KR102337822B1 - Cover film and electronic component packaging employing same - Google Patents

Abstract

The present invention provides a cover film in which the peeling strength at the time of peeling the cover film is continuously constant within a predetermined value range, excellent in transparency, and difficult to cause "film breakage" during high-speed peeling. 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 mainly composed of a polyester-based resin and a curing agent is 50 % by mass or more is isophorone diisocyanate, (D) heat seal (d-1) olefin-styrene block copolymer containing 58 to 82% by mass of olefin component, and ethylene- containing 75 to 88% by mass of olefin component A cover film comprising 50 to 90% by mass of an olefin-based resin comprising at least one kind of vinyl acetate copolymer, and (d-2) 10 to 40% by mass of a potassium ionomer having antistatic performance.

Description

Cover film and electronic component packaging using the same

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

With the miniaturization of electronic devices, miniaturization and high performance of electronic components used are also in progress. In addition, in the assembly process of an electronic device, automatically mounting an electronic component on a printed circuit board is performed. The electronic component for surface mounting is accommodated in a carrier tape in which an embossed pocket that can be accommodated according to the shape of the electronic component is interlocked. After accommodating the electronic component, a cover film as a cover material is overlapped on the upper surface of the carrier tape, and both ends of the cover film are successively heat-sealed in the longitudinal direction with a heated sealing bar to obtain a package body. As a cover film material, what laminated|stacked the sealant layer of the thermoplastic resin as a base material, etc. are used for the polyester film which carried out biaxial stretching.

When a cover film mounts an electronic component in manufacturing processes, such as an electronic device, it peels with an automatic peeling apparatus from a carrier tape. Therefore, it becomes especially important that peeling strength with a carrier tape is stable within a suitable range as a function of a cover film. If the peeling strength is too strong, the cover film may break. On the contrary, if the peel strength is too weak, the cover film may peel off from the carrier tape during transport of the carrier and the electronic component as the content may drop off. In addition, when transporting a carrier, it may be exposed to a high temperature environment of 40 to 60° C., and the heat sealing layer of the thermoplastic resin softens and adheres to the carrier tape at locations other than the heat-sealed ends in some cases, resulting in an increase in peel strength. sometimes do. In particular, the peeling speed of the cover film is also extremely high in 0.1 second or less/tact in accordance with the rapid increase in the mounting speed. During peeling, a large impact stress is applied to the cover film. As a result, the problem called "film breakage" in which a cover film is cut|disconnected arises.

The peel strength of the cover film is 0.1 to 1.0N in a carrier tape having a width of 8 mm, and 0.1 to 1.3N in a carrier tape having a width of 12 mm to 56 mm when the peeling rate is 300 mm per minute in JIS C0806-3. However, in the mounting process of electronic components, the peeling speed is faster than 300 mm per minute, and especially when large-sized connector parts are accommodated, taping is often performed with the peel strength of the upper limit, resulting in "film breakage" when peeling the cover film easy.

On the other hand, there are cases in which high transparency is required for the cover film so that electronic components, which are stored objects, can be easily identified. For example, in the inspection of electronic components such as ICs, there is a method of determining defects such as IC pin deformation by photographing with a CCD camera on such a cover film and analyzing the image, and for this, a cover film having high transparency is required. In this method of use, 50% or less is required as a haze (soak).

As a countermeasure against film breakage, a method of providing a layer excellent in impact resistance and tear propagation resistance such as polypropylene, nylon or polyurethane between a base material such as a biaxially stretched polyester film and a sealant layer has been proposed (Patent References 1 to 3). On the other hand, a method of preventing stress propagation to the base material layer by using a metallocene linear low-density polyethylene (LLDPE) having a specific specific gravity as the intermediate layer and making the adhesive layer between the intermediate layer and the base material layer a low Young's modulus has been proposed (Patent See document 4). In addition, for the purpose of obtaining a cover film with a stable sealability and small change in seal temperature dependence and aging of peel-off strength, a method for solving the above problems is obtained by mixing a styrene-butadiene-styrene block copolymer with polyethylene or polypropylene with a sealant resin composition. It has been proposed (refer to Patent Document 5). However, it was difficult to sufficiently suppress film breakage at high-speed peeling such as 100 m/min also according to these methods. As a countermeasure against film breakage, a cover film in which interlayer adhesion is improved by co-extruding each layer made of a styrene-based hydrocarbon resin has been proposed (see Patent Document 6). However, in this method, the stability of the peel strength after heat sealing was insufficient.

Patent Document 1: Japanese Patent Laid-Open No. 8-119373 Patent Document 2: Japanese Patent Laid-Open No. 10-250020 Patent Document 3: Japanese Patent Application Laid-Open No. 2000-327024 Patent Document 4: Japanese Patent Laid-Open No. 2006-327624 Patent Document 5: Japanese Patent Application Laid-Open No. 8-324676 Patent Document 6: Japanese Patent Application Laid-Open No. 2007-90725

An object of the present invention is to provide a cover film having a constant peel strength within a predetermined range, excellent transparency, and hardly causing "film breakage" during high-speed peeling.

As a result of closely examining the above subject, the present inventors have found that a cover film that overcomes the subject of the present invention can be obtained by providing a resin composition having a specific structure in the adhesive layer and the heat seal layer positioned between the base material layer and the intermediate layer. Thus, the present invention was reached.

