JPH07223674A - Lid material - Google Patents

Abstract

PURPOSE:To provide a lid material for a container made of resin, which has a combination of high adhesive properties and favorable peeling properties, by a method wherein the lid material is provided with a biaxially oriented resin layer, a heat sealant layer, a static electric diffusion layer adjacent to the heat sealant layer and positioned between the above-mentioned two layers, and an intermediate layer adjacent to the static electric diffusion layer and positioned between the biaxially oriented resin layer and the static electric diffusion layer. CONSTITUTION:A lid material 1 has a biaxially oriented resin layer 2, a heat sealant layer 6, a static electric diffusion layer 5 adjacent to the heat sealant layer 6 and provided between the biaxially oriented resin layer 2 and the heat sealant layer 6, and an intermediate layer 4 adjacent to the static electric diffusion layer 5 and provided between the biaxially oriented resin layer 2 and the static electric diffusion layer 5. Since the static electric diffusion layer 5 imparts a charging preventing characteristic to the lid material 1 and is peelable between the static electric diffusion layer and the intermediate layer 4, or cohesive failure in the static electric diffusion layer 5 or peeling between the static electric diffusion layer 5 and the heat sealant layer 6 is possible, the lid material 1 can be safely and reliably peeled irrespective of a thermal weld strength between a carrier tape and the heat sealant layer 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lid member, and more particularly to a lid member used for a synthetic resin container.

[0002]

2. Description of the Related Art Conventionally, various parts, solid or liquid foods, and the like are housed in a synthetic resin container, and the opening is sealed with a lid member for distribution and storage.

For example, an electronic component is housed in each embossed portion of a carrier tape on which a large number of embosses are formed, and a lid material (cover tape) is heat-sealed and sealed on the carrier tape so as to cover the embossed portion. Carrier type taping is used. The carrier tape used for such embossed carrier type taping is usually formed of a material such as polyvinyl chloride, polystyrene, polyester, or polycarbonate which is easy to form into a sheet. The lid member also includes a biaxially stretched resin film and a heat sealant layer formed on one surface of the film. Then, in the electronic component mounting process, the lid member is required to be peelable in order to take out the electronic component housed in the embossed carrier type taping.

Further, in the embossed carrier type taping in which the lid material is heat-sealed, it is inspected at the final stage of shipment whether or not the electronic parts are filled, and the appearance and function of the electronic parts are defective (lead bending, bending, It is necessary to visually check the voids in the packaging part).

Further, the static electricity generated when the stored electronic components come into contact with the embossed portion of the carrier tape or the lid member and the static electricity generated when the lid member is peeled off may cause deterioration and destruction of the electronic components. Because of the danger, carrier tapes and lids are required to have a means for preventing this.

As a means for preventing the generation of static electricity in a carrier tape, conductive carbon fine particles, conductive powder such as metal oxide, and metal fine particles are kneaded or applied into the carrier tape. In addition, as a means for preventing static electricity generation in the lid material, an antistatic agent such as a surfactant, a metal oxide-based conductive powder, conductive carbon fine particles, and metal fine particles are kneaded into a heat sealant layer that is in direct contact with electronic components. It is being applied. In particular, metal oxide (tin oxide, zinc oxide, etc.) is applied to the heat sealant layer.
The one in which fine powder made conductive is mixed is often used because it is relatively transparent.

[0007]

However, the heat-sealing of the lid member to the carrier tape is performed so that the lid member does not peel off during the transportation and storage of the embossed carrier type taping, and the electronic component does not drop off. , A predetermined strength is required, but if this heat fusion strength is too large, the carrier tape vibrates and the electronic component pops out from the embossed portion of the carrier tape when the lid material is peeled off in the mounting process of the electronic component. There was a problem that an accident occurred. Therefore, the lid material is required to be adhered to the carrier tape with sufficient strength and to have good peelability when using electronic parts.
A conventional lid material in which conductive fine powder or the like is mixed in the heat sealant layer has a problem that good peelability cannot be obtained.

Further, the lid material in which the conductive powder of the metal oxide is mixed in the heat sealant layer had relatively good transparency, but it was difficult to disperse the heat sealant layer at the time of formation,
In order to obtain transparency that allows visual inspection of electronic components, a skilled dispersion technique is required, which causes a problem of increase in manufacturing cost.

Further, when a surface active agent is applied, the surface condition of the heat sealant layer of the lid material is changed, and the sealing property becomes unstable, leading to a defective seal, and the temperature and humidity during storage. There is a problem in that a stable antistatic effect cannot be obtained because the static electricity diffusion effect due to the large dependence.

Furthermore, since the lid material is discarded after being peeled from the carrier tape, the cost of the lid material is required to be as low as possible, and the manufacturing cost is reduced by reducing the raw material cost without deteriorating the peeling property. It is required to

The present invention has been made in view of the above circumstances, and is an inexpensive lid having excellent electrostatic characteristics and having both high adhesion to a synthetic resin container and good peelability. The purpose is to provide wood.

[0012]

In order to achieve such an object, the present invention provides a biaxially stretched resin layer, a heat sealant layer, and the biaxially stretched resin layer and the heat layer adjacent to the heat sealant layer. The electrostatic diffusion layer is located between the sealant layer and the intermediate layer, which is adjacent to the electrostatic diffusion layer and between the biaxially stretched resin layer and the electrostatic diffusion layer. Further, the heat sealant layer is formed in a sea-island pattern on one surface of the lid member, and the area of one sea-island pattern is set to 0.01 to 0.5 mm ² .

[0013]

The lid member has a biaxially stretched resin layer, a heat sealant layer, and an electrostatic diffusion layer adjacent to the heat sealant layer between the biaxially stretched resin layer and the heat sealant layer. Adjacent to the layer, has an intermediate layer between the biaxially stretched resin layer and the electrostatic diffusion layer, the electrostatic diffusion layer imparts antistatic properties to the lid material, and is peelable between the intermediate layer and the layer,
Alternatively, because the cohesive failure in this static electricity diffusion layer or peeling between the static electricity diffusion layer and the heat sealant layer is possible, the peeling of the lid material is stable regardless of the heat fusion strength between the carrier tape and the heat sealant layer. And surely. Further, by forming the heat sealant layer on one surface of the lid material in a sea-island pattern, the heat sealant layer material can be reduced, so that the manufacturing cost can be kept low.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic sectional view of the lid member of the present invention.
In FIG. 1, a lid material 1 includes a biaxially stretched resin layer 2 and an adhesive layer 3.
An intermediate layer 4 sequentially laminated on the biaxially stretched resin layer 2 via
An electrostatic diffusion layer 5 and a heat sealant layer 6 are provided.

The biaxially stretched resin layer 2 can be formed of a biaxially stretched film such as a polyester resin such as polyethylene terephthalate (PET), a polyolefin resin such as polypropylene, a polyamide resin such as nylon and a polycarbonate resin. By providing the biaxially stretched resin layer 2 in this way, heat resistance can be imparted to the lid material 1. The thickness of the biaxially stretched resin layer 2 can be appropriately set according to the purpose of use of the lid material, and can be set to, for example, about 6 to 100 μm. If necessary, the surface of the biaxially stretched resin layer 2 on which the adhesive layer 3 is formed is previously corona treated,
Surface treatment such as plasma treatment or sandblast treatment may be performed to enhance the adhesiveness with the adhesive layer 3. In addition, a material that has been subjected to static electricity generation prevention processing as needed can also be used.

The adhesive layer 3 is made of low density polyethylene, ethylene-α / olefin copolymer having a density of 0.915 to 0.940 g / cm ³ , polyethylene vinyl acetate copolymer, ionomer, polypropylene, ethylene methacrylic acid copolymer. , Ethylene acrylic acid copolymer, or modified products thereof, such as polyolefin-based, polyethyleneimine-based, polybutadiene-based, organic titanium compounds, isocyanate-based, urethane-based adhesives, etc. The thickness is preferably about 0.2 to 60 μm. The adhesive layer 3 can be applied or extruded on a biaxially stretched resin film.
The intermediate layer 4 can be dry laminated or extruded laminated on top.

The intermediate layer 4 has a single layer structure and a density of 0.91.
5 to 0.940 g / cm ³ of ethylene-α / olefin copolymer, 50 to 90% by weight of styrene and 50 to butadiene
Styrene-butadiene block copolymer with 10 wt%, styrene 10-50 wt% and butadiene 90-50
It can be formed from three or more kinds of resins containing at least an ethylene-α-olefin copolymer and a styrene-butadiene block copolymer among hydrogenated products of styrene-butadiene block copolymer and high-impact polystyrene in an amount of 1% by weight. it can. The ethylene-α-olefin copolymer used for forming the mid layer 4 is ethylene,
For example, butene, pentene, hexene, heptene, octene, a copolymer with 4-methylpentene-1 and the like. The density of such ethylene-α-olefin copolymer is less than 0.915 g / cm ³ , or 0.940 g / cm ^3.
When it exceeds cm ³ , it is not preferable because the film forming property of the intermediate layer 4 due to the combination with the styrene-butadiene block copolymer is lowered.

When the amount of styrene constituting the styrene-butadiene block copolymer used for forming the intermediate layer 4 is less than 50% by weight, the tackiness of the film is increased and the handling becomes difficult. When it exceeds the above range, the adhesion to the electrostatic diffusion layer at low temperature is deteriorated, which is not preferable.

