Adhesive tape and wire harness

Abstract

The present invention addresses the problem of providing an adhesive tape for which the application of an adhesive is easier, and which has excellent lightweight properties and also has high adhesive force when wound around an electric wire or the like even in the case of a thinner adhesive layer.　One embodiment of the present invention is an adhesive tape comprising: a substrate layer that is composed of a resin composition including a thermoplastic resin; and an adhesive layer that is provided to one surface of the substrate layer. The thickness of the substrate layer is 58 μm or less, and a difference X between the maximum thickness and the minimum thickness of the substrate layer is within 30% of the thickness of the substrate layer. Said X and a thickness Y of the adhesive layer satisfy the relationship of X / 2 < Y.

Description

Adhesive tape and wire harnesses

[0001] The present invention relates to an adhesive tape and a wire harness.

[0002] As various adhesive films such as insulating tapes used in various electrical devices in automobiles, railways, aircraft, ships, houses, factories, etc., adhesive tapes in which an adhesive is applied to one side of a substrate made from a resin composition containing a thermoplastic resin are used because they have appropriate flexibility and extensibility, excellent flame retardancy, mechanical strength, heat deformation resistance, electrical insulation properties, and moldability, and are relatively inexpensive (Patent Documents 1 and 2).

[0003] Japanese Patent Application Laid-Open No. 11-209718 International Publication No. 2019 / 049565

[0004] In recent years, there has been a demand for such pressure-sensitive adhesive tapes to be lighter, i.e., for thinner base layers and thinner pressure-sensitive adhesive layers, for the purpose of improving fuel efficiency in, for example, automobiles and aircraft. However, when the pressure-sensitive adhesive layer is thinned, the adhesive strength of the pressure-sensitive adhesive tape may be reduced.

[0005] The present invention has been made in view of the above circumstances, and aims to provide an adhesive tape that is easy to apply an adhesive to, is lightweight, and has high adhesive strength when wrapped around an electric wire or the like even when the adhesive layer is thinned.

[0006] As a result of extensive research, the inventors have found that the above-mentioned problems can be solved by ensuring that the thicknesses of the substrate layer and the pressure-sensitive adhesive layer satisfy specific parameters, and have thus completed the present invention.

[0007] The present invention provides the following: [1] A pressure-sensitive adhesive tape comprising a base layer made of a resin composition containing a thermoplastic resin, and a pressure-sensitive adhesive layer provided on one surface of the base layer, wherein the thickness of the base layer is 58 μm or less, a difference X between the maximum thickness and the minimum thickness of the base layer is within 30% of the thickness, and X and a thickness Y of the pressure-sensitive adhesive layer satisfy the relationship X / 2<Y. [2] The pressure-sensitive adhesive tape according to [1], wherein the thickness Y of the pressure-sensitive adhesive layer is 15 μm or less. [3] The pressure-sensitive adhesive tape according to [1] or [2], wherein the low-speed unwinding force of the pressure-sensitive adhesive tape is 0.8 to 2.0 N / 10 mm. [4] The pressure-sensitive adhesive tape according to any of [1] to [3], wherein the elastic modulus of the pressure-sensitive adhesive tape is 2.0 to 3500.0 MPa. [5] The pressure-sensitive adhesive tape according to any of [1] to [4], wherein the resin composition does not contain an inorganic filler. [6] The pressure-sensitive adhesive tape according to any one of [1] to [5], wherein the resin composition contains 20 to 75 parts by mass of a plasticizer relative to 100 parts by mass of the thermoplastic resin. [7] The pressure-sensitive adhesive tape according to any one of [1] to [6], wherein the thermoplastic resin contains a vinyl chloride resin. [8] The pressure-sensitive adhesive tape according to any one of [1] to [7], which is used to bind electric wires. [9] A wire harness comprising electric wires and the pressure-sensitive adhesive tape according to any one of [1] to [8] that binds the electric wires.

[0008] According to the present invention, it is possible to provide an adhesive tape that is easy to apply an adhesive to, is lightweight, and has high adhesive strength when wrapped around an electric wire or the like even when the adhesive layer is thinned.

[0009] The present invention will be described in detail below. The present invention is not limited to these descriptions. The features of the following embodiments can be combined with each other. Furthermore, each feature can be an invention independently. Furthermore, elements of the following embodiments that are not defined in the claims are optional elements and can be omitted.

[0010] <Explanation of Terms> In this specification, for example, the expression "A to B" means greater than or equal to A and less than or equal to B. In this specification, for example, the expression "within a range between any two of the exemplified numerical values" means greater than or equal to A and less than or equal to B when the exemplified numerical values ​​are A and B (A<B).

[0011] 1. Pressure-sensitive adhesive tape The pressure-sensitive adhesive tape according to this embodiment includes a base layer and a pressure-sensitive adhesive layer. The pressure-sensitive adhesive layer according to this embodiment is provided on one surface (one side) of the base layer. In addition, in the pressure-sensitive adhesive tape according to this embodiment, the pressure-sensitive adhesive layer may be provided directly on one surface of the base layer, or the pressure-sensitive adhesive layer may be provided via another layer (for example, a primer layer described below).

[0012] The thickness of the pressure-sensitive adhesive tape according to this embodiment is preferably 100 μm or less, more preferably 80 μm or less, even more preferably 75 μm or less, and particularly preferably 70 μm or less. The lower limit of the thickness of the pressure-sensitive adhesive tape according to this embodiment is not particularly limited, but is, for example, 45 μm. The thickness of the pressure-sensitive adhesive tape may be, for example, 100, 95, 90, 85, 80, 75, 74, 73, 72, 71, 70, 69, 68, 67, 66, 65, 64, 63, 62, 61, 60, 59, 58, 57, 56, 55, 50, or 45 μm, or may be within a range between any two of the values ​​exemplified here. Note that the "thickness of the pressure-sensitive adhesive tape" in this specification can be measured using a method in accordance with JIS C2107:2011 and can be the average value measured at multiple measurement points (e.g., n = 10 measurement points). The pressure-sensitive adhesive tape according to this embodiment has high substrate strength even at such a thickness. The thickness of the adhesive tape can be measured, for example, using a thickness gauge (manufactured by Mitutoyo Corporation). When the thickness of the adhesive tape is equal to or greater than the lower limit, the base strength of the adhesive tape is further improved. When the thickness of the adhesive tape is equal to or less than the upper limit, the adhesive tape is more lightweight.

[0013] 1.1 Substrate Layer The thickness of the substrate layer according to this embodiment is preferably 58 μm or less, and more preferably 55 μm or less. The lower limit of the thickness of the substrate layer according to this embodiment is not particularly limited, but is, for example, 35 μm. The thickness of the substrate layer may be, for example, 58, 57, 56, 55, 54, 53, 52, 51, 50, 45, 40, or 35 μm, or may be within a range between any two of the values ​​exemplified herein. Note that the "thickness of the substrate layer" in this specification can be measured using a method in accordance with JIS C2107:2011 and can be the average value measured at multiple measurement points (e.g., n = 10 measurement points). The substrate according to this embodiment has high substrate strength even at such a thickness. The thickness of the substrate layer may be measured on the substrate layer before the pressure-sensitive adhesive layer is formed, or on the substrate layer from which the pressure-sensitive adhesive layer has been removed using a solvent after the pressure-sensitive adhesive tape is manufactured. The thickness of the substrate layer can be measured, for example, using a thickness gauge (manufactured by Mitutoyo Corporation). When the thickness of the substrate layer is equal to or less than the upper limit, the pressure-sensitive adhesive tape has excellent lightweight properties.

