JP2006158500A - Laminated body and pouch material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated body which prevents heat deterioration and a pouch material. <P>SOLUTION: The laminated body 40 is constituted of a laminate of a nonwoven fabric 41, a microporous film 42, and a sealant film 43. The sealant film 43 is equipped with a laminate layer 431, a seal layer 433, and an intermediate layer 432 laminated between the laminate layer 431 and the seal layer 433 and is set to have the intermediate layer 432 with a density higher than the density of the laminate layer 431 and the seal layer 433. Since the sealant film 43 is laminated in contact with the microporous film 42, the microporous film 42 is protected by the sealant film 43, is not exposed to excessive heat, and prevents the heat deterioration. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a laminate in which a plurality of layers are laminated, and a bag material provided with the laminate.

  Conventionally, a warmer using a packaging material of a heating element storage bag for storing a heating element is known. In such a warmer, a heat sealing sheet base material having a pressure-sensitive adhesive surface on one side, and a laminate heat-sealed to the heat sealing sheet base material are stored in a bag containing a heating element. There are so-called adhesive disposable warmers. As a laminate used for such a warmer, a laminate in which a nonwoven fabric having a high heat resistance such as a nylon nonwoven fabric and a rayon nonwoven fabric and a polyethylene microporous film are laminated has been used.

  In addition, the warmer to be pasted is, for example, a laminated body of a film made of a nylon nonwoven fabric and a polyethylene-based microporous film, and a heat-sealing sheet base material that has been subjected to adhesive processing on this laminated body. Processed and made into bags. This bag making and filling process is a process of filling a heating element and making a bag while ventilating the air inside the storage part because the heating element reacts with air and generates heat.

On the other hand, in recent years, there has been a demand for a nonwoven fabric made of an inexpensive resin having high productivity from the viewpoint of low cost. However, nylon nonwoven fabrics that are currently used generally have limitations in productivity and resin price, and cannot be handled.
On the other hand, nonwoven fabrics using polyolefin, particularly spunbond nonwoven fabrics using polypropylene are excellent in productivity, resin price, and versatility, and a laminate of this polypropylene-based spunbond nonwoven fabric is desired.
As a packaging material using such a polyolefin, an improved porous film (for example, see Patent Document 1) or a laminate in which a plurality of layers are laminated (for example, see Patent Document 2 and Patent Document 3). ) Moreover, the warmer using the packaging material using a polyolefin-type nonwoven fabric is known (for example, refer patent document 4).

  The thing of this patent document 1 is a porous film which consists of an extending | stretching process body of the film which mixed the linear low density polyethylene, the ethylene-type copolymer, and the inorganic filler. As the linear low density polyethylene, a copolymer of ethylene and an α-olefin such as butene or hexene is used.

  Moreover, the thing of patent document 2 is the sheet | seat base material for heat seal formed by laminating | stacking the heat seal layer which consists of ethylene-alpha-olefin copolymerization polymerized by the Ziegler catalyst, and the film layer. . In this heat seal layer, for example, 1-butene is preferable as an α-olefin having 4 or more carbon atoms and suitable for low temperature and short time heat sealability.

The one described in Patent Document 3 is melted in an applicator tank in a reactive polyurethane hot-milt adhesive. The spray pressure 0.5~2kgf / cm ² (about 0.05~0.2N / ^cm 2), and a curtain spray amide nonwoven at a flow rate of 30-50 liters / min, the surface by corona discharge on the It is produced by laminating a treated polyethylene-based porous film at 60 ° C. and a line speed of 20 m / min.

Japanese Patent Laid-Open No. 10-152570 (see right column on page 2 to right column on page 3) JP 2001-260293 A (refer to the left column on page 3 to the right column on page 4) Japanese Patent Laid-Open No. 10-314208 (see the second column on the right to the left column on page 3)

  By the way, in the structure as described in patent document 1, in order to improve the high-speed bag-making property with the other party (for example, the sheet | seat base material for a warmer, the base material for heat sealing, the base material for a heat generating body etc.) to make a bag. Moreover, the melting point of the porous film is lowered by mixing an ethylene copolymer. However, when the melting point of the porous film is lowered, it becomes difficult to control moisture permeability necessary for the body warmer. Also, in order to make a high-speed bag making while putting out a heating element inside like a sticking body warmer, it is necessary to raise the temperature of the heat seal device, and when the melting point of the porous film is lowered, this An example is the problem that the porous film may be thermally damaged by the temperature of the heat seal device.

  Moreover, also in the structure as described in patent document 2, the melting point of the heat seal layer is lowered by mixing ethylene and α-olefin. For this reason, when manufacturing a warmer to be applied with such a laminate, it becomes difficult to control the moisture permeability necessary for the warmer, and a heat sealing device for making a high-speed bag while putting a heating element inside and removing air As an example, there is a problem that the heat seal layer may be thermally damaged by the temperature of the heat seal device. Moreover, the performance of the porous film used as the counterpart material of the heat seal layer is not satisfactory, and the problem that the effect of the heat seal layer cannot be obtained is given as an example.

  Further, in the configuration as described in Patent Document 3, a reactive polyurethane hot-milt adhesive is curtain sprayed on an amide nonwoven fabric, and a polyethylene porous film is laminated thereon. For this reason, a reactive polyurethane hot-milt adhesive is present as a different material between the amide-based nonwoven fabric and the polyethylene porous film, and the presence of such a different material results in a stable laminate strength. On the other hand, there is a problem that it may cause a decrease in moisture permeability and a decrease in texture.

  Moreover, in the body warmer using the moisture-permeable film as described above, it is necessary to evacuate air during bag making. Therefore, in general, the manufacturing method is multi-stage. On the first stage, an unsealed part (air vent hole) is formed to remove air, and the bag is made in the second stage to block the air vent hole. Reseal the location. For this reason, the part sealed only once and the part sealed twice arise. Therefore, when the speed is increased, it is impossible to secure the seal strength of the portion that is sealed only once. As countermeasures, it is conceivable to increase the sealing conditions, that is, increase the temperature at the time of sealing, or increase the sealing pressure. However, if the sealing conditions are increased in this way, the portion that is sealed twice will be thermally damaged. For example, there is a problem that heat shrinkage or edge breakage of the microporous film may occur.

  Thus, the nonwoven fabric using polyolefin has lower heat resistance than nylon nonwoven fabric, and it is difficult to produce a heating element storage bag obtained by heat sealing in a laminate with a film made of polyethylene microporous film. is there.

  In view of such circumstances, an object of the present invention is to provide a laminate and a bag material that prevent thermal degradation.

  The present invention according to claim 1 is a laminate of a synthetic resin nonwoven fabric, a perforated thermoplastic resin film, and a microporous film provided between the nonwoven fabric and the thermoplastic resin film. The thermoplastic resin film includes at least a laminate layer in contact with the porous film, a sheet substrate to which the laminate is attached, or a seal layer in contact with the film substrate, the laminate layer, and the seal. And an intermediate layer formed between the layers and having a density higher than that of the laminate layer and the seal layer.

  According to this invention, the laminate is formed by laminating a nonwoven fabric, a perforated thermoplastic resin film, and a microporous film. The thermoplastic resin film includes a laminate layer, a seal layer, and an intermediate layer laminated between the laminate layer and the seal layer, and the intermediate layer has a higher density than the laminate layer and the seal layer. It is set to be. Thereby, since the thermoplastic resin film that has been perforated is laminated in contact with the microporous film, the microporous film is protected by the thermoplastic resin film and does not receive excessive heat. , Can prevent thermal degradation. Therefore, the microporous film can be prevented from curing and becoming brittle, and problems such as edge breakage can be prevented.

