Environmentally friendly polypropylene resin composition with improved friction and wear properties as well as scratch resistance and molded articles manufactured from it.

Abstract

An environmentally friendly polypropylene resin composition comprising 5 to 30 parts by weight of lignocellulose and 70 to 95 parts by weight of a polypropylene resin, based on 100 parts by weight of the polypropylene resin composition, and a molded body for automotive parts produced therefrom are disclosed.

Description

CROSS-REFERENCE TO RELATED REGISTRATION

[0001] This application claims priority over Korean patent application No. 10-2024-0132512, filed on September 30, 2024, the disclosure of which in its entirety is hereby expressly incorporated by reference. Background 1. Field of invention

[0002] The present invention relates to an environmentally friendly polypropylene resin composition containing lignocellulose and a molded body for automotive parts produced therefrom with improved friction and wear properties as well as scratch resistance. 2. Description of the relevant state of the art

[0003] Due to the demand for lighter vehicles to improve fuel efficiency and reduce carbon dioxide emissions, intensive research is being conducted into replacing metals with low-density materials such as plastics. Polypropylene resin, due to its excellent mechanical properties, formability, and chemical resistance, is widely used as a material for interior and exterior vehicle parts, components for electrical and household appliances, construction and industrial materials, films, pipes, and wires.

[0004] When a molded part produced by injection molding from such a polypropylene resin is used as a car part, the car's fuel efficiency can be improved due to the part's reduced weight. Furthermore, the polypropylene resin can lower manufacturing costs and has the advantage of being easily recyclable.

[0005] In the past, talc was frequently used as an inorganic filler in polypropylene materials for interior and exterior automotive parts to ensure excellent mechanical properties and a high-quality appearance. Korean patent application no. 10-0541496 and Korean patent publication no. 10-2024-0111056 disclose polypropylene resin compositions containing talc.

[0006] While increasing talc content improves mechanical properties and heat resistance, the disadvantage is that the molded part, due to its high whiteness and low inherent hardness, exhibits reduced scratch resistance. In other words, a high talc content leads to a rough appearance and a deterioration in surface hardness and scratch resistance. Therefore, for products where appearance is paramount, such as automotive interiors or household goods that use talc-filled polypropylene resin, costs increase because additional additives must be included or scratch resistance improved through a coating process.

[0007] For example, polypropylene resin, which is mainly used in automotive parts, is often manufactured with a high talc content (20% or more), resulting in low scratch resistance. To ensure the scratch resistance of these talc-rich products, additional rubber and silicone compounds, fluoropolymers, and amide-based additives have been used; however, achieving a specific level of scratch resistance is difficult, and the disadvantage lies in the low stain resistance.

[0008] In particular, most of these additives are made from petroleum-based materials and can exacerbate environmental pollution, which runs counter to efforts to combat climate change and achieve carbon neutrality. Therefore, there is a need to develop environmentally friendly materials from biomass that can improve scratch resistance. Brief description

[0009] The present invention aims to provide a polypropylene composition with improved wear resistance, friction resistance and scratch resistance, suitable for interior and exterior materials of motor vehicles.

[0010] The present invention also aims to provide an environmentally friendly polypropylene composition containing a lignocellulose-containing biomass material as a filler.

[0011] One aspect of the present invention relates to an environmentally friendly polypropylene resin composition comprising 5 to 30 parts by weight of lignocellulose and 70 to 95 parts by weight of a polypropylene resin, based on 100 parts by weight of the polypropylene resin composition.

[0012] According to one embodiment, the lignocellulose can have a ratio of lignin to cellulose in the range of 3:7 to 7:3.

[0013] According to one embodiment, the lignocellulose may also contain one or more metal salts selected from CaSO4, Na2SO4, K2SO4 and MgSO4.

[0014] According to one embodiment, the particle size of the lignocellulose can be in a range of 0.5 µm to 100 µm, preferably in a range of 3 µm to 40 µm.

[0015] According to one embodiment, the density of the lignocellulose can be in the range of 1.1 to 1.5 g / cm³. 3 lay.

[0016] According to one embodiment, the polypropylene resin can be a polypropylene homopolymer, a propylene-ethylene copolymer, or a mixture thereof.

