JP2006034683A - Soup stock bag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a soup stock bag with less dropping of fiber constituting a nonwoven fabric when used, excellently transparent for a user to confirm the content, and capable of reducing the leakage of the content and contributing to the preservation of the environment because of the easy disposal after the use. <P>SOLUTION: The soup stock bag is made of an aliphatic polyester long-fiber nonwoven fabric with 7-40 μm average fiber diameter, 7-70 g/m<SP>2</SP>basis weight, 50-80% transparency, and not more than 10 % by weight in powder leakage rate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a soup bag, and more particularly to a soup bag that has good transparency, can reduce leakage of contents, and contributes to environmental conservation by simple disposal after use.

For example, the soup bag extracts the extract of the contents by cooking bonito, tonkotsu, tongara, seaweed, vegetables, beef bones, etc. It is a bag that contains the contents used in manufacturing.
The soup bag has advantages such as ease of processing after the soup is taken out and ash juice is confined in the bag and is not easily taken out.
Conventionally, as a soup bag, a bag made of a woven or knitted fabric of a synthetic fiber such as polypropylene fiber, nylon fiber, ester fiber or the like, a polyester-type or polyolefin-based binder fiber so as not to be broken even if it is mainly made of pulp, or Bags made of paper bonded with adhesive have been used.

Such bags made of synthetic fibers and bags made of paper bonded with binder fibers or adhesives have been discharged as garbage after being used for extraction, and have been incinerated or landfilled.
However, incineration requires wet energy because it is in a wet state, and even if it is landfilled, synthetic fibers, binder fibers and adhesives remain in the ground without being decomposed. There was a problem that contributed.
In order to solve this problem, it has been disclosed to use a nonwoven fabric fused with a biodegradable aliphatic polyester heat-bonded short fiber as a filter bag for beverages (see, for example, Patent Document 1). .

According to this method, since the beverage filter bag is entirely composed of biodegradable short fibers, it can be finally returned to carbon dioxide and water by composting or landfill after use. However, since the short fibers are used, there are problems that the short fibers fall off due to friction or the like, or the short fibers are laminated, so that the contents and the state of the contents cannot be confirmed because of lack of transparency.
JP 2002-177148 A

  In the present invention, the fibers constituting the nonwoven fabric are less likely to drop out during use, the transparency is good, the contents can be confirmed, leakage of the contents can be reduced, and simple disposal after use can contribute to environmental conservation. An object is to provide a soup stock bag.

In order to solve the above problems, the present inventors use an aliphatic polyester long fiber nonwoven fabric as a packaging material for a soup bag, and combine a fiber diameter of a single yarn constituting the nonwoven fabric and a specific resin to shield a conventional nonwoven fabric. The present inventors have found that a non-woven fabric that is sufficiently excellent in transparency can be obtained without impairing the properties and good strength retention.
That is, the present invention is as follows.
(1) A soup bag comprising an aliphatic polyester long fiber nonwoven fabric having an average fiber diameter of 7 to 40 μm, a basis weight of 7 to 70 g / m ² , transparency of 50% to 80%, and a powder leakage rate of 10% by weight or less.
(2) The aliphatic polyester is a polymer of D-lactic acid, a polymer of L-lactic acid, a copolymer of D-lactic acid and L-lactic acid, a copolymer of D-lactic acid and hydroxycarboxylic acid, L -A polymer selected from a copolymer of lactic acid and hydroxycarboxylic acid and a copolymer of D-lactic acid, L-lactic acid and hydroxycarboxylic acid, or a blend of two or more selected from the above polymers ( The soup bag as described in 1).
(3) The soup bag according to (1) or (2), wherein the aliphatic polyester long fiber nonwoven fabric has a wet heat shrinkage of 10% or less.
(4) The soup bag according to any one of (1) to (3), wherein a partial thermocompression bonding rate of the aliphatic polyester long fiber nonwoven fabric is 5 to 30%.

  The soup bag of the present invention is less likely to drop off the fibers constituting the nonwoven fabric during use, has good transparency, can confirm the contents, can reduce the leakage of the contents, and can be easily discarded after use for environmental conservation. A soup bag that can be contributed can be provided.

