KR100610888B1 - An preparing method of an eelectrically conductive transparent composite with excellent antistatic property and light transmittance rate using carbon nano tube - Google Patents

Abstract

The present invention relates to an electrically conductive transparent composite having excellent antistatic properties and light transmittance using carbon nanotubes, and includes transparent ABS (acrylonitrile butadiene styrene), transparent PS (polystyrene), PET (polyethylene terephthalate), and PE (polyethylene). ), PC (polycarbonate), SAN (styrene acrylonitrile copolymer), cellulose, polysulfone, ADC (allyl diglycol carbonate), transparent SBS (styrene butadiene styrene) and at least one polymer selected from the group consisting of acrylic resins Electrically conductive transparent composite having excellent antistatic properties and light transmittance using carbon nanotubes, characterized in that the carbon nanotubes are dispersed in an amount of 0.008 to 0.02 parts by weight in 100 parts by weight of the basic insulating polymer resin made of a resin, and a method for manufacturing the same Electrical / electronic devices, components or parts made from electrically conductive transparent composite materials The interior and exterior are provided.

The composite material having an electric conductivity function according to the present invention is a micro-dispersion of carbon nanotubes in a basic insulating transparent polymer, which has electromagnetic shielding and antistatic function, and is capable of carrying out transparent (nude) design of electrical / electronic devices and components. And it can be used as a composite material for packaging.

Carbon nanotube, antistatic, light transmittance, conductivity, resin

Description

An preparing method of an eelectrically conductive transparent composite with excellent antistatic property and light transmittance rate using carbon nano tube}

The present invention relates to an electrically conductive transparent composite having excellent antistatic properties and light transmittance using carbon nanotubes, and more particularly, to a mobile phone exterior material of a nude type (a transparent object for viewing contents) that requires an electromagnetic shielding function. Anti-static properties using carbon nanotubes that can be used for transparent dust bins for vacuum cleaners that need anti-static function to suppress dust adhesion, and for transfer and storage of electrical / electronic parts that need anti-static function to eliminate static electricity The present invention relates to an electrically conductive transparent composite having excellent light transmittance.

Recently, electrical / electronic devices and parts thereof have a need for transparent (nude) design application, stability for human body and electromagnetic shielding to protect electrical / electronic circuits, damage to electrical / electronic circuits due to static electricity, and static electricity. There is a need in each industry for the prevention of contamination due to dust adhesion. In order to increase the product value and competitiveness of electric and electronic devices and components, there is a need for a composite material in which electromagnetic wave shielding and antistatic functions are combined based on a transparent function.

As a method of enabling electromagnetic shielding, antistatic, and transparent design for the exterior materials and packaging materials of electrical / electronic devices and components, the base insulating transparent polymer is used as the base material, and then molded into a shape suitable for each application. Coating and drying the coating of the electrically conductive material dispersed in a binder and a solvent by a conventional coating method is an appropriate method that can have an integrated or selective transparent function, an electromagnetic shielding function, an exterior material and a packaging material with antistatic functions. The electrically conductive material used above is a water-soluble conductive polymer such as carbon black, carbon fiber, powder or metal oxide in the form of a fiber, polypyrrole, polyaniline, polythiophene, etc., and can maintain a light transmittance of about 80%. Surface resistance values required for electromagnetic shielding and antistatic It is known to be possible in a wide range from ~ 10E12Ω.

However, when the base insulating material is molded into a desired shape using the basic insulating transparent polymer, and then coating and drying a coating having an electrically conductive function on the surface thereof, stains due to coating and drying may be caused by the complicated shape of the moldings. Problems that may occur are pointed out, and such stains further point out a problem of deteriorating the product value of the exterior and packaging materials of each electrical / electronic device and component.

In addition, the electrically conductive thin film coated on the surface of each molding has a problem that it is difficult to use for a long time because the characteristics such as friction resistance and chemical resistance are limited. In addition, since the components of the coated electrically conductive coating are heterogeneous with those of the base molding, it is further pointed out that a problem of difficulty in recycling through the conventional regeneration method is difficult.

