JPH11107153A - Packaging material comprising conjugate filament nonwoven fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a packaging material free from deterioration of a polymer in conjugate spinning or heat sealing of components having different melting points. SOLUTION: This packaging material comprises a conjugate filament nonwoven fabric in which filaments are melted in dot-like state by softening or melting of sheath component of a core-sheath type conjugate filament using a polypropylene-based polymer as a core component and using a polyethylene- based polymer having lower melting point than the core component as a sheath component. The conjugate filament nonwoven fabric simultaneously satisfies formula I and formula II. The formula I:HWD<=0. 04% and the formula II : HWS<=8%, wherein HWD represents elution ratio of hot water soluble component in subjecting the filament nonwoven fabric to hot water treatment for 10 min by using 98 deg.C hot water in a bath ratio of 1:100 and HWS represents area shrinkage factor of the filament nonwoven fabric in a hot water treatment.

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, a nonwoven fabric used as a packaging material such as a bag-like packaging material such as leather products such as shoes and bags and electric appliances and a packaging material for foodstuffs has a polyethylene-based polymer as a sheath component. 2. Description of the Related Art Nonwoven fabrics made of a core-sheath composite long fiber having a polypropylene-based polymer having a higher melting point than the sheath component as a core component are 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. In addition, the polypropylene-based polymer constituting the core component has a higher melting point than the polyethylene-based polymer constituting the sheath component, but is a substance having a relatively low melting point. As described above, low molecular weight components are easily generated.
Therefore, such a non-woven fabric is formed into coffee, tea,
When used as a tea bag-type food packaging material for tea, herbal medicine, etc., low molecular weight components elute into hot water and give off strange tastes and odors, and coffee and tea etc. are originally provided. There was a problem that the flavor that was used could not be used.

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,
To improve the heat sealing property, a three-layer laminated non-woven fabric in which a non-woven fabric composed of a high melting point component is disposed in an outer layer and a non-woven fabric composed of short fibers having a low melting point component is disposed in an inner layer is proposed in Utility Model Registration No. 251153. Have been. 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, and the heat sealing process is performed at a temperature suitable for the high melting point component. The low-melting-point component causes polymer deterioration, and as described above, there is a problem that it is unsuitable for a tea bag-type food packaging material for coffee, tea and the like.

[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 polypropylene-based polymer as a core component and softens or melts a sheath component of a core-sheath type composite continuous fiber having a polyethylene-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 ≦ 8% As described above, according to the present invention, a polyethylene-based polymer having a polypropylene polymer as a core component and a melting point lower than the core component is used. By using a core-sheath composite long fiber as a sheath component, a composite long-fiber nonwoven fabric having good heat sealability can be obtained.

In addition, the sheath components of the composite filaments are fused or melted in a scattered manner by the softening or melting of the sheath components. In the fusion zone, the sheath components are 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 polypropylene-based polymer and the polyethylene-based polymer in hot water or a solvent can be used. Eliminates the elution of low molecular weight components of the polymer, and eliminates the peculiar smell of polyethylene-based polymers even when used in food packaging used in hot water such as tea bags for coffee and tea . Further, by setting the area shrinkage HWS of the composite long-fiber nonwoven fabric at the time of hot water treatment to 8% or less, breakage due to shrinkage and accompanying exposure or breakage of contents are also eliminated.

[0010] Accordingly, it is possible to provide a packaging material which is made of a composite long-fiber non-woven fabric having excellent heat sealability and excellent moldability, and which is free from polymer deterioration during composite spinning and 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.

[0011]

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. In the core-sheath type composite long fiber, a polypropylene-based polymer is used as a core component, and a polyethylene-based polymer having a lower melting point than the polypropylene component is used as a sheath component. 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.

