Cover tape and electronic component packaging including same

Abstract

The object is to provide a cover tape in which the antistatic layer is prevented from falling off. [Solution] The cover tape has a base layer, a heat seal layer, and an antistatic layer on the side of the base layer opposite the heat seal layer, and the antistatic layer contains an acid-modified olefin resin and an antistatic agent.

Description

[Technical Field]

[0001] The present invention relates to a cover tape and an electronic component package including the same. [Background technology]

[0002] As electronic devices become smaller, the electronic components used are also becoming smaller and more powerful. At the same time, electronic components are being automatically mounted on printed circuit boards during the assembly process of electronic devices. These chip-type surface-mount electronic components are housed in a carrier tape with a series of thermoformed storage pockets formed to fit the shape of the electronic components. After the electronic components are housed in each storage pocket, a cover tape is placed on top of the carrier tape as a lid, and both ends of the cover tape are heat-sealed continuously in the longitudinal direction with a heated sealing iron to form a package for the electronic components.

[0003] On the other hand, as electronic components become smaller, problems are becoming more likely to occur during the mounting process, such as electronic components sticking to the cover tape and popping out due to static electricity that is generated when the cover tape is peeled off from the carrier tape to remove the electronic components. Therefore, measures to prevent static electricity from being generated in the carrier tape and cover tape have become an important issue. For example, Patent Document 1 proposes forming an antistatic layer on the base layer side of a cover tape. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2013 / 054867 Summary of the Invention [Problem to be solved by the invention]

[0005] However, it has been found that when an antistatic layer is formed on the base layer side of the cover tape, during the heat sealing process to the carrier tape, the cover tape passed through the guide rolls of the sealing machine may rub against the antistatic layer on the base layer side and the guide rolls, causing the antistatic layer to fall off and become foreign matter and become mixed in. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a cover tape in which the antistatic layer is prevented from falling off. [Means for solving the problem]

[0006] In response to the above-mentioned problems, the inventors of the present application conducted extensive research and discovered that in a cover tape having a base layer, a heat seal layer, and an antistatic layer on the side of the base layer opposite the heat seal layer, the antistatic layer can be prevented from falling off by configuring the antistatic layer to contain an acid-modified olefin resin and an antistatic agent.

[0007] In the present disclosure, the following means can be adopted to solve the above problems. [1] A cover tape having a base layer, a heat seal layer, and an antistatic layer on the surface of the base layer opposite the heat seal layer, wherein the antistatic layer contains an acid-modified olefin resin and an antistatic agent. [Effects of the Invention]

[0008] According to the present invention, a cover tape can be provided in which the antistatic layer is prevented from falling off. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of the present disclosure will be described in detail below. However, the scope of the present disclosure is not limited to the embodiment described herein, and various modifications can be made without departing from the spirit of the present disclosure. Each aspect disclosed in this specification can be combined with any other feature disclosed in this specification. Furthermore, when multiple upper and lower limits are described for a particular parameter, any of these upper and lower limits can be combined to form a suitable numerical range. Furthermore, the lower and / or upper limits of a numerical range described in this disclosure are numerical values ​​within that range and may be replaced with numerical values ​​shown in the examples. The expression "X to Y" indicating a numerical range means "X or more and Y or less." If a specific description described for one embodiment also applies to other embodiments, that description may be omitted in other embodiments.

[0010] The configurations and combinations thereof in each embodiment are merely examples, and additions, omissions, substitutions, and other modifications of the configurations are possible as appropriate without departing from the spirit of the present disclosure. The present disclosure is not limited to the embodiments. Each aspect disclosed in this specification can be combined with any other feature disclosed in this specification.

[0011] [Cover tape] A first embodiment of the present disclosure relates to a cover tape. The cover tape according to the first embodiment has a base layer, a heat seal layer, and an antistatic layer on the surface of the base layer opposite to the heat seal layer. The antistatic layer contains an acid-modified olefin resin and an antistatic agent.

[0012] <Layer configuration> The cover tape according to the first embodiment has at least an antistatic layer, a base layer, and a heat seal layer in this order.

[0013] <Base material layer> The substrate layer is a layer containing a thermoplastic resin, and is preferably made of a film formed from a thermoplastic resin. The thermoplastic resin constituting the substrate layer is preferably a polyester resin such as polyethylene terephthalate or polyethylene naphthalate, a polyolefin resin such as polypropylene, a polycarbonate resin, etc. The substrate layer is more preferably made of a biaxially stretched film.

