WO2016024529A1

WO2016024529A1 - Cover film and electronic component packaging employing same

Info

Publication number: WO2016024529A1
Application number: PCT/JP2015/072403
Authority: WO
Inventors: 佐々木　彰; 貴之岩崎; 高範阿津坂; 忠昭弘岡; 坂本　繁
Original assignee: 電気化学工業株式会社
Priority date: 2014-08-15
Filing date: 2015-08-06
Publication date: 2016-02-18
Also published as: JPWO2016024529A1; KR102337822B1; KR20170044661A; CN106604816A; CN106604816B; JP6694387B2; TWI659838B; TW201613761A

Abstract

　The present invention provides a cover film which exhibits peel strength that continuously remains constant within a range of prescribed values during peeling of the cover film, and which moreover has exceptional transparency, and does not readily give rise to "film rip" during high-speed peeling. This cover film comprises at least (A) a base material layer, (B) an adhesive layer, (C) an intermediate layer, and (D) a heat sealing layer containing a heat-sealable resin. The main component of the (B) adhesive layer is a polyester resin, and 50 mass% or more of the curing agent is isophorone diisocyanate. The (D) heat sealing layer includes (d-1) 50-90 mass% of an olefin resin comprising any one or more olefin-styrene block copolymers that contain 58-82 mass% of an olefin component and ethylene-vinyl acetate copolymers that contain 75-88 mass% of an olefin component, and (d-2) 10-40 mass% of a potassium ionomer having anti-static properties.

Description

Cover film and electronic component package using the same

The present invention relates to a cover film used for a package of electronic components and an electronic component package using the same.

With the downsizing of electronic equipment, the electronic components used are also becoming smaller and higher performance. In addition, electronic components are automatically mounted on a printed circuit board in an electronic device assembly process. The surface-mounting electronic component is stored in a carrier tape in which embossed pockets that can be stored in accordance with the shape of the electronic component are interlockedly formed. After storing the electronic components, a cover film is stacked as a lid on the upper surface of the carrier tape, and both ends of the cover film are continuously heat-sealed in the length direction with a heated seal bar to form a package. As the cover film material, a material in which a biaxially stretched polyester film is used as a base material and a thermoplastic resin sealant layer is laminated is used.

The cover film is peeled off from the carrier tape by an automatic peeling device when the electronic component is mounted in the manufacturing process of the electronic device or the like. Therefore, it is particularly important for the function of the cover film that the peel strength from the carrier tape is stable within an appropriate range. If the peel strength is too strong, the cover film may be cut off. If the peel strength is too weak, the cover film may be peeled off from the carrier tape when the transport body is transferred, and the electronic component as the contents may fall off. In addition, when the transport body is transferred, it may be exposed to a high temperature environment of 40 to 60 ° C., and the heat seal layer of the thermoplastic resin may be softened and the portions other than the heat sealed ends may adhere to the carrier tape. The peel strength may increase. In particular, with the rapid increase in the mounting speed, the peeling speed of the cover film is also extremely high at 0.1 second or less / tact. At the time of peeling, a large impact stress is applied to the cover film. As a result, there arises a problem called “film cut” in which the cover film is cut.

The peel strength of the cover film is 0.1 to 1.0 N for an 8 mm wide carrier tape and 0.1 to 1 .1 for a 12 mm to 56 mm wide carrier tape when the peel speed is 300 mm per minute in JIS C0806-3. 3N. However, in the electronic component mounting process, the peeling speed is faster than 300 mm per minute, and particularly when large connector parts are accommodated, taping is often performed at the upper limit peel strength. As a result, the cover film is peeled off. It is easy to cause “cut film” when doing.

On the other hand, the cover film may be required to have high transparency so that the electronic parts that are stored items can be easily identified. For example, in the inspection of electronic parts such as ICs, a method of discriminating defects such as deformation of IC pins by taking a picture with a CCD camera from the cover film and analyzing the image is performed. A cover film having properties is required. In such a method of use, a haze (cloudiness value) of 50% or less is required.

As a countermeasure against film breakage, a method has been proposed in which a layer having excellent impact resistance and tear propagation resistance, such as polypropylene, nylon and polyurethane, is provided between a base material such as a biaxially stretched polyester film and a sealant layer (patent) Reference 1 to 3). On the other hand, by using a metallocene linear low density polyethylene (LLDPE) with a specific gravity as the intermediate layer, and by making the adhesive layer between this intermediate layer and the base material layer have a low Young's modulus, stress propagation to the base material layer is achieved. A method for preventing this has been proposed (see Patent Document 4). In addition, for the purpose of obtaining a cover film having a peel-off strength dependency on the seal temperature and having a small change with time and a stable seal property, the above-mentioned sealant composition is mixed with polyethylene or polypropylene by mixing a styrene-butadiene-styrene block copolymer. A method for solving the problem has been proposed (see Patent Document 5). However, even with these methods, it has been difficult to sufficiently suppress film breakage at high speed peeling such as 100 m / min. As a countermeasure against film breakage, a cover film has been proposed in which layers made of styrene-based hydrocarbon resin are coextruded to improve the adhesion between the layers (see Patent Document 6). However, this method has insufficient stability of peel strength after heat sealing.
JP-A-8-119373 Japanese Patent Laid-Open No. 10-250020 JP 2000-327024 A JP 2006-327624 A JP-A-8-324676 JP 2007-90725 A

An object of the present invention is to provide a cover film having a peel strength that is constant within a predetermined value range, excellent in transparency, and less likely to cause “film breakage” during high-speed peeling.

As a result of earnestly examining the above problems, the present inventor has provided a resin composition having a specific structure in the adhesive layer and the heat seal layer located between the base material layer and the intermediate layer. The present inventors have found that a cover film overcoming the above can be obtained, and have reached the present invention.

