JP6950323B2 - Transparent antistatic packaging material and packaging bag using the packaging material - Google Patents

Description

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

Conventionally, various parts, solid or liquid foods, etc. have been stored in a synthetic resin container and the opening has been sealed with a lid material, or stored in a bag and sealed, distributed and stored. There is.
Examples of the packaging include a bag-shaped packaging (packaging bag) made by folding and heat-sealing one type of packaging material, and heat-sealing a bottom material and a lid material made of different materials. There is also something like embossed carrier tape type taping that is sealed.

As for the material composition of the packaging material, the carrier tape (bottom material) used for the embossed carrier tape type taping has conventionally been formed by using a material such as polyvinyl chloride that can be easily formed into a sheet. Due to the problem of disposal, there is an increasing tendency to use polystyrene resin for carrier tape. On the other hand, the cover tape (cover material) used for the embossed carrier tape type taping and the above-mentioned bag-shaped package are made of, for example, a packaging material containing a biaxially stretched resin film and having a sealant layer on one side. There is.

The heat-sealed portion of the package is required to have a certain level of adhesive strength so that the heat-sealed portion does not peel off during transportation or storage and the stored contents do not spill out. At the same time, the heat-sealed portion is also required to be removable so that the contents once stored can be easily taken out.
Further, when the stored contents are electronic parts or the like, the electronic parts are deteriorated due to the static electricity generated when the electronic parts come into contact with the inner wall of the package and the static electricity generated when the package is peeled off. Since there is a risk of breakage, measures to prevent this are required for packaging materials.

As an antistatic measure for packaging materials, antistatic agents such as surfactants, conductive carbon fine particles, conductive metal oxide powder, and metal fine particles can be kneaded into the packaging material or applied onto the packaging material. It has been.

Further, the packaging material containing conductive carbon fine particles and metal fine particles as an antistatic agent has a problem that the transparency is extremely low and it is difficult to visually recognize the contents stored in the packaging body 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 is known as a method of achieving both sufficient transparency and antistatic performance (Patent Document 1). When the shape of the fine particles is spherical, the amount of metal oxide fine particles added must be increased in order to obtain sufficient antistatic performance, and there are problems such as deterioration of transparency and coloring. Not achieved.

On the other hand, when the surface resistivity of the packaging material attempts to set the 10 ⁹ Ω / □ degree of area, since the amount of practically available added is less than the conventional metal oxide fine particles amount Conversely, in the coating film There is a problem that the contact between the metal oxide fine particles is insufficient and the surface resistivity of the coating film is 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 applied to the surface opposite to the sealant layer, when it is rolled or stacked. In addition, the surfactant is transferred to the sealant layer, the surface condition of the sealant layer changes, and the sealant property of the sealant layer becomes unstable, which causes sealing failure, and the temperature and humidity during storage. Since the static electricity diffusion effect changes greatly depending on the conditions, there is a problem that a stable antistatic effect cannot be obtained.

Japanese Unexamined Patent Publication No. 7-251860

The present invention provides a packaging material, a packaging film, and a packaging bag having good heat-sealing property, stable adhesiveness, good peelability, and excellent antistatic property and transparency. The purpose.

The transparent antistatic packaging material of the present invention includes a base material layer, an inorganic vapor deposition layer, and a sealant layer, and the sealant layer is an antistatic sealant on the outermost surface layer of the surface opposite to the base material layer of the packaging material. It has a layer, and the antistatic sealant layer exhibits antistatic property and heat-sealing property by containing conductive metal oxide particles and a heat-sealing thermoplastic elastomer.
The present invention is characterized by the following points.

