WO2018181419A1

WO2018181419A1 - Top tape for carrier tape and manufacturing method thereof

Info

Publication number: WO2018181419A1
Application number: PCT/JP2018/012636
Authority: WO
Inventors: 五藤　靖志
Original assignee: 住化積水フィルム株式会社
Priority date: 2017-03-28
Filing date: 2018-03-28
Publication date: 2018-10-04
Also published as: TW202017752A; JPWO2018181419A1

Abstract

A top tape for carrier tape is provided which has the characteristics that (i) acid generation caused by shrinkage and hydrolysis during heat sealing is prevented or suppressed, (ii) delamination between a substrate layer and a heat seal layer is suppressed, and (iii) excellent mechanical strength is achieved. Specifically, this top tape for a carrier tape, which is for covering and heat-sealing an opening in a carrier tape that houses an electronic component in a recess, is a laminate comprising at least 2 layers, (1) a substrate layer formed from a non-stretch film containing a polybutylene terephthalate resin, and (2) a heat seal layer containing a copolymer of ethylene and an acrylic acid ester.

Description

Top tape for carrier tape and manufacturing method thereof

The present invention relates to a top tape for carrier tape and a method for producing the same.

Conventionally, a carrier tape has been used to store and transport electronic components such as semiconductor components. In the carrier tape, an electronic component is accommodated in the recess, and a top tape is attached to the opening side of the recess to cover the electronic tape, and the electronic component is held and transported in a state where the recess is sealed.

Conventionally, as a top tape, for example, a layer composed of two layers obtained by laminating a layer formed from a biaxially stretched polyethylene terephthalate (PET) resin and a layer formed from a polyolefin resin, or a layer formed from PET Known is a three-layer structure in which a layer formed from a polyolefin resin and a layer formed from an ethylene-vinyl acetate copolymer (EVA) are sequentially laminated.

For example, Patent Document 1 describes a top tape using a three-layer laminate film of biaxially stretched polyester film / polyethylene film / biaxially stretched polyester film as the base material of the top tape.

Registered Utility Model No. 2551931

However, the biaxially stretched PET film generally used as the biaxially stretched polyester has a problem that when it is used as a base material for a top tape, the shrinkage is large during heat sealing. Therefore, for example, when a biaxially stretched PET film is used as the base material of the top tape, the base material contracts due to heating in the heat sealing step, and warping or the like may occur when the base tape is bonded to the carrier tape.

Also, when a biaxially stretched PET film is used as the base material of the top tape, when the adhesion between the layer formed from the polyolefin resin and the carrier tape is strong, the layer formed from the biaxially stretched PET resin and the polyolefin system There is a risk of delamination with a layer formed from the resin.

Furthermore, when EVA is used as the material for the top tape, EVA may generate acetic acid by hydrolysis during heat sealing, which may affect the electronic components housed in the carrier tape.

Therefore, the object of the present invention is to (i) prevent or suppress the generation of acid due to shrinkage and hydrolysis during heat sealing, and (ii) suppress delamination between the base material layer and the heat sealing layer. And (iii) providing a top tape for carrier tape having the characteristics of excellent mechanical strength and a method for producing the same.

As a result of intensive studies to achieve the above-mentioned object, the present inventors have found that at least two layers of a base material layer made of a specific unstretched film and a heat seal layer containing a copolymer of ethylene and an acrylic ester It has been found that the above object can be achieved by using a top tape for a carrier tape having the following. Based on such knowledge, the present invention has been further researched and completed.

That is, this invention provides the invention of the aspect hung up below.
Item 1. A top tape for covering and heat-sealing an opening of a carrier tape that accommodates an electronic component in a recess, wherein the top tape is a laminate having at least two layers of a base material layer and a heat seal layer,
(1) The base material layer is composed of an unstretched film containing a polybutylene terephthalate resin,
(2) The heat seal layer contains a copolymer of ethylene and an acrylic ester.
A top tape for carrier tape.
Item 2. The top layer for a carrier tape according to Item 1, wherein the laminate has a layer containing a polyethylene resin on one side of the heat seal layer and on the side opposite to the side having the base material layer.
Item 3. Item 3. The carrier tape top tape according to

Item

1 or 2, wherein the carrier tape is made of paper.
Item 4. A top tape manufacturing method for covering and heat-sealing an opening of a carrier tape that houses an electronic component in a recess,
(1) The top tape is a laminate having at least two layers of a base layer made of an unstretched film containing a polybutylene terephthalate resin and a heat seal layer containing a copolymer of ethylene and an acrylic ester. Become
(2) having a step of forming the laminate by a coextrusion method;
A method for producing a top tape for a carrier tape.

