High-gloss resin composition having excellent balance between rigidity and impact resistance, method for preparing same, and article comprising same

Abstract

The present invention relates to a high-gloss resin composition having an excellent balance between rigidity and impact resistance, a method for preparing same, and an article comprising same and, more specifically, to a resin composition, a method for preparing same, and an article comprising same, wherein, by comprising, in combination, an ethylene-propylene block copolymer having specific physical properties and high-density polyethylene at a specific weight ratio, the resin composition has an excellent balance between rigidity and impact resistance and exhibits excellent gloss, and thus can be very suitably used for pipe applications, in particular, non-pressure sewage pipes or drain pipes.

Description

High-gloss resin composition with excellent balance between rigidity and impact resistance, method of manufacturing the same, and article containing the same

[0001] The present invention relates to a high-gloss resin composition having an excellent balance between stiffness and impact resistance, a method for manufacturing the same, and an article containing the same. More specifically, by combining an ethylene-propylene block copolymer having specific physical properties and high-density polyethylene in a specific weight ratio, the invention relates to a resin composition having an excellent balance of stiffness and impact resistance and exhibiting excellent gloss, which can be very suitable for pipe applications, particularly for non-pressure sewer pipes or drainage pipes, a method for manufacturing the same, and an article containing the same.

[0002] Polypropylene resin, a type of general-purpose resin, is widely used as a material for films, pipes, automotive interior and exterior parts, electrical and home appliance components, and construction and industrial materials due to its excellent economic efficiency, mechanical properties, moldability, and chemical resistance.

[0003] In particular, polypropylene resin is lightweight and has excellent chemical and heat resistance, making it widely used for various pipe applications. For instance, it is used for transporting fluids or powders, as well as for buried pipes and protecting indoor electrical wires and cables.

[0004] When polypropylene resin is used for pipes, particularly as non-pressure pipes for sewage or drainage purposes, a balance between stiffness and impact resistance is crucial. Since non-pressure sewer pipes, which are generally buried underground, are subjected to pressure from ground loads, stiffness is important for durability. Additionally, impact resistance is essential to absorb shocks applied to the ground; furthermore, impact strength at low temperatures is critical, especially during winter, as exposure to low temperatures can make pipes more vulnerable.

[0005] Furthermore, gloss is an important characteristic for polypropylene resin compositions used in sewer and drainage pipes in terms of functionality and maintenance. Pipes with high gloss have a smooth inner surface, which reduces frictional resistance to fluid flow, thereby enabling efficient flow management. Additionally, it reduces blockage caused by contaminants or sediment adhering to the pipe walls and decreases the frequency of maintenance. Moreover, high-gloss pipes have fewer surface defects, which can reduce the risk of cracking or breakage during installation.

[0006] In polypropylene resin compositions for sewer and drainage pipes, inorganic fillers such as talc, glass fiber, and calcium carbonate are sometimes added to improve the physical properties required for the pipe. For example, U.S. Patent Publication No. 2009 / 0304968 A1 discloses a technology for increasing rigidity by adding calcium carbonate after manufacturing a hetero-phase block polypropylene pipe in a continuous process, and Korean Registered Patent No. 10-0544352 discloses a resin composition for pipes that improves pressure resistance, impact resistance, and processability by mixing a polypropylene resin containing random polypropylene and ethylene block polypropylene with rubber and talc.

[0007] However, excluding inorganic fillers eliminates the need for material separation during the recycling process, enables the production of high-quality recycled raw materials, reduces the burden of chemical registration and evaluation under the European REACH system or the Chemical Substances Control Act, and facilitates the fulfillment of requirements for eco-friendly certifications. Therefore, developing products that do not use inorganic fillers is desirable as it strengthens responsiveness to recent regulations and allows for flexible adaptation to future regulatory changes.

[0008] From this perspective, adding inorganic fillers to resin compositions, as in the aforementioned prior art, is disadvantageous in terms of recycling and environmental regulations. Furthermore, U.S. Patent Publication No. US 2009 / 0304968 A1 makes no mention of low-temperature impact resistance or gloss, and Korean Registered Patent No. 10-0544352 shows a maximum flexural modulus of 14,000 kgf / cm² despite the inclusion of talc. 2 The situation was inferior to the following.

