JP2006104344A - Cover tape for carrier tape - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cover tape which is used for a carrier tape, has excellent blocking resistance, excellent adhesiveness/repeelability to/from the carrier tape, and effectively prevents the formation of burrs extruded from the carrier tape. <P>SOLUTION: This cover tape having an adhesive layer to be heat-sealed to a paper carrier tape having pockets for receiving electronic parts is characterized in that the adhesive layer disposed on one side of the substrate film is formed by a coating/drying method using an aqueous dispersion of ethylene-vinyl acetate copolymer having a vinyl acetate content of 5 to 70 mass% as a main component. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a chip-type electronic component storage board (paper having a storage pocket formed therein) which has a function of protecting electronic components from contamination, arranging them for mounting on an electronic circuit board, and taking them out when storing, transporting and mounting the electronic components. The present invention relates to a cover tape that covers and heat-seals the storage portion of the manufactured carrier tape.

To mount a chip-type electronic component on a circuit board, the chip-type electronic component is packaged and transported to a mounting factory, a carrier tape is set in an automatic mounting machine, and the chip-type electronic component is picked up from the carrier tape by a vacuum nozzle or the like. However, it is mounted after centering. The carrier tape for chip-type electronic components is usually processed as follows and used as a carrier for chip-type electronic components.
Slit to a predetermined width.
Open a square hole and a round hole of a predetermined size. The square hole is for storing chip-type electronic components, and the round hole is for feeding into the filling machine.
Adhere the bottom tape to the back of the carrier tape. In addition, a square embossing of a predetermined size may be performed without making a square hole, and in this case, this step is omitted. The carrier tape and the cover tape are bonded by a so-called heat sealing method in which the carrier tape and the cover tape are overlapped and bonded by applying heat and pressure from above the cover tape.
Fill with chip-type electronic components.
A cover tape is bonded to the surface of the carrier tape by a heat seal method.
It is wound around a cassette reel of a predetermined size and shipped with a chip-type electronic component.
The end user (mounting factory) removes the cover tape and takes out the chip-type electronic components.

Since it is used as described above, as a quality item required for the cover tape, the adhesiveness with the carrier tape is good, that a stable peel strength can be obtained when the cover tape is peeled off from the carrier tape, In addition, it has been mentioned that the cracks coming out of the carrier tape are suppressed. As such a cover tape, one (Patent Document 1) in which an ethylene-vinyl acetate copolymer solution is applied and dried on one side of a base film to provide a heat seal adhesive layer is disclosed. The type of resin cannot increase the concentration (about 5 to 10%), and the thickness of the adhesive layer formed by the coating method is thin, so that there is a problem that sufficient adhesive strength cannot be obtained.

  In addition, the ethylene-vinyl acetate copolymer resin can be applied with an ordinary extruder for low density polyethylene resin, but has a low melting point and has an acetyl group in the side chain, Compared to ethylene-ethyl acrylate copolymer resin, etc., it is inferior in thermal stability, and when it is placed at a temperature of 250 ° C. or higher for a long time, it causes a deacetic acid reaction in the molecule and rapidly decomposes, resulting in a rapid adhesion. It has a serious disadvantage that it is lowered.

JP-A-10-17015 (Claims 1 to 4)

  An object of the present invention is to provide a cover tape for a carrier tape that is excellent in blocking resistance of the cover tape, adhesiveness to the carrier tape, and removability, and that effectively suppresses the occurrence of fluff coming out of the carrier tape. .

  As a result of intensive studies to solve the above problems, the present inventors applied an adhesive layer mainly composed of an aqueous dispersion of an ethylene-vinyl acetate copolymer having a specific vinyl acetate content. It has been found that by using the drying method, the adhesiveness to the carrier tape and the removability are excellent, and the generation of nicks coming out of the carrier tape can be effectively suppressed.

The present invention includes the following aspects.
In a cover tape having an adhesive layer heat-sealed to a paper carrier tape having a pocket for storing electronic components, the adhesive layer provided on one surface of the substrate film has an ethylene acetate content of 5 to 70% by mass. A cover tape for a carrier tape, characterized in that it is formed by a coating / drying method with an aqueous dispersion of a vinyl acetate copolymer as a main component.

The cover tape for a carrier tape according to item (1), wherein the adhesive layer further comprises a fine particle filler having an average particle size of 0.1 to 20.0 μm and a melting point or softening point of 80 to 150 ° C.