[0012] The non-woven fabric composed of 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 needs to be 0.04% or less, preferably 0.04% or less.
It is desirable that the content be 2% or less, more preferably 0.01% or less, and still more 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. Further, the area shrinkage HWS during the hot water treatment needs to be 8% or less, preferably 7% or less, more preferably 6% or less, and further preferably 5% or less. If the area shrinkage ratio HWS of the composite long-fiber nonwoven fabric during hot water treatment exceeds 8%, the nonwoven fabric shrinks greatly when used in hot water,
When used as a tea bag for coffee or black tea as described above, the 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 splatters. 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 filaments fall within the scope of the present invention, the polymer degradation of the low melting point component during 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 blended in this way, the oxidative decomposition of the polymer is suppressed and the heat resistance is improved, and when the neutralizing agent is added, the residual acidic substance due to a catalyst or the like at the time of polymerizing the polymer. Is inactivated, so that polymer deterioration can be suppressed. Further, although the polypropylene polymer constituting the core component has a higher melting point than the polyethylene polymer constituting the sheath component, it is a substance having a relatively low melting point, so that not only the sheath component but also the phenol is contained in the core component. By adding a system additive and a neutralizing agent, the deterioration of the polymer is further suppressed and the heat resistance is improved, so that a food package used in hot water such as a tea bag for coffee or tea etc. Even when used as a material, low molecular weight components generated by polymer deterioration 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. If the melting point of the phenolic additive is lower than 140 ° C., the additive is almost vaporized when being released from the spinneret as a polymer yarn during melt spinning, and the polymer is prevented from being oxidized in a subsequent step. And deterioration of the polymer is 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 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. The rate of heat loss measured in an atmosphere of air at 230 ° C. at a rate of temperature increase of 20 ° C./min was 5
% Is preferably used. The smaller the heat loss rate is, the more suitable it is as a packaging material, and it is desirable that it is 3% or less for a food packaging material.

By setting the heat loss rate of the polyethylene polymer to 5% or less, deterioration of the polymer during composite spinning and heat sealing hardly occurs as described above, resulting in contamination of the spinneret surface and derivation of yarn bending. Even when used as a food bag in the form of a tea bag for coffee, black tea, etc., elution of low molecular weight components into hot water is eliminated. When the heat loss rate exceeds 5%, the polymer deteriorates at the time of composite spinning or heat sealing, and is not suitable for a tea bag type food packaging material such as coffee and black tea.

In the nonwoven fabric composed of the core-sheath composite long fibers constituted as described above, the strength of the nonwoven fabric in the longitudinal direction (hereinafter referred to as "tensile strength MD") is 5 kg / 5 cm or more in width 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 polyethylene polymer used for the sheath component of the core-sheath type composite long fiber in the present invention includes polyethylene or a copolymer mainly composed of ethylene.
Examples of the polyethylene include linear low-density polyethylene, medium-density polyethylene, and high-density polyethylene.
The melt index value measured by the method described in STM-D-1238E 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.

Examples of the polypropylene polymer used for the core component include polypropylene or a polypropylene polymer mainly composed of propylene. As the viscosity of the polypropylene, the melt flow rate measured by the method described in ASTM-D-1238L is 20 to 70 g /
Preferably, it is 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 the melt flow rate value is 70 g.
If the time exceeds / 10 minutes, the melt viscosity is too low, and a slimy feeling is generated, and the cooling of the fiber is not effective, resulting in adhesion.

