Heating composite resin composition using carbon-based conductive filler and plastic molded article using same

Abstract

An embodiment of the present specification provides: a heating composite resin composition and a plastic molded article manufactured by injection molding of the composition, the composition comprising an olefin-based resin and a conductive filler, the conductive filler comprising carbon nanotubes, carbon black, and carbon fibers, wherein the weight ratio of the carbon fibers to the carbon nanotubes is 10-40, and the weight ratio of the carbon fibers to the carbon black is 0.8-2.0.

Description

Heat-generating composite resin composition utilizing carbon-based conductive filler and plastic molded product using the same

[0001] The present specification relates to a heat-generating composite resin composition having excellent heat-generating performance and injection moldability, and a plastic molded product using the same.

[0002] With the electric vehicle market rapidly growing, the heat energy generated by internal combustion engines cannot be utilized in electric vehicles, leading to an expansion of the development of electrically-powered heat-generating components. Furthermore, home appliance components typically utilize electrically conductive metal components to convert electrical energy into heat. However, metal components, as integrated heat-generating components, face limitations in molding and assembly, as well as high power consumption. Consequently, the development of new component materials is essential.

[0003] Driven by this need, the automotive and home appliance markets are recently pursuing efforts to apply heat-generating properties to plastics, which offer higher processability and productivity than metals. In particular, the increasing use of polypropylene (PP), a material primarily used in automotive plastic components, is driving efforts to reduce the weight of electric vehicle components. Therefore, many researchers are developing new heat-generating component materials by adding electrically conductive materials to polypropylene resin.

[0004] In particular, in the case of a heat-generating resin containing a conductive filler, it has both electrical and thermal conductivity, so it has high potential for use in various industrial fields such as automobiles, electronics, and energy storage devices.

[0005] Graphite, metal powder, and metal fiber are used as existing conductive fillers, but there is a problem in that it is difficult to secure sufficient heat generation performance at room temperature and low temperature when only these materials are mixed.

[0006] In addition, when carbon nanotubes (CNTs), carbon fibers (CFs), and carbon black (CBs) are individually applied as conductive fillers to impart electrical conductivity, it is difficult to secure optimal electrical conductivity and injection moldability of the heat-generating composite resin.

[0007] For example, in the case of a heat-generating composite resin using only carbon nanotubes, it is difficult to finely control the amount of input to secure an electrical conductivity level that allows current to flow, and even if a content that exhibits the desired electrical conductivity is found, it is difficult to implement a high melting index property for injection molding large parts with a heat-generating composite resin composition having the corresponding composition ratio.

[0008] In addition, when carbon fiber is applied alone, the electrical conductivity and injection moldability of the heat-generating composite resin can be secured, but there is a disadvantage in that the electrical conductivity is uneven due to low dispersibility and the surface appearance of the injection-molded product becomes rough.

[0009] Lastly, when carbon black is applied alone, a high content of 35% by weight or more must be added to secure electrical conductivity of the heat-generating resin, and carbon black located on the surface of the molded product may become detached from the surface and become a factor that interferes with securing uniformity of electrical conductivity.

[0010] Therefore, it is necessary to develop a heat-generating composite resin that has uniform electrical conductivity, exhibits a certain level of heat-generating performance at both room temperature and low temperature conditions, and has excellent injection moldability.

[0011] The present specification is intended to solve the problems revealed in the above-mentioned prior art, and one object of the present specification is to provide a heat-generating composite resin composition having high melting index and impact strength and thus excellent injection moldability.

[0012] Another object of the present specification is to provide a plastic molded article having excellent heat dissipation performance at room temperature and low temperature conditions.

[0013] According to one aspect, a heat-generating composite resin composition is provided, which comprises an olefin resin and a conductive filler, wherein the conductive filler comprises carbon nanotubes, carbon black and carbon fibers, wherein a weight ratio of the carbon fibers to the carbon nanotubes is 10 to 40, and a weight ratio of the carbon fibers to the carbon black is 0.8 to 2.0.

