Tape and packaging for electronic components, including this tape.

Abstract

The invention relates to an environmentally friendly covering tape containing a predetermined amount of biomass-derived resin and capable of achieving mechanical properties equivalent to those of conventional covering tapes, as well as packaging for electronic components incorporating such a covering tape. This covering tape consists of a substrate layer, a core layer, and a heat-sealed layer laminated in this order, the core layer containing a linear low-density polyolefin resin (A) and a polyolefin resin (B) different from resin (A), the proportion of the biomass-derived low-density polyolefin resin (a1) to the total mass of resin (A) is between 0 and 50% by mass, and the proportion of the biomass-derived polyolefin resin (b1) to the total mass of resin (B) is between 50 and 100% by mass.

Description

Cover tape and electronic component packaging including same

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

[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] In recent years, with the growing demand for the creation of a recycling-oriented society, there has been a desire to move away from fossil fuels in the materials field, just as there is in energy, and the use of biomass has attracted attention. Biomass is an organic compound photosynthesized from carbon dioxide and water, and is a so-called "carbon-neutral" renewable energy source. Recently, the practical application of biomass plastics (biomass-derived resins) made from these biomass raw materials has been rapidly progressing, and the replacement of petroleum-derived resins with biomass-derived resins is also being considered for cover tapes and carrier tapes for electronic component packaging. For example, Patent Document 1 proposes a cover film having a layer containing a polylactic acid polymer.

[0004] Special Publication No. 2022-527487

[0005] The inventors of the present application conducted research into cover tapes containing biomass-derived resins and found that simply replacing petroleum-derived resins with biomass-derived resins would not satisfy the mechanical properties required of cover tapes.

[0006] Therefore, an object of the present invention is to provide an environmentally friendly cover tape that contains a certain amount of biomass-derived resin and can achieve mechanical properties equivalent to those of conventional cover tapes, as well as an electronic component packaging body that includes the same.

[0007] As a result of intensive research into the above-mentioned problems, the inventors of the present application have surprisingly found that a cover tape comprising a base material layer, a support layer, and a heat seal layer laminated in this order, wherein the support layer comprises a linear low-density polyolefin resin (A) and a polyolefin resin (B) other than the resin (A), wherein the proportion of the biomass-derived linear low-density polyolefin resin (a1) relative to the total mass of the resin (A) is 0 to 50 mass%, and the proportion of the biomass-derived polyolefin resin (b1) relative to the total mass of the resin (B) is 50 to 100 mass%, can achieve mechanical properties equivalent to those of conventional cover tapes while containing a certain amount of biomass-derived resin.

[0008] According to the present invention, it is possible to provide an environmentally friendly cover tape that contains a certain amount of biomass-derived resin and that can achieve mechanical properties equivalent to those of conventional cover tapes, as well as an electronic component packaging body that includes the cover tape.

[0009] 1 is a cross-sectional view showing an example of a cover tape according to the present embodiment; 2 is a cross-sectional view showing a layer structure of a cover tape described in Examples;

[0010] 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.

[0011] 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.

[0012] [Cover Tape] The first embodiment of the present disclosure relates to a cover tape. The cover tape comprises a substrate layer, a support layer, and a heat seal layer laminated in this order. The support layer comprises a linear low-density polyolefin resin (A) and a polyolefin resin (B) other than the resin (A), wherein the proportion of the biomass-derived linear low-density polyolefin resin (a1) relative to the total mass of the resin (A) is 0 to 50 mass% and the proportion of the biomass-derived polyolefin resin (b1) relative to the total mass of the resin (B) is 50 to 100 mass%. The cover tape according to the first embodiment is an environmentally friendly cover tape that contains a certain amount of biomass-derived resin, yet can achieve mechanical properties equivalent to those of conventional cover tapes. In the cover tape according to the first embodiment, "achieving mechanical properties equivalent to those of conventional cover tapes" includes achieving lamination strength and tape tear strength equivalent to those of conventional cover tapes that do not contain biomass-derived components.

[0013] 1, the cover tape according to the first embodiment has a structure in which a base material layer 1, a support layer 2, and a heat seal layer 3 are laminated in this order. By blending a biomass-derived resin (a1) and / or a biomass-derived resin (b1) into the support layer 2, the above-mentioned problems can be solved.

[0014] <Base Material Layer> The cover tape according to the first embodiment includes a base material layer. The base material layer preferably has mechanical strength and heat resistance sufficient to withstand external stress and thermal history during the manufacture of the cover tape and the manufacture of the electronic component packaging. In addition, the material constituting the base material layer is preferably in a film-like form for ease of processing.

[0015] The above-described characteristics of the substrate layer can be adjusted by appropriately selecting the material constituting the substrate layer. Specific examples of materials constituting the substrate layer include polyester-based resins, polyamide-based resins, polyolefin-based resins, polyacrylate-based resins, polymethacrylate-based resins, polyimide-based resins, polycarbonate-based resins, and acrylonitrile-butadiene-styrene (ABS) resins. Among these, polyester-based resins and polyamide-based resins are preferred from the viewpoint of improving the mechanical properties and flexibility of the cover tape according to the first embodiment. The substrate layer may further contain additives such as lubricants.