In the polyethylene constituting the sheath component and the polypropylene constituting the core component, if necessary, a matting agent, a pigment, a light stabilizer, a heat stabilizer, an antioxidant, a crystallization accelerator may be used. 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 to the sheath component in the composite spinning of the polyethylene constituting the sheath component and the polypropylene 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 more 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 above-mentioned phenolic additives having a melting point of 140 ° C. or more 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 polyethylene polymer or the polypropylene polymer is preferably in the range of 200 ppm to 1000 ppm, and the weight ratio thereof is (phenolic 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 polyethylene polymer and the polypropylene polymer tends to decrease, and when the blending ratio of the phenolic additive exceeds 1000 ppm. In addition, smoke generated during spinning due to thermal decomposition of the phenolic additive 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 composite 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 fineness of the single fiber of the long fiber and the degree of clogging of the packaging material are controlled 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 of the sheath component formed when the core-sheath type composite long fiber is subjected to 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 from 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 ^TwoTo be about
preferable. The density of the crimping part is 6 pieces / cm^TwoIf it is less than
The flexibility of the woven fabric increases, but the strength of the nonwoven fabric decreases,
Fraying is likely to occur when the surface is rubbed.
Problems arise. In addition, the density of the crimping part is 150 pieces / cm. ^Two
If it exceeds, the nonwoven fabric itself becomes extremely hard and
Gets worse. Therefore, more preferably, the density of the crimped 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 a polyethylene polymer and a core component is constituted by a polypropylene polymer having a higher melting point than the sheath component. To
The long-fiber nonwoven fabric is embossed, 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 polyethylene-based polymer forms a sheath component as described above, and the polypropylene-based polymer and the polypropylene-based polymer melted such that the polypropylene-based polymer forms a core component. 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, the pulling of the fiber yarn by air soccer is desirably performed at a spinning speed as high as possible within a range in which yarn breakage does not occur, specifically, about 2000 m / min or more. 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. In other words, to achieve a high spinning speed,
It is preferable from the viewpoint of productivity, and is also preferable from the viewpoint of increasing the degree of crystal orientation of the fiber. In addition, heat resistance and dimensional stability are improved because the heat shrinkage property is reduced. Further, the strength of the nonwoven fabric is increased because the strength of the fiber itself is maintained. On the other hand, if the spinning speed is lower than about 2000 m / min, the dimensional stability of the nonwoven fabric is reduced, and a rough feeling is generated, which is not so good.

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 processing 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 a heat sealer may be used for heat sealing in a bag shape. 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 an ultrasonic wave 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 softens, 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.

It should be noted that the packaging material according to the present invention may contain a small amount of other fibers or short fibers other than the core-sheath composite fibers.

[0042]

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 endothermic curve was defined as the melting point.

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

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

(4) Thermal loss of polymer: Using a thermogravimeter (model number TGA-7) manufactured by PerkinElmer, at a heating rate of 20 ° C./min, the temperature reached 230 ° C. in the air. It is a heat loss rate in an atmosphere after 10 minutes while maintaining the temperature.

(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 CD direction of the nonwoven fabric, using a constant-speed elongation type tensile tester (Tensilon UTM-4-1-100 manufactured by Toyo Baldwin Co., Ltd.), the gripping interval of the sample was 10 cm, and the tensile speed was 10 cm / Extended in minutes.
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, and 9
Immersion in hot water at 8 ° C. for 10 minutes at a bath ratio of 1: 100, followed by further washing with pure water, dehydration, and determination of the elution rate (%) of hot water-soluble components when dried at 60 ° C. for 1 hour. Was.

(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 an ordinary heat sealing machine, 50 packaging materials were prepared under appropriate temperature conditions, and the bag-making properties were examined and judged as follows. ◎ There was no problem at all and it was good.

○ Generally good. △ It was a little problem. X: defective.

(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.

A: There was no problem at all and it was good. ○ Generally good. △ It was a little problem.

× Bad.

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-1238E of 20 g / 10 min and a loss on heat of the polymer at 230 ° C. of 2.0% was used. The core component has a melting point of 162 ° C. and a melt flow rate measured by ASTM D-1238L of 3%.
A polypropylene having 0 g / 10 min and a heat loss rate of the polymer at 230 ° C. of 1.6% was used. The polyethylene constituting the sheath component and the polypropylene constituting the core component include 1,3,5-
500 ppm of tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanuric acid, hydrotalcite compound 300 as an inorganic neutralizing agent
ppm was blended in the same amount.

The polyethylene melts at 220 ° C.
The polypropylene is melted at 230 ° C. and individually melted and weighed so as to have a weight ratio of 1: 1. Using a core-sheath type composite spinning die device having a round die hole, a single hole discharge amount is 1.0 g.
The melt spinning was performed at a temperature of 230 ° C./min.