That is, the present invention provides (1) a cover film having at least (A) a base material layer, (B) an adhesive layer, (C) an intermediate layer, and (D) a heat seal layer, wherein (B) the adhesive layer is (D) The resin constituting the heat seal layer comprises (d-1) an olefin component in an amount of 58% by mass to 82% by a cured product of a main component containing a polyester resin and a curing agent containing 50% by mass or more of isophorone diisocyanate. 50% by mass to 90% by mass of an olefin resin containing one or both of an olefin-styrene block copolymer containing 75% by mass and an ethylene-vinyl acetate copolymer containing 75% by mass to 88% by mass of an olefin component; d-2) 10% to 40% by mass of potassium ionomer having antistatic performance, and (D) surface resistance value of the outermost surface on the heat seal layer side of the cover film A cover film to equal to or less than 10 ¹² Omega.

In another embodiment, the cover film comprises at least (A) a base material layer, (B) an adhesive layer, (C) an intermediate layer, and (D) a heat seal layer having a heat sealable resin, B) The adhesive layer is composed of a cured product of a two-component curable adhesive of a main agent and a curing agent, the main agent is a polyester resin, and 50% by mass or more of the curing agent is isophorone diisocyanate, (D) The resin constituting the heat seal layer is any one of (d-1) an olefin-styrene block copolymer containing 58 to 82% by mass of an olefin component and an ethylene-vinyl acetate copolymer containing 75 to 88% by mass of an olefin component. 50% to 90% by mass of one or more olefinic resins, (d-2) 10% to 40% by mass of potassium ionomer having antistatic performance, and (D) The surface resistance of Toshiru layer can be configured to be below 10 ¹² Omega.

(2) In the present invention, (D) the heat seal layer preferably contains (d-3) one or both of organic fine particles and inorganic fine particles in a total of 10% by mass or less.

(3) In the present invention, the content of isophorone diisocyanate in the precuring agent is preferably 4% by mass to 13% by mass with respect to the total with the polyester resin.

(4) In this invention, it is preferable that the interlayer adhesive strength of (A) base material layer and (C) intermediate | middle layer is 5 N / 15mm or more.

(5) In the present invention, (C) the intermediate layer is made of a metallocene linear low density polyethylene resin having a density of 0.900 × 10 ³ kg / m ³ to 0.925 × 10 ³ kg / m ³ , Is preferably 15 μm to 25 μm.

(6) In the present invention, (D) the heat seal layer is configured to have (E) a second heat seal layer mainly composed of an acrylic resin on the surface opposite to the (B) intermediate layer side. Can do.

(6) The present invention is an electronic component package using the cover film according to any one of the above (1) to (6) as a cover material for a carrier tape made of a thermoplastic resin.

According to the present invention, it is possible to obtain a cover film in which the peel strength is constant within a predetermined value range, excellent in transparency, and difficult to cause “film breakage” during high-speed peeling.

It is sectional drawing which shows an example of the laminated constitution of the cover film of this invention.

As shown in FIG. 1, the cover film of the present invention includes at least (A) a base material layer, (B) an adhesive layer, (C) an intermediate layer, and (D) a heat seal layer. An example of the structure of the cover film of the present invention is shown in FIG. A cover film 1 shown in FIG. 1 includes a base material layer 2, an adhesive layer 3, an intermediate layer 4, and a heat seal layer 5. In this cover film 1, a base material layer 2, an adhesive material layer 3, an intermediate layer 4, and a heat seal layer 5 are laminated in this order.

[(A) Base material layer]
(A) The base material layer is a layer made of biaxially stretched polyester or biaxially stretched nylon, and biaxially stretched polyethylene terephthalate (PET), biaxially stretched polyethylene naphthalate (PEN), or biaxially stretched 6 , 6-nylon or 6-nylon can be used particularly preferably. As biaxially stretched PET, biaxially stretched PEN, biaxially stretched 6,6-nylon or 6-nylon, an antistatic agent for antistatic treatment was applied or kneaded in addition to those commonly used. Can be used, or those subjected to corona treatment or easy adhesion treatment. If the base material layer is too thin, the tensile strength of the cover film itself is lowered, so that “breakage of the film” tends to occur when the cover film is peeled off. On the other hand, if it is too thick, not only does the heat sealability of the carrier tape decrease, but it also increases costs. For this reason, a thickness of (A) the base material layer of usually 12 μm to 25 μm can be suitably used.

[(B) Adhesive layer]
(B) The adhesive layer is composed of a cured product of a two-component curable adhesive of a main agent and a curing agent, the main agent is a polyester resin, and 50% by mass or more constituting the curing agent is isophorone diisocyanate. Preferably isophorone diisocyanate is 60 mass% or more. The upper limit is not particularly limited, and may be 80% by mass or less, 90% by mass or less, or 100% by mass. When other acrylic resin, olefin resin, or polyether resin is used as the main agent, the adhesive strength with the (A) substrate layer becomes insufficient.

Examples of the polyester-based resin include polyester-based resins having two or more hydroxyl groups and active hydrogen groups such as amino groups in the molecule, specifically polyester polyols and polyester polyamines. The polyester polyol preferably has a hydroxyl value (mgKOH / g) of 1 to 200 and a number average molecular weight of 1,000 to 50,000. In addition, the number average molecular weight here is a value when measured according to JIS K7252. Examples of the polyester polyol include a condensation reaction product of a polyhydric hydroxyl group-containing compound and an ester-forming derivative such as a polycarboxylic acid or an anhydride and a lower alkyl (alkyl group having 1 to 4 carbon atoms) ester. .

