KR100379599B1 - High electric non-woven fabrics and manufacturing method for the same - Google Patents

Abstract

The present invention relates to a high dielectric constant nonwoven fabric and a method for manufacturing the same, and more particularly, (a) a fiber for producing fibers by mixing and spinning polyvinylidene fluoride (PVDF) and polypropylene (PP: polypropylene). It includes a manufacturing step, (b) a polarization treatment step to improve the dielectric constant by polarizing the fibers produced in the fiber manufacturing step, and (c) a nonwoven fabric manufacturing step of producing a nonwoven fabric with a dielectric constant improved fibers in the polarization step It relates to a high dielectric constant nonwoven fabric manufacturing method and a nonwoven fabric produced by the above method. The high-k dielectric nonwoven fabric of the present invention has a significantly improved electrostatic retention compared to the conventional nonwoven fabric having dielectric properties, and when the nonwoven fabric of the present invention is applied to an electrostatic filter or an electrostatic mop, it has excellent filtration ability for fine particles and ionic materials. In addition, it is possible to manufacture a long-life electrostatic filter, and it is possible to manufacture a long-life electrostatic mop with high static electricity retention.

Description

High dielectric constant nonwoven fabric and its manufacturing method {HIGH ELECTRIC NON-WOVEN FABRICS AND MANUFACTURING METHOD FOR THE SAME}

[TECHNICAL FIELD OF THE INVENTION]

The present invention relates to a high-k dielectric nonwoven fabric and a method for manufacturing the same, and more particularly, in the case of applying to an electrostatic filter or an electrostatic mop, the electrostatic retention is greatly improved as compared to the conventional nonwoven fabric having dielectric properties. The present invention relates to a high dielectric constant nonwoven fabric capable of producing an electrostatic filter having excellent filtration capability and a long lifespan, and capable of manufacturing an electrostatic mop having a high static electricity retention capability and a long lifetime.

The present invention also relates to an electrostatic filter and an electrostatic mop manufactured using the nonwoven fabric.

[Private Technology]

Nonwovens are fabrics made directly from fibers without passing through the medium of the yarn. Nonwoven fabrics are used in various fields, and the characteristics of the nonwoven fabric are determined by factors such as the type of fiber used, the density, and the bonding material.

Nonwovens can be applied as filters for the filtration of dust, ie dust. The filter processes fibers such as synthetic fibers or natural fibers into a nonwoven fabric to remove dust from the air by allowing air to pass through the fine pores between the fibers in the nonwoven fabric and preventing dust from passing through the air.

The filter should be considered first. In particular, conventional filters and dust masks mainly rely on mechanical filtering. Recently, many researches have been conducted on the electrostatic filter for the purpose of filtering fine particles of dust and ionic materials, but there is a problem that the electrostatic retention period of the filter is very short, which is not practical.

For the purpose of improving electrostatic retention, U. S. Patent No. 5,645, 627 used a method of injecting electric charges into fibers made of polymers comprising polypropylene, polyethylene, polyester, polyamide, polyvinyl chloride and polymethyl methacrylate. A satisfactory improvement in electrostatic retention has not been achieved.

Therefore, there is still a need for the development of a nonwoven fabric that can be applied to an electrostatic filter having excellent filtration capability and excellent electrostatic retention.

The nonwoven can also be applied to manufacturing a sweeper, a cleaning tool. In particular, it is recommended that the electrostatic mop is charged with static electricity to clean the fine materials such as dust of computer or TV CRT. However, currently marketed electrostatic mop has a problem of low dielectric constant or short static retention period, there was a problem that the collection rate of dust significantly reduced when reuse after washing the electrostatic mop once. Accordingly, there is still a need for an electrostatic mop having a high dielectric constant, good static electricity retention, and a small reduction in dust collection performance even after reuse after washing.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the prior art, and an object of the present invention is to provide a nonwoven fabric having a high dielectric constant and a long electrostatic retention period.

It is another object of the present invention to provide a method for producing the nonwoven fabric.

In addition, the present invention provides a high dielectric constant electrostatic filter and a high electrostatic retention ability to maintain the function as a filter for a long time as a filter having excellent filtration ability, in particular, fine filtration ability to dust and ionic materials, such as fine particle size using the nonwoven fabric The purpose is to provide an electrostatic mop.

In order to achieve the above object, the present invention provides a fiber manufacturing step of producing a fiber by mixing (a) polyvinylidene fluoride (PVDF) and polypropylene (PP: polypropylene), (b) the fiber production A polarization treatment step of improving the dielectric constant by polarizing the fibers prepared in the step; and (c) a non-woven fabric manufacturing method of manufacturing a nonwoven fabric having a dielectric constant improved fiber in the polarization treatment step. to provide.