That is, the present invention is a cover film having (1) 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 contains a polyester resin and a cured product of a curing agent containing 50% by mass or more of isophorone diisocyanate and a main agent that 50% by mass to 90% by mass of an olefin-based resin containing either one or both of an olefin-styrene block copolymer and an ethylene-vinyl acetate copolymer containing 75% by mass to 88% by mass of an olefin component, and (d- 2) A cover film comprising 10% by mass to 40% by mass of potassium ionomer having antistatic performance, and a surface resistance value of the outermost surface of the cover film (D) on the heat-sealing layer side of 10 ¹² Ω or less to be.

Further, in another aspect, as a cover film comprising at least (A) a base material layer, (B) an adhesive layer, (C) an intermediate layer, and a (D) heat seal layer having a heat-sealable resin, (B) the adhesive layer comprises a main agent and The curing agent is composed of a cured product of a two-component curing adhesive, the main agent is a polyester resin, 50% by mass or more of the curing agent is isophorone diisocyanate, (D) the resin constituting the heat seal layer is (d) -1) 50 to 90 mass of an olefin-based resin comprising at least one of an olefin-styrene block copolymer containing 58 to 82 mass % of an olefin component and an ethylene-vinyl acetate copolymer containing 75 to 88 mass % of an olefin component % and (d-2) 10-40 mass % of potassium ionomer which has antistatic performance, and (D) It can be comprised so ^{that the surface resistance value of a heat-sealing layer may be 10 12 ohms or less.}

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

(3) In this invention, it is preferable that content of isophorone diisocyanate in the said hardening|curing agent is 4 mass % - 13 mass % with respect to the total with 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/15 mm or more.

(5) In the present invention, (C) the intermediate layer is made of a metallocene-based 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 preferably has a thickness of 15 μm to 25 μm.} do.

(6) In the present invention, it can be constituted so as to have a second heat-sealing layer containing (E) an acrylic resin as a main component on the surface of the (D) heat-sealing layer opposite to the (B) intermediate layer side.

(7) This invention is an electronic component packaging body using the cover film in any one of said (1)-(6) as a cover material of the carrier tape which consists of a thermoplastic resin.

According to the present invention, it is possible to obtain a cover film having a constant peel strength within a predetermined range, excellent transparency, and hardly causing "film breakage" during high-speed peeling.

BRIEF DESCRIPTION OF THE DRAWINGS 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 this invention is shown in FIG. The cover film 1 shown in FIG. 1 includes a base material layer 2 , an adhesive material layer 3 , an intermediate layer 4 , and a heat seal layer 5 . In this cover film 1, the base material layer 2, the adhesive material layer 3, the intermediate|middle layer 4, and the heat-sealing layer 5 are laminated|stacked in this order.

[(A) Base material layer]

(A) The base material layer is a layer made of biaxially stretched polyester or biaxially stretched nylon. Biaxially stretched polyethylene terephthalate (PET) or biaxially stretched polyethylene naphthalate (PEN) or biaxially stretched 6,6-nylon Alternatively, 6-nylon may be particularly suitably used. As biaxially stretched PET, biaxially stretched PEN, biaxially stretched 6,6-nylon, or 6-nylon, other than those normally used, antistatic agents for antistatic treatment are applied or impregnated, or corona treatment or easy adhesion treatment, etc. can be used that has been carried out. When the base material layer is too thin, the tensile strength of the cover film itself is lowered, and thus "breaking of the film" tends to occur when the cover film is peeled off. On the other hand, when it is too thick, not only the heat-sealing property with respect to a carrier tape will fall, but it will cause cost increase. Therefore, as for the thickness of the (A) base material layer, the thing of the thickness of 12 micrometers - 25 micrometers can be used suitably normally.

[(B) Adhesive layer]

(B) The adhesive layer is composed of a cured product of a two-component curing adhesive with 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. Preferably, isophorone diisocyanate is 60 mass % or more. The upper limit is not specifically limited, It can be 80 mass % or less, 90 mass % or less, or 100 mass %. When other acrylic resins, olefin resins, or polyether resins are used as main agents, the adhesive strength with the (A) base material layer becomes insufficient.

Examples of the polyester-based resin include polyester-based resins having active hydrogens such as two or more hydroxyl groups or amino groups in the molecule, specifically polyester polyols and polyester polyamines. As a polyester polyol, 1-200 of hydroxyl value (mgKOH/g) and 1000-50000 of number average molecular weights are preferable. In addition, the number average molecular weight here is a value at the time of measuring by JISK7252. Examples of the polyester polyol include a condensation reaction product of a polyhydric hydroxyl group-containing compound, polycarboxylic acid or anhydride, and an ester-forming derivative such as a lower alkyl (alkyl group having 1 to 4 carbon atoms) ester.

As for the mass fraction of isophorone diisocyanate used as a hardening|curing agent, 4-13 mass % is preferable with respect to the total with polyester-type resin, More preferably, it is 5 mass % - 10 mass %. By setting it as 4 mass % or more, it can prevent that the adhesive strength of (A) base material layer and (C) intermediate|middle layer becomes inadequate, and by setting it as 13 mass % or less, a cost increase is suppressed and it becomes brittle and the breaking strength falls. can be prevented

When an isocyanate other than isophorone diisocyanate is used alone as a curing agent, for example, tolylene diisocyanate or xylene diisocyanate, (B) the adhesive layer is brittle and sufficient breaking strength of the film may not be obtained. In addition, when diphenylmethane diisocyanate is used as another curing agent, the curing rate is significantly faster than that of isophorone diisocyanate used in the present invention. The adhesive strength between the base material layer and the (C) intermediate layer may become insufficient.

