JP2006061699A - Disposable warmer and method of manufacturing nonwoven fabric for warmer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disposal heat warmer and a nonwoven fabric for the disposal warmer with soft and fiber tactile sensitivity and good thermal efficiency to make good use of the heat of an exothermic body. <P>SOLUTION: A disposal warmer is formed by enclosing a composition generating heat in air into a packing material which has the nonwoven fabric laminated with a film at least on one surface and air permeability, and the nonwoven fabric includes a hydrophobic synthetic fiber and is bonded by fluid-entanglement to have 60% or more, preferably 82% or more, constant thermal efficiency at 20°C and under 65% humidity atmosphere. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a disposable warmer such as a disposable body warmer and a nonwoven fabric used for the packaging material thereof, and more particularly to the warmer and the nonwoven fabric which are flexible and have good heat retaining properties.

Disposable warmers such as disposable warmers are generally made by wrapping a composition that generates heat in the air with a nonwoven fabric or paper laminated with a film of polyethylene or the like. A hole is made after lamination to give air permeability. Although the film itself is hard, by laminating the non-woven fabric, it is possible to prevent the sticking touch peculiar to the film, the tingling touch, etc., and to give the cloth a feeling of touch and to give the fiber layer hard to tear. However, the non-woven fabric used for the packaging material of the conventional heat insulator has a fiber tactile sensation in consideration of the strong surface in terms of bag breakage and the like, and becomes a comfortable heat transfer medium on the contact surface with the human body. Considering the fluffing during use, there are many points that conflict with the idea of heat insulation with an air layer for heat insulation, and there are some ideas to make effective use of the heat generated by the heating element, such as making the temperature perceived by the human body appropriate. It is difficult to say that it is sufficient, and there is a problem in that the thermal efficiency is low, for example, it is necessary to design the heating element at a higher maintenance temperature.
Japanese Utility Model Publication No. 61-24026

  An object of the present invention is to solve the above-mentioned problems, and to provide a disposable warmer having a good heat retention efficiency and a nonwoven fabric for the warmer, which makes effective use of the heat of the heating element while having a particularly soft and tactile feel. is there. Moreover, the other subject of this invention is providing the measuring method of the heat retention efficiency of this nonwoven fabric for evaluating appropriately the heat retention of the said nonwoven fabric for heat insulators.

As a result of various investigations to solve the above problems, the present inventor has various fiber packaging materials and thermal conductivity of various packaging materials in order to effectively utilize the heat of the heating element while having a good tactile feel and suitable strength and little heat loss. Based on this, a measurement method of heat insulation efficiency suitable for a nonwoven fabric for disposable heat insulation devices was developed based on this, and various nonwoven fabric packaging materials having good heat insulation efficiency were examined. As a result, the following non-woven fabric was found to be extremely effective in increasing the heat retention efficiency of the disposable heat retaining device, and reached the present invention.
That is, the invention claimed in the present application is as follows.

(1) A disposable heat retaining device in which a composition that generates heat in air is enclosed in a packaging material having a nonwoven fabric laminated with a film on at least one surface, and the packaging material has air permeability, and the nonwoven fabric is hydrophobic A disposable warmer comprising synthetic fibers and joined by fluid entanglement so that a steady warming efficiency in an atmosphere of temperature 20 ° C and humidity 65% is 60% or more.
(2) The disposable warmer according to (1), characterized in that the steady warming efficiency is 82% or more.
(3) The disposable warmer according to (1) or (2), wherein the hydrophobic synthetic fiber is made of a polyester-based or polypropylene-based synthetic fiber.
(4) The disposable warmer according to any one of (1) to (3), wherein the hydrophobic synthetic fiber is a modified cross-section yarn and / or a crimped fiber.
(5) Disposable characterized in that non-woven fabrics containing polyester-based or polypropylene-based synthetic fibers are joined by hydroentanglement so that the non-woven fabric has a temperature retention efficiency of 60% or more in an atmosphere of 20 ° C. and 65% humidity. A method for producing a nonwoven fabric for a warmer.
(6) The method for producing a nonwoven fabric for disposable warmers according to (5), wherein the polyester-based or polypropylene-based synthetic fiber is a modified cross-section yarn and / or a crimped fiber.
(7) A non-woven fabric sample piece is placed on a hot plate A maintained at a constant temperature, and a hot plate B maintained at a temperature higher than the constant temperature is placed thereon, and the amount of heat transmitted through the sample piece is determined by the hot plate B. The heat retention efficiency of the nonwoven fabric for disposable warmers is measured as the amount of heat C for maintaining the temperature of the sample, while the heat retention amount D when the sample piece is not placed is measured and determined as the steady heat retention efficiency according to the following formula: Measuring method.
Constant heat retention efficiency (%) = {(D−C) / D} × 100

