JP2000126217A - Colored air permeable base material and throw-away body warmer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to allow coloration without the hindrance of air permeability, or the like, to maintain a heat generation temperature and heat generation duration time similar to those of the case the coloration is not executed, to substantially prevent decoloration and color change and to maintain a concealing effect and beauty by the coloration. SOLUTION: This throw-away body warmer consists of a colored air permeable base material 7 which is formed by adhering a porous film 1 and an air permeable base material 3 via an air permeable adhesive layer 2 and in which either or both of the porous film 1 and the air permeable base material 3 consist of colored layers. The throw-away body warmer described above is formed by housing a heating element into a housing bag using such colored air permeable base material 7 in at least a part thereof. As a result, the throw-away body warmer which is protected by the porous film and the air permeable base material as a result of the coloration of the air permeable adhesive layer, is exceedingly excellent in the preventiveness of the decoloration and color change and is improved in the adhesive power, the stability of a water vapor transmission rate and heat resistance by the use of the fiber deposition type adhesive layer is obtained. The occurrence of wrinkling, peeling and the degradation in the water vapor transmission rate are substantially prevented. The excellent hand based on the cushion property, or the like, by the adhesive layer is obtained as well.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a colored air-permeable base material having excellent long-term stability of a colored state, and a disposable body warmer using the same.

[0002]

2. Description of the Related Art Conventionally, as a colored air-permeable base material which can be used for a storage bag of a disposable body warmer, a porous film and a gas-permeable base material bonded to each other via a porous adhesive layer can be used. Known are those having a colored surface and those using a colored non-woven fabric as a breathable substrate (Japanese Patent Laid-Open No. 8-131).
472).

[0003] The coloring process is the same color system as the underwear and the background, etc., which adhere and support the disposable body warmer when the disposable body warmer is worn. It is intended to improve the aesthetic appearance by preventing the development of the color and to make it more decorative.

[0004] However, in the conventional coloring treatment of the outer surface, there have been problems such as that the coloring layer easily falls off, and that the temperature and duration of heat generation are reduced due to bad air permeability. That is, the storage bag of the disposable body warmer is usually formed with the porous film inside and the air-permeable base material outside,
By coloring the outer surface (the inside of the bag) of the porous film,
There is a problem that the colored ink is easily peeled off by water vapor or the like generated from the heating element, and that the air permeability is reduced.

On the other hand, when coloring the outer surface (outside of the bag) of the air-permeable base material, there is a problem that the colored layer is severely dropped due to rubbing or the like, and a color change due to fuzzing is liable to occur. The color change due to the fluffing occurs similarly when a colored nonwoven fabric is used, which impairs the blinding effect by coloring and also impairs the appearance.

[0006]

SUMMARY OF THE INVENTION The present invention can be colored without impairing air permeability and the like, can maintain the same heat generation temperature and heat generation duration as in the case of not being colored, hardly cause decoloration and color change, and can be blindfolded by coloring. An object of the present invention is to obtain a colored ventilation base material and a disposable body warmer capable of maintaining the effects and aesthetic appearance for a long period of time.

[0007]

According to the present invention, a porous film and a gas-permeable substrate are adhered via a gas-permeable adhesive layer, and one or both of the porous film and the gas-permeable adhesive layer are formed of a colored layer. The present invention provides a disposable body warmer characterized in that a heating element is accommodated inside a colored ventilation base material and a storage bag using at least a part of the colored ventilation base material.

[0008]

According to the present invention, it is possible to form a disposable body warmer which does not impair the air permeability and the like by the coloring of the formation layer itself and maintains the same exothermic temperature and exothermic duration as when not colored. The colored layer is less likely to be decolorized or changed in color by rubbing during the production process or wearing of the disposable body warmer, and it is possible to obtain a colored ventilation base material that maintains the blinding effect and aesthetic appearance by coloring for a long time. In particular, when the air-permeable adhesive layer is colored, the colored layer is protected by the porous film or the air-permeable base material, and is extremely excellent in preventing decolorization and color change.

