Polypropylene resin composition and molded article comprising same

Abstract

Disclosed are a polypropylene resin composition and a molded article comprising the same, the polypropylene resin composition having improved chemical stability to external factors because it prevents deterioration of physical properties due to moisture and having low surface energy, the molded article having low ion elution (which is the most important requirement), and a molded article comprising the same. And excellent weight reduction can be realized.

Description

Technical Field

[0001] The present invention relates to a polypropylene resin composition and a molded article comprising the same. Background Art

[0002] Generally, a fuel cell vehicle includes a fuel cell stack, an air supply, and a thermal management system (TMS). The thermal management system is used to keep the battery stack and each component at an appropriate temperature and improve the operating efficiency during the operation of the fuel cell electric vehicle (FCEV). Specifically, the cathode oxygen consumption heater is a component that quickly heats the low-temperature coolant during the cold start process to ensure that the vehicle can travel quickly even in winter, thereby improving user convenience, and consumes the remaining electric energy in the battery stack when stopping driving.

[0003] The COD heater mainly uses polyphthalamide resin (PPA-GF35 material), which is expensive and has the following problems: its physical properties continue to deteriorate when exposed to high-temperature coolant, and the conductivity of the coolant increases due to ion elution.

[0004] The information contained in this background section of the present invention is only for enhancement of understanding of the overall background of the invention and should not be taken as an acknowledgment or any form of suggestion that this information constitutes the relevant technology already known to those skilled in the art. Summary of the invention

[0005] Various aspects of the present invention are directed to providing a polypropylene resin composition having stable physical properties.

[0006] Another object of the present invention is to provide a molded article comprising the composition which is lightweight and has chemical resistance, water resistance and low ion elution.

[0007] The objects of the present invention are not limited to the above objects. Other objects of the present invention will be clearly understood from the following description and can be achieved by the means defined in the claims and their combinations.

[0008] In one aspect, the present invention provides a polypropylene resin composition comprising a polypropylene resin, a fiber reinforcement agent and a surface modifier.

[0009] The polypropylene resin composition may include 100 to 120 parts by weight of the fiber reinforcement and 0.1 to 1 parts by weight of the surface modifier, based on 100 parts by weight of the polypropylene resin.

[0010] The number average molecular weight (Mn) of the polypropylene resin may be 15,000 g / mol to 30,000 g / mol.

[0011] The polypropylene resin may include at least one selected from the group consisting of homopolypropylene, ethylene-propylene copolymer, and combinations thereof.

[0012] The polypropylene resin may have a melt index (MI) of 30 to 50 g / 10 min at 230° C. and a load of 2.16 kg.

[0013] The fiber reinforcement may include at least one selected from glass fiber, carbon fiber, graphite fiber, metal fiber, basalt fiber, cotton fiber, wool fiber, silk fiber, aramid fiber, polyacrylonitrile (PAN) fiber, arylate fiber, polyetheretherketone (PEEK) fiber, nylon fiber, polyethylene terephthalate (PET) fiber, and combinations thereof.

[0014] The length of the fiber reinforcement may be from 6 mm to 25 mm.

[0015] The diameter of the fiber reinforcement may be 12 μm to 20 μm.

[0016] The surface modifier may include at least one selected from the group consisting of an organosilicon-based surface modifier, a wax-based surface modifier, a stearate-based surface modifier, and combinations thereof.

[0017] The polypropylene resin composition may further include an additive, wherein the additive includes at least one selected from the group consisting of a compatibilizer, an impact resistant agent, a heat resistant agent, and a combination thereof.

[0018] The compatibilizer may include at least one selected from homopolypropylene, ethylene-propylene copolymer, ethylene-octene copolymer, and combinations thereof.

[0019] The compatibilizer may be grafted with 0.8 wt % to 1.2 wt % maleic anhydride, based on the total weight of the compatibilizer.

[0020] The compatibilizer may be present in an amount of 1 to 10 parts by weight based on 100 parts by weight of the polypropylene resin.

