JPH11198299A - Lid material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide stable adhesion, good peeling characteristics, and excellent antistatic effect by composing a heat sealant layer from a thermoplastic resin having an acrylic resin having a glass transition point of a specified temperature range as main component, and conductive fine powder having tin oxide as main component. SOLUTION: A lid material 10 is composed of at least an HS layer 3, an interlayer 2, and a base sheet 1, where the HS layer 3 is composed of a thermoplastic resin having an acrylic resin having a glass transition point Tg of -10 to 100 deg.C as main component, and conductive fine powder having tin oxide as main component. A weight ratio of the thermoplastic resin and the conductive fine powder composing the HS layer 3 is 10-400/100 (the conductive fine powder). In the case that the interlayer 2 is a single-layer structure, the lid material 10 is composed of a resin composition comprising 30-70 wt.% E/O copolymer having a density of 0.915-0.940, and 70-30 wt.% S-B copolymer composed of 50-90 wt.% styrene and 50-10 wt.% butadiene.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an easily peelable heat sealant layer and a laminate using the same, and particularly to semiconductors, IC parts and products thereof, liquid crystal display parts and liquid crystal products, syringes and pharmaceuticals. It belongs to a heat sealant layer (hereinafter, referred to as an HS layer) of a lid material used for sealing a synthetic resin container for storing medical-related articles such as automotive parts and the like, and a laminate using the same.

[0002]

2. Description of the Related Art Conventionally, various kinds of solid or liquid parts, food and industrial parts are housed in a synthetic resin container and the opening is sealed with a lid or sealed with a bag for distribution and storage. That is being done. For example, a carrier tape is used in which electronic components are housed in a large number of concave portions provided in a molded container such as a carrier tape, and the concave portions are covered with a lid material (lid material) and heat-sealed. Such carrier tapes are usually made of polyvinyl chloride, polystyrene,
It is formed using a material such as polyester, polycarbonate, and ABS resin, which can be easily formed into a sheet. Also,
The lid material is made of a base sheet and at least one side of the base sheet is made of HS.
It is composed of a laminate provided with layers. Then, it is required that the electronic component is easily detachable when housed in a concave portion of the carrier tape of the electronic component and sealed with a lid material, and when the electronic component stored in the mounting process is taken out, the lid material can be easily peeled off.

Further, there is a danger that the electronic components may be deteriorated or destroyed due to static electricity generated when the stored electronic components come into contact with the concave portions or the cover of the carrier tape or when the cover is peeled off. was there. Means for preventing the generation of the static electricity have been required for the carrier tape and the lid material. As means for preventing the generation of static electricity in the carrier tape, kneading, mixing or coating conductive tape with conductive carbon fine particles, conductive powder of metal oxide, and metal fine particles are performed. Means for preventing the generation of static electricity in the cover material include an antistatic agent such as a surfactant, a conductive powder of metal oxide, conductive carbon fine particles, and metal fine particles in a tape on the HS layer which is in direct contact with the electronic component. They are kneaded and coated. In particular, a material obtained by mixing a conductive powder of a metal oxide (such as tin oxide and zinc oxide) in an HS layer has relatively good transparency, has a stable electrostatic diffusion property, and is effectively used.

[0004]

However, a lid material obtained by heat-sealing a carrier tape containing contents therein is:
A predetermined peel strength is required so that the lid material does not peel off and the electronic component does not fall off during transportation and storage of the carrier tape. If the difference between the maximum value and the minimum value of the peel strength (hereinafter referred to as zip-up) is too large, the carrier tape vibrates when the cover material is peeled off in the mounting process of the electronic component, and the electronic component becomes There is a problem that an accident of jumping out of the concave portion of the carrier tape occurs. Therefore, it is required that the zip-up is small when mounting the electronic component. However, there is a problem that a low zip-up cannot be obtained with a lid material in which a conductive fine powder or the like is mixed in a conventional HS layer.

[0005] Further, although the lid material in which the conductive powder of the metal oxide is mixed in the HS layer has relatively good transparency,
Dispersion when forming the HS layer is difficult, and in order to obtain transparency that allows visual inspection of the stored electronic components, a skilled dispersing technique is required, which raises the problem of increasing the manufacturing cost. Was.