[0014] In this embodiment, the difference between the maximum and minimum thicknesses of the substrate layer is preferably within 30% of the thickness of the substrate layer, more preferably within 25%, and even more preferably within 20%. The lower limit of the difference between the maximum and minimum thicknesses of the substrate layer is not particularly limited, but may be, for example, 2% of the thickness of the substrate layer. The difference between the maximum and minimum thicknesses of the substrate layer may be, for example, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, or 2% of the thickness of the substrate layer, or may be within a range between any two of the values ​​exemplified here. The difference between the maximum and minimum thicknesses of the substrate layer can be measured, for example, by a method in accordance with JIS C2107:2011, similar to the above-mentioned "thickness of the substrate layer," and can be the difference between the maximum and minimum values ​​when measured multiple times (e.g., n = 10). When the difference between the maximum and minimum thicknesses of the base layer is equal to or greater than the lower limit, the anchoring properties of the pressure-sensitive adhesive layer are improved, making the pressure-sensitive adhesive tape less likely to peel off. When the difference between the maximum and minimum thicknesses of the base layer is equal to or less than the upper limit, workability in applying the pressure-sensitive adhesive layer is improved, the pressure-sensitive adhesive can be applied uniformly and thinly, and a pressure-sensitive adhesive tape with stable high adhesive strength can be produced. In the case of calender molding, the difference between the maximum and minimum thicknesses of the base layer can be adjusted, for example, by the face length and diameter of the calender roll and the calender roll temperature.

[0015] The substrate layer according to this embodiment may have an uneven surface on the other side (the surface opposite to the surface on which the pressure-sensitive adhesive layer is provided). The uneven surface on the other side is preferably produced by, for example, embossing, as described below. Therefore, the other side according to this embodiment is preferably an uneven surface or an embossed surface.

[0016] The arithmetic mean roughness Ra of the other surface of the substrate layer according to this embodiment is preferably 0.05 to 2.50 μm, more preferably 0.10 to 2.00 μm, even more preferably 0.30 to 1.50 μm, and particularly preferably 0.50 to 1.50 μm. The arithmetic mean roughness Ra of the other surface of the substrate layer may be, for example, 0.05, 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, 1.00, 1.10, 1.20, 1.30, 1.40, 1.50, 1.60, 1.70, 1.80, 1.90, 2.00, 2.10, 2.20, 2.30, 2.40, or 2.50 μm, or may be within a range between any two of the values ​​exemplified here. The arithmetic mean roughness Ra can be measured, for example, using a surface roughness measuring instrument under conditions of λc / λs = 2.5 mm / 8 μm and a measurement speed of 0.5 mm / s by scanning a scanning probe over the sample surface. If the arithmetic mean roughness Ra of the other surface of the substrate layer is equal to or greater than the lower limit, a more preferable appearance is obtained with less gloss and less noticeable. If the arithmetic mean roughness Ra of the other surface of the substrate layer is equal to or less than the upper limit, the substrate strength is increased, the elongation of the substrate is improved, and the self-back adhesive strength of the adhesive tape is further improved.

[0017] The maximum valley depth Rv of the other surface of the base layer according to this embodiment is preferably 0.40 to 12.00 μm, more preferably 0.50 to 10.00 μm, and even more preferably 1.00 to 5.00 μm. The maximum valley depth Rv of the other surface of the base layer may be, for example, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, 1.00, 1.50, 2.00, 2.50, 3.00, 3.50, 4.00, 4.50, 5.00, 5.50, 6.00, 6.50, 7.00, 7.50, 8.00, 8.50, 9.00, 9.50, 10.00, 10.50, 11.00, 11.50, or 12.00 μm, or may be within a range between any two of the values ​​exemplified here. The maximum valley depth Rv can be measured in the same manner as the arithmetic mean roughness Ra described above. When the maximum valley depth Rv on the other surface of the substrate layer is equal to or greater than the lower limit, the surface has a less glossy and less noticeable appearance, resulting in a more preferable appearance. When the maximum valley depth Rv on the other surface of the substrate layer is equal to or less than the upper limit, the substrate strength is increased, the elongation of the substrate is improved, and the self-backside adhesive strength of the adhesive tape is also improved.

[0018] The arithmetic mean roughness Ra of one surface of the base layer according to this embodiment (the surface on which the pressure-sensitive adhesive layer is provided) is preferably 2.50 μm or less, more preferably 0.10 to 2.00 μm, and even more preferably 0.50 to 1.50 μm. The arithmetic mean roughness Ra of the other surface of the base layer may be, for example, 0.05, 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, 1.00, 1.10, 1.20, 1.30, 1.40, 1.50, 1.60, 1.70, 1.80, 1.90, 2.00, 2.10, 2.20, 2.30, 2.40, or 2.50 μm, or may be within a range between any two of the values ​​exemplified here. When the arithmetic mean roughness Ra of one surface of the base layer is equal to or greater than the lower limit, the anchoring property of the pressure-sensitive adhesive layer is improved and the pressure-sensitive adhesive layer is less likely to peel off.When the arithmetic mean roughness Ra of one surface of the base layer is equal to or less than the upper limit, the strength of the base material is increased and the elongation of the base material is improved.

[0019] The base layer according to the present embodiment is preferably composed of a resin composition containing a thermoplastic resin. The resin composition according to the present embodiment may contain, in addition to the thermoplastic resin, for example, a plasticizer, a filler, and other additives.

[0020] 1.1.1 Thermoplastic Resin The resin composition according to this embodiment contains a thermoplastic resin. In the resin composition according to this embodiment, the thermoplastic resin preferably accounts for 50% by mass or more, more preferably 70% by mass or more. In the resin composition according to this embodiment, the thermoplastic resin preferably accounts for 95% by mass or less, more preferably 80% by mass or less. Examples of thermoplastic resins according to this embodiment include vinyl chloride resins, ester resins, imide resins, amide resins, and olefin resins. These thermoplastic resins may be used alone or in combination of two or more. The thermoplastic resin according to this embodiment preferably contains a vinyl chloride resin. In this embodiment, the thermoplastic resin preferably comprises 80% by mass or more, more preferably 90% by mass or more, of 100% by mass of the thermoplastic resin. It is even more preferable that the thermoplastic resin consists solely of vinyl chloride resin (100% by mass). Such types of thermoplastic resins provide the pressure-sensitive adhesive tape with excellent insulation and wire binding properties (flexibility and stretchability).