[0021] The impact resistant agent may be present in an amount of 1 to 5 parts by weight based on 100 parts by weight of the polypropylene resin.

[0022] The heat-resistant agent may include at least one selected from the group consisting of a phenol-based heat-resistant agent, a phosphorus-based heat-resistant agent, and a combination thereof.

[0023] The heat resistant agent may be present in an amount of 0.1 to 1 parts by weight based on 100 parts by weight of the polypropylene resin.

[0024] The polypropylene resin composition may have a tensile strength of 140 MPa or more according to ISO 527, a flexural strength of 200 MPa or more according to ISO 178, a thermal conductivity of 25 kJ / m according to ISO 180, and a thermal conductivity of 25 kJ / m 2Impact strength of 1000 Nm or higher, heat deflection temperature of 158°C or higher under a load of 1.8 MPa according to ISO 75.

[0025] In another aspect, the present invention provides a molded article comprising the polypropylene resin composition.

[0026] The molded article may include a cathode oxygen consumption (COD) heater.

[0027] The ion elution amount of the molded article can be 2.1 ppm or less.

[0028] Other aspects and exemplary embodiments of the invention are discussed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The electron microscope analysis results of Example 2 are shown.

[0030] Figure 2 The electron microscope analysis results of Comparative Example 1 are shown.

[0031] It is to be understood that the accompanying drawings are not necessarily to scale, and that they show various features that are somewhat simplified to illustrate the basic principles of the invention. The specific design features of the invention as disclosed herein (including, for example, specific size, orientation, location, and shape) will be determined in part by the specific target application and use environment.

[0032] In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing. DETAILED DESCRIPTION

[0033] Now will be referred to in detail various embodiments of the present invention, examples of which are shown in the accompanying drawings and are described below. Although the present invention will be described in conjunction with exemplary embodiments of the present invention, it should be understood that this specification is not intended to limit the present invention to those exemplary embodiments. On the contrary, the present invention is intended to not only cover the exemplary embodiments of the present invention, but also to cover various alternatives, variants, equivalents and other embodiments that may be included within the spirit and scope of the present invention as defined by the appended claims.

[0034] The above objects and other objects, features and advantages will be clearly understood through the following exemplary embodiments with reference to the accompanying drawings. However, the present invention is not limited to these embodiments, but can be implemented in different forms. These embodiments are recommended only to provide a complete and full understanding of the disclosed content and to fully convey the technical concept of the present invention to those skilled in the art.

[0035] Throughout the description of the accompanying drawings, the same reference numerals refer to the same elements. In the accompanying drawings, the size of the structure may be enlarged for clarity. It will be understood that, although the terms "first", "second", etc. are used herein to describe each element, these elements should not be interpreted as being limited by these terms, which are only used to distinguish one element from another. For example, within the scope defined by the present invention, a "first" element may be referred to as a "second" element, and similarly, a "second" element may be referred to as a "first" element. Singular forms are intended to also include plural forms, unless the context clearly indicates otherwise.

[0036] It will also be understood that the terms "include / comprise" and / or "have" when used in this specification indicate the presence of the described features, integers, steps, operations, elements, components, or combinations thereof, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof. In addition, it will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element, or there can be intervening elements. It will also be understood that when an element such as a layer, film, region, or substrate is referred to as being "below" another element, it can be directly below the other element, or there can be intervening elements.

[0037] Unless otherwise clearly stated in the context, all numerals, numerical values ​​and / or expressions representing the amount of components, reaction conditions, polymer compositions and mixtures used in this specification are such approximate values, i.e., they reflect, among other aspects, the various measurement uncertainties inherently present when obtaining these numerical values. For this reason, it should be understood that the term "about" should be understood to modify all numerals, numerical values ​​and / or expressions in all cases. In addition, when numerical ranges are disclosed in this specification, unless otherwise defined, these ranges are continuous and include all numerals from the minimum to the maximum (including the maximum in each range). Moreover, when range refers to an integer, unless otherwise defined, it includes all integers from the minimum to the maximum (including the maximum in the described range).

