TW202246438A - Adhesive tape - Google Patents

Abstract

To provide adhesive tape configured such that pinhole formation is suppressed even if the substrate is thinned and that tends not to crack as a result of binding work performed under an environment of a low-temperature of -30 DEG C or lower. This adhesive tape is provided with a substrate layer and an adhesive agent layer disposed on at least one surface of the substrate layer, wherein the substrate layer is formed from a resin composition that contains a polyvinyl chloride resin and 40 to 70 parts by mass of a plasticizer and 1 to 10 parts by mass of an acrylic resin per 100 parts by mass of the polyvinyl chloride resin and that has a melt rupture tensile strength at 180 DEG C of 0.02 to 0.10 N.

Description

Adhesive tape

The invention relates to an adhesive tape.

A polyvinyl chloride adhesive tape is known as an adhesive tape for binding and protecting electric wires of an automobile. The polyvinyl chloride adhesive tape is an adhesive tape having a base material layer containing polyvinyl chloride, and also has electrical insulation. In recent years, in the automobile industry, from the viewpoint of improving fuel efficiency by utilizing the weight reduction of the vehicle, the parts arranged in the vehicle are required to be reduced in size or weight. Thinning of the base layer is effective for reducing the weight of the adhesive tape. As a method for this, there is, for example, a method of increasing the elongation ratio of the base layer to reduce the film thickness. However, if the base layer is thinned simply by increasing the stretch ratio, there is a problem that the base layer is broken and pinholes are generated in the base layer during film formation. In addition, when the base material layer is thinned, cracks or cracks (hereinafter also referred to as "cracks") are likely to occur in the bundled adhesive tape. The above-mentioned cracks tend to be more noticeable when the bundled product is stored in a low-temperature environment.

Regarding this problem, for example, Patent Document 1 describes an adhesive tape comprising a base material layer containing polyvinyl chloride and an elastomer component, and having a tensile elongation at break of 80% or more at -20°C. Patent Document 1 describes that an adhesive tape that is less prone to cracking at low temperatures can be obtained even if the base layer is thinned. [Prior Art Literature] [Patent Document]

Patent Document 1: Japanese Patent Laid-Open No. 2017-119806

[Problem to be solved by the invention]

The adhesive tape of Patent Document 1 does not have enough thin film of the base material layer, and it is difficult to respond to the desire for further weight reduction of the adhesive tape. In addition, in recent years, there has been a demand for lightweight adhesive tapes that are less prone to cracks even when stored in a severer low-temperature environment. Therefore, an object of the present invention is to provide an adhesive tape that can suppress the generation of pinholes even if the base layer is thinned, and that is less prone to cracks even when the converging operation is performed in a low temperature environment below -30°C. [Means to solve the problem]

As a result of the above-mentioned problems, the inventors of the present invention have found that by constituting the base layer with a resin composition, even if the base layer is thinned, pinholes are not generated, and the temperature at -30°C or below can be obtained. Adhesive tape that is not easy to produce cracks in low temperature environment, and then complete the present invention, the resin composition is a resin composition that blends a certain amount of plasticizer and acrylic resin in polyvinyl chloride resin, and its melting temperature at 180 ° C The breaking tension is within a certain range. That is, the present invention has the following aspects. [1] An adhesive tape comprising a base material layer and an adhesive layer provided on at least one side of the base material layer, wherein the base material layer is composed of a resin composition containing polychloride Vinyl resin, and 40 to 70 parts by mass of a plasticizer relative to 100 parts by mass of the aforementioned polyvinyl chloride resin, and 1 to 10 parts by mass of an acrylic resin, and a melt fracture tension at 180°C of 0.02 to 0.10 N. [2] The adhesive tape according to [1], wherein the polyvinyl chloride resin has an average degree of polymerization of 700 to 1800. [3] The adhesive tape according to [1] or [2], wherein the plasticizer has a melting point of -60°C or lower. [4] The adhesive tape according to any one of [1] to [3], wherein the acrylic resin has a mass average molecular weight of 5×10 ⁵ to 50×10 ⁵ . [5] The adhesive tape according to any one of [1] to [4], wherein the base material layer has a thickness of 0.03 to 0.10 mm. [6] The adhesive tape described in any one of [1] to [5], which is used for binding electric wires. [7] A member bound with the adhesive tape according to any one of [1] to [6]. [Effect of Invention]

According to the present invention, it is possible to provide an adhesive tape that suppresses the occurrence of pinholes even when the base layer is thinned, and that is less prone to cracks even when performing a converging operation in a low temperature environment of -30°C or lower.

[Mode for Carrying Out the Invention]

The present invention will be described in detail below, but the present invention is not limited to the following aspects. [adhesive tape] The adhesive tape of the present invention is an adhesive tape comprising a base material layer and an adhesive layer provided on at least one side of the base material layer, wherein the base material layer is composed of a resin composition, and the resin composition contains Polyvinyl chloride resin, and 40 to 70 parts by mass of a plasticizer relative to 100 parts by mass of the aforementioned polyvinyl chloride resin, and 1 to 10 parts by mass of an acrylic resin, and the melt rupture tension at 180°C is 0.02 ~0.10N. The adhesive tape of the present invention can suppress the occurrence of pinholes even if the base layer is thinned, and even when the converging operation is performed in a low temperature environment below -30°C, cracks are not easily generated.