  Examples of the aliphatic polyester fiber constituting the long fiber nonwoven fabric used in the soup bag of the present invention include the following thermoplastic resins. For example, poly (α-hydroxy acid) such as polyglycolic acid or polylactic acid or a copolymer containing these as main repeating unit elements can be mentioned. In addition, poly (ω-hydroxyalkanoate) such as poly (ε-caprolactone) and poly (β-propiolactone) may further include poly-3-hydroxypropionate, poly-3-hydroxybutyrate, Poly (β-polyhydroxyalkanoates) such as poly-3-hydroxycaprolate, poly-3-hydroxyheptanoate, poly-3-hydroxyoctanoate, and repeating unit elements constituting them and poly- Examples thereof include copolymers with repeating unit elements constituting 3-hydroxyvalerate or poly-4-hydroxybutyrate. Examples of polyalkylene dicarboxylates comprising a condensation polymer of glycol and dicarboxylic acid include, for example, polyethylene oxalate, polyethylene succinate, polyethylene adipate, polyethylene azelate, polybutylene oxalate, polybutylene succinate, and polybutylene adipate. , Polybutylene sebacate, polyhexamethylene sebacate, polyneopentyl oxalate, or a polyalkylene dicarboxylate copolymer having repeating unit elements constituting them. Furthermore, it is also possible to select a plurality of polymers having biodegradability here and blend them together.

  In the present invention, polylactic acid-based polymers can be particularly preferably used from the viewpoints of biodegradability, spinnability, transparency, practicality, and the like. Examples of the polylactic acid-based polymer include poly (D-lactic acid), poly (L-lactic acid), a copolymer of D-lactic acid and L-lactic acid, a copolymer of D-lactic acid and hydroxycarboxylic acid, L- A polymer selected from a copolymer of lactic acid and hydroxycarboxylic acid and a copolymer of D-lactic acid, L-lactic acid and hydroxycarboxylic acid, or a blend thereof, is preferred. A polymer having a temperature not lower than ° C. can be suitably used. Here, as the hydroxycarboxylic acid in the case of a copolymer of lactic acid and hydroxycarboxylic acid, glycolic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxypentanoic acid, hydroxycaproic acid, hydroxyheptanoic acid, hydroxyoctanoic acid, etc. Can be mentioned. Of these, glycolic acid and hydroxycaproic acid are preferred.

The molecular weight of the polylactic acid polymer is not particularly limited, but if the molecular weight is lowered, spinning becomes difficult, or even if spinning is possible, the strength of the obtained fiber is lowered. Further, when the molecular weight is increased, the processability is lowered and spinning tends to be difficult. Considering these points, a preferable weight average molecular weight is selected from the range of 10,000 to 1,000,000. A weight average molecular weight range of 30,000 to 500,000 is particularly preferred. In order to increase the degree of polymerization, the chain may be extended with a small amount of diisocyanate or tetracarboxylic dianhydride.
A crystal nucleating agent may be added to the polylactic acid polymer. Examples of the crystal nucleating agent include talc, titanium oxide, boron nitride, calcium carbonate, magnesium carbonate, and carbon. When such a crystal nucleating agent is added, crystallization of the polylactic acid polymer is promoted, and heat resistance and mechanical strength are improved. Further, when spinning a polylactic acid polymer, it is possible to prevent fusion (blocking) between yarns in the spinning / cooling step.

  For the above reasons, the crystallinity of the polylactic acid-based long fibers is preferably in the range of 10% to 40%. In order to achieve a crystallinity in this range, the amount of the crystal nucleating agent added to the polylactic acid polymer is 0.1 wt% to 3.0 wt%, more preferably 0.5 wt% to 2. wt%. 0% by weight. The crystallinity referred to here is obtained by obtaining a powdered long fiber (nonwoven fabric) by a Roland method using a wide-angle X-ray diffraction pattern. When the crystallinity of the fiber is less than 10%, the effect of improving heat resistance and mechanical strength is small. When the degree of crystallinity exceeds 40%, not only the flexibility as a fiber is poor and the spinnability is inferior, but also the decomposition rate during the composting process may be remarkably slow.

