JP3568094B2 - Heating element storage substrate and disposable body warmer - Google Patents

Description

【００４１】
上表において、○、△、×は下記を意味する。
○：糊残りなし
△：糊残りはないが、粘着層の糸引きが発生
×：糊残りあり
【図面の簡単な説明】
【図１】参考例の断面図
【図２】実施例の断面図
【図３】製造工程の説明図
【図４】使い捨てカイロの説明断面図
【符号の説明】
１：発熱体収容用基材
１１：ヒートシール層
１２：ポリオレフィン系ベース層
１３：付加層
２：粘着層
３：セパレータ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a heating element housing base material suitable for a disposable body warmer and the like, which prevents contamination of clothes and the like due to adhesive residue of an attached adhesive layer.
[0002]
[Prior art]
There has been proposed a disposable body warmer that can be adhered and held on clothing or the like via an adhesive layer. That is, as illustrated in FIG. 4, the heating element 7 is housed in a bag formed by heat-sealing the periphery of the heating element housing base 9 and the air-permeable base 4 made of plastic, and is adhered to the outside of the storage bag. A disposable body warmer in which a layer 2 is provided and temporarily covered with a separator 3 has been proposed.
[0003]
Conventionally, as the heating element accommodating base material 9, a material in which a styrene-based hot melt adhesive layer 2 is provided on a polyolefin-based base layer 92 on which a heat seal layer 91 is laminated has been known. However, when a practical disposable body warmer is adhered to clothing and peeled off, a part of the adhesive layer remains on the clothing side, and there is a problem that the clothing is contaminated as glue residue. Cloth contamination due to the adhesive layer cannot be easily removed, and the fabric is easily damaged at the time of removal, which is a serious problem in practical use.
[0004]
Technical Problems of the Invention
The present invention provides a heating element that can be peeled off without causing adhesive residue when the adhesive layer is used, while taking advantage of the styrene-based hot melt adhesive layer, such as being able to be coated without a solvent and being excellent in mass productivity of a warmer. The task is to develop a base material for storage.
[0005]
[Means for solving the problem]
The present invention relates to an outer surface of a laminate film having a polyolefin-based base layer containing a styrene-based elastomer in an amount of 5 to 80% by weight, a heat seal layer, and at least three polyolefin-based additional layers interposed therebetween. In addition, a heating element containing base material having a styrene-based hot melt adhesive layer, wherein the air-permeable base material is heat-sealed in a tubular or bag shape via the heat seal layer as necessary, and The present invention provides a disposable body warmer characterized in that a heating element is sealed in a gap between a heat seal layer and a gas permeable substrate in the heating element accommodating base material.
[0006]
【The invention's effect】
According to the present invention, the adhesion of the styrene-based hot-melt adhesive layer to the polyolefin-based base layer can be improved by blending the styrene-based elastomer. A heating element housing base material that can be peeled off without leaving adhesive residue from clothing can be obtained. In addition, the advantages of the styrene-based hot-melt adhesive layer, such as solvent-free coating and efficient mass production of base materials, can be utilized, and the stable quality of the adhesive, which is excellent in the stability and persistence of adhesive retention through clothing, etc. A disposable body warmer or the like can be efficiently formed.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The heating element housing substrate of the present invention is a laminate film having at least three layers of a polyolefin-based base layer containing a styrene-based elastomer in an amount of 5 to 80% by weight, a heat-sealing layer, and a polyolefin-based additional layer interposed therebetween. Having a styrene-based hot melt adhesive layer on the outer surface of the base layer. An example is shown in FIG . Reference numeral 1 denotes a heating element accommodating base comprising a heat seal layer 11, a polyolefin base layer 12, and a polyolefin addition layer 13, reference numeral 2 denotes a styrene hot melt adhesive layer, and reference numeral 3 denotes a separator. FIG. 1 is a reference example having no additional layer.
[0008]
The heating element accommodating base material has a polyolefin-based additional layer 13 at least between the heat seal layer 11 and the polyolefin-based base layer 12, as shown in the example of FIG. 2, and a styrene-based hot melt adhesive layer on the outer surface of the base layer. It only has to have 2. Thus the substrate may be one having an appropriate layer configuration having one or more layers of the additional layer 13 between the heat Toshiru layer 11 and a polyolefin base layer 12.
[0009]
The heat seal layer, the polyolefin-based base layer , the polyolefin-based additional layer, and the optional layer as needed are usually formed as a laminated body in which they are in close contact with each other. There is no particular limitation on the material for forming each of the layers, and an appropriate material can be used.
