Spun-bonded nonwoven fabric for filters and method of making same

Abstract

The present disclosure relates to a spunbonded nonwoven fabric for a filter and a method of making the same. According to the present disclosure, provided are a spun-bonded nonwoven fabric for a filter, which exhibits excellent filtration performance while having low pressure loss and high air permeability, and a method for preparing the same.

Description

Technical Field

[0001] The present disclosure relates to a spunbond nonwoven fabric for a filter and a method for preparing the same. Background Art

[0002] A filter is a material or device that creates a pressure difference between both sides of a partition wall through which a gas or liquid including different phases passes, thereby separating the different phases from the gas or liquid.

[0003] Generally, polyolefin meltblown nonwoven fabrics, polyolefin spunbond nonwoven fabrics, polyester spunbond nonwoven fabrics, etc. that have been electrostatically treated are mainly applied to the electrostatic filter layer of air filters.

[0004] However, polyolefin meltblown nonwoven fabrics are prepared from ultrafine yarns and have good collection efficiency, but have low air permeability and large pressure loss. Therefore, polyolefin meltblown nonwoven fabrics are suitable for manufacturing HEPA filters that require high efficiency and low air permeability, but are limited in their application to cabin filters, bag filters, air conditioner filters, and various medium-performance filters that require relatively high air permeability.

[0005] In the case of polyolefin or polyester spunbond nonwoven fabrics, when designing a filter that requires high air permeability appropriately, the collection efficiency is relatively reduced. On the contrary, when designing a filter that requires high collection efficiency appropriately, there is a limitation in that the air permeability is relatively reduced.

[0006] In recent years, attempts have been made to apply nonwoven fabrics prepared by a nanofiber spinning process to filters, thereby satisfying both high air permeability and high collection efficiency. However, the commercialization of the technology for preparing nonwoven fabrics using the nanofiber spinning process is still insufficient, and even if the technology is commercialized, its widespread application to medium-performance filters is limited due to high manufacturing costs. Summary of the Invention

[0007] Technical Problem

[0008] An object of the present disclosure is to provide a spunbond nonwoven fabric for a filter that has low pressure loss and high air permeability while exhibiting excellent filtration performance.

[0009] Another object of the present disclosure is to provide a method for preparing the spunbond nonwoven fabric for a filter.

[0010] Technical Solution

[0011] According to an embodiment of the present disclosure, there is provided a spunbond nonwoven fabric for a filter, including:

[0012] A fiber web formed by entangling fine denier filaments split from a split filament,

[0013] Among them, the fine denier filament contains 60% to 90% by weight of polyester filaments with a melting point above 250°C and 10% to 40% by weight of polyethylene filaments with a melting point of 130°C to 150°C, and

[0014] Among them, based on the content of polyethylene, the polyethylene filaments contain 0.1% to 5.0% by weight of a light stabilizer.

[0015] According to another embodiment of the present disclosure, a method for preparing the spunbond nonwoven fabric for a filter is provided, and the method includes the following steps:

[0016] Forming a split filament, and the split filament splits into fine denier filaments containing polyester filaments and polyethylene filaments,

[0017] Forming a fiber web including the split filament,

[0018] Thermally bonding the fiber web to form a pre-bonded fiber web,

[0019] Applying a physical force to the pre-bonded fiber web to form a spunlace fiber web, the spunlace fiber web including the polyester filaments and the polyethylene filaments split from the split filament, and

[0020] Thermally bonding the spunlace fiber web to form a spunbond nonwoven fabric,

[0021] Among them, the fine denier filament contains 60% to 90% by weight of polyester filaments with a melting point above 250°C and 10% to 40% by weight of polyethylene filaments with a melting point of 130°C to 150°C, and

[0022] Among them, based on the content of polyethylene, the polyethylene filaments contain 0.1% to 5.0% by weight of a light stabilizer.

[0023] Now, the spunbond nonwoven fabric for a filter according to the embodiments of the present disclosure and its preparation method will be described in more detail.

[0024] Unless otherwise stated throughout the specification, the technical terms used in this specification are only for reference to specific embodiments and are not intended to limit the present disclosure.

[0025] Unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" used in this specification include plural references.