[0014] The average thickness of the base material layer is generally set arbitrarily within the range of 5 to 50 μm, taking into consideration the mechanical properties of the cover tape, etc. In one embodiment, the average thickness of the base material layer is preferably 5 to 30 μm, more preferably 8 to 20 μm, and even more preferably 10 to 16 μm. The layer thickness was measured by cutting 20 mm square pieces from five equally spaced locations across the width of the cover tape, smoothing the edges so that the layer structure could be determined, and then using a laser microscope (Keyence Corporation: VK-8510). The average thickness of the cover tape refers to the average thickness from one surface of the cover tape to the other. The average thickness of each layer of the cover tape was measured at five locations for each layer, and the arithmetic mean value was used as the average thickness.

[0015] At least one surface of the substrate layer may be surface-treated. Examples of the surface treatment include sandblasting, corona discharge treatment, and plasma treatment. In one embodiment, the surface of the substrate layer on which the antistatic layer is laminated is preferably surface-treated. By surface-treating the substrate layer, the adhesive strength between the substrate layer and the antistatic layer is likely to be improved. The substrate layer may have an anchor coat layer on the surface of the antistatic layer and / or the surface of the heat seal layer. The anchor coat layer can be formed by applying any anchor coat agent. Examples of the anchor coat agent include polyurethane resins, polyester resins, and polyolefin resins.

[0016] <Heat seal layer> The heat-seal layer contains a thermoplastic resin that has heat-sealability to the carrier tape and exhibits easy peelability, allowing for easy peeling during use. Preferred thermoplastic resins contained in the heat-seal layer include ethylene-based resins such as polyethylene (e.g., low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), very low-density polyethylene (VLDPE)), ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-butene-1 random copolymer; and styrene-based resins such as styrene-butadiene copolymer (SB), styrene-butadiene-styrene block copolymer (SBS) or its hydrogenated product (SEBS), polystyrene (PS), styrene-butadiene copolymer (SBC), and high-impact polystyrene (HIPS). These thermoplastic resins may be used alone or in combination.

[0017] In one embodiment, the heat seal layer preferably contains a styrene-based resin as a main component. In the present disclosure, "containing a styrene-based resin as a main component" refers to containing more than 50% by mass of the styrene-based resin relative to the total amount (100% by mass) of all resin components. The proportion of the styrene-based resin in the heat seal layer is preferably more than 50% by mass and not more than 100% by mass, more preferably 70 to 100% by mass, and particularly preferably more than 70% by mass and not more than 100% by mass. In a preferred embodiment, the heat seal layer more preferably contains at least one styrene-based resin selected from SB, SEBS, and SBC as a main component.

[0018] The average thickness of the heat seal layer is generally set from the viewpoint of heat sealing properties with the carrier tape. In the cover tape according to the first embodiment, the average thickness of the heat seal layer is preferably 1 to 25 μm, more preferably 2 to 20 μm, and more preferably 3 to 15 μm.

[0019] In one embodiment, the heat seal layer may contain one or more antistatic agents, which will be described later. When the heat seal layer contains an antistatic agent, the heat seal layer has both heat sealability and antistatic properties.

[0020] <Antistatic layer> The antistatic layer is a layer provided on the surface of the base layer opposite the heat seal layer. The antistatic layer contains an antistatic agent and an acid-modified olefin resin as a binder resin. The inclusion of the antistatic layer imparts an antistatic effect to the cover tape, making it easier to prevent insulation breakdown of electronic components due to static electricity and preventing dust from adhering to the cover tape surface due to static electricity. The total content of the acid-modified olefin resin and the antistatic agent in the antistatic layer is preferably 50% by mass or more, may be 65% by mass or more, may be 75% by mass or more, may be 90% by mass or more, or may be 100% by mass. The average thickness of the antistatic layer is preferably from 0.05 to 2.0 μm, more preferably from 0.1 to 1.0 μm, and even more preferably from 0.1 to 0.5 μm.

[0021] As the acid-modified olefin resin, for example, a copolymer having a structure in which an unsaturated carboxylic acid is randomly copolymerized or graft copolymerized with an olefin resin is preferably used. Specific examples of the olefin resin that forms the skeleton of the acid-modified olefin resin include low-density polyethylene, high-density polyethylene, polypropylene, ethylene-butene-1 copolymer, ethylene-propylene copolymer, and polybutadiene. The unsaturated carboxylic acid is an unsaturated carboxylic acid having at least one radically polymerizable bond (particularly a double bond) and at least one carboxyl group in one molecule, and an anhydride thereof. Specific examples thereof include acrylic acid, acrylic acid esters such as ethyl acrylate and butyl acrylate, methacrylic acid, methacrylic acid esters such as ethyl methacrylate and butyl methacrylate, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, aconitic acid, aconitic anhydride, fumaric acid, crotonic acid, citraconic acid, etc. The acid-modified olefin resin may contain two or more compounds as unsaturated carboxylic acids, and maleic anhydride and ethyl acrylate are preferred. When maleic anhydride and ethyl acrylate are contained, the molar ratio of maleic anhydride to ethyl acrylate is preferably 1:2 to 1:25, more preferably 1:3 to 1:20, and even more preferably 1:4 to 1:8.

