KR20170117525A - Single-layer or double-layer polyester long-fiber nonwoven fabric and food filter using the same - Google Patents

Abstract

The present invention provides a single-layer or multi-layer polyester long-fiber nonwoven fabric having excellent transparency, dimensional stability, dust-leaking property and component extractability, and a food filter using the same. The single-layer or multilayer polyester long-fiber nonwoven fabric according to the present invention is characterized in that the content of the inorganic particles is 0 to 100 ppm, the 10% point hole diameter is less than 1,000 占 퐉, the difference between the 10% point hole diameter and the 2.3% Mu m or less, and the unit weight is 10 to 30 g / m < 2 >.

Description

Single-layer or double-layer polyester long-fiber nonwoven fabric and food filter using the same

The present invention relates to a single-layer or multi-layer polyester long-fiber nonwoven fabric having excellent transparency, dimensional stability, dust-leaking property and component extractability, and a food filter for extracting beverage using the same.

BACKGROUND ART Conventionally, as a packaging material, a nonwoven fabric made of a resin such as polyethylene, polypropylene, polyester, or polyamide has been used. However, in general, in order to utilize the shielding function such as the filter property of the nonwoven fabric, it is required to make the fibers dense and the inside can not be confirmed. Further, in the case of extracting components such as black tea, green tea, oolong tea, etc., a tea bag method is widely used as a simple method. Although paper is often used in packaging materials used for tea bag applications, there are problems that the contents of the packaging material are not visible because the transparency is poor and heat sealing processing can not be performed.

The following Patent Document 1 discloses a nonwoven fabric for a tea bag improved in transparency, but there is no description about dimensional stability and is not particularly specified. The maximum pore diameter measured by the bubble point method (JIS-K-3832) is used for evaluation of powder leakage, but the pore diameter range suitable for measurement is nanometer to micrometer size, Because it expresses the diameter of the hole, it is not an appropriate evaluation method for the tea leaves actually used.

Patent Document 2 below discloses a biodegradable monofilament for a tea bag having a fineness of 15 to 35 dtex made of poly (L-lactic acid). However, since the monofilament shrinkage rate of the monofilament is 20 %, And the dimensional stability is low.

Further, Patent Document 3 below discloses a nonwoven fabric comprising a core-sheath type composite long fiber having a polyolefin-based polymer as a sheath component and a polyester-based polymer having a melting point higher than that of the sheath component as a core component However, it has low dimensional stability, and there is no mention of transparency, and it is not particularly specified.

Patent Document 1: Japanese Patent No. 3939326 Patent Document 2: Japanese Patent Application Laid-Open No. 2001-131826 Patent Document 3: Japanese Patent Application Laid-Open No. 11-43855

In view of the problems of the prior art, the present invention is to provide a polyester long-fiber nonwoven fabric having excellent transparency, dimensional stability, dust-leaking property and component extractability, and a food filter using the same.

As a result of intensive studies and experiments to solve the above-mentioned problems, the inventors of the present invention have found that a polyester resin having a titanium element content within a specific range is selected, and the structure of the fibers constituting the nonwoven fabric, The present inventors have found that a nonwoven fabric having good radioactivity and excellent in both component extraction property as a food filter and good both in transparency and dimensional stability can be obtained by conducting a detailed examination in view of the thermocompression area ratio. Further, the present invention has been completed by defining the pore diameter by using the pore diameter calculated by directly observing the nonwoven fabric as an evaluation of the powder leakage property.

That is, the present invention is as follows.

Wherein the inorganic particle content is 0 to 100 ppm, the 10% point pore diameter is less than 1000 μm, the difference between the 10% point pore diameter and the 2.3% point pore diameter is 500 μm or less and the unit weight is 10 to 30 g / m < 2 >.

[2] The single-layer or double-layer polyester long-fiber nonwoven fabric according to [1], wherein the thermocompression bonding area ratio is 5 to 40% and the average apparent density is 0.1 to 0.5 g / cm 3.

[3] The monolayer or multilayer polyester long-fiber nonwoven fabric according to [1] or [2], wherein the average fiber diameter is 13 to 40 탆.

[4], wherein (1) at least one layer is the average value of the Raman half-intensity width of the peak width of groups C = O near 1740 ㎝ ^-1 which is observed in the spectrum consisting of 18 ~ 24 ㎝ ^-1 fibers - [ 3]. ≪ / RTI >

[5] The monolayer or multilayer polyester long-fiber nonwoven fabric according to any one of [1] to [4], wherein at least one layer is composed of fibers having a crystallinity of 30 to 50%.

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

[7] The monolayer or multilayer polyester long-fiber nonwoven fabric according to any one of [1] to [6], wherein the transparency is 60% or more.

[8] The monolayer or multilayer polyester long-fiber nonwoven fabric according to any one of [1] to [7], wherein the non-water shrinkage ratio is 2.0% or less.

[9] The monolayer or multilayer polyester long-fiber nonwoven fabric according to any one of [1] to [8], wherein the cohesion coefficient is 0.5 to 2.0.

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

[11] The single-layer or multilayer polyester long-fiber nonwoven fabric according to any one of [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-mentioned [1] to [11], wherein the layer a and the layer b are composed of a laminated nonwoven fabric formed by thermocompression bonding.

a layer: a polyester long-fiber non-woven fabric comprising a high melting point resin and a low melting point resin having a melting point difference of 30 ° C to 150 ° C

layer b: a polyester long-fiber nonwoven fabric made of the high melting point resin

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

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

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

[16] The single-layer or multilayer polyester long-fiber nonwoven fabric according to the above-mentioned [15], which is made of a resin having a titanium element content of 0 to 0.1 ppm.

[17] The monolayer or multilayer polyester long-fiber nonwoven fabric according to any one of [1] to [16], wherein the IV value of the resin after being made into a nonwoven fabric is 0.6 or more.

[18] A food-grade filter comprising the monolayer or multilayer polyester long-fiber nonwoven fabric according to any one of [1] to [17].

The fiber constituting the single- or multi-layer polyester long-fiber nonwoven fabric according to the present invention is good in radioactivity, and the filter for food prepared using the nonwoven fabric made of the above-mentioned fibers is excellent in extractability of components and has transparency, dimensional stability, Resistant to powder leakage.

1 is a schematic view showing an example of an apparatus for controlling an air flow such as a plate-like dispersing plate or the like.
2 is a graph showing the relationship between the water shrinkage ratio and transparency.
3 is a graph showing the relationship between the draft ratio and the orientation crystallinity.
4 is a graph showing the relationship between the spinning temperature and the orientation crystallinity.
5 is a graph showing the relationship between the resin IV value and the orientation crystallinity.

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

As the polyester resin constituting the polyester long-fiber constituting the polyester long-fiber nonwoven fabric of the present embodiment, polyethylene terephthalate, polybutylene terephthalate and polytrimethylene terephthalate are used as typical examples of the thermoplastic polyester However, it may be a polyester obtained by polymerizing or copolymerizing isophthalic acid or phthalic acid as an acid component for forming an ester. The thermoplastic polyester may also be a biodegradable resin such as a poly (? -Hydroxy acid) such as polyglycolic acid or polylactic acid, or a copolymer containing the repeating unit as a main component. These resins may be used singly or in combination of two or more kinds.

Since the polyester long-fiber nonwoven fabric of the present embodiment is preferred to have higher transparency (lower hiding power), the lower the content of the inorganic particles used as the matting agent in the thermoplastic synthetic fiber nonwoven fabric is, the better.

As the inorganic particles used as a matting agent, any of synthetic products and natural products can be used without particular limitation. Examples of the inorganic particles include oxide ceramics such as alumina, silica, titania, zirconia, magnesia, ceria, yttria, zinc oxide and iron oxide, nitride ceramics such as silicon nitride, titanium nitride and boron nitride, Calcium carbonate, aluminum sulfate, aluminum hydroxide, magnesium hydroxide, potassium titanate, talc, kaolin clay, kaolinite, dickite, nakhlite, halloysite, pyrophyllite, but are not limited to, odinite, montmorillonite, beidellite, nontronite, volkonskoite, saponite, sauconite, swinefordite, vermiculite, But are not limited to, berthierine, sericite, amesite, kellyite, fraiponite, brindleyite, Zeolite, biotite, gold mica, gray iron, eastonite, siderophyllite tetra-ferri-annite, phylum mica, polylithionite, Ceramics and glass fibers such as dolomite, dolomite, dolomite, dolomite, dolomite, dolomite, dolomite, dolomite, dolomite, dolomite, dolomite, These inorganic particles may be used singly or in combination of two or more kinds. From the viewpoint of the reaction activity to the resin, the inorganic particles to be used are preferably inert inorganic particles such as titanium oxide, magnesium stearate and calcium stearate.