The mass fraction of isophorone diisocyanate used as a curing agent is preferably 4 to 13 mass%, more preferably 5 to 10 mass%, based on the total amount with the polyester resin. By making it 4% by mass or more, it is possible to prevent the adhesive strength between the (A) base material layer and the (C) intermediate layer from becoming insufficient, and by making it 13% by mass or less, suppressing an increase in cost, It can be prevented that the material becomes brittle and the breaking strength decreases.

When an isocyanate other than isophorone diisocyanate, such as tolylene diisocyanate or xylene diisocyanate, is used alone as the curing agent, (B) the adhesive layer tends to become brittle and sufficient film breaking strength may not be obtained. In addition, when diphenylmethane diisocyanate is used as the other curing agent, the curing speed is remarkably faster compared to the isophorone diisocyanate used in the present invention, so that the coating stability over time is impaired and the transparency is lowered. In addition, the adhesive strength between (A) the base material layer and (C) the intermediate layer may be insufficient.

The two-component curable adhesive is preferably used after being diluted in a solvent and then mixed at a predetermined ratio. The dilution solvent is not particularly limited, and water, ethyl acetate, toluene, methyl ethyl ketone, or the like can be used. The (B) adhesive layer is formed by applying a two-component curable adhesive to the (A) substrate layer and then drying it. The thickness after drying (that is, the thickness of the (B) adhesive layer) is preferably 1 μm to 5 μm. By setting it to 1 μm or more, it is possible to prevent (C) the surface roughness of the intermediate layer from being fully followed and the adhesive strength from becoming insufficient, and by setting it to 5 μm or less, the peel strength after heat sealing to the carrier tape An increase in variation can be further prevented.

[(C) Intermediate layer]
In the present invention, (C) an intermediate layer is provided on one side of (A) the base material layer via (B) an adhesive layer. (C) As the resin constituting the intermediate layer, linear low-density polyethylene (hereinafter referred to as LLDPE) having flexibility and moderate rigidity and excellent tear strength at room temperature is preferably used. The cover film can be used, and in particular, by using a resin having a density in the range of 0.900 × 10 ³ kg / m ³ to 0.925 × 10 ³ kg / m ³ , due to heat and pressure at the time of heat sealing. The intermediate layer resin hardly protrudes from the end. For this reason, not only is it difficult for the iron to become dirty during heat sealing, but the intermediate layer softens when the cover film is heat-sealed, so that the contact spots on the heat-sealing iron are alleviated. Peel strength is easily obtained.

The LLDPE includes those polymerized with a Ziegler type catalyst and those polymerized with a metallocene catalyst (hereinafter referred to as m-LLDPE). Since m-LLDPE has a narrow molecular weight distribution, it has particularly high tear strength, and it is particularly preferable to use m-LLDPE as the (B) intermediate layer of the present invention.

The above-mentioned m-LLDPE is a copolymer of ethylene with an olefin having 3 or more carbon atoms as a comonomer, preferably a linear, branched or aromatic nucleus substituted with 3 to 18 carbon atoms. Examples of the linear monoolefin include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, -Octadecene and the like. Examples of the branched monoolefin include 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 2-ethyl-1-hexene and the like. Moreover, styrene etc. are mentioned as a monoolefin substituted by the aromatic nucleus. These comonomers can be copolymerized with ethylene singly or in combination of two or more. In this copolymerization, polyenes such as butadiene, isoprene, 1,3-hexadiene, dicyclopentadiene, and 5-ethylidene-2-norbornene may be copolymerized.

(C) The thickness of the intermediate layer is preferably 15 μm to 25 μm, more preferably 15 μm to 20 μm. (C) If the thickness of the intermediate layer is less than 15 μm, it may be difficult to obtain the effect of alleviating unevenness of the heat seal iron when the cover film is heat sealed to the carrier tape. On the other hand, if it exceeds 25 μm, the total thickness of the cover film is so thick that it may be difficult to obtain sufficient peel strength when the cover film is heat-sealed to the carrier tape.

[(D) Heat seal layer]
In the cover film of the present invention, (D) a heat seal layer is formed on the surface of (C) the intermediate layer. (D) The resin of the heat seal layer contains (d-1) an olefin resin and (d-2) an antistatic potassium ionomer.

(D-1) Olefin resin (d-1) Olefin-styrene block copolymer containing 58% by mass to 82% by mass of olefin component and ethylene-vinyl acetate copolymer containing 75% by mass to 88% by mass of olefin component Any one or more of these olefin resins are contained in the heat seal layer in the range of 50% by mass to 90% by mass.

Examples of the olefin-styrene block copolymer include hydrogenated styrene-butadiene block copolymer, hydrogenated styrene-isoprene block copolymer, hydrogenated styrene-butadiene-styrene block copolymer, styrene- Examples thereof include hydrogenated products of isoprene-styrene copolymer resin, and one or more selected from these can be used. Among them, the hydrogenated styrene-butadiene-styrene block copolymer or ethylene-vinyl acetate is excellent in heat sealability with carrier tapes composed of polystyrene, polycarbonate, polyethylene terephthalate, etc. during heat sealing. Moreover, since it is hard to raise | generate a film break, it can use especially suitably.

In the hydrogenated product of the olefin-styrene block copolymer, a preferable content ratio of the olefin component is 58% by mass to 70% by mass. When the olefin component is less than 58% by mass, since the styrene content is large, the (D) heat seal layer becomes hard, so the variation in peel strength tends to increase, and when it exceeds 82% by mass, the heat sealability is high. It tends to be insufficient.

In the ethylene-vinyl acetate copolymer, the preferred olefin component ratio is 75% by mass to 84% by mass. When the olefin component is less than 75% by mass, the content of vinyl acetate is large, and the adhesiveness of the heat seal layer (D) becomes strong. Therefore, when exposed to a high temperature environment, the carrier tape other than the heat seal location Adhesion may occur. If it exceeds 88% by mass, the heat sealability tends to be insufficient. The olefin-styrene block copolymer and the ethylene-vinyl acetate copolymer may be used in combination.

