JP2008163485A - Woven fabric for beverage extraction filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a woven fabric for a beverage extraction filter, which has excellent safety as a filter for extracting a taste drink, causes little leakage of tea leaves, etc., from a beverage extraction bag, has excellent formability as the woven fabric, and achieves luxury feeling of the beverage extraction bag owing to the soft feeling of the woven fabric. <P>SOLUTION: The warps and wefts of the woven fabric for a beverage extraction filter are made of a polyester monofilament. The warps use a sheath-core conjugate fiber containing a high-melting polyester as the core component and a low-melting copolyester as the sheath component and having a sheath/core weight ratio falling within a specific range, and the wefts use a flat profiled fiber composed of a high-melting polyester, containing three to six single fibers having a round cross-section and linearly bonded with each other in longitudinal direction, and having a specific cross-section with a flatness (A/B) of 3-6. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fabric for a palatable beverage extraction filter. More specifically, it is excellent in safety as a tasteful beverage extraction filter using specific polyester monofilaments for warps and wefts, and the contents such as tea leaves in the tasteful beverage extraction bag are difficult to leak during extraction. The present invention relates to a novel fabric for a taste-extracting beverage extraction filter that is excellent in moldability and can express the high-class feeling of a taste-extracting beverage extraction bag by the soft feel of the fabric.

  Conventionally, as a material of an extraction bag used for extraction of palatable beverage extraction filters, particularly palatable beverages such as black tea, green tea, and oolong tea, a nonwoven fabric of paper, polypropylene, or polyethylene has been mainly used. As a tendency, there is an increasing demand for a textile-like palatability beverage extraction bag as a high-quality feeling due to the appearance of leaves such as tea in the palatability beverage extraction bag.

  As the composition of such a woven fabric, a shear woven fabric in which monofilaments are plain-woven is mainly used for the purpose of easily seeing leaves such as tea in a palatable beverage extraction bag and preventing the leaves from coming out. As the material fiber of the palatability beverage extraction filter used for palatability beverage extraction pag of textiles, nylon fiber has been the mainstream conventionally, and the filter for extraction or the bag for extraction made of nylon fiber has excellent three-dimensional shape retention, In addition, it is rich in elastic resilience when deformed, and has an excellent texture in terms of the softness of the fabric. However, the extraction bag made of nylon fiber is inevitable in the dimensional change of the extraction bag due to the swelling of the nylon fiber in hot water and the color change due to the absorption of the taste beverage component, and the extraction bag is taken out from the container after extraction. Problems have been pointed out in the past, such as poor drainage of the liquid and poor settling of the extraction bag in hot water due to the high specific gravity of nylon.

In recent years, for the purpose of improving the problems of such nylon fibers, research on a palatable beverage extraction filter using polyester fibers has been conducted. For example, Japanese Patent No. 3459951 (Patent Document 1) has a melting point difference of 100 ° C. There has been proposed a taste-extracting beverage extraction filter for fabrics made of polyester fibers having a double core / sheath structure. However, in this technique, there is no consideration for a metal catalyst used as a catalyst for producing polyester during polyester fineness, and no consideration is given to the safety as a palatable beverage extraction filter using the polyester fiber. In addition, there is a problem in that contents such as tea leaves in a palatable beverage extraction bag made of a shear fabric made of plain polyester monofilaments leak out of the bag, and there is a need for improvement.
Japanese Patent No. 3459951

  The object of the present invention is excellent in safety as a palatable beverage extraction filter, content such as tea leaves in the palatable beverage extraction bag is less likely to leak during extraction, and is excellent in moldability in textiles, Another object of the present invention is to provide a fabric for a taste-extracting beverage extraction filter made of polyester monofilament that can give a high-class feeling to the taste-extracting beverage extraction bag due to the softness of the fabric.

As a result of diligent research in view of the above prior art, the present inventors use polymers obtained by using light metals having a density of 5 g / cm ³ or less as a raw material polyester as a catalyst for producing polyester, and a palatability beverage extraction filter. By using a core-sheath type composite monofilament composed of two-component polymers having different melting points as warp yarns for fabrics and using monofilaments having a special flat cross section as weft yarns, it is excellent in safety as a taste beverage extraction filter, and is a taste beverage Taste beverages such as black tea leaves in the extraction bag are difficult to leak during extraction, have excellent formability in textiles, and the softness of the textiles makes you feel the luxury of a tasteful beverage extraction bag. The inventors found that a fabric for an extraction filter can be obtained, and further studied to complete the present invention. .