In another aspect, the present invention provides a nonwoven fabric produced by the high-k dielectric nonwoven fabric manufacturing method.

In another aspect, the present invention provides an electrostatic filter made of the high-k dielectric nonwoven fabric.

The present invention also provides an electrostatic mop (sweeper) made of the high-k dielectric nonwoven fabric.

Hereinafter, the present invention will be described in detail.

The inventors of the present invention, while researching to produce a non-woven fabric having excellent electrostatic retention capacity to produce a fiber from a raw material of polyvinylidene fluoride (PVDF) and polypropylene (PP; Polypropylene) with excellent piezoelectric properties as a fiber material, the fiber After imparting static electricity to the nonwoven fabric, it is found that the present invention has a significantly improved static electricity retention compared to the conventional nonwoven fabric and the present invention has been completed.

The method of manufacturing a high dielectric constant nonwoven fabric of the present invention includes (a) a fiber manufacturing step of manufacturing a fiber by mixing and spinning polyvinylidene fluoride (PVDF) and polypropylene (PP: polypropylene), and (b) producing the fiber. Polarization treatment step to improve the dielectric constant by polarizing the fiber produced in the step and (c) characterized in that it comprises a non-woven fabric manufacturing step of producing a nonwoven fabric with a dielectric constant improved fibers in the polarization treatment step.

In the fiber manufacturing step, the fiber used for the nonwoven fabric is prepared according to a conventional fiber method, characterized in that the mixed spinning of polyvinylidene fluoride and polypropylene.

Herein, the content of polyvinylidene fluoride is preferably 1 to 20% by weight, and the content of polypropylene is 99 to 80% by weight. Preferably the content of polyvinylidene fluoride is 8 to 12% by weight, most preferably 10% by weight polyvinylidene fluoride. As the polyvinylidene fluoride content is increased in the range of 1 to 20% by weight of polyvinylidene fluoride, the filtration efficiency of the electrostatic filter gradually increases, and when the content reaches 10% by weight, the filtration efficiency of the electrostatic filter is almost 100%. Will reach%.

The thickness of the fiber produced is 5 to 20 μm, preferably 10 to 14 μm. As the thickness of the fiber increases, the filtration efficiency of the electrostatic filter decreases, and the filtration efficiency of the electrostatic filter is high at the thickness within the above range.

In the polarization treatment step, the prepared fiber is polarized to improve dielectric constant. Polyvinylidene fluoride has an alpha form and a beta form, and the thing with high electric charge is a beta form. In this step, the α form of the polyvinylidene fluoride contained in the fiber is changed to the β form, resulting in high chargeability.

The polarization treatment repeats winding / unwinding / rewinding the fibers, and scans the electron beams sequentially so as to polarize the intramolecular electron distribution of the high dielectric constant fibers constituting the nonwoven fabric by the impact of the high-charged electron beam at the scanned portion. Polarization). This can be easily understood by those skilled in the art.

In the nonwoven fabric manufacturing step, a nonwoven fabric is manufactured from fibers having improved dielectric constant prepared in the polarization treatment step. The dielectric constant-improved fibers can be produced by nonwovens alone or in combination with other common fibers in accordance with conventional nonwoven fabrics, and in particular, a nonwoven fabric having a structure suitable for use as a filter can be obtained. In the nonwoven fabric, all methods commonly used for the production of the nonwoven fabric may be applied, but a method of needle punching is preferable. In addition, in the present invention, when the other dielectric fibers are mixed with the dielectric constant improved fibers, the mixing ratio of the other general fibers may be polarized to use 200 parts by weight or less of the normal fibers based on 100 parts by weight of the dielectric constant improved fibers. When the amount of the normal fibers exceeds 200 parts by weight, it is not preferable that the static electricity holding capacity of the nonwoven fabric produced is low.

The density of the fiber in the nonwoven fabric manufacturing step is not particularly limited, but preferably 30 to 600 g / m ² in consideration of the filtration capacity and economical efficiency of the electrostatic filter, more preferably 100 to 300 g / m ² , and more preferably 250 to 300 g / m ² .

In addition, the method of manufacturing the high dielectric constant nonwoven fabric of the present invention may further include a treatment step selected from the group consisting of plasma treatment, corona discharge, and ion beam treatment of the nonwoven fabric produced in the nonwoven fabric manufacturing step after the nonwoven fabric manufacturing step. The plasma treatment is preferably carried out in a conventional method at 100 KW, 0.1 Torr in an oxygen atmosphere. In addition, after the nonwoven fabric manufacturing step, the corona discharge or ion beam treatment, which may be further performed on the nonwoven fabric produced in the nonwoven fabric manufacturing step, is performed by a conventional method. Such plasma treatment, corona discharge, or ion beam treatment may increase the electrostatic force by 20 to 50% relative to the same weight of the fiber.