[0017] According to one embodiment, the environmentally friendly polypropylene resin composition may also contain one or more additives selected from an antioxidant, a filler, an antistatic agent, a lubricant, and a lubricating agent.

[0018] Another aspect of the present invention relates to a molded article for car parts, which is manufactured using the environmentally friendly polypropylene resin composition.

[0019] The molded article can have a ΔL value in the range of 2.5 to 6.5 as a result of the Erichsen scratch resistance assessment according to the test method KS B 0182.

[0020] The molded part can have an average coefficient of friction in the range of 0.1 to 0.2 and an average frictional force in the range of 13 to 17.5, as measured according to the standard ASTM G99-23. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and other objectives, features and advantages of the present invention will become clearer to the person skilled in the art by describing exemplary embodiments thereof in detail, with reference to the accompanying drawings; in this regard: is Fig. 1 a SEM photograph of lignocellulose; are the Fig. 2 and Fig. 3 photographs showing the results of the scratch resistance assessment of molded parts according to examples and comparative examples; and are the Fig. 4 and Fig. 5 photographs showing the results of the friction and wear assessment of molded parts according to changes in filler content in the examples and comparison examples. DETAILED DESCRIPTION

[0022] The present invention is explained in more detail below with reference to embodiments and drawings. The following embodiments serve only as examples and are intended to facilitate understanding of the present invention. The scope of the present invention is not limited to these. The present invention can be modified in many ways and implemented in many different forms. All modifications, equivalents, and substitutions are included within the scope of the present invention.

[0023] The terms used in this application serve solely to describe specific embodiments and are not intended to limit the present invention. Singular terms include plural terms unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" and the like are to be understood as indicating the presence of certain features, numbers, steps, implementations, components, parts, or combinations thereof, but not as excluding the presence or addition of one or more other features, numbers, steps, implementations, components, parts, and combinations thereof.

[0024] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as they are commonly understood by a person skilled in the art. Terms as defined in commonly used dictionaries should be interpreted to have a meaning consistent with their meaning in the context of the prior art and should not be interpreted in an ideal or overly formal sense unless expressly defined in this application.

[0025] The present invention relates to an environmentally friendly polypropylene resin composition containing lignocellulose, a biomass material, and a molded body for automotive parts produced therefrom with improved friction and wear properties as well as scratch resistance.

[0026] An environmentally friendly polypropylene resin composition according to one embodiment is characterized in that it contains 5 to 30 parts by weight of lignocellulose and 70 to 95 parts by weight of a polypropylene resin, based on 100 parts by weight of the polypropylene resin composition.

[0027] The following section describes in detail all components and ingredients of the polypropylene resin composition. 1) Polypropylene resin

[0028] Polypropylene resin, which is a lightweight polymer with excellent mechanical properties, formability and processability, can be used as a base resin for environmentally friendly resin compositions.

[0029] The polypropylene resin can be selected from a polypropylene homopolymer, a propylene-ethylene copolymer, or a mixture thereof. If the polypropylene resin is, for example, an ethylene-propylene copolymer, it can contain approximately 5 to 10 percent ethylene by weight.

[0030] According to one embodiment, the polypropylene resin can be contained in an amount of about 70 to 95 parts by weight and particularly preferably 80 to 90 parts by weight, based on 100 parts by weight of the environmentally friendly polypropylene resin composition containing lignocellulose.

[0031] If the polypropylene resin is included in an amount within the above range in a polypropylene resin composition with improved scratch resistance, costs can be reduced and excellent processability can be achieved; and if lignocellulose, a filler made from biomass, is included in the composition, excellent mechanical strength and impact resistance can be achieved.

[0032] The polypropylene resin can be a highly crystalline ethylene-propylene copolymer resin with an isotactic index of about 97 to about 99 and can provide excellent stiffness and heat resistance.

[0033] Furthermore, the polypropylene resin has a melt flow index of approximately 10 g / 10 min to 30 g / 10 min, measured at a temperature of 230 °C and a load of 2.16 kg, thus ensuring excellent formability as well as excellent mechanical stiffness and impact resistance.