It is preferable to use the two-component curing adhesive by mixing it in a predetermined ratio after diluting it in a solvent. The diluting solvent is not specifically limited, Water, ethyl acetate, toluene, methyl ethyl ketone, etc. can be used. (B) The adhesive layer is formed by applying a two-component curing adhesive to the (A) base material layer and then drying it. It is preferable that the thickness after drying (that is, (B) the thickness of an adhesive material layer) is 1 micrometer - 5 micrometers. By setting it as 1 µm or more, it is possible to prevent the adhesive strength from becoming insufficient without tracking the surface roughness of the (C) intermediate layer, and by setting it to 5 µm or less, it is possible to further prevent the variation in peel strength after heat sealing to the carrier tape from increasing.

[(C) Middle layer]

In the present invention, (C) the intermediate layer is provided by laminating on one side of the (A) base material layer through the (B) adhesive layer. (C) As the resin constituting the intermediate layer, linear low-density polyethylene (hereinafter referred to as LLDPE) having particularly flexibility, moderate rigidity, and excellent tear strength at room temperature can be suitably used, and particularly having a density of 0.900×10 ³ kg ^{By using a resin in the range of /m 3 to} 0.925×10 3 kg/m 3 , it is difficult for the intermediate layer resin to protrude from the end of the cover film due to heat or pressure during heat sealing. Therefore, not only is it difficult to generate dirt on the iron during heat sealing, but also when the cover film is heat-sealed, the intermediate layer is softened to relieve spots on the heat-sealing iron.

Examples of LLDPE include those polymerized with a Ziegler 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 intermediate layer (B) of the present invention.

The m-LLDPE is a copolymer of ethylene and an α-olefin substituted with an olefin having 3 or more carbon atoms, preferably a linear, branched, aromatic nucleus having 3 to 18 carbon atoms as a comonomer. 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, 1 -octadecene, etc. are mentioned. Further, examples of the branched monoolefin include 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, and 2-ethyl-1-hexene. Moreover, styrene etc. are mentioned as monoolefin substituted by the aromatic nucleus. These comonomers can be copolymerized with ethylene individually or in combination of 2 or more types. In this copolymerization, polyenes such as butadiene, isoprene, 1,3-hexadiene, dicyclopentadiene, and 5-ethylidene-2-norbornene may be copolymerized.

(C) As for the thickness of an intermediate|middle layer, 15 micrometers - 25 micrometers are preferable, More preferably, they are 15 micrometers - 20 micrometers. (C) When the thickness of an intermediate|middle layer is less than 15 micrometers, it may be difficult to acquire the effect which relieves the spot of the heat-sealing iron at the time of heat-sealing a cover film to a carrier tape. On the other hand, when it exceeds 25 micrometers, since the total thickness of a cover film is thick, when heat-sealing a cover film to a carrier tape, it may become difficult to obtain sufficient peeling strength.

[(D) Heat seal layer]

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

(d-1) Olefin-based resin

(d-1) an olefin comprising at least one of an olefin-styrene block copolymer containing 58 mass % to 82 mass % of an olefin component and an ethylene-vinyl acetate copolymer containing 75 mass % to 88 mass % of an olefin component System resin is contained in a heat-sealing layer in 50 mass % - 90 mass %.

As the olefin-styrene block copolymer, a hydrogenated product of a styrene-butadiene block copolymer, a hydrogenated product of a styrene-isoprene block copolymer, a hydrogenated product of a styrene-butadiene-styrene block copolymer, a hydrogenated product of a styrene-isoprene-styrene copolymer resin, etc. and 1 type or 2 or more types selected from these can be used. Among them, the hydrogenated substance of the styrene-butadiene-styrene block copolymer or ethylene-vinyl acetate has excellent heat-sealing properties with a carrier tape composed of polystyrene, polycarbonate, polyethylene terephthalate, etc. at the time of heat sealing, and film breakage is difficult to occur. It can be used especially suitably from a point.

The hydrogenated substance of an olefin-styrene block copolymer WHEREIN: The content rate of a preferable olefin component is 58 mass % - 82 mass %. If the olefin component is less than 58 mass %, since the content of styrene is large (D) the heat seal layer becomes hard, so the variation (non-uniformity) in peel strength tends to become large, and when the olefin component exceeds 82 mass %, the heat sealing property becomes insufficient. easy.

The ethylene-vinyl acetate copolymer WHEREIN: A preferable olefin component ratio is 75 mass % - 84 mass %. If the olefin component is less than 75% by mass, since the content of vinyl acetate is large (D), the adhesiveness of the heat seal layer becomes strong. . When it exceeds 88 mass %, heat-sealing property tends to become inadequate. Moreover, you may use an olefin-styrene block copolymer and an ethylene- vinyl acetate copolymer using these together.

(D) Olefin resin which comprises a heat-sealing layer WHEREIN: The preferable addition amount is 50 mass % - 70 mass %. If it is less than 50 mass %, the heat seal performance is insufficient, and if it exceeds 90 mass %, (D) Since the adhesiveness of the heat seal layer becomes strong, when exposed to a high temperature environment, adhesion to the carrier tape occurs outside the heat seal area. There are cases.