The range of the particle diameter of the inorganic particles of the polyester resin constituting the polyester filament of the present embodiment is 1.0 占 퐉 or less, preferably 0.8 占 퐉 or less, and more preferably 0.7 占 퐉 or less. If the particle diameter exceeds 1.0 占 퐉, not only the transparency as a nonwoven fabric is lowered but also the stability of spinning is deteriorated, so that radiation defects such as yarn breakage also increase.

An appropriate content of the inorganic particles of the polyester resin constituting the polyester long fiber of the present embodiment is 0 to 100 ppm, preferably 0 to 50 ppm, and more preferably 0 to 0.1 ppm. By making the content of the inorganic particles in the fibers fall within the above-mentioned range, it becomes possible to sufficiently secure the transparency of the nonwoven fabric. When the inorganic particles are used as the catalyst, the decomposition reaction of the resin at the time of melt extrusion can be suppressed, and radiation defects such as yarn breakage can be suppressed.

The inorganic particles used as the matting agent for the polyester resin constituting the polyester long-fiber of the present embodiment are inexpensive and general-purpose, and therefore it is preferable to use titanium-based particles such as titanium oxide in which the reaction activity is inactivated Do. When a titanium element is used as the inorganic particles in the polyester resin constituting the polyester filament of the present embodiment, the content is preferably 0 to 100 ppm, more preferably 0 to 50 ppm, still more preferably 0 to 0.1 ppm ppm.

Concretely, it is preferable that a colorless transparent super-bright resin which does not add inorganic inert particles such as titanium dioxide used as a matting agent, and further a resin which 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, and radiation defects such as yarn breakage can be suppressed.

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

The representative value of the pore diameter can be expressed by the pore diameter at the area ratio of 10% when the pore size of each hole in the nonwoven fabric image is sequentially integrated from the largest area to the small area, and it is necessary that the pore diameter is 1000 mu m or less. A preferable range is 30 占 퐉 or more and 600 占 퐉 or less, more preferably 400 占 퐉 or less, still more preferably 300 占 퐉 or less, and most preferably 250 占 퐉 or less. Above this range, the eyes of the fabric become clumsy, so that powder leakage of inclusions can not be suppressed. On the other hand, below this range, the eyes of the fabric are denser, so that the transparency of the filter is lowered. Further, since the fluid resistance of the filter is increased, extraction time is increased when it is used as a food filter, which is not practical.

It is necessary that the difference between the points of 2.3% and 10% when the pore diameter distribution with a large diameter is integrated from the maximum pore diameter is 0 占 퐉 to 500 占 퐉. A preferable range is 300 mu m or less, more preferably 200 mu m or less, and still more preferably 150 mu m or less. In the case of a fabric bag having a large pore diameter distribution such as a nonwoven fabric, by making the frequency of the large-diameter pores fall within this range, it is possible to obtain a nonwoven fabric excellent in dust-leaking property. In addition, by combining with the range of the 10% pore diameter, it is possible to define an optimal pore diameter distribution for packing the tea leaves.

In the case of holes having the same hole area, it is preferable that the shape has a longer diameter and a shorter diameter than an ellipse like an ellipse. When the contents such as tea leaves are packed, the surface is not a smooth sphere. Therefore, in the case of a hole having a long diameter and a short diameter even if the same hole area is present, the tea leaves are caught around the hole, and leakage tends to be difficult. Particularly, it is the shape of a relatively large hole included in the nonwoven fabric that is largely affected by leakage of tea leaves and the like. The shape of the hole can be represented by a value obtained by dividing the average of the diameters of the holes from the 2.3% hole diameter to the 10% hole diameter by the average of the hole diameters from the 2.3% hole diameter to the 10% hole diameter. The above value is preferably 1.3 or more. In general, when the transparency of the resin is the same, if the leakage of the contents is to be controlled while maintaining the transparency, the transparency is in the trade-off relationship, the fiber surface area included in a certain area, that is, the fiber diameter is small, The leakage property of the contents becomes small. One method of securing transparency from this relationship and suppressing leakage of the contents is to reduce the large pore diameter included in the nonwoven fabric. Another method is to make the shape of the hole difficult to leak. By combining these two methods, it is possible to obtain a nonwoven fabric which satisfies both of transparency and suppression of leakage of contents.

The shape of the polyester filament of the present embodiment can be arbitrarily selected in accordance with its purpose and application, such as a hollow cross section, a core sheath type cross section, a split type cross section, and a flat cross section, in addition to a normal round cross section .

In order to use the polyester long-fiber nonwoven fabric of the present embodiment in the form of a bag such as a tea bag, it is preferable that the adhesive strength is high in the heat sealing process by a bag making machine. In order to obtain a good heat sealing property with good bonding strength, fibers containing a low-melting-point resin having a melting point of 240 캜 or lower are laminated on at least one surface of the polyester long-fiber nonwoven fabric to form a melting point, Only the melting point resin component softens or melts to function as an adhesive, and a high heat sealing strength can be effectively obtained.

The melting point of the low melting point resin is 30 to 150 占 폚 lower than the melting point of the high melting point resin, and preferably 30 to 100 占 폚. Examples of the low-melting-point resin include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid and naphthalenedicarboxylic acid, and diols such as ethylene glycol, diethylene glycol, 1,4-butanediol and cyclohexanedimethanol And aliphatic polyester resins such as copolymer polyester resins and polylactic acid. Further, in addition to a single component as the fiber structure, a composite fiber structure composed of two components such as a sheath core structure and a side by side, for example, a composite fiber structure in which the core has a high melting point and a sheath has a low melting point, A high melting point resin such as terephthalate or polybutylene terephthalate is preferable, and a low melting point resin such as copolymerized polyester and aliphatic polyester is preferable. A method of laminating the low melting point fibers is, for example, a curtain spraying method in which the resin is melted and a resin in a semi-molten state or a fibrous material thereof is applied to a nonwoven fabric, Or a method in which a laminate nonwoven fabric is obtained by laminating a high melting point fiber web and a low melting point fiber web and then bonding them with a heat roll or the like.

The low melting point resin is used, for example, by copolymerizing a second aromatic dicarboxylic acid such as isophthalic acid, phthalic acid or naphthalenedicarboxylic acid with terephthalic acid as a main aromatic dicarboxylic acid as a component. The amount of the aromatic dicarboxylic acid of the second kind relative to the total aromatic dicarboxylic acid is 0 to 25%, preferably 0 to 22%, more preferably 0 to 18%. Addition of an amount exceeding this range lowers the crystallinity and prevents molecular orientation due to stretching, so that radiation stability and mechanical strength and dimensional stability when formed into a nonwoven fabric are lowered.

The polyester long-fiber nonwoven fabric of this embodiment is preferably capable of ultrasonic wave 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 may be appropriately selected. For example, the temperature condition of the heat seal is preferably 5 to 80 占 폚 lower than the melting point of the resin on the sealing surface.

In addition, various additive components such as various impact modifiers such as various elastomers, a nucleating agent, a coloring preventing agent, an antioxidant, a heat stabilizer, a plasticizer, a lubricant, a lubricant, An antiseptic agent, a coloring agent, a pigment, and a dye.

The polyester long-fiber nonwoven fabric of this embodiment can be efficiently produced by the spunbond method. That is, the above-mentioned polyester resin is heated and melted and discharged from the spinneret, the resultant spinneret is cooled using a known cooling device, and the spinneret is towed by a suction device such as an air sucker Make it thin. Subsequently, the yarn bundle discharged from the suction device is opened and deposited on a conveyor to form a web. Subsequently, the web formed on the conveyor is subjected to partial thermocompression bonding using a partially thermocompression bonding apparatus such as an emboss roll heated to obtain a long-spun, spunbonded nonwoven fabric.

In the case of using the spunbond method, there is no particular limitation, but in order to improve the uniformity of the web, for example, a method of charging the fibers by a corona facility or the like as disclosed in Japanese Patent Application Laid-open No. 11-131355, (Refer to FIG. 1) such as a dispersing plate of the ejector to regulate the velocity distribution of the airflow of the jetting portion of the ejector, etc., to blow out the web after the fibers are opened, A more preferable method is used.

