TWI624571B - Single-layer or multi-layer polyester long fiber non-woven fabric and food filter using the same - Google Patents

Abstract

The present invention provides a single-layer or multi-layer polyester long fiber non-woven fabric excellent in transparency, dimensional stability, powder leakage, and component extractability, and a food filter using the same. The content of the inorganic particles of the single-layer or multi-layer polyester long-fiber nonwoven fabric of the present invention is 0-100 ppm, the 10% point pore size is less than 1000 μm, the difference between the 10% point pore size and 2.3% point pore size is less than 500, and the unit area The weight is 10 ~ 30g / m ² .

Description

Single-layer or multi-layer polyester long fiber non-woven fabric and food filter using the same

The present invention relates to a single-layer or multi-layer polyester long-fiber nonwoven fabric excellent in transparency, dimensional stability, powder leakage, and component extractability, and a food filter for extracting beverages using the same.

Previously, non-woven fabrics containing resins such as polyethylene, polypropylene, polyester, and polyamide were used as packaging materials. However, in order to make full use of the shielding function such as the filterability of the non-woven fabric, it is required to make the fiber dense, so that the inside cannot be confirmed. In addition, when extracting components such as black tea, green tea, and oolong tea, the tea bag method is often used as a simple method. The packaging materials used for tea bags often use paper, but there are problems such as poor transparency, inability to see the contents of the packaging materials, and the inability to perform heat sealing processing.

The following Patent Document 1 discloses a nonwoven fabric for tea bags with improved transparency, but there is no description related to dimensional stability, and no special attention is paid. Furthermore, the maximum pore diameter measured by the bubble point method (JIS-K-3832) is used as an evaluation of powder leakage, but the pore diameter suitable for measurement is in the range of nanometers to micrometers, and the pore diameter is expressed after converting the pressure, Therefore, it is not an evaluation method suitable for the actual tea used.

In addition, Patent Document 2 below discloses that a biodegradable monofilament for tea bags containing poly L-lactic acid with a fineness of 15 to 35 dtex has a high fineness and high transparency, but the boiled water shrinkage rate of the monofilament exists. The problem of less than 20% and low dimensional stability.

Furthermore, it is disclosed in Patent Document 3 below that the polyolefin-based polymer is included as A nonwoven fabric with a sheath component and a core sheath type composite long fiber with a polyester polymer having a melting point higher than the above sheath component as a core component, which has excellent heat sealability, but has low dimensional stability and is not related to transparency Records, but not pay special attention to.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 3939326

[Patent Document 2] Japanese Patent Laid-Open No. 2001-131826

[Patent Document 3] Japanese Patent Laid-Open No. 11-43855

In view of the above-mentioned problems of the prior art, the present invention provides a polyester long-fiber nonwoven fabric excellent in transparency, dimensional stability, powder leakage, and component extractability, and a food filter using the same.

In order to solve the above problems, the inventors of the present invention conducted intensive research and repeated experiments. As a result, it was found that a polyester resin having a titanium content in a specific range was selected, and the structure, fiber diameter, and unit area of the fiber constituting the nonwoven fabric were selected. A detailed study was carried out from the viewpoint of weight and thermocompression bonding area ratio to obtain a nonwoven fabric with good spinnability, excellent component extractability as a filter for food, and good transparency and dimensional stability. Furthermore, the use of the pore diameter calculated by directly observing the nonwoven fabric was defined as the evaluation of the powder leakage property, thereby completing the present invention.

That is, the present invention is as follows.

[1] A single-layer or multi-layer polyester long-fiber nonwoven fabric, in which the content of inorganic particles is 0-100 ppm, the 10% point pore size is less than 1000 μm, and the difference between the 10% point pore size and 2.3% point pore size is 500 or less, and The weight per unit area is 10 ~ 30g / m ² .

[2] The single-layer or multi-layer polyester long-fiber non-woven fabric as described in [1] above has a thermocompression bonding area ratio of 5 to 40% and an average apparent density of 0.1 to 0.5 g / cm ³ .

[3] The single-layer or multi-layer polyester long fiber non-woven fabric as described in [1] or [2] above has an average fiber diameter of 13-40 μm.

[4] The single-layer or multi-layer polyester long-fiber nonwoven fabric as described in any one of the above [1] to [3], wherein at least one layer is composed of C = around 1740cm ^-1 observed in the Raman spectrum Fibers with an average value of the half-peak full amplitude of the peak width generated by the O group are 18 ~ 24 cm ^-1 .

[5] The single-layer or multi-layer polyester long fiber nonwoven fabric according to any one of the above [1] to [4], wherein at least one layer contains fibers with a crystallinity of 30 to 50%.

[6] The single layer or multi-layer polyester long fiber nonwoven fabric according to any one of the above [1] to [5], wherein at least one layer contains fibers with a birefringence of 0.04 to 0.12.

[7] The single-layer or multi-layer polyester long-fiber nonwoven fabric according to any one of the above [1] to [6], whose transparency is 60% or more.

[8] The single-layer or multi-layer polyester long-fiber nonwoven fabric according to any one of the above [1] to [7] has a boiling water shrinkage rate of 2.0% or less.

[9] The single-layer or multi-layer polyester long-fiber non-woven fabric according to any one of the above [1] to [8] has a texture coefficient of 0.5 to 2.0.

[10] The single layer or multi-layer polyester long fiber nonwoven fabric according to any one of the above [1] to [9], wherein at least one layer has a tensile strength of 5 N / 30 mm or more.

[11] The single-layer or multi-layer polyester long fiber nonwoven fabric according to any one of the above [1] to [10], wherein at least one layer contains low-melting-point fibers having a melting point of 240 ° C or lower.

[12] The polyester long-fiber nonwoven fabric according to any one of the above [1] to [11], which includes a laminated nonwoven fabric in which the following a layer and b layer are integrated by thermocompression bonding.

Layer a: Polyester long-fiber non-woven fabric containing low-melting point resin with a melting point difference of 30-150 ° C from the high-melting point resin

Layer b: polyester long fiber non-woven fabric containing the above-mentioned high melting point resin

[13] The single-layer or multi-layer polyester long-fiber nonwoven fabric according to any one of the above [1] to [12], It has a structure in which the orientation of the fibers of the polyester long fiber nonwoven fabric is different in the cross-sectional direction.

[14] The single-layer or multi-layer polyester long fiber nonwoven fabric according to any one of the above [1] to [13], wherein at least one layer contains a resin containing 0 to 25% of phthalic acid.

[15] The single layer or multi-layer polyester long fiber nonwoven fabric according to any one of the above [1] to [14], wherein the inorganic particles are titanium oxide.

[16] The single-layer or multi-layer polyester long-fiber nonwoven fabric as described in [15] above, which contains a resin with a titanium content of 0 to 0.1 ppm.

[17] The single-layer or multi-layer polyester long-fiber non-woven fabric according to any one of the above [1] to [16], wherein the IV value of the resin after making the non-woven fabric is 0.6 or more.

[18] A food filter comprising the single-layer or multi-layer polyester long-fiber nonwoven fabric according to any one of the above [1] to [17].

The fibers constituting the single-layer or multi-layer polyester long-fiber non-woven fabric of the present invention have good spinnability, and the food filter manufactured using the non-woven fabric containing the fiber has excellent extractability of components, transparency, dimensional stability, and further resistance Powder leakage is also good.

Fig. 1 is a schematic diagram showing an example of a device for controlling airflow such as a plate-shaped dispersion plate.

Figure 2 is a graph showing the relationship between boiling water shrinkage and transparency.

Fig. 3 is a graph showing the relationship between stretch ratio and alignment crystallinity.

Fig. 4 is a graph showing the relationship between spinning temperature and alignment crystallinity.

Fig. 5 is a graph showing the relationship between the IV value of the resin and the crystallinity of the alignment.

Hereinafter, the embodiments of the present invention will be described in detail.

Examples of the polyester resin constituting the polyester long fibers constituting the polyester long fiber nonwoven fabric of the present embodiment include polyethylene terephthalate and polyparaphenylene as thermoplastic polyesters. Butyl dicarboxylate or polytrimethylene terephthalate is a typical example, and it may also be a polyester obtained by polymerizing or copolymerizing phthalic acid, phthalic acid, or the like between acid components forming an ester. The thermoplastic polyester may further be a resin having biodegradability, such as polyglycolic acid or polylactic acid-like poly (α-hydroxy acid), or a copolymer containing these as a main repeating unit element. These resins may be used alone, or two or more kinds may be combined.

The higher transparency (lower concealment) of the polyester long-fiber nonwoven fabric of the present embodiment is better. Therefore, the lower the content of inorganic particles generally used as a matting agent in the thermoplastic synthetic fiber nonwoven fabric, the better.

