JP2014023642A - Method for producing bag body component member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a bag body component member capable of producing a bag body not causing trouble such as edge breakage even when heat seal is performed under a strong heat seal condition, and excellent in heat resistance and heat seal strength (seal strength).SOLUTION: A laminate is made by sticking a nonwoven fabric 11 and a porous film 13 to each other, and an electron beam having an absorbed dose of 25-200 kGy is irradiated thereon to produce a bag body component member. In one embodiment, the electron beam is irradiated from the nonwoven fabric side of the laminate. In the other embodiment, the thickness of the porous film 13 is 45-150 μm.

Description

  The present invention relates to a method for manufacturing a bag member.

  Conventionally, a bag member is widely used when a heating element is enclosed to manufacture a disposable body warmer or when a dehumidifying agent or a deodorant is enclosed (for example, see Patent Documents 1 and 2).

  Examples of the disposable body warmer include those shown in FIG. Specifically, two bag body members (the front material 6 and the backing material 7) are bonded together by heat sealing to form a bag body, and a heating element whose main component is iron powder or the like inside the bag body. 3 is enclosed.

  In recent years, it has been required to increase the production speed for the purpose of improving the productivity of disposable warmers. Therefore, by heat-sealing the bag-constituting member (for example, a laminated body obtained by laminating a porous film and a nonwoven fabric) under stronger heat-sealing conditions (for example, higher temperature and / or higher-pressure conditions), It has been studied to shorten the time required for heat sealing processing and increase the production speed. However, in the conventional bag member, when heat sealing is performed under strong heat sealing conditions, the edge breaks (the boundary between the heat sealing portion and the non-heat sealing portion (the edge portion, for example, the heat sealing portion and the non-heat sealing portion in FIG. 2). In some cases, such as the phenomenon that the film tears at the boundary portion 5).

  That is, even when heat-sealed under heat-sealing conditions stronger than conventional heat-sealing conditions (for example, conditions of 110 to 140 ° C.), defects such as edge breakage do not occur and heat resistance is excellent, and heat-sealing strength (sealing strength) The present condition is that a method for producing a bag-constituting member excellent in the above is required.

Japanese Patent Laid-Open No. 11-19113 JP 2002-36471 A

  Accordingly, an object of the present invention is to produce a bag-constituting member that is excellent in heat resistance and excellent in heat seal strength (seal strength) without causing defects such as edge breakage even when heat sealed under strong heat seal conditions. Is to provide.

  As a result of intensive studies to achieve the above object, the present inventor has heat-sealed under a strong heat-sealing condition by irradiating a laminated body obtained by laminating a nonwoven fabric and a porous film with an electron beam having a specific absorbed dose. Even in this case, it was found that a bag-constituting member having excellent heat resistance without causing defects such as edge breakage and excellent heat seal strength (seal strength) was obtained, and the present invention was completed.

  That is, this invention provides the manufacturing method of the bag body structural member characterized by including the irradiation process which irradiates the electron beam of 25-200 kGy of absorbed dose to the laminated body obtained by bonding together a nonwoven fabric and a porous film. To do.

  In the irradiation step, the electron beam is preferably irradiated from the nonwoven fabric side of the laminate.

  The thickness of the porous film is preferably 45 to 150 μm.

  Since the manufacturing method of the bag constituting member of the present invention has the above-described configuration, even when heat-sealed under strong heat-sealing conditions, defects such as edge breakage do not occur and heat resistance is excellent, and heat-sealing strength (sealing strength) Can be produced.

It is a schematic sectional drawing which shows an example of the disposable body warmer containing the bag body structural member obtained with the manufacturing method of this invention. It is the schematic plan view seen from the upper surface which shows an example of the disposable body warmer containing the bag body structural member obtained with the manufacturing method of this invention. It is a schematic sectional drawing which shows an example of the conventional disposable warmer.

The manufacturing method of the bag structural member of the present invention includes at least a step of irradiating an electron beam having an absorbed dose of 25 to 200 kGy to a laminate obtained by laminating a nonwoven fabric and a porous film.
In the present specification, the step of irradiating the laminated body with an electron beam having an absorbed dose of 25 to 200 kGy may be referred to as an “irradiation step”. Further, in this specification, a laminate before irradiation with an electron beam is referred to as a “laminate”, and a laminate (bag body member obtained by the production method of the present invention) irradiated with an electron beam in an irradiation step is referred to as a “book”. It will be referred to as a “bag member of the invention”.

[Irradiation process]
(Laminate)
The laminate is a laminate obtained by bonding the nonwoven fabric and the porous film. The said laminated body should just have the said nonwoven fabric bonded together and the said porous film, and may have an intermediate | middle layer, an adhesive bond layer, etc. other than the said nonwoven fabric and the said porous film.

  Although it does not specifically limit as said nonwoven fabric (nonwoven fabric layer), For example, known nonwoven fabrics, such as a polyamide nonwoven fabric (nylon nonwoven fabric etc.), a polyester nonwoven fabric (polyethylene terephthalate nonwoven fabric etc.), a polyolefin nonwoven fabric, a rayon nonwoven fabric, etc. (Nonwoven fabrics made of natural fibers, nonwoven fabrics made of synthetic fibers, etc.) can be used. Among these, a nylon nonwoven fabric and a polyester nonwoven fabric are preferable, and a polyethylene terephthalate nonwoven fabric is more preferable, from the viewpoint of easily obtaining the heat resistance improvement effect by electron beam irradiation, heat resistance, texture, and the like. The said nonwoven fabric can be used individually or in combination of 2 or more types. The nonwoven fabric may have either a single layer or multiple layers.

Although the manufacturing method of the said nonwoven fabric is not specifically limited, For example, the nonwoven fabric manufactured by the spunbond method (spunbond nonwoven fabric) may be sufficient, and the nonwoven fabric manufactured by the spunlace method (spunlace nonwoven fabric), Also good. Among these, a spunbonded nonwoven fabric is preferable from the viewpoint of strength. In the above nonwoven fabric, the fiber diameter, fiber length, basis weight, etc. are not particularly limited. For example, from the viewpoint of processability and cost, the basis weight is preferably 20-100 g / m ² , more preferably 20-80 g / m. ² .

  Although the said porous film (porous film layer) is not specifically limited, For example, it forms from the raw material containing resin and an inorganic filler at least. The porous film may have any form of a single layer or a multilayer.

  Although it does not specifically limit as resin which comprises the said porous film, For example, a polyester-type resin, polyolefin-type resin (olefin resin), a polystyrene-type resin etc. are mentioned. Among these, polyethylene resins are preferable from the viewpoints of price, flexibility, and heat sealability. That is, the porous film is preferably a porous film formed from a raw material containing a polyethylene resin. The said resin can be used individually or in combination of 2 or more types.