[0016] The substrate layer may be a single-layer film containing the above-mentioned materials, or a multilayer film containing the above-mentioned materials in each layer. The film used to form the substrate layer may be an unstretched film, or a uniaxially or biaxially stretched film. In one embodiment, from the viewpoint of easily improving the mechanical strength of the cover tape, a uniaxially or biaxially stretched film is preferred, and a biaxially stretched film (biaxially stretched film) is more preferred. In a particularly preferred embodiment, the substrate layer is a biaxially stretched polyethylene terephthalate film. In one embodiment, from the viewpoint of obtaining a cover tape with a high biomass content, the substrate layer may contain biomass-derived polyethylene terephthalate.

[0017] The thickness of the base material layer is preferably 12 to 25 μm from the viewpoint of easily achieving good lamination strength of the cover tape and good heat sealability with the carrier tape. The thickness of the base material layer can be appropriately adjusted within the above range.

[0018] In one embodiment, the substrate layer may be one to which an antistatic agent is applied or kneaded for antistatic treatment, or one to which a corona treatment or an easy-adhesion treatment is applied. In a preferred embodiment, an antistatic layer may be provided on the surface of the substrate layer on the side on which the support layer is not laminated. Hereinafter, the antistatic layer provided on the surface of the substrate layer on the side on which the support layer is not laminated will be referred to as "antistatic layer I."

[0019] (Antistatic Layer (I)) The antistatic layer (I) may contain a binder resin and an antistatic agent (hereinafter, the binder resin and antistatic agent contained in the antistatic layer (I) will be referred to as "binder resin (I)" and "antistatic agent (I)"). The antistatic agent (I) may be selected from inorganic antistatic agents; conductive fine 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.), polyalkylene glycols such as polyether esters having a polyoxyalkylene structure and an ester bond, and the like. Of these, it is preferable that the antistatic agent (I) contains an inorganic antistatic agent, from the viewpoint of easily controlling the surface resistivity of the substrate layer side within a suitable range and easily producing a cover tape with fewer petroleum-derived components. Examples of inorganic antistatic agents include magnesium silicate, smectite, montmorillonite, beidellite, nontronite, hectorite, and savonite, or a combination thereof. Of these, magnesium silicate is preferred. The inorganic antistatic agent is preferably contained in an amount of 40 to 80% by mass relative to the total (100% by mass) of all components constituting the antistatic layer (I).

[0020] Examples of the binder resin (I) include thermoplastic resins selected from the group consisting of polyurethane resins, acrylic resins, polyvinyl chloride resins, ethylene-vinyl acetate resins, polyester resins, butadiene resins, styrene resins, acrylic-modified polyester resins, polyolefin resins, and combinations thereof. Among these, polyester resins or polyolefin resins are preferred, and it is preferable to include a polyethylene resin. When a polyethylene resin is used as the binder resin (I), a biomass-derived polyethylene resin (e.g., a biomass-derived low-density polyethylene resin, etc., as described below) may be used as the polyethylene resin.

[0021] The thickness of the antistatic layer I is preferably 0.1 to 1.0 μm from the viewpoint of easily achieving a desired surface resistivity.

[0022] <Support Layer> The cover tape according to the first embodiment includes a support layer provided on a substrate layer. The support layer includes a linear low-density polyolefin resin (A) and a polyolefin resin (B) other than the resin (A), wherein the proportion of the biomass-derived linear low-density polyolefin resin (a1) relative to the total mass of the resin (A) is 0 to 50 mass %, and the proportion of the biomass-derived polyolefin resin (b1) relative to the total mass of the resin (B) is 50 to 100 mass %. In the cover tape according to the first embodiment, by using the biomass-derived resin (a1) and / or resin (b1) as the biomass-derived resin blended into the support layer and controlling the proportions thereof, it is possible to achieve a biomass content of the cover tape above a certain value while achieving mechanical properties equivalent to those of conventional cover tapes.

[0023] (Linear Low-Density Polyolefin Resin (A)) The support layer contains a linear low-density polyolefin resin (A). The resin (A) also contains 0 to 50 mass% of a biomass-derived linear low-density polyolefin resin (a1) relative to the total mass of the resin (A). That is, the resin (A) is a resin consisting solely of a petroleum-derived linear low-density polyolefin resin, or a portion of the resin is replaced with a biomass-derived linear low-density polyolefin resin (a1).

[0024] The petroleum-derived linear low-density polyolefin resin contained in resin (A) is preferably a linear low-density polyethylene resin or a linear low-density polypropylene resin, from the viewpoint of flexibility, appropriate rigidity, and tendency to have good tear strength at room temperature (for example, tape break strength, etc., as described below), and more preferably contains a linear low-density polyethylene resin (LLDPE). The petroleum-derived LLDPE has a density of 0.880 to 0.925 g / cm ３ It is preferable to use a resin in the range of

[0025] Petroleum-derived LLDPE includes those polymerized with Ziegler catalysts and those polymerized with metallocene catalysts (m-LLDPE). Of these, m-LLDPE has a narrowly controlled molecular weight distribution, making it easier to achieve higher tear strength.

[0026] Petroleum-derived m-LLDPE is a copolymer of ethylene and an olefin having 3 or more carbon atoms, preferably an α-olefin having 3 to 18 carbon atoms and a linear, branched, or aromatic group, as a comonomer. Examples of linear monoolefins include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-octadecene. Examples of branched monoolefins include 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, and 2-ethyl-1-hexene. Examples of aromatic monoolefins include styrene. These comonomers can be copolymerized with ethylene either alone or in combination. In this copolymerization, polyenes such as butadiene, isoprene, 1,3-hexadiene, dicyclopentadiene, and 5-ethylidene-2-norbornene may be copolymerized.