The nonwoven fabric obtained by the spunbond method has characteristics of physical properties such as strong cloth strength and no short fibers falling off due to breakage of the bonding portion and is also low in cost and high in productivity, Horticulture, and living materials.

The polyester filament of the present embodiment has a fiber diameter of 13 to 40 占 퐉, preferably 15 to 40 占 퐉, more preferably 18 to 35 占 퐉, and particularly preferably 21 to 30 占 퐉. If the fiber diameter is 13 占 퐉 or more, transparency can be designed to be sufficient. Further, when the fiber diameter is 40 占 퐉 or less, the fiber is not sufficiently able to withstand the tension of the ejector at the time of spinning so that a part of the fiber is less likely to be broken, thereby forming a nonwoven fabric. Transparency, and sealability, and is suitable as a food filter.

The surface area per square area (i.e., the specific surface area m2 / g x unit weight g / m2 of the long fibrous nonwoven fabric) of the polyester long-fiber nonwoven fabric of the present embodiment is 1.0 to 3.5 (m2 / m2), more preferably 1.2 to 3.0 M 2 / m 2), particularly preferably 1.3 to 2.7 (m 2 / m 2). If the surface area per area is 3.5 (m 2 / ㎡) or less, transparency can be designed to be sufficient. When the surface area per area is 1.0 or more, a sufficient number of fibers can be obtained when the nonwoven fabric is formed. Therefore, when used as a food filter, it is excellent in mechanical strength and rigidity, component extraction property and sealing property, Do.

The layer structure of the polyester long-fiber nonwoven fabric of the present embodiment is not particularly limited as long as it is thermally / chemically integrated into a nonwoven fabric, but may be a laminated nonwoven fabric. At this time, it is preferable that the layer structure is divided into the roles each layer plays. For example, when the first layer is a layer having a high heat seal strength and the other layer is a layer having excellent mechanical strength such as tensile strength, rigidity, dimensional stability, etc., A nonwoven fabric having excellent physical properties can be obtained. When a nonwoven fabric having a structure in which the mechanical strength and the sealing property are combined in a single-layer structure is used in the step of discharging the nonwoven fabric into a bag-like form, in the step of producing a bag- The thermoplastic resin is melted and adhered to the heat roll or the hot plate heater of the discharge equipment so that the product quality is lowered or the processing speed is lowered and if it is tried to be improved, I will not. On the other hand, in the case of the nonwoven fabric of the present embodiment, the sealing layer is disposed on the inner surface, and production can be performed without lowering the quality and production speed while exhibiting good sealing strength.

In the case of using a laminated nonwoven fabric as the polyester long-fiber nonwoven fabric of the present embodiment, the structure of the layer responsible for sealing can be a single fiber structure such as a spunbond method or a meltblown method, a sheath core structure, (Split), but it is preferable that the low melting point resin for sealing performance is disposed on the surface of the fiber. For example, the core is a composite fiber structure having a high melting point and a low melting point. More specifically, the core is a high melting point resin such as polyethylene terephthalate or polybutylene terephthalate, and the sheath is a copolymerized polyester or aliphatic polyester. Is a nonwoven fabric having a sheath core structure composed of the above-mentioned low melting point resin.

When a laminated nonwoven fabric is used as the polyester long-fiber nonwoven fabric of the present embodiment, the production method of the layer responsible for the mechanical strength is not particularly limited, but from the viewpoint of productivity, the spunbond method is preferable.

Particularly, when a laminated nonwoven fabric is used as the polyester long-fiber nonwoven fabric of the present embodiment, the production and physical properties of the layer responsible for mechanical strength can be produced by the above-mentioned method, thereby making the nonwoven fabric more excellent in dimensional stability and mechanical strength.

The pressing method in the case of using the laminated nonwoven fabric as the polyester long-fiber nonwoven fabric of the present embodiment is not particularly limited as long as the fibers can be unified to form a nonwoven fabric. However, the layers may be laminated and heat- . By laminating the respective layers and then thermocompression bonding, strength of adhesion between the layers can be further strengthened, and mechanical strength and sealing performance can be more effectively expressed.

By making the layer structure of the laminated nonwoven fabric in this embodiment a lamination structure as described above, the sealing strength can be set in a more suitable range. The specific seal strength 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.

Further, the mechanical strength, that is, the tensile strength can be set to a more suitable range. 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 polyester long-fiber nonwoven fabric of the present embodiment can be thermally pressed by a heat roll between a pair of heating rolls formed of an embossing roll and a flat roll having a concavo-convex surface structure, To form a thermocompression bonding portion uniformly dispersed throughout the entire nonwoven fabric. In the case of performing thermocompression by emboss roll, it is preferable that thermocompression is performed at a thermocompression area ratio in a range of 5 to 40% with respect to the total area of the nonwoven fabric, more preferably 7 to 30% And more preferably 7 to 20%.

When the thermocompression area ratio is within this range, good thermocompression bonding between the fibers can be carried out, and it is preferable in order to achieve appropriate mechanical strength, rigidity, transparency, component extraction property and dimensional stability of the resultant nonwoven fabric. The thermocompression treatment temperature and pressure should be appropriately selected according to the conditions such as the unit weight and the speed of the web to be supplied and are not uniformly set but are preferably 10 to 90 ° C lower than the melting point of the polyester resin Deg.] C, more preferably 20 to 60 [deg.] C.

In addition to using the embossing roll in the thermocompression bonding step, an air through method may be used in which hot air is passed through a web to press the yarn and yarn into heat. In the case of thermocompression bonding by the air-through method, partial irregularities such as an embossed shape disappear on the fabric surface, so that the apparent transparency of the nonwoven fabric can be further enhanced.

The nonwoven fabric shrinkage percentage of the polyester long-fiber nonwoven fabric of the present embodiment is preferably 2.0% or less, more preferably 1.6% or less, still more preferably 1.0%, and particularly preferably 0.5% or less. When the water shrinkage percentage is 2.0% or less, shrinkage hardly occurs in the thermoforming process and the like, and therefore the process stability is excellent and the shape retention property is excellent even in the use form such as being exposed in a high temperature environment near 100 캜. The lower limit is preferably 0%, but practically 0.2% or more.

The transparency of the polyester long-fiber nonwoven fabric of the present embodiment is preferably 60% or more, more preferably 65% or more, and still more preferably 70% or more. When the transparency is less than 60%, the state of the contents is difficult to see through the nonwoven fabric, and it becomes unclear.

The unit weight of the polyester long-fiber nonwoven fabric of the present embodiment is 10 to 30 g / m 2, preferably 12 to 25 g / m 2. When the unit weight is 10 g / m < 2 > or more, sufficient mechanical strength can be secured while maintaining transparency and component extractability. On the other hand, if the unit weight is 30 g / m 2 or less, transparency and component extractability can be obtained.

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

The polyester long-fiber nonwoven fabric of the present embodiment has an average apparent density of preferably 0.10 to 0.50 g / cm3, more preferably 0.12 to 0.30 g / cm3. The average apparent density relates to the rigidity, transparency, dust-leaking property and component extractability of the nonwoven fabric. If the above-mentioned range is appropriate, the fiber gap is suitable, and therefore, it is suitable as a food filter. If the average apparent density is 0.10 g / cm 3 or more, mechanical strength can be sufficiently obtained while appropriately restricting the leakage amount of the powder by adjusting the fiber clearance. On the other hand, if the average apparent density is 0.50 g / cm 3 or less, the fiber clearance is not made too small, the component extractability can be properly maintained, and the product quality can be sufficiently obtained.

The tensile strength in the MD direction of the polyester long-fiber nonwoven fabric of the present embodiment is preferably 5 to 40 N / 30 mm, more preferably 6 to 40 N / 30 mm, still more preferably 7 to 40 N / 30 mm. When the tensile strength is higher than the above range, production stability at the time of production of the cord is excellent, and tearing is prevented at the time of use as a food filter.

The conjugation coefficient of the polyester long-fiber nonwoven fabric of this embodiment is preferably 0.5 to 2.0, more preferably 0.5 to 1.5. The cohesion coefficient is related to the strength, rigidity, transparency, dust leaking property, and component extractability because it shows the uniformity of the nonwoven fabric. Since the uniformity of the nonwoven fabric is optimum in the above-mentioned range, it is excellent in strength, rigidity, transparency as a food filter, processability in a bag shape, and powder leakage property.

