KR101675624B1 - Conductive propylene based thermoplastic resin composition having less amount of TVOCs and improved mechanical properties - Google Patents

Abstract

The present invention relates to a conductive propylene-based thermoplastic resin composition having a small amount of total volatile organic compound emission and excellent mechanical properties.
The present invention relates to a thermoplastic resin composition which effectively prevents TVOCs from being released by adding a carbon-based material to a blend of homopolypropylene and an impact copolymer, and has excellent mechanical properties such as impact resistance and processability and conductivity.

Description

[0001] The present invention relates to a conductive propylene-based thermoplastic resin composition having a reduced amount of total volatile organic compounds and having excellent mechanical properties,

The present invention relates to a conductive propylene-based thermoplastic resin composition having a small amount of total volatile organic compound emission and excellent mechanical properties. More specifically, the present invention relates to a thermoplastic resin composition that effectively prevents TVOCs from being released by adding a carbon-based material to a blend of homopolypropylene and impact copolymer, and has excellent mechanical properties such as impact resistance and processability and conductivity.

Polypropylene (PP) is a universal resin that is easy to process and has excellent physical properties for a price. It is increasing in demand and it can be used for replacing traditional materials such as glass, wood, paper, metal, It is expanding.

Polypropylene products can be largely divided into homopolymers which are propylene homopolymers and copolymers where ethylene, butene, etc. are additionally used in addition to propylene, depending on the type of monomer used. Homopolymers are divided into isotactic, syndiotactic and atactic polypropylenes, but most commercial products are isotactic PP (iPP), and with the advent of metallocene catalysts, Small amounts of diatomic polypropylene (sPP) are being produced. Atactic polypropylene (aPP) is either produced as a byproduct during the production of iPP or is produced in a single plant, but its application is limited due to its physical properties as a material.

Polypropylene copolymers are divided into random copolymers and impact copolymers. Random copolymers are made by simultaneously polymerizing propylene and a small amount of comonomer (mainly ethylene or butene) in the same reactor. When a comonomer is used, the crystal structure of the polypropylene is defective, so that the melting point is reduced and the transparency is improved. Therefore, random copolymers are mainly used for applications in which it is necessary to improve the transparency or lower the processing temperature such as the heat sealing temperature.

Two or more reactors are needed to produce the impact copolymer. Propylene homopolymer is made in the front reactor and ethylene-propylene rubber (EPR) is made in the rear reactor and blended in the reactor. Structurally, it has a two-phase structure in which EPR is dispersed in a PP homopolymer matrix. Impact copolymers, also called block copolymers or heterophasic copolymers, are aimed at increasing the impact strength at low temperatures, which is the greatest disadvantage of polypropylene homopolymers.

 In order to improve the processability and various mechanical properties of the polypropylene, studies on blends thereof have been made. However, the amount of volatile organic compounds generated during processing and use is still a problem, and a high content The impact resistance and fluidity in the case of containing a filler are also problematic.

A problem to be solved by the present invention is to provide a conductive propylene-based thermoplastic resin composition having a small amount of total volatile organic compound emission and excellent impact characteristics and processability.

Another object of the present invention is to provide a molded article comprising the conductive propylene-based thermoplastic resin composition.

According to an aspect of the present invention,

Homopolypropylene;

Impact copolymer; And

And a carbon-based material. The present invention also provides a conductive propylene-based thermoplastic resin composition.

According to another aspect of the present invention,

And a molded product comprising the conductive propylene-based thermoplastic resin composition.

The conductive propylene-based thermoplastic resin composition according to one embodiment is obtained by blending homopolypropylene and impact copolymer and adding a carbon-based material thereto. As a result, the emission amount of the total volatile organic compound decreases and the mechanical properties such as impact resistance and workability And fluidity and the like can be improved even when a large amount of carbon-based material is added for imparting conductivity. Therefore, it can be usefully used for various electric / electronic parts such as a wafer transfer device.

Hereinafter, the present invention will be described in detail. The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and the inventor may appropriately define the concept of the term in order to best describe its invention It should be construed as meaning and concept consistent with the technical idea of the present invention.

In the conductive propylene-based thermoplastic resin composition according to one embodiment,

Homopolypropylene; Impact copolymer; And carbon-based materials.