Alternatively, a method of obtaining a composite material by copolymerizing a hydrophilic polymer to a transparent insulating polymer and a method of obtaining an antistatic transparent composite material by combining a conductive polymer present in powder form with a transparent insulating polymer. The hydrophilic polymer resin exhibits an antistatic effect by adsorbing moisture in the air on the surface and inside of the transparent polymer composition to form a fine moisture layer, thereby imparting excellent light transmittance characteristics. However, it is pointed out that when the humidity in the air drops, the antistatic effect tends to be reduced, and since the surface resistance that can be realized is about 10E11Ω, the use is limited. The antistatic transparent composite material in which the powdery conductive polymer is dispersed in the transparent insulating polymer has a surface resistance of about 10E7 to 10E11Ω and excellent light transmittance. However, the narrow range of surface resistance values points to a limited use.

The present invention is to provide a composite material having electromagnetic shielding, antistatic, and transparent by dispersing carbon nanotubes in a basic insulating transparent polymer in order to improve such a conventional problem, by using the composite without a conventional process The general molding method alone is intended to be used to manufacture transparent molded articles having electromagnetic shielding and antistatic functions.

According to one aspect of the invention, transparent ABS (acrylonitrile butadiene styrene), transparent PS (polystyrene), PET (polyethylene terephthalate), PE (polyethylene), PC (polycarbonate), SAN (styrene acrylonitrile copolymer ), Cellulose, polysulfone, ADC (allyl diglycol carbonate), transparent SBS (styrene butadiene styrene) and 100 parts by weight of the basic insulating polymer resin consisting of at least one polymer resin selected from the group consisting of acrylic resin carbon nanotubes 0.008 Provided is an electrically conductive transparent composite having excellent antistatic property and light transmittance using carbon nanotubes, which is dispersed at 0.02 part by weight.

According to another aspect of the present invention,

Palletized transparent ABS (acrylonitrile butadiene styrene), transparent PS (polystyrene), PET (polyethylene terephthalate), PE (polyethylene), PC (polycarbonate), SAN (styrene acrylonitrile copolymer), cellulose, poly Based on 100% by weight of a basic insulating polymer resin and an electrically conductive coating containing carbon nanotubes consisting of at least one polymer resin selected from the group consisting of sulfone, ADC (allyl diglycol carbonate), transparent SBS (styrene butadiene styrene) and acrylic resin Injected at a concentration of 0.6% to 1.6% by weight relative to the weight of the insulating transparent polymer resin,

The mixture was first stirred for 20-40 seconds at a rotational speed of 500-1,500 rpm and then stirred for 20-40 seconds at the same rotational speed to raise the surface temperature of the pallet to 50-60 ° C. to cure the coating. After facilitating the process, coating the electrically conductive coating on an insulating polymer resin pallet by third stirring for 20-40 seconds at the same rotational speed;

Repeating the coating process 5-20 times to form an electrically conductive thin film on a resin pallet; And

Administering a resin pallet having an electrically conductive thin film formed therein to an extruder, performing a re-pallet forming operation, and then administering the formed pallet to a molding machine to obtain a molded product;

Consist of, 10E2 A method for producing an electrically conductive transparent composite having a surface resistance of ˜10E11 Ω and a light transmittance of 30 to 80% is provided.

According to still another aspect of the present invention, there is provided an electrical / electronic device, a component or an interior and exterior materials manufactured using the electrically conductive transparent composite material.

Hereinafter, the present invention will be described in more detail.

The present invention relates to a composite material in which carbon nanotubes are dispersed in an amount of 0.008 to 0.02 parts by weight in a basic insulating polymer resin, and 10E2. Surface (or volume) resistance in the range of ~ 10E11Ω, characterized by having a light transmittance of 30 to 80%.

