JP2001322209A - Antistatic film and packaging bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique capable of effectively preventing impurity seal and capable of also preventing the peeling of a base material and a plastic layer. SOLUTION: A seal part 20 to be heat-sealed is formed to an outer peripheral edge and a non-seal part 30 is provided inside the seal part 20. An antistatic layer provided over the whole region of the non-seal part 30 and the seal part 20 and the area ratio of the antistatic layer 43 of the non-seal part 30 is larger than that of the antistatic layer 42 of the seal part 20. The antistatic layer 42 of the seal part 20 is pattern like and there are gaps between adjacent patterns and an adhesive entering the gaps to bond upper and lower layers. Therefore, the antistatic layer is inferior to water resistance but a laminated film is not peeled. Impurity seal can be prevented by the antistatic layer 42 over the whole region of the seal part 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antistatic film obtained by laminating a base plastic film and a plastic layer with an antistatic layer for antistatic therebetween, and a packaging bag formed by using the antistatic film. In particular, the present invention relates to a technique in which the antistatic layer is made of a resin material containing a crosslinkable copolymer polymer having a carboxyl group and a quaternary ammonium group in a side chain.

[0002]

BACKGROUND OF THE INVENTION The general layer structure of this kind of antistatic film itself and the use of the above-mentioned specific resin material as the material of the antistatic layer are already known. For example, Japanese Patent Application Laid-Open No. 11-58628 discloses that an antistatic film made of a material similar to a specific resin material which is a problem in the present invention is provided between a plastic base material (1) and a heat sealant layer (2). The antistatic laminate film (5) sandwiching the layer (3) is shown. The technology of this publication is
In particular, since the antistatic layer of the previous antistatic film is exposed from the edge of the film, the moisture absorption from the exposed portion reduces the adhesive strength of the laminate film, and the base material and the plastic layer are separated. The problem is to be solved (see paragraph 0004). As a means for achieving this, a method is employed in which the antistatic layer (3) is not exposed from the ends of the front base material (1) and the heat sealant layer (2). It is proposed that the heat sealing portion (4) be prevented from reaching the seal portion (4) or reach a part inside the heat seal portion (4) but not the entire outer periphery.

[0003]

However, if the antistatic layer is provided so as to avoid at least a part of the heat-sealed portion, the problem of peeling due to moisture absorption can be effectively solved. The antistatic function in the area of the heat-sealed portion without the prevention layer is reduced. As a result, when packing contents made of antistatic film are filled with dried contents such as bonito cuts and powdered medicine, the contents adhere to the heat-sealed part and the contents powder is sandwiched in the heat-sealed part. (The so-called contaminant seal or powder bite seal) may occur. In particular, since the dried contents rub against the bag at the time of filling to generate static electricity, the powder easily adheres to the heat seal portion serving as an opening, and foreign matter seals easily occur.

Accordingly, the present invention, of course, provides an antistatic layer over the entire area of the non-seal portion,
By providing the antistatic layer over the entire area of the seal portion to be heat-sealed, firstly, it is possible to effectively prevent foreign substance sealing, and also to prevent peeling of the base material and the plastic layer. The aim is to provide technology that can be prevented. Another object of the present invention is to provide a technique capable of giving characteristics or functions suitable for each part by making the area ratio of the antistatic layer different between the sealed part and the non-sealed part.

[0005]

According to the present invention, an antistatic film including a sealed portion and a non-sealed portion basically satisfies the following conditions. A. The material of the antistatic layer is a resin material containing a crosslinkable copolymer having a carboxyl group and a quaternary ammonium group in a side chain. B. The antistatic layer is provided over the entire area of each of the sealed portion and the non-sealed portion. C. At least the seal portion of the antistatic layer is in a pattern shape, so that the upper and lower layers sandwiching the antistatic layer have a portion to be bonded without interposing the antistatic layer. D. The area ratio of the antistatic layer in the non-seal portion is larger than the area ratio of the antistatic layer in the seal portion.

The antistatic film has a structure in which a base plastic film and a plastic layer are laminated with an antistatic layer interposed therebetween. Usually, the bonding between the upper and lower layers sandwiching the antistatic layer is based on the bonding function of an adhesive. As an adhesive,
Use a material that is more resistant to water (moisture absorption) and has higher adhesive strength than a resin material for preventing static charge. In that regard, urethane-based ones are preferred. In laminating, each method of dry lamination, sand lamination (so-called extrusion lamination), or extrusion coating can be applied.