  That is, according to the present invention, in order to achieve the above-mentioned object, in the fabric for a palatable beverage extraction filter, the warp and the weft are made of polyester monofilaments in which 80 mol% or more of the polymer repeating units are composed of ethylene terephthalate units. The monofilament (I) of the warp has a core-sheath cross-sectional structure in which the core component is made of a polyester having a melting point of 250 to 260 ° C., and the sheath component is made of a copolyester having a melting point of 200 ° C. to 240 ° C. Is a core-sheath type composite fiber having a weight ratio of 85:15 to 50:50, and the monofilament (II) of the weft is a flat cross-section fiber made of polyester having a polymer melting point in the range of 250 to 260 ° C. The flat shape has such a shape that 3 to 6 pieces of round cross-section single yarns are linearly joined in the long axis direction. The flatness (A / B) represented by the ratio between the length A of the maximum diameter (major axis) of the face fiber and the length B of the maximum diameter (minor axis) perpendicular to the major axis is 3-6. A fabric for a palatable beverage extraction filter characterized by the above is provided.

  In this palatable beverage extract filter fabric, the melting point in which the sheath component in the core-sheath composite fiber of the warp monofilament (I) is copolymerized with isophthalic acid at a ratio of 2 to 20 mol% with respect to the total acidity of the polyester. It preferably consists of a copolyester at 200 ° C to 240 ° C.

  Furthermore, according to the present invention, in the above-described palatable beverage extraction filter fabric, the warp and weft polyester monofilaments are both composed of a polyester in which at least 80 mol% of the polymer repeating units are ethylene terephthalate units, The content of the metal element having a true specific gravity of 5.0 or more in the polyester is 1.0 ppm by weight or less, the elongation is 20 to 50%, the single yarn fineness is 10 to 40 dtex, and the number of filaments is 4. There is provided a highly safe fabric for a taste-extracting beverage filter, which is a monofilament split from a polyester multifilament yarn for splitting that is equal to or greater than 20 in length.

  According to the present invention, it is excellent in safety as a tasteful beverage extraction filter, and by using a flat cross section for the weft, the contents such as tea leaves in the tasteful beverage extraction bag are difficult to leak at the time of extraction. There is provided a palatability beverage extraction filter that is excellent in moldability and can feel the luxury of palatability beverage extraction bags due to the soft feel of the fabric.

As a material for the fabric for a palatability beverage extraction filter according to the present invention, the polymer constituting the fiber is a polyethylene terephthalate-based polyester in which at least 80 mol% is composed of ethylene terephthalate units, and has a true specific gravity of 5.0. It was obtained by splitting a polyester multifilament yarn for splitting consisting of a polymer having a metal element content of 1.0 ppm by weight or less and satisfying all the following conditions (1) to (3): Monofilament is excellent in safety and is preferably used.
(1) Elongation: 20-50%
(2) Single yarn fineness: 10 to 40 dtex (3) Number of filaments: 4 or more and 20 or less

  Specifically, a polyester having a metal element content of true specific gravity of 5.0 or more and 1.0 weight ppm or less is a polyester having a specific content of metal elements having a specific gravity of 5.0 or more, particularly antimony and germanium. Say. These polyesters are preferably produced using titanium trimellitic acid as a polyester production catalyst. More specifically, a phosphonate compound represented by the following general formula (1) is used in the polyester production process, and the titanium (Ti) and phosphorus (P) contents in the polyester satisfy the following formula (A). Thus, it is preferable to synthesize.

  The intrinsic viscosity (o-chlorophenol, measured at 35 ° C.) of the polyester in the present invention is preferably in the range of 0.40 to 0.80, more preferably 0.45 to 0.75, particularly 0.50. A range of ˜0.70 is preferred. An intrinsic viscosity of less than 0.40 is not preferable because the strength of the fiber is insufficient. On the other hand, if the intrinsic viscosity exceeds 0.80, it is necessary to raise the intrinsic viscosity of the raw polymer excessively, which is uneconomical. When producing the fabric for a palatable beverage extraction filter of the present invention, it is preferable in terms of productivity and cost to produce such a polyester multifilament yarn and use a monofilament obtained by dividing the yarn into monofilaments.