[0009] The objective of the present invention is to provide a resin composition that exhibits excellent rigidity and impact resistance in balance without the addition of inorganic fillers, and furthermore has excellent gloss, making it highly suitable for pipe applications, particularly for non-pressure sewer pipes or drainage pipes, a method for manufacturing the same, and an article containing the same.

[0010] One aspect of the present invention provides a resin composition comprising (A) an ethylene-propylene block copolymer comprising an ethylene-propylene rubber component; and (B) high-density polyethylene; wherein the ethylene content as a polymerization unit per 1 part by weight of the ethylene-propylene rubber component in the ethylene-propylene block copolymer is greater than 0.15 parts by weight and less than 0.46 parts by weight, the intrinsic viscosity of the ethylene-propylene rubber component is greater than 2.3 dl / g and less than 8.7 dl / g, the melt strength of the high-density polyethylene is 20 mN or more, and the content of component (B) is less than 10 parts by weight based on 100 parts by weight of the total of components (A) and (B).

[0011] In one embodiment, the ethylene-propylene block copolymer may exhibit a melt index greater than 0.1 g / 10 min and less than 1 g / 10 min when measured at 230°C with a 2.16 kg load.

[0012] In one embodiment, the ethylene content as a polymerization unit in 100 weight% of the ethylene-propylene block copolymer may be 1 weight% to 10 weight%.

[0013] In one embodiment, the content of the ethylene-propylene rubber component in 100 weight% of the ethylene-propylene block copolymer may be 2 weight% to 20 weight%.

[0014] In one embodiment, the ethylene-propylene block copolymer may be obtained by block copolymerizing an ethylene-propylene rubber component with a propylene homopolymer component or an ethylene-propylene random copolymer component.

[0015] In one embodiment, the ethylene-propylene block copolymer may be polymerized in the presence of a Ziegler-Natta catalyst.

[0016] In one embodiment, the Ziegler-Natta catalyst may be prepared by reacting a titanium compound with a non-phthalate-based internal electron donor on a magnesium compound carrier.

[0017] In one embodiment, the high-density polyethylene may exhibit a melt index greater than 0.1 g / 10 min and less than 10 g / 10 min when measured with a 2.16 kg load at 190°C.

[0018] In one embodiment, the density of the high-density polyethylene is 0.930 g / cm³ 3 Up to 0.970 g / cm³ 3 It could be.

[0019] In one embodiment, the resin composition may not include an inorganic filler.

[0020] In one embodiment, the resin composition has 17,500 kgf / cm² 2 It can exhibit a larger flexural modulus.

[0021] In one embodiment, the resin composition is 345 kgf / cm² 2 It can exhibit greater tensile strength.

[0022] In one embodiment, the resin composition may exhibit a break elongation greater than 135%.

[0023] In one embodiment, the resin composition may exhibit a room temperature (23°C) notched Izod impact strength greater than 55 kgfcm / cm.

[0024] In one embodiment, the resin composition may exhibit a low-temperature (-10°C) notched Izod impact strength greater than 4.8 kgfcm / cm.

[0025] In one embodiment, the glossiness of the resin composition as a reflection angle at 45° may be 50% or more.

[0026] Another aspect of the present invention provides a method for preparing a resin composition comprising the step of (A) adding and mixing (B) high-density polyethylene to an ethylene-propylene block copolymer containing an ethylene-propylene rubber component, wherein the ethylene content as a polymerization unit per 1 part by weight of the ethylene-propylene rubber component in the ethylene-propylene block copolymer is greater than 0.15 parts by weight and less than 0.46 parts by weight, the intrinsic viscosity of the ethylene-propylene rubber component is greater than 2.3 dl / g and less than 8.7 dl / g, the melt strength of the high-density polyethylene is 20 mN or more, and the amount of added component (B) is less than 10 parts by weight based on 100 parts by weight of the total of the components (A) and (B).

[0027] Another aspect of the present invention provides an article comprising a resin composition of the present invention.

[0028] In one specific example, the above article may be a pipe.

[0029] In one embodiment, the pipe may be a non-pressure sewer pipe or a drain pipe.

[0030] The resin composition according to the present invention exhibits excellent rigidity and impact resistance in balance without the addition of inorganic fillers, and furthermore possesses high gloss, so resin molded articles manufactured therefrom can be effectively used for pipe applications, particularly for non-pressure sewer pipes and drainage pipes.