[0007] The antistatic layer covers the entire area of each of the seal portion and the non-seal portion, and at least the seal portion has a pattern. The pattern includes a plurality of stripes parallel to each other extending along the seal portion, a plurality of stripes formed of closed lines, a plurality of concentric lines from the inside to the outside, and minute rings distributed throughout the seal portion. Or a minute geometric pattern, a plurality of lines radially extending from the inside to the outside with respect to the seal portion, a halftone-processed portion of the entire seal portion, or the stripe, a minute ring, a minute geometric pattern or The pattern itself, such as a plurality of lines extending radially, is composed of halftone dots,
The halftone processing and the stripe, such as configuring the pattern such as the stripe as a set of minute rings and minute geometric patterns, at least one of a plurality of radially extending lines, the stripe, minute ring or minute geometric pattern, It is a shape or arrangement in which there is a gap between adjacent patterns, such as a combination. Incidentally, the pattern-like antistatic layer, in each region of the seal portion and the non-seal portion, a plurality of stripes or lines can be arranged at substantially uniform intervals, the interval can also be changed by location, In addition, the thickness of the lines constituting the pattern can be made substantially uniform or can be changed depending on the place, and the size of the pattern can be made substantially uniform or can be changed depending on the place. Based on the above pattern arrangement, the area ratio of the antistatic layer in the seal portion is limited to a maximum of 95% in order to secure a gap into which the adhesive enters, and is preferably set to 80% or less. Is good. On the other hand, from the viewpoint of the antistatic effect, the area ratio of the antistatic layer should be at least 10%, preferably 30% or more, and the higher the area ratio, the stronger the charging. The prevention effect can be obtained. Further, when the area ratio is set to 80 to 95%, it is possible to obtain almost the same antistatic effect as in the case where the area ratio is 100%. Therefore, the area ratio of the antistatic layer in the sealing portion is 10 to 95%, preferably 30 to 80%, in order to obtain an appropriate sealing strength while preventing foreign matter sealing.
It is better to On the other hand, the area ratio of the antistatic layer in the non-seal portion, which focuses on the antistatic effect, is 10 to 100.
%, Preferably 80% or more, and should be at least larger than that of the seal portion.

When a bag is formed using an antistatic film, the plastic layer on one surface of the film can be heat-sealed as a sealant layer. As a form of the bag, a known packaging form such as a two-sided seal bag, a three-sided seal bag (flat bag, pillow bag), a four-sided seal bag, or the like can be applied. Here, some aspects of the antistatic layer in each region of the seal portion and the non-seal portion will be clarified with reference to schematic configuration diagrams in plan view shown in FIGS. 1 and 2. Each figure shows a four-sided seal bag 10, in which a seal portion 20 to be heat-sealed is provided on the outer peripheral portion of the two-layered rectangular bag of antistatic film, and a non-seal portion 30 is provided inside the seal portion. In the embodiment shown in FIG.
An antistatic layer 43 having a large area ratio is provided on the non-sealed portion 30, and an antistatic layer 42 having an area ratio smaller than the antistatic layer 43 of the non-sealed portion 30 is provided over the entire area of the seal portion 20. Further, in another embodiment shown in FIG. 2, the non-sealing portion 30 is the same as the embodiment of FIG. 1, but the sealing portion 20 is divided into the inner region 20i close to the non-sealing portion 30 and the non-sealing portion 3
It is divided into two, that is, an outer region 20o away from 0.
The area ratio of the antistatic layer 42i in the inner region 20i is set to be smaller than that of the antistatic layer 43 in the non-sealed portion 30, and the area ratio of the antistatic layer 42o in the outer region 20o is reduced. It is set smaller than the area ratio of the layer 42i. further,
1 and 2, the area ratio of the antistatic layer 43 in the non-sealed portion 30 can be 100% (that is, solid) or an area ratio close thereto, and such a solid area or a large area close thereto can be achieved. As long as the antistatic layer 43 does not reach the outer end face of the seal portion 20, the antistatic layer 43 may extend to the inner portion of the seal portion 20.

