JP7741191B2 - Method for manufacturing insect repellent masterbatch for nonwoven fabric, insect repellent masterbatch for nonwoven fabric, nonwoven fabric and articles thereof - Google Patents

Description

The present invention relates to a method for producing an insect repellent masterbatch for nonwoven fabrics, an insect repellent masterbatch for nonwoven fabrics, nonwoven fabrics and articles made thereof. More specifically, the present invention relates to a method for producing an insect repellent masterbatch for nonwoven fabrics, an insect repellent masterbatch for nonwoven fabrics, nonwoven fabrics and articles made thereof, which contain an insect repellent that is harmless to humans, thereby providing insect repellency and insect growth inhibition effects as well as improved antibacterial properties, and allowing the production of nonwoven fabrics for a variety of uses, such as hygiene, bedding and agriculture.

Conventional nonwoven fabrics had satisfactory levels of mechanical strength and fine dust removal, but lacked insect repellent and antibacterial properties, which meant they were prone to attracting pests during storage and could irritate the skin if contaminated with bacteria.

One embodiment of the present invention provides a method for producing an insect repellent masterbatch for nonwoven fabrics.

Another embodiment of the present invention provides an insect repellent masterbatch for nonwoven fabrics produced by the method for producing an insect repellent masterbatch for nonwoven fabrics.

Another embodiment of the present invention provides a nonwoven fabric containing the insect repellent masterbatch for nonwoven fabrics.

Another embodiment of the present invention provides an article comprising the nonwoven fabric.

One aspect of the present invention is
Mixing raw materials including a base resin, a liquid insect repellent, and a carrier material to obtain a raw material mixture;
In the raw material, the content of the liquid insect repellent is 9,000 to 11,000 ppm by weight,
The content of the carrier material in the raw material is 30,000 to 50,000 ppm by weight.

The base resin may also include a non-conductive polymer selected from polyolefin, polystyrene, polycarbonate, polyester, polyamide, copolymers thereof, or combinations thereof.

The insect repellent may also contain cinnamaldehyde, α-copaene, apiol, oleic acid, or a combination thereof.

The carrier material may also include silica, zeolite, kaolin, or a combination thereof.

Another aspect of the present invention is
The present invention provides an insect repellent masterbatch for nonwoven fabrics, which is produced by the method for producing an insect repellent masterbatch for nonwoven fabrics.

Yet another aspect of the present invention is
comprising a base resin, an insect repellent component, and a carrier material;
The content of the insect repellent component is 300 to 500 ppm by weight,
The content of the carrier material is 30,000 to 50,000 ppm by weight in the insect repellent masterbatch for nonwoven fabric.

The insect repellent masterbatch for nonwoven fabric also has a dispersion index of 0.6 or more and less than 1.0.

Yet another aspect of the present invention is
A nonwoven fabric containing the insect repellent masterbatch for nonwoven fabric is provided.

The nonwoven fabric also contains the insect repellent masterbatch for nonwoven fabric in an amount of 5 to 20% by weight based on the total weight of the nonwoven fabric.

The nonwoven fabric has a bacteriostatic activity value of 5.0 or higher against Staphylococcus aureus and 6.0 or higher against Streptococcus pneumoniae, as measured by the bacteriostatic activity value measurement method (JIS L 1902).

The nonwoven fabric has an insect repellency rate against adult red flour beetles of 60% or more one week after treatment, and can maintain this rate at 40% or more even two weeks after treatment.

The nonwoven fabric also has a skin patch test grade of 1 or higher.

The nonwoven fabric also has a color difference meter deviation (ΔE*) of 2.0 to 3.0.

The nonwoven fabric can exhibit an air permeability of 300 to 700 ^{cm 3} /cm ² /s.

Yet another aspect of the present invention is
An article is provided that includes the nonwoven fabric.

The above-mentioned items may also be health or medical items.

An insect repellent masterbatch for nonwoven fabrics produced by a method for producing an insect repellent masterbatch for nonwoven fabrics according to one embodiment of the present invention contains an insect repellent that is harmless to humans, thereby providing insect repellency and insect growth inhibition effects as well as improved antibacterial properties, making it suitable for a variety of nonwoven fabric applications, including hygiene, bedding, and agricultural use.

1 is a schematic diagram illustrating a composite nonwoven fabric including a nonwoven fabric according to an embodiment of the present invention. 1 is a schematic diagram illustrating a composite nonwoven fabric manufacturing apparatus used to continuously manufacture a composite nonwoven fabric including a nonwoven fabric according to an embodiment of the present invention.

Below, a method for producing an insect repellent masterbatch for nonwoven fabric according to one embodiment of the present invention will be described in detail.

As used herein, "liquid insect repellent" refers to an insect repellent in the form of a solution, oil, or suspension.

In addition, in this specification, the term "dispersion index" refers to the value obtained by dividing the discharge amount by the input amount when an insect repellent masterbatch for nonwoven fabrics is spun through a spinning nozzle.