  In addition to the crystal nucleating agent, the polylactic acid-based polymer is easily plasticized by a plasticizer, so that a plasticizer may be contained in order to obtain an appropriate texture and flexibility. As plasticizers, phthalic acid derivatives such as di-n-octyl phthalate, di-2-ethylhexyl phthalate, dibenzine phthalate, diisodecyl phthalate, ditridecyl phthalate, diundecyl phthalate, isophthalic acid derivatives such as diisooctyl phthalate, di -Adipic acid derivatives such as n-butyl adipate and dioctyl adipate, maleic derivatives such as di-n-butyl malate, citric acid derivatives such as tri-n-butyl citrate, itaconic acid derivatives such as monobutyl itaconate, butyl oleate, etc. Oleic acid derivatives, ricinoleic acid derivatives such as glycerin monolysylate, low molecular weight compounds such as phosphate esters such as tricresyl phosphate and trixylenyl phosphate, and acetic acid derivatives such as triacetin (glycerin triacetate) Body, the degree of polymerization from 2 to 10 approximately lactic acid oligomer, polyethylene adipate, polymeric plasticizers such as polyacrylates and the like. Among the plasticizers, preferable plasticizers include triacetin and lactic acid oligomers having a polymerization degree of 2 to 10. The plasticizer content is preferably 1% to 35% by weight, more preferably 5% to 15% by weight, based on the polylactic acid polymer.

The fiber form of the aliphatic polyester used in the soup bag of the present invention is not particularly limited, and the aliphatic polyester may be used alone or may be a composite fiber using two or more aliphatic polyesters. . In addition to the usual round cross section, the cross-sectional shape of the fiber can be a hollow cross section, a modified cross section, a parallel composite cross section, a multilayer composite cross section, a core-sheath composite cross section, a split composite cross section, etc. Any fiber cross-sectional shape can be selected accordingly.
Long-fiber nonwoven fabric used for the soup bag of the present invention, basis weight is ^{7g / m 2 ~70g / m 2} , preferably ^{12g / m 2 ~50g / m 2} , more preferably ^15g / m 2 ^~35g / a m ^2. When the basis weight is in the above range, the transparency is excellent, the inter-fiber gap is moderate, and the powder leakage and strength retention are excellent.

Since the long fiber nonwoven fabric used for the soup bag of the present invention may contaminate fingers and the like due to leakage of the contents, the powder leakage rate is 10% by weight or less, preferably 7.5% by weight or less, more preferably 5.0%. % By weight or less.
The average apparent density of the long-fiber nonwoven fabric used for the soup bag of the present invention, transparency, powder leakage resistance, the balance of the strength retention 0.05 g / cm ³ or more and 0.25 g / cm ³ or less. ^Preferably, a ^{0.08g / cm 3 ~0.20g / cm 3} . The average apparent density is related to the texture, hardness, and transparency of the long-fiber nonwoven fabric. When the average apparent density is within this range, the transparency is excellent as well as the powder leakage and strength retention.

The long fiber nonwoven fabric used for the soup bag of the present invention has an average fiber diameter of 7 μm or more from the viewpoint of transparency and spinnability, and is 40 μm or less, preferably 10 μm to 37 μm from the balance of transparency, leakage, and strength. More preferably, it is 12 micrometers-35 micrometers.
The transparency of the long-fiber nonwoven fabric used in the soup bag of the present invention is 50% or more from the viewpoint of design by film printing, 80% or less from the viewpoint of strength retention and powder leakage, and preferably 55% to 80%. More preferably, it is 60% to 80%.

In addition, the transparency of the long-fiber nonwoven fabric referred to in the present invention refers to that measured by the following method.
CIE L * a * b * (1976) from an average value measured five times using a C light source with a standard color management system Macbeth CE-3000 manufactured by Sakata Inx Engineering Co., Ltd., including 2 ° visual field, specular gloss, and ultraviolet region of the light source. ) Use the L * value calculated by the color difference formula.
A white board with L * w0 value = 93 ± 2 and a blackboard with L * b0 value = 20 ± 2 are used.
The above-mentioned white plate is placed behind the sample and the L * w value is measured. Next, the L * b value is measured by placing the above blackboard behind the sample. Transparency is given by:
Transparency (%) = ΔL * / ΔL * 0 × 100
ΔL * 0 = L * w0−L * b0
ΔL * = L * w−L * b
In addition, when measuring transparency from a soup bag, if the content is contained, it measures in the state which took out the content completely. Moreover, the process which removes the influence of the coloring by a content, for example, water washing etc., is implemented, and it measures in the state dried at low temperature so that a structural change does not occur.