1. 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 and has.
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-sealing thermoplastic elastomer.
The total light transmittance of the transparent antistatic packaging material is 70% or more and 95% or less.
The water vapor transmission rate of the transparent antistatic packaging material in a 40 ° C. 90% RH environment is 0.01 g / m ² / day / atm or more and 2.0 g / m ² / day / atm or less.
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. 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. 3. The average particle size of the conductive metal oxide particles is 0.2 μm or more and 2.0 μm or less in the major axis direction, 0.01 μm or more and 0.02 μm or less in the minor axis direction, and is long. The transparent antistatic packaging material according to 1 or 2 above, wherein the shaft / minor 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. The transparent antistatic packaging material according to any one of 1 to 3 above.
5. The glass transition temperature of the heat-sealing thermoplastic elastomer is −60 ° C. or higher, −
The transparent antistatic packaging material according to any one of 1 to 4 above, which is 30 ° C. or lower.
6. The transparent antistatic packaging material according to any one of 1 to 5 above, wherein the heat-sealing thermoplastic elastomer has a tensile elastic modulus of 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 above, wherein the heat-sealing 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, which have good heat-sealing property, stable adhesiveness, and good peelability, and have excellent antistatic property 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.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Further, the present invention is not limited to the various specific examples and figures listed below.
1 and 2 are cross-sectional views showing an example of a laminated structure of the packaging material of the present 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 laminated in this order. The laminated structure in FIG. 2 is a layer structure in which an intermediate layer and an adhesive layer for adhering 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 contains an antistatic sealant layer on the outermost surface layer of the surface 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 visually applied to the correct position and read accurately, and it can be exported. Customs clearance can be done without opening the package even at the customs office of the time. If the transmittance of the laser light having the above wavelength is lower than the above range, a reading error is likely to occur, and if the transmittance is higher than the above range, it tends to be difficult to balance with the antistatic property.

The temperature at which the packaging material of the present invention is heat-sealed is preferably 100 ° C. or higher and 180 ° C. or lower, and 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 it tends to be difficult to adjust the thickness of the sealant layer.

The water vapor transmission rate of the transparent antistatic packaging material of the present invention in a 40 ° C. and 90% RH environment is 0.01 g / m ² / day / atm or more and 2.0 g / m ² / day / atm or less. It is more preferably 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., it is preferable to store them under low humidity, and it is necessary to prevent the inflow of moisture from the external environment after packaging.
If the water vapor transmission rate is larger than the above range, the contents are easily affected by moisture, and if it is smaller than the above range, it tends to be 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 layer>
As the base material layer, a metal or metal oxide which is excellent in chemical or physical strength, can withstand the conditions for forming an inorganic vapor-deposited film, and can be well retained without impairing the characteristics of the inorganic-deposited film or the like. Inorganic materials such as, and organic materials such as resins can be used, for example, as films and sheets. In the present invention, the term 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 a resin film.
As the base material layer, a single-layer film or a multilayer laminated film is used, but is not particularly limited, and any film used for various packaging materials can be used. From these, a suitable one is freely selected and used according to the usage conditions such as the type of contents to be packaged and the presence or absence of heat treatment after filling.

(Resin film)
As the resin used for the resin film, cellophane, polyamide resin (nylon 6, nylon 66, MXD6 (polymethoxylylen adipamide), etc.), polyester resin (polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate, etc.) (PEN), etc.), Polyethylene-based resins (low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, polypropylene, polybutene, polypropylene, acid-modified polyolefin-based resins, etc.), polystyrene-based resins, polyurethane-based resins, Acetal resin, polyvinyl alcohol, ethylene-vinyl acetate copolymer, ionomer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer, ethylene-propylene copolymer, methylpentene, Polyacrylonitrile, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, polycarbonate, polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), vinylidene fluoride (PVDF), ethylene-tetrafluoroethylene copolymer (ETFE), Polytetrafluoroethylene (PTFE), Polygonic (PI), Polyethersulfone (PES), Polyetheretherketone (PEEK), Polyetherimide (PEI), Polyphenylene sulfide (PPS), Polyarylate (PA) , Polyester ether (PEE), Polyamiimide (PAI) and the like.

