JPH1143855A - Packing material composed of non-woven fabric of conjugate, continuous fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject packing material, characterized by no deterioration of the constituent polymers of different melting point during a multi- component fiber spinning or heat sealing process. SOLUTION: This packing material is composed of a non-woven fabric of conjugate, continuous fibers of core-sheath structure with a polyester-based polymer serving as the core component and polyolefin-based polymer of lower melting point serving as the sheath component, wherein the latter is softened or molten to be fused to the former in places. The non-woven fabric of conjugate, continuous fibers simultaneously satisfies the relationships shown by formula I and II: formula I: HWD <= 0.04% and formula II: HWS <= 10% (HWD is elution rate of the component soluble in hot water, when the non-woven fabric is treated with hot water of 98 deg.C at a bath ratio of 1:100 for 10 min, and HWS is area shrinkage of the non-woven fabric treated with the hot water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wrapping material made of a composite long-fiber non-woven fabric, and more particularly to a packaging material made of a composite long-fiber non-woven fabric which can be suitably used as a so-called tea bag type food wrapping material for coffee or tea. About.

[0002]

2. Description of the Related Art Conventionally, as a nonwoven fabric used as a packaging material such as a leather-like product such as shoes or bags, a bag-like packaging material such as electric appliances, or a packaging material for foodstuffs, a polyolefin-based polymer is used as a sheath component. BACKGROUND ART A nonwoven fabric made of a core-sheath composite long fiber having a polyester polymer having a higher melting point than a sheath component as a core component is known.

[0003] Composite filaments constituting such a nonwoven fabric can be obtained by simultaneously spinning a low-melting component and a high-melting component at the same time. The spinning temperature at that time is generally a spinning temperature suitable for the high-melting component. Apply However, the spinning temperature adjusted to the high melting point component is too high for the low melting point component, so that the low melting point component causes polymer deterioration. When polymer degradation occurs, low-molecular-weight components in the low-melting-point components are converted into volatile gas and contaminate the spinneret surface.Therefore, it is necessary to clean the spinneret surface during operation to remove dirt, and sometimes replace the spin pack. However, there is a problem that operability is poor and cost is high. In addition, there has been a problem that the yarn spun in the composite spun fiber is liable to be broken and the like. Furthermore, when polymer degradation occurs,
Since the low molecular weight component is present in the low melting point component of the composite long fiber and on the fiber surface, when the nonwoven fabric made of such a composite long fiber is immersed in hot water or a solvent, the low molecular weight component is eluted. Become. Therefore, when such a non-woven fabric is formed and used as a tea bag type food packaging material for coffee, tea, tea, herbal medicine, etc., low molecular weight components are eluted into hot water and have an unusual taste. There is a problem that the flavor originally provided by coffee, tea, etc., cannot be utilized.

As a nonwoven fabric used as a packaging material, a laminated nonwoven fabric comprising a natural fiber layer and a thermoplastic fiber layer has been proposed, but such a laminated nonwoven fabric is inferior in heat sealability and inferior in moldability. Was something. for that reason,
A laminated nonwoven fabric consisting of three layers in which a nonwoven fabric made of a high-melting-point component is arranged in the outer layer and a nonwoven fabric made of short fibers having a low-melting-point component is arranged in the inner layer is a registered utility model No. 2513153. Proposed.
However, the cost of such a laminated nonwoven fabric is higher than that of a nonwoven fabric made of the core-sheath composite long fiber,
In addition, at the time of heat sealing, since the heat sealing treatment is performed at a temperature suitable for the high melting point component, the low melting point component of the inner layer causes polymer deterioration, and as described above, it becomes a tea bag type food packaging material for coffee, tea etc. Had the problem of being unsuitable.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems and provides a packaging material comprising a composite long-fiber non-woven fabric which is free from polymer deterioration during composite spinning and heat sealing of components having different melting points. The present invention provides a packaging material comprising a composite long-fiber nonwoven fabric that can be suitably used as a food packaging material in the form of a tea bag for black tea, tea, herbal medicine, and the like.

[0006]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have reached the present invention. That is, the present invention uses a polyester-based polymer as a core component and softens or melts the sheath component of a core-sheath type composite continuous fiber having a polyolefin-based polymer having a lower melting point than the core component as a sheath component. It consists of a composite long-fiber nonwoven fabric in which the fibers are fused in a scattered manner, and
The composite long-fiber nonwoven fabric satisfies the following formulas and the following formulas at the same time. In the following formulas and formulas, HWD represents the elution rate of hot water-soluble components when the long-fiber nonwoven fabric is treated with hot water at 98 ° C. for 10 minutes in a bath ratio of 1: 100, and HWS Represents the area shrinkage rate of the composite long-fiber nonwoven fabric during the hot water treatment. HWD ≦ 0.04% HWS ≦ 10% According to the present invention, a polyester-based polymer is used as a core component, and a polyolefin-based polymer having a lower melting point than the core component is used as a sheath component. By using the core-sheath type composite continuous fiber, a composite continuous fiber nonwoven fabric having good heat sealability can be obtained.

In addition, the long fibers are fused in a scattered manner by the softening or melting of the sheath component of the composite long fiber. In the fusion zone, the sheath component is softened or melted. Since the core component maintains the fiber form as it is or is slightly deformed, the nonwoven fabric has good shape retention, easy bending of the nonwoven fabric, and good handling, and can be suitably used as a packaging material.

Further, by adjusting the elution rate HWD of the hot water-soluble component of the composite continuous fiber nonwoven fabric to 0.04% or less, the low molecular weight of the polyolefin polymer in hot water or in a solvent can be reduced. Almost no components are eluted, and even when used as a food packaging material used in hot water, such as a tea bag for coffee or black tea, an odor peculiar to the polyolefin-based polymer does not occur. Further, by setting the area shrinkage HWS of the composite long-fiber nonwoven fabric at the time of hot water treatment to 10% or less, breakage due to shrinkage and accompanying exposure or breakage of contents are also eliminated.

Accordingly, it is possible to provide a packaging material which is made of a composite long-fiber nonwoven fabric having good heat sealability and excellent moldability, and which is free from deterioration of the polymer during composite spinning or heat sealing of components having different melting points. Therefore, since the problem of elution of low molecular weight components into hot water is solved, it is possible to provide a packaging material made of a composite long-fiber nonwoven fabric that can be suitably used for a tea bag type food packaging material for coffee, tea, and the like. it can.