  The polyolefin resin is not particularly limited. For example, at least olefin components (ethylene, propylene, butene-1, pentene-1, hexene-1, 4-methyl-pentene-1, heptene-1, octene-1, etc.) It is a resin containing a monomer component such as α-olefin. Specifically, for example, polyethylene resin (low density polyethylene, linear low density polyethylene (linear low density polyethylene), medium density polyethylene, high density polyethylene, ethylene-α-olefin copolymer, etc.), polypropylene type Examples thereof include resins (polypropylene, propylene-α-olefin copolymer, etc.), polybutene resins (eg, polybutene-1), and poly-4-methylpentene-1. Examples of the polyolefin resin include ethylene-unsaturated carboxylic acid copolymers such as ethylene-acrylic acid copolymers and ethylene-methacrylic acid copolymers; ionomers; ethylene-methyl acrylate copolymers, ethylene -Ethylene- (meth) acrylic ester copolymers such as ethyl acrylate copolymer and ethylene-methyl methacrylate copolymer; ethylene-vinyl acetate copolymer; ethylene-vinyl alcohol copolymer, etc. it can. Among these, from the viewpoint of improving heat sealability, polyethylene resins are preferable, and low density polyethylene, linear low density polyethylene, and ethylene-α-olefin copolymers are more preferable. The said polyolefin resin can be used individually or in combination of 2 or more types.

The density of the low density polyethylene is not particularly limited, for example, preferably 0.90~0.93g / cm ^3, more preferably 0.91~0.92g / cm ^3. Moreover, the weight average molecular weight of the said low density polyethylene is although it does not specifically limit, For example, 30,000-200000 are preferable, More preferably, it is 50,000-60,000. The MFR (melt mass flow rate) at 190 ° C. of the low-density polyethylene is not particularly limited, but is preferably 1.0 to 5.0 g / 10 minutes, and more preferably 2.0 to 4.0 g / 10 minutes. In addition, the density in this specification shall mean the density obtained based on JISK6922-2 and JISK7112. Moreover, the weight average molecular weight in this specification can be measured by GPC (gel permeation chromatography) method. Especially, it is preferable to measure by the high temperature GPC method (high temperature GPC apparatus). Specifically, for example, a high temperature GPC method described in JP-A-2009-184705 can be used. Moreover, MFR in this specification can be measured based on ISO1133 (JIS K7210).

  Although the said linear low density polyethylene is not specifically limited, For example, the short chain branch (branch length is comprised (formation)) as an essential monomer component with ethylene and a C4-C8 alpha olefin. Linear polyethylene having 1 to 6 carbon atoms is preferable. Although it does not specifically limit as an alpha olefin used for the said linear low density polyethylene, For example, 1-butene, 1-octene, 1-hexene, and 4-methylpentene-1 are preferable. In the above linear low density polyethylene, the content of ethylene monomer repeating units (repeating units derived from (derived from) ethylene monomers) with respect to repeating units of all constituting monomers (repeating units derived from (derived from) all structural monomers) Although (content rate) is not specifically limited, For example, 90 weight% or more is preferable. The linear low-density polyethylene is not particularly limited. For example, from the viewpoint of price and heat sealability, a so-called metallocene linear low-density polyethylene (metallocene LLDPE) prepared using a metallocene catalyst is used. Is particularly preferred.

The density of the linear low-density polyethylene is not particularly limited, for example, preferably 0.90~0.93g / cm ^3, more preferably 0.91~0.92g / cm ^3. Although the weight average molecular weight of the said linear low density polyethylene is not specifically limited, For example, 30,000 to 200,000 are preferable, More preferably, it is 50,000 to 100,000, More preferably, it is 50,000 to 60,000. The MFR at 190 ° C. of the linear low density polyethylene is not particularly limited, but is preferably 1.0 to 5.0 g / 10 minutes, and more preferably 2.0 to 4.0 g / 10 minutes. It is.

  The ethylene-α-olefin copolymer is a copolymer composed (formed) with ethylene and α-olefin as essential monomer components. The α-olefin is not particularly limited as long as it is an α-olefin other than ethylene. For example, propylene, butene-1, pentene-1, hexene-1, 4-methyl-pentene-1, heptene-1, octene Examples include α-olefins having 3 to 10 carbon atoms such as −1. Accordingly, examples of the ethylene-α-olefin copolymer include an ethylene-propylene copolymer and an ethylene- (butene-1) copolymer. In the ethylene-α-olefin copolymer, the content of the repeating unit of the ethylene monomer with respect to the repeating units of all the constituent monomers is not particularly limited, but is preferably 60 to 99 mol%, more preferably 80 to 99 mol, for example. %.

Although the density of the said ethylene-alpha-olefin copolymer is not specifically limited, For example, less than 0.90 g / cm < ³ > is preferable, More preferably, it is 0.86-0.89 g / cm < ³ >, More preferably, it is 0.87. -0.89 g / cm < ³ >. Moreover, although the weight average molecular weight of the said ethylene-alpha-olefin copolymer is not specifically limited, For example, 50,000-200,000 are preferable, More preferably, it is 80,000-150,000. The MFR at 190 ° C. of the ethylene-α-olefin copolymer is not particularly limited, but is preferably 1.0 to 5.0 g / 10 minutes, more preferably 2.0 to 4.0 g / 10, for example. Minutes.

  The inorganic filler constituting the porous film is not particularly limited. For example, talc, silica, stone powder, zeolite, alumina, aluminum powder, iron powder, calcium carbonate, magnesium carbonate, magnesium carbonate-calcium, carbonate Metal salt of carbonic acid such as barium; Metal salt of sulfuric acid such as magnesium sulfate and barium sulfate; Metal oxide such as zinc oxide, titanium oxide and magnesium oxide; Aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, calcium hydroxide, Metal hydroxides such as barium hydroxide; metal hydrates (hydrated metal compounds) such as magnesium oxide-nickel oxide hydrate, magnesium oxide-zinc oxide hydrate, and the like. Of these, calcium carbonate and barium sulfate are preferable. The said inorganic filler can be used by 1 type or in combination of 2 or more types.

  Although the shape of the said inorganic filler is not specifically limited, For example, flat plate shape, a granular form, etc. are mentioned. Among these, granular (particulate) is preferable from the viewpoint of forming voids (micropores) by stretching. As the inorganic filler, inorganic particles (inorganic fine particles) made of calcium carbonate are particularly preferable.

  The particle size (average particle size) of the inorganic filler (inorganic particles) is not particularly limited, but is preferably 0.1 to 10.0 μm, more preferably 0.1 μm from the viewpoint of void formability and appearance. 5 to 5.0 μm.

