JP2019023102A - Transparent antistatic packing material and packing bag using packing material - Google Patents

Abstract

To provide packing material, a packing film, and a packing bag which have a good heat sealing property, a steady adhesive property and a good peelability, and further have an excellent antistatic property and transparency.SOLUTION: Transparent antistatic packing material 1 of this invention has a base material layer 2, an inorganic vapor deposition layer 3, and an antistatic sealant layer 6b which is the most surface layer that is the face of the side opposed to the base material layer of the packing material. The antistatic sealant layer includes electro conductive metallic oxide particles and thermoplastic elastomer having a heat sealing property so that a good antistatic property and a good heat sealing property are appeared.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heat-sealing packaging material having antistatic properties and transparency, and a packaging bag using the packaging material. Specifically, the packaging material comprises a base material layer, a sealant layer, and inorganic vapor deposition. A transparent charging material, wherein the sealant layer has at least an antistatic sealant layer, and the antistatic sealant layer is an outermost surface layer on a surface opposite to the base material layer of the packaging material. It relates to prevention packaging materials. The transparent antistatic packaging material can be used for packaging materials such as various packaging bags and carrier tape cover tape materials, etc., and the products to be packaged include semiconductors, IC components and products using these, and liquid crystal displays. Examples include parts, liquid crystal products, syringes, medical-related articles for pharmaceuticals, and automobile parts.

Conventionally, various parts, solid or liquid food, etc. are stored in a synthetic resin container and the opening is sealed with a lid material, or stored in a bag body and sealed, distributed and stored. Yes.
As a package, for example, a bag-shaped package (packaging bag) produced by folding and sealing one kind of packaging material and heat sealing a bottom material and a lid material made of different materials. Some of them are like embossed carrier tape type taping sealed.

  As the material composition of the packaging material, the carrier tape (bottom material) used for embossed carrier tape type taping has been conventionally formed using a material that is easy to form a sheet such as polyvinyl chloride. Has a problem of disposal, and therefore, there is an increasing tendency to use polystyrene resin for carrier tape. On the other hand, a cover tape (cover material) used for embossed carrier tape-type taping and the above bag-shaped package are made of a packaging material including, for example, a biaxially stretched resin film and a sealant layer on one side. Yes.

The package is required to have a certain level of adhesive strength at the heat-sealed portion so that the heat-sealed portion is not peeled off during transportation or storage, and the stored contents do not spill out. At the same time, in order to easily take out the contents once stored, the heat seal portion is also required to be peelable.
Furthermore, when the stored contents are electronic parts, the electronic parts are deteriorated due to static electricity generated when the electronic parts come into contact with the inner wall of the package and static electricity generated when the package is peeled off. Due to the risk of breakage, packaging materials are required to prevent this.

  As a measure against static electricity in packaging materials, antistatic agents such as surfactants, conductive carbon fine particles, conductive metal oxide powders, and metal fine particles are kneaded into the packaging material or applied onto the packaging material. It has been broken.

Moreover, the packaging material containing conductive carbon fine particles and metal fine particles as an antistatic agent has a problem that transparency is extremely low and it is difficult to visually recognize the contents stored in the package from the outside.
A method of using metal oxide fine particles having an average particle size of 0.1 μm or less as an antistatic agent (Patent Document 1) is known as a method for achieving both sufficient transparency and antistatic performance. When the shape of the fine particles is spherical, in order to obtain sufficient antistatic performance, the addition amount of the metal oxide fine particles must be increased, and there are problems such as a decrease in transparency and coloring. Not achieved.

On the other hand, when trying to set the surface resistivity of the packaging material in the region of about 10 ⁹ Ω / □, on the contrary, since the amount of practically added metal oxide fine particles is small, There was a problem that the contact between the metal oxide fine particles became insufficient, and the surface resistivity of the coating film was not stable.

  In addition, when an antistatic surfactant is applied to the packaging material, not only when it is applied directly to the sealant layer, but also when it is wound or stacked even when applied to the surface opposite to the sealant layer The surface active agent is transferred to the sealant layer, and the surface condition of the sealant layer changes and the sealability of the sealant layer becomes unstable, which may cause a seal failure, and the temperature and humidity during storage. Since the electrostatic diffusion effect varies greatly depending on conditions, there is a problem that a stable antistatic effect cannot be obtained.

Japanese Patent Laid-Open No. 7-251860

  The present invention provides a packaging material, a packaging film, and a packaging bag that have good heat sealability, stable adhesiveness, and good peelability, and have both excellent antistatic properties and transparency. Objective.