[0027] Biomass-derived linear low-density polyolefin resin (a1) The resin (a1) contained in resin (A) is a linear low-density polyolefin resin obtained by polymerizing monomers containing olefin monomers such as ethylene monomers and propylene monomers that have been chemically purified using plant-derived ethanol or propanol produced from renewable natural raw materials (e.g., corn, sugarcane, beet, manioc, etc.). The natural raw materials for resin (a1) are not particularly limited, but it is preferable to include sugarcane-derived resin. Since sugarcane-derived resin is obtained using by-products generated during the sugar production process, it is easy to produce a cover tape with less environmental impact and also easily improve the mechanical properties of the cover tape. It is preferable to select the same resin as the petroleum-derived linear low-density polyolefin resin that constitutes resin (A). In a preferred embodiment, when resin (A) contains a linear low-density polyethylene resin (LLDPE), resin (a1) also preferably contains a biomass-derived linear low-density polyethylene resin (biomass-derived LLDPE). In one embodiment, the biomass-derived LLDPE is preferably a plant-derived LLDPE obtained by copolymerizing a plant-derived ethylene monomer with an α-olefin having 4 to 6 carbon atoms. Resin (a1) may contain two or more types of biomass-derived linear low-density polyolefin resins.

[0028] As for biomass-derived LLDPE, from the viewpoint of easily exhibiting physical properties equivalent to those of petroleum-derived LLDPE, a copolymer of an olefin having 3 or more carbon atoms as a comonomer, preferably an α-olefin having 3 to 18 carbon atoms and a linear, branched or aromatic group, and an ethylene monomer is preferred, similar to petroleum-derived LLDPE. The comonomer is more preferably butene-1 (C4).

[0029] In one embodiment, the density of the biomass-derived LLDPE is 0.910 to 0.925 g / cm ３ is preferred, and 0.910 to 0.920 g / cm ３ More preferably, 0.913 to 0.918 g / cm ３Here, the density of the biomass-derived LLDPE can be measured in accordance with JIS K 7112.

[0030] In one embodiment, the MFR (190°C, load 2.16 N) of the biomass-derived LLDPE is preferably 0.5 to 4.0 g / 10 min, more preferably 1.5 to 3.0 g / 10 min, and even more preferably 2.0 to 2.5 g / 10 min.

[0031] In one embodiment, the resin (a1) preferably has a biomass content of 80 to 100% as determined by radiocarbon dating (14C). A particularly preferred embodiment of the resin (a1) is a biomass-derived LLDPE having a biomass content of 80 to 100%.

[0032] Here, "biomass degree by radiocarbon dating 14C" (biomass degree in this disclosure) refers to the proportion of biomass-derived components in a resin, determined by measuring the concentration of 14C (radiocarbon-14, half-life 5730 years) using accelerator mass spectrometry (AMS). Because petroleum-derived resins do not contain 14C, the proportion of biomass-derived components in the resin can be determined by measuring the 14C concentration. Biomass degree can be measured by the following method. (Method for measuring biomass degree (AMS)) The sample to be measured is burned to generate carbon dioxide. The generated carbon dioxide is purified in a vacuum line and then reduced with hydrogen using iron as a catalyst to produce graphite. The generated graphite is loaded into a tandem accelerator-based dedicated 14C-AMS device (e.g., manufactured by NEC Corporation) to measure 14C counting, the 13C concentration (13C / 12C), and the 14C concentration (14C / 12C). From the obtained measurements, the ratio of the 14C concentration of the sample carbon to the standard modern carbon is calculated. In this measurement, oxalic acid (HO) provided by the National Institute of Standards (NIST) was used. ｘ II) is used as the standard sample.

[0033] The proportion of resin (a1) contained in resin (A) is 0 to 50% by mass. The present inventors have discovered that by blending a linear low-density polyolefin resin (A) and a polyolefin resin (B) other than resin (A) in the support layer of the cover tape, and further controlling the proportion of biomass-derived resin (a1) in the resin (A) to a low level, it is possible to achieve an environmentally friendly cover tape while achieving mechanical properties equivalent to those of conventional cover tapes. From the perspective of easily maintaining the mechanical properties of the cover tape, it is preferable that the proportion of resin (a1) in resin (A) is as low as possible. In one embodiment, the proportion of resin (a1) in resin (A) is preferably 0 to 40% by mass, more preferably 0 to 30% by mass, and even more preferably 0 to 25% by mass. It is also particularly preferable that resin (A) does not contain resin (a1) (i.e., resin (A) contains only petroleum-derived linear low-density polyolefin resin).

[0034] In a preferred embodiment, the resin (A) may contain only petroleum-derived LLDPE, or a resin in which a portion (50% by mass or less) of the petroleum-derived LLDPE is replaced with biomass-derived LLDPE.

[0035] (Polyolefin resin (B) other than resin (A)) The support layer contains the above-mentioned resin (A) and a polyolefin resin (B) other than resin (A). Furthermore, resin (B) contains 50 to 100 mass% of biomass-derived polyolefin resin (b1) relative to the total mass of resin (B). In other words, resin (B) is a resin in which part or all of the petroleum-derived polyolefin resin other than resin (A) has been replaced with a biomass-derived polyolefin resin (excluding resin (a1)).