In addition, the method of manufacturing a high dielectric constant nonwoven fabric of the present invention may further include an antibacterial treatment step. Conventional antimicrobial treatment may be applied to the antimicrobial treatment. For example, a method of mixing and spinning an appropriate amount of an inorganic antimicrobial agent may be applied when preparing fibers by mixing and spinning polyvinylidene fluoride and polypropylene.

In another aspect, the present invention provides a high-k dielectric nonwoven fabric produced by the above method, the high-k dielectric nonwoven fabric produced by the present invention is characterized by high electrostatic force, the long-term retention of static electricity. The dielectric constant of the nonwoven fabric prepared in accordance with the present invention (Example 1 below) was measured. As a result, an excellent value of 3.59 was obtained. The dielectric constant was measured by changing a voltage while putting a nonwoven fabric to be measured between parallel plates of a constant distance. The measurement was measured in the electronic materials laboratory of Korea University, the calculation of the dielectric constant is calculated using the following equation 1.

[Calculation 1]

E = E ⁰ / K

In Equation 1, E represents an electric field in the presence of a dielectric, E ⁰ represents an electric field in the absence of a dielectric, and K represents a dielectric constant.

The present invention also provides an electrostatic filter made of the nonwoven fabric. The method for manufacturing the nonwoven electrostatic filter is generally applied to the filter manufacturing method for producing a filter with a nonwoven fabric, the electrostatic filter of the present invention is particularly preferably applied as an electrostatic filter, such as a dust mask, air filter or vacuum cleaner. The electrostatic filter of the present invention has an excellent electrostatic force and shows a significantly improved filtration efficiency compared to a conventional filter for the filtration of ionic materials and fine dust. Compared to the above-mentioned problem, the electrostatic filter of the present invention is maintained at a level similar to the initial level even after several decades of use.

The present invention also provides an electrostatic mop made of the high-k dielectric nonwoven fabric. The electrostatic mop is manufactured through a conventional method such as cutting the nonwoven fabric to an appropriate size. The electrostatic mop of the present invention has a high electrostatic force, has excellent cleaning efficiency, and has a long electrostatic retention period, which has a characteristic of remarkably improved life compared to a conventional electrostatic mop. This has almost the same advantages as the early days.

Hereinafter, examples of the present invention will be described. However, the following examples are for illustrating the present invention, and the present invention is not limited to the following examples.

Example 1

10 wt% of polyvinylidene fluoride and 90 wt% of polypropylene are mixed and spun to obtain a 10 μm-thick fiber, and the dielectric constant is improved through the polarization treatment of scanning the electron beam while repeating winding / unwinding / rewinding the fiber. Fibers were prepared. The dielectric constant-enhanced fiber was manufactured into a high dielectric constant nonwoven fabric by needle punching while controlling the density to 250 g / m ² .

Example 2

A high dielectric constant nonwoven fabric was prepared in the same manner as in Example 1 except that 5 wt% of polyvinylidene fluoride and 95 wt% of polypropylene were mixed and spun to obtain a high dielectric constant fiber.

Example 3

A high dielectric constant nonwoven fabric was prepared in the same manner as in Example 1 except that 15 wt% of polyvinylidene fluoride and 85 wt% of polypropylene were mixed and spun to obtain a high dielectric constant fiber.

Example 4

A nonwoven fabric was prepared in the same manner as in Example 1, except that 10 wt% of polyvinylidene fluoride and 90 wt% of polypropylene were mixed and spun to prepare a 5 μm-thick fiber.

Example 5

A nonwoven fabric was prepared in the same manner as in Example 1, except that 10 wt% of polyvinylidene fluoride and 90 wt% of polypropylene were mixed and spun to prepare a fiber having a thickness of 15 μm.

Example 6

A high dielectric constant nonwoven fabric was prepared in the same manner as in Example 1 except that the fiber density of the nonwoven fabric was 100 g / m ² .

Example 7

A high dielectric constant nonwoven fabric was prepared in the same manner as in Example 1 except that the fiber density of the nonwoven fabric was 300 g / m ² .

Example 8

10 wt% of polyvinylidene fluoride and 90 wt% of polypropylene are mixed and spun to obtain a 10 μm-thick fiber, and the dielectric constant is improved through the polarization treatment of scanning the electron beam while repeating winding / unwinding / rewinding the fiber. Fibers were prepared. The dielectric constant of 100 parts by weight of the fiber with improved dielectric fibers were mixed with 100 parts by weight of the high dielectric constant nonwoven fabric by needle punching while adjusting the density to 250 g / m ² .