[0026] As used in this specification, the terms "comprising" or "including" specify particular features, regions, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of different particular features, regions, integers, steps, operations, elements, components, and / or groups.

[0027] In addition, terms including ordinal numbers such as "first" and "second" are used only for the purpose of distinguishing one component from another and are not limited by the ordinal numbers. For example, without departing from the scope of the present disclosure, the first component may be referred to as the second component, or similarly, the second component may be referred to as the first component.

[0028] As used in this specification, the term "split filament" refers to a filament in which two or more polymer components each have a fine denier filament form and are contained within a single filament. The split filament has a cross-sectional shape that splits into multiple filaments. The split filament splits into multiple filaments composed of the corresponding polymer components by a physical force applied from the outside.

[0029] As used in this specification, the term "denier" is a unit of fineness measured by the mass (grams) of a single fiber strand that is 9000 meters long. For example, 1 denier can be expressed as 1 g / 9000 m, or 0.11 mg / m, or 0.11 tex.

[0030] According to one embodiment of the present disclosure, there is provided a spunbond nonwoven fabric for a filter, comprising:

[0031] A fiber web formed by entangling fine denier filaments split from split filaments,

[0032] wherein the fine denier filaments comprise 60 wt% to 90 wt% of polyester filaments having a melting point of 250 °C or higher and 10 wt% to 40 wt% of polyethylene filaments having a melting point of 130 °C to 150 °C, and

[0033] wherein, based on the content of polyethylene, the polyethylene filaments comprise 0.1 wt% to 5.0 wt% of a light stabilizer.

[0034] As a result of research conducted by the present inventors, it has been confirmed that a spunbond nonwoven fabric satisfying the structure in the above embodiment has low pressure loss and high air permeability while exhibiting excellent filtration performance.

[0035] In particular, since the spunbond nonwoven fabric for a filter satisfying the above structure includes filaments, it can increase the collection amount of particles filtered by the nonwoven fabric and reduce the pressure on the surface of the nonwoven fabric caused by the particles, thereby ensuring a long service life.

[0036] According to one embodiment, a spunbond nonwoven fabric for a filter comprises a fiber web formed by entangling fine denier filaments split from split filaments.

[0037] The term "split-filament" refers to a filament in which two or more polymer components each have a fine-denier filament form and are contained within a single filament. Split-filaments have a cross-sectional shape that splits into multiple parts. Split-filaments are split into multiple filaments composed of the corresponding polymer components by a physically applied external force.

[0038] There is no particular limitation on the split form of the split-filament, and it can be determined according to the shape of the spinneret. As an example, the split-filament can have a cross-section such as an orange shape, a hollow shape, or a chrysanthemum shape. In addition, the split-filament can be a multi-split filament that splits into 8 to 64 strands. Specifically, the split-filament can be a multi-split filament that splits into 8, 16, 32, or 64 strands.

[0039] According to one embodiment, the split-filament has a fineness of 2 to 5 denier, and the fine-denier filament can have a fineness of 0.05 to 0.2 denier.

[0040] Considering the number of splits of the fine-denier filaments split from the split-filament, the mechanical properties of the filaments, etc., the fineness of the split-filament is preferably 2 to 5 denier.

[0041] Considering the efficiency of forming the fine-denier filaments, the shape retention of the fine-denier filaments, etc., the fineness of the fine-denier filament is preferably 0.05 to 0.2 denier, or 0.06 to 0.2 denier, or 0.06 to 0.15 denier, or 0.06 to 0.13 denier.

[0042] According to one embodiment, the fine-denier filament contains a polyester filament with a melting point above 250 °C and a polyethylene filament with a melting point of 130 °C to 150 °C.

[0043] The fine-denier filament contains polyester and polyethylene, which are polymer components with strong hydrophobicity, and are beneficial for ensuring the water repellency of the nonwoven fabric. In addition, it contains polyester and polyethylene, which have a relatively low density compared to other polymer components (such as nylon) used in spunbond nonwoven fabrics for filters, and thus is beneficial for reducing the weight of the nonwoven fabric.

[0044] The polyester filament has a melting point above 250 °C, or 250 °C to 265 °C, or 250 °C to 260 °C, or 255 °C to 260 °C.