[0036] Examples of petroleum-derived polyolefin resins contained in resin (B) include polyethylene resins such as low-density polyethylene resin and ultra-low-density polyethylene resin; copolymers of ethylene and α-olefins such as ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-pentene copolymer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer, and ethylene-vinyl acetate copolymer; copolymers of ethylene and other monomers such as ethylene-acrylic acid ester copolymer, ethylene-maleic acid copolymer, styrene-ethylene graft copolymer, styrene-propylene graft copolymer, and styrene-ethylene-butadiene block copolymer; and polypropylene resins such as homopolypropylene resin and random polypropylene resin. Among these, from the viewpoint of easier improvement in processability, it is preferable to contain polyethylene resin or polypropylene resin, and low-density polyethylene resin (LDPE) is more preferable.

[0037] Biomass-derived polyolefin resin (b1) The resin (b1) contained in the resin (B), like the resin (a1), is a polyolefin resin obtained by polymerizing olefin monomers such as ethylene monomers and propylene monomers that have been chemically purified using plant-derived ethanol or propanol produced from renewable natural raw materials (e.g., corn, sugarcane, beet, manioc, etc.). The natural raw materials for the resin (b1) are not particularly limited, but plant-derived resins are preferred, and sugarcane-derived resins are preferred. Sugarcane-derived resins tend to produce cover tapes with less environmental impact and also tend to improve the mechanical properties of the cover tape.

[0038] It is preferable to select the same resin as the petroleum-derived polyolefin resin constituting the resin (B) as the resin (b1). In a preferred embodiment, when the resin (B) contains a low-density polyethylene resin (LDPE), the resin (b1) also preferably contains a biomass-derived low-density polyethylene resin (biomass-derived LDPE). In one embodiment, the biomass-derived LDPE may be a plant-derived LDPE. The resin (b1) may contain two or more types of biomass-derived low-density polyolefin resins.

[0039] In one embodiment, the density of the biomass-derived LDPE is 0.910 to 0.930 g / cm ３ is preferred, and 0.915 to 0.925 g / cm ３ More preferably, 0.918 to 0.925 g / cm ３ The density of the biomass-derived LDPE can be measured in the same manner as the density of the biomass-derived LLDPE described above.

[0040] In one embodiment, the MFR (190°C, load 2.16 N) of the biomass-derived LDPE is preferably 0.1 to 2.0 g / 10 min, more preferably 0.1 to 1.0 g / 10 min, and even more preferably 0.1 to 0.5 g / 10 min.

[0041] In one embodiment, the resin (b1) preferably has a biomass content of 80 to 100%, more preferably 90 to 100%, as determined by the above-mentioned radiocarbon dating method (14C). A particularly preferred embodiment of the resin (b1) is biomass-derived LDPE having a biomass content of 80 to 100%.

[0042] From the viewpoint of maintaining a high biomass content of the cover tape and improving the mechanical properties of the cover tape, it is preferable that the proportion of resin (b1) in resin (B) is higher. In one embodiment, the proportion of resin (b1) in resin (B) is preferably 60 to 100% by mass, more preferably 70 to 100% by mass, and even more preferably 80 to 100% by mass. Furthermore, from the viewpoint of maintaining a high biomass content and improving the mechanical properties of the cover tape, it is particularly preferable that resin (B) contains only resin (b1) (i.e., resin (B) does not contain a petroleum-derived polyolefin resin).

[0043] In a preferred embodiment, the resin (B) may contain only biomass-derived LDPE, or a resin in which a portion (50% by mass or less) of the biomass-derived LDPE is replaced with petroleum-derived LDPE.

[0044] In one embodiment, the proportion of resin (A) relative to the total (100% by mass) of resins (A) and (B) in the support layer is preferably 50 to 70% by mass, more preferably 55 to 70% by mass. If the proportion of resin (A) is within this range, it is easy to achieve mechanical strength comparable to that of conventional cover tapes while maintaining a high biomass content of the cover tape.

[0045] In one embodiment, the total amount of biomass-derived resins, including resin (b1), in the support layer is preferably 30% by mass or more relative to the total mass of the resin components constituting the support layer. If the proportion of biomass-derived resins is 30% by mass or more, the biomass content of the cover tape is likely to be high, making it an environmentally friendly cover tape. On the other hand, if the proportion of biomass-derived resins is too high, the mechanical strength of the cover tape is likely to decrease. Therefore, from the viewpoint of easily maintaining high mechanical strength of the cover tape, the total amount of biomass-derived resins, including resin (b1), in the support layer is preferably 30% by mass or more but less than 70% by mass, more preferably 30 to 60% by mass, and even more preferably 30 to 50% by mass.

[0046] In a preferred embodiment, the support layer contains only a mixture of resin (A) and resin (B) as the resin component. When the support layer contains only the mixture as the resin component, the total amount of resin (a1) and resin (b1) in the mixture (i.e., the total amount of biomass-derived components) is preferably 30% by mass or more relative to the total mass of the mixture. From the viewpoint of the mechanical strength of the cover tape, the total amount of resin (a1) and resin (b1) is preferably 30% by mass or more but less than 70% by mass, more preferably 30 to 60% by mass, and even more preferably 30 to 50% by mass.

[0047] In one embodiment, when the support layer contains only the mixture as a resin component, the proportion of resin (b1) relative to the total mass of the mixture is preferably 30 to 50 mass%, more preferably 35 to 50 mass%, and even more preferably 35 to 45 mass%.

[0048] In one embodiment, the thickness of the support layer is preferably 5 to 50 μm, more preferably 10 to 40 μm. When the thickness of the support layer is within this range, uneven contact with the heat-sealing iron when heat-sealing the cover film to the carrier tape is easily alleviated, and the peel strength during heat-sealing is likely to be good.