  The content of the inorganic filler (inorganic particles) in the porous film is not particularly limited. For example, from the viewpoint of void formation and appearance, the resin component (100 parts by weight) constituting the porous film is used. On the other hand, it is preferably 50 to 150 parts by weight, more preferably 80 to 120 parts by weight. By setting the content of the inorganic filler to 50 parts by weight or more, void formability is improved. By making the content of the inorganic filler 150 parts by weight or less, film formation is broken and appearance defects can be suppressed.

  The raw material for forming the porous film further includes various additives such as a colorant, an anti-aging agent, an antioxidant, an ultraviolet absorber, a flame retardant, and a stabilizer within the range that does not impair the effects of the present invention. It may be blended.

  The porous film is not particularly limited. For example, the porous film can be produced by stretching (stretching) an unstretched film. More specifically, for example, it can be made porous by stretching an unstretched film formed from a raw material containing a resin and an inorganic filler. The porous film can be produced by, for example, a melt film forming method (T-die method, inflation method). Of these, the T-die method is preferable. For example, specifically, the raw materials are mixed and dispersed in a twin-screw kneading extruder to produce raw material pellets, and then melt-extruded in a single-screw extruder to produce an unstretched film. It can be made porous by stretching (for example, uniaxial or biaxial stretching). When a porous film is used as a laminated film, a coextrusion method can be preferably used.

  In the method for producing the porous film, the extrusion temperature is preferably 170 to 270 ° C, more preferably 180 to 260 ° C, and further preferably 190 to 220 ° C. Moreover, 5-25 m / min is preferable for the taking-up speed at the time of preparation of an unstretched film, and 5-40 degreeC is preferable for take-off roll temperature (cooling temperature), More preferably, it is 20-30 degreeC.

  The porous film can be produced by making the unstretched film porous, for example, by stretching it uniaxially or biaxially (sequential biaxial, simultaneous biaxial). As a method for stretching uniaxially or biaxially, a known and usual stretching method such as a roll stretching method or a tenter stretching method can be used. The stretching temperature is preferably 50 to 100 ° C, more preferably 60 to 90 ° C. From the viewpoints of making it porous and stable film formation, the draw ratio (uniaxial direction) is preferably 2 to 5 times, more preferably 3 to 4 times. In the case of biaxial stretching, the area stretch ratio is preferably 2 to 10 times, more preferably 3 to 7 times.

  Although the thickness of the said porous film is not specifically limited, For example, 45-150 micrometers is preferable, More preferably, it is 50-120 micrometers.

  The said porous film is used as a structural member of a bag body structural member (member which comprises a bag body). Among these, it is preferably used as a constituent member of a bag-constituting member having air permeability from the viewpoints of air permeability and oxygen supply capability to the heating element.

  Although the said laminated body is not specifically limited, For example, the laminated body whose one surface layer (surface layer) is a nonwoven fabric and the other surface layer is a porous film is preferable, and has one bonded nonwoven fabric and a porous film. A laminate (in particular, a laminate obtained by bonding a nonwoven fabric and a porous film) is more preferable.

  The laminate can be produced by a step of bonding the non-woven fabric and the porous film to obtain a laminate (sometimes referred to as a “bonding step”). Although the method of bonding the said nonwoven fabric and the said porous film is not specifically limited, For example, the method of bonding the said nonwoven fabric and the said porous film using an adhesive agent is mentioned. That is, in the bonding step, the nonwoven fabric and the porous film may be bonded using an adhesive. The adhesive includes “pressure-sensitive adhesive (pressure-sensitive adhesive)”.

  Although it does not specifically limit as an adhesive agent used when bonding the said nonwoven fabric and the said porous film, For example, rubber type (natural rubber, a styrene-type elastomer, etc.), urethane type (acryl urethane type), polyolefin type (ethylene -Vinyl acetate copolymer (EVA), ethylene-methyl acrylate copolymer (EMA), etc.), known acrylic, silicone, polyester, polyamide, epoxy, vinyl alkyl ether, fluorine, etc. An adhesive can be used. Moreover, the said adhesive agent can be used individually or in combination of 2 or more types. Among these, from the viewpoints of price and processability, polyolefin adhesives, polyamide adhesives, and polyester adhesives are preferable, and polyamide adhesives are more preferable.

  In addition, the adhesive may be an adhesive having any form and is not particularly limited, but can be applied by melting with heat without using a solvent, However, a hot melt type (hot melt type) adhesive is preferable because it has an advantage that an adhesive layer can be formed by direct application and an advantage that a larger adhesive force can be obtained by heat seal processing at the heat seal part. . That is, in the bonding step, it is preferable to bond the nonwoven fabric and the porous film using a polyamide-based or polyester-based hot melt adhesive (particularly, a polyamide-based hot melt adhesive). It is more preferable to bond using a plastic polyamide hot melt adhesive or a thermoplastic polyester hot melt adhesive (particularly, a thermoplastic polyamide hot melt adhesive).

The specific method of laminating the nonwoven fabric and the porous film (lamination method, composite method) varies depending on the type of adhesive and the like, and is not particularly limited, but when using a hot melt adhesive, A preferable example is a method in which an adhesive is applied (coated) on the nonwoven fabric and then the porous film is bonded to bond the nonwoven fabric and the porous film together.
The adhesive can be applied by a publicly known and commonly used method for applying a hot-melt adhesive, and is not particularly limited. For example, from the viewpoint of maintaining air permeability, spray application (spray coating) can be used. ), Stripe coating, and dot coating are preferred. The application amount (solid content) of the adhesive is not particularly limited, but is preferably 0.5 to 20 g / m ² , and more preferably 1 to ²⁰ g / m ² from the viewpoints of adhesiveness and economical efficiency of the heat seal portion at the time of bag formation. 8 g / m ² .

  A method of providing a layer other than the nonwoven fabric and the porous film is not particularly limited, and examples thereof include a method of bonding using the adhesive used when the nonwoven fabric and the porous film are bonded.

  Although the thickness of the said laminated body is not specifically limited, For example, 60-500 micrometers is preferable, More preferably, it is 70-400 micrometers, Especially preferably, it is 80-300 micrometers.