  If the thermoplastic resin film is a single layer, for example, if a low-density resin is used for this thermoplastic resin film in order to give priority to low-temperature heat sealability (that is, the magnitude of seal strength in a low-temperature region), When the heat seal part of the plastic resin film is melted, the film strength cannot be maintained, and the edge breakage of the microporous film cannot be prevented. When a high-density resin is used for the thermoplastic resin film, lamination with the microporous film is hindered, the laminate strength (hereinafter referred to as “lami strength”) is lowered, or the texture becomes hard as a warmer. Furthermore, if the thermoplastic resin film has two layers, for example, when a low-density resin is used for the layer in contact with the microporous film and the side in contact with the sheet substrate is made of a high-density resin, at least the characteristic of the warmer to be pasted In the bag making method, the heat sealability with the sheet substrate is lowered, and the sealing speed is lowered. On the other hand, even when a high-density resin is used on the side in contact with the microporous film and a low-density resin is used on the side in contact with the sheet substrate, the laminate strength itself cannot be secured, and the microporous film and the thermoplastic resin film Heat sealability cannot be secured. Further, when a low density resin is used for two layers or a high density resin is used, it is the same as the case where it is formed by one layer.

  On the other hand, as in the present invention, when the thermoplastic resin film has a three-layer structure, a high-density resin is used for the intermediate layer, and a low-density layer is used for the laminate layer and the seal layer, the intermediate layer In addition, the laminate layer and the seal layer in contact with the intermediate layer can suppress the influence of heat on the microporous film. Furthermore, since the laminate layer has a low density, the laminate strength with the microporous film is stabilized and the heat sealability is also improved. Similarly, since the sealing layer has a low density, for example, heat sealability with a sheet substrate or the like can be improved. Therefore, thermal deterioration and edge breakage of the microporous film can be more efficiently suppressed.

  Invention of Claim 2 is a laminated body of Claim 1, Comprising: The said thermoplastic resin film is a laminated body characterized by including an ethylene-alpha-olefin copolymer.

  In the structure of this invention, the said thermoplastic resin film contains an ethylene-alpha-olefin copolymer. Since the α-olefin is excellent in heat-sealability, it can easily form the thermoplastic resin film, and has a heat-seal property between the thermoplastic resin film and the microporous film. Can be good. Examples of such α-olefins include linear olefins such as 1-butene, 1-pentene, 1-hexene, 1-octene, 1-nonene, 1-decene, 1-undecene and 1-dodecene. And branched olefins such as -methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, and 2,2,4-trimethylpentene.

Invention of Claim 3 is a laminated body of Claim 1 or Claim 2, Comprising: The said intermediate | middle layer is a laminated body characterized by the density being 0.910 g / cm < ³ > or more. .

In such a configuration, since the density of the intermediate layer is 0.910 g / cm ³ or more, the intermediate layer can efficiently suppress the influence of heat and edge breakage on the microporous film. Moreover, the intermediate layer set to this density is easy to form a film, and the productivity of the laminate can be improved.

Invention of Claim 4 is a laminated body in any one of Claim 1 thru | or ^3, Comprising: The said laminate layer and the said sealing layer are 0.915 g / cm < ³ > or less in density. It is a featured laminate.

In this configuration, the density of the laminate layer and the seal layer is 0.915 g / cm ³ or less. Thereby, when the said laminate layer is laminated on the said microporous film, favorable lamination strength is obtained and the said thermoplastic resin film and the said microporous film can be adhere | attached reliably. In addition, when manufacturing a bag material using such a laminate and a sheet base material, such as a body warmer, for example, it is stable in the process of sealing the seal layer and the sheet base material while removing air. Seal strength is obtained.

  Invention of Claim 5 is a laminated body in any one of Claim 1 thru | or 4, Comprising: The said nonwoven fabric, the said thermoplastic resin film, and the said microporous film are adhere | attached by thermal lamination. It is a laminated body characterized by being laminated.

  In this configuration, the non-woven fabric, the thermoplastic resin film, and the microporous film can be easily bonded by thermal lamination. Therefore, the productivity of the laminate can be improved, and the production cost can be reduced.

  The invention according to claim 6 is the laminate according to any one of claims 1 to 5, wherein the nonwoven fabric is a polypropylene nonwoven fabric.

  In this invention, since a polypropylene-based nonwoven fabric is used as the nonwoven fabric, productivity can be improved with an inexpensive resin as compared with a conventional nylon-based nonwoven fabric. Therefore, the production cost can be reduced.

  The invention according to claim 7 is a sheet substrate or film substrate that can be heat-sealed with the laminate according to any one of claims 1 to 6 and at least one surface of the sealing layer of the thermoplastic resin film. A bag material for storing the contents therein, wherein the bag peripheral portion of the bag material heat seals the sealing layer of the thermoplastic resin film and the sheet base material or the film base material. It is the bag material characterized by being made.

  In the bag material having this configuration, by using the laminate as described above, the microporous film is formed by heat at the time of bag making even if a material having low heat resistance such as polypropylene is used for the microporous film. The sealing layer can be heat sealed to the sheet substrate or film substrate without thermal degradation. Therefore, a bag material using a microporous film made of inexpensive polypropylene or the like can be easily manufactured. Therefore, productivity can be improved and production cost can be reduced.

  Invention of Claim 8 is the bag material of Claim 7, Comprising: The said content is a heat generating body accommodated in the said bag material in the state which does not contact | connect the said microporous film, The sheet base material or the film base material is provided with a heat seal layer that can be heat-sealed with the seal layer, a base material layer that becomes a main body of the sheet base material or the film base material, and an adhesive that imparts adhesiveness to the base material layer. The multi-laminate is obtained by laminating the pressure-sensitive adhesive layer and release paper covering the pressure-sensitive adhesive of the pressure-sensitive adhesive layer in this order.

  In such a configuration, since the heating element does not directly contact the microporous film, the microporous film is not deteriorated by the heat of the heating element. Therefore, it is suitable as a bag material for storing the heating element. Moreover, a sheet | seat base material is provided with the release layer which covers an adhesion layer and an adhesion layer, and a bag material can be affixed on heat retention objects, such as clothes, by removing a release paper. Therefore, this bag material can be used for various purposes such as warmers and heat generation ships.

  Hereinafter, a warmer according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing a body warmer according to the present embodiment. FIG. 2 is a schematic diagram schematically showing a laminated body manufacturing apparatus that constitutes the warmer of the present embodiment.

  In FIG. 1, reference numeral 100 denotes a warmer, and the warmer 100 is an adhesive warmer that can be used by being attached to a heat retaining object such as clothes. The warmer 100 includes a heating element 10 and a bag material 20 that covers the heating element 10. Moreover, the bag material 20 seals the heat sealing sheet base material 30 (hereinafter referred to as a sheet base material) provided with an attachment surface to which the body 100 is attached, and the laminate 40 to be sealed with the sheet base material. The bag is made by pasting.

[Heating element]
The heating element 10 includes, for example, iron powder, moisture that accelerates the oxidation rate of iron, salts, activated carbon that adsorbs oxygen in the air to increase the oxygen concentration, water retention agent that contains moisture to prevent sticking of the iron powder, and the like. It is configured.