[0021] The vinyl chloride resin according to this embodiment preferably has an average degree of polymerization of 500 to 2000, more preferably 700 to 1800. The average degree of polymerization of the vinyl chloride resin may be, for example, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, or 2000, or may be within a range between any two of the values ​​exemplified herein. Two or more vinyl chloride resins with different average degrees of polymerization may be used as the vinyl chloride resin according to this embodiment. When the average degree of polymerization of the vinyl chloride resin is equal to or greater than the lower limit, the polymer chains become entangled, improving the tensile strength of the adhesive tape and providing excellent abrasion resistance. When the average degree of polymerization of the vinyl chloride resin is equal to or less than the upper limit, gelation is facilitated, film-forming properties are excellent, and the substrate condition is improved.

[0022] 1.1.2 Plasticizer The resin composition according to this embodiment preferably contains a plasticizer. Examples of plasticizers according to this embodiment include trimellitate ester-based plasticizers, adipate ester-based plasticizers, phthalate ester-based plasticizers, epoxy-based plasticizers, isophthalate ester-based plasticizers, terephthalate ester-based plasticizers, and phosphoric acid-based plasticizers. These plasticizers may be used alone or in combination of two or more. Preferred plasticizers according to this embodiment are trimellitate ester-based plasticizers, phthalate ester-based plasticizers, and adipate ester-based plasticizers. Using such types of plasticizers provides a high plasticizing effect on the thermoplastic resin and reduces bleed-out.

[0023] The resin composition according to this embodiment preferably contains 20 to 75 parts by mass of plasticizer per 100 parts by mass of thermoplastic resin. The content of the plasticizer may be, for example, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, or 75 parts by mass per 100 parts by mass of thermoplastic resin, or may be within a range between any two of the values ​​exemplified herein. When the content of the plasticizer is equal to or greater than the lower limit, the substrate has excellent flexibility, improving workability. When the content of the plasticizer is equal to or less than the upper limit, the occurrence of pinholes during film formation and stretching is suppressed, and even thinned substrates have sufficient elasticity, improving workability. When multiple plasticizers are used in combination, the "content of plasticizer" refers to the total amount of the multiple plasticizers.

[0024] 1.1.2.1 Trimellitic Acid Ester-Based Plasticizer The trimellitic acid ester-based plasticizer according to this embodiment is preferably a trimellitic acid trialkyl ester (trimellitic acid tri(C4-11 alkyl) ester) represented by Formula 1. n in Formula 1 is preferably 5 to 10, more preferably 6 to 9, and even more preferably 8.

[0025] Examples of trimellitic acid tri(C4-11 alkyl) esters according to this embodiment include tributyl trimellitate, trihexyl trimellitate, tri-n-octyl trimellitate, triisooctyl trimellitate, tri-2-ethylhexyl trimellitate, and trinonyl trimellitate. As the trimellitic acid tri(C4-11 alkyl) ester according to this embodiment, tri-n-octyl trimellitate is preferred. When the plasticizer is of this type, the efficiency of plasticizing the thermoplastic resin is high, and the elongation and heat resistance of the substrate are excellent.

[0026] The molecular weight of the trimellitic acid ester according to this embodiment is, for example, preferably 378 to 672, more preferably 420 to 630, and even more preferably 462 to 588.

[0027] 1.1.2.2 Phthalate Ester Plasticizers Examples of phthalate ester plasticizers according to this embodiment include DINP (diisononyl phthalate), DHP (diheptyl phthalate), DOP (di-2-ethylhexyl phthalate), n-DOP (di-n-octyl phthalate), and diisodecyl phthalate (DIDP). Diesters of phthalic acid and alcohols having 9 to 10 carbon atoms, such as DINP (diisononyl phthalate) and diisodecyl phthalate (DIDP), are preferred as phthalate ester plasticizers according to this embodiment. Such types of plasticizers provide a high plasticizing effect on vinyl chloride resins, reduce bleedout, and minimize adverse effects on the human body. DINP (diisononyl phthalate) is particularly preferred as the phthalate ester plasticizer according to this embodiment. Such types of plasticizers provide high plasticizing efficiency.

[0028] 1.1.2.3 Adipate Plasticizers Examples of the adipate plasticizers according to this embodiment include adipic acid-propylene glycol polyesters and adipic acid-butylene glycol polyesters. Adipic acid polyesters are preferred as the adipate plasticizers according to this embodiment. When such plasticizers are used, the substrate has excellent heat resistance.

[0029] The resin composition according to the present embodiment may contain a filler. The filler according to the present embodiment is not particularly limited as long as it can easily separate the substrate from the calender roll in the molding step described below.

[0030] The resin composition according to this embodiment preferably contains 10 parts by mass or less of inorganic filler, more preferably 5 parts by mass or less, and even more preferably 1 part by mass or less of inorganic filler, per 100 parts by mass of thermoplastic resin. It is particularly preferred that the resin composition according to this embodiment does not contain an inorganic filler. Examples of inorganic fillers according to this embodiment include calcium carbonate, aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, calcium hydroxide, potassium hydroxide, barium hydroxide, triphenyl phosphite, ammonium polyphosphate, polyphosphate amide, zirconium oxide, magnesium oxide, zinc oxide, titanium oxide, molybdenum oxide, guanidine phosphate, hydrotalcite, smectite, zinc borate, zinc borate anhydrous, zinc metaborate, barium metaborate, antimony oxide, antimony pentoxide, red phosphorus, talc, alumina, silica, boehmite, bentonite, sodium silicate, calcium silicate, calcium sulfate, and magnesium carbonate. If the content of the filler in the resin composition is equal to or less than the upper limit, or if the resin composition does not contain any filler, pinholes are less likely to occur during film formation and stretching.

[0031] 1.1.4 Other Additives The resin composition according to this embodiment may contain other additives as needed, as long as the effects of the present invention are not impaired. Examples of other additives include colorants (including pigments such as carbon black), stabilizers, lubricants, antioxidants, and UV absorbers.

[0032] 1.1.4.1 Stabilizers Examples of stabilizers according to this embodiment include metal soaps (metal-based composite stabilizers). The inclusion of a stabilizer such as a metal soap facilitates improving the thermal stability of the substrate. Examples of metal-based composite stabilizers include fatty acid calcium, fatty acid zinc, and fatty acid barium. Examples of fatty acid components of metal-based composite stabilizers include lauric acid, stearic acid, and ricinoleic acid. Specific examples of such metal-based composite stabilizers include calcium laurate, calcium stearate, calcium laurate, calcium stearate, calcium ricinoleate, zinc laurate, zinc ricinoleate, zinc stearate, barium laurate, barium stearate, and barium ricinoleate. These may be used alone, or two or more may be used in combination. From the viewpoint that the thermal stability effect is more likely to be enhanced by combining them, a Ca—Zn-based metal stabilizer containing fatty acid calcium and fatty acid zinc is preferably used.