As the resin film used for the base material layer, for example, one kind or two or more kinds of resins selected from the above-mentioned resin group are used, and conventional methods such as extrusion method, cast molding method, T-die method, cutting method, and inflation method are used. A 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 kinds of resins. Further, from the viewpoint of film strength, dimensional stability, and heat resistance, the film can be stretched in the uniaxial or biaxial directions by 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.

Further, in particular, transparent vapor-deposited PET such as silica-deposited biaxially stretched 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.

The thickness of the base material layer can be arbitrarily selected, but from the viewpoint of moldability and transparency, it can be selected and used from a range of about 1 μm to 300 μm, and a range of 1 μm or more and 100 μm 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 processing may become difficult.

Further, in order to improve the adhesion at the time of laminating, the base material layer and the film constituting the base material layer are subjected to corona discharge treatment and ozone treatment in advance on the surface to be laminated before laminating or vapor deposition, if necessary. , Low temperature plasma treatment using oxygen gas or nitrogen gas, physical treatment such as glow discharge treatment, chemical treatment such as oxidation treatment using chemicals, adhesive layer, primer coating agent layer, under A treatment for forming a coating layer, a vapor deposition anchor coating agent layer, or the like, and other treatments may be performed.

The resin film used for the base material may have workability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant properties, slipperiness, releasability, flame retardancy, and antifungal properties, if necessary. , Plastic compounding agents such as lubricants, cross-linking agents, antioxidants, UV absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, etc. for the purpose of improving and modifying electrical properties, strength, etc. Additives and the like can be added, and the amount of the additive can be arbitrarily added according to the purpose as long as it does not adversely affect other performance.

(Inorganic vapor deposition layer)
The inorganic vapor deposition layer is a barrier membrane having a gas barrier property that prevents the permeation of water vapor and the like, and examples thereof include a vapor deposition film made of an inorganic substance or an inorganic oxide.
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 has an alumina vapor deposition layer.

The inorganic vapor deposition layer can be directly provided on the film forming the base material layer, the film forming the intermediate layer, or the film forming the sealant layer. For example, it is preferably formed on a PET film of a base material layer or an intermediate layer.
Further, if necessary, it is possible to impart a light-shielding property that blocks the transmission of ultraviolet rays and the like. Further, the inorganic vapor deposition layer may be composed of one layer or two or more layers. When composed of two or more layers, each may have the same composition or may have a different composition.

The thickness of the inorganic thin-film deposition layer is preferably 1 nm or more and 200 nm or less, and the more preferable thickness varies depending on the vapor deposition type, but in the case of an aluminum-deposited film, it is more preferably 1 nm or more and 100 nm or less, and even more preferably. Is 15 nm or more and 60 nm or less, and particularly preferably 10 nm or more and 40 nm or less. In the case of a silica-deposited film or an alumina-deposited film, it is more preferably 1 nm or more and 100 nm or less, further 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, it becomes difficult for the inorganic vapor deposition layer to exhibit sufficient gas barrier properties, and if it is thicker than the above range, transparency tends to be impaired.
The inorganic vapor deposition layer can be formed by a conventionally known method using a conventionally known inorganic substance or an inorganic oxide, and the composition and the forming method thereof are not particularly limited.
Examples of the forming method include a physical vapor deposition method (Physical Vapor Deposition method, PVD method) such as a vacuum deposition method, a sputtering method, and an ion plating method, or a plasma chemical vapor deposition method, a thermochemical vapor deposition method, and the like. And a chemical vapor deposition method (Chemical Vapor Deposition method, CVD method) such as a photochemical vapor deposition method can be mentioned.

<Middle layer>
The intermediate layer is a layer provided between the base material layer and the sealant layer, if necessary. For example, in order to improve various strengths of the packaging material, 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 printed by a usual printing method. The formed print layer can also be provided. The type of film used and the laminating method are the same as those for the base material layer.
It can also be formed by applying various resins to the base material layer, the sealant layer and the like.