Further, the HS layer coated with a heat-sealing resin containing a liquid surfactant changes the surface state of the HS layer with the passage of time, making heat sealing unstable and causing poor sealing. In addition, there is a problem that the effect of diffusing static electricity is easily dependent on the temperature and humidity during storage, and a stable antistatic effect cannot be obtained. The present invention has been made in view of such circumstances, and has a laminate having a stable antistatic property, a stable adhesive property (heat sealing property) to a synthetic resin container, a good peeling property, and excellent properties. It is an object of the present invention to provide a lid material having an antistatic effect.

[0007]

Means for Solving the Problems To solve the above-mentioned problems, in a cover material comprising at least an HS layer, an intermediate layer and a base sheet, the HS layer has a glass transition point Tg.
Is a lid material composed of a thermoplastic resin whose main component is an acrylic resin at −10 to 100 ° C. and conductive fine powder mainly containing tin oxide. And the second invention is the above-mentioned HS
The lid material has a weight ratio of the thermoplastic resin and the conductive fine powder constituting the layer of 10 to 400/100. Also,
In a third aspect, the intermediate layer has a single-layer structure, and has a density of 0.1.
915 to 0.940 g / cm ³ (hereinafter, g / cm ^{3 as} a unit of density is omitted) of 30 ethylene / α-olefin copolymers (hereinafter referred to as EO copolymers).
70 to 70% by weight, 50 to 90% by weight of styrene, and 50 to 10% by weight of butadiene in a styrene / butadiene block copolymer (hereinafter referred to as SB copolymer).
A lid material formed from a resin composition consisting of up to 30% by weight. In a fourth aspect of the present invention, the intermediate layer has a single-layer structure, an E / O copolymer having a density of 0.915 to 0.940, 50 to 90% by weight of styrene and 50 to 10% of butadiene.
% By weight of a SB copolymer and a hydrogenated product of a styrene / butadiene copolymer of 10 to 50% by weight of styrene and 90 to 50% by weight of butadiene (hereinafter referred to as hydrogenated SB / B copolymer). And a high impact polystyrene (hereinafter, referred to as HIPS). The intermediate layer according to the fifth invention has a multilayer structure including a reinforcing intermediate layer provided on the base sheet side, a buffer intermediate layer provided as needed, and a peeling intermediate layer located on the HS layer side. The layer has a density of 0.915
The buffer intermediate layer is formed of an EO copolymer having a density of 0.915 to 0.940 and an EO copolymer having a density of 0.915 to 0.940.
And 50 to 90% by weight of styrene, 50 to 90% by weight of butadiene, and 70 to 30% by weight of an SB copolymer. The release intermediate layer has a density of 0.1 to 30% by weight. 915 to 0.940 EO copolymer is 30 to
10 to 50% by weight of styrene based on 100% by weight of a resin composition containing 70% by weight, 70 to 30% by weight of an SB copolymer of 50 to 90% by weight of styrene and 50 to 10% by weight of butadiene. Of butadiene with 90 to 50% by weight of S
5 to 30 parts by weight of hydrogenated B copolymer and 5 to 5 HIPS
0 parts by weight of the resin composition. The surface resistivity of the HS layer according to the sixth invention is in the range of 10 ⁵ to 10 ¹² Ω / □, and the charge decay time is 2 seconds or less. Further, the HS layer of the seventh invention can be heat-sealed with a carrier tape made of polycarbonate, polystyrene, polyester, polyvinyl chloride, acrylonitrile / styrene / butadiene copolymer (ABS resin). This is a cover material that is delaminated with the HS layer or cohesively separated within the HS layer.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to solve the above-mentioned problems, the present invention relates to a cover material 10 comprising at least an HS layer 3, an intermediate layer 2 and a base sheet 1, as shown in FIG. The layer 3 is a lid member 10 composed of a thermoplastic resin whose main component is an acrylic resin having a glass transition point Tg of −10 to 100 ° C. and conductive fine powder mainly containing tin oxide. Then, the lid material 10 has a weight ratio of the thermoplastic resin constituting the HS layer 3 to the conductive fine powder of 10 to 400/100 (conductive fine powder). In the case where the intermediate layer 2 has a single-layer structure, E having a density of 0.915 to 0.940 is used.
30% to 70% by weight of an O copolymer and 50% to 9% of styrene
The lid 10 is formed of a resin composition comprising 70 to 30% by weight of an SB copolymer of 0% by weight and 50 to 10% by weight of butadiene. Another structure in which the intermediate layer 2 has a single-layer structure includes an EO copolymer having a density of 0.915 to 0.940, 50 to 90% by weight of styrene, and 50 to 1 butadiene.
0% by weight of the SB copolymer and further styrene 10-5%
The lid material 10 is formed from a resin composition comprising a hydrogenated SB copolymer of 0% by weight and 90 to 50% by weight of butadiene and HIPS.