[0049] <Heat Seal Layer> The cover tape according to the first embodiment comprises a base layer, a support layer, and a heat seal layer laminated in this order. The heat seal layer is made of a thermoplastic resin that has heat sealability to the carrier tape and exhibits easy peelability, allowing it to be easily peeled from the carrier tape as needed. For example, a molten mixture of the following resins (C) and (D) can be used. (Resin (C)) At least one resin selected from polyethylene resins (e.g., various polyethylene resins such as low-density polyethylene and linear low-density polyethylene) and ethylene copolymers (e.g., ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butene-1 copolymer, etc.). (Resin (D)) At least one resin selected from polystyrene and styrene-based resins containing styrene as a copolymerization component (e.g., styrene-butadiene copolymer, hydrogenated styrene-butadiene copolymer, styrene-isoprene copolymer, hydrogenated styrene-isoprene copolymer, styrene-butene-butadiene copolymer, copolymer of methacrylic acid and styrene, impact-resistant polystyrene, etc.). The polyethylene resin in resin (C) may be a biomass-derived resin such as the aforementioned resin (a1) or resin (b1). When the heat seal layer contains a biomass-derived resin, the content of the biomass-derived resin is preferably 40 mass% or less relative to the total mass of the resin composition constituting the heat seal layer.

[0050] Among the above-mentioned molten mixtures of resins (C) and (D), a molten mixture of an ethylene copolymer and at least one resin selected from the group consisting of a styrene-butadiene copolymer and an impact-resistant polystyrene resin is preferred from the viewpoint of continuously and stably maintaining the peel strength when heat-sealed to a carrier tape and then peeled from the carrier tape. Furthermore, as the ethylene copolymer in the mixture, an ethylene-butene-1 copolymer is particularly preferred.

[0051] In a preferred embodiment, when the heat seal layer is composed of a mixture of resin (C) and resin (D), it is more preferable to use a mixture containing 15 to 60 mass% of an ethylene copolymer and 40 to 85 mass% of a styrene-butadiene copolymer, when the mixture is taken as 100 mass%, in terms of stability of peel strength.

[0052] In one embodiment, the thickness of the heat seal layer is preferably 3 to 25 μm, more preferably 5 to 20 μm. When the thickness of the heat seal layer is within this range, good peel strength is easily obtained and the peel strength is less likely to vary.

[0053] In one embodiment, the heat seal layer may be coated with or kneaded with an antistatic agent for antistatic treatment, or may be subjected to corona treatment, easy-adhesion treatment, or the like. In a preferred embodiment, an antistatic layer may be provided on the surface of the heat seal layer on the side on which the support layer is not laminated. Hereinafter, the antistatic layer provided on the surface of the heat seal layer on the side on which the support layer is not laminated will be referred to as "antistatic layer (II)."

[0054] (Antistatic Layer (II)) Like the antistatic layer (I), the antistatic layer (II) can also contain a binder resin and an antistatic agent (hereinafter, the binder resin and antistatic agent contained in the antistatic layer (II) will be referred to as "binder resin (II)" and "antistatic agent (II)"). Like the antistatic agent (I), the antistatic agent (II) can be selected from inorganic antistatic agents; conductive fine 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.), and polyalkylene glycols such as polyether esters having a polyoxyalkylene structure and an ester bond. The antistatic layer (II) is provided on the surface that comes into contact with the contents such as electronic components when the electronic component packaging body is formed, and therefore it is preferable that the antistatic layer (II) be a layer having a lower surface resistivity. For example, the surface resistivity of the surface of the antistatic layer (II) is 10 １２ Ω or less is preferred. As the antistatic agent (II), conductive fine particles are preferred, and aluminum oxide is more preferred, from the viewpoint of the aforementioned surface resistivity, heat sealability with the carrier tape, and ease of reducing the proportion of petroleum-derived components in the cover tape. The proportion of the antistatic agent (II) is preferably 100 to 1,000 parts by mass, more preferably 100 to 700 parts by mass, per 100 parts by mass of the binder resin (II) described below.

[0055] As the binder resin (II), a (meth)acrylic resin is preferred from the viewpoint of easily improving the releasability from the carrier tape, particularly high-speed releasability.The (meth)acrylic resin is not particularly limited, but examples thereof include resins containing at least one or more (meth)acrylic residues in an amount of 50% by mass or more, such as acrylic acid esters such as methyl acrylate, ethyl acrylate, propyl acrylate, and butyl acrylate, and methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, and cyclohexyl methacrylate.These may be used alone or in combination of two or more.

[0056] The thickness of the antistatic layer (II) is preferably from 0.1 to 2.0 μm, more preferably from 0.15 to 1.0 μm, from the viewpoints of antistatic properties and peel strength.

[0057] (Laminate Layer) In one embodiment, a laminate layer may be provided between the support layer and the base layer. By providing a laminate layer, the laminate strength of the cover tape is likely to be improved. The laminate layer may be provided, for example, directly on one side of the base layer, or may be provided via an anchor coat layer. That is, when a laminate layer is provided, it may be provided in the order of "base layer / laminate layer / support layer / heat seal layer" or "base layer / anchor coat layer / laminate layer / support layer / heat seal layer". As the resin constituting the laminate layer, LLDPE, which is particularly flexible and has appropriate rigidity and excellent tear strength at room temperature, can be preferably used, and petroleum-derived LLDPE is more preferred. Among these, LLDPE, particularly those having a density of 0.880 to 0.925 g / cm ３ By using an LLDPE in this range, the laminate layer is less likely to protrude from the edge of the cover film due to the heat and pressure during heat sealing. In addition, the laminate layer softens when the cover film is heat-sealed, which helps to reduce uneven contact with the heat-sealing iron, making it easier to obtain stable peel strength when peeling the cover film.