The long fiber nonwoven fabric used for the soup bag of the present invention has a wet heat shrinkage of 10% or less, preferably 8% or less, more preferably 5% or less, due to shrinkage due to thermoforming. Thereby, even in the usage form exposed to a high temperature environment close to 100 ° C., the form retainability is excellent.
The form of the long-fiber nonwoven fabric used in the soup bag of the present invention is one in which the constituent fibers are entangled and integrated by hydroentanglement treatment, etc., and the fiber intersection is heat-fused and integrated by hot air treatment etc. Moreover, the nonwoven fabric etc. which are integrated by having a partial thermocompression bonding part by a partial thermocompression-bonding process are mentioned. Among these, a non-woven fabric that is partially thermocompression-bonded and maintains its form as a non-woven fabric is preferred from the viewpoint of strength. The partially heat-bonded non-woven fabric is bonded only in the point-like fused area, and thus has both flexibility and form retention, and becomes a non-woven fabric that is soft and hardly fluffs. Here, the partial thermocompression bonding refers to forming a spot-like fusion zone by embossing or ultrasonic fusion treatment, and specifically, a heated embossing roll and a roll having a smooth surface. There are a method of forming a dot fusion zone between fibers through a web in between, a method of forming a dot fusion zone between fibers of a pattern portion by applying a high frequency by ultrasonic waves on a pattern roll, and the like.

Below, the representative example of the manufacturing method of the long-fiber nonwoven fabric used for the soup bag of this invention is demonstrated.
The long fiber nonwoven fabric used for the soup bag of the present invention can be efficiently produced by a so-called spunbond method. That is, the above-described polylactic acid polymer is heated and melted and discharged from a spinneret, and the obtained spun yarn is cooled using a conventionally known cooling device, and then pulled by a suction device such as an air soccer. Refine. Subsequently, the yarn group discharged from the suction device is opened and then deposited on a moving deposition device such as a conveyor made of a screen to form a web. Next, the web formed on the moving deposition apparatus is partially subjected to thermocompression bonding using a partial thermocompression bonding apparatus such as a heated embossing roll or an ultrasonic fusing apparatus, whereby a long fiber spunbond nonwoven fabric is obtained. Obtainable. The spun yarn is preferably drawn and thinned at a high speed of 3500 m / min or more from the viewpoint of mechanical properties and wet heat shrinkage of the long fiber nonwoven fabric and 6000 m / min or less from the viewpoint of preventing yarn breakage.

  When the long fiber nonwoven fabric used for the soup bag of the present invention is partially thermocompression bonded, the fiber gap constituting the long fiber nonwoven fabric can be reduced, which is effective in transparency, powder leakage, and strength retention. In the partial thermocompression bonding, a fused portion is formed that is uniformly dispersed throughout the nonwoven fabric by the above method. The partial thermocompression bonding rate is expressed by the area ratio of the thermocompression bonding part with respect to the entire long-fiber non-woven fabric. The partial thermocompression bonding rate is 5% or more from the viewpoint of transparency, powder leakage property, and strength. From the viewpoint of embrittlement, it is 30% or less, preferably 10% to 28%, more preferably 14% to 25%. An important point in the production of the long-fiber nonwoven fabric used in the soup bag of the present invention is to satisfy the specified partial thermocompression bonding rate, and the shape of the so-called dotted fused area is not limited at all.

The hydrophilicity of the long-fiber nonwoven fabric used for the soup bag of the present invention is less than 10 seconds, preferably less than 7 seconds, more preferably less than 5 seconds, from the point of familiarity with hot water. The hydrophilicity measuring method is as described later.
In order to impart hydrophilicity, a hydrophilic agent may be applied to the nonwoven fabric. For example, by applying a hydrophilic agent to 0.05 wt% or more from the point of familiarity with hot water and 5.0 wt% or less, preferably 0.1 to 3.0 wt% from the viewpoint of elution problems of the hydrophilic agent, It can be less than 10 seconds.
Examples of the hydrophilic agent include surfactants used for foods, for example, aqueous solutions such as sorbitan fatty acid ester, polyglycerin fatty acid ester, sucrose fatty acid ester, ethyl alcohol solution, or a mixed solution of ethyl alcohol and water. These may be applied to the nonwoven fabric by a gravure roll method, a kiss roll method, a dipping method, a spray method, or the like.