The spinning temperature in obtaining the polyester filament of the present embodiment is preferably 10 to 60 占 폚 higher than the melting point of the polyester-based resin, more preferably 10 to 30 占 폚. When the spinning temperature is within this range, it is possible to obtain a nonwoven fabric which is free from single yarn breakage, is suitable for orientation crystallinity, and is excellent in mechanical strength and dimensional stability.

The intrinsic viscosity (IV value) of the resin after forming the nonwoven fabric of the polyester long-fiber nonwoven fabric of the present embodiment is preferably 0.6 or more, more preferably 0.65 or more, still more preferably 0.7 or more. When the resin pellets are melt-extruded, the resin is decomposed by heat at the time of melting and shearing load at the time of kneading. If the IV value of the resin after the melting, that is, the nonwoven fabric, is in the above range, decomposition of the resin can be suitably suppressed and the stretching and crystallization of the resin during spinning can be promoted. A nonwoven fabric having excellent stability can be obtained.

The spinning rate in obtaining the polyester filament of the present embodiment is preferably from 3,000 to 6,000 m / min, and more preferably from 3,500 to 5,000 m / min. When the yarn speed at the time of pulling down the yarn yarn is within the above-mentioned range, it is possible to obtain a nonwoven fabric having sufficient orientation crystallization of the polyester long fibers and excellent in mechanical properties and dimensional stability, and there is little possibility of yarn breakage during spinning , And the productivity of the nonwoven fabric.

The draft ratio in obtaining the polyester filament of the present embodiment is preferably from 400 to 2500, more preferably from 700 to 2,200. When the draft ratio in pulling out the yarn yarn is within the above-mentioned range, it is possible to obtain a nonwoven fabric excellent in mechanical properties and dimensional stability due to sufficient orientation crystallization of the polyester filament yarns. Further, yarn breakage during spinning, The possibility of occurrence of " sticking of the roll " is low, so that it is preferable from the viewpoint of the productivity of the nonwoven fabric.

The birefringent index n of the polyester filament of the present embodiment is 0.04 to 0.12, preferably 0.06 to 0.1. When the birefringence is in this range, the orientation of the fibers is appropriate, and a nonwoven fabric having excellent mechanical strength and dimensional stability can be obtained.

The method for evaluating the crystallinity is not particularly limited, and for example, the crystallinity can be measured by DSC, Raman spectroscopy or the like.

The crystallinity of the polyester filament of the present embodiment is 30 to 50%, preferably 40 to 50%. When the crystallinity is within this range, fibers having excellent mechanical strength and dimensional stability can be obtained.

When the crystallinity of the polyester filament of the present embodiment is measured by Raman spectroscopy, it can be evaluated by the average value of the full width at half maximum of the peak width due to the C = O group near 1740 cm ^-1 observed in the Raman spectrum of the fiber cross section have. The average value of the full width at half maximum of the peak width is 18 to 24 cm ^-1 , preferably 19 to 24 cm ^-1 , and more preferably 20 to 23 cm ^-1 . When the average value of the full width at half maximum of the peak width is within this range, fibers having excellent mechanical strength and dimensional stability can be obtained.

The polyester filament of the present embodiment can have different crystallinity in the radial direction of the fiber, for example, high crystallinity of the outer peripheral portion and low crystallinity inside. By increasing the crystallinity of the peripheral portion, it is difficult to shrink and the fiber having excellent mechanical strength can be obtained. Further, by lowering the crystallinity of the inside, the compression strength of the fibers can be sufficiently obtained at the time of thermocompression bonding, A nonwoven fabric having excellent stability can be obtained. This can be confirmed by evaluating the melting peak when measuring the crystallinity by DSC.

Fig. 2 shows the relationship between the non-water shrinkage ratio and the transparency of the polyester long-fiber non-woven fabric in the examples of the present invention. If the fiber diameter is increased, the transparency can be increased, but since orientation crystallization is difficult to proceed, the non-aqueous shrinkage ratio increases and the dimensional stability is lowered.

Figs. 3 and 4 show the relationship between the draft ratio and the spinning temperature, the birefringence (n) and the orientation crystallinity of the polyester long-fiber nonwoven fabric in the examples of the present invention, respectively. The larger the draft ratio, the greater the crystallinity of the orientation of the fibers. Further, in the spinning condition of the coarse fiber diameter, as the spinning temperature is lowered, the cooling efficiency is increased and the drawing efficiency is increased, so that the orientation crystallization of the fiber can be advanced.

Fig. 5 shows the relationship between the intrinsic viscosity (IV value), the birefringence index (n) and the crystallinity of orientation of the resin of the polyester long-fiber nonwoven fabric in the embodiment of the present invention. By increasing the IV value of the resin, orientation crystallization of the resin is promoted, and orientation crystallization of the fiber can be promoted.

From these data, the present inventors have made intensive studies to show the desired effect of the present invention. As a result, the inventors of the present invention have found that by increasing the crystallinity of the orientation while maintaining the coarse fiber diameter by lowering the spinning temperature and expanding the draft ratio, Of the improvement of the performance. In other words, the improvement in transparency and the improvement in dimensional stability caused by the non-water shrinkage ratio of the nonwoven fabric are contradictory, but the inventors of the present invention have found that by setting the fiber diameter and the orientation crystallinity of the fibers to be in the optimum range, Respectively.

In addition, in the present invention, the optimum range of the orientation crystal can be achieved by optimizing the intrinsic viscosity (IV value) of the resin used. The range of the IV value for achieving the object is 0.7 or more, preferably 0.85 or less, and more preferably 0.72 to 0.8. When the intrinsic viscosity is in this range, stable productivity can be ensured without causing single yarn breakage or the like, and high dimensional stability and high mechanical strength can be obtained by obtaining high orientation crystallinity when the molten resin is pulled down have.

The polyester long-fiber nonwoven fabric of the present embodiment is preferably excellent in hydrophilicity so that it does not float on the surface when put in hot water and sinks quickly. As the hydrophilic agent, a surfactant used for foods, for example, an aqueous solution of a sorbitan fatty acid ester, a polyglycerin fatty acid ester, a sucrose fatty acid ester or the like, an ethyl alcohol solution, or a mixed solution of ethyl alcohol and water is preferable. As a coating method, known methods such as a gravure roll method, a kiss roll method, an immersion method, and a spray method can be applied.

The polyester long-fiber nonwoven fabric of the present embodiment may be imparted with a commercial post-processing such as a deodorant, an antibacterial agent, or the like in a range not impairing the desired effect of the present invention, and may be subjected to dyeing, water- .

Since the polyester long-fiber nonwoven fabric of the present embodiment has excellent transparency, the contents are clearly visible, and therefore, the polyester resin long-fiber nonwoven fabric has excellent design characteristics and excellent dimensional stability. I have. The filter for food may be a flat bag, but a three-dimensional shape is preferable because the contents are more visible and the extraction is performed effectively. The three-dimensional shape is preferably a tetrahedral shape, a triangular-pyramid shape, or the like.

The three-dimensional food filter is filled with the extract to be filled and then packed in a pocket. However, when the consumer purchases the product from the bag and uses it, it is required to quickly return to the original three-dimensional shape. Since the long-fiber nonwoven fabric of the present invention is elastic and has appropriate rigidity, the above requirement can be sufficiently satisfied.

Example

Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited by them. On the other hand, the measuring method and evaluation method used are as follows.

(1) Content of titanium element (ppm)

The content of the titanium element in the polyester resin was determined using an ICP emission spectrometer manufactured by Thermofix Scientific Corporation.

(2) Average fiber diameter (占 퐉)

Using a microscope microscope (VH-8000) manufactured by GUENZUSA, the diameter of the fibers was measured by increasing the diameter to 1000 times, and the average value of 20 fibers was measured.

(3) Birefringence index (? N)

Using a BH2 type polarizing microscope compensator manufactured by OLYMPUS, birefringence of fibers immediately after traction was determined from retardation and fiber diameter by a conventional interference fringe method.

(4) Crystallinity (%)

Using a differential scanning calorimeter DSC6000 manufactured by PerkinElmer, the heating rate was raised from 40 占 폚 to 300 占 폚 at a rate of 10 占 폚 / min to measure the crystallization heat generation? Hc and the crystal melting heat amount? Hm. The crystallinity (%) was determined by the following formula:

Crystallinity degree? C (%) = (? Hm -? Hc) /126.4 占 100

* 126.4 J / g is the melting calorie of the complete crystal of polyethylene terephthalate.