In addition, as used herein, "non-woven fabric composite" refers to a nonwoven fabric in which two or more types of nonwoven fabrics are manufactured in a single device through continuous processes, rather than a nonwoven fabric laminate manufactured by separately manufacturing two or more types of nonwoven fabrics and then subjecting them to a separate laminating process. Therefore, in this specification, "composite nonwoven fabric" is also referred to as "monolithic non-woven fabric." The composite nonwoven fabric has stronger interlayer bonding than the nonwoven fabric laminate, and is characterized by excellent dimensional stability and filtration performance.

In addition, in this specification, an "electrically charged meltblown nonwoven fabric layer" or a "electrically charged meltblown nonwoven fabric sublayer" can also be one manufactured by a continuous process. Specifically, an "electrically charged meltblown nonwoven fabric layer" or a "electrically charged meltblown nonwoven fabric sublayer" can also be one manufactured by carrying out "meltblown nonwoven fabric production" and "electrically charging" sequentially or simultaneously in a continuous process.

In addition, in this specification, "charged" refers to a state in which an electric charge is semi-permanently imparted to the nonwoven fibers, allowing an electrostatic field to be formed between adjacent fibers. Charged nonwoven fabrics are characterized by higher charge density and fine dust removal efficiency than nonwoven fabrics that have not been charged.

In addition, in this specification, "tensile strength" refers to the tensile strength measured in the MD (mechanical direction) by pulling a 5 cm wide test piece (grip spacing at the time of evaluation: 10 cm) using a tensile strength tester (Instron) according to KSK 0520 at a pulling speed of 500 mm/min.

In this specification, "bending resistance" is measured in mm in accordance with measurement standard WSP 90.1 by taking 16 samples (25 mm x 150 mm) in the MD and CD directions, placing the samples on a bending resistance tester, and pressing the specimen in the direction of the inclined surface until it touches the inclined surface. The length of the sample from the point where it bends to the point where it touches the inclined surface is measured.

In this specification, the "fine dust permeability,""fine dust removal efficiency," and "pressure loss" were evaluated for the composite nonwoven fabric after production and before use by the following methods:
(1) Measuring device: TSI-8130 model manufactured by TSI was used.
(2) Aerosol formation: The measuring device evaporated the water from the sodium chloride aqueous solution mist generated by the fine aerosol generator to form sodium chloride aerosol dispersed in the air. The sodium chloride aerosol thus formed had an average particle size of 0.3 μm and a sodium chloride concentration of 18.5 mg/ ^m3 .
(3) Fine dust transmittance evaluation: The aerosol transmittance surface velocity was 16 cm/sec, and the evaluation area of the nonwoven fabric was 100 cm ^2. The transmittance of the aerosol particles was recorded as the fine dust transmittance.
(4) Aerosol removal efficiency evaluation: The aerosol permeation surface velocity was 16 cm/sec, and the evaluation area of the nonwoven fabric was 100 cm ^2. The aerosol removal efficiency was recorded as the fine dust removal efficiency.
(5) Pressure loss evaluation: The surface velocity of the aerosol permeation was 16 cm/sec, and the evaluation area of the nonwoven fabric was 100 ^cm2 .

A method for producing an insect repellent masterbatch for nonwoven fabric according to one embodiment of the present invention includes a step (S10) of mixing raw materials including a base resin, a liquid insect repellent, and a carrier material to obtain a raw material mixture.

The content of the liquid insect repellent in the raw material is 9,000 to 11,000 ppm by weight, and the content of the carrier material in the raw material is 30,000 to 50,000 ppm by weight.

If the content of the liquid insecticide and the content of the carrier material are each within the above ranges, an insecticide masterbatch for nonwoven fabrics with excellent insecticidal performance and dispersion index can be obtained. If at least one of the content of the liquid insecticide and the content of the carrier material is outside the above ranges, an insecticide masterbatch for nonwoven fabrics with inferior insecticidal performance and dispersion index can be obtained.

The base resin may also include a non-conductive polymer selected from polyolefin, polystyrene, polycarbonate, polyester, polyamide, copolymers thereof, or combinations thereof.

The polyolefin may also include polyethylene, polypropylene, poly-4-methyl-1-pentene, polyvinyl chloride, or a combination thereof.

The polyester may also include polyethylene terephthalate, polylactic acid, or a combination thereof.

The liquid insect repellent may also be a natural insect repellent extracted from plants. For example, the liquid insect repellent may have a solids content of 3 to 5% by weight.

The liquid insect repellent may also contain cinnamaldehyde, α-copaene, apiol, oleic acid, or a combination thereof.

The carrier material acts as a cross-linker between the liquid insect repellent and the base resin, and can also increase the dispersion index of the insect repellent masterbatch for nonwoven fabrics.

The carrier material may also include silica, zeolite, kaolin, or a combination thereof.

Furthermore, the method for producing the insect repellent masterbatch for nonwoven fabric may further include, after step (S10), a step (S20) of extruding and pelletizing the raw material mixture.