The long fiber nonwoven fabric used for the soup bag of the present invention has a maximum pore diameter of preferably 200 to 2000 μm, more preferably 400 to 1600 μm, and still more preferably 600 to 1200 μm. When the maximum pore diameter is within this range, the fiber gap constituting the nonwoven fabric is moderate, excellent in transparency, and the powder leakage rate is small. The measuring method of the maximum pore diameter is as described later.
The shape of the soup bag of the present invention is not particularly limited as long as the contents can be charged and the contents can be sealed. As the shape of the soup bag of the present invention, for example, as a flat bag, a rectangular non-woven fabric of the present invention is folded in half and both sides perpendicular to the crease are heat-sealed into a bag shape, or two non-woven fabrics of the present invention It is preferable that the three sides are heat sealed and formed into a bag shape because the contents can be easily charged. In addition, for example, a three-dimensional shape is preferable because the contents can be seen better when placed in hot water, and the familiarity with hot water can be obtained quickly and extraction can be performed effectively. As the three-dimensional shape, a so-called tetrapack having a tetrahedral shape (for example, a triangular pyramid three-dimensional shape) can be cited as a preferable example.

The method for heat-sealing the soup bag into a flat bag or a three-dimensional bag shape is not particularly limited. For example, a bag making machine such as a welding seal, a fusing seal, an ultrasonic seal or an impulse seal is used. Can do.
The soup bag of the present invention is sealed after the contents are charged, but the sealing method may be heat sealing, or may be tied with a string or tape. In addition, when tying up with a string, a tape, etc., it is preferable that a string, a tape, etc. are also biodegradable materials. Examples of biodegradable materials include cellulosic materials and polylactic acid.

The present invention will be described based on examples.
The measurement method and the evaluation method are as follows.
(1) Weight per unit area (g / m ² )
Three test pieces each having a length of 20 cm and a width of 25 cm are sampled per 1 m width of the sample by the method prescribed in JIS L-1906, the weight is measured, and the average value is obtained by converting the mass per unit area.
(2) Thickness The thickness of a load of 10 kPa is measured by the method specified in JIS L-1906. The average apparent density (g / cm ³ ) is calculated from the basis weight and thickness by the following formula.
Average apparent density (g / cm ³ ) = (weight per unit area g / m ² ) / ((thickness mm) × 1000)
(3) Average fiber diameter (μm)
Samples of 1 cm square were sampled and photographs were taken with an electron microscope, 20 single yarn fiber diameters were measured from each photograph, and the average fiber diameter was calculated from the total average value. Here, the average fiber diameter means the diameter of the single yarn fiber in the case of a perfect circle single yarn fiber, and in the case of an irregular cross-section fiber, the single yarn in the case of a perfect circle from the cross-sectional area of the single yarn fiber cross section The value is converted to the fiber diameter.

(4) Transparency (%)
Measure by the method described above.
(5) Wet heat shrinkage (%)
Using a method specified in JIS L-1906, three test pieces of 25 cm in length and 25 cm in width are sampled per 1 m width of the sample, immersed in boiling water for 3 minutes, and after natural drying, the vertical and horizontal shrinkage rates are obtained. The average value of each is calculated, and the larger one of the vertical and horizontal shrinkage is defined as the wet heat shrinkage of the nonwoven fabric.
(6) Partial thermocompression rate (%)
A 1 cm square test piece was sampled and photographed with an electron microscope. The area of the thermocompression bonding part was measured from each of the 20 photographs, and the total average value was taken as the area of the thermocompression bonding part. The ratio of the thermocompression bonding area per unit area of the nonwoven fabric was calculated as the partial thermocompression bonding rate.

(7) Powder leakage rate (%)
Using metal powder CR53 (manufactured by Taiheiyo Metal Co., Ltd.) divided into particles of 650/300 μm with a 25/50 mesh filter, a mass (W1: 2 g) of metal powder was placed on a nonwoven fabric stretched on a 10 cm square sieve. Then, it was vibrated at 60 rpm for 5 minutes at 3 cm width on a vibrator, and the mass (W2) of the metal powder that passed through the nonwoven fabric was measured to determine the powder leakage rate.
Powder leakage rate (%) = (W2 / W1) × 100
When the powder leakage rate is low, the shielding properties and retention of the nonwoven fabric are improved.
(8) Composting test Using a composting tester, the state of the sample piece after 4 weeks was visually observed under a constant environment at 60 ° C.
○: The sample piece was broken into small pieces ×: No change in the appearance of the sample was observed

(9) Maximum hole diameter A circular sample having a diameter of 40 mm was used according to JIS-K-3832 (bubble point method).
(I) Fill the sample with a liquid (toluene) and use capillary action to bring the liquid into all the pores of the sample.
(Ii) Air pressure is gradually applied from the lower surface of the sample, and bubbles are generated when the pressure overcomes the liquid surface tension in the capillary tube.
(Iii) At this time, bubbles appear first from the maximum pore diameter, and the maximum pore diameter was calculated by measuring the pressure at that time.