In the present invention, carbon nanotubes are included in an amount of 0.008 to 0.02 parts by weight in the basic insulating transparent polymer. If the carbon nanotubes are included in the basic insulating transparent polymer less than 0.008 parts by weight, it is difficult to meet the above-described physical properties of the surface resistance and light transmittance, and when included in more than 0.02 parts by weight, the electrical function is excellent. However, due to the relatively high concentration of carbon nanotubes, the color of carbon nanotubes is discolored to a substantial part, making it difficult to have transparency.

The basic insulating transparent polymer resin used in the present invention is transparent ABS (acrylonitrile butadiene styrene), transparent PS (polystyrene), PET (polyethylene terephthalate), PE (polyethylene), PC (polycarbonate), SAN (styrene acryl Nitrile copolymer), cellulose, polysulfone, ADC (allyl diglycol carbonate), transparent SBS (styrene butadiene styrene) and at least one selected from the group consisting of acrylic resins. These polymer resins have excellent mechanical properties and are available in pallet form. The basic insulating polymer resin may be transparent, translucent or opaque, and preferably, the basic insulating polymer resin is transparent.

Carbon nanotubes that can be used in the present invention are commercially available and are described in detail, for example, in Korean Patent Publication No. 1996-7005089 (graphite fibrillated material). The bulk carbon nanotubes have an outer diameter of about 10 to 20 nm, an inner diameter of up to 5 nm, and a length of 100 to about 20,000 nm, and have a surface resistance of up to 10 Ω · cm and are commercially available.

In addition, the carbon nanotubes usable in the present invention basically exist in a bulk state, and the bulk state is a basic insulating transparent polymer because a large number of carbon nanotubes are attached to a metal seed such as fine nano-sized iron and nickel. This is difficult to disperse. Accordingly, it can be used only after purification with carbon nanotubes in which metal seeds such as iron and nickel are removed. As a purification method, an acid treatment with hydrofluoric acid and sulfuric acid is known. The purified carbon nanotubes exist as a liquid pigment in a highly dispersed state in an organic solvent or water, and finally, an insulating transparent binder and an organic It is available as a coating in the form of a solvent or a combination of water and carbon nanotubes. Tablets and liquid pigments and coatings for the carbon nanotubes used in the present invention are disclosed in Korea Patent Publication No. 2000-0016055 (Method for unwinding hollow carbon microfibers, electrically conductive transparent carbon microfibers and coatings for forming such films) Composition).

Referring to the method of producing an electrically conductive transparent composite of the present invention in detail.

After inserting the basic insulating transparent polymer obtained in the form of a pallet into a mechanical stirrer (hensel, supermixer, automatic coloring machine, mixer, etc.) used conventionally, the carbon nanotube-containing electrically conductive coating is 0.6% to the weight of the basic insulating transparent polymer. Add at 1.6% concentration. Here, if the electrically conductive coating is less than 0.6% by weight of the basic insulating transparent polymer, it is difficult to wet the surface of each pallet as a whole, and if it is more than 1.6%, excessive loss occurs, resulting in loss of raw materials and contamination in the agitator. In addition, it prolongs the curing process and lowers productivity, and also makes it difficult to control fine dispersion of carbon nanotubes. In addition, the electrically conductive coating may be generally used as long as it includes carbon nanotubes, for example, 5-15% by weight of carbon nanotubes, 20-40% by weight of acrylic and acetone: isopropyl alcohol = 5: 5 The ratio consisting of 40-80% by weight of the mixed solution can be used.

The stirrer is then first stirred for 20-40 seconds, preferably 30 seconds, at a speed of 500-1,500 rpm, preferably 1,000 rpm. The electrically conductive coating introduced into the stirrer during the first stirring time is sufficiently wetted with respect to the total volume of each transparent insulating polymer in the form of a pallet. When the basic insulating transparent polymer in the form of a pallet sufficiently wet with the electrically conductive coating is stirred for 20-40 seconds, preferably for 30 seconds, at the same rotational speed as the first, each pallet is subjected to surface friction between the pallets. Their surface temperature will rise to 50 to 60 degrees. At the same time, the solvent of the electrically conductive coating wetted on each pallet surface is rapidly volatilized to accelerate the curing process.