(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) Examples of the antistatic potassium ionomer include a potassium ionomer in which part or all of the carboxyl groups of an ethylene copolymer composed of ethylene and unsaturated carboxylic acid or other monomers as optional components are neutralized with potassium. These provide sufficient antistatic properties to the outermost surface of the cover film (D) on the heat-sealing layer side. Specifically, the surface resistance value of the heat-sealing layer at an atmospheric temperature of 23°C and an atmospheric humidity of 30% RH is 10 ¹² Ω or less. , preferably 10 ¹¹ Ω or less.

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

10 mass % - 40 mass % of antistatic potassium ionomers are contained in (D) heat-sealing layer. A preferable addition amount is 10 mass % - 30 mass %. When this component is less than 10 mass %, (D) ^{it is difficult to make the surface resistance value of the heat seal layer 10 12} Ω or less, and when it exceeds 40 mass %, the heat sealing property of the cover film decreases and sufficient peel strength cannot be obtained. there is

(d-3) fine particles

(D) In order to prevent blocking when the cover film is wound on the heat seal layer, (d-3) fine particles comprising at least one of organic fine particles and inorganic fine particles (hereinafter referred to simply as (d-3) fine particles) may contain. (d-3) As the fine particles, organic fine particles such as spherical or crushed acrylic particles, styrene particles and silicon particles, and inorganic fine particles such as talc particles, silica particles, mica particles, calcium carbonate and magnesium carbonate can be added. In particular, when acrylic particles or silica particles are added, there is little decrease in transparency and can be used more suitably.

(d-3) As for the maximum frequency diameter obtained from the mass distribution curve of fine particles, 1 micrometer - 10 micrometers are preferable, More preferably, they are 2 micrometers - 7 micrometers. When the maximum frequency diameter is less than 1 µm, the blocking prevention effect by the addition of particles may not be sufficiently exhibited. On the other hand, when it exceeds 10 μm, the anti-blocking effect becomes good, but a large amount of addition is required to prevent blocking, which leads to an increase in cost or causes visible irregularities on the surface of the heat seal layer of the cover film. There is a risk of damaging the appearance of

In addition, the maximum frequency diameter by a mass distribution curve means the maximum frequency diameter obtained by laser diffraction/scattering method, for example, "LS13320" by Beckman Coulter.

(D) It is preferable that it is 10 mass % or less in total, and, as for content of (d-3) fine particle in a heat-sealing layer, it is more preferable that they are 5 mass % - 10 mass %. A balance can be achieved in transparency, heat-sealing property, and blocking prevention effect all that the addition amount is 10 mass % or less.

(D) As for the thickness of a heat-sealing layer, 5 micrometers - 40 micrometers are preferable, More preferably, they are 7-20 micrometers. When the thickness of a heat-sealing layer is less than 5 micrometers, when heat-sealing with a carrier tape, sufficient peeling strength cannot be acquired, but there exists a possibility of raising a film breakage. When it exceeds 40 micrometers, it not only causes cost increase, but transparency is easy to fall.

[(E) Second heat seal layer]

In the cover film of the present invention, (E) a second heat seal layer may be formed on the outermost surface of the (D) heat seal layer located on the opposite surface of the (C) intermediate layer, if necessary. In other words, it can be configured to have the (E) second heat seal layer on the surface opposite to the (B) intermediate layer side of the (D) heat seal layer.

(E) The 2nd heat-sealing layer is comprised from the thermoplastic resin. The thermoplastic resin is not particularly limited, but a thermoplastic resin containing an acrylic resin as a main component is preferable from the viewpoint of extremely excellent heat-sealing properties to polystyrene, polycarbonate, etc., which are materials constituting the carrier tape. In particular, as for the glass transition temperature of acrylic resin, 45 degreeC - 80 degreeC are preferable, More preferably, they are 50 degreeC - 80 degreeC. 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. Moreover, (E) 2nd heat-sealing layer can also be made into the layer which consists of an acrylic resin.

(E) Examples of the acrylic resin constituting the second heat seal layer include acrylic acid esters such as methyl acrylate, ethyl acrylate, propyl acrylate, and butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, Resin which copolymerized these 2 or more types as resin containing 50 mass % or more of at least 1 or more types of (meth)acrylate components, such as methacrylic acid ester, such as methacrylic acid cyclohexyl, may be sufficient.

(E) As for the thickness of a 2nd heat-sealing layer, 0.1 micrometer - 5 micrometers are preferable, More preferably, it is 0.1 micrometer - 3 micrometers, More preferably, it is the range of 0.1 micrometer - 0.5 micrometer. When the thickness of a heat seal is 0.1 micrometer or more, (E) 2nd heat-sealing layer shows more sufficient peeling strength. On the other hand, when the thickness of a heat-sealing layer is 5 micrometers or less, while suppressing an increase in cost, when peeling a cover film, it is hard to generate|occur|produce the dispersion|variation in peeling strength.