＜Substrate layer＞ The base material layer is composed of a resin composition, and the resin composition includes a polyvinyl chloride resin, 40 to 70 parts by mass of a plasticizer relative to 100 parts by mass of the polyvinyl chloride resin, and 1 to 10 parts by mass Acrylic resin, and the melt fracture tension at 180°C is 0.02-0.10N.

From the viewpoint of reducing the weight of the adhesive tape, the thickness of the base layer is preferably 0.10 mm or less. Also, from the viewpoint of preventing the belt from breaking during the converging operation, it is preferable to set it to 0.03 mm or more. From these viewpoints, the thickness of the substrate layer is preferably from 0.03 to 0.10 mm, more preferably from 0.03 to 0.06 mm, and most preferably from 0.03 to 0.05 mm. In addition, the thickness of the base layer can be confirmed by measuring the thickness using a thickness gauge (for example, manufactured by Mitutoyo Co., Ltd.) after removing only the adhesive layer of the adhesive tape with a solvent.

(resin composition) The resin composition of the present invention is characterized by comprising polyvinyl chloride resin, 40 to 70 parts by mass of a plasticizer relative to 100 parts by mass of the polyvinyl chloride resin, and 1 to 10 parts by mass of an acrylic acid resin, and the melt fracture tension at 180°C is 0.02-0.10N. In this specification, "melt fracture tension at 180°C" means the numerical value of the melt tension when the resin melted at 180°C is wound up at a speed within a certain range and the resin breaks. In addition, the melting fracture tension of a resin composition means the numerical value measured under the following conditions. (Measurement method of melt fracture tension) Using a Capilograph (for example, Toyo Seiki Seisakusho Co., Ltd. product, device name "Capilograph 1D"), the pellets of the resin composition were used to measure the melt fracture tension under the following conditions. (measurement conditions) Resin temperature: 180°C Piston speed: 10mm/min Capillary length: 40mm Capillary diameter: 1.0mm Coiling speed: 1.0～6.0m/min

The melting fracture tension of the resin composition at 180°C is 0.02-0.10N, preferably 0.02-0.09N, more preferably 0.03-0.08N. If it is a resin composition having a melt fracture tension at 180° C. of 0.02 to 0.10 N, a base material layer in which pinholes do not occur even when thinned can be obtained. In addition, it is possible to obtain an adhesive tape that is less likely to be cracked even if the converging operation is performed in a low-temperature environment of -30°C or lower. The take-up speed at resin breakage at 180°C is preferably at least 2.0 m/min, more preferably 2.0 to 5.0 m/min. In addition, the above-mentioned take-up speed at break means the take-up speed at break of the molten resin when the molten resin at 180° C. extruded from the capillary is taken up while changing the speed in the range of 1.0 to 6.0 m/min. In one aspect, it is further preferable that the melt fracture tension when the resin breaks at a winding speed of 2.0 m/min or more is 0.02 to 0.10 N. If it is a resin composition having the above-mentioned melt properties, it is easy to prepare a base material layer with a small thickness. In particular, it is easy to prepare a base layer with a small thickness by increasing the elongation ratio of the base layer to make the film thickness thinner. Furthermore, it becomes easy to obtain a base material layer in which pinholes are less likely to occur even when the thickness is reduced. In addition, it is easy to suppress a decrease in film-forming properties due to excessive softness of the resin.

(polyvinyl chloride resin) Examples of polyvinyl chloride resins 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. Wait. These may be used alone or in combination of two or more. Among them, polyvinyl chloride is preferable in terms of excellent strength, and excellent 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 effect of the present invention. The average degree of polymerization is preferably from 700 to 1800, more preferably from 1000 to 1300, from the viewpoint of easy adjustment of the melt fracture tension of the base material layer. In addition, the said average degree of polymerization is the numerical value measured based on JISK6720-2.

(Plasticizer) As plasticizers, for example, phthalates, isophthalates, terephthalates, adipates, trimellitates and polyesters and phosphoric acid-based plastics of these can be used. Chemical agent, epoxy plasticizer, etc. Specific examples include diisononyl phthalate (DINP), diheptyl phthalate (DHP), di-2-ethylhexyl phthalate (DEHP), phthalic acid Di-n-octyl (n-DOP), diisodecyl phthalate (DIDP), di-2-ethylhexyl isophthalate (DOIP), di-2-ethylhexyl terephthalate (DOTP), benzyl butyl phthalate (BBP), tris-2-ethylhexyl trimellitate (TOTM), di-2-ethylhexyl adipate ( DOA), diisononyl adipate (DINA), diisodecyl adipate (DIDA), di-2-ethylhexyl azelate (DOZ), di-2-ethylhexyl sebacate ester (DOS), tricresyl phosphate (TCP), benzyl octyl adipate (BOA), adipate-propylene glycol polyester, adipate-butylene glycol polyester, Phthalate-propylene glycol-based polyester, diphenyl cresyl phosphate (DPCP), diisodecyl adipate, epoxidized soybean oil, epoxidized linseed oil, chlorinated paraffin, and the like. These may be used alone or in combination of two or more. Among the above-mentioned plasticizers, a plasticizer having a melting point of -60°C or lower is preferable from the viewpoint of easily improving the elongation at break in a low temperature environment of -30°C or lower and easily suppressing cracks. Examples of the above-mentioned plasticizer include: diisononyl adipate (DINA, melting point: -68°C), di-2-ethylhexyl adipate (DOA, melting point: -68°C) , Diisodecyl adipate (DIDA, melting point: -70°C), Di-2-ethylhexyl azelate (DOZ, melting point: -60°C), Di-2-ethylhexyl sebacate (DOS, melting point: -62°C), etc. These plasticizers having a melting point of -60°C or lower may be used alone or in combination of two or more. Among them, DINA and DOA are more preferable.

