KR102014813B1 - Electromagnetic wave shielding sheet manufacturing apparatus - Google Patents

Abstract

The present invention relates to an electromagnetic wave shielding sheet, a manufacturing method thereof and a manufacturing apparatus thereof. The electromagnetic wave shielding sheet has excellent electromagnetic wave shielding effects due to an enough specific surface area by coating a conductive metal on a web-type nanofiber layer, has excellent mechanical strength by forming the nanofiber layer on a sheet such as a PET non-woven fabric or the like and has flexibility, ultra thin film and excellent electromagnetic wave shielding performance by increasing an enough specific surface area and strength by nanofiber webs.

Description

Electromagnetic wave shielding sheet manufacturing apparatus

The present invention relates to an electromagnetic wave shielding material, a method and a device for manufacturing the same, and more particularly, by stacking a nanofiber web on a sheet such as a PET nonwoven fabric and applying an electromagnetic wave shielding material to improve the specific surface area to improve the electromagnetic shielding performance and The present invention relates to an electromagnetic wave shielding material which is ultra-thin and flexible and can be mass-produced.

Electromagnetic waves (electromagnetic waves) are generated from various electronic devices, which are known to be harmful to the human body and cause interference by other electronic devices.

Such electromagnetic waves are reflected and absorbed when they meet an object in progress. Since the higher the conductivity, the higher the reflection and the absorption rate, the electromagnetic wave shielding material using a conductive metal is applied to various electronic products.

In particular, as the 4th industrial revolution smart products based on information and communication technology (ICT) such as autonomous vehicles, drones, IoT, smart healthcare, and wearable devices have been rapidly advanced, electromagnetic interference (Electromagnetic Interference: The necessity of blocking the possibility of malfunction of the device and communication due to EMI) is further required, and since the smart product is miniaturized, lightened, and slimmed, the electromagnetic shielding material applied to the present invention needs to secure thin film characteristics and flexibility.

Accordingly, in recent years, a method of imparting electrical conductivity necessary for shielding electromagnetic waves by coating a metal on a fiber surface is known. For example, excellent mechanical strength, such as tensile strength, puncture strength, and dimensional stability, is disclosed in Korean Patent No. 10-1423169. A technique of coating a conductive metal on polyethylene terephthalate (PET) fibers having excellent air permeability and good wettability with a plating solution and an electrolyte is proposed.

However, the above-described prior art uses a nonwoven fabric manufactured using PET fiber having an average diameter of 0.6-6 μm, and the specific surface area is sufficient to have sufficient electromagnetic shielding ability, although the surface area is wider than conventional fibers. There was not this wide issue.

Accordingly, in order to obtain a sufficient electromagnetic shielding effect, the amount of conductive metal coating must be increased, but in this case, the thickness is thick and the flexibility is deteriorated by the conductive metal coating layer. There was an unsuitable problem below.

In addition, if the PET nonwoven fabric is formed too thin in order to solve the above thickness problem, the mechanical strength is lowered. In the case of the electromagnetic shielding material using the same, the handling is difficult and the mechanical strength is low. Breakage, such as tearing, occurred, there was a difficulty in mass production.

An object of the present invention for solving the above problems is to provide an electromagnetic wave shielding material having an excellent electromagnetic shielding effect by a sufficient specific surface area by coating a conductive metal on the nanofiber layer in the form of a web (web).

In addition, by forming the nanofibrous layer on a sheet such as PET nonwoven fabric, it has an excellent mechanical strength and improves sufficient specific surface area and strength by the nanofiber web to provide an electromagnetic shielding material having flexibility and ultra-thin and excellent electromagnetic shielding performance It is an object of the present invention to provide an apparatus and a method for manufacturing the same.

In addition, it is another object to enable the mass production by enabling the continuous production of the electromagnetic shielding material by enabling the nano-radiation web to be continuously produced.

A feature of the present invention for achieving the above object is an electromagnetic wave shielding material having a thickness of 5-50㎛ including a nanofiber layer in the form of a web and a metal plating layer formed on the nanofiber web.

The nanofiber layer may be formed on a sheet selected from among a PET nonwoven fabric, a copper plate, a fiber, a metal thin film, and a film, and a metal plating layer is formed on the entire sheet and the nanofiber web layer.

And another feature of the present invention is a sheet manufacturing process, a nanofiber web manufacturing process for producing a nanofiber web using electrospinning, the bonding process for bonding the sheet and the nanofiber web, the entire sheet and the nanofiber web as a conductive metal Electromagnetic shielding material is a manufacturing method including a plating process for electroless plating.