[0033] In one aspect of this embodiment, the proportion of the metal-based composite stabilizer contained in the substrate layer is preferably 0.1 to 10 parts by mass, and more preferably 1 to 5 parts by mass, relative to 100 parts by mass of the thermoplastic resin. In another aspect of this embodiment, the proportion of the metal-based composite stabilizer contained in the substrate layer is preferably 0.5 to 10% by mass, and more preferably 1 to 5% by mass, relative to 100% by mass of the resin composition.

[0034] 1.1.4.2 Lubricant Examples of lubricants according to this embodiment include higher fatty acids such as stearic acid and palmitic acid; higher alcohols such as palmityl alcohol and stearyl alcohol; metal salts of higher fatty acids such as calcium stearate, zinc stearate, barium stearate, aluminum stearate, magnesium stearate, and sodium palmitate; higher fatty acid esters such as butyl stearate and glyceryl monostearate; and higher fatty acid amides such as oleic acid amide, stearic acid amide, and erucic acid amide. Here, "higher" refers to a group having 9 or more carbon atoms, preferably 9 to 30 carbon atoms. These may be used alone, or two or more may be used in combination. Among these, stearic acid is preferably included from the viewpoint of the film-forming properties of the substrate. The content of the lubricant according to this embodiment is preferably 0.01 to 5.0 parts by mass, and more preferably 0.1 to 1.0 part by mass, per 100 parts by mass of the thermoplastic resin.

[0035] 1.2 Pressure-sensitive Adhesive Layer The pressure-sensitive adhesive layer according to this embodiment is preferably composed of a pressure-sensitive adhesive.

[0036] The thickness of the pressure-sensitive adhesive layer according to this embodiment is preferably 17 μm or less, more preferably 15 μm or less, and even more preferably 13 μm or less. The lower limit of the thickness of the pressure-sensitive adhesive layer according to this embodiment is not particularly limited, but the thickness of the pressure-sensitive adhesive layer is, for example, 3 μm. The thickness of the pressure-sensitive adhesive layer may be, for example, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, or 3 μm, or may be within a range between any two of the values ​​exemplified herein. Note that, in this specification, the "thickness of the pressure-sensitive adhesive layer" refers to the difference (absolute value) between the thickness of the pressure-sensitive adhesive tape and the thickness of the base layer. The thickness of the pressure-sensitive adhesive layer can be measured, for example, by measuring the thickness of the pressure-sensitive adhesive tape according to a method in accordance with JIS C2107:2011 and calculating the difference (absolute value) from the thickness of the base layer measured by the above-mentioned method. The thickness of the pressure-sensitive adhesive layer can be measured, for example, using a thickness gauge (manufactured by Mitutoyo Corporation). When the thickness of the pressure-sensitive adhesive layer is equal to or greater than the lower limit, the adhesive strength of the pressure-sensitive adhesive tape is improved. When the thickness of the pressure-sensitive adhesive layer is at most the upper limit, the pressure-sensitive adhesive tape has excellent tape spreadability and is even lighter in weight.

[0037] In this embodiment, when the difference between the maximum and minimum thicknesses of the base layer is X and the thickness of the adhesive layer is Y, it is preferable that the relationship X / 2<Y is satisfied. When the difference between the maximum and minimum thicknesses of the base layer and the thickness of the adhesive layer satisfy this relationship, workability in applying the adhesive layer is improved, the adhesive can be applied uniformly, and an adhesive tape with high adhesive strength when wrapped around an electric wire or the like can be produced. In other words, in this embodiment, the value of (X / 2) / Y is preferably less than 1.0. Furthermore, the value of (X / 2) / Y is more preferably 0.9 or less, and even more preferably 0.8 or less. When the value of (X / 2) / Y is equal to or less than the upper limit, workability (applicability) in applying the adhesive layer is further improved. In the case of calender molding, for example, the difference between the maximum and minimum thicknesses of the base layer can be adjusted by the face length and diameter of the calender roll and the calender roll temperature. The thickness of the adhesive layer can be adjusted, for example, by the amount and concentration of the adhesive applied.

[0038] 1.2.1 Pressure-sensitive adhesive The pressure-sensitive adhesive according to this embodiment preferably contains a rubber-based pressure-sensitive adhesive, and is preferably composed of a rubber-based pressure-sensitive adhesive. The rubber-based pressure-sensitive adhesive according to this embodiment may be either a melt-type or an emulsion-type. The rubber-based pressure-sensitive adhesive according to this embodiment preferably contains a base polymer (rubber component) and a tackifier. When the rubber-based pressure-sensitive adhesive contains such components, it is more likely to exhibit adhesive strength to any adherend.

[0039] 1.2.1.1 Base Polymer Examples of base polymers according to this embodiment include natural rubber, styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene-styrene block copolymer (SBS), hydrogenated products of the above styrene-based block copolymers (SIPS, SEBS), synthetic rubbers such as styrene-butadiene rubber (SBR), polyisoprene rubber (IR), polyisobutylene (PIB), and butyl rubber (IIR), as well as graft copolymers of at least one rubber component selected from (meth)acrylic acid alkyl esters, natural rubber, and the above synthetic rubbers. These base polymers may be used alone or in combination of two or more. The base polymer according to this embodiment preferably includes a graft copolymer of at least one rubber component selected from (meth)acrylic acid alkyl esters, natural rubber, and the above synthetic rubbers (hereinafter also referred to as "graft rubber"). When the base polymer is of this type, the elastic modulus of the PSA layer is improved, cohesive failure is suppressed, and the self-backed adhesive strength of the PSA tape is improved.

[0040] 1.2.1.2 Tackifier The tackifier according to this embodiment can be selected taking into consideration the softening point and compatibility with each component. Examples of tackifiers according to this embodiment include emulsions of terpene resins, rosin resins, hydrogenated rosin resins, coumarone-indene resins, styrene-based resins, petroleum resins, terpene-phenol resins, xylene-based resins, and other aliphatic hydrocarbon resins or aromatic hydrocarbon resins. These tackifiers may be used alone or in combination of two or more.

[0041] 1.3 Other Layers The pressure-sensitive adhesive tape according to this embodiment may further include other layers as long as the effects of the present invention are not impaired. The pressure-sensitive adhesive tape according to this embodiment may further include a primer layer between the substrate layer and the pressure-sensitive adhesive layer for the purpose of improving the adhesion between the substrate layer and the pressure-sensitive adhesive layer.

[0042] 1.3.1 Primer Layer The primer layer according to this embodiment is preferably made of a composition containing 25 to 300 parts by mass of an acrylonitrile-butadiene copolymer per 100 parts by mass of a graft polymer obtained by graft polymerizing methyl methacrylate onto natural rubber.

[0043] 2. Manufacturing Method of Adhesive Tape The manufacturing method of the adhesive tape according to this embodiment includes, for example, a base layer manufacturing step of manufacturing a base layer, and a pressure-sensitive adhesive layer manufacturing step of laminating a pressure-sensitive adhesive on one surface of the base layer.

[0044] 2.1 Substrate Layer Preparation Process The substrate layer preparation process according to this embodiment preferably includes, for example, a resin composition preparation process for preparing a resin composition, a molding process for molding the substrate, and a surface processing process for processing the surface of the substrate.