[0034] Since the polypropylene resin also has a molecular weight distribution (weight mean of molecular weight / number mean of molecular weight, polydispersity index) of 3 to 7, in particular a molecular weight distribution of about 4 to 6, it can impart excellent processing effects in addition to excellent mechanical properties and good formability. 2) Lignocellulose

[0035] The polypropylene resin composition according to one embodiment of the present invention is characterized by the use of lignocellulose, a biomass material, as a filler.

[0036] Fig.Figure 1 shows a SEM image of lignocellulose. Lignocellulose is a biomass material consisting of a mixture of lignin and cellulose and is typically blackish-brown in color. It is desirable to produce lignocellulose from inedible, unused wood (waste wood). Among the methods for producing lignocellulose is the one described in Korean patent application No. 10-2660285.

[0037] The lignocellulose used as a filler in the environmentally friendly propylene resin composition of the present invention is preferably a mixture of lignin and cellulose in a ratio of 3:7 to 7:3. If the lignin content exceeds this range, odor formation can occur during the production of the polypropylene composite resin. If the cellulose content exceeds this range, the mechanical strength decreases due to the poor dispersibility in the polypropylene resin. Therefore, lignocellulose, a mixture of lignin and cellulose in the aforementioned ratio, is suitable.

[0038] Furthermore, lignocellulose may contain one or more metal salts selected from CaSO4, Na2SO4, K2SO4 and MgSO4, and among these it is desirable to include calcium sulfate (CaSO4).

[0039] The addition of metal salts can increase the dimensional stability of plastic parts. For example, the proportion of calcium sulfate (CaSO4) in the mixture is preferably 5 to 25 parts by weight, based on 100 parts by weight of lignocellulose. If the proportion of calcium sulfate is below this range, the dimensional stability of the plastic decreases, necessitating the use of additional inorganic fillers. If it exceeds the aforementioned range, the weight of the plastic part increases due to the high density of CaSO4.

[0040] The particle size of the lignocellulose used as a biomass filler in the polypropylene resin composition can range from 0.5 to 100 µm, preferably from 3 to 40 µm. If the particle size of the lignocellulose particles falls below the aforementioned range, processability deteriorates, for example, due to the formation of fine dust and the difficulty of introducing it into the extruder during the production of a polypropylene composite resin. If the particle size exceeds the aforementioned range, the mechanical properties of the polypropylene composite resin deteriorate.

[0041] The density of usable lignocellulose can range between 1.1 and 1.5 g / cm³. 3The polypropylene composite resin requires a decomposition temperature of 250 °C or higher, a moisture content of less than 5%, and a pH value between 6 and 8. In terms of density, the polypropylene composite resin is easier to produce, as its density is only half that of conventional inorganic fillers. Since the processing temperature of the polypropylene composite resin is 250 °C or less, even when the thermal decomposition temperature is 250 °C or higher, surface defects caused by thermal decomposition can be avoided. Furthermore, a moisture content of less than 5% prevents moisture-related surface defects during processing of the polypropylene composite resin. 3) Environmentally friendly polypropylene resin composition

[0042] The environmentally friendly polypropylene resin composition according to one embodiment of the present invention comprises 5 to 30 parts by weight of lignocellulose and 70 to 95 parts by weight of a polypropylene resin.

[0043] With a lignocellulose content of less than 5 parts by weight, the friction and wear properties as well as the scratch resistance are only insufficiently improved, and if this content exceeds 30 parts by weight, problems with moisture absorption and dispersibility can occur, and physical properties such as impact strength and stiffness can decrease significantly. Therefore, the lignocellulose content is advantageously 5 to 30 parts by weight, preferably 20 to 30 parts by weight, based on 100 parts by weight of the resin composition. According to the present invention, the environmentally friendly polypropylene resin composition with improved scratch resistance can additionally contain one or more additives, depending on the intended use, selected from a compatibilizer, a lubricant, an antioxidant, a light stabilizer, an antistatic agent, and a lubricant.The additives can be used in amounts of 0.1 to 5 parts by weight, based on 100 parts by weight of the polypropylene resin composition. The compatibilizer is intended to improve the compatibility between the filler and the polypropylene resin and, by increasing this compatibility, can provide excellent mechanical stiffness and impact resistance while also ensuring dimensional stability.