[0009] In the case of a material treated with an adhesive layer consisting of a layer of fibers, the adhesiveness, moisture permeability stability, and heat resistance are excellent, and even as a disposable warmer, wrinkles, peeling, and reduction in moisture permeability are reduced. And the texture is excellent based on the cushioning property of the adhesive layer.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The colored air-permeable substrate according to the present invention is obtained by bonding a porous film and an air-permeable substrate through an air-permeable adhesive layer, and one or both of the porous film and the air-permeable substrate are colored. Consisting of An example is shown in FIG. 1 is a porous film, 2 is a gas-permeable adhesive layer, and 3 is a gas-permeable substrate.

As the porous film, a colored material or an appropriate film according to a conventional disposable body warmer or the like can be used, and there is no particular limitation. Incidentally, examples thereof include polyethylene, especially, polyolefin resins such as linear low-density polyethylene and polypropylene, and inorganic fillers such as calcium carbonate, especially those having an average particle size of 30 μm or less, and extrusion methods and the like. Porous films obtained by subjecting a film formed by a simple method to stretching treatment in a uniaxial or biaxial manner are exemplified.

A porous film which can be preferably used from the viewpoint of appropriate heat generation due to air permeability when used as a disposable body warmer has an average pore diameter of 0.1 to 10 μm and a moisture permeability of 1 to 10.
It is a thing of 00 to 1500 g / m ² · day. In addition, the coloring treatment of the porous film can be obtained by, for example, a method in which an appropriate coloring agent composed of a dye, a pigment, or the like is mixed in the polymer for forming a film in the above.

On the other hand, as the air-permeable base material, an appropriate base material according to a conventional disposable body warmer or the like can be used, and there is no particular limitation. Incidentally, examples thereof include air-permeable base materials such as nonwoven fabric-like or felt-like fiber aggregates made of polyamide-based fibers, polyester-based fibers, polypropylene-based fibers, and the like. A breathable substrate that can be preferably used is a fiber assembly having a basis weight (weighed) of 10 to 100 g / m ² .

The colored air-permeable base material can be formed by bonding the porous film and the air-permeable base material through an appropriate air-permeable adhesive layer. Such as melt-type porous adhesive films,
It can be formed of an appropriate adhesive layer exhibiting air permeability.
Less unevenness in air permeability and adhesive strength due to fineness and uniform distribution of pores, etc. Adhesion treatment via an air-permeable adhesive layer is preferred.

In order to form such a gas-permeable adhesive layer, for example, the adhesive substance is sprayed and developed through hot air while being heated and melted.
The adhesive substance 4 is made into a fiber by an appropriate method such as a curtain spray method, a melt blow method, or a slot spray method, and is developed and deposited on an appropriate supporting substrate made of a porous film, a gas-permeable substrate, a separator, or the like. It can be performed by an appropriate method of forming an adhesive substance into fibers by an appropriate method and disposing it in a porous state, such as a method of forming the adhesive layer 2 in a porous state. By forming the adhesive substance into a fibrous form while being heated and melted, the odor is volatilized and the odor is excellent.

In the curtain spray method shown in FIG. 1, the adhesive material 4 in the closed container is heated and melted and supplied to the die 5 while the air-permeable base material 3 is sequentially fed from the winding roll 32. By blowing hot air from above the dice as indicated by the arrow, the molten adhesive substance
1 is formed into fibers 41 and blown out in the form of a curtain, which is spread and applied onto the air-permeable base material 3 which sequentially moves through a conveyor 6 and has a nonwoven fabric-like porous structure in which the fibers are deposited. A layer 2 is formed, on which a porous film 1 sequentially fed from a take-up roll 11 is arranged and subjected to an adhesive treatment via a pinch roll 61 to take up a take-up roll 71.
And the target colored ventilation base material 7 is formed in a series of the same steps.

In the above, the air-permeable adhesive layer, which is preferable from the viewpoint of the balance between the adhesive force and the air permeability, has an average diameter of the fibers forming the adhesive layer of 0.1 to 500 μm, preferably 0.5 to 500 μm.
100 [mu] m, in particular at 1 to 50 [mu] m, such fibers having an average diameter of basis weight of 50 g / m ² or less, a nonwoven fabric or entangled porous fibrous at a rate of especially 1 to 30 g / m ^2, in particular 2 to 10 g / m ² It is deposited on the structure. The average fiber diameter can be determined by, for example, a method of randomly taking a photograph of the air-permeable adhesive layer with a scanning microscope and calculating the average value of the fiber diameters at arbitrary 10 points.