[0045] For example, the polyester filament can include at least one first polyester selected from polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polytetrafluoroethylene, and copolymers thereof that satisfy the above melting point range.

[0046] Considering the formation of the split-filament and the mechanical properties of the fine-denier filament, the polyester filament preferably includes a polyester with an intrinsic viscosity of 0.6 to 0.9 dl / g.

[0047] The polyethylene filaments have a melting point that is at least 100 °C lower than that of the polyester filaments. Preferably, the polyethylene filaments have a melting point of 130 °C to 150 °C, or 130 °C to 145 °C, or 130 °C to 140 °C.

[0048] Considering the formation of split filaments and the mechanical properties of fine denier filaments, the polyethylene filaments preferably comprise polyethylene having a melt index of 10 g / 10 min to 30 g / 10 min, which is measured at a temperature of 190 °C and a load of 2.16 kg in accordance with ISO 1133-1:2011.

[0049] To ensure the splitting quality of the split filaments (e.g., the shape of the splitting interface and its cross-section, splitting ratio, etc.), the physical properties of the fine denier filaments, and the physical properties of the spunbond nonwoven fabric for the filter, it is preferred that the polyester and polyethylene satisfy the above characteristics.

[0050] As an example, the fine denier filaments comprise 60 wt% to 90 wt% of polyester filaments having a melting point above 250 °C and 10 wt% to 40 wt% of polyethylene filaments having a melting point of 130 °C to 150 °C. As another example, the fine denier filaments may comprise 60 wt% to 85 wt% of polyester filaments and 15 wt% to 40 wt% of polyethylene filaments. As yet another example, the fine denier filaments may comprise 60 wt% to 80 wt% of polyester filaments and 20 wt% to 40 wt% of polyethylene filaments.

[0051] To ensure the bonding strength of the fine denier filaments in the fiber web, it is preferred to comprise polyethylene filaments in an amount of 10 wt% or more, or 15 wt% or more, or 20 wt% or more.

[0052] However, when the fiber web contains an excessive amount of polyethylene filaments, the mechanical properties and heat resistance of the nonwoven fabric may be reduced due to the decrease in the content of polyester filaments, and the processability of the spinning process and subsequent processes may be reduced. Therefore, it is preferred to comprise polyethylene filaments in an amount of 40 wt% or less.

[0053] According to one embodiment, the polyethylene filaments in the fine denier filaments comprise a light stabilizer.

[0054] The light stabilizer is an additive for maintaining the electrostatic properties and tensile strength of the electrostatically treated spunbond nonwoven fabric. Preferably, in order to exhibit a uniform effect and improve dispersibility, the light stabilizer is added to the polyethylene filaments by masterbatch processing with polyethylene.

[0055] There is no particular limitation on the specific type of the light stabilizer, and it can be selected within the range that does not inhibit the formation of the split fiber and its physical properties. Preferably, the light stabilizer can be a hindered amine compound. Specifically, the light stabilizer can be at least one compound selected from the following: tetra(1,2,2,6,6-pentamethyl-4-piperidyl) butane-1,2,3,4-tetracarboxylate, tetra(2,2,6,6-tetramethyl-4-piperidyl) butane-1,2,3,4-tetracarboxylate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis(1-undecyloxy-2,2,6,6-tetramethyl-4-piperidyl) carbonate, 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, 2,2,6,6-tetramethyl-4-piperidyl methacrylate, 2,2,6,6-tetramethyl-4-piperidyl palmitate, 2,2,6,6-tetramethyl-4-piperidyl stearate, 944, 2020, 622, 765 and XT55.

[0056] According to one embodiment, based on the content of polyethylene, the polyethylene filament contains 0.1 wt% to 5.0 wt% of the light stabilizer.

[0057] In order to exhibit and maintain the electrostatic properties due to the addition of the light stabilizer, based on the content of polyethylene, it is preferably contained in an amount of more than 0.1 wt%, more than 0.3 wt% or more than 0.5 wt%.

[0058] However, when an excessive amount of the light stabilizer is contained, the pressure of the spinning assembly may increase during the production of the split fiber, the processability may deteriorate, such as yarn breakage may occur, and the physical properties of the nonwoven fabric may deteriorate. Therefore, based on the content of polyethylene, it is preferably contained in an amount of 5.0 wt% or less, or 4.0 wt% or less, or 3.0 wt% or less.