Then, in the intermediate layer 4, ethylene-α.
The mixing ratio of the olefin copolymer and the styrene-butadiene block copolymer greatly affects the peel strength when the lid material 1 is heat-sealed to the synthetic resin container and then peeled off, and the transparency of the lid material 1. To do. In the present invention, the mixing ratio of the ethylene-α-olefin copolymer and the styrene-butadiene block copolymer in the mid layer 4 is 30 to 70% by weight of the ethylene-α-olefin copolymer and the styrene-butadiene block copolymer. The combined amount is 70 to 30% by weight. Ethylene-α
-Olefin copolymer amount less than 30% by weight, styrene-
When the content of the butadiene block copolymer is more than 70% by weight, the film-forming property of the intermediate layer 4 becomes low and the transparency of the lid material also decreases, and the adhesive force between the intermediate layer 4 and the electrostatic diffusion layer 5 is too large. The peel strength of the lid material exceeds the suitable strength described below, which is not preferable. On the other hand, when the amount of the ethylene-α / olefin copolymer exceeds 70% by weight and the amount of the styrene-butadiene block copolymer is less than 30% by weight, the intermediate layer 4
The adhesion between the electrostatic diffusion layer 5 and the electrostatic diffusion layer 5 is too small, and the peel strength of the lid material is less than the appropriate strength, which is not preferable.

When the intermediate layer 4 is formed of four kinds of resins using a hydrogenated product of a styrene-butadiene block copolymer and high-impact polystyrene, 30 to 70 parts by weight of the above-mentioned ethylene-α-olefin copolymer is used. %
And a styrene-butadiene block copolymer 70-30
5 parts by weight of the styrene-butadiene block copolymer hydrogenated product of 10 to 50% by weight of styrene and 90 to 50% by weight of butadiene is added to 100 parts by weight of the resin composition.
Add ~ 30 parts by weight and add high impact polystyrene to 5
It is preferable to add about 50 parts by weight.

When the content of the hydrogenated product in the styrene-butadiene block copolymer is less than 5 parts by weight, styrene-
The effect of adding the hydrogenated product of the butadiene block copolymer is not exhibited, and when it exceeds 30 parts by weight, the blocking resistance of the obtained film is insufficient, which is not preferable. When the hydrogenated product of the styrene-butadiene block copolymer is not actually a hydrogenated product, this copolymer has a high butadiene content, so that it is easily oxidized and the intermediate layer 4 is easily oxidized. Gel is likely to be generated during formation.

Further, when an anhydrous additive is used, the film forming accuracy is poor and it may be difficult to form a film.

When the amount of high-impact polystyrene added is less than 5 parts by weight, the effect of adding high-impact polystyrene is not exhibited, and when it exceeds 50 parts by weight, the intermediate layer 4 and the electrostatic diffusion layer 5 adhere to each other. Too much power,
The peel strength of the lid material exceeds the appropriate strength, which is not preferable.

The intermediate layer 4 is made of ethylene-α.
To 100 parts by weight of the resin composition of 30 to 70% by weight of the olefin copolymer and 70 to 30% by weight of the styrene-butadiene block copolymer, 5 to 5 parts of the hydrogenated product of the styrene-butadiene block copolymer is used. It may be formed by a resin composition containing 30 parts by weight of three kinds of resins. Further, ethylene-α / olefin copolymer 30-
Resin containing three kinds of resins by adding only 5 to 50 parts by weight of high-impact polystyrene to 100 parts by weight of a resin composition of 70% by weight and styrene-butadiene block copolymer 70 to 30% by weight. It may be formed by the composition.

In the present invention, the intermediate layer 4 having a single layer structure is
In addition to the above structure, the density is 0.915 to 0.940.
g / cm ³ ethylene-α / olefin copolymer 30 to 7
0 parts by weight, 50 to 90% by weight of styrene and 5 parts of butadiene
It can be formed by a resin composition to which 0 to 10% by weight and 70 to 30 parts by weight of a styrene-butadiene block copolymer are added.

In this case, if the amount of styrene constituting the styrene-butadiene block copolymer to be used is less than 50% by weight, the tackiness of the film increases and handling becomes difficult. Adhesion to the static electricity diffusion layer deteriorates, which is not preferable. And the middle layer 4
The mixing ratio of the ethylene-α-olefin copolymer and the styrene-butadiene block copolymer in the above is the peel strength when the lid material 1 is heat-sealed to the synthetic resin container and then peeled off, and the transparency of the lid material 1 is Greatly affects the sex. Ethylene-α
-Olefin copolymer amount less than 30% by weight, styrene-
When the content of the butadiene block copolymer is more than 70% by weight, the film-forming property of the intermediate layer 4 becomes low and the transparency of the lid material also decreases, and the adhesive force between the intermediate layer 4 and the electrostatic diffusion layer 5 is too large. The peel strength of the lid material exceeds the suitable strength described below, which is not preferable. On the other hand, when the amount of the ethylene-α / olefin copolymer exceeds 70% by weight and the amount of the styrene-butadiene block copolymer is less than 30% by weight, the intermediate layer 4
The adhesion between the electrostatic diffusion layer 5 and the electrostatic diffusion layer 5 is too small, and the peel strength of the lid material is less than the appropriate strength, which is not preferable.

In the present invention, the intermediate layer 4 having a single-layer structure is prepared by using 30 to 70 parts by weight of an ethylene-α.olefin copolymer having a density of 0.915 to 0.940 g / cm ³ and 10 to 50 of styrene. Hydrogenated product of styrene-butadiene block copolymer of 7 wt% and 90-50 wt% of butadiene 7
It can be formed of a resin composition to which 0 to 30 parts by weight is added.

In this case, the density of the ethylene-α-olefin copolymer is less than 0.915 g / cm ³ , or 0.9
When it exceeds 40 g / cm ³ , the film forming property of the intermediate layer 4 due to the combination of the styrene-butadiene block copolymer with a hydrogenated product is deteriorated, which is not preferable. Further, when the amount of styrene constituting the hydrogenated product of the styrene-butadiene block copolymer used is less than 10% by weight, the tackiness of the film increases to cause blocking, which makes handling difficult, and exceeds 50% by weight. Adhesion to the electrostatic diffusion layer at low temperature is poor, which is not preferable. By using a hydrogenated material, flexibility is imparted to the mid layer 4, and
Since the compatibility with the ethylene-α / olefin copolymer is good, the transparency of the mid layer 4 is high. And the middle layer 4
The mixing ratio of the ethylene-α-olefin copolymer and the hydrogenated product of the styrene-butadiene block copolymer in the above is the peeling strength when peeling after the lid material 1 is heat-sealed to the synthetic resin container and the lid. It greatly affects the transparency of the material 1.
When the amount of the ethylene-α / olefin copolymer is less than 30% by weight and the hydrogenated product of the styrene-butadiene block copolymer is more than 70% by weight, the film forming property of the intermediate layer 4 becomes low and the transparency of the lid material is also increased. In addition, the adhesive strength between the intermediate layer 4 and the electrostatic diffusion layer 5 is too large, and the peeling strength of the lid material exceeds the appropriate strength described below, which is not preferable. On the other hand, the amount of ethylene-α / olefin copolymer exceeds 70% by weight,
When the hydrogenated product of the styrene-butadiene block copolymer is less than 30% by weight, the intermediate layer 4 and the electrostatic diffusion layer 5 are
Adhesion strength with is too small, and peel strength of the lid material is lower than appropriate strength, which is not preferable.

Further, in the present invention, the intermediate layer 4 having a single layer structure can be formed of a linear saturated polyester resin having a glass transition temperature of 40 ° C. or higher.

Examples of the linear saturated polyester resin having a glass transition temperature of 40 ° C. or higher include alcohol components such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, and adipic acid. , A dicarboxylic acid component of an aliphatic dicarboxylic acid such as sebacic acid or an aromatic dicarboxylic acid such as terephthalic acid, isophthalic acid or diphenylcarboxylic acid, specifically, ethylene glycol and terephthalic acid,
Ethylene glycol, isophthalic acid and terephthalic acid,
Co-condensation polymers such as 1,4-cyclohexanedimethanol, ethylene glycol and terephthalic acid, propylene glycol, isophthalic acid and terephthalic acid can be used. The glass transition temperature was set to 40 ° C. or higher in consideration of the environmental condition of using the lid material being lower than 40 ° C.

The thickness of the intermediate layer 4 having a single layer structure as described above is usually preferably about 10 to 60 μm. When the thickness of the intermediate layer is less than 10 μm, the film-forming property is poor, and when it exceeds 60 μm, the heat-sealing property of the lid material 1 is poor.

Further, in the cover material 1 of the present invention, the intermediate layer 4 can have a multi-layer structure.

FIG. 2 is a schematic cross-sectional view showing an example of the lid material of the present invention in which the intermediate layer has a two-layer structure. The intermediate layer 4 is composed of a first resin layer 4a and a second resin layer 4b. There is.

In this case, the first resin layer 4a has a density of 0.9.
It can be formed of 15 to 0.940 g / cm ³ of ethylene-α · olefin copolymer.

The second resin layer 4b has a density of 0.915.
To 0.940 g / cm ³ of ethylene-α / olefin copolymer 30 to 70% by weight, styrene 50 to 90% by weight and butadiene 50 to 10% by weight, styrene-butadiene block copolymer 70 to 30% by weight Resin composition with 10
Formed by a resin composition containing 5 to 30 parts by weight of a hydrogenated product of a styrene-butadiene block copolymer of 10 to 50% by weight of styrene and 90 to 50% by weight of butadiene, relative to 0 parts by weight. You can Further, the second resin layer 4b has a density of 0.915 to 0.940 g / cm ³
Ethylene-α / olefin copolymer of 30 to 70% by weight
And 50 to 90% by weight of styrene and 50 to 10 of butadiene
Styrene-butadiene block copolymer with 70% by weight
It is also possible to form the resin composition by adding 5 to 50 parts by weight of high-impact polystyrene to 100 parts by weight of the resin composition of 30 to 30% by weight. The second resin layer 4b has a density of 0.915 to 0.940 g / cm ³
Ethylene-α / olefin copolymer of 30 to 70% by weight
And 50 to 90% by weight of styrene and 50 to 10 of butadiene
Styrene-butadiene block copolymer with 70% by weight
10 to 50% by weight of styrene and 90 to 50% by weight of butadiene based on 100 parts by weight of the resin composition of 30 to 30% by weight.
5 to 30 parts by weight of a hydrogenated product of a styrene-butadiene block copolymer with
The resin composition may be formed by adding 50 parts by weight.