The content of the plasticizer in the base layer is 40-70 parts by mass relative to 100 parts by mass of polyvinyl chloride resin, preferably 45-65 parts by mass, more preferably 50-60 parts by mass. When the compounding quantity of the plasticizer in a base material layer exists in the said range, even if it thins a base material layer, generation|occurrence|production of a pinhole can be suppressed.

(acrylic resin) Examples of acrylic resins include acrylates such as acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, methyl Polymers mainly composed of methacrylates such as ethyl acrylate, n-butyl methacrylate, isobutyl methacrylate, and 2-ethylhexyl methacrylate. These acrylic resins may be used alone or in combination of two or more.

In the adhesive tape of the present invention, the mass average molecular weight (Mw) of the acrylic resin can be easily adjusted to the range of 0.02 to 0.10 N in terms of the melt fracture tension at 180°C of the resin composition constituting the base layer. , preferably in the range of 5×10 ⁵ to 50×10 ⁵ , more preferably in the range of 15×10 ⁵ to 40×10 ⁵ , particularly preferably in the range of 25×10 ⁵ to 35×10 ⁵ . By combining an acrylic resin having the aforementioned Mw with a polyvinyl chloride resin, it is easy to adjust the melt fracture tension of the resin composition within a certain range. In addition, even if the base material layer is thinned, it becomes easy to suppress the occurrence of pinholes. In addition, Mw of an acrylic resin means the numerical value calculated by polystyrene conversion using GPC. In addition, the details of the measurement conditions are as follows. (Measurement conditions for GPC) Column: GPC K-806L 10μm 8.0×300mm×2 Temperature: 40°C Mobile phase: THF Flow rate: 1.0mL/min Sample concentration: 0.1% by mass Injection volume: 100μL

As acrylic resin, a commercial item can also be used. As commercially available products, for example, "METABLEN (registered trademark) P-551A (Mw: 1.5 million)" and "METABLEN P-530A (Mw: 3 million)" manufactured by Mitsubishi Chemical Co., Ltd.; KANEKA ( Co., Ltd.) trade names "KANE ACE (registered trademark) PA-20 (Mw: 1 million)", "KANE ACE PA-30 (Mw: 3 million)", etc.

Content of the acrylic resin in a resin composition is 1-10 mass parts with respect to 100 mass parts of polyvinyl chloride resins. By blending 1 to 10 parts by mass of the acrylic resin, it becomes easy to adjust the melt fracture tension of the resin composition within a constant range. In addition, it is possible to suppress pinholes and tape breakage due to thinning of the substrate layer.

Pinholes tend to occur when the base layer is thinned, especially when the base layer is thinned by stretching the base layer to increase the elongation ratio. The reason for this is presumed to be that when the resin constituting the base material layer is stretched, microseparation occurs between molecules and the resin is broken. The inventors of the present invention found that by adding a certain amount of acrylic resin to the resin composition constituting the base layer, the entanglement points of the molecules increase, and even if the base layer is stretched, the resin becomes less likely to break. In addition, since the Tg (glass transition temperature) of acrylic resin is lower than that of polyvinyl chloride resin, it is considered that the resin softens due to the resin properties of acrylic resin, and the elongation of the resin itself is also improved. Furthermore, it was also found that the generation of pinholes can be more effectively suppressed even when the base material layer is stretched to reduce the film thickness if it is the following resin composition: a resin composition containing a certain amount of For the resin composition of the acrylic resin, the melt tension when the molten resin (180°C) is wound up in a certain speed range and the resin breaks is 0.02-0.10N. As mentioned above, the resin composition of the present invention that combines polyvinyl chloride resin, plasticizer, and acrylic resin in such a manner as to satisfy specific melt properties can change the base layer even by increasing the elongation ratio of the base layer. In the thin case, it can also effectively suppress the occurrence of pinholes.