The adhesive layer is composed of 0.1 to 5.0 parts by mass of a fine particle filler with respect to 100 parts by mass of an ethylene-vinyl acetate copolymer. Cover tape for carrier tape.

The cover tape for carrier tape according to any one of (1) to (3), wherein the fine particle filler is polymethyl methacrylate.

The cover tape for carrier tape according to any one of (1) to (4), wherein a layer containing an antistatic agent is provided on any of the layers constituting the cover tape for carrier tape.

The cover tape for carrier tape according to any one of (1) to (5), wherein the solid content mass of the adhesive layer is 3 to 20 g / m ² .

  The cover tape for carrier tape of the present invention is excellent in blocking resistance, adhesion to the carrier tape, and removability, and can extremely effectively suppress the occurrence of nicks coming out of the carrier tape when peeling from the carrier tape. It is extremely suitable as a cover tape for carrier tape used for packaging and transporting chip-type electronic components.

  The cover tape for carrier tape of the present invention has a structure in which a heat-sealable adhesive layer is provided by applying and drying an ethylene-vinyl acetate copolymer aqueous dispersion on one surface of a base film.

  As a base film used in the present invention, a thermoplastic resin such as polyethylene terephthalate, polypropylene, polyethylene, polystyrene, polyvinyl chloride, ethylene-vinyl acetate copolymer, or a resin obtained by heating and mixing two or more kinds in a film form is used. Examples include films obtained by extruding from a T-die and biaxially stretching, but since the adhesive layer is provided by applying and drying an adhesive layer coating solution, polyethylene terephthalate and polypropylene film having excellent heat-resistant dimensional stability preferable. The thickness of the film is 5 to 100 μm, preferably 12 to 50 μm.

  As the adhesive resin used in the present invention, an aqueous dispersion of an ethylene-vinyl acetate copolymer having a vinyl acetate content of 5 to 70% by mass is mainly used. The ethylene-vinyl acetate copolymer is copolymerized. The vinyl acetate content at that time needs to be 5 to 70% by mass. When the vinyl acetate content is less than 5% by mass, the wettability to the base film is poor, and the adhesive layer may remain on the carrier tape side when the cover tape is peeled off. On the other hand, when the vinyl acetate content exceeds 70% by mass, the stickiness at room temperature becomes too large, and blocking may occur when the cover tape is constructed.

  Here, the polymerization method of the ethylene-vinyl acetate copolymer resin is not particularly limited. For example, a bulk polymerization method at 1000 atm or more, a solution polymerization method at about 350 atm, or an emulsion polymerization method at 70 atm or less. Although it mentions, the bulk polymerization system from which solid ethylene-vinyl acetate copolymer resin is obtained directly is desirable.

The method for producing the aqueous dispersion of the ethylene-vinyl acetate copolymer of the present invention is not particularly limited, but using the ethylene-vinyl acetate copolymer resin obtained by the bulk polymerization method, the following (1) to ( It is produced by the method described in 5) alone or in combination thereof.
Inversion emulsification method: Water is dispersed in a hot-melted ethylene-vinyl acetate copolymer resin to produce a W / O emulsion, and then the phase is changed to an O / W emulsion.
Atmospheric pressure homomixer method: An ethylene / vinyl acetate copolymer resin is emulsified in water by an ordinary homomixer to produce an O / W emulsion, and then the solvent is removed. Since the softening point of the ethylene-vinyl acetate copolymer resin is 100 ° C. or lower and its viscosity is not extremely high, it can be directly applied to a homomixer without being dissolved in a solvent.
Pressure-resistant homomixer method: In order to emulsify without dissolving or diluting with a solvent, the boiling point of water is raised in a high-pressure atmosphere in a pressure-resistant vessel, and the ethylene-vinyl acetate copolymer resin is heated and melted and emulsified in water. .
High-pressure homogenizer method: A pre-emulsion (pre-emulsion) obtained by pre-emulsifying ethylene-vinyl acetate copolymer resin in water is treated with a homogenizer at a high pressure of 200 to 1500 kg / cm ² to obtain an aqueous dispersion.
Extrusion Luder Method: An ethylene-vinyl acetate copolymer resin is supplied to a hopper of a twin screw extruder, and an aqueous solution containing an emulsifier or a protective colloid agent is supplied under pressure to a compression or metering zone to obtain an aqueous dispersion.