[0058] As mentioned above, LLDPE includes LLDPE polymerized with a Ziegler catalyst and m-LLDPE. Of these, m-LLDPE (more preferably petroleum-derived m-LLDPE) is preferably used for the laminate layer from the viewpoint of easily exhibiting high tear strength. Here, it is preferable to use LLDPE having different densities for the laminate layer and the resin (A) in the support layer. In one embodiment, the laminate layer has a density of 0.910 g / cm ３ 0.916g / cm or more ３ It is preferable to use m-LLDPE of less than 0.916 g / cm ３ 0.920g / cm or more ３ It is preferable to use the following m-LLDPE:

[0059] In one embodiment, the thickness of the laminate layer is preferably 10 to 20 μm from the viewpoint of easily obtaining good laminate strength.

[0060] The biomass content of the entire cover tape according to the first embodiment, as measured by the AMS method, is preferably 10% or more, and more preferably 12% or more. It is preferable to set the proportion of biomass-derived resin in the support layer and other layers so that the biomass content of the entire cover tape is 10% or more.

[0061] In one embodiment, the laminate strength of the cover tape measured using the method described below is preferably 6.5 N / 15 mm or more, and more preferably 7.0 N / 15 mm or more. The laminate strength of a conventional cover tape that does not contain a biomass-derived resin is, for example, approximately 7.0 N / 15 mm, as shown in Reference Example 1. The cover tape according to the first embodiment can achieve a laminate strength comparable to that of conventional cover tapes while containing a biomass-derived resin. The cover tape is also required to not break when peeled at a high speed of 100 m / min or more. Tape breakage during high-speed peeling can be evaluated, for example, by the tape break strength measured using the method described below. Conventional cover tapes with excellent high-speed peelability have a tape break strength of approximately 1.2 N when peeled at a high speed. The cover tape according to the first embodiment can also achieve a tape break strength comparable to that of conventional cover tapes. That is, in one embodiment, the tape break strength of the cover tape measured using the method described below may be 1.2 N or more, or may be 1.3 N or more.

[0062] [Cover Tape Manufacturing Method] The manufacturing method of the cover tape according to the first embodiment is not particularly limited, and a general method can be used. For example, the heat seal layer is formed in advance by a method such as a T-die casting method or an inflation method. Furthermore, an anchor coating agent (anchor coating layer) such as polyurethane, polyester, polyolefin, or polyethyleneimine is applied to the surface of a substrate layer (preferably a biaxially oriented polyester film). A resin composition (containing resins (A) and (B), preferably a mixture of LLDPE and LDPE) constituting the support layer is extruded from a T-die between the coated surface of the anchor coating agent and the film of the heat seal layer by a sand lamination method, thereby obtaining a three-layer cover tape in which the substrate layer, support layer, and heat seal layer are laminated in this order.

[0063] In one embodiment, when a cover tape is obtained in which a substrate layer, a laminate layer, a support layer, and a heat-seal layer are laminated in this order, the resin composition constituting the support layer and the resin composition constituting the heat-seal layer are extruded from separate single-screw extruders and laminated using a multi-manifold die to produce a two-layer film consisting of the support layer and the heat-seal layer. Furthermore, the anchor coating agent (anchor coating layer) described above is applied to the surface of the substrate layer, and the resin composition constituting the laminate layer (preferably m-LLDPE) is extruded from a T-die between the surface coated with the anchor coating agent and the two-layer film, thereby producing a four-layer cover tape consisting of the substrate layer, the laminate layer, the support layer, and the heat-seal layer.

[0064] In addition to the above steps, if necessary, an antistatic layer (I) or (II) can be provided on the surface of the base layer of the cover film and / or on the surface of the heat seal layer. The antistatic layer (I) or (II) can be provided by applying the resin composition constituting the antistatic layer (I) or (II) to the predetermined surface of each layer using a roll coater or lip coater using a gravure roll, a spray, or the like. Furthermore, before performing the antistatic treatment, the surface of the base layer or the heat seal layer may be subjected to corona discharge treatment or ozone treatment.

[0065] [Use] The cover tape according to the first embodiment can be used as a cover tape for an electronic component package.

[0066] [Electronic Component Packaging] The second embodiment is an electronic component packaging including the cover tape according to the first embodiment. The electronic component packaging according to the second embodiment can be obtained, for example, by storing electronic components in recesses in a carrier tape for storing the electronic components, using the cover tape according to the first embodiment as a lid, continuously heat-sealing both longitudinal edges of the cover tape using a heat-sealing iron or the like to package the electronic components, and then winding the cover tape onto a reel. Packaged in this form, the electronic components are stored and transported. The packaging according to this embodiment can be used to store and transport various electronic components, such as connectors, ICs, diodes, transistors, capacitors, resistors, and LEDs.

[0067] 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.

[0068] The carrier tape included in the electronic component packaging according to the second embodiment is a strip-shaped material approximately 8 mm to 100 mm wide and having a recess for accommodating 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 a (meth)acrylic resin.

[0069] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following description.