[0014] In one embodiment, the olefin resin may be a polypropylene copolymer.

[0015] In one embodiment, the polypropylene copolymer may be a polypropylene block copolymer.

[0016] In one embodiment, the melt index of the polypropylene block copolymer may be 80 g / 10 min or more and 120 g / 10 min or less.

[0017] In one embodiment, with respect to 100 parts by weight of the conductive filler, the content of the carbon nanotubes may be 0.1 to 10 parts by weight, the content of the carbon black may be 20 to 65 parts by weight, and the content of the carbon fiber may be 30 to 70 parts by weight.

[0018] In one embodiment, the carbon nanotube is a bundle-shaped carbon nanotube, and may have an average bundle diameter of 10 to 20 nm and an average bundle length of 10 to 200 μm.

[0019] In one embodiment, the carbon black may include one selected from the group consisting of Ketjen black, acetylene black, furnace black, channel black, Timcal carbon black, and combinations thereof.

[0020] According to another aspect, a plastic molded product manufactured by injection molding the above-described heat-generating composite resin composition is provided.

[0021] In one embodiment, the plastic molded product may have a surface temperature of 80°C or higher when heated, as measured by the following method, at room temperature (23°C).

[0022] [Method of measuring heat generation performance]

[0023] After injection molding a mirror-like mold with a specimen length of 200 mm, width of 50 mm, and thickness of 2 mm by setting the injection temperature to 265℃ and the mold temperature to 50℃, electrodes were made with metal tapes to allow current to pass through both ends of the specimen, and (+) and (-) charge application lines were connected to the metal tape portions of both ends, and then 12 V of direct current was applied for 5 minutes, and the surface temperature was checked through a contact-type temperature sensor attached to the center of the specimen.

[0024] In one embodiment, the plastic molded product may have a surface temperature of 20°C or higher when heated as measured by the method under low temperature (-40°C) conditions.

[0025] In one embodiment, the melt index of the plastic molded product may be 46 g / 10 min or more.

[0026] In one embodiment, the impact strength of the plastic molded product may be 3.9 kgf·cm / cm or more.

[0027] A heat-generating composite resin composition according to one aspect of the present specification can be applied to the manufacture of plastics that are used as materials with excellent injection moldability and heat-generating performance.

[0028] In addition, a plastic molded product according to another aspect of the present specification can have excellent heat generation performance at room temperature and low temperature conditions and high melting index and impact strength by securing dispersibility of a conductive component.

[0029] It should be understood that the effects of one aspect of this specification are not limited to the effects described above, but include all effects that can be inferred from the detailed description or claims of this specification.

[0030] Below, aspects of this specification will be described with reference to the attached drawings. However, the contents of this specification may be implemented in various different forms and are therefore not limited to the embodiments described herein.

[0031] Throughout the specification, when a part is said to be "connected" to another part, this includes not only "directly connected" but also "indirectly connected" with other elements intervening. Furthermore, when a part is said to "include" a component, this does not exclude other components, but rather implies that the other components may be included, unless otherwise specifically stated.

[0032] When a range of numerical values ​​is stated herein, unless the specific range is otherwise specified, the values ​​have the precision of the significant figures provided according to the standard rules in chemistry for significant figures. For example, the number 10 includes the range of 5.0 to 14.9, and the number 10.0 includes the range of 9.50 to 10.49.

[0033] Heat-generating composite resin composition

[0034] A heat-generating composite resin composition according to one aspect of the present specification comprises an olefin-based resin and a conductive filler.

[0035] The above olefin resin is a matrix of a composite resin used to improve injection moldability, and may be one selected from the group consisting of homopolyethylene, homopolypropylene, polyethylene copolymer, polypropylene copolymer, and a combination of two or more thereof, and may preferably be a polypropylene copolymer, but is not limited thereto.