[0038] In recent years, the automotive industry is working to solve the social problems of environmental pollution and improving vehicle efficiency through various developments. In order to solve the problem of environmental pollution, traditional internal combustion engine vehicles are replaced by electric vehicles and hydrogen fuel cell vehicles. However, lightweighting is more important for environmentally friendly vehicles because the weight of environmentally friendly vehicles increases compared to internal combustion engine vehicles.

[0039] Meanwhile, the cathode oxygen consumption (COD) heater is a key component of hydrogen fuel cell vehicles, which is installed in the coolant line of the fuel cell stack used in fuel cell vehicles and is used to heat the coolant during the start-up, shutdown and cold start of the fuel cell stack. Due to the characteristics of the component, the material of the cathode oxygen consumption (COD) heater basically requires excellent mechanical strength and low ion elution.

[0040] For parts in contact with antifreeze in internal combustion engine vehicles, ion elution is not very important. However, fuel cell vehicles should minimize ion elution from all parts. Therefore, it is difficult to solve the ion elution problem using conventional polyphthalamide resins.

[0041] Conventional polyphthalamide resins contain 30 to 40% by weight of short glass fibers having a length of 2 to 3 mm, thereby improving thermal stability, but due to the characteristics of polyphthalamide resins, conventional polyphthalamide resin products suffer from degradation of physical properties when exposed to water. In addition, conventional polyphthalamide resins disadvantageously fail to ensure high fluidity to optimize the productivity of injection molds because they use only modified polyphthalamide resins having low relative viscosity.

[0042] That is, in conventional internal combustion engines, because the corresponding parts have very high cooling fluid temperatures due to the heat generated in the internal combustion engine, modified polyamide resins with high thermal stability have been used. On the other hand, fuel cell vehicles generate relatively low heat, so the temperature rise of the cooling fluid is relatively low. Therefore, a temperature atmosphere is formed in which ordinary polypropylene resins can be applied instead of modified amide resins. In addition, when using polypropylene resins, chemical stability to external factors can be improved due to low surface energy and prevention of physical property degradation caused by moisture. In addition, most importantly, low ion elution and excellent lightweight can be obtained.

[0043] The polypropylene resin composition according to an exemplary embodiment of the present invention may include a polypropylene resin, a fiber reinforcement, and a surface modifier.

[0044] Hereinafter, each component of the composition will be described in detail.

[0045] Polypropylene resin

[0046] The polypropylene resin according to the exemplary embodiment of the present invention may refer to a thermoplastic resin including an aliphatic molecular chain.

[0047] The number average molecular weight (Mn) of the polypropylene resin may be 15,000 g / mol to 30,000 g / mol.

[0048] The polypropylene resin may include at least one selected from the group consisting of homopolypropylene, ethylene-propylene copolymer, and combinations thereof.

[0049] The melt index (MI) of the polypropylene resin at 230°C and 2.16kg load may be 30g / 10min to 50g / 10min. When the melt index is less than 30g / 10min, the impregnation and mechanical properties of the fiber reinforcement may be low due to the low fluidity caused by the production characteristics of long fiber reinforced thermoplastics (LFT), and when the melt index is higher than 50g / 10min, the physical properties of the resin itself may be reduced due to the low molecular weight, resulting in poor mechanical properties.

[0050] (B) Fiber reinforcement

[0051] The fiber reinforcement according to an exemplary embodiment of the present invention may include at least one selected from glass fiber, carbon fiber, graphite fiber, metal fiber, basalt fiber, cotton fiber, wool fiber, silk fiber, aramid fiber, polyacrylonitrile (PAN) fiber, arylate fiber, polyetheretherketone (PEEK) fiber, nylon fiber, polyethylene terephthalate (PET) fiber and a combination thereof, and preferably, may be glass fiber.

[0052] The length of the fiber reinforcement may be 6 mm to 25 mm, for example, 7 mm to 20 mm, 8 mm to 18 mm, or 9 mm to 15 mm.