[0022] The proportion of the acid-modified component in the acid-modified olefin resin is preferably 0.5 to 10 mol %, more preferably 0.8 to 5 mol %, and even more preferably 1 to 2 mol %, from the viewpoint of improving adhesion to the base layer.

[0023] The melting point of the acid-modified olefin resin is preferably 70 to 130° C., more preferably 80 to 120° C., and even more preferably 98 to 110° C. In one embodiment, the melting point of the acid-modified olefin resin is preferably 98° C. or higher.

[0024] Acid-modified olefin resins can be produced by polymerizing a specific monomer using known methods such as interfacial polymerization, solution polymerization, and suspension polymerization. Alternatively, they can be commercially available in the form of an aqueous emulsion using water as the main dispersion medium or a solution using an organic solvent as the main solvent. From the viewpoint of environmental compatibility, it is preferable to use an acid-modified olefin resin in the form of an aqueous emulsion. Aqueous emulsions of acid-modified olefin resins can be produced, for example, by methods described in Japanese Patent Nos. 3699935 and 3759160. Examples of commercially available products include "Arrowbase (registered trademark)" manufactured by Unitika Ltd., product numbers SA-1200, SB-1200, SE-1200, and SB-1010. These commercially available products are aqueous emulsions of acid-modified olefin resins. As the acid-modified olefin resin, two or more types of acid-modified olefin resins having different compositions, molecular weights and / or melting points may be used, as long as each of the two or more types of acid-modified olefin resins is within the above-mentioned ranges.

[0025] The antistatic agent is selected from the viewpoint of easily achieving the surface resistivity required for the cover tape. In one embodiment, the antistatic agent may be selected from magnesium silicate, metal oxide particles, carbon nanotubes, etc. Examples of metal oxide particles include tin oxide, zinc oxide, indium oxide, titanium oxide, aluminum oxide, and antimony-doped tin oxide (ATO). The average particle size of the antistatic agent is preferably 0.01 to 1 μm, more preferably 0.01 to 0.5 μm, and even more preferably 0.01 to 0.2 μm. The value at 50% cumulative volume determined from the volume particle size distribution curve obtained from a laser diffraction particle size analyzer (e.g., "LS-230" manufactured by Beckman Coulter) can be used as the average particle size of the antistatic agent. Examples of carbon nanotubes include single-walled carbon nanotubes (SWCNTs) formed from one layer of graphene, and multi-walled carbon nanotubes (MWCNTs) formed from two or more layers of graphene (e.g., 2 to 20 layers, typically 2 to 60 layers).

[0026] When magnesium silicate or metal oxide particles are used, the mass ratio of the acid-modified olefin resin to the antistatic agent in the antistatic layer is preferably 1:9 to 5:5, more preferably 1:9 to 4:6, and even more preferably 1:9 to 3:7. When carbon nanotubes are used, the mass ratio of the acid-modified olefin resin to the antistatic agent in the antistatic layer is preferably 70:30 to 99:1, more preferably 80:20 to 98:2, and even more preferably 90:10 to 97:3.

[0027] The antistatic layer may further contain a wax, and examples of the wax that can be suitably used include plant-derived carnauba wax, rice wax, candelilla wax, petroleum-derived paraffin wax, microcrystalline wax, and synthetic waxes such as olefin wax, ester wax, ketone wax, and amide wax, or a combination thereof. The content of wax relative to the total components constituting the antistatic layer is preferably 5 to 50% by mass, more preferably 5 to 40% by mass, and even more preferably 5 to 20% by mass. The average particle size of the wax is preferably less than 4 μm, more preferably 0.05 to 3.5 μm, and even more preferably 0.08 to 3.2 μm. The particle size at 50% cumulative volume measured using the Cole counter method can be used as the average particle size of the wax. When using a commercially available wax, the catalog value can be used as the average particle size.

[0028] In one embodiment, the cover tape comprises, in order, an antistatic layer, a substrate layer, an intermediate layer, a heat seal layer, and an antistatic heat seal layer.