[0036] For example, the polyethylene copolymer may be an ethylene / α-olefin block copolymer in which ethylene comprises at least 50 mol% of the total polymer and an α-olefin having 3 or more carbon atoms as a monomer as a substantial remainder. The α-olefin may be propylene, 1-butene, 1-hexene, or 1-octene.

[0037] For example, the polypropylene copolymer may be a block copolymer comprising propylene as a monomer in an amount of at least 50 mol% of the total polymer, and ethylene or an α-olefin having 4 or more carbon atoms as a substantial remainder. The α-olefin may be 1-hexene or 1-octene.

[0038] More preferably, the polypropylene copolymer may be a polypropylene block copolymer, but is not limited thereto. The polypropylene block copolymer has higher low-temperature impact strength than homopolypropylene, making it easy to secure impact resistance at low temperatures, and has a high melting index and tensile strength.

[0039] The above polypropylene block copolymer may have a melt index of 80 g / 10 min or more and 120 g / 10 min or less. If the melt index is below the above range, injection moldability may be reduced, making it difficult to manufacture plastic molded products. If the melt index exceeds the above range, the viscosity may be excessively low.

[0040] The conductive filler is a material that is dispersed throughout the resin to impart electrical conductivity and to enable the resin to perform a heat-generating function when current flows through the resin, and may be one selected from the group consisting of carbon nanotubes, carbon black, carbon fibers, and mixtures thereof. Preferably, a carbon-based hybrid conductive filler composed of a combination of carbon nanotubes, carbon black, and carbon fibers may be used, but is not limited thereto.

[0041] The above carbon nanotube may be one selected from the group consisting of a single-wall carbon nanotube, a double-wall carbon nanotube, a multi-wall carbon nanotube, a cup-stacked carbon nanofiber in which a plurality of truncated cone-shaped graphenes are stacked, and a mixture of two or more thereof, depending on the number of walls, and preferably, a multi-wall carbon nanotube (MWCNT) having excellent ease and economy of manufacture, but is not limited thereto.

[0042] The above carbon nanotube may be a bundle-shaped carbon nanotube in which a plurality of carbon nanotubes are arranged in a parallel or entangled bundle or rope form, but is not limited thereto.

[0043] The above-mentioned bundle-shaped carbon nanotubes may have an average bundle diameter of 10 to 20 nm and an average bundle length of 10 to 200 μm, but are not limited thereto.

[0044] If the average bundle diameter is less than the above range or the average bundle length is greater than the above range, dispersibility may be reduced, causing electrical conductivity of each region of the heat-generating composite resin composition to become non-uniform and injection moldability to be reduced. If the average bundle diameter is more than the above range or the average bundle length is less than the above range, the network structure may become unstable and electrical conductivity may be reduced.

[0045] The above carbon black may be one selected from the group consisting of ketjen black, acetylene black, furnace black, channel black, timcal carbon black, and mixtures thereof, and ketjen black, which has excellent conductivity, may be used, but is not limited thereto.

[0046] The above carbon fiber may be one selected from the group consisting of pan series or pitch series and mixtures thereof, but is not limited thereto.

[0047] The higher the aspect ratio of the carbon fibers, the higher the electrical conductivity. Furthermore, while the strength of fiber-reinforced composites generally tends to increase with longer carbon fibers, if the carbon fibers are too long, their dispersibility within the composite resin may be reduced, resulting in a lower melt index and poor injection moldability. If the carbon fibers are too short, network formation between materials may be difficult, resulting in poor electrical conductivity.