(Electron beam irradiation)
The absorbed dose of the electron beam in the irradiation step is 25 to 200 kGy, preferably 25 to 150 kGy, more preferably 30 to 100 kGy. By setting the absorbed dose to 25 kGy or more, the porous film is appropriately crosslinked and has excellent heat resistance. Therefore, even when heat sealing is performed at a high temperature, the edge breakage hardly occurs. By setting the absorbed dose to 200 kGy or less, the porous film is hardly excessively crosslinked. Therefore, the heat-sealability of the porous film is unlikely to deteriorate, and the bag-constituting member after electron beam irradiation is less likely to cause poor appearance. In addition, it is estimated that the appearance defect of the bag structural member after electron beam irradiation occurs because the porous film is excessively crosslinked (cured) and contracts by electron beam irradiation, and the nonwoven fabric does not change its shape. Although the electron beam irradiation in the irradiation process is not particularly limited, it is sufficient that the total absorbed dose by the electron beam irradiation falls within the above range, and the irradiation may be performed once or divided into a plurality of times. .
In this specification, the absorbed dose 1 kGy of an electron beam is a dose when 1 J of energy is absorbed by a 1 kg substance by an electron beam. The absorbed dose of the electron beam can be measured using a dosimeter such as (cellulose triacetate (CTA) dosimeter (trade name “FTR-125”, manufactured by Fuji Film Co., Ltd.)).

Although the acceleration voltage of the electron beam in the said irradiation process is not specifically limited, For example, 10-250 kV is preferable, More preferably, it is 20-200 kV. Especially, when irradiating an electron beam from the nonwoven fabric side of a laminated body, 100-200 kV (especially 120-180 kV) is preferable, and when irradiating from the porous film side of a laminated body, 50-150 kV (especially 80-120 kV). Is preferred.
By setting the acceleration voltage to 10 kV or more, even when the electron beam is irradiated from the nonwoven fabric side of the laminate, the electron beam reaches the porous film, and a bag-constituting member having excellent heat resistance is obtained. Moreover, since the porous film surface is not crosslinked, the heat sealability can be maintained. By setting the acceleration voltage to 250 kV or less, the irradiated electron beam does not penetrate the stacked body, and the irradiation efficiency is improved.

  The line speed of the laminate (irradiated body) when irradiating the electron beam in the irradiation step is not particularly limited, but is preferably 1 to 150 m / min, and more preferably 5 to 120 m / min. Productivity is improved by setting the line speed to 1 m / min or more.

  The apparatus (electron beam irradiation apparatus) used in the irradiation process is not particularly limited. For example, the trade name “EC300” (manufactured by Iwasaki Electric Co., Ltd.), the trade name “CB200” (manufactured by Iwasaki Electric Co., Ltd.) Etc. When the above apparatus is used, the output of the electron beam can be kept constant by current control as long as the line speed is in the range of 1 to 150 m / min regardless of whether the line speed is high or low. .

  In the irradiation step, the electron beam irradiation direction is not particularly limited. For example, the electron beam is irradiated from the nonwoven fabric side of the laminate to the laminate in which the nonwoven fabric and the porous film are bonded. Or irradiation from the porous film side of the laminate. Especially, it is preferable to irradiate an electron beam from the nonwoven fabric side of a laminated body from a viewpoint which can bridge | crosslink a bag body structural member moderately, is easy to provide the outstanding heat resistance, and can maintain heat seal property. In addition, when an electron beam is irradiated from the porous film side of a laminated body, depending on irradiation conditions, the electron beam irradiation surface (surface) of a porous film may bridge | crosslink too much, and heat sealability may fall.

  The angle at which the electron beam is irradiated is not particularly limited, but from the viewpoint of irradiation efficiency, for example, the electron beam may be substantially perpendicular to the surface of the laminate (nonwoven fabric side surface or porous film side surface). Irradiation is preferred.

  In the irradiation step, it is preferable to irradiate the electron beam with an oxygen concentration as low as possible from the viewpoint of suppressing oxygen inhibition of the electron beam. Although it does not specifically limit as said oxygen concentration, For example, 10,000 ppm or less is preferable, More preferably, it is 6000 ppm or less. Among them, it is preferable to irradiate an electron beam in a nitrogen atmosphere (for example, in a nitrogen atmosphere having an oxygen concentration of 2000 ppm or less) after nitrogen substitution (nitrogen purge).

  When the electron beam is irradiated from the porous film side of the laminate, the electron beam irradiated to the electron beam irradiation surface (surface) of the porous film can be reduced by oxygen inhibition, and excessive crosslinking of the porous film surface can be achieved. From the viewpoint that it can be suppressed, it is preferable to irradiate an electron beam in the presence of oxygen (for example, in the atmosphere or under an oxygen concentration of 20000 to 100000 ppm) without nitrogen replacement.

  In the production method of the present invention, from the viewpoint of production efficiency, after obtaining the laminate by the step of attaching the nonwoven fabric and the porous film to obtain a laminate (bonding step), the irradiation step is continuously performed. Preferably it is done. Although the space | interval of the said bonding process and the said irradiation process is not specifically limited, For example, 2-120 seconds are preferable, More preferably, it is 2-100 seconds.

According to the production method of the present invention, since the porous film is appropriately crosslinked, when heat sealing is performed under strong heat sealing conditions (for example, a temperature higher than 150 ° C., a high temperature of 200 ° C. or higher, and / or a high pressure condition). However, it is possible to manufacture a bag member that is unlikely to cause problems such as edge breakage. For this reason, when the bag constituting member obtained by the production method of the present invention is used, the time required for heat sealing can be shortened (the production speed can be increased), and the production efficiency is improved. In addition, when setting heat sealing conditions, it becomes possible to select heat sealing processing conditions such as high temperature and / or high pressure, and the range of heat sealing conditions that can be set is widened. Easy to set.
Moreover, according to the manufacturing method of this invention, since the crystallization of an adhesive advances by electron beam irradiation, the delamination force between the said nonwoven fabric and the said porous film increases the bag body structural member of this invention. Therefore, when using a bag structural member, it is hard to produce malfunctions, such as a non-woven fabric and a porous film peeling off, or a tear entering between a nonwoven fabric and a porous film. In addition, when the nonwoven fabric after electron beam irradiation and the porous film after electron beam irradiation are bonded together, the delamination force of a nonwoven fabric and a porous film may become low.
Moreover, according to the manufacturing method of this invention, since a porous film is bridge | crosslinked moderately at an irradiation process, the heat seal intensity | strength after heat seal processing is maintained. In particular, when an electron beam is irradiated from the nonwoven fabric side of the laminate, the surface of the porous film is not excessively crosslinked, and a bag-constituting member that is more excellent in heat seal strength is obtained. In addition, when the electron beam is irradiated from the porous film side of the laminate in the presence of oxygen (for example, in the air or under an oxygen concentration of 20000 to 100000 ppm), the surface of the porous film is not easily crosslinked. A bag constituting member having excellent heat seal strength can be obtained.

[Bag component]
Although the gel fraction of the porous film in the bag structural member (laminated body after an irradiation process) of this invention is not specifically limited, For example, 2-60% is preferable, More preferably, it is 15-50%. When the gel fraction is 60% or less, heat sealability can be maintained. When the gel fraction is 2% or more, the heat resistance is improved.