[0059] Specifically, based on the content of polyethylene, the light stabilizer can be contained in an amount of 0.1 wt% to 5.0 wt%, or 0.3 wt% to 5.0 wt%, or 0.3 wt% to 4.0 wt%, or 0.5 wt% to 4.0 wt%, or 0.5 wt% to 3.0 wt%.

[0060] There is no particular limitation on the weight and thickness of the spunbond nonwoven fabric for the filter, and it can be adjusted within an appropriate range according to the application field.

[0061] Preferably, the spunbond nonwoven fabric for the filter can have 30 g / m2 to 120 g / m 2 or 50 g / m 2 to 120 g / m 2 or 50 g / m 2 to 110 g / m 2 per unit area weight.

[0062] In addition, the spunbond nonwoven fabric for filters may have a thickness of 0.1 mm to 5.0 mm, or 0.1 mm to 4.0 mm, or 0.1 mm to 3.0 mm.

[0063] The spunbond nonwoven fabric for filters can be applied to gas turbine filters, dust collection filters, air filters, etc. In addition, the spunbond nonwoven fabric for filters can be widely used, such as automotive cabin filters, bag filters, air conditioner filters, air purification filters, HEPA filters, ULPA filters, and plenums.

[0064] According to another embodiment of the present disclosure, there is provided a method for preparing a spunbond nonwoven fabric for filters, the method comprising the following steps:

[0065] Forming split filaments, the split filaments splitting into fine denier filaments comprising polyester filaments and polyethylene filaments,

[0066] Forming a fiber web comprising the split filaments,

[0067] Thermally bonding the fiber web to form a pre-bonded fiber web,

[0068] Applying a physical force to the pre-bonded fiber web to form a hydroentangled fiber web, the hydroentangled fiber web comprising the polyester filaments and the polyethylene filaments split from the split filaments, and

[0069] Thermally bonding the hydroentangled fiber web to form a spunbond nonwoven fabric,

[0070] wherein the fine denier filaments comprise 60 wt% to 90 wt% of polyester filaments having a melting point above 250 °C and 10 wt% to 40 wt% of polyethylene filaments having a melting point of 130 °C to 150 °C, and

[0071] wherein, based on the content of polyethylene, the polyethylene filaments comprise 0.5 wt% to 3.0 wt% of a light stabilizer.

[0072] According to one embodiment, the spunbond nonwoven fabric for filters can be prepared by the following method: forming a fiber web using split filaments obtained by spinning polyester and polyethylene, and then pre-bonding, hydroentangling, and thermally bonding.

[0073] In the preparation method, the properties of the polyester, polyester filament, polyethylene, and polyethylene filament are the same as those described above.

[0074] According to one embodiment, the step of forming the split filament can be carried out according to a conventional method of forming split filaments using polyester and polyethylene as polymer components. As an example, in the above step, a spinneret designed such that the discharge holes are controlled to an appropriate number and the filament has a cross-sectional shape that can be split into multiple filaments can be used. In the split filament, the content ratio of the polymer components and the fineness of the filament can be controlled by adjusting the number and shape of the discharge holes of the spinneret, the discharge amount of the polymer components, and the like.

[0075] There is no particular limitation on the splitting form of the split filament, and it can be determined according to the shape of the spinneret. As an example, the split filament can have a cross-section such as an orange shape, a hollow shape, or a chrysanthemum shape. In addition, the split filament can be a multi-split filament split into 8 to 64 strands. Specifically, the multi-split filament can be a multi-split filament split into 8, 16, 32, or 64 strands.

[0076] In the step of forming the split filament, the spinning speed and tension can be adjusted in consideration of the fineness of the split filament and the fine denier filament. If necessary, a step of drawing the split filament can be carried out.

[0077] According to one embodiment, the polyethylene filament in the fine denier filament contains a light stabilizer. Preferably, in order to exhibit a uniform effect and improve dispersibility, in the step of forming the split filament, a filament obtained by masterbatch processing using polyethylene and a light stabilizer can be used. The specific type and preferred content range of the light stabilizer are the same as those described above.