[0044] In particular, the compatibilizer is a modified polyolefin resin containing a reactive group that reacts with an inorganic filler at the main chain or end of the polyolefin. Examples of the reactive group include maleic acid, maleic anhydride, carboxylic acid, hydroxyl groups, vinyl acetate, glycidyl methacrylate, vinyloxazoline, acrylic acid, and the like.

[0045] The compatibilizer content can be 0.1 to 3 parts by weight, based on 100 parts by weight of the polypropylene resin composition, which can improve the compatibility between the filler and the resin, thereby improving the degree of dispersion and providing excellent mechanical stiffness and impact resistance while also providing dimensional stability.

[0046] The lubricant can be selected from the group consisting of a siloxane-based lubricant, an amide-based lubricant and a combination thereof, thereby increasing the lubricity during the molding of the polypropylene resin composition and improving scratch resistance.

[0047] The antioxidant can be selected from the group consisting of a phenolic antioxidant, a phosphite-based antioxidant, thiodipropionate and a combination thereof.

[0048] According to one embodiment, a molded body produced using the environmentally friendly polypropylene resin composition exhibited excellent scratch resistance. In particular, a ΔL value can range from 2.5 to 6.5, as shown by the Erichsen scratch resistance rating according to test method KS B 0182.

[0049] Furthermore, a molded article manufactured using the environmentally friendly polypropylene resin composition had an average coefficient of friction of 0.1 to 0.2 and an average frictional force of 13 to 17.5, measured according to the ASTM G99-23 test method, and thus met all applicable standards for automotive parts, etc.

[0050] In this way, the polypropylene resin composition according to the invention, due to its high content of lignocellulose, a biomass material, can contribute to solving environmental problems by reducing climate-damaging carbon emissions. Furthermore, as a lightweight material with excellent scratch resistance and outstanding mechanical properties, it is suitable for the manufacture of automotive parts. Specific examples of automotive interior and exterior parts for which the environmentally friendly polypropylene resin composition of the present invention can be used include glove compartments, defroster vents, center consoles, lamp housings, bumpers, instrument panels, door panels, and the like. It is suitable for parts requiring high scratch resistance. <Beispiele und Vergleichsbeispiele>

[0051] The lignocellulose listed in Table 1 was used as a filler in a polypropylene resin composition. In lignocellulose (LC), the lignin-to-cellulose ratio was 7:3, and lignocellulose with 5% CaSO4 was used (manufacturer: Lignum, product name: SSEIF-L). [Table 1] Keywords Physical properties composition Lignin + Cellulose + CaSO4 Density (g / cm³) 3 ) 1,2 Particle refractive index 1,52 Color dark brown Decomposition temperature 250°C or higher moisture content less than 5% PH value 6 to 8 specific surface 727 m 2 / kg Particle size Dv(10) 3,46 µm Particle size Dv(50) 14,7 µm Particle size Dv(90) 36,9 µm

[0052] The lignocellulose (LC) mentioned above was used to produce the polypropylene resin compositions of the examples and comparative examples according to the compositions in Tables 2 and 3 below. In Examples 1 to 4, polypropylene resin compositions with 5%, 10%, 20%, and 30% lignocellulose (LC) were produced. In Comparative Example 1, a highly crystalline polypropylene resin with a crystallinity in the range of 60 ± 10% was used. In Comparative Examples 2 to 5, polypropylene resin compositions with 5%, 10%, 20%, and 30% talc (TD) were produced. Highly crystalline polypropylene is suitable for use in environmentally friendly polypropylene resin compositions because it allows the production of highly stiff resin compositions that meet the mechanical properties required for interior and exterior materials of automobiles. - Polypropylene resin: Highly crystalline polypropylene (crystallinity: 60 ± 10%) - Lignocellulose (LC): Lignin and cellulose in a 7:3 ratio, contains 5% CaSO4 (Manufacturer: Lignum, Product name: SSEIF-L) - Talk (TD) [Table 2] Example 1 Example 2 Example 3 Example 4 PP-LC5 PP-LC10 PP-LC20 PP-LC30 TD content (%) 0 0 0 0 LC content (%) 5 10 20 30 [Table 3] Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative example 5 Basic PP PP-TD5 PP-TD10 PP-TD20 PP-TD30 TD content (%) 0 5 10 20 30 LC content (%) 0 0 0 0 0 <Testbeispiel 1> Evaluation of basic characteristics

[0053] After preparing samples using the polypropylene resin compositions prepared according to the examples and comparisons above, their basic properties and performance were measured, and the results are shown in [Table 4].