(D) In the olefin resin constituting the heat seal layer, a preferable addition amount is 50 mass% to 70 mass%. If it is less than 50% by mass, the heat seal performance is insufficient, and if it exceeds 90% by mass, the (D) heat seal layer becomes more sticky. In some cases, adhesion to the carrier tape may occur.

(D-2) Antistatic Potassium Ionomer (D) To the heat seal layer, (d-2) antistatic potassium ionomer is added in the range of 10% by mass to 40% by mass. (D-2) The antistatic potassium ionomer includes neutralization of some or all of the carboxyl groups of an ethylene copolymer composed of ethylene and an unsaturated carboxylic acid or, optionally, another monomer as potassium. Potassium ionomers. These impart sufficient antistatic properties to the outermost surface on the (D) heat seal layer side of the cover film. Specifically, the ambient temperature is 23 ° C., the ambient humidity is 30% R.D. H. The surface resistance value of the heat seal layer is 10 ¹² Ω or less, preferably 10 ¹¹ Ω or less.

Examples of unsaturated carboxylic acids in such antistatic potassium ionomers include acrylic acid, methacrylic acid, maleic anhydride, monoethyl maleate, etc., depending on other additives contained in the heat seal layer. it can. Among these, acrylic acid or methacrylic acid is particularly preferable from the viewpoint of copolymerization with ethylene. Moreover, as said other monomer which can become a copolymerization component, the vinyl ester mentioned above and unsaturated carboxylic acid ester can be mentioned as a representative example. Such other monomers are contained in the above copolymer in a proportion of, for example, 0 to 30% by mass.

The antistatic potassium ionomer is contained in 10 to 40% by mass in the (D) heat seal layer. A preferable addition amount is 10% by mass to 30% by mass. If this component is less than 10% by mass, it is difficult to make the surface resistance value of the (D) heat seal layer 10 ¹² Ω or less, and if it exceeds 40% by mass, the heat sealability of the cover film will be lowered and sufficient. Peel strength may not be obtained.

(D-3) Fine particles (D) In order to prevent blocking when the cover film is wound, (d-3) fine particles comprising at least one of organic fine particles and inorganic fine particles ( Hereinafter, it may simply contain (d-3) fine particles). (D-3) Examples of the fine particles include organic fine particles such as spherical or crushed acrylic particles, styrene particles, and silicone particles; inorganic particles such as talc particles, silica particles, mica particles, calcium carbonate, and magnesium carbonate. Fine particles can be added. In particular, acrylic particles and silica particles are less likely to decrease transparency when added, and can be used more suitably.

(D-3) The maximum frequency diameter obtained from the mass distribution curve of the fine particles is preferably 1 μm to 10 μm, more preferably 2 μm to 7 μm. If the maximum frequency diameter is less than 1 μm, the antiblocking effect due to the addition of particles may not be sufficiently exhibited. On the other hand, when it exceeds 10 μm, the blocking prevention effect is good, but a large amount is required to prevent blocking, which causes an increase in cost and is visible on the heat seal layer surface of the cover film. Since the projections and depressions are generated, the appearance of the cover film may be impaired.
The maximum frequency diameter based on the mass distribution curve means a maximum frequency diameter obtained by a laser diffraction / scattering method, for example, “LS13320” manufactured by Beckman Coulter.

(D) The content of (d-3) fine particles in the heat seal layer is preferably 10% by mass or less, more preferably 5% by mass to 10% by mass. If the addition amount is 10% by mass or less, a balance can be achieved in any of transparency, heat sealability and antiblocking effect.

(D) The thickness of the heat seal layer is preferably 5 to 40 μm, more preferably 7 to 20 μm. When the thickness of the heat seal layer is less than 5 μm, sufficient peel strength cannot be obtained when heat sealing with the carrier tape, and the film may be cut. If it exceeds 40 μm, not only will the cost be increased, but the transparency tends to decrease.

[(E) Second heat seal layer]
The cover film of this invention can form (E) 2nd heat seal layer in the outermost surface of (D) heat seal layer located in the other surface of (C) intermediate | middle layer as needed. In other words, (D) the heat seal layer can be configured to have (E) a second heat seal layer on the surface opposite to the (B) intermediate layer side.

(E) The second heat seal layer is made of a thermoplastic resin. The thermoplastic resin is not particularly limited, but the thermoplastic resin mainly composed of an acrylic resin is extremely excellent in heat sealability with respect to polystyrene, polycarbonate and the like which are materials constituting the carrier tape. preferable. In particular, the glass transition temperature of the acrylic resin is preferably 45 ° C. to 80 ° C., more preferably 50 ° C. to 80 ° C. The “main component” means that the content of the acrylic resin in the thermoplastic resin is 30% by mass or more, preferably 50% by mass or more. E) The second heat seal layer may be a layer made of an acrylic resin.

(E) As the acrylic resin constituting the second heat seal layer, acrylic acid esters such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate , A resin containing 50 mass percent or more of at least one (meth) acrylate component such as methacrylic acid esters such as butyl methacrylate and cyclohexyl methacrylate, and a resin obtained by copolymerizing two or more of these.

(E) The thickness of the second heat seal layer is preferably 0.1 μm to 5 μm, more preferably 0.1 μm to 3 μm, and still more preferably 0.1 μm to 0.5 μm. When the thickness of the heat seal is 0.1 μm or more, (E) the second heat seal layer shows more sufficient peel strength. On the other hand, when the thickness of the heat seal layer is 5 μm or less, an increase in cost is suppressed, and variation in peel strength when peeling the cover film hardly occurs.