[0031] Figure 1 is a scanning electron microscope (SEM) image showing the morphology of the ethylene-polypropylene block copolymer prepared in Example 1.

[0032] Figure 2 is a scanning electron microscope (SEM) image showing the morphology of the ethylene-polypropylene block copolymer prepared in Comparative Example a-3.

[0033] The present invention will be described in more detail below.

[0034] The resin composition of the present invention comprises (A) an ethylene-propylene block copolymer containing an ethylene-propylene rubber component; and (B) high-density polyethylene.

[0035] (A) Ethylene-propylene block copolymer

[0036] The ethylene-propylene block copolymer included in the resin composition of the present invention comprises an ethylene-propylene rubber component and ethylene as a polymerization unit.

[0037] The above ethylene-propylene rubber component may be a solvent extract obtained from the above ethylene-propylene block copolymer using a xylene solvent at 135°C.

[0038] The ethylene content as a polymerization unit per 1 part by weight of the ethylene-propylene rubber component in the above ethylene-propylene block copolymer is greater than 0.15 parts by weight and less than 0.46 parts by weight. If the ethylene content in the ethylene-propylene block copolymer is 0.15 parts by weight or less per 1 part by weight of the ethylene-propylene rubber component, the low-temperature impact resistance of the resin composition is reduced, and in this case, the performance of products such as pipes installed in particularly cold regions is reduced, and long-term durability may be reduced. Conversely, if the ethylene content in the copolymer is 0.46 parts by weight or more per 1 part by weight of the ethylene-propylene rubber component, the stiffness of the resin composition is reduced, and in this case, long-term durability may be reduced as durability is reduced when pressure is applied by ground load.

[0039] More specifically, the ethylene content as a polymerization unit per 1 part by weight of the ethylene-propylene rubber component in the ethylene-propylene block copolymer may be greater than 0.15 parts by weight, 0.16 parts by weight or more, 0.18 parts by weight or more, 0.2 parts by weight or more, 0.22 parts by weight or more, 0.24 parts by weight or more, or 0.26 parts by weight or more, and may also be less than 0.46 parts by weight, 0.45 parts by weight or less, 0.44 parts by weight or less, 0.42 parts by weight or less, 0.4 parts by weight or less, or 0.38 parts by weight or less, but is not limited thereto.

[0040] The intrinsic viscosity of the above ethylene-propylene rubber component is greater than 2.3 dl / g and less than 8.7 dl / g, which may be measured using a viscometer under a 135°C decalin solution of the ethylene-propylene rubber component (i.e., a solvent extract obtained from an ethylene-propylene block copolymer using a xylene solvent at 135°C). If the intrinsic viscosity of the above ethylene-propylene rubber component is 2.3 dl / g or less, the impact resistance of the resin composition is reduced, and conversely, if it is 8.7 dl / g or more, the stiffness of the resin composition is reduced, which may reduce the long-term durability of products such as pipes.

[0041] More specifically, the intrinsic viscosity of the ethylene-propylene rubber component may be greater than 2.3 dl / g, greater than or equal to 2.5 dl / g, greater than or equal to 3 dl / g, greater than or equal to 3.5 dl / g, greater than or equal to 4 dl / g, greater than or equal to 4.5 dl / g, greater than or equal to 5 dl / g, greater than or equal to 5.5 dl / g, or greater than or equal to 5.7 dl / g, and may also be less than 8.7 dl / g, less than or equal to 8.5 dl / g, less than or equal to 8 dl / g, less than or equal to 7.5 dl / g, less than or equal to 7 dl / g, or less than or equal to 6.5 dl / g, but is not limited thereto.

[0042] In one embodiment, the ethylene-propylene block copolymer may exhibit a melt index greater than 0.1 g / 10 min and less than 1 g / 10 min when measured at 230°C with a 2.16 kg load, but is not limited thereto. More specifically, the melt index (230°C, 2.16 kg) of the ethylene-propylene block copolymer may be 0.15 g / 10 min or more, 0.2 g / 10 min or more, or 0.25 g / 10 min or more, and may also be 0.9 g / 10 min or less, 0.8 g / 10 min or less, 0.7 g / 10 min or less, 0.6 g / 10 min or less, 0.5 g / 10 min or less, or 0.4 g / 10 min or less, but is not limited thereto.