The transparent antistatic packaging material of the present invention includes a base material layer, an inorganic vapor-deposited layer, and a sealant layer, and the sealant layer is an antistatic sealant on the outermost surface layer of the packaging material opposite to the base material layer. The antistatic sealant layer includes conductive metal oxide particles and a heat-sealable thermoplastic elastomer, and exhibits antistatic properties and heat-seal properties.
The present invention is characterized by the following points.

1. A transparent antistatic packaging material having a base material layer, an inorganic vapor deposition layer, and a sealant layer,
The sealant layer has at least an antistatic sealant layer,
The antistatic sealant layer is the outermost surface layer on the surface opposite to the base material layer of the transparent antistatic packaging material,
The antistatic sealant layer contains conductive metal oxide particles and a heat-sealable thermoplastic elastomer,
The transparent antistatic packaging material has a total light transmittance of 70% or more and 95% or less,
The transparent antistatic packaging material has a water vapor permeability of 0.01 g / m ² / day / atm or more and 2.0 g / m ² / day / atm or less in a 40 ° C. and 90% RH environment,
The surface resistivity of the antistatic sealant layer is 1 × 10 ⁷ Ω / □ or more and 1 × 10 ¹⁰ Ω / □ or less.
Transparent antistatic packaging material.
2. 2. The transparent antistatic packaging material according to 1 above, wherein the content of the conductive metal oxide particles in the antistatic sealant layer is 40% by mass or more and 80% by mass or less.
3. The conductive metal oxide particles have an average particle size of 0.2 to 2.0 μm in the major axis direction, 0.01 to 0.02 μm in the minor axis direction, 3. The transparent antistatic packaging material according to 1 or 2 above, wherein the axis / short axis ratio is 20 or more and 30 or less.
4). The conductive metal oxide particles are one or more selected from the group consisting of antimony-doped tin oxide, tin-doped indium oxide, fluorine-doped tin oxide, gallium-doped zinc oxide, and aluminum-doped zinc oxide. 4. The transparent antistatic packaging material according to any one of 1 to 3 above.
5. The glass transition temperature of the heat-sealable thermoplastic elastomer is −60 ° C. or higher, −
The transparent antistatic packaging material according to any one of 1 to 4, which is 30 ° C or lower.
6). The transparent antistatic packaging material according to any one of 1 to 5 above, wherein a tensile elastic modulus of the heat-sealable thermoplastic elastomer is 1.5 MPa or more and 10 MPa or less at 23 ° C.
7). The transparent antistatic packaging material according to any one of 1 to 6, wherein the heat-sealable thermoplastic elastomer is a SEBS-based block polymer.

  According to the present invention, it is possible to obtain a packaging material, a packaging film, and a packaging bag that have good heat sealability, stable adhesiveness, and good peelability, and have both excellent antistatic properties and transparency. .

It is a figure which shows the example of the laminated structure of the transparent antistatic packaging material of this invention. It is a figure which shows the example of the laminated structure of the transparent antistatic packaging material of this invention.

Embodiments of the present invention will be described below with reference to the drawings. The present invention is not limited to the specific examples and figures listed below.
FIG.1 and FIG.2 is sectional drawing which shows the example of the laminated structure of the packaging material of this invention. The laminated structure in FIG. 1 is a layer structure in which a base material layer, an inorganic vapor deposition layer, an adhesive layer, an insulating sealant layer, and an antistatic sealant layer are sequentially laminated. The laminated structure in FIG. 2 is a layer structure in which an intermediate layer and an adhesive layer for bonding the intermediate layer are added to the packaging material shown in FIG.

The packaging material of the present invention includes a base material layer, an inorganic vapor deposition layer, and a sealant layer, and the sealant layer includes an antistatic sealant layer on the outermost surface layer on the side opposite to the base material layer of the packaging material. However, in addition to these, an intermediate layer, an adhesive layer, and a normal insulating sealant layer can also be included.
The transparent antistatic packaging material of the present invention is transparent, and the total light transmittance according to JIS K7361-1 is 70% or more and 95% or less, preferably 80% or more and 93% or less. When reading the barcode printed on the contents of the transparent antistatic packaging material of the present invention, if the packaging material is transparent, the input terminal can be applied to the correct position by visual inspection and can be read accurately. Customs processing is possible without opening at customs at the time. When the transmittance of the laser beam having the above wavelength is lower than the above range, a reading error is likely to occur, and when the transmittance is higher than the above range, it is difficult to balance the antistatic property.