[0029] <Middle class> The intermediate layer can be provided for the purpose of strengthening the adhesive strength between the base layer and the heat seal layer, and can contain a thermoplastic resin. Examples of the thermoplastic resin include: (i) Polyethylene resins such as low-density polyethylene, linear low-density polyethylene, and ultra-low-density polyethylene (ii) Ethylene-1-butene, copolymers of ethylene and unsaturated carboxylic acids, ethylene-(meth)acrylic acid ester copolymers, ethylene-vinyl acetate copolymers, and terpolymers further containing acid anhydrides, and mixtures thereof (iii) Styrene-ethylene graft copolymers, styrene-propylene graft copolymers, styrene-ethylene-butadiene block copolymers, and mixtures thereof etc.

[0030] The thermoplastic resin used for the intermediate layer is preferably a polyethylene resin, more preferably a low-density polyethylene resin or a linear low-density polyethylene resin, for the above-mentioned purposes and because the layer can be easily formed.

[0031] The intermediate layer may have a two or more layer structure. In this case, by producing a co-extruded film of a heat seal layer and an intermediate layer, the extrusion stability of the heat seal layer can be improved, while the adhesion between the co-extruded film and the base layer can be improved by the use of another intermediate layer. An intermediate layer having a two or more layer structure may have, for example, a first intermediate layer on the side in contact with the heat seal layer containing one or more of the resins shown in (i), (ii), and (iii) above, and a second intermediate layer on the side in contact with the base layer containing one or more of the resins shown in (i) and (ii) above. The intermediate layer can be formed by a general method.

[0032] In order to ensure extrusion stability during film formation, various additives such as commonly used antioxidants and lubricants may be added to the intermediate layer.

[0033] The thickness of the intermediate layer may be 3 to 70 μm, 5 to 60 μm, or 10 to 50 μm, from the viewpoint of ensuring the adhesive strength between the base layer and the heat seal layer and the peel strength of the cover tape.

[0034] The thermoplastic resin (ii) or (iii) may be used as an anchor coating agent, and in that case, the average thickness of the layer is preferably 50 to 7000 nm, more preferably 100 to 5000 nm.

[0035] <Antistatic heat seal layer> The cover tape according to the first embodiment may further include an antistatic heat seal layer. The antistatic heat seal layer may be provided on the heat seal layer. By providing the antistatic heat seal layer, the cover tape can be provided with an antistatic effect, which makes it easier to prevent static breakdown of electronic components. Note that if the heat seal layer contains an antistatic agent, it is not necessary to provide an antistatic heat seal layer on the heat seal layer.

[0036] The antistatic heat seal layer is a layer containing an antistatic agent. The antistatic agent is selected from the viewpoint of easily achieving the surface resistivity and transmittance required for the cover tape. In one embodiment, the antistatic agent may be selected from conductive particles such as barium sulfate, tin oxide, zinc oxide, indium oxide, titanium oxide, aluminum oxide, and antimony-doped tin oxide (ATO); ionic liquids containing cyclic quaternary nitrogen-containing cations; cationic surfactants such as quaternary ammonium salts; polyalkylene oxides (e.g., polyethylene glycol, polypropylene glycol, polybutylene glycol, ethylene oxide-propylene oxide copolymer, etc.), polyether esters having a polyoxyalkylene structure and an ester bond, and the like.

[0037] As the ionic liquid containing a cyclic quaternary nitrogen-containing cation (hereinafter simply referred to as "ionic liquid"), from the viewpoint of easily achieving the above-mentioned transmittance and easily imparting the desired antistatic properties, for example, 1,3-dimethylimidazolium ethyl sulfate, 1-ethyl-3-methylimidazolium ethyl sulfate, 1-ethyl-3-methylimidazolium acetate, 1-butyl-3-dimethylimidazolium phosphate, 1,3-dimethylimidazolium hydrozine sulfate, etc. can be used.

[0038] As the quaternary ammonium salt, from the viewpoint of easily achieving the aforementioned transmittance and easily imparting the desired antistatic properties, for example, trimethyl lauryl ammonium methyl sulfate, ethyl dimethyl stearyl ammonium ethyl sulfate, ethyl dimethyl oleyl ammonium ethyl sulfate, ethyl dimethyl lauryl ammonium ethyl sulfate, ethyl dimethyl stearyl ammonium metasulfonium, ethyl dimethyl lauryl ammonium metasulfonium, etc. can be used.

[0039] The antistatic heat seal layer may further contain the antistatic agent and a binder resin, which may be a polyurethane resin, an acrylic resin, a polyvinyl chloride resin, an ethylene-vinyl acetate resin, a polyester resin, a butadiene resin, a styrene resin including a hydrogenated resin, an acrylic-modified polyester resin, or the like, used alone or in combination.