Moreover, (E) The inorganic filler aimed at provision of blocking prevention and antistatic performance can be added to a 2nd heat-sealing layer. Although the inorganic filler is not specifically limited, For example, it can contain at least 1 of electroconductive tin oxide particle, electroconductive zinc oxide particle, and electroconductive titanium oxide particle. Among them, by using tin oxide doped with antimony, phosphorus, or gallium, conductivity is improved and transparency is less reduced, so it can be used more suitably. As the conductive tin oxide particles, conductive zinc oxide particles and conductive titanium oxide particles, spherical or needle-shaped particles can be used. In particular, when needle-like tin oxide doped with antimony is used, a cover film having particularly good antistatic performance can be obtained.

(E) The mass fraction of an inorganic filler in a 2nd heat-sealing layer is 50 mass % - 90 mass %, Preferably they are 65 mass % - 90 mass %. When the addition amount of the conductive particles is less than 50% by mass, there is a fear that the surface resistance value of the (D)heat-sealing layer side of the cover film can ^{not be obtained that is 10 12} Ω or less, and when it exceeds 90% by mass, the relative amount of the thermoplastic resin decreases. There exists a possibility that it may become difficult to obtain sufficient peeling strength by a heat seal.

[Manufacturing method of cover film]

The method of producing the said cover film is not specifically limited, A general method can be used. For example, a two-component curing adhesive composed of a polyester resin and isophorone diisocyanate is applied to the surface of the biaxially stretched polyester film of the base material layer (A) to form (B) an adhesive layer, and (C) the intermediate layer By extruding the resin composition containing m-LLDPE as a main component from the T-die and coating it on the coated surface of the adhesive layer (B), a two-layer film consisting of (A) the base material layer and (C) the intermediate layer is formed and the adhesive is cured at the same time. . Furthermore, the target cover film can be obtained by coating (D) heat-sealing layer resin extruded from the T-die on the surface of (C) intermediate|middle layer.

As another method, the films constituting the (C) intermediate layer and (D) the heat seal layer are respectively formed by a T-die casting method or an inflation method, and the (A) biaxially stretched PET film and each film are coated with a polyester resin. The target cover film can also be obtained by the dry lamination method which adhere|attaches via the two-component curable adhesive layer which consists of and isophorone diisocyanate.

As another method, the target cover film can be obtained also by the sand lamination method. That is, (D) the film constituting the heat seal layer is formed by a T-die casting method or an inflation method or the like. Next, a resin composition containing m-LLDPE dissolved between the (D) heat seal layer film and (A) the base material layer film is supplied, and (C) an intermediate layer is formed and laminated to obtain the target cover film. to be. In the case of this method as well, as in the above method (A), a two-component curable adhesive composed of a polyester resin and isophorone diisocyanate is coated on the laminated side of the base material layer film.

In particular, the cover film of the present invention is prepared by using (C) a resin composition containing m-LLDPE as an intermediate layer as a main component and (D) a heat seal layer resin using a multi-manifold or feed block using a T-die casting method or an inflation method. It is preferable to laminate by co-extrusion, and to obtain a cover film by laminating this two-layer film to a PET film coated with a two-component curable adhesive layer comprising a polyester-based resin and isophorone diisocyanate by extrusion lamination. Furthermore, it is more preferable to laminate this two-layer film on the PET film coated with the two-component curing adhesive layer which consists of a polyester resin and isophorone diisocyanate by the dry lamination method. In these methods, (C) the intermediate layer is co-extruded with the (D) heat seal layer, so that the adhesive strength between (C) the intermediate layer and (D) the sealant layer becomes stronger. It is thought that the film breaking strength of the cover film which is the main subject of this invention improves further since it is hard to produce.

In addition to the above process, an antistatic treatment may be performed on at least one surface of the cover film as needed. As an antistatic agent, for example, surfactant-type antistatic agents such as anionic, cationic, nonionic, betaine, etc., polymeric antistatic agents, and conductive materials dispersed in a binder are applied to a roll coater using a gravure roll, lip coater, spray, etc. can be applied by Moreover, in order to apply|coat these antistatic agents uniformly, it is preferable to carry out corona discharge treatment or ozone treatment on the film surface before performing an antistatic treatment, and corona discharge treatment is especially preferable.

[Electronic component packaging body]

The electronic component package of this invention is the package which used the said cover film as a cover material of the carrier tape which is a storage container of an electronic component. Carrier tape is a strip of about 8 mm to 100 mm wide with pockets for accommodating electronic components. In the case of heat sealing using the cover film as a cover material, the material constituting the carrier tape is not particularly limited, and commercially available ones may be used. For example, polystyrene, polyester, polycarbonate, polyvinyl chloride, etc. may be used. have. When an acrylic resin is used for a 2nd heat-sealing layer, the combination with the carrier tape of polystyrene and polycarbonate is used suitably. Carrier tapes are those to which conductivity is imparted by kneading carbon black or carbon nanotubes into a resin, those in which an antistatic agent or conductive filler is kneaded, or a surfactant-type antistatic agent or a conductive material such as polypyrrole or polythiophene on the surface of the acrylic A coating solution dispersed in an organic binder such as those to which antistatic properties are imparted can be used.

The package housing the electronic component is, for example, after the electronic component is accommodated in the electronic component housing portion of the carrier tape, the cover film is used as a cover material, and both edges in the longitudinal direction of the cover film are continuously heat-sealed and packaged. It is obtained by winding on a reel. By packaging in this form, electronic components and the like are stored and transported. The package housing electronic components, etc. is intermittently removed from the cover film while conveying using a hole called a carrier tape conveying sprocket hole provided at the edge of the carrier tape in the longitudinal direction, and electronic components, etc. It is taken out while checking the presence, direction, and position of the device and mounted on the board.