  The temperature when heat-sealing the packaging material of the present invention is preferably 100 ° C. or higher and 180 ° C. or lower, more preferably 120 ° C. or higher and 160 ° C. or lower. If the temperature is lower than the above range, a sufficient molten state cannot be obtained, the heat sealability is lowered, and the thickness of the sealant layer tends to be uneven. If the temperature is higher than the above range, the melt viscosity becomes too low and the adjustment of the thickness of the sealant layer tends to be difficult.

The water vapor permeability of the transparent antistatic packaging material of the present invention in an environment of 40 ° C. and 90% RH is 0.01 g / m ² / day / atm or more and 2.0 g / m ² / day / atm or less. Preferably, it is 0.1 g / m ² / day / atm or more and 1.0 g / m ² / day / atm or less.
When the contents to be packaged are electronic parts, chemicals, etc., some are preferably stored under low humidity, and it is necessary to prevent the inflow of moisture from the external environment after packaging.
When the water vapor transmission rate is larger than the above range, the contents are easily affected by moisture. When the water vapor transmission rate is smaller than the above range, it is difficult to balance the transparency and the laser light transmittance.
Next, each layer of the packaging material of the present invention will be described.

<Base material layer>
As a base material layer, a metal or metal oxide that has excellent chemical or physical strength, can withstand the conditions for forming an inorganic vapor-deposited film, etc., and can be retained well without impairing the properties of the inorganic vapor-deposited film For example, an inorganic material such as a resin or an organic material such as a resin can be used as a film or a sheet. In addition, in this invention, the word film is described as a general term including a film and a sheet.
Specific examples of the film preferably used as the base material layer include paper, aluminum foil, and resin film.
As a base material layer, although a single layer film or a multilayer laminated film is used, it is not particularly limited, and any film used for various packaging materials can be used. Among these, a suitable one is freely selected and used according to the use conditions such as the type of contents to be packaged and the presence or absence of heat treatment after filling.

(Resin film)
Examples of the resin used for the resin film include cellophane, polyamide resin (nylon 6, nylon 66, MXD6 (polymetaxylylene adipamide), etc.), polyester resin (polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate). (PEN), etc.), polyolefin resins (low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, polypropylene, polybutene, polypropylene, acid-modified polyolefin resins, etc.), polystyrene resins, polyurethane resins, Acetal resin, polyvinyl alcohol, ethylene-vinyl acetate copolymer, ionomer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer, ethylene- Lopylene copolymer, methylpentene, polyacrylonitrile, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, polycarbonate, polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polyvinylidene fluoride (PVDF), Ethylene-tetrafluoroethylene copolymer (ETFE), polytetrafluoroethylene (PTFE), polyimide (PI), polyethersulfone (PES), polyetheretherketone (PEEK), polyetherimide (PEI), polyphenylene sulfide ( PPS), polyarylate (PA), polyester ether (PEE), polyamideimide (PAI) and the like.

  The resin film used for the base material layer uses, for example, one or more kinds of resins selected from the group of the above-mentioned resins, and the conventional methods such as extrusion method, cast molding method, T-die method, cutting method, and inflation method The composite film can be produced by the film-forming method used from the above, or by the multilayer co-extrusion film-forming method using two or more resins. Furthermore, from the viewpoint of the strength, dimensional stability, and heat resistance of the film, the film can be stretched uniaxially or biaxially using, for example, a tenter method or a tubular method. When it is desired to impart heat resistance, it is preferable to stretch in the biaxial direction.

  In particular, transparent vapor-deposited PET such as silica-deposited PET and alumina-deposited biaxially stretched PET, aluminum-deposited biaxially-stretched polypropylene film (OPP), and the like are suitable. Further, it is more preferable to use a nylon film or the like together.

  Although the thickness of a base material layer can be selected arbitrarily, from a moldability and transparency viewpoint, it can select and use from the range of about 1 micrometer to 300 micrometers, and the range of 1 micrometer or more and 100 micrometers or less is preferable. If it is thinner than this, the strength is insufficient, and if it is thicker than this, the rigidity becomes too high, and the processing may be difficult.