As the inorganic particles used as the matting agent, either synthetic products or natural products can be used without particular limitation. Examples of the inorganic particles include oxide-based ceramics such as aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, magnesium oxide, ceria, yttrium oxide, zinc oxide, and iron oxide; silicon nitride, titanium nitride, and nitride Boron and other nitride-based ceramics; silicon carbide, calcium carbonate, aluminum sulfate, aluminum hydroxide, magnesium hydroxide, potassium titanate, talc, kaolin clay, kaolinite, dickite, translucent olive achondrite, water Kaolin, pyrophyllite, magnificent porphyry, montmorillonite, aluminon bentonite, nontronite, chromite, saponite, zinc bentonite, hectorite, vermiculite, iron aluminum serpentine, sericite, Magnesite, manganese aluminum serpentine, zinc aluminum serpentine, nickel aluminum serpentine, bentonite, zeolite, biotite, phlogopite, iron mica, magnesium rich biotite, conifer mica iron mica, scale mica, silicon rich scale Mica, muscovite, chlorite, magnesium-rich biotite, ferrochlorite, iron aluminum chlorite, calcium silicate, magnesium silicate, diatomaceous earth, silica sand and other ceramic and glass fibers. These inorganic particles are used alone or in combination of two or more. From the viewpoint of the reactivity with the resin, the inorganic particles used are preferably inert inorganic particles such as titanium oxide, magnesium stearate, and calcium stearate.

The preferred particle size range of the inorganic particles of the polyester resin constituting the polyester long fibers of this embodiment is 1.0 μm or less, preferably 0.8 μm or less, and more preferably 0.7 μm or less. If the particle diameter exceeds 1.0 μm, as a nonwoven fabric, not only the transparency is lowered, but also the spinning stability is deteriorated, so spinning defects such as end breakage also increase.

In the polyester resin constituting the polyester long fiber of the present embodiment, the preferable content of the inorganic particles is 0 to 100 ppm, preferably 0 to 50 ppm, and more preferably 0 to 0.1 ppm. By setting the content of the inorganic particles in the fiber within the above range, the transparency of the nonwoven fabric can be sufficiently ensured. Furthermore, when inorganic particles are used as a catalyst, the decomposition reaction of the resin at the time of melt extrusion is suppressed within the above-mentioned range, and spinning defects such as thread breakage can be suppressed.

As the inorganic particles used as a matting agent in the polyester resin constituting the polyester long fiber of the present embodiment, it is preferable to use titanium oxide after inactivating the reaction activity in view of being inexpensive and versatile. Titanium particles. When the titanium element is used as the inorganic particle in the polyester resin constituting the polyester long fiber of this embodiment, the preferred content is 0 to 100 ppm, preferably 0 to 50 ppm, and more preferably 0 to 0.1 ppm .

Specifically, it is preferably a colorless and transparent super-bright resin to which inorganic inert particles such as titanium dioxide used as a matting agent are not added, and further preferably a resin that does not use a titanium compound as a catalyst. By not using a titanium compound as a catalyst, the decomposition reaction of the resin at the time of melt extrusion is suppressed, so that spinning defects such as end breakage can be suppressed.

When the polyester long-fiber nonwoven fabric of this embodiment is used as a packaging material, the leakage of the inclusions can be defined by the distribution of pore diameters.

The representative value of the pore diameter can be represented by the pore diameter at the point of 10% of the area ratio when the area of each hole in the non-woven image is accumulated from the largest area to the smaller area in sequence, and must be 1000 μm or less. The preferred range is 30 μm or more and 6000 μm or less, the more preferred range is 400 μm or less, and the more preferred range is 300 μm or less, and the most preferred is 250 μm or less. If it is above this range, the seam of the fabric becomes thinner, so the powder leakage of the inclusions cannot be suppressed. On the other hand, if it is below this range, the seam of the fabric becomes thinner, so the transparency of the filter decreases. In addition, the filter suppresses the increase in fluid resistance, so when used as a filter for food, the extraction time increases and is not practical.

The difference between the 2.3% and 10% points when the diameter of the larger diameter is accumulated from the maximum diameter Must be 0μm or more and 500μm or less. The preferred range is 300 μm or less, the more preferred range is 200 μm or less, and the further preferred range is 150 μm or less. In the case of a fabric with a large pore size distribution of the nonwoven fabric, by setting the frequency of the hole with a larger diameter within this range, a nonwoven fabric with excellent powder leakage can be produced. Furthermore, by combining with the above 10% pore size range, the optimal pore size distribution for packaging tea can be defined.

Furthermore, in the case of holes with the same hole area, the shape preferably has a longer diameter and a shorter diameter like an ellipse compared to a true circle. In the case of packing tea and other contents, it is not a real ball with a smooth surface, so even if it is the same hole area, when there is a hole with a longer diameter and a shorter diameter, it is not easy for the tea to get stuck around the hole leakage. The shape of the relatively large pores contained in the non-woven fabric is particularly important for the leakage of tea etc. The shape of the hole can be expressed by the average value of the long diameter of the hole with a diameter of 2.3% to 10% divided by the average value of the hole with a diameter of 2.3% to 10%. This value is preferably 1.3 or more. Generally, as long as the transparency of the resin is the same, if the transparency is kept while suppressing the leakage of the content, there will be a trade-off relationship. The transparency is the surface area of the fiber contained in the fixed area, that is, the thinner the fiber diameter and the weight per unit area The larger and worse, the leakage of the content is reduced. According to this relationship, one method of ensuring the transparency while suppressing the leakage of the content is to reduce the large pore size contained in the nonwoven fabric, and the other method is to set the shape of the hole to a shape where the content does not easily leak. By using these two methods at the same time, a nonwoven fabric can be obtained that further satisfies both the transparency and the leakage of the content.

In addition to the general circular cross-section, the shape of the polyester long fiber of this embodiment can be selected from any fiber cross-sectional shape such as a hollow cross-section, a core-sheath composite cross-section, a split composite cross-section, and a flat cross-section according to its purpose and application.

The polyester long-fiber nonwoven fabric of the present embodiment is used to form a bag shape such as a tea bag, and it is preferably high in strength during heat sealing processing by a bag making machine. In order to obtain heat sealability with good adhesive strength, fibers containing a low-melting point resin with a melting point of 240 ° C or less are laminated on at least one side of the polyester long-fiber nonwoven fabric and a melting point difference is set, thereby heat-sealing During the sealing process, only the low-melting-point resin component softens or melts and functions as an adhesive, so that a high heat seal strength can be effectively obtained.

The melting point of the above-mentioned low melting point resin is higher than that of the melting point resin by 30 to 150 ° C, preferably 30 to 100 ° C. Examples of low melting point resins include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, and naphthalene dicarboxylic acid, and ethylene glycol, diethylene glycol, and 1,4-butanedi. Copolymerized polyester resin or aliphatic polyester resin, such as polylactic acid, polymerized by glycols such as alcohol and cyclohexane dimethanol. Furthermore, as the fiber structure, in addition to a single component, a composite fiber structure including two components such as a sheath-core structure or a parallel structure is preferable. For example, the core has a high melting point and the sheath has a low melting point. Specifically, the core It is a high melting point resin such as polyethylene terephthalate or polybutylene terephthalate, and the sheath is a low melting point resin such as copolyester or aliphatic polyester. The method of laminating low-melting-point fibers includes, for example, a method of melting the above resin and applying a semi-molten resin or its fibrous material to a non-woven curtain spray method to spray the melted resin from the nozzle and A coating method for applying to a non-woven fabric, or a method of obtaining a laminated non-woven fabric by laminating a high-melting-point fiber web and a low-melting-point fiber web and joining them with a heat roller or the like.

Low-melting-point resin, for example, when an aromatic dicarboxylic acid mainly containing terephthalic acid is used as a component, a second aromatic dicarboxylic acid such as isophthalic acid, phthalic acid, and naphthalene dicarboxylic acid can be copolymerized After use. In this case, the amount of the second aromatic dicarboxylic acid relative to the total aromatic dicarboxylic acid is 0-25%, preferably 0-22%, and more preferably 0-18%. If added in an amount exceeding this range, the crystallinity is lowered, and the molecular alignment formed by extension does not occur, so the spinning stability or the mechanical strength or dimensional stability of the nonwoven fabric is reduced.

The polyester long-fiber nonwoven fabric of this embodiment is preferably capable of ultrasonic fusing or heat sealing. The seal strength is preferably 0.1 N / 30 mm or more, and more preferably 0.2 N / 30 mm or more. The heat sealing conditions can be appropriately selected. For example, the temperature condition of the heat sealing is preferably 5 to 80 ° C lower than the melting point of the resin on the sealing surface.

Furthermore, other commonly used additions can be added within a range that does not hinder the desired effect Ingredients, such as various elastomers, impact modifiers, crystal nucleating agents, coloring inhibitors, antioxidants, heat stabilizers, plasticizers, lubricants, weathering agents, antibacterial agents, colorants, pigments, dyes and other additives .

The polyester long-fiber nonwoven fabric of this embodiment can be efficiently produced by the spun bond method. That is, the polyester-based resin is heated and melted and discharged from the spinning head, the obtained spun yarn is cooled using a known cooling device, and is drawn and refined by a suction device such as an air tray (Air Sucker). Then, after the fiber group discharged from the suction device is opened, it is deposited on a conveyor belt to form a net. Then, a local thermocompression bonding device such as a heated embossing roller is used to locally thermally press-bond the web formed on the conveyor belt, thereby obtaining a long-fiber spunbonded nonwoven fabric.

