Eco-friendly resin composition for blow-molded automotive interior components and blow-molded automotive interior components comprising same

Abstract

The present invention relates to an eco-friendly resin composition for blow-molded automotive interior components, the resin composition comprising recycled resin pellets derived from high-density polyethylene waste and virgin high-density polyethylene resin pellets, wherein the eco-friendly resin composition has an MI 2.16 of 0.1 to 0.5 g / 10 min and a melt index ratio (MI 21.6 / MI 2.16) of 30 to 200, where MI 2.16 is the melt index at 190 °C under a 2.16 kg load, and MI 21.6 is the melt index at 190 °C under a 21.6 kg load. The present invention provides an eco-friendly resin composition suitable for carbon-neutral applications, which contributes to carbon-dioxide reduction and, despite using a large amount of recycled high-density polyethylene derived from waste, exhibits excellent extrusion blow moldability, outstanding mechanical properties, good deodorization performance, and reliable detectability of recycled-resin content, and thus can be usefully employed in blow-molded automotive interior components.

Description

Eco-friendly resin composition for hollow molded automobile interior parts and hollow molded automobile interior parts containing the same

[0001] The present invention relates to an eco-friendly resin composition for a hollow molded product for automobile interior materials and a hollow molded product for automobile interior materials comprising the same.

[0002] Recently, as carbon dioxide emissions, the main culprit of global warming, have increased worldwide, the need for 'carbon neutrality', which means reducing net carbon dioxide emissions emitted by humans to '0', has emerged as a solution, leading to the declaration of the so-called 'Carbon Neutrality 2050' around the world.

[0003] Accordingly, various methods are being proposed and significant efforts are being made to achieve carbon neutrality in each sector. For example, the automotive industry is actively promoting plastic material recycling, aiming to use recycled resins derived from plastic waste in plastic parts within automobiles. A prime example is Europe, which plans to mandate the use of 25% recycled plastics (75% Post-Consumer Recycled (PCR) materials and 25% plastics derived from scrapped vehicles) in new car plastics starting in 2031. Failure to meet this standard could lead to a serious situation where car exports to Europe are blocked.

[0004] The most common PCR materials include film products like high-density polyethylene (HDPE) shopping bags and delivery envelopes; bottles like milk, shampoo, detergent, and motor oil bottles; and waste materials like pallets, transport boxes, and pipes. Efforts are underway to apply the pelletized, high-density polyethylene recycled resin obtained by crushing and melt-extruding these materials to automotive parts. A prime example is the use of HDPE recycled resin in air ducts and connection ducts manufactured through a hollow extrusion process.

[0005] However, depending on the type of waste used, there was an urgent need to solve the serious problem of a large number of various types of molding defects such as parison sagging and fusion, air holes, and bottom non-fusion cracks occurring in a certain ratio while trying to mix high-density polyethylene recycled resin and high-density polyethylene virgin resin with various melting indices in a certain ratio for hollow extrusion molding.

[0006] In conclusion, there is an urgent and essential need to develop an eco-friendly resin composition that uses recycled resin derived from high-density polyethylene waste and has excellent hollow extrusion moldability, and a hollow molded product for automotive interior materials obtained therefrom.

[0007] One object of the present invention is to provide an eco-friendly resin composition having excellent hollow extrusion moldability using recycled resin derived from high-density polyethylene waste, and a hollow molded product for automobile interior materials obtained therefrom.

[0008] One object of the present invention is to provide an eco-friendly resin composition suitable for carbon neutrality, which has excellent hollow extrusion moldability even when using a large amount of recycled resin derived from high-density polyethylene waste, has excellent mechanical properties, deodorizing properties, and recycled resin content recognition, and has a carbon dioxide reduction effect, and a hollow molded product for automobile interior materials obtained therefrom.

[0009] One aspect of the present invention is an eco-friendly resin composition obtained by melt blending or dry blending, comprising high-density polyethylene waste-derived recycled resin pellets and high-density polyethylene new resin pellets,

[0010] The present invention relates to an eco-friendly resin composition for a hollow molded product of an automobile interior, wherein the melting index of the above eco-friendly resin composition at 190°C and a load of 2.16 kg is MI2.16, and the melting index at 190°C and a load of 21.6 kg is MI21.6, and the MI2.16 is 0.1 to 0.5 g / 10 min, and the melting index ratio (MI21.6 / MI2.16) is 30 to 200.

[0011] In the above eco-friendly resin composition, the melting index ratio may be 30 to 200, 60 to 165, 80 to 135, or 100 to 120. Within the above range, the properties applicable to hollow molded products for automobile interiors can be satisfied.

[0012] In one aspect, the recycled resin pellets derived from high-density polyethylene waste may be pellets obtained by crushing and melting and extruding one or more waste materials selected from the group consisting of films, bottles, pallets, transport boxes, and pipes made of high-density polyethylene material discarded after use.

[0013] In one aspect, the eco-friendly resin composition may further contain a crystal nucleating agent.

[0014] In one embodiment, the crystal nucleating agent may be one or a mixture of two or more selected from the group consisting of a sorbitol-based crystal nucleating agent, a nonitol-based crystal nucleating agent, an organic acid-based crystal nucleating agent, a phenol-based crystal nucleating agent, and a phosphate ester-based crystal nucleating agent.

[0015] In one aspect, the eco-friendly resin composition may further contain an inorganic deodorant.

[0016] In one embodiment, the inorganic deodorant may be one or a mixture of two or more selected from the group consisting of porous active catalyst ceramic particles, porous zeolite particles, porous silica aerogel particles, and porous calcium silicate particles.

[0017] In one aspect, the eco-friendly resin composition may further contain a polyolefin-based elastomer.

[0018] In one embodiment, the polyolefin-based elastomer may be one or more selected from the group consisting of a polyethylene-based elastomer, a polypropylene-based elastomer, and an ethylene-propylene copolymer-based elastomer.

[0019] In one aspect, the eco-friendly resin composition may further include one or more additives selected from a heat stabilizer, an ultraviolet stabilizer, an activator, a processing aid, a compatibilizer, and a dispersant.

[0020] In one aspect, the recycled resin pellets derived from the high-density polyethylene waste and the pellets of the remaining components have different colors and can be an eco-friendly resin composition for a dry-blended hollow molded automobile interior material.

[0021] In one embodiment, the pellets of the remaining components may be pellets of one or more components selected from high-density polyethylene new resin pellets, polyethylene resin masterbatch pellets containing an inorganic deodorant, polyethylene resin masterbatch pellets containing a crystal nucleating agent, and polyolefin elastomer pellets.

[0022] In one embodiment, the content of recycled resin pellets derived from high-density polyethylene waste in the eco-friendly resin composition may be 25 to 95 wt%.

[0023] Another aspect of the present invention relates to a hollow molded automobile interior material product comprising the eco-friendly resin composition of the above aspect, which is hollow extruded.

[0024] In one aspect, the hollow molded product for automobile interior may have a flexural modulus of 1,000 MPa or more, an IZOD impact strength (23°C) of 20 kg·cm / cm or more, and an odor grade of 1 to 3 according to the Hyundai-Kia Motors standard MS300-34.

