"Adhesive tape for fastening and method for manufacturing the same"

Abstract

Provided are an adhesive tape having little stickiness on the tape-side surface even with long-term storage and having exceptional adhesive strength for bundling objects such as electrical wires and cables, and a method for producing the adhesive tape.　An adhesive tape comprising a base material containing a polyvinyl chloride resin, and an adhesive agent layer provided on at least one surface of the base material, wherein the gel fraction of the adhesive agent layer is 2.5-30 mass%, the 23°C storage modulus (E'23°C) of the adhesive agent layer is 6.8×104 to 3.0×105 Pa, and the 80°C storage modulus (E'80°C) and the (E'23°C) of the adhesive agent layer satisfy formula (1).　Formula (1) 1.5≤(E'23°C) / (E'80°C)≤8.0

Description

[Technical Field]

[0001] The present invention relates to adhesive tape and a method for manufacturing the same. [Background technology]

[0002] Polyvinyl chloride resin-based adhesive tapes are used for bundling wiring of various electrical equipment in automobiles, railways, aircraft, ships, houses, factories, etc., because they have appropriate flexibility and elongation, excellent properties such as flame retardancy, mechanical strength, heat deformation resistance, electrical insulation, and moldability, and are relatively inexpensive (for example, Patent Documents 1 and 2).

[0003] [Patent Document 1] Japanese Patent Publication No. 11-209718 [Patent Document 2] International Publication No. 2020 / 026697 [Overview of the Initiative]

[0004] The above-mentioned polyvinyl chloride resin-based adhesive tapes require high adhesive strength to bundle objects such as electric wires and cables. On the other hand, adhesive tapes with improved adhesive strength have the problem of becoming sticky on the sides of the tape when stored for long periods of time.

[0005] This invention has been made in view of the above circumstances, and aims to provide an adhesive tape that exhibits less stickiness on the sides of the tape even after long-term storage, and has excellent adhesive strength for bundling objects such as electric wires and cables, as well as a method for manufacturing the same.

[0006] As a result of diligent research, the inventors of this invention have found that by optimizing the storage modulus of the adhesive layer at room temperature to improve adhesive properties, and by controlling the storage modulus of the adhesive layer at high temperatures and the gel fraction of the adhesive layer to suppress the flow of the adhesive, it is possible to obtain an adhesive tape with high adhesive strength while suppressing stickiness on the sides of the tape during long-term storage, thus completing the present invention. That is, the present invention has the following aspects. [1] An adhesive tape comprising a base material containing polyvinyl chloride resin and an adhesive layer provided on at least one surface of the base material, wherein the gel fraction of the adhesive layer is 2.5 to 30% by mass, and the storage modulus of the adhesive layer at 23°C (E'23°C) is 6.8 × 10 4 ~3.0×10 5 An adhesive tape having a density of Pa, wherein the storage modulus of the adhesive layer at 80°C (E'80°C) and the storage modulus of the adhesive layer (E'23°C) satisfy the following formula (1). 1.5≦(E'23℃) / (E'80℃)≦8.0 (1) [2] The adhesive tape according to [1], wherein the adhesive layer comprises styrene-butadiene rubber (A) and a tackifier (X). [3] The adhesive tape according to [2], wherein the styrene-butadiene rubber (A) comprises a crosslinked styrene-butadiene copolymer rubber (A1). [4] The adhesive tape according to [2] or [3], wherein the gel fraction of the styrene-butadiene rubber (A) is 10 to 80% by mass. [5] The adhesive tape according to any one of [1] to [4], wherein the adhesive layer comprises at least one rubber component (B) selected from natural rubber and natural rubber derivatives. [6] The adhesive tape according to any one of [1] to [5], wherein the ester value of the adhesive layer is 90 to 150 mg KOH / g. [7] The adhesive tape according to any one of [1] to [6], wherein the adhesive layer comprises a graft copolymer (C) of natural rubber and an alkyl (meth)acrylate. [8] The adhesive tape according to any one of [2] to [7], wherein the tackifier (X) comprises a petroleum resin. [9] The adhesive tape according to any one of [1] to [8], wherein the adhesive layer further comprises a plasticizer (Y1).

[10] The adhesive tape according to any one of [1] to [9], comprising 5 to 40% by mass of styrene-butadiene rubber (A) with respect to the total mass of the adhesive layer.

[11] The adhesive tape according to any one of [1] to

[10] , comprising 5 to 40% by mass of at least one rubber component (B) selected from natural rubber and natural rubber derivatives, based on the total mass of the adhesive layer.

[12] The adhesive tape according to any one of [1] to

[11] , comprising 30 to 65% by mass of the tackifier (X) with respect to the total mass of the adhesive layer.

[13] The adhesive tape according to any one of [1] to

[12] , comprising 10 to 40% by mass of a plasticizer (Y1) with respect to the total mass of the adhesive layer.

[14] The adhesive tape according to any one of [1] to

[13] , wherein the average degree of polymerization of the polyvinyl chloride resin is 500 to 2,000.

[15] The adhesive tape according to any one of [1] to

[14] , wherein the base material contains 25 to 75 parts by mass of a plasticizer (Y2) per 100 parts by mass of the polyvinyl chloride resin.

[16] The adhesive tape according to

[15] , wherein the plasticizer (Y2) comprises at least one selected from trimellitic acid ester plasticizers, phthalic acid ester plasticizers, adipic acid ester plasticizers, and adipic acid polyester plasticizers.

[17] The adhesive tape according to any one of [1] to

[16] , wherein the substrate comprises an inorganic filler (Z).

[18] The adhesive tape according to

[17] , wherein the inorganic filler (Z) comprises at least one selected from hydrotalcite, talc, mica, calcium carbonate, and magnesium carbonate.

[19] The adhesive tape according to any one of [1] to

[18] , wherein the substrate comprises a metal-based composite stabilizer.

[20] The adhesive tape according to any one of [1] to

[19] , wherein the thickness of the adhesive layer is 10 to 40 μm.

[21] The adhesive tape according to any one of [1] to

[20] , wherein the thickness of the base material is 100 to 250 μm.

[22] The adhesive tape according to any one of [1] to

[21] , which is for bundling.

[23] The adhesive tape according to any one of [1] to

[22] , which is for bundling electric wires.

[24] Electric wires bundled with the adhesive tape according to any one of [1] to

[23] .

[25] A method for manufacturing an adhesive tape according to any one of [1] to

[23] , including forming the adhesive layer on at least one surface of the base material.

[26] The method for manufacturing an adhesive tape according to

[25] , wherein the step of forming the adhesive layer includes coating an aqueous latex of an adhesive composition on the base material.

[0007] According to the present invention, it is possible to provide an adhesive tape and a method for manufacturing the same, which have little stickiness on the side surface of the tape even after long-term storage and have excellent adhesive force for bundling objects such as electric wires and cables.

Embodiments for Carrying Out the Invention

[0008] Hereinafter, an embodiment of the present invention will be described in detail. The present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within the range that does not inhibit the effects of the present invention. In this specification, "~" means "above and below". For example, "10~40μm" means "10μm or more and 40μm or less".

[0009] [Adhesive Tape] The adhesive tape according to this embodiment is an adhesive tape including a base material containing a polyvinyl chloride resin and an adhesive layer provided on at least one surface of the base material, wherein the gel fraction of the adhesive layer is 2.5 to 30% by mass, and the storage elastic modulus (E’23°C) of the adhesive layer at 23°C is 6.8×10 4 ~3.0×10 5It is Pa, and it is characterized in that the storage elastic modulus (E’80°C) of the adhesive layer at 80°C and the storage elastic modulus (E’23°C) satisfy the following formula (1). 1.5 ≤ (E’23°C) / (E’80°C) ≤ 8.0 ···(1) The adhesive tape according to this embodiment has little stickiness on the side surface of the tape even after long-term storage, and has excellent adhesive force for binding objects such as electric wires and cables. Hereinafter, the details of the adhesive tape according to this embodiment will be described.