<Sealant layer>
The packaging material of the present invention has a sealant layer, which 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 surface opposite to the base material layer of the packaging material, and has a structure in which conductive metal oxide particles are dispersed in the binder resin, and has antistatic properties and heat. It is a layer having a sealing property.
For example, a packaging bag formed by folding and heat-sealing the antistatic sealant layers so as to face each other exhibits antistatic properties on the inner wall of the packaging bag by having the antistatic sealant layer, and is housed in the packaging bag. It is possible to prevent electronic parts and the like from being destroyed by static electricity.
In the present invention, the laminating method for forming the antistatic sealant layer is not particularly limited, and a known or conventional laminating method can be applied.

For example, using a coating liquid or composition containing conductive metal oxide particles, a binder resin and a solvent, an air doctor method, a blade coating method, a knife coating method, a rod coating method, a direct roll coating method, a reverse roll coating method, etc. A laminating method by coating such as a gravure coating method or a slide coating method, or a resin composition forming an antistatic sealant layer is extracted on a base material layer, an intermediate layer, or an insulating sealant layer, sometimes via an adhesive layer. Laminating method by rouge coating, laminating method by co-extrusion by inflation method or casting method together with resin or resin composition for intermediate layer, resin or resin composition for insulating sealant layer on the base material layer, Examples thereof include a laminating method in which a film or sheet for an antistatic sealant layer prepared in advance is attached via an adhesive layer.

Among the above, the antistatic sealant layer is preferably a coating film layer formed by coating.
Further, before laminating, the surface to be laminated may be subjected to surface treatment such as corona treatment or plasma treatment in advance, if necessary, to improve the adhesiveness.
Further, the antistatic sealant layer can contain additives such as a dispersion stabilizer and an antiblocking agent, if necessary.
The thickness of the antistatic sealant layer is preferably 0.3 μm or more and 5.0 μm or less, and more preferably 0.5 μm or more and 3.0 μm or less. 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, if the thickness is thicker than the above, the amount of heat required for heat sealing is required. As the size increases, 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 at ^{22 ° C. and 40% RH, and 1 × 10 8} Ω / □ or more and 1 ×. 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 tends to be difficult to protect the contents such as electronic parts from electrostatic damage, and if it is smaller than the above range. , It is not preferable because there is a possibility that electricity is energized to the electronic component from the outside through the packaging material and there is a risk that the electronic component is electrically destroyed.

(Binder resin)
The binder resin used for the antistatic sealant layer preferably contains a heat-sealable thermoplastic elastomer. The molecular structure of the heat-sealable thermoplastic elastomer is composed of a hard block resin and a soft block resin, and these block polymers are bonded in a non-three-dimensional cross-linking manner, so that they are thermoplastic and adhesive. Furthermore, it exhibits low elasticity (rubber elasticity).

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

The glass transition temperature of the heat-sealing thermoplastic elastomer is preferably −60 ° C. or higher and −30 ° C. or lower, and more preferably −50 ° C. or higher and −40 ° C. or lower. If the glass transition temperature is higher than the above range, it is difficult to exhibit sufficient heat-sealing properties, and if 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. Regardless of whether 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 evenly, and the thickness of the sealant layer is not stable, so that the heat seal strength becomes difficult to stabilize.

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

The heat-sealing thermoplastic elastomer MFR (Melt Flow Rate) is preferably 2 g / 10 minutes or more and 40 g / 10 minutes or less, and more preferably 4 g / 10 minutes or more and 30 g / 10 minutes or less under a load of 230 ° C. and 5 kg. .. If the MFR is higher than the above range, the heat sealability is inferior, and if it 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 poor.
Specific commercially available products of the heat-sealable thermoplastic elastomer include G1657 (SEBS block polymer) and G1652 (SEBS block polymer) manufactured by Kraton Polymer Japan Co., Ltd.
Further, as the binder resin, if necessary, a heat-sealing thermoplastic elastomer and a resin used for a normal insulating sealant layer can be mixed and used.

