JP6976092B2 - Multifilament for tasteful beverage extraction filter - Google Patents

Description

The present invention relates to a multifilament for a palatable beverage extraction filter.

Conventionally, paper, polypropylene, or polyethylene non-woven fabric has been mainly used as the material for the tasteful beverage extraction filter, but the transparency is poor and the tea leaves in the packaging material are difficult to see, and the paper is heat-sealed. There is a problem such as not being able to do it. Therefore, as a trend in recent years, the number of high-quality woven beverage extraction bags in which tea leaves in the beverage extraction bag can be seen is increasing.

Polyamide fiber is the mainstream as the material fiber of the tasteful beverage extraction filter used for the tasteful beverage extraction bag made of woven fabric. The extraction filter made of a woven fabric using a polyamide fiber has excellent morphological retention of a three-dimensional shape and also has abundant elastic recovery power against deformation, so that the woven fabric is soft and has an excellent texture. However, the extraction bag made of polyamide fiber is yellowed due to the influence of oxygen in the air, the size of the extraction bag changes due to the swelling of the polyamide fiber in boiling water, and the liquid runs out when the bag after extraction is taken out of the container. Problems such as poor sedimentation of the extraction bag in boiling water due to the light specific gravity of polyamide and environmental pollution due to the generation of nitrogen oxides due to incineration after use have been pointed out for some time.

For the purpose of improving such a problem of polyamide fiber, a tasteful beverage extraction filter using polyester fiber and the like have been studied. For example, Patent Document 1 proposes a method for producing a palatable beverage extraction filter made of a woven fabric using a polyester fiber having a core-sheath structure in which a core and a sheath have a melting point difference. Further, Patent Document 2 proposes a polyester monofilament for a tasteful beverage extraction filter made of a copolymerized polyester containing isophthalic acid or the like as a copolymerization component, a multifilament for fiber division which can be formed, and a tasteful beverage extraction filter obtained from the polyester monofilament. There is.

Japanese Patent No. 3459951 Japanese Unexamined Patent Publication No. 2008-45244

However, in Patent Documents 1 and 2, when used as a woven fabric for a tasteful beverage extraction filter, monofilaments are woven, heat-set, and misaligned to prevent misalignment, and are used as filters. It is also excellent in moldability, but in recent years, there has been a demand for a product that is cheaper and has excellent extractability.
The present invention has been made in view of the above background, and an object of the present invention is to provide a filament for obtaining a tasteful beverage extraction filter having excellent moldability, lower cost, and better extractability.

The present invention solves the above-mentioned problems, and the gist of the present invention is as follows.
(1) The core component is a homopolyester having a melting point of 220 ° C. or higher, and the sheath component is a copolymerized polyester containing terephthalic acid and a diol having a melting point lower than that of the core component by 40 ° C. or higher. Sheath type composite multifilament.
(2) The core-sheath type composite multifilament for a palatable beverage extraction filter according to (1), which comprises 2 to 5 filaments.
(3) The core-sheath type composite for a palatable beverage extraction filter according to (1) or (2), wherein the mass change rate after immersion in an aqueous ethanol solution having a concentration of 10% by mass for 1 hour is 4% or less. Multifilament.
(4) The core-sheath type composite multifilament for a palatable beverage extraction filter according to any one of (1) to (3), wherein the amount of heavy metal eluted is less than 0.1 ppm.
(5) The multifilament for a tasteful beverage extraction filter according to any one of (1) to (4), wherein the catalyst for polycondensation of the copolymerized polyester of the sheath component is a titanium-based catalyst.
(6) The multifilament for a tasteful beverage extraction filter according to any one of (1) to (5), wherein the catalyst for polycondensation of the core component homopolyester is a titanium-based catalyst.
(7) A woven fabric for a palatable beverage extraction filter using the multifilaments of (1) to (6).
(8) The core component of the warp is a homopolyester having a melting point of 220 ° C. or higher, and the sheath component is a core-sheath type monofilament made of a copolymerized polyester containing terephthalic acid and a diol having a melting point lower than that of the core component by 40 ° C. or higher. A woven fabric for a palatability beverage extraction filter using the multifilaments (1) to (6) for the weft.

According to the present invention, there is provided a filament for a palatable beverage extraction filter, which has excellent moldability, is inexpensive, and has good extractability when used in a palatable beverage extraction filter. Further, by using the multifilament, it becomes easy to control the size of the opening which is effective with a small amount of thread used at the time of manufacturing the palatability beverage extraction filter.