[0040] When the cover tape includes an antistatic heat seal layer, it preferably contains at least one selected from an ionic liquid, ATO, and alumina oxide. When the above-mentioned preferable antistatic agent is blended, the proportion of the antistatic agent is preferably 90% by mass or less based on the total mass of the resin composition constituting the antistatic heat seal layer.

[0041] The average thickness of the antistatic heat seal layer is preferably 0.01 to 2.0 μm, more preferably 0.1 to 0.7 μm, from the viewpoint of easily achieving both antistatic properties and the above-mentioned transmittance.

[0042] (Total thickness of cover tape) The total thickness of the cover tape according to the first embodiment is preferably 40 to 65 μm, from the viewpoint of easily achieving the physical properties required of the cover tape, and may also be 40 to 60 μm, 45 to 60 μm, or 45 to 55 μm.

[0043] (surface resistivity of cover tape) In one embodiment, the surface resistivity of the antistatic layer side of the cover tape measured in accordance with JIS K6911 at an atmospheric temperature of 23°C, an atmospheric humidity of 50% RH, and an applied voltage of 10 V is 1×10 5 ~1×10 12 Ω / □ is preferred, and 2.5×10 5 ~5×10 11 Ω / □ is more preferable, and 5×10 5 ~5×10 10 It is more preferably Ω / □. After the friction test, the surface resistivity of the antistatic layer side of the cover tape was 1×10 13 It is preferable that the resistance is Ω / □ or less, and 1×10 10 It is more preferable that it is Ω / □ or less, and 1×10 8 It is more preferable that it is Ω / □ or less. Furthermore, the ratio of the surface resistivity of the antistatic layer side of the cover tape "after friction test" to "before friction test" ("after friction test" / "before friction test") is preferably 100 or less, more preferably 10 or less, and even more preferably 5 or less. The surface resistivity before and after the friction test can be measured as follows. As with the surface resistivity evaluation of the cover tape, the surface resistivity is measured at an ambient temperature of 23°C and an ambient humidity of 50%RH (this value is referred to as "before the friction test"). Next, at the measurement point, a 2 kg weight (shaped like a 70 mm diameter cylinder) is applied to a paper cloth, and the paper cloth and weight are moved back and forth once to rub the surface (friction test). As with the before the friction test, the surface resistivity after the friction test is measured (this value is referred to as "after the friction test").

[0044] The cover tape of the present disclosure exhibits antistatic properties even in a low-humidity environment. In one embodiment, the surface resistivity of the antistatic layer side of the cover tape measured in accordance with JIS K6911 at an ambient temperature of 23°C, an ambient humidity of 12% RH (low-humidity environment), and an applied voltage of 10 V is 1×10 5 ~5×10 13 Ω / □ is preferred, and 2.5×10 5 ~2.5×10 13 Ω / □ is more preferable, and 5×10 5 ~1×10 13 It is more preferably Ω / □.

[0045] <Cover tape manufacturing method> The cover tape according to the first embodiment can be manufactured by laminating the aforementioned layers (e.g., antistatic layer, base layer, and heat seal layer). Hereinafter, one embodiment of a method for manufacturing a cover tape having an antistatic layer, a base layer, an intermediate layer, a heat seal layer, and an antistatic heat seal layer will be described.

[0046] The manufacturing method according to this embodiment includes laminating an antistatic layer, a substrate layer, an intermediate layer, a heat seal layer, and an antistatic heat seal layer. This preferably includes selecting a thermoplastic resin for each layer. The lamination method is not particularly limited, and a conventional method can be used. For example, a resin composition constituting the intermediate layer and a resin composition constituting the heat seal layer are extruded from separate single-screw extruders and laminated using a multi-manifold die to form a two-layer film consisting of the intermediate layer and the heat seal layer. Furthermore, a substrate layer coated with an anchor coating agent on its surface and the two-layer film are laminated by dry lamination to form a three-layer film consisting of the substrate layer, the intermediate layer, and the heat seal layer. A second intermediate layer may be formed between the substrate layer and the two-layer film. The antistatic layer is then formed by applying the resin composition constituting the antistatic layer to the surface of the substrate layer using, for example, a gravure coater, reverse coater, kiss coater, air knife coater, Mayer bar coater, or dip coater. Furthermore, before applying the resin composition constituting the antistatic layer, it is preferable to subject the surface of the base layer to corona discharge treatment or ozone treatment, and corona discharge treatment is particularly preferable. Furthermore, the antistatic heat seal layer is formed by applying the resin composition constituting the antistatic heat seal layer to the surface of the heat seal layer using, for example, a gravure coater, a reverse coater, a kiss coater, an air knife coater, a Mayer bar coater, a dip coater, or the like.