In addition, the third stirring at the same rotational speed for 20-40 seconds, preferably 30 seconds, the solvent of the coating wetted on each pallet surface is volatilized 90% or more to almost complete the curing process. Separate dryers may be used to promote curing. Here, stirring from primary to tertiary takes place in a continuous operation. In order to finely control the concentration of carbon nanotubes, the process may be repeated several times, preferably 5-20 times, preferably 10 times. As a result, the transparent electrically conductive thin film is completed on the surface of each pallet. Each pallet in which the electrically conductive thin film is formed is put into a single or twin extruder having a standard molding temperature of the polymer, and then re-palletized. As a result, the carbon nanotubes are optimally dispersed in the basic insulating transparent polymer and provide a transparent composite material having an electromagnetic shielding and antistatic function.

When the electrically conductive transparent composite pellets manufactured through the above method are processed through extrusion molding, vacuum molding, blow molding, injection molding, etc. according to the purpose of use, the light transmittance can be adjusted up to 30 to 80% according to the thickness of the molding, and the electromagnetic wave The surface resistance required for shielding and antistatic can be adjusted from 10E2 to 10E11Ω.

In addition, by additionally prescribing silver nanopowder, various kinds of color pigments, etc. to the electrically conductive transparent composite material according to the present invention, the antibacterial function, the color function, etc. may be embodied in combination to further improve the product value.

    EXAMPLE

The invention is further illustrated and described by the following examples. Further objects of the present invention will become apparent from the following examples of the present invention, along with the additional features and accompanying advantages provided. Various modifications may be made in the forms described by those skilled in the art without departing from the spirit or scope of the invention as defined in the appended claims.

An electrically conductive coating containing carbon nanotubes used in Examples and Comparative Examples of the present invention was prepared as follows. 150 ml of 98 wt% sulfuric acid was added to 7.5 g of carbon nanotubes, and 50 ml of 60 wt% nitric acid was added as an oxidizing agent. After the slurry was sufficiently stirred, the carbon nanotubes were stirred at 120 ° C. for 15 minutes without stirring. Treatment gave carbon nanotubes from which metal seeds were removed. Next, 30 wt% of acrylic (30 g) as a polymer resin for binder and 60 wt% (60 g) of acetone: isopropyl alcohol = 5: 5 ratio were used as solvent and 10 wt% (10 g) of the carbon nanotube. As a method for stabilizing dispersion, carbon nanotubes were exposed to X-rays before being introduced into a binder to change the surface interfacial energy potential values of the carbon nanotubes to zero. 60 g of solvent was added to the stirrer, and 30 g of acrylic was added thereto, followed by stirring at room temperature to prepare a binder. Stirring to prepare an electrically conductive coating containing 10% by weight of carbon nanotubes.

<Example 1>

An electrically conductive coating consisting of 500 g of pallet-shaped transparent ABS and carbon nanotubes 3.0 g was added to the stirrer, followed by primary stirring at a rotational speed of 1,000 rpm for 30 seconds. Second stirring for 30 seconds at the same rotational speed raised the surface temperature of the pallet to 50-60 ° C. to accelerate the curing process of the coating. The curing process of the coating was continued by stirring 3 times for 30 seconds at the same rotational speed. This procedure was repeated 10 times to complete the final electrically conductive thin film formation. Pallets in which the electrically conductive thin film was formed were administered to a small single extruder set at 215 ° C., and then re-pallet forming was performed. The pellet thus formed was administered to a small injection molding machine set at 215 ° C., and a flat molded article having a thickness of 1t and 3.5t was obtained.

<Example 2>

Except for changing the addition amount of the electrically conductive coating made of carbon nanotubes in Example 1 to 4.0g was carried out in the same manner as in Example 1.

<Example 3>

Except for changing the addition amount of the electrically conductive coating made of carbon nanotubes in Example 1 to 4.5g was carried out in the same manner as in Example 1.