[0010]

Next, the present invention will be described in detail.
The packaging material made of the composite long fiber according to the present invention has a core-sheath type composite long fiber as a constituent fiber. The core-sheath type composite long fiber, a polyester polymer is used for the core component,
As the sheath component, a polyolefin polymer having a lower melting point than the polyester component is used. As long as it is a core-sheath composite long fiber composed of such components, the cross-sectional shape may be such that the core component and the sheath component are concentric or eccentric. Such a core-sheath type composite filament is heat-treated to soften or melt the sheath component, which is a low melting point component, so that the filaments are fused in a scattered manner to form a composite filament nonwoven fabric.

[0011] The non-woven fabric comprising the composite filaments is 1: 1.
In a bath ratio of 00, the long-fiber nonwoven fabric is heated to 1 using hot water of 98 ° C.
The elution rate HWD of the hot water-soluble component after the hot water treatment for 0 minute must be 0.04% or less, and preferably 0.02% or less.
%, More preferably 0.01% or less, further preferably 0.008% or less. When the elution rate HWD of the hot water-soluble component exceeds 0.04%, the nonwoven fabric made of the composite long fiber is used for a food packaging material used in hot water such as a tea bag for coffee or tea. In this case, the low-molecular-weight component in the low-melting-point component is eluted into the hot water and emits an unusual odor, which impairs the flavor and aroma of coffee and tea. The area shrinkage HWS during the hot water treatment needs to be 10% or less, preferably 8% or less, more preferably 7% or less, and further preferably 6% or less. When the area shrinkage ratio HWS of the composite long-fiber nonwoven fabric during hot water treatment exceeds 10%, it greatly shrinks when used in hot water, and when used as a tea bag for coffee or tea as described above. However, there is a problem in that extraction of the extract due to the flow of the contents becomes incomplete, and sometimes the packaging material is damaged due to shrinkage, and the contents are exposed or scattered. In the composite long-fiber nonwoven fabric according to the present invention, the elution rate HWD and the area shrinkage rate HWS of the hot water-soluble component must satisfy the above ranges at the same time.

In order to make the dissolution rate HWD and the area shrinkage rate HWS of the hot water-soluble component of the nonwoven fabric composed of the composite long fibers fall within the range of the present invention, the polymer degradation of the low melting point component at the time of composite spinning or heat sealing. Must be prevented. In the present invention, in order to prevent deterioration of the polymer of the low melting point component, at least the sheath component of the core-sheath type conjugate long fiber constituting the conjugate long fiber nonwoven fabric has a phenol having a melting point of 140 ° C or higher for the purpose of preventing oxidation. It is preferable to add a neutralizing agent for the purpose of adding a system additive and inactivating a catalyst or the like. When the phenolic additive is added to the sheath component, the oxidative decomposition of the polymer is suppressed and the heat resistance is improved.When the neutralizing agent is added, the phenolic additive is caused by a catalyst or the like at the time of polymer polymerization. Since the remaining acidic substance is inactivated, polymer deterioration can be suppressed. Further, by adding the phenolic additive and the neutralizing agent to the core component as well as the sheath component, the polymer deterioration is further suppressed and the heat resistance is improved. Even when used for food packaging materials used in hot water such as bags, low molecular weight components generated by polymer degradation do not elute into hot water and generate no odor or the like. That is, by adding a phenolic additive having a melting point of 140 ° C. or more and a neutralizing agent to at least the sheath component of the core-sheath type composite filament, a high temperature history during melt spinning and a nonwoven fabric form are retained. Also in the heat bonding step, the polymer is prevented from being oxidized and degraded, and the residual acidic substances caused by the catalyst and the like are inactivated, and the low molecular weight components generated by the polymer degradation are reduced. It is possible to prevent the low-molecular-weight component in the low-melting-point component from being eluted even in a solvent or a solvent. Melting point of phenolic additive is 1
When the temperature is lower than 40 ° C., during the melt spinning, the additive is almost vaporized when the polymer yarn is released from the spinneret, and it becomes impossible to prevent the oxidation of the polymer in the subsequent process, and the polymer is deteriorated. Is more likely to occur. Further, if the neutralizing agent is not blended, complete neutralization of the catalyst used at the time of polymer polymerization becomes impossible, so that it becomes impossible to inactivate the acidic substance caused by the remaining catalyst, and the polymer is easily deteriorated. Therefore, in any case, when used as a food packaging material used in hot water such as a tea bag for coffee or black tea, the low-molecular weight components easily elute into the hot water, and are preferably used. You may not be able to use it.

Further, in order to further prevent the polymer deterioration, a thermogravimeter (model number TGA-7) manufactured by PerkinElmer Co., Ltd. is used as a sheath component of the core-sheath type composite long fiber constituting the nonwoven fabric. And a heat loss rate of 9 at a heating rate of 20 ° C./min and 290 ° C. in an air atmosphere.
% Or less is preferably used. The smaller the heat loss rate is, the more suitable as a packaging material, and 5% or less, most preferably, 3% or less as a food packaging material.
% Is desirable.

The heat loss rate of the polyolefin polymer is 9%.
By the following, the polymer deterioration during composite spinning or heat sealing is less likely to occur as described above, eliminating yarn breakage due to contamination of the spinneret surface and derivation of yarn bending, and also for coffee, tea, etc. Even when used as a tea bag-type food packaging material, the elution of low molecular weight components into hot water is eliminated. When the heat loss rate exceeds 9%, the polymer deteriorates at the time of composite spinning or heat sealing, and is unsuitable for a tea bag type food packaging material such as coffee and black tea.

[0015] The nonwoven fabric composed of the core-sheath composite long fibers constructed as described above has a strength of the nonwoven fabric in the longitudinal direction (hereinafter referred to as "tensile strength MD") of 5 kg / 5 cm width or more and the transverse direction (hereinafter referred to as "tensile strength MD"). The tensile strength of the nonwoven fabric is 1).
Preferably, the width is at least kg / 5 cm. Here, the tensile strength MD and the tensile strength CD indicate the maximum strength values in the machine direction and the transverse direction of the nonwoven fabric. Tensile strength MD is 5kg
If the width is smaller than / 5 cm, there is a case where the content is scattered due to insufficient strength at the time of packaging. Further, the tensile strength CD may be lower than the tensile strength MD, but if it is smaller than 1 kg / 5 cm width, the nonwoven fabric is less likely to be stretched in the lateral direction, and the packaged contents will be broken. . Therefore, it is desirable that the tensile strength MD is preferably 7 kg / 5 cm width or more, more preferably 9 kg / 5 cm width or more. The tensile strength CD is preferably 2 kg / 5 cm width or more, more preferably 3 kg / 5 c.
It is desirable that the width is not less than m width.

