JPH1150019A - Antimicrobial porous adhesive layer, porous sheet and housing bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a porous sheet excellent in stability and durability of antimicrobial action and bond strength between a porous film and an air- permeable film, hardly releasable, slight in unevenness of air permeability and excellent in handle. SOLUTION: This porous film is obtained by bonding a porous film 1 through an antimicrobial porous adhesive film 2 prepared by arranging fibers composed of a hot melt type adhesive substance mixed with an antimicrobial agent in a porous state to an air-permeable substrate 3. A housing bag of an air- permeable heat build-up composition composed of a bag uses at least partially the porous sheet. The porous sheet highly maintains performances such as air permeability which the materials have, is hardly releasable even by practical use as a housing bag for disposable pocket heater, etc., has a faint odor, hardly emits an unpleasant smell and stably exhibits antimicrobial actions for a long period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antibacterial porous adhesive layer having an excellent antibacterial effect, a porous sheet and a bag for containing a ventilating heat-generating composition using the same, which are excellent in uniformity of ventilation or moisture permeability.

[0002]

2. Description of the Related Art Conventionally, an olefin-based porous film is bonded to a breathable substrate through a porous adhesive layer formed by fibrillating a sticky substance made of a styrene-based elastomer or an ethylene / vinyl acetate-based copolymer. And a porous film containing an antimicrobial agent and a breathable substrate (Japanese Patent Application Laid-Open Nos. 6-49253 and 9-48868). Gazette).

[0003] The above-mentioned porous sheet is used for various uses as a packing material such as a sanitary article such as a disposable diaper, clothing, a waterproof moisture-permeable sheet such as a building, a storage bag of a disposable body warmer, etc. by utilizing its air permeability or moisture permeability. It is used for By the way, the storage bag of the disposable body warmer is for storing a ventilation heat-generating composition composed of metal powder, water, a water retention agent, an oxidizing agent, etc., and takes in air based on the air permeability of the porous sheet to generate heat. The object generates heat by contact with oxygen, and ignition is not required.

However, even when a porous sheet is formed using a porous film or a breathable base material containing an antibacterial agent, depending on the intended use and use environment, for example, in the case of a disposable diaper in which a humid state is easily maintained. However, there was a problem that the antibacterial action was not satisfactory because of the large growth of the bacteria.

[0005]

The present invention has excellent antibacterial action stability and persistence, has excellent adhesive strength between a porous film and a gas-permeable base material, does not easily peel off, and has little variation in gas permeability or moisture permeability. The task is to develop a porous sheet with excellent texture.

[0006]

An object of the present invention is to provide an antimicrobial porous adhesive layer characterized in that fibers made of a hot-melt type adhesive substance containing an antimicrobial agent are arranged in a porous state, and the antimicrobial porous adhesive layer is provided. A porous sheet characterized in that a porous film and a gas-permeable base material are adhered to each other through a porous film, and a bag-shaped heat-generating composition characterized in that a bag body is formed using at least a part of the porous sheet. A storage bag is provided.

[0007]

According to the present invention, the porous adhesive layer made of the fiber of the adhesive substance exhibits an excellent antibacterial action stably for a long period of time, and has a small bias in air permeability or moisture permeability and adhesive strength. Excellent in uniformity, excellent in cushioning and odor emission by heating and melting. As a result, it is possible to obtain a laminate having a high degree of material performance such as air permeability provided by the porous film and the air-permeable substrate provided through the porous adhesive layer. Further, the porous sheet made of such a laminate does not peel off even when practically used as a storage bag for a disposable body warmer or the like based on its excellent adhesion and stability of moisture permeability, and the adhesive layer has a cushioning property and a slight odor. It also has the advantage of exhibiting a good texture based on the above-mentioned characteristics, and hardly emitting an unpleasant odor.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The antimicrobial porous adhesive layer of the present invention comprises fibers made of a hot-melt type adhesive substance containing an antimicrobial agent arranged in a porous state. It consists of a porous film and a gas-permeable substrate bonded together via a layer. Figure 1 shows an example of the porous sheet.
It was shown to. 1 is a porous film, 2 is an antimicrobial porous adhesive layer, and 3 is a breathable substrate.