According to one embodiment, the homopolymer used in the composition means a homopolymer of propylene, and the isotactic pentad fraction (mmmm fraction) representing the stereoregularity is preferably 85 to 99%. A more preferable isotactic pentad fraction is 90 to 98%. The isotactic pentad fraction (mmmm fraction) refers to the ratio of the isotactic pentad fraction (mmmm fraction) to the total number of methyl groups in the three-dimensional structure in which all five methyl groups as side chains are located in the same direction .

As the homopolypropylene resin, it is preferable that Mw / Mn, which is a parameter indicating the molecular weight distribution, is 2.0 to 8.0. More preferable Mw / Mn is 2.0 to 5.0, and more preferably 2.0 to 3.0. The smaller Mw / Mn means that the molecular weight distribution is narrow. When the Mw / Mn is less than 2.0, problems such as deterioration of extrusion moldability are caused, and it is also difficult to produce them industrially. On the other hand, when Mw / Mn is more than 8.0, low molecular weight components are increased, which leads to decrease of mechanical strength and release of outgass. The Mw / Mn is a value measured by GPC (Gel Permeation Chromatography).

The melt flow rate (MFR) of the homopolypropylene resin is not particularly limited. Generally, the MFR is preferably 5 to 40 g / 10 min, more preferably 10 to 30 g / 10 min. When the MFR is 5 g / 10 min or more, the melt viscosity of the resin during molding processing is high, and sufficient productivity can be ensured. On the other hand, when it is 40 g / 10 min or less, the mechanical strength of the resulting polypropylene type resin porous film can be sufficiently maintained. The MFR is a value measured under conditions of a temperature of 230 DEG C and a load of 2.16 kg in accordance with JIS K7210.

The method for producing the homopolypropylene resin is not particularly limited. Known polymerization methods using known polymerization catalysts, for example, a polymerization method using a multi-site catalyst typified by a Ziegler-Natta catalyst or a single site catalyst typified by a metallocene catalyst.

Examples of the homopolypropylene resin include Novatec PP, WINTEC (manufactured by Nippon Polypro Corporation), Bashifie, Norti, Tafema XR (manufactured by Mitsui Chemicals) Adflex ", " Adsyl ", " HMS-1 ", "Quot; PP (PF814) " (manufactured by Suna Romaji), and " Inspire " (Dow Chemical).

In the development of materials using such homopolypropylene, the impact resistance and the stiffness tend to be inversely proportional. In general, homopolypropylene is susceptible to impact, so that the impact modifier may be added to the polypropylene homopolymer in order to increase the impact resistance.

According to one embodiment, impact-resistant polypropylene can be used as the impact copolymer used in the conductive propylene-based thermoplastic resin composition. Such impact-resistant polypropylene can be obtained by polymerizing an ethylene propylene copolymer in a subsequent reactor after polypropylene homopolymerization A method of producing a heterophase resin in which an ethylenepropylene copolymer as a dispersed phase is dispersed in a polypropylene homopolymer which is a matrix or a method of producing a heterophase resin by adding a rubber or an elastomer having excellent impact modifying effect, There is a method in which the two are manufactured in parallel. Although the content of the impact modifier contained in the impact-resistant polypropylene varies depending on the level of impact resistance of the product, it is generally preferred that the content of the ethylene-propylene copolymer and the rubber- From 5% by weight to 50% by weight.

In order to produce impact copolymers as described above, for example, impact resistant polypropylene, two or more reactors are required, the propylene homopolymer is made in the front reactor, and the ethylene-propylene rubber (EPR) is made in the rear reactor and blended in the reactor . Structurally, it has a two-phase structure in which EPR is dispersed in a matrix of homopolypropylene. The impact copolymer is also referred to as a block copolymer or a heterophasic copolymer and can improve the low temperature impact strength which is the greatest disadvantage of the homopolypropylene.

In the conductive propylene-based thermoplastic resin composition according to one embodiment, the homopolypropylene and the impact copolymer as described above are blended to improve the impact resistance while improving the workability. In addition, it is possible to improve the amount of total volatile organic compounds released during processing and use.