Another aspect of the present invention provides an insect repellent masterbatch for nonwoven fabrics produced by the above-described method for producing an insect repellent masterbatch for nonwoven fabrics.

Yet another aspect of the present invention provides an insect repellent masterbatch for nonwoven fabrics, comprising a base resin, an insect repellent component, and a carrier material, wherein the content of the insect repellent component is 300 to 500 ppm by weight, and the content of the carrier material is 30,000 to 50,000 ppm by weight. If the content of the insect repellent component and the content of the carrier material are each within the above ranges, an insect repellent masterbatch for nonwoven fabrics with excellent insect repellent performance and dispersion index can be obtained. If at least one of the content of the insect repellent component and the content of the carrier material is outside the above ranges, an insect repellent masterbatch for nonwoven fabrics with inferior insect repellent performance and dispersion index can be obtained.

The insect repellent component is also a residue of the liquid insect repellent mentioned above.

The insect repellent masterbatch for nonwoven fabrics also has a dispersion index of 0.6 or more but less than 1.0. If the dispersion index of the insect repellent masterbatch for nonwoven fabrics is less than 0.6, when an attempt is made to produce nonwoven fabric by adding the insect repellent masterbatch for nonwoven fabrics, spinning becomes impossible due to increased pressure in the extruder and die, making it impossible to use the insect repellent masterbatch for nonwoven fabrics. If the insect repellent masterbatch for nonwoven fabrics does not contain the carrier material, its dispersion index will be 1.0, and if it contains even a small amount of the carrier material, its dispersion index will be less than 1.0.

Another embodiment of the present invention provides a nonwoven fabric containing the insect repellent masterbatch for nonwoven fabrics.

The nonwoven fabric also contains the insect repellent masterbatch for nonwoven fabrics in a ratio of 5 to 20% by weight based on the total weight of the nonwoven fabric. If the content of the insect repellent masterbatch for nonwoven fabrics is within this range, the nonwoven fabric can be obtained with excellent spinnability, insect repellent effect, skin patch test grade, breathability performance, mechanical strength, and abrasion/fuzz evaluation grade, and with an appropriate level of color difference meter deviation (ΔE*).

Furthermore, the nonwoven fabric has a bacteriostatic activity value of 5.0 or higher against Staphylococcus aureus and 6.0 or higher against Streptococcus pneumoniae, as measured by the bacteriostatic activity value measurement method (JIS L 1902).

Furthermore, the nonwoven fabric has an insect repellency rate against adult red flour beetles of 60% or more one week after treatment, and can maintain this rate at 40% or more even two weeks after treatment.

In addition, the nonwoven fabric has a skin patch test grade of 1 or higher.

The nonwoven fabric also has a color difference meter deviation (ΔE*) of 2.0 to 3.0. This color difference meter deviation (ΔE*) is effective in terms of quality control. Specifically, qualitative and quantitative analysis can be performed to determine whether the insect repellent content is appropriate, but this is inefficient in terms of time and cost, and this can be easily resolved by measuring the color difference meter deviation (ΔE*). That is, if the nonwoven fabric has a color difference meter deviation (ΔE*) of 2.0 to 3.0, this is evidence that the insect repellent content is appropriate. Furthermore, if the nonwoven fabric has a color difference meter deviation (ΔE*) of 2.0 to 3.0, it will exhibit a slight brown color, but since the color difference meter deviation (ΔE*) of organic cotton and natural pulp is at the 2.0 level, it also has the advantage of appealing to consumers as an organic product.

The nonwoven fabric can also exhibit an air permeability of 300 to 700 ^{cm 3} /cm ² /s.

The nonwoven fabric has a maximum breaking strength of 40-60 N/5 cm, a breaking elongation of 40-80%, and an abrasion and fuzz rating of Grade 1 or 2.

Two or more of the above nonwoven fabrics can be laminated and integrated, or they can be laminated and integrated with one or more different types of nonwoven fabric to form a composite nonwoven fabric.

The composite nonwoven fabric has insect repellent and antibacterial properties.

The composite nonwoven fabric also includes a first spunbond nonwoven fabric layer, a meltblown nonwoven fabric layer, and a second spunbond nonwoven fabric layer. Specifically, the composite nonwoven fabric also includes a first spunbond nonwoven fabric layer, a meltblown nonwoven fabric layer, and a second spunbond nonwoven fabric layer that are integrated with each other and are each manufactured by a continuous process using a single device.

At least one of the first spunbond nonwoven fabric layer and the second spunbond nonwoven fabric layer also contains the insect repellent masterbatch for nonwoven fabrics.

The meltblown nonwoven fabric layer is also at least partially electrostatically treated.

The meltblown nonwoven fabric layer may also contain an insect repellent. For example, the meltblown nonwoven fabric layer may also contain an insect repellent masterbatch for nonwoven fabrics.

The composite nonwoven fabric is characterized by its ability to capture fine particles, due to the inclusion of at least a partially electrostatically treated meltblown nonwoven fabric layer. However, conventional spunbond meltblown multilayer nonwoven fabrics have average pores on the order of several to several tens of microns, so they have little ability to remove fine particles on the order of 0.1 to 0.6 microns.