  In the reverse emulsification method, in order to emulsify a high molecular weight resin, a large amount of an emulsifier must be used, and there is a possibility that the adhesiveness and water resistance are poor.

  In the normal pressure homomixer method, when the viscosity is remarkably high even at a softening point of 100 ° C. or less, it must be emulsified by dissolving or diluting with a solvent, and further, a solvent removal step is required, and storage stability There is a possibility that it may be inferior in nature.

Among the above production methods, for example, ethylene-vinyl acetate copolymer is mechanically emulsified with a high-pressure homomixer, high-pressure homogenizer, and extrusion ruder using a protective colloid agent made of a water-soluble (meth) acrylic copolymer having an amino group. Those produced by dispersion are preferred.

  The protective colloid agent used in the present invention is a water-soluble (meth) acrylic copolymer having an amino group, and includes the following components (a) and (b), and optionally other monomers. The copolymer obtained by polymerization is produced by partially or completely neutralizing with an acid.

（ａ）成分

(A) Component

（ｂ）成分
［式中、Ｒ_１はＨ又はＣＨ_３；Ｒ_２はＣ_１〜Ｃ_４のアルキレン基又はヒドロキシ置換アルキレン基；Ｒ_３とＲ_４はＨ又はＣ_１〜４のアルキル基；Ｒ_５はＣ_１〜２２のアルキル基、アルケニル基、シクロアルキル基又はアラルキル基；ＡはＯ又はＮＨである］

(B) Component [wherein R ₁ is H or CH ₃ ; R ₂ is a C ₁ -C ₄ alkylene group or a hydroxy-substituted alkylene group; R ₃ and R ₄ are H or C _1-4 alkyl group; R ₅ is a C _1-22 alkyl group, alkenyl group, cycloalkyl group or aralkyl group; A is O or NH]

  As the component (a), N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylamide, N, N-dimethylamino- Examples include 2-hydroxypropyl (meth) acrylate, 4-vinylpyridine, 2-vinylpyridine and the like.

(B) Component (meth) acrylic acid ester includes methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylic acid-2-ethylhexyl, (meth) acrylic acid Examples thereof include alkyl, alkenyl, cycloalkyl, and aralkyl esters of acrylic acid or methacrylic acid such as lauryl, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, allyl (meth) acrylate, and benzyl (meth) acrylate. These may be used alone or in combination of two or more. In addition to these components (a) and (b), monomers such as vinyl acetate, styrene and vinyl ether are used as necessary. Constituting the copolymer component (b) of the mole fraction M _i of an acrylic acid ester _i, the number of carbon atoms in the ester of the acrylic acid ester i when the N _i, the sum of the product of M _i and N _i It is preferable to select and use the component (b) at a ratio such that (ΣM _i N _i ) is a value of 0.5 to 10, preferably 1 to 8. When (ΣM _i N _i ) is less than 0.5, the lipophilicity of the copolymer neutralized product becomes too weak, and when it exceeds 10, the lipophilicity becomes too strong. Can not be manufactured.

  These (a) component, (b) component and other monomers are (a) component 10 to 80 mol%, preferably 15 to 75 mol%, (b) component 90 to 20 mol%, preferably 85 to 25 mol%. A copolymer is produced by reacting in the presence of a polymerization initiator at a mole percentage of 0 to 180 ° C., preferably 40 to 120 ° C. for 0.5 to 20 hours, preferably 2 to 10 hours. Here, the polymerization reaction is performed in the presence of water or a hydrophilic solvent such as ethyl alcohol, isopropyl alcohol, cellosolve or the like.

  Examples of the polymerization initiator include azobisisobutyronitrile, t-butyl peroxyisobutyrate, 1,1-bis (t-butylperoxy) cyclohexene, t-butyl peroxybenzoate, and the like.

  When the amount of the component (a) is less than 10 mol%, the hydrophilicity of the resulting copolymer neutralized product is weak, and when it exceeds 80 mol%, the hydrophilicity of the neutralized product is too strong and stable aqueous polymer dispersion. The liquid cannot be manufactured. If the amount of the component (b) is less than 20 mol%, the resulting copolymer neutralized product has poor lipophilicity, and if it exceeds 90 mol%, the neutralized product is too lipophilic and stable in any case. An aqueous polymer dispersion cannot be obtained.