  According to the present invention, it is possible to provide a disposable warmer and a non-woven fabric for packaging material, which is made of a non-woven fabric with good heat retention efficiency and that effectively uses the heat of the heating element while having a soft and tactile feel.

  The disposable heat insulating device of the present invention comprises a packaging material having a nonwoven fabric laminated with a film on at least one surface, and a composition that generates heat in the air, and the packaging material has air permeability. In addition, it includes a hydrophobic synthetic fiber, and is joined by fluid entanglement so that the steady heat retention efficiency in an atmosphere of temperature 20 ° C. and humidity 65% is 60% or more.

  In the present invention, the fibers used for the nonwoven fabric are hydrophobic such as polyolefin fibers such as polypropylene and polyethylene, polyester fibers such as polyethylene terephthalate, polypropylene terephthalate and polybutylene terephthalate, and polyamide fibers such as nylon 6 and nylon 66. From the viewpoint of strength or flexibility. From the viewpoint of heat retention, a material that hardly conducts heat and has low thermal conductivity, such as polyolefin-related fibers and polyester fibers, is preferable.

  From the viewpoint of flexibility and touch of the nonwoven fabric, polyamide fiber, polyester fiber from the viewpoint of dimensional stability, rigidity and heat resistance, and polyolefin fiber from the viewpoint of hydrophobicity and flexibility are preferable. If necessary, mixing with these composite fibers, mixed fibers, cellulosic fibers, and other fibers having special functions is also effective.

  The nonwoven fabric is not particularly limited, such as a papermaking method, a short fiber nonwoven fabric by a card machine, a long fiber nonwoven fabric such as a spunbond method, etc., but a long fiber nonwoven fabric is preferable from the viewpoint of suitable strength, for example, a spunbond method. A continuous long fiber melt-spun by the above method is used as a web, and this is joined by fluid entanglement in which the fiber is entangled with a water flow or the like.

The nonwoven fabric used in the present invention needs to have a constant heat retention efficiency of 60% or more in an atmosphere of a temperature of 20 ° C. and a humidity of 65%. The heat retention efficiency in the present invention is described as a model as follows. That is, to measure the amount of heat supplied to the hot plate so that the hot plate maintains a constant temperature (40 ° C.) in order to measure the amount of heat transferred from the hot plate through the non-woven fabric by stacking the hot plate and the non-woven fabric sample, The thermal insulation efficiency is calculated by quantifying this. That is, the steady-state heat-retaining efficiency as used in the present invention is a non-woven fabric sample piece placed on a hot plate A (5 cm square) maintained at a constant temperature (20 ° C.), and a temperature higher than the constant temperature (40 ° C.) thereon. The amount of heat transmitted through the sample piece is measured as the amount of heat C that maintains the temperature of the hot plate B, while the amount of maintenance heat D when the sample piece is not placed is measured (described later). In the examples, D = 14.06 W / 25 cm ² · 20 ° C.), which is calculated by the following equation, and represents the practical heat retention of the nonwoven fabric for disposable warmers. The larger this value, the higher the heat retention of the nonwoven fabric.
Constant heat retention efficiency (%) = {(D−C) / D} × 100

  In addition, the thermal insulation efficiency at the time of steady state of the nonwoven fabric for packaging materials of disposable warmers currently marketed is around 35%, the amount of heat of the heating element is dissipated, and it is not effectively utilized, and it cannot be said that the thermal insulation efficiency is good. I understood it.