The antimicrobial porous adhesive layer can be formed by arranging fibers of a hot-melt type adhesive substance containing an antimicrobial agent in a porous state. As the adhesive substance, for example, a hot-melt type adhesive or adhesive, which can be heated and melted and shows tackiness at room temperature or at the time of heat melting or at the time of heat-melting into a fiber, or re-forming the formed fiber Appropriate materials such as those exhibiting adhesiveness upon heating can be used.

Incidentally, as an example of the adhesive substance, 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.

[0011] It is difficult to cause bleeding of low molecular weight components due to aging with the passage of time, which tends to block the pores of the porous film and reduce air permeability, and has excellent storage stability. Adhesive substances that can be preferably used in terms of heat resistance and the like that can prevent wrinkles between the porous film and the air-permeable substrate due to heat generation, etc., include hot-melt polyamide copolymers and reactive polyurethanes. Component.

Incidentally, examples of the above-mentioned hot-melt type polyamide copolymer include dimer acid composed of dibasic acid, ethylenediamine, hexamethylenediamine, xylylenediamine, 4,4'-diaminodicyclohexylamine, and the like. Examples include amines such as p, p'-methylenediamine and alkanolamines, and those obtained by polymerizing acid components such as adipic acid, azelaic acid and sebacic acid for the purpose of controlling the softening point and crystallinity as required. Can be

In particular, a low-viscosity dimer containing one or more of ε-caprolactam, lauryl lactam, (1-, 2- or 3-) methylpentamethylenediamine and polycondensate of dodecanediacid. Acid-based polyamides and the like are preferably used. Further, from the viewpoint of compatibility between adhesive strength and heat resistance, a polyamide copolymer having a melting point of 70 to 120 ° C can be preferably used.

On the other hand, as a hot-melt type reactive polyurethane, for example, HOR ¹ OH and OCNR ² NCO
By reaction with the general formula: OCN-R ² -NHCOO-
An appropriate material whose reaction curing progresses with time, such as those represented by R ¹ -OCONH-R ² -NCO (where R ¹ and R ² are organic groups), can be used.

Incidentally, the hot-melt type reactive polyurethane mainly composed of a urethane prepolymer having an isocyanate group at a terminal as described above contains (1) an adhesive state, (2) a dissolved state, and (3) 3) After the adhesive fixation state, in the air, or in the adherend such as a porous film or a gas-permeable substrate, through a reaction mechanism such as a chain extension reaction (a) or a branching / crosslinking reaction (b) illustrated in FIG. The curing reaction proceeds at room temperature through moisture such as moisture (4) to form a crosslinked structure.

The above-mentioned polymer for forming an adhesive substance is as follows:
They 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.

[0018] In the present invention, the melt viscosity is considered from the viewpoints of maintaining a fiber state in which flow and deviation are prevented during application through a hot melt applicator, preventing clogging of a porous film, and forming uniform fibers. Especially 90 to 200 ° C
Adhesive substances prepared so as to be 1500 p or less, especially 20 to 500 p, especially 50 to 200 p can be preferably used. By using the hot-melt type adhesive substance as described above, it is possible to avoid the necessity of heat treatment such as drying on the supporting base material, and it is possible to make the supporting base material thinner and lower the necessary heat resistance. .

There is no particular limitation on the antibacterial agent to be added to the adhesive substance, and the antibacterial property, safety, heat resistance, weather resistance, water resistance, chemical resistance, appearance, and other required characteristics according to the use are determined. An appropriate inorganic or organic material can be used accordingly. An inorganic carrier into which a metal-based antibacterial ion is introduced can be preferably used from the viewpoints of durability of antibacterial action, thermal stability, safety, and the like.

Incidentally, specific examples of the above-mentioned inorganic carrier include silver, copper, zinc, tin and the like in the skeleton structure of an inorganic carrier made of zeolite, zirconium phosphate, hydroxyapatite, phosphate ceramics and the like. And those carrying a metal-based antibacterial ion.

The amount of the antibacterial agent can be appropriately determined according to the antibacterial activity and the like. However, in general, from 0.2 to 10 parts by weight, In particular, 0.3 to 5 parts by weight, especially 0.5 to 3 parts by weight, of an antibacterial agent is incorporated. One or more antibacterial agents may be used.