[0070] [Examples 1-3, Comparative Examples 1-3, and Reference Example 1] The following resins (C) and (D) were pre-blended and then kneaded using a single-screw extruder to obtain a resin composition for the heat-seal layer. This resin composition for the heat-seal layer and the resin composition for the support layer listed in Table 1 were extruded from separate single-screw extruders and laminated using a multi-manifold T-die to obtain a two-layer film with a heat-seal layer and a support layer thickness of 5 μm and 20 μm, respectively. Next, a two-component curing polyurethane anchor coating agent was applied to the substrate layer (thickness 13 μm) using a roll coater, and the molten resin composition constituting the laminate layer was extruded between the coated surface and the support layer surface of the two-layer film to a thickness of 13 μm, and a laminate film was obtained by extrusion lamination. After corona treatment of the surface of the base layer and the surface of the heat seal layer of the laminated film, the resin composition for the antistatic layer (I) and the resin composition for the antistatic layer (II) were applied using a gravure coater so that the thickness after drying would be 0.4 μm, respectively, to obtain a cover tape having a layer structure of antistatic layer I / base layer / (anchor coat layer) / laminate layer / support layer / heat seal layer / antistatic layer (II) as shown in Figure 2. Note that the anchor coat layer is not shown in Figure 2.

[0071] The materials used in each example are as follows: <Base layer> PET: biaxially oriented polyethylene terephthalate film, thickness 13 μm <Laminate layer> m-LLDPE1: petroleum-derived m-LLDPE (density: 0.92 g / cm ３ <Support layer> (Resin (A)) m-LLDPE2: petroleum-derived m-LLDPE (density: 0.918 g / cm ３ (Resin (a1)) Biomass-derived LLDPE: Plant-derived LLDPE (a copolymer of plant-derived ethylene and hexene) MFR: 2.3 g / 10 min, density: 0.916 g / cm ３ , Biomass content: about 84%) (Resin (B)) LDPE: Petroleum-derived LDPE (density: 0.922 g / cm ３ (Resin (b1)) Biomass-derived LDPE: plant-derived LDPE (MFR: 0.32 g / 10 min, density: 0.923 g / cm３ , biomass content: about 95%). <Heat seal layer> Resin (C): ethylene-α-olefin copolymer (density: 0.885 g / cm ３ Resin (D): Styrene-butadiene block copolymer (density: 1.03 g / cm ３ <Antistatic layer (I)> Resin composition for antistatic layer (I): A resin composition containing a binder resin (I) (polyolefin resin) and an antistatic agent (I) (magnesium silicate). <Antistatic layer (II)> Resin composition for antistatic layer (II): A resin composition containing a binder resin (II) ((meth)acrylic resin) and an antistatic agent (II) (alumina).

[0072] <Measurement of Biomass Degree of Cover Tape (AMS Method)> The biomass degree of the cover tape obtained in each example was measured by the following method. The results are shown in Table 1. (Method of Measuring Biomass Degree (AMS Method)) The sample to be measured was burned to generate carbon dioxide. The generated carbon dioxide was purified in a vacuum line and then reduced with hydrogen using iron as a catalyst to generate graphite. The generated graphite was loaded into a tandem accelerator-based dedicated 14C-AMS device (manufactured by NEC Corporation) to measure 14C counting, 13C concentration (13C / 12C), and 14C concentration (14C / 12C). From the obtained measurements, the ratio of the 14C concentration of the sample carbon to standard modern carbon was calculated. In this measurement, oxalic acid (HO) provided by the National Bureau of Standards (NIST) was used. ｘ II) was used as the standard sample.

[0073] <Evaluation of Mechanical Properties of Cover Tape> (Lamination Strength) The laminate strength of the cover tape obtained in each example was measured using the following method. The results are shown in Table 1. Five samples measuring 15 mm wide x 250 mm long were cut out from the cover tape. A slit was made in the width direction at the top of the sample, and the slit was immersed in ethanol solvent and split using fingertips or tweezers so that only the laminate layer stretched. The stretched laminate layer was slowly peeled off from the base layer while being held and stretched with tweezers or the like. When the laminate layer and base layer began to peel off, a small amount of ethanol solvent was applied to the peeled portion and further slowly peeled off, creating a gripped portion (approximately 3 cm) of the sample. If a white area was formed on the surface of the base layer at this time, the base layer and laminate layer were peeled off until the white area disappeared. Next, the gripped portion was clamped in a tensile jig of a small tabletop testing machine (manufactured by Shimadzu Corporation, product name "EZ-TEST"), and the base layer was peeled off from the other layers. The peeling speed was 200 mm / min, the measurement length was 50 mm, and the sample width was 15 mm. The resistance force was measured using a load cell attached to the tensile jig, and the maximum strength during the measurement was determined as the laminate strength.

[0074] (Tape Break Strength) The tape break strength of the cover tape obtained in each example was measured using the following method. The results are shown in Table 1. First, the cover tape (21.5 mm wide) obtained in each example was heat-sealed to a 24.0 mm wide polystyrene carrier tape (manufactured by Denka Co., Ltd.) using a taping machine (manufactured by Vanguard Systems Co., Ltd., product name "VS-120") under the following conditions to obtain an electronic component package. O Seal head width 0.5 mm x 2, seal head length 32 mm, sealing pressure 5.0 kg, feed length 16 mm, sealing time 0.4 seconds x 2 times, sealing iron temperature 150 ° C to 200 ° C in 5 ° C intervals. First, a sample of the electronic component package (length 500 mm x width 24.0 mm) with a sealing iron temperature of 200 ° C was attached to a vertical wall with double-sided adhesive tape. At this time, the sample was attached so that the carrier tape side was in contact with the wall. Next, a load (1 kg) was applied to the top of the cover tape, and the cover tape was peeled off from the carrier tape at a maximum peel speed of 180 m / min. Next, a similar high-speed peel test was performed on samples with sealing iron temperatures ranging from 150°C to 195°C. The high-speed peel test was performed three times for each sample at each temperature, and the test was continued until the number of samples with breaks in the cover tape reached 0 to 1. The peel strength of all evaluated samples was then measured under the following conditions. The peel strength of the sample with breaks was defined as the minimum peel strength, and the peel strength of the sample without breaks was defined as the maximum peel strength. The average of the minimum and maximum peel strengths was defined as the tape's cut strength. (Peel Strength Measurement) The sample (length 300 mm x width 24.0 mm) was peeled off at a peel angle of 170 to 180° and a peel speed of 300 mm / min using a peel strength tester (manufactured by Vanguard Systems Co., Ltd., product name "VG-35") to measure the peel strength.