The heat retention efficiency of the nonwoven fabric used in the present invention is 60% or more, particularly preferably 82% or more.
Improving the heat retention of the nonwoven fabric can be achieved, for example, by increasing the thickness of the nonwoven fabric with the same basis weight and reducing the contact area of the nonwoven fabric surface layer fibers.

Furthermore, it is also preferable from the viewpoint of heat retention to increase the bulk by entanglement of fibers with a high-pressure fluid by fluid entanglement treatment.
For fluid entanglement, a normal water flow is used, the nozzle diameter is 0.05 to 0.5 mm, the nozzle interval is 0.2 to 10 mm, and a water flow of 1 to 15 MPa is preferable.

  As the cross-sectional shape of the fiber, irregular cross-section yarns such as C-type, Y-type, and V-type are used. It is preferable from the viewpoints of bulkiness and heat retention to use the soaked fibers.

  As a non-woven fabric structure, the warming effect of the air layer with the bulkiness of the non-woven fabric and the warming effect resulting from the heat conduction characteristics of the material itself, the combined warming effect, is a practical warming effect. This is obtained by the above-described measurement method, and is shown as the steady-state heat retention efficiency.

The fineness is preferably 0.8 to 5 dtex from the viewpoint of strength, flexibility, etc., but 2 to 8 dtex is preferable when emphasis is placed on bulk retention. The basis weight of the nonwoven fabric to be applied is set depending on how it is used, but 30 to 100 g / m ² is preferable from the viewpoint of practical strength and touch.
These non-woven fabrics are fibers having a fine contact surface with the human body and become a comfortable heat transfer medium.

  Films to be bonded to non-woven fabrics are LD, LLD, HD, various polyethylenes such as metallocene catalyst PE, polyolefins such as polypropylene, polyolefins such as EVA and various copolymers such as ethylene, propylene and butene, polyolefins such as polypropylene, polyamides Further, a polyester-based one or a microporous film having moisture permeability may be used. From the viewpoint of flexibility, sealing properties, and price, polyethylene or a copolymer olefin film thereof is preferable. Moreover, what combined the film of 2-3 layers from the point of the compatibility with a fiber layer and the sealing performance around a packaging material may be used.

The non-woven fabric and the film may be bonded to each other by heat sealing, heat bonding, or a method of laminating with an adhesive such as a hot melt agent, or may be full surface bonding or partial bonding to maintain flexibility.
In general, a vent hole required as a disposable heat insulating device is a hole after post-lamination or a perforated or microporous film is used in advance.

Hereinafter, the present invention will be further described with reference to Examples and Comparative Examples.
Measurement methods and evaluation methods are as follows.
(1) Fabric weight of nonwoven fabric The weight was measured with a 10 cm square sample, and the fabric weight (g / m ² ) was measured.
(2) Strength of nonwoven fabric and stress at 5% elongation Measured according to JIS L-1906.
(3) Non-woven fabric warming efficiency

A sample piece of the same size is placed on a hot plate A (5 cm square) set to be circulated from a constant temperature water bath and maintained at 20 ° C. in an environment of 20 ° C. and humidity 65%, and further 5 cm above it. The heat plate B (6 g / cm ² ) having a corner of 40 ° C. was overlapped, and the amount of heat transmitted through the sample was measured as the amount of heat for maintaining the temperature of the heat plate B, and was defined as the thermal conductivity of the sample. The heat retention efficiency of 14.06 W / 25 cm ² · 20 ° C. when the sample was not placed was defined as the heat retention efficiency 0%, and the value of the following equation (1) was defined as the steady heat retention efficiency (%).