From the point of view that it is easy to adjust the melting fracture tension of the resin composition at 180°C to a certain range, and to control the influence caused by the resin physical properties of the acrylic resin, the content of the acrylic resin in the resin composition, relative to 100 parts by mass of polyvinyl chloride resin, preferably 1 to 5 parts by mass, more preferably 1 to 3 parts by mass. By mixing 1 to 10 parts by mass, preferably 1 to 5 parts by mass of polyvinyl chloride with an average degree of polymerization of 700 to 1800 relative to 100 parts by mass of polyvinyl chloride resin, preferably 100 parts by mass of polyvinyl chloride An acrylic resin with a lower molecular weight can more effectively suppress the generation of pinholes caused by the thinning of the substrate layer.

(other additives) In the resin composition, other additives may be blended within the range that does not inhibit the effects of the present invention. Examples of other additives include inorganic fillers, modifiers, dispersants, colorants, light absorbers, slip agents, antiblocking agents, antistatic agents, stabilizers, and antioxidants.

From the viewpoint of preventing the resin composition from adhering to lamination rolls and the like to contaminate the device during the production of the adhesive tape, an inorganic filler may be blended into the resin composition. Examples of inorganic fillers include aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, calcium hydroxide, potassium hydroxide, barium hydroxide, ammonium polyphosphate, amide polyphosphate, zirconium oxide, magnesium oxide, Zinc, titanium oxide, molybdenum oxide, guanidine phosphate, smectite, zinc borate, anhydrous zinc borate, zinc metaborate, barium metaborate, antimony oxide, antimony trioxide, antimony pentoxide, red phosphorus, talc, kaolin, clay , alumina, silicon oxide, diaspore, bentonite, sodium silicate, calcium silicate, calcium sulfate, calcium carbonate, magnesium carbonate, carbon black, etc. These may be used individually by 1 type, and may use 2 or more types together.

Examples of modifiers include chlorinated polyethylene, ethylene-vinyl acetate copolymer, acrylonitrile-butadiene-styrene copolymer, methyl methacrylate-butadiene-styrene copolymer, Methyl methacrylate-butyl acrylate copolymer, etc. These may be used alone or in combination of two or more.

When blending additives other than the above-mentioned other plasticizers, inorganic fillers, and modifiers, the blending amount is not particularly limited as long as it is within a range that does not inhibit the effects of the present invention. For example, with respect to 100 mass parts of polyvinyl chloride resins, more than 0 mass parts and 10 mass or less can be blended.

＜Adhesive layer＞ The adhesive tape of this invention is equipped with the adhesive agent layer provided in at least one surface of the said base material layer. The adhesive layer is preferably directly disposed on one surface of the substrate layer.

The adhesive constituting the adhesive layer is not particularly limited as long as it has the effect of the present invention, and an adhesive conventionally used for an adhesive tape can be suitably used. Specifically, as an adhesive, an acrylic adhesive, a rubber adhesive, a silicone adhesive, a urethane adhesive etc. can be used, for example.

As said acrylic adhesive agent, the thing which has an acrylic polymer as a main component can be used, for example. The "main component" means that the ratio of the acrylic polymer in the acrylic adhesive is 50% by mass or more. As said acrylic polymer, the polymer etc. of an alkyl (meth)acrylate and a carboxyl group containing unsaturated monomer are mentioned, for example. Examples of the alkyl (meth)acrylate include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, and isopropyl acrylate. , isopropyl methacrylate, n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, secondary butyl acrylate, secondary butyl methacrylate, tertiary butyl acrylate ester, tertiary butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, n-octyl acrylate, n-octyl methacrylate, isooctyl acrylate, isooctyl methacrylate ester, n-nonyl acrylate, n-nonyl methacrylate, isononyl acrylate, isononyl methacrylate, etc. These may be used alone or in combination of two or more.

As the carboxyl group-containing unsaturated monomer, as long as it can be copolymerized with the above-mentioned alkyl (meth)acrylate, it is not particularly limited as long as it has the effect of the present invention. For example, acrylic acid, methacrylic acid, Conic acid, fumaric acid, maleic acid, etc. These may be used alone or in combination of two or more.

啉、(甲基)丙烯腈等含氮(甲基)丙烯酸酯；乙酸乙烯酯、苯乙烯、二氯亞乙烯、丙酸乙烯酯等。此等可單獨使用一種，亦可組合兩種以上而使用。 The above-mentioned acrylic polymer may also be a copolymer containing other monomers than the alkyl (meth)acrylate and carboxyl group-containing unsaturated monomers as exemplified above. As other monomers, for example: hydroxyl-containing monomers such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and hydroxyhexyl (meth)acrylate; base) acrylamide, acryl

Nitrogen-containing (meth)acrylates such as phylloline and (meth)acrylonitrile; vinyl acetate, styrene, vinylidene chloride, vinyl propionate, etc. These may be used alone or in combination of two or more.

As a rubber-based adhesive, for example: a material selected from the group consisting of natural rubber, styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene-styrene block copolymer ( SBS), hydrogenated products of the aforementioned styrenic block copolymers (SIPS, SEBS), styrene-butadiene rubber (SBR), polyisoprene rubber (IR), polyisobutylene (PIB), and butyl In at least one rubber component of rubber (IIR) and the like, at least one tackifier selected from the group consisting of rosin-based resins, terpene-based resins, and petroleum-based resins is suitably blended. Moreover, adhesives etc. of the graft polymer which polymerized (meth)acrylate to the said rubber component can also be mentioned.