Furthermore, the composite nonwoven fabric has a QF factor of 0.15 to 0.90, as expressed by the following formula 1:

[Formula 1]
QF factor = -ln (fine dust permeability/pressure loss)

In the above formula 1, the symbol "ln" means natural logarithm.

For example, the QF factor may be 0.20 to 0.90, 0.25 to 0.90, 0.30 to 0.90, 0.35 to 0.90, 0.40 to 0.90, 0.50 to 0.90, 0.60 to 0.90, 0.70 to 0.90, or 0.8 to 0.90.

The higher the QF factor, the better the filtration performance.

The composite nonwoven fabric may have a tensile strength in the machine direction of 0.1 to 0.3 kgf/5cm/gsm, 0.15 to 0.3 kgf/5cm/gsm, 0.20 to 0.3 kgf/5cm/gsm, or 0.25 to 0.30 kgf/5cm/gsm, where gsm is an abbreviation for g/ ^m2 and refers to the weight per unit area of the composite nonwoven fabric.

Furthermore, the composite nonwoven fabric has a bending resistance in the machine direction of 20 mm or more, 25 mm or more, 30 mm or more, or 35 mm or more.

Furthermore, the composite nonwoven fabric has a bending resistance in the CD direction of 10 mm or more, 15 mm or more, 20 mm or more, 25 mm or more, or 30 mm or more.

Furthermore, the composite nonwoven fabric has a fine dust removal efficiency of 20 to 99.9%, 30 to 99.9%, 40 to 99.9%, 50 to 99.9%, 60 to 99.9%, 70 to 99.9%, 80 to 99.9%, or 90 to 99.9%.

The composite nonwoven fabric also has a pressure loss of 0.80 to 12 mmH ₂ O, 1.0 to 10 mmH ₂ O, 1.5 to 8 mmH ₂ O, 2.0 to 6 mmH ₂ O, 2.5 to 7 mmH ₂ O, 3.0 to 6 mmH ₂ O, 3.5 to 5 mmH ₂ O, or 4.0 to 5 mmH ₂ O.

The composite nonwoven fabric may also include the first spunbond nonwoven fabric layer, the meltblown nonwoven fabric layer, and the second spunbond nonwoven fabric layer, in that order. However, the present invention is not limited thereto, and the composite nonwoven fabric may also include the first spunbond nonwoven fabric layer, the meltblown nonwoven fabric layer, and the second spunbond nonwoven fabric layer in another order.

The first spunbond nonwoven fabric layer and the second spunbond nonwoven fabric layer each include a plurality of spunbond nonwoven fabric sublayers. Specifically, the first spunbond nonwoven fabric layer and the second spunbond nonwoven fabric layer each include a plurality of spunbond nonwoven fabric sublayers that are integrated together and manufactured by a continuous process on a single device.

The meltblown nonwoven fabric layer also includes at least one electrically charged meltblown nonwoven fabric sublayer. Specifically, the meltblown nonwoven fabric layer may include only one electrically charged meltblown nonwoven fabric sublayer, or may include multiple electrically charged meltblown nonwoven fabric sublayers that are each manufactured by a continuous process and integrated with one another in a single device.

The meltblown nonwoven fabric layer may further include at least one uncharged meltblown nonwoven fabric sublayer in addition to at least one charged meltblown nonwoven fabric sublayer. Specifically, the meltblown nonwoven fabric layer may further include only one uncharged meltblown nonwoven fabric sublayer in addition to at least one charged meltblown nonwoven fabric sublayer, or may further include multiple uncharged meltblown nonwoven fabric sublayers that are each manufactured by a continuous process and integrated with one another on a single device.

At least one spunbond nonwoven fabric, at least one electrostatically treated meltblown nonwoven fabric, and/or at least one non-electrostatically treated meltblown nonwoven fabric contained in the composite nonwoven fabric each independently contain a non-conductive polymer.

The non-conductive polymer is also the same as the non-conductive polymer contained in the base resin of the insect repellent masterbatch for nonwoven fabrics.

Each of the spunbond nonwoven fabrics, each of the electrostatically treated meltblown nonwoven fabrics, and/or each of the non-electrostatically treated meltblown nonwoven fabrics may further contain, independently of one another, an additive.

The additives may also include pigments, light stabilizers, primary antioxidants, secondary antioxidants, metal deactivators, hindered amines, hindered phenols, fatty acid metal salts, triester phosphites, phosphates, fluorine-containing compounds, nucleants, or combinations thereof.

Also, in one embodiment, the antioxidant can function as a charge-enhancing agent. Possible charge-enhancing agents include thermally stable organic triazine compounds, oligomers, or combinations thereof, where the compounds or oligomers further contain at least one nitrogen atom in addition to the nitrogen in the triazine ring.

