TW202035159A - Cover film and electronic component package using same - Google Patents

Abstract

The present invention primarily addresses the problem of providing a cover film that has both anti-blocking performance and peeling strength stability. Provided is a cover film having at least (A) a substrate layer, (B) an adhesive layer, (C) an intermediate layer, and (D) a heat seal layer, wherein the surface of the heat seal layer (D) that not in contact with the intermediate layer (C) has protrusions and the protrusions are disposed in a zigzag form with respect to the layered film length direction and width direction.

Description

Cover film and electronic component packaging body using it

The present invention relates to a cover film used for a packaging body of electronic parts and an electronic part packaging body using the cover film.

With the miniaturization of electronic equipment, the electronic components used have also been miniaturized and improved. At the same time, in the assembling step of the electronic equipment, electronic components are automatically mounted on the printed circuit board. The electronic component for surface mounting is accommodated in a carrier tape, and the carrier tape is interlocked with an embossed pocket that can accommodate the shape of the electronic component. After accommodating the electronic components, a cover film is superimposed on the carrier tape as a cover material, and both ends of the cover film are continuously heat-sealed in the longitudinal direction with a heated seal bar to form a package. As the cover film material, a heat-sealing layer in which a thermoplastic resin is laminated using a biaxially stretched polyester film as a base material is used.

Patent Document 1 discloses a cover tape that has low dependence on the heat sealing temperature and can easily adjust the peel strength and a carrier tape using the cover tape.

In addition, Patent Document 2 discloses a cover tape for packaging electronic parts that has an excellent balance of tack property and transparency.

In addition, Patent Document 3 discloses a cover film that has a constant peel strength within a predetermined value range, is excellent in transparency, and is unlikely to cause "film breakage" during high-speed peeling.

However, in any of the documents, it cannot necessarily be said that it is sufficient to balance the adhesion resistance of the cover film and the stability of the peel strength. [Prior Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Application Publication No. 2002-154573 Patent Document 2: Japanese Patent Application Publication No. 2017-222387 Patent Document 3: International Publication No. 2016/024529 Brochure

[The problem to be solved by the invention]

The main subject of the present invention is to provide a cover film that has both adhesion resistance and peel strength stability. In addition, the subject of the present invention is also to provide a cover film with improved productivity.

The inventors of the present invention intensively reviewed the aforementioned issues, and found the following, and completed the present invention: a material having at least (A) a base layer, (B) an adhesive layer, (C) an intermediate layer, and (D) a heat seal layer The cover film of the laminate film has a convex shape on the surface of the (D) heat seal layer that is not in contact with the (C) intermediate layer, and the convex shape is arranged in a chidori shape with respect to the width direction and the length direction of the laminate film , A cover film that overcomes the problem of the present invention can be obtained.

That is, the present invention relates to the following cover film: a laminate film having at least (A) a base layer, (B) an adhesive layer, (C) an intermediate layer, and (D) a heat-sealing layer, which is heat-sealed in (D) The surface of the layer that is not in contact with the (C) intermediate layer has a convex shape, and the convex shape is arranged in a chidori shape with respect to the width direction and the length direction of the laminated film.

In addition, in the present invention, it is preferable that (B) the adhesive layer is a urethane-based adhesive having a skeleton including the following components: at least one selected from the group consisting of polyether polyol and polyester polyol One component and at least one component selected from the group consisting of diphenylmethane diisocyanate, 2,4-toluene diisocyanate, and isophorone diisocyanate.

In addition, in the present invention, it is preferable that the resin constituting the (D) heat seal layer contains: (d-1) ethylene-vinyl acetate copolymer 60% to 98% by mass, and (d-2) ethylene (former The potassium ionomer of the base) acrylic copolymer is 2% to 40% by mass.

In addition, in the present invention, it is preferable that the resin constituting the heat-sealing layer (D) further contains a styrene-butadiene copolymer.

In addition, in the present invention, it is preferable that (A) the base material layer contains a polyethylene terephthalate film.

In addition, in the present invention, a polyethylene terephthalate film-based biaxially stretched polyethylene terephthalate film is preferred.

