably 0.001% by weight or more, more preferably 0, because if the amount is too small, the above effect may not be sufficiently exhibited. 0.01% by weight or more, more preferably 0.1% by weight or more, and particularly preferably 1% by weight or more.

  Examples of the material for forming the back layer include the above << A-1-1. Any other appropriate additive described in the section of the back layer may be contained.

  As a method for preparing the material for forming the back layer, preferably, 1) a method in which these materials are dry blended with a mixer such as a tumble mixer, a ribbon blender, or a Henschel mixer, and 2) a dry blend of these materials. 3) A method of preparing a master batch of these materials in advance and dry blending with a polyolefin resin or the like with the above mixer and mixing. , Etc.

  The material for forming the intermediate layer is preferably the above << A-1-2. The polyolefin resin described in the section of the intermediate layer >> is included. The content ratio of the polyolefin resin in the material for forming the intermediate layer is preferably 50% by weight to 100% by weight, more preferably 70% by weight to 100% by weight, and further preferably 90% by weight to 100% by weight. Particularly preferred is 95% to 100% by weight, and most preferred is substantially 100% by weight. When the forming material of the intermediate layer contains the polyolefin resin in the above content ratio, the pressure-sensitive adhesive tape of the present invention has better unwinding property, good unwinding property after storage over time, and low contamination after peeling. It can be expressed in a better balance.

  Examples of the material for forming the intermediate layer include the above << A-1-2. Any other appropriate additive described in the section of the intermediate layer >> may be contained.

  The material for forming the pressure-sensitive adhesive layer is preferably the above << A-2. A styrene-based elastomer or an olefin-based elastomer described in the section of the pressure-sensitive adhesive layer >> is included. The content ratio of these resins in the material for forming the pressure-sensitive adhesive layer is preferably 50% by weight or more, more preferably 60% by weight or more, still more preferably 70% by weight or more, and particularly preferably 80% by weight. Or more, and most preferably 90% by weight or more. When the material for forming the pressure-sensitive adhesive layer contains the styrene-based elastomer or the olefin-based elastomer in the above content ratio, the pressure-sensitive adhesive tape of the present invention has a good rewinding property, a good rewinding property after storage over time, and a good adhesive force. In addition, good adhesive strength after storage over time, low contamination after peeling, and the like can be expressed in a well-balanced manner.

  Examples of the material for forming the pressure-sensitive adhesive layer include the above << A-2. Any appropriate other component described in the section of the pressure-sensitive adhesive layer >> may be contained.

  When manufacturing the adhesive tape of this invention, you may irradiate ionizing radiation to the laminated body obtained by integrating by said coextrusion molding. Specifically, for example, the obtained laminate may be irradiated with ionizing radiation before being wound in a roll shape or in a state of being rewound again after being wound in a roll shape. Irradiation with ionizing radiation is preferably performed in an inert gas atmosphere such as nitrogen. Examples of the ionizing radiation include X-rays, γ-rays, ultraviolet rays, visible rays, and electron beams. An electron beam is preferable as the ionizing radiation because of the high generation rate of the reactive species upon irradiation and the deep penetration of the irradiation target. As the electron beam source, various electron beam accelerators such as a Cockloft Walton type, a bandegraft type, a resonant transformer type, an insulating core transformer type, a linear type, a dynamitron type, and a high frequency type can be used. The ionizing radiation may be irradiated from one side of the laminate or from both sides. In terms of simplification of the process, the ionizing radiation is preferably irradiated by ionizing radiation by guiding the laminate to an ionizing radiation irradiating apparatus before winding it into a roll. The irradiation dose of ionizing radiation is preferably 10 kGy to 500 kGy, more preferably 10 kGy to 400 kGy, and even more preferably 10 kGy to 300 kGy, from the viewpoint of improving interlayer adhesion and maintaining the physical properties of the adhesive tape. The acceleration voltage of ionizing radiation can be appropriately selected according to the type of resin used for the adhesive tape and the thickness of the adhesive tape. The acceleration voltage of ionizing radiation is usually preferably in the range of 50 kV to 300 kV. The ionizing radiation may be irradiated once or a plurality of times (preferably twice).

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples at all. In addition, the test and evaluation method in an Example etc. are as follows. Moreover, a part means a weight part. Moreover,% means weight%.