When the spunbond method is used, it is not particularly limited. In order to improve the uniformity of the mesh, for example, a method of charging the fiber using a corona device, etc., as disclosed in Japanese Patent Laid-Open No. 11-131355, or a flat plate shape is used. The airflow control device (see Figure 1) such as the dispersing plate adjusts the velocity distribution of the airflow of the ejection part of the ejector, etc., after the fiber is opened, the net is blown, while suppressing the scattering of the net, an area is on the catching surface. This becomes a better method.

The nonwoven fabric obtained by the spunbond method has the characteristics of strong cloth strength and no physical properties such as the shedding of short fibers caused by the damage of the joint, and it has low cost and high productivity, so it is used for hygiene, Civil engineering, construction, agriculture / horticulture, and living materials are widely used.

The fiber diameter of the polyester long fiber of this embodiment is 13-40 μm, preferably 15-40 μm, more preferably 18-35 μm, and a particularly preferable range is 21-30 μm. If the fiber diameter is 13 μm or more, it can be designed to have sufficient transparency. In addition, if the fiber diameter is less than 40 μm when the fiber cannot fully withstand the tension of the ejector during spinning and less likely to break a part of the fiber, when it is made into a nonwoven fabric and used as a filter for food, the mechanical strength or It is excellent in rigidity, component extractability, transparency, and sealability, and is suitable as a food filter.

The surface area per unit area of the polyester long-fiber nonwoven fabric of this embodiment (that is, the specific surface area m ² / g of the long-fiber nonwoven fabric × unit weight g / m ² ) is 1.0 to 3.5 (m ² / m ² ), more preferably It is 1.2 ~ 3.0 (m ² / m ² ), especially the range is 1.3 ~ 2.7 (m ² / m ² ). If the surface area per unit area is 3.5 (m ² / m ² ) or less, it can be designed to have sufficient transparency. In addition, if the surface area per unit area is 1.0 or more, a sufficient number of fibers can be obtained when making a nonwoven fabric, so when used as a food filter, it has excellent mechanical strength or rigidity, component extractability, and sealability. Suitable as a filter for food.

The layer configuration of the polyester long-fiber nonwoven fabric of this embodiment is not particularly limited as long as it is a method of forming a nonwoven fabric through thermal / chemical integration, and it may be a laminated nonwoven fabric. In this case, it is preferable to set the layer structure to distinguish the roles assumed by the layers. For example, the first layer is a layer with high heat seal strength, and the other layer is a layer with excellent mechanical strength such as tensile strength, rigidity, and dimensional stability, which can be used to make the seal required for bag making Non-woven fabric with excellent characteristics and excellent mechanical properties. In addition, in the step of making the non-woven fabric into a bag shape, if a non-woven fabric with a structure of only one layer having both mechanical strength and sealing characteristics is used, in the step of manufacturing the bag by heat bonding, the high temperature The heating and pressure bonding process is carried out under the condition that the thermoplastic resin melts and adheres to the hot roller or hot plate heater of the bag-making equipment, which leads to a reduction in product quality or a reduction in processing speed. . On the other hand, if it is the nonwoven fabric structure of this embodiment, by arranging the sealing layer on the inner surface, good sealing strength can be exhibited, and production can be performed without reducing the quality and production speed.

When the laminated non-woven fabric is used as the polyester long-fiber non-woven fabric of this embodiment, the structure of the layer that bears the sealing property can be a single fiber structure or a sheath core structure or a parallel structure, split cutting, etc. The composite fiber structure containing two kinds of components, such as fiber, is preferably a structure in which a low-melting-point resin that bears sealing performance is disposed on the surface of the fiber. For example, the core is a composite fiber structure with a high melting point and the sheath is a low melting point. Specifically, the core is made of a high melting point resin such as polyethylene terephthalate or polybutylene terephthalate and the sheath is a copolymer. Ester or fat Nonwoven fabric of sheath core structure composed of aliphatic polyester and other low melting point resins.

In the case where the laminated nonwoven fabric is used as the polyester long fiber nonwoven fabric of the present embodiment, the method of producing the layer that bears mechanical strength is not particularly limited, and from the viewpoint of productivity, the spunbond method is preferred.

Especially when the laminated non-woven fabric is used as the polyester long-fiber non-woven fabric of the present embodiment, the production method and physical properties of the layer that bears mechanical strength can be made dimensionally stable and mechanically strong by using the above method for production Excellent non-woven fabric.

When the laminated non-woven fabric is used as the polyester long-fiber non-woven fabric of this embodiment, the pressure bonding method is not particularly limited as long as the fibers are integrated with each other to make the non-woven fabric, and it is preferable to laminate each layer After that, they are thermo-compression-bonded with a hot roller or the like to make a non-woven fabric. By thermocompression bonding each layer after lamination, the bonding strength between the layers can be made stronger, so that the mechanical strength or sealing performance can be more effectively reflected.

By setting the layer structure of the laminated nonwoven fabric in the present embodiment to the layered structure as described above, the seal strength can be set to a more preferable range. As a specific sealing strength, it is 1.5 N / 30 mm or more, preferably 2.0 N / 30 mm or more, and more preferably 2.5 N / 30 mm or more.

In addition, the mechanical strength, that is, the tensile strength may be set to a more preferable range, and the range is 15 N / 30 mm or more, preferably 20 N / 30 mm or more, and more preferably 23 N / 30 mm or more.

The thermocompression bonding of the polyester long-fiber nonwoven fabric of this embodiment is not particularly limited as long as it is a method of crimping the filaments of the nonwoven fabric with heat, and the nonwoven fabric may be passed through a surface structure having irregularities A pair of embossing rollers and smoothing rollers is heated between the heating rollers to form a thermocompression-bonded portion that is evenly distributed over the entire nonwoven fabric and is preferably performed. When using embossing rollers for thermal compression bonding, it is preferable to perform thermal compression bonding at a thermal compression bonding area ratio in the range of 5-40% relative to the total area of the nonwoven fabric, more preferably 7-30%. Furthermore, it is preferably 7 to 20%.

If the area of thermocompression bonding is within this range, good thermocompression bonding between fibers can be performed to achieve moderate mechanical strength or rigidity, transparency, component extraction, and dimensional stability of the obtained nonwoven fabric The aspect is better. The temperature and pressure of the thermocompression bonding process should be appropriately selected according to the conditions such as the weight per unit area and the speed of the supplied net, and are not generalized. It is preferably a temperature lower than the melting point of the polyester resin by 10 to 90 ° C, and more preferably lower 20 ~ 60 ℃ temperature.

In the above-mentioned thermocompression bonding step, in addition to using an embossing roller, an air blowing method in which the filaments are crimped with heat by passing hot air through a net can also be used. In the case of thermocompression bonding by the air blowing method, since there is no local unevenness like the embossed shape on the surface of the fabric, the appearance of the nonwoven fabric can be made more transparent.

The boiling water shrinkage of the polyester long-fiber nonwoven fabric of the present embodiment is preferably 2.0% or less, more preferably 1.6% or less, and further preferably 1.0%, and a particularly preferable range is 0.5% or less. If the shrinkage of boiling water is 2.0% or less, there is almost no shrinkage in thermoforming, etc., and the step stability is excellent. Even in the form of use such as exposure to high temperatures near 100 ° C, the shape retention Excellent. The lower limit is preferably 0%, actually 0.2% or more.

The transparency of the polyester long-fiber nonwoven fabric of this embodiment is preferably 60% or more, more preferably 65% or more, and still more preferably 70% or more. If the transparency is less than 60%, it is difficult to see the content through the non-woven fabric and become unclear.

The weight per unit area of the polyester long fiber nonwoven fabric of this embodiment is 10 to 30 g / m ² , preferably 12 to 25 g / m ² . If the weight per unit area is 10 g / m ² or more, the transparency and component extractability can be maintained, and the mechanical strength can be sufficiently ensured. On the other hand, if the weight per unit area is 30 g / m ² or less, transparency and component extractability can be obtained.

The thickness of the polyester long fiber nonwoven fabric of this embodiment is preferably 0.02 to 0.50 mm, and more preferably 0.03 to 0.30 mm. When the weight per unit area and the thickness are within this range, excellent transparency, mechanical strength, and component extractability when used as a filter for food can be obtained.

The average apparent density of the polyester long-fiber nonwoven fabric of this embodiment is preferably 0.10 to 0.50 g / cm ³ , and more preferably 0.12 to 0.30 g / cm ³ . The average apparent density is related to the rigidity, transparency, powder leakage and component extractability of the non-woven fabric. If it is within the above range, the fiber gap is moderate, so it is suitable as a food filter. If the average apparent density is 0.10 g / cm ³ or more, the fiber gap can be adjusted to appropriately suppress the amount of powder leakage, and the mechanical strength can also be sufficient. On the other hand, if the average apparent density is 0.50 g / cm ³ or less, the fiber gap is not too small, the component extractability can be appropriately maintained, and the product quality can be sufficient.

The MD (Machine Direction, MD) direction tensile strength of the polyester long fiber nonwoven fabric of the present embodiment is preferably 5-40N / 30mm, more preferably 6-40N / 30mm, and further preferably 7-40N / 30mm. If the tensile strength is above this range, the production stability at the time of bag-making processing or the prevention of breakage when used as a food filter is excellent.