According to the present invention, (i) generation of acid due to shrinkage and hydrolysis during heat sealing is prevented or suppressed, and (ii) delamination between the base material layer and the heat seal layer is suppressed. And (iii) a top tape for carrier tape having the characteristics of excellent mechanical strength and a method for producing the same.

It is a figure which shows an example of the usage condition of the top tape for carrier tapes of this invention.

Hereinafter, the top tape for carrier tape of the present invention and the manufacturing method thereof will be described in detail.

In this specification, the seal strength is based on a measurement method based on JIS Z 0237: 2009.

TECHNICAL FIELD The present invention relates to a top tape for covering and heat-sealing an opening of a carrier tape that accommodates an electronic component in a recess, and the top tape includes at least a base material layer and a heat seal layer. (1) The base material layer is made of an unstretched film containing a polybutylene terephthalate resin, and (2) the heat seal layer is a co-polymer of ethylene and an acrylic ester. It contains a coalescence.

The top tape for carrier tape of the present invention having the above characteristics is a laminate having at least two layers of a base material layer and a heat seal layer, and satisfies the requirements (1) and (2) above, (i) The generation of acid due to shrinkage and hydrolysis during heat sealing is prevented or suppressed, (ii) delamination between the base material layer and the heat seal layer is suppressed, and (iii) mechanical strength. It has the property of being excellent.

When the carrier tape top tape of the present invention has a two-layer structure, the carrier tape top tape is preferably composed of a laminate in which a base material layer and a heat seal layer are laminated in this order.

In the present invention, when the heat seal layer and an adherend such as paper are heat sealed and the seal strength per 10 mm width is measured, the seal is concerned from the viewpoint of suppressing delamination between the base material layer and the heat seal layer. The strength is preferably 1 to 10 N / 10 mm, more preferably 2 to 8 N / 10 mm, still more preferably 2.5 to 7 N / 10 mm, and particularly preferably 3 to 5 N / 10 mm.

As the paper as the adherend, for example, carrier tape paper having a thickness of about 1 mm can be used.

Base material layer The base material layer in the top tape for carrier tapes of this invention consists of an unstretched film which contains polybutylene terephthalate (PBT) resin as a main component.

In this specification, “including as a main component” means that the content of the PBT resin is 50% by mass or more in 100% by mass of the resin component of the base material layer.

The base material layer is made of a non-stretched film containing a PBT resin, so that the film does not easily shrink even during heat sealing. When a film stretched in a uniaxial direction or a biaxial direction is used, the thermal shrinkage rate of the film becomes as large as about 1%. Therefore, the warp due to the shrinkage of the top tape after heat sealing causes 1) It is not preferable from the viewpoint that reel winding of the transport tape becomes difficult, and 2) equipment troubles easily occur when the top tape is peeled off.

In the present invention, the base material layer is preferably an unstretched film made of only a PBT resin, from the viewpoint that a predetermined strength can be imparted even when unstretched. That is, in this invention, it is preferable that content of PBT resin in a base material layer is 100 mass%.

In the present invention, it is more preferable that the base material layer is used by blending subcomponents in addition to the PBT resin as the main component from the viewpoint of improving heat resistance. Examples of the subcomponent include aromatic polyesters such as PET resin, PEN (polyethylene naphthalate) resin, PC (polycarbonate) resin, and PBN (polybutylene naphthalate). These aromatic polyesters may be used alone or in combination of two or more.

In the present invention, as described above, in the case where a subcomponent is blended and used in addition to the PBT resin, the content of the PBT resin in the base material layer is the resin component of the base material layer from the viewpoint of maintaining the strength without stretching. More preferably, it is more than 50% by mass and less than 70% by mass in 100% by mass.

The thickness of the base material layer is preferably 10 μm or more and 55 μm or less, and more preferably 15 μm or more and 40 μm or less. When the thickness is in such a range, the mechanical strength of the base material layer is suitable.

PET has a slow crystallization speed due to its resin characteristics, and crystals are not sufficiently grown in normal film formation, so that the film strength is weak. Therefore, in general, a PET film is often biaxially stretched to develop strength.

On the other hand, PBT has a high crystallization speed due to its resin characteristics, and sufficient crystals grow even in normal film formation, so that it is possible to develop film strength necessary for normal use even without stretching.

The intrinsic viscosity (IV: Intrinsic Viscosity) of the PBT resin is preferably 1 to 1.6 and more preferably 1.1 to 1.3 from the viewpoint of obtaining good fluidity. When the intrinsic viscosity is in such a range, moderate fluidity can be imparted to the PBT resin, so that an unstretched film containing the PBT resin can be easily formed. Moreover, it becomes difficult to generate fish eyes in the non-stretched film containing the formed PBT resin.