[0078] A step of forming a fiber web containing the split filament is carried out. The split filament is laminated on a continuously moving mesh belt conveyor by a conventional opening method such as an electrostatic charging method, a collision plate method, and an air flow diffusion method to form a fiber web.

[0079] A step of thermally bonding the fiber web to form a pre-bonded fiber web is carried out. This step is a step of providing weak bonding to the fiber web to prevent deformation due to the tension applied during the conveyance of the fiber web.

[0080] The step of forming the pre-bonded fiber web can be carried out by passing the fiber web through a heated calender roll. The roll is heated to a temperature capable of melting the polyethylene filament to an extent where it can be bonded. As an example, the step of forming the pre-bonded fiber web can be carried out at a temperature of 100 °C to 130 °C and a pressure of 80 N / cm 2 to 100 N / cm 2 of pressure.

[0081] The step of applying a physical force to the pre-bonded fiber web to form a spunlace fiber web, the spunlace fiber web comprising polyester filaments and polyethylene filaments split from the split filaments. This step is a step of splitting the split filaments into fine denier filaments by utilizing the incompatibility of polyester and polyethylene.

[0082] According to one embodiment, the step of forming the spunlace fiber web can be carried out by hydro-punching the pre-bonded fiber web under a water pressure of 80 kgf / cm 2 to 200 kgf / cm 2 of the water pressure.

[0083] In order to ensure that the fine denier filaments can be sufficiently split from the split filaments, in the step of forming the spunlace fiber web, the pre-bonded fiber web is preferably hydro-punched at a water pressure of 80 kgf / cm 2 or more, or 100 kgf / cm 2 or more, or 120 kgf / cm 2 or more of the water pressure.

[0084] However, if the water pressure applied to the pre-bonded fiber web in the above step is too high, the pre-bonded fiber web may be torn or pierced, and the distribution of the fine denier filaments may become uneven. Therefore, in the step of forming the spunlace fiber web, the pre-bonded fiber web is preferably hydro-punched at a water pressure of 200 kgf / cm 2 or less, or 190 kgf / cm 2 or less, or 180 kgf / cm 2 or less of the water pressure.

[0085] Specifically, hydro-punching is carried out at a water pressure of 80 kgf / cm 2 to 200 kgf / cm 2 , or 100 kgf / cm 2 to 200 kgf / cm 2 , or 100 kgf / cm 2 to 190 kgf / cm 2 , or 120 kgf / cm 2 to 190 kgf / cm 2 , or 120 kgf / cm 2 to 180 kgf / cm 2 of the water pressure

[0086] In addition, a step of thermally bonding the hydroentangled fiber web to form a spunbond nonwoven fabric is performed. This step can be carried out in a manner similar to the step of forming the pre-bonded fiber web. As an example, the step of forming the spunbond nonwoven fabric can be carried out by passing the hydroentangled fiber web through a heated calender roll. The roll is heated to a temperature capable of melting the polyethylene filaments to an extent that they can be bonded. As an example, the step of forming the spunbond nonwoven fabric can be carried out at a temperature of 110°C to 150°C and a pressure of 80 N / cm 2 to 110 N / cm 2 .

[0087] Optionally, a step of electrostatically treating the spunbond nonwoven fabric can be further carried out. There is no particular limitation on the method of electrostatically treating the spunbond nonwoven fabric, and any conventional method in the technical field to which the present disclosure pertains can be applied. For example, in the step of electrostatically treating the spunbond nonwoven fabric, methods such as corona discharge, plasma charging, and water charging using charged water droplets can be applied to the spunbond nonwoven fabric.

[0088] Beneficial effects

[0089] According to the present disclosure, there is provided a spunbond nonwoven fabric for a filter that has a low pressure loss and high air permeability while exhibiting excellent filtration performance, and a method for preparing the same. Detailed embodiments

[0090] Hereinafter, preferred embodiments are provided to better understand the present invention. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present disclosure.

[0091] Example 1

[0092] Thirty-two split filaments with a fineness of 2 denier are formed using 60 wt% of a first component and 40 wt% of a second component.