In addition, (E) an inorganic filler for the purpose of imparting anti-blocking and antistatic properties can be added to the second heat seal layer. The inorganic filler is not particularly limited, and can contain, for example, at least one of conductive tin oxide particles, conductive zinc oxide particles, and conductive titanium oxide particles. Among them, the use of tin oxide doped with antimony, phosphorus, or gallium improves conductivity and reduces transparency, so that it can be used more suitably. The conductive tin oxide particles, the conductive zinc oxide particles, and the conductive titanium oxide particles can be spherical or needle-shaped. In particular, when acicular tin oxide doped with antimony is used, a cover film having particularly good antistatic performance can be obtained.

(E) The mass fraction of the inorganic filler in the second heat seal layer is 50% by mass to 90% by mass, and preferably 65% by mass to 90% by mass. When the addition amount of the conductive particles is less than 50% by mass, there is a possibility that the surface resistance value on the (D) heat seal layer side of the cover film is 10 ¹² Ω or less, and when it exceeds 90% by mass, Since the relative amount of the thermoplastic resin is reduced, it may be difficult to obtain sufficient peel strength by heat sealing.

[Cover Film Production Method]
The method for producing the cover film is not particularly limited, and a general method can be used. For example, a two-component curable adhesive composed of a polyester-based resin and isophorone diisocyanate is applied to the surface of the biaxially stretched polyester film of (A) the base material layer, (B) an adhesive layer is formed, and (C) intermediate A resin composition mainly composed of m-LLDPE is extruded from a T-die and coated on the coated surface of the (B) adhesive layer, whereby (A) a base layer and (C) an intermediate layer. A layer film is formed and the adhesive is cured. Furthermore, the target cover film can be obtained by coating the surface of the (C) intermediate layer with the (D) heat seal layer resin extruded from the T-die.

As another method, (C) the intermediate layer and (D) the film constituting the heat seal layer are each formed by T-die casting method or inflation method, (A) biaxially stretched PET film, The target cover film can also be obtained by a dry laminating method in which each film is bonded through a two-component curable adhesive layer composed of a polyester resin and isophorone diisocyanate.

As another method, the target cover film can be obtained also by the sand laminating method. That is, (D) a film constituting the heat seal layer is formed by a T-die casting method or an inflation method. Next, a resin composition containing molten m-LLDPE as a main component is supplied between (D) the heat seal layer film and (A) the substrate layer film, and (C) an intermediate layer is formed and laminated. This is a method for obtaining a target cover film. Also in the case of this method, as in the above method, (A) a surface on which the base layer film is laminated is coated with a two-component curable adhesive composed of a polyester resin and isophorone diisocyanate.

In particular, the cover film of the present invention uses a multi-manifold or a feed block, (C) a resin composition mainly composed of m-LLDPE as an intermediate layer, and (D) a heat seal layer resin. Alternatively, the two-layer film is laminated by coextrusion by an inflation method, etc., and this cover film is laminated by extrusion lamination method on a PET film coated with a two-part curable adhesive layer composed of polyester resin and isophorone diisocyanate. It is preferable to obtain. Further, it is more preferable to laminate this two-layer film by a dry laminating method on a PET film coated with a two-component curable adhesive layer composed of a polyester resin and isophorone diisocyanate. In these methods, by coextruding the (C) intermediate layer with the (D) heat seal layer, the adhesive strength between the (C) intermediate layer and the (D) sealant layer becomes stronger. Since the starting point of the cover film breakage due to the stress applied to the film is difficult to occur, it is considered that the film breakage strength of the cover film which is the main subject of the present invention is further improved.

In addition to the above steps, if necessary, an antistatic treatment can be performed on at least one side of the cover film. As an antistatic agent, for example, an anionic, cationic, nonionic, or betaine surfactant type antistatic agent, a polymer type antistatic agent, or a conductive material dispersed in a binder, a gravure roll is used. It can be applied by a conventional roll coater, lip coater, spray or the like. In order to uniformly apply these antistatic agents, the corona discharge treatment or ozone treatment is preferably performed on the film surface before the antistatic treatment, and corona discharge treatment is particularly preferred.

[Electronic parts packaging]
The electronic component package of the present invention is a package using the above-described cover film as a cover material for a carrier tape that is a storage container for electronic components. The carrier tape is a belt-like object having a width of about 8 mm to 100 mm having a pocket for storing an electronic component. When heat-sealing with a cover film as a cover material, the material constituting the carrier tape is not particularly limited, and commercially available materials can be used, for example, polystyrene, polyester, polycarbonate, polyvinyl chloride, etc. Can do. When an acrylic resin is used for the second heat seal layer, a combination with a carrier tape of polystyrene and polycarbonate is preferably used. Carrier tapes are those in which conductivity is imparted by kneading carbon black or carbon nanotubes into the resin, those in which an antistatic agent or conductive filler is kneaded, or surfactant type antistatic agents or polypyrrole on the surface. In addition, an antistatic property can be used by applying a coating liquid in which a conductive material such as polythiophene is dispersed in an organic binder such as acrylic.

For example, the packaging body containing the electronic components may include, for example, the cover film as a cover after the electronic components are stored in the electronic component storage portion of the carrier tape, and heat sealing both edges in the longitudinal direction of the cover film. Obtained by packaging and winding on a reel. Electronic parts and the like are stored and transported by packaging in this form. The packaging body containing electronic components etc. is peeled off the cover film intermittently while being transported using a hole called a carrier tape transport sprocket hole provided at the longitudinal edge of the carrier tape, and the component mounting apparatus Thus, the electronic component is taken out while confirming the presence, orientation, and position of the electronic component and mounted on the substrate.