The intrinsic viscosity of the PBT resin is measured and calculated according to JIS K7390: 2003.

The base material layer can contain other additives such as an antistatic agent, an antiblocking agent, and a slipping agent as long as the effects of the present invention are not impaired.

An antistatic agent can be added to prevent the static electricity generated when the top tape is unwound from causing discharge and damaging the housed parts.

The content of the antistatic agent in the base material layer is preferably 10% by mass to 30% by mass, more preferably 12% by mass to 20% by mass. When the content of the antistatic agent in the base material layer is in such a range, the occurrence of static electricity is suppressed, thereby further preventing damage caused by the discharge of the housed components.

Anti-blocking agent and slip agent can be added to prevent blocking after winding the tape and to prevent troubles due to catching when the tape is applied to the machine.

Heat Seal Layer The heat seal layer in the top tape for carrier tape of the present invention contains a copolymer of ethylene and an acrylic ester.

A copolymer of ethylene and acrylic acid ester contains an acid having a double bond on the main chain side of the copolymer, and a low-molecular decomposition product generated when the ester portion is hydrolyzed is an acid. It is important to be alcohol rather than alcohol.

Copolymers of ethylene and acrylic acid ester are ethylene-methyl acrylate copolymer (EMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-isopropyl acrylate copolymer, ethylene-acrylic acid. n-propyl copolymer, ethylene-n-butyl acrylate copolymer, ethylene-isobutyl acrylate copolymer, ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl methacrylate copolymer, ethylene- Isopropyl methacrylate copolymer, ethylene-n-propyl methacrylate copolymer, ethylene-n-butyl methacrylate copolymer, ethylene-isobutyl methacrylate copolymer, ethylene-2-ethylpropenoic acid methyl copolymer, Ethylene-2-ethylpropenoic acid ethyl copolymer, ethylene -Ethylpropenoic acid isopropyl copolymer, ethylene-2-ethylpropenoic acid n-propyl copolymer, ethylene-2-ethylpropenoic acid n-butyl copolymer, ethylene-2-ethylpropenoic acid isobutyl copolymer, ethylene -2-Butenoic acid methyl copolymer, ethylene-2-butenoic acid ethyl copolymer, ethylene-2-butenoic acid isopropyl copolymer, ethylene-2-butenoic acid n-propyl copolymer, ethylene-2-butene Examples thereof include an acid n-butyl copolymer and an ethylene-2-butenoate isobutyl copolymer. These copolymers may be used alone or in combination of two or more.

Content of copolymerization of ethylene and acrylic acid ester in the heat seal layer includes resin flowability, melting point, adhesion to base material layer, adhesion to carrier tape, prevention of fish eye generation, etc. Determined from the viewpoint of

In the present invention, in the case of the two-layer configuration of the base material layer and the heat seal layer, from the viewpoint of the balance between the adhesiveness between the base material layer and the heat seal layer and the adhesiveness between the heat seal layer and the carrier tape. The content of the copolymer of ethylene and acrylic acid ester in the heat seal layer is preferably 1% by mass to 30% by mass, more preferably 5% by mass to 15% by mass.

In the present invention, in the case of a structure of three or more layers having a layer containing a polyethylene resin on one side of the heat seal layer and opposite to the side having the base material layer, the heat seal layer is a carrier tape. Do not touch directly. Therefore, from the viewpoint of further strengthening the adhesion between the base material layer and the heat seal layer, the content of the copolymer of ethylene and acrylic acid ester in the heat seal layer is preferably Is 30% by mass or more, more preferably 50% by mass or more, and still more preferably 70% by mass or more.

As a copolymer of ethylene and acrylic acid ester, at least one of EMA, EEA, and EMMA among the above from the viewpoint of fluidity of resin, melting point, adhesion to carrier tape, prevention of occurrence of fish eye, etc. Is preferred.

In the ethylene-vinyl acetate copolymer (EVA), the main chain side of the copolymer is not an acid but an alcohol. Therefore, acetic acid is generated by hydrolysis, which may damage the electronic components housed in the carrier tape. Therefore, in the present invention, EVA is not included as a copolymer of ethylene and acrylic acid ester.

The thickness of the heat seal layer is preferably 10 μm or more and 55 μm or less, and more preferably 15 μm or more and 40 μm or less. When the thickness is in such a range, the mechanical strength of the heat seal layer is suitable.