The present invention is a core-sheath type composite multifilament for a palatable beverage extraction filter.

The core component of the core-sheath type composite multifilament for a palatable beverage extraction filter of the present invention is a homopolyester having a melting point of 220 ° C. or higher. Examples of the homopolyester include polyesters mainly composed of polyalkylene terephthalate such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT) and polytrimethylene terephthalate (PTT). When the melting point of the core component is less than 220 ° C., the strength retention rate of the woven core-sheath type composite multifilament tends to be low after the dry heat treatment. From the viewpoint of maintaining the strength retention of the filter woven fabric, the core component is preferably polyethylene terephthalate.

The intrinsic viscosity of the polyester as the core component is preferably in the range of 0.4 or more and 0.8 or less, and in particular, the range of 0.5 or more and 0.7 or less, particularly 0.55 or more and 0.65 or less. preferable. If the intrinsic viscosity is too small, the strength after knitting and knitting tends to be insufficient, and if the intrinsic viscosity is too large, the intrinsic viscosity of the raw material polymer needs to be excessively increased, which tends to increase the cost. The range is preferred.

From the viewpoint of environmental safety, the polymerization catalyst of the core component homopolyester is preferably a titanium-based catalyst.

Preferred examples of the titanium-based catalyst used as the polymerization catalyst include titanium acetate, tetraalkoxyside titanium, titanium halides, titanates, and titanium alkoxides.
For these, in order to further enhance the activity of the catalyst, a complex with a compound using magnesium can be preferably used. A particularly preferable example is a magnesium compound having a coating layer made of titanium acid. In the present invention, the magnesium compound on which the coating layer made of titanium acid is formed is a titanium compound at a temperature in the range of 5 to 100 ° C., preferably in the temperature range of 15 to 70 ° C. in the presence of the magnesium compound. By hydrolyzing the magnesium compound and precipitating titanium acid on the surface thereof, a coating layer made of titanium acid is provided on the surface of the magnesium compound.
The content of the titanium-based catalyst is preferably 10 to 500 ppm, more preferably 50 to 200 ppm with respect to the polyester resin.

The sheath component of the core-sheath type composite multifilament of the present invention is a copolymerized polyester containing terephthalic acid and diol having a melting point lower than that of the core component by 40 ° C. or more as main components. Specifically, a copolymerized polyester containing terephthalic acid and a diol such as ethylene glycol as main components is preferable. Preferred examples of the copolymerization component include isophthalic acid, adipic acid and sebacic acid. Of these, isophthalic acid is preferable in consideration of the ease of compounding the core-sheath structure and the ease of handling. In the present invention, in the case of an amorphous component in which a melting point peak does not occur, the softening point is defined as the melting point.

When the copolymerization component is isophthalic acid, the ratio of terephthalic acid to isophthalic acid is 90/10 to 10 in terms of molar ratio (terephthalic acid / isophthalic acid) because it is easy to heat-bond and has excellent handleability. The range is preferably 70/30.
The melting point of the sheath component can be controlled by adjusting the amount of the copolymerization component and the component thereof.

When the above-mentioned copolymerized polyester is used as the sheath component, it has a moderately lower melting point than the core component and is easily heat-bonded, so that it is preferable from the viewpoint of excellent moldability.

From the viewpoint of environmental safety, the polymerization catalyst of the copolymerized polyester of the sheath component is preferably a titanium-based catalyst.

Preferred examples of the titanium-based catalyst used as the polymerization catalyst include titanium acetate, tetraalkoxyside titanium, titanium halides, titanates, and titanium alkoxides.
For these, in order to further enhance the activity of the catalyst, a complex with a compound using magnesium can be preferably used. A particularly preferable example is a magnesium compound having a coating layer made of titanium acid. In the present invention, the magnesium compound on which the coating layer made of titanium acid is formed is a titanium compound at a temperature in the range of 5 to 100 ° C., preferably in the temperature range of 15 to 70 ° C. in the presence of the magnesium compound. By hydrolyzing the magnesium compound and precipitating titanium acid on the surface thereof, a coating layer made of titanium acid is provided on the surface of the magnesium compound.
The content of the titanium-based catalyst is preferably 10 to 500 ppm, more preferably 50 to 200 ppm with respect to the polyester resin.