As shown in FIG. 2 or FIG. 3, the intermediate layer 2 composed of multiple layers includes a reinforcing intermediate layer 21 located on the side of the base sheet 1 and a buffer provided as necessary as shown in FIG. It has a three-layer structure including the intermediate layer 22 and the release intermediate layer 20 located on the HS layer 3 side. The reinforcing intermediate layer 21 is formed of an E · O copolymer having a density of 0.915 to 0.940, and the buffer intermediate layer 22 has a density of 0.915 to 0.915.
A resin composition comprising 30 to 70% by weight of an E / O copolymer of 0.940, and 70 to 30% by weight of an SB copolymer of 50 to 90% by weight of styrene and 50 to 10% by weight of butadiene. Formed. The peeling intermediate layer 20 has a density of 0.1.
30 to 70% by weight of an EO copolymer of 915 to 0.940, 50 to 90% by weight of styrene and 50 to 1% of butadiene.
100 parts by weight of a resin composition comprising 0 to 30% by weight of an SB copolymer in 0% by weight,
S. of 0 to 50% by weight and 90 to 50% by weight of butadiene
5 to 30 parts by weight of hydrogenated B copolymer and 5 to 5 parts of HIPS
0 part by weight of the lid material 10 formed from the resin composition.

The HS layer 3 of the present invention has a surface resistivity of 1
0 a ^{5 ~10 12 Ω} / □ in the range of, and the charge decay time is lid of less than 2 seconds. The HS layer 3 can be heat-sealed with a carrier tape 5 made of polycarbonate, polystyrene, polyester, polyvinyl chloride, or ABS resin.
The heat seal portion 35 as shown in FIG.
When peeled and opened as shown in (B), the intermediate layer 2 and H
A peeling portion 31 is formed between the S layer 3 and the interlayer is peeled off. Although not shown, it is configured to coagulate and peel in the HS layer 3. Therefore, the peel strength between the lid member 10 and the carrier tape 5 can be stably and reliably performed regardless of the heat sealing strength between the HS layers.

The base sheet constituting the present invention includes polyester such as polyethylene terephthalate and polyethylene naphthalate, polyolefin such as polypropylene,
It can be formed of a uniaxially or biaxially stretched film such as polyamide such as nylon 6 or nylon 66, polycarbonate, and polyimide. By providing such a base sheet, the laminate can have heat resistance. The thickness of the base material sheet can be appropriately set depending on the size of the lid material, the purpose of use, and the material.
00 μm. Then, an antistatic treatment can be performed as necessary. In addition, a surface treatment such as a corona discharge treatment, a plasma treatment, and a sand blast treatment may be performed on the side of the base sheet on which the HS layer is provided, if necessary, to strengthen the adhesion to the intermediate layer and stabilize it. .

The lamination of the base sheet 1 and the intermediate layer 2 may be performed by providing an adhesive layer 4 as shown in FIG. 1 for dry lamination, or by laminating the base sheet and / or the intermediate layer as shown in FIG. This is performed by providing the primer layers 41 and 42 and sandwiching the thermoplastic resin as the adhesive resin layer 40 by sandwich lamination. The adhesive layer for dry lamination may be a lacquer-type adhesive obtained by dissolving ordinary polyester / polyisocyanate, polyether / polyisocyanate, polyester, or epoxy-based adhesive in a solvent, or a so-called non-sol type adhesive containing no solvent. This is performed using a material having a thickness of 10 to 10 μm (dry thickness). In addition, for example, the primer layer of the base sheet used for sandwich lamination is provided with a solution of polyethyleneimine, polybutadiene, an organic titanium compound, isocyanate, polyurethane, or the like with a thickness of 0.1 to 2 μm, and is subjected to a primer treatment. In addition, the sheet used for lamination is subjected to corona discharge treatment and ozone treatment, so that the adhesion to the base sheet and the intermediate layer on which the adhesive resin 40 is extruded and coated can be strengthened.