[0075]

[0076] As shown in Table 1, the cover tapes of Examples 1 to 3, which satisfied the configuration of the first embodiment, had a high biomass content of 13 to 14.5%, making them environmentally friendly cover tapes. Furthermore, the cover tapes of Examples 1 to 3 had laminate strength and tape tear strength comparable to those of the conventional cover tape shown in Reference Example 1. Surprisingly, both the laminate strength and tape tear strength were improved compared to the cover tape of Reference Example 1. On the other hand, the cover tapes of Comparative Examples 1 to 3, which did not satisfy the configuration of the first embodiment, showed significantly reduced laminate strength and tape tear strength. From the above results, it was confirmed that the cover tape according to the first embodiment is an environmentally friendly cover tape containing a certain amount of biomass-derived resin, yet can achieve mechanical properties equivalent to those of conventional cover tapes.

[0077] A non-limiting list of exemplary embodiments and combinations of exemplary embodiments of the present disclosure is described below. [1] A cover tape, comprising a base layer, a support layer, and a heat seal layer laminated in this order, wherein the support layer comprises a linear low-density polyolefin resin (A) and a polyolefin resin (B) other than the resin (A), wherein the proportion of the biomass-derived linear low-density polyolefin resin (a1) relative to the total mass of the resin (A) is 0 to 50 mass%, and the proportion of the biomass-derived polyolefin resin (b1) relative to the total mass of the resin (B) is 50 to 100 mass%. [2] The cover tape according to [1], wherein the biomass content of the entire cover tape measured by the AMS method is 10% or more. [3] The cover tape according to [1] or [2], wherein the total amount of biomass-derived resins, including the resin (b1), in the support layer is 30 mass% or more relative to the total mass of the resin components constituting the support layer. [4] The cover tape according to any one of [1] to [3], wherein in the support layer, the proportion of the resin (A) relative to the total (100% by mass) of the resins (A) and (B) is 50 to 70% by mass. [5] The cover tape according to any one of [1] to [4], wherein the resin (B) comprises a low-density polyethylene resin, and the resin (b1) comprises a biomass-derived low-density polyethylene resin. [6] The cover tape according to any one of [1] to [5], wherein the resin (A) comprises a linear low-density polyethylene resin, and the resin (a1) comprises a biomass-derived linear low-density polyethylene resin. [7] The cover tape according to any one of [1] to [6], wherein the support layer comprises a mixture of the resins (A) and (B), and wherein the combined amount of the resins (a1) and (b1) relative to the total mass of the mixture is 30% by mass or more. [8] The cover tape according to any one of [1] to [7], wherein the cover tape is for use in packaging for electronic components. [9] An electronic component packaging body comprising the cover tape according to any one of [1] to [8].

[0078] The cover tape according to the first embodiment can achieve mechanical properties equivalent to those of conventional cover tapes while containing a certain amount of biomass-derived resin, and therefore has industrial applicability as an environmentally friendly cover tape for electronic component packages.

[0079] 1: Base material layer 2: Support layer 3: Heat seal layer 4: Laminate layer 5: Antistatic layer (I) 6: Antistatic layer (II) 10, 20: Cover tape

Claims

1. A cover tape comprising a base layer, a support layer and a heat seal layer laminated in this order, the support layer comprising a linear low density polyolefin resin (A) and a polyolefin resin (B) other than the resin (A), the proportion of the biomass-derived linear low density polyolefin resin (a1) to the total mass of the resin (A) being 0 to 50 mass%, and the proportion of the biomass-derived polyolefin resin (b1) to the total mass of the resin (B) being 50 to 100 mass%.

2. The cover tape according to claim 1, wherein the biomass ratio of the entire cover tape measured by the AMS method is 10% or more.

3. A cover tape as described in claim 1 or 2, wherein the total amount of biomass-derived resins including the resin (b1) in the support layer is 30 mass% or more relative to the total mass of the resin components constituting the support layer.

4. A cover tape as described in claim 1 or 2, wherein in the support layer, the ratio of the resin (A) to the total (100 mass%) of the resin (A) and the resin (B) is 50 to 70 mass%.

5. The cover tape according to claim 1 or 2, wherein the resin (B) comprises a low-density polyethylene resin, and the resin (b1) comprises a biomass-derived low-density polyethylene resin.

6. The cover tape according to claim 1 or 2, wherein the resin (A) comprises a linear low-density polyethylene resin, and the resin (a1) comprises a biomass-derived linear low-density polyethylene resin.

7. A cover tape as described in claim 1 or 2, wherein the support layer is made of a mixture of the resin (A) and the resin (B), and the combined amount of the resin (a1) and the resin (b1) relative to the total mass of the mixture is 30 mass% or more.

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

9. An electronic component package comprising the cover tape of claim 1 or 2.

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