[0093] Here, polyethylene terephthalate (PET) with a melting point of 255°C and an intrinsic viscosity of 0.65 dl / g is used as the first component. As the second component, polyethylene (PE; melting point of 133°C; and melt index measured at a temperature of 190°C under a load of 2.16 kg is 12 g / 10 min) subjected to masterbatch processing and a light stabilizer (hindered amine compound; from BASF ) are used. Here, the light stabilizer is included in an amount of 3.0 wt% based on the content of polyethylene.

[0094] The split filaments are laminated on a continuously moving mesh belt conveyor to form a fiber web.

[0095] The fiber web is passed through while maintaining a temperature of 110°C and a pressure of 90 N / cm 2A calender roll with linear pressure is used to form a pre-bonded fibrous web.

[0096] The pre-bonded fibrous web is hydro-pressed under a water pressure of 170 kgf / cm 2 to form a spunlace fibrous web including fine denier filaments with a fineness of about 0.06 denier split from split-type filaments. The fine denier filaments contain 60 wt% polyethylene terephthalate filaments and 40 wt% polyethylene filaments.

[0097] The spunlace fibrous web is passed through a calender roll maintaining a temperature of 120 °C and a linear pressure of 100 N / cm 2 to prepare a spunbond nonwoven fabric (weight per unit area is 100 g / m 2 ; thickness is 0.14 mm).

[0098] Examples 2 to 4 and Comparative Examples 1 to 7

[0099] Except for applying the contents (wt%) of the first component and the second component, the polymer types of the first component and the second component, the content of the light stabilizer (wt% relative to the polymer content of the second component), whether hydro-pressing is performed (O; X), or the water pressure of hydro-pressing (kgff / cm 2 ), the spunbond nonwoven fabric is prepared in the same manner as in Example 1.

[0100] [Table 1]

[0101]

[0102] * Second component polymer (PET) of Comparative Example 5: Polyethylene terephthalate with a melting point of 210 °C and an intrinsic viscosity of 0.82 dl / g

[0103] * First component polymer (PP) of Comparative Example 6: Polypropylene (PP) with a melting point of 165 °C and a melt index of 40 g / 10 min (measured at a temperature of 190 °C and a load of 2.16 kg)

[0104] * Second component polymer (nylon) of Comparative Example 7: Nylon 6 with a melting point of 220 °C and a melt viscosity of 1,100 poise (measured at 270 °C and a shear rate of 1,000)

[0105] Test Example

[0106] (1) Air permeability of the nonwoven fabric (ccs)

[0107] The air permeability (cm 2 / cm 2 / sec; CcS) of the nonwoven fabrics according to the examples and comparative examples was measured using an air permeability tester (FX 3300 LabAir IV; TEXTEST AG) according to the test method ASTM D 737-04. Nonwoven fabric specimens were prepared from 10 pieces each having an area of 100 cm 2 . An air pressure of 120 Pa was applied thereto. The air permeability was measured 10 times in total, and the average values are shown in Table 2 below.

[0108] (2) Pressure loss (mmAq) and filtration efficiency (%)

[0109] The pressure loss (mmAq) and filtration efficiency (%) of the nonwoven fabrics according to the examples and comparative examples were measured using an automatic filter tester 8130 (TSI Inc.).

[0110] An aerosol containing NaCl (particle size of 0.3 μm) was prepared by heating an aqueous solution of 20 wt% NaCl. Nonwoven fabric specimens (with an area of 100 cm 2 ) according to the examples and comparative examples were installed on the tester, and the aerosol was passed through the nonwoven fabric specimens at an air flow rate of 32 LPM (surface wind speed of 5.33 cm / sec).

[0111] The air pressure before / after passing through the nonwoven fabric specimens was measured to determine the pressure loss (mmAq). The NaCl concentration before / after passing through the nonwoven specimens was measured to calculate the filtration efficiency (%).

[0112] [Table 2]

[0113]

[0114] Referring to Table 1 and Table 2, it was confirmed that the spunbond nonwoven fabric of the example had a filtration efficiency of more than 80.1%, and thus had excellent filtration performance and exhibited an air permeability of 20 ccs to 29 ccs and a pressure loss of 2.6 mmAq to 3.8 mmAq.