For example, charge enhancers for improving charging characteristics are disclosed in U.S. Patent Nos. 6,268,495, 5,976,208, 5,968,635, 5,919,847, and 5,908,598. For example, the charge enhancers may include hindered amine-based additives, triazine-based additives, or combinations thereof.

As another example, the charge enhancing agent may include poly[((6-(1,1,3,3-tetramethylbutyl)imino-1,3,5-triazine-2,4-diyl)((2,2,6,6-tetramethyl-4-piperidyl)imino)hexamethylene((2,2,6,6-tetramethyl-4-piperidyl)imino)] (CHIMASSORB 944 (manufactured by BASF)), (reaction product of 2,4,6-trichloro-1,3,5-triazine with 1,6-hexanediamine, N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)polymer, N-butyl-1-butanamine, and N-butyl-2,2,6,6-tetramethyl-4-piperidinamine) (CHIMASSORB 2020 (manufactured by BASF)), or a combination thereof.

The charge enhancer can also be an N-substituted amino aromatic compound, particularly a tri-amino substituted compound, such as 2,4,6-trianilino-p-(carbo-2'-ethylhexyl-1'-oxy)-1,3,5-triazine (UVINUL T-150, manufactured by BASF). Another charge enhancer is 2,4,6-tris-(octadecylamino)-triazine, also known as tristearylmelamine ("TSM").

The content of the charge-enhancing agent is 0.25 to 5 parts by weight per 100 parts by weight of the total weight of each charged meltblown nonwoven fabric. If the content of the charge-enhancing agent is within this range, not only can the high level of charging performance targeted by the present invention be achieved, but spinnability is good, the strength of the nonwoven fabric is maintained at a high level, and it is also advantageous from a cost perspective.

In addition to the above additives, the composite nonwoven fabric may also contain commonly known additives such as heat stabilizers and weathering agents.

In the composite nonwoven fabric, the total content of the electrically charged meltblown nonwoven fabric is 3 to 50 parts by weight per 100 parts by weight of the total weight of the composite nonwoven fabric. If the total content of the electrically charged meltblown nonwoven fabric is within this range, a composite nonwoven fabric with excellent filtration performance, shape stability, and durability can be obtained.

The composite nonwoven fabric also has a basis weight (mass per unit area) in the range of 10 to 500 g/m ² , for example, 20 to 100 g/m ² .

The multiple nonwoven fabrics contained in the composite nonwoven fabric are integrated (i.e., bonded) to each other by thermal fusion rather than ultrasonic fusion.

The composite nonwoven fabric may further include at least one additional layer.

By way of example, each of the additional layers may include one or more separate nonwoven fabrics that are neither spunbond nonwoven fabrics nor meltblown nonwoven fabrics.

As another example, each of the additional layers may not be made of nonwoven fabric, but may include one or more layers of other materials.

Below, a method for manufacturing a composite nonwoven fabric according to one embodiment of the present invention will be described in detail.

A method for manufacturing a composite nonwoven fabric according to one embodiment of the present invention includes the step of continuously forming a spunbond nonwoven fabric layer (S100) and the step of continuously forming a meltblown nonwoven fabric layer on the spunbond nonwoven fabric layer (S200).

The spunbond nonwoven fabric layer continuous formation step (S100) involves melt-extruding, cooling, and stretching a blend of a thermoplastic, non-conductive polymer and the aforementioned insect repellent masterbatch for nonwoven fabric to form fiber yarns, which are then layered on a screen belt to form a web.

The meltblown nonwoven fabric layer continuous formation step (S200) involves melt-extruding, hot-air drawing, and cooling a thermoplastic, non-conductive polymer (to which an electrostatic performance improver may be added) to form a fiber yarn, and then laminating the fiber yarn onto the spunbond web formed in the spunbond nonwoven fabric layer continuous formation step (S100) to form a web.

Specifically, the step of continuously forming the meltblown nonwoven fabric layer (S200) includes the steps of continuously forming free fibers using a nonconductive polymer (or a blend of a nonconductive polymer and the aforementioned insect repellent masterbatch for nonwoven fabrics) (S200-1), continuously spinning the free fibers (S200-2), continuously spraying a polar solvent (e.g., water) onto the free fibers to continuously charge the free fibers (S200-3), and continuously collecting the free fibers to continuously form the meltblown nonwoven fabric (S200-4).

The free fiber continuous charging treatment step (S200-3) can also be performed by continuously spraying the polar solvent together with a gas (e.g., air).

Below, we will explain in detail how the free fiber continuous charging treatment step (S200-3) is unique or has significant advantages compared to conventional techniques.

(1) Generally, the most commonly used methods for charging during the meltblowing process are those described in U.S. Patent No. 6,375,886, which involves friction between a polar solvent and the melt-spun filaments, and those described in U.S. Patent No. 6,969,484, which involve immersing a meltblown nonwoven fabric in a polar solvent and using a suction device to allow water to permeate through the nonwoven fabric, resulting in friction between the water and the nonwoven fabric. These charging methods, which use polar solvents, require a separate post-processing step of drying the polar solvent after charging, making it essentially impossible to laminate or composite nonwoven fabrics in a continuous process. U.S. Patent Nos. 6,375,886 and 6,969,484 are incorporated herein by reference in their entireties.