The polyolefin polymer used for the sheath component of the core-sheath type composite continuous fiber in the present invention includes polyethylene, polypropylene, a copolymer mainly composed of ethylene, a copolymer mainly composed of propylene, and the like. As polyethylene, linear low-density polyethylene,
Medium-density polyethylene, high-density polyethylene, and the like. Among polyethylenes, ASTM-D-1238
The melt index value measured by the method described in (E) is preferably 10 to 80 g / 10 minutes. If the melt index value is less than 10 g / 10 minutes, the melt viscosity is too high to obtain high-speed spinning properties, and if the melt index value exceeds 80 g / 10 minutes, the melt viscosity is too low and a slimy feeling may occur. In addition, the fibers are not sufficiently cooled, and the fibers adhere to each other, so that a core-sheath type long fiber cannot be obtained. On the other hand, the viscosity of polypropylene is ASTM-D-1.
The melt flow rate measured by the method described in 238 (L) is preferably 20 to 70 g / 10 minutes. If the melt flow rate value is less than 20 g / 10 minutes, the melt viscosity is too high to obtain high-speed spinning properties, and if the melt flow rate value exceeds 70 g / 10 minutes, the melt viscosity is too low, resulting in a slimy feeling. This is due to the occurrence of cracks and inadequate cooling of the fibers, resulting in close contact.

Examples of the polyester polymer used for the core component include polyethylene terephthalate and polybutylene terephthalate, and polyesters whose main repeating units are ethylene terephthalate or butylene terephthalate. In the case of a polyester having ethylene terephthalate or butylene terephthalate as a main repeating unit, it is preferable that the ethylene terephthalate unit or butylene terephthalate unit is contained in at least 85 mol% or more based on the entire polyester. Specific examples of the components forming the polyester include sebacic acid, terephthalic acid, isophthalic acid, phthalic acid, glutaric acid, adipic acid, 5-sodium sulfoisophthalic acid, dicarboxylic acid components such as naphthalic acid, ethylene glycol, diethylene glycol, propylene Examples of the diol component include glycol, 1,4-butanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, and xylylene glycol.

In the polyolefin constituting the sheath component and the polyester constituting the core component, a matting agent, a pigment, a light stabilizer, a heat stabilizer, an antioxidant, a crystallization accelerator may be contained, if necessary. And the like may be added within a range that does not impair the purpose of the present invention.

The weight ratio of the core component and the sheath component in the composite spinning of the polyolefin constituting the sheath component and the polyester constituting the core component is such that the ratio of the sheath component to the core component is 0.1 to 5% by weight. Part, especially 0.2-4
It is preferably in parts by weight. Since the sheath component is a component for fusing between the composite long fibers in the fusion zone, if the weight ratio is less than 0.1 part by weight, fusion will be insufficient and the tensile strength of the nonwoven fabric will be low. On the other hand, the sheath component is 5
When the amount is more than the weight part, the fusion in the fusion zone becomes severe, the proportion of the portion maintaining the fiber form in the fusion zone decreases, the hand becomes hard and the strength of the nonwoven fabric decreases.

As described above, the phenolic additive having a melting point of 140 ° C. or higher used in the present invention has an effect of suppressing the oxidative decomposition of a polymer or a composite filament and improving the heat resistance. More specifically, in general, a polymer tends to deteriorate under various conditions during melting, molding, and actual use, and the polymer deterioration is caused by autoxidation induced by heat, ultraviolet rays, and the like. In order to prevent such a polymer from being oxidized and degraded, it is important to prevent the generation of radicals and stop the autoxidation cycle by capturing the radicals. Therefore, in the present invention, various antioxidants can be applied to suppress the oxidative degradation, but in order to enhance the effect of suppressing the oxidative decomposition reaction, in particular, a phenol additive having a melting point of 140 ° C. or higher. Is used. Melting point of phenolic additive is 1
When the temperature is lower than 40 ° C., the polymer yarn is almost vaporized when the prevention spinneret is opened and hardly exists in the subsequent steps, so that it becomes difficult to suppress the oxidative decomposition of the polymer.

Examples of the phenolic additive having a melting point of 140 ° C. or higher include 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl). -4-Hydroxybenzyl) benzene (melting point 240 ° C)
And tris (3,5-di-t-butyl-4-hydroxybenzyl) -isocyanurate (melting point 220 ° C.) and 1,
3,5-tris (4-t-butyl-3-hydroxy-
2,6-dimethylbenzyl) isocyanuric acid (mp 15
0 ° C.). Among them, 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanuric acid (melting point 150 ° C.) can be most preferably used from the viewpoint of preventing oxidative deterioration.

Further, as described above, the neutralizing agent used in the present invention acts on the remaining acidic substance in the polymer caused by the Ziegler-Natta catalyst or the like used at the time of polymer polymerization and inactivates it. . Commonly used neutralizing agents include stearic acid (melting point 50 ° C.),
Bis (2-phenoxypropionyl hydrazide) isophthalic acid (melting point 225 ° C.), 3- (N-salicyloyl) amino 1,2,4 triazole (melting point 325 ° C.),
NN'-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine (melting point 2
27 ° C.). In the present invention, an inorganic neutralizing agent can be suitably used. The inorganic neutralizing agent has a high effect of inactivating residual acidic substances in the polymer, and does not maintain a melting point, so that it can be used during melt spinning, a subsequent thermal processing step, and other various conditions. Without melting, the effect as a neutralizing agent can be sufficiently exhibited. Examples of the inorganic neutralizing agent having such an effect include hydrotalcite and hydrotalcite compounds synthesized therefrom, and hydrotalcite is a natural mineral such as Mg ₆ Al ₂ (OH) ₁₆ CO ₃ · 4H ₂ O, and examples of the hydrotalcite compound _{Mg 4.5 Al 2 (OH) 13} CO 3 · 3.5H
₂ O can be suitably used.