The above-mentioned impact copolymer in the composition may be used in an amount of 10 to 200 parts by weight, or 20 to 150 parts by weight based on 100 parts by weight of the homopolypropylene. It is possible to ensure workability while ensuring sufficient impact resistance in the above range.

According to one embodiment, the conductive propylene-based thermoplastic resin composition may include a carbon-based material for imparting conductivity. Examples of the carbon-based material include carbon black, graphene, carbon fiber, carbon nanofiber, fullerene, carbon nanowire, and carbon nanotube. These may be added in an amount of about 5 to 30 parts by weight based on 100 parts by weight of the homopolypropylene. In such a range, the conductivity of the resin composition can be improved without deteriorating the physical properties of the resin composition.

Examples of the carbon black used as the carbon-based material include, but are not limited to, furnace black, channel black, acetylene black, lamp black, thermal black and Ketjen black. The carbon black having an average particle diameter of 20 to 60 nm can be used, and the conductivity can be efficiently improved in this range.

The graphene used as the carbon-based material is a two-dimensional carbon isotope. Methods for producing the graphene include a peeling method in which a physically graphene layer is separated from graphite, a method in which graphite is chemically reduced by dispersing it in a dispersion, A pyrolysis method in which a graphene layer is obtained through pyrolysis at a high temperature in a silicon carbide (SiC) substrate, and a chemical vapor deposition method. Of these, a chemical vapor deposition method is a method of synthesizing high quality graphene For example.

According to one embodiment, the graphene may exhibit a shape aspect ratio of not more than 0.1, a number of graphene layers of not more than 100, and a specific surface area of 300 m ² / g or more. The graphene refers to a single mesh web of carbon (C) SP ² bonds in the hcp structure of graphite. Recently, a graphene composite layer having a plurality of layers has been broadly classified into graphene.

According to one embodiment, the carbon fibers used as the carbon-based material may be carbon-based or graphite-based carbon fibers. Examples of the carbon fibers belonging to the carbon-based carbon include carbon powder, carbon fine particles, carbon black, Can be exemplified.

According to one embodiment, the carbon nanofibers used as the carbon-based material have a high specific surface area, excellent electrical conductivity, adsorptivity, etc., and are produced by decomposing and growing a gaseous compound containing carbon at a high temperature, Can be obtained by growing the metal catalyst in a fiber form. The pyrolyzed carbons are deposited in the form of a graphene layer through adsorption, decomposition, absorption, diffusion, and precipitation on a specific metal catalyst surface of several nanometers in size to form carbon nanofibers with excellent crystallinity and purity. . The carbon nanofibers formed on the catalyst particles of the transition metal such as nickel, iron, cobalt and the like are grown to a diameter of nano-scale, which is about 100 times thinner than that of the other kinds of general-purpose carbon fibers having a diameter of 10 μm It is more useful because it has a high specific surface area, excellent electrical conductivity, adsorptivity and mechanical properties.

The carbon nanofibers can be synthesized by an electric discharge method, a laser deposition method, a plasma chemical vapor deposition method, or a chemical vapor deposition (CVD) method. Factors that affect the growth of carbon nanofibers include temperature, carbon source, catalyst, and substrate type. Among them, the diffusing action of the substrate and the catalyst particles and the difference in the interfacial action between the substrates affects the shape and microstructure of the synthesized carbon nanofibers.

According to one embodiment, carbon nanotubes (CNTs) can be used as the carbon-based material. The carbon nanotubes are substances having carbon atoms arranged in a hexagonal shape and having a tube shape, nm. < / RTI > The carbon nanotubes exhibit nonconductive, conductive, or semiconducting properties depending on their specific chirality. The carbon atoms are connected by a strong covalent bond, so that the tensile strength is about 100 times larger than that of steel, and excellent flexibility and elasticity , And is chemically stable.

Examples of carbon nanotubes include single-walled carbon nanotubes (SWCNTs) composed of one layer and having a diameter of about 1 nm, double-walled carbon nanotubes composed of two layers and having a diameter of about 1.4 to 3 nm walled carbon nanotubes (DWCNTs), and multi-walled carbon nanotubes (MWCNTs) composed of a plurality of three or more layers and having a diameter of about 5 to 100 nm, Can be used without limitation.