[0048] With respect to 100 parts by weight of the above conductive filler, the content of the carbon nanotubes may be 0.1 to 10 parts by weight. For example, for 100 parts by weight of the conductive filler, the content of the carbon nanotube is 0.1 parts by weight, 0.2 parts by weight, 0.3 parts by weight, 0.4 parts by weight, 0.5 parts by weight, 0.6 parts by weight, 0.7 parts by weight, 0.8 parts by weight, 0.9 parts by weight, 1.0 parts by weight, 1.1 parts by weight, 1.2 parts by weight, 1.3 parts by weight, 1.4 parts by weight, 1.5 parts by weight, 1.6 parts by weight, 1.7 parts by weight, 1.8 parts by weight, 1.9 parts by weight, 2.0 parts by weight, 2.1 parts by weight, 2.2 parts by weight, 2.3 parts by weight, 2.4 parts by weight, 2.5 parts by weight, 2.6 parts by weight, 2.7 parts by weight, 2.8 parts by weight, 2.9 parts by weight, 3.0 parts by weight, 3.5 parts by weight, It may be 4.0 parts by weight, 4.5 parts by weight, 5.0 parts by weight, 5.5 parts by weight, 6.0 parts by weight, 6.5 parts by weight, 7.0 parts by weight, 7.5 parts by weight, 8.0 parts by weight, 8.5 parts by weight, 9.0 parts by weight, 9.5 parts by weight, 10.0 parts by weight, or a value between any two of these values. Preferably, it may be 0.5 to 7 parts by weight, and more preferably, 1 to 6 parts by weight.

[0049] For 100 parts by weight of the above conductive filler, the content of the carbon black may be 20 to 65 parts by weight. For example, for 100 parts by weight of the conductive filler, the content of the carbon black is 20 parts by weight, 21 parts by weight, 22 parts by weight, 23 parts by weight, 24 parts by weight, 25 parts by weight, 26 parts by weight, 27 parts by weight, 28 parts by weight, 29 parts by weight, 30 parts by weight, 31 parts by weight, 32 parts by weight, 33 parts by weight, 34 parts by weight, 35 parts by weight, 36 parts by weight, 37 parts by weight, 38 parts by weight, 39 parts by weight, 40 parts by weight, 41 parts by weight, 42 parts by weight, 43 parts by weight, 44 parts by weight, 45 parts by weight, 46 parts by weight, 47 parts by weight, 48 parts by weight, 49 parts by weight, 50 parts by weight, 51 parts by weight, 52 parts by weight, 53 parts by weight, 54 parts by weight, 55 parts by weight, 56 parts by weight, It may be 57 parts by weight, 58 parts by weight, 59 parts by weight, 60 parts by weight, 61 parts by weight, 62 parts by weight, 63 parts by weight, 64 parts by weight, 65 parts by weight, or a value between two of these values. Preferably, it may be 25 to 60 parts by weight, and more preferably, 30 to 54 parts by weight.

[0050] With respect to 100 parts by weight of the above conductive filler, the content of the carbon fiber may be 30 to 70 parts by weight. For example, for 100 parts by weight of the conductive filler, the content of the carbon fiber is 30 parts by weight, 31 parts by weight, 32 parts by weight, 33 parts by weight, 34 parts by weight, 35 parts by weight, 36 parts by weight, 37 parts by weight, 38 parts by weight, 39 parts by weight, 40 parts by weight, 41 parts by weight, 42 parts by weight, 43 parts by weight, 44 parts by weight, 45 parts by weight, 46 parts by weight, 47 parts by weight, 48 parts by weight, 49 parts by weight, 50 parts by weight, 51 parts by weight, 52 parts by weight, 53 parts by weight, 54 parts by weight, 55 parts by weight, 56 parts by weight, 57 parts by weight, 58 parts by weight, 59 parts by weight, 60 parts by weight, 61 parts by weight, 62 parts by weight, 63 parts by weight, 64 parts by weight, 65 parts by weight, 66 parts by weight, It may be 67 parts by weight, 68 parts by weight, 69 parts by weight, 70 parts by weight, or a value between two of these values. Preferably, it may be 35 to 70 parts by weight, and more preferably, it may be 41 to 67 parts by weight.

