JP2811421B2 - Breathable transparent bag - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention has transparency and air permeability,
The present invention also relates to a packaging bag having excellent mechanical strength, heat sealing properties, and the like, and having a feature that a printed surface is not stained by friction.

[0002]

2. Description of the Related Art Conventionally, tangerines, onions, potatoes, shiitake mushrooms,
As a packaging bag used for peppers and the like, a mesh bag made of a synthetic resin net is used. However, in the case of a net bag, there is a problem that the mesh is in the way and it is difficult to see the contents, and it is not possible to print a bar code or the display of the contents. The problem has been solved by pasting
No. 71, Shokai Sho 52-44184, Shokai Sho 5
JP-A-3-12416), but the manufacturing process is complicated,
High cost. Further, in the case of a packaging bag made of various films, many holes are formed in the film in order to provide air permeability, but there is still a problem that the air permeability is not sufficient.

On the other hand, a canister bag (Japanese Utility Model Application No. 53-14711) formed by polymerizing a water-permeable film formed by arranging a number of elongated strips of a synthetic resin film in parallel with an appropriate gap and a synthetic resin support film. Japanese Utility Model Publication No. 55-2897), and Japanese Utility Model Publication No. 52-136808 discloses a packaging made of a nonwoven fabric made of a thermoplastic resin microfiber and a film. Bags and the like have been proposed. However, these bags have poor heat-sealing strength at the joint, and when filled with heavy materials such as tangerines, onions, potatoes, etc., have the problem that the bottom of the bag breaks, and have sufficient transparency. is not. Further, since the conventional bag is printed on the outer surface, there is a problem that the print is peeled off or stained due to rubbing, and it is difficult to determine the printed display.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a packaging bag having high transparency and air permeability and high heat sealing strength. Things. Another object of the present invention is to provide a breathable transparent bag in which a bar code, a content, a manufacturer and the like are not peeled off or stained. Also,
Another object is to provide a breathable transparent bag using a colored net to improve commercial value.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in accordance with the above-mentioned object, and have found that a transparent film made of a synthetic resin and a random nonwoven fabric or a resin net containing thermo-adhesive fibers are used. The present inventors have found that a packaging bag having high heat seal strength while maintaining transparency and air permeability can be obtained by bonding via a seal layer, and reached the present invention. That is, the present invention includes a synthetic resin of the transparent film which constitutes one side of the bag, to configure the other side of the bag, one or both sides of the draining possible random nonwoven or refractory resin layer including at least heat-adhesive fiber to the mesh body a laminated film having a low melting point resin layer was drained can form, have
Inner sides and / or bottom of either edge
To provide a folded part, and this folded part
The other peripheral portion is provided without a folded portion, and
The end of one folded part and the end of the other peripheral part are opposite to each other
As anxious, via the seal layer, the thermally bonded
The present invention relates to a more formed breathable transparent bag having drainage properties . Another invention is a laminate in which a transparent film made of a synthetic resin is printed on the inner surface and a seal layer is formed thereon, and a low melting point is formed on one or both sides of a random nonwoven fabric containing a heat-adhesive fiber or a high melting point resin layer. An air-permeable transparent bag characterized in that an opening is provided in a part thereof and a peripheral portion thereof is thermally bonded to a net-like body having a resin layer laminated thereon via a sealing layer. Another aspect of the present invention is a breathable transparent bag characterized in that a high-melting resin layer and / or a low-melting resin layer of a net are colored.

Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1A is a schematic perspective view showing one embodiment of the present invention, and FIG. 1B is an end view taken along line bb of FIG. 1A. A breathable transparent bag 1 shown in FIG. 1A includes a transparent film 2 made of a synthetic resin and a reticulated body 3 and a sealing layer 4.
, An opening 5 is provided and the peripheral edge 6 is thermally bonded. The transparent film 2 and the seal layer 4 made of synthetic resin are laminated in advance and formed on the laminate 7. FIGS. 2A and 2B are front views showing another embodiment of the present invention. The air-permeable transparent bag 1a of FIG.
Sets the length of the laminate 7 at the opening 5
The air-permeable transparent bag 1b of FIG. 2B has a length of the mesh 3 longer than that of the laminate 7. In any case, the elongated portion is folded so as to cover the opening after storing the contents, and can be used as a lid. If necessary, an adhesive 8 may be applied to the leading end and fixed, or a stapler or the like may be used.