  Examples of the acid that neutralizes a part or the whole of this copolymer include formic acid, acetic acid, hydrochloric acid, phosphoric acid, nitric acid, and the like. Among these, volatile formic acid, acetic acid, and hydrochloric acid are used at room temperature. When the aqueous dispersion is dried to form a film, these acids are liberated from the neutralized product and the hydrophobicity of the dispersant is increased, so that the water resistance of the film is improved. The neutralization reaction is performed by reacting the copolymer and the acid at 20 to 100 ° C. for 0.1 to 3 hours.

  Further, prior to the production of the copolymer, the component (a) is neutralized with these acids in advance, and this is polymerized with monomers such as the component (b) to produce a neutralized product of the copolymer. Also good. The usage-amount of the acid used for neutralization is 10-100 mol% of the (a) component which comprises a copolymer.

  The neutralized product of a part or the whole of the copolymer is generally preferably water-soluble, but may be a poorly water-soluble solid having a particle size of 0.01 to 5 μm. This is because the neutralized product itself is a polymer and has a film forming ability. However, when the compatibility between the ethylene-vinyl acetate copolymer to be dispersed and the neutralized product is poor, the transparency of the film is lowered, so that the water-soluble one is desirable.

This neutralized product is generally diluted with water and used as a protective colloid agent (dispersant). The amount used is 2 to 20 parts by mass, preferably 5 to 15 parts by mass in terms of solid content, with respect to 100 parts by mass of the ethylene-vinyl acetate copolymer to be dispersed. If the amount is less than 2 parts by mass, a stable aqueous dispersion cannot be produced. On the other hand, when the amount exceeds 20 parts by mass, the mechanical strength of the film becomes too weak to be practically used.

In order to produce an aqueous dispersion of an ethylene-vinyl acetate copolymer resin using this neutralized product as a protective colloid agent, a molten ethylene-vinyl acetate copolymer is added to the protective colloid agent aqueous solution, a high-pressure homomixer, It is carried out by stirring uniformly with a high-pressure homogenizer, an extrusion ruder or the like. The most preferred embodiment uses a multi-screw extrusion ruder having two or more screws described in JP-A-56-2149 in the casing, and the ethylene-vinyl acetate copolymer is supplied from the hopper of the extrusion ruder. This is produced by heating, melting and kneading, and kneading with an aqueous solution of a protective colloid agent supplied from at least one liquid supply port provided in the compression zone or / and the metering zone of the extrusion ruder.

  Alternatively, an ethylene-vinyl acetate copolymer and an aqueous solution of a protective colloid agent are supplied from an extrusion rudder hopper, heated to a temperature about 15 ° C. higher than the plasticization temperature of the ethylene-vinyl acetate copolymer, and kneaded with a screw. Can also be manufactured.

  The aqueous dispersion of the present invention is adjusted so as to have a solid content concentration of 20 to 65% by mass. In addition to the ethylene-vinyl acetate copolymer and the protective colloid agent, an antifoaming agent, a viscosity adjusting agent, an anionic property is used. You may mix | blend surfactant, nonionic surfactant, antioxidant, etc.

  The aqueous dispersion of the ethylene-vinyl acetate copolymer thus produced has an average particle size of 5 μm or less, and an average particle size of 1 μm or less is 10% by mass or more, preferably 20% by mass or more. The viscosity at 25 ° C. dispersed in water is 10 to 10,000 cps, preferably 50 to 5000 cps.

  In order to prevent the occurrence of blocking when the cover tape adhesive layer of the present invention is formed and winding is produced, it is preferable to incorporate a fine particle filler in the adhesive layer. The fine particle filler used in the present invention is not particularly limited, but organic or inorganic fine particles having an average particle diameter of 0.1 to 20.0 μm, a melting point or a softening point of 80 to 150 ° C. are preferable. Fatty acids such as stearic acid; fatty acid amides such as stearic acid amide and stearic acid bisamide; fatty acid salts such as zinc stearate and calcium stearate; polystyrene resin; polymethyl methacrylate resin; silicone resin; polyamides such as aromatic polyamide Resins: Polyimide resins such as polyimide resins, bismaleimide / triazine resins, polyamideimide resins, polyamide bismaleimide resins; epoxy resins, polyacetal resins, polyphenylene oxide resins, modified polyphenylene oxide resins, polyethers Polyether resins such as ether ketone resins, polyether sulfone resins, polysulfone resins; Polyester resins such as polybutylene terephthalate resins, polyarylate resins, polycarbonate resins, polyoxybenzoate resins; benzoguanamine / formaldehyde resins; benzoguanamine / melamine / Formaldehyde resin; inorganic pigments such as silica, calcium carbonate, talc, kaolin and the like.