  In addition, the polyester in the present invention is a small amount of additives such as a lubricant, a pigment, a dye, an antioxidant, a solid phase polymerization accelerator, a fluorescent whitening agent, a charge, as long as the purpose of the present invention is not impaired. An inhibitor, an antibacterial agent, an ultraviolet absorber, a light stabilizer, a heat stabilizer, a light-shielding agent, a matting agent and the like may be contained.

  In the present invention, as the polyester monofilament constituting the palatable beverage extraction filter fabric, multifilament yarns composed of 4 to 20 filaments are preferably used.

  It is important that the multifilament yarn has a fiber elongation in the range of 20 to 50%. If the elongation is less than 20%, the yarn breakage in the spinning process and the yarn breakage in the splitting process increase and the process passability decreases. On the other hand, when the elongation exceeds 50%, an unstretched portion due to stretch spots is generated, and this portion becomes a factor of yarn breakage in the fiber separation process, and the process passability decreases. In the present invention, the elongation is particularly preferably in the range of 25 to 40%.

  The single yarn fineness after splitting of the polyester multifilament yarn for splitting manufactured according to the present invention (that is, the fineness of the monofilament) is suitably 10 to 40 dtex, and if the single yarn fineness is smaller than this range, Splitting becomes difficult, and conversely, if it is larger than this range, the package loses its shape or traverses during winding, resulting in a marked deterioration in processability. The number of single filaments of the multifilament yarn is preferably 4 to 20 from the viewpoint of securing the splitting property and the process passability in the splitting step.

  The fabric for a preference beverage extraction filter according to the present invention is composed of a polyethylene terephthalate polyester monofilament for both the warp and the weft. The polyester monofilament (I) used for the warp in the present invention has a core-sheath cross-sectional structure. Type composite fiber, the core component of which is a homopolymer whose melting point of the polymer is in the range of 250 to 260 ° C., and the sheath component is 20 mol% or less, in particular 2 to 20 mol% of isophthalic acid or the like. A sheath having a core-sheath type structure made of a copolyester having a melting point of 200 ° C. to 240 ° C. in which three components are copolymerized, and having a weight ratio of the core portion to the sheath portion of 85:15 to 50:50 It is a core type composite fiber.

  Thus, in this invention, it is a core-sheath type composite filament which consists of the said core-sheath component as monofilament (I) of warp, Comprising: Melting | fusing point of the polymer which comprises the sheath component exists in the range of 200 to 240 degreeC. It is important to use a material having a core-sheath component arranged substantially concentrically in the cross section of the fiber.

  Filters made of homopolyester fibers are less weldable by the ultrasonic seal method or heat seal method used to form beverage extraction bags than filters made of nylon fibers. This is the reason why many polyester fibers have not been used in this field. However, in the case of a polyester fiber made of a polymer obtained by copolymerizing a third component such as isophthalic acid at a ratio of 20% mol% or less so that the surface portion of the fiber has a melting point of 200 ° C. to 240 ° C., an ultrasonic sealing method, etc. The workability due to can be made almost as high as that of nylon fibers. However, when the melting point of the sheath component exceeds 240 ° C., the weldability by the ultrasonic seal method or the heat seal method is poor, and it is easy to peel even once welded, so the yarn at the seal portion when forming the extraction bag Fraying occurs and cannot be used as an extraction bag. In addition, when the melting point is less than 200 ° C., the weldability by the ultrasonic sealing method or the heat sealing method is high, and it is difficult to peel off even after being once welded, but the strength of the fiber is weak and the yarn breakage in the splitting process increases. Process passability deteriorates. The polymer melting point of the sheath component is particularly preferably in the range of 200 ° C to 220 ° C.

  Moreover, it is important that the weight ratio of the core part to the sheath part in the above-described sheath-core type composite fiber is in the range of 85:15 to 50:50. When the sheath ratio is less than 15% by weight, the weldability by the ultrasonic sealing method or the heat sealing method is poor, and it is easy to peel off even if it is once welded. It occurs and cannot be used as an extraction bag. When the sheath ratio exceeds 50% by weight, the weldability by the ultrasonic seal method or heat seal method is high, and it is difficult to peel once welded, but the strength of the fiber is weak, and yarn breakage in the fiber separation process increases. Process passability deteriorates. The preferred core: sheath weight ratio of the sheath-core type composite fiber in the present invention is 80:20 to 70:30.