In addition, in the present invention, it is preferable that (C) the intermediate layer contains linear low-density polyethylene.

Furthermore, in the present invention, it is preferable that the linear low-density polyethylene contains m-LLDPE.

In addition, in the present invention, it is preferable that the height of the convex shape arranged in the shape of a thousand birds is 2 μm or more.

In addition, the present invention also relates to an electronic component package that uses the above-described cover film as a cover material of a carrier tape containing a thermoplastic resin.

In addition, in the present invention, "A-B" means "A or more and B or less". [Effects of Invention]

According to the present invention, it is possible to provide a cover film that has both adhesion resistance and peel strength stability. In addition, the present invention can further provide a cover film that also improves productivity.

[Form to implement the invention]

As shown in FIG. 1, the cover film of the present invention includes at least (A) a base 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. 1. The cover film 1 shown in FIG. 1 includes a base layer 2, an adhesive layer 3, an intermediate layer 4, and a heat seal layer 5. The cover film 1 is laminated with a substrate layer 2, an adhesive layer 3, an intermediate layer 4, and a heat seal layer 5 in this order.

[(A) Substrate layer] (A) As for the base material layer, a polyethylene terephthalate film can be used especially suitably. In addition, the polyethylene terephthalate film is preferably a biaxially stretched polyethylene terephthalate film. In addition, as the base material layer, one coated or kneaded with an antistatic agent for antistatic treatment, one with corona treatment, easy bonding treatment, etc. can be used. If the base material layer is too thin, the tensile strength of the cover film itself becomes low, and therefore "film breakage" is likely to occur when the cover film is peeled off. On the other hand, if it is too thick, not only the heat-sealability to the carrier tape decreases, but also the cost increases. Therefore, (A) the thickness of the base material layer can usually be suitably used for the thickness of 12-25 micrometers.

[(B) Adhesive layer] The (B) adhesive layer is preferably composed of a cured product of a two-component curing type adhesive of a main agent component and a curing agent component. In addition, the adhesive layer more preferably includes a urethane-based adhesive having a skeleton containing the following components: at least one component selected from the group consisting of polyether polyol and polyester polyol, and At least one component of the group of phenylmethane diisocyanate, 2,4-toluene diisocyanate, and isophorone diisocyanate. If such a two-component curing adhesive is used, the (A) base layer and the (C) intermediate layer are indirectly attached to each other, and a practical and sufficient adhesive strength can be exhibited in a short time. Therefore, a coating film can be obtained. This effect is excellent in productivity.

The two-component hardening adhesive is preferably diluted in a solvent and mixed in a predetermined ratio for use. The dilution solvent is not particularly limited, and water, ethyl acetate, toluene, methyl ethyl ketone, etc. can be used. The (B) adhesive layer can be formed by applying a two-component curing type adhesive to the (A) base 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 1μm or more, it is possible to prevent the surface roughness from being unable to fully follow (C) the intermediate layer and the adhesive strength becomes insufficient. By setting it to 5μm or less, it is possible to more prevent peeling after heat sealing the carrier tape A situation where the deviation of intensity becomes larger.

[(C) Intermediate layer] In the present invention, the (C) intermediate layer is laminated through the (B) adhesive layer and is provided on one side of the (A) base layer. As for the resin constituting the intermediate layer (C), linear low-density polyethylene (hereinafter also referred to as LLDPE) can be suitably used, which is particularly flexible and has moderate rigidity, and has excellent tensile strength at room temperature , Especially by using a resin with a density in the range of 0.900×10 ³ kg/m ³ to 0.925×10 ³ kg/m ³ , and the heat or pressure during heat sealing is caused by the middle of the end of the cover film The overflow of layer resin is difficult to occur. Therefore, not only the contamination of the soldering iron during heat sealing is difficult to produce, but also because the intermediate layer softens when the cover film is heat-sealed, the solder mark of the heat-sealing soldering iron is alleviated, so stable peeling can be easily obtained when the cover film is peeled off. strength.