Antistatic layers 43, 42; 43, 42i, 4
Examples of paints for forming 2o include crosslinkable resins having a carboxyl group and a quaternary ammonium base in the side chain, such as commercially available Bondip PW, Bondip P, and Bondip P100 (all are trade names of Altec). A resin paint containing a polymer can be used. The composition of the paint is as follows. And are monomers for obtaining an antistatic function, a function of obtaining a crosslinked product as a resin, and a function of obtaining a crosslinking function, respectively. Monomer having terminal -COOH group: 3 to 13 mol
% Acrylic acid (including meth), acroyloxyether succinic acid, phthalic acid, hexahydrophthalic acid (including meth) and the like. Monomer with quaternary ammonium base: 15 to 40 m
ol% dimethylaminoether acrylate 4 oxide (including anions such as chloride, sulfate, sulfonate, and alkylsulfonate as counter ions). Other monomers: 63.5 to 79.5 mol% Examples thereof include alkyl acrylates, alkyl methacrylates, styrene, vinyl acetate, vinyl halides, and vinyl derivatives such as olefins. Monomer as cross-linking curing agent: 0.5 to 1.5 mol
% Polyglycidyl ethers of aliphatic alcohols having 2 to 4 valences, such as bifunctional monomers such as glycerin diglycidyl ether, diethylene glycol diglycidyl ether, bisphenol A diglycidyl ether, polyethylene glycol diglycidyl ether, and polypropylene glycol diglycidyl ether; Trifunctional monomers include trimethylolpropane triglycidyl ether, and tetrafunctional monomers include epoxy derivatives such as tetraglycidyl ether such as pentaerythritol and neopentyl. The epoxy derivative is used as a mixture with polyethyleneimine, and has an average molecular weight of 20.
0 to 70000. Polyethyleneimine is linear, but may be partially branched. Catalyst: 1 to 25% (weight ratio) with 10 as a crosslinking curing agent As a ring-opening reaction catalyst for an epoxy derivative of a bifunctional or trifunctional monomer, 2-methylimidazole, 2-ethyl-4-
Imidazole derivatives such as methylimidazole; polyamines and polyethyleneimine derivatives.

[0010]

EXAMPLE A pattern was formed on a PET (polyethylene terephthalate) base film having a thickness of 12 μm by gravure printing, a white background layer serving as the background of the pattern was printed by gravure printing, and then an ink having the following composition was applied. Then, a stripe-shaped antistatic layer was printed by gravure printing. Ink (paint) for antistatic: Bondip PA100 main agent (manufactured by Altec) 100 parts Bondip PA100 curing agent (manufactured by Altec) 100 parts Isopropyl alcohol 100 parts Water 50 parts In each of the embodiments shown in FIGS. 1 and 2, the area ratio of the antistatic layer was changed as follows. After printing of the antistatic layer, an anchor coat of a urethane-based adhesive was applied, and then a 20 μm-thick CPP (unstretched polypropylene) laminated film was extruded with a polyethylene resin to form an antistatic film. For comparison, the antistatic layer was not formed on the entire area of the seal portion in the embodiment of FIG. 1 (Comparative Example 1), but the antistatic layer was not formed on the outer region of the seal portion in the embodiment of FIG. (Comparative Example 2) and those without the antistatic layer formed on both the sealed portion and the non-sealed portion (Comparative Example 3) were prepared.

For these samples, the chargeability and lamination strength, and the residual property of the contaminants at the seal portion were measured and evaluated. Regarding the chargeability, JIS L-10
According to the method specified in the 94B method, temperature 25 ° C, humidity 40%
Under the condition of RH, the friction electrostatic voltage of the non-sealed portion on the PET base film side 60 seconds after the start of friction was measured. Regarding the lamination strength, T is often used in relation to lamination.
Using a mold peel test, the resistance to water was examined. That is, the target laminated film was left for 24 hours in an environment of a humidity of 80%, and then the adhesion of each film was tested by a T-type peel test. Furthermore, regarding the residual property of the contaminants in the seal portion, after charging the entire surface of each film, place each film horizontally, spray the ground crushed knot powder with a commercially available mixer, and then shake each film at a right angle and shake it firmly. The bonito flour was dropped, and the residual amount of the bonito flour at that time was visually inspected. This evaluation is based on the fact that bonito flour is clearly adhering to the surface: “Yes”, and the bonito flour is adhering to the surface but is not noticeable at first glance:
When "less" and no bonito flour adheres to the surface:
"None". The results are as follows.