[0053] The material currently used for the COD heater housing is a material comprising a polyphthalamide resin and 35% by weight of a short fiber reinforcement (glass fiber) having a length of 2mm to 3mm, which is used to produce components. However, disadvantageously, the material is expensive, the physical properties are constantly deteriorated when exposed to high-temperature coolants, and the conductivity of the coolant is increased due to ion elution. In order to solve these problems, a material comprising a polypropylene resin and 30% to 70% by weight of a long fiber reinforcement (glass fiber) having a length of 6mm to 25mm is used, and the role of the component is fully utilized based on stable physical properties under a mild environment, and due to the change of the polymer resin, chemical resistance, water resistance, reduced ion elution and lightweight can be achieved.

[0054] The diameter of the fiber reinforcement may be 12 μm to 20 μm.

[0055] The fiber reinforcement may be included in an amount of 100 to 120 parts by weight, preferably 102.73 to 115.85 parts by weight, based on 100 parts by weight of the polypropylene resin. When the amount is less than 100 parts by weight, tensile strength and flexural strength are reduced, and when the amount is greater than 120 parts by weight, injection performance is reduced due to surface defects or reduced fluidity of the molded article.

[0056] The fiber reinforcement may be glass fiber, and the glass fiber may be in the form of E-glass roving having wound infinite length glass fibers. Preferably, the silane may be coupled to the surface of the glass fiber to ensure interfacial adhesion with the final composition.

[0057] (C) Surface modifier

[0058] The surface modifier according to the exemplary embodiment of the present invention is used to improve fluidity to enhance the surface quality of a product injected with the polypropylene resin composition.

[0059] The surface modifier includes at least one selected from the group consisting of an organosilicon-based surface modifier, a wax-based surface modifier, a stearate-based surface modifier, and combinations thereof, and may be, for example, an organosilicon-based surface modifier.

[0060] The content of the surface modifier may be 0.1 to 1 part by weight, preferably 0.44 to 0.66 parts by weight, based on 100 parts by weight of the polypropylene resin. When the content is less than 0.1 parts by weight, the surface modifier is difficult to play a role in surface modification, and when the content is higher than 1 part by weight, the surface modifier itself may act as an impurity and reduce the mechanical properties.

[0061] (D) Additives

[0062] The polypropylene resin composition according to the exemplary embodiment of the present invention may further include an additive including at least one selected from the group consisting of a compatibilizer, an impact resistant agent, a heat resistant agent, and a combination thereof.

[0063] Compatibilizers are used to improve the compatibility between polypropylene resin and fiber reinforcement.

[0064] The compatibilizer may include at least one selected from homopolypropylene, ethylene-propylene copolymer, ethylene-octene copolymer, and combinations thereof.

[0065] The compatibilizer may be grafted with 0.8 wt % to 1.2 wt % maleic anhydride, based on the total weight of the compatibilizer.

[0066] The content of the compatibilizer may be 1 to 10 parts by weight, preferably 3.93 to 5.90 parts by weight, based on 100 parts by weight of the polypropylene resin. When the content is less than 1 part by weight, the compatibility between the polypropylene resin and the fiber reinforcement may not increase, resulting in decreased mechanical properties, while when the content is higher than 10 parts by weight, an excess of the compatibilizer may remain unreacted, resulting in deterioration of the physical properties of the product.

[0067] The impact resistance agent is used to improve the impact properties of the polypropylene resin composition.

[0068] Based on 100 parts by weight of the polypropylene resin, the content of the impact-resistant agent can be 1 to 5 parts by weight, preferably 2.62 to 3.93 parts by weight. When the content is less than 1 part by weight, it is difficult to improve the impact performance due to the poor dispersibility of the overall impact-resistant agent, and when the content is higher than 5 parts by weight, the impact performance can be improved, but the tensile strength, flexural strength and other mechanical properties may be deteriorated.

[0069] The heat-resistant agent is used to improve the heat resistance of the polypropylene resin composition.

[0070] The heat-resistant agent may include at least one selected from the group consisting of a phenol-based heat-resistant agent, a phosphorus-based heat-resistant agent, and a combination thereof.