  When the average particle size of the fine particle filler of the present invention is less than 0.1 μm, there is a possibility that a sufficient antiblocking effect cannot be obtained when a cover tape is formed. If the average particle size of the fine particle filler exceeds 20.0 μm, the adhesive force to the carrier tape may be too low. On the other hand, if the melting point or softening point is less than 80 ° C., when the adhesive layer is applied and dried, the particles may melt or soften, and a sufficient anti-blocking effect may not be obtained. When the melting point or softening point exceeds 150 ° C., it may be difficult to fix the particles in the adhesive layer.

  The mixing ratio of the fine particle filler of the present invention is preferably 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the ethylene-vinyl acetate copolymer. When the blending ratio of the fine particle filler is less than 0.1 parts by mass, the frictional force on the surface of the adhesive layer becomes too high, and there is a possibility of blocking when the cover tape is formed. When the blending ratio of the fine particle filler exceeds 5.0 parts by mass, the adhesive force is greatly reduced, and unintended peeling may occur during the transportation of the electronic component.

  Of the above-described fine particle fillers, polymethyl methacrylate resin particles are preferred because adhesion and removability can be ensured without impairing the transparency of the adhesive layer.

  Furthermore, it is preferable to add an antistatic agent to any one of the layers constituting the cover tape in order to suppress frictional charging when the cover tape is peeled off from the carrier tape or adhesion of floating paper powder. That is, it is preferable to provide an antistatic agent layer in the adhesive layer, the adhesive layer surface, the base film, the surface and / or the back surface of the base film. Antistatic agents used in the present invention include alkali metal salts such as sodium chloride and potassium chloride, alkaline earth metal salts such as calcium chloride and barium chloride, glycerin fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene alkyl Phenyl ether, alkyldiethanolamine, hydroxyalkyl monoethanolamine, polyoxyethylene alkylamine, polyoxyethylene alkylamine fatty acid ester, alkyldiethanolamide, alkylsulfonate, alkylbenzenesulfonate, alkylphosphate, polyacrylate, polystyrenesulfone Of styrene polymer block and hydrophilic polymer block containing acid salt, polystyrene sulfonate amine salt, styrene as essential constituent monomer Block copolymer, resin grafted with (meth) acrylic acid ester in which polyethylene glycol is introduced into polystyrene resin, hydrophilic polymer with antistatic segment of polyether compound, polymaleate, polymaleic acid amine salt, tetraalkylammonium Salts, trialkylbenzylammonium salts, alkylbetaines, alkylimidazolium betaines, and the like.

The blending amount of the antistatic agent is an amount that can make the surface resistance value of the cover tape 1 × 10 ¹¹ Ω or less, and is usually in the range of 0.1 to 5.0 mass%. If the blending amount of the antistatic agent is less than 0.1% by mass, the antistatic effect is poor and the electronic component may be damaged by static electricity. When the blending amount of the antistatic agent exceeds 5.0% by mass, the antistatic agent is likely to migrate, and the adhesive force to the carrier tape may be excessively reduced.

  The adhesive layer of the present invention can be formed by applying and drying an adhesive layer coating solution on a substrate film by a conventionally known method. Examples of the coating apparatus that can be used in the present invention include a knife coater, a slot die coater, a curtain coater, a reverse roll coater, a bar coater, an air knife coater, a reverse gravure coater, a direct gravure coater, and a micro gravure coater. it can. Examples of the drying apparatus usable in the present invention include a hot air jet dryer (high-speed air cap type, tunnel type, air floating type), Yankee cylinder type dryer, counterflow type dryer, air-through dryer, and infrared type dryer. , Microwave dryers, induction heating dryers, and the like.