[Sheet substrate]
The sheet base material 30 is adhesive to the base material layer 32, the heat seal layer 31 to be sealed with the laminate 40, the base material layer 32 that is laminated in contact with the heat seal layer 31 and becomes the main body of the sheet base material 30. It is a multilayer body in which an adhesive layer 33 to which a pressure-sensitive adhesive is applied and a release paper 34 covering the adhesive layer 33 are laminated. Then, the adhesive layer 33 is exposed by removing the release paper 34. A storage space in which the heating element 10 is stored is formed between the sheet base material 30 and the laminated body 40. The heating element 10 is stored in a state where air does not enter the storage space. The heat seal layer 31 is formed with a seal edge portion 35 for heat sealing with the laminate 40. In addition, if the base material layer 32 of the sheet base material 30 can be heat-sealed with the sealing layer 433 of a perforated film, the heat sealing layer 31 may not be formed. In this case, the base material layer 32 and the heat seal layer 31 are preferably the same.

  As the heat seal layer 31, a resin material such as a thermoplastic resin having a heat seal property can be appropriately adopted. However, a thermoplastic resin (low melting point resin material) and / or an elastomer having a melting point of 105 ° C. or less, a melting point Is preferably made of a mixed material of thermoplastic resin (high melting point resin material) exceeding 105 ° C.

  As the low melting point resin material, for example, a thermoplastic resin having a melting point of 105 ° C. or less is preferably used, and polyethylene, ethylene-α-olefin copolymer, and ethylene-polar vinyl monomer copolymer may be used. Specifically, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl meta Resin such as acrylate copolymer (EMMA), ethylene-methacrylic acid copolymer (EMAA), various ionomers such as ethylene ionomer, ethylene-ethyl acrylate-maleic anhydride terpolymer (EEA-MAH) Materials. These may be used singly or as a blend material combining two or more. In addition, as a catalyst used when manufacturing these resin materials, a multi-site catalyst may be sufficient and a single site catalyst (metallocene catalyst etc.) may be sufficient, The kind in particular is not restrict | limited.

  On the other hand, as the high melting point resin material, a thermoplastic resin having a melting point of 105 ° C. may be used. For example, among the resin materials constituting the low melting point resin material, those having a melting point exceeding 105 ° C. are appropriately selected. Can be used. That is, in the warmer 1 of the present invention, when selecting the constituent material of the heat seal layer 31 constituting the sheet base material 30, among the above-described resin materials, those having a melting point of 105 ° C. or less and a low melting point resin material, Further, a material having a melting point exceeding 105 ° C. may be appropriately selected as the high melting point resin material in the above-described blending ratio. Even in the case of the same type of resin material, the melting point is high or low due to the difference in the composition ratio of the copolymerization monomer, so even in this case, a low melting point resin material having a melting point of 105 ° C. or lower is used. What is necessary is just to select as a high melting point resin material with melting | fusing point exceeding 105 degreeC.

  Further, in place of the low melting point resin material or in combination with the low melting point resin material, ethylene / propylene rubber (EPR), ethylene butene rubber (EBM), styrene / butadiene / styrene block copolymer (SBS), hydrogenated styrene. Various elastomers such as a series elastomer (SEBS) and styrene / isoprene / styrene block copolymer (SIS) may be used.

  The blending ratio of the low melting point resin material or elastomer and the high melting point resin material described above may be 40 to 100% by mass of the low melting point resin material or elastomer (hereinafter simply referred to as “%”) with respect to the heat seal layer 31 as a whole. It is preferable that the high melting point resin material is 60 to 0%, the low melting point resin material is 40 to 90%, and the high melting point resin is 50 to 10%. When the blending ratio of the low melting point resin material or the elastomer is smaller than 40% (when the high melting point resin material is larger than 60%), the temperature for bringing the entire heat seal layer 31 into a molten state becomes high. This is not preferable because the width becomes narrow and the heat sealing performance may deteriorate.

  In the present embodiment, when selecting a resin material constituting the heat seal layer 31, a blending ratio of a low melting point resin material having a melting point of 105 ° C. or less and a high melting point resin material having a melting point of greater than 105 ° C. However, when the melting point of the low-melting resin material used is relatively high (for example, about 95 to 105 ° C.), the above-mentioned elastomer may be used in combination. Or it is preferable for improving the heat sealability of the base material layer 32. On the other hand, when the melting point of the low melting point resin material to be used is relatively low (for example, about 55 to 85 ° C.), it is possible to increase the blending ratio of the high melting point resin material to about 0 to 50%. It is preferable at the point of improving the film surface characteristics, such as.

  When the heat seal layer 31 is present, the thickness of the heat seal layer 31 is preferably 5 to 50 μm, and particularly preferably within the range of 5 to 30 μm. When the thickness of the heat seal layer 31 is smaller than 5 μm, a desired sealing strength may not be expressed when heat-sealing with a laminate 40 described later to form a bag, while the thickness of the heat seal layer 31 is not sufficient. If it is larger than 50 μm, the warmer 100 may become too hard and the touch may be deteriorated.

  Next, as the base material layer 32 laminated with the heat seal layer 31, polyethylene, homopolypropylene (HPP), random polypropylene (RPP), or random of propylene and ethylene or ethylene-α-olefin copolymer. The use of resin materials such as polypropylene resins such as copolymers and block copolymers, polyolefin resins such as ethylene-α-olefin copolymers, ethylene-polar vinyl monomer copolymers, polyamide (nylon), polyester resins, etc. In particular, the use of polyethylene having a melting point of 110 ° C. or higher, ethylene-α-olefin copolymer, ethylene-polar vinyl monomer copolymer, etc. may cause wrinkles due to passage of a die roll or the like during the production of the warmer 100 And the machine for the production of Cairo During stop, preferably in that it is possible to prevent the occurrence of wrinkles of the adhesive layer 33 by the preheating of the die roll. In addition, these resin materials may be used individually by 1 type, or may be used as a blend material which combined 2 or more types. In addition, in FIG. 1, although the base material layer 32 showed the aspect which is a single layer body, it is not limited to this, The base material layer 32 is good also as a laminated body which consists of a some layer.

  Regardless of the presence or absence of the heat seal layer 31, the thickness of the base material layer 32 is preferably 10 to 150 μm, and particularly preferably in the range of 40 to 100 μm. When the thickness of the base material layer 32 is smaller than 10 μm, the mechanical strength of the sheet base material 30 is deteriorated. On the other hand, when the thickness of the base material layer 32 is larger than 150 μm, the sheet base material 30 becomes hard, and the warmer 1 The texture may be worse.

  In addition, in the above-mentioned heat seal layer 31 and the base material layer 32 which comprise the sheet | seat base material 30, in the range which does not prevent the effect of this invention, an antiblocking agent, antioxidant, and resin deposit | attachment as needed You may add well-known additives, such as (so-called "meani") inhibitor and various inorganic substances. For the purpose of coloring each layer, a conventionally known color pigment may be added to the resin material constituting each layer.

  And in order to laminate | stack this heat seal layer 31 and the base material layer 32, and obtaining the sheet | seat base material 30, what is necessary is just to use a conventionally well-known lamination | stacking means, for example, an inflation method, T-die casting method, T-die touch roll method. A laminating means such as can be appropriately employed.

  The pressure-sensitive adhesive layer 33 may be coated with a pressure-sensitive adhesive on the surface of the base material layer 32, or a double-sided pressure-sensitive adhesive sheet, tape, or the like may be attached to the surface. Since the thickness of the adhesive layer 33 can be reduced, the level difference due to the presence or absence of the adhesive layer 33 is small, and good heat sealing can be performed, etc., the adhesive layer 33 is formed by applying an adhesive. Is preferred.