<Measurement of unwinding force>
In accordance with JIS-Z-0237 (2009) “high-speed rewinding force”, an adhesive tape wound in a roll shape is used as a test sample, and an initial state and 50 ° C. × are measured using a rewinding force measuring device. The unwinding force after storage for 7 days (left at room temperature for 2 hours immediately before measurement) was measured, and each was defined as the initial unwinding force and the unwinding force after storage at 50 ° C. for 7 days. In addition, the average value of N = 3 was used as the measurement value.
Measurement temperature: 23 ° C
Measurement humidity: 50% RH
Specimen width: 20 mm
Tensile speed: 10 m / min Peeling angle: 90 °

<Evaluation of rewinding force>
The measured unwinding force was evaluated according to the following criteria.
○: Rewinding force is 2 N / 20 mm or less.
X: Rewinding force exceeds 2 N / 20 mm.

<Measurement of adhesive strength>
Adhesive tape was affixed to a SUS plate (SUS430BA, toluene ultrasonic cleansed product) at a linear pressure of 78.5 N / cm, and after 30 minutes, a high-speed adhesive force measuring device was used at a temperature of 23 ° C., humidity of 50% RH, peeling angle of 180 °. The film was peeled off under a peeling speed of 10 m / min, and the initial adhesive strength was measured. In addition, the average value of N = 3 was used as the measurement value.
Further, after being stored in a roll state at 50 ° C. for 7 days and then allowed to stand at room temperature for 2 hours, pasting and measurement were performed in the same manner as described above, and the adhesive strength after storage at 50 ° C. for 7 days was measured.

<Evaluation of initial adhesive strength>
The measured initial adhesive strength was evaluated according to the following criteria.
When the adhesive layer contains a styrene elastomer,
○: Initial adhesive strength is 3.0 N / 20 mm or more.
X: Initial adhesive force is less than 3.0 N / 20 mm.
When the adhesive layer contains an olefin elastomer,
○: Initial adhesive strength is 1.5 N / 20 mm or more.
X: Initial adhesive force is less than 1.5 N / 20 mm.

<Evaluation of adhesive strength reduction>
Based on the measured initial adhesive strength and the adhesive strength after storage at 50 ° C. for 7 days, the following criteria were used for evaluation.
○: Adhesive strength after storage at 50 ° C. for 7 days is 80% or more of initial adhesive strength.
X: Adhesive strength after storage at 50 ° C. for 7 days is less than 80% of initial adhesive strength.

<Evaluation of contamination>
The peeled surface of the SUS plate (after peeling the adhesive tape) after measuring the initial adhesive strength was observed at a magnification of 500 times using VHX-100F manufactured by KEYENCE, and evaluated according to the following criteria.
○: Contaminants having a diameter of 50 μm or more are not observed.
X: Contaminants having a diameter of 50 μm or more are observed.

<Measurement of content of release agent per unit area of back layer>
The content (g / m ² ) of the release agent per unit area of the back layer was calculated based on the following formula.
Content of release agent per unit area of back layer (g / m ² )
= 100 (cm) x 100 (cm) x thickness of back layer (cm) x specific gravity of back layer (g / cm ³ ) x (release agent content (wt%) / 100)

<Measurement of haze>
Using a haze meter HM-150 (manufactured by Murakami Color Research Laboratory Co., Ltd.), in accordance with JIS-K-7136, haze (%) = (Td / Tt) × 100 (Td: diffuse transmittance, Tt: (Total light transmittance).

[Example 1]
Release agent (ethylene bisbehenamide, Nippon Kasei Co., Ltd., SLIPAX B, d = 0.8 g / cm ^{2 to} 1.0 g / cm ² ) and polypropylene resin (manufactured by Nippon Polypro Co., Ltd., WINTEC) WFX4, d = 0.9 g / cm ² , MFR = 7.0 g / 10 minutes) was mixed in advance at the blending ratio shown in Table 1, and a twin screw extruder (Toshiba Machine Co., Ltd., TEM-35). , Screw diameter = 35mm, L / D = 50), extrusion under conditions of cylinder set temperature = 180 ° C., screw rotation speed = 100 rpm, raw material feed rate = 5 kg / hour, and then pelletized after cooling in water bath The obtained pellets were used as a material for forming the back layer.
Polyethylene (manufactured by Tosoh, Petrocene 186R, low density polyethylene (LDPE)) was used as a material for forming the intermediate layer.
Hydrogenated styrene-butadiene rubber (styrene content = 10% by weight, manufactured by JSR, trade name: Dynalon 1321P) 85% by weight and tackifier (Arakawa Chemical Industries, Ltd .: Alcon P-125) 15% by weight, The material for forming the pressure-sensitive adhesive layer was used.
Each of the above forming materials is coextruded at a die temperature = 160 ° C. by a three-type three-layer inflation molding method (blow ratio = 2.0, take-off speed = 10 m / min), and back layer / intermediate layer / adhesive layer A pressure-sensitive adhesive tape (1) having a laminated structure was obtained.
The back layer had a thickness of 3 μm, the intermediate layer had a thickness of 50 μm, and the pressure-sensitive adhesive layer had a thickness of 10 μm.
The results are shown in Table 1.