(5) Half width (cm ^-1 )

Using a brown Raman spectrometer manufactured by Renishaw, the spectrum was measured at an excitation light of 532 nm and an excitation light intensity of 10%. The full width at half maximum of the peak width due to the C = O group in the vicinity of 1740 cm < ^-1 >

(6) Intrinsic viscosity (IV value)

And measured according to JIS K-7367-5.

(7) Unit weight (g / m 2)

And measured according to JIS L-1906.

(8) Thickness (mm)

And the thickness of a load of 100 g / cm < 2 > was measured by the method specified in JIS L-1906.

(9) Average apparent density (g / cm3)

The mass per unit volume was determined from the unit weight and thickness measured by the method specified in JIS L-1906:

Average apparent density (g / cm3) = (unit weight g / m2) / ((thickness mm) x 1000)

(10) Thermal compression area ratio (%)

A test piece of 1 cm in length and length was sampled and taken by an electron microscope. The area of the thermocompression bonding portion was measured from each photograph, and the average value was defined as the area of the thermocompression bonding portion. The pitch of the pattern of the thermocompression bonding portion was measured in the MD direction and the CD direction, and the ratio of the thermocompression area occupied per unit area of the nonwoven fabric was calculated as the thermocompression area ratio based on these values.

(11) Transparency (%)

The reflectance (L value) was measured with a Macbeth spectrophotometer (model CE-7000A: manufactured by Sakata Ink), and the difference between the L value (L _w0 ) of the standard white plate and the L value (L _b0 ) the samples were obtained transparency according to the following equation from the L value (L _b) place Like L value (L _w) placed on a white board on the blackboard:

Transparency _{(%) = {(L w} -L b) / (L w0 -L b0)} × 100

(12) Shrinkage percentage of dull water (%)

Three test specimens having a length of 25 cm and a width of 25 cm were sampled in accordance with JIS L-1906 per 1 m width of the sample, immersed in boiling water (boiling water) for 3 minutes, Shrinkage ratio. The average value of each was calculated, and the shrinkage ratio of either the MD direction or the CD direction was defined as the non-water shrinkage ratio of the nonwoven fabric.

(13) Tensile strength (N / 30 mm)

A sample of 30 mm in width was stretched at a holding length of 100 mm and a tensile speed of 300 mm / min by using Autograph AGS-5G manufactured by Shimadzu Seisakusho Co., , And the average value was obtained.

(14) Cohesion coefficient

A specimen of 20 cm x 30 cm was sampled and the transmission image photographed in the range of 18 cm x 25 cm was photographed by a CCD camera using a measurement tester (FMT-MIII) manufactured by Nomura Shoji Co., Ltd. into 128 x 128 pixels , And the intensity of light received by each pixel was measured to calculate the transmittance. The cohesion coefficient is a value obtained by dividing the standard deviation (?) Of the transmittance of each minute portion (5 mm x 5 mm) of the measurement sample by the average transmittance (E), and represents the fluctuation of the minute unit weight. Indicating that the surname is high.

Cohesion coefficient = σ / E × 100

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

The heat-sealed portion of a 30 mm wide sample was peeled and attached in a vertical direction of about 50 mm using an Autograph AGS-5G model manufactured by Shimadzu Seisakusho Co., Ltd., stretched at a holding length of 50 mm and a tensile speed of 100 mm / The measurement was performed five times with respect to the MD direction of the nonwoven fabric, taking the load at the time of breaking obtained as an intensity, and the average value was obtained. The heat sealing conditions were a seal temperature of 210 占 폚, a seal time of 1 second, a pressure of 0.5 MPa, and a seal area of 7 mm 占 25 mm.

(16) Draft ratio

The draft ratio was calculated from the following equation:

Draft ratio = spinning rate (m / min) / discharge line speed (m / min)

(G / cm < 3 >) x (radial diameter (cm) / 2) ² x [pi]

* Melt density of polyester: 1.20 g / ㎤ is used.

(17) Surface area per unit area of polyester nonwoven fabric

The specific surface area m2 / g of the long fibrous nonwoven fabric was expressed by unit weight g / m2.

The specific surface area (m < 2 > / g) of the long fibrous nonwoven fabric was determined by an automatic specific surface area measuring instrument Gemini 2360 manufactured by Shimadzu Corporation. When the specific surface area is less than 0.1 m < 2 > / g, it is determined by the following formula.

(G / m 2) / density of resin (g / cm 3) / fiber diameter (탆)

When the fiber diameter is two or more kinds of sheets, the surface area of each fiber diameter is totaled.

(18) 10% hole diameter

10 samples of 2 cm in length and 2 cm were cut out from one sample, platinum was deposited by an ion sputtering apparatus for SEM observation, and nonwoven fabric images of 10 samples in one sample were taken at a magnification of 100 times with the transmitted light. The image was binarized into black by the nonwoven fabric portion and white by the image analysis software, and the area and the maximum diameter of all the holes in the image were numerically expressed. The image analysis software was "A Jokun (TM)" manufactured by Asahi Kasei Engineering. All the holes in one sample image are arranged in order from the largest area to the small area and integrated, and from the hole area of the point reaching 10% of the total hole area, the diameter of the circle The hole diameter was determined by the following equation.

Pore diameter (占 퐉) = ((4S) /?)? 0.5

In the above equation, S means the hole area (mu m ^ 2), and " ^ 0.5 " means " 0.5 ".

(19) 2.3% Hole diameter

Instead of the 10% pore diameter, the pore diameter was determined from the pore area at the point at which the total pore area reached 2.3%.

(20) Long diameter / hole diameter

All of the holes in one sample image are arranged in order from the largest area to the small area and are integrated so that the total diameter of all the holes included in the holes reaching 10% from the holes reaching 2.3% And the average of the pore diameters were obtained.

Long diameter / hole diameter = average of long diameter / average of hole diameter

[Example 1]

A polyester resin having a titanium element content of 0 ppm, an intrinsic viscosity (IV) of 0.8 and a melting point of 247 DEG C was fed to a commercial melt-spinning apparatus and melted at 275 DEG C, At a spinning speed of 4500 m / min and at a draft ratio of 2120 to obtain a polyester filament having a fiber diameter of 20.5 占 퐉. Next, this fiber was subjected to carding and dispersing using a dispersing device (inclined angle 4 ° with respect to the filament of the flat plate) for controlling a flat plate air current to produce a web having a unit weight of 12 g / m 2, To obtain a polyester long-fiber nonwoven fabric by partial thermocompression at a thermocompression bonding area ratio of 15%. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 2]

A polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 1 except that the polyester filaments were spinnable so that the filament diameter of the polyester filaments was 25.7 탆 in Example 1. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 3]

A polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 1, except that the polyester fiber was spinnable so that the fiber length of the polyester long fiber was 30.0 탆. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 4]

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

[Example 5]

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

[Example 6]

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

[Example 7]

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

[Example 8]

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

[Example 9]

The same procedure as in Example 1 was carried out except that the yarn was melt-spun at a spinning rate of 3770 m / min and a draft ratio of 707 to give a polyester fiber having a fiber diameter of 34.9 mu m, . The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 10]

A polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 2, except that the polyester nonwoven fabric in Example 2 was spun in such a manner that the unit weight of the polyester nonwoven fabric was 20 g / m 2 and thermocompression was performed with a flat roll. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 11]

A polyester resin having a titanium element content of 0 ppm, an intrinsic viscosity (IV) of 0.8 and a melting point of 246 DEG C was fed to a commercial melt-spinning apparatus and melted at 275 DEG C, At a spinning rate of 4000 m / min and a draft ratio of 942 to obtain a polyester filament having a fiber diameter of 30.1 탆. Next, this fiber was subjected to carding and dispersing by using a dispersing device (inclined angle of 4 degrees with respect to the filament of the flat plate) for controlling a flat-type airflow to produce a web having a unit weight of 20 g / To obtain a polyester long-fiber nonwoven fabric by partial thermocompression at a thermocompression area ratio of 5%. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 12]

A polyester resin having a titanium element content of 0 ppm, an intrinsic viscosity (IV) of 0.8 and a melting point of 246 DEG C was fed to a commercial melt-spinning apparatus and melted at 275 DEG C, At a spinning speed of 4000 m / min and a draft ratio of 942 to obtain a polyester filament having a fiber diameter of 30.0 탆. Next, this fiber was carded and dispersed to prepare a web having a unit weight of 12 g / m 2, and the polyester filament nonwoven fabric was obtained by partially thermocompression bonding at a thermocompression bonding area ratio of 15% between the embossing roll and the flat roll. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 13]