The mixing ratio of the phenolic additive and the neutralizing agent to the olefin polymer or the polyester polymer is preferably in the range of 200 ppm to 1000 ppm, and the weight ratio thereof is (phenol additive). / (Neutralizer) = 1/2 to 2/1 In the above range, when the blending ratio of the phenolic additive is less than 200 ppm, the heat resistance effect of the olefin polymer tends to decrease, and when the blending ratio of the phenolic additive exceeds 1000 ppm, the phenolic additive Smoke during spinning due to thermal decomposition increases, and the spinning environment is polluted. On the other hand, if the amount of the neutralizing agent is less than 200 ppm, it becomes impossible to neutralize the acid component derived from the catalyst used during the polymerization, and the corrosion of the roll in the spinning line or the thermocompression bonding process, or in the packaging material forming process. Corrosion of equipment occurs. On the other hand, when the compounding amount of the neutralizing agent exceeds 1000 ppm, the spinning property is lowered and the cost is increased, which is not preferable in terms of operability and economic efficiency.

The single-filament fineness of the core-sheath type conjugate fiber is preferably in the range of 1 to 15 denier. If the single-fiber fineness exceeds 15 denier, the rigidity of the long fiber becomes high, and when used as a packaging material, the coarse and hard feeling becomes strong, and its use is limited. In addition, in the melt spinning step, it is not preferable because cooling and solidification of the spun yarn may be hindered. Also,
If the single-filament fineness is smaller than 1 denier, the spinning operability is lowered and the cost is increased.

By controlling the single hole discharge amount and the drawing speed when spinning the long fiber, the single fiber fineness of the long fiber and the degree of clogging of the packaging material within the range of the area shrinkage of the present invention. Can be set arbitrarily.

The shape of the scattered fusion zone between the long fibers formed by softening or melting the sheath component formed when the core-sheath type composite long fiber is subjected to a heat treatment is round, elliptical, or slit. Type, cross, ten leaf, triangle, three leaf, square, pentagon,
Hex, octagon, diamond, T, well, rectangular four-leaf, five-leaf, six-leaf, eight-leaf, swastika, etc.
The pattern of the fused areas provided in a large number of scattered points is measured by enlarging and photographing a small piece of the nonwoven fabric using a scanning electron microscope. The average value when the ratio of the sum of the areas of the parts that are point-pressed to the area of the minimum repeating unit measured using the scanning electron microscope is individually measured 10 times is referred to as the press-bonding area ratio, The non-woven fabric according to the present invention preferably has a compression area ratio of 3 to 50%. When the compression area ratio is less than 3%, the flexibility of the nonwoven fabric is improved, but the strength of the nonwoven fabric is reduced, and when the nonwoven fabric is rubbed, fluffing is likely to occur, which is problematic in practical terms. In addition, the crimping area ratio is 5
If it exceeds 0%, the nonwoven fabric itself becomes extremely hard and handling becomes poor. Therefore, more preferably, the compression area ratio is 5 to 40%.

The size of each fusion zone is 0.1 to 2.
It is preferably about 0 mm ² . And individual fusion zone 0.1 mm ² smaller than lowered nonwoven strength,
Fuzz is likely to occur, and the individual fused area is 2.0 m
If it is larger than m ² , the flexibility of the nonwoven fabric is undesirably reduced.

In the present invention, the presence of the pressure-bonded portion of the nonwoven fabric
Existing density is 6-150 pieces / cm ^TwoIs preferred. Crimping
6 parts / cm^TwoIf less than the flexibility of the nonwoven fabric
Improves but reduces the strength of the nonwoven fabric or when the nonwoven fabric rubs
Fluffing is likely to occur, causing a problem in practical use.
In addition, the density of the crimping part is 150 pieces / cm.^TwoNon-woven when exceeding
The fabric itself becomes extremely hard and the handling is poor. Obedience
More preferably, the density of the crimping portion is 8 to 120 pieces /
cm^TwoIs good.

The basis weight of the nonwoven fabric in the present invention is 100% so that handling as a packaging material can be suitably performed.
g / m ² or less. In particular, when used as food packaging materials can be suitably used by a ^{40g / m 2 ~15g / m 2} .

The wrapping material made of the composite long-fiber nonwoven fabric of the present invention can be produced, for example, by the following method. That is, a long-fiber nonwoven web formed by a spunbond method using a core-sheath type long fiber in which a sheath component is constituted by an olefin polymer and a core component is constituted by a polyester polymer having a higher melting point than the sheath component. Then, a long-fiber nonwoven fabric is formed by embossing, and the long-fiber nonwoven fabric is heat-sealed to be processed as a packaging material.

Specifically, a composite continuous fiber web is first produced by a spunbond method. At that time, in the completed yarn, the olefin polymer and the polyester polymer are melted such that the olefin polymer forms the sheath component and the polyester polymer forms the core component as described above. Are individually weighed, and then composite spinning is performed using an ordinary core-sheath composite spinneret. Subsequently, the spun conjugate fiber is cooled and solidified by a spraying device, pulled by air soccer, opened by an opener, deposited on a moving conveyor net to form a long fiber web, and heat embossed After being point-pressed by a machine, the film is wound up by a winding machine to form a nonwoven fabric.

In the method of the present invention, it is desirable that the pulling of the fiber yarn by air soccer be performed at the highest possible spinning speed as long as the yarn breakage does not occur. By doing so, it is possible to increase the orientation of the fibers, suppress the heat shrinkage, and improve the physical properties of the nonwoven fabric. That is, high spinning speed is preferable from the viewpoint of productivity, and
It is preferable from the viewpoint of increasing the degree of crystal orientation of the fiber, and the heat shrinkage property is also reduced, so that heat resistance and dimensional stability are also improved. Further, the strength of the nonwoven fabric is increased because the strength of the fiber itself is maintained. However, the spinning speed is 2000m
At a low spinning speed lower than about / min, the heat shrinkage of the fiber becomes extremely high, and the dimensional stability of the nonwoven fabric is reduced, and a rough feeling is generated.

In the above-described manufacturing method, an embossing method is used to maintain the shape of the nonwoven fabric by point compression. However, as the embossing machine, a known hot embossing machine currently used for dry nonwoven fabrics or a super embossing machine may be used. A sonic welding machine or the like can be applied.