As used herein, the term "bundle" refers to a bundle or rope shape in which a plurality of carbon nanotubes are arranged or intertwined in parallel, unless otherwise specified. The term 'non-bundle or entangled type' means a form without any uniform shape such as a bundle or a rope shape.

The bundle-type carbon nanotubes basically have a shape in which a plurality of carbon nanotube strands are gathered together to form a bundle, and the plurality of strands have a straight shape, a curved shape, or a mixture thereof. The bundle-type carbon nanotubes may also have a linear, curved or mixed form. According to one embodiment, such a bundle of carbon nanotubes may have a thickness of 50 nm to 100 탆.

According to one embodiment, the average diameter of the carbon nanotube strands may be, for example, 1 nm to 20 nm.

According to one embodiment, the carbon nanotubes may have an average length of about 1 탆 or more, for example, 5 to 1,000 탆, or 10 to 300 탆. A bundle of carbon nanotubes having an average length in this range corresponds to a structure advantageous for improving the conductivity of the thermoplastic resin. Since the carbon nanotubes have a network structure in the matrix of the thermoplastic resin, the long carbon nanotubes are more advantageous in the formation of such a network, and as a result, the frequency of the inter-network contact decreases, Thereby contributing to an increase in conductivity.

According to one embodiment, the carbon nanotubes used as the carbon-based material may have an I _D / I _G ratio of 0.01 to 1.0. The I _D / I _G ratio represents a relative ratio to the intensity of the D peak (D band) and G peak (G band) in the Raman spectrum of the carbon nanotubes. In general, Raman spectrum of the carbon nanotube is divided into a lower peak of two of the sp ² bonded graphite castle main peak, i.e. 1,100 to 1,400cm ^-1 and 1,500 to a high peak of 1,700cm ^-1. Near 1,300cm ^-1, for example, the first peak (D- band) of 1,350cm ^-1 is incomplete near to the presence of carbon particles and shows properties of the chaotic wall, 1,600cm ^-1, for example, 1580cm ^-1 The second peak (G-band) represents a continuous form of the carbon-carbon bond (CC), which indicates the characteristics of the crystalline graphite layer of the carbon nanotube. The wavelength value may vary somewhat depending on the wavelength of the laser used in the spectrum measurement.

The intensity ratio (I _D / I _G ) of the D-band peak and the G-band peak can be used to evaluate the degree of disorder or defect of the carbon nanotube. If this ratio is high, it can be evaluated as disordered or defective. It can be estimated that the carbon nanotubes have less defects and higher crystallinity. The defect referred to herein refers to an incomplete portion of the carbon nanotube array caused by unnecessary atoms entering the carbon-carbon bond constituting the carbon nanotube, such as an insufficient amount of atoms entering the carbon nanotube, insufficient carbon atoms, or the like, (lattice defect), whereby the defect portion can be easily cut by the external stimulus.

The intensity of the D-band peak and the G-band peak can be defined, for example, as the height of the X-axis center value in the Raman spectrum or the area of the lower peak, and the height value of the X- .

According to one embodiment, the I _D / I _G of the carbon nanotube is limited to a range of 0.01 to 1.0, for example, in the range of 0.01 to 0.7, or 0.01 to 0.5, so that a carbon nanotube having few defects and high crystallinity is used The content of the thermoplastic resin composition can be reduced even when the thermoplastic resin composition is processed in a process such as extrusion or injection. That is, the content of the carbon nanotubes cut by the external stimulus generated in the processing step is reduced, so that the length of the carbon nanotubes remaining in the resulting molded article can be further improved.

When the length of the carbon nanotubes remaining in the resulting molded article increases, it is more advantageous to improve the conductivity of the thermoplastic resin. Since the carbon nanotubes have a network structure in the matrix of the thermoplastic resin, carbon nanotubes having a longer length remaining in the resultant material are more advantageous in forming such a network, and as a result, the frequency of inter-network contact is reduced The contact resistance value is reduced, which contributes to the increase of the conductivity.

According to one embodiment, the average length of the carbon nanotubes remaining on the thermoplastic resin-containing molded article may be in the range of 0.5 탆 to 30 탆, or 1 탆 to 10 탆.