The thickness of each of the first resin layer 4a and the second resin layer 4b can be about 5 to 30 μm.

FIG. 3 is a schematic cross-sectional view showing an example of the lid member of the present invention in which the intermediate layer has a three-layer structure. The intermediate layer 4 includes the first resin layer 4a, the second resin layer 4b and the electrostatic diffusion layer 5. And a third resin layer 4c in contact with.

In this case, the first resin layer 4a has a density of 0.9.
The second resin layer 4b is formed of an ethylene-α-olefin copolymer of 15 to 0.940 g / cm ³ and has a density of 0.
Styrene-butadiene block copolymer 70-30 wt% of 915-0.940 g / cm ³ ethylene-α / olefin copolymer 30-70 wt%, styrene 50-90 wt% and butadiene 50-10 wt%. % Resin composition.

The third resin layer 4c has a density of 0.91.
5 to 0.940 g / cm ³ of ethylene-α / olefin copolymer 30 to 70% by weight and styrene 50 to 90% by weight
Composition of styrene-butadiene block copolymer 70 to 30% by weight of styrene and 50 to 10% by weight of butadiene
It is formed by a resin composition in which 5 to 30 parts by weight of a hydrogenated product of a styrene-butadiene block copolymer of 10 to 50% by weight of styrene and 90 to 50% by weight of butadiene is added to 00 parts by weight. . In addition, the third resin layer 4
c is a styrene-butadiene block copolymer of 30 to 70% by weight of an ethylene-α-olefin copolymer having a density of 0.915 to 0.940 g / cm ³ , 50 to 90% by weight of styrene and 50 to 10% by weight of butadiene. The resin composition may be formed by adding 5 to 50 parts by weight of high-impact polystyrene to 100 parts by weight of the resin composition containing 70 to 30% by weight of the polymer. Further, the third resin layer 4c contains 30 to 70% by weight of an ethylene-α-olefin copolymer having a density of 0.915 to 0.940 g / cm ³ , 50 to 90% by weight of styrene and 50 to 10% by weight of butadiene. Of styrene-butadiene block copolymer of 70 to 30% by weight relative to 100 parts by weight of the resin composition,
Hydrogenated product of styrene-butadiene block copolymer of 0-50% by weight and butadiene 90-50% by weight 5-3
It can also be formed by a resin composition containing 0 parts by weight and 5 to 50 parts by weight of high-impact polystyrene.

Such first resin layer 4a and second resin layer 4
The thicknesses of b and the third resin layer 4c are 3 to 20 μm, respectively.
It can be set in the range of m.

The intermediate layer 4 as described above can be formed by a dry lamination method or an extrusion lamination method.

Since the lid member 1 of the present invention includes the intermediate layer 4 as described above, the intermediate layer 4 and the static electricity diffusion layer 5 are separated from each other when the lid member 1 thermally fused to the synthetic resin container is peeled off. Peeling between layers (delamination), cohesive failure in the electrostatic diffusion layer 5, or peeling between the electrostatic diffusion layer 5 and the heat sealant layer 6. The peeling strength in this case is weaker than the adhesive strength between the electrostatic diffusion layer 5 and the heat sealant layer 6 described later or the heat fusion strength between the heat sealant layer 6 and the synthetic resin container,
It is preferably in the range of 100 to 1200 g / 15 mm. If the peel strength is less than 100 g / 15 mm, there is a risk that peeling will occur between the intermediate layer 4 and the electrostatic diffusion layer 5 when the container after heat-sealing the lid material is transferred, and the contents will fall off. is there. If the peel strength exceeds 1200 g / 15 mm, the synthetic resin container may vibrate when the lid material is peeled off, and the contents may pop out, which is not preferable. The peel strength is 18 at 23 ° C. and 40% RH.
It is a value of 0 ° peeling (peeling speed = 300 mm / min). Also,
Delamination (delamination) between the intermediate layer 4 and the electrostatic diffusion layer 5 as described above is caused, or cohesive failure in the electrostatic diffusion layer 5 or between the electrostatic diffusion layer 5 and the heat sealant layer 6 is formed. Whether to cause peeling can be appropriately selected by controlling the heat sealing conditions. That is, by deteriorating the conditions at the time of heat sealing (higher heating temperature, longer heating time, stronger pressure), delamination between the intermediate layer 4 and the electrostatic diffusion layer 5 can be caused, and the heat sealing can be performed. By loosening the conditions at this time, cohesive failure in the electrostatic diffusion layer 5 or peeling between the electrostatic diffusion layer 5 and the heat sealant layer 6 can be caused. As a specific example of the above heat sealing conditions, in the case of delamination, heating temperature = 130 to 200 ° C., heating time = 0.3 to 2.0.
Seconds, pressurization = about 0.7 to 3.0 kgf / cm ² , and in the case of cohesive failure, heating temperature = 90 to 150 ° C., heating time =
The pressure is 0.1 to 0.5 seconds and the pressure is about 0.3 to 1.2 kgf / cm ² .

As described above, the lid member 1 should be sufficiently peeled from the synthetic resin container after being heat-sealed by sufficiently increasing the heat sealing strength of the heat sealant layer 6 to the synthetic resin container. You can

The static electricity diffusion layer 5 of the lid member 1 of the present invention comprises a thermoplastic resin composed of at least one of polyester resin, polyurethane resin, vinyl chloride-vinyl acetate copolymer resin and acrylic resin, and a conductive material as described later. It is formed of fine particles. As a combination of two or more kinds of thermoplastic resins, for example, a mixed resin of polyurethane resin and vinyl chloride-vinyl acetate copolymer resin (mixing ratio is preferably in the range of 9: 1 to 4: 6), polyester resin and Mixed resin of vinyl chloride-vinyl acetate copolymer resin (mixing ratio is preferably in the range of 1: 1 to 9.5: 0.5), mixed resin of acrylic resin and vinyl chloride-vinyl acetate copolymer resin (The mixing ratio is 1: 1 to 9.5: 0.5.
Is preferable). When the intermediate layer 4 is formed of a linear saturated polyester resin having a glass transition temperature of 40 ° C. or higher, it is preferable to use a mixed resin of polyurethane resin and vinyl chloride-vinyl acetate copolymer resin. .

Further, the static electricity diffusion layer 5 includes metal fine particles such as carbon black, gold, silver, nickel, aluminum and copper,
Conductive particles obtained by adding conductivity to metal oxides such as tin oxide, zinc oxide and titanium oxide, conductive particles obtained by adding conductivity to barium sulfate, zinc sulfide, copper sulfide, cadmium sulfide, nickel sulfide, palladium sulfide, etc. Contains conductive fine particles obtained by imparting conductivity to the sulfide, a Si-based organic compound, a surfactant, and the like. Such conductive fine particles,
The primary particles having an average particle diameter of about 0.01 to 30 μm are preferable. In this case, the mixing ratio of the thermoplastic resin and the conductive fine particles in the electrostatic diffusion layer 5 is 10: 1 to
It is preferably in the range of 1:10. If the mixing ratio of the conductive fine particles or the like is less than the above range, the effect of mixing the conductive fine particles or the like cannot be obtained, and if it exceeds the above range, the adhesive strength between the electrostatic diffusion layer 5 and the heat sealant layer 6 is increased. Is too low, which is not preferable.

The thickness of the electrostatic diffusion layer 5 is 0.1-10.
The range is preferably μm, particularly 1 to 5 μm.

The surface resistivity of such an electrostatic diffusion layer 5 is 10 ⁵ to 10 ¹² Ω at 22 ° C. and 40% RH.
In addition, the charge decay time required to decay from 5000 V to 99% under 23 ± 5 ° C. and 12 ± 3% RH is 2 seconds or less, and excellent electrostatic characteristics are exhibited. If the surface low efficiency exceeds 10 ¹² Ω, the electrostatic diffusion effect becomes extremely poor, and it becomes difficult to protect electronic parts from electrostatic breakdown. If the surface efficiency is less than 10 ⁵ Ω, the lid material is externally applied. Electricity may be applied to the electronic component through the electronic component, and there is a risk that the electronic component may be electrically damaged. On the other hand, if the charge decay time, which is a measure of the diffusion rate of charges generated by static electricity, exceeds 2 seconds, the electrostatic diffusion effect becomes extremely poor, and it becomes difficult to protect electronic components from electrostatic breakdown. The surface resistivity and the charge decay time described above are MIL-B-8170, which is a US military standard.
It can be measured according to 5C.

If necessary, the static electricity diffusion layer 5 may contain additives such as a dispersion stabilizer and an antiblocking agent.

The electrostatic diffusion layer 5 as described above is the intermediate layer 4
The coating can be formed by using a known coating means.

Heat sealant layer 6 of lid 1 of the present invention
Is formed of a thermoplastic resin including at least one of a polyurethane resin, a polyester resin, a vinyl chloride-vinyl acetate copolymer resin, and an acrylic resin. As a combination of two or more kinds of thermoplastic resins, for example, a mixed resin of polyurethane resin and vinyl chloride-vinyl acetate copolymer resin (mixing ratio is preferably in the range of 9: 1 to 4: 6), polyester resin and Mixed resin with vinyl chloride-vinyl acetate copolymer resin (mixing ratio is 1: 1 to 9.5:
0.5 is preferable), a mixed resin of acrylic resin and vinyl chloride-vinyl acetate copolymer resin (mixing ratio is preferably 1: 1 to 9.5: 0.5). it can.