There are those polymerized by Ziegler-type catalysts and those polymerized by metal-aromatic catalysts (hereinafter, also referred to as m-LLDPE). The m-LLDPE-based molecular weight distribution is controlled to be narrow and therefore has a particularly high tensile strength. For the (B) intermediate layer of the present invention, it is particularly preferable to use m-LLDPE.

The above-mentioned m-LLDPE is an olefin with 3 or more carbons as a comonomer, preferably a linear, branched, aromatic nucleus substituted α-olefin with 3 to 18 carbons, and a copolymer with ethylene . The linear monoolefins include, for example, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-nonene, 1-decene, 1-decene Diene, 1-tetradecene, 1-hexadecene, 1-octadecene, etc. In addition, as branched monoolefins, for example, 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 2-methyl- 1-hexene etc. In addition, examples of monoolefins substituted by aromatic nuclei include styrene and the like. These comonomers can be copolymerized with ethylene alone or in combination of two or more kinds. This copolymerization can also copolymerize polyenes such as butadiene, isoprene, 1,3-hexadiene, dicyclopentadiene, 5-ethylidene-2-norbornene, and the like.

(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 the solder mark of the heat-sealing soldering iron when the cover film is heat-sealed to the carrier tape. On the other hand, if the thickness exceeds 25 μm, the total thickness of the cover film is thick, and it may become difficult to obtain sufficient peel strength when heat-sealing the cover film to the carrier tape.

[(D) Heat seal layer] The cover film of the present invention has (D) a heat seal layer formed on the surface of the (C) intermediate layer. In the cover film of the present invention, the surface of the (D) heat-sealing layer that is not in contact with the (C) intermediate layer has a convex shape, and the convex shape is arranged in a chidori shape with respect to the width direction and the length direction of the laminated film. shape. By arranging the convex shape of the heat-seal layer in a chidori shape with respect to the width direction and the length direction of the laminated film, it is possible to obtain a coating with excellent adhesion resistance and less variation in peel strength, that is, excellent peel strength stability. membrane.

The height of the convex shape is preferably 1.5 μm or more, more preferably 2.0 μm or more. In addition, the interval between the convex shapes is preferably 50 to 300 μm, more preferably 70 to 150 μm or more.

(D) The resin of the heat-sealing layer preferably contains (d-1) an olefin resin and (d-2) an antistatic potassium ion polymer. In addition, the resin constituting the (D) heat-sealing layer preferably further contains a styrene-butadiene copolymer.

(D-1) The olefin resin preferably contains 60% to 98% by mass of the ethylene-vinyl acetate copolymer, and (d-2) the antistatic potassium ion polymer is preferably The potassium ion polymer containing an ethylene (meth)acrylic acid copolymer is 2% by mass to 40% by mass.

(D) The thickness of the heat sealing layer is preferably 5 μm to 40 μm, more preferably 7 to 20 μm. When the thickness of the heat-sealing layer is less than 5 μm, sufficient peel strength cannot be obtained when heat-sealing with the carrier tape, and furthermore, there is a possibility that the film may break. If it exceeds 40 μm, not only will the cost increase, but the transparency will also tend to decrease.

[Making method of cover film] The method of producing the above-mentioned cover film is not particularly limited, and general methods can be used. For example, a two-component curing adhesive is applied to the surface of (A) the substrate layer and the (B) adhesive layer is formed first, and the resin composition of (C) the intermediate layer is formed by extruding from a T die, and then applied to ( B) The coated surface of the adhesive layer to form a three-layer film including (A) a base layer, (B) an adhesive layer, and (C) an intermediate layer. In addition, the target cover film can be obtained by applying the resin extruded from the T die to form the (D) heat seal layer on the surface of the (C) intermediate layer.

As another method, the resin constituting the (C) intermediate layer and (D) the heat-sealing layer can be made into a film by the T die casting method, or the expansion method, respectively, and the (A) base layer For example, the target cover film is obtained by a dry lamination method in which the (B) adhesive layer containing a two-component curing type adhesive is adhered.