Steady temperature retention efficiency (%) = {(14.06-thermal conductivity of sample) /14.06} × 100 (1)
Moreover, the sample surface temperature of the counter-heated plate surface of the sample placed on the hot plate B at 40 ° C. was also used as a measure of thermal conductivity.

[Example 1]
A water web entanglement device (nozzle) on which a card web formed of 80% polyester short fibers (2.0 dtex, 53 mm length) and 20% rayon short fibers (1.2 dtex, 53 mm length) is placed on an 80 mesh wire mesh and is oscillated at 150 rpm. A spunlace nonwoven fabric having a basis weight of 70 g / m ² was obtained by passing the front and back three times through a nozzle having a diameter of 0.15 mm, a nozzle interval of 5 mm × 5 rows, and a water pressure of 6 MPa. The performance of this nonwoven fabric is shown in Table 1.

  After laminating a 40 μ film in which LDPE and metallocene catalyst-based polyethylene (seal surface) were half-laminated on the surface of the obtained nonwoven fabric, it was narrowed with a needle roll (about 6%) as usual to obtain a packaging material for warmers. . The nonwoven fabric was used as an upper layer, and the lower layer was made of the same non-laminated laminate. A disposable body warmer was produced in which the film surface was filled inside, the exothermic composition was filled, and the periphery was heat-sealed. The obtained disposable warmer was a warmer, smoother and softer toucher with active surface fibers.

[Comparative Example 1]
As a comparative example, a nonwoven fabric of each woven pattern (crimp area ratio 22%) of polyethylene terephthalate fiber (2.0 dtex) used in a commercially available disposable warmer nonwoven fabric was manufactured, and the performance was compared. . The performance of the nonwoven fabric is shown in Table 1. The non-woven fabric of Comparative Example 1 had a constant heat retention efficiency of less than 40%, and the heat retention efficiency was lower than that of the example.
According to the said Example, it can be said that the nonwoven fabric by hydroentanglement has the favorable thermal insulation efficiency at the time of steadyness, has a soft fiber tactile sense as a disposable body warmer, and the thermal insulation efficiency as a heat generating body is favorable.

Claims (7)

A disposable heat-retaining device in which a composition that generates heat in air is enclosed in a packaging material having a nonwoven fabric laminated with a film on at least one surface, and the packaging material has air permeability, the nonwoven fabric comprising hydrophobic synthetic fibers A disposable warmer that is joined by fluid entanglement so that the steady warming efficiency in an atmosphere of 20 ° C. and humidity 65% is 60% or more. The disposable warmer according to claim 1, wherein the warming efficiency is 82% or more. The disposable heat insulating device according to claim 1 or 2, wherein the hydrophobic synthetic fiber is made of a polyester-based or polypropylene-based synthetic fiber. The disposable heat insulating device according to any one of claims 1 to 3, wherein the hydrophobic synthetic fiber is a modified cross-section yarn and / or a crimped fiber. For a disposable warmer characterized in that a nonwoven fabric containing a polyester-based or polypropylene-based synthetic fiber is joined by hydroentanglement so that the steady-state warming efficiency of the nonwoven fabric at a temperature of 20 ° C. and a humidity of 65% is 60% or more. Nonwoven fabric manufacturing method. The said polyester type or polypropylene type synthetic fiber is a modified cross-section thread and / or a crimped fiber, The manufacturing method of the nonwoven fabric for disposable warmth articles of Claim 5 characterized by the above-mentioned. A non-woven fabric sample piece is placed on a hot plate A maintained at a constant temperature, a hot plate B maintained at a temperature higher than the constant temperature is placed thereon, and the amount of heat transmitted through the sample piece is set to the temperature of the hot plate B. A method for measuring the heat retention efficiency of a nonwoven fabric for disposable warmers, which is measured as the amount of heat C to be maintained, and on the other hand, the heat retention amount D when the sample piece is not placed is measured and obtained as a steady heat retention efficiency by the following equation.
Constant heat retention efficiency (%) = {(D−C) / D} × 100