And, another feature of the present invention is a sheet molding portion; A sheet conveying part configured to include a plurality of conveying rollers to convey the sheet conveyed from the sheet forming part; An adhesive applying unit provided at one side of the sheet conveying unit to apply an adhesive to one surface of the sheet; A spinning member and a flat member provided in front of the spinning nozzle, a belt-type support circulating along the surface of the flat member, and a plurality of feed rollers, and a circulation means for circulating the support. A nanofiber spinneret forming a nanofiber web; An adhesive unit configured to include a pair of compression rollers provided in the supporter circulation direction in which the nanofiber web is formed and transported on the support, thereby adhering the sheet to which the adhesive is applied and the nanofiber web formed on the support and circulating the support; Electromagnetic shielding agent manufacturing apparatus comprising a plating portion for electroless plating the sheet and the nanofiber web passed through the adhesive portion with a conductive metal.

According to the present invention having the above characteristics, since the nanofiber web has a sufficient specific surface area, there is an effect of providing an electromagnetic shielding material having an ultra-thin and excellent electromagnetic shielding performance.

In addition, by forming the nanofiber web on a sheet such as PET non-woven fabric, the strength can be improved to provide an electromagnetic shielding material having excellent mechanical strength, flexibility and ultra-thin and excellent electromagnetic shielding performance.

Therefore, the electromagnetic wave shielding material of the present invention can be applied as a flexible EMI shielding material.

In addition, the present invention has a high mechanical strength and easy handling, such as PET non-woven fabric for forming a sheet, not only can be applied to automated devices, but also continuous production of nanofiber web by circulating the support for manufacturing the nanofiber web As a result, there is an effect capable of continuous production and mass production of the electromagnetic shielding material.

1 is a SEM photograph showing a cross section of an electromagnetic shielding material according to an embodiment of the present invention
Figure 2 is a photograph showing the surface of the electromagnetic shielding material according to an embodiment of the present invention
Figure 3 is a photograph showing a nanofiber layer according to an embodiment of the present invention
4 is an enlarged view of FIG.
5 is a comparison picture of the electromagnetic shielding material and the conventional electromagnetic shielding material according to an embodiment of the present invention
6 is a process chart showing a method for manufacturing an electromagnetic shielding material according to the present invention
7 is a view showing an electromagnetic shielding material manufacturing apparatus according to the present invention

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

However, this is not intended to limit the techniques described in this document to specific embodiments, but should be understood to cover various modifications, equivalents, and / or alternatives to the embodiments of this document. In connection with the description of the drawings, similar reference numerals may be used for similar components.

In addition, terms used in the present specification are merely used to describe particular embodiments, and may not be intended to limit the scope of other embodiments. Singular expressions may include plural expressions unless the context clearly indicates otherwise. The terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by one of ordinary skill in the art. Among the terms used in this document, terms defined in the general dictionary may be interpreted as having the same or similar meaning as the meaning in the context of the related art, and ideally or excessively formal meanings are not clearly defined in this document. Not interpreted as In some cases, even if terms are defined in the specification, they may not be interpreted to exclude embodiments of the present disclosure.

As shown in FIGS. 1 to 4, the electromagnetic shielding material according to the present invention includes a sheet 10 made of a PET nonwoven fabric, a nanofiber web 20 in the form of a web formed on the sheet 10, and an entire sheet and a nanofiber web. It is configured to include a metal plating layer 30 applied to.

In the embodiment of the present invention, the sheet 10 will be described as a non-woven PET.

In addition, the nanofiber web is formed by forming a web having a fiber thickness of 50 nm to 1 μm through electrospinning. The tensile strength of the electron shielding material to which the nanofiber is applied is 350 kgf / cm 2 or more. Polymers to be used for this purpose are PU (polyurethane), PVDF (poly vinylidenefluoride), PLA (polylactic acid), PGA (poly glycolic acid), PLLA (poly-l-lactic acid), PCL (polyacproactone), PS (polystylene), PVA (polyvinylalchol), polyacylonitrile (PAN), polyamide (PA), polysulfone (PS), polyvinylpyrrolidone (PVP), polyethersulfone (PES), gelatin, collagen, or a mixture thereof may be used. .

In addition, as a solvent for dissolving the polymer to a spinning degree, dimethylacetamide, dimethylformamide, dimethyl ethyl ketone, acetone, dichlorobenzene, dichlorobenzene, Ethanol, methanol, isopropylalcohol, trifluoroethanol, trichloroethanol, tetra hydrofuran, n-methyl-2-phyllolidon n-methyl-2-pyrrolidinone, dimethyl sulfoxide, phenol, monochlorobenzne, xylene, formic acid, ethyl acetate, chloroform (chloroform), methylene chloride (methylene chloride), acetic acid (acetic acid), sulfuric acid (sulfuric acid), water (water), etc. can be used alone or in combination.