According to one embodiment, the conductive propylene-based thermoplastic resin composition is used in combination with a flame retardant, an impact modifier, a flame retardant, a flame retardant, a lubricant, a plasticizer, a heat stabilizer, an antioxidant, a compatibilizer, a light stabilizer, a pigment, And an anti-dripping agent. The content of the additive may be 0.1 to 10 parts by weight based on 100 parts by weight of the homopolypropylene. The specific types of these additives are well known in the art, and examples that can be used in the compositions of the present invention can be appropriately selected by those skilled in the art.

According to one aspect, the method for producing the thermoplastic resin composition is not particularly limited. However, the raw material mixture may be supplied to a commonly known melt mixer such as a single shaft or a biaxial extruder, a Banbury mixer, a kneader, , A method of kneading at a temperature, and the like.

The order of mixing the raw materials is not particularly limited. The homopolypropylene, the impact copolymer, the carbon-based material and, if necessary, the additives are blended in advance, and then the homopolypropylene and / A method of homogeneously melt-kneading with a single-screw or twin-screw extruder, a method of removing the solvent after mixing in a solution, and the like are used. Of these, from the viewpoint of productivity, a method of homogeneously melt-kneading with a single-screw or twin-screw extruder is preferred. In particular, a method of uniformly melt-kneading at a melting point or higher of the thermoplastic resin using a twin screw extruder is preferably used.

As the kneading method, homopolypropylene, an impact copolymer, a method of collectively kneading a carbonaceous material, and a resin composition (master pellet) containing homopolypropylene and an impact copolymer at a high concentration are prepared, A method in which the resin composition and the carbon-based material are added and melt-kneaded (master pellet method), and the like, and any kneading method may be used. As another method, homopolypropylene, an impact copolymer and other additives necessary for inhibiting the breakage of the carbonaceous material are introduced from the extruder side and the carbonaceous material is supplied to the extruder by using a side feeder A method for preparing the composition is preferably used.

A composite material having a shape such as pellets can be produced through the above extrusion method.

According to one embodiment, the average length of the carbon nanotubes, which is one of the carbon-based materials used in the production of the composite material, can be measured through a scanning electron microscope (SEM) or a transmission electron microscope (TEM) photograph. That is, after obtaining photographs of the powdered carbon nanotubes as a raw material through these measuring devices, they were analyzed through an image analyzer, for example, Scandium 5.1 (Olympus soft Imaging Solutions GmbH, Germany) Can be obtained.

In the case of the carbon nanotubes contained in the composite material, the resin solids may be dissolved in an organic solvent such as acetone, ethanol, n-hexane, chloroform, p-xylene, 1-butanol, petroleum ether, 1,2,4- Benzene, and dodecane in a predetermined concentration, and then the result of measurement by SEM or TEM using this dispersion is analyzed using the image analyzer to obtain an average length and a distribution state.

The composite material obtained by the above method has no problem in the production process and secondary processability as well as the mechanical strength such as impact resistance and workability is not lowered and the amount of the total volatile organic compound released is small and a high content of carbon The impact resistance and the fluidity of the composite material can be improved even when a base material is added.

The composite material according to one embodiment can be molded by any known method such as injection molding, blow molding, press molding, and spinning, and can be processed into various molded articles. As the molded article, it can be used as an injection molded article, an extrusion molded article, a blow molded article, a film, a sheet, a fiber and the like.

As a method for producing the film, a known melt film-forming method can be employed. For example, raw materials are melted in a single-screw or twin-screw extruder, then extruded from a film die, and cooled on a cooling drum to form an unstretched film Or a uniaxial stretching method and a biaxial stretching method in which the film produced in this way is appropriately stretched in the transverse direction by a transverse stretching device called a roller type longitudinal stretching device and a tenter .

The fibers can be used as various kinds of fibers such as unstretched fibers, drawn fibers, primary rolled fibers and the like. As a method of producing fibers using the resin composition, a known melt spinning method can be applied. For example, Is extruded from a spinneret through a polymer flow line switcher or filtration layer provided at the tip of the extruder, and is then cooled, , Stretching, and heat setting may be employed.