Examples of silicone-based adhesives include those in which silicone resin, silicone oil, and the like are appropriately blended with silicone rubber.

Examples of urethane adhesives include polyols such as polyether polyols and polyester polyols with toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), hexamethylene Polyisocyanate (HDI), xylylene diisocyanate (XDI) and other polyisocyanates are reacted.

Among the adhesives forming the adhesive layer, the aforementioned adhesives may contain arbitrary additives. Examples of additives include softeners, adhesion imparting agents, surface lubricants, leveling agents, antioxidants, anticorrosion agents, light stabilizers, ultraviolet absorbers, heat-resistant stabilizers, polymerization inhibitors, silane coupling agents, Sliding agents, inorganic or organic fillers, metal powders, pigments, etc. These may be used alone or in combination of two or more.

Examples of tackifiers include petroleum-based resins such as aliphatic copolymers, aromatic copolymers, aliphatic-aromatic copolymers, and alicyclic copolymers, coumarone-indene, etc. Indene)-based resins, terpene-based resins, terpene-phenol-based resins, rosin-based resins such as polymerized rosin, (alkyl)phenol-based resins, xylene-based resins, hydrogenated products thereof, and the like. These may be used alone or in combination of two or more.

It is preferable to use a rubber-based adhesive as the adhesive because it is easy to exhibit good adhesive properties even in a low-temperature environment of -30° C. or lower. Moreover, rubber-based adhesives such as natural rubber and SBR are more preferable.

The thickness of the adhesive layer is, for example, preferably from 5 to 50 μm, more preferably from 10 to 20 μm, from the viewpoint of the light weight of the adhesive tape and the workability of tightening. In addition, the adhesive layer may be composed of a plurality of layers. When the adhesive layer is composed of a plurality of layers, it is preferable to adjust so that the total thickness of the adhesive layer falls within the aforementioned range.

＜Middle layer＞ In one aspect of the present invention, an intermediate layer may also be provided between the aforementioned base material layer and the adhesive layer. As an intermediate layer, it will not specifically limit if it has the effect of this invention, For example, various films, cloth, etc. can be used.

From the viewpoint of reducing the weight of the adhesive tape, the total thickness of the adhesive tape of the present invention is preferably 0.03 to 0.10 mm, more preferably 0.04 to 0.07 mm.

[Manufacturing method of adhesive tape] The adhesive tape of the present invention can be produced by a method comprising the following steps: after melting and kneading the above-mentioned resin composition, forming a film into a predetermined thickness, width, and length to obtain a base layer (I); and The step (II) of forming an adhesive layer by coating an adhesive on at least one side of the aforementioned substrate layer. Step (I) is the film forming step of the substrate layer. In step (I), the melt-kneading method of the resin composition is not particularly limited as long as it has the effect of the present invention, and for example, twin-screw extruders, continuous and batch kneaders, rolls, shift kneaders, etc. can be used. Various mixers and kneading machines equipped with heating devices such as Brie mixers. The resin composition in which the raw materials are uniformly dispersed by the above-mentioned method can be formed into a thin film by a conventional method, such as calendering, T-die method, inflation method, etc., and used as a base material layer. In addition, from the viewpoint of thickness accuracy, it is more preferable to use a rolling method.

The temperature of the calender rolls when melting and kneading the resin composition is preferably 160 to 200°C from the viewpoint of stretching with an appropriate melt fracture tension and film formation below the thermal decomposition temperature of the vinyl chloride resin. , more preferably 170-190°C.

The film forming step of the base layer may also be a step of thinning the base layer. As a method of thinning the base material layer, for example, when forming the base material layer by a calendering method, "a method of reducing the thickness of the base material layer by narrowing the roll interval between calender rolls" (hereinafter referred to as "thin film method 1"), and "a method of reducing the thickness of the base layer by extending the base layer to increase the elongation ratio" (hereinafter referred to as "thin film method 2"), etc. In the manufacturing method of the adhesive tape of the present invention, step (I) preferably includes the film method 2. Moreover, it is more preferable to carry out the thin film method 2 after the thin film method 1. As mentioned above, thin film method 2 is generally difficult to use due to the generation of pinholes or the occurrence of resin breakage. However, since the adhesive tape of the present invention uses a resin composition containing a specific amount of acrylic resin and has a melt fracture tension at 180°C within a certain range to form the base layer, even if the film method 2 is used, it can suppress The generation of pinholes. In addition, when the molten resin calendered by the calender roll is recovered by increasing the speed of the roll in the next step (for example: take-off roll, etc.), the ratio of the speed of the calender roll to the speed of the take-off roll (take-off roll speed/ Calender roll speed), preferably 1.6-3.3, more preferably 2.0-3.3. If it is the said speed ratio, it becomes easy to adjust the thickness of a base material layer to 0.1 mm or less, Preferably it is the range of 0.03-0.05 mm. The speed of the calender rolls is preferably from 30 to 50 m/min, more preferably from 35 to 45 m/min. Also, the speed of the pulling roll is preferably from 50 to 170 m/min, more preferably from 70 to 150 m/min. Also, when the rolled resin (base layer) is stretched to increase the stretch ratio, the thickness of the stretched resin relative to the thickness of the rolled resin (that is, the final thickness of the base layer/the base layer after rolling) The thickness of the material layer), preferably 0.3-0.6, more preferably 0.3-0.5.