[0010] <Adhesive layer> The adhesive tape according to this embodiment has an adhesive layer provided on at least one surface of the base material. The gel fraction of the adhesive layer in this embodiment is 2.5 to 30% by mass. The gel fraction of the adhesive layer can be measured by the following method. <Method for measuring the gel fraction of the adhesive layer> Scrape off 0.1 g (W0: [g]) of the adhesive composition constituting the adhesive layer from the adhesive tape and immerse it in 50 mL of toluene. Then, shake it for 24 hours at a temperature of 23°C and 200 rpm using a shaker. After shaking, use a metal mesh (mesh size #200 mesh) to separate the toluene and the adhesive composition that has absorbed and swelled with toluene. Dry the separated adhesive composition under the condition of 110°C for 1 hour. Measure the weight (W1: [g]) of the adhesive composition including the metal mesh after drying, and calculate the gel fraction from the following formula (2). Gel fraction (weight%) = (W1 - W2) / W0 × 100 ···(2) (W0: weight of the initial adhesive composition (g), W1: weight of the adhesive composition including the metal mesh after drying (g), W2: initial weight of the metal mesh (g))

[0011] In this embodiment, the gel fraction of the adhesive layer is preferably 3.0 to 26% by mass, more preferably 3.1 to 20% by mass, and even more preferably 3.3 to 15% by mass. When the gel fraction of the adhesive layer is 2.5 to 30% by mass, the flow of the adhesive is likely to be suppressed, and the stickiness on the side surface of the tape after long-term storage is reduced. The adhesive layer having a gel fraction of 2.5 to 30% by mass can be easily achieved, for example, by adjusting the gel fraction of the rubber component (A) described later as an adhesive component.

[0012] The storage elastic modulus (E’23°C) of the adhesive layer according to this embodiment is 6.8×10 4 ~3.0×10 5 Pa. Further, the storage elastic modulus (E’80°C) of the adhesive layer and the storage elastic modulus (E’23°C) satisfy the following formula (1). 1.5≦(E’23°C) / (E’80°C)≦8.0 ···(1) The storage elastic modulus (E’) of the adhesive layer can be measured by the following method. (Method for measuring the storage elastic modulus (E’) of the adhesive layer) Scrape off 0.1 g of the adhesive composition constituting the adhesive layer of the adhesive tape and mold it into a sheet with a thickness of 1 mm to prepare a sample for measuring the storage elastic modulus. Then, using a dynamic elastic modulus measuring device (for example, manufactured by TA Instruments, product name “ARES”), measure under the following measurement conditions to calculate the storage elastic modulus (E’23°C) and the storage elastic modulus (E’80°C). (Measurement conditions) Measurement start temperature: -60°C Measurement end temperature: 120°C Temperature increase rate: 4°C / min Frequency: 1 Hz

[0013] In this embodiment, the storage elastic modulus (E’23°C) of the adhesive layer is 6.8×10 4 ~3.0×10 5 Pa, preferably 7.0×10 4 ~2.5×10 5 Pa, and more preferably 8.0×10 4 ~2×10 5Pa is more preferable. Also, in the above formula (1), (E'23℃) / (E'80℃) is between 1.5 and 8.0, preferably between 1.55 and 7.0, and more preferably between 1.60 and 6.0. The storage modulus of the adhesive layer at 23℃ (E'23℃) is 6.8 × 10⁻⁶. 4 ~3.0×10 5 If the temperature is Pa, the adhesive layer will have a ratio of (E'23°C) / (E'80°C) in equation (1) of 1.5 to 8.0. As a result, the flow of the adhesive is more easily suppressed, and the stickiness of the tape's sides after long-term storage is reduced. Furthermore, an adhesive tape with excellent adhesive strength at room temperature can be obtained. Furthermore, the storage modulus (E'23℃) is 6.8 × 10⁻⁶. 4 ~3.0×10 5 An adhesive layer having Pa and whose storage modulus (E'23°C) and storage modulus (E'80°C) satisfy formula (1) can be easily achieved, for example, by adjusting the ester component in the adhesive layer and adjusting the blending ratio of the rubber component (A) and other adhesive components in the adhesive layer.

[0014] In one embodiment, the storage modulus (E'80°C) of the adhesive layer at 80°C is 9.0 × 10⁻⁶. 3 ~1.5×10 5 It may also be Pa, 9.0 × 10 3 ~1.0×10 5 It may also be Pa, 1.0 × 10 4 ~9.0×10 4 Pa may also be used. An adhesive layer in which (E'80℃) is within the above range can be easily achieved, for example, by adjusting the amounts of a graft copolymer (C) of natural rubber and alkyl (meth)acrylate, or by adjusting the amounts of a tackifier (X) to the preferred range described later.

[0015] (Adhesive composition) The adhesive layer according to this embodiment may be composed of an adhesive composition capable of achieving the aforementioned gel fraction and storage modulus. In one embodiment, the adhesive layer may be composed of an adhesive composition comprising styrene-butadiene rubber (A) and a tackifier (X). By using an adhesive composition comprising styrene-butadiene rubber (A) and a tackifier (X), it is easier to control the storage modulus of the adhesive layer and the adhesive strength of the adhesive tape to its own back surface (hereinafter referred to as "back surface adhesive strength") is easily improved. An example of an adhesive composition containing the above components will be described below.

[0016] (Styrene-butadiene rubber (A)) Styrene-butadiene rubber (A) (hereinafter sometimes referred to as "rubber component (A)") is an elastomer containing styrene blocks and butadiene blocks in its structure, such as styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene-butylene-styrene block copolymer (SEBS), and styrene-butadiene copolymer rubber (SBR). These rubber components (A) may be non-crosslinked or crosslinked. In one embodiment, it is preferable that rubber component (A) includes at least one selected from crosslinked styrene-butadiene copolymer rubber (A1) (hereinafter sometimes referred to as "component (A1)") and non-crosslinked styrene-butadiene copolymer rubber (A2) (hereinafter sometimes referred to as "component (A2)"), and more preferably component (A1).

[0017] In one embodiment, the proportion of rubber component (A) in the adhesive layer is preferably 5 to 40% by mass, more preferably 5 to 35% by mass, and even more preferably 10 to 30% by mass, based on the total mass of the adhesive layer. In one embodiment, the proportion of rubber component (A) in the adhesive layer may be 5 to 30% by mass, 10 to 40% by mass, 20 to 40% by mass, or 30 to 40% by mass. By including rubber component (A) within the above ranges in the adhesive layer, compatibility with the tackifier (X) is improved, and good adhesive strength is easily achieved. The "total mass of the adhesive layer" refers to the total mass of the resin composition constituting the adhesive layer.

[0018] (Ingredient (A1)) Component (A1) is a crosslinked styrene-butadiene copolymer rubber. Component (A1) may be, for example, a crosslinked styrene-butadiene copolymer rubber having a gel fraction of 10 to 80% by mass. The gel fraction may be 15 to 50% by mass or 20 to 40% by mass. When rubber component (A) contains component (A1), the proportion of component (A1) in rubber component (A) is preferably 10% by mass or more, more preferably 30% by mass or more, and even more preferably 50% by mass or more, based on the total mass of rubber component (A). The proportion of component (A1) in rubber component (A) may be 100% by mass. That is, the proportion of component (A1) in rubber component (A) may be 10 to 100% by mass, 30 to 100% by mass, 50 to 100% by mass, 10 to 30% by mass, 10 to 50% by mass, or 30 to 50% by mass. Furthermore, the proportion of component (A1) in the adhesive layer is preferably 4 to 40% by mass, more preferably 4.5 to 39% by mass, and even more preferably 4.75 to 38.5% by mass. As the proportion of component (A1) falls within the aforementioned range, the gel fraction of the adhesive layer tends to be 2.5 to 30% by mass, making it easier to obtain adhesive tape with less stickiness on the sides of the tape after long-term storage.

[0019] A commercially available product may be used as component (A1). Examples of commercially available products include "0533" (gel fraction: 81% by mass), "0113" (gel fraction: 80% by mass), and "0545" (gel fraction: 85% by mass), all manufactured by JSR Corporation. Component (A1) may be used alone or in combination of two or more types.