  On the other hand, the monofilament (II) used for the weft of the fabric for palatable beverage extraction filter of the present invention is a flat cross section comprising a polyester having a melting point of 250 to 260 ° C., preferably a homopolymer of polyethylene terephthalate. As shown in FIG. 1, the flat shape of the fiber has a shape in which 3 to 6 pieces of the round cross-section single yarn are linearly joined in series in the long axis direction, and the maximum diameter of the flat cross-section fiber. The flatness (A / B) represented by the ratio of the length A of the (major axis) and the length B of the maximum diameter (minor axis) perpendicular to the major axis is required to be 3-6.

  FIG. 1 exemplifies the cross-sectional shape of such a flat cross-section fiber. By making the weft yarn into such a special cross-sectional shape, the contact point of the fiber cross-section at the intersection of the warp and the weft yarn in the woven fabric is round. It becomes more than the cross-sectional fibers, and the weldability by the ultrasonic sealing method or heat sealing method used when forming a bag for extraction with a woven fabric is improved.

  Furthermore, such a cross-sectional shape makes it extremely soft compared to a woven fabric made of a conventional round cross-section polyester fiber, has an excellent texture, and has physical properties suitable for realizing a high-class feeling of a tasteful beverage extraction filter or extraction bag. . In addition, even if the fabric density configuration is the same as that of the round cross-section fiber, the fabric made of this flat cross-section fiber has a smaller mesh size compared to the round cross-section fiber, thereby improving the performance of the palatability beverage extraction filter. To do. Furthermore, there is an advantage that the content of leaves such as tea in the extraction bag is difficult to leak into hot water.

  In addition, a micron-sized fine cavity is formed at the intersection of the warp and weft of the fabric, and hot water enters the cavity by capillary action, so that the settling of the extraction bag in hot water is less than that of conventional polyester fibers. It has the effect that it improves compared with the textiles etc. which become.

  The method for producing a polyester multifilament yarn for splitting for obtaining monofilaments of warp and weft in the present invention is not particularly limited, but the polyester multifilament yarn for splitting is made of the above-mentioned polymer as a raw material. For example, using a spinning device as shown in FIG. 2, the molten multifilament yarn discharged from the spinneret (1) having a spinning nozzle for producing a composite fiber or a spinning nozzle for producing a flattened right fiber is directly under the spinneret. After passing through the heat-retaining region (10) having a length of 50 to 200 mm held at the atmospheric temperature of 50 to 200 ° C. to suppress rapid cooling, cooling air (11) is applied to the molten multifilament yarn from the lateral direction. Sprayed and rapidly cooled to change to solid multifilament yarn, separated into monofilaments by thread separation guide (3) The first godet roller (4) and its separate roller which are concentrated in one, heated to 70 ° C to 120 ° C after being applied with an oil agent in the form of a monofilament by the rolling roller (2) A second godet roller (6) that is wound at (5) at a constant speed of 500 to 2000 m / min and is rotated at a peripheral speed faster than that of the first godet roller without being wound up continuously. ) And its separate roller (7) and stretched to a predetermined draw ratio of 2.0 to 5.0 times between the first godet roller (4) and the second godet roller, It can be manufactured by winding at a lower speed than the second godet roller (6) in 8).

  The thus obtained polyester multifilament yarn for splitting of the present invention is used after being split as it is, or after being crimped by false twisting or the like and then split into monofilaments for use.

  The filter fabric of the present invention is preferably a plain weave with the above warp and weft and woven into a taffeta or shear fabric, for example, when used as a tea bag, in a bag shape. After forming and storing leaves such as black tea in it, the opening can be heated and pressurized and heat sealed to make a tea bag.

  Hereinafter, the present invention will be described more specifically with reference to examples. In addition, each item in an Example was measured with the following method.

(1) Polymer melting point It measured by the conventional method using DSC.