  Although there is no restriction | limiting in particular in the kind of adhesive which forms this adhesion layer 33, Generally, when Cairo 1 is affixed to heat retention objects, such as underwear, it adheres firmly, and when it peels, it remains on the heat retention object side. It is preferable to use non-transferable pressure-sensitive adhesives, and for example, organic solvent type or aqueous type non-transferable pressure-sensitive adhesives such as rubber-based, acrylic resin-based and vinyl acetate resin-based ones can be used.

  The area of the adhesive layer 33 is only required to have a strength that does not peel off naturally when the warmer 100 is attached to a heat retaining object, and is usually 10 to 90% with respect to the entire area of one side of the warmer, preferably It is in the range of 20 to 80%, and is appropriately determined depending on the shape, size, weight, type of pressure sensitive adhesive, ease of removal of the release paper 34, and the like.

  In addition, the thickness of the adhesive layer 33 is preferable from the viewpoint of heat-seal strength, but the thinner one is preferable in that the step difference from the non-adhesive portion 25 is reduced. Generally, about 5 to 200 μm is preferable, and about 10 to 50 μm is particularly preferable.

  As the release paper 34 to be attached to the adhesive layer 33, a commercially available release sheet, tape, emblem, sticker, etc. can be used. It is preferable to use a mold that has been applied with a mold and has improved peelability from the adhesive layer 33.

[Laminate]
Next, the laminate 40 that is a feature of the present invention will be described. As shown in FIG. 1, the laminate 40 is configured by laminating a nonwoven fabric 41, a microporous film 42, and a sealant film 43 as a thermoplastic resin film. The sealant film 43 is formed with a plurality of holes (not shown) that communicate between the outside air and the heating element 10, and supplies air to the heating element 10 through the holes.

[Nonwoven fabric]
The nonwoven fabric 41 is made of polypropylene (PP). For example, homopolypropylene (HPP) or random polypropylene (RPP) can be used as the polypropylene, and a random copolymer or block copolymer of propylene and an ethylene-α-olefin copolymer can be used. Furthermore, these may be used alone or in combination of two or more. In addition, since the polypropylene-based nonwoven fabric 41 is a general-purpose product and has high productivity and low cost, by adopting it as a constituent material of the breathable base material, compared to the case of using a polyamide (nylon) nonwoven fabric, The cost of the disposable hand warmer 1 can be greatly reduced.

  When the polypropylene resin is a copolymer of propylene and other components, the proportion of the other components is preferably 10% by mass or less with respect to the propylene component. In addition, in the laminated body of the present invention, it is preferable to use homopolypropylene (HPP) having excellent heat resistance in consideration of being applied to a storage bag for storing the heating element 10 of the warmer 100.

  In addition, you may add 3rd components, such as conventionally well-known various additives, to these polypropylene resin in the range which does not impair the effect of this invention as needed. Examples of the third component include antioxidants, inorganic and organic pigments, heat stabilizers, nucleating agents, ultraviolet absorbers, light stabilizers, antistatic agents, flame retardants, dyes, silica, talc Inorganic powders such as calcium carbonate, calcium oxide, and magnesium oxide.

  The nonwoven fabric 41 is formed by a general-purpose manufacturing method. As this method, for example, a dry method such as a card method in which a synthetic resin or the like is defibrated using a card machine or the like, or an air raid method in which the defibrated fibers are collected by an air flow to form a sheet, A wet method in which fibers are evenly dispersed in water and flowed on a wire to form a sheet, followed by dehydration and drying, a spunbond method in which spun continuous yarns are spread and accumulated to form a web, and a spinning machine. Examples thereof include a direct spinning method represented by a melt-blow method such as a melt blow method in which continuous yarn is blown off with hot air and then collected on a conveyor to form a web. In addition, in this Embodiment, although the nonwoven fabric 41 manufactured by the spun bond method which has high productivity and can be manufactured from a continuous fiber is suitable, it is not limited to this in particular. In addition, the nonwoven fabric manufactured by the several manufacturing method may be compounded.

When this nonwoven fabric 41 is used for an application that touches human skin such as the warmer 100 or the heat generation ship as in the present embodiment, the weight per square meter of the fabric, that is, the basis weight is 5 to 100 g / cm, for example. ² is preferable, and 20 to 50 g / cm ² is more preferable. When the weight per unit area of the nonwoven fabric 41 is 5 g / cm ² or less, the touch of the laminate 40 laminated with the nonwoven fabric 41, that is, the texture becomes soft, but the fibers are easy to fall off and are not suitable for applications that touch human skin. . Moreover, when the fabric weight of the nonwoven fabric 41 is 100 g / cm ² or more, the texture becomes too hard and is not suitable as an application for touching human skin. The fiber thickness of the nonwoven fabric 41 is preferably 2 to 20 denier. When the fiber thickness of the non-woven fabric 41 is less than 2 denier, fluff tends to come out, and when it is 20 denier or more, the texture becomes hard and is not suitable for use in contact with human skin.

[Microporous film]
The microporous film 42 is formed mainly of a polyolefin resin having excellent tensile strength, tensile elastic modulus, oil resistance, and the like. Among these, the microporous film 42 mainly composed of polypropylene has good heat resistance as compared with a conventionally used polyethylene-based porous film. It is suitable because it is hardly affected by heat during production.

  The microporous film 42 has a plurality of unillustrated micropores. The micropores are formed to have a diameter smaller than the particle diameters of iron powder, salts, activated carbon, and water retention agent constituting the heating element 10 accommodated in the warmer 100. Specifically, the micropores may have a pore diameter of 100 μm or less, preferably 50 μm, more preferably 10 μm or less. When the hole diameter of the micropores exceeds 100 μm, the heating element 10 oozes out from the micropore diameter, causing a problem in appearance, or the heating element 10 goes out.

  The microporous film 42 has a predetermined air permeability. Specifically, the microporous film 42 preferably has an air permeability of 5000 seconds / 100 cc or less, more preferably 2000 seconds / 100 cc or less, in a test by the Gurley method (JIS P8117). When the air permeability is 5000 seconds / 100 cc or more, air permeability is hardly obtained when the sealant film 43 is laminated, and it is difficult to ensure appropriate air permeability as the warmer 100. Moreover, when the air permeability is measured by the Gurley method, for example, every 10 cm, it is preferable that the variation with respect to the average value of the standard deviation is within 30%. This variation is preferably as small as possible, more preferably within 20%, and even more preferably within 10%. If this air permeability exceeds 30%, the air permeability of the manufactured warmer 100 will vary. For example, in the warmer 100 where there are many portions with good air permeability, abnormal heat may be generated or there may be portions where the air permeability is poor. In many warmers 100, the temperature does not increase.

  Furthermore, the microporous film 42 is preferably formed to have a thickness dimension of 15 to 200 μm, more preferably 20 to 150 μm, and even more preferably 30 to 50 μm. When the thickness dimension of a microporous film exceeds 200 micrometers, the thickness dimension of the laminated body 40 will become large and the texture of the laminated body 40 will become hard. On the other hand, if the thickness of the microporous film is smaller than 15 μm, the strength at the seal edge portion 35 cannot be maintained due to thermal damage during bag making.

  The microporous film 42 is mainly composed of a polypropylene-diameter resin, but is not limited to this as long as the above-described conditions are satisfied. For example, a film obtained by stretching a film using a mixture of a thermoplastic resin and an inorganic filler and then making it microporous by causing interfacial peeling between the thermoplastic resin and the inorganic filler may be used. A film formed by any other method may be used.