The melt flow rate (MFR) of the copolymer of ethylene and acrylic acid ester is preferably 1 to 20 g / 10 minutes, and more preferably 2 to 10 g / 10 minutes. When the MFR is in such a range, it is possible to impart appropriate fluidity when the copolymer of ethylene and acrylic acid ester is melted, so that it is excellent in moldability when formed into a film, and a heat seal layer is formed. Can be easily performed. Moreover, it is excellent in the heat sealing | fusion (heat seal) performance to a carrier tape. Furthermore, when the material of the carrier tape is made of paper, the penetration of the copolymer of ethylene and acrylic acid ester between the fibers of the carrier tape is not hindered, so that the heat sealing performance is excellent.

MFR in this specification is a value measured under the conditions of JIS K7210: 1999, Method A, 190 ° C., and load 21.18N.

The melting point of the copolymer of ethylene and acrylic acid ester is preferably 70 ° C to 130 ° C, more preferably 80 ° C to 110 ° C. When the melting point is in such a range, the heat sealing (heat sealing) performance to the carrier tape is excellent. In addition, it is possible to prevent stickiness from occurring at room temperature, and thus it is possible to prevent products such as electronic components housed in the carrier tape from adhering to the top tape.

The melting point of the copolymer of ethylene and acrylic acid ester is measured by the method of JIS K7121: 2012.

In the case where the top tape for carrier tape of the present invention has a structure of three or more layers having a layer containing a polyethylene resin on the side opposite to the side having the base material layer on one side of the heat seal layer, The heat seal layer may further contain an adhesive resin. When the heat seal layer contains an adhesive resin, the interlayer adhesion between the base material layer and the heat seal layer is improved, and therefore, delamination between the base material layer and the heat seal layer is further prevented. Is done.

The content of the adhesive resin in the heat seal layer is preferably 3 to 50% by mass, more preferably 5 to 40% by mass, and further preferably 10 to 30% by mass. When the content of the adhesive resin in the heat seal layer is in such a range, the interlayer adhesive force between the base material layer and the heat seal layer is further improved, and the base material layer when the top tape is peeled off Delamination with the heat seal layer is further prevented.

As the adhesive resin, it is preferable to use a modified polyolefin resin from the viewpoint of interlayer adhesion between the base material layer and the heat seal layer.

The modified polyolefin resin is more preferably a polyolefin resin modified with an unsaturated dicarboxylic acid, a polyolefin resin modified with a silane coupling agent having an unsaturated bond, or a polyolefin resin modified with a compound having a glycidyl group.

Examples of the polyolefin resin include low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, polypropylene, and a polyethylene / polypropylene copolymer.

Examples of the unsaturated dicarboxylic acid include acrylic acid, methacrylic acid, maleic anhydride, and fumaric acid.

Examples of the silane coupling agent having an unsaturated bond include vinyltrimethoxysilane and vinyltriethoxysilane.

Examples of the compound having a glycidyl group include glycidyl methacrylate.

In the present invention, the adhesive resin is particularly preferably a maleic anhydride-modified polyolefin resin from the viewpoint of significantly improving the interlayer adhesion between the base material layer and the heat seal layer.

In the present invention, the heat seal layer can contain other additives such as an antistatic agent as long as the effects of the present invention are not impaired.

Antistatic agents can cause damage to stored parts due to static electricity generated when the top tape is unwound or peeled off from the carrier tape, or the parts can be damaged by static electricity. It can be added to prevent adhesion to the top tape side.

The content of the antistatic agent in the heat seal layer is preferably 10 to 30% by mass, more preferably 12 to 20% by mass. When the content of the antistatic agent in the heat seal layer is 10% by mass or more, the occurrence of static electricity is suppressed, so that the damage caused by the discharge of the housed parts is reduced, and the parts are on the top tape side. The adhesion is further prevented. When the content of the antistatic agent in the heat seal layer is 30% by mass or less, the fluidity of the resin does not change, so that film formation can be performed satisfactorily.

The laminate in the top tape for carrier tape of the present invention has a three-layer structure having a layer containing a polyethylene resin on one side of the heat seal layer and opposite to the side having the base material layer. Preferably there is. When the laminate in the top tape for carrier tape of the present invention has the three-layer structure, the layer containing the polyethylene resin (the layer in contact with the three-layer carrier tape) is peeled off from the carrier tape. In that case, it is more preferable not to contain ethylene and an acrylic ester copolymer from the viewpoint of further preventing peeling between the base material layer and the heat seal layer. That is, when the laminated body in the top tape for carrier tapes of this invention is the said 3 layer structure, it is more preferable that the layer which is in contact with the said 3 layer structure carrier tape consists only of a polyethylene resin.

Also in the case of the above three-layer structure, the heat seal layer can contain other additives such as an antistatic agent as long as the effects of the present invention are not impaired.