[0071] The content of the heat-resistant agent may be 0.1 to 1 part by weight, preferably 0.44 to 0.66 parts by weight, based on 100 parts by weight of the polypropylene resin. When the content is less than 1 part by weight, the effect of improving heat resistance cannot be obtained, and when the content exceeds 1 part by weight, the effect of improving heat resistance is not significant in terms of economic efficiency.

[0072] In addition, the polypropylene resin composition according to the exemplary embodiment of the present invention may further include antioxidants, flame retardants, fluorescent whitening agents, plasticizers, thickeners, antistatic agents, mold release agents, pigments, nucleating agents, and mixtures thereof as long as the purpose of the present invention is not impaired.

[0073] Conventional melt kneading methods and equipment can be used to prepare polypropylene resin compositions. For example, the device used for melt kneading is a single screw or twin screw extruder. When using a single screw or twin screw extruder to uniformly mix the raw materials, polypropylene resin and heat-resistant agent are preferably injected into the inlet, because uniform mixing can be obtained by the shearing force of the screw in the extruder. It is preferred to minimize the retention time in a device such as an extruder to reduce the volatilization of additives in the melt kneading process and maximize the physical properties of the composition.

[0074] The polypropylene resin composition can be prepared by melt-kneading a polypropylene resin, a heat-resistant agent, and glass fiber as a fiber reinforcement at 230° C. to 300° C. When the melt-kneading temperature is lower than 230° C., although it is higher than the melting point of the polypropylene resin, the fluidity is low and sufficient impregnation cannot be obtained; when the melt-kneading temperature is higher than 300° C., the additive or the polypropylene resin may be thermally decomposed or volatilized, resulting in quality deterioration.

[0075] In addition, in order to improve the rigidity of the polypropylene resin composition, the impregnation process is performed such that glass fibers as fiber reinforcement are continuously released from a separate rack and injected into an impregnation mold instead of through the same extruder, and the injected resin and the polypropylene resin composition are fed into the impregnation mold to fill the gaps between the filaments of the glass fiber bundle by shear force.

[0076] The polypropylene resin composition according to an exemplary embodiment of the present invention has a tensile strength of 140 MPa or more according to ISO 527, a flexural strength of 200 MPa or more according to ISO 178, a thermal conductivity of 25 kJ / m 2 according to ISO 180, and a thermal conductivity of 25 kJ / m 2 according to ISO 181. 2 or higher impact strength, and a heat distortion temperature of 158° C. or higher under a load of 1.8 MPa according to ISO 75.

[0077] In another aspect, the present invention relates to a molded article comprising the above-mentioned polypropylene resin composition.

[0078] Applications of the molded article are not limited and the molded article may be applied to a cathode oxygen consumption (COD) heater.

[0079] The COD heater including the polypropylene resin composition according to the exemplary embodiment of the present invention has excellent chemical resistance and water resistance, low ion elution, and lightness based on stable physical properties under a mild environment.

[0080] The ion elution amount of the molded article can be 2.1 ppm or less.

[0081] Hereinafter, the present invention will be described in more detail with reference to the following Examples and Comparative Examples. However, the Examples and Comparative Examples are provided only for a better understanding of the present invention and therefore should not be construed as limiting the scope of the present invention.

[0082] Examples 1 to 3 and Comparative Examples 2 to 17

[0083] Based on 100 parts by weight of polypropylene resin (PolyMirae Co., Ltd., HP480S), 4.92 parts by weight of a compatibilizer (Woosung Chemical, NB1620), 3.28 parts by weight of an impact agent (Dow Chemical, Engage 8200), 0.55 parts by weight of a heat-resistant agent (Songwon Industrial, Songnox 1010) and a surface modifier were added in the amounts shown in Table 1 and mixed using a twin-screw kneader TEX-44 having a diameter of 44 mm. Here, glass fiber (Owens Corning, SE4121, 15 to 20 μm in diameter), which is a fiber reinforcement fed from roving, was impregnated in the amounts shown in Table 1 based on 100 parts by weight of the polypropylene resin to prepare polypropylene resin pellets having a length of 10 mm.