[0045] 2.1.1 Resin Composition Preparation Step The resin composition preparation step according to this embodiment can be carried out by melt-kneading a thermoplastic resin, and, if necessary, a plasticizer, a filler, other additives, etc. The melt-kneading method is not particularly limited, but various mixers and kneaders equipped with a heating device, such as a twin-screw extruder, a continuous or batch kneader, a roll, or a Banbury mixer, are used to mix the resin composition so that it is uniformly dispersed.

[0046] 2.1.2 Molding process The molding process according to this embodiment can be carried out by molding (forming a film) the mixture obtained in the resin composition preparation process using a molding machine. Known molding methods can be used, such as the calendar method, the T-die method, and the inflation method. From the viewpoint of achieving a desired difference between the maximum thickness and the minimum thickness of the substrate layer, the molding according to this embodiment is preferably the calendar method or the T-die method, and particularly preferably calendar molding using a calendar molding machine. The roll arrangement method in calendar molding can be, for example, a known method such as an L-type, an inverted L-type, or a Z-type.

[0047] 2.1.2.1 Calendar Molding Process In the calendar molding process according to this embodiment, when the face length of the calendar roll is L and the diameter is D, the L / D value is preferably 3.5 or less, and more preferably 3.3 or less. The smaller the L / D value, the more the deflection of the calendar roll is reduced, and the difference between the maximum thickness and the minimum thickness of the base layer can be reduced. Furthermore, the calendar roll temperature during calendar molding is preferably 160°C or higher, more preferably 165°C or higher, and even more preferably 170°C or higher. When the calendar roll temperature is equal to or higher than the lower limit, the viscosity of the resin composition can be reduced, and the thickness of the base layer becomes more uniform.

[0048] 2.1.3 Stretching Process The base layer production process according to this embodiment may further include a stretching process of stretching the resin composition. After molding (film formation), the temperature of the resin composition immediately before stretching is preferably 165°C or higher, more preferably 170°C or higher, and even more preferably 175°C or higher. When the temperature of the resin composition immediately before stretching is equal to or higher than the lower limit, the viscosity of the resin composition can be reduced, and the thickness of the base layer becomes more uniform. The upper limit of the temperature of the resin composition immediately before stretching is not particularly limited, but can be, for example, 190°C or lower. When the temperature of the resin composition immediately before stretching is equal to or lower than the upper limit, decomposition of the resin can be suppressed. Note that the temperature of the resin composition immediately before stretching is, for example, in the case of molding using a calendar molding machine, the temperature at which, after film formation with a calendar roll, stretching begins while the formed resin composition is peeled off from the calendar roll with a take-off roll (take-off roll).

[0049] 2.1.4 Surface Treatment Step The base layer preparation step according to this embodiment may optionally include a surface treatment step. The surface treatment step according to this embodiment may be a mirror-finishing step that does not provide irregularities on the surface of the base material, or an embossing step that provides irregularities. A mirror roll may be used for the mirror-finishing step according to this embodiment. In the embossing step according to this embodiment, it is preferable to emboss the other surface of the base material layer (the surface opposite to the surface on which the pressure-sensitive adhesive layer is provided) using an embossing roll. In the embossing step according to this embodiment, for example, an embossing roll is used to emboss the other surface of the base material layer so that the arithmetic mean roughness Ra is preferably 0.05 to 2.50 μm, more preferably 0.10 to 2.00 μm, even more preferably 0.20 to 1.50 μm, and particularly preferably 0.30 to 1.00 μm. In the embossing step according to this embodiment, for example, an embossing roll is used to emboss the other surface of the base layer so that the maximum valley depth Rv is preferably 0.40 to 12.00 μm, more preferably 0.50 to 10.00 μm, and even more preferably 1.00 to 5.00 μm. The arithmetic mean roughness Ra and / or maximum valley depth Rv of the other surface of the base layer can be adjusted by the unevenness of the embossing roll used (specifically, the arithmetic mean roughness Ra and maximum valley depth Rv) and the embossing conditions (e.g., pressure and temperature). The unevenness of the embossing roll can be created, for example, by sandblasting, and the arithmetic mean roughness Ra and / or maximum valley depth Rv of the embossing roll can be adjusted, for example, by the abrasive and speed used in sandblasting.

[0050] In the embossing step according to this embodiment, it is preferable to further emboss one surface of the base layer (the surface on which the pressure-sensitive adhesive layer is provided) using a rubber roll. In the embossing step according to this embodiment, for example, embossing is performed using a rubber roll so that one surface of the base layer preferably has an arithmetic mean roughness Ra of 2.50 μm or less, more preferably an arithmetic mean roughness Ra of 0.10 to 2.00 μm, and even more preferably an arithmetic mean roughness Ra of 0.50 to 1.50 μm. The arithmetic mean roughness Ra of one surface of the base layer can be adjusted by the unevenness of the rubber roll used (specifically, the arithmetic mean roughness Ra and maximum valley depth Rv) and the embossing conditions (e.g., pressure and temperature). In the embossing step according to this embodiment, it is preferable to sandwich the base layer between an embossing roll and a rubber roll, and simultaneously emboss one surface and the other surface of the base layer. By performing such an embossing step, production efficiency can be improved.

[0051] 2.1.5 Cooling Step The substrate layer preparation step according to this embodiment may further include a cooling step. The cooling step according to this embodiment may be performed by cooling the substrate layer after the molding step or the surface processing step. In the cooling step, the substrate temperature may be set to 40°C or less, for example.

[0052] 2.1.6 Trimming Step The base layer preparation step according to this embodiment can further include a trimming step. The trimming step according to this embodiment can be performed by cutting both longitudinal ends of the base material. Since thickness variations tend to occur at both longitudinal ends of the base material, performing the trimming step can reduce the difference between the maximum thickness and the minimum thickness of the base material layer. Therefore, when forming by the calendering step, it is preferable to make the face length of the calender roll longer than the desired width of the base material layer.

[0053] 2.2 Pressure-sensitive adhesive layer preparation process The pressure-sensitive adhesive layer preparation process according to this embodiment includes, for example, a coating process in which a pressure-sensitive adhesive is applied to one side of the substrate layer obtained as described above, and a drying process in which the solvent is removed in a drying oven. A pressure-sensitive adhesive tape can be obtained by such a production method. Examples of pressure-sensitive adhesive application methods include the comma method, lip die method, gravure method, roll method, and slot die method. Furthermore, a tape logging process in which the pressure-sensitive adhesive tape is wound onto a dried paper tube to a desired length to form a tape log, and a cutting process in which the obtained tape log is cut to a desired width can be performed to obtain a pressure-sensitive adhesive tape of a desired width.