[Sealant film]
[Resin forming the sealant film]
The sealant film 43 is not particularly limited as long as it can be heat-sealed with the heat seal layer 31 or the base material layer 32 of the sheet base material 30, but is not limited to an ethylene-α-olefin copolymer resin, which is a polyethylene resin, or random polypropylene. Formed. In order to increase the heat sealing speed, an ethylene-α-olefin polymer is preferable. Examples of the α-olefin copolymer include linear olefins such as 1-butene, 1-pentene, 1-hexene, 1-octene, 1-nonene, 1-decene, 1-undecene, and 1-dodecene. And branched olefins such as -methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, and 2,2,4-trimethylpentene. The sealant film 43 may be formed of ethylene-α-olefin using one of these α-olefins, and may be an ethylene-α-olefin combined with a plurality of α-olefins. It may be formed. The sealant film 43 is not limited to one type of ethylene-α-olefin, and the sealant film 43 may be formed by mixing a plurality of types of ethylene-α-olefin.

  In addition, there is no restriction | limiting in particular as a production | generation method of an ethylene-alpha-olefin copolymer. For example, it may be manufactured by a manufacturing method using a Ziegler-Nazda catalyst or a homogeneous catalyst. The homogeneous catalyst may be, for example, a combination of a vanadium compound and an organoaluminum that are generally used conventionally, and may be a single site catalyst.

  Moreover, it is preferable that the melt flow index (MI) value which shows the fluidity | liquidity of the polymer in a solution state of the sealant film 43 is 1-50 g / 10min. Furthermore, the weight average molecular weight / number average molecular weight (Mw / Mn) is preferably 1.8 to 3.0. In the present embodiment, the sealant film 43 formed with the MI value and the Mw / Mn in the above ranges is shown, but the present invention is not limited to this. That is, these MI values and Mw / NW values may be different from those described above, and these values are not particularly problematic in the present embodiment.

[Structure of sealant film]
The sealant film 43 has a three-layer structure including a laminate layer 431, an intermediate layer 432, and a seal layer 433. The laminate layer 431 is a layer for laminating the sealant film 43 to the microporous film 42. The density of the laminate layer 431 is preferably 0.915 g / cm ³ or less, more preferably ^{0.890g / cm 3 ~0910g / cm 3} . When the density of the laminate layer 431 is 0.915 g / cm ³ or more, the laminate strength that is the strength of the laminate adhesion to the microporous film 42 cannot be maintained. If the density of the laminate layer 431 is too low, specifically 0.88 g / cm ³ or less, the laminate layer 431 may be dissolved by the heat generated by the heating element 10.

The intermediate layer 432 is a layer stacked between the laminate layer 431 and the seal layer 433. The intermediate layer 432 is formed to have a higher density than the laminate layer 431 and the seal layer 433. If the density of the intermediate layer 432 is lower than the density of the laminate layer 431 and the seal layer 433, the laminate 40 has a laminate strength, a seal strength when the bag is made, and a thermal effect on the seal edge portion, and the warmer 100 is not balanced. As a result, stable performance cannot be obtained. The density of the intermediate layer 432, specifically, preferably from 0.910 g / cm ³ or more, particularly preferably equal to 0.915 g / cm ³ or more. When the density of the intermediate layer 432 is less than 0.910 g / cm ^3, it is difficult to form the sealant film 43 having a three-layer structure. The shrinkage cannot be suppressed.

The seal layer 433 is a layer that is heat sealed to the heat seal layer 31 of the sheet substrate 30. The seal layer 433 is formed at a lower density than the intermediate layer 432, as with the laminate layer 431. Specifically, the density of the sealing layer 433 is preferably 0.915 g / cm ³ or ^less, particularly preferably as long as ^{0.890g / cm 3 ~0.910g / cm 3} . When the density of the seal layer 433 is greater than 0.915 g / cm ³ , the seal strength cannot be stably obtained when the bag is made.

[Production of sealant film]
The manufacturing method of the sealant film 43 having the three-layer structure as described above is not particularly limited. For example, after the laminate layer 431, the intermediate layer 432, and the seal layer 433 are separately formed, these three layers are laminated and bonded by a dry laminate method, a wet laminate method, a thermal laminate method, an extrusion method, a co-extrusion method, or the like. . In particular, the coextrusion method is a method in which three layers are simultaneously formed to form a film, and is most preferable because it has high productivity and easily secures a softness suitable for the bag material 20 used in the warmer 100. Further, the film forming method is not particularly limited, and any film forming method such as a casting method or an inflation method can be applied.

  Further, in the three layers of the laminate layer 431, the intermediate layer 432, and the seal layer 433 constituting the sealant film 43, a third component such as various conventionally known additives can be used as long as the purpose of the present invention is not impaired. May be added. Examples of the third component include an antioxidant, a neutralizer, a slip agent, an antiblocking agent, an antistatic agent, a heat stabilizer, a nucleating agent, a flame retardant, and a colorant.

  The overall thickness of the sealant film 43 is not particularly limited, but a dimension in the range of 10 to 150 μm is preferable, and a thickness dimension in the range of 20 to 50 μm is particularly preferable from the viewpoint of improving the texture of the warmer 100. The thickness ratio of each layer is (laminated layer 431) :( intermediate layer 432) :( seal layer 433) is (0.1-0.5): 1: (0.1-0.5). Is preferable, and (0.2 to 0.3): 1: (0.2 to 0.3) is more preferable. When the relative thickness ratio of the laminate layer 431 to the intermediate layer 432 is less than 0.1, the laminate strength decreases when the sealant film 43 and the microporous film 42 are laminated and bonded. Further, when the relative thickness ratio of the laminate layer 431 to the intermediate layer 432 is greater than 0.5, the rigidity of the sealant film 43 is lowered. Similarly, when the relative thickness ratio of the seal layer 433 to the intermediate layer 432 is less than 0.1, the heat sealability between the sealant film 43 and the sheet base material 30 is deteriorated, and the seal strength cannot be ensured. Further, when the relative thickness ratio of the seal layer 433 to the intermediate layer 432 is greater than 0.5, the rigidity of the sealant film 43 is lowered.

[Perforated sealant film]
The sealant film 43 is provided with a plurality of holes that penetrate the laminate layer 431, the intermediate layer 432, and the seal layer 433. This hole may be formed by melting and burning with a heated needle, for example, may be formed with a laser, or may be formed by punching using a fine punch or the like. It may be formed using techniques.

  This pore has a low airflow resistance with respect to the microporous film 42. Specifically, the sealant film 43 preferably has air permeability such that the air permeability is 10 seconds / 100 cc or less in the air permeability measurement by the Gurley method, and the air permeability is 5 seconds / 100 cc or less. More preferably. When the air permeability is 10 sec / 100 cc "or more, even if the microporous film 42 has suitable air permeability, the warmer 100 having a stable heat generation behavior cannot be manufactured. The interval at which the air is provided can be selected in accordance with the air permeability of the microporous film 42 and the laminating method when the three layers of the sealant film 43 are laminated.

[Lamination method of laminate]
The laminate 40 can be obtained by laminating the above-described nonwoven fabric 41, the microporous film 42, and the sealant film 43 together. The lamination means of both is not particularly limited as long as it can secure a sufficient bonding strength and a good texture when used as a constituent material of the warming warmer 100. For example, an extrusion laminating method, a hot melt What is necessary is just to bond together by conventionally well-known bonding means, such as a laminating method, a dry laminating method, and a wet laminating method. In particular, by using the sealant film 43, the microporous film 42 is not easily deteriorated by heat. Therefore, it is preferable to laminate by a thermal laminating method in which foreign materials are not mixed.