[0051] The weight ratio of the carbon fiber to the carbon nanotube may be 10 to 40. For example, the weight ratio of the carbon fiber to the carbon nanotube is 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5, 20, 20.5, 21, 21.5, 22, 22.5, 23, 23.5, 24, 24.5, 25, 25.5, 26, 26.5, 27, 27.5, 28, 28.5, 29, 29.5, 30, 30.5, 31, 31.5, 32, It can be 32.5, 33, 33.5, 34, 34.5, 35, 35.5, 36, 36.5, 37, 37.5, 38, 38.5, 39, 39.5, 40, or a value between two of these values. Preferably, it can be 15 to 40, more preferably, 20 to 40. If the weight ratio exceeds the above range, the dispersibility may be reduced, which may deteriorate the injection moldability of the exothermic composite resin, and if it is less than the above range, the exothermic performance of the exothermic composite resin may be reduced.

[0052] The weight ratio of the carbon fiber to the carbon black may be 0.8 to 2.0. For example, the weight ratio of the carbon fiber to the carbon black may be 0.8, 0.85, 0.9, 0.95, 1.0, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, 1.9, 1.95, 2.0, or a value between any two of these values. Preferably, it may be 0.9 to 2.0, more preferably, 1.0 to 2.0. If the weight ratio exceeds the above range, the dispersibility may be reduced, which may result in poor injection moldability of the exothermic composite resin, and if it is below the above range, the impact strength of the plastic molded product manufactured by injection molding the exothermic composite resin composition may be reduced.

[0053] plastic molded products

[0054] A plastic molded product according to another aspect of the present specification is characterized in that it is manufactured by injection molding the above-described heat-generating composite resin composition.

[0055] The above plastic molded product may have a surface temperature of 80°C or higher when heated, as measured by the following method, at room temperature (23°C). If the surface temperature is lower than 80°C when heated at room temperature, the heat-generating performance due to electrical conduction may be insufficient, making it difficult to utilize as a heat-generating material.

[0056] [Method of measuring heat generation performance]

[0057] After injection molding a mirror-like mold with a specimen length of 200 mm, width of 50 mm, and thickness of 2 mm by setting the injection temperature to 265℃ and the mold temperature to 50℃, electrodes are made with metal tapes to allow current to pass through both ends of the specimen, and (+) and (-) charge application lines are connected to the metal tape portions of both ends, and then 12 V of direct current is applied for 5 minutes, and the surface temperature is checked through a contact-type temperature sensor attached to the center of the specimen. At this time, the room temperature condition is set to 23℃, and the low temperature condition is set to the temperature of the low-temperature chamber to -40℃.

[0058] The above plastic molded product may have a surface temperature of 20°C or higher when heated, as measured by the above method, under low-temperature conditions (-40°C). If the surface temperature falls below 20°C when heated under low-temperature conditions, problems may arise in which heating performance is not secured in electric vehicles and some home appliances that must be operated at sub-zero temperatures.

[0059] The melt index of the above plastic molded product may be 46 g / 10 min or higher. If the melt index falls outside the above range, a problem may arise in which sufficient injection moldability is not secured during the injection molding step for manufacturing the molded product.

[0060] The impact strength of the above plastic molded product may be 3.9 kgf·cm / cm or higher. If the impact strength exceeds the above range, the physical properties of the manufactured plastic molded product may be excessively weak, making it difficult to utilize in industrial fields such as electric vehicles and home appliances.

[0061] Hereinafter, the embodiments of this specification will be described in more detail. However, the experimental results below represent only representative experimental results among the above embodiments, and the scope and content of this specification cannot be interpreted as being reduced or limited by the embodiments, etc. The effects of each of the various implementation examples of this specification that are not explicitly presented below will be specifically described in the relevant sections.

[0062] Examples and Comparative Examples

[0063] A composition containing olefin resin, carbon nanotubes, carbon fibers, carbon black, and other additives was manufactured by injection molding using a twin-screw extruder at an injection temperature of 265°C to produce a test piece having a length of 200 mm, a width of 50 mm, and a thickness of 2 mm.