In addition to the above three-layer structure, the laminate in the top tape for carrier tape of the present invention is one side of the heat seal layer and has the base material layer in order to control adhesiveness with the carrier tape. It can also be set as the 3 layer structure which has a layer containing the copolymer of a polyethylene resin and ethylene and an acrylic ester on the surface on the opposite side. As the copolymer of ethylene and acrylic acid ester, EMMA is preferable from the viewpoints of resin fluidity, melting point, adhesion to carrier tape, prevention of fish eye generation, and the like. Even in the case of the three-layer configuration, the layer containing the polyethylene resin and a copolymer of ethylene and an acrylic ester (a layer in contact with the carrier tape having the three-layer configuration) has the effect of the present invention. Other additives such as an antistatic agent can be included as long as they are not impaired.

The thickness of the carrier tape top tape in the case of a three-layer structure is preferably 15 μm or more and 90 μm or less, and more preferably 30 μm or more and 75 μm or less. When the thickness is within such a range, the mechanical strength of the top tape for carrier tape is suitable.

Examples of the polyethylene resin include low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE). These polyethylene resins may be used alone or in combination of two or more. Among these polyethylene resins, at least one of low density polyethylene (LDPE) and linear low density polyethylene (LLDPE) is preferable from the viewpoint of melting point.

In the ethylene-vinyl acetate copolymer (EVA), the main chain side of the copolymer is not an acid but an alcohol. Therefore, acetic acid is generated by hydrolysis, which may damage the electronic components housed in the carrier tape. Therefore, when the top tape for carrier tape of the present invention has a three-layer structure, EVA is not included in the copolymer of ethylene and acrylic acid ester.

The MFR of LDPE and LLDPE is preferably 1 to 20 g / 10 minutes, and more preferably 2 to 10 g / 10 minutes. When the MFR is in such a range, an appropriate fluidity can be imparted at the time of melting, so that the moldability at the time of forming into a film is excellent and the heat seal layer can be easily formed. Moreover, it is excellent in the heat sealing | fusion (heat seal) performance to a carrier tape. Furthermore, when the material of the carrier tape is made of paper, the penetration of the copolymer of ethylene and acrylic acid ester between the fibers of the carrier tape is not hindered, so that the heat sealing performance is excellent. Furthermore, when the top tape is peeled off from the carrier tape, the occurrence of a stringing state due to the heat seal layer resin remaining between the fibers of the carrier tape can be reduced.

The melting point of LDPE and LLDPE is preferably 70 ° C to 130 ° C, more preferably 80 ° C to 110 ° C. When the melting point is in such a range, the heat sealing (heat sealing) performance to the carrier tape is excellent. In addition, stickiness can be prevented from occurring at room temperature, and products such as electronic components housed in a carrier tape can be prevented from adhering to the top tape.

Examples of the material of the carrier tape include paper, polystyrene, PET, and polypropylene. Among these, it is preferable that the carrier tape is a paper carrier tape from the viewpoint of the degree of freedom of shape formation for the component storage portion (pocket) and the balance between adhesion and peelability.

Method for Producing Top Tape for Carrier Tape A method for producing a top tape for carrier tape of the present invention is a method for producing a top tape for covering and heat-sealing an opening of a carrier tape that accommodates an electronic component in a recess. (1) The top tape is a laminate having at least two layers of a base layer made of an unstretched film containing a polybutylene terephthalate resin and a heat seal layer containing a copolymer of ethylene and an acrylic ester. And (2) a step of forming the laminate by a coextrusion method.

When producing a top tape for carrier tape by coextrusion, a method of forming a multilayer film such as an inflation method or a cast (T-die) method is used. The co-extrusion method generally prepares a molten resin composition by melting and kneading components such as resins constituting each layer in an extruder, and supplies the resin composition from the extruder to a die. The top tape for carrier tape is manufactured by laminating the resin composition in the inside to form a film.

According to this method, since both the resin of the base material layer and the heat seal layer are laminated in a molten state, the balance of shrinkage due to cooling of each resin can be changed by changing the cooling rate of the base material layer and the heat seal layer. As a result, curling of the top tape can be suppressed.

Further, according to this method, since the base material layer and the heat seal layer are laminated in a molten state, the interlayer adhesive force between the base material layer and the heat seal layer is increased, and the top tape is peeled off from the carrier tape. In addition, it is possible to prevent the base material layer and the heat seal layer from being delaminated and the heat seal layer remaining on the carrier tape.

The extrusion lamination method in which a heat-seal layer resin is melted and laminated on a preformed base layer to form a top tape shrinks when the melted heat-seal layer resin is cooled, and the formed top tape curls. This is not suitable for the present invention.