(2) U.S. Patent No. 5,227,172 discloses a method of applying a high potential difference between a meltblown die and a collector, causing the melt-spun resin to be induced-charged by the surrounding electric field as it filaments. This method allows for the production of a charged meltblown nonwoven fabric without any additional post-processing. However, nonwoven fabrics induced-charged by this potential difference exhibit a phenomenon in which the charging efficiency drops sharply depending on heat and the surrounding environment, making them unsuitable for applications that require long-term storage during the sales process, such as fine dust masks, or that require a long service life, such as air purifier filters. U.S. Patent No. 5,227,172 is incorporated herein by reference in its entirety.

The inventors developed a charging treatment device that sprays a polar solvent and air onto a meltblown nonwoven fabric layer in a two-fluid form, allowing the polar solvent particles, which have sufficient kinetic energy with a small amount of spray, to rub against the filaments being melt-spun, resulting in a highly efficient frictional charging effect. This charging treatment device is characterized by the fact that it does not require separate drying equipment because the small amount of sprayed solvent is sufficiently heated and evaporated by heated air within the DCD (die to collector distance) section. This characteristic makes it possible to combine the charging treatment device with the nonwoven fabric manufacturing process and combine nonwoven fabrics through continuous lamination.

The nonwoven fabric obtained by charging the meltblown nonwoven fabric is permanently polarized, with negative and positive charges existing semi-permanently. Such a nonwoven fabric is called an electret nonwoven fabric.

As mentioned above, the composite nonwoven fabric manufacturing method does not include a separate drying step to remove the polar solvent sprayed in the free fiber continuous charging treatment step (S200-3).

As mentioned above, the polar solvent continuously sprayed in the free fiber continuous charging treatment step (S200-3) can be continuously heated and evaporated by heated air within the DCD (die to collector distance) section of the composite nonwoven fabric manufacturing apparatus.

The method for manufacturing the composite nonwoven fabric may further include a step (S300) of continuously forming another spunbond nonwoven fabric layer on the meltblown nonwoven fabric layer using the same method as the step (S100) of continuously forming the spunbond nonwoven fabric layer.

The method for manufacturing the composite nonwoven fabric may further include, after the step of continuously forming the meltblown nonwoven fabric layer (S200) or the step of continuously forming the other spunbond nonwoven fabric layer (S300), a step of continuously heat-compressing each of the spunbond nonwoven fabric layers to one or both sides of the meltblown nonwoven fabric layer (S40).

Figure 1 is a schematic diagram illustrating a composite nonwoven fabric 10 including a nonwoven fabric according to one embodiment of the present invention.

The composite nonwoven fabric 10 according to one embodiment of the present invention includes a first spunbond nonwoven fabric layer 11, a meltblown nonwoven fabric layer 12, and a second spunbond nonwoven fabric layer 13.

At least one of the first spunbond nonwoven fabric layer 11, the meltblown nonwoven fabric layer 12, and the second spunbond nonwoven fabric layer 13 is a nonwoven fabric according to one embodiment of the present invention (i.e., a nonwoven fabric containing an insect repellent masterbatch for nonwoven fabrics).

Furthermore, by modifying the composite nonwoven fabric manufacturing method, composite nonwoven fabrics with various structures and/or configurations can be manufactured.

Yet another aspect of the present invention provides an article comprising the nonwoven fabric or the composite nonwoven fabric.

The above-mentioned items may also be health or medical items.

The present invention will be described in more detail below through examples. These examples are intended to more specifically explain the present invention, and the scope of the present invention is not limited to these examples.

Examples 1-1 to 1-3 and Comparative Examples 1-1 to 1-4: Preparation of Insect Repellent Masterbatches Insect repellent masterbatches were prepared by melt-kneading using a propylene homopolymer (H7700, manufactured by LG Chemical) with a melt index (MI) of 34 g/10 min as the base resin, a liquid insect repellent mixture of cinnamaldehyde, α-copaene, apiol, and oleic acid in a weight ratio of 20:8:7:9 as the base resin, and silica as the carrier material. In Examples 1-1 to 1-3 and Comparative Examples 1-1 to 1-4, the contents (by weight) of the liquid insect repellent and the carrier material (by weight) for the raw materials consisting of the base resin, liquid insect repellent, and carrier material are shown in Table 1 below.

The contents (by weight) of the insecticide components and the carrier material (by weight) of the insecticide masterbatches produced in Examples 1-1 to 1-3 and Comparative Examples 1-1 to 1-4 are shown in Table 2 below.