[0047] Alternatively, a three-layer film consisting of a heat-sealing layer formed by a T-die casting method or an inflation method, a substrate layer coated with an anchor coating agent on its surface, and an intermediate layer formed by a T-die casting method may be sandwiched by lamination to form the substrate layer, intermediate layer, and heat-sealing layer. Furthermore, an antistatic layer and an antistatic heat-sealing layer are formed in the same manner as described above.

[0048] [Application] The cover tape according to the first embodiment can be used as a cover tape for an electronic component package.

[0049] [Electronic component packaging] A second embodiment of the present disclosure relates to an electronic component packaging body. A package containing electronic components, etc. (hereinafter referred to as "electronic component package") can be obtained, for example, by placing the electronic components, etc. in recesses in a carrier tape for storing the electronic components, etc., using a cover tape as a lid, continuously heat-sealing both longitudinal edges of the cover tape using a heat iron or the like to package the components, and then winding the package onto a reel. Packaged in this manner, the electronic components, etc. are stored and transported. The electronic component package according to the second embodiment can be used to store and transport various electronic components, such as connectors, ICs, diodes, transistors, capacitors, resistors, and LEDs. Because the electronic component package according to the second embodiment includes the cover tape, it is easy to prevent the antistatic layer from falling off and becoming mixed in as foreign matter.

[0050] The electronic component package is transported using holes called sprocket holes for transporting the carrier tape, which are provided on the longitudinal edge of the carrier tape, while the cover tape is intermittently peeled off.The electronic components are then removed using a component mounting device, while checking the presence, orientation, and position of the electronic components, and are then mounted on a board.

[0051] The carrier tape included in the electronic component packaging according to the second embodiment is a strip-shaped material approximately 4 mm to 100 mm wide and having a recess for storing electronic components. When the cover tape according to the first embodiment is heat-sealed as a lid, the material of the carrier tape is not particularly limited, but carrier tapes containing polystyrene-based resins, polyester-based resins, or polycarbonate-based resins are suitable. The carrier tape may be imparted with conductivity by kneading carbon black or carbon nanotubes into the resin; or may be kneaded with a surfactant-type antistatic agent such as a cationic, anionic, or nonionic agent, or a persistent antistatic agent such as polyether ester amide; or may be imparted with antistatic properties by coating the surface with a coating liquid in which a surfactant-type antistatic agent or a conductive material such as polypyrrole or polythiophene is dispersed in an organic binder such as acrylic.

[0052] Furthermore, electronic component packages are inspected by an IR camera through the cover tape to detect defects in the electronic components contained therein and to recognize circuits printed on the electronic components. The cover tape according to the first embodiment has high transmittance in the near-infrared range, and therefore has good visibility with an IR camera.

[0053] A non-limiting list of exemplary embodiments and combinations of exemplary embodiments of the present disclosure are set forth below. [1] A cover tape having a base layer, a heat seal layer, and an antistatic layer on the surface of the base layer opposite to the heat seal layer, The cover tape, wherein the antistatic layer contains an acid-modified olefin resin and an antistatic agent. [2] The cover tape according to [1], wherein the acid-modified olefin resin is an olefin resin acid-modified with an unsaturated carboxylic acid component. [3] The cover tape according to [1] or [2], wherein the melting point of the acid-modified olefin resin is 98°C or higher. [4] The cover tape according to any one of [1] to [3], wherein the mass ratio of the acid-modified olefin resin to the antistatic agent in the antistatic layer is 1:9 to 5:5. [5] A cover tape according to any one of [1] to [4], wherein the antistatic agent contains at least one material selected from the group consisting of magnesium silicate, metal oxide particles, and carbon nanotubes. [6] The surface resistivity of the antistatic layer side is 10 under an atmosphere of 23°C x 12% RH. 13 The cover tape according to any one of [1] to [5], having a resistance of Ω / □ or less. [7] The cover tape according to any one of [1] to [6], wherein the antistatic layer further contains wax. [8] The cover tape according to [7], wherein the wax has an average particle size of less than 4 μm. [9] A cover tape according to any one of [1] to [8], which has, in this order, an antistatic layer, a base layer, an intermediate layer, a heat seal layer, and an antistatic heat seal layer.

[10] The cover tape according to any one of [1] to [9], which is for use in packaging for electronic components.