For example, when a hot embossing machine is applied, the working temperature is preferably 5 to 50 ° C. lower than the melting point of the sheath component. If the processing temperature is higher than the above range, the hand becomes hard, the handling is poor, and the nonwoven fabric has a low tensile strength. Further, when the processing temperature is further increased, the long fiber web is taken up by an engraving roll or a metal smooth roll, and the operability deteriorates. When the processing temperature is lower than the melting point of the sheath component by 50 ° C. or more, the long fiber web is not thermocompression-bonded, and the shape retention of the nonwoven fabric is reduced. Further, when the processing temperature is lowered, the long fiber web is taken up by the engraving roll, and the operability is deteriorated. Thus, even if the processing temperature is below the melting point, the softening point of the sheath component is within the processing temperature range, and the pressure is applied at the pressure bonding point portion of the engraving roll, so that the sheath is securely fused. Becomes

In the production of a nonwoven fabric, the point compression pattern is important because it affects the strength, flexibility and texture of the nonwoven fabric, and the engraving area and shape of this engraving roll is one point. The standard of the engraving area can be indicated by the compression area ratio at the time of thermocompression, and the compression area ratio for obtaining the nonwoven fabric of the present invention is preferably 3 to 50%. If it is less than 3%, the feeling is soft but the strength is insufficient. Conversely, if the compression area ratio exceeds 50%, the strength increases, but a hard nonwoven fabric is not preferred in the present invention.

As the ultrasonic welding machine, the web may be passed between an engraving roll and a support having an ultrasonic welding mechanism, and an ultrasonic wave of about 20 kHz may be oscillated. When changing the welding state, the wavelength, that is, the frequency of the ultrasonic wave is appropriately changed depending on the material used. In this case, the linear pressure is 0.5 to 2 kg unlike the hot embossing machine.
/ Cm is preferably used. Further, the compression area ratio is preferably 4 to 50%.

In the nonwoven fabric subjected to the point compression by the ultrasonic welding, since the fibers other than the point compression part are hardly affected by heat, the texture does not become hard and can be used more favorably than the hot embossing.

As a method of using the composite long-fiber nonwoven fabric formed as described above as a packaging material, generally, an ultrasonic welder or heat sealing in a bag shape using a heat sealer may be used. The ultrasonic welding may be performed by passing the long-fiber nonwoven fabric between an engraving roll and a support having an ultrasonic welding mechanism and oscillating ultrasonic waves of about 20 kHz. When changing the welding state, the wavelength of the ultrasonic wave may be appropriately changed depending on the material used. In this case, a linear pressure of about 0.5 to 2 kg / cm may be used.

The heat sealer may be set at a temperature at which the low-melting-point component constituting the non-woven fabric can be welded. Generally, the low-melting-point component constituting the non-woven fabric is softened, and the high-melting-point component constituting the non-woven fabric begins to soften from the bonding temperature. Processing may be performed at temperatures up to. The linear pressure in this case is 0.5 to 2 kg /
cm.

The packaging material according to the present invention may contain a small amount of other fibers or short fibers other than the core-in-sheath composite fibers.

[0041]

Next, the present invention will be specifically described based on examples, but the present invention is not limited to only these examples. The measurement of various physical property values in the examples was performed by the following methods.

(1) Melting point (° C.): Using a differential scanning calorimeter DSC-2 manufactured by Perkin Elmer Co., Ltd.
The temperature was measured at 0 ° C./min, and the temperature at which an extreme value was obtained in the obtained melting absorption curve was defined as the melting point.

(2) Melt index (g / 10
Min): Measured according to the method described in ASTM-D-1238 (E).

(3) Melt flow rate (g / 10
Min): Measured according to the method described in ASTM-D-1238 (L).

(4) Thermal loss rate (%) of polymer: Using a thermogravimeter (model number TGA-7) manufactured by PerkinElmer, the temperature reached 290 ° C in air at a heating rate of 20 ° C / min. After that, the temperature was held, and the heat loss rate in an atmosphere after 10 minutes was measured.

(5) Tensile strength of nonwoven fabric (kg / 5cm
Width) and tensile elongation (%): Measured according to the strip method described in JIS-L-1096. That is, 10 pieces of sample pieces each having a sample length of 15 cm and a sample width of 5 cm are created in the machine direction (MD) and the transverse direction (CD) of the nonwoven fabric, respectively.
For each sample piece, in the MD direction and the CD direction of the nonwoven fabric, a constant-speed elongation type tensile tester (Tensilon UTM-4-1-100 manufactured by Toyo Baldwin Co., Ltd.) was used. Per minute.
Then, the average value of the obtained load values at cutting (kg / 5 cm width) was defined as the tensile strength. The average value of the maximum elongation at that time was defined as the tensile elongation of the nonwoven fabric.

(6) Elution rate of hot water soluble component of nonwoven fabric [H
WD] (%): A test piece having a length of 1 m and a width of 1 m was prepared, weighed, immersed in hot water of 98 ° C. at a bath ratio of 1: 100 for 10 minutes, and then further washed with pure water and then dehydrated. Then 60
After drying at 1 ° C. for 1 hour, the weight was measured again, and the weight difference before and after immersion in hot water was divided by the original weight before immersion to determine the elution rate (%) of the hot water-soluble component. .

(7) Hot water area shrinkage of nonwoven fabric [HWS]
(%): After placing four frames each having a length of 5 cm and a width of 5 cm on a test piece of 1 m in length and 1 m in width, 9
Immerse in hot water of 8 ° C. for 10 minutes at a bath ratio of 1: 100, then wash with pure water, dehydrate, measure the length when dried at 60 ° C. for 1 hour, and measure the area described first. Was calculated as the area shrinkage (%), and the average value was defined as the hot water area shrinkage of the nonwoven fabric.

(8) Bag-making properties: Using a normal heat sealing machine, 50 packaging materials were prepared under appropriate temperature conditions, and the bag-making properties were investigated and determined as follows. ◎ There was no problem at all and it was good. ○ Generally good. △ It was a little problem. X: Poor.

(9) Practicality: A long-fiber nonwoven fabric was produced in a tea bag type packaging material using a heat sealing machine. Then, 10 g of commercially available ground coffee beans from Brazil were weighed and sealed in the packaging material to prepare a coffee bag.
The prepared coffee bag was put into 200 cc of hot water at 98 ° C. and subjected to an extraction treatment for one minute. Then, a monitor test including tasting by five panelists was performed, and the practicality was evaluated as follows. ◎ There was no problem at all and it was good. ○ Generally good. △ It was a little problem. X: Poor.