[0025] In one aspect, the hollow molded product for automobile interiors may be selected from among air ducts and connection ducts.

[0026] According to one embodiment of the present invention, an eco-friendly resin composition having excellent hollow extrusion moldability even when using a recycled resin derived from high-density polyethylene waste, and a hollow molded product for automobile interior materials obtained therefrom are provided.

[0027] In addition, the present invention can provide an eco-friendly resin composition and a hollow molded product for automobile interior materials that have excellent hollow extrusion moldability even when using a large amount of recycled resin derived from high-density polyethylene waste, and have excellent mechanical properties, deodorizing properties, and recycled resin content recognition, and are suitable for carbon neutrality that bring about a carbon dioxide reduction effect.

[0028] FIG. 1 is a photograph of an eco-friendly resin composition (10) in which two types of pellets, namely, black-colored high-density polyethylene waste-derived recycled resin pellets (11) and uncolored pellets (12) of the remaining components, are dry-blended according to one embodiment of the present invention.

[0029] 10: Eco-friendly resin composition made by dry blending two types of pellets

[0030] 11: Black-colored high-density polyethylene waste-derived recycled resin pellets

[0031] 12: Pellets of the remaining components colored non-black

[0032] The present invention is further described in detail with the accompanying examples. However, the following examples are merely references for further explanation of the present invention and are not intended to limit the present invention, which may be implemented in various forms.

[0033] Additionally, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is merely for the purpose of describing specific embodiments and is not intended to limit the invention.

[0034] Additionally, the singular forms used in the specification and the appended claims are intended to include the plural forms as well, unless the context clearly dictates otherwise.

[0035] The present invention seeks to find a solution to the mandatory use of 25% recycled plastic, consisting of 75% PCR material and 25% plastic derived from scrapped vehicles, in new vehicle manufacturing in Europe from 2031.

[0036] Plastics derived from scrapped vehicles are not economically viable due to difficulties in sorting components, and the resulting plastics are colored, hindering free coloring when recycled into automotive interior materials. Therefore, using recycled plastics derived from PCR materials could be a viable solution. However, PCR materials should be sourced from waste plastic products that are easily available in large quantities and are often disposable.

[0037] Strong candidates include products made of high-density polyethylene (HDPE). Examples include: HDPE film products, such as shopping bags and delivery envelopes, which are produced in quantities of hundreds of thousands of tons annually; HDPE bottles, such as milk bottles, shampoo bottles, detergent bottles, and motor oil bottles; HDPE transport boxes, such as HDPE pallets, soft drink boxes, and liquor boxes; and HDPE pipe waste, such as gas pipes, water and sewage pipes, and pressure pipes. As long as the waste is made of HDPE, there are no restrictions on its shape or intended use.

[0038] However, since the high-density polyethylene waste mentioned above is mostly printed in the case of film, and many of the products already have colors on the body, and these are mixed together, it is difficult to give them a consistent color, so most of the recycled resins derived from this waste are usually black.

[0039] Meanwhile, although the amount of plastic for automobiles varies depending on the vehicle, it is around 200 kg per vehicle, and high-density polyethylene is used at around 7%, or 14 kg, and its main parts include air ducts and connection ducts manufactured by hollow extrusion molding. The hollow molded products for automobiles are interior materials, but since they are invisible parts and are black, the recycled resin derived from black high-density polyethylene waste, which can be easily obtained in large quantities, can be used usefully.

[0040] When forming hollow products using melt extrusion of polymers such as high-density polyethylene, the melt index (MRI) is evaluated as a crucial tool for predicting excellent moldability, considering the rheological properties of the polymer during melting. Typically, a high molecular weight polymer has a low MRI, while a low molecular weight polymer has a high MRI. Depending on the molding method and required properties, a polymer with an appropriate MRI range is required.

[0041] From this point of view, when forming a hollow extrusion molded product using high-density polyethylene, an appropriate raw material is preferably MI2.16 of 0.1 to 0.5 g / 10 min, 0.15 to 0.45 g / 10 min, or 0.2 to 0.4 g / 10 min.

[0042] Meanwhile, the molecular weight of high-density polyethylene waste decreases somewhat due to decomposition by heat or light during use, and the molecular weight also decreases due to thermal decomposition during the process of manufacturing recycled resin pellets through crushing and melt extrusion of the waste, so the melting index tends to be higher than that of virgin resin. Accordingly, for example, the recycled resin derived from a film made of high-density polyethylene material manufactured by extrusion molding has an MI2.16 of 0.05 to 0.09 g / 10 min, the recycled resin derived from a bottle made of high-density polyethylene material manufactured by hollow extrusion molding has an MI2.16 of 0.5 to 1.0 g / 10 min, the recycled resin derived from a pallet or a transport box made of high-density polyethylene material manufactured by injection molding has an MI2.16 of 5.0 to 10 g / 10 min, and the recycled resin derived from a pipe made of high-density polyethylene material manufactured by extrusion molding has an MI2.16 of 0.05 to 0.09 g / 10 min, so that these recycled resins derived from high-density polyethylene waste can be used 100% as they are to manufacture air ducts and connection ducts by hollow extrusion molding, which normally requires an MI2.16 of 0.1 to 0.5 g / 10 min. It is difficult to manufacture the back.

[0043] Therefore, a method was attempted to manufacture a melt-blended or dry-blended resin composition by adding some high-density polyethylene virgin resin pellets instead of 100% of the high-density polyethylene waste-derived recycled resin pellets, and adjusting the MI2.16 of the resin composition to 0.1 to 0.5 g / 10 min, which is suitable for blow molding. For example, a hollow extrusion molding was attempted with a melt-blended or dry-blended resin composition of high-density polyethylene film-derived recycled resin pellets having an MI2.16 of 0.05 to 0.09 g / 10 min and high-density polyethylene virgin resin pellets having an MI2.16 of 0.5 to 1.0 g / 10 min. The composition was manufactured by changing various composition ratios, but a large number of various types of molding defects such as parison sagging and fusion, air holes, and bottom non-fusion cracks occurred periodically, frequently, or constantly. Above all, the results were uneven, that is, very irregular moldability was exhibited. Therefore, it was found that it is not suitable for hollow molded automobile parts that strongly require uniform and stable part manufacturing, and a solution to this was urgently requested. Therefore, a composition that has excellent product uniformity according to processing and does not cause the above problems stably even with slight changes in processing conditions should be manufactured, but these problems have not been solved yet. Despite these problems, the applicant made efforts to commercialize the composition, but until the present invention, the defect rate was too high, and the product uniformity was very poor even with changes in the processing machine, external conditions, or slight changes in the thermal sensor during processing.

[0044] When only high-density polyethylene virgin resin is used, even if MI2.16 is used at only 0.1 to 0.5 g / 10 min, uniform and excellent moldability is secured, but when all of the recycled resin made of high-density polyethylene material or mixed with high-density polyethylene virgin resin is used, the serious problem is that very irregular moldability is exhibited.

[0045] Accordingly, the inventors of the present invention have noted that, in the case of polymers such as high-density polyethylene, the rheological properties upon melting significantly affect not only the molecular weight of the polymer but also its molecular weight distribution, which in turn significantly influences its formability. Furthermore, they have noted that petrochemical companies manufacturing high-density polyethylene maintain excellent physical properties of their products while simultaneously ensuring excellent processability by ensuring a variety of multimodal molecular weight distributions, such as unimodal and bimodal, according to their own unique technologies.