[0010]
Incidentally, as a material for forming the heat seal layer, for example, an ethylene / vinyl acetate copolymer, especially a copolymer having a vinyl acetate content of 10 to 30% by weight, an ethylene having a melting point of 100 ° C. or less, especially 70 to 80 ° C. One or two of an ethyl acrylate copolymer, an ethylene methacrylate copolymer, a low-density to ultra-low-density polyethylene, particularly a linear low-density polyethylene having a density of 0.88 to 0.91 g / cm ³ And mixtures of more than one species.
[0011]
Those which can be particularly preferably used in terms of heat sealing properties, slip properties (smoothness of work), blocking properties, strength, etc. are metallocene polyethylenes obtained by polymerization using a metallocene catalyst, and especially linear low density Material or other low density material.
[0012]
The purpose of the heat seal layer is to heat seal with a gas permeable substrate made of a porous film or the like via the heat seal layer. Therefore, as shown in the figure, the heat seal layer 11 is usually disposed on the outer surface of the heating element housing base material. The thickness of the heat seal layer can be appropriately determined depending on the adhesive strength and the like, but is generally 5 to 100 μm, preferably 10 to 80 μm, particularly 15 to 60 μm.
[0013]
Examples of the material for forming the polyolefin base layer include linear or other polyolefins such as low-density polyethylene and medium-density polyethylene, high-density polyethylene and ultra-high-molecular-weight polyethylene, polypropylene, and ethylene-propylene copolymers and ethylene-propylene.・ Olefin copolymers such as diene copolymers, olefins such as olefin / ethyl acrylate copolymers ・ Olefins such as (meth) acrylate copolymers and olefin / methacrylic acid copolymers ・ (meth) acrylic acid copolymers An olefin / vinyl copolymer comprising an olefin such as ethylene or propylene and one or more other suitable vinyl monomers, such as a copolymer, an olefin / vinyl acetate copolymer, or two or more of these. A mixture used in combination is exemplified. For example, a polymer other than a polyolefin such as polyester or a polymer other than an olefin / vinyl copolymer may be used.
[0014]
The material for forming the polyolefin-based layer, which can be preferably used from the viewpoint of preventing wrinkling due to elongation and elongation during the preheating process during heat sealing and preventing curling due to elongation, is a DSC (differential scanning calorimeter). ) Is 135 ° C. or higher, particularly 140 ° C. or higher. The thickness of the polyolefin-based base layer can be appropriately determined depending on the strength and the like, but is generally from 5 to 200 μm, preferably from 10 to 100 μm, particularly from 15 to 80 μm.
[0015]
In the present invention, the polyolefin-based base layer is provided with a styrene-based hot-melt pressure-sensitive adhesive layer with good adhesion. Therefore, the polyolefin-based base layer is formed as a layer containing 5 to 80% by weight of the styrene-based elastomer. The preferred content of the styrene-based elastomer is 8 to 70% by weight, especially 10 to 60% by weight, from the viewpoint of the releasability of the styrene-based hot-melt pressure-sensitive adhesive layer from clothes or the like having no adhesive residue.
[0016]
An appropriate styrene-based elastomer containing styrene as a component can be used. Above all, a copolymer containing olefin and styrene forming the polyolefin base layer can be preferably used from the viewpoint of the adhesion of the pressure-sensitive adhesive layer. Incidentally, examples thereof include styrene-ethylene-butylene copolymer-styrene and styrene-ethylene-propylene copolymer-styrene, ABA type block polymers such as styrene-butadiene-styrene and styrene-isoprene-styrene, Styrene-based blocks such as hydrogenated products thereof, AB-type block polymers such as styrene-ethylene-butylene copolymer and styrene-ethylene-propylene copolymer, styrene-butadiene and styrene-isoprene, and hydrogenated products thereof. One or a mixture of two or more polymers can be used.
[0017]
Heating element containment substrate 1 as illustrated in Figure 2, is intended to have a single layer or two layers or more additional layers 13 between the heat seal layer 11 and a polyolefin base layer 12. The additional layer may have an appropriate purpose such as reinforcement and improvement of heat resistance, and examples of the forming material include those exemplified for the above-mentioned polyolefin-based base layer. The thickness of the additional layer can be appropriately determined according to the purpose of the addition and the like, but is generally 5 to 200 μm, preferably 10 to 100 μm, particularly 15 to 80 μm.
[0018]
The heat seal layer or the polyolefin-based base layer , the polyolefin-based additional layer or the additional layer as necessary, which forms the heating element housing base, may be appropriately formed by, for example, a casting method, a melt molding method, a calendar rolling method, or a multi-coating method. It can be formed by a close contact superposition method. From the viewpoint of production efficiency and the like, an extrusion molding method via a T die, an inflation die, or the like is preferable. Further, from the viewpoint of suppressing internal strain, an extrusion molding method via a T-die is particularly preferable.
[0019]
According to the extrusion molding method, a laminate film having two or three or more layers can be efficiently formed through a multilayer extrusion method such as two or three layers. The laminated film having two or more layers may be formed by an appropriate method such as a thermocompression bonding method of the film or the above-mentioned solution coating method.