[0054] The melting index (MI) decreased with increasing LC content, and the density was below 1 up to PP-LC20 with an LC content of 20%. Furthermore, with increasing LC content, tensile strength, elongation and IZOD impact strength decreased slightly, but flexural modulus, flexural strength and HDT improved with increasing LC content. [Table 4] Test procedure Example 1 Example 2 Example 3 Example 4 Material composition - PP-LC5 PP-LC10 PP-LC20 PP-LC30 MI (g / 10 min) ISO 1133 25,2 25,1 19,5 13,6 Density (g / cm³) 3 ) ISO 1183 0,926 0,943 0,980 1,017 Tensile strength (MPa) ISO 527 29,9 28,9 26,6 24,2 Elongation (%) 63 33 18 11 Flexural modulus (MPa) ISO 178 1,858 1,963 2,265 2,488 Flexural strength (MPa) 49,0 48,9 47,5 44,2 IZOD impact strength (kJ / m²) 2 ) 23°C ISO 180 TYPE A 3,6 3,3 2,9 1,5 -10°C 2,9 2,8 1,7 1,8 Heat deflection temperature (°C), 0.45 MPa ISO 75 119,8 130,5 137,5 141,3 <Testbeispiel 2> Scratch resistance rating

[0055] After forming the polypropylene resin compositions of the above examples and comparison examples for the production of samples, the scratch resistance properties were evaluated by scratching 20 or more grid patterns at intervals of 2 mm under the evaluation conditions shown in [Table 5] below, measuring the L-values ​​before and after the scratch evaluation, and calculating the ΔL-value according to the Erichsen test method and KS B 0812. [Table 5] Classification Classification Conditions Evaluation equipment Last (N) 10 Scratch length (mm) 40 Distance (mm) 2 scoring tool φ1 Number of scratches 20 (width / height) Measuring equipment light source D65 Measurement method d / 8 (rotating ball)

[0056] The scratch resistance (ΔL value) measurement results of the polypropylene resin molded parts of the examples and comparison examples, evaluated using the Erichsen test method mentioned above, are shown in [Table 6], [Table 7], Fig. 2 and Fig.Figure 3 below. As the ΔL value measurement results and the scratch photos in the drawings show, the scratch resistance of the polypropylene resin molded parts improves significantly when the lignocellulose content (LC) is increased in the examples, compared to an increase in the talc content (TD) in the comparison examples. [Table 6] Scratch resistance Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative example 5 Erichsen rating Basic PP PP-TD5 PP-TD10 PP-TD20 PP-TD30 ΔL 1,02 3,5 6,46 10,99 12,46 [Table 7] Scratch resistance Example 1 Example 2 Example 3 Example 4 Erichsen rating PP-LC5 PP-LC10 PP-LC20 PP-LC30 ΔL 2,86 3,68 4,56 6,07 <Testbeispiel 3> Evaluation of friction and wear properties

[0057] After molding the polypropylene resin compositions of the above examples and comparative examples for the production of samples, their friction and wear properties were evaluated. The friction and wear evaluation was carried out by applying the counter material SUJ2, a load of 100 N, a speed of 1 Hz, a stroke of 10 mm and a time of 1 hour according to test method ASTM G99-23 to measure the average coefficient of friction, the average frictional force and the wear depth.

[0058] The friction and wear assessment (see [Table 8], [Table 9] as well as Fig. 4 and Fig.5) confirmed that with increasing talc content (TD), frictional force and wear depth increased, while with increasing lignocellulose content (LC), frictional force and wear depth decreased. In particular, it was shown that the friction and wear resistance of a polypropylene resin composition with a lignocellulose content (LC) of 10% or more is excellent. [Table 8] Friction and wear assessment Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative example 5 Material composition Basic PP PP-TD5 PP-TD10 PP-TD20 PP-TD30 Surface roughness (Ra, µm) 0,05 0,05 0,05 0,05 0,08 Average coefficient of friction 0,177 0,182 0,188 0,206 0,245 Average friction force 17,5 18 18,5 20,3 24,1 Wear depth (mm) 0,0562 0,0687 0,0717 0,11 0,1419 [Table 9] Friction and wear assessment Example 1 Example 2 Example 3 Example 4 Material composition PP-LC5 PP-LC10 PP-LC20 PP-LC30 Surface roughness (Ra, µm) 0,05 0,06 0,08 0,27 Average coefficient of friction 0,175 0,162 0,141 0,136 Average friction force 17,4 16,1 14,0 13,6 Wear depth (mm) 0,0532 0,0267 0,0081 0,0080