A polyester resin having a titanium element content of 0 ppm, an intrinsic viscosity (IV) of 0.8 and a melting point of 246 DEG C was fed to a commercial melt-spinning apparatus and melted at 275 DEG C, At a spinning speed of 4000 m / min and a draft ratio of 942 to obtain a polyester filament yarn having a fiber diameter of 26.7 mu m as a dispersing device (inclined angle 4 [deg.] With respect to the flat filament) To prepare a web having a unit weight of 18 g / m < 2 >. Next, a polyester resin having a titanium element content of 12 ppm, an intrinsic viscosity (IV) of 0.65 and a melting point of 217 DEG C was supplied to a commercial melt-spinning apparatus and melted at 275 DEG C, The polyester filament yarn having a fiber diameter of 15 mu m was melt-spun at a spinning speed of 4150 m / min at a draft ratio of 412 to obtain a dispersion device (an inclination angle of 4 [deg.] With respect to the flat filament) , A web having a unit weight of 3 g / m < 2 > was produced. The two-layered web was subjected to partial thermocompression bonding at a thermocompression bonding area ratio of 15% between the emboss roll and the flat roll to obtain 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 having a titanium element content of 0 ppm, an intrinsic viscosity (IV) of 0.8 and a melting point of 246 DEG C was fed to a commercial melt-spinning apparatus and melted at 275 DEG C, At a spinning speed of 4000 m / min and a draft ratio of 942 to obtain a polyester filament yarn having a fiber diameter of 24.6 占 퐉 by using a dispersing device (inclined angle of 4 ° with respect to the flat filament) , And a web having a unit weight of 10 g / m < 2 > Next, a polyester resin having a titanium element content of 12 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 254 DEG C was used as a core, and a titanium element content of 12 ppm and an intrinsic viscosity (IV) of 0.65 , A polyester resin having a melting point of 217 DEG C as a sheath was supplied to a commercial melt-spinning apparatus and melted at 275 DEG C to obtain a yarn having a spinning speed of 4500 m / min from a spinneret having a circular- 895 to prepare a polyester filament having a fiber diameter of 20 占 퐉, which was subjected to carding and dispersing using a dispersing device (inclined angle 4 [deg.] With respect to the filament of a flat plate) Respectively. The two-layered web was subjected to partial thermocompression bonding at a thermocompression bonding area ratio of 15% between the emboss roll and the flat roll to obtain a polyester long-fiber nonwoven fabric. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 15]

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

[Example 16]

A polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 1 except that the polyester long-fiber non-woven fabric was spinnable so that the unit weight of the polyester long-fiber non-woven fabric was 18 g / m 2. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 17]

A polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 1 except that the polyester long-fiber nonwoven fabric was spinnable so that the unit weight of the polyester long-fiber nonwoven fabric in Example 3 was 18 g / m 2. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 18]

The non-woven fabric of the first layer was prepared so that the unit weight of the polyester long-fiber nonwoven fabric in Example 1 was 18 g / m 2. A PET resin having an IV value of 0.65, a titanium content of 0 ppm, and a melting point of 217 캜 was spun under the conditions of a spinning temperature of 260 캜 and a heating air of 500 Nm 3 / hr / m to obtain a meltblend having a fiber diameter of 10 탆 The nonwoven fabric was sprayed on the above spunbonded nonwoven fabric at a unit weight of 5 g / m < 2 > to obtain a nonwoven fabric laminate. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 19]

The nonwoven fabric of the first layer was prepared so that the unit weight of the polyester long-fiber nonwoven fabric in Example 2 was 18 g / m 2. A PET resin having an IV value of 0.65, a titanium content of 0 ppm, and a melting point of 217 캜 was spun under the conditions of a spinning temperature of 255 캜 and heated air of 400 Nm 3 / hr / m to obtain a meltblend having a fiber diameter of 15 탆 The nonwoven fabric was blown onto the above spunbond nonwoven fabric in a unit weight of 4 g / m < 2 > to obtain a nonwoven fabric laminate. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 20]

A nonwoven fabric of the first layer was prepared so that the unit weight of the polyester long-fiber nonwoven fabric in Example 3 was 18 g / m 2. A PET resin having an IV value of 0.65, a titanium content of 0 ppm, and a melting point of 217 캜 was spun under the conditions of a radiation temperature of 265 캜 and a heating air of 1000 Nm 3 / hr / m to obtain a meltblend having a fiber diameter of 7 탆 The nonwoven fabric was blown onto the above spunbond nonwoven fabric in a unit weight of 4 g / m < 2 > to obtain a nonwoven fabric laminate. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 21]