[0043] In one embodiment, the ethylene content as a polymerization unit within 100 wt% of the ethylene-propylene block copolymer may be 1 wt% to 10 wt%, but is not limited thereto. More specifically, the ethylene content as a polymerization unit within 100 wt% of the ethylene-propylene block copolymer may be 1.1 wt% or more, 1.3 wt% or more, 1.5 wt% or more, 1.7 wt% or more, 1.9 wt% or more, or 2 wt% or more, and may also be 9 wt% or less, 8 wt% or less, 7 wt% or less, 6 wt% or less, 5 wt% or less, 4 wt% or less, or 3 wt% or less, but is not limited thereto. The ethylene content in the ethylene-propylene block copolymer is determined using an infrared absorption spectrum at 720 cm⁻¹ -1 730 cm -1 It can be measured using the characteristic peak of.

[0044] In one embodiment, the content of the ethylene-propylene rubber component in 100 weight% of the ethylene-propylene block copolymer may be 2 weight% to 20 weight%, but is not limited thereto. More specifically, the content of the ethylene-propylene rubber component in 100 weight% of the ethylene-propylene block copolymer may be 2.5 weight% or more, 3 weight% or more, 3.5 weight% or more, 4 weight% or more, 4.5 weight% or more, or 5 weight% or more, and may also be 19 weight% or less, 18 weight% or less, 17 weight% or less, 16 weight% or less, 15 weight% or less, 14 weight% or less, 13 weight% or less, or 12 weight% or less, but is not limited thereto. The content of the ethylene-propylene rubber component in the ethylene-propylene block copolymer can be measured from the weight extracted after 2 hours at room temperature following the dissolution of the ethylene-propylene block copolymer in xylene at a concentration of 1 wt% at 135°C for 1 hour.

[0045] In one embodiment, the propylene content as a polymerization unit in the ethylene-propylene block copolymer may be 90 to 99 weight% based on 100 weight% of the ethylene-propylene block copolymer, but is not limited thereto. More specifically, the propylene content in 100 weight% of the ethylene-propylene block copolymer may be 91 weight% or more, 92 weight% or more, 93 weight% or more, 94 weight% or more, 95 weight% or more, 96 weight% or more, or 97 weight% or more, and may also be 98.9 weight% or less, 98.7 weight% or less, 98.5 weight% or less, 98.3 weight% or less, 98.1 weight% or less, or 98 weight% or less, but is not limited thereto.

[0046] In one embodiment, the content of the ethylene-propylene block copolymer in the resin composition of the present invention exceeds 90 parts by weight based on 100 parts by weight of the total of the ethylene-propylene block copolymer [component (A)] and the high-density polyethylene [component (B)]. If the content of the ethylene-propylene block copolymer in the resin composition is lower than this, the low-temperature impact resistance of the resin composition is reduced.

[0047] More specifically, the content of the above-mentioned component (A) (i.e., ethylene-propylene block copolymer) in the resin composition may be greater than 90 parts by weight, 91 parts by weight or more, 92 parts by weight or more, 93 parts by weight or more, 94 parts by weight or more, or 95 parts by weight or more, based on 100 parts by weight of the total of the above-mentioned components (A) and (B), and may also be 99.9 parts by weight or less, 99.5 parts by weight or less, 99 parts by weight or less, 98.5 parts by weight or less, or 98 parts by weight or less, but is not limited thereto.

[0048] In one embodiment, the ethylene-propylene block copolymer may be obtained by block copolymerizing an ethylene-propylene rubber component with a propylene homopolymer component or an ethylene-propylene random copolymer component.

[0049] There are no particular limitations on the method for manufacturing the above ethylene-propylene block copolymer, and the method for manufacturing an ethylene-propylene block copolymer known in the technical field to which the present invention belongs may be used as is or appropriately modified. For example, bulk polymerization, solution polymerization, slurry polymerization, gas phase polymerization, etc., may be used, and either batch or continuous methods are possible.

[0050] In one embodiment, an ethylene-propylene block copolymer can be produced by a polymerization method known to a person skilled in the art using a process in which one or more bulk reactors and one or more gaseous reactors are connected in series to polymerize continuously (e.g., Mitsui Hypol process) or a process in which two or more gaseous reactors are connected in series to polymerize continuously (e.g., WR Grace Unipol process).