Example 9

Plasma treatment of the nonwoven fabric of Example 6 at 100 KW and 0.1 torr was performed in an oxygen atmosphere to prepare a high dielectric constant nonwoven fabric.

Comparative Example 1

Fibers were prepared using only polypropylene, and nonwoven fabrics were manufactured from the fibers. The same method as in Example 1 was used for the polarization treatment and the nonwoven fabrics.

[Experiment 1]

In order to test the filtration capacity of the ionic material of the high dielectric constant nonwoven fabric prepared according to the present invention, the filtration test was carried out according to the NaCl aerosol test method.

The NaCl aerosol test method pressurizes and warms up a 1% sodium chloride (NaCl) solution, disperses it in air in the form of an aerosol having a particle diameter of about 0.3 μm, and then passes the filter to be tested at a flow rate of 34 L / min. The filtration rate was expressed as a percentage (%) by measuring the amount of sodium chloride remaining in the air after passage. In this experiment, the filtration rate of the nonwoven fabrics of Examples 1, 6, and 9 and Comparative Example 1 was measured. As a result of the experiment, the nonwoven fabric of Example 1 according to the present invention had a filtration rate of 99.7%, the nonwoven fabric of Example 6 had a filtration rate of 70%, the nonwoven fabric of Example 9 had a filtration rate of 99.0%, and a nonwoven fabric of Comparative Example 1 In the case of the filter performance was not shown to nearly 0%. The results of the experiment shows that the nonwoven fabric according to the present invention has a very good filtration efficiency for the ionic material, it can be seen that the filtration performance is more excellent when the plasma treatment.

[Experiment 2]

In order to test the performance of the nonwoven fabric as an electrostatic mop according to the present invention, the dust of the computer monitor was wiped with Example 1 and Comparative Example 1. The nonwoven fabric of Example 1 according to the invention was wiped much better than the nonwoven fabric of Comparative Example 1. In addition, after one use, the nonwoven fabrics of Example 1 and Comparative Example 1 were washed with water and dried to find out whether they can be reused as electrostatic mops. In the nonwoven fabric of Example 1 according to the present invention, the dust of the computer monitor was well wiped to the same extent as when used for the first time, but the nonwoven fabric of Comparative Example 1 showed that the dust collecting performance was remarkably degraded when reused because the dust was not wiped. The results of this experiment show that when the nonwoven fabric according to the present invention is used as an electrostatic mop, the dust collection performance is superior to that of the conventional electrostatic mop, and the life is maintained at the initial level even when reused after washing. Significantly improved.

As described above, the high-k dielectric nonwoven fabric prepared by the present invention has excellent electrostatic holding power as compared to the conventional nonwoven fabric, and when the nonwoven fabric is applied to the electrostatic filter, the filtration efficiency for the ionic material is remarkably superior to that of the conventional filter. It can be seen that the function as a filter lasts a long time. In addition, even when the nonwoven fabric according to the present invention is applied to the electrostatic mop, the electrostatic holding power is excellent, the cleaning function is excellent, and the service life is significantly extended.

Claims (9)

(A) a fiber manufacturing step of producing a fiber by mixing and spinning polyvinylidene fluoride (PVDF: poly vinylidene fluoride) and polypropylene (PP: polypropylene); (b) polarization treatment step of improving the dielectric constant by polarizing the fiber produced in the fiber manufacturing step; And (C) non-woven fabric manufacturing step of producing a nonwoven fabric with improved dielectric constant in the polarization step Method of producing a high dielectric constant nonwoven fabric comprising a. The method of manufacturing a high dielectric constant nonwoven fabric according to claim 1, wherein the content of the polyvinylidene fluoride in the fiber manufacturing step is 1 to 20 wt%, and the amount of the polypropylene is 99 to 80 wt%. The method of manufacturing a high dielectric constant nonwoven fabric according to claim 1, wherein the thickness of the fiber produced in the fiber manufacturing step is 5 to 20 µm. The method of manufacturing a high dielectric constant nonwoven fabric according to claim 1, wherein the high dielectric constant nonwoven fabric prepared in the nonwoven fabric manufacturing step is 30 to 600 g / m ² . The method of claim 1, wherein the nonwoven fabric prepared in the nonwoven fabric manufacturing step after the nonwoven fabric manufacturing step further comprises the step of selecting from the group consisting of plasma treatment, corona discharge (corona discharge) and ion beam treatment Way. The method of manufacturing a high dielectric constant nonwoven fabric according to claim 1, wherein an inorganic antimicrobial agent is added and spun during the mixed spinning of the fiber manufacturing step. A high dielectric constant nonwoven fabric according to any one of claims 1 to 6. delete delete