FIG. 3 (a) is a schematic perspective view showing another embodiment of the present invention, and FIG. 3 (b) is a sectional view taken along line bb of FIG. 3 (a).
It is an end elevation in a line. Breathable transparent bag 1c is bent both side portions of the peripheral portion 6 of the mesh body 3 to form a breathable transparent bag 1 of Figure 1 to the inside, it was the folded portion 9 and the sealing layer 4 and the thermal bonding of Ramine bets 7 Things. By providing the folded portion on the peripheral portion and bonding as described above, the tensile strength of that portion can be increased. It is also possible to provide a folded portion <br/> periphery of Ramine bets, 4 of the example is an end view corresponding to FIG. 3 (b). Breathable transparent bags 1d are folded both side portions inward by a sealing layer 4 of Ramine bets 7 outwardly is a sealing layer 4 of the folded portion 9a those like body 3 and the thermal bonding. In addition, also about the bottom part of a peripheral part, a folded part can be provided and adhered similarly to the above.

Examples of the material of the synthetic resin transparent film used in the present invention include polyolefin resins such as polyethylene and polypropylene, polyester resins, polyamide resins, polycarbonate, cellophane, and the like.
Preferably, these resins are oriented by stretching, rolling or the like. Specific examples include oriented polypropylene (OPP), oriented polyester (OPET), and oriented polyamide (ONY). Oriented polypropylene (OPP) is most preferable in terms of transparency, mechanical strength, economy, and the like.

[0009] The random nonwoven fabric used in the present invention is a staple fiber obtained by accumulating multifilaments such as synthetic fibers such as high-density polyethylene, polypropylene, polyester, polyamide and polyacryl, natural fibers such as cotton, wool and hemp. Includes those that are accumulated. The heat-adhesive fiber may be a filament or the like made of a heat-fusible resin having a lower melting point than the random nonwoven fabric. More preferably, the first fiber having a high melting point and the second fiber having a low melting point are used. It is a used fiber (conjugate fiber) or a random nonwoven fabric obtained by accumulating them. Specifically, a random nonwoven fabric obtained by accumulating a mixture of a high-melting first fiber web and a low-melting second fiber web or a heat-adhesive fiber, and a high-melting first fiber forming a core component A core-type composite fiber composed of a fiber and a low-melting second fiber forming a sheath component, or a random nonwoven fabric obtained by accumulating them, a high-melting first fiber and a low-melting second fiber; And a nonwoven fabric obtained by accumulating them, a random nonwoven fabric obtained by accumulating meltblown filaments, a high-melting synthetic pulp and / or a fiber web and a low-melting synthetic pulp and / or a fibrous web. And a random nonwoven fabric obtained by papermaking. Specific examples of the heat-bondable random nonwoven fabric include “Elves” (trademark, manufactured by Unitika Ltd.),
Non-woven fabrics such as "Sunmore" (trademark, manufactured by Sanwa Paper Co., Ltd.) are exemplified.

[0010] Among the above random nonwoven fabrics, a nonwoven fabric obtained by mixing a core type or parallel type composite fiber with rayon fiber is preferable. Rayon fiber includes rayon staple fiber and filament, and rayon fiber and cotton,
It may be blended with other fibers such as silk, wool, acetate, vinylon, nylon and polyester. The amount of the heat-adhesive fiber is preferably in the range of 5 to 100 parts by weight based on 100 parts by weight of the rayon fiber.

Examples of the first fiber having a high melting point include synthetic fibers such as high-density polyethylene, polypropylene, polyester, polyamide, and acrylic resin, and natural fibers such as cotton, wool, and hemp. In addition, the low melting point second
As the fiber, a fiber made of a thermoplastic resin having a melting point lower than that of the first fiber having a high melting point is selected, and a resin used as a low-melting-point resin layer of a mesh body described later may be used.