The yarn spun from the core-sheath type composite spinneret is pulled by an 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.
With a hot embossing machine consisting of a 7 mm ² engraving roll and a flat roll, point press bonding was performed at a working temperature of 123 ° C. and a linear pressure between the rolls of 40 kg / cm, and the basis weight was about 20 g / m.
^Two long fiber nonwoven fabrics were produced.

The obtained long-fiber nonwoven fabric was heat-sealed at a temperature of 135 ° C. using a heat-sealing machine 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.

[0060]

[Table 1]

Example 2 When forming a core-sheath type long fiber constituting a composite long-fiber nonwoven fabric, a melting point was 126 ° C. and a density was 0.938 g as a sheath component.
/ Cm ^3, ASTM polymer thermal weight loss of at 230 ° C. The melt index value measured by D-1238E is at 26 g / 10 min was used 2.2% of the linear low density polyethylene. A phenolic additive and an inorganic neutralizing agent were blended into the linear low-density polyethylene constituting the sheath component in the same manner as in Example 1, and melted at 210 ° 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 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 at a temperature of 130 ° C. using a heat-sealing machine, and a tea bag-type packaging material and coffee in which Brazilian coffee powder was sealed in the packaging material in the same manner as in Example 1. 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 the core-sheath type long fiber constituting the composite long-fiber nonwoven fabric, the sheath component had a melting point of 125 ° C. and a density of 0.936 g.
A linear low-density polyethylene having a melt index value of 43 g / 10 min./cm ³ , measured by ASTM D-1238E, and a loss on heat of the polymer at 230 ° C. of 3.2% was used. 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. The core component has a melting point of 16%.
At 2 ° C, the density is 0.918 g / cm ³ , ASTM D-
Melt flow rate value measured at 1238L is 50g
/ 10 min, the loss of heat of the polymer at 230 ° C. is 5.3.
% Commercial polypropylene was used. The linear low density polyethylene melted at 200 ° C and the polypropylene 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. The obtained long-fiber nonwoven fabric was heated at a temperature of 1 using a heat sealing machine.
A heat-sealing process was performed at 30 ° C. to produce a tea bag-type packaging material and a coffee bag in which Brazilian coffee powder was sealed in the packaging material in the same manner as in Example 1.

Table 1 shows the physical properties and the like 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 6.4%.

Otherwise, the core-sheath type long fiber was melt-spun in the same manner as in Example 1 to produce a long fiber web.
The obtained long-fiber nonwoven fabric was heated at a temperature of 1 using a heat sealing machine.
Heat sealing was performed at 35 ° C. to produce a tea bag-type packaging material and a coffee bag in which Brazilian coffee powder was sealed in the packaging material.

Table 1 shows the physical properties 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 as a neutralizing agent added to polyethylene constituting the sheath component and N having a melting point of 227 ° C.
N'-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 reduced by 4.8%. And

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.
The obtained long-fiber nonwoven fabric was heated at a temperature of 1 using a heat sealing machine.
Heat sealing was performed at 35 ° C. to produce a tea bag-type packaging material and a coffee bag in which Brazilian coffee powder was sealed in the packaging material.

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

Example 6 At the time of forming the core-sheath type long fiber constituting the composite long-fiber nonwoven fabric, the single-hole discharge rate was reduced to 0.9 g / min, and melt spinning was performed at a temperature of 230 ° C. Further, the drawing speed at the time of drawing the yarn spun from the core-sheath type composite spinneret by the air soccer through the cooling device is reduced, and the same single yarn fineness as that of Example 1, namely 3.0. I got what would be denier. The processing temperature during hot embossing was set to 120 ° C.

Otherwise, a long-fiber nonwoven fabric was prepared in the same manner as in Example 1, and the long-fiber nonwoven fabric was heat-sealed at a temperature of 135 ° C. using a heat-sealing machine to obtain a tea bag type packaging material. A coffee bag in which Brazilian coffee powder was enclosed in this packaging material was produced.