The thickness of the heat sealant layer 6 is 0.1 to 1
0 μm, particularly 0.3 to 2 μm is preferable. When the thickness of the heat sealant layer 6 is less than 0.1 μm, it is difficult to form the heat sealant layer, the haze value is 50% or more, and sufficient transparency cannot be obtained. Is more than 10 μm, the total light transmittance becomes 75% or less, which is also not preferable because the transparency is lowered. Even if such a heat sealant layer 6 is laminated on the electrostatic diffusion layer 5, if the surface resistivity of the electrostatic diffusion layer 5 is within the above range (10 ⁵ to 10 ¹² Ω), the surface resistance of the heat sealant layer 6 The rate is within the range of 10 ⁵ to 10 ¹² Ω under the condition of 22 ° C. and 40% RH, and is 23 ± 5.
5000V to 99% under 12 ° C and 12 ± 3% RH
The charge decay time required to decay is less than 2 seconds,
It will have excellent electrostatic properties.

The above-mentioned heat sealant layer 6 is formed on the entire surface of one side of the lid member 1. However, in the lid member of the present invention, the heat sealant layer 6 is formed on one side of the lid member 1 in a sea-island shape. It may be formed in a pattern. in this case,
The area of one sea-island pattern is 0.01-0.5 mm ^2.
Is preferred. The area of one sea-island pattern is 0.
If it is less than 01 mm ² , it cannot be heat-sealed as a heat sealant layer into a synthetic resin container, and it is difficult to obtain sufficient peeling strength, and the vibration of the synthetic resin container becomes large at the time of peeling the lid material. There is a risk of popping out, which is not preferable. On the other hand, if it exceeds 0.5 mm ² , it is necessary to form the heat sealant layer thinly and accurately in order to achieve the two purposes of stable peel strength and reduction of manufacturing cost. It becomes difficult, and conversely, the manufacturing cost increases, which is not preferable. Further, the total area of the sea-island-shaped heat sealant layer 6 provided on one surface of the lid material 1 is preferably in the range of 35 to 90% of the area of one of the lid materials.

The sea-island pattern described above is not particularly limited, but for example, a circular pattern shape as shown in FIG.
It is possible to have a square pattern shape as shown in FIG. Further, the heat sealant layer 6 having the above-described sea-island pattern may be formed in a region slightly larger than a region corresponding to the line-shaped heat-melted portion H as described later.

By thus forming the heat sealant layer 6 on one surface of the lid member 1 in a sea-island pattern,
The heat sealant layer material can be reduced, and the manufacturing cost of the lid material can be kept low. Further, as described above, since the static electricity diffusion layer 5 contains conductive fine particles and the like in a predetermined resin, the heat sealant layer is formed in a sea-island pattern to expose a large amount of the static electricity diffusion layer 5, and this static electricity diffusion layer 5 is exposed. The thermal fusion properties of layer 5 can be utilized. That is, the heat sealing temperature can be lowered while maintaining good peeling characteristics, and the demand for energy saving can be met.

The lid 1 of the present invention is separated from the intermediate layer 4 and the electrostatic diffusion layer 5 between layers, or cohesively broken in the electrostatic diffusion layer 5, or between the electrostatic diffusion layer 5 and the heat sealant layer 6. Since the peeling occurs, the stable peeling performance is obtained without being affected by the conditions for heat fusion to the synthetic resin container. Such delamination or peeling due to cohesive failure will be described with reference to FIGS. 6 to 9. First, as shown in FIGS. 6 and 7, for example, the embossed portion 1
The lid material 1 as shown in FIG. 1 is heat-sealed to the carrier tape 11 provided with 2. This heat fusion is applied to the embossed portion 1
It is performed in a line shape with a predetermined width at both end portions of 2. In the illustrated example, the line-shaped heat-sealing portion H is shown by a shaded portion. In this state, the adhesion strength between the intermediate layer 4 of the lid material 1 and the static electricity diffusion layer 5 is in the range of 100 to 1200 g / 15 mm, and the adhesion strength between the static electricity diffusion layer 5 and the heat sealant layer 6 or the heat sealant layer 6 is It is smaller than the heat fusion strength with the carrier tape 11. Next, when the lid member 1 is peeled off from the carrier tape 11, the static electricity diffusion layer 5 and the heat sealant layer 6 are still heat-sealed to the carrier tape 11 in the line-shaped heat-sealed portion H, and the intermediate layer 4 Peeling occurs between the layer and the static electricity diffusion layer 5 (FIG. 8). Therefore, the lid member 1 is peeled off with the line-shaped heat-sealed portion H of the static electricity diffusion layer 5 and the heat sealant layer 6 left on the carrier tape. Alternatively, in the line-shaped heat-sealed portion H, cohesive failure occurs in the static electricity diffusion layer 5, and a part of the static electricity diffusion layer 5 and the heat sealant layer 6 are heat-sealed to the carrier tape 11 and the lid member is kept. 1 is peeled off (FIG. 9). That is, the lid member 1 of the present invention has the contradictory characteristics of high heat fusion property to the carrier tape 11 and easy peeling property at the time of peeling.

The lid member of the present invention may have an antireflection film or an antireflection film and an antistatic layer on the biaxially stretched resin layer, in addition to the above-mentioned embodiments. 10 and 11 are schematic cross-sectional views showing other examples of such a lid member of the present invention. In FIG. 10, the lid member 21 includes a biaxially stretched resin layer 22, and an intermediate layer 24 sequentially laminated on one surface of the biaxially stretched resin layer 22 with an adhesive layer 23 interposed therebetween.
An electrostatic diffusion layer 25 and a heat sealant layer 26 are provided, and an antireflection film 27 is provided on the other surface of the biaxially stretched resin layer 22. Further, in FIG. 11, an antistatic layer 28 is further provided between the biaxially stretched resin layer 22 and the antireflection film 27.

The antireflection film 27 is intended to suppress diffused reflection in the lid member or the reflection of light from the light source, and to make it easier to visually observe the inside of the container. Such an antireflection film 27 is formed of calcium fluoride, sodium fluoride, lithium fluoride, magnesium fluoride, lanthanum fluoride,
Neodymium fluoride, cerium fluoride, silicon dioxide, aluminum oxide, magnesium monoxide, thorium oxide, lanthanum oxide, silicon monoxide, yttrium oxide, zirconium oxide, titanium oxide, cerium oxide, zinc oxide, bismuth oxide, cadmium sulfide, etc. One kind or two or more kinds can be formed by using an ink dispersed in a thermoplastic resin or can be directly formed into a film. As the thermoplastic resin, polyester type, polyurethane type, acrylic type, vinyl chloride-
Vinyl acetate copolymer type, polyvinyl acetate type, phenol type, xylene type, urea resin type and melanin type, ketone type, coumarone / indene type, petroleum resin type, terpene type,
Cyclized rubber type, chlorinated rubber type, alkyd type, polyamide type,
Examples thereof include polyvinyl alcohol type, polyvinyl butyral type, chlorinated polypropylene type, styrene type, epoxy type and cellulose derivatives. As a method for forming the antireflection film 27 by applying ink, an air doctor coating method, a blade coating method, a knife coating method, a rod coating method, a roll coating method, a gravure coating method, a screen method, a kiss coating method, a bead coating method, a slot orifice. The coating method, the spray method, etc. can be mentioned.
When directly forming a film, a vacuum vapor deposition method, a sputtering method, or the like can be used. Such an antireflection film 27
May have either a single-layer structure or a multi-layer structure, and the film thickness is preferably about 0.01 to 0.5 μm.

The antistatic layer 28 is formed for the purpose of preventing dust from adhering to the surface of the lid member 21 due to static electricity. This antistatic layer 28
Is an anionic, cationic, nonionic or amphoteric surfactant as an antistatic agent, a fatty acid derivative,
At least one of tetrafunctional silicon partial hydrolyzate, conductive fine powder obtained by subjecting metal fine powder, metal oxide, metal sulfide or sulfate to conductive treatment, and conductive carbon It is a layer.

As the above-mentioned anionic surfactant, sulfated oil, soap, sulfated ester oil, sulfated amide oil, olefin sulfate ester salts, fatty alcohol sulfate ester salt, alkyl sulfate ester salt, fatty acid ethyl sulfonic acid. Examples thereof include salts, alkyl sulfonates, alkyl benzene sulfonates, mixtures of naphthalene sulfonic acid and formalin, succinic acid ester sulfonic acid salts, and phosphoric acid ester salts.

Examples of cationic surfactants include primary amine salts, tertiary amine salts, quaternary ammonium compounds, pyridine derivatives and the like.

As the nonionic surfactant, partial fatty acid ester of polyhydric alcohol, ethylene oxide adduct of fatty alcohol, ethylene oxide adduct of fatty acid, ethylene oxide adduct of fatty amino or fatty acid amide, alkylphenol. And ethylene oxide adduct of alkyl naphthol, ethylene oxide adduct of partial fatty acid ester of polyhydric alcohol, and the like.

Further, examples of the amphoteric surfactant include a carboxylic acid derivative and an imidazoline derivative.

The antistatic layer 28 can be formed on the biaxially stretched resin layer 22 by using the above antistatic agent alone. Alternatively, it may be formed by applying an ink in which an antistatic agent is dispersed to a thermoplastic resin that can be used in forming the antireflection film 27. The thickness of such an antistatic layer 28 is preferably about 0.2 to 20 μm.