The thermoplastic resin used for the adhesive resin for sandwich lamination is for bonding the base sheet and the intermediate layer, and is a low-density polyethylene that can be melt-extruded, and has a density of 0.915 to 0.940. And a thermoplastic resin capable of being melt-extruded and coated, such as an E / O copolymer, an ethylene / vinyl acetate copolymer, an ethylene / acrylic acid copolymer, an ethylene / acrylic ester copolymer, an ionomer, and a polypropylene. The thickness of the adhesive resin layer is 10 to 60 μm, and the resin layer can have a cushion function of the lid. 10μ
If it is less than m, the flow of the resin tends to be turbulent when performing the melt extrusion coating, which causes unevenness in the thickness. When a cushioning effect is expected, its function cannot be exhibited. On the other hand, when the thickness exceeds 60 μm, the heat sealability decreases.

Although not shown, the intermediate layer is melt-extruded directly, without providing an adhesive layer on the base material sheet, or through a primer layer, co-extruded multi-layered coating, or a hot solution for applying a solution containing a thermoplastic resin. A lacquer coat may be used to form a single-layer or multilayer intermediate layer.

The single intermediate layer has a density of 0.915 to 0.1.
940 of EO copolymer, 30 to 70% by weight of styrene, 50 to 90% by weight of styrene and 50 to 10% by weight of butadiene.
-It is formed of a resin composition comprising 70 to 30% by weight of a B copolymer. The EO copolymer used for forming the intermediate layer is a copolymer of ethylene and, for example, butene, pentene, hexene, heptene, octene, 4-methylpentene 1, and the like. When the density of such an EO copolymer is less than 0.915 or more than 0.940, the film forming property of the intermediate layer due to the combination with the SB copolymer is undesirably reduced. If the amount of styrene forming the SB copolymer is less than 50% by weight, the adhesiveness of the film increases, making it difficult to handle. If it exceeds 90% by weight, the peel strength with the HS layer is weak, and as a lid material, Is also not preferred because the peel strength is also weakened.

The EO copolymer of the intermediate layer and S
The mixing ratio with the B copolymer greatly affects the peel strength of the synthetic resin container (carrier tape) and the lid of the present invention after heat sealing, and the transparency of the lid. When the mixing ratio of the EO copolymer and the SB copolymer is 30 and the EO copolymer is 30
% By weight and more than 70% by weight of the SB copolymer,
The film formability of the intermediate layer deteriorates, and the transparency also decreases. In addition, the peel strength between the intermediate layer and the HS layer also increases, and the peel strength of the lid member exceeds the practical strength, which is not preferable. On the other hand, if the EO copolymer exceeds 70% by weight and the SB copolymer is less than 30% by weight, the adhesion between the intermediate layer 25 and the HS layer 1 is weak, and the peel strength of the lid material is appropriate. The value is below the value, which is not preferable. The thickness of the intermediate layer is preferably from 10 to 60 μm. When the thickness of the intermediate layer is less than 10 μm, the film-forming property is poor, and the thickness tends to be uneven. However, the stiffness becomes stronger, which causes a decrease in heat sealing and productivity.

The intermediate layer can be preferably formed by multilayer co-extrusion as shown in FIG. 2 or FIG.
By forming a multilayer film, a laminar flow is formed by co-extruding a peeling intermediate layer with poor film forming aptitude and a buffering intermediate layer, and a reinforcing intermediate layer with excellent film forming properties to form an intermediate layer with a stable film thickness. it can. In this case, the release intermediate layer 20 in contact with the HS layer is composed of 30 to 70% by weight of an EO copolymer having a density of 0.915 to 0.940, 50 to 90% by weight of styrene, and 50 to 10% by weight of butadiene. SB copolymer 50 ~
90% by weight of the SB copolymer is formed from a resin composition of 70 to 30% by weight.

FIG. 2 shows a lid member 1 provided with a two-layered intermediate layer.
FIG. 2 is a schematic cross-sectional view of FIG. 0, wherein the intermediate layer 2 is composed of a reinforcing intermediate layer 21 and a release intermediate layer 20. In this case, the reinforcing intermediate layer 21 is formed of an EO copolymer having a density of 0.915 to 0.940. The peeling intermediate layer 20 which comes into contact with the HS layer 3 has a density of 30 to 70% by weight of an EO copolymer having a density of 0.915 to 0.940 and 50 to 90% by weight of styrene.
SB copolymer 70 of butadiene and 50 to 10% by weight
It is formed by a resin composition consisting of about 30% by weight. And the total thickness of these two intermediate layers is 30 μm or more,
Each thickness can be configured to be at least about 5 μm. The preferred configuration is such that the peeling intermediate layer 20, which is difficult to form a film, is expensive, is thinned to 5 to 10 μm, and the reinforcing intermediate layer 21, which is inexpensive and easy to form a film, is thicker, from the viewpoint of productivity and cost. This is an advantageous method.