Specific examples of the above-mentioned core-type or parallel-type composite fibers include high-density polyethylene (HDPE) / low-density polyethylene (LDPE), HDPE / ethylene-vinyl acetate copolymer (EVA), and polypropylene (PP). )
/ Propylene-ethylene copolymer (PEC), PP / L
DPE, PP / HDPE, polyester (PEs) / copolyester (CPEs), PEs / LDPE, PE
s / HDPE, PEs / PP, polyamide (PA) / P
Various combinations such as P, PA / HDPE and the like can be mentioned. Products include NBF (trademark, Daiwa Spinning Co., Ltd.)
), "ES Fiber" (trademark, manufactured by Chisso Corporation),
"UC Fiber" (trademark, manufactured by Ube Nitto Kasei Co., Ltd.) and the like.

The reticulated body used in the present invention comprises a thermoplastic resin multilayer described later. In particular, it is preferable that the low melting point resin layer is provided on one or both sides of the high melting point resin layer. Specifically, it is selected from those having the configurations described below. (1) Uniaxially oriented network film formed by laminating a low melting point resin layer on one side or both sides of a high melting point resin layer. (2) Weft laminated netted film formed by laminating the above uniaxially oriented network film so that the orientation directions intersect. (3) A non-woven fabric obtained by uniaxially orienting a laminate composed of the high-melting resin layer and the low-melting resin layer, and laminating uniaxially oriented tape obtained by cutting before or after the orientation so that the orientation directions intersect. 4) A woven fabric obtained by weaving the uniaxially oriented tape so that the orientation directions intersect. (5) A laminate formed by laminating the uniaxially oriented network film and the uniaxially oriented tape so that the orientation directions intersect.

FIG. 5 shows an example of the uniaxially oriented network film (1). FIG. 5A is a partially enlarged perspective view showing an example of a longitudinally uniaxially oriented net-like film. The longitudinally uniaxially oriented net-like film 10 is formed by laminating the high-melting resin layer 11 and the low-melting resin layer 12 and performing uniaxial orientation in the longitudinal direction (the direction in which the film is conveyed). Things. FIG. 5B is a partially enlarged perspective view showing an example of a horizontal uniaxially oriented net-like film. The horizontal uniaxially oriented net-like film 10a is formed by laminating the high-melting resin layer 11 and the low-melting resin layer 12 and finely orienting them in the vertical direction as necessary, and then performing slit processing in the horizontal direction (width direction of the film) using a hot blade or the like. Alms,
The uniaxial orientation was performed in the lateral direction.

FIG. 6 shows an example of the weft laminated net-like film of the above (2). FIG. 6A is a partial plan view of a weft laminated net-like film composed of a longitudinally uniaxially oriented net-like film, and FIG. 6B is an enlarged end view taken along the line bb of FIG. Shown. The weft laminated net-like film 13 is obtained by laminating the longitudinally uniaxially oriented net-like film 10 shown in FIG. 5A so that the orientation axes intersect, and heat-fixed.

FIG. 7 is a partial perspective view of the uniaxially oriented tape described in (3). The uniaxially oriented tape 14 is obtained by laminating the high melting point resin layer 11 and the low melting point resin layer 12, orienting in a uniaxial direction, and cutting before or after the orientation. The width of the stretched tape is generally 3 mm to 50 m
m, preferably in the range of 5 mm to 30 mm.

FIG. 8 is a partial plan view of the nonwoven fabric obtained by laminating the uniaxially oriented tape 14 in (3) above. FIG. 9 is a partial perspective view of a woven fabric obtained by laminating and weaving the uniaxially oriented tape (4). The nonwoven fabric 15 and the woven fabric 16 are
Both are formed using the uniaxially oriented tape 14 shown in FIG.