  Moreover, in order to improve the adhesion at the time of lamination, the base material layer and the film constituting the base material layer are preliminarily subjected to corona discharge treatment, ozone treatment on the surface to be laminated before lamination or vapor deposition. , Physical treatment such as low temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, chemical treatment such as oxidation treatment using chemicals, adhesive layer, primer coating agent layer, under You may perform the process which forms a coating layer or a vapor deposition anchor coating agent layer, and other processes.

  The resin film used for the base material layer has processability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant properties, slipperiness, release properties, flame retardancy, and antifungal properties as necessary. For the purpose of improving and modifying electrical properties, strength, etc., plastic compounding agents such as lubricants, crosslinking agents, antioxidants, UV absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, etc. Additives and the like can be added, and the amount added can be arbitrarily added according to the purpose within a range that does not adversely affect other performances.

(Inorganic vapor deposition layer)
An inorganic vapor deposition layer is a barrier film which has gas barrier property which prevents permeation | transmission of water vapor | steam etc., and the vapor deposition film which consists of an inorganic substance or an inorganic oxide is mentioned.
The inorganic vapor deposition layer is preferably a layer having one or more selected from the group consisting of an aluminum vapor deposition layer, an alumina vapor deposition layer, and a silica vapor deposition layer, and particularly preferably an alumina vapor deposition layer.

The inorganic vapor deposition layer can be directly provided on any of the film constituting the base material layer, the film constituting the intermediate layer, and the film constituting the sealant layer. For example, it is preferably configured on a PET film of a base material layer or an intermediate layer.
Furthermore, if necessary, light shielding properties that prevent the transmission of ultraviolet rays or the like can be imparted. Moreover, the inorganic vapor deposition layer may be comprised by 1 layer or 2 layers or more. When composed of two or more layers, each may have the same composition or a different composition.

  The thickness of the inorganic vapor deposition layer is preferably 1 nm or more and 200 nm or less, and the more preferable thickness varies depending on the vapor deposition species, but in the case of an aluminum vapor deposition film, it is more preferably 1 nm or more and 100 nm or less. Is from 15 nm to 60 nm, particularly preferably from 10 nm to 40 nm. In the case of a silica vapor deposition film or an alumina vapor deposition film, it is more preferably 1 nm or more and 100 nm or less, still more preferably 5 nm or more and 50 nm or less, and particularly preferably 10 nm or more and 30 nm or less.

If the inorganic vapor deposition layer is thinner than the above range, sufficient gas barrier properties due to the inorganic vapor deposition layer are difficult to be exhibited, and if it is thicker than the above range, the transparency tends to be impaired.
An inorganic vapor deposition layer can be formed by a conventionally well-known method using a conventionally well-known inorganic substance or inorganic oxide, The composition and formation method are not specifically limited.
Examples of the forming method include physical vapor deposition methods (Physical Vapor Deposition method, PVD method) such as vacuum deposition method, sputtering method, and ion plating method, plasma chemical vapor deposition method, thermal chemical vapor deposition method, And chemical vapor deposition (chemical vapor deposition, CVD) such as photochemical vapor deposition.

<Intermediate layer>
An intermediate | middle layer is a layer provided in the middle of a base material layer and a sealant layer as needed. For example, in order to improve various strengths of packaging materials, a resin film according to the purpose can be included as an intermediate layer, and characters, figures, symbols, and other desired patterns can be arbitrarily selected by a normal printing method. A formed printing layer can also be provided. The kind of film used and the lamination method are the same as those of the base material layer.
It is also possible to form various resins by applying them to the base material layer and the sealant layer.

<Sealant layer>
The packaging material of the present invention has a sealant layer, and the sealant layer has at least an antistatic sealant layer and, if necessary, an insulating sealant layer.

[Antistatic sealant layer]
The antistatic sealant layer is the outermost surface layer on the side opposite to the base material layer of the packaging material, and has a configuration in which conductive metal oxide particles are dispersed in a binder resin. It is a layer having a sealing property.
For example, a packaging bag formed by being folded and heat-sealed so that the antistatic sealant layer is opposed to each other exhibits an antistatic property on the inner wall of the packaging bag and is contained by having the antistatic sealant layer. Electronic parts and the like can be prevented from being destroyed by static electricity.
In the present invention, the lamination method for forming the antistatic sealant layer is not particularly limited, and a known or common lamination method can be applied.