(10) Qualitative measurement evaluation of fallen fibers After washing a container of pure water containing a sample with an ultrasonic washing machine, the pure water is filtered, and sensory judgment is made on the amount of fibers remaining on the filter paper. The evaluation methods and judgment levels are as follows.
Evaluation method: A sample 25 cm * 25 cm is prepared and placed in a 500 ml beaker containing 300 ml of pure water. Place water in the BRANSON B2210 ultrasonic cleaner to operating level and a 500 ml beaker with sample. After washing with an ultrasonic cleaner for 15 minutes, filter with black filter paper (ADVANTEC NO131). Put it in a constant temperature room (20 ° C * 65%) for 12 hours and let it dry.
Judgment level ○: There is almost no lint on the black filter paper. △: Remaining lint on the black filter paper is conspicuous. ×: Remaining lint so that the color of the black filter paper disappears.

[Example 1]
Using a 65 mm extruder, a polylactic acid (copolymerization ratio (molar ratio) of D-form / L-form = 1.3 / 98.7) thermoplastic resin is melted at a melting point of 170 ° C. and an MFR value of 10 g / 10 min. Extruded at a temperature of 215 ° C, spun filaments using a 1540-hole spinneret, pulled using a high-speed airflow traction device, and received on a wire mesh web conveyor with a moving suction device. Formed. The MFR value was measured in accordance with “Thermal Plastic Flow Test Method” JIS K-7210 (test temperature 190 ° C., test load 21.18 N) to obtain MFR.

The obtained web was transported and partially thermocompression bonded at a pressure of 50 kg / cm with a thermocompression roll combining an engraving roll and a smooth roll to obtain a long fiber spunbond nonwoven fabric.
The evaluation results of the obtained long fiber nonwoven fabric are shown in Table 1. As can be seen from the table, the obtained long fiber nonwoven fabric had good transparency, good powder leakage, and a small environmental load.
Two sheets of the obtained long fiber nonwoven fabric were stacked and heat-sealed in three directions to obtain an 18cm x 30cm soup bag. Boiled koji was put into the obtained soup bag, the opening of the bag was heat-sealed and then boiled in 2 L of hot water for 60 minutes, and the condition of the soup stock and the degree of omission of fine koji knot were confirmed.
The resulting soup bag had a good view of the bonito inside, the condition of the soup stock was good, there was little dropout of the bonito, and the environmental load was low.

[Example 2]
A long fiber spunbonded nonwoven fabric was obtained under the same conditions as in Example 1 except that the amount of polymer discharged from the spinneret was increased and the speed of the web conveyor was slightly reduced.
The evaluation results of the obtained long fiber nonwoven fabric are shown in Table 1. As can be seen from the table, the obtained long fiber nonwoven fabric had good transparency, good powder leakage, and a small environmental load.
A soup bag was obtained in the same manner as in Example 1, and the same confirmation was performed.
The resulting soup bag had a good view of the bonito inside, the condition of the soup stock was good, there was little dropout of the bonito, and the environmental load was low.

[Example 3]
A long fiber spunbonded nonwoven fabric was obtained under the same conditions as in Example 1 except that the amount of polymer discharged from the spinneret was increased and the speed of the web conveyor was slightly reduced.
The evaluation results of the obtained long fiber nonwoven fabric are shown in Table 1. As can be seen from the table, the obtained long fiber nonwoven fabric had good transparency, good powder leakage, and a small environmental load.
A soup bag was obtained in the same manner as in Example 1, and the same confirmation was performed. The resulting soup bag had a good view of the bonito inside, the condition of the soup stock was good, there was little dropout of the bonito, and the environmental load was low.

[Comparative Example 1]
A long fiber spunbonded nonwoven fabric was obtained under the same conditions as in Example 1, except that the amount of polymer discharged from the spinneret was reduced and the speed of the web conveyor was decreased.
The evaluation results of the obtained long fiber nonwoven fabric are shown in Table 1. As can be seen from the table, the obtained long-fiber non-woven fabric had good powder leakage and low environmental load, but was inferior in transparency.
A soup bag was obtained in the same manner as in Example 1, and the same confirmation was performed.
Although the obtained soup bag had few dropouts of fine bonito and the environmental load was low, the bonito in the soup bag could not be seen well, and the state of the soup stock was not as good as in the examples.