[0046] That is, the inventors of the present invention inferred that in the case of recycled resin derived from waste high-density polyethylene material, products with various molecular weight distributions from various manufacturers are randomly mixed, and thus, in the case of high-density polyethylene using these, the moldability is very irregular during hollow extrusion molding, and conducted research to solve this problem.

[0047] To solve this problem, as a result of repeated research, in addition to the melt index, which can evaluate the rheological properties during melting as a means of predicting the moldability during hollow extrusion molding, the melt index ratio, which is closely related to the molecular weight distribution of the polymer, was introduced separately. That is, when the MI2.16 of the resin composition including the recycled resin pellets derived from high-density polyethylene waste and the virgin high-density polyethylene resin pellets is 0.1 to 0.5 g / 10 min and the melt index ratio (MI21.6 / MI2.16) is 30 to 200, 60 to 165, 80 to 135, or 100 to 120, it was recognized for the first time that excellent hollow extrusion moldability is secured, which is the first time that various types of molding defects such as parison sagging and fusion, air holes, and bottom non-fusion cracks are manufactured uniformly and stably, thereby completing the present invention.

[0048] That is, one aspect of the present invention relates to an eco-friendly resin composition for an automobile interior hollow molded product, which is obtained by melt blending or dry blending and includes recycled resin pellets derived from high-density polyethylene waste and new high-density polyethylene resin pellets, wherein the eco-friendly resin composition has an MI2.16 of 0.1 to 0.5 g / 10 min and a melt index ratio (MI21.6 / MI2.16) of 30 to 200, 60 to 165, 80 to 135, or 100 to 120.

[0049] As a specific method for obtaining a resin composition under the above conditions, for example, first, the M2.16, M21.6 and melt index ratio (MI21.6 / MI2.16) of the selected high-density polyethylene waste-derived recycled resin pellets are measured, and also the M2.16, M21.6 and melt index ratio (MI21.6 / MI2.16) of the high-density polyethylene virgin resin are measured. Then, the mixing ratio is adjusted so that the MI2.16 of the obtained resin composition is 0.1 to 0.5 g / 10 min and the melt index ratio (MI21.6 / MI2.16) is 30 to 200, 60 to 165, 80 to 135, or 100 to 120.

[0050] In some cases, the MI2.16, MI21.6 and melt index ratio (MI21.6 / MI2.16) of a plurality of high-density polyethylene waste-derived recycled resin pellets are measured and prepared, and further, the MI2.16, MI21.6 and melt index ratio (MI21.6 / MI2.16) of a plurality of high-density polyethylene virgin resins are measured, and then the combination and mixing ratio are adjusted so that the resin composition obtained has MI2.16 of 0.1 to 0.5 g / 10 min and the melt index ratio (MI21.6 / MI2.16) of 30 to 200, 60 to 165, 80 to 135, or 100 to 120.

[0051] When the above melt index and melt index ratio are satisfied at the same time, the melt flow property is excellent during hollow extrusion molding, the hollow extrusion molding speed can be increased, the parison resistance does not increase, and the surface uniformity or surface defects of the extruded molded product do not occur. In other words, when the above conditions are satisfied, defects such as parison sagging, bottom non-fusion, and cracking do not occur, and the molded product is manufactured uniformly and stably without any molding defects. In other words, excellent moldability is secured, and the blow molding extruder can be changed under the same conditions or the molded product can be stably obtained without the above defects depending on the part. In addition, when the above melt index and melt index ratio are satisfied at the same time, excellent hollow moldability can be provided even when the content of waste-derived recycled resin pellets is included at 25 wt% or more.

[0052] In one aspect of the present invention, the recycled resin pellet derived from high-density polyethylene waste refers to a pellet-shaped product obtained by crushing and melting and extruding waste products made of high-density polyethylene material that have been discarded after use, such as films, bottles, pallets, transport boxes, pipes, etc. made of high-density polyethylene material.

[0053] One aspect of the present invention may further comprise a crystal nucleating agent in the eco-friendly resin composition. The eco-friendly resin composition may further comprise a crystal nucleating agent. The inclusion of the crystal nucleating agent is preferred because it enhances formability and improves physical properties such as flexural modulus.

[0054] The above crystal nucleating agent is at least one selected from the group consisting of sorbitol-based crystal nucleating agents such as benzylidene sorbitol, dibenzylidene sorbitol, methylbenzylidene sorbitol, ethylbenzylidene sorbitol, and 3,4-dimethylbenzylidene sorbitol; nonitol-based crystal nucleating agents such as 1,2,3-trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonitol; organic acid-based crystal nucleating agents such as heptane-2,3-dicarboxylic acid disodium salt, 1,2-cyclohexanedicarboxylic acid calcium salt, zinc stearate, and sodium benzoate salt; phenol-based crystal nucleating agents such as phenolphthalein; and phosphate ester-based crystal nucleating agents.

[0055] The above crystal nucleating agent induces the formation of crystals of the recycled resin derived from high-density polyethylene waste more uniformly, thereby allowing it to have a crystallinity equivalent to or higher than that of the new high-density polyethylene resin, thereby drastically improving and excellently expressing the mechanical properties of the recycled resin derived from poor high-density polyethylene waste. Examples thereof include, but are not limited to, Millad 3988 (sorbitol acetal), Millad NX8000 (nonitol acetal) from Milliken, Hyperform HPN-68L (heptane-2,3-dicarboxylic acid disodium salt 1,2-cyclohexanedicarboxylic acid calcium salt), Hyperform HPN-20E (1,2-cyclohexanedicarboxylic acid calcium salt / stearate zinc salt (=66 / 34) mixture), and ADK STAB NA-27 (phosphate ester compound) from ADEKA, Japan.

[0056] The content of the above crystal nucleating agent is not particularly limited, but can be used in amounts of 0.001 to 1.0 parts by weight, 0.005 to 0.9 parts by weight, 0.1 to 0.8 parts by weight, or 0.2 to 0.6 parts by weight per 100 parts by weight of high-density polyethylene waste-derived recycled resin pellets. When the amount of crystal nucleating agent added is within the above range, mechanical properties such as flexural modulus are improved, and molding stability and product uniformity can be significantly improved. The crystal nucleating agent may be added as is, but it may be preferred in terms of quality uniformity to manufacture it in the form of a masterbatch using polyethylene as a carrier resin and then add it.

[0057] One aspect of the present invention may further include an inorganic deodorant in the eco-friendly resin composition.

[0058] The above inorganic deodorant is at least one selected from the group consisting of porous active catalyst ceramic particles, porous zeolite particles, porous silica aerogel particles, porous calcium silicate particles, etc., and among these, porous active catalyst ceramic particles are preferred, but are not limited thereto.

[0059] Typically, recycled resins derived from high-density polyethylene waste often have a foul odor, making them very difficult to apply to the automotive industry, which thoroughly evaluates and manages the odor and volatile organic compound (VOC) emissions of materials or parts.