FIG. 3 shows a lid member 1 provided with a three-layer intermediate layer.
FIG. 2 is a schematic cross-sectional view taken along a line 0 in FIG.
In this case, the reinforcing resin layer 21 has a density of 0.915 to 0.1.
940 EO copolymer. And HS layer 3
The peeling intermediate layer 20 that comes into contact with the metal has a density of 0.915 to 0.1.
940 of EO copolymer, 30 to 70% by weight of styrene, 50 to 90% by weight of styrene and 50 to 10% by weight of butadiene.
-It is formed by a resin composition comprising 70 to 30% by weight of the B copolymer. The buffer intermediate layer 22 is a layer having a higher mixing ratio of the EO copolymer than the release intermediate layer 20. In addition, scraps at the edges of the film, which are by-produced when the intermediate layer is formed, can be appropriately mixed. This 3
The total thickness of the intermediate layers of the layers can be greater than or equal to 30 μm, and their respective thicknesses can be as low as about 3 μm. A preferable configuration is that the peeling intermediate layer 20 which is difficult to form a film and is expensive in price is 3 to 1
A configuration in which a layer containing a large amount of an EO copolymer which is thin and inexpensive and easy to form a film in the range of 0 μm is thick is also an advantageous method from the viewpoint of productivity and cost.

The intermediate layer 2 is formed by laminating a film obtained by a single-layer or multilayer co-extrusion film forming method such as an inflation method or a T-die method by an ordinary method such as dry lamination or sandwich lamination, Can be directly provided on the substrate sheet by a co-extrusion coat.
The intermediate layer formed into a film in another step is thicker in the working process than the intermediate layer obtained by co-extrusion coating, but is suitable for a small lot production method.

A single intermediate layer is composed of a hydrogenated SB copolymer,
And a resin using HIPS, 30 to 70 parts by weight of the above EO copolymer and 50 to 9 parts of styrene.
SB consisting of 0% by weight and 50 to 10% by weight of butadiene
10 to 50 parts by weight of styrene and 90 parts of butadiene are added to 100 parts by weight of the resin composition containing 70 to 30 parts by weight of the copolymer.
It is preferable to add 5 to 30 parts by weight of the hydrogenated SB copolymer with 50 to 50 parts by weight, and further add 5 to 50 parts by weight of HIPS. When the amount of the hydrogenated SB copolymer is less than 5 parts by weight, the butadiene component is high, easily oxidized, and easily forms a gel when forming the film of the intermediate layer. On the other hand, if the hydrogenated amount of the SB copolymer exceeds 30 parts by weight, the resulting film has insufficient blocking resistance, which is not preferred. If the hydrogenation rate of the hydrogenated SB copolymer is insufficient, the butadiene component is high and easily oxidized at the temperature at the time of film formation, so that a gel is easily generated. SB
When a non-hydrogenated copolymer is used, film forming properties are poor,
Sometimes a film cannot be formed.

When the addition amount of HIPS exceeds 50 parts by weight with respect to 100 parts by weight of the resin composition of the above-mentioned EO copolymer and SB copolymer, the laminate and the lid material using the same may be used. Is undesirably low in transparency. Further, when the HIPS is less than 5 parts by weight, the adhesive strength with the HS layer is insufficient, and when it exceeds 50 parts by weight, the peel strength with the HS layer is too large, and the peel strength of the lid material has an appropriate value. It is not more preferable.

The peeling intermediate layer 20 in which the intermediate layer is formed in a three-layer structure is composed of 30 to 70% by weight of an EO copolymer having a density of 0.915 to 0.940, 50 to 90% by weight of styrene, and butadiene. SB copolymer 70 to 3 with 50 to 10% by weight
With respect to 100 parts by weight of the resin composition comprising 0% by weight,
0 to 30 parts by weight of an SB copolymer hydrogenated product of 10 to 50% by weight of styrene and 50 to 90% by weight of butadiene;
It can also be formed from a resin composition to which 5 to 50 parts by weight of PS is added. The total thickness of the three intermediate layers is 30 μm or more, and the thickness of each of the three intermediate layers can be at least about 5 μm. A preferable configuration is that the thickness of the layer containing a large amount of the EO copolymer, which is difficult to form a film and makes the peeling intermediate layer 20 which is expensive and thin is 3 to 10 μm, and which is inexpensive and easy to form, is high in productivity. This is an advantageous method in terms of price.