[0054] 2.3 Primer Layer Preparation Step The method for producing a pressure-sensitive adhesive tape according to this embodiment may further include a primer layer preparation step before the pressure-sensitive adhesive layer preparation step. The primer layer preparation step according to this embodiment includes, for example, a coating step of applying a primer to one surface of the substrate layer obtained as described above, and a drying step of removing the solvent in a drying oven. Examples of primer application methods include gravure, spray, kiss roll, bar, and knife methods. After the primer layer preparation step, a pressure-sensitive adhesive is applied to the surface of the primer layer, thereby obtaining a pressure-sensitive adhesive tape with improved adhesion between the substrate layer and the pressure-sensitive adhesive layer.

[0055] 3. Physical Properties of the Pressure-Sensitive Adhesive Tape 3.1 Adhesive Strength (Normal, to SUS) The adhesive strength (normal, to SUS) of the pressure-sensitive adhesive tape according to this embodiment is preferably 0.5 N / 10 mm or more, more preferably 0.7 N / 10 mm or more. The adhesive strength (normal, to SUS) of the pressure-sensitive adhesive tape according to this embodiment is preferably 1.5 N / 10 mm or less. The adhesive strength (normal, to SUS) of the pressure-sensitive adhesive tape according to this embodiment can be measured, for example, by a method in accordance with JIS C2107:2011 using a SUS plate as the test plate. When the adhesive strength (normal, to SUS) of the pressure-sensitive adhesive tape is equal to or greater than the lower limit, the pressure-sensitive adhesive tape has excellent adhesive strength and can be suitably used in operating mechanical devices or components for mechanical devices. When the adhesive strength (normal, to SUS) of the pressure-sensitive adhesive tape is equal to or less than the upper limit, the pressure-sensitive adhesive tape has excellent spreadability and improved workability.

[0056] 3.2 Adhesive Strength (Normal State, Towards the Back Surface) The adhesive strength (normal state, to the back surface) of the pressure-sensitive adhesive tape according to this embodiment is preferably 0.5 N / 10 mm or more, more preferably 0.7 N / 10 mm or more, and even more preferably 1.0 N / 10 mm or more. The adhesive strength (normal state, to the back surface) of the pressure-sensitive adhesive tape according to this embodiment is preferably 2.0 N / 10 mm or less. The adhesive strength (normal state, to the back surface) of this embodiment can be measured, for example, by punching out a portion of the pressure-sensitive adhesive tape and pressing it against a test plate using a method in accordance with JIS C2107:2011. When the adhesive strength (normal state, to the back surface) of the pressure-sensitive adhesive tape is equal to or greater than the lower limit, the adhesive strength is excellent and the tape can be suitably used in operating mechanical devices or components for mechanical devices. When the adhesive strength (normal state, to the back surface) of the pressure-sensitive adhesive tape is equal to or less than the upper limit, the adhesive tape has excellent spreadability and improved workability.

[0057] 3.3 Tackiness The tackiness of the pressure-sensitive adhesive tape according to this embodiment is 1.0 to 4.0 N / 20 mm ２ It is preferable that the strength is 1.5 to 3.5 N / 20 mm. ２ The tackiness according to this embodiment can be measured by a probe tack test. The probe tack test is carried out, for example, at a room temperature of 23±2°C and a humidity of 50±2% RH using a probe tack tester ("TE-6001-S" manufactured by Tester Sangyo Co., Ltd.) on a substrate made of SUS and having a contact area of ​​0.25 cm. ２ The probe was applied with a force of 100 gf / cm for 0.2 seconds. ２ The tackiness can be measured by pressing the probe against the adhesive layer side of the adhesive tape with a load of 0.01 mm / sec and measuring the load when the probe is raised at a speed of 10 mm / sec. When the tackiness is at least the lower limit, the adhesive tape has excellent adhesion to the adherend. When the tackiness is at most the upper limit, the adhesive tape is easily repositioned, improving workability.

[0058] 3.4 Holding Power The holding power of the pressure-sensitive adhesive tape according to this embodiment is preferably 200 min or more, and more preferably 250 min or more. The holding power according to this embodiment can be measured, for example, by a method in accordance with JIS Z0237:2009. The greater the holding power, the longer the adhesive strength can be maintained.

[0059] 3.5 Low-Speed ​​Unwinding Force The low-speed unwinding force according to this embodiment is preferably 0.5 to 2.5 N / 10 mm, more preferably 0.8 to 2.0 N / 10 mm, and even more preferably 1.0 to 1.8 N / 10 mm. The low-speed unwinding force according to this embodiment can be measured, for example, by a method in accordance with JIS Z0237:2009. When the low-speed unwinding force is equal to or greater than the lower limit, the adhesive tape is appropriately unwound when unfolded, improving the workability of winding the tape around the electric wire. When the low-speed unwinding force is equal to or less than the upper limit, the adhesive tape is appropriately unwound, making it less likely to deform or break.

[0060] 3.6 Tensile Strength The tensile strength of the pressure-sensitive adhesive tape according to this embodiment is preferably 11 N / 10 mm or more, more preferably 13 N / 10 mm or more, and even more preferably 15 N / 10 mm or more. The tensile strength in this embodiment can be, for example, the tensile strength when a tensile test of the pressure-sensitive adhesive tape is performed according to a method in accordance with JIS C2107:2011. The higher the tensile strength, the higher the substrate strength of the pressure-sensitive adhesive tape.

[0061] 3.7 Elongation at Break The elongation at break of the pressure-sensitive adhesive tape according to this embodiment is preferably 120% or more, more preferably 180% or more, and even more preferably 200% or more. The elongation at break in this embodiment can be, for example, the strain at break when a tensile test of the pressure-sensitive adhesive tape is performed according to a method in accordance with JIS C2107:2011. The greater the elongation at break, the higher the substrate strength of the pressure-sensitive adhesive tape.

[0062] 3.8 Elastic Modulus The elastic modulus of the pressure-sensitive adhesive tape according to the present embodiment is preferably 2.0 to 3500.0 MPa. The elastic modulus of the pressure-sensitive adhesive tape according to the present embodiment is preferably 100.0 MPa or more, more preferably 200.0 MPa or more, and even more preferably 250.0 MPa or more. The elastic modulus of the pressure-sensitive adhesive tape according to the present embodiment is preferably 3000.0 MPa or less, more preferably 2000.0 MPa or less, and even more preferably 1000.0 MPa or less. The elastic modulus according to the present embodiment can be calculated, for example, by the following formula when a tensile test of the pressure-sensitive adhesive tape is performed according to a method in accordance with JIS C2107:2011: (Elastic Modulus [MPa]) = {(Tensile stress [MPa] measured at a strain of 0.02) - (Tensile stress [MPa] measured at a strain of 0.015)} / 0.005 When the elastic modulus is equal to or greater than the lower limit, the substrate strength of the pressure-sensitive adhesive tape is increased, and the wire binding property and workability are improved. When the elastic modulus is equal to or less than the upper limit, the adhesive tape has excellent flexibility, and the wire binding property and workability are improved.