[0084] Comparative Example 1

[0085] Polypropylene resin pellets were prepared in the same manner as in Example 1, except that no surface modifier was added.

[0086] Comparative Example 18

[0087] Polypropylene resin pellets were prepared in the same manner as in Example 1, except that PA6T / 6I (poly(hexamethylene terephthalamide-co-isophthalamide)) resin and glass fibers (short (chopped) glass fibers, 15 to 20 μm in diameter and 2 to 5 mm in length) were used instead of the polypropylene resin and glass fibers (Owens Corning, SE4121, 15 to 20 μm in diameter) of Example 1.

[0088] Comparative Examples 19 to 21

[0089] Polypropylene resin pellets were prepared in the same manner as in Example 1, except that short (chopped) glass fibers (15 μm to 20 μm in diameter and 2 mm to 5 mm in length) were used as a fiber reinforcement.

[0090] [Table 1]

[0091]

[0092]

[0093] [Table 2]

[0094]

[0095] Experimental Example 1: Comparison of physical properties between examples and comparative examples

[0096] The pellets of Examples 1 to 3 and Comparative Examples 1 to 21 prepared using an injection molding machine with a clamping force of 170 tons were prepared into samples according to ISO test standards, and then the fluidity of the resin and the tensile strength, flexural strength, flexural modulus and impact strength of the samples were measured. The results are shown in Table 3.

[0097] Resin temperature setting: 260°C (260°C, 255°C, 250°C, 245°C, 240°C)

[0098] Mold temperature setting: 80℃

[0099] Maintaining pressure: 50MPa

[0100] Hold time: 5 seconds

[0101] Cooldown: 15 seconds

[0102] Tensile strength: measured according to ISO 527

[0103] Flexural strength: measured according to ISO 178

[0104] Flexural modulus: measured according to ISO 178

[0105] Impact strength: measured according to ISO 180

[0106] Heat Deflection Temperature: Measured according to ISO 75

[0107] Specific gravity: measured according to ISO 1183-1

[0108] [Table 3]

[0109]

[0110]

[0111] It can be seen from the above results that as the content of the surface modifier increases (Examples 1 to 3 compared to Comparative Example 1), the fluidity of the resin is improved, making it easier for the resin to impregnate the filaments in the glass fiber bundle, and the mechanical properties are also improved.

[0112] In addition, when the surface modifier is not added as in Comparative Example 1, the fluidity of the resin is low, the impregnation of the filaments in the glass fiber bundle is reduced, and the mechanical properties are relatively poor. As in Comparative Examples 4 and 5, when the content of the surface modifier is too low or too high, the mechanical strength is also significantly reduced.

[0113] In Comparative Example 18 using a conventional polyphthalamide (PPA) resin, it can be seen that the mechanical properties are slightly insufficient and the specific gravity is high. Therefore, when a polypropylene resin is used instead of a polyphthalamide resin as in the present invention, a lightweight effect can be expected.

[0114] Comparing Examples 1 to 3 with Comparative Examples 1 to 5, similar specific gravity results were obtained using the same content of fiber reinforcement, but Examples 1 to 3 had higher strength than Comparative Examples 1 to 5, thus being able to prepare parts with stronger mechanical properties without increasing weight.

[0115] In addition, although the type of the surface modifier is not particularly limited, it can be seen that Examples 1 to 3 using the silicone-based surface modifier exhibit slightly better physical properties than Comparative Example 2 using the wax-based surface modifier and Comparative Example 3 using the stearate surface modifier.

[0116] Experimental Example 2: Comparison of surface quality

[0117] The surface quality of the injection products using the compositions of Example 2 and Comparative Example 1 was measured using an electron microscope at a magnification of 150 times. The results are shown in Figure 1 and Figure 2 middle.

[0118] Figure 1 The electron microscope analysis results of Example 2 are shown. Figure 2 The results of electron microscope analysis of Comparative Example 1 are shown. It can be seen that the surface roughness of Example 2 to which a surface modifier was added was greatly improved compared to Comparative Example 1 to which a surface modifier was not added.