[0059] In this way it is evident that the polypropylene resin composition containing lignocellulose as a filler according to the present invention is an environmentally friendly, lightweight material with excellent scratch resistance and friction and wear resistance, and is suitable for the manufacture of interior and exterior parts for cars.

[0060] A polypropylene composition according to the present invention is an environmentally friendly resin composition that contains lignocellulose, a biomass material, as a filler and can reduce environmental impact by achieving carbon neutrality.

[0061] Since the environmentally friendly polypropylene resin composition with lignocellulose also has good mechanical properties and excellent scratch resistance, it can replace talc materials that cause clouding and have low scratch resistance.

[0062] In particular, the molded article produced according to the embodiment using the environmentally friendly polypropylene resin composition containing lignocellulose exhibits a ΔL value in the range of 2.5 to 6.5 as a result of the Erichsen scratch resistance assessment according to test method KS B 0182 and has an average coefficient of friction in the range of 0.1 to 0.2 and an average frictional force in the range of 13 to 17.5, measured according to the standard ASTM G99-23, which indicates a high potential for use in interior or exterior parts of automobiles.

[0063] The effects of the present invention are not limited to the effects mentioned above, and other, unmentioned effects will be clearly apparent to the person skilled in the art from the above description.

[0064] From the above description, it will be clear to those skilled in the art of the present invention that the present invention can be implemented in other specific forms without altering the underlying technical concept or essential features. In this context, it should be noted that the embodiments described above are in every respect exemplary and not limiting. The scope of the present invention includes all changes or modifications that result from the meaning and scope of the claims described below and their equivalent concepts, and not from the detailed description above. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] KR 10-2024-0132512

[0001] KR 10-0541496

[0005] KR 10-2024-0111056

[0005] KR 10-2660285

[0036]

Claims

[1] Environmentally friendly polypropylene resin composition, comprising: 5 to 30 parts by weight lignocellulose; and 70 to 95 parts by weight of a polypropylene resin, based on 100 parts by weight of the polypropylene resin composition. [2] Environmentally friendly polypropylene resin composition according to claim 1, wherein the lignocellulose has a ratio of lignin to cellulose in the range of 3:7 to 7:

3. [3] Environmentally friendly polypropylene resin composition according to claim 1, wherein the lignocellulose further contains one or more metal salts selected from CaSO4, Na2SO4, K2SO4 and MgSO4. [4] Environmentally friendly polypropylene resin composition according to claim 1, wherein the lignocellulose has a particle size in the range of 0.5 µm to 100 µm. [5] Environmentally friendly polypropylene resin composition according to claim 1, wherein the lignocellulose has a density in the range of 1.1 to 1.5 g / cm³ 3 exhibits. [6] Environmentally friendly polypropylene resin composition according to claim 1, wherein the polypropylene resin is a polypropylene homopolymer, a propylene-ethylene copolymer or a mixture thereof. [7] Environmentally friendly polypropylene resin composition according to claim 1, further comprising one or more additives selected from a compatibilizer, a lubricant, an antioxidant, a light stabilizer, an antistatic agent and a lubricant. [8] Molded bodies for automotive parts, produced by molding the environmentally friendly polypropylene resin composition according to claim 1. [9] Molded body according to claim 8, wherein a ΔL value as a result of the Erichsen scratch resistance assessment according to test method KS B 0182 is in the range of 2.5 to 6.

5. [10] Molded body according to claim 8, wherein the molded article has an average coefficient of friction in the range of 0.1 to 0.2 and an average frictional force in the range of 13 to 17.5, measured according to the test method ASTM G99-23.

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