Furthermore, when peeling off the cover film, if the peel strength is too small, it may be peeled off from the carrier tape, and the stored parts may fall off. If it is too large, it will be difficult to peel off the carrier tape and the cover film. Therefore, when heat-sealing at 120 ° C. to 220 ° C., a layer having a peel strength of 0.05 N to 1.0 N is preferable. Those below 4N (less than 0.4N) are preferred.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by these. In the examples and comparative examples, the following resin raw materials were used for (A) the base material layer, (B) the adhesive layer, (C) the intermediate layer, and (D) the heat seal layer.
(A) Base layer resin (a-1) Biaxially stretched polyethylene terephthalate film (o-PET): E-5100 (manufactured by Toyobo), thickness 16 μm

(B) Main ingredient component in adhesive layer (b-1) Main ingredient: LIOSTAR1000 (manufactured by Toyo Morton), polyester resin (polyester polyol), ethyl acetate solution, solid content concentration 50% by mass
(B-2) Main agent: LIS-441A (manufactured by Toyo Morton), olefin resin, methyl ethyl ketone solution, solid content concentration 50 mass%
(B-3) Main agent: Seika Bond A-159 (manufactured by Dainichi Seika Co., Ltd.), polyether resin, ethyl acetate solution, solid content concentration 60% by mass
(B-4) Main agent: N-3495HS (manufactured by Nippon Synthetic Chemical Co., Ltd.), acrylic resin, ethyl acetate / toluene / acetone solution, solid content concentration 45% by mass

(B) Curing agent component in adhesive layer (b-5) Curing agent: LIOSTAR 500H (manufactured by Toyo Morton), isophorone diisocyanate, ethyl acetate solution, solid content concentration 70% by mass
(B-6) Curing agent: CAT-CT (manufactured by Toyo Morton), diphenylmethane diisocyanate, ethyl acetate solution, solid content concentration 70% by mass
(B-7) Curing agent: CAT-10 (manufactured by Toyo Morton), tolylene diisocyanate, ethyl acetate solution, solid content concentration 75% by mass
(B-8) Curing agent: CAT-RT8 (manufactured by Toyo Morton), xylylene diisocyanate, ethyl acetate solution, solid concentration 75% by mass

(C) Intermediate layer resin (c-1) m-LLDPE: Umerit 2040F (manufactured by Ube Maruzen Polyethylene),
MFR 4.0 g / 10 min (measuring temperature 190 ° C., load 2.16 kgf),
Density 0.904 × 10 ³ kg / m ³

(D) Resin for heat seal layer (d-1-1) Resin: Tuftec H1041 (manufactured by Asahi Kasei Chemicals), hydrogenated resin of styrene-butadiene-styrene triblock copolymer (SEBS), olefin component 70% by mass
(D-1-2) Resin: Septon 2007 (manufactured by Kuraray Co., Ltd.), hydrogenated resin (SEPS) of styrene-isoprene-styrene triblock copolymer, olefin component 70% by mass
(D-1-3) Resin: Tuftec H1051 (manufactured by Asahi Kasei Chemicals Corporation), hydrogenated resin (SEBS) of styrene-butadiene-styrene triblock copolymer, olefin component 58 mass%
(D-1-4) Resin: Tuftec H1062 (manufactured by Asahi Kasei Chemicals), hydrogenated resin of styrene-butadiene-styrene triblock copolymer (SEBS), olefin component 82% by mass
(D-1-5) Resin: Tuftec H1221 (manufactured by Asahi Kasei Chemicals), hydrogenated resin (SEBS) of styrene-butadiene-styrene triblock copolymer, olefin component 88% by mass
(D-1-6) Resin: Tuftec H1517 (manufactured by Asahi Kasei Chemicals Corporation), hydrogenated resin of styrene-butadiene-styrene triblock copolymer (SEBS), 57% by mass of olefin component
(D-1-7) Resin: Tuftec H1043 (manufactured by Asahi Kasei Chemicals), hydrogenated resin of styrene-butadiene-styrene triblock copolymer (SEBS), 33% by mass of olefin component

(D-1-8) Resin: Evaflex EV360 (manufactured by Mitsui DuPont Polychemical Co., Ltd.), ethylene-vinyl acetate copolymer resin (EVA), olefin component 75% by mass
(D-1-9) Resin: EVAFLEX EV460 (Mitsui / DuPont Polychemical Co., Ltd.), ethylene-vinyl acetate copolymer resin (EVA), olefin component 81% by mass
(D-1-10) Resin: EVAFLEX V5714 (Mitsui / DuPont Polychemical Co., Ltd.), ethylene-vinyl acetate copolymer resin (EVA), olefin component 84% by mass
(D-1-11) Resin: Evaflex V421 (Mitsui / DuPont Polychemical Co., Ltd.), ethylene-vinyl acetate copolymer resin (EVA), olefin component 72 mass%
(D-1-12) Resin: Everflex P1205 (Mitsui / DuPont Polychemical Co., Ltd.), ethylene-vinyl acetate copolymer resin (EVA), olefin component 88% by mass
(D-1-13) Resin: EVAFLEX EV170 (Mitsui / DuPont Polychemical Co., Ltd.), ethylene-vinyl acetate copolymer resin (EVA), olefin component 67% by mass
(D-1-14) Resin: Evaflex V5711 (manufactured by Mitsui DuPont Polychemical Co., Ltd.), ethylene-vinyl acetate copolymer resin (EVA), olefin component 90% by mass

(D) Antistatic agent in heat seal layer (d-2-1) Antistatic agent: ENTILA MK440 (Mitsui / DuPont), Potassium ionomer (d-2-2) Antistatic agent: Pelestat HS (Sanyo Kasei) ), Polyether ester amide (d-2-3) antistatic agent: Elest Master HE-110 (manufactured by Kao Corporation), nonionic surfactant master batch (1% by weight of nonionic surfactant, High density polyethylene 99% by mass)