  As shown in FIG. 2, a general thermal laminating laminating apparatus performs thermal lamination by passing a nonwoven fabric 41, a microporous film 42, and a sealant film 43. In FIG. 2, a laminating apparatus 50 includes a popper 51 into which, for example, HPP (homopolypropylene) as a raw material of the nonwoven fabric 41 is charged, a single-screw extruder 511 for extruding HPP sent from the popper 51, and a spunbond method from HPP. A spunbond spinning section 52 provided with a spunbonding die to be spun at a spinning pulling device 53 provided with a cooling tower, a filament stretching section, and a fiber opening section, a feeding machine 54 for feeding out the microporous film 42, Conveyor device with suction 55 for laminating and feeding the nonwoven fabric web, first laminating device 56 for thermally laminating the nonwoven fabric web and the microporous film 42, a feeding device 57 for feeding the sealant film 43, and a fine sealant film 43. Second laminating device 58 for laminating the porous film, and winding to wind up the laminate 40 Is provided with a device 59, a. The first and second laminating apparatuses 56 and 58 include at least one heating roller. And these heating roll materials, surface pattern, temperature, pressure, etc. are the melting point and thickness of the nonwoven fabric 41, the microporous film 42 and the sealant film 43, the basis weight of the nonwoven fabric 41, the layer ratio of the laminate 40, the processing speed, It can be appropriately selected depending on the texture and appearance of the laminate 40.

  In such a laminating apparatus 50, when HPP is introduced by the popper 51, this HPP is extruded to the spunbond spinning section 52 by the single screw extruder 511, and the nonwoven fabric made of HPP is spun by the spunbond spinning section 52. A web is generated.

  The nonwoven fabric web is cooled while being stretched and opened by the spinning and pulling device 53 and collected by the conveyor device 55 with suction having good air permeability. On the other hand, the microporous film 42 generated in advance from the feeding machine 54 is fed out. When the nonwoven web and the microporous film 42 are laminated and bonded by the heat laminating method in the first laminating device 56, the nonwoven web is fixed by heat to obtain the nonwoven fabric 41.

  Next, the sealant film 43 is fed out by the feeding device 57, and the laminate layer 431 of the sealant film 43 is arranged on the microporous film 42 side. And the multilayer body which consists of the nonwoven fabric 41 and the microporous film 42, and the sealant film 43 are laminated-bonded in the 2nd laminating apparatus 58, and the laminated body 40 is produced | generated. And the produced laminated body 40 is wound up by the winding device 59.

  Moreover, it is preferable that the 1st and 2nd laminating apparatuses 56 and 58 are embossed by the engraving, the etching, etc. on the surface of at least one heating roller. As the embossing, various embossing patterns can be adopted. Examples of the embossing include an embossing having a lattice shape in which the welding portions are continuous, an embossing having an independent lattice shape, and an embossing having an arbitrary distribution. The embossing pattern, embossing area ratio, temperature, pressure and the like of such a heating roller are the melting point and thickness of the nonwoven fabric 41, the microporous film 42 and the sealant film 43, the basis weight of the nonwoven fabric 41, the layer ratio of the laminate 40, and the processing The speed can be selected as appropriate depending on the texture and appearance of the laminate 40.

  In addition, although the example in which the laminating apparatus is provided in multiple stages of the first laminating apparatus and the second laminating apparatus has been shown, it may not be multistage. For example, the nonwoven fabric web, the microporous film 42, and the sealant film 43 may be simultaneously passed through the laminating apparatus. When the laminating apparatus is provided in multiple stages as in this example, the lamination strength is stabilized and the processing speed is increased. For example, before laminating the nonwoven web and the microporous film 42, the nonwoven web 41 can be fixed by heat embossing by sandwiching the nonwoven web with a heating roller. You can also.

[Method for producing Cairo]
As a method for producing the warming warmer 100 of the present invention, the heat seal layer 31 of the sheet substrate 30 and the seal layer 433 of the sealant film 43 of the laminate 40 are directly overlapped, and then iron powder, water In addition, a method of processing into a bag shape by heat-sealing four sides with a heat sealing machine or the like while filling a predetermined amount of the heating element 10 made of wood powder, activated carbon, inorganic salt, or the like.

  Specifically, the heat seal layer 31 of the sheet base material 30 and the seal layer 433 of the sealant film 43 of the laminate 40 are directly overlapped with a conventionally known die roll type automatic filling bag making machine (not shown). Unwinding, filling the heating element 10 with a predetermined amount, and heat-sealing the four sides with a heat sealing machine (tie roll) mounted on the bag making machine. At this time, at least a part of the air vent hole for venting air is formed. Then, after filling the heating element 10, while removing the internal air from the air vent hole portion, the four-side seal portion is again heat-sealed by a heat sealing machine (tie roll), whereby the sticking warmer 100 of the present invention is obtained. It can be easily obtained.

  Moreover, it is preferable that the sticking disposable body warmer 100 of the present invention has a seal strength between the sheet base material 30 (heat seal layer 31) to be heat sealed and the laminate 40 (sealant film 43) of 5 N / 15 mm width or more. The width is preferably 8 N / 15 mm or more. Furthermore, it is suitable that it is 9.8 N / 15 mm width or more. If the seal strength is 5 N / 15 mm width or more, a sufficient seal strength can be exhibited in the warmer 100, and there is no problem in practical use. On the other hand, if the seal strength is less than 5 N / 15 mm width, peeling from the heat-sealed portion may occur when using the warmer 100, and the heating element 10 as the contents may leak out. The value is reduced. Further, a wide sealing temperature range capable of securing a preferable 8N / 15 mm width is advantageous in increasing the speed of the bag making of the warmer.

  The seal strength in the present invention refers to, for example, the heat resistance of the sheet base material 30 using a seal tester capable of tight sealing the heat seal layer 31 of the sheet base material 30 and the sealant film 43 of the laminate 40. The heat seal layer 31 and the sealant film 43 of the laminate 40 are directly overlapped with each other and heat sealed, and the seal portion is subjected to 180 ° peeling (T-type peeling) at a tensile speed of 300 mm / min using a tensile tester. What is necessary is just to measure the maximum intensity | strength per 15 mm at the time of performing. For example, it is preferable that the pressure is 0.4 MPa, the sealing time is 2 seconds, and a wide sealing temperature range in which a preferable 8 N / 15 mm width, more preferable 9.8 N / 15 mm width or more can be secured.

  And when using the body warmer 100 for sticking of this invention, after removing the release paper 34 which exists on the surface, and making the adhesive layer 33 into the exposed state, the adhesive layer 33 is adhered to the part to be kept warm. You can do it.

[Effect of this embodiment]
As described above, the laminate 40 according to the embodiment is configured by laminating the nonwoven fabric 41, the microporous film 42, and the sealant film 43. The sealant film 43 includes a laminate layer 431, a seal layer 433, and an intermediate layer 432 laminated between the laminate layer 431 and the seal layer 433. The intermediate layer 432 is formed from the laminate layer 431 and the seal layer 433. Also, the density is set to be high. For this reason, when such a sealant film 43 is laminated in contact with the microporous film 42, the microporous film 42 is protected by the sealant film 43 and can prevent thermal degradation, edge breakage, thermal shrinkage, and the like. Therefore, the microporous film 42 can be prevented from becoming brittle, and problems such as edge breakage can be prevented. Also, in the high-speed bag making process for forming a bag at a high speed, the sealing layer 433 is formed at a low density, so that the sealing strength between the laminate 40 and the sheet base material 30 does not decrease.