The surface resistivity of the antistatic layer 28 is within the range of 10 ⁵ to 10 ¹² Ω at 22 ° C. and 40% RH, and at 23 ± 5 ° C. and 12 ± 3% RH. The charge decay time required to decay from 5000 V to 99% is 2 seconds or less, and has an excellent antistatic effect.

In the lid member 21, the biaxially stretched resin layer 22, the adhesive layer 23, the intermediate layer 24, and the static electricity diffusion layer 25 are used.
The heat sealant layer 26 is the same as the corresponding layers constituting the lid member 1 described above, and thus the description thereof is omitted.

As the synthetic resin container to which the lid material of the present invention as described above is applied, polyvinyl chloride (PV
C), polystyrene (PS), polyester (A-PE
T, PEN, PET-G, PCTA), polypropylene (PP), polycarbonate (PC), polyacrylonitrile (PAN), acrylonitrile-butadiene-styrene copolymer (ABS), etc. As conductive carbon fine particles, metal fine particles, conductive fine powder obtained by imparting conductivity to metal oxides such as tin oxide, zinc oxide, and titanium oxide, Si-based organic compounds, and those obtained by kneading or coating a surfactant, etc. Can be mentioned. Further, a PS-based resin sheet or ABS-based resin sheet having a composite plastic sheet formed by integrally co-extruding a PS-based or ABS-based resin film or sheet containing carbon black on one or both sides is also exemplified. To be Alternatively, as the conductive treatment, a plastic film having a conductive polymer formed on its surface can be used.

Next, the lid material of the present invention will be described in more detail with reference to specific examples. (Example 1-A) As a biaxially stretched resin layer, a biaxially stretched polyethylene terephthalate (PET) film (Spett 6140, manufactured by Toyobo Co., Ltd., thickness 12 μm, corona treated product) was prepared. A polyethyleneimine solution (P-100 manufactured by Nippon Shokubai Kagaku Co., Ltd.) was prepared as an adhesive. Furthermore, as an adhesive layer, low density polyethylene (LDPE) (Mitsui Petrochemical Co., Ltd. Mirason 16-
P) was prepared.

Next, in order to form an intermediate layer, the following linear low density polyethylene (L.LDPE) as an ethylene-.alpha..olefin copolymer and styrene 70-90 are used.
The following S / B copolymer as a styrene-butadiene block copolymer (S / B copolymer) of 20% by weight and 30 to 10% by weight of butadiene, 20 to 50% by weight of styrene and 80 to 50% by weight of butadiene. The following S.B copolymer hydrogenated products and high-impact polystyrene (HIPS) were prepared as hydrogenated products of the styrene-butadiene block copolymer (S.B copolymer). Further, the following S / B block elastomer was prepared as a non-hydrogenated product of a styrene-butadiene block copolymer (S / B copolymer) of 20 to 50% by weight of styrene and 80 to 50% by weight of butadiene.

L / LDPE: Mitsui Petrochemical Industry Co., Ltd.
Ultzex 3550A manufactured by Density = 0.925 g / cm ³ S / B copolymer: Asaflex 8 manufactured by Asahi Kasei Corporation
10 S / B copolymer hydrogenated product: Asahi Kasei Kogyo Co., Ltd. Tuftec H1041 HIPS: Asahi Kasei Kogyo Co., Ltd. Styron 475
DSB Block Elastomer: Toughprene A manufactured by Asahi Kasei Kogyo Co., Ltd. Next, using each of these materials, an adhesive is first applied to a PET film, and then an LDPE layer (thickness 20 μm) is formed by an extrusion lamination method. An intermediate layer (single layer structure, thickness 30 μm) was formed under the mixing conditions shown in Table 1 below. After that, an electrostatic diffusion layer coating solution having the following composition is applied on the intermediate layer by a gravure reverse method to form an electrostatic diffusion layer (thickness 2 μm), and then a heat sealant layer coating solution having the following composition is gravure-coated. Apply by the reverse method to form a heat sealant layer (thickness 0.5 μm),
Lids (Samples 1 to 11 and Comparative Samples 1 to 5) were created. (Composition of coating liquid for electrostatic diffusion layer) Polyurethane resin (Nipporan 5120 manufactured by Nippon Polyurethane Industry Co., Ltd.) 30 parts by weight Vinyl chloride-vinyl acetate copolymer resin (Vinylite VAGH manufactured by Union Carbide Co., Ltd.) 7.5 Parts by weight Conductive fine powder (conductive fine particles T-1 manufactured by Mitsubishi Materials Corp.) 62.5 parts by weight (composition of coating liquid for heat sealant layer) Polyurethane resin (EX7240 manufactured by Honey Chemical Co., Ltd.) 100 Parts by weight

[0071]

[Table 1] Further, using each of the above materials, first, an adhesive is applied to the PET film, and then the L·LDPE layer is formed through the LDPE layer (thickness 20 μm) by the extrusion lamination method.
An intermediate layer (two-layer structure, thickness 30 μm) as shown in FIG. 2 is formed by forming a first layer (thickness 15 μm) consisting of layers and a second layer (thickness 15 μm) having the composition shown in Table 2 below. ) Was formed. After that, the electrostatic diffusion layer coating liquid and the heat sealant layer coating liquid having the above-mentioned compositions are applied on the intermediate layer by a gravure reverse method, and the electrostatic diffusion layer (thickness 2 μm) and the heat sealant layer (thickness 0. 5 μm) to form a lid material (Samples 12 to 17 and Comparative Samples 6 to 8).

[0072]

[Table 2] Further, using each of the above materials, first, an adhesive is applied to the PET film, and then the L·LDP is formed through the LDPE layer (thickness 20 μm) by the extrusion lamination method.
As shown in FIG. 3, a first layer (thickness 10 μm) consisting of an E layer, a second layer (thickness 10 μm) and a third layer (thickness 10 μm) having the compositions shown in Table 3 below are formed. An intermediate layer (three-layer structure, thickness 30 μm) was formed. Thereafter, the electrostatic diffusion layer coating liquid of the above composition, the heat sealant layer coating liquid on the intermediate layer is applied by a gravure reverse method,
An electrostatic diffusion layer (thickness 2 μm) and a heat sealant layer (thickness 0.5 μm) were formed, and a lid material (samples 18 to 2) was formed.
5, comparative samples 9-12) were prepared.

[0073]

[Table 3] Furthermore, except that the heat sealant layer was not formed, Sample 2
(Intermediate layer is a single layer), Sample 15 (intermediate layer is two layers) and Sample 25 (intermediate layer is three layers) in the same manner as the lid material (Comparative Sample 1).
3-15) was prepared.

Next, the haze, total light transmittance, surface resistivity and charge decay time of each of the above-mentioned lid materials (Samples 1 to 25 and Comparative Samples 1 to 15) were measured under the following conditions. Further, each of the above lid materials was attached to a conductive polyvinyl chloride resin base material (XEG47 manufactured by Taihei Chemical Co., Ltd.) using a heat seal bar under the conditions of 150 ° C., 0.5 seconds and 3.0 kgf / cm ² . After heat-sealing, the peel strength was measured under the following conditions. (Measurement conditions of haze degree and total light transmittance) Suga Test Instruments Co., Ltd. color computer SM-5SC was used for measurement. (Measurement condition of surface resistivity) It was measured at 22 ° C. and 40% RH with Hiresta IP manufactured by Mitsubishi Petrochemical Co., Ltd. (Measurement condition of charge decay time) 23 ± 5 ° C, 12 ± 3% R
The time required for 99% attenuation from 5000 V under H is based on E according to MIL-B-81705C.
STATIC DECAY made by TS (Electro-Tech Systems, Inc)
Measured with METER-406C. (Peeling strength measurement conditions) Tensilon universal tester manufactured by Toyo Baldwin Co., Ltd. at 23 ° C. and 40% RH
It was measured with HTH-100. (Peeling speed = 300 mm / min, 1
80 ° peeling) The measurement results and peeling form of the above items for each lid material are shown in Table 4 below.

[0075]

[Table 4] (Example 1-B) A heat sealant layer coating solution was applied by a gravure method to form a heat sealant layer (thickness 0.5 μm).
m, sea-island pattern (pattern shape = square, one pattern area = 0.04 mm ² ) except that the lid material (Samples 1 to 25, Comparative sample 1) was prepared in the same manner as in Example 1-A. ~
15) was created. Using this cover material, each cover material was heat-sealed to a conductive polyvinyl chloride resin base material (XEG47 manufactured by Taihei Chemical Co., Ltd.) in the same manner as in Example 1-A, and then,
The peel strength was measured as in Example 1-A.

Since the measurement results and the peeling form of each lid material were the same as those in Example 1-A, the description thereof is omitted. (Example 1-C) Lids (Samples 1 to 25 and Comparative samples 1 to 15) were prepared in the same manner as in Example 1-B. Using this lid material, heat fusion conditions were 140 ° C, 0.4 seconds, 1.0 kgf /
In the same manner as in Example 1-A except that cm ² was used, each lid material was heat-sealed to a conductive polyvinyl chloride resin substrate (XEG47 manufactured by Taihei Chemical Co., Ltd.), and then, as in Example 1-A. Similarly, the peel strength was measured.

The measurement results and peeling morphology of each lid material are shown in Table 5 below.

[0078]

[Table 5] (Example 1-D) Lids (Samples 1 to 25 and Comparative samples 1 to 15) were prepared in the same manner as in Example 1-A. Using this lid material,
Conductive polyvinyl chloride resin base material (XEG47 manufactured by Taihei Chemical Co., Ltd.) in the same manner as in Example 1-A except that the heat fusion conditions were 140 ° C., 0.4 seconds, and 1.0 kgf / cm ^2. Then, each lid material was heat-sealed, and then the peel strength was measured in the same manner as in Example 1-A.

The measurement results and peeling morphology of each lid material are shown in Table 6 below.