As for the application quantity of the adhesive bond layer of this invention, 3-20 g / m < ² > is preferable by solid content mass. When the application amount of the adhesive layer is less than 3 g / m ² , the adhesive force to the carrier tape or the base film becomes insufficient, and the cover tape may be peeled off during transportation of the electronic component. Moreover, when the application amount of the adhesive layer exceeds 20 g / m ² , the adhesive strength becomes too strong, and the workability of peeling the cover tape may be deteriorated.

  Examples of the present invention will be described below, but the present invention is not limited to these examples. In the examples, “parts” and “%” are parts by mass and mass% unless otherwise specified.

Example 1
An aqueous dispersion of ethylene / vinyl acetate copolymer resin as an adhesive (trade name: AD-37R-345J, manufactured by Toyo Morton, vinyl acetate content 10% by mass) and 100 parts by mass of polymethyl methacrylate as a fine particle filler (Product name: Eposter MA1006, Nippon Shokubai Co., Ltd., average particle size 6.0 μm, softening point 125 ° C.) was blended in 2 parts by mass to obtain an adhesive layer coating liquid for carrier tape cover tape (concentration 50% by mass). .
Prepare in advance on the antistatic surface side of a biaxially stretched polyethylene terephthalate film (trade name: T-100G, manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., thickness 25 μm), which is a base material provided with an antistatic layer on one side. The above adhesive layer coating solution was applied with a gravure coater so that the dry mass was 5 g / m ^2, and dried at 130 ° C. for 30 seconds using an air floating dryer to form the adhesive layer of the present invention. A cover tape for carrier tape was obtained.

(Example 2)
1 part by mass of main agent (trade name: Bondip PA100 [acrylic resin], manufactured by Altec AP Co., Ltd.) and a curing agent (trade name: Bondip PA100 [epoxy resin], manufactured by Altech AP Co., Ltd.) as an antistatic agent An antistatic agent layer coating solution was prepared by partially blending.
Antistatic agent layer coating solution prepared in advance on one side of a biaxially stretched polyethylene terephthalate film (trade name: E-5100, manufactured by Toyobo Co., Ltd., thickness 25 μm), which is an antistatic base material, in a dry mass It applied with a bar coater so that it might become 0.05 g / m < ² >, and it dried at 100 degreeC for 30 second using the tunnel type dryer, and formed the antistatic layer. A carrier tape cover tape of the present invention was obtained in the same manner as in Example 1 except that the above base material was used and the adhesive coating amount was 12 g / m ² .

(Example 3)
The carrier tape cover tape of the present invention is the same as in Example 2 except that a biaxially stretched polypropylene film (trade name: E-200, manufactured by Oji Paper Co., Ltd., thickness: 50 μm) is used as the non-static antistatic substrate. Got.

Example 4
(Synthesis of protective colloid agent) N, N-dimethylaminoethyl methacrylate 62.9 parts by mass (0.4 mol), butyl methacrylate 71 parts by mass (0.5 mol), lauryl methacrylate 25.4 parts by mass (0.1 Mol) and 200 parts by mass of isopropyl alcohol as a solvent are charged into a four-necked flask equipped with a stirrer, reflux condenser, thermometer, and dropping funnel, and after substitution with nitrogen gas, 2,2′-azobisiso is used as a polymerization initiator. 0.9 parts by mass of butyronitrile was added, and a polymerization reaction was performed at 60 ° C. for 4 hours. Next, after neutralizing with 24 parts by mass (0.4 mol) of acetic acid, water was added while distilling off isopropyl alcohol, and finally an aqueous solution of a viscous protective colloid agent having a solid content concentration of 35% by mass was added. Obtained.
A twin screw extruder (trade name: PCM43, manufactured by Ikekai Co., Ltd.) of ethylene-vinyl acetate copolymer resin (trade name: Ultrasen 634, manufactured by Tosoh Corporation, vinyl acetate content 26 mass%) at a rate of 100 parts by mass / hour. ) Was continuously supplied from the hopper.

Further, an aqueous solution obtained by further diluting 23 parts by mass of the protective colloid agent aqueous solution (solid content: 8.05 parts by mass) with 350 parts by mass of water from a supply port provided in the vent part of the extruder at a rate of 170 parts by mass / hour. Milky white ethylene-vinyl acetate copolymer resin extruded continuously at a heating temperature (cylinder temperature) of 130 ° C. and a screw speed of 100 rpm while being continuously pressurized and supplied with a gear pump (discharge pressure 3 kg / cm ² G). An aqueous dispersion (solid concentration 45% by mass) was obtained.