[Example 2]
Release agent (ethylenebisbehenamide, Nippon Kasei Co., Ltd., SLIPAX B, d = 0.8 g / cm ^{2 to} 1.0 g / cm ² ) and polyethylene resin (Nippon Polyethylene Co., Ltd., Novatec) LC720, d = 0.922 g / cm ² , MFR = 9.4 g / 10 min) was mixed in advance with the blending ratios shown in Table 1, and a twin screw extruder (Toshiba Machine Co., Ltd., TEM-35). , Screw diameter = 35mm, L / D = 50), extrusion under conditions of cylinder set temperature = 180 ° C., screw rotation speed = 100 rpm, raw material feed rate = 5 kg / hour, and then pelletized after cooling in water bath The obtained pellets were used as a material for forming the back layer.
Polyethylene (manufactured by Tosoh, Petrocene 186R, low density polyethylene (LDPE)) was used as a material for forming the intermediate layer.
Hydrogenated styrene-butadiene rubber (styrene content = 10% by weight, manufactured by JSR, trade name: Dynalon 1321P) 85% by weight and tackifier (Arakawa Chemical Industries, Ltd .: Alcon P-125) 15% by weight, A material for forming the adhesive layer was obtained.
Each of the above forming materials is coextruded at a die temperature = 160 ° C. by a three-type three-layer inflation molding method (blow ratio = 2.0, take-off speed = 10 m / min), and back layer / intermediate layer / adhesive layer A pressure-sensitive adhesive tape (2) having a laminated structure was obtained.
The back layer had a thickness of 3 μm, the intermediate layer had a thickness of 50 μm, and the pressure-sensitive adhesive layer had a thickness of 10 μm.
The results are shown in Table 1.

Example 3
Release agent (ethylene bisbehenamide, Nippon Kasei Co., Ltd., SLIPAX B, d = 0.8 g / cm ^{2 to} 1.0 g / cm ² ) and polypropylene resin (manufactured by Nippon Polypro Co., Ltd., WINTEC) WFX4, d = 0.9 g / cm ² , MFR = 7.0 g / 10 minutes) was mixed in advance at the blending ratio shown in Table 1, and a twin screw extruder (Toshiba Machine Co., Ltd., TEM-35). , Screw diameter = 35mm, L / D = 50), extrusion under conditions of cylinder set temperature = 180 ° C., screw rotation speed = 100 rpm, raw material feed rate = 5 kg / hour, and then pelletized after cooling in water bath The obtained pellets were used as a material for forming the back layer.
Polyethylene (manufactured by Tosoh Corporation, Petrocene 186R, low density polyethylene (LDPE)) was used as a material for forming the intermediate layer.
A polyolefin-based adhesive resin (Tufselen H5002 manufactured by Sumitomo Chemical Co., Ltd.) was used as the material for forming the adhesive layer.
Each of the above forming materials is coextruded at a die temperature of 180 ° C. by a three-type three-layer inflation molding method (blow ratio = 2.0, take-off speed = 10 m / min), and back layer / intermediate layer / adhesive layer An adhesive tape (3) having a laminated structure of was obtained.
The back layer had a thickness of 3 μm, the intermediate layer had a thickness of 50 μm, and the pressure-sensitive adhesive layer had a thickness of 10 μm.
The results are shown in Table 1.