[0060] Although the evaluation methods for odor and VOCs are similar for each automobile manufacturer, the standards are different. For example, Hyundai-Kia Motors, a representative automobile manufacturer, classifies odor into 6 grades according to the MS300-34 standard, and grades 1 to 3 are judged as passing. In addition, VOCs are evaluated based on the emission amount (μg / m) of 8 components: benzene, toluene, ethylbenzene, xylene, styrene, formaldehyde, acetaldehyde, and achlorane according to the MS300-34 (material) and MS300-55 (part) standards. 3) and only those that are all within the management values ​​for each compound are judged as passing. Based on the above criteria, there is a risk that the recycled resin derived from high-density polyethylene waste will be judged as failing, and therefore the inorganic deodorant of the present invention can be a powerful solution.

[0061] The above porous active catalyst ceramic particles are particles in which an active catalyst component is supported on a porous ceramic carrier, and can more effectively remove odor-causing factors by adsorbing low-molecular substances and impurities and then decomposing them with the supported active catalyst. Examples of the above porous active catalyst ceramic particles include, but are not limited to, KESMON (average particle size 0.1 to 3.0 μm) manufactured by Dongwha Synthetic Co., Ltd. in Japan, and SmellCut (average particle size 0.5 to 2.0 μm) manufactured by Shin-A Chemical Co., Ltd.

[0062] The content of the above inorganic deodorant may be 0.1 to 10 parts by weight, 0.5 to 8 parts by weight, 1 to 7 parts by weight, or 2 to 5 parts by weight per 100 parts by weight of the recycled resin derived from high-density polyethylene waste. The inorganic deodorant may be injected as is, but it is better in terms of quality uniformity to manufacture it in the form of a masterbatch using polyethylene as a carrier resin and then insert it.

[0063] In one aspect of the present invention, the eco-friendly resin composition may further contain a polyolefin elastomer as needed.

[0064] The above polyolefin-based elastomer is very effective in improving the impact resistance of the eco-friendly resin composition, but if too much is used, there is a problem of the flexural modulus decreasing, so it is necessary to add an appropriate amount. The polyolefin-based elastomer may include, but is not limited to, a polyethylene-based elastomer, a polypropylene-based elastomer, an ethylene-propylene copolymer-based elastomer, and the like. The content of the polyolefin-based elastomer may be added to the eco-friendly resin composition in an amount of 0.01 to 20 wt%, 0.1 to 10 wt%, 2 to 10 wt%, or 4 to 7 wt%, but is not limited thereto.

[0065] In one embodiment of the present invention, the resin composition may further contain conventional additives, for example, one or a mixture of two or more selected from a heat stabilizer, an ultraviolet stabilizer, a lubricant, a processing aid, a compatibilizer, a dispersant, etc. It is preferable to use the additives in a range that does not deteriorate the physical properties and appearance characteristics of the resin composition, and may be added to the resin composition in an amount of 0.001 to 3 wt%, but is not limited thereto.

[0066] Recently, in Europe, along with mandatory regulations requiring the use of recycled resin, there has been a growing demand for methods for easily identifying the amount of recycled resin used. As a solution to this, one embodiment of the present invention comprises a resin composition for hollow molded automotive interior parts, wherein the pellets of recycled resin derived from high-density polyethylene waste and the pellets of the remaining components have different colors and are dry-blended.

[0067] Here, the pellets of the remaining components may be an eco-friendly resin composition for an automobile interior hollow molded product, which further includes at least one selected from high-density polyethylene new resin pellets, polyethylene resin masterbatch pellets containing an inorganic deodorant, polyethylene resin masterbatch pellets containing a crystal nucleating agent, and polyolefin elastomer pellets.

[0068] Pellets of the remaining components can be conveniently manufactured in the form of a single pellet by gathering desired components. For example, as can be seen in the appearance of the resin composition pellet (10) in which the black-colored high-density polyethylene waste-derived recycled resin pellet (11) and the non-black-colored pellets (12) of the remaining components are dry-blended, the recycled resin content can be very simply and easily recognized by the color difference.

[0069] In addition, the pellets of the remaining components may be composed of two or more pellets to take advantage of the characteristics of the components, and the color of the pellets of the remaining components may be any color as long as they are different from the color of the high-density polyethylene waste-derived recycled resin pellets and can be distinguished with the naked eye.

[0070] In the present invention, the color of the high-density polyethylene waste-derived recycled resin pellets or pellets of the remaining components can be imparted by adding a certain amount of pigment or dye.

[0071] Examples of the pigments include organic pigments such as carbon black, graphite, inactive azo pigments, activated azo pigments, copper phthalocyanine pigments, lake pigments, quinatoridone pigments, dioxazine pigments, and condensed azo pigments; inorganic pigments such as titanium oxide, titanium yellow, chromium oxide, yellow lead, calcium carbonate, barium sulfate, magnesium carbonate, and aluminum oxide; and dyes such as oil-soluble dyes and dispersible dyes. It is preferable to use the pigments in a range that does not deteriorate the physical properties and appearance characteristics of the resin composition, and may be added to the resin composition in an amount of 0.001 to 5 wt%, but is not limited thereto.

[0072] In one embodiment of the present invention, the content of the recycled resin derived from high-density polyethylene waste in the eco-friendly resin composition may be 25 to 95 wt%, 30 to 90 wt%, or 35 to 75 wt%, but there is no limitation on the content. However, the Enforcement Decree of the Act on Promotion of Saving and Recycling of Resources stipulates that "recycled products" are automobile parts with a recycled resin content of 25 wt% or more, so it is preferable that the content of the recycled resin derived from high-density polyethylene waste is added in an amount of 25 wt% or more, preferably 50 wt% or more, but if it exceeds 95 wt%, the economic efficiency is excellent, but it may be difficult to secure the desired mechanical properties.

[0073] The present invention may be an eco-friendly automobile interior hollow molded product manufactured by hollow extrusion molding using the above eco-friendly resin composition, and specifically may be an air duct, a connection duct, etc.

[0074] In addition, the hollow molded product for automotive interiors according to one aspect of the present invention may have a flexural modulus of 1,000 MPa or more, 1200 MPa or more, or 1400 MPa or more. In addition, the IZOD impact strength (23°C) may be 20 kg·cm / cm or more, 25 kg·cm / cm or more, or 30 kg·cm / cm or more. In addition, the hollow molded product for automotive interiors may have an odor grade of 1 to 3 or lower according to the Hyundai-Kia Motors standard MS300-34.

[0075] Below, examples are provided to specifically illustrate the present invention, but the present invention is not limited to these examples. Furthermore, measurements in the following examples and comparative examples were conducted as follows.

[0076] (1) Melting index (MI) and melting index ratio (MI21.6 / MI2.16)

[0077] The melting index MI2.16 at 190℃ and 2.16kg load of the resin composition and the melting index MI21.6 at 190℃ and 21.6kg load were measured according to ASTM D1238, and the melting index ratio (MI21.6 / MI2.16) was obtained from these.

[0078] (2) Formability

[0079] According to the level of occurrence of molding defects such as parison fusion, air holes, and bottom non-fusion cracks that may occur during hollow extrusion molding of resin compositions, the moldability was evaluated into 5 grades as shown in Table 1.