In addition, as another method, the intended cover film may be obtained by the sandwich lamination method. That is, the resin constituting the (D) heat-sealing layer is formed into a film by a T die casting method, an expansion method, or the like. Next, between the (D) heat-sealing layer and (A) the base layer, the resin composition forming the intermediate layer is supplied to form and laminate the (C) intermediate layer to obtain the intended cover film. In the case of this method, in the same manner as the above-mentioned method, for example, a two-component curing type adhesive coated with a two-component curing type adhesive is used as the (B) adhesive layer on the surface of the laminate side of the (A) base layer.

In particular, the cover film of the present invention preferably uses a multi-manifold or feedblock, and is laminated by co-extrusion to form the resin of the (C) intermediate layer by a T die casting method or an expansion method. The composition and (D) heat-sealable resin, and the two-layer film is laminated through the (B) adhesive layer by the extrusion lamination method as the (B) adhesive layer and coated with, for example, two-component curing type Adhesive (A) substrate layer to obtain a cover film. In addition, it is more preferable to use a dry lamination method to penetrate the (B) adhesive layer to laminate the two-layer film on the (B) adhesive layer coated with, for example, a two-component curing type adhesive (A) base layer .

In addition to the aforementioned steps, at least one side of the cover film may be subjected to antistatic treatment as needed. A roll coater using a gravure roll, a lip coater, spraying, etc. can be used to coat antistatic agents such as anionic, cationic, nonionic, betaine and other surfactant-type antistatic agents and polymers. Type antistatic agent and conductive material dispersed in the binder. In addition, in order to uniformly apply these antistatic agents, it is preferable to perform corona discharge treatment or ozone treatment on the film surface before performing the antistatic treatment, and corona discharge treatment is particularly preferable.

[Electronic parts packaging] The electronic component packaging system of the present invention uses the above-mentioned cover film as a packaging body of the cover material of the carrier tape of the electronic component storage container. The carrier tape refers to a belt with a width of approximately 8 mm to 100 mm for storing electronic parts. When heat-sealing is performed using a cover film as a cover material, the material constituting the carrier tape is not particularly limited, and a commercially available one can be used. For example, polystyrene, polyester, polycarbonate, polyvinyl chloride, etc. can be used. Carrier tapes can be used: those that impart conductivity by kneading carbon black or carbon nanotubes in resin; those kneading antistatic agents or conductive fillers; or coating the surface with antistatic agents of surfactant type or Conductive materials such as polypyrrole and polythiophene are dispersed in a coating liquid of an organic binder such as acrylic acid to impart antistatic properties.

A package containing electronic components can be obtained, for example, by using a cover film as a cover material after accommodating electronic components and the like in the electronic component accommodating portion of the carrier tape, and continuous both edges of the cover film in the longitudinal direction It is heat-sealed, packaged, and wound on a reel. Electronic parts are stored and transported by packaging in this form. A package containing electronic parts, etc., is transported using a hole called sprocket hole for carrier tape transport provided at the edge of the carrier tape in the longitudinal direction, while being torn intermittently The cover film is removed, and while the presence, direction, and position of the electronic components are confirmed by the component mounting device, the electronic components are taken out and mounted on the substrate.

If the peel strength when tearing off the cover film is too small, the cover film may peel off the carrier tape during storage or transport of the package, and the storage parts may fall off. If it is too large, it may be The peeling of the tape becomes difficult and there is a risk of breaking the cover film when peeling it off. Therefore, in the case of heat sealing at 120°C to 220°C, it is preferable to have a peel strength of 0.05N to 1.0N, and the deviation in peel strength is preferably less than 0.4N (less than 0.4N) By. [Example]

Hereinafter, the present invention will be described in detail with examples, but the present invention is not limited thereto. In the Examples and Comparative Examples, the following resin raw materials were used for (A) base layer, (B) adhesive layer, (C) intermediate layer, and (D) heat seal layer. (A) Resin film of base layer (a-1) Biaxially stretched polyethylene terephthalate film (o-PET): E-5100 (manufactured by Toyobo), thickness 16μm