Examples 2-1 to 2-5 and Comparative Examples 2-1 to 2-6: Preparation of Composite Nonwoven Fabrics A propylene homopolymer (H7700, manufactured by LG Chemicals) having a melt index (MI) of 34 g/10 min was used as the polymer for forming the spunbond nonwoven layer (SB), and a resin (H7910, manufactured by LG Chemicals) having a melt flow index (MFR) of 1,000 g/10 min was used as the polymer for forming the meltblown nonwoven layer (MB). Furthermore, one of the insecticide masterbatches prepared in Examples 1-1 to 1-3 and Comparative Examples 1-1 to 1-4 was added to the polymer for forming the spunbond nonwoven layer (SB) in the proportions shown in Table 3 below, based on the total weight of the polymer. Furthermore, Chimassorb 944, a hindered amine light stabilizer, was added to the polymer for forming the meltblown nonwoven layer (MB) in an amount of 0.5 wt %. Then, a spunbond-meltblown-spunbond (SMS) composite nonwoven fabric was continuously produced using a composite nonwoven fabric production apparatus such as that shown in FIG. 1. Specifically, a meltblown nonwoven fabric layer (MB) was continuously charged by contacting it with air and water through a two-fluid nozzle in the composite nonwoven fabric production apparatus, and then laminated on top of a spunbond nonwoven fabric layer (SB). Another spunbond nonwoven fabric layer (SB) was then laminated on top of the meltblown nonwoven fabric layer (MB). As a result, an SMS nonwoven fabric laminate was obtained. The SMS nonwoven fabric laminate was then subjected to a thermocompression process between an embossed patterned roll and a smooth roll to produce a single composite nonwoven fabric. Here, the overall basis weight of the SMS composite nonwoven fabric was adjusted to 100 gsm (g/m ² ), and the basis weight of the meltblown nonwoven fabric layer (MB) was adjusted to 22 gsm.

Evaluation Example 1: Evaluation of dispersion index of insect repellent master batches The dispersion index of the insect repellent master batches prepared in Examples 1-1 to 1-3 and Comparative Examples 1-1 to 1-4 was evaluated, and the results are shown in Table 4 below.

Evaluation Example 2: Evaluation of physical properties of composite nonwoven fabrics The physical properties of the composite nonwoven fabrics prepared in Examples 2-1 to 2-5 and Comparative Examples 2-1 to 2-6 were evaluated by the following methods, and the results are shown in Table 5 below.

(1) Spinnability: The nonwoven web was observed to see if it broke, and if it did not break, it was recorded as "good."

(2) Bacteriostatic Activity Value: The bacteriostatic activity value measurement method involves inoculating bacteria (i.e., Staphylococcus aureus or Streptococcus pneumoniae) (i.e., allowing the test sample to completely absorb the test bacterial solution), culturing for 18 hours, and then confirming the number of bacteria before and after culturing. The bacteriostatic activity value is measured as follows: When the number of bacteria after culturing in the untreated control group is C and the number of bacteria after culturing in the insect-repellent-treated product is B, the bacteriostatic activity value is calculated using the following equation 2. Here, the untreated control group and the treated product are identical in that they have a configuration comprising three layers, in that order: a first spunbond nonwoven fabric layer, a meltblown nonwoven fabric layer, and a second spunbond nonwoven fabric layer. However, they differ from each other in that the untreated control group has not been treated with an insect repellent, while the treated product has been treated with an insect repellent.

[Formula 2]
Bacteriostatic activity value = Log (C/B)

(3) Insect repellency rate and durability against adult red flour beetles: The insect repellency rate against adult red flour beetles is the percentage (%) of the number of surviving red flour beetles in the treated product relative to the number of surviving red flour beetles in the untreated control group, and indicates the repellency performance of the insect-repellent treated product. Here, the untreated control group and the treated product are identical in that they have a configuration comprising three layers, in that order: a first spunbond nonwoven fabric layer, a meltblown nonwoven fabric layer, and a second spunbond nonwoven fabric layer; however, they differ from each other in that the untreated control group has not been treated with an insect repellent, while the treated product has been treated with an insect repellent. The insect repellency rate for adult red flour beetles is measured as follows: First, adult red flour beetle culture medium is placed in large petri dish 1, with small petri dish 1 placed in the center, and an untreated control group and an attractant sample placed in small petri dish 1. Next, adult red flour beetle culture medium is placed in large petri dish 2, with small petri dish 2 placed in the center, and the insect-repellent-treated product and an attractant sample placed in small petri dish 2. The mixture is then placed in an airtight container, and after 24 hours, small petri dish 1 and small petri dish 2 are removed and the number of surviving mites in each is confirmed. Finally, the insect repellency rate for adult red flour beetles is calculated using the following formula 3.

[Formula 3]
Insect repellency rate (%) of adult red flour beetles = (number of red flour beetles in small dish 1 - amount of red flour beetle water in small dish 2) / number of red flour beetles in small dish 1 x 100

In the above formula 3, surviving red flour beetles means adult red flour beetles that respond to external stimuli.

(3) Skin patch test grade: The skin test measurement method is as follows:
(i) Sample preparation: 5 cm x 5 cm size per sample. (ii) The sample was attached to a person's wrist to elbow and aged for 24 hours.
(iii) After 24 hours, remove the sample and check for changes in the skin. Grade 1: Same as initial skin; Grade 2: Slight flushing; Grade 3: Flushing of more than half of the skin; Grade 4: Flushing of all parts of the skin.