In addition, additives for imparting mechanical properties and surface properties of the nanofiber web include fluorine-based additives, surfactants, slip agents, antistatic agents, siloxane-based, silane-based, silicon-based additives, titanium oxide (TiO 2), and graphene oxide. (grphene oxide) or zinc oxide (ZnO), one or a mixture thereof is used.

The concentration of the polymer and the solvent is appropriate to maintain the fibrous form during the electrospinning, the range of about 5 to 90% by weight based on the polymer material relative to the solvent is suitable.

In addition, the additive may further add a polymer for hot melt (Hot melt) for adhesion of the nanofiber web, for example, PP (polypropylene) hot melt, EVA (ethylene vinyl acetate) hot melt, polyamide hot Melt, polyurethane hot melt, etc. may be used alone or in combination, and 1-30 parts by weight based on 100 parts by weight of the polymer and solvent mixture for the nanofiber web.

In addition, the hot melt polymer resin may be used as an adhesive for bonding the sheet of the present invention and the nanofiber web.

The electromagnetic wave shielding material thus prepared is manufactured to have an ultra-thin thickness of 5-50 µm, preferably 25 µm or less, and as shown in FIG. 5 (a), the electromagnetic wave shielding material of the present invention is made of only a PET nonwoven fabric layer by a nanofiber web. It can be seen that the specific surface area is significantly improved compared with the conventional electromagnetic wave shielding material (b).

On the other hand, in the embodiment of the present invention described as an example that the nanofiber layer is formed on the sheet consisting of PET nonwoven fabric, in addition to the nanofiber layer is used alone, or the sheet in addition to the PET nonwoven fabric of copper plate, fiber, metal thin film, film Alternatively, it may be used.

In the method of manufacturing the electromagnetic wave shielding material of the present invention, as shown in FIG. Process (S103), the sheet and the nanofiber web is configured to include a plating process (S104) for electroless plating with a conductive metal.

The sheet is a PET non-woven fabric, the PET non-woven fabric manufacturing process may be used by any known method, for example, by applying a wet (wet-laid) technology to produce a island-in-the-sea PET split yarn as an ultra-thin non-woven fabric It is.

The island-in-the-sea type is a method of dissolving the sea component in the composite fibers spun with different two-component polymers to obtain a microfiber from the island component. An ultra thin nonwoven fabric was produced by calendering.

In the wet technique, the yarn is cut, reduced and dispersed to form a web and dried.

At this time, the sea component of the yarn is a soluble PET, and the island component is usually a PET SD (semi-dull). Instead of SD, CDP (Cation Dyeable Polyester) or Black (Black) yarn is used. The complex spinning used is progressing.

The composite ratio of PET: Co-PET polymer is 75:25, 70:30 and consists of 36 ~ 37 island components, and it dissolves sea components through alkaline hydrolysis process. Fineness is about 0.05 ~ 0.06d level can produce ultrafine fibers with a lower fineness than the split microfiber.

On the other hand, in addition to the PET as the island (Island) component, there are nylon 6, nylon 66, PP, PE, PPS (Polyphenylene sulfide), etc. As the sea component (polystyrene), 2-ethyl hexyl acrylate copolymer , Copolymers of PET / natrium sulfoisophthalate, PEG and the like can also be used.

In addition, the weight loss processing is usually carried out in a batch, continuous or semi-continuous method, the present invention is put in a certain amount of sea island yarn cut in the form of short fibers in a strong basic aqueous solution to raise the temperature Minimize the difficulty of cutting process by adopting batch type method that dissolves sea component and obtains ultra fine yarn of island component.

However, in the case of the batch type, the capacity to be treated at one time is small, and if the weight loss time is long or the strong base concentration or temperature is high, the weight loss is excessive and there is a problem in that not only sea components but also some components are dissolved.

Therefore, by applying a weight reduction method to give the strong basic aqueous solution to increase the island-in-the-sea yarn input up to 25wt%.

In addition, the bonding process is to apply an adhesive to one side of the sheet by a common coating method such as spray coating, paint brushing, etc. to bond the sheet and the nanofiber web to which the adhesive is applied using a pressing roll. The adhesive may bond the sheet and the nanofiber web, and it is preferable to use it as a material that does not weaken the adhesive force in the plating process.