[0020] (Component (A2)) Component (A2) is a non-crosslinked styrene-butadiene copolymer rubber. Component (A2) may be, for example, a non-crosslinked styrene-butadiene copolymer rubber with a styrene content of 20 to 50% by mass. Component (A2) may be used alone or in combination of two or more types. When rubber component (A) contains component (A2), the proportion of component (A2) in rubber component (A) is preferably 90% by mass or less, more preferably 70% by mass or less, and even more preferably 50% by mass or less, based on the total mass of rubber component (A). The proportion of component (A2) in the adhesive layer is preferably 0 to 30% by mass, more preferably 5 to 30% by mass, and even more preferably 5 to 25% by mass. Furthermore, the proportion of component (A2) in the adhesive layer may be greater than 0% by mass and 15% by mass or less, 5 to 15% by mass, or 15 to 26% by mass. If the proportion of component (A2) in the adhesive layer is within the above range, the compatibility with the tackifier (X) tends to improve, resulting in good adhesive strength.

[0021] In one embodiment, the gel fraction of the rubber component (A) contained in the adhesive layer is preferably 10 to 80% by mass, more preferably 20 to 80% by mass, and even more preferably 22.5 to 75% by mass. If the gel fraction of the rubber component (A) is within the above range, the gel fraction of the adhesive layer tends to be in the range of 2.5 to 30% by mass, resulting in an adhesive tape that is less sticky on the sides of the tape even after long-term storage. The gel fraction of the rubber component (A) can be measured by the same method as the method for measuring the gel fraction of the adhesive layer described above. That is, 0.1 g of the composition constituting the rubber component (A) is taken as W0 (g) and immersed in 50 mL of toluene. Then, it is shaken in a shaker at a temperature of 23°C and 200 rpm for 24 hours. After shaking, the toluene and the adhesive composition that has absorbed toluene and swollen are separated using a metal mesh (mesh size #200). The separated composition is dried at 110°C for 1 hour. The weight (W1: [g]) of the composition containing the metal mesh after drying is measured, and the gel fraction of the rubber component (A) is calculated using formula (2) above.

[0022] (Other adhesive components) The adhesive layer according to this embodiment may contain adhesive components other than the aforementioned rubber component (A). Examples of other adhesive components include rubber-based adhesives other than rubber component (A), acrylic adhesives, silicone adhesives, urethane adhesives, etc. From the viewpoint of compatibility with rubber component (A), it is preferable to include rubber-based adhesives other than rubber component (A). Examples of rubber-based adhesives other than rubber component (A) include natural rubber (NR); natural rubber derivatives such as cyclized natural rubber, chlorinated natural rubber, and epoxidized natural rubber; synthetic rubbers such as styrene-isoprene-styrene block copolymer (SIS), hydrogenated styrene-based block copolymer (SIPS), polyisoprene rubber (IR), polyisobutylene (PIB), and butyl rubber (IIR); and graft copolymers of at least one rubber component selected from natural rubber and the synthetic rubbers with alkyl (meth)acrylate. These may be used individually or in combination of two or more. In one embodiment, the adhesive layer may contain at least one rubber component (B) selected from natural rubber and natural rubber derivatives. It may also contain a graft copolymer (C) of natural rubber with alkyl (meth)acrylate.

[0023] (Rubber component (B)) In one embodiment, the adhesive layer may contain at least one rubber component (B) selected from natural rubber and natural rubber derivatives. From the viewpoint of compatibility, natural rubber may be included as rubber component (B). When the adhesive layer contains rubber component (B), its proportion is preferably 5 to 40% by mass, more preferably 6 to 35% by mass, and even more preferably 7 to 30% by mass, based on the total mass of the adhesive layer. By including rubber component (B) within the above range, and more preferably by combining the aforementioned rubber component (A) and rubber component (B), it becomes easier to obtain an adhesive tape with excellent adhesive properties at room temperature.

[0024] (Graft copolymer (C)) In one embodiment, the adhesive layer may contain a graft copolymer (C) of natural rubber and an alkyl (meth)acrylate. By including the graft copolymer (C) in the adhesive layer, it becomes easier to adjust the amount of ester in the adhesive layer, making it easier to obtain an adhesive layer that satisfies formula (1). In this specification, "alkyl (meth)acrylate" may include both alkyl acrylate and alkyl methacrylate. The proportion of graft copolymer (C) in the adhesive layer is preferably 5 to 40% by mass, more preferably 6 to 35% by mass, and even more preferably 7 to 30% by mass, based on the total mass of the adhesive layer.

[0025] In the graft copolymer (C), the mass ratio of (meth)acrylate alkyl ester to natural rubber ((meth)acrylate alkyl ester / natural rubber) may be in the range of 3 / 97 to 30 / 70, 3 / 97 to 24 / 76, or 3 / 97 to 18 / 82. Furthermore, as the (meth)acrylate alkyl ester, an alkyl ester with 1 to 18 carbon atoms in the alkyl group is preferred. More preferred alkyl methacrylate examples include methyl methacrylate, methyl acrylate, ethyl methacrylate, ethyl acrylate, butyl methacrylate, and butyl acrylate. Of these, methyl methacrylate (MMA) is particularly preferred from the viewpoint of easily adjusting the amount of ester in the adhesive layer and easier control of the elastic modulus.

[0026] In one embodiment, the adhesive layer may be a mixture of rubber component (A), rubber component (B), and graft copolymer (C). When the adhesive layer contains the mixture, the ratio of each component ((A):(B):(C)) may be in the range of (50-85):(5-30):(5-30) (provided that the sum of (A) to (C) does not exceed 100%). Also, the ratio of rubber component (A) to the total amount of rubber component (A), rubber component (B), and graft copolymer (C) may be 50-70% by mass, the ratio of rubber component (B) may be 1-30% by mass, and the ratio of graft copolymer (C) may be 1-30% by mass (provided that the total amount of the components does not exceed 100% by mass). By blending each component in the above ratios, it becomes easier to control the gel fraction and storage modulus of the adhesive layer. As a result, it becomes easier to obtain adhesive tapes with less stickiness on the sides of the tape after long-term storage. It also becomes easier to obtain highly adhesive tapes. Furthermore, the total amount of components (A) to (C) in the adhesive layer is preferably 40 to 60% by mass, more preferably 42 to 58% by mass, and even more preferably 43 to 55% by mass, based on the total mass of the adhesive layer.

[0027] (Tackifier (X)) The adhesive layer according to this embodiment preferably contains a tackifier (X). Including a tackifier (X) makes it easier to obtain an adhesive tape with higher tackiness. Examples of tackifiers (X) include rosin resins such as unmodified rosin, modified rosin, and rosin derivatives; terpene resins such as unmodified terpenes, aromatically modified terpenes, hydrogenated terpenes, and terpenephenols; petroleum resins such as aliphatic petroleum resins, aromatic petroleum resins, aliphatic and aromatic petroleum resins, and hydrogenated versions thereof; coumarone-indene resins; and condensation resins such as phenolic resins and xylene resins. These may be used individually or in combination of two or more. From the viewpoint of improving tackiness, it is preferable to include at least one tackifier selected from terpene resins and petroleum resins, and more preferably to include a petroleum resin.

[0028] The proportion of the tackifier (X) in the adhesive layer may be 30-65% by mass, 30-60% by mass, 32-58% by mass, or 35-55% by mass, relative to the total mass of the adhesive layer. If the proportion of the tackifier (X) in the adhesive composition is within the above range, the tackifying effect will be more easily obtained.

[0029] (Plasticizer (Y1)) The adhesive layer according to this embodiment may contain a plasticizer (Y1). By including a plasticizer (Y1), the adhesive layer becomes more flexible, and its wettability to the object is improved. Furthermore, it becomes easier to control the storage modulus of the adhesive layer (especially E'23°C). The same plasticizer (Y1) as the plasticizer (Y2) described later for the substrate can be exemplified, and the preferred examples are also the same.

[0030] The proportion of plasticizer (Y1) in the adhesive layer may be 10-40% by mass, 12-38% by mass, 15-35% by mass, 10-25% by mass, or 10-20% by mass, relative to the total mass of the adhesive layer. If the proportion of plasticizer (Y1) is within the above range, it is easy to adjust the amount of ester component in the adhesive layer while controlling the storage modulus of the adhesive layer (especially E'23℃).