(4) Colorimeter deviation (ΔE*): The skin test measurement method was as follows: A colorimeter (CM3700D (Minolta)) was used to measure the colorimeter deviation (ΔE*) of the composite nonwoven fabric.

(5) Air permeability: Using an FX3300 air permeability measuring instrument, the sample was placed in the measuring instrument and the air permeability (air permeability) was measured under the measuring area and measuring pressure according to the KSK 0507 method.

(6) Breaking strength and breaking elongation: Using a tensile strength and elongation tester (Instron) measuring equipment, a 5 cm wide test piece was stretched at a grip spacing of 10 cm and a pulling speed of 500 mm/min according to the KSK 0520 method, and the breaking strength and breaking elongation were measured.

(7) Abrasion and fuzzing: Using a Martindale 404 measuring device, a 15 cm piece was rubbed several times using the measuring device according to the KSK 0504 method, and fuzzing was measured.

Referring to Table 5 above, it can be seen that the composite nonwoven fabrics produced in Examples 2-1 to 2-3 were excellent in spinnability, insect repellency, skin patch test grade, breathability performance, mechanical strength, and abrasion and fuzz evaluation grade, and that the color difference meter deviation (ΔE*) was at an appropriate level.

However, in Comparative Examples 2-1, 2-3, and 2-4, spinning itself was impossible, and nonwoven fabric could not be produced.

Furthermore, the composite nonwoven fabrics produced in Comparative Examples 2-2, 2-5, and 2-6 were shown to have reduced insect repellent effectiveness. In particular, the composite nonwoven fabric produced in Comparative Example 2-5 had a color difference meter deviation (ΔE*) that was outside the appropriate level, making it unable to appeal to consumers as being organic.

The present invention has been described with reference to drawings and examples, but these are merely illustrative, and a person skilled in the art would understand that various modifications and equivalent alternative embodiments are possible. Therefore, the true technical scope of protection of the present invention is defined by the technical spirit of the claims.

Claims (15)

Mixing raw materials including a base resin, a liquid insect repellent, and a carrier material to obtain a raw material mixture;
In the raw material, the content of the liquid insect repellent is 9,000 to 11,000 ppm by weight,
In the raw material, the content of the carrier material is 30,000 to 50,000 ppm by weight;
The liquid insect repellent has a solid content of 3 to 5% by weight,
The method for producing an insect repellent masterbatch for nonwoven fabrics, wherein the carrier material comprises silica, zeolite, kaolin, or a combination thereof. The method for producing an insect repellent masterbatch for nonwoven fabric according to claim 1, wherein the base resin comprises a non-conductive polymer selected from polyolefin, polystyrene, polycarbonate, polyester, polyamide, copolymers thereof, or combinations thereof. The method for producing an insect repellent masterbatch for nonwoven fabrics according to claim 1, wherein the liquid insect repellent contains cinnamaldehyde, α-copaene, apiol, oleic acid, or a combination thereof. An insect repellent masterbatch for nonwoven fabrics produced by the method for producing an insect repellent masterbatch for nonwoven fabrics described in any one of claims 1 to 3. comprising a base resin, an insect repellent component, and a carrier material;
The content of the insect repellent component is 300 to 500 ppm by weight,
The content of the carrier material is 30,000 to 50,000 ppm by weight,
The nonwoven fabric insect repellent masterbatch, wherein the carrier material comprises silica, zeolite, kaolin, or a combination thereof . The insect repellent masterbatch for nonwoven fabric according to claim 5, wherein the dispersion index of the insect repellent masterbatch for nonwoven fabric is 0.6 or more and less than 1.0. A nonwoven fabric containing the insect repellent masterbatch for nonwoven fabric described in claim 6. The nonwoven fabric according to claim 7, wherein the nonwoven fabric contains the insect repellent masterbatch for nonwoven fabric in an amount of 5 to 20% by weight based on the total weight of the nonwoven fabric. The nonwoven fabric according to claim 7, wherein the nonwoven fabric has a bacteriostatic activity value of 5.0 or higher against Staphylococcus and a bacteriostatic activity value of 6.0 or higher against Streptococcus pneumoniae, as measured by the bacteriostatic activity value measurement method (JIS L 1902). The nonwoven fabric according to claim 7, wherein the nonwoven fabric has an insect repellency rate against adult red flour beetles of 60% or more one week after treatment, and maintains this rate at 40% or more even two weeks after treatment. The nonwoven fabric according to claim 7, wherein the nonwoven fabric has a skin patch test grade of 1 or higher. The nonwoven fabric according to claim 7, wherein the color difference meter deviation (ΔE*) is 2.0 to 3.0. 8. The nonwoven fabric according to claim 7, which exhibits an air permeability of 300 to 700 ^{cm 3} /cm ² /s. An article comprising the nonwoven fabric of claim 13. The article described in claim 14, wherein the article is a health or medical article.