Example 1 In forming a core-sheath type long fiber constituting a composite long-fiber nonwoven fabric, a melting point of 132 ° C. and a density of 0.958 g were used as a sheath component.
/ Cm ³ , a polyethylene having a melt index value measured by ASTM D-1238 (E) of 20 g / 10 min and a loss on heat of the polymer at 290 ° C. of 4.1% was used. In the polyethylene constituting the sheath component, 500 ppm of 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanuric acid was used as a phenolic additive, and inorganic neutralization was performed. As an agent, 300 ppm of a hydrotalcite compound was blended. The core component has a melting point of 256 ° C. and an intrinsic viscosity of 0.7.
0 polyethylene terephthalate was used. Then, the polyethylene is melted at 230 ° C., and the polyethylene terephthalate is melted at 290 ° C. and individually melted and weighed so as to have a volume ratio of 1: 1. Using a core-sheath type composite spinneret having a round hole. Then, melt spinning was performed at a temperature of 290 ° C.

The yarn spun from the core-sheath type composite spinneret is pulled by air soccer through a cooling device, opened by a known opening device, and deposited on a moving conveyor net. A long fiber web composed of a core-sheath type long fiber having a single fiber fineness of 3.0 denier was obtained. Subsequently, the heat-welding treatment was applied to the long fiber web. At the time of the heat-pressing treatment, the crimping area ratio is 15%, the crimping portion density is 22 pieces / cm ² , and the crimping portion area is 0.1 mm.
Using a hot embossing machine consisting of a 7 mm ² engraving roll and a flat roll, a point pressure was applied at a processing temperature of 125 ° C. and a linear pressure between the rolls of 40 kg / cm, and the basis weight was about 20 g / m 2.
^Two long fiber nonwoven fabrics were produced.

The obtained long-fiber nonwoven fabric was heat-sealed using a heat-sealing machine at a temperature of 140 ° C. to prepare a tea bag-type packaging material that can be used as a food packaging material for coffee, black tea, tea and the like. Further, in order to examine the practicality of the obtained packaging material, a pulverized product of commercially available Brazilian coffee beans was enclosed in the packaging material to prepare a coffee bag.

Table 1 shows the physical properties and the like of the long-fiber nonwoven fabric and the packaging material.

[0055]

[Table 1]

Example 2 When forming the core-sheath type long fiber constituting the composite long-fiber nonwoven fabric, the sheath component had a melting point of 126 ° C. and a density of 0.938 g.
/ Cm ^3, a polymer thermal weight loss of at 290 ° C. The melt index value measured by D-1238 (E) of ASTM is at 26 g / 10 min was used 5.3% of the linear low density polyethylene. The linear low-density polyethylene constituting the sheath component was mixed with a phenolic additive and an inorganic neutralizing agent in the same manner as in Example 1, and melted at 220 ° C. And
Otherwise, the core-sheath type long fiber was melt-spun in the same manner as in Example 1 to produce a long fiber web.

A hot pressing treatment was performed in the same manner as in Example 1 except that the processing temperature in the hot embossing performed on the long fiber web was 110 ° C. The obtained long-fiber nonwoven fabric was heat-sealed using a heat-sealing machine at a temperature of 130 ° C., and in the same manner as in Example 1, a tea bag-type packaging material and coffee in which Brazilian coffee beans were enclosed in the packaging material And a bag.

Table 1 shows the physical properties and the like of the long-fiber nonwoven fabric and the packaging material.

Example 3 When forming a core-sheath type long fiber constituting a composite long-fiber nonwoven fabric, a melting point of 162 ° C. and a density of 0.920 g were used as a sheath component.
/ Cm ³ , a polypropylene having a melt flow rate value measured by ASTM D-1238 (L) of 30 g / 10 min and a polymer weight loss rate of 3.2% at 290 ° C. was used. A phenolic additive and an inorganic neutralizing agent were blended in the polypropylene constituting the sheath component in the same manner as in Example 1, and were melted at 230 ° C. Other than that, the core-sheath type long fiber was melt-spun in the same manner as in Example 1 to produce a long fiber web.

A hot press treatment was performed in the same manner as in Example 1 except that the processing temperature in the hot embossing performed on the long fiber web was 155 ° C. The obtained long-fiber nonwoven fabric was heat-sealed at a temperature of 170 ° C. using a heat-sealing machine, and in the same manner as in Example 1, a tea bag-type packaging material and coffee in which Brazilian coffee beans were sealed in the packaging material And a bag.

Table 1 shows the physical properties of the long-fiber nonwoven fabric and the packaging material.

Example 4 In forming the core-sheath type long fiber constituting the composite long-fiber nonwoven fabric, a phenolic additive to be added to the polyethylene constituting the sheath component was added to n-octadecyl-3-melting point having a melting point of 52 ° C.
(3 ′, 5′-di-t-butyl 4′-hydroxyphenyl) -propionate, and the polyethylene constituting the sheath component had a heat loss rate of 9.2%.

Other than that, a long-fiber non-woven fabric was produced in the same manner as in Example 1, and the long-fiber non-woven fabric was formed and processed into a tea bag-type wrapping material and coffee in which Brazilian coffee beans were sealed in the wrapping material. And a bag.

Table 1 shows the physical properties and the like of the long-fiber nonwoven fabric and the packaging material.

Example 5 In forming the core-sheath type long fiber constituting the composite long-fiber nonwoven fabric, calcium stearate and NN'-bis [3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionyl] hydrazine was added in an amount of 200 ppm, and the polyethylene constituting the sheath component was made to have a heat loss rate of 7.5%.

Otherwise, a long-fiber non-woven fabric was prepared in the same manner as in Example 1, and the long-fiber non-woven fabric was formed and processed into a tea bag-type wrapping material and coffee in which Brazilian coffee beans were enclosed in the wrapping material. And a bag.

Table 1 shows the physical properties and the like of the long-fiber nonwoven fabric and the packaging material.

Example 6 In forming the core-sheath type long fiber constituting the composite long-fiber nonwoven fabric, the discharge amount of single holes was reduced, and the yarn spun from the core-sheath type composite spinning die was cooled. The pulling speed at the time of pulling by air soccer through the device was reduced to obtain a yarn having the same single yarn fineness as that of Example 1, that is, 3.0 denier. The processing temperature during hot embossing was set to 120 ° C.

Other than that, a long-fiber non-woven fabric was prepared in the same manner as in Example 1, and the long-fiber non-woven fabric was formed and processed into a tea bag-type wrapping material and a coffee in which Brazilian coffee beans were sealed in the wrapping material. And a bag.

Table 1 shows the physical properties and the like of the long-fiber nonwoven fabric and the packaging material.