(2) Metal component qualitative analysis with a specific gravity of 5.0 or more in the fiber, content of metal element with a true specific gravity of 5.0 or more The fiber sample is mixed with ammonium sulfate, sulfuric acid, nitric acid and perchloric acid at about 300 ° C. After wet decomposition for 9 hours, the sample was diluted with distilled water and qualitatively analyzed using a 1CP emission spectrometer (JY170ULTRACE) manufactured by Rigaku Corporation to confirm the presence or absence of a metal element having a specific gravity of 5.0 or more. About the metal element with which existence of 1 weight ppm or more was confirmed, the element content was shown.

(3) Elongation Based on JlS-L-1013, using a “Tensilon” manufactured by Orientec Co., Ltd., which is a constant speed extension tensile tester, it was ruled at a grip interval of 20 cm and a tensile speed of 20 cm / min.

(4) Intrinsic viscosity The intrinsic viscosity of the polyester polymer was determined from the value of the viscosity measured at 35 ° C for an orthochlorophenol solution.

(5) Split yarn rate (%)
A 10kg drum-shaped package wound with polyester multifilament yarn for splitting is filled with the ratio of multifilament yarn for splitting that can be split at a splitting speed of 500m / min. Expressed as a tube rate (%). The split amount of monofilament is 1 kg. The acceptance criterion was 70% or higher.

[Example 1]
Polyethylene terephthalate (melting point: 256 ° C.) having an intrinsic viscosity of 0.650 containing 5 mmol% of titanium trimetate as a titanium compound and 30 mmol% of triethylphosphonoacetate as a phosphorus compound as a polymerization catalyst is referred to as homopolymer A, A polyethylene terephthalate copolymer having an intrinsic viscosity of 0.650 (melting point 205 ° C.) obtained by copolymerizing homopolymer A with isophthalic acid at a ratio of 17 mol% of the polymer component is designated as copolymer B, and each polymer pellet is formed at 5 ° C. at 5 ° C. Dry for hours. Thereafter, extrusion is carried out with a polymer spinning temperature of 280 ° C. and a discharge rate of 8.0 g / min through a single discharge hole in a melt spinning apparatus having two spinnerets in which 5 discharge holes are concentrically arranged, and a monofilament Oiling was performed in a state divided into two, and 10 multifilament yarns obtained by combining monofilaments discharged from the two spinnerets were turned 16 times with a first godet roller heated to 100 ° C., and taken up at 700 m / min. The second godet roller rotating at a peripheral speed 4.4 times that of the first roller was turned 10 times and wound as a multifilament yarn having 10 filaments.

  A multifilament yarn of core-sheath type composite fiber (I) (sheath: core weight ratio = 35: 65) having a concentric core-sheath cross-sectional shape made of homopolymer A / copolymer B under these conditions by a core-sheath type composite spinning device Manufactured. On the other hand, a multifilament of flat cross-section fibers (II) having a flatness of 4 in which four round cross-section single yarns are joined linearly in the major axis direction consisting only of homopolymer A by a spinning device equipped with a spinneret for flat cross-section fibers. Yarns were produced under conditions similar to those described above.

  Each of the obtained multifilament yarns was split to produce two types of polyester monofilaments (27 dtex). The concentric core-sheath composite fiber and the multifilament yarn of the flat cross-section fiber both had good splitting properties.

  Of the two types of monofilaments thus produced, the concentric core-sheath composite fiber of (I) above is used for the warp, and the flat cross-section fiber of (II) is used for the weft to produce a plain fabric [taffeta, 27 dtex monofilament, weaving number (97 × 97 / inch)], refining, washing with water, drying, heat treatment in heated air (200 ° C.) under tension, and light at the intersection of yarns An extraction bag for black tea was formed from the plain fabric obtained by applying the welding by an ultrasonic sealing method.

  As shown in Table 1, this plain woven fabric has good weldability by the ultrasonic sealing method, the texture of the woven fabric is soft, the settling property in hot water is good, and the contents (tea leaves) leak from the extraction bag. There was little discharge | emission and it was a thing suitable for a taste drink extraction filter or an extraction bag.

[Comparative Example 1]
An extraction bag was formed under the same conditions as in Example 1 except that the concentric core-sheath composite fiber comprising homopolymer A / copolymer B of Example 1 was used for both warp and weft. The evaluation results are also shown in Table 1.