[0051] More specifically, in the Hypol process, for example, two bulk reactors and two gas-phase reactors are connected in series, so that in the 1st, 2nd, and 3rd stage reactors, propylene alone is injected to produce a propylene homopolymer or ethylene is additionally injected to produce an ethylene-propylene random copolymer, and in the subsequent 4th stage reactor, ethylene and propylene are injected to block copolymerize the ethylene-propylene rubber component to obtain a final ethylene-propylene block copolymer. The melt index of the copolymer produced can be controlled by injecting hydrogen into each reactor. When polymerizing the propylene homopolymer, the melt index can be adjusted by additionally injecting hydrogen in addition to propylene into each reactor, and when polymerizing the ethylene-propylene random copolymer, the ratio of ethylene to propylene can be adjusted so that an equal amount of ethylene is copolymerized in each reactor.

[0052] Furthermore, more specifically, in the Unipol process, for example, two or more gas-phase reactors can be connected in series to perform continuous polymerization. Specifically, in the case of a process in which two gas-phase reactors are connected in series, propylene alone can be injected into the first-stage reactor to produce a propylene homopolymer. In the subsequent second-stage reactor, propylene and ethylene are injected to block copolymerize the propylene-ethylene rubber components, thereby obtaining a propylene-ethylene block copolymer. The melt index of the resulting copolymer can be controlled by injecting hydrogen into each reactor.

[0053] In one embodiment, the ethylene-propylene block copolymer may be polymerized in the presence of a Ziegler-Natta catalyst.

[0054] In one embodiment, the Ziegler-Natta catalyst may be prepared by reacting a titanium compound with a non-phthalate-based internal electron donor on a magnesium compound carrier.

[0055] Examples of such commercially available catalysts include W. R. Grace’s CONSISTA C601 catalyst, but are not particularly limited thereto. It is preferable to use an organoaluminum compound (e.g., triethylaluminum) as a co-catalyst and an organosilicon compound (e.g., trialkoxysilane) as an external electron donor in this catalyst, but are not particularly limited thereto.

[0056] (B) High-density polyethylene

[0057] The high-density polyethylene (HDPE) included in the resin composition of the present invention is a concept that includes not only ethylene homopolymers but also copolymers of ethylene and one or more monomers. Examples of comonomers that can be used include linear or branched alpha-olefins containing 4 to 6 carbon atoms, such as butene-1, hexene-1, and 4-methylpentene-1.

[0058] The melt strength of the high-density polyethylene included in the resin composition of the present invention is 20 mN or higher. If the melt strength of the high-density polyethylene is lower than this, the impact resistance of the resin composition is reduced. The melt strength can be obtained by measuring the stabilizing force as the speed of pulling the resin increases at a resin temperature of 200°C and a chamber temperature of 180°C.

[0059] More specifically, the melt strength of the high-density polyethylene may be 20 mN or more, 30 mN or more, 50 mN or more, 70 mN or more, 90 mN or more, 100 mN or more, 110 mN or more, or 120 mN or more, but is not limited thereto. There is no special limit on the upper limit of the melt strength of the high-density polyethylene, and for example, it may be 250 mN or less, 230 mN or less, 210 mN or less, 200 mN or less, 190 mN or less, or 180 mN or less, but is not limited thereto.

[0060] The high-density polyethylene content in the resin composition of the present invention is less than 10 parts by weight based on 100 parts by weight of the total of the ethylene-propylene block copolymer [Component (A)] and the high-density polyethylene [Component (B)]. If the high-density polyethylene content in the resin composition is higher than this, the low-temperature impact resistance of the resin composition is reduced.

[0061] More specifically, the content of component (B) (i.e., high-density polyethylene) in the resin composition may be less than 10 parts by weight, 9 parts by weight or less, 8 parts by weight or less, 7 parts by weight or less, 6 parts by weight or less, or 5 parts by weight or less, based on 100 parts by weight of the total of components (A) and (B), but is not limited thereto. There is no special limit on the upper limit of the content of the high-density polyethylene, and for example, based on 100 parts by weight of the total of components (A) and (B), it may be 0.1 parts by weight or more, 0.5 parts by weight or more, 1 part by weight or more, 1.5 parts by weight or more, or 2 parts by weight or more, but is not limited thereto.