[0063] 4. Method of Using the Adhesive Tape The adhesive tape according to this embodiment can be used to bundle electric wires, specifically to bundle wire harnesses. Accordingly, one embodiment of the present invention is a wire harness having electric wires and an adhesive tape for bundling the electric wires. The adhesive tape according to this embodiment can be used in various mechanical devices or components for mechanical devices, such as automobiles, aircraft, trains, factory automation equipment, home appliances, office automation equipment, medical equipment, communications equipment, and play equipment. Because the adhesive tape according to this embodiment has excellent adhesive strength, it can be particularly suitably used in operating mechanical devices or components for mechanical devices, such as automobiles, aircraft, trains, factory automation equipment, home appliances, and play equipment.

[0064] The present invention will be described in more detail below with reference to examples. Note that the examples described below are representative examples of the present invention and should not be construed as narrowing the scope of the present invention.

[0065] <Preparation of Base Layer> A resin composition was prepared by melt-kneading a thermoplastic resin, a plasticizer, a filler, and an additive in a Banbury mixer so as to uniformly disperse the resin. The formulations of the thermoplastic resin, the plasticizer, and the filler are shown in Tables 1 to 3. The additives in each resin composition were added so that the stabilizer was 1.5 parts by mass and the lubricant was 0.25 parts by mass per 100 parts by mass of the thermoplastic resin. Stabilizer: Metal composite stabilizer: "OW-5200" manufactured by Sakai Chemical Industry Co., Ltd. Lubricant: Stearic acid: "Sakura Stearic Acid" manufactured by NOF Corporation

[0066] The obtained resin composition was formed into a film and stretched using a calendar molding machine to prepare a substrate layer of a predetermined thickness. The L / D value of the calendar roll used here was 3.3 or less. The calendar roll temperatures during calendar molding are also shown in Tables 1 to 3. Furthermore, the substrate layer was sandwiched between an embossing roll having a predetermined arithmetic mean roughness Ra and maximum valley depth Rv (only in Example 6, a mirror-finished roll was used instead of the embossing roll) and a rubber roll having a predetermined arithmetic mean roughness Ra, and the other side and one side of the substrate layer were simultaneously subjected to uneven processing.

[0067] The substrate layer after the surface treatment was cooled to 40° C. or less, and then both ends in the length direction were cut.

[0068] <Preparation of Adhesive Tapes> A primer prepared according to the formulations shown in Tables 1 to 3 was applied to one side of each substrate layer by gravure coating, and the moisture was thoroughly removed in a drying oven to prepare a primer layer. The thickness of the primer layer after drying was 0.3 μm. Next, a pressure-sensitive adhesive prepared according to the formulations shown in Tables 1 to 3 was applied onto the primer layer by roll coating, and the moisture was thoroughly removed in a drying oven to prepare a pressure-sensitive adhesive tape. The pressure-sensitive adhesive tapes of the Examples and Comparative Examples prepared in this manner (some of which only had the substrate layer) were subjected to the tests and evaluations described below, and the results are shown in Tables 1 to 3. The thicknesses of the substrate layer, pressure-sensitive adhesive layer, and pressure-sensitive adhesive tape were measured using a thickness gauge (manufactured by Mitutoyo Corporation) according to a method in accordance with JIS C2107:2011 (n=10).

[0069] The components used to obtain the resin composition are as follows. Thermoplastic resins: Vinyl chloride resin 700: "TH-700" manufactured by Taiyo Vinyl Corporation, average degree of polymerization 700 Vinyl chloride resin 1000: "TH-1000" manufactured by Taiyo Vinyl Corporation, average degree of polymerization 1000 Vinyl chloride resin 1300: "TH-1300" manufactured by Taiyo Vinyl Corporation, average degree of polymerization 1300 Vinyl chloride resin 1700: "TH-1700" manufactured by Taiyo Vinyl Corporation, average degree of polymerization 1700

[0070] Plasticizers: Phthalate ester plasticizer: "DINP" manufactured by J-Plus Corporation, diisononyl phthalate Trimellitate ester plasticizer: "Monocizer (registered trademark) W-750" manufactured by DIC Corporation, trioctyl trimellitate Adipate ester plasticizer: "Polycizer (registered trademark) W-2050" manufactured by DIC Corporation, polyester adipate

[0071] Filler: Calcium carbonate: "Calcises (registered trademark) P" manufactured by Konoshima Chemical Co., Ltd., calcium carbonate, average particle size 0.18 μm Magnesium hydroxide: "200-06H" manufactured by Kyowa Chemical Industry Co., Ltd., magnesium hydroxide, average particle size 0.54 μm

[0072] The ingredients used in preparing the primer layer are as follows: Primer: "KT4612A" manufactured by E-Tech Co., Ltd., a mixed emulsion of graft polymer latex obtained by graft polymerizing methyl methacrylate onto natural rubber and acrylonitrile-butadiene copolymer emulsion.

[0073] The components used in producing the pressure-sensitive adhesive layer are as follows. The formulations shown in Tables 1 to 3 are values ​​converted into solid content. Base polymer: Natural rubber: "HA LATEX" manufactured by Regtex Co., Ltd. Styrene-butadiene rubber latex: "KT-4615B" manufactured by E-Tech Co., Ltd.

[0074] Tackifier: Petroleum resin: "AP-1100" manufactured by Arakawa Chemical Industries, Ltd.

[0075] <Film Formability> The presence or absence of pinholes when the resin composition was stretched was evaluated. (Pinholes) The state of the substrate when the resin composition was stretched was visually evaluated according to the following criteria: A: No pinholes were observed B: Pinholes were observed, but 1 to 5 pinholes were observed within a 5 cm x 5 cm area C: Pinholes were observed, and 6 or more pinholes were observed within a 5 cm x 5 cm area

[0076] <Manufacturability> The coatability when applying the adhesive to the base layer was evaluated. (Coatability) The coatability when applying the adhesive was evaluated according to the following criteria: A: When an adhesive with a solid content of 50% was applied and dried, (X / 2) / Y was 0.8 or less. B: When an adhesive with a solid content of 50% was applied and dried, (X / 2) / Y was more than 0.8 and 0.9 or less. C: When an adhesive with a solid content of 50% was applied and dried, (X / 2) / Y was more than 0.9.

[0077] <Maximum Thickness and Minimum Thickness of Base Material Layer> The maximum and minimum values ​​were recorded when the thickness of the base material layer was measured (n=10) using a thickness gauge (manufactured by Mitutoyo Corporation) according to a method in accordance with JIS C2107:2011. (Difference between Maximum and Minimum Thickness of Base Material Layer) The difference between the maximum and minimum values ​​of the base material layer obtained by the above measurement was calculated.

[0078] <Surface Analysis Test> The substrate was cut to 50 mm x 20 mm to obtain a sample. An acrylic plate (100 mm x 300 mm) was placed on a flat surface with the measurement surface of the sample facing upward. A small surface roughness measuring instrument ("Surftest (registered trademark) SJ-210" manufactured by Mitutoyo Corporation) and its scanning probe were placed on the sample so that they were parallel to the sample flow direction. Measurements were performed by scanning the scanning probe over the sample surface under conditions of λc / λs = 2.5 mm / 8 μm and a measurement speed of 0.5 mm / s. (Arithmetic Mean Roughness Ra) The arithmetic mean roughness Ra was calculated from the measurement results obtained in the above-mentioned surface analysis test. (Maximum Valley Depth Rv) The maximum valley depth Rv was calculated from the measurement results obtained in the above-mentioned surface analysis test.