The antimicrobial porous adhesive layer is formed by, for example, spraying and developing an adhesive substance containing an antimicrobial agent through hot air while being heated and melted, such as a curtain spray method, a melt blow method or a slot spray method as shown in FIG. Adhesive substance 4 is formed into a fiber by an appropriate method, developed and deposited on an appropriate supporting base material such as a separator, a porous film, a gas-permeable base material, and the like to form porous adhesive layer 2. It can be carried out by an appropriate method of fibrillating the substance in an appropriate manner and arranging it in a porous state. By forming the adhesive substance into a fibrous form while being heated and melted, the odor is volatilized, and the adhesive substance has excellent odor.

In the curtain spray method shown in FIG. 1, the adhesive material 4 in the closed container is heated and melted while the air-permeable base material 3 is sequentially fed out from the winding roll 31 and supplied to the die 5, and the arrow is drawn. The hot air is blown from above the die as shown in FIG.
The fibers are blown into 41 in a curtain form, and are spread and applied on a gas-permeable base material 3 which sequentially moves through a conveyor 6 to form an adhesive layer 2 having a nonwoven fabric-like porous structure. The porous film 1 sequentially fed from the take-up roll 11 is arranged, adhered through a pinch roll 7 and taken up by a take-up roll 9, and a target porous sheet 8 is formed in a series of the same steps. .

The antibacterial porous adhesive layer, which is preferable from the viewpoint of the balance between the adhesive force based on the fineness and uniform distribution of the pores and the air permeability or moisture permeability, has an average diameter of the fibers forming the adhesive layer of 0. 1 μm to 1 mm, especially 0.5 to 100 μm, especially 1 to 50 μm, and 100 g of fibers having such an average diameter
/ M ² or less, especially 1 to 30 g / m ² , particularly ^{2 to} 10 g / m
^It was deposited in a nonwoven fabric, entangled fibrous, or spider web porous structure at a rate of ² . The average fiber diameter can be determined, for example, by a method of randomly taking a photograph of the antibacterial porous adhesive layer with a scanning microscope and calculating the average value of the fiber diameters at arbitrary 10 points.

The porous adhesive layer satisfying the above fiber diameter and basis weight usually shows a porosity of 5% by weight or more, especially 15 to 75% by weight. In the present invention, the porosity is 75% by weight or more. May be used. The porosity is
When the weight per unit area of the porous adhesive layer and the solid-coated adhesive layer having the same thickness is W ₁ and W ₂ , respectively, the formula: (W ₂ −
W ₁ ) / W ₂ × 100.

The porous sheet is formed by a method of forming an antimicrobial porous adhesive layer on a porous film and / or a gas-permeable substrate and laminating them, as in the method of FIG. The antibacterial porous adhesive layer thus formed can be transferred to an adhesive surface of a porous film or / and a gas-permeable substrate, and can be laminated by an appropriate method such as a method of laminating through the transfer layer.

The porous film and the air-permeable substrate used for forming the porous sheet can be in accordance with the conventional one, and are not particularly limited. Accordingly, a porous film made of an appropriate thermoplastic resin or the like, a nonwoven fabric-like or felt-like air-permeable base made of polyamide fiber, polyester fiber, polypropylene fiber or the like is generally used.

Further, one or both of the porous film and the air-permeable substrate may contain an antibacterial agent. By using a porous film or a breathable substrate containing an antibacterial agent, a porous sheet having more excellent antibacterial action reliability can be obtained. The adhesive surface of the porous film or the air-permeable substrate may be subjected to an appropriate treatment such as a corona treatment, a plasma treatment, a sputter etching treatment, or an anchor treatment with a primer or the like for the purpose of improving the adhesion force, if necessary. Is also good.

The porous sheet according to the present invention is excellent in adhesion, air permeability, etc., and uses its air permeability or moisture permeability to form materials for sanitary articles such as disposable diapers, waterproof moisture permeable cloths for clothing, buildings, etc. And a packaging material as a storage bag for disposable warmers and the like.

[0030] The storage bag according to the present invention is one in which a bag is formed using at least a part of the porous sheet,
This is for forming a disposable body warmer or the like by containing the ventilation heat generating composition. A preferable storage bag from the viewpoint of moderate heat generation of the heat generation composition based on air permeability is 0.1 to 1
With a mean pore size of 0 μm and a moisture permeability of 100 to 7000 g
/ M ² · day porous film, particularly an olefin-based porous film containing polyethylene, especially linear low-density polyethylene, polypropylene and the like.