(B) The main agent component in the adhesive layer (b-1) Main agent: TM-319 (manufactured by Toyo Morton), polyether polyol, ethyl acetate solution, solid content concentration 70% by mass (b-2) Main agent: own synthetic product, polyether polyol, ethyl acetate solution, solid content concentration 70% by mass (b-3) Main agent: LIOSTAR1000 (manufactured by Toyo Morton), polyester polyol, ethyl acetate solution, solid content concentration 50% by mass

(B) Hardener components in the adhesive layer (b-4) Hardener: CAT-11B (manufactured by Toyo Morton Co., Ltd.), diphenylmethane diisocyanate system, ethyl acetate solution, solid content concentration 60% by mass (b-5) Hardener: Coronaate 2067 (manufactured by Tosoh), diphenylmethane diisocyanate system, solid content concentration 100% by mass (b-6) Hardener: Coronaate L-45E (manufactured by Tosoh), 2,4-toluene diisocyanate system, ethyl acetate solution, solid content concentration 45% by mass (b-7) Hardener: LIOSTAR500H (manufactured by Toyo Morton), isophorone diisocyanate series, ethyl acetate solution, solid content concentration 70% by mass

(C) Resin of the middle layer (c-1) m-LLDPE: UMERIT 2040F (manufactured by Ube Maruzen Polyethylene Co., Ltd.), MFR 4.0g/10min (measurement temperature 190°C, load 2.16kgf), density 0.904×10 ³ kg/m ³

(D) Resin of heat seal layer (d-1) Resin: EVAFLEX EV360 (manufactured by Mitsui Dupont Polychemical), ethylene-vinyl acetate copolymer resin (EVA) (d-2) Resin: CLEAREN 335A (manufactured by Denka), styrene-butadiene copolymer resin (SBC)

(D) Antistatic agent in heat seal layer (d-3) Antistatic agent: ENTIRA MK440 (manufactured by Mitsui Dupont), potassium ion polymer

(Example 1) As the raw material for the (D) heat seal layer, 90% by mass of ethylene-vinyl acetate copolymer resin (manufactured by Mitsui Dupont Polychemical Co., "EVAFLEX EV360") and potassium ion polymer (manufactured by Mitsui Dupont Co., Ltd., " MK440") 10% by mass was pre-blended with a drum machine, and kneaded at 200°C using a single-screw extruder with a diameter of 40 mm to obtain a resin composition at a linear speed of 20 m per minute. This resin composition and the straight-chain low-density polyethylene (manufactured by Ube Maruzen Polyethylene Co., Ltd., "UMERIT 2040F") used as the intermediate layer (C) were extruded from their respective single-screw extruders, and a multi-manifold was used. When the T-die is laminated and extruded, a transfer roll and a touch roll are used for casting to obtain a two-layer film with a convex shape on the surface of the heat seal layer (D). The roller system is laser engraved, and the surface is uniformly given a hemispherical concave shape with a diameter of 56 μm and a depth of 10 μm at intervals of 125 μm between the centers of the diameter in a thousand birds shape. The temperature adjustment of the transfer roller and the touch roller was 25°C, and the contact pressure was 0.25 MPa. Next, the surface of the biaxially stretched polyethylene terephthalate film (thickness 16μm) of (A) base layer that is bonded to (C) the intermediate layer will contain one of the main agents by gravure method Polyether polyol (manufactured by Toyo Morton Co., "TM-319"), and a two-component curing type of diphenylmethane diisocyanate (manufactured by Toyo Morton Co., "CAT-11B") as the main component of the hardener The adhesive is mixed with 50 (main agent): 50 (curing agent) in terms of solid content, and the (B) adhesive layer is formed so that the thickness after drying becomes 3 μm, and the two layers are combined by dry lamination. The (C) middle layer of the film was bonded together and stored at 40°C for one day to obtain a cover film for a carrier tape of an electronic component having the configuration shown in FIG.

(Examples 2～10) The cover film was obtained in the same manner as in Example 1, except that the (B) adhesive layer and (D) the heat seal layer were formed using raw materials such as resins described in Table 1.