The said gel fraction is calculated | required as a weight fraction (unit: weight%) with respect to the sample before immersion of the xylene insoluble part after performing a heated xylene extraction in the xylene using a Soxhlet extraction apparatus in xylene. Specifically, it is a value calculated by the following “Method for measuring gel fraction”.
(Measurement method of gel fraction)
99.0% or more of an isopropyl alcohol solution (a solution having an isopropyl alcohol concentration of 99.0% or more) of the laminate before electron beam irradiation and the bag constituting member of the present invention after the laminate is irradiated with an electron beam A member other than the porous film (nonwoven fabric, adhesive layer, etc.) is removed by dipping in a porous film to obtain a porous film before and after electron beam irradiation. The obtained porous film before and after electron beam irradiation: After wrapping about 0.6 g of each in a Teflon (registered trademark) film, tied with a string, a sample (porous before electron beam irradiation) A film sample and a porous film sample after electron beam irradiation) are prepared. At that time, the weight (Ta) of the Teflon (registered trademark) film enclosing the porous film before the electron beam irradiation, the weight of the string (Tb), the weight of the entire porous film sample before the electron beam irradiation (T1) ( The total weight of the Teflon (registered trademark) membrane, the kite string, and the porous film) is measured in advance. Also, the weight (Wa) of the Teflon (registered trademark) film enclosing the porous film after the electron beam irradiation, the weight (Wb) of the kite string, the weight (W1) of the entire porous film sample after the electron beam irradiation (Teflon) (Registered trademark) membrane, silk thread, and the total weight of the porous film) are respectively measured. Therefore, the weight of the porous film before electron beam irradiation is [T1- (Ta + Tb)], and the weight of the porous film after electron beam irradiation is [W1- (Wa + Wb)].
Next, a sample (a porous film sample before electron beam irradiation, a porous film sample after electron beam irradiation) is put into a Soxhlet extraction apparatus, and xylene is refluxed at a boiling point (140 ° C.). After continuous extraction for 12 hours, a sample (a porous film sample before electron beam irradiation or a porous film sample after electron beam irradiation) is taken out, placed on an aluminum petri dish, dried at 130 ° C. for 2 hours, The sample is allowed to stand at room temperature for 30 minutes, and the weight (T2) of the porous film sample before the electron beam irradiation after immersion and the weight (W2) of the porous film sample after the electron beam irradiation after immersion are measured. Therefore, the weight of xylene-insoluble matter in the porous film sample before electron beam irradiation is [T2- (Ta + Tb)], and the weight of xylene-insoluble matter in the porous film sample after electron beam irradiation is [W2- (Wa + Wb)]. Become.
Then, the gel fraction (% by weight) is calculated based on the following formula.
Polymer insoluble fraction = ([W2− (Wa + Wb)] / [W1− (Wa + Wb)] × 100) − ([T2− (Ta + Tb)] / [T1− (Ta + Tb)] × 100)
Polymer amount = 100 − ([T2− (Ta + Tb)] / [T1− (Ta + Tb)] × 100)
Gel fraction (% by weight) = polymer insoluble fraction / polymer amount [In the above formula, W1 is the weight of the porous film sample after electron beam irradiation before immersion, W2 is the porosity after electron beam irradiation after immersion. The weight of the porous film sample, Wa is the weight of the Teflon (registered trademark) film enclosing the porous film after electron beam irradiation, Wb is the weight of the kite string enclosing the porous film after electron beam irradiation, and T1 is before immersion The weight of the porous film sample before the electron beam irradiation, T2 is the weight of the porous film sample before the electron beam irradiation after the immersion, Ta is the Teflon (registered trademark) film covering the porous film before the electron beam irradiation , Tb is the weight of the silk thread wrapped around the porous film before electron beam irradiation]

  The gel fraction can be controlled by, for example, electron beam irradiation conditions for the laminate, the type of resin constituting the porous film, and the like.

  The bag structural member of the present invention can be used as a bag structural member for heat sealing which is processed (formed) into a bag by heat sealing. The bag member of the present invention can be used for various purposes depending on the contents enclosed in the bag, and is particularly preferably used as a bag member for disposable body warmers enclosing a heating element. For example, it can be used also for a bag constituent member for the purpose of enclosing a dehumidifying agent, a deodorant, a fragrance, an oxygen scavenger and the like.

[Bag body]
The bag body is preferably a bag body constituent member (bag body constituent member of the present invention) in which at least one of the bag body constituent members is manufactured by the manufacturing method of the present invention. A bag body may be formed by heat sealing, or a bag body constituent member other than the bag body constituent member of the present invention and the bag body constituent member of the present invention (hereinafter referred to as “other bag body constituent member”). May be heat-sealed to form a bag.

  There is no particular limitation on the above-described other bag-constituting members (bag-constituting members other than the bag-constituting members of the present invention that are heat-sealed with the bag-constituting members of the present invention to constitute the bag), and are well-known and commonly used A breathable and non-breathable bag member can be used. For example, when used for a disposable body warmer to be attached to clothes or the like (for example, a disposable body warmer attached to a body, clothing or footwear), a bag constituting member having an adhesive layer is preferable. And a pressure-sensitive adhesive layer (a bag-shaped structural member having at least a base material and a pressure-sensitive adhesive layer), “Nitotac” manufactured by Nitto Lifetech Co., Ltd. (polyolefin base material having heat sealability and SIS) A pressure-sensitive adhesive sheet for warmers, which is a laminate of a PSA-based pressure-sensitive adhesive layer, is commercially available.

  The base material in the other bag-constituting members is preferably composed of, for example, a heat seal layer, a fiber layer (for example, a nonwoven fabric layer), a film layer, or the like. More specifically, a heat seal layer (including a heat sealable film layer) alone, a laminate of a heat seal layer and a fiber layer, a laminate of a heat seal layer and a film layer having no heat sealability, and the like are mentioned. It is done.

  The above-mentioned thing can be used as a nonwoven fabric used for the nonwoven fabric layer in the said other bag body structural member. Among these, a polyester nonwoven fabric is preferable.

The heat seal layer in the other bag-constituting member can be formed of a heat sealable resin (heat sealable resin) or a heat sealable resin composition containing a heat sealable resin. An example of such a heat sealable resin is a resin in the raw material of the porous film. Among them, as the heat sealable resin, polyolefin resins such as low density polyethylene, linear low density polyethylene, and ethylene-α-olefin copolymer are preferable, and ethylene-α-olefin copolymer is particularly preferable. Can be used.
In addition, it does not specifically limit as a content rate of the said ethylene-alpha-olefin copolymer in the said heat sealable resin, For example, 5 weight% or more (preferably 10-50) with respect to the heat sealable resin total weight. % By weight, more preferably 15 to 40% by weight). Furthermore, as said linear low density polyethylene, it is preferable to use the linear low density polyethylene prepared, for example using the metallocene catalyst.