  In addition, since the sealant film 43 has a three-layer structure and the laminate layer 431 and the seal layer 433 are formed so as to have a lower density than the intermediate layer 432, the lamination strength with the microporous film can be increased. Similarly, the sealing layer 433 can increase the sealing strength with the sheet base material 30.

  The sealant film 43 includes an ethylene-α-olefin copolymer. Since α-olefin is excellent in film formation and heat sealability, the sealant film 43 can be easily formed, and the heat sealability between the sealant film 43 and the microporous film 42 can be improved.

Furthermore, since the density of the intermediate layer 432 is 0.910 g / cm ³ or more, the influence of heat on the microporous film 42 can be efficiently suppressed by the intermediate layer 432.

Furthermore, the density of the laminate layer 431 and the seal layer 433 is 0.915 g / cm ³ or less. Thereby, when the laminate layer 431 is laminated on the microporous film 42, good laminating strength is obtained, and the sealant film 43 and the microporous film 42 can be securely bonded. Moreover, when manufacturing the bag material 20 using the laminated body 40 and the sheet base material 30, a stable sealing strength is obtained in the process of heat-sealing the seal layer 433 and the sheet base material 30 while removing air. Can do.

  In addition, since the density of the intermediate layer 432 is higher than the density of the laminate layer 431 and the seal layer 433, and the density of the laminate layer 431, the intermediate layer 432, and the seal layer 433 is approximate, It is easy to form a film substantially uniformly, and the sealant film 43 can be easily formed.

  And the nonwoven fabric 41, the microporous film 42, and the sealant film 43 can be easily adhere | attached by the heat laminating method. For this reason, productivity of the laminated body 40 can be made favorable and reduction of production cost can be aimed at.

  The nonwoven fabric 41 is made of a polypropylene resin. For this reason, productivity can be made favorable with cheap resin compared with the conventional nylon nonwoven fabric. Therefore, the production cost can be reduced.

  In such a laminate 40, even if a material having low heat resistance such as polypropylene as described above is used for the microporous film 42, the seal layer 433 is formed on the sheet base without thermal deterioration during bag making. The material 30 can be heat sealed. Therefore, the bag material 20 using the microporous film 42 made of polypropylene or the like can be easily manufactured. Therefore, productivity can be improved and production cost can be reduced.

  Examples and comparative examples will be given below to confirm the effects of the embodiment. FIG. 3 is a diagram illustrating measurement results of seal strengths of Examples 1 to 5 and Comparative Examples 1 to 4.

[Examples 1 to 5 and Comparative Examples 1 to 3]

Using the resin A to resin D shown below, a sealant film with a thickness of 30 μm constituting the warmers of Examples 1 to 5 and Comparative Examples 1 to 3 was manufactured using the manufacturing method shown below.

Here, the resin characteristics of the resins A to D were as follows. In addition, the density of the following resin material was measured by the method based on JISK7112 (23 degreeC), and the melt flow index (MI) was measured by the method based on JISK7219, respectively.
(Resin A) Resin: Moretec 0356CN (manufactured by Idemitsu Petrochemical Co., Ltd.)
Density: 0.931 g / cm ³
Mel and Flow Index: MI = 2.8
(Resin B) Resin: Moretec 0238CN (manufactured by Idemitsu Petrochemical Co., Ltd.)
Density: 0.916 g / cm ³
Mel and Flow Index: MI = 2.1
(Resin C) Resin: Moretech V0398CN (manufactured by Idemitsu Petrochemical Co., Ltd.)
Density: 0.907 g / cm ³
Mel and Flow Index: MI = 3.3
(Resin D) Resin: Evolue SP0510 (manufactured by Mitsui Chemicals, Inc.)
Density: 0.903 g / cm ³
Mel and Flow Index: MI = 3.8

  In Example 1, a sealant film using resin D for the laminate layer, resin A for the intermediate layer, and resin D for the seal layer was manufactured. In Example 2, a sealant film using resin D for the laminate layer, resin B for the intermediate layer, and resin C for the seal layer was manufactured. In Example 3, a sealant film using resin C for the laminate layer, resin A for the intermediate layer, and resin D for the seal layer was manufactured. In Example 4, a sealant film was produced using resin B for the laminate layer, resin A for the intermediate layer, and resin D for the seal layer. In Example 5, a sealant film was produced using resin D for the laminate layer, resin A for the intermediate layer, and resin B for the seal layer.

  In Comparative Example 1, a sealant film was manufactured using Resin A for the laminate layer, Resin A for the intermediate layer, and Resin D for the seal layer. In Comparative Example 2, a sealant film using resin D for the laminate layer, resin D for the intermediate layer, and resin D for the seal layer was manufactured. In Comparative Example 3, a sealant film using resin D for the laminate layer, resin A for the intermediate layer, and resin A for the seal layer was manufactured.

Table 1 shows the density of each layer of the sealant films of Examples 1 to 5 and Comparative Examples 1 to 3 manufactured as described above. In Table 1, the unit of resin density is g / cm ³ .

  In Comparative Example 4, a PP-based coextrusion cast film “Unilux” RS-512 (manufactured by Idemitsu Petrochemical Co., Ltd.), which is a three-layer CPP sealant film with good thermal lamination, was used as the sealant film. In Comparative Example 4, a sealant film having a thickness dimension of 20 μm was used.

(Sealant film manufacturing method)
The sealant films constituting the warmers of Examples 1 to 5 and Comparative Examples 1 to 4 use a coextrusion casting apparatus (not shown), and the laminate layer: intermediate layer: seal layer is 1: 5 according to the following production conditions. 1 and co-extrusion was carried out by adjusting the number of revolutions of the extrusion apparatus so that the overall thickness dimension was 30 μm.

Screw diameter corresponding to the laminate layer: 50mm
Screw diameter corresponding to the intermediate layer: 65mm
Screw diameter corresponding to the seal layer: 40mm
Die temperature: 230 ° C
Chill roll temperature: 50 ° C
Total discharge rate: 100kg / hr
Take-off speed: 50m / min

(Microporous film)
In Examples 1 to 5 and Comparative Examples 1 to 4, a PP microporous film (manufactured by Mitsui Chemicals, Inc.) prepared by a known method was used. The microporous film had a thickness of 24 μm and an air permeability of 310 seconds / 100 cc.

The laminated body was manufactured with the laminating apparatus as shown in FIG. At this time, a homopolypropylene resin (Idemitu PP “Y6005GM” (MI = 60) manufactured by Idemitsu Petrochemical Co., Ltd.) was introduced into the popper 51 and extruded at 230 ° C. so that the basis weight was 40 g / m ^2. Generated the web. Note that. The fiber system of this nonwoven fabric was 3 denier.

  Next, the nonwoven fabric and the microporous film were laminated and bonded with the first laminator. The laminating conditions at this time were a line speed of 10 m / min and a heating roller temperature of 150 ° C. for both.

  Further, a sealant film was combined with the microporous film and laminated and bonded with a second laminating apparatus, and a laminate was produced to obtain a sample. The lamination conditions at this time were a line speed of 10 m / min, a temperature of the heating roller on the nonwoven fabric side was 150 ° C., a temperature of the heating roller on the sealant film side was 85 ° C., and the winding speed was 10 m / min.