The film forming temperature is preferably 230 ° C. to 280 ° C., more preferably 240 ° C. to 260 ° C., from the viewpoint of the melting temperature of the base material layer.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the scope of the examples.

The following raw materials were used as raw materials for producing the carrier tape top tape, and the carrier tape top tapes of Examples and Comparative Examples were produced by the following method.

(material)
・ PBT resin 1: Mitsubishi Engineering Plastics, Novaduran 5050CS (IV value 1.5)
-PBT resin 2: Polyplastics, Juranex-800FP (IV value 1.35)
-PBT resin 3: Polyplastics, Juranex-700FP (IV value 1.1)
PET resin: Bell Polyester Products, Bellpet DFG1 (IV value 1.1)
・ PEN resin: manufactured by Teijin DuPont ・ Teonex TN8065S (IV value 1.4)
・ PC resin: manufactured by Teijin DuPont ・ Panlite L-1250Y (IV value 1.1)
-Biaxially stretched PET film: Toyobo's ester film E5101 (thickness 25 µm)
-EMMA1: Sumitomo Chemical Co., Ltd., ACRlift-WH303-F, melting point 89 ° C, MFR = 7g / 10min.-EMMA2: Sumitomo Chemical Co., Ltd., ACRlift-WD201-F, melting point 100 ° C, MFR = 2g / 10min. : Nippon Polyethylene, Lexpearl EB330H, melting point 90 ° C., MFR = 10 g / 10 min. EEA: Nihon Polyethylene, Lexpearl A4250, melting point 92 ° C., MFR = 5 g / 10 min. EVA: Nippon Polyethylene Novatec LV342, melting point 94 ° C., MFR = 2 g / 10 min. LDPE: manufactured by Nippon Polyethylene, Novatec LC522, melting point 111 ° C., MFR = 4 g / 10 min. Adhesive resin (abbreviation: AD): anhydrous male Acid-modified polyolefin resin, manufactured by Mitsui Chemicals, Admer SF731, softening point 43 ° C., MFR = .6g / 10 minutes

[Example 1]
A multi-layer inflation film forming device is prepared, in which two extruders (for forming each layer of the base material layer and the heat seal layer 1) are connected to a circular multi-layer die having a lip gap of 1.0 mm via a connector. did.

Next, 100% by mass of PBT resin 1 as the material of the base material layer, 50% by mass of EMMA1 and 50% by mass of LDPE as the material of the heat seal layer 1 are supplied to each of the above extruders, and the temperature is increased to 250 ° C. After melt-kneading, the molten resin was subjected to multilayer coextrusion and inflation from the circular die under the condition of a die temperature of 250 ° C. to form a two-layer top tape for carrier tape. The thickness of the base material layer was 25 μm, and the thickness of the heat seal layer 1 was 25 μm.

[Example 2]
In the same manner as in Example 1, except that 100% by mass of PBT resin 1 is used as the material for the base material layer, and 40% by mass of EMA and 60% by mass of LDPE are used as the material for the heat seal layer 1, two layers are used. A top tape for carrier tape was formed. The thickness of the base material layer was 20 μm, and the thickness of the heat seal layer 1 was 30 μm.

[Example 3]
In the same manner as in Example 1, except that 100% by mass of PBT resin 1 was used as the material for the base material layer, and 30% by mass of EEA and 70% by mass of LDPE were used as the material for the heat seal layer 1, two layers were used. A top tape for carrier tape was formed. The thickness of the base material layer was 30 μm, and the thickness of the heat seal layer 1 was 20 μm.

[Example 4]
Three extruders (for forming each layer of the base material layer, the heat seal layer 1 and the heat seal layer 2) are supplied to the resin junction (feed block) through the connector, and from there, the lip gap 1 A multilayer film forming apparatus connected to a 0.0 mm cast (T die) method die was prepared. Supply 100% by mass of PBT resin 1 as the material of the base material layer, 100% by mass of EMMA1 as the material of the heat seal layer 1, and 100% by mass of LDPE as the material of the heat seal layer 2 to each of the above extruders. Then, after melt-kneading at 260 ° C., a three-layer top tape for carrier tape was formed by multilayer coextrusion of the molten resin at a die temperature of 260 ° C. and T-die molding. The thickness of the base material layer was 20 μm, the thickness of the heat seal layer 1 was 15 μm, and the thickness of the heat seal layer 2 was 15 μm.

[Example 5]
In the same manner as in Example 1 except that 70% by mass of PBT resin 2 and 30% by mass of PET resin are used for the base material layer, 50% by mass of EMMA2 and 50% by mass of LDPE are used for the heat seal layer 1, Layered carrier tape top tape was deposited. The thickness of the base material layer was 25 μm, and the thickness of the heat seal layer 1 was 25 μm.