[0020]
When forming a disposable body warmer, the preferred thickness of the heating element containment substrate excluding the adhesive layer from the standpoint of its practicality, 200 [mu] m or less, especially 150μm or less, Ru especially 10~100μm der.
[0021]
Heating element accommodating substrates, especially its polyolefin-based layer and with pressurized layer, for example need inorganic fillers or pigments or antioxidants, antistatic agents and flame retardants, suitable additives such as lubricants and softening agents Can be blended according to The layers are cross-linked by an appropriate method such as a method of irradiating radiation such as an electron beam or an ultraviolet ray as necessary, or a method of mixing a forming material with a cross-linking agent and cross-linking by heating or / and irradiation. You can also. The cross-linking treatment is effective in improving the strength, heat resistance, and the like of the heating element housing base material.
[0022]
The pressure-sensitive adhesive layer provided on the heating element housing substrate is formed of a styrene-based hot-melt pressure-sensitive adhesive layer for the purpose of holding the substrate through clothing or the like. As the pressure-sensitive adhesive for forming the styrene-based hot melt pressure-sensitive adhesive layer, one or more of the styrene-based block polymers exemplified as the above-mentioned styrene-based elastomers from the viewpoint of suppressing an increase in adhesive force due to a rise in temperature are used as components. Can be preferably used.
[0023]
In the preparation of the pressure-sensitive adhesive, for example, α-pinene and β-pinene polymers, terpene resins such as diterpene polymers and α-pinene-phenol copolymers, fats Proper adhesion of hydrocarbon resins such as aromatic, aromatic and aliphatic / aromatic copolymers, rosin resins, coumarone indene resins, (alkyl) phenol resins and xylene resins Agents can be included. Further, for example, appropriate additives such as a softening agent and a filler such as a liquid polymer and a paraffin-based oil, a pigment, an antioxidant, and a stabilizer can be added as necessary.
[0024]
The adhesive layer may be provided on the entire outer surface of the polyolefin-based base layer forming the heating element housing base material, or may be provided partially as shown in the drawings. The attachment of the adhesive layer can be performed by an appropriate method such as a hot melt coating method using an extrusion method of an adhesive or a transfer method of an adhesive layer provided on a separator.
[0025]
The thickness of the styrene-based hot-melt pressure-sensitive adhesive layer may be appropriately determined according to the adhesive strength and the like, but is generally 1 to 300 μm, preferably 5 to 200 μm, particularly 10 to 100 μm. The polyolefin base layer provided with the pressure-sensitive adhesive layer may be subjected to an appropriate surface treatment such as a corona treatment, a plasma treatment, or an undercoat treatment, for the purpose of improving the adhesion, if necessary.
[0026]
For the styrenic hot-melt adhesive layer provided on the heating element housing substrate, it is necessary to temporarily attach a separator and cover the adhesive surface until it is used for holding the adhesive through clothing etc. It is more preferable to prevent a decrease in the value. The separator can be obtained by a method in which a suitable thin leaf is provided with a surface coat of a suitable release agent such as a silicone-based, long-chain acryl-based, or fluorine-based material as necessary.
[0027]
The heating element housing base material of the present invention can be preferably used for forming a storage bag for housing a heating element made of a ventilation heat-generating composition or the like. The storage bag is formed according to a conventional method such as a method of heat-sealing the heat-sealing layer of the heating element housing base 1 and the end of the air-permeable base 4 such as a porous film as illustrated in FIG. In this case, it can be carried out by molding into a tubular or bag-like shape capable of filling a heating element in a space between the heat seal layer and the air-permeable base material.
[0028]
In the method shown in FIG. 3, the heating element accommodating base material 1 and the air permeable base material 4 are introduced between the pair of pressure bonding rolls 6 while being continuously supplied from the winding rolls 14 and 41. The heat seal layer of the body housing base material 1 is preheated by the heating device 5 via far infrared rays or the like.
[0029]
Next, the heating element housing base material 1 and the gas permeable base material 4 introduced between the pair of pressure bonding rolls 6 have the ends thereof heated to a predetermined sealing temperature, for example, 100 to 200 ° C. A cylindrical body 61 is formed which is heat-sealed under the rotation of, and to which parts corresponding to both sides of the storage bag to be formed are adhered.
[0030]
The air-permeable base material is not particularly limited, and an appropriate material such as an olefin porous film obtained by an extraction method, a stretching method, or the like can be used. Incidentally, any of the air-permeable base materials used in conventional disposable warmers can be used.