The core-sheath ratio of the core-sheath type multifilament of the present invention is preferably 20/80 to 80/20 (volume ratio). Within this range, it is possible to maintain an appropriate strength due to the core component and suppress the heat shrinkage rate of the core-sheath type composite filament for a palatable beverage extraction filter. Therefore, it becomes easy to prevent the woven fabric from being misaligned, and the formability as a filter is good.

The core-sheath type multifilament of the present invention preferably has 2 to 5 filaments. Within this range, in particular, as compared with monofilament, the size of the opening can be effectively controlled with a small amount of thread used, and the extractability is low and the extractability is good. That is, by fusing the sheath component of the multifilament, each filament can be uniformly and flatly aligned and fixed in the fiber longitudinal direction, resulting in excellent moldability, a small amount of thread used, and control of the size of the opening. , Good extractability and excellent effect of preventing misalignment. If the number of filaments is larger than this range, the threads do not converge uniformly when molding the filter, it becomes difficult to secure uniform opening, and the quality of the filter may deteriorate. In addition, the filter performance may be inferior because the opening is not constant.

When the number of filaments is used, the fineness of the core-sheath type multifilament of the present invention may be 15 to 40 dtex in consideration of the moldability when the woven fabric for the tasteful beverage extraction filter is used, the extractability of the filter, and the like. It is preferable, more preferably 20 to 35 dtex. The single yarn fineness is preferably 3 to 20 dtex, more preferably 4 to 18 dex.

The core-sheath type composite multifilament of the present invention preferably has a mass change rate of 4% or less after being immersed in an aqueous ethanol solution having a concentration of 10% by mass for 1 hour.
By setting such a mass change rate, the tasteful beverage extraction filter becomes more excellent in environmental safety and safety. More preferably, the mass change rate is 2% or less, and even more preferably, the mass change rate is 1% or less.
The mass change rate is a value obtained by the following formula.
Mass change rate (%) = [(mass before immersion-mass after immersion) / (mass before immersion)] x 100

The core-sheath type composite multifilament of the present invention preferably has a heavy metal elution amount of less than 0.10 ppm. Here, the elution amount is such that the multifilament is immersed in an ethanol solution having a concentration of 10% by mass at 100 ° C. for 1 hour to elute, and the amount of the metal element having a true specific gravity of 5.0 or more is taken as the elution amount.
As described above, when the amount of heavy metal eluted is less than 0.10 ppm, it can be suitably used for a palatable beverage extraction filter, and it is also excellent in environmental safety.

The core-sheath type composite multifilament of the present invention preferably has a shrinkage rate of 10% or less after hot water treatment, and more preferably 8% or less. Within this range, the woven fabric does not bend during heat setting and is excellent in processability during molding. The hot water shrinkage rate is preferably 3% or more from the viewpoint of good adhesiveness and easy handling without misalignment. The shrinkage rate of the core-sheath type composite multifilament after hot water treatment is a value measured by the method described later.

By weaving the core-sheath type composite multifilament of the present invention, it is possible to produce a woven fabric suitable for use in a palatable beverage extraction filter.

As the structure of the woven fabric, a plain woven fabric or the like is suitable.
In the present invention, as the woven fabric for the tasteful beverage extraction filter, the core-sheath type composite filament of the present invention may be woven using 100% or may be partially used. It is preferable to use 40% or more.

When the core-sheath type composite multifilament of the present invention is partially used, the warp yarn is a regular polyester yarn such as homo PET, or the core-sheath type polyester monofilament whose sheath component has a lower melting point than the melting point of the core component, and the weft yarn is the core of the present invention. The sheath-type composite multifilament is suitable because it has good heat-sealing properties at the intersections of the woven fabrics and is excellent in moldability and extractability.

When a core-sheath type polyester monofilament is used for the warp, it is preferable to use a core-sheath type composite multifilament whose sheath component has a melting point of 40 ° C. or higher, and in particular, the core component is a homopolyester having a melting point of 220 ° C. or higher. Is preferably a copolymerized polyester containing terephthalic acid and a diol having a melting point lower than that of the core component by 40 ° C. or more as main components. Further, in the core-sheath type composite multifilament of the present invention, a monofilament having at least one suitable embodiment other than the number of filaments is preferable.

The woven fabric using the core-sheath type composite multifilament of the present invention preferably has a tear strength of 5N or more, particularly 7N or more, from the viewpoint of improving processability when molding into a palatability beverage extraction filter. Is preferable.