[0031] The ester value of the adhesive layer according to this embodiment, measured in accordance with the neutralization titration method described in JIS K0070 (1992), may be 90 to 150 mg KOH / g or 95 to 140 mg KOH / g. By adjusting the amount of ester components in the adhesive layer and the substrate (described later) so that the ester value of the adhesive layer falls within the above range, the polarity of the adhesive layer increases, making it easier to obtain an effect of improving adhesive strength. The ester value of the adhesive layer can be measured by the following method. (Method for measuring ester value) In accordance with JIS K0070 (1992), the saponification value and acid value are measured by neutralization titration, and the ester value is calculated from the following formula (3). Specifically, 1 g of the sample is taken from the adhesive layer of the adhesive tape using a spatula or the like, and the saponification value and acid value of the sample are measured. Ester value (mgKOH / g) = Saponification value (mgKOH / g) - Acid value (mgKOH / g) ... (3) Furthermore, the ester value of the adhesive layer may be measured after curing the adhesive tape immediately after manufacturing at 23°C ± 2°C for 18 to 24 hours.

[0032] The ester value in the adhesive layer can be adjusted, for example, by incorporating a plasticizer (Y1) with an ester value of 50 to 500 mg KOH / g, as measured according to the neutralization titration method described in JIS K0070 (1992), into the adhesive layer. The ester value of the plasticizer (Y1) may be 100 to 450 mg KOH / g or 200 to 400 mg KOH / g. Specifically, it is preferable that the plasticizer (Y1) includes a phthalate ester plasticizer, as described later.

[0033] (Other additives) The adhesive layer according to this embodiment may contain other additives such as softeners, surface lubricants, leveling agents, antioxidants, surfactants, corrosion inhibitors, light stabilizers, ultraviolet absorbers, heat stabilizers, polymerization inhibitors, silane coupling agents, lubricants, inorganic fillers, organic fillers, metal powders, and pigments. These may be used individually or in combination of two or more. From the viewpoint of maintaining adhesive properties against heat and light during storage of the adhesive tape, as well as wettability and affinity to the adherend, it is preferable that the other additives be at least one selected from surfactants, antioxidants, leveling agents, light stabilizers, ultraviolet absorbers, silane coupling agents, inorganic fillers, and organic fillers, and more preferably at least one selected from surfactants and antioxidants. If the adhesive layer contains other additives, the total amount thereof is preferably 0.1 to 10% by mass, and more preferably 0.3 to 5% by mass, relative to the total mass of the adhesive layer.

[0034] From the viewpoint of obtaining an adhesive tape with higher adhesive strength, the thickness of the adhesive layer in this embodiment may be 10 to 40 μm, 12 to 39 μm, or 15 to 38 μm. The thickness of the adhesive layer can be measured using a thickness gauge.

[0035] In one embodiment, the adhesive composition constituting the adhesive layer may be an aqueous emulsion. That is, the adhesive composition may contain water as a dispersion medium. If the adhesive composition is an aqueous emulsion, the amount of solvent remaining in the adhesive tape will be reduced (or there will be no residual solvent at all), making it easier to produce a low-VOC adhesive tape. In addition, the solvent evaporation process can be omitted from the manufacturing process, which tends to reduce the environmental impact during manufacturing. When the adhesive composition is an aqueous emulsion, the proportion of water in the adhesive composition can be appropriately adjusted within a range where the solid content concentration of the adhesive composition is 5 to 70% by mass, preferably 7 to 65% by mass, and more preferably 9 to 60% by mass.

[0036] <Base material> The adhesive tape according to this embodiment comprises a base material containing polyvinyl chloride resin. That is, in the adhesive tape according to this embodiment, the base material is composed of a resin composition containing polyvinyl chloride resin (hereinafter referred to as the "resin composition for the base material"). An embodiment of the resin composition for the base material will be described below.

[0037] (Resin composition for base material) (Polyvinyl chloride resin) The resin composition for the base material contains polyvinyl chloride resin. Examples of polyvinyl chloride resins included in the base material include homopolymers of vinyl chloride (hereinafter referred to as "polyvinyl chloride"), vinyl chloride-vinyl acetate copolymers, vinyl chloride-ethylene copolymers, and vinyl chloride-propylene copolymers. These may be used individually or in combination of two or more. Among these, polyvinyl chloride is preferred because it has excellent strength, abrasion resistance, water resistance, and dust resistance. The average degree of polymerization of the polyvinyl chloride resin is not particularly limited as long as it has the effects of the present invention. From the viewpoint of film-forming properties of the substrate, a degree of polymerization of 500 or more is preferred. Furthermore, from the viewpoint of the wrapability of the adhesive tape (preventing the substrate from becoming too hard), a degree of polymerization of 2,000 or less is preferred. In one embodiment, the average degree of polymerization may be 700 to 1,800 or 1,000 to 1,300. Note that the average degree of polymerization is a value measured in accordance with JIS K6720-2.

[0038] The proportion of polyvinyl chloride resin in the base material may be 50 to 75% by mass or 50 to 70% by mass, based on the total mass of the resin composition for the base material.

[0039] (Plasticizer (Y2)) In this embodiment, it is preferable that the substrate further contains a plasticizer (Y2). Including a plasticizer (Y2) makes it easier to improve the elongation and film-forming properties of the substrate. It is preferable that the plasticizer (Y2) contains at least one selected from trimellitic acid ester plasticizers, phthalic acid ester plasticizers, adipic acid ester plasticizers, and adipic acid polyester plasticizers.

[0040] Examples of trimellitic acid ester plasticizers include tri-n-octyl trimellitic acid, tri-2-ethylhexyl trimellitic acid (TOTM), triisooctyl trimellitic acid, tri-n-nonyl trimellitic acid, triisononyl trimellitic acid, tri-n-decyl trimellitic acid, and triisodecyl trimellitic acid. These may be used individually or in combination of two or more. Of these, it is preferable that the product contains tri-n-octyl trimellitic acid.

[0041] Examples of phthalate ester plasticizers include diisononyl phthalate (DINP), diheptyl phthalate (DHP), di-2-ethylhexyl phthalate (DEHP), di-n-octyl phthalate (n-DOP), diisodecyl phthalate (DIDP), di-2-ethylhexyl isophthalate (DOIP), di-2-ethylhexyl terephthalate (DOTP), and phthalate-propylene glycol polyesters. These may be used individually or in combination of two or more. Of these, the inclusion of diisononyl phthalate (DINP) is preferred.

[0042] Examples of adipate ester plasticizers include di-2-ethylhexyl adipate (DOA), diisononyl adipate (DINA), and diisodecyl adipate (DIDA). These may be used individually or in combination of two or more.

[0043] Examples of adipic acid polyester plasticizers include adipic acid-propylene glycol polyesters and adipic acid-butylene glycol polyesters. These may be used individually or in combination of two or more. Of these, it is preferable to include adipic acid-propylene glycol polyester or adipic acid-butylene glycol polyester. Furthermore, the mass-average molecular weight (Mw) of the adipic acid polyester may be 400 to 3,000. The aforementioned Mw refers to the value measured using gel permeation chromatography (GPC) (for example, manufactured by Tosoh Corporation), with a total of four GPC columns: two "KF-806L" columns, one "KF-802" column, and one "KF-801" column, all manufactured by Shodex, connected in the order of KF-806L, KF-806L, KF-802, and KF-801 from upstream. High-performance liquid chromatography tetrahydrofuran (without stabilizers) (for example, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used as the mobile phase, and the values ​​were measured under the following conditions: flow rate of 1.0 mL / min, column temperature of 40°C, sample concentration of 1 mg / mL, and sample injection volume of 100 μL.

[0044] The base material may contain plasticizers other than the trimellitic acid ester plasticizers, phthalic acid ester plasticizers, adipic acid ester plasticizers, and adipic acid polyester plasticizers (other plasticizers). Examples of other plasticizers include benzyl butyl phthalate (BBP), di-2-ethylhexyl azelaic acid (DOZ), di-2-ethylhexyl sebacate (DOS), tricresyl phosphate (TCP), benzyl octyl adipate (BOA), diphenyl cresyl phosphate (DPCP), epoxidized soybean oil, epoxidized linseed oil, and chlorinated paraffin. These other plasticizers may be used individually or in combination of two or more.