[0031]
Further, the heating element housing base material or the storage bag of the present invention can be preferably used for forming a disposable warmer. As shown in FIG. 4, the disposable body warmer includes, for example, a heat-sealable layer 91 in the heat-generating body-containing base material 9 and a heat-generating body-containing base material of a storage bag formed by heat sealing the periphery of the gas-permeable base material 4. The heating element 7 can be housed in a space between the heating element 7 and the encapsulation process. In this case, the disposable body warmer according to the invention can be obtained by using the substrate 1 according to the invention as the heating element accommodation substrate. Is formed.
[0032]
In the method illustrated in FIG. 3 described above, after the formation of the cylindrical body 61, as a subsequent step outside the figure, a storage bag for the purpose of formation is formed by heat-sealing the heating element housing base and the air-permeable base in the width direction. By providing the upper and lower sides forming step and the filling and enclosing step of the breathable heat generating composition, the disposable body warmer is formed into a storage bag by heat sealing the heating element housing base material and the breathable base material and a series of manufacturing steps. It can be formed efficiently. As the heating element made of any air-permeable heating composition or the like, any suitable heating element can be used, and any of the heating elements in a conventional disposable body warmer can be used.
[0033]
【Example】
Example 1
In a three-layer extrusion method via a T-die, a heat seal layer of linear low density polyethylene having a thickness of 15 μm, an intermediate layer (additional layer) of polypropylene having a thickness of 40 μm, 70% by weight of polypropylene and A laminate film of a three-layer structure having a 20 μm-thick polyolefin-based base layer made of a mixture of an ethylene / butylene copolymer-styrene block polymer at 30% by weight was obtained, and the outer surface of the base layer was hot-melt coated on a separator. An adhesive layer having a thickness of 30 μm and made of a styrene-based block polymer formed by a working method was adhered to obtain a heating element housing base material.
[0034]
Example 2
A heating element containing base material was obtained in the same manner as in Example 1 except that the mixing amount of the polypropylene / styrene-ethylene / butylene copolymer-styrene block polymer in the polyolefin-based base layer was 85% by weight / 15% by weight.
[0035]
Example 3
A heating element containing base material was obtained in the same manner as in Example 1 except that the mixing amount of the polypropylene / styrene-ethylene / butylene copolymer-styrene block polymer in the polyolefin base layer was changed to 50% by weight / 50% by weight.
[0036]
Comparative Example 1
A heating element containing base material was obtained in the same manner as in Example 1 except that the mixing amount of the styrene-ethylene-butylene copolymer-styrene block polymer in the polyolefin-based base layer was 0% by weight (no blending).
[0037]
Comparative Example 2
Except that the polyolefin-based layer was formed of a linear low-density polyethylene containing no styrene-ethylene / butylene copolymer-styrene block polymer, a heating element-containing substrate was obtained in the same manner as in Example 1.
[0038]
Using the heating element-containing base material and the polyethylene-based porous film obtained in the evaluation test examples and comparative examples, a cylindrical body was formed by heat sealing according to the method shown in FIG. Into a commercially available standard-sized disposable body warmer, placed on a twill woven polyester cloth via the adhesive layer from which the separator was removed, and left in a constant temperature room at 40 ° C. for 4 hours with a load applied thereon. After that, it was taken out, the body was peeled off, and the presence or absence of adhesive residue was examined.
[0039]
In the test, A: load 500 g, peeling angle 90 degrees, peeling time 10 seconds, B: load 500 g, peeling angle 180 degrees, peeling time 5 seconds, C: load 500 g, peeling angle 180 degrees, peeling time 10 seconds, D : The test was performed under the conditions of a load of 1000 g, a peel angle of 180 °, and a peel time of 10 seconds.
[0040]
The results are shown in the following table.

[0041]
In the above table, ○, Δ, and × mean the following.
○: No adhesive residue △: No adhesive residue, but stringing of the adhesive layer occurred ×: Adhesive residue [Simplified explanation of drawings]
[1] [Description of symbols] sectional view FIG. 2 is a cross-sectional view of the solid施例Figure 3 is an explanatory diagram of a manufacturing process [4] of the disposable warmer explanatory cross-sectional view of a reference example
1: heating element housing substrate 11: heat seal layer 12: polyolefin base layer 13: additional layer 2: adhesive layer 3: separator

Claims (3)

A styrene-based base layer containing 5 to 80% by weight of a styrene-based elastomer, a heat seal layer, and at least three polyolefin-based additional layers interposed therebetween have a styrene-based layer on the outer surface of the base layer. A heating element containing base material having a hot melt adhesive layer. The heating element housing base according to claim 1, wherein the air-permeable base material is heat-sealed in a tubular shape or a bag shape via the heat sealing layer, and the outer surface of the styrene-based hot melt adhesive layer is temporarily attached by a separator. Wood. A disposable body warmer, wherein a heating element is sealed in a space between the heat sealing layer and the air permeable substrate in the heating element housing substrate according to claim 2.

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