[0080] Classification ◎◎(Extremely good)◎(Excellent)○(Good)△(Average)X(Poor)Defective molding degreeNoneExtremely minimalAlmost noneSomewhat very severe

[0081] (3) Flexural modulus

[0082] As one of the measures of mechanical properties, the flexural modulus (MPa) was measured according to ASTM D790 and evaluated into 5 grades as shown in Table 2.

[0083] Classification ◎◎(Extremely good) ◎(Excellent) ○(Good) △(Average) X(Poor) Flexural modulus (MPa) 1,400 or more 1,200 or more less than 1,400 1,000 or more less than 1,200 700 or more less than 1,000 Less than 700

[0084] (4) 23℃ IZOD impact strength As one of the scales of mechanical properties, 23℃ IZOD impact strength (Kg·cm / cm) was measured according to ASTM D256 and evaluated into 5 grades as shown in Table 3.

[0085] Classification ◎◎(Extremely good) ◎(Excellent) ○(Good) △(Average) X(Poor) 23℃ IZOD Impact strength (Kg·cm / cm) 30 or more 25 or more less than 30 20 or more less than 25 15 or more less than 20 Less than 15

[0086] (5) As one of the measures of odor deodorization, the degree of odor generation for hollow extrusion molded specimens was evaluated into 6 grades as shown in Table 4 based on the Hyundai-Kia Motors standard MS300-34. Grades 1 to 3 were judged as ‘suitable’, and grades 4 to 6 were judged as ‘unsuitable’.

[0087] Grade Odor Occurrence Level 1 No Odor 2 Cannot tell what it is, but can feel the smell 3 Weakly detectable odor, but can tell what it is 4 Easily detectable odor 5 Very strong odor 6 Intense odor that is difficult to tolerate and causes breathing difficulties

[0088] (6) As one of the measures of VOC deodorization, the level of VOCs generation in hollow extrusion molded specimens was evaluated according to the criteria in Table 5 based on the Hyundai-Kia Motors standard MS300-55. When all criteria for VOCs were passed, it was judged as ‘suitable.’

[0089] VOCs unit standard benzene μg / m 2 Toluene below 30 μg / m 2 Less than 1,000 μg / m of ethylbenzene 2 Less than 1,000 μg / m 2 870 or less styrene μg / m 2 220 or less formaldehyde μg / m 2 210 or less acetaldehyde μg / m 2 300 or less achlorane μg / m 2 50 or less

[0090] (7) 300g of pellet samples of the recycled resin content-recognizable resin composition were collected and classified by pellet color. If the content of recycled resin derived from high-density polyethylene waste could be visually recognized, it was judged as ‘suitable’, and if not, it was judged as ‘unsuitable’.

[0091] [Example 1]

[0092] High-density polyethylene shopping bags, delivery bags, etc. are separated and collected by a recycling company and processed through a melt extrusion process to obtain MI2.16 of 0.08 g / 10min, MI21.6 of 1.6 g / 10min, MI21.6 / MI2.16 of 20, and density of 0.960 g / cm. 3 High-density polyethylene recycled resin pellets (RPE-A) were prepared. Carbon black (CB), a black pigment, was prepared. In addition, MI2.16 had a viscosity of 0.35 g / 10 min, MI21.6 had a viscosity of 14.9 g / 10 min, MI21.6 / M2.16 had a viscosity of 43 g / 10 min, and the density was 0.960 g / cm. 3 High-density polyethylene new resin pellets (Lotte Chemical 6200B, PE-A) were prepared.

[0093] A resin composition was prepared by melt extrusion in a twin-screw extruder using the blending ratios shown in Table 6. The MI2.16 and MI21.6 of the obtained resin compositions were measured, and the melt index ratio (MI21.6 / MI2.16) was derived from these measurements. In addition, the flexural modulus and IZOD impact strength were measured, and the results are shown in Table 7.

[0094] In addition, the hollow extrusion moldability of the obtained resin composition was evaluated using a hollow extrusion molding machine, and the results are shown in Table 7.

[0095] [Example 2]

[0096] A recycling company collects, crushes, washes, and dries high-density polyethylene water pipes, and through a melt extrusion process, produces a melt index MI2.16 of 0.07 g / 10 min, MI21.6 of 12.4 g / 10 min, MI21.6 / MI2.16 of 177, and a density of 0.961 g / cm at 190℃ and 2.16 kg load. 3 High-density polyethylene recycled resin pellets (RPE-B) were prepared. The same procedure as Example 1 was followed, except that the composition ratio was changed to that shown in Table 6, and the results are shown in Table 7.

[0097] [Example 3]

[0098] The recycling company separates, collects, crushes, washes and dries high-density polyethylene milk bottles and processes them through a melt extrusion process to obtain MI2.16 of 0.7 g / 10 min, MI21.6 of 63.8 g / 10 min, MI21.6 / MI2.16 of 91, and density of 0.957 g / cm. 3 High-density polyethylene recycled resin pellets (RPE-C) were prepared. MI2.16 was 0.05 g / 10 min, MI21.6 was 4.5 g / 10 min, MI21.6 / MI2.16 was 90, and the density was 0.956 g / cm 3 High-density polyethylene new resin pellets (Hanwha Total F120A, PE-B) were prepared. The same procedure as Example 1 was followed except that the composition ratio was changed to that shown in Table 6, and the results are shown in Table 7.

[0099] [Example 4]

[0100] The recycling company collects, crushes, washes, and dries mixed waste materials such as milk bottles, shampoo bottles, and motor oil bottles made of high-density polyethylene, and processes them through a melt extrusion process to produce MI2.16 of 0.62 g / 10 min, MI21.6 of 65.9 g / 10 min, MI21.6 / MI2.16 of 106, and density of 0.955 g / cm. 3 High-density polyethylene recycled resin pellets (RPE-D) were prepared. The same procedure as Example 1 was followed, except that the composition ratio was changed to that shown in Table 6, and the results are shown in Table 7.

[0101] [Example 5]

[0102] The recycling company collects, crushes, washes, and dries waste mixed with high-density polyethylene material such as water pipes, gas pipes, shampoo bottles, and motor oil bottles, and through the melt extrusion process, produces waste with MI2.16 of 0.44 g / 10 min, MI21.6 of 75.0 g / 10 min, MI21.6 / MI2.16 of 170, and density of 0.955 g / cm. 3High-density polyethylene recycled resin pellets (RPE-E) were prepared. MI2.16 was 0.27 g / 10 min, MI21.6 was 10.3 g / 10 min, MI21.6 / MI2.16 was 38, and the density was 0.945 g / cm 3 High-density polyethylene new resin pellets (Lotte Chemical 4100M, PE-C) were prepared. The same procedure as Example 1 was followed except that the composition ratio was changed to that shown in Table 6, and the results are shown in Table 7.

[0103] [Example 6]

[0104] The recycling company collects, crushes, washes and dries high-density polyethylene pallets and boxes, and then processes them through a melt extrusion process to produce MI2.16 of 5.5 g / 10 min, MI21.6 of 774 g / 10 min, MI21.6 / MI2.16 of 141, and density of 0.955 g / cm. 3 High-density polyethylene recycled resin pellets (RPE-F) were prepared. In addition, the same procedure as Example 1 was performed except that the composition ratio was changed to that described in Table 6, and the results are shown in Table 7.