[0045] In other embodiments, the plasticizer (Y2) may include di-n-octyl phthalate (n-DOP) or diisodecyl phthalate (DIDP).

[0046] In this embodiment, the proportion of plasticizer (Y2) contained in the substrate is preferably 25 to 75 parts by mass, more preferably 28 to 71 parts by mass, and even more preferably 35 to 60 parts by mass, per 100 parts by mass of polyvinyl chloride resin. If the proportion of plasticizer (Y2) in the substrate is within the above range, good processability is likely to be achieved.

[0047] In one embodiment, the plasticizer (Y2) contained in the substrate and the plasticizer (Y1) contained in the adhesive layer may be the same plasticizer. For example, if the plasticizer (Y2) contains a phthalate ester plasticizer, the plasticizer (Y1) may also contain a phthalate ester plasticizer. Furthermore, the difference between the proportion (mass%) of plasticizer (Y1) in the adhesive layer and the proportion (mass%) of plasticizer (Y2) in the substrate (plasticizer (Y2) (mass%) - plasticizer (Y1) (mass%) may be 30% by mass or less, or 25% by mass or less. By designing the mixture so that the proportion of plasticizer (Y2) is higher than the proportion of plasticizer (Y1), the ester components in the substrate migrate more easily to the adhesive layer, making it easier to control the storage modulus of the adhesive layer (especially E'23℃).

[0048] (Other resins) The base material may contain resins other than polyvinyl chloride resin (hereinafter referred to as "other resins"), to the extent that they do not impair the effects of the present invention. Examples of other resins include polyester resins, polyimide resins, polyamide resins, and polyolefin resins. These may be used individually or in combination of two or more. When the base material contains other resins, it is preferable that the amount of other resins is 20% by mass or less of the total mass of the resin composition for the base material.

[0049] (Other additives) The base material may contain other additives, to the extent that they do not impair the effects of the present invention. Examples of other additives include inorganic fillers, modifiers, dispersants, colorants, light absorbers, lubricants, antiblocking agents, antistatic agents, stabilizers, antioxidants, and processing aids. Of these, at least one selected from inorganic fillers, stabilizers, and lubricants may be included.

[0050] (Inorganic filler (Z)) Examples of inorganic fillers (Z) include aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, calcium hydroxide, potassium hydroxide, barium hydroxide, ammonium polyphosphate, polyphosphate amide, zirconium oxide, magnesium oxide, zinc oxide, titanium oxide, molybdenum oxide, guanidine phosphate, smectite, zinc borate, anhydrous zinc borate, zinc metaborate, barium metaborate, antimony oxide, antimony trioxide, antimony pentoxide, red phosphorus, hydrotalcite, talc, mica, kaolin, clay, alumina, silica, boehmite, bentonite, sodium silicate, calcium silicate, calcium sulfate, calcium carbonate, magnesium carbonate, and carbon black. These may be used individually or in combination of two or more. It is preferable to include at least one selected from hydrotalcite, talc, mica, calcium carbonate, and magnesium carbonate, and it is more preferable to include calcium carbonate.

[0051] The average particle size (D50) of the inorganic filler (Z) may be 0.03 to 20 μm or 0.1 to 10 μm from the viewpoint of processability and substrate smoothness. The average particle size of the inorganic filler (Z) refers to the particle size corresponding to 50% of the cumulative value in the volume-based cumulative particle size distribution measured using a laser diffraction particle size distribution analyzer. The cumulative particle size distribution is represented by a distribution curve with particle size (μm) on the horizontal axis and cumulative value (%) on the vertical axis.

[0052] In one embodiment, the proportion of inorganic filler (Z) contained in the substrate is preferably 0.1 to 30 parts by mass, more preferably 1 to 27 parts by mass, and even more preferably 2.5 to 25 parts by mass, per 100 parts by mass of polyvinyl chloride resin. In another embodiment, the proportion of inorganic filler (Z) in the substrate may be 3 to 30 parts by mass, 4 to 30 parts by mass, or 3 to 22 parts by mass, per 100 parts by mass of polyvinyl chloride resin.

[0053] (Stabilizer) Examples of stabilizers include metal-based composite stabilizers. Including metal-based composite stabilizers makes it easier to improve the thermal stability of the substrate. Examples of metal-based composite stabilizers include at least one selected from calcium fatty acid, zinc fatty acid, and barium fatty acid. 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 that are preferably used 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 individually or in combination of two or more. Furthermore, from the viewpoint of easily increasing the thermal stability effect by combining them, Ca-Zn-based metal stabilizers containing calcium fatty acid and zinc fatty acid are preferably used.

[0054] In one embodiment, the proportion of the metal-based composite stabilizer contained in the substrate is preferably 0.1 to 10 parts by mass, and more preferably 1 to 7 parts by mass, per 100 parts by mass of polyvinyl chloride resin.

[0055] (Lubricant) Examples of lubricants 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 oleamide, stearamide, and erucamide. Here, "higher" refers to having 9 or more carbon atoms, preferably 9 to 30 carbon atoms. These may be used individually or in combination of two or more. Of these, it is preferable to include stearic acid from the viewpoint of film-forming properties of the substrate.

[0056] The proportion of lubricant in the base material is preferably 1% by mass or less, and more preferably 0.5% by mass or less, relative to the total mass of the resin composition for the base material.

[0057] The thickness of the substrate according to this embodiment may be 100 to 250 μm or 110 to 225 μm, from the viewpoint of lightness, the breaking strength of the substrate, and the dielectric strength of the substrate. The thickness of the substrate can be measured using a thickness gauge.

[0058] <Undercoat layer> In one embodiment of the adhesive tape according to this embodiment, a primer layer may be provided between the substrate and the adhesive layer from the viewpoint of improving the adhesion between the substrate and the adhesive layer.

[0059] Examples of compositions for forming the undercoat layer include compositions containing 100 parts by mass of the aforementioned graft copolymer (C) and 25 to 300 parts by mass of acrylonitrile-butadiene copolymer. The ratio of acrylonitrile (AN) to butadiene (BD) in the acrylonitrile-butadiene copolymer can be appropriately adjusted within a range that does not hinder the effects of the present invention. For example, one or more copolymers such as copolymer 1 with an AN / BD (mass ratio) of (25-30) / (70-75), copolymer 2 with an AN / BD (mass ratio) of (31-35) / (65-69), and copolymer 3 with an AN / BD (mass ratio) of (36-43) / (57-64) can be used.

[0060] In one embodiment, the thickness of the undercoat layer can be adjusted in the range of 0.1 to 1.0 μm, and may be 0.3 to 0.5 μm. The undercoat layer may be a single layer or two or more layers may be laminated. When there are two or more undercoat layers, the total thickness can be adjusted in the range of 5 to 50 μm. Furthermore, from the viewpoint of reducing stickiness on the sides of the tape after long-term storage, the thickness of the undercoat layer may be greater than 0.1 μm and less than or equal to 0.8 μm.

[0061] The adhesive strength of the adhesive tape according to this embodiment to its own back surface may be 1.5 N / 10 mm or more, or 1.7 N / 10 mm or more. The adhesive tape according to this embodiment has excellent adhesive strength for binding objects together, and also has high adhesive strength to its own back surface. The adhesive strength of the adhesive tape to its own back surface refers to the value measured under the following conditions. (Method for measuring the self-adhesive strength of adhesive tape) Measurements are performed in accordance with JIS Z 0237. Specifically, a 10 mm wide adhesive tape is first left to stand for at least 24 hours in an evaluation test chamber set to a temperature of 23 ± 2°C and a humidity of 50 ± 5% RH. After curing, a 150 mm long adhesive tape is attached to a 1 mm thick metal plate to prepare a sample of the adhesive tape substrate surface for self-back surface measurement. Then, a 150 mm long adhesive tape is prepared, and its adhesive layer surface is attached to the substrate surface of the adhesive tape for self-back surface measurement. A 2,000 g roller is then used to press the tape back and forth once at a speed of 5 mm / s to ensure adhesion. Twenty minutes after adhesion, the 180-degree peel strength (N / 10 mm) between the adhesive surface of the tape and the tape substrate surface is measured using a tensile testing machine (for example, Shimadzu Corporation, product name "Autograph AGX").