(Comparative example 1) As the raw material for the (D) heat seal layer, 90% by mass of ethylene-vinyl acetate copolymer resin (manufactured by Mitsui Dupont Polychemical Co., "EVAFLEX EV360") and potassium ion polymer (manufactured by Mitsui Dupont Co., Ltd., " MK440") 10% by mass was pre-blended with a drum machine, and kneaded at 200°C using a single-screw extruder with a diameter of 40 mm to obtain a resin composition at a linear speed of 20 m per minute. This resin composition and the straight-chain low-density polyethylene (manufactured by Ube Maruzen Polyethylene Co., Ltd., "UMERIT 2040F") used as the intermediate layer (C) were extruded from their respective single-screw extruders, and a multi-manifold was used. When the T-die is laminated and extruded, a two-layer film is obtained by casting with a metal roll and a touch roll having no concave shape on the surface. Except for the film forming method of the two-layer film, the cover film was obtained in the same manner as in Example 1.

(Comparative example 2) As the resin constituting the heat seal layer (D), 90% by mass of ethylene-vinyl acetate copolymer resin (manufactured by Mitsui Dupont Polychemical Co., "EVAFLEX EV360") and potassium ion polymer (manufactured by Mitsui Dupont Co., Ltd., "MK440") 10% by mass was pre-blended with a drum machine, and kneaded at 200°C using a single-screw extruder with a diameter of 40 mm to obtain a resin composition at a linear speed of 20 m per minute. This resin composition and the straight-chain low-density polyethylene (manufactured by Ube Maruzen Polyethylene Co., Ltd., "UMERIT 2040F") used as the intermediate layer (C) were extruded from their respective single-screw extruders, and a multi-manifold was used. When the T-die is laminated and extruded, the transfer roll and the touch roll are used for casting to obtain a two-layer film with a convex shape on the surface of the heat seal layer (D), and the transfer roll is laser engraved , And the surface is uniformly given a hemispherical concave shape with a diameter of 56 μm and a depth of 10 μm in a grid with an interval of 125 μm between the centers of the diameter. The temperature adjustment of the concave transfer roller and the touch roller was 25°C, and the contact pressure was 0.25 MPa. Except for the film forming method of the two-layer film, the cover film was obtained in the same manner as in Example 1.

>Evaluation Method> The evaluation shown below was performed about the cover film for carrier tapes of the electronic component produced in each Example and each comparative example. These results were compiled and shown in Tables 1 and 2.

(1) Tightness Use a taping machine (Nagata Seiki Co., Ltd., NK-600) to seal head width 0.5mm×2, seal head length 24mm, sealing pressure 0.5kgf, transport length 12mm, sealing time 0.3 seconds × 2 times, sealing iron temperature from 140 The cover film having a width of 21.5 mm was heat-sealed to a carrier tape made of polycarbonate (manufactured by Denka Corporation) and a carrier tape made of polystyrene (manufactured by Denka Corporation) with a width of 24 mm at intervals of 10°C from 190°C. After being placed in a gas environment with a temperature of 23°C and a relative humidity of 50% for 24 hours, it peeled off at a speed of 300mm per minute and a peeling angle of 170°～180° in a gas environment with a temperature of 23°C and a relative humidity of 50%. Cover film. The sealing performance was evaluated based on the average peel strength when the soldering iron temperature was 140°C to 190°C when heat sealing was performed at 10°C intervals. In addition, the number of samples for which the peel strength was measured at each temperature was set to 3. "3": Those whose average peel strength falls within the range of 0.3N to 0.9N at all temperatures. "2": The temperature at which the average peel strength exceeds the range of 0.3N to 0.9N has 1 to 5 points. "1": The average peel strength at all temperatures exceeds the range of 0.3N to 0.9N. The results are shown in the sealing performance column of Tables 1-2.

(2) Deviation of peel strength The polystyrene carrier tape (manufactured by Denka) was heat-sealed so that the peel strength of the carrier tape became 0.4N. After being placed in a gas environment with a temperature of 23°C and a relative humidity of 50% for 24 hours, it peeled off at a speed of 300mm per minute and a peeling angle of 170°～180° in a gas environment with a temperature of 23°C and a relative humidity of 50%. Cover film. The deviation of peel strength was derived from the graph obtained when the cover film of 100 mm was peeled in the peeling direction. Mark the deviation of peel strength less than 0.2N as "3", mark the deviation from 0.2N to 0.4N as "2", and mark the deviation greater than 0.4N as "1". The results are shown in the column of deviation of the peel strength in Tables 1 and 2.