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

In each of Examples 1 to 3, a core-sheath composite long fiber having a polypropylene polymer as a core component and a sheath polymer of a polyethylene polymer having a lower melting point than the core 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. Further, since the elution rate HWD of the hot water-soluble component was 0.04% or less and the area shrinkage HWS was 8% or less, the low molecular weight component of the polyethylene polymer constituting the sheath component even when used as a coffee bag. Did not elute in hot water to give off-flavors, or the coffee bag shrank and the content of coffee powder leaked out, so that it could be suitably used as a coffee bag. In addition, since a phenolic additive having a melting point of 140 ° C. or higher and an inorganic neutralizing agent were added to the sheath component, there was no polymer deterioration during composite spinning or heat sealing, and the low molecular weight component Elution into hot water was eliminated, and the original aroma of Brazilian coffee comparable to coffee obtained by siphon extraction method was utilized, and a practical coffee bag with satisfactory taste and richness was obtained. Further, in Example 3, since commercially available polypropylene was used as the core component, although the heat loss rate of the core component was slightly increased, a material having good practicability as a packaging material was obtained as described above.

In Example 4, since the phenol-based additive having a low melting point was used, the dissolution rate due to thermal degradation of the sheath component was slightly increased, and the food used in hot water such as a tea bag for coffee or the like was used. Although the packaging material was somewhat inferior in flavor, there was no practical problem.

In Example 5, since the organic neutralizing agent was used in place of the inorganic neutralizing agent, the elution rate due to the thermal degradation of the sheath component was slightly increased. As in the cases of Nos. 1 to 3, good packaging materials were obtained.

In Example 6, since the long-fiber nonwoven fabric was manufactured at a reduced pulling speed, the physical properties of the long-fiber nonwoven fabric tended to slightly decrease in mechanical strength and slightly increased in heat shrinkage. There was no problem in the bag making property of the packaging material.
In addition, in terms of its practicality, it was improved to a good state by slightly extending the coffee extraction time.

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-1238E of 20 g / 10 min and a heat loss rate of the polymer at 230 ° C. of 8.4% was used.
In the polyethylene constituting the sheath component, tetrakis- [methylene-3- (3 ′,
5'-di-tert-butyl-4'-hydroxy-phenyl) -propionate] methane (melting point 120 ° C) 800
ppm and calcium stearate 300p as neutralizer
pm was melted at 220 ° 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 in which Brazilian coffee powder was enclosed. And were produced.

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

[0083]

[Table 2]

Comparative Example 2 Melting point: 126 ° C., density: 0.945 g / cm ³ , AST
Only polyethylene having a melt index value measured by D-1238E of M of 25 g / 10 minutes and a loss on heat of the polymer at 230 ° C. of 8.0% was used. N-octadecyl-3- (3 ', 5'-di-t-butyl4'-hydroxyphenyl) -propionate (melting point 52 ° C) 500 as a phenolic additive in the polyethylene.
ppm and calcium stearate 300p as neutralizer
pm. The polyethylene compounded with the additive is applied to a normal single-axis type melt spinning device that is not a core-sheath type spinneret, using a spinneret device having a round hole,
Melt spinning was performed at a single hole discharge rate of 1.0 g / min and a spinning temperature of 230 ° C. 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 in the same manner as in Example 1, a tea bag-type packaging material and coffee in which Brazilian coffee powder was sealed 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 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-1238E of 20 g / 10 min and a polymer weight loss at 230 ° C. of 9.0%.
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.

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 heat-sealed at a temperature of 135 ° C. using a heat-sealing machine to obtain a tea bag type packaging material. A coffee bag in which Brazilian coffee powder was enclosed in this packaging material was produced.

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-1238E of 20 g / 10 min and a heat loss rate of the polymer at 230 ° C. of 8.5% 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, 300 ppm of a hydrotalcite compound was blended.