[Comparative Example 2]
A long fiber spunbonded nonwoven fabric was obtained under the same conditions as in Example 1, except that the amount of polymer discharged from the spinneret was increased and the speed of the web conveyor was decreased.
The evaluation results of the obtained long fiber nonwoven fabric are shown in Table 1. As can be seen from the table, the obtained long-fiber nonwoven fabric had good transparency and a small environmental load, but was inferior in powder leakage.
A soup bag was obtained in the same manner as in Example 1, and the same confirmation was performed.
The resulting soup bag showed good bonito inside, the soup stock was good, and the environmental load was low, but there were many drops of fine bonito.

[Comparative Example 3]
Using a 65 mm extruder, a polyethylene terephthalate thermoplastic resin having a melting point of 256 ° C. and [η] = 0.71 was extruded at an extrusion temperature of 300 ° C., and a filament group was spun using a 1540 hole spinneret. This was pulled using a high-speed airflow traction device, and received on a wire mesh web conveyor with a moving suction device to create a web. [Η] is the intrinsic viscosity, and the intrinsic viscosity [η] is a value obtained based on the following definition formula.
[η] = lim (ηr−1)
C → 0
In the formula, ηr is a value obtained by dividing the viscosity at 35 ° C. of a polyethylene terephthalate solution dissolved in o-chlorophenol having a purity of 98% or more by the viscosity of the solvent itself measured at the same temperature, as a relative viscosity. Is defined. C is the mass value of the solute in units of grams in 100 ml of the above solution.

The obtained web was conveyed, and was subjected to partial thermocompression bonding at a pressure of 50 kg / cm with a thermocompression bonding roll in which an engraving roll and a smooth roll were combined to obtain a long fiber spunbonded nonwoven fabric.
The evaluation results of the obtained long fiber nonwoven fabric are shown in Table 1. As can be seen from the table, the obtained long fiber nonwoven fabric had good transparency and good powder leakage, but had a problem in environmental load.
A soup bag was obtained in the same manner as in Example 1, and the same confirmation was performed.
The resulting soup bag had a good view of the bonito inside, the condition of the soup stock was good, and there was little dropout of the bonito, but there was a problem with the environmental load.

[Comparative Example 4]
Polylactic acid composite short fibers were obtained by the method described in Example 1 of JP-A-2002-177148. The obtained composite short fiber and rayon short fiber 5.6 dtex were mixed to a fiber length of 51 mm by 50%, and then a web was formed. Subsequently, thermocompression treatment was performed to obtain a short fiber nonwoven fabric having a basis weight of 45 g / m ² .
The evaluation results of the obtained short fiber nonwoven fabric are shown in Table 1. As can be seen from the table, the obtained short fiber nonwoven fabric had good powder leakage and environmental load, but lacked transparency and had fiber falling off.
A soup bag was obtained in the same manner as in Example 1, and the same confirmation was performed.
The obtained soup bag had little dropout of bonito and low environmental impact, but lacked transparency, and the soup stock was slightly inferior to the examples.

  The soup bag of the present invention is less likely to drop off the fibers constituting the nonwoven fabric during use, has good transparency, can confirm the contents, can reduce the leakage of the contents, and can be easily discarded after use for environmental conservation. And can be used suitably for a soup stock bag.

Claims (4)

A soup bag comprising an aliphatic polyester long fiber nonwoven fabric having an average fiber diameter of 7 to 40 μm, a basis weight of 7 to 70 g / m ² , transparency of 50% to 80% and a powder leakage rate of 10% by weight or less.   The aliphatic polyester is a polymer of D-lactic acid, a polymer of L-lactic acid, a copolymer of D-lactic acid and L-lactic acid, a copolymer of D-lactic acid and hydroxycarboxylic acid, and L-lactic acid. 2. A polymer selected from a copolymer of hydroxycarboxylic acid and a copolymer of D-lactic acid, L-lactic acid and hydroxycarboxylic acid, or a blend of two or more selected from the polymers. The soup bag described.   The soup bag according to claim 1 or 2, wherein the aliphatic polyester long fiber nonwoven fabric has a wet heat shrinkage of 10% or less.   The soup bag according to any one of claims 1 to 3, wherein the aliphatic polyester continuous fiber nonwoven fabric has a partial thermocompression bonding rate of 5 to 30%.