[0062] When highly adhesive tapes are stored for extended periods, a problem arises where the adhesive seeps out from the sides of the tape, causing it to become sticky. The inventors of this invention investigated the cause of adhesive seepage during storage of highly adhesive tapes and concluded that it is due to the low storage modulus at high temperatures, which causes the adhesive to fluidize over time. To increase the storage modulus at high temperatures, applying a polymer that is highly elastic at high temperatures is effective, but this also leads to the problem of the elastic modulus at room temperature becoming too high, resulting in a decrease in adhesive strength. Therefore, the inventors of this invention focused on the storage modulus at room temperature (23°C) and conducted evaluations. They found that the adhesive properties can be improved by controlling the elastic modulus of the adhesive layer so that the storage modulus at 23°C is within a certain range, and that the storage modulus at high temperatures (80°C) can be kept low by controlling the gel fraction of the adhesive layer by adjusting the crosslinking and ester components in the adhesive layer. The adhesive tape according to this embodiment maintains high adhesive strength while simultaneously controlling the storage modulus of the adhesive layer at room temperature and high temperature, thereby improving the stickiness on the sides of the tape caused by the leakage of the adhesive layer.

[0063] [Method of manufacturing adhesive tape] The method for manufacturing the adhesive tape according to this embodiment is characterized by forming the adhesive layer on at least one surface of the substrate. The manufacturing method according to this embodiment will be described below.

[0064] <Process (I-1)> The manufacturing method according to this embodiment may include a substrate formation step (step (I-1)) before forming the adhesive layer (step (I)). In one embodiment, step (I-1) may involve melt-kneading a resin composition for the substrate containing polyvinyl chloride resin and, if necessary, a plasticizer (Y2) and an inorganic filler (Z) to obtain the substrate. The method for melt-kneading the resin composition for the substrate in step (I-1) is not particularly limited as long as it has the effects of the present invention, and various mixers and kneaders equipped with heating devices such as twin-screw extruders, continuous and batch type kneaders, rolls, and Banbury mixers can be used. The resin composition for the substrate, in which the raw materials are uniformly dispersed by the above method, can be formed into a sheet by conventional methods, such as the calendering method, T-die method, or inflation method, to obtain the substrate. As a molding machine, the calendering method is more preferable from the viewpoint of productivity, color change, uniformity of shape, and thickness accuracy. In calendering, known roll arrangement methods such as L-type, inverted L-type, and Z-type can be employed, and the roll temperature is usually set to 150-200°C, preferably 155-190°C.

[0065] In the manufacturing method according to this embodiment, a primer layer formation step (I-2) may be provided after step (I-1). The primer layer formation step may include, for example, a step of forming a primer layer by applying a water-based latex containing the above-mentioned primer layer composition to one surface of the substrate using a gravure method, spray method, kiss roll method, bar method, or knife method.

[0066] <Process (I)> In one embodiment, step (I) may include coating the substrate with an aqueous latex adhesive composition. The adhesive composition may include the aforementioned rubber component (A) and a tackifier (X). Furthermore, it may include at least one component selected from rubber component (B), graft copolymer (C), and plasticizer (Y1). Gravure coating, comma coating, or die coating are preferred coating methods.

[0067] Furthermore, after step (I), heat treatment may be applied to promote the migration of the plasticizer. Examples of heat treatment include treatment at 100-120°C for 1-8 hours.

[0068] [Application] The adhesive tape according to this embodiment can be suitably used as a tape for bundling and protecting electrical wires and cables installed in automobiles and the like. The adhesive tape according to this embodiment exhibits minimal stickiness on the sides of the tape even after long-term storage, and has excellent adhesive strength for bundling objects such as electrical wires and cables. Of course, the use of the adhesive tape according to this embodiment is not limited to bundling and protecting electrical wires and cables in automobiles and aircraft.

[0069] A more preferred embodiment of the adhesive tape according to this embodiment is as follows. <1> An adhesive tape comprising a base material containing polyvinyl chloride resin and an adhesive layer provided on at least one surface of the base material, wherein the adhesive layer comprises styrene-butadiene rubber (A) containing crosslinked styrene-butadiene copolymer rubber (A1) and graft copolymer (C), wherein the proportion of component (A1) is 4 to 40% by mass of the total mass of the adhesive layer, the proportion of graft copolymer (C) is 5 to 40% by mass, the gel fraction of the adhesive layer is 2.5 to 30% by mass, and the storage modulus of the adhesive layer at 23°C (E'23°C) is 6.8 × 10⁻¹⁴ 4 ~3.0×10 5 An adhesive tape having a coefficient of Pa, wherein the storage modulus of the adhesive layer at 80°C (E'80°C) and the storage modulus at 23°C (E'23°C) satisfy the following formula (1). 1.5≦(E'23℃) / (E'80℃)≦8.0 (1) <2> The adhesive layer further comprises a tackifier (X), <1> The adhesive tape described above. <3> The adhesive layer further contains a natural rubber component (B), <1> or <2> The adhesive tape described above. <4> The ratio of the natural rubber component (B) to the total mass of the adhesive layer is 5 to 40% by mass. <3> The adhesive tape described above. <5> In the adhesive layer, the proportion of rubber component (A) to the total amount of rubber component (B) and graft copolymer (C) is 50 to 70% by mass, the proportion of rubber component (B) is 1 to 30% by mass, and the proportion of graft copolymer (C) is 1 to 30% by mass (provided that the total amount of the components does not exceed 100% by mass). <3> or <4> The adhesive tape described above. [Examples]

[0070] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following description.

[0071] [Example 1] (Making adhesive tape) A resin composition for a base material was obtained by blending 100 parts by mass of polyvinyl chloride (manufactured by Taiyo Vinyl Chloride Co., Ltd., product name "TH-1000", average degree of polymerization 1,000) with 45 parts by mass of diisononyl phthalate (DINP) as a plasticizer (Y2), 3 parts by mass of calcium carbonate as an inorganic filler (Z), and 2 parts by mass of a metal-based composite stabilizer and 1 part by mass of a lubricant as other additives. This resin composition for a base material was melt-kneaded in a Banbury mixer to ensure uniform dispersion of each component, and then molded using a calender at a roll temperature of 165°C to obtain a base material with a thickness of 160 μm.

[0072] As styrene-butadiene rubber (A), a mixture of 35 parts by mass of crosslinked styrene-butadiene copolymer rubber (A1-1) (manufactured by JSR Corporation, product name "0533") and 35 parts by mass of non-crosslinked styrene-butadiene copolymer rubber (A2) (manufactured by JSR Corporation, product name "T-093A") was used as the adhesive component. As rubber component (B), a mixture of 15 parts by mass of natural rubber (manufactured by Resitex Co., Ltd., product name "HA-LATEX", gel fraction: 68%) was used as the adhesive component. As graft copolymer (C), a mixture of 15 parts by mass of graft polymer latex (manufactured by Resitex Co., Ltd., product name "MG-40S") obtained by graft polymerization of methyl methacrylate onto natural rubber was used as the adhesive component. Furthermore, to 100 parts by mass of the adhesive component, 100 parts by mass of petroleum resin (manufactured by Arakawa Chemical Industries, Ltd., product name "AP-1100") as a tackifier (X), 20 parts by mass of diisononyl phthalate (DINP) as a plasticizer (Y1), 1 part by mass of surfactant (manufactured by Kao Corporation, product name "OT-P") as other additives, 10 parts by mass of antioxidant / plasticizer (manufactured by San-ai Petroleum Co., Ltd., product name "DIEM"), and water as a dispersion medium were added to obtain an aqueous emulsion of the adhesive composition.