[Comparative Example 2]
An extraction filter bag was formed under the same conditions as in Example 1 except that the circular cross-section shape fiber having 100% homopolymer A in Example 1 was used as the warp. The evaluation results are also shown in Table 1.

  As apparent from Table 1, the fabric of Example 1 using the concentric core-sheath composite fiber (I) having a melting point of the sheath component polymer of 205 ° C. as the warp and the flat cross-section fiber (II) as the weft. Has good cross-weldability and ultrasonic sealability of fabric during heat treatment (200 ° C), soft texture as fabric, good settling of extraction bag into hot water, hot water from extraction bag There was no leakage of tea leaves.

  In comparison, the fabric using the core-sheath composite fiber having a concentric core-sheath cross-sectional shape having a sheath polymer melting point of 205 ° C. according to Comparative Example 1 for both the warp and the weft is the intersection of the fabrics at the heat treatment (200 ° C.). Although the weldability and ultrasonic sealability were good, the texture as a fabric was hard, and the settling property of the extraction bag and the leakage of tea leaves were not satisfactory.

  In addition, the fabric of Comparative Example 2 having a polymer melting point of 256 ° C. and a round cross-section fiber for warp and a flat cross-section fiber for weft is relatively soft, but has a poor ultrasonic seal and is used as an extraction bag. It was impossible.

  The fabric for palatability beverage extraction filter of the present invention is excellent in safety, and the content of tea leaves etc. in the palatability beverage extraction bag by using the above-mentioned core-sheath type composite fiber as the warp and the flat cross-section fiber as the weft There is almost no leakage of the product during extraction, the moldability in the fabric is excellent, and the softness of the fabric makes it possible to realize the high-class feeling of a tasteful beverage extraction bag. It is extremely useful as a material for use.

It is a figure which illustrates the cross-sectional shape of the flat cross-section fiber used for a weft in this invention. It is a schematic diagram which shows the outline of the spinning apparatus used for the production of the multifilament yarn for splitting suitable for use in the present invention.

Explanation of symbols

1: Spinneret 2: Oiling roller 3: Thread separation guide
4: 1st godet roller 5: 1st separate roller 6: 2nd godet roller 7: 2nd separate roller 8: Winding machine 9: Multifilament yarn package 10: Thermal insulation area 11: Cooling air

Claims (3)

  In a fabric for a preference beverage extraction filter, wherein the warp and weft are made of polyester monofilament in which 80 mol% or more of polymer repeating units are composed of ethylene terephthalate units, the core component of the warp monofilament (I) has a melting point of 250 to 260. A core-sheath type having a core-sheath cross-sectional structure consisting of a polyester having a melting point of 200 ° C to 240 ° C and a weight ratio of the core component to the sheath component being 85:15 to 50:50 The monofilament (II) of the weft, which is a composite fiber, is a flat cross-sectional fiber made of polyester having a polymer melting point in the range of 250 to 260 ° C., and the flat shape is 3 -6 pieces having a shape joined linearly, the maximum diameter (long axis) of the flat cross-section fiber and the maximum diameter perpendicular to the long axis Minor axis) of flatness represented by the ratio of the length B (A / B) preference beverage extraction filter for textiles, characterized in that it is 3-6.   The sheath component in the core-sheath composite fiber of the monofilament (I) of the warp is composed of a copolyester having a melting point of 200 ° C. to 240 ° C. in which isophthalic acid is copolymerized at a ratio of 2 to 20 mol% with respect to the total acidity of the polyester. The fabric for a palatable beverage extraction filter according to claim 1.   3. The palatable beverage extract filter fabric according to claim 1 or 2, wherein the warp and the weft are each made of a polyester monofilament, and the polyester monofilament of the warp and the weft is composed of at least 80 mol% of the polymer repeating unit. A single yarn composed of polyester which is a terephthalate unit, the content of a metal element having a true specific gravity of 5.0 or more in these polyesters is 1.0 ppm by weight or less, and the fiber elongation is 20 to 50%. A fabric for a taste-extracting beverage extraction filter, characterized in that it is a monofilament split from a polyester multifilament yarn for splitting having a fineness of 10 to 40 dtex and a filament number of 4 or more and 20 or less.

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