[0064] Here, the olefin resin and conductive filler used in Examples 1 to 4 and Comparative Examples 1 to 4 are as follows.

[0065] - Olefin resin 1: CB5290 (polypropylene block copolymer) from Daehan Oil & Chemical Co., Ltd.

[0066] - Olefin resin 2: Polymirae's YH5035 (homopolypropylene)

[0067] - Carbon nanotubes: Kumho Petrochemical's K-Nanos 430T

[0068] - Carbon fiber: CBZ-SP2 from Ace C&T

[0069] - Carbon Black: CCK7067 from Columbian Chemicals Korea

[0070] Tables 1 and 2 below show the content of each component of the exothermic composite resin composition used in injection molding of plastic molded products of Examples 1 to 4 and Comparative Examples 1 to 4.

[0071] Classification (weight part) Example 1 Example 2 Example 3 Example 4 Olefin resin 164.574.569.5-Olefin resin 2---64.5Carbon nanotube 0.50.50.50.5Carbon black 15101015Carbon fiber 20152020

[0072] Classification (weight part) Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Olefin resin 179.575.577.579 Olefin resin 2---- Carbon nanotube 0.50.50.51 Carbon black 1012105 Carbon fiber 10121215

[0073] Experimental examples 1-6

[0074] Experimental Example 1: Physical Property Evaluation 1) Melting Index (g / 10 min) Measurement

[0075] According to ASTM D1238, it was measured at 200℃ and 10kg.

[0076] Experimental Example 2: Physical Property Evaluation 2) Impact Strength (kgf·cm / cm) Measurement

[0077] According to ASTM D256, measurements were made at 3.2 mm.

[0078] Experimental Example 3: Physical Property Evaluation 3) Measurement of Tensile Strength (kgf / ㎠)

[0079] According to ASTM D638, measurements were taken at 50 mm / min.

[0080] Experimental Example 4: Physical Property Evaluation 4) Measurement of Heat Deflection Temperature

[0081] It was measured under the condition of 18.6 (kgf / ㎠) according to ASTM D648.

[0082] Experimental Example 5: Evaluation of Heating Performance 1) Room Temperature Heating Test

[0083] With the external temperature condition set to 23℃, electrodes were made with metal tape to allow current to pass through both ends of the test piece, and (+) and (-) charge application lines were connected to the metal tape portions of both ends. After applying 12 V of direct current for 5 minutes, the surface temperature was checked through a contact temperature sensor attached to the center of the test piece.

[0084] Experimental Example 6: Evaluation of Heating Performance 2) Low-Temperature Heating Test

[0085] With the temperature of the low-temperature chamber set to -40℃, electrodes were made with metal tape to allow current to pass through both ends of the test piece, and (+) and (-) charge application lines were connected to the metal tape portions of both ends. After applying 12 V of direct current for 5 minutes, the surface temperature was checked through a contact-type temperature sensor attached to the center of the test piece.

[0086] The melting index, impact strength, tensile strength, heat distortion temperature, room temperature surface temperature, and low temperature surface temperature of the above experimental examples 1 to 6 are shown in Tables 3 and 4 below.

[0087] Classification Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Heat distortion temperature (℃) 139.5 138.5 138.3 141.5 131.3 135.2 133.7 135.5 Room temperature surface temperature (℃) 117 80 83 88 36 58 4 87 1 Low temperature surface temperature (℃) 55 22 27 33-200-118

[0088] From the above Table 3, it was confirmed that the test pieces manufactured with the compositions of Examples 1 to 4 had high high-temperature stability, as the heat distortion temperature was maintained at 138°C or higher. In addition, as a result of measuring the heat generation performance under room temperature conditions, the test pieces manufactured with the compositions of Examples 1 to 4 had a surface temperature of 80°C or higher, which confirmed that they exhibited superior room-temperature heat generation performance compared to Comparative Examples 1 to 3, in which the weight ratio of carbon fiber to carbon nanotube was less than 1.3 and the weight ratio of carbon fiber to carbon black was less than 30. In the case of Comparative Example 4, the weight ratio of carbon fiber to carbon nanotube exceeded 2.0, and therefore, like Comparative Examples 1 to 3, the test pieces failed to exhibit heat generation performance under low-temperature conditions. On the other hand, in the case of Examples 1 to 4, it was confirmed that the surface temperature was maintained high at 20°C or higher even under low-temperature conditions, so that the heat generation performance was exhibited.