[11] An electronic component packaging body comprising the cover tape according to any one of [1] to

[10] . [Example]

[0054] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following description.

[0055] The various raw materials used in the examples are as follows: <Antistatic layer> Antistatic agent 1: Magnesium silicate "Laponite S482" (BYK), flake-shaped (short side: 1 nm, long side: 25 nm) Antistatic agent 2: Tin oxide "Ceramace S-8" (manufactured by Taki Chemical Industry Co., Ltd.), aqueous dispersion Antistatic agent 3: Phosphorus-doped tin oxide "9747SN" (Tokushiki Co., Ltd.), aqueous dispersion Antistatic agent 4: Antimony-doped tin oxide (ATO) "TDL-1" (Mitsubishi Materials Electronic Chemicals Co., Ltd.), water dispersion, average particle size 0.1 μm Antistatic agent 5: Carbon nanotube "HW002B" (KJ Specialty Paper Co., Ltd.), single-wall carbon nanotube water dispersion, concentration 0.2% by mass Acid-modified olefin resin 1: "Arrowbase (registered trademark) SD-1200" (manufactured by Unitika Ltd.), water dispersion, melting point 105°C Acid-modified olefin resin 2: "Arrowbase (registered trademark) SA-1200" (manufactured by Unitika Ltd.), water dispersion, melting point 100°C Acid-modified olefin resin 3: "Arrowbase (registered trademark) SE-1200" (manufactured by Unitika Ltd.), water dispersion, melting point 95°C Acid-modified olefin resin 4: "Arrowbase (registered trademark) SB-1200" (manufactured by Unitika Ltd.), water dispersion, melting point 85°C Acrylic resin 1: Acrylic copolymer water dispersion "NK Polymer EC-242" (manufactured by Shin-Nakamura Chemical Co., Ltd.) Polyester resin 1: Polyester water dispersion, "Elite® KA-3556" (manufactured by Unitika Ltd.) Wax 1: "Polylon L-618" (manufactured by Chukyo Yushi Co., Ltd.), olefin wax water dispersion, average particle size 0.1 μm Wax 2: "Chemipearl W-100" (Mitsui Chemicals), olefin wax water dispersion, average particle size 3.0 μm (Coulter counter method) Wax 3: "Chemipearl W-400" (Mitsui Chemicals), olefin wax water dispersion, average particle size 4.0 μm (Coulter counter method) Thickness: 0.2 μm

[0056] <Base material layer> Polyester resin: Biaxially oriented polyethylene terephthalate "Ester Film E5100" (manufactured by Toyobo Co., Ltd.) Thickness: 16 μm Anchor coating agent: Polyurethane resin (a reaction product of polyester resin ("LIOSTAR1000", manufactured by Artience (main agent)) and a curing agent ("LIOSTAR500H", manufactured by Artience) containing hexamethylene diisocyanate / isophorone diisocyanate as the main components)

[0057] <Middle class> Ethylene resin 1: Linear low-density polyethylene "Yumerit 0540F" (manufactured by Ube Maruzen Polyethylene Co., Ltd.) Thickness: 20 μm

[0058] <Heat seal layer> Styrene-based resin 1: Styrene-butadiene rubber "TR" (manufactured by ENEOS Materials Co., Ltd.) Styrene-based resin 2: Styrene-butadiene copolymer "Clearen" (manufactured by Denka) Styrene-based resin 3: High-impact polystyrene "HIPS E640N" (manufactured by Toyo Styrene Co., Ltd.) Ethylene-based resin 2: Ethylene-1-butene copolymer "Tafmer A" manufactured by Mitsui Chemicals, Inc. Thickness: 5 μm

[0059] <Antistatic heat seal layer> Antistatic agent 6: Antimony-doped tin oxide "SN-100D" (manufactured by Ishihara Sangyo Kaisha) Acrylic resin 2: Acrylic copolymer "NK Polymer EC-242" (manufactured by Shin-Nakamura Chemical Co., Ltd.), glass transition temperature 60°C Thickness: 0.2 to 0.5 μm

[0060] [Example 1] The cover tape of Example 1 was obtained using the resins listed in Table 1. Specifically, the resin composition for the heat-seal layer was obtained by kneading and extruding the resins at 210°C using a single-screw extruder. This resin composition and the polyethylene resin constituting the intermediate layer were extruded from separate single-screw extruders and laminated and extruded at 225°C using a multi-manifold T-die extruder to obtain a two-layer film with a heat-seal layer thickness of 5 μm and an intermediate layer thickness of 20 μm. On the other hand, a two-component curing polyurethane anchor coating agent was applied to a biaxially oriented polyethylene terephthalate film (thickness 16 μm) constituting the base layer using a roll coater, and the coated surface was bonded to the surface of the intermediate layer side of the above-mentioned two-layer film to obtain a laminated film. Further, an antistatic layer was coated on the base layer and dried, and further, an antistatic heat seal layer was coated on the heat seal layer and dried to obtain a cover tape.