  For example, using a coating solution or composition containing conductive metal oxide particles, a binder resin and a solvent, air doctor method, blade coating method, knife coating method, rod coating method, direct roll coating method, reverse roll coating method, Lamination methods such as gravure coating and slide coating, and resin compositions that form an antistatic sealant layer can be applied onto a substrate layer, intermediate layer, or insulating sealant layer, optionally via an adhesive layer. Lamination method by coating with a coating, a base layer, a resin or resin composition for an intermediate layer, a resin or resin composition for an insulating sealant layer, a lamination method by coextrusion by an inflation method or a cast method, Product obtained by pasting an antistatic sealant film or sheet prepared in advance through an adhesive layer Method, and the like.

Among the above, the antistatic sealant layer is preferably a coating film layer formed by coating.
Further, before the lamination, the surface to be laminated may be subjected to a surface treatment such as a corona treatment or a plasma treatment in advance, if necessary, to enhance the adhesion.
Furthermore, the antistatic sealant layer may contain additives such as a dispersion stabilizer and an antiblocking agent as necessary.
The thickness of the antistatic sealant layer is preferably from 0.3 μm to 5.0 μm, and more preferably from 0.5 μm to 3.0 μm. If the thickness is thinner than the above, the cushioning property at the time of heat sealing is poor and it becomes difficult to apply heat and pressure uniformly.Furthermore, the heat seal strength is insufficient. Larger, high-speed heat sealing becomes difficult, and productivity decreases.

The surface resistivity of the antistatic sealant layer is preferably 1 × 10 ⁷ Ω / □ or more and 1 × 10 ¹⁰ Ω / □ or less, preferably 1 × 10 ⁸ Ω / □ or more, at 22 ° C. and 40% RH. 10 ¹⁰ Ω / □ or less is more preferable. If the surface resistivity is larger than the above range, the antistatic effect tends to be extremely deteriorated, and it is difficult to protect the contents such as electronic components from static electricity damage. This is not preferable because electricity may be applied to the electronic component from the outside through the packaging material, and the electronic component may be electrically destroyed.

(Binder resin)
The binder resin used for the antistatic sealant layer preferably includes a heat-sealable thermoplastic elastomer. The molecular structure of heat-sealable thermoplastic elastomers is composed of hard block resin and soft block resin, and these block polymers are non-three-dimensionally cross-linked to provide thermoplasticity and adhesion. Furthermore, it exhibits low elasticity (rubber elasticity).

  Examples of the hard block resin include styrene, polyester, polyurethane, polyamide, and vinyl chloride. Examples of the soft block resin include polymers of conjugated diene compounds such as isoprene and butadiene and copolymers thereof, butylene and ethylene. Examples thereof include polymers of olefin compounds such as these, copolymers thereof, polyethers, and polyesters. Specific combinations of hard block resins and soft block resins include SBS (styrene, butadiene, styrene) block polymers, SEBS (styrene, ethylene, butylene, styrene) block polymers, and their Examples include hydrogenated products. Among the above combinations, SEBS block polymers are preferable.

  The glass transition temperature of the heat-sealable thermoplastic elastomer is preferably −60 ° C. or higher and −30 ° C. or lower, more preferably −50 ° C. or higher and −40 ° C. or lower. When the glass transition temperature is higher than the above range, it is difficult to exhibit sufficient heat sealing properties, and when it is lower than the above range, problems such as stickiness and blocking are likely to occur.

  The tensile elastic modulus of the heat-sealable thermoplastic elastomer is preferably 1.5 MPa or more and 10 MPa or less, more preferably 2 MPa or more and 6 MPa or less at 23 ° C. Even if the tensile elastic modulus is higher or lower than the above range, the elastic modulus of the antistatic sealant layer becomes too high or too low, resulting in poor cushioning during heat sealing and heat and pressure. It becomes difficult to apply uniformly, and the thickness of the sealant layer is not stable, so that the heat seal strength is difficult to stabilize.

  The tensile strength of the heat-sealable thermoplastic elastomer is preferably 15 MPa or more and 40 MPa or less, more preferably 20 MPa or more and 35 MPa or less at 23 ° C. When the tensile strength is higher than the above range, the unsealing property is inferior. When the tensile strength is lower than the above range, the heat seal strength is low, and peeling failure during transportation tends to occur.