  The film layer in the said other bag body structural member can utilize the film conventionally used. As the resin for forming the film layer, for example, a polyester resin, a polyolefin resin, or the like can be used. Among these, polyolefin resins can be suitably used from the viewpoints of price and flexibility. As the polyolefin resin, it is possible to use a resin similar to the resin exemplified in the heat seal layer. The film layer may be a single layer film or a laminated film having two or more layers. Further, the film may be a non-oriented film or a film stretched and oriented in a uniaxial or biaxial direction, but is preferably a non-oriented film.

  The thickness of the base material in the other bag-constituting member is not particularly limited, and is, for example, 10 to 500 μm (preferably 12 to 200 μm, more preferably 15 to 100 μm). The base material may be subjected to various treatments such as back treatment and antistatic treatment as necessary.

  The pressure-sensitive adhesive layer provided on the other bag-constituting members plays a role of attaching the bag to the adherend during use. The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is not particularly limited. For example, a rubber-based pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive (acrylic urethane-based pressure-sensitive adhesive), an acrylic pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, a polyester-based pressure-sensitive adhesive, Known pressure-sensitive adhesives such as polyamide-based pressure-sensitive adhesives, epoxy-based pressure-sensitive adhesives, vinyl alkyl ether-based pressure-sensitive adhesives, and fluorine-based pressure-sensitive adhesives can be used. Moreover, the said adhesive can be used individually or in combination of 2 or more types. Among these, rubber-based and urethane (acrylic urethane) pressure-sensitive adhesives are particularly preferable.

  Examples of the rubber-based pressure-sensitive adhesive include rubber-based pressure-sensitive adhesives using natural rubber and various synthetic rubbers as a base polymer. Examples of rubber-based pressure-sensitive adhesives based on synthetic rubber include styrene-butadiene (SB) rubber, styrene-isoprene (SI) rubber, styrene-isoprene-styrene block copolymer (SIS) rubber, and styrene-butadiene- Styrene block copolymer (SBS) rubber, styrene-ethylene-butylene-styrene block copolymer (SEBS) rubber, styrene-ethylene-propylene-styrene block copolymer (SEPS) rubber, styrene-isoprene-propylene-styrene block Copolymer (SIPS) rubber, styrene rubber (also called styrene elastomer) such as styrene-ethylene-propylene block copolymer (SEP) rubber, polyisoprene rubber, recycled rubber, butyl rubber, polyisobutylene, and their modified body Etc., and the like. Among them, a styrene elastomer adhesive is preferable, and a SIS adhesive and an SBS adhesive are more preferable. These 1 type or 2 or more types of mixtures can be selected suitably, and can be used.

  As the urethane pressure-sensitive adhesive, a known and commonly used urethane pressure-sensitive adhesive can be used, and is not particularly limited. For example, the urethane type illustrated in Japanese Patent No. 3860880 and Japanese Patent Application Laid-Open No. 2006-288690. An adhesive or the like can be suitably used. Among these, an acrylic urethane pressure-sensitive adhesive composed of isocyanate / polyester polyol is preferable. Moreover, it is preferable that the said acrylic urethane type adhesive is a foaming type adhesive which has a bubble from a viewpoint of reducing the irritation | stimulation to the skin at the time of sticking directly on skin. Such a foaming type pressure-sensitive adhesive can be produced by, for example, a method of adding a known and usual foaming agent to the pressure-sensitive adhesive.

  The pressure-sensitive adhesive may be any pressure-sensitive adhesive, such as an emulsion-type pressure-sensitive adhesive, a solvent-type pressure-sensitive adhesive, and a hot-melt-type pressure-sensitive adhesive (hot-melt-type pressure-sensitive adhesive). It is done. Of the above, a hot-melt adhesive (hot melt adhesive) is particularly preferred because it can be directly applied without using a solvent to form an adhesive layer.

  The pressure-sensitive adhesive may be a pressure-sensitive adhesive having any of the characteristics, for example, a pressure-sensitive adhesive (thermosetting pressure-sensitive adhesive) which is cured by crosslinking or the like caused by heating. ), And a pressure-sensitive adhesive having active energy ray curability that cures by crosslinking or the like caused by irradiation with active energy rays (active energy ray-curable pressure-sensitive adhesive). Among these, an active energy ray-curable pressure-sensitive adhesive is suitable because it is solvent-free and does not excessively impregnate non-woven fabrics or porous substrates. For the thermosetting pressure-sensitive adhesive, a crosslinking agent, a polymerization initiator, or the like for exhibiting thermosetting properties is appropriately used. For the active energy ray-curable pressure-sensitive adhesive, a cross-linking agent or a photopolymerization initiator for exhibiting active energy ray curability is appropriately used.

  The pressure-sensitive adhesive layer may be protected by a known or commonly used release film (separator) until use.

  A method (apparatus) for heat-sealing when forming a bag body using the bag-constituting member of the present invention is not particularly limited, but pressure bonding with a heat sealer is preferable.

  Although it does not specifically limit as heat seal temperature, For example, 90-140 degreeC is mentioned. In particular, the bag-constituting member of the present invention can produce a bag having excellent heat seal strength without causing problems such as edge breakage even when the heat seal temperature is high, so that the heat seal temperature is 150 ° C. or higher (for example, 150 to 180 ° C.).

Although it does not specifically limit as a heat seal pressure, For example, 0.5-5.0 kgf / cm < ² > is mentioned. In particular, the bag-constituting member of the present invention can produce a bag having excellent heat seal strength without causing defects such as edge breakage even when the heat seal pressure is high, and therefore the heat seal pressure is 5.0 kgf / cm. ^It may be ² or more (for example, 5.0 to 10.0 kgf / cm ² ). Among them, even when the heat seal temperature is high (for example, 150 to 180 ° C.) and the heat seal pressure is high (for example, 5.0 to 10.0 kgf / cm ² ), there is no defect such as edge breakage, A bag body excellent in heat seal strength can be manufactured.

Although it does not specifically limit as heat seal time, For example, 0.001-1.0 second is mentioned. In particular, by using the bag component of the present invention, under strong heat seal conditions (for example, high temperature of 150 to 180 ° C. and / or high pressure of 5.0 to 10.0 kgf / cm ² ), 1.0 second or less. (For example, 0.1 to 0.8 seconds, more preferably 0.1 to 0.5 seconds) Even when heat-sealed, a bag body excellent in heat-sealing strength can be produced.

  A disposable body warmer can be formed by encapsulating a heating element inside the bag.