[0080]

[Table 6] (Example 2-A) As a biaxially stretched resin layer, a biaxially stretched polyethylene terephthalate (PET) film (Spett 6140, manufactured by Toyobo Co., Ltd., thickness 12 μm, corona treated product) was prepared.

Next, in order to form an intermediate layer, the following linear low density polyethylene (L.LDPE) as an ethylene-.alpha..olefin copolymer and styrene 50-90 are used.
The following S.B copolymer was prepared as a styrene-butadiene block copolymer (S.B copolymer) containing 50% by weight of butadiene and 50 to 10% by weight of butadiene, and a film was obtained by an inflation method.

L.LDPE: Mitsui Petrochemical Industry Co., Ltd.
Ultzex 3550A manufactured by Density = 0.925 g / cm ³ S / B copolymer: Asaflex 8 manufactured by Asahi Kasei Corporation
10 Further, in order to form the static electricity diffusion layer, the following polyester resin, vinyl chloride-vinyl acetate copolymer resin, polyurethane resin and conductive fine powder were prepared.

Polyester resin: manufactured by Toyobo Co., Ltd. Byron (glass transition temperature = 50 ° C.) Vinyl chloride-vinyl acetate copolymer resin: manufactured by Union Carbide Vinylite VAGH Polyurethane resin: manufactured by Nippon Polyurethane Industry Co., Ltd. Nipporan 5120 Conductive Fine powder: Mitsui Mining & Smelting Co., Ltd. Pastran IV
(Average particle size = 0.1 μm) Further, in order to form the heat sealant layer, a polyurethane resin (EX7240 manufactured by Honey Chemical Industry Co., Ltd.) was prepared. Next, using each of the above materials, first,
After applying the adhesive to the PET film, an intermediate layer (under the mixing conditions of L / LDPE and S / B copolymers shown in Tables 7 and 8 below via an LDPE layer (thickness 20 μm) by an extrusion lamination method ( A thickness of 30 μm) was formed. Then, an electrostatic diffusion layer (thickness: 2 μm) having the composition shown in Tables 7 and 8 below was formed on the intermediate layer by a gravure reverse method, and then a heat sealant layer (thickness: 0.5 μm) was formed by a gravure reverse method. ) Is formed, and a lid material (Samples 1 to 26)
It was created.

Further, a lid member (Sample 27, Sample 27, Sample 15) was prepared in the same manner as Sample 4 and Sample 15 except that the heat sealant layer was not formed.
28) was prepared.

[0085]

[Table 7]

[0086]

[Table 8] Next, for each of the above-mentioned lid materials (Samples 1 to 28), the haze degree, total light transmittance, surface resistivity, charge decay time and peel strength were measured in the same manner as in Example 1-A. In addition, blocking resistance was measured under the following conditions. (Blocking resistance) A lid material having a length of 100 m and a width of 50 mm was wound into a reel and allowed to stand in an environment of 40 ° C. and 90% RH for 24 hours, and the occurrence of blocking was observed.

The measurement results of the above items and the peeling form of each lid material are shown in Tables 9 and 10 below.

[0088]

[Table 9]

[0089]

[Table 10] As shown in Table 9 and Table 10, Samples 1 to 6 and Samples 15 to 20 have good transparency and electrostatic characteristics, and peeling occurs between the intermediate layer and the electrostatic diffusion layer with an appropriate peeling strength. It was On the other hand, in Samples 7, 9 and 12, the content of the conductive fine powder was large, so that the total light transmittance was less than 75% and the transparency was poor. In addition, since Samples 8, 10 and 22 have a low content of conductive fine powder, the peel strength is below the appropriate strength, the surface resistivity is 10 ¹³ Ω or more, the electrification decay time exceeds 2 seconds, and the static electricity It had no properties. Further, Samples 11, 12, and 24 had poor coatability because the amount of vinyl chloride-vinyl acetate copolymer resin in the static electricity diffusion layer was large. Further, since the sample 23 had a large amount of polyurethane resin, the peel strength was below the appropriate strength. Samples 13 and 2
Sample No. 5 had a relatively large amount of LLDPE in the intermediate layer, and conversely, Sample 1
Since Nos. 4 and 26 had a small amount of L·LDPE, Samples 13 and 25 had low peel strength, and Samples 14 and 26 had too high peel strength. Furthermore, the samples 27 and 28 are
Since there was no heat sealant layer, it had a high haze value and did not have sufficient transparency. (Example 2-B) A heat sealant layer coating solution was applied by a gravure method to form a heat sealant layer (thickness 0.5 μm).
m, a sea-island pattern (pattern shape = square, one pattern area = 0.04 mm ² ) was formed, and lid materials (samples 1 to 28) were prepared in the same manner as in Example 2-A. .
The haze, total light transmittance, surface resistivity, charge decay time, blocking resistance, and peel strength of this lid material were measured in the same manner as in Example 2-A.

The measurement results and the peeling form of each lid material were the same as those in Example 2-A, so the description thereof is omitted. (Example 2-C) Lids (Samples 1 to 28) were prepared in the same manner as in Example 2-A. About this lid material, Example 2-
Similar to A, haze, total light transmittance, surface resistivity,
The charge decay time, blocking resistance and peel strength were measured. The heat fusion conditions are 140 ° C, 0.4 seconds, 1.0 k
It was set to gf / cm ² .

The measurement results and peeling morphology of each lid material are shown in Tables 11 and 12 below.

[0092]

[Table 11]

[0093]

[Table 12] (Example 3-A) As a biaxially stretched resin layer, a biaxially stretched polyethylene terephthalate (PET) film (Spett 6140, manufactured by Toyobo Co., Ltd., thickness 12 μm, corona treated product) was prepared. A polyethyleneimine solution (P-100 manufactured by Nippon Shokubai Kagaku Co., Ltd.) was prepared as an adhesive. Furthermore, as an adhesive layer, low density polyethylene (LDPE) (Mitsui Petrochemical Co., Ltd. Mirason 16-
P) was prepared.

Next, in order to form an intermediate layer, the following linear low density polyethylene (L.LDPE) as an ethylene-.alpha..olefin copolymer and styrene 10 to 50 are used.
As a hydrogenated product of a styrene-butadiene block copolymer (S / B copolymer) containing 90% by weight of styrene and 90 to 50% by weight of butadiene, the following hydrogenated product of the S / B copolymer is prepared,
A film was obtained by the inflation method.

L / LDPE: Mitsui Petrochemical Industry Co., Ltd.
Ultzex 3550A manufactured by Density = 0.925 g / cm ³ S / B copolymer Hydrogenated product: Tuftec H1041 manufactured by Asahi Kasei Kogyo Co., Ltd. Further, in order to form an electrostatic diffusion layer, the following polyester resin, vinyl chloride-acetic acid is used. A vinyl copolymer resin, a polyurethane resin, and conductive fine powder were prepared.

Polyester resin: manufactured by Toyobo Co., Ltd. Byron (glass transition temperature = 50 ° C.) Vinyl chloride-vinyl acetate copolymer resin: manufactured by Union Carbide Vinylite VAGH Polyurethane resin: manufactured by Nippon Polyurethane Industry Co., Ltd. Nipporan 5120 Conductive Fine powder: Mitsui Mining & Smelting Co., Ltd. Pastran IV
(Average particle size = 0.1 μm) Further, in order to form the heat sealant layer, a polyurethane resin (EX7240 manufactured by Honey Chemical Industry Co., Ltd.) was prepared. Next, using each of the above materials, first,
After applying the adhesive to the PET film, the L / LDPE and S / B copolymer hydrogenated compounds shown in Tables 13 and 14 below were mixed through the LDPE layer (thickness 20 μm) by the extrusion lamination method. Intermediate layer (thickness 30 μm)
Was formed. Then, the following Table 13 and Table 14 on the intermediate layer
After forming the static electricity diffusion layer (thickness 2 μm) having the composition shown in 1) by the gravure reverse method, the heat sealant layer (thickness 0.5 μm) was formed by the gravure method, and the lid material (samples 1 to 26). It was created.

Further, a lid member (sample 27, sample 27, sample 15) was prepared in the same manner as sample 4 and sample 15 except that the heat sealant layer was not formed.
28) was prepared.

[0098]

[Table 13]

[0099]

[Table 14] Next, for each of the above-mentioned lid materials (Samples 1 to 28), in the same manner as in Example 1-A and Example 2-A, the haze degree, total light transmittance, surface resistivity, charge decay time, peeling strength and The blocking resistance was measured.

The measurement results of the above items and the peeling form of each lid material are shown in Tables 15 and 16 below.

[0101]

[Table 15]

[0102]

[Table 16] As shown in Table 15 and Table 16, each lid member of Example 3 (Samples 1 to 28) is the same as each lid member of Example 2-A (Sample 1).
The same tendency as that observed in Samples 1 to 28)
6. Samples 15 to 20 had good transparency and electrostatic characteristics, and peeling occurred between the intermediate layer and the electrostatic diffusion layer with an appropriate peeling strength. On the other hand, in Samples 7, 9 and 12, the content of the conductive fine powder was large, so that the total light transmittance was less than 75% and the transparency was poor. In addition, samples 8, 10, 22
Since the content of the conductive fine powder was small, the peel strength was lower than the appropriate strength, the surface resistivity was 10 ¹³ Ω or more, the electrification decay time was more than 2 seconds, and the material had no electrostatic property. Further, Samples 11, 12, and 24 had poor coatability because the amount of vinyl chloride-vinyl acetate copolymer resin in the static electricity diffusion layer was large. Further, since the sample 23 had a large amount of polyurethane resin, the peel strength was below the appropriate strength. Samples 13 and 25 had a slightly large amount of L.LDPE in the intermediate layer, and conversely, samples 14 and 26 had a small amount of L.LDPE.
In No. 6, the peel strength was too high. Furthermore, sample 2
Since Nos. 7 and 28 had no heat sealant layer, they had a high haze value and did not have sufficient transparency. (Example 3-B) A heat sealant layer coating solution was applied by a gravure method to form a heat sealant layer (thickness 0.5 μm).
m, a sea-island pattern (pattern shape = square, one pattern area = 0.04 mm ² ) was formed, and lid materials (samples 1 to 28) were prepared in the same manner as in Example 3-A. .
The haze, total light transmittance, surface resistivity, charge decay time, blocking resistance and peel strength of this lid material were measured in the same manner as in Example 3-A.