Furthermore, when peeling off the cover film, if the peeling strength is too small, it may peel off from the carrier tape and the housing parts may fall off. Therefore, when heat-sealing at 120 degreeC - 220 degreeC, it is good to have a peeling strength of 0.05N - 1.0N, and it is preferable to be less than 0.4N (less than 0.4N) about the dispersion|variation in peeling strength.

Example

Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by these. In 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) Resin of the base material layer

(a-1) Biaxially stretched polyethylene terephthalate film (o-PET): E-5100 (manufactured by Toyobo Corporation), thickness 16 μm

(B) Main ingredient in the adhesive layer

(b-1) Main agent: LIOSTAR1000 (manufactured by Toyo Morton), polyester-based resin (polyester polyol), ethyl acetate solution, solid content concentration of 50% by mass

(b-2) Main agent: LIS-441A (manufactured by Toyo Morton), olefin resin, methyl ethyl ketone solution, solid content concentration of 50% by mass

(b-3) Main agent: Seikabond A-159 (manufactured by Dainichi Seika Co., Ltd.), polyether-based resin, ethyl acetate solution, solid content concentration of 60% by mass

(b-4) Main agent: N-3495HS (made by Nippon Synthetic Chemicals), acrylic resin, ethyl acetate/toluene/acetone solution, solid content concentration 45% by mass

(B) Hardener component in the adhesive layer

(b-5) Hardening|curing agent: LIOSTAR500H (made by Toyo Morton), isophorone diisocyanate, ethyl acetate solution, solid content concentration 70 mass %

(b-6) Hardening|curing agent: CAT-CT (made by Toyo Morton), diphenylmethane diisocyanate, ethyl acetate solution, solid content concentration 70 mass %

(b-7) Hardening|curing agent: CAT-10 (made by Toyo Morton), tolylene diisocyanate, ethyl acetate solution, solid content concentration 75 mass %

(b-8) Hardening|curing agent: CAT-RT8 (made by Toyo Moton), xylylene diisocyanate, ethyl acetate solution, solid content concentration 75 mass %

(C) Intermediate layer of resin

(c-1) m-LLDPE: Umerit 2040F (manufactured by Ube-Maruzen Polyethylene), MFR4.0g/10min (measured temperature 190°C, load 2.16kgf), density 0.904×10 ³ kg/m3

(D) Resin of heat seal layer

(d-1-1) Resin: Taphtech H1041 (manufactured by Asahi Kasei Chemicals), hydrogenated resin (SEBS) of styrene-butadiene-styrene triblock copolymer, olefin component 70% by mass

(d-1-2) Resin: Septon 2007 (manufactured by Kurares), hydrogenated resin (SEPS) of styrene-isoprene-styrene triblock copolymer, olefin component 70% by mass

(d-1-3) Resin: Taphtech H1051 (manufactured by Asahi Kasei Chemicals), styrene-butadiene-styrene triblock copolymer hydrogenated resin (SEBS), olefin component 58% by mass

(d-1-4) Resin: Taphtech H1062 (manufactured by Asahi Kasei Chemicals), hydrogenated resin (SEBS) of styrene-butadiene-styrene triblock copolymer, olefin component 82% by mass

(d-1-5) Resin: Taphtech H1221 (manufactured by Asahi Kasei Chemicals), hydrogenated resin (SEBS) of styrene-butadiene-styrene triblock copolymer, olefin component 88% by mass

(d-1-6) Resin: Taphtech H1517 (manufactured by Asahi Kasei Chemicals), styrene-butadiene-styrene triblock copolymer hydrogenated resin (SEBS), olefin component 57% by mass

(d-1-7) Resin: Taphtech H1043 (manufactured by Asahi Kasei Chemicals), styrene-butadiene-styrene triblock copolymer hydrogenated resin (SEBS), olefin component 33% by mass

(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 (manufactured by Mitsui DuPont Polychemical), ethylene-vinyl acetate copolymer resin (EVA), olefin component 81% by mass

(d-1-10) Resin: Evaflex V5714 (made by Mitsui DuPont Polychemicals), ethylene-vinyl acetate copolymer resin (EVA), olefin component 84% by mass

(d-1-11) Resin: Evaflex V421 (manufactured by Mitsui DuPont Polychemicals), ethylene-vinyl acetate copolymer resin (EVA), olefin component 72% by mass

(d-1-12) Resin: Evaflex P1205 (manufactured by Mitsui DuPont Polychemical Co., Ltd.), ethylene-vinyl acetate copolymer resin (EVA), olefin component 88% by mass

(d-1-13) Resin: Evaflex EV170 (manufactured by Mitsui DuPont Polychemicals), ethylene-vinyl acetate copolymer resin (EVA), olefin component 67% by mass

(d-1-14) Resin: Evaflex V5711 (made by Mitsui DuPont Polychemical), ethylene-vinyl acetate copolymer resin (EVA), olefin component 90% by mass

(D)Antistatic agent in the heat seal layer

(d-2-1) Antistatic agent: Entira MK440 (manufactured by DuPont Mitsui), potassium ionomer

(d-2-2) Antistatic agent: Pelestat HS (manufactured by Sanyo Kasei Corporation), polyether esteramide