[0061] [Examples 2-11, Comparative Examples 1-6] The materials were changed as shown in Table 1, but the method was the same as in Example 1.

[0062] <Evaluation method> The cover tapes produced in each of the Examples and Comparative Examples were evaluated as follows, and the results are shown in Table 1. (1) Measurement of the surface resistivity of the cover tape Using a Hiresta UX MCP-HT800 manufactured by Nitto Seiko Analytech Co., Ltd., the surface resistivity of the surface of the antistatic layer of the cover tape was measured according to the method of JIS K6911 at an ambient temperature of 23°C, an ambient humidity of 50% RH or 12% RH (low humidity environment), and an applied voltage of 10 V (500 V was used if surface resistivity was not obtained).

[0063] (2) Evaluation of adhesion between the base layer and the antistatic layer The surface resistivity was measured at an ambient temperature of 23°C and an ambient humidity of 50% RH, and this value was designated "before the friction test." Next, at the measurement location, a load was applied using a 2 kg weight (shaped like a cylinder with a diameter of 70 mm) to a JK Wiper "150-S" (paper cloth) manufactured by Nippon Paper Crecia Co., Ltd., and the paper cloth and the weight were moved back and forth once to rub the surface, and then the surface resistivity was measured in the same manner as before the friction test, and this value was designated "after the friction test." The evaluation criteria for adhesion are as follows: Good: Both the measured values ​​"before friction test" and "after friction test" are 10 13Ω / □ or less, and the ratio of "after friction test" to "before friction test" ("after friction test" / "before friction test") is 100 or less Pass: Both the measured values ​​"before friction test" and "after friction test" are 10 13 Ω / □ or less, and the ratio of "after friction test" to "before friction test" ("after friction test" / "before friction test") is greater than 100 Unacceptable: The measurement value of "After friction test" is 10 14 Ω / □ or more

[0064] [Table 1]

[0065] As shown in Table 1, the cover tapes of Examples 1 to 11 obtained results of "good" or "fair" in the adhesion evaluation, and the surface resistivity was 10 13 It was confirmed that the resistance was Ω / □ or less. On the other hand, in Comparative Examples 1 to 4, in which a resin other than an acid-modified olefin resin was used as the resin for the antistatic layer, it was confirmed that the antistatic layer fell off due to the friction test, and the surface resistivity after the friction test was higher than that before the friction test. In Comparative Example 5, in which the antistatic layer did not contain an antistatic agent, the surface resistivity was high even before the friction test. In Comparative Example 6, in which the antistatic layer did not contain a binder resin, the antistatic layer peeled off during the friction test, and it was confirmed that the surface resistivity after the friction test was higher than that before the friction test.

Claims

1. A cover tape having a base layer, a heat seal layer, and an antistatic layer on a surface of the base layer opposite to the heat seal layer, The cover tape, wherein the antistatic layer contains an acid-modified olefin resin and an antistatic agent.

2. The cover tape according to claim 1 , wherein the acid-modified olefin resin is an olefin resin acid-modified with an unsaturated carboxylic acid component.

3. The cover tape according to claim 1 or 2, wherein the acid-modified olefin resin has a melting point of 98°C or higher.

4. 2. The cover tape according to claim 1, wherein the mass ratio of the acid-modified olefin resin to the antistatic agent in the antistatic layer is 1:9 to 5:

5.

5. 3. The cover tape according to claim 1, wherein the antistatic agent contains at least one material selected from the group consisting of magnesium silicate, metal oxide particles, and carbon nanotubes.

6. The surface resistivity of the antistatic layer side under an atmosphere of 23°C x 12% RH is 10 １３ The cover tape according to claim 1 or 2, having a resistance of Ω / □ or less.

7. The cover tape of claim 1 or 2, wherein the antistatic layer further comprises a wax.

8. The cover tape of claim 7 , wherein the wax has an average particle size of less than 4 μm.

9. The cover tape according to claim 1 or 2, comprising the antistatic layer, the base material layer, the intermediate layer, the heat seal layer, and an antistatic heat seal layer in this order.

10. The cover tape according to claim 1 or 2, which is for use in packaging for electronic components.

11. An electronic component package comprising the cover tape according to claim 1 or 2.

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