The measurement results and the peeling form of each lid material were the same as in Example 3-A, and thus the description thereof is omitted. (Example 3-C) Lid materials (Samples 1 to 28) were prepared in the same manner as in Example 3-A. About this lid material, Example 3-
Similar to A, haze, total light transmittance, surface resistivity,
The charge decay time, blocking resistance and peel strength were measured. The heat fusion conditions are 140 ° C, 0.4 seconds, 1.0 k
It was set to gf / cm ² .

The measurement results and peeling morphology of each lid material are shown in Tables 17 and 18 below.

[0105]

[Table 17]

[0106]

[Table 18] (Example 4-A) As a biaxially stretched resin layer, a biaxially stretched polyethylene terephthalate (PET) film (Spett 6140 manufactured by Toyobo Co., Ltd., thickness 12 μm, corona treated product) was prepared. A polyethyleneimine solution (P-100 manufactured by Nippon Shokubai Kagaku Co., Ltd.) was prepared as an adhesive. Furthermore, as an adhesive layer, low density polyethylene (LDPE) (Mitsui Petrochemical Co., Ltd. Mirason 16-
P) was prepared.

Next, in order to form an intermediate layer, a saturated polyester resin film (KS-0 manufactured by Tohcello Chemical Co., Ltd.)
11C, thickness 30 μm, glass transition temperature 50 ° C.) was prepared.

Further, in order to form the static electricity diffusion layer, the following polyurethane resin, vinyl chloride-vinyl acetate copolymer resin and conductive fine powder were prepared.

Polyurethane resin: Nippon Polyurethane Industry Co., Ltd. Nipporan 5120 Vinyl chloride-vinyl acetate copolymer resin: Union Carbide Vinylite VAGH Conductive fine powder: Mitsui Mining & Smelting Co., Ltd. Pastran IV
(Average particle size = 0.1 μm) Further, in order to form the heat sealant layer, a polyurethane resin (EX7240 manufactured by Honey Chemical Industry Co., Ltd.) was prepared. Next, using each of the above materials, first,
After applying the adhesive to the PET film, an intermediate layer (thickness: 30) made of a saturated polyester resin film is formed through an LDPE layer (thickness: 20 μm) by an extrusion lamination method.
μm) was formed. After that, an electrostatic diffusion layer (thickness 2 μm) having the composition shown in Table 19 below is formed on the intermediate layer by a gravure reverse method, and then a heat sealant layer (thickness 0.5 μm) is formed by the gravure reverse method. Then, lid materials (Samples 1 to 10) were prepared.

[0110]

[Table 19] Next, for each of the above-mentioned lid materials (Samples 1 to 10), the haze degree, total light transmittance, surface resistivity, charge decay time and peel strength were measured in the same manner as in Example 1-A.

The measurement results of the above items and the peeling form of each lid material are shown in Table 20 below.

[0112]

[Table 20] (Example 4-B) A heat sealant layer coating solution was applied by a gravure method to form a heat sealant layer (thickness 0.5 μm).
m, a sea-island pattern (pattern shape = square, one pattern area = 0.04 mm ² ) was formed, and lid materials (samples 1 to 10) were prepared in the same manner as in Example 4-A. .
The haze, total light transmittance, surface resistivity, charge decay time and peel strength of this lid material were measured in the same manner as in Example 4-A.

The measurement results and the peeling form of each lid material were the same as in Example 4-A, and thus the description thereof is omitted. (Example 4-C) Lids (Samples 1 to 10) were prepared in the same manner as in Example 4-A. About this lid material, Example 4-
Similar to A, haze, total light transmittance, surface resistivity,
The charge decay time and peel strength were measured. The heat fusion conditions were 140 ° C., 0.4 seconds and 1.0 kgf / cm ² .

The measurement results and peeling morphology of each lid material are shown in Table 21 below.

[0115]

[Table 21] (Example 5) As a biaxially stretched resin layer, a biaxially stretched polyester film (Tetoron Tetron Co., Ltd., thickness 16 μm)
An intermediate layer, an electrostatic diffusion layer, and a heat sealant layer were formed on one surface of the biaxially stretched polyester film in the same manner as in Sample 15 of Example 2-A except that m) was used.

Next, the following two types of antistatic agents were prepared as antistatic agents.

Nippon Oil & Fats Co., Ltd. New Elegan A (cationic) ... A Catalytic Chemicals Co., Ltd. ELCOM P3501 ... B Further, as an antireflection film, an antireflection film coating having the following composition Prepared. (Composition of coating for antireflection film) Magnesium fluoride 30 parts by weight Polyester resin (Vylon manufactured by Toyobo Co., Ltd.) (Glass transition temperature 50 ° C) 20 parts by weight Solvent (toluene / methyl ethyl ketone = 1/1) 50 By weight, an antistatic agent is applied by a gravure reverse method to the surface opposite to the surface on which the intermediate layer, the static electricity diffusion layer and the heat sealant layer of the biaxially stretched polyester film are formed to form an antistatic layer (thickness: 0.5 μm). ) Is formed on the antistatic layer, and a coating for an antireflection film is applied to the antistatic layer by a gravure reverse method to form an antireflection film (thickness 0.1 μm). Created.

Next, for each of the above-mentioned lid materials (Samples 1 and 2), the haze degree, total light transmittance, surface resistivity and charge decay time were measured in the same manner as in Example 1-A and Example 2-A. It was measured.

Table 22 below shows the measurement results of the above items and the presence / absence of surface reflection for each lid member.

[0120]

[Table 22] As shown in Table 22, Samples 1 to 1 each provided with an antireflection layer
In No. 2, there was no surface reflection, and it was possible to effectively prevent irregular reflection in the lid material and shadowing of the light source.

[0121]

As described in detail above, according to the present invention, the static electricity diffusion layer is located between the biaxially stretched resin layer and the heat sealant layer, which is adjacent to the heat sealant layer constituting the lid member. Since the intermediate layer is located between the biaxially stretched resin layer and the static electricity diffusion layer adjacent to the diffusion layer, the lid material is provided with excellent static electricity characteristics, and the contents are destroyed by static electricity.
Deterioration can be prevented, and when peeling the lid material, peeling occurs between the intermediate layer and the electrostatic diffusion layer, or inside the electrostatic diffusion layer or between the electrostatic diffusion layer and the heat sealant layer. Good peelability can be obtained while maintaining high adhesiveness of the heat sealant layer, and it becomes easy to set the conditions for heat-sealing the lid member to the synthetic resin container. Furthermore, by forming the heat sealant layer in a sea-island pattern, it is possible to reduce the raw material for the heat sealant layer and reduce the manufacturing cost.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a lid member of the present invention.

FIG. 2 is a schematic cross-sectional view showing another example of the lid material of the present invention.

FIG. 3 is a schematic cross-sectional view showing another example of the lid material of the present invention.

FIG. 4 is a diagram showing an example of a pattern shape of a heat sealant layer of the lid material of the present invention.

FIG. 5 is a diagram showing another example of the pattern shape of the heat sealant layer of the lid material of the present invention.

FIG. 6 is a perspective view showing a state in which the lid member of the present invention is heat-sealed on a carrier tape.

7 is a sectional view taken along line VII-VII of FIG.

FIG. 8 is a view corresponding to FIG. 7, showing a state in which the lid member is peeled off from the carrier tape.

FIG. 9 is a view corresponding to FIG. 7, showing a state in which the lid member is peeled off from the carrier tape.

FIG. 10 is a schematic cross-sectional view showing another example of the lid material of the present invention.

FIG. 11 is a schematic cross-sectional view showing another example of the lid material of the present invention.

[Explanation of symbols]

 1, 21 ... Lid material 2, 22 ... Biaxially stretched resin layer 3, 23 ... Adhesive layer 4, 24 ... Intermediate layer 4a ... First resin layer 4b ... Second resin layer 4c ... Third resin layer 5, 25 ... Static electricity Diffusion layer 6, 26 ... Heat sealant layer 11 ... Carrier tape 12 ... Embossed portion 27 ... Antireflection film 28 ... Antistatic layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B32B 27/00 104 8413-4F 27/32 103 8115-4F B65D 65/40 D

Claims (23)