[Example 6]
80% by mass of PBT resin 1 and 20% by mass of PEN resin are used as a base material layer, 80% by mass of EMMA2 and 20% by mass of AD as a material for heat seal layer 1, and 100% by mass as a material for heat seal layer 2. A three-layer top tape for carrier tape was formed in the same manner as in Example 4 except that the LDPE was used. The thickness of the base material layer was 20 μm, the thickness of the heat seal layer 1 was 15 μm, and the thickness of the heat seal layer 2 was 15 μm.

[Example 7]
70% by mass of PBT resin 3 and 30% by mass of PC resin as the base material layer, 70% by mass of EMMA1 and 30% by mass of AD as the material of heat seal layer 1, and 90% by mass of the material of heat seal layer 2 A three-layer top tape for a carrier tape was formed in the same manner as in Example 4 except that 10 wt% EMMA1 was used. The thickness of the base material layer was 15 μm, the thickness of the heat seal layer 1 was 18 μm, and the thickness of the heat seal layer 2 was 12 μm.

[Comparative Example 1]
On one side of 100% by mass biaxially stretched PET film (thickness 25μm), extrusion lamination method was used to extrude 100% EVA by 25μm thickness by setting the temperature of the extruder cylinder to 160 ° C. A two-layer top tape for carrier tape (thickness 50 μm) was formed.

[Comparative Example 2]
A two-layer top tape for carrier tape was formed in the same manner as in Comparative Example 1 except that 100% by mass of biaxially stretched PET film and 100% by mass of EMMA1 were used. A two-layer top tape for carrier tape was formed. The thickness of the base material layer was 25 μm, and the thickness of the heat seal layer 1 was 25 μm.

[Comparative Example 3]
A two-layer top tape for carrier tape was formed in the same manner as in Example 1 except that 100% by mass of PBT resin 1 and 100% by mass of EVA were used. The thickness of the base material layer was 25 μm, and the thickness of the heat seal layer 1 was 25 μm.

[Comparative Example 4]
100% by mass of biaxially stretched PET film (thickness 25 μm) and heat seal layer 1 (thickness 13 μm) as material of 100% by mass LDPE and heat seal layer 2 (thickness 17 μm) as material of 100% by mass EVA In the same manner as in Comparative Example 1, a three-layer top tape for carrier tape (thickness: 55 μm) was formed.

Thus, the top tapes for carrier tapes of Examples 1 to 7 and Comparative Examples 1 to 4 having a total thickness of 45 to 55 μm were formed.

The following evaluation was performed on the top tapes for carrier tapes formed in Examples 1 to 7 and Comparative Examples 1 to 4.

<Evaluation of thermal shrinkage>
A 100 mm square test piece was cut out such that the length direction of the top tape for carrier tape was the vertical direction (MD) of the top tape, and the perpendicular direction was the horizontal direction (TD). A marked line was put in MD · TD of the test piece, and the test piece was heated in an oven at 150 ° C. for 30 minutes, and then taken out and allowed to cool to room temperature. Thereafter, the distance between the marked lines before and after heating was measured, and the heat shrinkage rate was measured.
The evaluation criteria are as follows:
A: Thermal shrinkage of MD and TD was less than 0.3% B: Either MD or TD had thermal shrinkage of 0.3% or more.

<Evaluation of acetic acid generation>
After the 100 mm square test piece was heated at 200 ° C. for 30 minutes using a pyrolyzer, it was analyzed by gas chromatography whether acetic acid was generated in the generated gas.
The evaluation criteria are as follows:
A: Acetic acid was not generated B: Acetic acid was generated.

<Measurement method of seal strength>
A test piece (width 10 mm, length 100 mm) was cut out so that the length direction of the top tape for carrier tape was the vertical direction (MD) of the top tape. Heat sealing was performed using the test piece and a paper for carrier tape having a thickness of 1 mm as an adherend.
Heat sealing was performed using a heat seal tester (TP-701-S, manufactured by Tester Sangyo Co., Ltd.) under the conditions of a temperature of 160 ° C., single-sided seal, seal gauge pressure of 0.5 kgf / cm ² , and seal time of 60 seconds. .
The test piece after heat sealing was naturally cooled and peeled off at a tensile speed of 100 mm / min using an A & D Tensilon Universal Material Testing Machine RTG-1210, and the seal strength was measured.