In the above-mentioned orientation treatment, the orientation ratio (elongation ratio) is in the range of 1.1 to 15. However, it is desirable to carry out orientation in a plurality of stages in order to prevent stretching unevenness. For example, the first stage is 1.1 to 8 times, preferably 5 to 7 times.
After the second alignment, the second and subsequent stages are subjected to secondary and tertiary alignment at an orientation ratio of 5 to 15, preferably 6 to 10 with respect to the initial dimension. If the orientation ratio of the uniaxially oriented network film or the uniaxially oriented tape is less than 1.1, the mechanical strength of the woven or nonwoven fabric is not sufficient. On the other hand, when the orientation magnification exceeds 15, it is difficult to perform orientation by a normal method, and problems such as the necessity of an expensive apparatus arise. As a method of heat fixing, the method of continuously heating and fixing the woven fabric or the laminated sheet while rotating it on a heating cylinder drum is most preferable.

The orientation method may be either a rolling method or a stretching method, but the stretching method is particularly preferably a pseudo-uniaxial stretching method. The rolling method as referred to in the present invention means that a thermoplastic resin film is passed between two heating rolls having a gap smaller than the thickness of the film, and squeezed at a temperature lower than the melting point (softening point) of the resin film. This is a method of extending the length by an amount corresponding to the decrease in the length. The pseudo-uniaxial stretching method is a method in which a thermoplastic resin film is passed between a low-speed roll and a high-speed roll (proximity roll) in which the roll gap is reduced as much as possible, and the film is stretched while suppressing shrinkage in the width direction as small as possible.

The thickness ratio between the high-melting resin layer and the low-melting resin layer used for the net is not particularly limited. When a low-melting resin is used as the adhesive layer, the thickness is 50% or less of the entire thickness. Preferably, it is 40% or less. If the thickness of the low melting point resin layer is 3 μm or more, various physical properties such as adhesive strength at the time of thermal bonding can be satisfied, but preferably 5 to 100 μm
Is selected from the range.

The high melting point resin used in the present invention is a high melting point resin.
Medium density polyethylene, polypropylene, polybutene
1, poly-4-methylpentene-1, polyhexene-1
And polyolefins such as copolymers of α-olefins such as propylene-ethylene copolymer, and thermoplastic resins such as polyamide, polyester, polycarbonate and polyvinyl alcohol.

The low melting point resin used in the present invention is a high melting point resin.
Medium / low density polyethylene, linear low density polyethylene,
Ultra-low density polyethylene, ethylene-vinyl acetate copolymer; ethylene-acrylic acid copolymer and ethylene-methacrylic acid copolymer; ethylene-acrylate copolymer such as ethylene-ethyl acrylate copolymer and ethylene- Methacrylate copolymer; ethylene-
(Maleic acid or ester thereof) copolymer; propylene-based polymer such as polypropylene and propylene-ethylene copolymer; polyolefin modified with unsaturated carboxylic acid;
A thermoplastic resin such as a copolymerized polyester is exemplified. For production reasons, the difference in melting point from the high melting point resin must be 5 ° C. or more, and preferably 10 to 50 ° C. or more.

Specific lamination structures of the resin in the network include high-density polyethylene (HDPE) / low-density polyethylene (LDPE), LDPE / HDPE / LDP
E, HDPE / ethylene-vinyl acetate copolymer (EV
A), EVA / HDPE / EVA, HDPE / linear low density polyethylene (LLDPE), LLDPE / HDPE
/ LLDPE, polypropylene (PP) / propylene-
Ethylene copolymer (PEC), PEC / PP / PEC,
Polyester (PEs) / Copolyester (CPE)
s), CPEs / PEs / CPEs and the like.

As the sealing layer of the present invention, a medium / low density polyethylene, a linear low density polyethylene, an ultra low density polyethylene, an ethylene-vinyl acetate copolymer;
Acrylic acid copolymer and ethylene-methacrylic acid copolymer; Ethylene-acrylate copolymer and ethylene-methacrylate copolymer such as ethylene-ethyl acrylate copolymer; ethylene- (maleic acid or its ester ) Copolymers; propylene-based polymers such as polypropylene and propylene-ethylene copolymers; polyolefins modified with unsaturated carboxylic acids; copolymerized polyesters and the like. A system resin, in particular, a polyethylene mainly composed of a linear low-density polyethylene is preferable.