(D) Fine particles in heat seal layer (d-3) Fine particles: PEX-ABT-16 (manufactured by Tokyo Ink), talc, silica masterbatch (talc content 5 mass%, silica content 45 mass%, low density polyethylene 50 mass%)

(E) Resin of second heat seal layer (e-1) Resin: NK polymer ECS-706 (manufactured by Shin-Nakamura Chemical Co., Ltd.), styrene-butyl methacrylate random copolymer emulsion, solid content concentration: 36% by mass
(E) Conductive filler added to the heat seal layer 2
(E-2) Conductive filler: SN-100D (manufactured by Ishihara Sangyo Co., Ltd.), spherical antimony-doped tin oxide, number average major axis 0.1 μm, water dispersion type, solid content concentration 30% by mass

(Example 1)
As a resin constituting the sealant layer (heat seal layer), 50% by mass of styrene-butadiene-styrene triblock copolymer hydrogenated resin (Asahi Kasei Chemicals Co., Ltd., “Tuftec H1041”, olefin component amount 70% by mass) and styrene -Butadiene-styrene triblock copolymer hydrogenated resin (Asahi Kasei Chemicals, "Tuftec H1043", olefin component amount 33% by mass) 30% by mass, and potassium ionomer (Mitsui DuPont, "MK440") 20% by mass was pre-blended with a tumbler and kneaded at 200 ° C. using a single screw extruder having a diameter of 40 mm to obtain a resin composition constituting a sealant layer at a line speed of 20 m / min. Separate single-screw extrusion of this resin composition and a metallocene linear low density polyethylene ("Umerit 2040F" manufactured by Ube Maruzen Polyethylene Co., Ltd.) as an olefin resin constituting the intermediate layer (C) shown in Tables 1 and 2 Extrusion from the machine and lamination extrusion with a multi-manifold T-die yielded a two-layer film (D) having a heat seal layer thickness of 10 μm and (C) an intermediate layer having a thickness of 20 μm. Next, on the bonding surface of the biaxially stretched polyethylene terephthalate film (thickness: 16 μm), by a gravure method, a polyester resin (“LIOSTAR1000” manufactured by Toyo Morton Co., Ltd.) as a main agent and isophorone diisocyanate (Toyo) as a curing agent. (B) Adhesive so that the two-part curable adhesive made of Morton, "LIOSTAR500H") is mixed at 91 (main agent): 9 (curing agent) in terms of solid content, and the thickness after drying is 3 μm An agent layer was formed, and the (C) intermediate layer surface of the two-layer film was bonded together by a dry laminating method to obtain a cover film for a carrier tape of an electronic component having the configuration shown in FIG.

(Examples 2 to 11, Examples 13 to 24, Examples 26 to 40, Comparative Examples 1 to 22)
A cover film was produced in the same manner as in Example 1 except that the adhesive layer and the heat seal layer were formed using raw materials such as resins listed in Tables 1 to 5.

Example 12
Using the laminated film obtained in Example 4, (D) the surface of the heat seal layer was corona-treated, and then relative to 20% by mass of a random copolymer of styrene-butyl methacrylate [(e-1) resin]. [(E-2) Conductive filler] A carrier tape cover film having conductive performance was obtained by applying a solution of 80% by mass so that the thickness after drying was 0.3 μm.

(Example 25)
A cover film was produced in the same manner as in Example 12 except that the laminated film obtained in Example 17 was used.

<Evaluation method>
The evaluation shown below was performed about the cover film for carrier tapes of the electronic component produced by each Example and each comparative example. These results are summarized in Tables 1 to 5, respectively.

(1) Haze value The haze value was measured using an integrating sphere type measuring device according to the measuring method A of JIS K 7105: 1998. The results are shown in the haze values column of Tables 1-5.

(2) Sealing performance Using a taping machine (Nagata Seiki Co., Ltd., NK-600), seal head width 0.5 mm x 2, seal head length 24 mm, seal pressure 0.5 kgf, feed length 12 mm, seal time 0.3 seconds × Two times, a cover film with a width of 21.5 mm at intervals of 10 ° C. from a seal iron temperature of 140 ° C. to 190 ° C., a 24 mm wide polycarbonate carrier tape (manufactured by Denki Kagaku Kogyo), and a polystyrene carrier tape (Electrochemical Industry Co., Ltd.) Manufactured). After leaving for 24 hours in an atmosphere with a temperature of 23 ° C. and a relative humidity of 50%, the cover film was peeled off at a speed of 300 mm / min and a peeling angle of 170 ° to 180 ° in the same atmosphere at a temperature of 23 ° C. and a relative humidity of 50%. . Sealability was evaluated based on the average peel strength when heat-sealing at a 10 ° C. interval from a seal iron temperature of 140 ° C. to 190 ° C. The number of samples for which peel strength was measured at each temperature was 3.
“Excellent”: An average peel strength in a range of 0.3 N to 0.9 N at all temperatures.
“Good”: The average peel strength was outside the range of 0.3 N to 0.9 N and the temperature was 1 to 5 points.
“Bad”: An average peel strength outside the range of 0.3 N to 0.9 N at all temperatures.
The results are shown in the sealability column of Tables 1-5.

(3) Variation in peel strength Heat sealing was performed so that the peel strength with respect to a polystyrene carrier tape (manufactured by Denki Kagaku Kogyo) was 0.4N. The cover film was peeled off under the same conditions as in (2) Sealability. Variation in peel strength was derived from the chart obtained when the cover film for 100 mm was peeled in the peel direction. When the variation in peel strength was less than 0.2N, it was marked as “excellent”, when it was between 0.2N and 0.4N as “good”, and when it was greater than 0.4N as “bad”. The results are shown in the column of variation in peel strength in Tables 1-5.