(Conductive metal oxide particles)
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 (ATO). AZO), etc. are mentioned, and among them, fine needle-shaped ones are preferable, and fine needle-shaped antimony-doped zinc oxide is particularly preferable. These conductive metal oxide particles can easily exhibit stable and good antistatic properties independent of humidity in the packaging material.

In the present invention, the conductive metal oxide particles are mixed with the binder resin together with the 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 the above range, it becomes easy to balance good antistatic performance, heat sealability and transparency.

If the content is lower than the above range, it tends to be difficult to obtain a sufficient antistatic effect, and if it is higher than the above range, the melt viscosity of the antistatic sealant layer increases too much and the heat sealability deteriorates. It tends to be a tendency, and the transparency tends to decrease.
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 particle size of 0.2 μm or more and 2 μm or less, and a minor axis particle size. It is needle-shaped with a major axis / minor axis ratio of 20 or more and 30 or less, 0.01 μm or more and 0.02 μm or less.
When the primary particles of the conductive metal oxide particles are needle-shaped with a particle size in the above range, they come into contact with each other in a smaller amount in the antistatic sealant layer than when a spherical conductive filler is used. Because it is easy, it has excellent antistatic properties, and because it is small in size and small in quantity, the antistatic sealant layer tends to be colorless and transparent, has excellent visibility of the contents, and has a low incidence of bar code reading errors in the contents. It becomes easier to give packaging materials.

The conductive metal oxide particles used in the present invention are, for example, commercially available products from Ishihara Techno Co., Ltd., which are fine needle-shaped antimony-doped tin oxide, MPT270 (MEK dispersion, solid content 30%), FSS. It is offered under the trade names of -10P (powdered state) and FSS-10D (aqueous dispersion, solid content 30%).

[Insulating sealant layer]
The insulating sealant layer is a normal, heat-sealing sealant layer. In the present invention, it is referred to as an insulating sealant layer in order to distinguish it from the antistatic sealant layer.
The insulating sealant layer is a layer that is laminated in contact with the antistatic sealant layer, if necessary. For example, when used in combination with the antistatic sealant layer, it is possible to easily balance the heat sealability and the antistatic property of the sealant layer as a whole.
The insulating sealant layer needs to have good adhesion to the antistatic sealant layer and not to 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 coating method, and a knife. A laminating method by coating such as a coating method, a rod coating method, a direct roll coating method, a reverse roll coating method, a gravure coating method, a slide coating method, or a resin or resin composition forming an insulating sealant layer may be used as an adhesive layer. A laminating method by extrusion coating on the base material layer or the intermediate layer, or a laminating method by coextrusion by the inflation method or the casting method together with the resin or the resin composition for the intermediate layer on the base material layer. Examples thereof include a laminating method in which a film or sheet for an insulating sealant layer prepared in advance is attached via an adhesive layer.
Further, before laminating, the surface to be laminated may be subjected to surface treatment such as corona treatment or plasma treatment in advance, if necessary, to improve the adhesiveness.

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

Further, a film obtained by vapor-depositing an inorganic film on unstretched polypropylene (CPP) capable of heat-sealing, low-density polyethylene, or 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.
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 sealing strength is insufficient, and if it is thicker than the above, the amount of heat required for heat sealing becomes large, which makes high-speed heat sealing difficult and reduces productivity.
In addition, the insulating sealant layer can contain various additives as needed.
Next, the present invention will be described in more detail with reference to specific examples.