It is preferable that the seal layer is previously laminated on the synthetic resin transparent film by a method such as extrusion lamination or dry lamination. Also, after printing a bar code or the name of the content or the name of the manufacturer on the transparent film made of synthetic resin,
By laminating the seal layer on the printing surface by a method such as extrusion lamination or dry lamination, peeling of the printed display can be prevented.

Further, in order to improve the commercial value, the high-melting resin layer and / or the low-melting resin layer of the mesh forming the air-permeable transparent bag may be provided with a coloring agent such as a pigment or a dye having a color according to the contents. Can also be colored.

Although the air-permeable transparent bag is particularly suitable for packaging vegetables and the like, it can be reused as a draining garbage bag for a kitchen, a storage bag, and the like. Is also a valid product.

Hereinafter, the present invention will be described with reference to examples. <Example 1> [Preparation of laminated net-like film] High-density polyethylene (MFR: 1.0 g / 10 min, density: 0.956 g / cm ³ , melting point: 12) as a high melting point resin layer by a multilayer water-cooled inflation method.
9 ° C .; trade name: Nisseki Staphrene E710, manufactured by Nippon Petrochemical Co., Ltd., hereinafter referred to as “HDPE”) for the inner layer,
Low-density polyethylene (M
FR 3.0 g / 10 min, density 0.924 g / cm ³ , melting point 109
° C; Trade name: Nisseki Lexlon F30, Nippon Petrochemical Co., Ltd.
(Hereinafter referred to as “LDPE”), and has a thickness of 15 μm.
m (LDPE) / 100 μm (HDPE) / 15 μm
A laminated film of (LDPE) was produced, the obtained laminated film was stretched 8 times, and then split to obtain a basis weight of 18 g / m ² ,
A vertically uniaxially oriented net-like film having a three-layer structure with a width of 1 m was obtained (see FIG. 5A). Next, the longitudinally uniaxially oriented net-like film was vertically laminated so that the orientation axes were perpendicular to each other to produce a vertically laminated net-like film (A) (see FIG. 6). [Production of air-permeable transparent bag] Oriented polypropylene (OP
P) with a barcode and a manufacturer's name printed thereon, and a linear low-density polyethylene (hereinafter referred to as “LLDP”) as a sealing layer.
E) was laminated by a dry lamination method to obtain a laminate. The weft laminated net-like film (A)
And the surface of the laminate on the LLDPE side were polymerized, and the peripheral portion was thermally bonded except for an opening on one side to produce a breathable transparent bag (see FIG. 1). Table 1 shows the results of measuring the tensile strength at the bottom and the like.

<Examples 2 and 3> Non-woven fabric (B) and woven fabric (C) each consisting of a uniaxially oriented tape shown in FIGS. 8 and 9 instead of the weft laminated net film (A) used in Example 1 Was used. Table 1 shows the results.

<Example 4> Instead of the weft-laminated net-like film (A) used in Example 1, "ES fiber" 3
A random nonwoven fabric (D) mixed with 0% by weight was used.
Table 1 shows the results.

<Comparative Example 1> The same procedure as in Example 1 was carried out except that oriented polypropylene having no LLDPE as a seal layer was laminated on the weft lamination network film (A). Table 1 shows the results.

<Comparative Examples 2 to 5> Instead of the laminate (OPP / LLDPE) used in Example 1, an HDPE film used in a conventional vegetable bag was used. (B), a woven fabric (C) and a random nonwoven fabric (D) were respectively laminated, and the same procedure as in Example 1 was performed. Table 1 shows the results.

<Test Method> (1) Bottom Tensile Strength (according to JIS Z1711) The bottom seal portion is cut into a strip having a width of 15 mm, and a 180 ° peel test is performed. The average of the five data was determined. (2) Onion test Five onions were placed in a small sample bag, and the state of the bottom heat-sealed portion was observed by applying vibration, and evaluated according to the following criteria. ○ ----- No change × ----- Bottom broken

[0034]

[Table 1]

[0035]

As described above, the air-permeable transparent bag of the present invention maintains air permeability and transparency and has a high heat seal strength, so that heavy fresh fruits and vegetables such as onions, potatoes, tangerines and the like can be obtained. Suitable for packaging. Further, it is easy to determine the contents, the printed name such as the product name and the bar code does not peel off, and the product value can be increased by coloring as necessary.