The texture coefficient of the polyester long-fiber nonwoven fabric of this embodiment is preferably 0.5 to 2.0, and more preferably 0.5 to 1.5. The texture coefficient indicates the uniformity of the non-woven fabric, so it is related to the strength, rigidity, transparency, powder leakage and component extractability. Within the above range, the uniformity of the non-woven fabric is the best, so it has excellent strength, rigidity, transparency, adaptability to a bag shape, and powder leakage as a food filter.

The spinning temperature when obtaining the polyester long fiber of the present embodiment is preferably a temperature higher than the melting point of the polyester resin by 10 to 60 ° C, and more preferably a temperature higher by 10 to 30 ° C. If the spinning temperature is within this range, monofilament breakage and the like will not occur, and the orientation crystallinity is moderate, so that a nonwoven fabric excellent in mechanical strength or dimensional stability can be obtained.

The inherent viscosity (IV value) of the resin after the polyester long-fiber nonwoven fabric of this embodiment is made into a nonwoven fabric is preferably 0.6 or more, more preferably 0.65 or more, and still more preferably 0.7 or more. When the resin pellets are melt-extruded, the resin will decompose due to heat load during melting or shear load during kneading. If the IV value of the resin after melting, that is, after being made into a non-woven fabric is above this range, the decomposition of the resin can be better suppressed and the extension and crystallization of the resin during spinning can be promoted, so the mechanical strength, Non-woven fabric with excellent dimensional stability.

The spinning speed when obtaining the polyester long fiber of the present embodiment is preferably 3000 to 6000 m / min, more preferably 3500 to 5000 m / min. If the drawing speed of the spun yarn is refined within the above range, the orientation crystallization of the polyester long fiber is sufficient to obtain a nonwoven fabric with excellent mechanical properties or dimensional stability, and breakage occurs during spinning There is less possibility, and it is better in terms of productivity of non-woven fabrics.

When the polyester long fiber of the present embodiment is obtained, the stretching is preferably 400 to 2500, and more preferably 700 to 2200. If the draw ratio of the spun yarn is refined within the above range, the orientation crystallization of the polyester long fiber is sufficient to obtain a nonwoven fabric with excellent mechanical properties or dimensional stability, and breakage occurs during spinning Or the possibility of "winding around the roller" during thermocompression bonding is low, so it is also preferable in terms of productivity of nonwoven fabrics.

The birefringence Δn of the polyester long fiber of this embodiment is 0.04 to 0.12, preferably 0.06 to 0.1. If the birefringence is in this range, the alignment of the fiber is moderate, and a nonwoven fabric excellent in mechanical strength or dimensional stability can be obtained.

The method for evaluating the crystallinity is not particularly limited, and for example, it can be measured by crystallinity measurement based on DSC (Differential scanning calorimetry) or Raman spectrometry.

The crystallinity of the polyester long fiber of this embodiment is 30-50%, preferably 40-50%. If the crystallinity is within this range, fibers with excellent mechanical strength or dimensional stability can be obtained.

When the crystallinity of the polyester long fiber of this embodiment is implemented by Raman spectroscopy, the peak generated by the C = O group near 1740 cm ^-1 observed in the Raman spectrum of the fiber profile can be used The average value of the full amplitude at half maximum of the width is evaluated. The average value of the half-peak amplitude of the peak width is 18 ~ 24cm ^-1 , preferably 19 ~ 24cm ^-1 , and the more preferable range is 20 ~ 23cm ^-1 . If the average value of the full width at half maximum of the peak width is within this range, a fiber with excellent mechanical strength or dimensional stability can be obtained.

The polyester long fiber of this embodiment can crystallize differently in the radial direction of the fiber For example, the crystallinity of the outer periphery is higher, and the crystallinity of the interior is lower. By making the crystallinity of the outer peripheral part higher, it is possible to make fibers that are less likely to shrink and have excellent mechanical strength, and by making the internal crystallinity low, the crimping strength of the fibers can be sufficiently obtained during thermocompression bonding. As a result, a nonwoven fabric excellent in mechanical strength and dimensional stability can be produced. This case can be confirmed by evaluating the melting peak when measuring the crystallinity by DSC.

FIG. 2 shows the relationship between the boiling water shrinkage and transparency of the polyester long-fiber nonwoven fabric in the embodiment of the present invention. If the fiber diameter is increased, the transparency can be increased, but alignment crystallization is not easy, so the shrinkage of boiling water becomes larger and the dimensional stability decreases.

3 and 4 respectively show the relationship between the draw ratio and spinning temperature of the polyester long fiber nonwoven fabric and the alignment crystallinity expressed by the birefringence (Δn) and crystallinity in the examples of the present invention. The greater the draw ratio, the more the orientation crystallinity of the fiber increases. In addition, under the spinning conditions of the thick fiber diameter, the lower the spinning temperature, the higher the cooling performance, thereby increasing the elongation efficiency, and aligning and crystallizing the fibers.

FIG. 5 shows the relationship between the intrinsic viscosity (IV value) of the resin of the polyester long-fiber nonwoven fabric and the alignment crystallinity expressed by the birefringence (Δn) and crystallinity in the embodiment of the present invention. By increasing the IV value of the resin, the orientation crystallization of the resin can be promoted, so that the orientation crystallization of the fiber can be performed.

Based on these data, and diligent research was conducted in such a way as to exert the effects required by the present invention, as a result, the inventors of the present invention used the lowering of the spinning temperature and the expansion of the draw ratio to maintain the diameter of the coarse fiber and improve the alignment crystal To improve transparency and boiling water shrinkage at the same time. That is, the improvement in transparency in the nonwoven fabric is inversely related to the improvement in dimensional stability indicated by the shrinkage rate of boiling water, but the inventors of the present invention set the optimal range of the diameter of the coarse fiber and the alignment crystallinity of the fiber At the same time, it improves transparency and dimensional stability.

Furthermore, by optimizing the intrinsic viscosity (IV value) of the resin used in the present invention, an optimal range of alignment crystallization can also be achieved. The range of IV values used for cost purposes is 0.7 The above is preferably 0.85 or less, and more preferably 0.72 to 0.8. If the inherent viscosity is within this range, monofilament breakage and the like will not occur and stable productivity can be ensured, and higher alignment crystallinity can be obtained when the molten resin is drawn and refined, thereby obtaining higher Dimensional stability and mechanical strength.

The polyester long fiber nonwoven fabric of the present embodiment is preferably excellent in hydrophilicity, so that it does not float to the surface but sinks quickly when placed in hot water. The hydrophilic agent is preferably used as a surfactant for food, for example, an aqueous solution such as sorbitan fatty acid ester, polyglycerin fatty acid ester, or sucrose fatty acid ester, an ethanol solution, or a mixed solution of ethanol and water. As the coating method, known methods such as a gravure roll method, a touch roll method, a dipping method, and a spray method can be applied.

The polyester long-fiber non-woven fabric of this embodiment can also be subjected to common post-processing, such as deodorant, antibacterial agent, etc., dyeing, water repellent processing, water permeable processing can also be performed within the range that does not impair the effects required by the present invention Wait.

The polyester long-fiber nonwoven fabric of the present embodiment has excellent transparency, so the contents can be clearly seen, so it has excellent designability, and because of its excellent dimensional stability, it has a filter suitable for foods such as green tea, black tea, coffee, etc. The characteristics. The filter for food may be a flat bag, but if it has a three-dimensional shape, the contents can be seen more clearly and extraction can be performed efficiently, which is preferable. The three-dimensional shape is preferably a tetrahedral shape, a triangular pyramid three-dimensional shape, or the like.

The three-dimensional shape of the food filter is filled with the extract and sealed and put into a bag for sale. However, it is required that the purchased consumer quickly restore the original three-dimensional shape when taken out of the bag and use it. The long-fiber non-woven fabric of the present invention has elasticity and thus has moderate rigidity, so it can fully meet the above-mentioned requirements.

[Example]

The present invention will be specifically described below using examples, but the present invention is not limited to these. In addition, the measurement method and evaluation method used are as follows.

(1) Titanium content (ppm)

The ICP (Inductively Coupled Plasma, Inductively Coupled Plasma) luminescence analyzer manufactured by Thermo Fisher Scientific was used to determine the titanium content in the polyester resin.

(2) Average fiber diameter (μm)

The diameter of the fiber was magnified by 1000 times using a Microscope microscope (VH-8000) manufactured by KEYENCE Corporation, and the average fiber diameter was determined using the average value of each 20.

(3) Birefringence (△ n)

The pressure of the BH2 polarizing microscope manufactured by OLYMPUS is used to compensate the pressure, and the birefringence of the fiber immediately after the traction is determined according to the retardation and fiber diameter using the usual interference fringe method.

(4) Crystallinity (%)

The differential scanning calorimeter DSC6000 manufactured by PerkinElmer was used to measure the calorific value △ Hc and the crystal melting amount △ Hm after the temperature was increased from 40 ° C to 300 ° C at a heating rate of 10 ° C / min. The crystallinity (%) is determined according to the following formula: Crystallinity χc (%) = (△ Hm- △ Hc) /126.4×100

＊ 126.4J / g is the heat of fusion for the complete crystallization of polyethylene terephthalate.

(5) Full amplitude at half peak (cm ^-1 )

The spectrum was measured with the excitation light of 532 nm and the excitation light intensity of 10% using a microscope Raman spectroscopic device manufactured by Renishaw. Find the half-peak full amplitude of the peak width generated by the C = O base around 1740 cm ^-1 observed in the spectrum.