The above-mentioned adhesive substance for forming a fiber is, for example, a hot-melt type adhesive or an adhesive, which can be heated and melted and exhibits tackiness at room temperature or at the time of heat-melting or when the heat-melted product is fiberized. A suitable material such as a material or a material showing adhesiveness by reheating the formed fiber can be used.

Incidentally, examples of the adhesive substance include S
Styrene-based elastomers such as IS, SBS, SEBS and SIPS, polyethylene, especially ultra-low-density polyethylene and polypropylene, olefin-based polymers such as ethylene-vinyl acetate copolymer, and acrylics containing alkyl esters such as acrylic acid and methacrylic acid. And those containing a thermoplastic resin such as a polyester polymer, a polyester resin, a polyamide resin or a urethane resin as a component.

In particular, it is difficult to cause bleeding of low molecular weight components due to aging over time because the pores of the porous film are closed and air permeability is likely to be reduced, and the storage stability is excellent. Adhesive substances that can be preferably used from the viewpoint of heat resistance and the like that can prevent wrinkles between the porous film and the air-permeable substrate due to heat generation during use are hot-melt type polyamide-based copolymers and Mold polyurethane is used as a component.

The adhesive substance may be used alone or in combination of two or more. In addition, in preparing the adhesive substance, an appropriate additive such as an adhesiveness-imparting agent, a softening agent, or an antioxidant is blended as needed for the purpose of adjusting the melt viscosity, the dynamic elastic modulus, the adhesive properties, and the like. be able to. Incidentally, tackiness and strength can be adjusted by adding an olefin-based polymer to the styrene-based elastomer.

As the above-mentioned adhesiveness-imparting agent, for example, styrene-based resin, rosin-based resin, petroleum-based resin, terpene-based resin, or a hydrogenated or partially hydrogenated product thereof may be used. Alternatively, two or more kinds can be used. As the softening agent, for example, one or more suitable oils such as paraffins, polybutene, polyisobutylene, terpene-based oils, and hydrogenated or partially hydrogenated products thereof can be used.

In the above, an adhesive substance which can be preferably used from the viewpoint of maintaining a fiber state in which flow and deviation are prevented during application via a hot melt applicator, preventing clogging of a porous film, and forming uniform fibers. Is prepared such that its melt viscosity, especially at 90-250 ° C., is below 1500 poise, in particular between 20 and 500 poise, in particular between 50 and 200 poise.

The coloring treatment of the air-permeable adhesive layer is carried out, for example, by blending an appropriate coloring agent such as a dye or a pigment with the forming material of the adhesive layer to obtain a forming material colored to a desired color. It can be performed by a method of forming an adhesive layer or the like.

The color to be colored is arbitrary as in the case of the above-mentioned porous film. For example, in the case of a direct-attached disposable body warmer directly attached to the ground, a flesh-color system is preferable from the viewpoint of blindfolding. Red or blue if desired
An appropriate color such as green or pink can be set according to the taste. In the above-described fiber-permeable air-permeable adhesive layer, it is also possible to form a marble color or the like by blowing fibers colored in different colors from a plurality of nozzles.

The colored air-permeable base material is formed by, for example, forming a gas-permeable adhesive layer on a porous film and / or a gas-permeable base material and laminating them, as shown in FIG. Alternatively, it can be carried out by an appropriate method such as a method in which a gas-permeable adhesive layer formed on a separator is transferred to the bonding surface of a porous film or / and a gas-permeable base material, and laminated via the transfer layer. .

[0027] The adhesive surface of the porous film or the air-permeable base material needs an appropriate treatment such as a corona treatment, a plasma treatment, a sputter etching treatment, or an anchor treatment with a primer to improve the adhesion. It can also be applied accordingly.
The porous film, the air-permeable substrate and the air-permeable adhesive layer forming the colored air-permeable substrate according to the present invention may optionally contain an antimicrobial agent for the purpose of improving hygiene by antimicrobial action. .

The colored gas-permeable base material according to the present invention can be preferably used for various uses requiring air permeability, such as a storage bag for disposable warmers. An example of the disposable body warmer is shown in FIG. This is because the heat sealing layer 81 and the colored ventilation substrate 7 in the heating element housing substrate 8 are
The heating element 9 is accommodated in the space between the heating element accommodation base material 8 and the colored ventilation base material 7 of the storage bag formed by heat sealing the periphery of the porous film 1 and sealed. . 83 is an adhesive layer for adhering to clothing or the like;
Is a separator that temporarily protects it.