<Example 4>

Except for changing the addition amount of the electrically conductive coating made of carbon nanotubes in Example 1 to 5.0g was carried out in the same manner as in Example 1.

Example 5

Except for changing the addition amount of the electrically conductive coating made of carbon nanotubes in Example 1 to 5.5g was carried out in the same manner as in Example 1.

<Example 6>

Except for changing the addition amount of the electrically conductive coating made of carbon nanotubes in Example 1 to 6.0g was carried out in the same manner as in Example 1.

<Example 7>

Except for changing the addition amount of the electrically conductive coating made of carbon nanotubes in Example 1 to 6.5g was carried out in the same manner as in Example 1.

<Example 8>

Except for changing the addition amount of the electrically conductive coating made of carbon nanotubes in Example 1 to 7.0g was carried out in the same manner as in Example 1.

Example 9

Except for changing the addition amount of the electrically conductive coating made of carbon nanotubes in Example 1 to 7.5g was carried out in the same manner as in Example 1.

<Example 10>

Except for changing the addition amount of the electrically conductive coating made of carbon nanotubes in Example 1 to 8.0g was carried out in the same manner as in Example 1.

Comparative Example 1

Except for changing the addition amount of the electrically conductive coating made of carbon nanotubes in Example 1 to 1.0g, and the number of repeated coating addition was changed to 20 times was carried out in the same manner as in Example 1.

Comparative Example 2

Except for changing the addition amount of the electrically conductive coating made of carbon nanotubes in Example 1 to 2.0g, the coating was repeated in the same manner as in Example 1 except for changing to 20 times.

Comparative Example 3

Except for changing the addition amount of the electrically conductive coating made of carbon nanotubes in Example 1 to 9.0g was carried out in the same manner as in Example 1.

<Comparative Example 4>

Except for changing the addition amount of the electrically conductive coating made of carbon nanotubes in Example 1 to 10.0g was carried out in the same manner as in Example 1.

The surface resistance and the light transmittance of the molded article formed by the methods of Examples 1 to 10 and Comparative Examples 1 to 4 are described in Table 1 below. Surface resistance measurements were measured using an insulation resistance meter at 50% relative humidity, and transparency was observed in the UV spectrum.

TABLE 1

division Coating amount added / time Coating repeat count Surface resistance (Ω) Light transmittance Thickness (1t) Thickness (3.5t) Example 1 3.0 g 10 10 ¹²  90%  80% Example 2 4.0g 10 10 ¹¹ 83% 72% Example 3 4.5 g 10 10 ¹⁰ 78% 65% Example 4 5.0 g 10 10 ⁷ 74% 58% Example 5 5.5g 10 10 ⁷ 68% 49% Example 6 6.0 g 10 10 ⁵ 65% 45% Example 7 6.5g 10 10 ⁵ 58% 42% Example 8 7.0 g 10 10 ⁴ 54% 33% Example 9 7.5g 10 10 ³ 50% 30% Example 10 8.0g 10 10 ²  45%  30% Comparative Example 1 1.0 g 20 Bad Bad Bad Comparative Example 2 2.0 g 20 Bad Bad Bad Comparative Example 3 9.0 g 10 Bad Bad Bad Comparative Example 4 10.0 g 10 Bad Bad Bad

* Poor-Because of poor dispersion control, staining was detected with the naked eye, and therefore, light transmittance and electrical characteristics were considered to be poor.

Examples 2 to 10 of Table 1 show the results meeting the desired physical property targets, whereas in Comparative Examples 1 to 4, it is difficult to disperse the carbon nanotubes so that the physical property targets are satisfied. It can be seen that it is difficult to make.

The examples exemplified in the above table are merely a part of the present invention and exemplify only representative compositions. Other compositions not illustrated also show results consistent with the present invention.