(6) Intrinsic viscosity (IV value)

Measured according to JIS K-7367-5.

(7) Weight per unit area (g / m ² )

Measured according to JIS L-1906.

(8) Thickness (mm)

The thickness of 100 g / cm ^{2 was} measured by the method specified in JIS L-1906.

(9) Average apparent density (g / cm ³ )

Determine the mass per unit volume based on the weight per unit area and thickness measured by the method specified in JIS L-1906: average apparent density (g / cm ³ ) = (weight per unit area g / m ² ) / ((thickness mm ) × 1000)

(10) Thermal compression area ratio (%)

A 1 cm square test piece was sampled and a photograph was taken with an electron microscope, and the area of the thermocompression-bonded part was measured from each photo, and the average value was used as the area of the thermocompression-bonded part. In addition, the distance between the patterns of the thermocompression bonding part in the MD direction and CD (cross direction) direction is measured, and the ratio of the thermocompression bonding area to the unit area of the nonwoven fabric is calculated based on these values as the thermocompression bonding area ratio .

(11) Transparency (%)

Measure the reflectance (L value) using a Macbeth spectrophotometer (CE-7000A model: manufactured by Sakata Inx Corporation) to find the difference between the L value of the standard whiteboard (L _w0 ) and the L value of the standard blackboard (L _b0 ) As a reference, based on the L value (L _w ) of the sample placed on the whiteboard and the L value (L _b ) placed on the blackboard in the same way, the transparency is calculated according to the following formula: Transparency (%) = {(L _w -L _b ) / (L _w0 -L _b0 )) × 100

(12) Boiling water shrinkage (%)

According to JIS L-1906, three specimens with a length of 25 cm and a width of 25 cm were taken on a sample with a width of 1 m, which was immersed in boiling water for 3 minutes, and the shrinkage in the MD and CD directions was obtained after natural drying . The average value of each is calculated, and the shrinkage rate of the larger one of the MD direction and the CD direction is taken as the boiling water shrinkage rate of the nonwoven fabric.

(13) Tensile strength (N / 30mm)

Using Auto Stereograph AGS-5G manufactured by Shimadzu Corporation, a 30mm wide sample is extended with a grip length of 100mm and a tensile speed of 300mm / min, and the load at break obtained is used as the strength. Make 5 measurements in the MD direction and find Its average.

(14) Texture factor

Take a 20cm × 30cm test piece, use Nomura Corporation ’s Formation Tester (FMT-MIII) measuring device, and decompose the transmission image obtained by shooting a range of 18cm × 25cm with a CCD (Charge Coupled Device) camera For 128 × 128 pixels, measure the intensity of light received by each pixel and calculate the transmittance. The texture coefficient is the value obtained by dividing the standard deviation (σ) of the transmittance of each minute part (5mm × 5mm) of the measured sample by the average transmittance (E), which represents the deviation of the unit weight per unit area. The higher the uniformity.

Texture factor = σ / E × 100

(15) Heat seal strength (N / 30mm)

Using the auto-stereograph AGS-5G manufactured by Shimadzu Corporation, the heat-sealed part of the 30mm wide sample is peeled up and down by about 50mm, and then installed, and it is stretched by holding the length of 50mm and the stretching speed of 100mm / min Take the obtained load at break as the strength, and measure the MD direction of the non-woven fabric 5 times to determine the average value. The heat sealing condition is a sealing temperature of 210 ° C, a sealing time of 1 second, a pressure of 0.5 MPa, and a sealing area of 7 mm × 25 mm.

(16) Stretching ratio

Calculate the draw ratio according to the following formula: draw ratio = spinning speed (m / min) / ejection linear speed (m / min)

Linear ejection speed (m / min) = single-hole ejection amount (g / min) / {melt density (g / cm ³ ) × [spin nozzle diameter (cm) / 2] ² × π}

* Melt density of polyester: use 1.20g / cm ³

(17) Surface area per unit area of polyester long fiber non-woven fabric

It is determined from the specific surface area m ² / g of the long-fiber nonwoven fabric × the weight per unit area g / m ² .

The specific surface area (m ² / g) of the long-fiber non-woven fabric was obtained by using Gemini 2360, an automatic specific surface area measuring machine of Shimadzu Corporation. In addition, when the specific surface area is less than 0.1 m ² / g, it is determined by the following formula.

Surface area (m ² / m ² ) = 4 × weight per unit area (g / m ² ) / density of resin (g / cm ³ ) / fiber diameter (μm)

In the case of two or more fiber diameter sheets, the surface area of each fiber diameter is totaled.

(18) 10% aperture

Ten pieces of 2 cm square samples were cut out from one sample, and platinum sputtering was performed using an ion sputtering device for SEM (scanning electron microscope) observation, and the test was conducted at a magnification of 100 times using transmitted light 10 nonwoven images in the sample were taken. The image analysis software is used to binarize the non-woven part into black, and the hole part into white, and to quantify the area and longest diameter of all holes in the image. The image analysis soft system uses "A Xiangjun (TM)" manufactured by Asahi Kasei Engineering. Accumulate all holes in a sample image from the largest area to a smaller area in sequence, according to the hole area that reaches the point of 10% of the total hole area, as the diameter of the circle with the area equal to the area by the following The formula calculates the aperture.

Aperture (μm) = ((4 × S) / π) ^{^} 0.5

In the above formula, S means the hole area (μm ^{^} 2), and " ^{^} 0.5" means "multiply by 0.5".

(19) 2.3% aperture

Instead of the above-mentioned 10% pore size, the pore size is obtained from the pore area that reaches the point of 2.3% of the total pore area.

(20) Long diameter / Aperture

Accumulate all the holes in a sample image from the largest area to the smaller area in sequence, and find the long diameter of all the holes included between the holes that reach 2.3% of the total hole area and the holes that reach 10% The average value and the average value of the pore diameter are obtained by the following formula.

Long diameter / Aperture = average long diameter / average diameter

[Example 1]

A polyester resin with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.8, and a melting point of 247 ° C is supplied to a commonly used melt spinning device and melted at 275 ° C, from a spinning hole having a circular cross-section. The head was melt-spun at a spinning speed of 4500 m / min and a draw ratio of 2120 to obtain polyester long fibers with a fiber diameter of 20.5 μm. Then, a flat-plate-shaped airflow-controlling dispersing device [the inclination angle of the flat plate with respect to the filament is 4 °] was used to disperse the fibers to produce a mesh with a weight per unit area of 12 g / m ² . During the local thermal compression bonding at a thermal compression bonding area rate of 15%, a polyester long fiber nonwoven fabric was obtained. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 2]

In Example 1, a polyester long fiber nonwoven fabric was obtained in the same manner as in Example 1, except that the polyester long fiber was spun so that the fiber diameter became 25.7 μm. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 3]

In Example 1, a polyester long fiber nonwoven fabric was obtained in the same manner as in Example 1 except that the polyester long fiber was spun so that the fiber diameter became 30.0 μm. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 4]

In Example 3, except that the resin having an IV value of 0.8 and a titanium oxide content of 12 ppm was used, a polyester long fiber nonwoven fabric was obtained in the same manner as in Example 3. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 5]

In Example 3, except that the resin having an IV value of 0.8 and a titanium oxide content of 70 ppm was used, a polyester long fiber nonwoven fabric was obtained in the same manner as in Example 3. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 6]

Except that the resin having an IV value of 0.72 and a titanium oxide content of 0 ppm was used in Example 3, a polyester long fiber nonwoven fabric was obtained in the same manner as in Example 3. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 7]

Except that the resin having an IV value of 0.77 and a titanium oxide content of 0 ppm was used in Example 3, a polyester long fiber nonwoven fabric was obtained in the same manner as in Example 3. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 8]

In Example 3, the polyester long-fiber nonwoven fabric was spun so that the basis weight of the polyester long-fiber nonwoven fabric was 20 g / m ² , except that the polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 3. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 9]

In Example 1, melt spinning was carried out at a spinning speed of 3770 m / min and a draw ratio of 707, and spinning was carried out in such a way that the fiber diameter of the polyester long fiber became 34.9 μm, except that it was the same as Example 1. Way to obtain polyester long fiber non-woven fabric. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 10]

In Example 2, it was spun in such a way that the weight per unit area of the polyester long-fiber nonwoven fabric became 20 g / m ² , and the entire surface was thermally pressure-bonded with a smooth roll, except that it was obtained in the same manner as in Example 2. Polyester long fiber non-woven fabric. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 11]

A polyester resin with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.8, and a melting point of 246 ° C is supplied to a commonly used melt spinning device and melted at 275 ° C, from a spinning hole with a circular cross section The spinning head was melt-spun at a spinning speed of 4000 m / min and a draw ratio of 942 to obtain polyester long fibers with a fiber diameter of 30.1 μm. Then, a flat-plate-shaped airflow-controlling dispersing device [the inclination angle of the flat plate with respect to the filament is 4 °] was used to disperse the fibers to produce a net with a basis weight of 20 g / m ² , which was applied to the embossing roll and smoothing roll. During the local thermal compression bonding at a thermal compression bonding area rate of 5%, polyester long fiber nonwoven fabric was obtained. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 12]