The storage bag may be formed by a suitable method according to the prior art, such as a method of forming the bag body by joining the ends of the base material by an appropriate method such as an adhesive or sewing in addition to a heat sealing method. In such a case, the disposable body warmer according to the present invention may be one in which the colored breathable base material according to the present invention is used at least in part for the purpose of breathability in its storage bag. Therefore, the use location can be an appropriate location such as the entire surface or one surface of the storage bag, or a part thereof.

The heating element to be stored in the bag is also oxygen (air) taken in based on the gas permeability of the storage bag, such as a gas-flowing heat-generating composition comprising metal powder, water, a water retention agent, an oxidation promoter and the like. Any suitable heating element such as one that generates heat upon contact with the heating element can be used, and any heating element in a conventional disposable body warmer can be used.

[0031]

EXAMPLE 1 Blue pellets of a polyamide hot melt adhesive containing 2% by weight of a blue colorant were placed on a polyamide nonwoven fabric having a basis weight of 40 g / m ² and placed in an applicator tank.
What was melted at 80 ° C. (melt viscosity 100 poise) was formed into fibers by curtain spraying, developed and deposited, and the basis weight was 7 g /
While forming a non-woven air-permeable adhesive layer of m ² , a porous film was laminated thereon to form a colored air-permeable substrate continuously.

In the above, the average fiber diameter in the air-permeable adhesive layer was about 10 μm. The porous film is formed by extruding a mixture of 120 parts by weight of calcium carbonate and 100 parts by weight of linear low-density polyethylene on the same production line to form a film, and stretching the film four times uniaxially. In addition, the adhesive surface is laminated while being subjected to corona discharge treatment, and has an average pore diameter of 0.5 μm and a moisture permeability of 600 g / m ² · day.

Example 2 A colored air-permeable base material was formed in the same manner as in Example 1 except that the porous film was made blue using a linear low-density polyethylene containing 2% by weight of a blue colorant. .

Example 3 A colored air-permeable adhesive layer was formed in the same manner as in Example 2 except that an air-permeable adhesive layer (appearance was white according to a non-woven fabric with voids interposed therebetween) was formed with a non-colored polyamide hot melt adhesive. A material was formed.

Comparative Example A gas-permeable base material was obtained in the same manner as in Example 1 except that a gas-permeable adhesive layer was formed with an uncolored polyamide hot melt adhesive.

Evaluation Test With respect to the (colored) air-permeable base materials obtained in Examples and Comparative Examples, changes in air permeability were examined based on Comparative Examples, and disposable warmers according to FIG. 3 were formed. And the color change at the time of practical use of Cairo was investigated, and comprehensive evaluation of practicality was performed.

The results are shown in the following table.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an example of a colored ventilation base material.

FIG. 2 is an explanatory view of an example of a manufacturing process.

FIG. 3 is a sectional view of an example of a disposable body warmer.

[Description of Signs] 7: Colored air-permeable substrate 1: Porous film 2: Air-permeable adhesive layer 3: Air-permeable substrate 9: Heating element

Claims (4)

[Claims] 1. A colored gas-permeable base material comprising a porous film and a gas-permeable substrate bonded together via a gas-permeable adhesive layer, wherein the gas-permeable adhesive layer comprises a colored layer. 2. A colored ventilation film comprising a porous film and a permeable substrate bonded together via a permeable adhesive layer, and one or both of the porous film and the permeable adhesive layer are formed of a colored layer. Base material 3. The porous film according to claim 1, wherein the porous film has an average pore diameter of 0.1 to 10 μm and a moisture permeability of 100 to 100 μm.
-1,500 g / m ² · day, the air-permeable base material is made of a nonwoven fabric fiber assembly, and the air-permeable adhesive layer is
A colored air-permeable base material comprising a deposited layer of 0 μm diameter fibers having a basis weight of 1 to 30 g / m ² . 4. A disposable body warmer, wherein a heating element is housed inside a storage bag using at least a part of the colored ventilation base material according to claim 1.