The MFR (Melt Flow Rate) of the heat-sealable thermoplastic elastomer is preferably 2 g / 10 min or more and 40 g / 10 min or less, more preferably 4 g / 10 min or more and 30 g / 10 min or less at 230 ° C. and 5 kg load. . When the MFR is higher than the above range, the heat sealability is inferior. When the MFR is lower than the above range, it is difficult to adjust the thickness of the antistatic sealant layer and the laminating workability tends to be inferior.
Specific examples of commercially available heat-sealable thermoplastic elastomers include G1657 (SEBS block polymer) and G1652 (SEBS block polymer) manufactured by Kraton Polymer Japan Co., Ltd.
In addition, the binder resin may be used by mixing a heat-sealable thermoplastic elastomer and a resin used for a normal insulating sealant layer, if necessary.

(Conductive metal oxide particles)
Examples of the conductive metal oxide particles used in the antistatic sealant layer include antimony-doped tin oxide (ATO), tin-doped indium oxide (ITO), fluorine-doped tin oxide (FTO), gallium-doped zinc oxide, and aluminum-doped zinc oxide ( AZO), and the like. Among them, fine needle-like ones are preferable, and fine needle-like antimony-doped tin oxide is particularly preferable. These conductive metal oxide particles can easily cause the packaging material to exhibit stable and good antistatic properties that do not depend on humidity.

In the present invention, the conductive metal oxide particles are mixed with a binder resin together with a solvent to form an antistatic sealant layer in a form dispersed in the binder resin.
The content of the conductive metal oxide particles in the antistatic sealant layer is preferably 40% by mass or more and 80% by mass or less, and more preferably 50% by mass or more and 70% by mass or less. By containing the conductive metal oxide particles in a proportion within the above range, it is easy to balance the good antistatic performance, heat sealability and transparency.

When the content is lower than the above range, it is difficult to obtain a sufficient antistatic effect. When the content is higher than the above range, the melt viscosity of the antistatic sealant layer is excessively increased and the heat sealability is lowered. It tends to become a tendency and transparency tends to be lowered.
The primary particles of the conductive metal oxide particles preferably have a particle size of 0.2 μm or more and 0.4 μm or less, a major axis direction particle size of 0.2 μm or more and 2 μm or less, and a minor axis direction particle size of The needle shape is 0.01 μm or more and 0.02 μm or less, and the major axis / minor axis ratio is 20 or more and 30 or less.
When the primary particles of the conductive metal oxide particles are needle-shaped within the above range, they are in contact with each other in a smaller amount in the antistatic sealant layer than when a spherical conductive filler is used. Excellent antistatic properties because of its small size, and its small size and small quantity make the antistatic sealant layer easily colorless and transparent, excellent in the visibility of the contents, and low in the barcode reading error rate of the contents, excellent It becomes easy to give packaging materials.

  As the conductive metal oxide particles used in the present invention, for example, commercially available products from Ishihara Techno Co., Ltd., fine acicular antimony-doped tin oxide is MPT270 (MEK dispersion, solid content 30%), FSS. -10P (powder state) and FSS-10D (aqueous dispersion, solid content 30%).

[Insulating sealant layer]
The insulating sealant layer is a normal sealant layer having heat sealability. In this invention, in order to distinguish with an antistatic sealant layer, it describes as an insulating sealant layer.
An insulating sealant layer is a layer laminated | stacked in contact with an antistatic sealant layer as needed. For example, when used in combination with an antistatic sealant layer, the entire sealant layer can be easily balanced between heat sealability and antistatic properties.
The insulating sealant layer needs to have good adhesion to the antistatic sealant layer and does not hinder the heat sealability of the antistatic sealant layer.

In the present invention, the laminating method for forming the insulating sealant layer is not particularly limited, and a known or conventional film forming method can be applied. Specific methods include, for example, an air doctor method, a blade coat method, and a knife. Lamination method by coating such as coating method, rod coating method, direct roll coating method, reverse roll coating method, gravure coating method, slide coating method, resin or resin composition forming an insulating sealant layer, and optionally an adhesive layer Through a layering method by extrusion coating on a base material layer or an intermediate layer, and a base material layer or a laminating method by coextrusion by an inflation method or a cast method together with a resin or resin composition for an intermediate layer, The product obtained by pasting a film or sheet for insulating sealant layer prepared in advance through an adhesive layer Method, and the like.
Further, before the lamination, the surface to be laminated may be subjected to a surface treatment such as a corona treatment or a plasma treatment in advance, if necessary, to enhance the adhesion.

Examples of the resin suitable for the insulating sealant layer include polyethylene, low density polyethylene, linear low density polyethylene, metallocene polyethylene, unstretched polypropylene, etc., and a resin film comprising one or more of these resins, or A coating film or the like can be used.
The layer structure of the insulating sealant layer may be a single layer or a multilayer such as polyethylene / polypropylene + polyethylene / polypropylene.