[0073] Next, a primer (water-based latex; manufactured by E-Tech Co., Ltd., product name "KT-4612-A") was applied to one side of the substrate using a gravure printing method and dried to form a primer layer with a thickness of 0.5 μm. On the aforementioned undercoat layer, the aqueous emulsion of the aforementioned adhesive composition was applied using the comma method and dried to form an adhesive layer with a thickness of 30 μm. The gel fraction of the adhesive layer, as well as (E'23°C) and (E'80°C), were measured for the obtained adhesive tape under the following conditions. As a result, the gel fraction of the adhesive layer was 12.1% by mass. The (E'23°C) of the adhesive layer was 1.3 × 10⁻⁶. 5 Pa is 6.7 × 10⁻⁶ (E'80°C). 4 The value was Pa. Furthermore, the (E'23℃) / (E'80℃) ratio was 2.0. Next, tests were conducted on the ester value of the adhesive layer, self-adhesion strength on the back, bundling properties of electrical wires, and long-term storage under the following conditions. The results are shown in Table 1.

[0074] <Method for measuring the gel fraction of the adhesive layer> 0.1 g (W0: [g]) of the adhesive composition constituting the adhesive layer was scraped off from the adhesive tape and immersed in 50 mL of toluene. Then, it was shaken in a shaker at a temperature of 23°C and 200 rpm for 24 hours. After shaking, the toluene and the adhesive composition that had absorbed toluene and swollen were separated using a metal mesh (mesh size #200). The separated adhesive composition was dried at 110°C for 1 hour. The weight (W1: [g]) of the adhesive composition including the metal mesh after drying was measured, and the gel fraction was calculated using the following formula (2). Gel fraction (weight %) = (W1 - W2) / W0 × 100 ... (2) (W0: Weight of the initial adhesive composition (g), W1: Weight of the adhesive composition containing the metal mesh after drying (g), W2: Initial weight of the metal mesh (g))

[0075] <Method for measuring the storage modulus of the adhesive layer> 0.1 g of the adhesive composition constituting the adhesive layer of the adhesive tape was scraped off and formed into a sheet with a thickness of 1 mm to prepare a sample for measuring the storage modulus. Subsequently, the sample was measured using a dynamic modulus measuring device (manufactured by T.A. Instruments, product name "ARES") under the following measurement conditions, and (E'23°C) and (E'80°C) were calculated. (Measurement conditions) Measurement start temperature: -60℃ Measurement end temperature: 120℃ Heating rate: 4°C / min Frequency: 1Hz

[0076] <Method for measuring the ester value of the adhesive layer> In accordance with JIS K0070 (1992), the saponification value and acid value were measured by neutralization titration, and the ester value was calculated from the following formula (3). Specifically, 1 g of sample was taken from the adhesive layer of adhesive tape using a spatula or the like, and the saponification value and acid value of the sample were measured. Ester value (mgKOH / g) = Saponification value (mgKOH / g) - Acid value (mgKOH / g) ... (3)

[0077] <Evaluation of the self-adhesive strength of adhesive tapes on the back> Measurements were performed in accordance with JIS Z 0237. Specifically, a 10 mm wide sample tape was first left to stand for more than 24 hours in an evaluation test chamber set to a temperature of 23 ± 2°C and a humidity of 50 ± 5% RH. After curing, a 150 mm long sample tape was attached to a 1 mm thick metal plate to create a substrate surface sample for self-back surface measurement. Then, a 150 mm long sample tape was prepared, and its adhesive layer surface was attached to the substrate surface for self-back surface measurement. A 2,000 g roller was then used to press the tape back and forth once at a speed of 5 mm / s. Twenty minutes after pressing, the 180-degree peel strength (N / 10 mm) between the adhesive surface of the tape and the substrate surface was measured using a tensile testing machine (Shimadzu Corporation, product name "Autograph AGX"). The samples were also evaluated according to the following evaluation criteria, with a rating of B or higher being considered a pass. (Evaluation Criteria) A: Self-adhesive strength on the back is 2.4N / 10mm or more. B: Self-adhesive strength on the back is 1.6N / 10mm or more and less than 2.4N / 10mm. C: Self-adhesive strength on the back is less than 1.6N / 10mm.

[0078] <Evaluation of the bundling properties of electrical wires> Ten electric wires (manufactured by Sumitomo Electric Industries, Ltd., product name "AVX0.5f") were wrapped in adhesive tape in a half-wrap fashion. The tape's adherence was visually evaluated for peeling during the wrapping process, and the binding strength was assessed according to the following evaluation criteria. A rating of B or higher was considered acceptable. (Evaluation Criteria) A: The tape could be wrapped around without peeling off, even without holding it down with your hand during the wrapping process. B: By holding the tape down with my hand while wrapping it, I was able to wrap it without it peeling off. C: When wrapping the tape, even when I held it down with my hand, the tape peeled off and I couldn't wrap it properly.

[0079] <Evaluation of long-term storage tests for adhesive tapes> The stickiness of the tape's sides was evaluated after storing the tape at 60°C for 10 days. The evaluation was conducted according to the following criteria, and a rating of B or higher was considered acceptable. (Evaluation Criteria) A: There is absolutely no stickiness on the sides of the tape. B: There is slight stickiness on the side of the tape. C: There is stickiness on the side of the tape.

[0080] <Overall evaluation of adhesive tapes> Based on the self-adhesive strength of the adhesive tape on the back, evaluation of its ability to fasten electrical wires, and evaluation of long-term storage tests, the adhesive tape was comprehensively evaluated according to the following criteria. A rating of B or higher was considered acceptable. (Evaluation Criteria) A: The self-adhesive strength, wire bundling ability, and long-term storage test all received an A rating. B: One or more of the following tests received a B rating: self-adhesion strength, bundling ability of electrical wires, or long-term storage test. C: One or more of the following tests received a C rating: self-adhesive strength, wire bundling ability, or long-term storage test.

[0081] [Examples 2-26 and Comparative Examples 1-6] Adhesive tapes were obtained in the same manner as in Example 1, except that the composition of the base resin composition and adhesive composition, and the thickness of each layer were as shown in Tables 1 and 2. For each adhesive tape, the gel fraction of the adhesive layer, (E'23°C) and (E'80°C) were measured in the same manner as in Example 1. In addition, the ester value of the adhesive layer, self-back adhesive strength, bundling ability of wires, and long-term storage test were evaluated in the same manner as in Example 1. The results are shown in Tables 1 and 2.

[0082] The details of the raw materials listed in Tables 1 and 2 are as follows:

[0083] [Adhesive layer] <Rubber component (A)> Rubber component (A1-1): Crosslinked styrene-butadiene copolymer rubber (manufactured by JSR Corporation, product name "533". Gel fraction: 81% by mass, styrene fraction: 33% by mass). Rubber component (A1-2): Crosslinked styrene-butadiene copolymer rubber (manufactured by JSR Corporation, product name "0113". Gel fraction: 80% by mass, styrene fraction: 33% by mass). Rubber component (A1-3): Crosslinked styrene-butadiene copolymer rubber (manufactured by JSR Corporation, product name "0545". Gel fraction: 85% by mass, styrene fraction: 45% by mass). Rubber component (A1-4): Crosslinked styrene-butadiene copolymer rubber (manufactured by JSR Corporation, product name "LX-426". Gel fraction: 80% by mass, styrene fraction: 33% by mass). Rubber component (A2): Non-crosslinked styrene-butadiene copolymer rubber (manufactured by JSR Corporation, product name "T-093A". Gel fraction: 0% by mass, styrene content: 35% by mass). <Rubber component (B)> Natural rubber: Manufactured by Resitex Co., Ltd., product name "HA-LATEX" (gel fraction: 68% by mass). <Graft copolymer (C)> Graft polymer latex made by graft polymerization of methyl methacrylate onto natural rubber: Manufactured by Resitex Co., Ltd., product name "MG-40S". <Plasticizer (Y1)> Diisononyl phthalate: Manufactured by J-Plus Co., Ltd., product name "DINP". Trioctyl trimellitate: Manufactured by J-Plus Co., Ltd., product name "TOTM". Polyester adipic acid: DIC Corporation, product name "Polysizer (registered trademark) W-2050" (Mw: 2300). <Tackifier (X)> Petroleum resin: C5C9 petroleum resin (manufactured by Arakawa Chemical Industries, Ltd., product name "AP-1100"). Terpene phenol: Manufactured by Arakawa Chemical Industries, Ltd., product name "E-200". <Other additives> Surfactant: Sodium dialkyl sulfosuccinate (manufactured by Kao Corporation, product name "Perex® OT-P"). Antioxidant / Plasticizer: Phenol-sulfur-based antioxidant / DINP (manufactured by San-ai Oil Co., Ltd., product name "DIEM").