  1 and 2 are a schematic sectional view showing an example of a disposable body warmer including a bag constituting member of the present invention and a schematic plan view seen from above. The disposable body warmer described in FIG. 1 and FIG. 2 includes a bag body constituting member 1 of the present invention (a bag body constituting member comprising a nonwoven fabric 11, an adhesive layer 12, and a porous film 13) and other bag body constituting members 2 (bases). The bag body is made by heat-sealing the end portion (heat seal portion 4) of the material 21 and the pressure-sensitive adhesive layer 22), and the heating element 3 is enclosed therein. As described above, in the case of a disposable body warmer that is provided with an adhesive layer on one surface and is attached to an adherend such as clothing (for example, a disposable body warmer that is attached to a body, clothing, or footwear), The bag member of the invention is preferably used at least as a member (so-called surface material) on the side opposite to the side in contact with the adherend from the viewpoint of the ability to supply oxygen to the heating element.

  The disposable warmers are stored in outer bags and sold as warmer products. The base material constituting the outer bag is not particularly limited. For example, a plastic base material, a fiber base material (nonwoven fabric base material or woven base material made of various fibers), metal base material (various types) For example, a metal foil-based substrate made of a metal component can be used. As such a base material, a plastic base material can be suitably used. Examples of plastic base materials include polyolefin base materials (polypropylene base materials, polyethylene base materials, etc.), polyester base materials (polyethylene terephthalate base materials, etc.), styrene base materials (in addition to polystyrene base materials). Styrene copolymer base materials such as acrylonitrile-butadiene-styrene copolymer base materials), amide resin base materials, acrylic resin base materials and the like. The base material for the outer bag (the base material constituting the outer bag) may be a single layer or a laminate. The thickness of an outer bag is not specifically limited, For example, 30-300 micrometers is preferable.

  Moreover, it is preferable that the said outer bag has a layer (gas barrier property layer) which has the characteristic (gas barrier property) which blocks | prevents permeation | transmission of gas components, such as oxygen gas and water vapor | steam. Although it does not specifically limit as a gas barrier layer, For example, an oxygen barrier resin layer (For example, a polyvinylidene chloride resin, an ethylene-vinyl alcohol copolymer, polyvinyl alcohol, a polyamide resin), a water vapor barrier resin layer (For example, a polyolefin resin, a polyvinylidene chloride resin), an oxygen barrier property or a water vapor barrier inorganic compound layer (for example, a metal simple substance such as aluminum, a metal oxide such as a metal oxide such as silicon oxide or aluminum oxide) Etc.). The gas barrier layer may be a single layer (or the outer bag base material itself) or a laminate.

  The outer bag may be a bag of any form or structure, for example, a so-called “4-side bag”, a so-called “3-side bag”, a so-called “pillow bag”, a so-called self-standing bag (a so-called “standing pouch”). )), And various forms of bags such as so-called “gusset bags”. Among these, a four-sided bag is particularly preferable. The outer bag may be produced using an adhesive, but is preferably produced by heat sealing (thermal fusion) such as a four-way heat sealing bag.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited at all by these.

Example 1
A non-woven fabric made of polyethylene terephthalate (PET) (trade name: “ELTAS E01030”, manufactured by Asahi Kasei Fibers Co., Ltd., basis weight 30 g / m ³ ) is coated with a hot melt adhesive by spray coating (trade name: “ VESTAMELT 722GETR ”, manufactured by Daicel-Evonik Co., Ltd., coating amount 5 g / m ³ ), porous film (polyethylene resin, film made by stretching an unstretched film formed from a raw material containing an inorganic filler) , A thickness of 70 μm) was laminated to produce a laminate.
Using an electron beam irradiation device (trade name “EC300”, manufactured by Iwasaki Electric Co., Ltd.), an electron beam with an absorbed dose of 30 kGy and an acceleration voltage of 150 kV is formed on the nonwoven fabric side of the laminate from a height of about 10 cm from the nonwoven fabric surface. To produce a bag-constituting member. The line speed when irradiating with an electron beam was 10 m / min (irradiation time to the laminate was about 1 second).

(Example 2)
A bag constituting member was produced in the same manner as in Example 1 except that the absorbed dose of the electron beam was 50 kGy.

(Example 3)
A bag constituting member was produced in the same manner as in Example 1 except that the absorbed dose of the electron beam was 100 kGy.

Example 4
A bag constituting member was produced in the same manner as in Example 1 except that the absorbed dose of the electron beam was 145 kGy.

(Comparative Example 1)
A laminate was produced in the same manner as in Example 1. In Comparative Example 1, since the electron beam was not irradiated on the laminate, the laminate is referred to as a bag constituent member.

(Comparative Example 2)
A bag constituting member was produced in the same manner as in Example 1 except that the absorbed dose of the electron beam was 15 kGy.

(Evaluation)
About the bag constituent members obtained in the above examples and comparative examples, the temperature at which the edge is cut, the gel fraction, the delamination force, the adhesive back to the stainless steel plate, the heat seal strength, the appearance, the tensile strength, evaluated. The evaluation method is shown below. The evaluation results are shown in Table 1.

(1) Edge breakage A heat seal bar heated to the following heat seal temperature is applied to the nonwoven fabric surface of the bag constituting member obtained in the above examples and comparative examples under the conditions of a pressure of 4 kg / cm ² and a time of 2 seconds. And a heat seal tester (trade name “HEATSEALTESTER”, manufactured by Tester Sangyo Co., Ltd.).
The heat sealing temperature is a temperature in increments of 10 ° C. from 100 ° C. to 200 ° C. (100 ° C., 110 ° C., 120 ° C., 130 ° C., 140 ° C., 150 ° C., 160 ° C., 170 ° C., 180 ° C., 190 ° C., 200 ° C. )
Observe the bag-constituting member visually after heat sealing, and measure the size (length of the longest part) in the heat-sealed portion of the porous film of the bag-constituting member (boundary portion between the heat-sealed portion and the non-heat-sealed portion). A) When the edge breakage of 0.5 mm or more was confirmed, it was determined as “edge breakage”, and when it was not confirmed, it was determined as “no edge breakage”.
The heat seal temperature (° C.) at the time when it was determined that “edge breakage” was determined as “edge breakage temperature” and is shown in the “edge breakage temperature” column of Table 1. When it was determined that “no edge break” even at 200 ° C., the “temperature at which the edge breaks” was determined to be “200 ° C. or higher”.

(2) Gel fraction The bag constituent members obtained in the above examples and comparative examples were dipped in an isopropyl alcohol solution of 99.0% or more to remove the PET nonwoven fabric and the hot melt adhesive, and the electron beam After obtaining the irradiated porous film, the gel fraction (%) of the porous film was measured.
The gel fraction was measured according to the above “Method for measuring gel fraction”. The results are shown in the column “Gel fraction (%)” in Table 1.