<Delamination evaluation>
When measuring the seal strength, the presence or absence of delamination (peeling of the interface between the base material layer and the heat seal layer 1) was evaluated by visually observing the peeled interface.
The case where all peeling occurred at the interface between the heat seal layer (heat seal layer 1 in the case of a two-layer structure and heat seal layer 2 in the case of a three-layer structure) and paper was evaluated as “A”.
Peeling of the interface between the base material layer and the heat seal layer 1 and peeling of the interface between the paper and the heat seal layer (heat seal layer 1 in the case of a two-layer configuration, heat seal layer 2 in the case of a three-layer configuration) are mixed. (Specifically, a case where a slight heat seal layer remains on the paper side to the extent that there is no hindrance to taking out the parts) was evaluated as “B”.
The case where all peeling occurred at the interface between the base material layer and the heat seal layer 1 was evaluated as “C”.

<Comprehensive evaluation>
Comprehensive evaluation was performed according to the following criteria. In addition, when comprehensive evaluation is A or B, it is evaluated that there is no problem in actual use.
A: Three items of heat shrinkage rate, acetic acid generation and delamination are A B: heat shrinkage rate, acetic acid generation item is A, delamination is A or B C: delamination is C, Alternatively, at least one of the items of heat shrinkage rate and acetic acid generation is B.

The results are shown in Table 1.

Based on the above results, the top tapes for carrier tapes of Examples 1 to 7 had a thermal shrinkage of MD and TD of 0.2% or less even when heated in an oven at 150 ° C. for 30 minutes. It was shown that it was excellent and acetic acid was not generated because EVA was not used as the heat seal layer.

The top tapes for carrier tapes of Examples 1 to 5 showed a seal strength in the range of 3 to 5 N / 10 mm and an evaluation of delamination of “B”. The top tapes for carrier tapes of Examples 6 and 7 were shown to have a seal strength in the range of 3 to 5 N / 10 mm and an evaluation of delamination of “A”.

When the top tapes for carrier tapes of Comparative Examples 1, 2, and 4 were heated in an oven at 150 ° C. for 30 minutes, the MD had a thermal shrinkage of 0.9% or more, which was higher than that of Examples 1-7. Shrinkage was shown. In Comparative Examples 1 and 3 using EVA, it was shown that acetic acid was generated. Furthermore, the carrier tape top tape of Comparative Example 3 using PBT1 resin instead of biaxially stretched PET as the base material layer had a low MD thermal shrinkage of 0.2%, but EVA was used as the heat seal layer. It was shown that acetic acid was generated because it was used.

The top tapes for carrier tapes of Comparative Examples 1 and 2 show a very high numerical value of seal strength of 6 N / 10 mm or more. Therefore, the adhesive strength of the base material layer-heat seal layer 1 and the heat seal layer 1-paper adhesion The balance with strength was lacking, and delamination between the base material layer and the heat seal layer 1 was confirmed. In the top tape for carrier tape of Comparative Example 3, delamination between the base material layer and the heat seal layer 1 was not confirmed, but it was shown that acetic acid was generated. The top tape for carrier tape of Comparative Example 4 had a low sealing strength of 3.7 N / 10 mm, but the balance between the adhesive strength of the base material layer-heat sealing layer 1 and the adhesive strength of heat sealing layer 2-paper. And delamination between the base material layer and the heat seal layer 1 was confirmed.

The top tape for carrier tape of the present invention has (i) prevention or suppression of acid generation due to shrinkage and hydrolysis during heat sealing, and (ii) delamination between the base material layer and the heat sealing layer. Since it has the properties of being suppressed and (iii) excellent in mechanical strength, it can be widely used as a tape for carrier tape.

1 Cover tape 2 Carrier tape 3 Pocket 4 Product (electronic parts)

Claims

A top tape for covering and heat-sealing an opening of a carrier tape that accommodates an electronic component in a recess, wherein the top tape is a laminate having at least two layers of a base material layer and a heat seal layer,
(1) The base material layer is composed of an unstretched film containing a polybutylene terephthalate resin,
(2) The heat seal layer contains a copolymer of ethylene and an acrylic ester.
A top tape for carrier tape.
2. The top tape for carrier tape according to claim 1, wherein the laminate has a layer containing a polyethylene resin on one side of the heat seal layer and on the side opposite to the side having the base material layer.
3. The carrier tape top tape according to claim 1, wherein the carrier tape is made of paper.
A top tape manufacturing method for covering and heat-sealing an opening of a carrier tape that houses an electronic component in a recess,
(1) The top tape is a laminate having at least two layers of a base layer made of an unstretched film containing a polybutylene terephthalate resin and a heat seal layer containing a copolymer of ethylene and an acrylic ester. Become
(2) having a step of forming the laminate by a coextrusion method;
A method for producing a top tape for a carrier tape.