The plating process is performed by electroless nickel plating. First, the process of washing with water after ultrasonic degreasing is performed one or more times, followed by treatment with a conditioner, pickling, washing with water, neutralization, followed by catalytic treatment, washing with water, activating washing with water, and plating. Wash with water and dry.

On the other hand, the electromagnetic wave shielding material manufacturing apparatus as shown in Fig. 7; A sheet conveying unit 200 for conveying the sheet 10 transferred from the sheet forming unit; An adhesive applying unit 300 for applying the adhesive 12 to one surface of the sheet 10; A nanofiber spinning unit 400 forming a nanofiber web 20 on a circulating support 410; The adhesive part 500 for adhering the sheet 10 to which the adhesive is passed through the adhesive applying part 300 and the nanofiber web 20 transferred along the support 410 but allowing the support 410 to be continuously circulated. ; The plate 10 and the plated portion 600 for electroless plating the surface of the nanofiber web 20 with the conductive metal is passed through the adhesive portion 500 is configured.

The sheet forming unit 100 may be used as long as it is a device for producing a known ultra-thin sheet, the sheet in the embodiment of the present invention uses a PET nonwoven fabric.

 And since the plating unit 600 also uses a known plating apparatus, a detailed description thereof will be omitted.

The sheet conveying part 200 is configured to include a plurality of feed rollers 210 and a motor and a chain (not shown) for rotating the feed rollers 210, the sheet conveyed from the sheet forming part 100 ( 10) to transfer, the sheet 10 is formed up and down so that the direction is reversed in the transfer process to minimize the space consumption of the device.

The adhesive applying unit 300 is provided on one side of the sheet conveying unit 200 to apply an adhesive to one surface of the sheet 10, the application means 310, such as spray, brush provided on the lower portion of the sheet conveying unit 200 And a support means 320 provided opposite to the application means 310 of the sheet transfer part 200 to support the sheet 10 flatly during the application process.

The nanofiber spinning unit 400 is a flat member 430 provided at a position spaced apart from the front end of the spinning nozzle 420 and the spinning nozzle 420, the belt type circulating along the surface of the flat member 430 It includes a support 410, including a plurality of feed rollers 442 circulating means 440 for circulating the support 410, the nanofiber web 20 on the circulating support 410 To form.

The adhesive part 500 includes a pair of pressing rollers 510 provided in the circulation direction of the support body 410, and the sheet 10 and the support member on which the adhesive has passed through the adhesive applying part 300 are applied. After adhering the nanofiber web 20 transported along 410, the support 410 continues to be circulated by the circulation means 440.

According to the present invention configured as described above it is possible to produce an electromagnetic shielding material by producing an ultra-thin PET non-woven fabric having excellent mechanical strength, which is easy to handle in the actual mass production process to enable continuous and mass production.

10 sheet 12 adhesive
20: nano fiber web 30: plating layer
100: sheet molding part 200: sheet conveying part
300: adhesive coating part 400: nanofiber spinning part
410: support 420: spinning nozzle
430: flat member 440: circulation means
500: bonding portion 600: plating portion

Claims (10)

delete delete delete delete delete delete delete Sheet forming part 100;
A sheet conveying unit 200 for conveying the sheet 10 transferred from the sheet forming unit;
An adhesive applying unit 300 for applying an adhesive to one surface of the sheet 10;
A nanofiber spinning unit 400 forming a nanofiber web 20 on a circulating support 410;
The adhesive part 500 for adhering the sheet 10 to which the adhesive is passed through the adhesive applying part 300 and the nanofiber web 20 transferred along the support 410 but allowing the support 410 to be continuously circulated. ;
It comprises a plating portion 600 for electroless plating the surface of the sheet 10 and the nanofiber web 20 passed through the adhesive portion 500 with a conductive metal,
The nanofiber spinning unit 400 is a flat member 430 provided at a position spaced apart from the front end of the spinning nozzle 420 and the spinning nozzle 420, the support circulating along the surface of the flat member (430) ( 410, comprising a plurality of feed rollers 442, including a circulation means 440 circulating the support 410, thereby forming the nanofiber web 20 on the circulating support 410. Electromagnetic shielding material manufacturing apparatus characterized in that.
delete The method of claim 8,
The adhesive part 500 includes a pair of pressing rollers 510 provided in the circulation direction of the support body 410, and the sheet 10 and the support member on which the adhesive has passed through the adhesive applying part 300 are applied. After adhering the nanofiber web 20 transported along the 410, the support 410 is characterized in that it continues to be circulated by the circulation means 440.

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