The woven fabric using the core-sheath type composite multifilament of the present invention has an aperture ratio of 40% to 70% because it is easy to run out of liquid when used as a palatability beverage extraction filter and the filter is less likely to be misaligned. Is preferable.

By using a woven fabric made of the core-sheath type composite multifilament of the present invention, heat-treating it, sealing it by an ultrasonic sealing method or the like, and molding it, it can be used as a filter for palatable beverages.

The woven fabric made of the core-sheath type composite multifilament of the present invention can maintain the fabric strength even when sealed and has excellent moldability. Therefore, it is rectangular, planar, spherical, or Tetra Pak. It is possible to easily obtain a tasteful beverage extraction filter having various three-dimensional shapes such as a four-handed net type and a polyhedral shape.

The palatability beverage extraction filter obtained by using the core-sheath type composite multifilament fabric of the present invention can be suitably used for various palatability beverages such as black tea, barley tea, oolong tea, jasmine tea, green tea and coffee. ..

An example of a suitable manufacturing method of the palatability beverage extraction filter in the present invention is shown below.
A core-sheath composite multifilament is produced by using polyethylene terephthalate using a titanium-based catalyst as a core component and isophthalic acid copolymer polyester using a titanium-based catalyst as a polymerization catalyst as a sheath component. At this time, there are a combe method (combe method) in which the undrawn yarn is wound and drawn to produce a filament, and a spin draw method (SPD method) in which the undrawn yarn is drawn and wound as it is without being wound. It is preferably manufactured by the SPD method. In this case, suitable spinning conditions are, for example, a spinning speed of 320 to 4200 m / min, a spinning temperature of 290 to 300 ° C., and a draw ratio of 3 to 4 times. Next, after weaving the obtained core-sheath type composite multifilament, the sheath component is heat-treated so that the intersections of the woven fabrics do not shift. Next, the obtained woven fabric can be sealed by an ultrasonic sealing method or the like and molded into an appropriate shape such as a Tetra Pak shape to obtain a palatable beverage extraction filter.

The physical properties were measured and evaluated as follows.
1) Intrinsic viscosity A polymer of 0.5 g was dissolved in 50 ml of a mixture of phenol / tetrachloroethane = 6/4 (weight ratio), and the measurement was carried out at a temperature of 20 ° C. using an Ostwald viscometer.
2) Melting point Using a DSC-7 type manufactured by PerkinElmer Co., Ltd., the measurement was carried out under the conditions of a chip of 10 mg and a heating rate of 10 ° C./min.
3) Strength and elongation According to JIS L 1013, using an AGS 1KNG autograph tensile tester manufactured by Shimadzu Corporation, the strength when the sample is stretched and fractured under the conditions of a sample yarn length of 200 mm and a tensile speed of 200 mm / min. (CN / dtex) and elongation (%) were determined.
4) Elution amount of heavy metal The ethanol solution obtained by immersing the thread sample in an aqueous ethanol solution having a concentration of 10% by mass at 100 ° C. for 1 hour was used with an ICP mass analyzer (Asilent 7500cs) manufactured by Agilent Technologies and ICP emission emission made by Ametec. Measurements were made using an analyzer (CIROS CCD).
5) Mass change rate The mass of the yarn sample was measured and used as the mass before immersion. Next, the thread sample was immersed in an aqueous ethanol solution having a concentration of 10% by mass at 100 ° C. for 1 hour, dried, and the thread sample was measured and used as the mass after immersion, and the mass change rate was calculated by the following formula. ..
Mass change rate (%) = [(mass before immersion-mass after immersion) / (mass before immersion)] x 1006) Shrinkage rate A thread with a sample length of 500 mm with a load of 2 mg / dtex is placed in boiling water for 15 minutes. After soaking and then air-drying, the shrinkage rate of the core-sheath type composite filament was determined by the following formula.
Shrinkage rate (%) = [(Initial sample length-Sample length after shrinkage) / Initial sample length] x 100
7) Tear strength
According to JIS L1096 8.15.1 A-1 method (single tongue method), using Tensilon RTA-500 tensile tester manufactured by Orientic Co., Ltd., sample width 50 mm, sample length 250 mm, chuck distance 100 mm, tensile speed The maximum load when tearing the sample was measured under the condition of 100 mm / min.
8) Extractibility When 3 g of green tea leaves were placed in the prepared tasteful beverage extraction filter and immersed in water at 90 ° C. for 1 minute, the change in water color was visually determined. From the best ones, ◎, ○, △, ×.