A polyester resin with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.8, and a melting point of 246 ° C is supplied to a commonly used melt spinning device and melted at 275 ° C, from a spinning hole with a circular cross section The spinning head was melt-spun at a spinning speed of 4000 m / min and a draw ratio of 942 to obtain polyester long fibers with a fiber diameter of 30.0 μm. Then, the fibers were opened and dispersed to produce a web with a weight per unit area of 12 g / m ² , and a local thermocompression bonding was performed between the embossing roll and the smoothing roll at a thermal compression bonding area ratio of 15% to obtain polyester long fibers Non-woven. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 13]

A polyester resin with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.8, and a melting point of 246 ° C is supplied to a commonly used melt spinning device and melted at 275 ° C, from a spinning hole with a circular cross section The spinning head is melt-spun at a spinning speed of 4000 m / min and a draw ratio of 942, using a flat-plate-shaped dispersion device that controls airflow [the inclination angle of the flat plate with respect to the filament is 4 °] so that the fiber diameter is 26.7 μm Polyester long fibers are opened and dispersed to produce a net with a basis weight of 18 g / m ² . Then, a polyester resin with a titanium content of 12 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 217 ° C was supplied to a conventional melt spinning device and melted at 275 ° C, from a spinning hole having a circular cross section The spinning head is melt-spun at a spinning speed of 4150 m / min and a draw ratio of 412 and uses a flat-plate-shaped dispersion device that controls the air flow [the inclination angle of the flat plate with respect to the filament is 4 °] so that the fiber diameter is 15 μm The long polyester fibers are spread and dispersed to produce a net having a basis weight of 3 g / m ² . The two-layer web was locally thermally pressure-bonded between the embossing roller and the smoothing roller at a thermal compression bonding area ratio of 15%, thereby obtaining a polyester long-fiber nonwoven fabric. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 14]

A polyester resin with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.8, and a melting point of 246 ° C is supplied to a commonly used melt spinning device and melted at 275 ° C, from a spinning hole with a circular cross section The spinning head is melt-spun at a spinning speed of 4000 m / min and a draw ratio of 942, using a flat-plate-shaped dispersion device that controls the air flow [the inclination angle of the flat plate with respect to the filament is 4 °] so that the fiber diameter is 24.6 μm The polyester long fibers are spread and dispersed to produce a net having a basis weight of 10 g / m ² . Next, a polyester resin with a titanium content of 12 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 254 ° C was used as the core, and a polymer with a titanium content of 12 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 217 ° C The ester-based resin is supplied as a sheath to a conventional melt spinning device and melted at 275 ° C, and melt spinning is performed at a spinning speed of 4500 m / min and a draw ratio of 895 from a spinning head having a spinning hole with a circular cross section Using a flat-plate-shaped dispersing device for controlling airflow [the inclination angle of the flat plate with respect to the filament is 4 °], the polyester filaments with a fiber diameter of 20 μm are opened and dispersed to produce a net with a weight per unit area of 8 g / m ² . The two-layer web was locally thermally pressure-bonded between the embossing roller and the smoothing roller at a thermal compression bonding area ratio of 15%, thereby obtaining a polyester long-fiber nonwoven fabric. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 15]

In Example 1, the polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 1 except that the polyester long-fiber nonwoven fabric had a spinning basis weight of 18 g / m ² . The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 16]

In Example 2, the polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 1 except that the basis weight of the polyester long-fiber nonwoven fabric was 18 g / m ² . The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 17]

In Example 3, the polyester long-fiber non-woven fabric was obtained in the same manner as in Example 1 except that the polyester long-fiber non-woven fabric had a spinning basis weight of 18 g / m ² . The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 18]

In Example 1, the first layer of non-woven fabric was prepared such that the weight per unit area of the polyester long-fiber non-woven fabric became 18 g / m ² . PET (polyethylene terephthalate) resin with an IV value of 0.65, a titanium content of 0 ppm, and a melting point of 217 ° C was used at a spinning temperature of 260 ° C and heated air of 500 Nm ³ / hr / m. After spinning, the obtained meltblown nonwoven fabric with a fiber diameter of 10 μm was blown onto the spunbond nonwoven fabric at a basis weight of 5 g / m ² to obtain a laminate of nonwoven fabric. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 19]

In Example 2, the first layer of non-woven fabric was prepared so that the weight per unit area of the polyester long-fiber non-woven fabric became 18 g / m ² . A PET resin with an IV value of 0.65, a titanium content of 0 ppm, and a melting point of 217 ° C was used for spinning at a spinning temperature of 255 ° C and heated air of 400 Nm ³ / hr / m, and the resulting fiber was melted at a diameter of 15 μm. The sprayed nonwoven fabric was blown onto the above spunbond nonwoven fabric at a basis weight of 4 g / m ² to obtain a laminate of nonwoven fabric. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 20]

In Example 3, the first layer of non-woven fabric was prepared such that the weight per unit area of the polyester long-fiber non-woven fabric became 18 g / m ² . A PET resin with an IV value of 0.65, a titanium content of 0 ppm, and a melting point of 217 ° C was used for spinning at a spinning temperature of 265 ° C and heated air of 1000 Nm ³ / hr / m, and the resulting fiber was melted at a diameter of 7 μm The sprayed nonwoven fabric was blown onto the above spunbond nonwoven fabric at a basis weight of 4 g / m ² to obtain a laminate of nonwoven fabric. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 21]

A polyester resin with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.8, and a melting point of 247 ° C is supplied to a commonly used melt spinning device and melted at 275 ° C, from a spinning hole with a circular cross section The spinning head was melt-spun at a spinning speed of 4500 m / min and a draw ratio of 230 to obtain polyester long fibers with a fiber diameter of 14 μm. Then, a flat-plate-shaped airflow-controlling dispersing device [the inclination angle of the flat plate with respect to the filament is 4 °] was used to spread and spread the fibers to prepare a net with a weight per unit area of 7.5 g / m ² . Then, a polyester resin with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 254 ° C was used as the core, and a polymer with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 217 ° C The ester-based resin is supplied as a sheath to a conventional melt spinning device and melted at 275 ° C, and melt spinning is performed at a spinning speed of 4500 m / min and a draw ratio of 380 from a spinning head having a spinning hole with a circular cross section Using a flat-plate-shaped airflow-controlling dispersing device [the inclination angle of the flat plate with respect to the filament is 4 °], a polyester filament with a fiber diameter of 14 μm is opened and dispersed to produce a net with a weight per unit area of 7.5 g / m ² . The two-layer web was locally thermally pressure-bonded between the embossing roller and the smoothing roller at a thermal compression bonding area ratio of 15%, thereby obtaining a polyester long-fiber nonwoven fabric. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 22]

A polyester resin with a titanium content of 12 ppm, an intrinsic viscosity (IV) of 0.8, and a melting point of 247 ° C is supplied to a commonly used melt spinning device and melted at 275 ° C, from a spinning hole with a circular cross section The spinning head was melt-spun at a spinning speed of 4500 m / min and a draw ratio of 590 to obtain polyester long fibers with a fiber diameter of 20.1 μm. Then, a flat-plate-shaped airflow-controlling dispersing device [the inclination angle of the flat plate with respect to the filament is 4 °] was used to spread and spread the fibers to prepare a net with a weight per unit area of 7.5 g / m ² . Then, a polyester resin with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 254 ° C was used as the core, and a polymer with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 217 ° C The ester-based resin is supplied as a sheath to a conventional melt spinning device and melted at 275 ° C, and melt spinning is performed at a spinning speed of 4500 m / min and a draw ratio of 380 from a spinning head having a spinning hole with a circular cross section Using a flat-plate-shaped airflow-controlling dispersing device [the inclination angle of the flat plate with respect to the filament is 4 °], a polyester filament with a fiber diameter of 14 μm is opened and dispersed to produce a net with a weight per unit area of 7.5 g / m ² . The two-layer web was locally thermally pressure-bonded between the embossing roller and the smoothing roller at a thermal compression bonding area ratio of 15%, thereby obtaining a polyester long-fiber nonwoven fabric. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 23]

A polyester resin with a titanium content of 12 ppm, an intrinsic viscosity (IV) of 0.8, and a melting point of 247 ° C is supplied to a commonly used melt spinning device and melted at 275 ° C, from a spinning hole with a circular cross section The spinning head was melt-spun at a spinning speed of 4500 m / min and a draw ratio of 740 to obtain polyester long fibers with a fiber diameter of 24.6 μm. Then, a flat-plate-shaped airflow-controlling dispersing device [the inclination angle of the flat plate with respect to the filament is 4 °] was used to spread and spread the fibers to prepare a net with a weight per unit area of 7.5 g / m ² . Then, a polyester resin with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 254 ° C was used as the core, and a polymer with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 217 ° C The ester-based resin is supplied as a sheath to a conventional melt spinning device and melted at 275 ° C, and melt spinning is performed at a spinning speed of 4500 m / min and a draw ratio of 380 from a spinning head having a spinning hole with a circular cross section Using a flat-plate-shaped airflow-controlling dispersing device [the inclination angle of the flat plate with respect to the filament is 4 °], a polyester filament with a fiber diameter of 14 μm is opened and dispersed to produce a net with a weight per unit area of 7.5 g / m ² . The two-layer web was locally thermally pressure-bonded between the embossing roller and the smoothing roller at a thermal compression bonding area ratio of 15%, thereby obtaining a polyester long-fiber nonwoven fabric. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 24]