Example 4
Release agent (ethylene bisbehenamide, Nippon Kasei Co., Ltd., SLIPAX B, d = 0.8 g / cm ^{2 to} 1.0 g / cm ² ) and polypropylene resin (manufactured by Nippon Polypro Co., Ltd., WINTEC) WFX4, d = 0.9 g / cm ² , MFR = 7.0 g / 10 minutes) was mixed in advance at the blending ratio shown in Table 1, and a twin screw extruder (Toshiba Machine Co., Ltd., TEM-35). , Screw diameter = 35mm, L / D = 50), extrusion under conditions of cylinder set temperature = 180 ° C., screw rotation speed = 100 rpm, raw material feed rate = 5 kg / hour, and then pelletized after cooling in water bath The obtained pellets were used as a material for forming the back layer.
Polyethylene (manufactured by Tosoh Corporation, Petrocene 186R, low density polyethylene (LDPE)) was used as a material for forming the intermediate layer.
A polyolefin-based adhesive resin (Tufselen H5002 manufactured by Sumitomo Chemical Co., Ltd.) was used as the material for forming the adhesive layer.
Each of the above forming materials is coextruded at a die temperature of 180 ° C. by a three-type three-layer inflation molding method (blow ratio = 2.0, take-off speed = 10 m / min), and back layer / intermediate layer / adhesive layer An adhesive tape (4) having a laminated structure of was obtained.
The back layer had a thickness of 3 μm, the intermediate layer had a thickness of 50 μm, and the pressure-sensitive adhesive layer had a thickness of 10 μm.
The results are shown in Table 1.

[Comparative Example 1]
A polypropylene resin (manufactured by Nippon Polypro Co., Ltd., WINTEC WFX4, d = 0.9 g / cm ² , MFR = 7.0 g / 10 min) is twin screw extruder (Toshiba Machine Co., Ltd., TEM-35, screw diameter) = 35mm, L / D = 50), extrusion is performed under the conditions of cylinder set temperature = 180 ° C., screw rotation speed = 100 rpm, raw material feed amount = 5 kg / hour, and pelletized after cooling in a water bath. The pellets were used as the back layer forming material.
Polyethylene (manufactured by Tosoh, Petrocene 186R, low density polyethylene (LDPE)) was used as a material for forming the intermediate layer.
Hydrogenated styrene-butadiene rubber (styrene content = 10% by weight, manufactured by JSR, trade name: Dynalon 1321P) 85% by weight and tackifier (Arakawa Chemical Industries, Ltd .: Alcon P-125) 15% by weight, The material for forming the pressure-sensitive adhesive layer was used.
Each of the above forming materials is coextruded at a die temperature of 180 ° C. by a three-type three-layer inflation molding method (blow ratio = 2.0, take-off speed = 10 m / min), and back layer / intermediate layer / adhesive layer An adhesive tape (C1) having a laminated structure of was obtained.
The back layer had a thickness of 3 μm, the intermediate layer had a thickness of 50 μm, and the pressure-sensitive adhesive layer had a thickness of 10 μm.
The results are shown in Table 1.

[Comparative Example 2]
A polyethylene resin (manufactured by Nippon Polyethylene Co., Ltd., Novatec LC720, d = 0.922 g / cm ² , MFR = 9.4 g / 10 min) is twin screw extruder (Toshiba Machine Co., Ltd., TEM-35, screw diameter) = 35mm, L / D = 50), extrusion is performed under the conditions of cylinder set temperature = 180 ° C., screw rotation speed = 100 rpm, raw material feed amount = 5 kg / hour, and pelletized after cooling in a water bath. The pellets were used as the back layer forming material.
Polyethylene (manufactured by Tosoh, Petrocene 186R, low density polyethylene (LDPE)) was used as a material for forming the intermediate layer.
Hydrogenated styrene-butadiene rubber (styrene content = 10% by weight, manufactured by JSR, trade name: Dynalon 1321P) 85% by weight and tackifier (Arakawa Chemical Industries, Ltd .: Alcon P-125) 15% by weight, The material for forming the pressure-sensitive adhesive layer was used.
Each of the above forming materials is coextruded at a die temperature = 160 ° C. by a three-type three-layer inflation molding method (blow ratio = 2.0, take-off speed = 10 m / min), and back layer / intermediate layer / adhesive layer An adhesive tape (C2) having a laminated structure of was obtained.
The back layer had a thickness of 3 μm, the intermediate layer had a thickness of 50 μm, and the pressure-sensitive adhesive layer had a thickness of 10 μm.
The results are shown in Table 1.