[0105] [Example 7]

[0106] MI2.16 is 0.55 g / 10min, MI21.6 is 114.7 g / 10min, MI21.6 / MI2.16 is 208, and density is 0.960 g / cm 3 High-density polyethylene new resin pellets (Daehan Yuhwa, HT306, PE-D) were prepared. In addition, the same procedure as Example 1 was performed except that the composition ratio was changed to that described in Table 6, and the results are shown in Table 7.

[0107] [Example 8]

[0108] The recycling company collects, crushes, washes, and dries waste mixed with high-density polyethylene material such as sewage pipes, wire pipes, detergent bottles, and shampoo bottles, and through the melt extrusion process, produces waste with MI2.16 of 0.35 g / 10 min, MI21.6 of 62.7 g / 10 min, MI21.6 / MI2.16 of 179, and density of 0.952 g / cm. 3 High-density polyethylene recycled resin pellets (RPE-G) were prepared. The same procedure as Example 1 was followed, except that the composition ratio was changed to that shown in Table 6, and the results are shown in Table 7.

[0109] [Example 9]

[0110] The recycling company collects, crushes, washes, and dries waste mixed with high-density polyethylene bottles and detergent bottles, and through the melt extrusion process, produces bottles with MI2.16 of 0.69 g / 10 min, MI21.6 of 73.2 g / 10 min, MI21.6 / MI2.16 of 106, and density of 0.956 g / cm. 3 High-density polyethylene recycled resin pellets (RPE-H) were prepared. Sorbitol acetal (Milliken Millad 3988, NA-A) was prepared as a crystal nucleating agent. The same procedure as Example 1 was followed except that the composition ratio was changed to that shown in Table 6, and the results are shown in Table 7.

[0111] [Example 10]

[0112] Example 1 was performed in the same manner as Example 1 except that the composition ratio was changed to that described in Table 6, and the results are shown in Table 7.

[0113] [Comparative Example 1]

[0114] Example 1 was performed in the same manner as Example 1 except that the composition ratio was changed to that described in Table 6, and the results are shown in Table 7.

[0115] [Comparative Example 2]

[0116] Example 1 was performed in the same manner as Example 1 except that the composition ratio was changed to that described in Table 6, and the results are shown in Table 7.

[0117] [Comparative Example 3]

[0118] The recycling company collects, crushes, washes, and dries mixed waste such as shopping bags, delivery bags, pill bottles, and powder detergent bottles made of high-density polyethylene, and processes them through a melt extrusion process to produce a MI2.16 of 0.19 g / 10 min, MI21.6 of 2.7 g / 10 min, MI21.6 / MI2.16 of 14.2, and a density of 0.957 g / cm. 3 High-density polyethylene recycled resin pellets (RPE-I) derived from human bottles were prepared. The same procedure as Example 1 was followed, except that the composition ratio was changed to that shown in Table 6, and the results are shown in Table 7.

[0119] [Comparative Example 4]

[0120] The recycling company collects, crushes, washes, and dries mixed waste such as high-density polyethylene water pipes, sewage pipes, gas pipes, milk bottles, and water containers, and through the melt extrusion process, produces waste with MI2.16 of 0.32 g / 10 min, MI21.6 of 69.2 g / 10 min, MI21.6 / MI2.16 of 216, and density of 0.961 g / cm. 3 High-density polyethylene recycled resin pellets (RPE-J) were prepared. The same procedure as Example 1 was followed, except that the composition ratio was changed to that described in Table 6, and the results are shown in Table 7.

[0121] [Comparative Example 5]

[0122] A recycled resin company collected, crushed, washed, and dried mixed waste of high-density polyethylene material such as cans, distilled water bottles, and pill bottles, and prepared high-density polyethylene recycled resin pellets (RPE-K) with MI2.16 of 0.93 g / 10 min, MI21.6 of 235.5 g / 10 min, MI21.6 / MI2.16 of 253, and density of 0.952 g / cm3 through a melt extrusion process. The same procedure as Example 1 was followed except that the composition ratio was changed to that described in Table 6, and the results are shown in Table 7.

[0123] Classification High-density polyethylene waste-derived recycled resin pigment High-density polyethylene new resin crystal nucleating agent Example 1 RPE-A 70 wt% CB 0.1 wt% PE-A 29.9 wt% Example 2 RPE-B 50 wt% CB 0.1 wt% PE-A 48.9 wt% Example 3 RPE-C 40 wt% CB 0.2 wt% PE-B 59.8 wt% Example 4 RPE-D 35 wt% CB 0.2 wt% PE-B 64.8 wt% Example 5 RPE-E 45 wt% CB 0.2 wt% PE-C 54.8 wt% Example 6 RPE-A 53 wt% RPE-F 7 wt% CB 0.2 wt% PE-B 39.8 wt% Example 7 RPE-B 40 wt% RPE-C 20 wt% CB 0.2 Weight %PE-D 39.8 Weight %Example 8 RPE-G 70 Weight %CB 0.2 Weight %PE-B 29.8 Weight %Example 9 RPE-B 30 Weight %RPE-H 30 Weight %CB 0.2 Weight %PE-B 39.5 Weight %NA-A 0.3 Weight %Example 10 RPE-A 69.7 Weight %CB 0.1 Weight %PE-A 29.9 Weight %NA-A 0.3 Weight %Comparative Example 1 RPE-A 40 Weight %RPE-B 30 Weight %CB 0.2 Weight %PE-B 29.8 Weight %Comparative Example 2 RPE-A 48 Weight %RPE-F 12 Weight %CB 0.2 Weight %PE-A 39.8 Weight %Comparative Example 3 RPE-I 50 Weight %CB 0.1 Weight %PE-C 49.9 Weight %Comparative Example 4 RPE-J 75 Weight %CB0.1 Weight %PE-D24.9 Weight %Comparative Example 5RPE-K 70 Weight %CB0.1 Weight %PE-D29.9 Weight %

[0124] Melt indexMI21.6 / MI2.16FormabilityMechanical propertiesMI2.16MI21.6Flexural modulusIZOD impact strengthExample 10.165.635○○○Example 20.2013.869◎~○○○Example 30.3228.288◎◎○Example 40.2526.0104◎◎◎◎○Example 50.3439.4116◎◎◎◎○Example 60.4559.4132◎◎○Example 70.3963.6163◎~○○○Example 80.4178.3191○○○Example 90.2527.5110◎◎◎◎◎Example 100.165.735.6◎○○Comparative example 10.075.781△△XComparative example 20.84100119△XXComparative example 30.236.528XXXComparative example 40.3780.6218XXXComparative example 50.70163233XXX

[0125] [Example 11]

[0126] A recycling resin company collects, crushes, washes, and dries waste mixed with high-density polyethylene water pipes, sewer pipes, and gas pipes, and through a melt extrusion process, produces MI2.16 of 0.07 g / 10 min, MI21.6 of 23.7 g / 10 min, MI21.6 / MI2.16 of 339, and density of 0.957 g / cm. 3 High-density polyethylene recycled resin pellets (RPE-L) were prepared. Nonitol acetal (Milliken Millad NX8000, NA-B) was prepared as a crystal nucleating agent, and porous active catalyst ceramic particles (Nippon Dowa Synthetic Co., Ltd., trade name: KESMON, PCP-A) with an average particle size of 1.2 μm were prepared as an inorganic deodorant. The same procedure as Example 1 was performed except that the composition ratio in Example 1 was changed to that shown in Table 8 and the deodorizing property was additionally evaluated, and the results are shown in Table 9.