The HS layer of the present invention can be composed of a thermoplastic resin whose main component is an acrylic resin having a glass transition temperature Tg of -10 ° C. to 100 ° C. and a conductive fine powder whose main component is tin oxide. When the glass transition temperature Tg is less than -10 ° C, the blocking resistance is poor. When the glass transition temperature Tg exceeds 100 ° C, the blocking resistance is improved but the heat sealing temperature is increased. Acrylic resin is methyl (meth) acrylate, (meth)
Selected from polymers or copolymers of one or more esters selected from ethyl acrylate, butyl (meth) acrylate, and the like (in the present specification, (meth) act... And acrylic.). In addition, polymers such as urethane (meth) acrylate, polyester (meth) acrylate, epoxy acrylate, and other thermoplastic resins such as linear saturated polyester and urethane resin,
A vinyl chloride / vinyl acetate copolymer or the like may be appropriately mixed and used. In the HS layer, if necessary,
It is constituted by adding a dispersion stabilizer, an anti-blocking agent and the like.

The conductive fine powder is mainly composed of tin oxide, conductive fine particles made of metal oxides such as zinc oxide and titanium oxide, and zinc sulfide, copper sulfide, cadmium sulfide, nickel sulfide, and the like. The composition of the HS layer can be formed by adding conductive fine particles obtained by imparting conductivity to a sulfide such as palladium sulfide to the acrylic resin. At this time, the ratio between the acrylic resin and the conductive fine powder is 10 to 400.
It is preferable to configure the ratio in the range of / 100. The coating thickness of the HS layer is 1 to 10 μm, preferably 1 to 5 μm. If the acrylic resin is less than 10/100, desired heat sealability and peel strength cannot be obtained, and 400/10
If it exceeds 0, the required conductivity cannot be obtained and the surface resistivity becomes 1
0 ¹² Ω / □ to exceed not only more than 2 seconds charge decay time, is also strongly practical peel strength After the carrier tape and the heat seal in which not subjected.

The cover 10 of the molded container of the present invention preferably exhibits the following peeling form. That is, FIG.
As shown in FIG. 5A, for example, when the cover material 10 heat-sealed to the carrier tape 5 is peeled off from the carrier tape, the peeling between the intermediate layer 2 and the HS layer 3 as shown in FIG. (Interlayer delamination, interfacial delamination) or, although not shown, when formed of a relatively thin film, a delamination form in which delamination due to cohesive failure in the layer of the HS layer 3 is preferable. In this case, the peel strength between the HS layer 3 and the intermediate layer 2 includes the heat sealing strength (peel strength) between the HS layer 3 and the carrier tape 5, the peel strength between the intermediate layers, and the strength between the base sheet and the intermediate layer. It is configured to be weaker than any of the adhesive strength (peel strength). The peel strength between the carrier tape and the lid material is preferably from 10 to 100 g / 1 mm. If the peel strength is less than 10 g / 1 mm width, peeling may occur between the intermediate layer 2 and the HS layer 3 when transferring the container after the lid material is heat-sealed, and there is a risk that the contents may fall off. . Further, the peel strength is 100 g / 1.
If the width exceeds mm, the carrier tape may vibrate when the cover material is peeled off, and the contents may fly out. Further, the zip-up is preferably not more than 40 g / 1 mm width, and if it is more than 40 g / 1 mm width, the synthetic resin container may vibrate and the contents may jump out, which is not preferable.

The application of the HS layer of the present invention is determined by the properties of the coating liquid such as the viscosity, fluidity and drying property of the coating liquid, and the properties such as heat resistance of the base sheet (on which the intermediate layer is laminated). Can be In order to stabilize the amount of coating, a gravure intaglio is used. If it is not desired that the screen lines of the gravure are embodied on the coating surface, a roll coating method is employed. When the coating surface needs to be smoothed, a reverse coat or an air knife coat is used. The coating amount of the HS layer is preferably 0.5 to 10 μm in dry thickness.
When it is less than 5 μm, the peel strength is uneven, and
When the thickness exceeds μm, the amount of heat required for heat sealing becomes large, and the heat sealing temperature becomes high, thereby lowering productivity and wasting material.