In all of Examples 1 to 3, a core-sheath composite long fiber having a polyester-based polymer as a core component and a polyolefin-based polymer having a lower melting point than the core component as a sheath component is used. Thus, a composite long-fiber nonwoven fabric having good heat sealing properties and good bag making properties was obtained. In addition, since the composite long fibers were embossed and fused between the long fibers in a scattered manner, the nonwoven fabric was excellent in tensile strength and tensile elongation. Furthermore, since the elution rate HWD of the hot water-soluble component was 0.04% or less and the area shrinkage HWS was 10% or less, the low molecular weight component of the polyolefin polymer constituting the sheath component even when used as a coffee bag. Did not elute in hot water and give off odor, and the coffee bag did not shrink and the content of the coffee powder spilled out, so that it could be suitably used as a coffee bag. In addition, the sheath component has a melting point of 1
Since the phenolic additive at 40 ° C. or higher and the inorganic neutralizing agent were added, polymer deterioration during composite spinning or heat sealing was eliminated, and elution of low molecular weight components into hot water was eliminated, Utilizing the original aroma of Brazilian coffee comparable to coffee obtained by siphon extraction, a practical coffee bag with satisfactory taste and richness was obtained.

In Example 4, since a phenolic additive having a low melting point was used, the sheath component was thermally degraded and the heat loss was slightly increased. Although the characteristics are good, the practicality is slightly inferior as a food packaging material used in hot water such as a tea bag for coffee or the like.

In Example 5, since an organic neutralizing agent was used, the heat loss rate of the sheath component was slightly increased, and the practicality of the packaging material was slightly inferior to those of Examples 1 to 3. However, in other characteristics, a material having good characteristics as a packaging material was obtained as in Examples 1 to 3 described above.

In Example 6, the tensile strength of the nonwoven fabric was slightly reduced since the long-fiber nonwoven fabric was manufactured by lowering the pulling speed.
The area shrinkage ratio also increased slightly. Therefore, the practicality of the packaging material was slightly inferior to those of Examples 1 to 3 above, but in other characteristics, good characteristics as the packaging material were obtained as in Examples 1 to 3. Was. In addition, when the coffee extraction time was set a little longer, the condition was improved.

Comparative Example 1 When forming the core-sheath type long fiber constituting the composite long-fiber nonwoven fabric, the sheath component had a melting point of 132 ° C. and a density of 0.958 g.
/ Cm ³ , a polyethylene having a melt index value measured by ASTM D-1238 (E) of 20 g / 10 min and a heat loss rate of the polymer at 290 ° C. of 11.4% was used. The polyethylene constituting the sheath component contains tetrakis- [methylene-3-) as a phenolic additive.
(3 ', 5'-di-tert-butyl-4'-hydroxy-phenyl) -propionate] methane (melting point 120
800 ° C.) and 300 ppm of calcium stearate as a neutralizing agent were melted at 230 ° C. Other than that, the core-sheath type long fiber was melt-spun in the same manner as in Example 1 to produce a long fiber web. In addition, this long fiber web was subjected to a heat press treatment in the same manner as in Example 1 to produce a long fiber nonwoven fabric.

The obtained long-fiber nonwoven fabric was heat-sealed using a heat-sealing machine at a temperature of 140 ° C., and in the same manner as in Example 1, a tea bag-type packaging material and a coffee bag enclosing Brazilian coffee beans were used. And were produced.

Table 2 shows the physical properties of the long-fiber nonwoven fabric and the packaging material.

[0078]

[Table 2]

Comparative Example 2 Melting point: 125 ° C., density: 0.935 g / cm ³ , AST
Only linear low-density polyethylene having a melt index value measured by D-1238 (E) of M of 30 g / 10 min and a loss on heat of the polymer at 290 ° C. of 10.5% at 290 ° C. was used. As a phenolic additive to the polyethylene,
n-octadecyl-3- (3 ', 5'-di-t-butyl4'-hydroxyphenyl) -propionate (melting point 5
(2 ° C.) 500 ppm and calcium stearate 300 ppm as a neutralizing agent. The polyethylene blended with the additive is applied to a normal single-axis type melt spinning device other than the core-sheath type spinneret, and is melted at a spinning temperature of 230 ° C. using a spinneret having a round hole. The fiber was spun to produce a long fiber web.

A hot press treatment was performed in the same manner as in Example 1 except that the processing temperature in the hot embossing performed on the long fiber web was 105 ° C. The obtained long-fiber nonwoven fabric was heat-sealed at a temperature of 123 ° C. using a heat-sealing machine, and a tea bag-type packaging material and coffee in which Brazilian coffee beans were enclosed in the packaging material in the same manner as in Example 1. And a bag.

Table 2 shows the physical properties and the like of the long-fiber nonwoven fabric and the packaging material.

Comparative Example 3 When forming the core-sheath type long fiber constituting the composite long-fiber nonwoven fabric, the sheath component had a melting point of 132 ° C. and a density of 0.958 g.
/ Cm ³ , a polyethylene having a melt index value measured by ASTM D-1238 (E) of 20 g / 10 min and a heat loss of the polymer at 290 ° C. of 15% was used. A phenolic additive was not added to the polyethylene constituting the sheath component, and 300 ppm of a hydrotalcite compound was added as a neutralizing agent.

Other than that, a long-fiber non-woven fabric was prepared in the same manner as in Example 1, and the long-fiber non-woven fabric was molded and processed, and a tea bag-type packaging material and coffee in which Brazilian coffee beans were enclosed in the packaging material And a bag.

Table 2 shows the physical properties of the long-fiber nonwoven fabric and the packaging material.

Comparative Example 4 When forming the core-sheath type long fiber constituting the composite long-fiber nonwoven fabric, the sheath component had a melting point of 132 ° C. and a density of 0.958 g.
/ Cm ³ , a polyethylene having a melt index value measured by ASTM D-1238 (E) of 20 g / 10 min and a heat loss rate of the polymer at 290 ° C. of 12.6% was used. 800 ppm of tris (2,4-di-t-butylphenyl) -phosphite, a phosphorus-based antioxidant having a melting point of 183 ° C., was added to the polyethylene constituting the sheath component instead of the phenol-based additive as an additive. As a neutralizing agent, a hydrotalcite compound is 300 ppm
Was blended.

Other than that, a long-fiber non-woven fabric was prepared in the same manner as in Example 1, and the long-fiber non-woven fabric was formed and processed into a tea bag-type packaging material and a coffee in which Brazilian coffee beans were enclosed in the packaging material. And a bag.

Table 2 shows the physical properties and the like of the long-fiber nonwoven fabric and the packaging material.