(3) Adhesion resistance After heat-sealing the polystyrene carrier tape (manufactured by Denka) so that the peel strength of it becomes 0.4N, the carrier tape that has been pasted so that the cover film becomes the outer circumferential direction is rolled on a paper tube with a diameter of 95 mm After that, it was left in an environment of 60°C for 24 hours. At this time, the flange part formed between the adjacent pockets of the carrier tape without a successor is marked as "3", and the visible successor is marked as "1". The results are shown in the column of adhesion resistance in Tables 1-2.

(4) The stability of the interlayer strength After the cover film was cut out of 50 samples with a length of 300 mm and a width of 15 mm, the (A) base layer and (C) the intermediate layer were peeled off in advance, and each peeled end was set in a tensile testing machine ( EZ Test manufactured by Shimadzu Corporation), under the condition of 23°C, the interlayer adhesion strength was evaluated by the T-shaped peeling at a speed of 200 mm per minute. The layer of 50 samples with the maximum and minimum bonding strength difference less than 3N is marked as "3", and the bonding strength above 3N is marked as "1". The results are shown in the columns of the layers in Tables 1 and 2 in terms of strength stability.

(5) Productivity It was evaluated that after the (A) base layer and (C) intermediate layer were laminated by the dry lamination method, when stored at 40°C, the (A) base layer and (C) intermediate layer reached the maximum strength. Days. "3": Less than 2 days "2": more than 2 days but less than 4 days "1": Over 4 days The results are shown in the productivity column of Tables 1-2.

(6) Antistatic Using Hiresta UP MCP-HT450 of Mitsubishi Chemical Corporation, in accordance with the method of JISK6911, the surface resistivity of the heat seal layer surface was evaluated at a gas environment temperature of 23°C, a gas environment humidity of 50%RH, and an applied voltage of 500V. "3": The surface resistivity is less than 1.0×10 to the 12th power "2": Those whose surface resistivity is 1.0×10 to the 12th power or more and less than 1.0×10 to the 14th power "1": Surface resistivity 1.0×10 to the 14th power or more The results are shown in the column of antistatic properties in Tables 1-2.

It is clear from Tables 1 to 2 that the cover films of Examples 1 to 10 have any of sealing properties, variation in peel strength, adhesion resistance, stability of interlayer adhesion strength, productivity, and antistatic properties. Both are excellent.

On the other hand, Comparative Example 1 without a convex shape is poor in adhesion resistance. In addition, Comparative Example 2 in which the convex shape is not arranged in a chidori shape but is arranged in a lattice shape is poor in the deviation of the peel strength.

[Table 1] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Substrate layer o-PET a-1 E-5100 100 100 100 100 100 100 100 100 100 100 Adhesive layer Main agent b-1 TM-319 50 50 50 50 50 50 50 50 Main agent b-2 Home synthesis 50 Main agent b-3 LIOSTAR1000 91 hardener b-4 CAT-11B 50 50 50 50 50 50 50 hardener b-5 Coronate 2067 50 hardener b-6 Coronate L-45E 50 hardener b-7 LIOSTAR500H 9 middle layer m-LLDPE c-1 2040F 100 100 100 100 100 100 100 100 100 100 Heat seal layer Resin d-1 EVAFLEX EV360 90 90 90 90 90 60 95 50 98 85 Resin d-2 CLEAREN 335A 5 Antistatic agent d-3 ENTIRA MK440 10 10 10 10 10 40 5 50 2 10 surface shape Convex shape Convex shape Convex shape Convex shape Convex shape Convex shape Convex shape Convex shape Convex shape Convex shape Configuration Chidori Chidori Chidori Chidori Chidori Chidori Chidori Chidori Chidori Chidori Composition thickness Thickness of substrate layer μm 16 16 16 6 16 16 16 16 16 16 Adhesive layer thickness μm 3 3 3 3 3 3 3 3 3 3 Thickness of the middle layer μm 20 20 20 20 20 20 20 20 20 20 Heat sealing layer thickness μm 13 13 13 13 13 13 13 13 13 13 Cover film thickness μm 52 52 52 52 52 52 52 52 52 52 Evaluation of physical properties Tightness 3 3 3 3 3 3 3 2 3 3 Deviation of peel strength 3 3 3 2 2 3 3 2 3 3 Adhesion resistance 3 3 3 3 3 3 3 3 3 3 The stability of the layer 3 3 3 3 3 3 3 3 3 3 Productive 3 3 3 3 2 3 3 3 3 3 Antistatic 3 3 3 3 3 3 3 3 2 3