[0062] In one embodiment, the high-density polyethylene may exhibit a melt index greater than 0.1 g / 10 min and less than 10 g / 10 min when measured at 190°C with a 2.16 kg load, but is not limited thereto. More specifically, the melt index (190°C, 2.16 kg) of the high-density polyethylene may be 0.15 g / 10 min or more, 0.2 g / 10 min or more, or 0.25 g / 10 min or more, and may also be 9 g / 10 min or less, 7 g / 10 min or less, 5 g / 10 min or less, 3 g / 10 min or less, 1 g / 10 min or less, or 0.5 g / 10 min or less, but is not limited thereto.

[0063] In one embodiment, the density of the high-density polyethylene is 0.930 g / cm³ 3 Up to 0.970 g / cm³ 3 It may be, but is not limited thereto. More specifically, the density of the high-density polyethylene is 0.930 g / cm³. 3 Above, 0.935 g / cm³ 3 Above or 0.940 g / cm³ 3 It may be above, and also 0.970 g / cm³ 3 Below, 0.965 g / cm³ 3 Below, 0.960 g / cm³ 3 Below, 0.955 g / cm³ 3Less than or equal to 0.950 g / cm³ 3 It may be less than, but is not limited to.

[0064] Resin composition

[0065] The resin composition of the present invention essentially comprises the above-described (A) component (i.e., an ethylene-propylene block copolymer containing an ethylene-propylene rubber component) and (B) component (i.e., high-density polyethylene).

[0066] In one embodiment, the resin composition of the present invention may not include an inorganic filler. However, this should not be interpreted as excluding inorganic fillers from the resin composition of the present invention, and it should be understood that the resin composition of the present invention may further include inorganic fillers to the extent that the purpose of the present invention can be achieved. Examples of such inorganic fillers include, but are not limited to, calcium carbonate, talc, glass fiber, quartz, etc.

[0067] In one embodiment, the resin composition of the present invention may further include conventional additives within a range that can achieve the purpose of the present invention. Such conventional additives may include, for example, antioxidants, neutralizing agents, slip agents, anti-blocking agents, weather stabilizers, antistatic agents, lubricants, nucleating agents, flame retardants, pigments, and dyes, but are not limited thereto. The content of such additional additives is not particularly limited, and depending on the purpose and use, each additional additive may be used in an amount of, for example, 0.01 to 2 parts by weight, more specifically within the range of 0.05 to 1 part by weight, based on 100 parts by weight of the total composition of the present invention, but is not limited thereto.

[0068] In one embodiment, the resin composition of the present invention has (1) 17,500 kgf / cm² 2 It can exhibit a larger flexural modulus, more specifically 17,600 kgf / cm² 2 Above, 17,800 kgf / cm²2 Above, 18,000 kgf / cm² 2 Above, 18,100 kgf / cm² 2 or greater than or equal to 18,300 kgf / cm² 2 The above flexural modulus may be exhibited, but is not limited thereto. There is no particular limit to the upper limit of the flexural modulus of the resin composition of the present invention, for example, 30,000 kgf / cm² 2 Below, 25,000 kgf / cm² 2 ≤ or 20,000 kgf / cm² 2 The above flexural modulus may be less than, but is not limited to. The above flexural modulus may be measured at 23°C using a Universal Test Machine (UTM) in accordance with ASTM D770.

[0069] In one embodiment, the resin composition of the present invention is (2) 345 kgf / cm 2 It can exhibit greater tensile strength, more specifically 346 kgf / cm² 2 Above, 348 kgf / cm² 2 Above, 350 kgf / cm² 2 Above, 352 kgf / cm² 2 355 kgf / cm² or higher 2 Tensile strengths above the above may be exhibited, but are not limited thereto. There is no particular limitation on the upper limit of the tensile strength of the resin composition of the present invention, for example, 500 kgf / cm² 2 Below, 450 kgf / cm² 2 400 kgf / cm² or less 2 The above tensile strength may be less than, but is not limited to, ASTM D638. The above tensile strength may be measured at 23°C using a UTM device in accordance with ASTM D638.