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 heat-sealed at a temperature of 135 ° C. using a heat-sealing machine to form a tea bag type packaging material. A coffee bag in which Brazilian coffee powder was enclosed in a packaging material was produced.

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

Comparative Example 5 In forming the core-sheath type long fiber constituting the composite long-fiber nonwoven fabric, the single hole discharge amount was set to 0.9 g / min as in Example 6. Further, the pulling speed at the time of pulling the yarn spun from the core-sheath type composite spinning die device by air soccer through the cooling device is further lowered than in Example 6, and the single yarn fineness is 4.
A long-fiber web composed of 5 denier core-sheath type long fibers was obtained. The long fiber web was subjected to hot embossing at a processing temperature of 118 ° C.

Otherwise, a long-fiber nonwoven fabric was prepared in the same manner as in Example 1, and the long-fiber nonwoven fabric was heat-sealed at a temperature of 135 ° C. using a heat-sealing machine to form a tea bag type packaging material. A coffee bag in which Brazilian coffee powder was enclosed in a packaging material was produced.

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

Comparative Example 1 uses a core-sheath composite long fiber having a polypropylene polymer as a core component and a polyethylene polymer having a lower melting point than the core component as a sheath component. 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 consisting of a single component of polyethylene was used instead 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 flavor of Brazilian coffee was not used, and the taste changed to a bitter taste, resulting in poor practicality.

In Comparative Example 3, since the phenol-based additive was not blended, the polymer when melted was greatly deteriorated by heat, and had little effect on the physical properties of the long-fiber nonwoven fabric, but the dissolution rate was extremely high. It became completely unsuitable for use as a packaging material used in hot water like a coffee bag, and was inferior in practicality as in Comparative Examples 1 and 2.

In Comparative Example 4, since the phosphorus-based antioxidant was used instead of the phenolic additive, the melting point of the additive was high, but the heat loss 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 reduced.
Lowering the heat-sealing temperature did not cause much problem with the bag-making properties of the packaging material, but when used as a coffee bag, the nonwoven fabric shrinks and the time it takes to extract the coffee becomes longer, and the original coffee Due to the problem of light taste, it became inferior in practical use.

[0101]

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 It is possible to eliminate the elution of the low molecular weight component of the polyethylene polymer into the medium or into the solvent. Further, by setting the area shrinkage HWS of the composite long-fiber nonwoven fabric at the time of hot water treatment to be less than 8%, even when used as a packaging material in hot water, damage due to shrinkage and accompanying exposure of contents are eliminated. Therefore, even when used as a packaging material used in hot water, such as a tea bag type food packaging material such as coffee or tea, there is no peculiar smell peculiar to the polyethylene polymer, and damage due to shrinkage and Since there is no accompanying exposure of the contents, 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 by softening or melting 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.

Therefore, the packaging material of the present invention composed of the nonwoven fabric of a composite long fiber is not limited to the above-mentioned tea bag type food packaging material, but also a food packaging material such as a sushi bag or a so-called food such as shoes and 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 filament obtained by softening or melting a sheath component of a core-sheath type composite filament having a polypropylene polymer as a core component and a polyethylene polymer having a lower melting point 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 ≤ 8% ... The above-mentioned HWD is obtained by treating the long-fiber nonwoven fabric 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. A phenolic additive having a melting point of at least 140 ° C.
The packaging material comprising a composite long-fiber nonwoven fabric according to claim 1, further comprising a neutralizing agent. 3. A thermogravimeter (Model No. TGA-7) manufactured by Perkin Elmer Co., Ltd., which was heated at a heating rate of 20 ° C./min to 230 ° C.
The packaging material comprising a composite long-fiber nonwoven fabric according to claim 1 or 2, wherein the sheath component is a polyethylene-based polymer having a heat loss rate of 5% or less measured in an air atmosphere. 4. The strength of the nonwoven fabric is 5 kg / 5 cm in the vertical 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.