The HS layer of the present invention has a temperature of 22 ° C. and a relative humidity of 40.
Surface resistivity measured by the% conditions of 10 ⁵ ~10 ¹² Ω /
□ range, 23 ± 5 ° C, relative humidity 12 ± 3%
Under the following conditions, it has excellent static electricity characteristics in which the charge decay time from 5000 V to 99% decay is 2 seconds or less. When the above surface resistivity exceeds 10 ¹² Ω / □, the effect of electrostatic diffusion is extremely deteriorated, and it becomes difficult to protect electronic components from electrostatic damage. If the resistance is less than 10 ⁵ Ω / □, there is a possibility that the electronic components may be energized from the outside via the lid member, which involves a risk of the electronic components being electrically destroyed. On the other hand, if the charge decay time, which is a measure of the rate of diffusion of charges generated by static electricity, exceeds 2 seconds, the electric diffusion effect becomes extremely poor, and it becomes difficult to protect the electronic components from electrostatic breakdown. The above-mentioned charge decay time can be measured in accordance with MIL-B-81705C which is a US military standard.

The cover material of the present invention may be a carrier tape formed from a sheet made of polycarbonate, polystyrene, polyester, polyvinyl chloride, ABS, or a conductive tape made of conductive carbon, metal fine particles, or metal oxide as a measure against static electricity. It can be heat-sealed to kneaded and mixed conductive fine particles, Si-based organic compounds, conductive polymers, and surfactants that have properties, and when peeled off, the HS layer and It has a stable peeling performance irrespective of heat sealing conditions for delamination with the intermediate layer or cohesive failure in the HS layer.

Hereinafter, the present invention will be described in more detail based on experimental examples of Examples and Comparative Examples.

Experimental Example (Examples and Comparative Examples) As shown in FIGS. 1 to 3, one side of a 9 μm-thick biaxially stretched polyethylene terephthalate sheet (base sheet 1) subjected to an antistatic treatment and Table 1 As shown, the intermediate layer 2 formed by inflation film formation with a total thickness of 35 μm was laminated by dry lamination via a curable urethane-based adhesive (adhesive layer 4). Then, the HS layer 3 having the composition shown in Tables 1 and 2 was applied on the side of the intermediate layer 2 with a thickness of 3 μm by the gravure reverse method to form the lid members 10 of Examples 1 to 8 and Comparative Examples 1 to 11. did. E / O copolymer: Ultzex 3550A manufactured by Mitsui Petrochemical Industry Co., Ltd. Product name Density 0.925 Abbreviation LL SB copolymer: Asaflex 810 Asahi Kasei Kogyo Co., Ltd. Product name SB copolymer Hydrogenated product: Tuftex H1041 Trade name abbreviation made by Asahi Kasei Kogyo Co., Ltd. SBC HIPS: Stylon 475D Trade name made by Asahi Kasei Kogyo Co., Ltd. PS

The following items were evaluated for the lid materials of the examples and comparative examples. -Film formation property of intermediate layer: The state of film formation when forming the intermediate layer was visually evaluated. Haze value: Based on JIS K7105 6.4
The total light transmittance and the haze value were calculated using an integrating sphere light transmittance measuring device. Peel strength: Polystyrene carrier tape (heat seal temperature 120 ° C. and 160 ° C., heat seal pressure 3 kg / cm ² , heat seal time 0.4 seconds × 2 times, heat seal width 0.5 mm × 2 Row), and the peel strength was measured at a peel angle of 165 to 180 degrees. -The difference between the maximum value and the minimum value of the peel strength was defined as zip-up. -The position of the peeled portion was visually evaluated, and the case where the HS layer was peeled off from another layer was evaluated as "O". Surface resistance value: Surface resistivity (JIS K69911) and charge decay time (MIL-B-8170, a U.S. military standard)
5C). -Blocking resistance (BL resistance): 2 of carrier tape
After the 00 m roll was stored at 40 ° C. and a relative humidity of 90% for 2 months, the state of adhesion was evaluated by unwrapping the roll, which did not adhere at all, and the partially felt resistance to peeling was evaluated as x.

[0032]

[Table 1]

[0033]

[Table 2]

[0034]

[Table 3]

[0035]

[Table 4]

[0036]

According to the present invention, an HS layer mainly composed of an acrylic resin having a glass transition point Tg of -10 to 100 ° C. has an excellent effect of preventing static electricity generation from conductive fine powder mainly containing tin oxide. It has something. Then, the EO copolymer and S
An intermediate layer formed of at least two resins including at least an EO copolymer and an SB copolymer among a hydrogenated product of a B copolymer, an SB copolymer, and HIPS; The lid member provided with has an effect of stably separating between the intermediate layer and the HS layer when peeled from the carrier tape.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a cross section of a lid material of the present invention.