[0070] In one embodiment, the resin composition of the present invention may exhibit a break elongation greater than (3) 135%. More specifically, it may exhibit a break elongation greater than 140%, 150%, 160%, 170%, 180%, 190%, 200%, or 210%, but is not limited thereto. There is no particular limit to the upper limit of the break elongation of the resin composition of the present invention, and for example, it may be 400% or less, 350% or less, or 300% or less, but is not limited thereto. The break elongation may be measured at 23°C using a UTM device in accordance with ASTM D638.

[0071] In one embodiment, the resin composition of the present invention may exhibit a room temperature (23°C) notched Izod impact strength greater than (4) 55 kgfcm / cm, and more specifically, may exhibit a room temperature notched Izod impact strength of 56 kgfcm / cm or more, 57 kgfcm / cm or more, 58 kgfcm / cm or more, 59 kgfcm / cm or more, 60 kgfcm / cm or more, 61 kgfcm / cm or more, or 62 kgfcm / cm or more, but is not limited thereto. There is no particular limit to the upper limit of the room temperature notched Izod impact strength of the resin composition of the present invention, and for example, it may be 100 kgfcm / cm or less, 90 kgfcm / cm or less, 80 kgfcm / cm or less, or 70 kgfcm / cm or less, but is not limited thereto. The above room temperature notched Izod impact strength can be measured using a notched specimen with a thickness of 3.2 mm at 23°C in accordance with ASTM D256.

[0072] In one embodiment, the resin composition of the present invention may exhibit a low-temperature (-10°C) notched Izod impact strength greater than (5) 4.8 kgfcm / cm, and more specifically, may exhibit a low-temperature notched Izod impact strength greater than 4.9 kgfcm / cm, greater than 5.0 kgfcm / cm, greater than 5.1 kgfcm / cm, greater than 5.2 kgfcm / cm, or greater than 5.3 kgfcm / cm, but is not limited thereto. There is no particular limit to the upper limit of the low-temperature notched Izod impact strength of the resin composition of the present invention, and may be, for example, 10 kgfcm / cm or less, 9 kgfcm / cm or less, 8 kgfcm / cm or less, or 7 kgfcm / cm or less, but is not limited thereto. The low-temperature notched Izod impact strength may be measured using a notched specimen with a thickness of 3.2 mm at -10°C in accordance with ASTM D256.

[0073] In one embodiment, the glossiness of the resin composition of the present invention, expressed as a reflection angle at 45° (6), may be 50% or more. The glossiness expressed as a reflection angle at 45° can be measured using a glossmeter on a flat sheet of 100*100*2 mm made from the resin composition.

[0074] The resin composition of the present invention may exhibit at least one of the above-described physical properties (1) to (6), more preferably may exhibit two or more, three or more, four or more, or five or more of the above-described physical properties (1) to (6), and most preferably may exhibit all of the above-described physical properties (1) to (6).

[0075] According to another aspect of the present invention, a method for preparing a resin composition is provided, comprising the step of (A) adding and mixing (B) high-density polyethylene to an ethylene-propylene block copolymer containing an ethylene-propylene rubber component, wherein the ethylene content as a polymerization unit per 1 part by weight of the ethylene-propylene rubber component in the ethylene-propylene block copolymer is greater than 0.15 parts by weight and less than 0.46 parts by weight, the intrinsic viscosity of the ethylene-propylene rubber component is greater than 2.3 dl / g and less than 8.7 dl / g, the melt strength of the high-density polyethylene is 20 mN or more, and the amount of added component (B) is less than 10 parts by weight based on 100 parts by weight of the total of the components (A) and (B).

[0076] However, the method for manufacturing the resin composition of the present invention is not particularly limited thereto, and a method for manufacturing a resin composition known in the technical field to which the present invention belongs may be used as is or appropriately modified.

[0077] In the method for manufacturing the polyolefin resin composition of the present invention, the (A) ethylene-propylene block copolymer containing the ethylene-propylene rubber component and (B) high-density polyethylene are as described above.

[0078] The mixing of the above components (A) and (B) may be carried out using methods known in the technical field to which the present invention belongs, either as is or by appropriately modifying them. For example, components (A) and (B), and if necessary, other additives, may be fed into a kneader, roll, Banbury mixer, or other mixing machine, or a 1-screw / 2-screw extruder, in predetermined amounts, and then the fed components may be mixed and blended. According to one embodiment, a resin composition in the form of pellets may be prepared by uniformly dispersing components (A) and (B), then placing them into the main feed section of an extruder and mixing them while melt-extruding at a temperature of 200 to 250°C.