A polyester resin with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.8, and a melting point of 247 ° C is supplied to a commonly used melt spinning device and melted at 275 ° C, and is spun from a spinning hole having a circular cross section The yarn end was melt-spun at a spinning speed of 4500 m / min and a draw ratio of 550 to obtain polyester long fibers with a fiber diameter of 20.1 μm. Next, a flat-plate-shaped airflow-controlling dispersing device [the inclination angle of the flat plate with respect to the filament is 4 °] was used to spread and spread the fibers to produce a net having a basis weight of 10 g / m ² . Then, a polyester resin with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 254 ° C was used as the core, and a polymer with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 217 ° C The ester resin is supplied as a sheath to a commonly used melt spinning device and melted at 275 ° C, and melt spinning is performed at a spinning speed of 4500 m / min and a draw ratio of 450 from a spinning head having a spinning hole with a circular cross section The filament was used to disperse a flat airflow-controlling dispersing device [the inclination angle of the flat plate with respect to the filament is 4 °] to disperse the polyester filament with a fiber diameter of 16 μm to produce a net with a weight per unit area of 5 g / m ² . The two-layer web was locally thermally pressure-bonded between the embossing roller and the smoothing roller at a thermal compression bonding area ratio of 15%, thereby obtaining a polyester long-fiber nonwoven fabric. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 25]

A polyester resin with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.8, and a melting point of 247 ° C is supplied to a commonly used melt spinning device and melted at 275 ° C, and is spun from a spinning hole having a circular cross section The yarn end was melt-spun at a spinning speed of 4500 m / min and a draw ratio of 590 to obtain polyester long fibers with a fiber diameter of 20.1 μm. Then, a flat-plate-shaped airflow-controlling dispersing device [the inclination angle of the flat plate with respect to the filament is 4 °] was used to spread and spread the fibers to prepare a net with a weight per unit area of 7.5 g / m ² . Then, a polyester resin with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 254 ° C was used as the core, and a polymer with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 217 ° C The ester resin is supplied as a sheath to a commonly used melt spinning device and melted at 275 ° C, and melt spinning is performed at a spinning speed of 4500 m / min and a draw ratio of 450 from a spinning head having a spinning hole with a circular cross section Using a flat-plate-shaped airflow-controlling dispersing device [the inclination angle of the flat plate with respect to the filament is 4 °], the polyester filaments with a fiber diameter of 16 μm are opened and dispersed to produce a net with a weight per unit area of 7.5 g / m ² . The two-layer web was locally thermally pressure-bonded between the embossing roller and the smoothing roller at a thermal compression bonding area ratio of 15%, thereby obtaining a polyester long-fiber nonwoven fabric. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 26]

A polyester resin with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.8, and a melting point of 247 ° C is supplied to a commonly used melt spinning device and melted at 275 ° C, and is spun from a spinning hole having a circular cross section The yarn end was melt-spun at a spinning speed of 4500 m / min and a draw ratio of 740 to obtain polyester long fibers with a fiber diameter of 24.6 μm. Then, a flat-plate-shaped airflow-controlling dispersing device [the inclination angle of the flat plate with respect to the filament is 4 °] was used to spread and spread the fibers to prepare a net with a weight per unit area of 7.5 g / m ² . Then, a polyester resin with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 254 ° C was used as the core, and a polymer with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 217 ° C The ester resin is supplied as a sheath to a commonly used melt spinning device and melted at 275 ° C, and melt spinning is performed at a spinning speed of 4500 m / min and a draw ratio of 450 from a spinning head having a spinning hole with a circular cross section Using a flat-plate-shaped airflow-controlling dispersing device [the inclination angle of the flat plate with respect to the filament is 4 °], the polyester filaments with a fiber diameter of 16 μm are opened and dispersed to produce a net with a weight per unit area of 7.5 g / m ² . The two-layer web was locally thermally pressure-bonded between the embossing roller and the smoothing roller at a thermal compression bonding area ratio of 15%, thereby obtaining a polyester long-fiber nonwoven fabric. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 27]

A polyester resin with a titanium content of 12 ppm, an intrinsic viscosity (IV) of 0.8, and a melting point of 247 ° C is supplied to a commonly used melt spinning device and melted at 275 ° C, from a spinning hole with a circular cross section The spinning head was melt-spun at a spinning speed of 4500 m / min and a draw ratio of 590 to obtain polyester long fibers with a fiber diameter of 20.1 μm. Then, a flat-plate-shaped airflow-controlling dispersing device [the inclination angle of the flat plate with respect to the filament 0 °] was used to spread and spread the fibers to produce a net with a weight per unit area of 7.5 g / m ² . Then, a polyester resin with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 254 ° C was used as the core, and a polymer with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 217 ° C The ester resin is supplied as a sheath to a commonly used melt spinning device and melted at 275 ° C, and melt spinning is performed at a spinning speed of 4500 m / min and a draw ratio of 450 from a spinning head having a spinning hole with a circular cross section Using a flat-plate-shaped airflow-controlling dispersing device [the inclination angle of the flat plate with respect to the filament is 0 °], polyester filaments with a fiber diameter of 16 μm are opened and dispersed to produce a net with a weight per unit area of 7.5 g / m ² . The two-layer web was locally thermally pressure-bonded between the embossing roller and the smoothing roller at a thermal compression bonding area ratio of 15%, thereby obtaining a polyester long-fiber nonwoven fabric. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 28]

Except that the inclination angle of the flat plate of the airflow-controlling dispersion device with respect to the filament was set to 0 °, the polyester filament nonwoven fabric was obtained by the same method as in Example 22. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 29]

Except that the self-sheath core structure using a low-melting-point resin is a side-by-side structure, a polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 21. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 30]

A layered self-sheathed core structure using a low-melting-point resin was used as a side-by-side structure, and a polyester long fiber nonwoven fabric was obtained in the same manner as in Example 24. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 31]

Except that the self-sheath core structure of the layer using a low-melting-point resin is a side-by-side structure, a polyester long fiber nonwoven fabric was obtained by the same method as in Example 22. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 32]

Except that the weight per unit area of each layer was 6 g / m ² , a polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 21. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 33]

Except that the weight per unit area of each layer was 6 g / m ² , a polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 22. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 34]

Except that the weight per unit area of each layer was 6 g / m ² , a polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 23. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 35]

A polyester resin with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.8, and a melting point of 247 ° C is supplied to a commonly used melt spinning device and melted at 275 ° C, and is spun from a spinning hole having a circular cross section The yarn end was melt-spun at a spinning speed of 4500 m / min and a draw ratio of 590 to obtain polyester long fibers with a fiber diameter of 20.1 μm. Then, a flat-plate-shaped airflow-controlling dispersing device [the inclination angle of the flat plate with respect to the filament is 4 °] was used to spread and spread the fibers to produce a net having a basis weight of 12 g / m ² . Then, a polyester resin with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 254 ° C was used as the core, and a polymer with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 217 ° C The ester resin is supplied as a sheath to a commonly used melt spinning device and melted at 275 ° C, and melt spinning is performed at a spinning speed of 4500 m / min and a draw ratio of 450 from a spinning head having a spinning hole with a circular cross section The filament was used to disperse a flat airflow-controlling dispersion device [the inclination angle of the flat plate with respect to the filament is 4 °] to disperse the polyester long fibers with a fiber diameter of 16 μm to produce a net weight of 6 g / m ² . The two-layer web was locally thermally pressure-bonded between the embossing roller and the smoothing roller at a thermal compression bonding area ratio of 15%, thereby obtaining a polyester long-fiber nonwoven fabric. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 36]

The weight per unit area of each layer was set to 9 g / m ² , except that the polyester long fiber nonwoven fabric was obtained in the same manner as in Example 25. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 37]

Except having set the weight per unit area of each layer to 9 g / m ² , a polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 21. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 38]

A polyester resin with a titanium content of 12 ppm, an intrinsic viscosity (IV) of 0.8, and a melting point of 247 ° C is supplied to a commonly used melt spinning device and melted at 305 ° C, from a spinning hole having a circular cross section The spinning head was melt-spun at a spinning speed of 4500 m / min and a draw ratio of 230 to obtain polyester long fibers with a fiber diameter of 10 μm. Then, a flat-plate-shaped airflow-controlling dispersing device [the inclination angle of the flat plate with respect to the filament is 4 °] was used to spread and spread the fibers to prepare a net with a weight per unit area of 7.5 g / m ² . Then, a polyester resin with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 254 ° C was used as the core, and a polymer with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 217 ° C The ester-based resin is supplied as a sheath to a conventional melt spinning device and melted at 275 ° C, and melt spinning is performed at a spinning speed of 4500 m / min and a draw ratio of 380 from a spinning head having a spinning hole with a circular cross section Using a flat-plate-shaped airflow-controlling dispersing device [the inclination angle of the flat plate with respect to the filament is 4 °], a polyester filament with a fiber diameter of 14 μm is opened and dispersed to produce a net with a weight per unit area of 7.5 g / m ² . The two-layer web was locally thermally pressure-bonded between the embossing roller and the smoothing roller at a thermal compression bonding area ratio of 15%, thereby obtaining a polyester long-fiber nonwoven fabric. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 39]

Except that the fiber diameter of each layer was 13 μm, a polyester long fiber nonwoven fabric was obtained in the same manner as in Example 32. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Comparative Example 1]

In Example 1, the content of the titanium element of the polyester-based resin was set to 3000 ppm, and spinning was carried out so that the weight per unit area of the polyester long fiber became 20.0 g / m ² , except that it was the same as Example 1. The polyester long fiber nonwoven fabric is obtained by this method, but the transparency of the nonwoven fabric is low, and sufficient transparency cannot be obtained as a filter for food. The physical properties of the obtained nonwoven fabric are shown in Table 3 below.