[0127] [Example 12]

[0128] The recycling company collects, crushes, washes, and dries mixed waste such as high-density polyethylene bottles, detergent bottles, and shampoo bottles, and then processes them through a melt extrusion process to produce bottles with MI2.16 of 0.71 g / 10 min, MI21.6 of 81.6 g / 10 min, MI21.6 / MI2.16 of 115, and a density of 0.955 g / cm. 3 High-density polyethylene recycled resin pellets (RPE-M) were prepared. A mixture of 1,2-cyclohexanedicarboxylic acid calcium salt / zinc stearate (=66 / 34) (Milliken Hyperform HPN-20E, NA-C) was prepared as a crystal nucleating agent, and porous silica aerogel particles (JIOS Aerogel, trade name JIOS AeroVa, PCP-B) with an average particle size of 3.5 μm were prepared as an inorganic deodorant. As a polyolefin elastomer, MI2.16 was 0.1 g / 10 min, MI21.6 was 15.8 g / 10 min, MI21.6 / MI2.16 was 158, and the density was 0.868 g / cm 3 Polyethylene elastomer pellets (SK Geocentric, Solumer 871, PEE-A) were prepared. The same procedure as in Example 7 was followed except that the composition ratio was changed to that shown in Table 8, and the results are shown in Table 9.

[0129] Classification High-density polyethylene waste-derived recycled resin pigment High-density polyethylene new resin Crystallization nucleating agent Inorganic deodorant Polyolefin elastomer Example 11 RPE-L55 wt% CB0.1 wt% PE-A4 2.6 wt% NA-B0.3 wt% PCP-A 2 wt% - Example 12 RPE-M45 wt% CB0.2 wt% PE-B4 5.6 wt% NA-C0.2 wt% PCP-B 2 wt% PEE-A7 wt%

[0130] Melt index MI21.6 / MI2.16 Formability Mechanical properties Deodorization MI2.16MI21.6 Flexural modulus IZOD Impact strength Odor VOCs Example 110.1919.4102◎◎◎◎◎SuitableSuitable Example 120.3539.9114◎◎◎◎◎SuitableSuitable

[0131] [Example 13]

[0132] The recycling company collects, crushes, washes, and dries waste mixed with high-density polyethylene bottles, detergent bottles, and water bottles, and then processes them through a melt extrusion process to produce MI2.16 of 0.58 g / 10 min, MI21.6 of 76.3 g / 10 min, MI21.6 / MI2.16 of 132, and density of 0.954 g / cm. 3 High-density polyethylene recycled resin pellets (RPE-N) were prepared. A mixture of calcium 1,2-cyclohexanedicarboxylic acid / zinc stearate (=66 / 34) (Milliken Hyperform HPN-20E, NA-C) was prepared as a crystal nucleating agent. The recycled resin derived from high-density polyethylene waste and the pigments listed in Table 10 were mixed and extruded in a twin-screw extruder to obtain black-colored pellets of the recycled resin derived from high-density polyethylene waste. In addition, the high-density polyethylene virgin resin, crystal nucleating agent, inorganic deodorant, and polyolefin elastomer listed in Table 10 were mixed and extruded in a twin-screw extruder to obtain pellets of the remaining uncolored components. The obtained black-colored pellets of the recycled resin derived from high-density polyethylene waste and the pellets of the remaining components were dry blended to obtain final resin composition pellets as shown in Fig. 1. The same procedure as Example 7 was performed except that the recognition of the content of the recycled resin was additionally evaluated, and the results are shown in Table 9.

[0133] [Example 14]

[0134] A recycling resin company collects, crushes, washes, and dries waste mixed with high-density polyethylene material such as drinking straws, makgeolli bottles, and medicine bottles, and through a melt extrusion process produces a MI2.16 of 0.92 g / 10 min, MI21.6 of 150.0 g / 10 min, MI21.6 / MI2.16 of 163, and a density of 0.958 g / cm. 3High-density polyethylene recycled resin pellets (RPE-O) were prepared. Phosphate ester compounds (ADK STAB NA-27, NA-D, ADEKA, Japan) were prepared as crystal nucleating agents. As polyolefin elastomers, MI2.16 was 0.1 g / 10 min, MI21.6 was 17.2 g / 10 min, MI21.6 / MI2.16 was 172, and the density was 0.857 g / cm. 3 Polyethylene elastomer pellets (SK Geocentric, Solumer 851T, PEE-B) were prepared. The same procedure as Example 9 was followed except that the composition ratio was changed to that shown in Table 10, and the results are shown in Table 11.

[0135] Classification High-density polyethylene waste-derived recycled resin pigment High-density polyethylene new resin Crystallization nucleating agent Inorganic deodorant Polyolefin elastomer Example 13 RPE-A 50 wt% RPE-N 25 wt% CB 0.1 wt% PE-A 16.6 wt% NA-C 0.3 wt% PCP-A 2 wt% PEE-A 6 wt% Example 14 RPE-A 40 wt% RPE-C 20 wt% CB 0.2 wt% PE-C 33.6 wt% NA-D 0.2 wt% PCP-B 2 wt% PEE-B 4 wt%

[0136] Melt indexMI21.6 / MI2.16FormabilityMechanical propertiesDeodorizationRecycled resin contentPerceptibilityMI2.16MI21.6Flexural modulusIZOD Impact strengthOdorVOCsExample 130.2523.393◎◎◎◎◎◎SuitableSuitableSuitableExample 140.3134.7112◎◎◎◎◎◎SuitableSuitable

[0137] As can be seen in Examples 1 to 10, an eco-friendly resin composition comprising recycled resin pellets derived from high-density polyethylene waste and virgin high-density polyethylene resin pellets obtained by melt blending, having an MI2.16 of 0.1 to 0.5 g / 10 min and a melt index ratio (MI21.6 / MI2.16) of 30 to 200, exhibits excellent hollow extrusion moldability and mechanical properties suitable for hollow molded automobile interior parts. In particular, as can be seen in Example 9, a resin composition with more crystal nucleating agents added exhibits even better flexural modulus, and when more crystal nucleating agents are added as in Example 10, the moldability is significantly improved compared to Example 1 with the same composition. In addition, when comparing the formability and mechanical properties in Examples 1 to 8, it was confirmed that the melt index ratio (MI21.6 / MI2.16) was the most excellent in the range of 90 to 120 (Examples 4 and 5), the range of 70 to 90 (Example 3) or the range of 120 to 140 (Example 6) was next best, the range of 50 to 70 (Example 2) or the range of 140 to 170 (Example 7) was next best, and the range of 30 to 50 (Example 1) or the range of 170 to 200 (Example 8) was next best. As such, it can be seen that the formability and mechanical properties greatly vary depending on the melt index ratio (MI21.6 / MI2.16), and the present invention, which suggests optimal conditions, can be said to have distinctive creativity and groundbreaking progress. On the other hand, as can be seen in Comparative Examples 1 and 2, when the melt index ratio (MI21.6 / MI2.16) is in the range of 30 to 200, but MI2.16 is outside the range of 0.1 to 0.5 g / 10 min, or as can be seen in Comparative Examples 3 and 4, when the melt index ratio (MI21.6 / MI2.16) is in the range of 0.1 to 0.5 g / 10 min, but MI2.16 is outside the range of 30 to 200, or as can be seen in Comparative Example 5, when MI2.16 is in the range of 0.1 to 0.It can be seen that when the melt index ratio (MI21.6 / MI2.16) is outside the range of 5 g / 10 min and also outside the range of 30 to 200, the hollow extrusion moldability is poor and the hollow molded product for automobile interior materials does not have mechanical properties suitable for the hollow molded product.