(d-2-3) Antistatic agent: Elastmaster HE-110 (manufactured by Kao Corporation), nonionic surfactant masterbatch (nonionic surfactant 1% by mass, high density polyethylene 99% by mass)

(D) Particles in the heat seal layer

(d-3) fine particles: PEX-ABT-16 (manufactured by Tokyo Inki Corporation), talc, silica masterbatch (talc content 5% by mass, silica content 45% by mass, low-density polyethylene 50% by mass)

(E) Resin of the second heat seal layer

(e-1) Resin: NK polymer ECS-706 (manufactured by Shin-Nakamura Chemical Company), styrene-butyl methacrylate random copolymer emulsion, solid content concentration of 36% by mass

(E) Conductive filler added to the second heat-sealing layer

(e-2) Conductive filler: SN-100D (manufactured by Ishihara Industrial Co., Ltd.), spherical antimony-doped tin oxide, number average length diameter 0.1 µm, water dispersion type, solid content concentration of 30% by mass

(Example 1)

As a resin constituting the sealant layer (heat seal layer), a hydrogenated resin of a triblock copolymer of styrene-butadiene-styrene (manufactured by Asahi Kasei Chemicals, "Taphtec H1041", olefin content 70 mass%) 50 mass% and styrene -Butadiene-styrene triblock copolymer hydrogenated resin (manufactured by Asahi Kasei Chemicals, "Taftec H1043", olefin content 33 mass%) 30 mass% and potassium ionomer (Mitsui DuPont, "MK440") 20 The 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 the sealant layer at a line speed of 20 m/min. Metallocene-based linear low-density polyethylene (“Umerit 2040F” manufactured by Ube-Maruzen Polyethylene Co., Ltd.) as the olefinic resin constituting the intermediate layer (C) described in Tables 1 and 2 with this resin composition was extruded from each single screw extruder. Then, by laminating and extruding with a multi-manifold T-die, (D) a two-layer film having a thickness of 10 µm and an intermediate layer (C) having a thickness of 20 µm was obtained. Next, a polyester-based resin (manufactured by Toyo Morton, “LIOSTAR1000”) as a main agent is a polyester-based resin (manufactured by Toyo Morton, “LIOSTAR1000”) as a main agent by a gravure method on the mating surface of a biaxially stretched polyethylene terephthalate film (thickness 16 μm), and a main component is isophorone diisocyanate (Toyo Morton) as a curing agent. (B) An adhesive layer is formed so that the thickness after drying is 3 μm by mixing the two-component curable adhesive consisting of “LIOSTAR500H”) at 91 (main agent):9 (hardener) in terms of solid content, and (C) The intermediate layer surface was laminated by a dry lamination method to obtain a cover film for a carrier tape of an electronic component having the configuration shown in Fig. 1 .

(Examples 2-11, Examples 13-24, Examples 26-40, Comparative Examples 1-22)

A cover film was produced in the same manner as in Example 1 except that the adhesive layer and the heat-sealing layer were formed using raw materials such as resin described in Tables 1 to 5.

(Example 12)

After corona-treating the (D) heat-sealing layer surface using the laminated film obtained in Example 4, [(e) -2) Electroconductive filler] The cover film for carrier tapes which has electroconductive performance was obtained by coating the solution which consists of 80 mass % so that thickness after drying might be set to 0.3 micrometer.

(Example 25)

Except having used the laminated|multilayer film obtained in Example 17, it carried out similarly to Example 12, and produced the cover film.

<Evaluation method>

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 put together in Tables 1-5, respectively, and are shown.

(1) soaking (曇價)

In accordance with the measurement method A of JIS K 7105: 1998, the immersion was measured using an integrating sphere measuring device. The results are shown in the soaking columns of Tables 1 to 5.

(2) sealability

Using a taping machine (Nagata Seiki Co., Ltd., NK-600), seal head width 0.5 mm × 2, seal head length 24 mm, seal pressure 0.5 kgf, feed length 12 mm, seal time 0.3 seconds × 2 circuits Seal at an iron temperature of 140°C A cover film having a width of 21.5 mm was heat-sealed to a carrier tape made of polycarbonate (manufactured by Denki Chemical Co., Ltd.) and a carrier tape made of polystyrene (manufactured by Denki Chemical Industry Co., Ltd.) having a width of 24 mm at intervals of 10 °C up to 190 °C. After standing for 24 hours in an atmosphere of a temperature of 23 ° C. and a relative humidity of 50%, the cover film was similarly peeled off at a rate of 300 mm per minute and a peeling angle of 170 ° to 180 ° in an atmosphere of a temperature of 23 ° C. and a relative humidity of 50%. Sealability was evaluated based on the average peeling strength at the time of heat-sealing at 10 degreeC intervals from sealing iron temperature 140 degreeC - 190 degreeC. In addition, the number of samples for which peeling strength was measured at each temperature was set to 3.

“Excellent”: The average peel strength at all temperatures is in the range of 0.3N to 0.9N.

"Good": The average peeling strength is 1-5 points|pieces at the temperature which deviates from the range of 0.3N-0.9N.

"Poor": The average peel strength deviates from the range of 0.3N-0.9N at all temperatures.

A result is shown in the sealing property column of Tables 1-5.