  In Comparative Example 4, in the step of laminating and bonding the microporous film and the sealant film, the line speed was 10 m / min, the temperature of the heating roller on the nonwoven fabric side was 150 ° C., and the temperature of the heating roller on the sealant film side was 120 ° C. The winding speed was 10 m / min at ° C.

Here, the laminate strength of the sealant film and the microporous film in the laminates of Examples 1 to 5 and Comparative Examples 1 to 4 manufactured as described above were the values shown below. That is, in Example 1, Example 2, Example 5, Comparative Example 2, and Comparative Example 3 in which a laminate layer was made of resin D, the laminar strength was 700 g / 25 mm width. In Example 3 in which a laminate layer was created with Resin C, the laminate strength was 610 g / 25 mm width. In Example 4 in which a laminate layer was made of the resin B, the laminate strength was 220 g / 25 mm width. In Comparative Example 1 in which a laminate layer was formed with Resin A, the laminate strength was 25 g / 25 mm width.
The laminar strength was measured by performing 180 ° peeling (T-type peeling) using a tensile tester with a tensile speed of 300 mm / min.

[Evaluation methods]
For the samples of Examples 1 to 5 and Comparative Examples 1 to 4 obtained as described above, the following condition seal strength and texture evaluation were measured and compared and evaluated.
(1) Seal strength:
In terms of seal strength, first, the nonwoven fabric surface of the laminate was placed on the seal bar side using a thermal inclination tester, and the sheet base material (Unicrest “750CW” (manufactured by Idemitsu Unitech Co., Ltd.), heat seal surface resin EVA system. And was heat-sealed under the following conditions.
Heat seal pressure: 0.4Mpa
Heat sealing time: 2 seconds

  Then, the heat seal part was subjected to 180 ° C. peeling (T-type peeling) at a tensile speed of 300 mm / min, and the maximum value was defined as the seal strength.

(2) Texture evaluation:
In the texture evaluation, first, the laminates obtained in the examples and comparative examples were 9.5 cm × 13 cm in size, and the sheet base material was heat-sealed to form a bag form. Then, the heating element was housed in the bag and heat sealed again to produce a warmer. In addition, as a sheet | seat base material, Unicrest "750CW" (made by Idemitsu Unitech Co., Ltd.) used with the evaluation method of the sealing strength mentioned above was used. Moreover, in order to eliminate the difference between the heating elements, the heating elements used in the commercially available warmer “Hockairo (manufactured by Hakumoto Co., Ltd.)” were accommodated. Moreover, the above-mentioned commercially available body warmer was used as the comparative example 7. And the warmer created by said method was made to touch 10 monitors for the comparative example 5, and the comparative evaluation questionnaire was implemented.

[Evaluation results]
(Evaluation of seal strength)
According to said method, the heat seal evaluation by a thermal inclination tester was implemented, and the result as shown in FIG. 3 was obtained.

  In the laminated body for a heating element storage bag such as a warmer, it is necessary to make a bag while venting the air when storing the heating element as described above. In addition, a sealing strength that does not cause heat shrinkage, heat melting, and edge breakage is required. Therefore, whether or not a temperature range in which the seal strength exceeds 1 kg / 15 mm width can be secured at 30 ° C. or higher was used as a criterion.

  As a result of the seal evaluation method, in Examples 1 and 3 and Comparative Example 3, when the seal temperature was set to 160 ° C. as the heat seal condition, thermal deterioration (melting of a part of the nonwoven fabric on the surface) occurred in the seal portion. In Example 2, an edge break occurred when the seal temperature was 155 ° C. and in Comparative Example 2 the seal temperature was 140 ° C.

  As can be seen from the results shown in FIG. 3, in Examples 1 to 5, a seal temperature range of 30 degrees or more could be secured, but in Comparative Examples 1 to 4, it could not be secured. Therefore, in Examples 1 to 5 provided with the conditions of the present invention, it was confirmed that thermal deterioration hardly occurs when heat sealing. Moreover, in Examples 1-5, since the polypropylene-type nonwoven fabric is employ | adopted as a nonwoven fabric, the disposable warmer for sticking can be provided at low cost.

(Texture evaluation)
As a result of the questionnaire in the texture evaluation method, it was clearly evaluated that the texture produced by the laminate of Comparative Example 4 was clearly hard. Other Cairo were evaluated to be equivalent or softer than Comparative Example 5. In particular, evaluation that the texture of Example 1, Example 3, and Comparative Example 2 was soft was obtained.

  As described above, in a laminate using a sealant film formed of an ethylene-α-olefin copolymer as described above and having a resin density of an intermediate layer having a three-layer structure lower than that of the other two layers. It was confirmed that it had a texture necessary as a warmer for pasting.

  Since the laminated body of the present invention is not easily damaged by heat at the time of bag making, it can be widely used as, for example, a heat-generating ship, in addition to a leisure warmer, a medical disposable warmer, and a warmer for sticking.

It is sectional drawing which showed typically the body warmer concerning one embodiment of this invention. It is the schematic which showed typically the lamination apparatus which manufactures a laminated body. It is a figure which shows the measurement result of the seal strength of Examples 1-5 and Comparative Examples 1-4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Heat generating body 20 Bag material 30 Sheet base material 31 Heat seal layer 40 Laminate body 41 Nonwoven fabric 42 Microporous film 43 Sealant film as a thermoplastic resin film 100 Cairo 431 Laminate layer 432 Intermediate layer 433 Seal layer

Claims (8)

A laminate in which a synthetic resin nonwoven fabric, a perforated thermoplastic resin film, and a microporous film provided between the nonwoven fabric and the thermoplastic resin film are laminated,
The thermoplastic resin film is formed between at least a laminate layer in contact with the porous film, a sheet substrate to which the laminate is attached or a seal layer in contact with the film substrate, and the laminate layer and the seal layer. An intermediate layer formed in a state in which the density is higher than that of the laminate layer and the seal layer. The laminate according to claim 1,
The thermoplastic resin film includes an ethylene-α-olefin copolymer. The laminate according to claim 1 or 2, wherein
The intermediate layer has a density of 0.910 g / cm ³ or more. It is a laminated body in any one of Claim 1 thru | or 3, Comprising:
The laminate and the seal layer have a density of 0.915 g / cm ³ or less. The laminate according to any one of claims 1 to 4,
The non-woven fabric, the thermoplastic resin film, and the microporous film are bonded and laminated by thermal lamination. It is a laminated body in any one of Claim 1 thru | or 5, Comprising:
The said nonwoven fabric is a polypropylene-type nonwoven fabric, The laminated body characterized by the above-mentioned. The laminate according to any one of claims 1 to 6,
At least one side is a sheet base material or a film base material that can be heat sealed with the sealing layer of the thermoplastic resin film,
A bag material for storing the contents in the interior,
The bag peripheral part of the said bag material heat-seals the said sealing layer of the said thermoplastic resin film, and the said sheet | seat base material or a film base material. The bag material characterized by the above-mentioned. The bag material according to claim 7,
The content is a heating element housed inside the bag material in a state not in contact with the microporous film,
The sheet base material or the film base material includes a heat seal layer that can be heat-sealed with the seal layer, a base material layer that is a main body of the sheet base material or the film base material, and an adhesive that imparts adhesiveness to the base material layer. A bag material, characterized in that the pressure-sensitive adhesive layer to be provided and a release paper covering the pressure-sensitive adhesive of the pressure-sensitive adhesive layer are multi-layered bodies laminated in this order.

Images