[0089] Classification Example 1 Example 2 Example 3 Example 4 Melt index (g / 10min) 46.28 0.17 9.03 3.7 Impact strength (kgf·cm / cm) 3.9 5.0 4.0 1.0 Tensile strength (kgf / ㎠) 476.7 45 8.3 44 2.0 5 5 0.3

[0090] From the above Table 4, it was confirmed that Examples 1 to 3 using polypropylene block copolymers had higher melting index and higher impact strength than Example 4 using homopolypropylene.

[0091] The description of this specification above is for illustrative purposes only, and those skilled in the art will readily appreciate that aspects of this specification can be readily modified into other specific forms without altering the technical concepts or essential features described herein. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single entity may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined manner.

[0092] The scope of this specification is indicated by the claims set forth below, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included within the scope of this specification.

Claims

1. Olefin resin; and Containing conductive filler; The above conductive filler includes carbon nanotubes, carbon black and carbon fibers, The weight ratio of the carbon fiber to the carbon nanotube is 10 to 40, The weight ratio of the carbon fiber to the carbon black is 0.8 to 2.0, Heat-generating composite resin composition.

2. In paragraph 1, A heat-generating composite resin composition wherein the above olefin resin is a polypropylene copolymer.

3. In paragraph 2, The above polypropylene copolymer is a heat-generating composite resin composition which is a polypropylene block copolymer.

4. In paragraph 3, A heat-generating composite resin composition, characterized in that the melting index of the polypropylene block copolymer is 80 g / 10 min or more and 120 g / 10 min or less.

5. In paragraph 1, For 100 parts by weight of the above conductive filler, A heat-generating composite resin composition, wherein the content of the carbon nanotubes is 0.1 to 10 parts by weight, the content of the carbon black is 20 to 65 parts by weight, and the content of the carbon fiber is 30 to 70 parts by weight.

6. In paragraph 1, The above carbon nanotubes are bundle-shaped carbon nanotubes, and the average bundle diameter is 10 to 20 nm, and the average bundle length is 10 to 200 μm, and the heat-generating composite resin composition.

7. In paragraph 1, A heat-generating composite resin composition, wherein the carbon black comprises one selected from the group consisting of Ketjen black, acetylene black, furnace black, channel black, Timcal carbon black, and combinations thereof.

8. A plastic molded product manufactured by injection molding the heat-generating composite resin composition of any one of claims 1 to 7.

9. In paragraph 8, A plastic molded product characterized in that the surface temperature of the plastic molded product is 80°C or higher when heated, as measured by the following method, under conditions of 23°C. [Method of measuring heat generation performance] After injection molding a mirror-like mold with a specimen length of 200 mm, width of 50 mm, and thickness of 2 mm by setting the injection temperature to 265℃ and the mold temperature to 50℃, electrodes were made with metal tapes to allow current to pass through both ends of the specimen, and (+) and (-) charge application lines were connected to the metal tape portions of both ends, and then 12 V of direct current was applied for 5 minutes, and the surface temperature was checked through a contact-type temperature sensor attached to the center of the specimen.

10. In paragraph 8, A plastic molded product, characterized in that the surface temperature of the plastic molded product is 20°C or higher when heated according to the method above under -40°C conditions.

11. In paragraph 8, A plastic molded product, characterized in that the melting index of the plastic molded product is 46 g / 10 min or more.

12. In paragraph 8, A plastic molded product, characterized in that the impact strength of the plastic molded product is 3.9 kgf·cm / cm or more.