FIG. 2 is a conceptual diagram showing a cross section showing another configuration of the present invention.

FIG. 3 is a conceptual diagram showing a cross section showing another configuration of the present invention.

FIG. 4 is a conceptual diagram showing a cross section showing another laminated structure of the present invention.

FIG. 5 is a conceptual diagram showing a cross section for explaining a peeling state of a carrier tape. FIG. 3A is a schematic cross-sectional view showing a state where a lid member and a carrier tape are heat-sealed. (B) is a conceptual diagram showing a cross section in a state where the heat-sealed lid material is peeled off from the carrier tape.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base sheet 2 Intermediate layer 3 HS layer 4 Adhesive layer 5 Carrier tape (molded container) 10 Cover material 20 Exfoliation intermediate layer 21 Reinforcement intermediate layer 22 Buffer intermediate layer 31 Exfoliation part 35 Heat seal part 40 Adhesive resin layer 41, 42 Primer layer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B32B 27/32 103 B32B 27/32 103 B65D 73/02 B65D 73/02 M

Claims (7)

[Claims] 1. A lid material for a molded container comprising at least a heat sealant layer, an intermediate layer and a base sheet, wherein the heat sealant layer has a glass transition point Tg of −
A lid material comprising a thermoplastic resin whose main component is an acrylic resin at 10 to 100 ° C. and conductive fine powder mainly containing tin oxide. 2. The weight ratio of the thermoplastic resin and the conductive fine powder constituting the heat sealant layer is 10 to 400 /
A cover material characterized by being 100. 3. The intermediate layer has a single-layer structure and a density of 0.1.
915 to 0.940 g / cm ^{3 of} an ethylene / α-olefin copolymer is 30 to 70% by weight, and styrene 50 to 90%.
2. A resin composition comprising 70 to 30% by weight of a styrene-butadiene block copolymer of 50% by weight and 50 to 10% by weight of butadiene.
3. The lid material according to any one of claims 1 to 2. 4. The intermediate layer has a single-layer structure and a density of 0.1.
915-0.940 g / cm ³ ethylene / α-olefin copolymer, styrene / butadiene block copolymer of 50-90% by weight of styrene and 50-10% by weight of butadiene, 10-50% by weight of styrene and butadiene 90
The lid material according to any one of claims 1 to 3, wherein the lid material is formed from a resin composition comprising a hydrogenated product of a styrene / butadiene copolymer of about 50% by weight and high impact polystyrene. 5. The intermediate layer has a multilayer structure of a reinforcing intermediate layer provided on the base sheet side, a buffer intermediate layer provided as necessary, and a peeling intermediate layer located on the heat sealant layer side. The layer has a density of 0.915 to 0.940 g /
cm ^{3 of} an ethylene / α-olefin copolymer, and the buffer intermediate layer has a density of 0.915 to 0.940 g / cm 3.
30 to 70% by weight of ethylene / α-olefin copolymer ³ , 50 to 90% by weight of styrene and 50 to 1% of butadiene.
A styrene-butadiene block copolymer of 0 to 30% by weight is formed from a resin composition comprising 70 to 30% by weight;
The release intermediate layer is composed of 30 to 70% by weight of an ethylene / α-olefin copolymer having a density of 0.915 to 0.940 g / cm ^3.
And 50 to 90% by weight of styrene and 50 to 10 of butadiene.
7% by weight of styrene-butadiene block copolymer
10 to 50% by weight of styrene and 90 to 50% of butadiene with respect to 100 parts by weight of the resin composition comprising 0 to 30% by weight.
5 to 30 parts by weight of a hydrogenated styrene-butadiene copolymer and 5 to 5 parts by weight of high impact polystyrene.
The lid material according to any one of claims 1 to 4, wherein the lid material is formed from a resin composition containing 0 parts by weight. 6. The heat sealant layer according to claim 1, wherein a surface resistivity of the heat sealant layer is in a range of 10 ⁵ to 10 ¹² Ω / □, and a charge decay time is 2 seconds or less.
A lid material according to any one of the above. 7. The heat sealant layer of the lid member can be heat-sealed with a molding container made of polycarbonate, polystyrene, polyester, polyvinyl chloride, acrylonitrile / styrene / butadiene copolymer (ABS resin), and the like. The lid according to any one of claims 1 to 6, wherein when the lid material is removed from the molded container after heat sealing with the molded container, delamination with the intermediate layer or cohesive peeling in the heat sealant layer is performed. Wood.