(Example 1)
Using terephthalic acid and ethylene glycol as raw materials, 180 ppm of a magnesium compound having a coating layer made of titanium acid was added as a polymerization catalyst for PET oligomers and polycondensed to obtain polyethylene terephthalate used as a core component (intrinsic viscosity: 0.629). Next, using an acid component of 25 mol% isophthalic acid added to terephthalic acid and ethylene glycol as raw materials, 180 ppm of a magnesium compound having a coating layer made of titanium acid was added to polyester as a polymerization catalyst and polycondensed. , 25 mol isophthalic acid copolymerized polyethylene terephthalate used as a sheath component was obtained (inherent viscosity: 0.643).
The two types of polyester resins obtained above are supplied to a melt-spinning apparatus, and a polymer is spun at a core-sheath volume ratio of 50:50 using a spinneret with a pore diameter of 0.45 mm and three pores, and a spinning temperature of 295. Discharge at ℃, wind it around the first godet roller with a peripheral speed of 950 m / min 7 times, and take it back. After stretching, a multifilament having 3 filaments was wound up. (Melting point of core component: 255 ° C, melting point of sheath component: 185 ° C).
The obtained multifilament was woven with a plain weave structure under the conditions of a warp density of 120 lines / 2.54 cm and a weft density of 120 lines / 2.54 cm to obtain a woven fabric. The obtained woven fabric was scoured and heat-treated at 200 ° C. to fuse the sheath components at the intersections of the yarns to obtain a woven fabric for a filter. The obtained woven fabric for a filter was formed into a Tetra Pak shape by an ultrasonic sealing method to produce a palatable beverage extraction filter.

(Example 2)
Polyester multifilament yarn was obtained by melt spinning in the same manner as in Example 1 except that the core-sheath volume ratio was changed to 70:30. Further, a palatable beverage extraction filter was produced in the same manner as in Example 1.

(Example 3)
Using terephthalic acid and ethylene glycol as raw materials, as a polymerization catalyst for PET oligomers, 200 ppm of a magnesium compound having a coating layer made of titanium acid was added to PET oligomers and polycondensed to obtain polyethylene terephthalate used as a core component. (Intrinsic viscosity: 0.63).
In addition, the isophthalic acid copolymerized polyethylene terephthalate used as the sheath component was obtained by the method described in Example 1.
These two types of polyester resins were melt-spun and stretched by the method described in Example 1 to obtain a polyester multifilament (melting point of core component: 255 ° C., melting point of sheath component: 185 ° C.). Using the obtained polyester multifilament, a palatable beverage extraction filter was produced in the same manner as in Example 1.

(Example 4)
Polymerization, melt spinning, and stretching were carried out in the same manner as in Example 1 except that the polymerization catalyst of polyethylene terephthalate used for the core component and the sheath component was 400 ppm of antimony trioxide to produce a palatable beverage extraction filter.

Evaluation of the polymerization catalyst used in Examples 1 to 4, the core-sheath ratio of the multifilament, the number of filaments, the amount of heavy metal elution, the mass change rate, the fineness, the strength, the elongation, the shrinkage rate, the tear strength of the filter fabric, and the extractability. , Table 1.

(Comparative Example 1)
Polymerization and melt spinning were carried out in the same manner as in Example 1 except that the core component was the copolymerized polyethylene terephthalate used for the sheath component of Example 1, to produce a palatable beverage extraction filter. The tear strength of the filter woven fabric was less than 5N, and the tear strength was low.

(Example 5)
The core-sheath type composite multifilament obtained in Example 1 was woven with a plain weave structure under the conditions of a warp density of 140 lines / 2.54 cm and a weft density of 140 lines / 2.54 cm to obtain a woven fabric. The obtained woven fabric was scoured and heat-treated at 200 ° C. to fuse the sheath components at the intersections of the yarns to obtain a woven fabric for a filter. The tear strength of this woven fabric was 5 N or more in both the vertical and horizontal directions, the elution amount of heavy metals was 0.02 ppm, and the mass change rate was 0.9%. The obtained woven fabric for a filter was formed into a Tetra Pak shape by an ultrasonic sealing method to produce a palatable beverage extraction filter.