(Embodiment of FIG. 1) Sealed part Non-sealed part Friction band voltage Peeling test Impurity residue 50% 95% 0.2 kV or less Material destruction None 20% 95% 0.2 kV or less Material destruction Less 50% 100% 0.2 kV or less Material destruction No 20% 100% 0.2kV or less Material destruction Low (Comparative Example 1) 0% 100% 0.2kV or less Material destruction Yes

(Embodiment of FIG. 2) Cutting side of sealing part Sealing part content side Non-sealing part Friction band voltage Peeling test Impurity residue 20% 95% 95% 0.2 kV or less Material destruction Less 50% 95% 95% 0.2 kV 20% 100% 100% 0.2kV or less Material destruction Low 50% 100% 100% 0.2kV or less Material destruction No 20% 80% 95% 0.2kV or less Material destruction Low 50% 80% 95% 0.2kV or less Material No destruction 20% 80% 100% 0.2kV or less Material destruction Low 50% 80% 100% 0.2kV or less Material destruction No (Comparative Example 2) 0% 100% 100% 0.2kV or less Material destruction Yes (Comparative Example 3) 0% 0% 0% 10kV or more Material destruction Yes

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a mode of an antistatic layer in plan view.

FIG. 2 is a configuration diagram similar to FIG. 1, showing another embodiment of an antistatic layer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Four-side seal bag 20 Seal part 20i Inner area 20o Outer area 30 Non-seal part 42 Seal part antistatic layer 42i Inner area antistatic layer 42o Outer area antistatic layer 43 Non-seal part antistatic layer

Continued on front page F-term (reference) 3E064 AA03 AA05 AA09 BA26 BA30 BA55 BB03 BC18 BC20 EA04 EA07 FA01 FA06 GA01 HN05 4F100 AK01A AK01B AK01C AK07 AK42 AK51G AL01A AL06A BA03 BA10B BA10C BA13 E03B03B00E

Claims (5)

[Claims] 1. An antistatic layer for preventing static electricity,
An antistatic film obtained by laminating a base plastic film and a plastic layer.
An antistatic film characterized by satisfying the following conditions, in which there are a seal portion for sealing and joining the plastic layers to each other and a non-seal portion without such seal joining. A. The material of the antistatic layer is a resin material containing a crosslinkable copolymer having a carboxyl group and a quaternary ammonium group in a side chain. B. The antistatic layer is provided over the entire area of each of the sealed portion and the non-sealed portion. C. At least the seal portion of the antistatic layer is in a pattern shape, so that the upper and lower layers sandwiching the antistatic layer have a portion to be bonded without interposing the antistatic layer. D. The area ratio of the antistatic layer in the non-seal portion is larger than the area ratio of the antistatic layer in the seal portion. 2. The antistatic film according to claim 1, wherein the area ratio of the antistatic layer in the sealed portion is 10 to 95%, and the area ratio of the antistatic layer in the non-sealed portion is 10 to 100%. 3. The antistatic layer in the seal portion includes a plurality of parallel stripes extending along the seal portion.
Micro-rings distributed over the entirety of the seal portion, a plurality of lines radially extending from the inside to the outside of the seal portion, halftone-processed portions of the entire seal portion, or the halftone process and the stripes, micro-rings, radial The antistatic film according to claim 1, wherein the antistatic film has a pattern having a gap between adjacent patterns, such as a combination of at least one of a plurality of lines extending in a direction. 4. The antistatic layer in the seal portion, wherein an area ratio of an outer region remote from the non-seal portion is smaller than an area ratio of an inner region near the non-seal portion.
Antistatic film. 5. A packaging bag for heat-sealing at least a part of a peripheral portion of a two-layered film and defining a storage space for storing dried contents therein,
A packaging bag wherein the film is an antistatic film obtained by laminating a base plastic film and a plastic layer with an antistatic layer for antistatic therebetween, and which satisfies the following conditions. a. The material of the antistatic layer is a resin material containing a crosslinkable copolymer having a carboxyl group and a quaternary ammonium group in a side chain. b. The antistatic layer is provided over the entire area of each of the seal portion to be heat-sealed and the non-seal portion in the housing space. c. At least the seal portion of the antistatic layer is in a pattern shape, so that the upper and lower layers sandwiching the antistatic layer have a portion to be bonded without interposing the antistatic layer. d. The area ratio of the antistatic layer in the non-seal portion is larger than the area ratio of the antistatic layer in the seal portion.