(3) Interlaminar peeling force A member piece having a width of 25 mm and a length of 150 mm was cut out from the bag constituting member obtained in the above examples and comparative examples. When the end of the porous film of the member piece and the end of the non-woven fabric made of PET are fixed to a tensile tester with a chuck (gripping tool), and the porous film and the non-woven fabric made of PET are peeled off under the following conditions. The maximum load (N / 25 mm) was measured. The test was performed three times (n = 3), and the average value was defined as the delamination force (N / 25 mm). The results are shown in the column of “Delamination force (N / 25 mm)” in Table 1.
Apparatus (tensile tester): Instron universal tensile tester (trade name “AUTOGRAPH AG-X”, manufactured by Shimadzu Corporation)
Measurement environment: Temperature 23 ° C, humidity 50% RH
Peeling angle: 180 ° C (T type)
Tensile speed: 300 mm / min Number of tests: 3 times

(4) Through-through of adhesive to stainless steel plate A member piece having a width of 50 mm and a length of 150 mm was cut out from the bag constituting member obtained in the above examples and comparative examples to obtain a measurement sample. A non-woven fabric surface of the member piece and a mirror-finished stainless steel plate (width 50 mm, length 150 mm, thickness 5 mm) are stacked so as to face each other, and a heat seal device (trade name “HEATSEALTERSTER”, manufactured by Tester Sangyo Co., Ltd.) Was used under the conditions of a pressure of 4.0 kgf / cm ² , a temperature of 120 ° C., and a time of 60 seconds.
After pressurization, the surface of the stainless steel plate is visually checked. If no adhesive is found on the stainless steel plate, “No adhesive missing” (◯), and if the adhesive is attached to the stainless steel plate, “adhesive” There was missing (×) ”. The results are shown in the column of “Hot-melt type adhesive back to stainless plate” in Table 1.

(5) Heat-sealing strength The bag-constituting members obtained in the above-mentioned examples and comparative examples and the Cairo pressure-sensitive adhesive sheet (trade name “Nitotack E12”, manufactured by Nitto Lifetech Co., Ltd.) The porous film surface and the base film surface of the warming pressure-sensitive adhesive sheet were stacked so as to face each other, and heat sealed under the following heat sealing conditions. The heat seal temperature was 10 ° C. increments from 70 ° C. to 130 ° C. shown in the following heat seal conditions.
The end of the bag component of each sample after heat sealing and the end of the adhesive sheet for the warmer are fixed to a tensile tester with a chuck (gripping tool), and the bag component and the adhesive for the warmer are subjected to the following peel test conditions. The maximum load (N / 25 mm) when peeling from the sheet and peeling was measured. The test was performed three times (n = 3), and the average value was defined as the heat seal strength (N / 25 mm). The results are shown in the column of “Heat seal strength (N / 25 mm)” in Table 1 for each heat seal temperature.
(Heat seal condition)
Heat seal tester: Trade name “HEAT SEAL TESTER”, manufactured by Tester Sangyo Co., Ltd. Heat seal temperature: 70 ° C., 80 ° C., 90 ° C., 100 ° C., 110 ° C., 120 ° C., 130 ° C.
Heat sealing pressure: 4.0 kgf / cm ²
Heat sealing time: 0.5 seconds (peeling test conditions)
Apparatus (tensile tester): Instron universal tensile tester (trade name “AUTOGRAPH AG-X”, manufactured by Shimadzu Corporation)
Measurement environment: Temperature 23 ° C, humidity 50% RH
Peeling angle: 180 ° C (T type)
Tensile speed: 300 mm / min Number of tests: 3 times

(6) Appearance The appearance of the bag constituent members obtained in the above examples and comparative examples was visually observed. Evaluates as “good” when there is no change in appearance before and after electron beam irradiation, and as “slightly wrinkled” when a slight wrinkle is observed on the nonwoven fabric surface of the bag component after electron beam irradiation. did. The results are shown in the “Appearance” column of Table 1.

(7) Tensile strength (lateral direction)
A member piece (25 mm in width and 25 mm in the flow direction (MD direction) and 100 mm in the lateral direction (TD direction)) is cut out from the bag constituent members obtained in the above examples and comparative examples. A measurement sample was obtained. Both ends in the longitudinal direction of the measurement sample were fixed to a tensile tester with a chuck (gripping tool), and the maximum load (N / 25 mm) when the bag member was broken under the following conditions was measured. The test was performed three times (n = 3), and the average value was taken as the tensile strength (N / 25 mm). The results are shown in the column of “Tensile strength (N / 25 mm)” in Table 1.
Apparatus (tensile tester): Instron universal tensile tester (trade name “AUTOGRAPH AG-X”, manufactured by Shimadzu Corporation)
Measurement environment: Temperature 23 ° C, humidity 50% RH
Distance between chucks: 100 mm
Tensile direction: transverse direction (TD direction)
Tensile speed: 300 mm / min Number of repetitions: n = 3

As is apparent from Table 1, the bag-constituting members (Examples 1 to 4) of the present invention did not cause edge breakage at a temperature of 140 ° C. or lower, and were excellent in heat seal strength. In the evaluation of the heat seal strength, the bag constituting member obtained in Example 1 was excellent in heat seal strength even when heat sealed at 140 ° C. Similarly, the bag member obtained in Example 2 is 170 ° C., and the bag member obtained in Examples 3 and 4 is 200 ° C., which is excellent in heat seal strength even when heat sealed. It was. In addition, the bag constituting member of the present invention was excellent in delamination force because the adhesive was cross-linked by electron beam irradiation, and there was no breakthrough of the adhesive.
On the other hand, the bag constituent member of the comparative example caused edge breakage under the strong heat seal condition (Comparative Examples 1 and 2). Moreover, the delamination force was low, and in Comparative Example 1, the adhesive slipped through.

DESCRIPTION OF SYMBOLS 1 Bag body structural member 11 Nonwoven fabric 12 Adhesive layer 13 Porous film 2 Other bag body structural member 21 Base material 22 Adhesive layer 3 Heating element 4 Heat seal part 5 Boundary between heat seal part and non-heat seal part Part 6 Bag body component (surface material)
7 Bag components (backing material)

Claims (3)

  The manufacturing method of the bag body structural member characterized by including the irradiation process which irradiates the electron beam of 25-200 kGy of absorbed dose to the laminated body obtained by bonding a nonwoven fabric and a porous film.   The manufacturing method of the bag body structural member of Claim 1 which irradiates the said electron beam from the said nonwoven fabric side of the said laminated body in the said irradiation process.   The manufacturing method of the bag structural member according to claim 1 or 2, wherein the porous film has a thickness of 45 to 150 µm.

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