[Claims] 1. A biaxially stretched resin layer, a heat sealant layer, an electrostatic diffusion layer adjacent to the heat sealant layer and located between the biaxially stretched resin layer and the heat sealant layer, and the electrostatic diffusion layer. And a middle layer located between the biaxially stretched resin layer and the static electricity diffusion layer. 2. The lid member according to claim 1, wherein the heat sealant layer is formed on the entire one surface of the lid member. 3. The heat sealant layer is formed in a sea-island pattern on one surface of the lid member, and 1
The lid material according to claim 1, wherein the area of each sea-island pattern is in the range of 0.01 to 0.5 mm ² . 4. The intermediate layer has a density of 0.915 to 0.94.
0 g / cm ³ ethylene-α / olefin copolymer, styrene-butadiene block copolymer of styrene 50 to 90% by weight and butadiene 50 to 10% by weight, styrene 1
A hydrogenated product of a styrene-butadiene block copolymer of 0 to 50% by weight and 90 to 50% by weight of butadiene, and at least an ethylene-α-olefin copolymer and a styrene-butadiene block copolymer among high-impact polystyrene. The lid member according to any one of claims 1 to 3, which is formed of three or more kinds of resins. 5. The intermediate layer has a single layer structure and a density of 0.9.
70 to 30% by weight of a styrene-butadiene block copolymer of 30 to 70% by weight of an ethylene-α-olefin copolymer of 15 to 0.940 g / cm ³ , 50 to 90% by weight of styrene and 50 to 10% by weight of butadiene. % With respect to 100 parts by weight of the resin composition, 5 to 30 parts by weight of hydrogenated product of styrene-butadiene block copolymer of 10 to 50% by weight of styrene and 90 to 50% by weight of butadiene, and high impact polystyrene 5 The lid material according to claim 4, wherein the lid material is formed of a resin composition to which -50 parts by weight is added. 6. The intermediate layer has a single layer structure and a density of 0.9.
70 to 30% by weight of a styrene-butadiene block copolymer of 30 to 70% by weight of an ethylene-α-olefin copolymer of 15 to 0.940 g / cm ³ , 50 to 90% by weight of styrene and 50 to 10% by weight of butadiene. % Of a resin composition of 100% by weight, and 5 to 30 parts by weight of a hydrogenated product of a styrene-butadiene block copolymer of 10 to 50% by weight of styrene and 90 to 50% by weight of butadiene. The lid member according to claim 4, wherein the lid member is formed of a composition. 7. The intermediate layer has a single layer structure and a density of 0.9.
70 to 30% by weight of a styrene-butadiene block copolymer of 30 to 70% by weight of an ethylene-α-olefin copolymer of 15 to 0.940 g / cm ³ , 50 to 90% by weight of styrene and 50 to 10% by weight of butadiene. % High-impact polystyrene 5 to 100 parts by weight of the resin composition
The lid material according to claim 4, wherein the lid material is formed of a resin composition to which -50 parts by weight is added. 8. The intermediate layer has a two-layer structure of a first resin layer and a second resin layer in contact with the heat sealant layer, and the first resin layer has a density of 0.915 to 0.940 g / cm ³ . The second resin layer is formed of an ethylene-α-olefin copolymer, and the second resin layer has an ethylene-α-olefin copolymer density of 0.915 to 0.940 g / cm ³ 30 to 70% by weight.
And 50 to 90% by weight of styrene and 50 to 10 of butadiene
Styrene-butadiene block copolymer with 70% by weight
10 to 50% by weight of styrene and 90 to 50% by weight of butadiene based on 100 parts by weight of the resin composition of 30 to 30% by weight.
The lid material according to claim 4, which is formed of a resin composition to which 5 to 30 parts by weight of a hydrogenated product of a styrene-butadiene block copolymer with is added. 9. The intermediate layer has a two-layer structure of a first resin layer and a second resin layer in contact with the heat sealant layer, and the first resin layer has a density of 0.915 to 0.940 g / cm ³ . The second resin layer is formed of an ethylene-α-olefin copolymer, and the second resin layer has an ethylene-α-olefin copolymer density of 0.915 to 0.940 g / cm ³ 30 to 70% by weight.
And 50 to 90% by weight of styrene and 50 to 10 of butadiene
Styrene-butadiene block copolymer with 70% by weight
5. The lid material according to claim 4, which is formed of a resin composition in which 5 to 50 parts by weight of high-impact polystyrene is added to 100 parts by weight of the resin composition of 30 to 30% by weight. . 10. The intermediate layer has a two-layer structure of a first resin layer and a second resin layer in contact with the heat sealant layer,
The first resin layer has a density of 0.915 to 0.940 g / cm ³
Formed of an ethylene-α / olefin copolymer of
The second resin layer has a density of 0.915 to 0.940 g / cm ^3.
Ethylene-α / olefin copolymer of 30 to 70% by weight
And 50 to 90% by weight of styrene and 50 to 10 of butadiene
Styrene-butadiene block copolymer with 70% by weight
10 to 50% by weight of styrene and 90 to 50% by weight of butadiene based on 100 parts by weight of the resin composition of 30 to 30% by weight.
5 to 30 parts by weight of a hydrogenated product of a styrene-butadiene block copolymer with
The lid member according to claim 4, wherein the lid member is formed of a resin composition to which 50 parts by weight is added. 11. The intermediate layer has a three-layer structure including a first resin layer, a second resin layer, and a third resin layer in contact with the heat sealant layer, and the first resin layer has a density of 0.915 to 0. 9
The second resin layer is formed of a 40 g / cm ³ ethylene-α-olefin copolymer, and the second resin layer has a density of 0.915 to 0.9.
40 g / cm ³ of ethylene-α / olefin copolymer 30
Of 70 to 30% by weight, 70 to 30% by weight of styrene-butadiene block copolymer of 50 to 90% by weight of styrene and 50 to 10% by weight of butadiene, and the third resin layer has a density of 0. .915-0.940 g /
ethylene-.alpha. · olefin copolymer 30-70 wt% of cm ^3, styrene 50-90% by weight of butadiene 50
10 to 50% by weight of styrene and 90 to 50% of butadiene based on 100 parts by weight of the resin composition containing 70 to 30% by weight of the styrene-butadiene block copolymer with 10% by weight.
The lid material according to claim 4, which is formed of a resin composition to which 5 to 30 parts by weight of a hydrogenated product of a styrene-butadiene block copolymer with 5% by weight is added. 12. The intermediate layer has a three-layer structure of a first resin layer, a second resin layer, and a third resin layer in contact with the heat sealant layer, and the first resin layer has a density of 0.915 to 0. 9
The second resin layer is formed of a 40 g / cm ³ ethylene-α-olefin copolymer, and the second resin layer has a density of 0.915 to 0.9.
40 g / cm ³ of ethylene-α / olefin copolymer 30
Of 70 to 30% by weight, 70 to 30% by weight of styrene-butadiene block copolymer of 50 to 90% by weight of styrene and 50 to 10% by weight of butadiene, and the third resin layer has a density of 0. .915-0.940 g /
ethylene-.alpha. · olefin copolymer 30-70 wt% of cm ^3, styrene 50-90% by weight of butadiene 50
It is formed of a resin composition in which 5 to 50 parts by weight of high-impact polystyrene is added to 100 parts by weight of the resin composition of 10 to 30% by weight of a styrene-butadiene block copolymer and 70 to 30% by weight. The lid material according to claim 4, wherein 13. The intermediate layer has a three-layer structure of a first resin layer, a second resin layer, and a third resin layer in contact with the heat sealant layer, and the first resin layer has a density of 0.915 to 0. 9
The second resin layer is formed of a 40 g / cm ³ ethylene-α-olefin copolymer, and the second resin layer has a density of 0.915 to 0.9.
40 g / cm ³ of ethylene-α / olefin copolymer 30
Of 70 to 30% by weight, 70 to 30% by weight of styrene-butadiene block copolymer of 50 to 90% by weight of styrene and 50 to 10% by weight of butadiene, and the third resin layer has a density of 0. .915-0.940 g /
ethylene-.alpha. · olefin copolymer 30-70 wt% of cm ^3, styrene 50-90% by weight of butadiene 50
10 to 50% by weight of styrene and 90 to 50% of butadiene based on 100 parts by weight of the resin composition containing 70 to 30% by weight of the styrene-butadiene block copolymer with 10% by weight.
% Of hydrogenated styrene-butadiene block copolymer and 5 to 50 parts by weight of high-impact polystyrene, and 5 to 50 parts by weight of the resin composition. Item 4. The lid member according to item 4. 14. The intermediate layer has a density of 0.915 to 0.9.
40 g / cm ³ of ethylene-α / olefin copolymer 30
To 70 parts by weight, and 70 to 30 parts by weight of a styrene-butadiene block copolymer of 50 to 90% by weight of styrene and 50 to 10% by weight of butadiene are added. The lid member according to any one of claims 1 to 3. 15. The intermediate layer has a density of 0.915 to 0.9.
40 g / cm ³ of ethylene-α / olefin copolymer 30
To 70 parts by weight and 70 to 30 parts by weight of a styrene-butadiene block copolymer hydrogenated product of 10 to 50% by weight of styrene and 90 to 50% by weight of butadiene. The lid member according to any one of claims 1 to 3, wherein 16. The intermediate layer has a glass transition temperature of 40 ° C.
The lid material according to any one of claims 1 to 3, which is formed of the linear saturated polyester resin described above. 17. The heat sealant layer contains at least one of a polyester resin, a polyurethane resin, a vinyl chloride-vinyl acetate copolymer resin, and an acrylic resin, according to any one of claims 1 to 16. The lid material described in the crab. 18. The electrostatic diffusion layer is a layer containing at least one of carbon black, metal fine particles, conductive fine particles, a Si-based organic compound and a surfactant in a thermoplastic resin. Claims 1 to 17
The lid material according to any one of 1. 19. The thermoplastic resin forming the static electricity diffusion layer contains at least one of a polyester resin, a polyurethane resin, a vinyl chloride-vinyl acetate copolymer resin, and an acrylic resin. The lid material described in. 20. The electrostatic diffusion layer has a surface resistivity of 1
The lid material according to any one of claims 1 to 19, wherein the charge decay time is within a range of 0 ⁵ to 10 ¹² Ω, and the charge decay time is 2 seconds or less. 21. The lid member according to claim 1, further comprising an antireflection film on the biaxially stretched resin layer. 22. An antistatic layer is provided between the biaxially stretched resin layer and the antireflection film.
The lid material according to 1. 23. The lid member according to claim 1, wherein the total light transmittance is 75% or more and the haze value is 50% or less.