(Example 6)
The two types of polyester resins obtained in Example 1 are supplied to a melt spinning apparatus, a polymer is discharged at a core-sheath volume ratio of 50:50, and a spinning base having a pore diameter of 0.45 mm is used to spin a spinning temperature of 290 ° C. , Unstretched polyester monofilament yarn was obtained by melt spinning under spinning conditions of a spinning speed of 1500 m / min. Further, this undrawn yarn was stretched 3.4 times at a heating roller temperature of 90 ° C. and subjected to relaxation heat treatment at a heating plate temperature of 160 ° C. to obtain a polyester monofilament (melting point of core component: 255 ° C., sheath component). Melting point: 185 ° C.).
The polyester monofilament obtained for the warp and the multifilament obtained in Example 1 for the weft are woven in a plain weave structure under the conditions of a warp density of 120 lines / 2.54 cm and a weft density of 120 lines / 2.54 cm to obtain a woven fabric. rice field. The tear strength of this woven fabric was 5 N or more in both the vertical and horizontal directions, the elution amount of heavy metals was 0.02 ppm, and the mass change rate was 0.9%. The obtained woven fabric was scoured and heat-treated at 200 ° C. to fuse the sheath components at the intersections of the yarns to obtain a woven fabric for a filter. The obtained woven fabric for a filter was formed into a Tetra Pak shape by an ultrasonic sealing method to produce a palatable beverage extraction filter.

(Comparative Example 2)
Using the two types of polyester resins obtained by polymerization using the polymerization catalyst of Example 4, a polyester monofilament was obtained in the same manner as in Example 6. Using the polyester monofilaments obtained for the warp and weft, a palatable beverage extraction filter was produced in the same manner as in Example 1.

Table 2 shows the results of evaluation of the extractability of Examples 1, 5 and 6 and Comparative Examples 1 and 2.

The multifilament filter woven fabric obtained from Examples 1 to 3 has improved the problems of polyamide, has excellent moldability, has sufficient dough strength, and can be sufficiently used as a tasteful beverage extraction filter, and is environmentally safe. It was a particularly excellent tasteful beverage extraction filter. Further, in Example 4 in which the antimony catalyst was used as the core component, the amount of heavy metals eluted was larger than in Examples 1 to 3, and the environmental safety was inferior.

The filter woven fabrics obtained from Examples 5 and 6 are all excellent in moldability, have a tear strength of 5 N or more, a heavy metal elution amount of 0.02 ppm, and a mass change rate of 0.9. %, Which was excellent in fabric strength and environmental safety.

The filter woven fabric obtained from Comparative Example 1 had insufficient dough strength and was inferior in moldability, and could not be used as a palatable beverage extraction filter.

When the extractability of the palatability beverage extraction filter obtained from Examples and Comparative Examples was evaluated, all of the Examples products were excellent in extractability. The filter obtained from Comparative Example 2 was inferior in extractability to the filters obtained from Examples 1, 5 and 6.

Although the multifilaments obtained from Examples 1 to 6 use a smaller amount of yarn than the filaments obtained from Comparative Example 2, the opening of the multifilament is controlled when the woven fabric for a filter is used. It was easy to remove, it was hard to be misaligned, it had good moldability and extractability, and it was possible to obtain an inexpensive product with good extractability.

Claims (5)

Core component has a melting point of 220 ° C. or higher homopolyester, the sheath component is Ri copolyester der having a melting point as a main component low terephthalic acid and diol 40 ° C. or higher than the core component, the number of filaments 2-5 present palatability beverage extraction core-sheath type composite multifilaments filter that consists in. The core-sheath type composite multifilament for a palatability beverage extraction filter according to claim 1, wherein the catalyst for polycondensation of the copolymerized polyester of the sheath component is a titanium-based catalyst. The core-sheath type composite multifilament for a palatability beverage extraction filter according to claim 1 or 2, wherein the catalyst for polycondensation of the core component homopolyester is a titanium-based catalyst. A woven fabric for a palatable beverage extraction filter using the multifilament according to any one of claims 1 to 3. The core component of the warp is homopolyester with a melting point of 220 ° C or higher, and the sheath component is a core-sheath monofilament made of copolymerized polyester containing terephthalic acid and diol whose melting point is 40 ° C or higher lower than the core component. A woven fabric for a palatability beverage extraction filter using the multifilament according to any one of Items 1 to 3.