A cover tape for carrier tape of the present invention was obtained in the same manner as in Example 1 except that the aqueous dispersion of the ethylene-vinyl acetate copolymer resin was used as an adhesive.

(Example 5)
For carrier tape of the present invention as in Example 4 except that ethylene-vinyl acetate copolymer resin (trade name: Ultrasen 750, manufactured by Tosoh Corporation, vinyl acetate content: 32% by mass) was used as the adhesive. A cover tape was obtained.

(Example 6)
Example 4 except that ethylene-vinyl acetate copolymer resin (trade name: Ultrasen 760, manufactured by Tosoh Corporation, vinyl acetate content 42 mass%) was used as the adhesive, and the coating amount was 18 g / m ^2. Similarly, the carrier tape cover tape of the present invention was obtained.

(Example 7)
The carrier tape of the present invention was used in the same manner as in Example 4 except that ethylene / bisstearic acid amide (trade name: Kao Wax EB-FF, average particle size 3.3 μm, melting point 144 ° C.) was used as the fine particle filler. A cover tape was obtained.

(Comparative Example 1)
Ethylene / vinyl acetate copolymer resin (trade name: Mirason 252; manufactured by Mitsui Chemicals, vinyl acetate content: 6% by mass) as an adhesive is blended with 2 parts by mass of a fatty acid amide as a lubricant, and a carrier tape cover It was set as the toluene solution (concentration 8 mass%) of a tape adhesive layer.
Prepare in advance on the antistatic surface side of a biaxially stretched polyethylene terephthalate film (trade name: T-100G, manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., thickness 25 μm), which is a base material provided with an antistatic layer on one side. The above adhesive layer coating solution was applied with a gravure coater so that the dry mass was 3 g / m ^2, and dried at 130 ° C. for 30 seconds using an air floating dryer to form the adhesive layer of the present invention. A cover tape for carrier tape was obtained.

(Comparative Example 2) [corresponding to Example 1 of Patent Document 1]
An isocyanate-based anchor coating agent is applied and dried on one side of a biaxially stretched polyethylene terephthalate film having a thickness of 16 μm, and low-density polyethylene (trade name: Mirason 10P, manufactured by Mitsui Chemicals, Inc.) is melt-extruded to the anchor-coated surface. A 20 μm intermediate layer was provided, and an adhesive layer having the following composition was melt extruded at a thickness of 30 μm to obtain a cover tape for carrier tape.
Materials constituting the adhesive layer: ethylene-vinyl acetate copolymer having a vinyl acetate content of 6% by mass (trade name: Mirason 252; manufactured by Mitsui Chemicals) 42 parts by mass, ethylene-butene having a density of 0.88 g / cm ³ -1 copolymer (trade name: Toughmer 4085, manufactured by Mitsui Chemicals) 42 parts by mass, alicyclic hydrocarbon resin having a softening point of 125 ° C. as a tackifier (trade name: Alcon P-125, manufactured by Arakawa Chemical Co., Ltd.) 16 parts by weight, fatty acid amide 0.2 parts by weight as a lubricant

(Comparative Example 3)
For carrier tape as in Example 1 except that ethylene-vinyl acetate copolymer resin (trade name: Sumikaflex S-471, manufactured by Sumitomo Chemical Co., Ltd., vinyl acetate content 87 mass%) was used as the adhesive. A cover tape was obtained.

<Evaluation method>
(1) Adhesive evaluation: Using a heat sealing machine (trade name: TP-701-B HEAT GRADENT, manufactured by Tester Sangyo Co., Ltd.), iron width 0.5 mm × 2 pieces, pressure 1.0 Kg / cm ² , time 0 A sample bonded to a carrier tape (trade name: MCC-TR TAPE) manufactured by Taiwan Electronics Co., Ltd. under the conditions of 2 seconds at a temperature of 170 ° C. was prepared, and the sample was 3 at a peeling angle of 180 ° and a peeling speed of 300 mm / min A peel test was performed to evaluate the adhesion.
○: Adhered completely and no gap is generated between the carrier tape and the cover tape. Δ: A gap is slightly generated between the carrier tape and the cover tape. Adhesive strength is weak, and many gaps are generated between the carrier tape and cover tape.