[use] As described above, the adhesive tape of the present invention can be suitably utilized as a tape for bundling and protecting electric wires of automobiles. The adhesive tape of the present invention can reduce the weight of the tape by reducing the thickness of the base layer. Therefore, it can contribute to the desire for weight reduction in the automotive field and the demand for improvement in fuel efficiency resulting from it. In addition, as a matter of course, the use of the adhesive tape of the present invention is not limited to restraining and protecting electric wires of automobiles.

More preferable aspects of the present invention are as follows. <1> An adhesive tape comprising a substrate layer and an adhesive layer provided on at least one side of the substrate layer, wherein the substrate layer is composed of a resin composition containing average polymerized Polyvinyl chloride with a density of 700 to 1800, 40 to 70 parts by mass of a plasticizer having a melting point of -60°C or lower relative to 100 parts by mass of the polyvinyl chloride, and 1 to 5 parts by mass of an acrylic resin , The melt fracture tension at 180°C is 0.02-0.10N, and the coiling speed of the resin at fracture is 2.0m/min or more. <2> The adhesive tape according to <1>, wherein the thickness of the base material layer is 0.03 to 0.06 mm. <3> The adhesive tape according to <1> or <2>, wherein Mw of the acrylic resin is 5×10 ⁵ to 50×10 ⁵ . <4> A method for producing an adhesive tape, which is the method for producing the adhesive tape described in any one of <1> to <3>, including thinning the base layer by increasing the elongation ratio of the base layer step. <5> The method for producing an adhesive tape as described in <4>, wherein the step of thinning the base material layer includes: after calendering the molten resin between calender rolls, increasing the speed of the traction roll to transfer the calendered resin extend. <6> The method for producing the adhesive tape according to <5>, wherein the speed of the pulling roll is 1.6 to 3.3 times the speed of the calender roll. [Example]

Although an Example is shown below and this invention is demonstrated in detail, this invention is not limited to the following description.

[Example 1] (Making of Adhesive Tape) For 100 parts by mass of polyvinyl chloride (manufactured by TAIYO VINYL Co., Ltd., product name "TH-700", average degree of polymerization 700), 55 parts by mass of diisononyl adipate (DINA) as a plasticizer, 3 parts by mass of acrylic resin (manufactured by Mitsubishi Chemical Co., Ltd., product name "METABLEN P-530A", Mw: 3 million) was used to obtain a resin composition. This resin composition was melted and kneaded with a Banbury mixer so that the components were uniformly dispersed, then charged into a calender, and rolled while adjusting the temperature of the rolls so that the resin temperature became 180°C. The calendered resin was stretched at a speed ratio of 2.0 between the calender roll and the next roll (drawing roll) to obtain a base material layer with a thickness of 0.05 mm.

As an adhesive, 30 parts by mass (solid content) of styrene-butadiene copolymer latex (manufactured by E-TEC Co., Ltd., product name "KT4615B"), 50 parts by mass (solid content) of methyl Graft polymer latex (manufactured by REGITEX Co., Ltd., product name "MG-40S") obtained by graft-polymerizing natural rubber with methyl acrylate, and 20 parts by mass (solid content) of a petroleum resin-based emulsion tackifier (Arakawa A rubber-based adhesive manufactured by Kagaku Kogyo Co., Ltd. (product name "AP-1199-NT") was coated on one side of the substrate layer by gravure to form an adhesive layer. The thickness of the adhesive layer was 0.01 mm. Then, after winding up into the tape roll shape, it cut into 19 mm width, and obtained the adhesive tape. In addition, the melting fracture tension of the resin composition, the film-forming property of the substrate layer (evaluation of pinholes), the tensile elongation at break of the substrate layer in a low temperature environment, and the crack evaluation of the adhesive tape in a low temperature environment were evaluated by The following conditions were evaluated. The results are shown in Table 1.

<Measurement of Melt Fracture Tension of Resin Composition> The resin composition was melt-kneaded using a 40 mmΦ pellet extruder (manufactured by TANABE PLASTICS Co., Ltd., product name "PASC21-A-S") to obtain resin pellets. Next, using a Capilograph (manufactured by Toyo Seiki Seisakusho Co., Ltd., device name "Capilograph 1D"), the obtained resin pellets were measured under the following conditions for the coiling speed when the resin first breaks and the melting at that time. breaking tension. Resin temperature: 180°C Piston speed: 10mm/min Capillary length: 40mm Capillary diameter: 1.0mm Coiling speed: 1.0～6.0m/min

＜Evaluation of substrate layer＞ The resin composition was formed into a film with a thickness of 0.05 mm to form a base material layer. Specifically, the resin composition was charged into a calender molding machine, and the roll temperature was adjusted so that the resin temperature became 180° C., and the calendering was performed. Thereafter, stretching was performed at a speed ratio of 2.0 between the calender roll and the next roll (drawing roll) to obtain a substrate layer having a thickness of 0.05 mm.