(3) Variation in peel strength (non-uniformity)

It heat-sealed so that the peeling strength with respect to the carrier tape made from polystyrene (made by Denki Chemical Industries, Ltd.) might be set to 0.4N. The cover film was peeled off under the conditions same as said (2) sealing property. The dispersion|variation in peeling strength was derived|led-out from the chart obtained when 100 mm of cover films were peeled in the peeling direction. Those having a variation in peel strength of less than 0.2N were described as “excellent”, those of 0.2N to 0.4N as “good”, and those larger than 0.4N as “poor”. A result is shown in the variation|variation column of peeling strength of Tables 1-5.

(4) blocking property

After heat-sealing so that the peel strength was 0.4N under the condition of (3), a carrier tape taped so that the cover film was in the outer circumferential direction was wound on a paper tube having a diameter of 95 mm, and then left in an environment of 60° C. for 24 hours. At this time, the thing in which adhesion|attachment was not seen in the flange part of the pocket part (located between) molded to the carrier tape (accommodating an electronic component) was described as "good", and what was visible was described as "poor". A result is shown in the blocking property column of Tables 1-5.

(5) interlayer adhesive strength

After cutting the cover film to 300mm in the longitudinal direction and 15mm in width, (A) the base material layer and (C) the middle layer were peeled off in advance, and each peeled end was installed in a tensile tester (EZ Test manufactured by Shimadzu Corporation) under the condition of 23℃. The interlayer adhesive strength was evaluated by T-shaped peeling at a speed of 200 mm per minute. If the interlayer adhesive strength is less than 5N/15mm, there is a possibility of peeling between the layers of (A) the base material layer and (C) the intermediate layer in the electronic component mounting process. The thing of the adhesive strength of less than 15 mm was described as "defect". A result is shown in the column of interlayer adhesive strength of Tables 1-5.

(6) Break resistance of cover film

It heat-sealed so that the peeling strength with respect to the carrier tape made from polystyrene (made by Denki Chemical Industries, Ltd.) might be set to 1.0N. The cover film was peeled off under the conditions same as said (2) sealing property. The carrier tape which sealed the cover film was cut out to the length of 550 mm, and the pocket bottom part of the carrier tape was affixed to the vertical wall which pasted the double-sided adhesive tape at 23 degreeC. The cover film was peeled off 50 mm from the upper part of the stuck carrier tape, the cover film was pinched|interposed with a clip, and the weight of 1000 g of mass was attached to this clip. After that, when the weight was dropped naturally, the case in which the cover film did not break even in 1 out of 50 samples was “excellent”, 1 to 5 out of 50 samples in which the cover film was broken was “good”, and 6 or more samples were broken in “poor”. ' was indicated. A result is shown in the film breakability column of Tables 1-5.

(7) Stability of peel strength over time

Heat-sealing was performed so that peeling strength might be set to 0.4N on the same conditions as said (3) sealing property. Put in the environment of temperature 60℃, relative humidity 10%, temperature 60℃, relative humidity 95% for 7 days, and after taking out, leave it for 24 hours in an atmosphere of temperature 23℃ and 50% relative humidity, the same temperature 23℃, relative humidity Peel strength was measured in a 50% atmosphere. Peel strength measurement was performed under the same conditions as said (3) sealing property. Those having an average peel strength in the range of 0.3N or more to 0.5N are called “excellent”, and those having an average peel strength in the range of 0.2N or more to less than 0.3N and 0.5N to 0.6N or less are called “good”. The thing of peeling strength was expressed as "defect". A result is shown in the sealing property column of Tables 1-5.

(8) surface resistance value

Using the Hirestar UP MCP-HT450 of Mitsubishi Chemical Company, the surface resistance value of the heat seal layer surface was measured by the method of JISK6911 at 23 degreeC of atmospheric temperature, 50% RH of atmospheric humidity, and 500V of applied voltages. A result is shown in the surface resistance value 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 the peel strength when peeling the cover film to take out electronic components is It is a cover film which is constant in a range of a predetermined value continuously, is excellent in transparency, and is hard to cause "film breakage" at the time of high-speed peeling.

1 cover film
2 base material layer
3 adhesive layer
4 mezzanine
5 heat seal layer

Claims (7)

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,
(d-1) containing any 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 an olefin-based resin to
(d-2) containing 10% by mass to 40% by mass of potassium ionomer having antistatic performance,
Moreover, the surface resistance value of the outermost surface on the side of the (D) heat-sealing layer ^{of the cover film is 10 12} ohms or less, The cover film characterized by the above-mentioned. The method according to claim 1,
(D) A cover film in which the heat seal layer contains 10% by mass or less in total of (d-3) any one or both of organic fine particles and inorganic fine particles. The method according to claim 1,
The cover film whose content of isophorone diisocyanate in a hardening|curing agent is 4 mass % - 13 mass % with respect to the total with a polyester resin. The method according to claim 1,
(A) A cover film having an interlayer adhesive strength of 5N/15mm or more between the base material layer and (C) the intermediate layer. The method according to claim 1,
(C) A cover film in which the intermediate layer is made of a metallocene-based 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 method according to claim 1,
(D) The cover film which has a 2nd heat-sealing layer which has (E) an acrylic resin as a main component on the surface opposite to the (B) intermediate|middle layer side of a heat-sealing layer. The electronic component package which used the cover film in any one of Claims 1-6 as a cover material of the carrier tape which consists of a thermoplastic resin.

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