In particular, the composite material of the present invention can be processed into a molded article such as a charge shielding material, an electric / electronic product housing, and an electric / electronic part, taking advantage of its excellent conductivity and excellent mechanical properties.

According to one embodiment, the various molded articles can be used for various purposes such as automobile parts, electric parts, and building members. Specific applications include airflow meters, air pumps, thermostat housings, engine mounts, ignition bobbins, ignition cases, clutch bobbins, sensor housings, idle speed control valves, vacuum switching valves, ECU housings, Pump case, Inhibitor switch, Rotary sensor, Accelerometer, Distributor cap, Coil base, ABS actuator case, Radiator tank top and bottom, Cooling fan, Fan shroud, Engine cover, Cylinder head cover, Oil cap , Oil pan, oil filter, fuel cap, fuel strainer, distributor cap, vapor canister housing, air cleaner housing, timing belt cover, brake booster parts, various cases, various tubes, various tanks, various hoses Under-hood parts for automobiles such as clips, various valves, various pipes, etc. Torque control Wheel rails, fenders, fenders, garnishes, knobs, and other parts, such as seatbelt components, seatbelt components, register blades, wash lever, wind regulator handle, knob of wind regulator handle, passing light lever, sun visor bracket, Automotive exterior parts such as bumper, door mirror stay, spoiler, hood louver, wheel cover, wheel cap, grille apron cover frame, lamp reflector, lamp bezel, door handle, wire harness connector, SMJ connector, PCB Relay case, coil bobbins, optical pickup chassis, motor case, notebook PC housings and internal parts, LED display housings and internal parts, printer housings and internal parts, mobile phones, etc., for various automobile connectors, connectors and door grommet connectors. , A portable terminal housing and internal parts such as a mobile PC, a portable mobile, a recording medium (CD, DVD, PD, FDD, etc.) There may be mentioned o electrical and electronic components, represented by the housing and internal components, a housing and inner parts of copying machine, facsimile housings and internal parts of the parabolic antenna and the like.

In addition, it is also possible to use a VTR component, a television component, an iron, a hair dryer, an electric rice cooker component, a microwave component, an acoustic component, , An optical recording medium such as a CD-R, a CD-RW, a DVD-ROM, a DVD-R, a DVD-RW, a DVD-RAM, Examples of household electrical appliances parts represented by parts and the like.

In addition, a housing, an internal part, various gears, various cases, a sensor, an LEP lamp, a connector, a socket, a resistor, a relay case, a switch, a coil bobbin, a capacitor, a variable capacitor, The present invention relates to a magnetic head base, a power module, a semiconductor, a liquid crystal, an FDD carriage, an FDD chassis, a motor, a motor, a case, an optical pickup, an oscillator, various terminal boards, transformers, plugs, printed wiring boards, tuners, Such as a brush holder, a transformer member, a coil bobbin, and the like, as well as various automotive connectors such as a wire harness connector, an SMJ connector, a PCB connector, and a door gray connector.

On the other hand, since the molded article has improved conductivity, it can be used as an electromagnetic wave shielding body by absorbing electromagnetic waves. The electromagnetic wave shielding material absorbs and extinguishes electromagnetic waves, and thus exhibits an improved performance in electromagnetic wave absorbing ability.

On the other hand, since the molded product has improved conductivity, it can be used, for example, as a wafer shipper. Generally, a wafer transfer device is a special container for transporting and storing substrates and semiconductor wafers. Since cleaning and contamination control are always important during transportation, storage or processing, contamination due to static electricity or destruction of the wafer does not occur Therefore, the molded article having conductivity as described above can be usefully used as a wafer transfer device.

Further, the thermoplastic resin-containing composite material of the present invention and the molded article composed of the composite material can be recycled. For example, the resin composition obtained by pulverizing the composite material and the molded product, preferably in the form of a powder, and then adding an additive, if necessary, may be used in the same manner as the composite material of the present invention, and may be formed into a molded product.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to examples. However, the embodiments according to the present invention can be modified into various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. The embodiments of the present invention are provided to enable those skilled in the art to more fully understand the present invention.

Example

The following components and carbon-based materials used in the following Examples and Comparative Examples are as follows.