(Evaluation of Film Formability of Substrate Layer (Pinhole Evaluation)) The obtained substrate layer was cut into 100 mm squares to prepare samples. Five samples of this substrate layer were used to detect perforation defects by the penetration method with a non-patterned surface inspection device (manufactured by NIRECO Co., Ltd., product name "Mujiken+"), and evaluated using the following evaluation criteria. (Evaluation Criteria) Good: None of the five samples had pinholes. Unacceptable: There are more than one sample with one or more pinholes with an area of 0.04 mm ² or more. Unable to form a film: The substrate layer was broken during film production.

(tensile elongation at break of substrate layer) The obtained substrate layer was cut into a size with a width of 10 mm and a length of 100 mm. According to the test method of "tensile properties of plastics" recorded in JIS K 7161, the thermostatic bath (manufactured by Shimadzu Corporation, product name) at -30°C "TCR2W-200P+125-X") was stored for 1 hour, and the tensile strength at -30°C was measured under the following conditions using a tensile tester (manufactured by Shimadzu Corporation, product name "Autograph AGC-X"). elongation at break. (measurement conditions) Distance between fixtures: 50mm Tensile speed: 300mm/min

＜Crack Evaluation of Adhesive Tape＞ The obtained adhesive tape was processed into width 19mm, and length 300mm. Next, the above-mentioned adhesive tape was wound 10 times by semi-overlapping winding about the electric wire bundle of 10 mm in diameter which bundled 20 electric wires of 1.0 mm in diameter, and the test piece was prepared. After storing the test piece at -30°C for 1 hour, the center of the harness was folded by hand in an environment of -30°C. After that, visually confirm the presence or absence of cracks and cracks that may hinder the use of the adhesive tape. Those with no cracks or cracks in the adhesive tape were regarded as "good", and those with large cracks or cracks in the adhesive tape were regarded as "failure", and the constriction workability was evaluated.

[Examples 2-8, Comparative Examples 1-6] Except having mixed the resin composition as shown in Tables 1-2, the base material layer which has the thickness described in Tables 1-2 was produced by the method similar to Example 1. Then, using the same adhesive as in Example 1, an adhesive layer was formed with a thickness of 0.01 mm on one side of the base material layer to obtain an adhesive tape. By the same method as in Example 1, the melt fracture tension of the resin composition, the film-forming property of the substrate layer (pinhole evaluation), the tensile elongation at break of the substrate layer in a low temperature environment, and the adhesive tape at Crack evaluation in low temperature environment. The results are shown in Tables 1-2.

[Example 9] A resin composition was prepared by blending as shown in Table 1, and this resin composition was melt-kneaded by a Banbury mixer so that each component was uniformly dispersed. Thereafter, it was charged into a calender molding machine, and the roll temperature was adjusted so that the resin temperature would be 180° C., and the calendering was performed. The stretching was carried out at a speed ratio of 3.3 between the calender roll and the next roll (drawing roll) to obtain a substrate layer having a thickness of 0.03 mm. On one side of the base material layer, the same adhesive as in Example 1 was used to form an adhesive layer with a thickness of 0.01 mm to obtain an adhesive tape. By the same method as in Example 1, the melt fracture tension of the resin composition, the film-forming property of the substrate layer (pinhole evaluation), the tensile elongation at break of the substrate layer in a low temperature environment, and the adhesive tape at Crack evaluation in low temperature environment. In addition, in Example 9, the said evaluation was performed by preparing the base material layer sample of thickness 0.03mm. The results are shown in Table 1.

The details of the raw materials described in Tables 1 to 2 are as follows. (Polyvinyl chloride resin) Polyvinyl chloride resin 1: polyvinyl chloride (average degree of polymerization: 500) (manufactured by Taiyo Vinyl Co., Ltd., trade name "TH-500"). Polyvinyl chloride resin 2: polyvinyl chloride (average degree of polymerization: 700) (manufactured by Taiyo Vinyl Co., Ltd., trade name "TH-700"). Polyvinyl chloride resin 3: polyvinyl chloride (average degree of polymerization: 1000) (manufactured by Taiyo Vinyl Co., Ltd., trade name "TH-1000 (for soft)"). Polyvinyl chloride resin 4: polyvinyl chloride (average degree of polymerization: 1300) (manufactured by Taiyo Vinyl Co., Ltd., trade name "TH-1300"). Polyvinyl chloride resin 5: polyvinyl chloride (average degree of polymerization: 1700) (manufactured by Taiyo Vinyl Co., Ltd., trade name "TH-1700"). Polyvinyl chloride resin 6: polyvinyl chloride (average degree of polymerization: 2000) (manufactured by Taiyo Vinyl Co., Ltd., trade name "TH-2000"). (Plasticizer) DINA: diisononyl adipate (manufactured by J-PLUS Co., Ltd., trade name "DINA", melting point: -68° C.). DINP: diisononyl phthalate (manufactured by J-PLUS Co., Ltd., brand name "DINP", melting point: -45° C.). (Acrylic resin) Acrylic resin: manufactured by Mitsubishi Chemical Co., Ltd., trade name "METABLEN P-530A" (Mw: 30×10 ⁵ ).