[0084] [Base material] <Polyvinyl chloride resin> Polyvinyl chloride 1: Polyvinyl chloride (average degree of polymerization 700) (manufactured by Taiyo Vinyl Chloride Co., Ltd., product name "TH-700"). Polyvinyl chloride 2: Polyvinyl chloride (average degree of polymerization 1000) (manufactured by Taiyo Vinyl Chloride Co., Ltd., product name "TH-1000"). Polyvinyl chloride 3: Polyvinyl chloride (average degree of polymerization 1300) (manufactured by Taiyo Vinyl Chloride Co., Ltd., product name "TH-1300"). Polyvinyl chloride 4: Polyvinyl chloride (average degree of polymerization 1800) (manufactured by Taiyo Vinyl Chloride Co., Ltd., product name "TH-1800"). <Plasticizer (Y2)> Diisononyl phthalate: Manufactured by J-Plus Co., Ltd., product name "DINP". Trioctyl trimellitate: Manufactured by J-Plus Co., Ltd., product name "TOTM". Polyester adipic acid: DIC Corporation, product name "Polysizer W-2050" (Mw: 2,300). <Inorganic filler (Z)> Hydrotalcite: Manufactured by Kyowa Chemical Industry Co., Ltd., product name "Alkamizer (registered trademark) 1" (average particle size: 0.62 μm). Talc: Manufactured by Nippon Talc Co., Ltd., product name "P-8" (average particle size: 2.8 μm). Mica: Manufactured by Yamaguchi Mica Co., Ltd., product name "SJ-005" (average particle size: 5 μm). Calcium carbonate: Manufactured by Kamishima Chemical Industry Co., Ltd., product name "Calcies® P" (average particle size: 0.18 μm). <Other additives> Metal-based composite stabilizer: Ca-Zn-Mg composite stabilizer (manufactured by Sakai Chemical Industry Co., Ltd., product name "OW-5200"). Lubricant: Stearic acid (manufactured by NOF Corporation, product name "Sakura Stearic Acid").

[0085] [Undercoat layer] Water-based latex: A mixture of grafted natural rubber, which is obtained by graft polymerization of MMA onto natural rubber, and an acrylonitrile-butadiene copolymer emulsion (manufactured by E-Tech Co., Ltd., product name "KT-4612-A").

[0086] [Table 1]

[0087] [Table 2]

[0088] As shown in Tables 1 and 2, the adhesive tape according to this embodiment exhibited minimal stickiness on the sides of the tape even after long-term storage, and possessed excellent adhesive strength for bundling wires and other electrical wires. On the other hand, the adhesive tapes of Comparative Examples 1 to 6, which did not satisfy any of the requirements for the gel fraction and storage modulus of the adhesive layer according to this embodiment, were inferior in adhesive strength, ability to bundle wires and other electrical wires, or stickiness on the sides of the tape after long-term storage, and thus failed to improve the problems of the present application. Based on the results above, it has been confirmed that the adhesive tape and its manufacturing method according to this embodiment provide an adhesive tape that exhibits minimal stickiness on the sides of the tape even after long-term storage, and has excellent adhesive strength for bundling objects such as electric wires and cables. [Industrial applicability]

[0089] The adhesive tape according to this embodiment exhibits minimal stickiness on its sides even after long-term storage, and possesses excellent adhesive strength for bundling objects such as electric wires and cables. Such adhesive tape can be suitably used as a tape for bundling and protecting electric wires and other wires installed in automobiles and the like.

Claims

1. A binding adhesive tape comprising a base material containing polyvinyl chloride resin and an adhesive layer provided on at least one surface of the base material, The gel fraction of the adhesive layer is 2.5 to 30% by mass. The storage modulus of the adhesive layer at 23°C (E'23°C) is 6.8 × 10⁻¹⁰. ４ ~3.0 x 10 ５ A binding adhesive tape wherein the material is Pa, and the storage modulus of the adhesive layer at 80°C (E'80°C) and the storage modulus of the adhesive layer (E'23°C) satisfy the following formula (1). 1.5≦(E'23℃) / (E'80℃)≦8.0...(1)

2. The adhesive tape for fastening according to claim 1, wherein the adhesive layer comprises styrene-butadiene rubber (A) and a tackifier (X).

3. The adhesive tape for fastening according to claim 2, wherein the styrene-butadiene rubber (A) comprises a crosslinked styrene-butadiene copolymer rubber (A1).

4. The adhesive tape for fastening according to claim 2 or 3, wherein the gel fraction of the styrene-butadiene rubber (A) is 10 to 80% by mass.

5. The adhesive tape for fastening according to any one of claims 1 to 3, wherein the adhesive layer comprises at least one rubber component (B) selected from natural rubber and natural rubber derivatives.

6. The adhesive tape for fastening according to any one of claims 1 to 3, wherein the ester value of the adhesive layer is 90 to 150 mg KOH / g.

7. The adhesive tape for fastening according to any one of claims 1 to 3, wherein the adhesive layer comprises a graft copolymer (C) of natural rubber and an alkyl (meth)acrylate.

8. The adhesive tape for fastening according to claim 2 or 3, wherein the tackifier (X) includes a petroleum resin.

9. The adhesive tape for fastening according to any one of claims 1 to 3, wherein the adhesive layer further comprises a plasticizer (Y1).

10. The adhesive tape for fastening according to any one of claims 1 to 3, comprising 5 to 40% by mass of styrene-butadiene rubber (A) based on the total mass of the adhesive layer.

11. The adhesive tape for fastening according to any one of claims 1 to 3, comprising 5 to 40% by mass of at least one rubber component (B) selected from natural rubber and natural rubber derivatives, based on the total mass of the adhesive layer.

12. The adhesive tape for fastening according to any one of claims 1 to 3, comprising 30 to 65% by mass of the tackifier (X) relative to the total mass of the adhesive layer.

13. The adhesive tape for fastening according to any one of claims 1 to 3, comprising 10 to 40% by mass of a plasticizer (Y1) based on the total mass of the adhesive layer.

14. The adhesive tape for fastening according to any one of claims 1 to 3, wherein the average degree of polymerization of the polyvinyl chloride resin is 500 to 2,000.

15. The adhesive tape for fastening according to any one of claims 1 to 3, wherein the base material contains 25 to 75 parts by mass of a plasticizer (Y2) per 100 parts by mass of the polyvinyl chloride resin.

16. The adhesive tape for fastening according to claim 15, wherein the plasticizer (Y2) comprises at least one selected from trimellitic acid ester plasticizers, phthalic acid ester plasticizers, adipic acid ester plasticizers, and adipic acid polyester plasticizers.

17. The adhesive tape for fastening according to any one of claims 1 to 3, wherein the base material includes an inorganic filler (Z).

18. The binding adhesive tape according to claim 17, wherein the inorganic filler (Z) comprises at least one selected from hydrotalcite, talc, mica, calcium carbonate, and magnesium carbonate.

19. The adhesive tape for fastening according to any one of claims 1 to 3, wherein the substrate comprises a metal-based composite stabilizer.

20. The adhesive tape for fastening according to any one of claims 1 to 3, wherein the thickness of the adhesive layer is 10 to 40 μm.

21. The adhesive tape for fastening according to any one of claims 1 to 3, wherein the thickness of the base material is 100 to 250 μm.

22. A binding adhesive tape for bundling electrical wires, as described in any one of claims 1 to 3.

23. Electric wires and other wires bound together with the adhesive binding tape described in any one of claims 1 to 3.

24. A method for manufacturing a binding adhesive tape according to any one of claims 1 to 3, A method for manufacturing a binding adhesive tape, comprising forming the adhesive layer on at least one surface of the substrate.

25. The method for manufacturing a binding adhesive tape according to claim 24, wherein the step of forming the adhesive layer includes coating the substrate with an aqueous latex of the adhesive composition.

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