[Table 2] Comparative example 1 Comparative example 2 Substrate layer o-PET a-1 E-5100 100 100 Adhesive layer Main agent b-1 TM-319 50 50 Main agent b-2 Main agent b-3 LIOSTAR1000 hardener b-4 CAT-11B 50 50 hardener b-5 Coronate 2067 hardener b-6 Coronate L-45E hardener b-7 LIOSTAR500H middle layer m-LLDPE c-1 2040F 100 100 Heat seal layer Resin d-1 EVAFLEX EV360 90 90 Resin d-2 CLEAREN 335A Antistatic agent d-3 ENTIRA MK440 10 10 surface shape No convex shape Convex shape Configuration no lattice Composition thickness Thickness of substrate layer μm 16 16 Adhesive layer thickness μm 3 3 Thickness of the middle layer μm 20 20 Heat sealing layer thickness μm 13 13 Cover film thickness μm 52 52 Evaluation of physical properties Tightness 3 3 Deviation of peel strength 3 1 Adhesion resistance 1 3 The stability of the layer 3 3 Productive 3 3 Antistatic 3 3

1: Cover film 2: Substrate layer 3: Adhesive layer 4: middle layer 5: Heat seal layer

Fig. 1 is a cross-sectional view showing an example of the layer structure of the cover film of the present invention. Fig. 2 is a diagram showing an example of a chidori-shaped arrangement.

1: Cover film

2: Substrate layer

3: Adhesive layer

4: middle layer

5: Heat seal layer

Claims (10)

A cover film, which is a laminated film having at least (A) a substrate layer, (B) an adhesive layer, (C) an intermediate layer, and (D) a heat seal layer, The surface of the (D) heat-sealing layer that is not in contact with the (C) intermediate layer has a convex shape, and the convex shape is arranged in a thousand birds shape with respect to the width direction and the length direction of the laminated film. The cover film of claim 1, wherein (B) the adhesive layer is a urethane-based adhesive having a skeleton including: at least one selected from the group consisting of polyether polyol and polyester polyol Component and at least one component selected from the group consisting of diphenylmethane diisocyanate, 2,4-toluene diisocyanate, and isophorone diisocyanate. The cover film of claim 1 or 2, wherein the resin constituting (D) the heat-sealing layer includes: (d-1) 60% to 98% by mass of ethylene-vinyl acetate copolymer, and (d-2) Potassium ionomer of ethylene (meth)acrylic copolymer is 2% by mass to 40% by mass. The cover film of claim 3, wherein the resin constituting the (D) heat-sealing layer further contains a styrene-butadiene copolymer. The cover film according to any one of claims 1 to 4, wherein (A) the substrate layer comprises a polyethylene terephthalate film. The cover film according to claim 5, wherein the polyethylene terephthalate film is a biaxially stretched polyethylene terephthalate film. The cover film according to any one of claims 1 to 6, wherein (C) the intermediate layer comprises linear low-density polyethylene. The cover film of claim 7, wherein the linear low density polyethylene contains m-LLDPE. The cover film according to any one of claims 1 to 8, wherein the height of the convex shape arranged in the shape of a thousand birds is 2 μm or more. An electronic component packaging body using the cover film of any one of claims 1 to 9 as a cover material of a carrier tape containing a thermoplastic resin.

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