Moreover, the film which vapor-deposited the unstretched polypropylene (CPP) which can heat seal an inorganic film | membrane, a low density polyethylene, and a linear low density polyethylene can also be used. The structure of the inorganic film is the same as that of the inorganic vapor deposition layer in the base material layer.
Further, the thickness of the insulating sealant layer is preferably 10 μm or more and 150 μm or less, and more preferably 20 μm or more and 100 μm or less. If the thickness of the insulating sealant layer is thinner than the above, the heat seal strength is insufficient, and if it is thicker than the above, the required amount of heat for heat sealing increases, making high-speed heat sealing difficult and reducing the productivity.
Moreover, various additives can be included in the insulating sealant layer as necessary.
Next, the present invention will be described in more detail by showing specific examples.

What raw materials were used to make the packaging material? It is as follows.
Conductive metal oxide particle dispersion 1: MEK dispersion of fine acicular antimony-doped tin oxide (MPT270 manufactured by Ishihara Sangyo Co., Ltd. Cumulative number 50% median diameter 0.11 to 0.16 μm, major axis direction particle diameter Is 0.2 μm or more and 2.0 μm or less, the minor axis direction particle size is 0.01 μm or more and 0.02 μm or less, and the major axis / minor axis ratio is 20 or more and 30 or less. %.)
Conductive compound 1: AS100 (manufactured by Nippon Emulsifier Co., Ltd .. Ionic liquid.
Binder resin solution 1: G1657 (manufactured by Kraton Polymer Japan Co., Ltd., SEBS-based thermoplastic elastomer. Glass transition temperature -42 ° C, 23 ° C tensile strength 23 MPa, 23 ° C tensile elastic modulus 2.4 MPa, MFR 22 g / 10 min) Toluene solution. 20% solids.
Binder resin solution 2: G1652 (manufactured by Kraton Polymer Japan Co., Ltd., SEBS thermoplastic elastomer. Glass transition temperature -42 ° C., 23 ° C. tensile strength 31 MPa, 23 ° C. tensile elastic modulus 4.8 MPa, MFR 5 g / 10 min) Toluene solution. 20% solids.

(Preparation of laminate laminate A)
25 μm thick biaxially stretched nylon film (Bonil W manufactured by Kojin Co., Ltd.) treated with double-sided corona treatment, and 12 μm thick alumina vapor-deposited PET film (IB manufactured by Dai Nippon Printing Co., Ltd.). -PET-PXB, vapor deposition thickness 10 nm.) Was dry laminated via an adhesive.
Then, on the opposite surface of the bonded nylon film, a single-sided corona-treated polyethylene film having a thickness of 50 μm (LL-XTN manufactured by Phutamura Chemical Co., Ltd.) was similarly dry laminated as an insulating sealant layer.
Thereafter, an aging treatment was performed at 37 ° C. for 3 days to obtain a laminate laminate A.

(Preparation of laminate laminate B)
25 μm thick biaxially stretched nylon film (Bonil W manufactured by Kojin Co., Ltd.) treated with double-sided corona treatment, and 12 μm thick alumina vapor-deposited PET film (IB manufactured by Dai Nippon Printing Co., Ltd.). -PET-PXB deposition thickness 10 nm.) Was dry laminated with an adhesive.
Then, on the opposite surface of the bonded nylon film, a 50 μm thick antistatic polyethylene film (L-110R-1 manufactured by Aicello Co., Ltd.) subjected to corona treatment on one side was similarly dry laminated as an insulating sealant layer. .
Thereafter, an aging treatment was performed at 25 ° C. for 7 days to obtain a laminate laminate B.

[Example 1]
The following raw materials were mixed to prepare a coating solution, which was applied to the polyethylene film surface of the laminate laminate A by gravure coating, heated at 80 ° C. for 30 seconds and dried to form an antistatic sealant layer. The antistatic sealant layer after drying was 0.5 μm.
Conductive metal oxide particle dispersion 1 60 parts by mass Binder resin 1 40 parts by mass

The content of the conductive metal oxide particles in the obtained antistatic sealant layer is calculated as follows.
Content of conductive metal oxide particles in conductive metal oxide particle dispersion 1: 30% by mass
Resin content in binder resin 1: 20% by mass
Therefore,
(60 × 30/100) / (60 × 30/100 + 40 × 20/100) = 69.2% by mass
Next, various evaluations were performed. The results are listed in Table 1.