[Brief description of the drawings]

FIG. 1 (a) is a schematic perspective view of one embodiment of the present invention, and FIG. 1 (b) is an end view taken along line bb of FIG. 1 (a).

FIGS. 2A and 2B are front views of two other embodiments of the present invention.

FIG. 3A is a schematic perspective view of another embodiment of the present invention, and FIG. 3B is an end view taken along line bb of FIG. 3A.

FIG. 4 is an end view of still another embodiment of the present invention, corresponding to FIG. 3 (b).

FIG. 5 shows an example of a uniaxially oriented network film. (A) is a partial enlarged perspective view of a longitudinally uniaxially oriented net-like film, (b)
1 is a partially enlarged perspective view of a horizontal uniaxially oriented network film.

FIG. 6 shows an example of a weft laminated net-like film. (A) is a partial plan view of a weft-laminated mesh film made of a longitudinally uniaxially oriented mesh film, and (b) is an enlarged end view taken along line bb of (a).

FIG. 7 is a partial perspective view of a uniaxially oriented tape.

FIG. 8 is a partial plan view of a nonwoven fabric obtained by laminating a uniaxially oriented tape in a weft manner.

FIG. 9 is a partial perspective view of a woven fabric obtained by weaving a uniaxially oriented tape.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1a, 1b, 1c, 1d Breathable transparent bag 2 Transparent film 3 Reticulated body 4 Seal layer 5 Opening 6 Peripheral edge 7 Laminate 8 Adhesive 9, 9a Folding part 10 Vertical uniaxially oriented network film 10a Horizontal uniaxially oriented network film REFERENCE SIGNS LIST 11 high melting point resin layer 12 low melting point resin layer 13 weft laminated net film 14 uniaxially oriented tape 15 nonwoven fabric 16 woven fabric

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-29752 (JP, A) JP-A 5-95883 (JP, U) JP-A 4-289 (JP, U) JP-A 63-297 190051 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B65D 30/00-30/28

Claims (8)

(57) [Claims] 1. A transparent film made of a synthetic resin constituting one side of a bag and one or both sides of a drainable random nonwoven fabric or a high melting point resin layer comprising at least one heat- adherable fiber and constituting another side of the bag. Fi formed by laminating a low-melting point resin layer
Either of a mesh and a mesh formed to allow drainage
Fold both sides and / or bottom of the edge of
To provide a folded part, and this folded part
The peripheral portion is not provided with a folded portion and the one folded portion is not provided.
The edge of the beveled part and the edge of the other peripheral part are in opposite directions
As shown in the figure, it is formed by heat bonding through a seal layer.
A breathable transparent bag with draining properties . 2. The reticulated body comprises: (1) a uniaxially oriented reticulated film, (2) a weft laminated reticulated film obtained by laminating the uniaxially oriented reticulated film so that the orientation directions intersect, (3) a uniaxially oriented reticulated film. A nonwoven fabric obtained by laminating oriented uniaxially oriented tapes so that the orientation directions intersect, (4) a woven fabric obtained by weaving the uniaxially oriented tapes so that the orientation directions intersect, and (5) the uniaxial net shape 2. The breathable transparent bag according to claim 1, wherein the bag is one of a laminate obtained by laminating a film and the uniaxially oriented tape such that their orientation directions intersect. 3. 3. The breathable transparent bag according to claim 1, wherein the synthetic resin transparent film is an oriented film. 4. The breathable transparent bag according to claim 1, wherein the transparent film made of a synthetic resin is made of a laminate including the seal layer in advance. 5. The breathable transparent bag according to claim 4, wherein the laminate is formed by printing on the inner surface of the transparent film made of the synthetic resin and providing the seal layer thereon. . 6. The breathable transparent bag according to claim 1, wherein the synthetic resin transparent film is made of an oriented polypropylene resin. 7. The breathable transparent bag according to claim 1, wherein the seal layer is made of linear low-density polyethylene. 8. The breathable transparent bag according to claim 1, wherein the high-melting resin layer and / or the low-melting resin layer of the net are colored.