[0119] Experimental Example 3: Comparison of tensile strength at different coolant temperatures

[0120] The pellets of Example 2 and Comparative Example 18 prepared using an injection molding machine with a clamping force of 170 tons were prepared into samples, and then the tensile strength at different coolant temperatures was measured.

[0121] [Table 4]

[0122]

[0123] It can be seen from Experimental Example 2 that Example 2 to which a surface modifier is added has a higher surface quality than Comparative Example 18 to which a surface modifier is not added. As a result, the gap between the fiber reinforcement and the polypropylene resin exposed to the surface can be minimized under a high-temperature antifreeze environment, and the physical properties of the surface layer of the glass fiber reinforced injection molded product can be prevented from being degraded (the physical properties may be weakened due to the penetration of the gap). That is, the addition of a surface modifier can prevent the deterioration of physical properties under a high-temperature antifreeze environment.

[0124] Due to its molecular structure, polypropylene resin minimizes the chemical reaction of the coolant (50 wt% antifreeze + 50 wt% water), thus greatly limiting the degradation of mechanical properties even when exposed to high-temperature coolant for a long time. Meanwhile, among polyamide resins (PA), polyphthalamide (PPA) hydrolyzes in high-temperature coolant due to the properties of amide materials, and the mechanical properties continue to deteriorate. It can be seen that in a high-temperature coolant environment, polypropylene resin materials have more advantages than polyphthalamide resin materials.

[0125] Experimental Example 4: Comparison of ion elution

[0126] The ion elution of the molded articles (COD heaters) comprising the polypropylene resin compositions of Example 2 and Comparative Example 18 was evaluated.

[0127] Measurement method: Measured according to MS211-80 (ion elution evaluation) and ICP-AES (inductively coupled plasma atomic emission spectrometry).

[0128] [Table 5]

[0129]

[0130] Compared to Comparative Example 18 using a PPA resin, Example 2 has a lower processing temperature, experiences a reduction in ambient temperature from an internal combustion engine environment to a hydrogen vehicle environment, and requires less heat resistance to exclude the addition of a heat stabilizer containing metal ions and an antioxidant, thereby improving ion elution compared to the prior art.

[0131] As is apparent from the above, the polypropylene resin composition according to the exemplary embodiment of the present invention can improve chemical stability against external factors because it prevents physical property degradation caused by moisture and has low surface energy. In addition, the molded article including the polypropylene resin composition has low ion elution (which is the most important requirement) and can achieve excellent lightweight.

[0132] For ease of interpretation and accurate definition of the appended claims, the terms "upper," "lower," "inner," "outer," "up," "lower," "upward," "downward," "front," "rear," "back," "inner," "outer," "inward," "outward," "inner," "outer," "inner," "external," "forward," and "rearward" are used to describe features of the exemplary embodiments with reference to the locations of such features as shown in the figures. It should also be understood that the term "connected" or its derivatives refer to both direct and indirect connections.

[0133] The term "and / or" may include a combination of a plurality of related listed items or any of a plurality of related listed items. For example, "A and / or B" includes all three situations such as "A", "B" and "A and B".

[0134] In this specification, unless otherwise specifically stated, a singular expression includes a plural expression unless the context clearly indicates otherwise.

[0135] In an exemplary embodiment of the present invention, "at least one of A and B" may mean "at least one of A or B" or "at least one of a combination of one or more of A and B". In addition, "one or more of A and B" may mean "one or more of A or B" or "one or more of a combination of one or more of A and B".

[0136] In the exemplary embodiments of the present invention, it should be understood that terms such as "include / comprise" or "have" are intended to indicate the presence of features, values, steps, operations, elements, parts, or a combination thereof described in the specification, but do not exclude the possibility of adding or existing one or more other features, values, steps, operations, elements, parts, or a combination thereof.