[Examples 2 to 5, Comparative Example 2]
In the same manner as in Example 1, the coating solution was prepared according to the formulation shown in Table 1, and an antistatic sealant layer was formed using the laminate laminate described in Table 1. Next, various evaluations were performed. The results are listed in Table 1.

[Comparative Example 1]
Various evaluations were performed using the laminate laminate B as it was. The results are listed in Table 1.

<Evaluation method>
[Measurement of laser light transmittance]
The total light transmittance was measured according to JIS K7361-1. A transmittance of 70% or more was accepted.
[Measurement of water vapor permeability]
Each laminate or packaging material is cut to A4 size, and water vapor permeability (g / m ² / day / atm) is measured at 40 ° C. and 90% RH using PERMATRAN 3/31 manufactured by MOCON USA. did.

[Measurement of surface resistivity]
The surface resistivity of the antistatic sealant layer or antistatic polyethylene film layer surface of each laminate or packaging material was measured with Hiresta UP manufactured by Mitsubishi Oil Kagaku Co., Ltd.
Applied voltage: 500V
Measurement environment: 25 ° C., 50% RH or less [heat seal strength measurement method]
Each laminate or packaging material was folded in two, the antistatic sealant layers or antistatic polyethylene film layers were heat sealed, and the seal strength was measured.
Heat sealing conditions: 140 ° C., 1 kgf, 1.0 s
Tensile conditions: seal width 15 mm, 300 mm / min

[Result Summary]
Examples 1 to 5 containing conductive metal oxide particles and heat-sealable thermoplastic elastomer in the antistatic sealant layer have good laser light transmittance, water vapor permeability, surface resistivity, and heat sealability. Indicated.
Comparative Example 1 having no antistatic sealant layer and only the antistatic polyethylene film as the sealant layer had high surface resistivity and insufficient antistatic properties.
Comparative Example 2 containing conductive compound 1 in the antistatic sealant layer instead of conductive metal oxide particles showed a low heat seal strength.

DESCRIPTION OF SYMBOLS 1 Packaging material 2 Base material layer 3 Inorganic vapor deposition layer 4 Adhesive layer 5 Intermediate layer 6 Sealant layer 6a Insulating sealant layer 6b Antistatic sealant layer

Claims (7)

A transparent antistatic packaging material having a base material layer, an inorganic vapor deposition layer, and a sealant layer,
The sealant layer has at least an antistatic sealant layer,
The antistatic sealant layer is the outermost surface layer on the surface opposite to the base material layer of the transparent antistatic packaging material,
The antistatic sealant layer contains conductive metal oxide particles and a heat-sealable thermoplastic elastomer,
The transparent antistatic packaging material has a total light transmittance of 70% or more and 95% or less,
The transparent antistatic packaging material has a water vapor permeability of 0.01 g / m ² / day / atm or more and 2.0 g / m ² / day / atm or less in a 40 ° C. and 90% RH environment,
The surface resistivity of the antistatic sealant layer is 1 × 10 ⁷ Ω / □ or more and 1 × 10 ¹⁰ Ω / □ or less.
Transparent antistatic packaging material.   The transparent antistatic packaging material of Claim 1 whose content rate of the said electroconductive metal oxide particle in the said antistatic sealant layer is 40 to 80 mass%.   The conductive metal oxide particles have an average particle size of 0.2 to 2.0 μm in the major axis direction, 0.01 to 0.02 μm in the minor axis direction, The transparent antistatic packaging material according to claim 1 or 2, wherein the axis / minor axis ratio is 20 or more and 30 or less.   The conductive metal oxide particles are one or more selected from the group consisting of antimony-doped tin oxide, tin-doped indium oxide, fluorine-doped tin oxide, gallium-doped zinc oxide, and aluminum-doped zinc oxide. The transparent antistatic packaging material of any one of Claims 1-3.   The transparent antistatic packaging material of any one of Claims 1-4 whose glass transition temperature of the said heat-sealable thermoplastic elastomer is -60 degreeC or more and -30 degrees C or less.   The transparent antistatic packaging material of any one of Claims 1-5 whose tensile elasticity modulus of the said heat-sealable thermoplastic elastomer is 1.5 MPa or more and 10 MPa or less in 23 degreeC.   The transparent antistatic packaging material according to any one of claims 1 to 6, wherein the heat-sealable thermoplastic elastomer is a SEBS-based block polymer.

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