[0138] As can be seen in Example 11, it can be seen that the flexural modulus and deodorizing properties are further improved in the case of a resin composition to which a crystal nucleating agent and an inorganic deodorizing agent are further added, and as can be seen in Example 12, it can be seen that the flexural modulus, deodorizing properties, and impact resistance are further improved in the case of a resin composition to which a crystal nucleating agent, an inorganic deodorizing agent, and a polyolefin elastomer are further added.

[0139] As can be seen in Examples 13 and 14, an eco-friendly resin composition comprising high-density polyethylene waste-derived recycled resin pellets and high-density polyethylene virgin resin pellets obtained by dry blending has excellent hollow extrusion moldability and excellent recycled resin content recognition when MI2.16 is 0.1 to 0.5 g / 10 min and melt index ratio (MI21.6 / MI2.16) is 30 to 200, and further, it can be seen that the flexural modulus, deodorization property, and impact resistance are very excellent when a crystal nucleating agent, an inorganic deodorant, and a polyolefin elastomer are further added.

[0140] As described above, the present invention has been described through specific matters and limited examples, but these are provided only to help a more general understanding of the present invention, and the present invention is not limited to the above examples, and those skilled in the art to which the present invention pertains can make various modifications and variations based on this description.

[0141] Therefore, the idea of ​​the present invention should not be limited to the described embodiments, and all things that are equivalent or equivalent to the following claims as well as the claims are considered to fall within the scope of the idea of ​​the present invention.

[0142] This invention is a result of the following national research and development project.

[0143] ① Project Unique Number (Unique number assigned by NTIS): 2420006244

[0144] ② Assignment number (detailed assignment number): RS-2024-00508682

[0145] ③ Ministry name: Ministry of SMEs and Startups

[0146] ④ Research Management Specialist Agency: Small and Medium Business Technology Information Promotion Agency

[0147] ⑤ Research Project Name: Small and Medium Enterprise Technology Innovation Development Project (Scale-up Tips R&D)

[0148] ⑥ Research Project Name: Development of new eco-friendly PP materials using HDPE recycled resin with high recycled resin content for automotive interiors

[0149] ⑦ Host organization: Anychem Co., Ltd.

[0150] ⑧ Research Period: September 1, 2024 - August 31, 2027

Claims

1. An eco-friendly resin composition obtained by melt blending or dry blending and including high-density polyethylene waste-derived recycled resin pellets and high-density polyethylene new resin pellets, An eco-friendly resin composition for hollow molded automobile interior parts, wherein the melting index of the above eco-friendly resin composition at 190°C and a load of 2.16 kg is MI2.16, and the melting index at 190°C and a load of 21.6 kg is MI21.6, and the MI2.16 is 0.1 to 0.5 g / 10 min, and the melting index ratio (MI21.6 / MI2.16) is 30 to 200.

2. In paragraph 1, The above high-density polyethylene waste-derived recycled resin pellets are an eco-friendly resin composition for hollow molded automobile interior parts, which are pellets obtained by crushing and melting and extruding one or more waste materials selected from the group consisting of films, bottles, pallets, transport boxes, and pipes made of high-density polyethylene material discarded after use.

3. In paragraph 1, The above eco-friendly resin composition is an eco-friendly resin composition for hollow molded automobile interior parts, which further contains a crystal nucleating agent.

4. In paragraph 3, An eco-friendly resin composition for hollow molded automobile interior parts, wherein the crystal nucleating agent is one or a mixture of two or more selected from the group consisting of a sorbitol-based crystal nucleating agent, a nonitol-based crystal nucleating agent, an organic acid-based crystal nucleating agent, a phenol-based crystal nucleating agent, and a phosphate ester-based crystal nucleating agent.

5. In paragraph 1, The above eco-friendly resin composition is an eco-friendly resin composition for hollow molded automobile interior parts, which further contains an inorganic deodorant.

6. In paragraph 5, The above-mentioned inorganic deodorant is an eco-friendly resin composition for hollow molded automobile interior parts, which is a mixture of one or two or more selected from the group consisting of porous active catalyst ceramic particles, porous zeolite particles, porous silica aerogel particles, and porous calcium silicate particles.

7. In paragraph 1, The above eco-friendly resin composition is an eco-friendly resin composition for hollow molded automobile interior parts, which further contains a polyolefin-based elastomer.

8. In paragraph 7, The above polyolefin-based elastomer is an eco-friendly resin composition for a hollow molded product of an automobile interior, wherein the polyolefin-based elastomer is one or more selected from the group consisting of a polyethylene-based elastomer, a polypropylene-based elastomer, and an ethylene-propylene copolymer-based elastomer.

9. In paragraph 1, The above eco-friendly resin composition further contains one or more additives selected from pigments, heat stabilizers, UV stabilizers, lubricants, processing aids, commercializing agents, and dispersing agents.

10. In paragraph 1, An eco-friendly resin composition for hollow molded automobile interior parts, wherein the pellets of the recycled resin derived from the above high-density polyethylene waste and the pellets of the remaining components have different colors and are dry-blended.

11. In paragraph 10, An environmentally friendly resin composition for hollow molded automobile interior parts, wherein the pellets of the remaining components are pellets of one or more components selected from high-density polyethylene new resin pellets, polyethylene resin masterbatch pellets containing an inorganic deodorant, polyethylene resin masterbatch pellets containing a crystal nucleating agent, and polyolefin elastomer pellets.

12. In paragraph 1, An eco-friendly resin composition for hollow molded automobile interior parts, wherein the content of recycled resin pellets derived from high-density polyethylene waste in the eco-friendly resin composition is 25 to 95 wt%.

13. A hollow molded automobile interior material product comprising an eco-friendly resin composition selected from any one of clauses 1 to 12, which is hollow extruded.

14. In paragraph 13, The above-mentioned hollow molded automobile interior material is an automobile interior material hollow molded automobile product having a flexural modulus of 1,000 MPa or more, an IZOD impact strength (23℃) of 20 kg·cm / cm or more, and an odor grade of 1 to 3 according to the Hyundai-Kia Motors standard MS300-34.

15. In paragraph 13, The above-mentioned hollow molded product for automobile interiors is an automobile interiors hollow molded product selected from air ducts and connection ducts.

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