[0137] The descriptions presented above of specific exemplary embodiments of the present invention are for the purpose of illustration and description. These descriptions are not intended to be exhaustive or to limit the present invention to the precise form disclosed, and it is apparent that many variations and variants are possible according to the above teachings. The exemplary embodiments are selected and described in order to explain certain principles of the present invention and their practical applications, so that other persons skilled in the art can realize and utilize various exemplary embodiments of the present invention and various variations and variants thereof. The scope of the present invention is intended to be limited by the appended claims and their equivalents.

Claims

1. A polypropylene resin composition, comprising: Polypropylene resin; Fiber reinforcements; and Surface modifiers.

2. The polypropylene resin composition according to claim 1, in, The polypropylene resin composition comprises: Based on 100 parts by weight of polypropylene resin, 100 to 120 parts by weight of a fiber reinforcement; and 0.1 to 1 parts by weight of a surface modifier.

3. The polypropylene resin composition according to claim 1, in, The number average molecular weight (Mn) of the polypropylene resin is 15,000 g / mol to 30,000 g / mol.

4. The polypropylene resin composition according to claim 1, in, The polypropylene resin includes at least one selected from homopolypropylene, ethylene-propylene copolymer and a combination thereof.

5. The polypropylene resin composition according to claim 1, in, The polypropylene resin has a melt index MI of 30 g / 10 min to 50 g / 10 min at 230° C. and a load of 2.16 kg.

6. The polypropylene resin composition according to claim 1, in, The fiber reinforcement includes at least one selected from glass fiber, carbon fiber, graphite fiber, metal fiber, basalt fiber, cotton fiber, wool fiber, silk fiber, aramid fiber, polyacrylonitrile fiber, arylate fiber, polyetheretherketone fiber, nylon fiber, polyethylene terephthalate fiber and combinations thereof.

7. The polypropylene resin composition according to claim 1, in, The length of the fiber reinforcement is 6 mm to 25 mm.

8. The polypropylene resin composition according to claim 1, in, The fiber reinforcement has a diameter of 12 μm to 20 μm.

9. The polypropylene resin composition according to claim 1, in, The surface modifier includes at least one selected from the group consisting of silicone surface modifiers, wax surface modifiers, stearate surface modifiers and combinations thereof. 10 . The polypropylene resin composition according to claim 1 , further comprising an additive, wherein the additive comprises at least one selected from the group consisting of a compatibilizer, an impact resistant agent, a heat resistant agent, and a combination thereof.

11. The polypropylene resin composition according to claim 10, in, The compatibilizer includes at least one selected from homopolypropylene, ethylene-propylene copolymer, ethylene-octene copolymer and a combination thereof.

12. The polypropylene resin composition according to claim 10, in, The compatibilizer is grafted with 0.8 wt % to 1.2 wt % of maleic anhydride based on the total weight of the compatibilizer.

13. The polypropylene resin composition according to claim 10, in, The compatibilizer is present in an amount of 1 to 10 parts by weight based on 100 parts by weight of the polypropylene resin.

14. The polypropylene resin composition according to claim 10, in, The impact resistant agent is present in an amount of 1 to 5 parts by weight based on 100 parts by weight of the polypropylene resin.

15. The polypropylene resin composition according to claim 10, in, The heat-resistant agent includes at least one selected from phenolic heat-resistant agents, phosphorus heat-resistant agents and combinations thereof.

16. The polypropylene resin composition according to claim 10, in, The heat-resistant agent is present in an amount of 0.1 to 1 parts by weight based on 100 parts by weight of the polypropylene resin.

17. The polypropylene resin composition according to claim 1, in, The polypropylene resin composition has a tensile strength of 140 MPa or more according to ISO 527, a flexural strength of 200 MPa or more according to ISO 178, and a thermal conductivity of 25 kJ / m according to ISO 180. 2 or higher impact strength, and a heat distortion temperature of 158° C. or higher under a load of 1.8 MPa according to ISO 75.

18. A molded article comprising the polypropylene resin composition according to claim 1.

19. The molded article according to claim 18, in, The molded article includes a cathode oxygen consuming heater.

20. The molded article according to claim 18, in, The molded article had an ion elution amount of 2.1 ppm or less.

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