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

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

(Preparation of laminated laminate B)
Biaxially stretched nylon film with a thickness of 25 μm treated with double-sided corona (Bonil W manufactured by Kohjin Co., Ltd.) and alumina-deposited PET film with a thickness of 12 μm treated with single-sided corona (IB manufactured by Dai Nippon Printing Co., Ltd.) -PET-PXB vapor deposition thickness 10 nm.) Was dry-laminated via an adhesive.
Then, an antistatic polyethylene film (L-110R-1 manufactured by Aicello Corporation) having a thickness of 50 μm treated with a single-sided corona was similarly dry-laminated on the opposite surface of the bonded nylon film as an insulating sealant layer. ..
Then, it was aged at 25 ° C. for 7 days to obtain a laminated 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 laminated laminate A by a gravure coating method, 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
Then, various evaluations were carried out. The results are shown 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 the antistatic sealant layer was formed using the laminated laminate shown in Table 1. Then, various evaluations were carried out. The results are shown in Table 1.

[Comparative Example 1]
Various evaluations were carried out using the laminated laminate B as it was. The results are shown 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 regarded as acceptable.
[Measurement of water vapor transmission rate]
^{Each laminate or packaging material is cut into A4 size, and the water vapor transmission rate (g / m 2} / day / atm) is measured under the conditions of 40 ° C. and 90% RH using PERMATRAN 3/31 manufactured by MOCON of the United States. bottom.

[Measurement of surface resistivity]
The surface resistivity of the surface of the antistatic sealant layer or the antistatic polyethylene film layer of each laminate or packaging material was measured by Hiresta UP manufactured by Mitsubishi Yuka 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, and the antistatic sealant layers or the antistatic polyethylene film layers were heat-sealed, and the sealing strength was measured.
Heat seal conditions: 140 ° C, 1 kgf, 1.0 s
Tensile conditions: Seal width 15 mm, 300 mm / min

[Result Summary]
Examples 1 to 5 in which the conductive metal oxide particles and the heat-sealing thermoplastic elastomer are contained in the antistatic sealant layer have good laser light transmittance, water vapor transmittance, surface resistance and heat-sealing property. Indicated.
In Comparative Example 1 which did not have an antistatic sealant layer and the sealant layer was only an antistatic polyethylene film, the surface resistivity was high and the antistatic property was insufficient.
Comparative Example 2 in which the conductive compound 1 was contained in the antistatic sealant layer instead of the conductive metal oxide particles showed a result of low heat seal strength.

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

Claims (6)

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 and has.
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 is one or more conductive metals 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. It has a structure in which oxide particles are dispersed in a binder resin made of a heat-sealing thermoplastic elastomer .
The total light transmittance of the transparent antistatic packaging material is 70% or more and 95% or less.
The water vapor transmission rate of the transparent antistatic packaging material in a 40 ° C. 90% RH environment is 0.01 g / m ² / day / atm or more and 2.0 g / m ² / day / atm or less.
The surface resistivity of the antistatic sealant layer is 1 × 10 ⁸ Ω / □ or more and 1 × 10 ¹⁰ Ω / □ or less.
Transparent antistatic packaging material. The transparent antistatic packaging material according to claim 1, wherein the content of the conductive metal oxide particles in the antistatic sealant layer is 40% by mass or more and 70% by mass or less. The average particle size of the conductive metal oxide particles is 0.2 μm or more and 2.0 μm or less in the major axis direction, 0.01 μm or more and 0.02 μm or less in the minor axis direction, and is long. The transparent antistatic packaging material according to claim 1 or 2, wherein the shaft / minor axis ratio is 20 or more and 30 or less. The transparent antistatic packaging material according to any one of claims 1 to 3 , wherein the glass transition temperature of the heat-sealable thermoplastic elastomer is −50 ° C. or higher and −40 ° C. or lower. The transparent antistatic packaging material according to any one of claims 1 to 4 , wherein the heat-sealing thermoplastic elastomer has a tensile elastic modulus of 2 MPa or more and 6 MPa or less at 23 ° C. The transparent antistatic packaging material according to any one of claims 1 to 5 , wherein the heat-sealing thermoplastic elastomer is a SEBS-based block polymer.

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