[0079] <Adhesion Test> (Adhesion (normal, against SUS)) Using a SUS plate as the test plate, the adhesive strength of the pressure-sensitive adhesive tape was measured by a method in accordance with JIS C2107:2011. For the measurement, a tabletop precision universal testing machine ("Autograph (registered trademark) AGS-1kNX" manufactured by Shimadzu Corporation) was used. (Adhesion (normal, against its back surface)) A portion of the adhesive tape was punched out and pressure-bonded to the test plate, and the adhesive strength of the adhesive tape was measured by a method in accordance with JIS C2107:2011. For the measurement, a tabletop precision universal testing machine ("Autograph (registered trademark) AGS-1kNX" manufactured by Shimadzu Corporation) was used.

[0080] <Probe Tack Test> In an environment of temperature 23±2°C and humidity 50±2% RH, a probe made of SUS with a contact area of ​​0.25 cm2 was applied to the test piece for 0.2 seconds at 100 gf / cm using a probe tack tester ("TE-6001-S" manufactured by Tester Sangyo Co., Ltd.). ２ The probe was pressed against the adhesive layer side of the adhesive tape with a load of 0.01 mm, and the load when the probe was raised at a speed of 10 mm / sec was measured (n=10). (Tackiness) The average value of the measurement results obtained in the above-mentioned probe tack test was calculated.

[0081] <Holding Force Test> (Holding Force) Measured according to a method in accordance with JIS Z 0237:2009. Specifically, a 19 mm wide, 100 mm long adhesive tape was left standing for 24 hours or more in an environment of 23±2°C temperature and 50±5% RH, and then a portion of the adhesive tape (25 mm long) was attached to a glass plate. Thereafter, a chuck for a weight of 500 g was attached to the portion of the adhesive tape opposite to the portion attached to the glass plate, and the weight was placed on a stand so as not to apply the weight of the weight. After preheating for 20 minutes in an atmosphere of 40°C, the stand was lowered to apply a weight of 500 g to the adhesive tape, and the elapsed time until the tape peeled off and fell from the glass plate was measured.

[0082] <Low-Speed ​​Unwinding Force Test> (Low-Speed ​​Unwinding Force) A low-speed unwinding force test of the pressure-sensitive adhesive tape was carried out according to JIS Z0237: 2009. Specifically, using a tabletop precision universal testing machine ("Autograph (registered trademark) AGS-1kNX" manufactured by Shimadzu Corporation) in an environment of 23±2°C temperature and 50±5% RH, a 19 mm wide rolled pressure-sensitive adhesive tape was manually unwound by about 50 mm, and the unwound portion was clamped in a chuck and unwound at a speed of 5.0±0.2 mm / s for measurement, and the average value of five measured values ​​was recorded.

[0083] <Tensile Test> A tensile test of the adhesive tape was performed according to JIS C2107:2011. Specifically, a benchtop precision universal testing machine (Shimadzu Corporation, "Autograph (registered trademark) AGS-1kNX") was used in an environment of 23±2°C temperature and 50±5% RH. A 19 mm wide, 200 mm long adhesive tape was attached to a chuck with a gripping distance of 100 mm so that a load was applied uniformly in the width direction. Measurement was performed at a tensile speed of 300 mm / min, and the average of five measured values ​​was recorded. (Tensile Strength) The tensile strength was calculated from the measurement results obtained in the above tensile test. (Elongation at Break) The elongation at break was calculated from the measurement results obtained in the above tensile test. (Elastic Modulus) The elastic modulus was calculated from the measurement results obtained in the above tensile test using the following formula. (Elastic modulus [MPa]) = {(tensile stress measured at strain 0.02 [MPa]) - (tensile stress measured at strain 0.015 [MPa])} / 0.005

[0084] <Wire Binding Test> Ten heat-resistant automotive wires ("AVX050" manufactured by Sumitomo Wiring Systems, Ltd., diameter: 50 mm) were cut to lengths of 800 mm, and four heat-resistant automotive wires ("AVX085" manufactured by Sumitomo Wiring Systems, Ltd., diameter: 85 mm) were cut to lengths of 800 mm. These 14 wires were bundled together and fixed at both longitudinal ends with adhesive tape to facilitate winding. Then, the adhesive tape (width: 19 mm) of each Example or Comparative Example was wrapped around the wires in a half-wrap to prepare evaluation samples. Here, "half-wrap wrapping" refers to wrapping the adhesive tape around the wire so that half of the width of the adhesive tape overlaps half of the width of the adhesive tape already wrapped around it. (Tape Spreadability) The spreadability of the adhesive tape when unwrapped was evaluated according to the following criteria. "Excessive payout" refers to the phenomenon in which, when a light force is applied during the unfolding of the adhesive tape, the tape is unwound more than desired. A: The adhesive tape can be unfolded without excessive deformation or excessive payout. B: The adhesive tape is excessively deformed or unwound. (Wire winding ability) The evaluation samples prepared in the above test were evaluated for the presence or absence of wrinkles, lifting, and peeling.

[0085] <Weighing test> The pressure-sensitive adhesive tape was weighed, and the mass per unit area was calculated. (Lightweightness) The mass per unit area obtained in the weighing test was evaluated according to the following criteria. A: 80 g / m ２ Less than B: 80 g / m ２ Above, 85g / m ２ Less than C: 85 g / m ２ End

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[0089]

Claims

1. An adhesive tape comprising: a substrate layer made of a resin composition containing a thermoplastic resin; and an adhesive layer provided on one surface of the substrate layer; wherein the thickness of the substrate layer is 58 μm or less; the difference X between the maximum thickness and the minimum thickness of the substrate layer is within 30% of the thickness of the substrate layer; and the relationship between X and the thickness Y of the adhesive layer satisfies X / 2<Y.

2. The adhesive tape according to claim 1, wherein the thickness Y of the adhesive layer is 15 μm or less.

3. The adhesive tape according to claim 1, wherein the low-speed unwinding force of the adhesive tape is 0.8 to 2.0 N / 10 mm.

4. The adhesive tape according to claim 1, wherein the adhesive tape has an elastic modulus of 2.0 to 3500.0 MPa.

5. The adhesive tape according to claim 1, wherein the resin composition does not contain an inorganic filler.

6. The adhesive tape according to claim 1, wherein the resin composition contains 20 to 75 parts by mass of a plasticizer per 100 parts by mass of the thermoplastic resin.

7. The adhesive tape according to claim 1, wherein the thermoplastic resin comprises a vinyl chloride resin.

8. The adhesive tape according to any one of claims 1 to 7, which is used for bundling electric wires.

9. A wire harness comprising electric wires and the adhesive tape according to claim 8 for bundling the electric wires.

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