(2) Fluff evaluation: Using a sample for evaluating adhesiveness, the state after peeling was visually determined.
○: The cover tape is not fluffed, and no trace of the cover tape adhered to the carrier tape is visible ○ △: The cover tape is not fluffed, and the trace of the cover tape adhered to the carrier tape is slightly visible Δ: Cover There is fluff on the tape, there is a mark that the cover tape is adhered to the carrier tape, and it is slightly fluffy. Δ: The binding tape of the carrier tape is taken on the cover tape, and continuous fluff is observed on the carrier tape. : The surface layer of the carrier tape is taken on the cover tape.

(3) Static electricity evaluation: At the time of adhesion evaluation, the amount of charge peeled between the carrier tape and the cover tape was measured with a static electricity checker (manufactured by KASUGA).
A: Almost no generation of static electricity and excellent (−0.5 to 0.5 KV)
○: Excellent with no generation of static electricity (-1.0 to 1.0 KV)
Δ: Static electricity is generated, but there is no practical problem (−5.0 to −1.0 KV, 1.0 to 5.0 KV)
×: Level of generation of static electricity and a problem in practical use (−5.0 KV or less, 5.0 KV or more)

(4) Workability evaluation: The film was blocked when used for winding the product, the winding end face was uneven, and the state of wrinkles was visually judged.
○: Blocking, end face irregularity, no wrinkle generation, excellent workability. Δ: Blocking or end face irregularity or wrinkle generation, but no problem in practical use. Practical problem level

(5) Surface resistivity: Digital insulation meter (trade name: DSM-8103, Toa Denpa Kogyo Co., Ltd.) in an atmosphere of temperature 23 ± 2 ° C. and humidity 50 ± 5% RH according to JIS-K-6911, 5.13 ).

(6) Comprehensive evaluation: Comprehensive evaluation as a cover tape for carrier tape was performed.
A: Excellent as a cover tape for carrier tape B: Excellent as a cover tape for carrier tape B: Slightly problematic as a cover tape for carrier tape There is a problem as a cover tape and it is not practical

  From Table 1, the cover tapes for carrier tapes of the present invention of Examples 1 to 7 are at a level with no problem with respect to blocking resistance, adhesion to the carrier tape, and re-peelability, and the occurrence of scuffing out of the carrier tape is effective. Is suppressed. On the other hand, in Comparative Example 1, since the adhesive layer was provided by the melt extrusion method, the adhesive force was greatly reduced. In Comparative Example 2, since the ethylene-vinyl acetate copolymer resin having a vinyl acetate content of 87% by mass was used as the adhesive, blocking of the cover tape winding was severe.

In the cover tape having an adhesive layer heat-sealed to a paper carrier tape having electronic component storage pockets according to the present invention, the adhesive layer provided on one surface of the base film has a vinyl acetate content of 5 to 70% by mass. It is excellent in blocking resistance, adhesion to carrier tape, and removability, and comes out of the carrier tape by being formed by coating and drying method with an aqueous dispersion of ethylene-vinyl acetate copolymer as the main component. A cover tape for carrier tape in which the occurrence of cracks is extremely effectively suppressed can be obtained.

Claims (6)

  In a cover tape having an adhesive layer heat-sealed to a paper carrier tape having a pocket for storing electronic components, the adhesive layer provided on one surface of the base film of the cover tape has a vinyl acetate content of 5 to 70% by mass. A cover tape for a carrier tape, which is formed by a coating / drying method using an aqueous dispersion of an ethylene-vinyl acetate copolymer as a main component.   The cover tape for a carrier tape according to claim 1, wherein the adhesive layer further comprises a fine particle filler having an average particle size of 0.1 to 20.0 µm, a melting point or a softening point of 80 to 150 ° C.   The carrier tape cover according to claim 1 or 2, wherein the adhesive layer is composed of 0.1 to 5.0 parts by mass of a fine particle filler with respect to 100 parts by mass of the ethylene-vinyl acetate copolymer. tape.   The carrier tape cover tape according to any one of claims 1 to 3, wherein the fine particle filler is polymethyl methacrylate.   The cover tape for carrier tapes of any one of Claims 1-4 comprised by providing the layer which contains an antistatic agent in any layer which comprises the cover tape for carrier tapes. Any one carrier tape cover tape according to claim 1 to 5 coating amount of the adhesive layer is 3 to 20 g / m ^2.