A polyester resin having a titanium element content of 0 ppm, an intrinsic viscosity (IV) of 0.8 and a melting point of 247 DEG C was fed to a commercial melt-spinning apparatus and melted at 275 DEG C, At a spinning speed of 4500 m / min and a draft ratio of 230 to obtain polyester filament yarns having a fiber diameter of 14 탆. Next, this fiber was subjected to carding and dispersing by using a dispersing device (inclined angle 4 ° with respect to the filament of the flat plate) for controlling the airflow of a flat plate type to prepare a web having a unit weight of 7.5 g / m 2. Next, a polyester resin having a titanium element content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 254 DEG C was used as a core, and the titanium element content was 0 ppm and the intrinsic viscosity (IV) was 0.65 , A polyester resin having a melting point of 217 DEG C as a sheath was supplied to a commercial melt-spinning apparatus and melted at 275 DEG C to obtain a yarn having a spinning speed of 4500 m / min from a spinneret having a circular- 380 to obtain a polyester web having a fiber diameter of 14 占 퐉 by carding and dispersing using a dispersing device (inclined angle of 4 ° with respect to the filament of a flat plate) for controlling the airflow of a flat plate type to obtain a web having a unit weight of 7.5 g / Respectively. The two-layered web was subjected to partial thermocompression bonding at a thermocompression bonding area ratio of 15% between the emboss roll and the flat roll to obtain 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 having a titanium element content of 12 ppm, an intrinsic viscosity (IV) of 0.8 and a melting point of 247 DEG C was fed to a commercial melt-spinning apparatus and melted at 275 DEG C, At a spinning speed of 4500 m / min and a draft ratio of 590 to obtain a polyester filament having a fiber diameter of 20.1 탆. Next, this fiber was subjected to carding and dispersing by using a dispersing device (inclined angle 4 ° with respect to the filament of the flat plate) for controlling the airflow of a flat plate type to prepare a web having a unit weight of 7.5 g / m 2. Next, a polyester resin having a titanium element content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 254 DEG C was used as a core, and the titanium element content was 0 ppm and the intrinsic viscosity (IV) was 0.65 , A polyester resin having a melting point of 217 DEG C as a sheath was supplied to a commercial melt-spinning apparatus and melted at 275 DEG C to obtain a yarn having a spinning speed of 4500 m / min from a spinneret having a circular- 380 to obtain a polyester web having a fiber diameter of 14 占 퐉 by carding and dispersing using a dispersing device (inclined angle of 4 ° with respect to the filament of a flat plate) for controlling the airflow of a flat plate type to obtain a web having a unit weight of 7.5 g / Respectively. The two-layered web was subjected to partial thermocompression bonding at a thermocompression bonding area ratio of 15% between the emboss roll and the flat roll to obtain 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 having a titanium element content of 12 ppm, an intrinsic viscosity (IV) of 0.8 and a melting point of 247 DEG C was fed to a commercial melt-spinning apparatus and melted at 275 DEG C, At a spinning speed of 4500 m / min and at a draft ratio of 740 to obtain a polyester filament yarn having a fiber diameter of 24.6 탆. Next, this fiber was subjected to carding and dispersing by using a dispersing device (inclined angle 4 ° with respect to the filament of the flat plate) for controlling the airflow of a flat plate type to prepare a web having a unit weight of 7.5 g / m 2. Next, a polyester resin having a titanium element content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 254 DEG C was used as a core, and the titanium element content was 0 ppm and the intrinsic viscosity (IV) was 0.65 , A polyester resin having a melting point of 217 DEG C as a sheath was supplied to a commercial melt-spinning apparatus and melted at 275 DEG C to obtain a yarn having a spinning speed of 4500 m / min from a spinneret having a circular- 380 to obtain a polyester web having a fiber diameter of 14 占 퐉 by carding and dispersing using a dispersing device (inclined angle of 4 ° with respect to the filament of a flat plate) for controlling the airflow of a flat plate type to obtain a web having a unit weight of 7.5 g / Respectively. The two-layered web was subjected to partial thermocompression bonding at a thermocompression bonding area ratio of 15% between the emboss roll and the flat roll to obtain 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 having a titanium element content of 0 ppm, an intrinsic viscosity (IV) of 0.8 and a melting point of 247 DEG C was fed to a commercial melt-spinning apparatus and melted at 275 DEG C, At a spinning speed of 4500 m / min and at a draft ratio of 550 to obtain a polyester filament having a fiber diameter of 20.1 탆. Next, this fiber was subjected to carding and dispersing by using a dispersing device (inclined angle of 4 ° with respect to the filament of the flat plate) for controlling a flat plate air current to prepare a web having a unit weight of 10 g / m 2. Next, a polyester resin having a titanium element content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 254 DEG C was used as a core, and the titanium element content was 0 ppm and the intrinsic viscosity (IV) was 0.65 , A polyester resin having a melting point of 217 DEG C as a sheath was supplied to a commercial melt-spinning apparatus and melted at 275 DEG C to obtain a yarn having a spinning speed of 4500 m / min from a spinneret having a circular- 450, and the polyester filament having a fiber diameter of 16 占 퐉 was subjected to carding and dispersing by using a dispersing device (inclined angle of 4 ° with respect to the filament of the flat plate) for controlling the air flow of a flat plate type to obtain a web having a unit weight of 5 g / Respectively. The two-layered web was subjected to partial thermocompression bonding at a thermocompression bonding area ratio of 15% between the emboss roll and the flat roll to obtain 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 having a titanium element content of 0 ppm, an intrinsic viscosity (IV) of 0.8 and a melting point of 247 DEG C was fed to a commercial melt-spinning apparatus and melted at 275 DEG C, At a spinning speed of 4500 m / min and a draft ratio of 590 to obtain a polyester filament having a fiber diameter of 20.1 탆. Next, this fiber was subjected to carding and dispersing by using a dispersing device (inclined angle 4 ° with respect to the filament of the flat plate) for controlling the airflow of a flat plate type to prepare a web having a unit weight of 7.5 g / m 2. Next, a polyester resin having a titanium element content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 254 DEG C was used as a core, and the titanium element content was 0 ppm and the intrinsic viscosity (IV) was 0.65 , A polyester resin having a melting point of 217 DEG C as a sheath was supplied to a commercial melt-spinning apparatus and melted at 275 DEG C to obtain a yarn having a spinning speed of 4500 m / min from a spinneret having a circular- 450, and the polyester filament having a fiber diameter of 16 占 퐉 was subjected to carding and dispersing using a dispersing device (inclined angle of 4 ° with respect to the filament of the flat plate) for controlling the airflow of a flat plate type to obtain a web having a unit weight of 7.5 g / Respectively. The two-layered web was subjected to partial thermocompression bonding at a thermocompression bonding area ratio of 15% between the emboss roll and the flat roll to obtain 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 having a titanium element content of 0 ppm, an intrinsic viscosity (IV) of 0.8 and a melting point of 247 DEG C was fed to a commercial melt-spinning apparatus and melted at 275 DEG C, At a spinning speed of 4500 m / min and at a draft ratio of 740 to obtain a polyester filament yarn having a fiber diameter of 24.6 탆. Next, this fiber was subjected to carding and dispersing by using a dispersing device (inclined angle 4 ° with respect to the filament of the flat plate) for controlling the airflow of a flat plate type to prepare a web having a unit weight of 7.5 g / m 2. Next, a polyester resin having a titanium element content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 254 DEG C was used as a core, and the titanium element content was 0 ppm and the intrinsic viscosity (IV) was 0.65 , A polyester resin having a melting point of 217 DEG C as a sheath was supplied to a commercial melt-spinning apparatus and melted at 275 DEG C to obtain a yarn having a spinning speed of 4500 m / min from a spinneret having a circular- 450, and the polyester filament having a fiber diameter of 16 占 퐉 was subjected to carding and dispersing using a dispersing device (inclined angle of 4 ° with respect to the filament of the flat plate) for controlling the airflow of a flat plate type to obtain a web having a unit weight of 7.5 g / Respectively. The two-layered web was subjected to partial thermocompression bonding at a thermocompression bonding area ratio of 15% between the emboss roll and the flat roll to obtain 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 having a titanium element content of 12 ppm, an intrinsic viscosity (IV) of 0.8 and a melting point of 247 DEG C was fed to a commercial melt-spinning apparatus and melted at 275 DEG C, At a spinning speed of 4500 m / min and a draft ratio of 590 to obtain a polyester filament having a fiber diameter of 20.1 탆. Next, this fiber was subjected to carding and dispersing by using a dispersing device (inclined angle of 0 ° with respect to the filament of a flat plate) for controlling a flat plate air current to prepare a web having a unit weight of 7.5 g / m 2. Next, a polyester resin having a titanium element content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 254 DEG C was used as a core, and the titanium element content was 0 ppm and the intrinsic viscosity (IV) was 0.65 , A polyester resin having a melting point of 217 DEG C as a sheath was supplied to a commercial melt-spinning apparatus and melted at 275 DEG C to obtain a yarn having a spinning speed of 4500 m / min from a spinneret having a circular- 450 to prepare a polyester filament having a fiber diameter of 16 占 퐉 by carding and dispersing using a dispersing device (inclined angle of 0 ° with respect to the filament of a flat plate) for controlling the airflow of a flat plate type to obtain a web having a unit weight of 7.5 g / Respectively. The two-layered web was subjected to partial thermocompression bonding at a thermocompression bonding area ratio of 15% between the emboss roll and the flat roll to obtain a polyester long-fiber nonwoven fabric. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 28]

A polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 22 except that the angle of inclination of the flat plate-shaped filament of the dispersing device for controlling a flat plate airflow was 0 °. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 29]

A polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 21 except that the layer using the low melting point resin was changed from a sheath core structure to a side by side structure. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 30]

A polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 24 except that the layer using the low melting point resin was changed from a sheath core structure to a side by side structure. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 31]

A polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 22 except that the layer using the low melting point resin was changed from the sheath core structure to the side by side structure. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 32]

A polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 21 except that the unit weight of each layer was changed to 6 g / m 2. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 33]

A polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 22 except that the unit weight of each layer was changed to 6 g / m 2. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 34]

A polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 23 except that the unit weight of each layer was changed to 6 g / m 2. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 35]

A polyester resin having a titanium element content of 0 ppm, an intrinsic viscosity (IV) of 0.8 and a melting point of 247 DEG C was fed to a commercial melt-spinning apparatus and melted at 275 DEG C, At a spinning speed of 4500 m / min and a draft ratio of 590 to obtain a polyester filament having a fiber diameter of 20.1 탆. Next, this fiber was subjected to carding and dispersing by using a dispersing device (inclined angle 4 ° with respect to the filament of the flat plate) for controlling the airflow of a flat plate type to prepare a web having a unit weight of 12 g / m 2. Next, a polyester resin having a titanium element content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 254 DEG C was used as a core, and the titanium element content was 0 ppm and the intrinsic viscosity (IV) was 0.65 , A polyester resin having a melting point of 217 DEG C as a sheath was supplied to a commercial melt-spinning apparatus and melted at 275 DEG C to obtain a yarn having a spinning speed of 4500 m / min from a spinneret having a circular- 450, and the polyester filament having a fiber diameter of 16 占 퐉 was subjected to carding and dispersing by using a dispersing device (inclined angle of 4 ° with respect to the filament of a flat plate) for controlling the airflow of a flat plate type to obtain a web having a unit weight of 6 g / Respectively. The two-layered web was subjected to partial thermocompression bonding at a thermocompression bonding area ratio of 15% between the emboss roll and the flat roll to obtain a polyester long-fiber nonwoven fabric. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 36]

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

[Example 37]

A polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 21 except that the unit weight of each layer was 9 g / m 2. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[Example 38]

A polyester resin having a titanium element content of 12 ppm, an intrinsic viscosity (IV) of 0.8, and a melting point of 247 DEG C was fed to a commercial melt-spinning apparatus and melted at 305 DEG C to obtain a spinneret At a spinning speed of 4500 m / min and at a draft ratio of 230 to obtain polyester filaments having a fiber diameter of 10 탆. Next, this fiber was subjected to carding and dispersing by using a dispersing device (inclined angle 4 ° with respect to the filament of the flat plate) for controlling the airflow of a flat plate type to prepare a web having a unit weight of 7.5 g / m 2. Next, a polyester resin having a titanium element content of 0 ppm, an intrinsic viscosity (IV) of 0.65, and a melting point of 254 DEG C was used as a core, and the titanium element content was 0 ppm and the intrinsic viscosity (IV) was 0.65 , A polyester resin having a melting point of 217 DEG C as a sheath was supplied to a commercial melt-spinning apparatus and melted at 275 DEG C to obtain a yarn having a spinning speed of 4500 m / min from a spinneret having a circular- 380 to obtain a polyester web having a fiber diameter of 14 占 퐉 by carding and dispersing using a dispersing device (inclined angle of 4 ° with respect to the filament of a flat plate) for controlling the airflow of a flat plate type to obtain a web having a unit weight of 7.5 g / Respectively. The two-layered web was subjected to partial thermocompression bonding at a thermocompression bonding area ratio of 15% between the emboss roll and the flat roll to obtain a polyester long-fiber nonwoven fabric. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Example 39]

A polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 32 except that the fiber diameter of each layer was changed to 13 탆. The physical properties of the obtained nonwoven fabric are shown in Table 2 below.