(4) Blocking property After heat-sealing so that the peel strength is 0.4 N under the condition of (3), a tape taped around a paper tube with a diameter of 95 mm is wound around the paper tube. Thereafter, it was left in an environment at 60 ° C. for 24 hours. At this time, if the flange part of the pocket part (located between the electronic parts) molded on the carrier tape (adjacent to the flange part) is not adhered, it is marked as “good”, and the visible part is marked as “bad”. did. The results are shown in the blocking properties column of Tables 1-5.

(5) Interlayer adhesive strength After cutting the cover film to 300 mm in the longitudinal direction and 15 mm in width, (A) the base material layer and (C) the intermediate layer are peeled off in advance, and a tensile tester (EZ Test manufactured by Shimadzu Corporation) Each peeled edge portion was placed on and the interlayer adhesive strength was evaluated by T-peeling at a rate of 200 mm per minute under the condition of 23 ° C. If the interlayer adhesive strength is less than 5N / 15mm, the adhesive strength of 5N / 15mm or more may be peeled off between the (A) base material layer and (C) intermediate layer in the electronic component mounting process. Is indicated as “bad” if the adhesive strength is less than 5 N / 15 mm. The results are shown in the column of interlayer adhesion strength in Tables 1-5.

(6) Breaking resistance of cover film Heat sealing was performed so that the peel strength with respect to a polystyrene carrier tape (manufactured by Denki Kagaku Kogyo) was 1.0 N. The cover film was peeled off under the same conditions as in (2) Sealability. The carrier tape with the cover film sealed was cut out to a length of 550 mm, and the pocket bottom of the carrier tape was attached to a vertical wall to which a double-sided adhesive tape was attached at 23 ° C. The cover film was peeled off by 50 mm from the upper part of the affixed carrier tape, the cover film was sandwiched between clips, and a weight having a mass of 1000 g was attached to the clip. After that, when the weight was allowed to fall naturally, 1 out of 50 samples where the cover film did not break was “excellent”, 1-50 out of 50 samples were broken, “good”, 6 samples or more What was cut was marked as “bad”. The results are shown in the film breakability column of Tables 1-5.

(7) Stability over time of peel strength Heat sealing was performed so that the peel strength was 0.4 N under the same conditions as in (3) Sealability. It was put in an environment with a temperature of 60 ° C., a relative humidity of 10%, and a temperature of 60 ° C. and a relative humidity of 95% for 7 days. After removal, it was left in an atmosphere of a temperature of 23 ° C. and a relative humidity of 50% for 24 hours. The peel strength was measured in an atmosphere with a relative humidity of 50%. The peel strength was measured under the same conditions as in (3) Sealability. A sample having an average peel strength in the range of 0.3N to 0.5N is defined as “excellent”, and a sample having an average peel strength in the range of 0.2N to less than 0.3N and greater than 0.5N to 0.6N And those having an average peel strength other than those described above were indicated as “bad”. The results are shown in the sealability column of Tables 1-5.

(8) Surface Resistance Value Using a Hiresta UP MCP-HT450 manufactured by Mitsubishi Chemical Corporation, the surface resistance value of the surface of the heat seal layer was measured at an ambient temperature of 23 ° C., an atmospheric humidity of 50% RH, and an applied voltage of 500 V by the method of JIS K6911. . The results are shown in the surface resistance column of Tables 1-5.

As is apparent from Tables 1 to 3, the cover films of Examples 1 to 40 are cover films used in combination with carrier tapes such as polystyrene and polycarbonate, and are peeled off when the cover film is peeled to take out electronic components. The cover film has a constant strength within a predetermined value range, is excellent in transparency, and is less likely to cause “film breakage” during high-speed peeling.

1 Cover film 2 Base material layer 3 Adhesive layer 4 Intermediate layer 5 Heat seal layer

Claims

A cover film having at least (A) a base material layer, (B) an adhesive layer, (C) an intermediate layer, and (D) a heat seal layer,
(B) The adhesive layer is composed of a cured product of a main agent containing a polyester-based resin and a curing agent containing 50% by mass or more of isophorone diisocyanate,
(D) The resin constituting the heat seal layer is
(D-1) Contains one or both of an olefin-styrene block copolymer containing 58% by mass to 82% by mass of an olefin component and an ethylene-vinyl acetate copolymer containing 75% by mass to 88% by mass of an olefin component. 50% by mass to 90% by mass of olefin resin,
(D-2) 10% by mass to 40% by mass of potassium ionomer having antistatic performance,
And the surface resistance value of the outermost surface by the side of the (D) heat seal layer of a cover film is 10 < 12 > (ohm) or less, The cover film characterized by the above-mentioned.
The cover film according to claim 1, wherein (D) the heat seal layer contains (d-3) one or both of organic fine particles and inorganic fine particles in total of 10% by mass or less.
The cover film according to claim 1 or 2, wherein the content of isophorone diisocyanate in the curing agent is 4% by mass to 13% by mass with respect to the total with the polyester resin.
The cover film according to any one of claims 1 to 3, wherein an interlayer adhesive strength between (A) the base material layer and (C) the intermediate layer is 5 N / 15 mm or more.
(C) the intermediate layer is made of a metallocene linear low-density polyethylene resin having a density of 0.900 × 10 3 kg / m 3 to 0.925 × 10 3 kg / m 3 and has a thickness of 15 μm to 25 μm. The cover film as described in any one of Claim 1 to 4.
(D) On the surface on the opposite side to the (B) intermediate | middle layer side of (D) heat seal layer, it has a 2nd heat seal layer which has an acrylic resin as a main component in any one of Claim 1 to 5. The cover film as described.
An electronic component package using the cover film according to any one of claims 1 to 6 as a cover material for a carrier tape made of a thermoplastic resin.