[Table 1] Example 1 2 3 4 5 6 7 8 9 Substrate layer resin composition PVC resin PVC resin 1 (parts by mass) PVC resin 2 100 100 100 100 PVC resin 3 100 100 PVC resin 4 100 PVC resin 5 100 100 PVC resin 6 Plasticizer DINA 55 55 55 55 40 70 55 55 55 DINP acrylic resin 3 3 3 3 3 3 1 10 3 Melt properties Resin temperature: 180°C melt fracture tension (N) 0.03 0.04 0.05 0.08 0.10 0.02 0.03 0.02 0.04 Coiling speed at break (m/min) 3.0 3.0 3.0 3.0 2.5 3.0 2.0 5.0 3.0 Evaluation of the substrate layer Pinhole evaluation (-) good good good good good good good good good Physicality The thickness of the substrate layer (mm) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.03 -30℃ environment Tensile elongation at break (%) 120 120 120 120 80 200 120 120 120 Crack evaluation (-) good good good good good good good good good

[Table 2] comparative example 1 2 3 4 5 6 Substrate layer resin composition PVC resin PVC resin 1 (parts by mass) 100 PVC resin 2 PVC resin 3 100 100 100 100 PVC resin 4 PVC resin 5 PVC resin 6 100 Plasticizer DINA 55 55 35 75 55 55 DINP acrylic resin 3 3 3 3 0 15 Melt properties Resin temperature: 180°C melt fracture tension (N) 0.01 0.12 0.12 0.01 0.04 0.01 Coiling speed at break (m/min) 3.0 3.0 1.8 3.0 1.8 6.0 Evaluation of the substrate layer Pinhole evaluation (-) unqualified unqualified Can't make film unqualified Can't make film unqualified Physicality The thickness of the substrate layer (mm) 0.05 0.05 It is impossible to form a substrate layer with a thickness of 0.05mm 0.05 It is impossible to form a substrate layer with a thickness of 0.05mm 0.05 -30℃ environment Tensile elongation at break (%) Can't evaluate Can't evaluate Can't evaluate Crack Evaluation (-)

As shown in Tables 1 and 2, the adhesive tape of the present invention can effectively suppress the occurrence of pinholes even when the thickness of the base material layer is reduced to 0.05 mm. Furthermore, it was also found that even if the base material layer is thinned, cracks are less likely to occur in the adhesive tape under a low-temperature environment of -30°C. On the other hand, in Comparative Example 1 in which the melt fracture tension at 180° C. was less than 0.02, and in Comparative Example 2 in which the melt fracture tension exceeded 0.10 N, pinholes occurred in the base material layer. In addition, in Comparative Example 3 in which the plasticizer was less than 40 parts by mass, the resin was broken and a film base layer could not be formed. The resin composition of Comparative Example 3 is considered to be because the melt fracture tension at 180° C. exceeds 0.10 N, so the tension of the molten resin is too high, and the elongation required for film formation cannot be obtained. On the other hand, in Comparative Example 4 in which the plasticizer exceeded 70 parts by mass, the tension of the molten resin was too low, and pinholes were generated in the base material layer. In Comparative Example 5, which did not contain an acrylic resin, the resin was broken in the step of stretching the base material layer. In addition, in Comparative Example 6 containing more than 10 parts by mass of an acrylic resin, the melt fracture tension was too low and pinholes were generated. In addition, the evaluation of cracks in the adhesive tapes of Comparative Examples 1, 2, 4, and 6 in which pinholes occurred in the base material layer, in a low-temperature environment of -30°C, deviations in the evaluation results were caused by the influence of pinholes, and it was not appropriate. evaluation of. From the above results, it was confirmed that the adhesive tape of the present invention can suppress the occurrence of pinholes even if the base layer is thinned, and that cracks are less likely to occur in a low-temperature environment of -30°C.

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Claims (7)

An adhesive tape comprising a substrate layer and an adhesive layer provided on at least one side of the substrate layer, The base material layer is composed of a resin composition, and the resin composition includes polyvinyl chloride resin, 40 to 70 parts by mass of plasticizer relative to 100 parts by mass of the polyvinyl chloride resin, and 1 to 10 parts by mass Parts of acrylic resin, and the melt fracture tension at 180°C is 0.02-0.10N. The adhesive tape according to claim 1, wherein the average degree of polymerization of the polyvinyl chloride resin is 700-1800. The adhesive tape according to claim 1 or 2, wherein the plasticizer has a melting point below -60°C. The adhesive tape according to any one of claims 1 to 3, wherein the mass average molecular weight of the acrylic resin is 5×10 ⁵ to 50×10 ⁵ . The adhesive tape according to any one of claims 1 to 4, wherein the thickness of the substrate layer is 0.03-0.10 mm. The adhesive tape according to any one of Claims 1 to 5 is used for binding electric wires. A member bound by the adhesive tape according to any one of claims 1 to 6.