The composite material having an electric conductivity function according to the present invention is a micro-dispersion of carbon nanotubes in a basic insulating transparent polymer, which has electromagnetic shielding and antistatic function, and is capable of carrying out transparent (nude) design of electrical / electronic devices and components. It can be used as a composite material for packaging and packaging materials, and can increase the product value and competitiveness of electric / electronic devices, parts exterior materials, and packaging materials, and various moldings used are carbon nanotubes mixed with basic insulating transparent polymer. There is an advantage that can be easily recycled using technology. In addition, the molded article according to the present invention has an advantage in that carbon nanotubes are dispersed in an optimized state and thus a trace amount is added, so that no special prescription is required for excellent mechanical properties of the existing insulating transparent polymer.

In addition, since the wear resistance on the surface is improved by not using the internal lubricant, the external lubricant, and the thermoplastic rubber during the dispersion treatment, durability of the surface friction action is increased, thereby reducing the contamination of the contents.

The transparent composite material having the electrically conductive function provided in the present invention can be used in the semi-permanent dust container of the vacuum cleaner. Through transparency, the contents and amount of dust inside can be checked and the static electricity generated by friction action between the dust flowing into the dust box and the surface is removed to minimize the amount of dust attached to the surface. Can be promoted. It can also be used for fan wings. It can improve the appearance cleanness by reducing the degree of dust adhesion on the wing surface. Limited to parts of office equipment that require antistatic protection, parts of industrial process equipment, parts of data (video, audio, text) storage devices, parts of powder transfer and mixer units, metal and ceramic transfer and storage containers, parts of medical equipment Can be used without.

The present invention can be applied to heat-resistant engineering polymers can be used as a heat dissipator for displays, semiconductors, electrical, electronic components and products that require heat external emission. For example, it can be used without limitation for applications requiring external heat emission such as transistors, plasma display panels (PDPs), central processor units (CPUs), and the like.

In addition, the present invention can implement the same electrical properties by the addition amount of the same carbon nanotubes to the semi-transparent and opaque insulating polymer, it can be used without limitation as a conventional electromagnetic shielding and antistatic packaging and packaging materials.

Claims (8)

delete delete delete Palletized transparent ABS (acrylonitrile butadiene styrene), transparent PS (polystyrene), PET (polyethylene terephthalate), PE (polyethylene), PC (polycarbonate), SAN (styrene acrylonitrile copolymer), cellulose, poly Based on 100% by weight of a basic insulating polymer resin and an electrically conductive coating containing carbon nanotubes consisting of at least one polymer resin selected from the group consisting of sulfone, ADC (allyl diglycol carbonate), transparent SBS (styrene butadiene styrene) and acrylic resin Injected at a concentration of 0.6% to 1.6% by weight relative to the weight of the insulating transparent polymer resin, The mixture was first stirred for 20-40 seconds at a rotational speed of 500-1,500 rpm and then stirred for 20-40 seconds at the same rotational speed to raise the surface temperature of the pallet to 50-60 ° C. to cure the coating. After facilitating the process, coating the electrically conductive coating on an insulating polymer resin pallet by third stirring for 20-40 seconds at the same rotational speed; Repeating the coating process 5-20 times to form an electrically conductive thin film on a resin pallet; And Administering a resin pallet having an electrically conductive thin film formed therein to an extruder, performing a re-pallet forming operation, and then administering the formed pallet to a molding machine to obtain a molded product; Consist of, 10E2 A method for producing an electrically conductive transparent composite having a surface resistance of ˜10E11Ω and a light transmittance of 30 to 80%. According to claim 4, wherein the carbon nanotube-containing electrically conductive coating is 5-15% by weight of carbon nanotubes, 20-40% by weight acrylic and 40-80% by weight of a mixture of acetone: isopropyl alcohol = 5: 5 ratio Method for producing an electrically conductive transparent composite, characterized in that made. The method of claim 4, wherein the carbon nanotubes are added to be included in an amount of 0.008 to 0.02 parts by weight based on 100 parts by weight of the basic insulating polymer resin of the final molding. delete delete