[Comparative Example 3]
Release agent (ethylene bisbehenamide, Nippon Kasei Co., Ltd., SLIPAX B, d = 0.8 g / cm ^{2 to} 1.0 g / cm ² ) and polypropylene resin (manufactured by Nippon Polypro Co., Ltd., WINTEC) WFX4, d = 0.9 g / cm ² , MFR = 7.0 g / 10 minutes) was mixed in advance at the blending ratio shown in Table 1, and a twin screw extruder (Toshiba Machine Co., Ltd., TEM-35). , Screw diameter = 35mm, L / D = 50), extrusion under conditions of cylinder set temperature = 180 ° C., screw rotation speed = 100 rpm, raw material feed rate = 5 kg / hour, and then pelletized after cooling in water bath The obtained pellets were used as a material for forming the back layer.
Polyethylene (manufactured by Tosoh Corporation, Petrocene 186R, low density polyethylene (LDPE)) was used as a material for forming the intermediate layer.
A polyolefin-based adhesive resin (Tufselen H5002 manufactured by Sumitomo Chemical Co., Ltd.) was used as the material for forming the adhesive layer.
Each of the above forming materials is coextruded at a die temperature of 180 ° C. by a three-type three-layer inflation molding method (blow ratio = 2.0, take-off speed = 10 m / min), and back layer / intermediate layer / adhesive layer An adhesive tape (C3) having a laminated structure of was obtained.
The back layer had a thickness of 3 μm, the intermediate layer had a thickness of 50 μm, and the pressure-sensitive adhesive layer had a thickness of 10 μm.
The results are shown in Table 1.

[Comparative Example 4]
A polypropylene resin (manufactured by Nippon Polypro Co., Ltd., WINTEC WFX4, d = 0.9 g / cm ² , MFR = 7.0 g / 10 min) is twin screw extruder (Toshiba Machine Co., Ltd., TEM-35, screw diameter) = 35mm, L / D = 50), extrusion is performed under the conditions of cylinder set temperature = 180 ° C., screw rotation speed = 100 rpm, raw material feed amount = 5 kg / hour, and pelletized after cooling in a water bath. The pellets were used as the back layer forming material.
Polyethylene (manufactured by Tosoh, Petrocene 186R, low density polyethylene (LDPE)) was used as a material for forming the intermediate layer.
A polyolefin-based adhesive resin (Tufselen H5002 manufactured by Sumitomo Chemical Co., Ltd.) was used as the material for forming the adhesive layer.
Each of the above forming materials is coextruded at a die temperature of 180 ° C. by a three-type three-layer inflation molding method (blow ratio = 2.0, take-off speed = 10 m / min), and back layer / intermediate layer / adhesive layer An adhesive tape (C4) having a laminated structure of was obtained.
The back layer had a thickness of 3 μm, the intermediate layer had a thickness of 50 μm, and the pressure-sensitive adhesive layer had a thickness of 10 μm.
The results are shown in Table 1.

  The pressure-sensitive adhesive tape obtained in the present invention is useful as a surface protective film for adherends such as optical members and electronic members.

DESCRIPTION OF SYMBOLS 100 Adhesive tape 10 Base material layer 20 Adhesive layer 30 Back layer 40 Intermediate layer

Claims (8)

An adhesive tape comprising a base material layer and an adhesive layer,
The base material layer has a back layer as an outermost layer opposite to the pressure-sensitive adhesive layer,
The base material layer contains a saturated fatty acid bisamide having 19 or more carbon atoms in the terminal alkyl chain,
In the back layer, the saturated fatty acid bisamide is contained at a content of 5% by weight or less,
The pressure-sensitive adhesive layer contains a styrene-based elastomer or an olefin-based elastomer,
Adhesive tape.   The pressure-sensitive adhesive tape according to claim 1, which is integrally formed by coextrusion molding.   The pressure-sensitive adhesive tape according to claim 1 or 2, wherein the base material layer contains an olefin resin.   The pressure-sensitive adhesive tape according to any one of claims 1 to 3, wherein the back layer contains a resin having an MFR of 1 g / 10 min to 100 g / 10 min.   The pressure-sensitive adhesive tape according to any one of claims 1 to 4, wherein the back layer contains a polypropylene resin. The pressure-sensitive adhesive tape according to any one of claims 1 to 5, wherein the content of the saturated fatty acid bisamide per unit area of the back layer is 0.15 g / m ² or less.   The unwinding force under the conditions of a temperature of 23 ° C., a humidity of 50% RH, a peeling angle of 90 °, and a tensile speed of 10 m / min is 0 for both the initial unwinding force and the unwinding force after storage at 50 ° C. × 7 days. The pressure-sensitive adhesive tape according to any one of claims 1 to 6, which is 0.01 N / 20 mm to 2.0 N / 20 mm. The adhesive tape in any one of Claim 1-7 whose haze is 60% or less.

Images