[Comparative Example 2]

In Example 1, the fiber diameter of the polyester long fiber after melt spinning at a draw ratio of 545 was set to 12.0 μm, and spinning was performed so that the weight per unit area of the polyester long fiber became 20 g / m ² , Other than this, the polyester long fiber nonwoven fabric was obtained in the same manner as in Example 1, but the transparency of the nonwoven fabric was low, and sufficient transparency could not be obtained as a filter for food. The physical properties of the obtained nonwoven fabric are shown in Table 3 below.

[Comparative Example 3]

A polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 1 except that a polyester resin having a titanium element content of 12 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 253 ° C was used. The physical properties of the obtained nonwoven fabric are shown in Table 3 below.

[Comparative Example 4]

A polyester long fiber nonwoven fabric was obtained in the same manner as in Example 2 except that a polyester resin having a titanium element content of 12 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 253 ° C was used. The physical properties of the obtained nonwoven fabric are shown in Table 3 below.

[Comparative Example 5]

A polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 3 except that a polyester resin having a titanium element content of 12 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 253 ° C was used. The physical properties of the obtained nonwoven fabric are shown in Table 3 below.

[Comparative Example 6]

Use titanium element content of 12ppm, inherent viscosity (IV) of 0.65, melting point of 253 ℃ Except for the polyester-based resin, a polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 4. The physical properties of the obtained nonwoven fabric are shown in Table 3 below.

[Comparative Example 7]

A polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 3 except that a polyester resin having a titanium element content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 253 ° C was used. The physical properties of the obtained nonwoven fabric are shown in Table 3 below.

[Comparative Example 8]

A polyester resin with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.8, and a melting point of 246 ° C is supplied to a commonly used melt spinning device and melted at 295 ° C, from a spinning hole with a circular cross section The spinning head was melt-spun at a spinning speed of 4000 m / min and a draw ratio of 191 to obtain polyester long fibers with a fiber diameter of 30.3 μm. Then, a flat-plate-shaped airflow-controlling dispersing device [the inclination angle of the flat plate with respect to the filament is 4 °] was used to spread the fibers to make a net with a weight per unit area of 20 / m ² , which was applied to the embossing roll and smoothing roll. During the local thermal compression bonding at a thermal compression bonding area ratio of 15%, a polyester long fiber nonwoven fabric is obtained, but as a food filter, sufficient dimensional stability cannot be obtained. The physical properties of the obtained nonwoven fabric are shown in Table 3 below.

[Comparative Example 9]

In Comparative Example 8, the fiber diameter of the polyester long fiber after melt spinning at a draw ratio of 345 was set to 50.0 μm, and spinning was performed so that the weight per unit area of the polyester long fiber became 20 g / m ² . However, the shrinkage of the roller is too large to obtain polyester long fiber nonwoven fabric. The physical properties of the obtained nonwoven fabric are shown in Table 3 below.

[Comparative Example 10]

In Example 3, a net was produced in such a way that the weight per unit area of the polyester long fiber became 40 g / m ² , except that the polyester long fiber nonwoven fabric was obtained in the same manner as in Example 3, but the transparency of the nonwoven fabric was low , As a food filter can not obtain sufficient transparency. The physical properties of the obtained nonwoven fabric are shown in Table 3 below.

[Comparative Example 11]

Except that the titanium content of the resin was set to 3000 ppm, a polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 21. The physical properties of the obtained nonwoven fabric are shown in Table 3 below.

[Comparative Example 12]

Except that the IV value of the resin was set to 0.7, in the same manner as in Comparative Example 11, a polyester long-fiber nonwoven fabric was obtained. The physical properties of the obtained nonwoven fabric are shown in Table 3 below.

[Comparative Example 13]

A polyester resin with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.65 and a melting point of 254 ° C is used as the core, and a polyester system with a titanium content of 0 ppm, an intrinsic viscosity (IV) of 0.65 and a melting point of 217 ° C The resin is supplied as a sheath to a commonly used melt spinning device and is melted at 275 ° C. Melt spinning is performed at a spinning speed of 4500 m / min from a spinning head having a spinning hole with a circular cross-section and a flat-shaped controlled air flow is used The dispersing device [the inclination angle of the flat plate with respect to the filament is 4 °] disperses the polyester long fibers with a fiber diameter of 14 μm, and disperses the net weight of 15 g / m ² between the embossing roller and the smoothing roller to heat The area of the crimping area is 15%, and local thermal crimping is performed to obtain a polyester long fiber nonwoven fabric. The physical properties of the obtained nonwoven fabric are shown in Table 3 below. Furthermore, when heat-sealing the obtained nonwoven fabric, the sealing machine produces serious resin contamination.

[Comparative Example 14]

Except that the weight per unit area of each layer was 10 g / m ² , a polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 21. Table 3 shows the physical properties of the obtained nonwoven fabric.

[Comparative Example 15]

Except that the weight per unit area of each layer was 4 g / m ² , a polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 26. Table 3 shows the physical properties of the obtained nonwoven fabric.

[Industry availability]

The single-layer or multi-layer polyester long-fiber nonwoven fabric of the present invention is excellent in transparency, dimensional stability, powder leakage, and component extractability, so it can be preferably used as a filter for food.

Claims (17)

A single-layer or multi-layer polyester long-fiber non-woven fabric used as a filter for food, the content of inorganic particles is 0-100ppm, the 10% point pore size is less than 1000μm, and the difference between the 10% point pore size and 2.3% point pore size is Below 500, the weight per unit area is 10 to 30 g / m ² , the transparency is 60% or more, and the surface area per unit area of the non-woven fabric is 1.0 to 3.5 m ² / m ² . If the single-layer or multi-layer polyester long-fiber non-woven fabric of claim 1, the area ratio of thermocompression bonding is 5-40%, and the average apparent density is 0.1-0.5g / cm ³ . If the single-layer or multi-layer polyester long fiber non-woven fabric of claim 1 or 2, the average fiber diameter is 13-40 μm. As claimed in claim 1 or 2, the single-layer or multi-layer polyester long-fiber non-woven fabric, at least one of which contains the half-peak width of the peak width generated by the C = O group near 1740 cm ^-1 observed in the Raman spectrum The average value of the amplitude is 18 ~ 24cm ^-1 fiber. As claimed in claim 1 or 2, a single-layer or multi-layer polyester long fiber nonwoven fabric, at least one of which contains fibers with a crystallinity of 30 to 50%. As claimed in claim 1 or 2, the single-layer or multi-layer polyester long fiber non-woven fabrics, at least one of which contains fibers with a birefringence of 0.04 to 0.12. If the single-layer or multi-layer polyester long-fiber non-woven fabric of claim 1 or 2, its boiling water shrinkage is less than 2.0%. If the single-layer or multi-layer polyester long-fiber non-woven fabric of claim 1 or 2, its texture coefficient is 0.5 ~ 2.0. As claimed in claim 1 or 2, the single-layer or multi-layer polyester long fiber non-woven fabrics, at least one of which has a tensile strength of 5N / 30mm or more. As claimed in claim 1 or 2, the single-layer or multi-layer polyester long fiber non-woven fabrics, at least one of which contains low-melting-point fibers with a melting point of 240 ° C or lower. The polyester long-fiber nonwoven fabric as claimed in claim 1 or 2, which includes a laminated nonwoven fabric formed by integrating the following a layer and b layer by thermocompression bonding, a layer: contains a melting point difference from the high melting point resin of 30 ℃ ~ 150 ℃ low-melting resin polyester long fiber non-woven fabric b layer: polyester long fiber non-woven fabric containing the above high-melting resin. The single-layer or multi-layer polyester long-fiber non-woven fabric according to claim 1 or 2 has a structure in which the orientation of the fibers of the polyester long-fiber non-woven fabric is different in the cross-sectional direction. As claimed in claim 1 or 2, single-layer or multi-layer polyester long-fiber non-woven fabrics, at least one of which contains a resin containing 0 to 25% phthalic acid. The single-layer or multi-layer polyester long-fiber non-woven fabric according to claim 1 or 2, wherein the inorganic particles are titanium oxide. The single-layer or multi-layer polyester long-fiber non-woven fabric according to claim 14 contains a resin with a titanium content of 0 to 0.1 ppm. For the single-layer or multi-layer polyester long-fiber non-woven fabric according to claim 1 or 2, the IV value of the resin after making the non-woven fabric is 0.6 or more. A food filter comprising the single-layer or multi-layer polyester long-fiber nonwoven fabric according to any one of claims 1 to 16.