The storage bag can be formed in a conventional manner, for example, by a method in which the ends of the packaging material are joined by an adhesive, sewing, heat sealing or the like to form a bag. In the present invention, the above-mentioned porous sheet is used in order to impart air permeability to the bag, and the location of use can be determined as appropriate, such as the entire surface, one surface, or a part thereof.

[0032]

【Example】

Example 1 50 parts of a styrene-based elastomer (SIS) (parts by weight, the same applies hereinafter), 50 parts of a petroleum-based resin, and 1 part of a powdered zeolite antibacterial agent in an anhydrous equivalent were kneaded at 160 ° C with a kneader, and then formed into chips. The chip is put in a die and spread on a silicone-coated separator by a melt blow method to form a nonwoven fabric-like antibacterial porous adhesive layer having a basis weight of 7 g / m ² , which is transferred to one surface of a polyethylene-based porous film. Then, a polyamide-based nonwoven fabric (40 g / m ² , basis weight) was laminated thereon to obtain a porous sheet.

In the above, the melt blow was performed at a die temperature of 200 ° C., a hot air temperature of 210 ° C., and a hot air pressure of 1 to 2 kgf.
/ Cm ² , and a line speed of 3 m / min by a conveyor. The average fiber diameter of the antibacterial porous adhesive layer is about 1
It was 0 μm. As the polyethylene porous film, a film composed of a mixture of 100 parts of linear low-density polyethylene and 120 parts of calcium carbonate is used as a uniaxial film.
It is composed of a product that has been stretched twice and has an average pore size of 0.5 μm
Moisture permeability 600g / m ² · day (variation range 50; maximum 6
25, minimum 575).

Example 2 A porous sheet was obtained in the same manner as in Example 1 except that the amount of the powdery zeolite antibacterial agent was 3 parts to form an antibacterial porous adhesive layer.

Example 3 A porous sheet was obtained in the same manner as in Example 1, except that the amount of the powdery zeolite antibacterial agent was 0.5 part of an antibacterial porous adhesive layer.

Comparative Example A porous sheet was obtained in the same manner as in Example 1, except that an antibacterial porous adhesive layer containing no powdery zeolite antibacterial agent was used.

Evaluation Test Adhesive Strength and Moisture Permeability The adhesive strength (180 ° peel, peeling speed 300 mm / min) and moisture permeability of the porous sheets obtained in Examples and Comparative Examples were examined.

Antibacterial activity The porous sheets obtained in Examples and Comparative Examples were cut into 5 cm squares, placed horizontally in a petri dish, and 1 cc of a liquid containing Escherichia coli was dropped on the porous sheets, and the mixture was heated at 23 ° C in an atmosphere. 1 hour or 2
After storing for 4 hours, the bacteria on the porous sheet were washed off and the number of bacteria was counted.

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 perforated sheet.

FIG. 2 is an explanatory view of a state change of a reactive polyurethane adhesive.

FIG. 3 is an explanatory diagram of a reaction mechanism of a reactive polyurethane adhesive.

FIG. 4 is an explanatory view of a manufacturing process of an antibacterial porous adhesive layer.

[Explanation of symbols]

1: porous film 2: antibacterial porous adhesive layer 3:
Breathable substrate

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI B65D 30/02 B65D 30/02 C09J 7/00 C09J 7/00 11/02 11/02 201/00 201/00 (72) Invention Person Eiji Takahata 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation

Claims (5)

[Claims] 1. An antimicrobial porous adhesive layer, wherein fibers made of a hot-melt adhesive material containing an antimicrobial agent are arranged in a porous state. 2. A porous sheet comprising a porous film and a gas-permeable substrate bonded to each other via the antibacterial porous adhesive layer according to claim 1. 3. The method according to claim 2, wherein the antimicrobial porous adhesive layer comprises a nonwoven fabric layer having a basis weight of 1 to 30 g / m ² , comprising fibers having a diameter of 1 to 50 μm, and a porous film having a thickness of 0.1 to 10 μm.
m having an average pore diameter of 100 to 7000 g / m ²
・ A porous sheet made of olefin-based film on day. 4. The porous sheet according to claim 2, wherein one or both of the porous film and the air-permeable substrate contains an antibacterial agent. 5. A bag for storing a ventilating heat-generating composition, wherein a bag is formed using at least a part of the porous sheet according to claim 2.