- Polypropylene resin

A1: Impact block copolymer

A2: homopolypropylene

A3: Impact block copolymer (polypropylene with high relative to A1)

- Carbon-based material (B1)

Examples 1 to 4 and Comparative Examples 1 to 3

The polypropylene and the carbon-based material described in Table 1 below were dry-blended to form a mixture. The resulting mixture was extruded from a twin-screw extruder (L / D = 42,? = 40 mm) while raising the temperature profile to 240 占 폚 to prepare pellets having a size of 2.5 mm X 2.5 mm X 2.5 mm.

The prepared pellets were injected from an injection machine under the condition of a flat profile at an injection temperature of 240 캜 to prepare plate specimens having a thickness of 2 mm. The prepared specimens were allowed to stand at 23 DEG C and 50% relative humidity for 48 hours.

division Example Comparative Example One 2 3 4 One 2 3 Polypropylene
(Parts by weight) A1 65.6 757.4 49.2 41.0 82.0 - - A2 16.4 24.6 32.8 41.0 - 82.0 - A3 - - - - - - 82.0 Carbon-based material
(Parts by weight) B1 18.0 18.0 18.0 18.0 18.0 18.0 18.0

Experimental Example

The properties of the specimens prepared in Examples 1-4 and Comparative Examples 1-3 were measured by the following methods, and the results are shown in Table 2 below.

- Emissions of total volatile organic compounds (TVOC)

Purge & Trap sampler-GC / MSD.

- Melt Index

And evaluated in accordance with the ASTM D1238 standard.

- Izod impact strength

And evaluated in accordance with the ASTM D256 standard.

- Evaluation resistor

It was evaluated according to ASTM D257 standard.

division Example Comparative Example One 2 3 4 One 2 3 TVOC
(ppm) 180 147 119 78 317 55 764 Impact strength
(kgcm / cm) 15.2 11.3 8.2 6.5 22.9 2.2 18.9 Melt Index
(g / 10 min) 7.8 9.1 8.9 8.8 6.5 11.6 8.7 Surface resistance
(ohm / sq.) 10 ² 10 ² 10 ² 10 ² 10 ² 10 ² 10 ²

As shown in Table 2, it can be seen that the molded articles obtained according to Examples 1 to 4 had a small amount of total volatile organic compound emission, excellent impact strength, improved flowability, and improved conductivity.

Claims (13)

Preparing homopolypropylene;
Producing an impact copolymer;
Blending the homopolypropylene and the impact copolymer; And
And blending the carbon-based material,
Wherein the content of the impact copolymer is 100 to 200 parts by weight based on 100 parts by weight of the homopolypropylene,
Wherein the homopolypropylene has a melt flow rate of 5 to 40 g / min. The method according to claim 1,
Wherein the homopolypropylene is a homopolymer of propylene. The method according to claim 1,
Wherein the homopolypropylene has an Mw / Mn of 2.0 to 10.0. The method according to claim 1,
Wherein the homopolypropylene is polymerized by a metallocene catalyst. The method according to claim 1,
Wherein the impact copolymer is an impact-resistant polypropylene. The method according to claim 1,
Wherein the impact copolymer is a mixed phase resin in which an ethylene propylene copolymer is dispersed in a polypropylene homopolymer. delete The method according to claim 1,
Wherein the carbon-based material is at least one of carbon black, graphene, carbon fiber, carbon nanofiber, fullerene, carbon nanowire, and carbon nanotube. The method according to claim 1,
Wherein the carbon-based material is a carbon nanotube having an _ID / _IG ratio of 0.01 to 1.0,
Wherein the I _D / I _G ratio is a ratio relative to the intensity of D peak (D band) and G peak (G band) in the Raman spectrum of the carbon nanotubes. The method according to claim 1,
Wherein the content of the carbon-based material is 5 to 50 parts by weight based on 100 parts by weight of the homopolypropylene. A molded article obtained by processing the conductive propylene-based thermoplastic resin according to any one of claims 1 to 6 and 8 to 10. 12. The method of claim 11,
Wherein the processing step is an extrusion step, an injection step, or an extrusion / injection step. 12. The method of claim 11,
Wherein the molded article is a wafer transfer apparatus.