Comparative Example 5 When forming the core-sheath type long fiber constituting the composite long-fiber nonwoven fabric, the single hole discharge amount was made the same as in Example 6, and the fiber was spun out from the core-sheath type composite spinning die device. The pulling speed at the time when the drawn yarn was pulled by air soccer via the cooling device was further lowered than in Example 6, to obtain a long fiber web composed of a core-sheath type long fiber having a single yarn fineness of 3.7 denier. . The long fiber web was subjected to hot embossing at a processing temperature of 118 ° C.

Otherwise, a long-fiber non-woven fabric was prepared in the same manner as in Example 1, and the long-fiber non-woven fabric was formed and processed into a tea bag-type packaging material and coffee in which Brazilian coffee beans were enclosed in the packaging material. And a bag.

Table 2 shows the physical properties and the like of the long-fiber nonwoven fabric and the packaging material.

In Comparative Example 1, a core-sheath type composite continuous fiber having a polyester polymer as a core component and a polyolefin polymer having a lower melting point than the core component as a sheath component was used. Although a composite long-fiber nonwoven fabric with good bag-making properties was obtained, the heat loss rate of the sheath component exceeded the upper limit of the present invention, and polymer deterioration was liable to occur during composite spinning or heat sealing, resulting in hot water. The low-molecular-weight components eluted at high rates, and when used as a coffee bag, unpleasant odor was generated in the coffee, resulting in poor practicality.

In Comparative Example 2, since a long fiber composed of a single component of polyethylene was used in place of the core-sheath type long fiber, the obtained long-fiber nonwoven fabric was inferior in tensile strength MD and consisted of a single component. In addition, the obtained coffee bag had poor heat sealability as much as 20% and was inferior in bag making property. Further, the processing temperature range is extremely narrow, and if the processing temperature during heat sealing is increased by 5 ° C., there is also a problem that the seal portion is completely melted and the operability is poor. In particular, since the area shrinkage rate is high, the problem that the time required for coffee extraction is twice as long and the problem that a part of the coffee bag is damaged and the contents are mixed into the extract have arisen. In addition, the rate of dissolution of the long-fiber nonwoven fabric into hot water was increased, and the original coffee flavor of Brazil was not utilized, resulting in a change to a bitter taste and poor practicality.

In Comparative Example 3, since no phenolic additive was blended, polymer degradation during melt spinning increased, the dissolution rate became extremely high, and the packaging used in hot water like a coffee bag was used. It was not suitable for use as a material at all, and was inferior in practicality as in Comparative Examples 1 and 2.

In Comparative Example 4, the phosphorus-based antioxidant was used in place of the phenolic additive. Therefore, although the melting point of the additive was high, the heat loss rate of the sheath component was high. As a result, the practicality was inferior as in Comparative Examples 1 and 2.

In Comparative Example 5, the area shrinkage of the long-fiber nonwoven fabric was extremely high because the pulling speed of the yarn was greatly reduced. Lowering the heat sealing temperature did not cause much problem in bag making, but when used as a coffee bag, the nonwoven fabric shrinks and the time required for coffee extraction becomes longer, and the original coffee taste is thin Therefore, the practicality was inferior.

[0096]

As described above, according to the present invention, by adjusting the dissolution rate HWD of the hot water-soluble component of the composite long-fiber nonwoven fabric constituting the packaging material to be 0.04% or less, the hot water The elution of low molecular weight components of the polyolefin polymer into the solvent or into the solvent can be eliminated. Further, by setting the area shrinkage ratio HWS of the composite long-fiber nonwoven fabric at the time of hot water treatment to be smaller than 10%, even when used as a packaging material in hot water, damage due to shrinkage and accompanying exposure of contents are eliminated. Therefore,
Especially when used as a packaging material used in hot water, such as a tea bag type food packaging material such as coffee or black tea, there is no unusual smell peculiar to polyolefin polymers, and damage due to shrinkage and the accompanying content Because there is no exposure of things,
A packaging material that can be suitably used as a tea bag type food packaging material can be provided.

Further, the nonwoven fabric constituting the packaging material is formed by fusing the long fibers with each other in a scattered manner due to softening or melting of the sheath component of the core-sheath type composite long fiber. It is extremely high, does not generate lint, has good shape retention, easy bending of the nonwoven fabric, and good handling.Moreover, since the nonwoven fabric is excellent in heat sealability, it is also excellent in bag making and practicality. It is possible to provide a packaging material made of a composite long fiber.

[0098] Therefore, the packaging material of the present invention composed of the nonwoven fabric of composite long fibers is not limited to the above-mentioned food packaging material in the form of a tea bag, but also a food packaging material such as a bag for boiled knots or so-called shoes or bags. It can be suitably used in a wide range of fields, such as bag-like packaging materials for leather goods, cassettes, recorders, radios, and other weak electric appliances, and protective materials for moving objects for moving.

Claims (4)

[Claims] 1. A long fiber obtained by softening or melting a sheath component of a core-sheath composite long fiber having a polyester polymer as a core component and a polyolefin polymer having a melting point lower than the core component as a sheath component. A packaging material comprising a composite long-fiber nonwoven fabric comprising a composite long-fiber nonwoven fabric fused to each other in a scattered manner, wherein the composite long-fiber nonwoven fabric simultaneously satisfies the following formulas. HWD ≤ 0.04% ... HWS ≤ 10% ... The above-mentioned HWD is obtained when the long-fiber nonwoven fabric is treated with hot water at 98 ° C for 10 minutes using hot water at a bath ratio of 1: 100. HWS represents the elution rate of the hot water soluble component, and HWS represents the area shrinkage rate of the long fiber nonwoven fabric during the hot water treatment. 2. A phenolic additive having a melting point of at least 140 ° C. to at least the polyolefin polymer of the sheath component,
The packaging material comprising a composite long-fiber nonwoven fabric according to claim 1, further comprising a neutralizing agent. 3. A thermogravimeter (model number TGA-7) manufactured by PerkinElmer Co., Ltd., at a temperature rising rate of 20 ° C./min and 290 ° C.
The packaging material comprising a nonwoven fabric of a composite long fiber according to claim 1 or 2, wherein the sheath component is a polyolefin polymer having a heat loss rate of 9% or less as measured in an atmosphere in the air. 4. The strength of the nonwoven fabric is 5 kg / 5 cm in the longitudinal direction.
The packaging material comprising the composite long-fiber nonwoven fabric according to any one of claims 1 to 3, wherein the packaging material has a width of not less than 1 kg / 5 cm in a width direction.