[0115] It was confirmed that the spunbond nonwoven fabric of the comparative example exhibited a low filtration efficiency of 40.8% or less, and had an air permeability or pressure loss level that did not reach that of the example. In Comparative Example 4, the spinnability was poor in the step of forming the split-type filaments, and thus a spunbond nonwoven fabric could not be prepared.

[0116] While the detailed description and specific examples are given by way of illustration only, while indicating the preferred embodiments of the present invention, those of ordinary skill in the art will readily recognize that many changes and modifications can be made thereto without departing from the spirit or scope of the present disclosure.

Claims

1. A spunbond nonwoven fabric for a filter, comprising: A fiber web formed by entangling fine denier filaments split from split-type filaments, wherein the fine denier filaments comprise 60 wt% to 90 wt% of polyester filaments with a melting point above 250 °C and 10 wt% to 40 wt% of polyethylene filaments with a melting point of 130 °C to 150 °C, and wherein, based on the content of polyethylene, the polyethylene filaments comprise 0.1 wt% to 5.0 wt% of a light stabilizer.

2. The spunbond nonwoven fabric for a filter according to claim 1, wherein, The split-type filaments have a fineness of 2 denier to 5 denier, and the fine denier filaments have a fineness of 0.05 denier to 0.2 denier.

3. The spunbond nonwoven fabric for a filter according to claim 1, wherein, The polyethylene filaments comprise a polyester with an intrinsic viscosity of 0.6 dl / g to 0.9 dl / g.

4. The spunbond nonwoven fabric for a filter according to claim 1, wherein, The polyethylene filaments comprise a polyethylene with a melt index of 10 g / 10 min to 30 g / 10 min, which is measured at a temperature of 190 °C and a load of 2.16 kg.

5. The spunbond nonwoven fabric for a filter according to claim 1, wherein, The light stabilizer is a hindered amine compound.

6. The spunbond nonwoven fabric for a filter according to claim 1, wherein the light stabilizer is at least one compound selected from the following: tetra(1,2,2,6,6-pentamethyl-4-piperidyl) butane-1,2,3,4-tetracarboxylate, tetra(2,2,6,6-tetramethyl-4-piperidyl) butane-1,2,3,4-tetracarboxylate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis(1-undecyloxy-2,2,6,6-tetramethyl-4-piperidyl) carbonate, 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, 2,2,6,6-tetramethyl-4-piperidyl methacrylate, 2,2,6,6-tetramethyl-4-piperidyl palmitate, 2,2,6,6-tetramethyl-4-piperidyl stearate, 944, 2020, 622, 765 and XT55.

7. The spunbond nonwoven fabric for a filter according to claim 1, having a weight per unit area of 30 g / m 2 to 120 g / m 2 .

8. The spunbond nonwoven fabric for a filter according to claim 1, having a thickness of 0.1 mm to 5.0 mm.

9. A method for preparing the spunbond nonwoven fabric for a filter as described in claim 1, the method comprising the following steps: Forming split-type filaments that split into fine denier filaments comprising polyester filaments and polyethylene filaments, Forming a fiber web comprising the split-type filaments, Thermally bonding the fiber web to form a pre-bonded fiber web, Applying a physical force to the pre-bonded fiber web to form a hydroentangled fiber web, the hydroentangled fiber web comprising the polyester filaments and the polyethylene filaments split from the split-type filaments, and Thermally bonding the hydroentangled fiber web to form a spunbond nonwoven fabric, wherein the fine denier filaments comprise 60 wt% to 90 wt% of polyester filaments with a melting point above 250 °C and 10 wt% to 40 wt% of polyethylene filaments with a melting point of 130 °C to 150 °C, and wherein, based on the content of polyethylene, the polyethylene filaments comprise 0.1 wt% to 5.0 wt% of a light stabilizer.

10. The method for preparing the spunbond nonwoven fabric according to claim 9, wherein, The split-type filaments are multi-split-type filaments that split into 8 to 64 strands.

11. The method for preparing the spunbond nonwoven fabric according to claim 9, wherein, The formation of the spunlace fiber web is carried out by hydro-punching the pre-bonded fiber web under a water pressure of 80 kgf / cm 2 to 200 kgf / cm 2 .

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