[Comparative Example 1]

The same procedure as in Example 1 was carried out except that the content of the titanium element in the polyester resin in Example 1 was changed to 3000 ppm and the unit weight of the polyester long fiber was 20.0 g / However, the transparency of the nonwoven fabric was low, and sufficient transparency as a food filter could not be obtained. The physical properties of the obtained nonwoven fabric are shown in Table 3 below.

[Comparative Example 2]

The same procedure as in Example 1 was carried out except that the polyester filaments melt-spun at a draft ratio 545 in Example 1 were 12.0 占 퐉 in fiber diameter and the polyester filament yarns were 20 g / To obtain a polyester long-fiber nonwoven fabric, the transparency of the nonwoven fabric was low, and sufficient transparency as a food filter could not be obtained. 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]

A polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 4 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 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 having a titanium element content of 0 ppm, an intrinsic viscosity (IV) of 0.8, and a melting point of 246 DEG C was supplied to a commercial melt-spinning apparatus and melted at 295 DEG C, At a spinning speed of 4000 m / min and at a draft ratio of 191 to obtain a polyester filament having a fiber diameter of 30.3 탆. Next, this fiber was subjected to carding and dispersing by using a dispersing device (inclined angle of 4 degrees with respect to the filament of the flat plate) for controlling a flat-type airflow to produce a web having a unit weight of 20 g / To obtain a polyester long-fiber nonwoven fabric by partial thermocompression at a thermocompression bonding area ratio of 15%, but sufficient dimensional stability could not be obtained as a food filter. The physical properties of the obtained nonwoven fabric are shown in Table 3 below.

[Comparative Example 9]

In Comparative Example 8, the polyester filaments melt-spun at a draft ratio of 345 had a fiber diameter of 50.0 占 퐉 and a polyester filament yarn of 20 g / m2, but the shrinkage in the roll was large, An ester long-fiber nonwoven fabric could not be obtained. The physical properties of the obtained nonwoven fabric are shown in Table 3 below.

[Comparative Example 10]

A polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 3 except that the web was made so that the unit weight of the polyester long-fiber was 40 g / m 2 in Example 3, but the transparency of the nonwoven fabric was low, Sufficient transparency as a filter could not be obtained. The physical properties of the obtained nonwoven fabric are shown in Table 3 below.

[Comparative Example 11]

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

[Comparative Example 12]

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

[Comparative Example 13]

A polyester resin having a titanium element content of 0 ppm, an intrinsic viscosity (IV) of 0.65 and a melting point of 254 DEG C as a core and having a titanium element content of 0 ppm, an intrinsic viscosity (IV) of 0.65, 217 ° C as a sheath, supplied to a commercial melt-spinning apparatus, melted at 275 ° C, and melt-spun at a spinning speed of 4500 m / min from a spinneret having a circular cross-section spinning hole to obtain a fiber having a fiber diameter of 14 탆 was subjected to carding and dispersing by using a dispersing device (an inclination angle of 4 [deg.] With respect to the filament of the flat plate) for controlling the airflow of a flat plate type to prepare a web having a unit weight of 15 g / m2 between the emboss roll and the flat roll To obtain a polyester long-fiber nonwoven fabric by partial thermocompression with a thermocompression area ratio of 15%. The physical properties of the obtained nonwoven fabric are shown in Table 3 below. On the other hand, when the obtained nonwoven fabric was heat sealed, resin contamination occurred severely in the sealer.

[Comparative Example 14]

A polyester long-fiber nonwoven fabric was obtained in the same manner as in Example 21 except that the unit weight of each layer was changed to 10 g / m 2. Table 3 shows the physical properties of the obtained nonwoven fabric.

[Comparative Example 15]

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

The single-layer or double-layer polyester long-fiber nonwoven fabric of the present invention is excellent in transparency, dimensional stability, dust-leaking property, and component extractability, and therefore can be suitably used as a food filter. m ²

Claims (18)

Wherein the content of the inorganic particles is 0 to 100 ppm, the 10% point hole diameter is less than 1,000 占 퐉, the difference between the 10% point hole diameter and the 2.3% point hole diameter is 500 占 퐉 or less and the unit weight is 10 to 30 g / Based single layer or double layer polyester long-fiber nonwoven fabric. The single-layer or double-layer polyester long-fiber nonwoven fabric according to claim 1, wherein the thermocompression bonding area ratio is 5 to 40% and the average apparent density is 0.1 to 0.5 g / cm 3. The single or double-layer polyester long-fiber nonwoven fabric according to claim 1 or 2, wherein the average fiber diameter is 13 to 40 탆. 4. The method according to any one of claims 1 to 3, wherein an average value of the full width at half maximum of the peak width due to the C = O group in the vicinity of 1740 cm ^-1 observed in Raman spectrum of at least one layer is 18 to 24 cm ^-1 Single-layer or double-layer polyester long-fiber nonwoven fabric composed of fibers. The single-layer or multi-layer polyester long-fiber nonwoven fabric according to any one of claims 1 to 4, wherein at least one layer is composed of fibers having a crystallinity of 30 to 50%. The single-layer or double-layer polyester long-fiber nonwoven fabric according to any one of claims 1 to 5, wherein at least one layer is composed of fibers having a birefringence of 0.04 to 0.12. The single-layer or multi-layer polyester long-fiber nonwoven fabric according to any one of claims 1 to 6, wherein the transparency is 60% or more. The single-layer or multi-layer polyester long-fiber nonwoven fabric according to any one of claims 1 to 7, wherein the shrinkage ratio of the boiling water is 2.0% or less. The single-layer or double-layer polyester long-fiber nonwoven fabric according to any one of claims 1 to 8, wherein the cohesion coefficient is 0.5 to 2.0. The single-layer or multi-layer polyester long-fiber nonwoven fabric according to any one of claims 1 to 9, wherein at least one layer has a tensile strength of 5 N / 30 mm or more. The single-layer or multi-layer polyester long-fiber nonwoven fabric according to any one of claims 1 to 10, wherein at least one layer contains low melting point fibers having a melting point of 240 캜 or less. 12. The polyester long-fiber nonwoven fabric according to any one of claims 1 to 11, wherein the layer a and the layer b are formed by thermocompression bonding.
a layer: a polyester long-fiber non-woven fabric comprising a high melting point resin and a low melting point resin having a melting point difference of 30 ° C to 150 ° C
layer b: a polyester long-fiber nonwoven fabric made of the high melting point resin The single-layer or multi-layer polyester long-fiber nonwoven fabric according to any one of claims 1 to 12, wherein the polyester long-fiber non-woven fabric has a structure in which the orientation properties of fibers are different in the cross-sectional direction. 14. The single-layer or multilayer polyester long-fiber nonwoven fabric according to any one of claims 1 to 13, wherein at least one layer comprises a resin containing 0 to 25% of isophthalic acid. 15. The single or double-layer polyester long-fiber nonwoven fabric according to any one of claims 1 to 14, wherein the inorganic particles are titanium oxide. The single-layer or multi-layer polyester long-fiber nonwoven fabric according to claim 15, which is made of a resin having a titanium element content of 0 to 0.1 ppm. 17. The single-layer or multilayer polyester long-fiber nonwoven fabric according to any one of claims 1 to 16, wherein the IV value of the resin after being converted into the nonwoven fabric is 0.6 or more. A food-grade filter comprising the single-layer or multilayer polyester long-fiber nonwoven fabric according to any one of claims 1 to 17.

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