[0079] article

[0080] The resin composition of the present invention exhibits excellent rigidity and impact resistance in balance, and also has excellent gloss, making it highly suitable for pipe applications, particularly for non-pressure sewer pipes or drainage pipes.

[0081] Accordingly, according to another aspect of the present invention, an article comprising a resin composition of the present invention is provided.

[0082] In one embodiment, the article may be a pipe, but is not limited thereto.

[0083] In one embodiment, the pipe may be a non-pressure sewer pipe or drain pipe, but is not limited thereto.

[0084] There are no particular limitations on the method of manufacturing an article from the resin composition of the present invention, and the article may be manufactured by molding the resin composition of the present invention using methods known in the technical field of the present invention (e.g., conventional methods such as injection molding or extrusion molding, more specifically by extrusion molding).

[0085] The present invention will be explained in more detail below through examples and comparative examples. However, the scope of the present invention is not limited to these.

[0086] [Example]

[0087] Examples 1 to 2, and Comparative Examples a-1 to a-4 and b-1 to b-4

[0088] (1) Preparation of ethylene-propylene block copolymer

[0089] The ethylene-propylene block copolymer used in each example and comparative example was prepared by the following method.

[0090] In the unipol manufacturing process of W. R. Grace, CONSISTA C601 catalyst containing a non-phthalate internal electron donor was used, and ethylene-propylene block copolymers were continuously polymerized using propylene, ethylene, a catalyst compound, a co-catalyst triethylaluminum (TEAL), and CONSISTA D8700 (external electron donor). The CONSISTA C601 catalyst was diluted in mineral oil and injected into the reactor in a slurry state. Polymerization was carried out continuously in a single gas-phase reactor, and the temperature, pressure, catalyst supply, monomer supply, hydrogen supply, and polymer concentration in the reactor during the polymerization step were maintained constant. In Examples 1 and 2, and Comparative Examples a-1 to a-4, the reactor conditions were varied so that each copolymer exhibited the properties listed in Table 1 below.

[0091]

[0092] (2) Preparation of resin composition

[0093] To the ethylene-propylene block copolymer prepared above, 2,000 ppm each of Irganox 1010 and Irganox 168 were added as antioxidants, 500 ppm of calcium stearate was added as a neutralizing agent, and additionally, 3,000 ppm of Milliken HPN-715 was added to improve stiffness.

[0094] Subsequently, high-density polyethylene (HDPE) was added to the prepared ethylene-propylene block copolymer according to each example and comparative example in the amounts shown in Table 2 below. However, no polyethylene was added in Comparative Example b-1, and the ethylene-polypropylene block copolymer applied in Example 2 was used in Comparative Examples b-2 to b-4. The properties of the high-density polyethylene (HDPE) used are shown in Table 3 below.

[0095] Subsequently, the prepared mixture was fed into an extruder and pelletized at 200–250°C to produce a resin composition. Then, ASTM No. 4 and 2T sheet injection specimens were produced using an injection molding machine (Engel, 180 ton) at a temperature of 250°C.

[0096]

[0097]

[0098] The resin components and compositions of each example and comparative example, and specimens prepared therefrom, were tested in the following manner, and the results are shown in Tables 4 and 5 below.

[0099] (1) Melt index

[0100] According to ASTM D1238, the melt index of the ethylene-propylene block copolymer was measured at 230°C with a 2.16 kg load, and the melt index of the polyethylene was measured at 190°C with a 2.16 kg load.

[0101] (2) Ethylene content in ethylene-propylene block copolymer

[0102] Using the infrared absorption spectrum (FT-IR), 720 cm⁻¹ -1 730 cm -1 The ethylene content was measured using characteristic peaks.

[0103] (3) Content of ethylene-propylene rubber components (xylene solvent extract (Xylene Soluble, “XS”)

[0104] According to ASTM D5492, the ethylene-propylene block copolymer was dissolved in xylene at a concentration of 1 wt% at 135°C for 1 hour, and then measured from the weight extracted after 2 hours at room temperature.

[0105] (4) Intrinsic viscosity of ethylene-propylene rubber components

[0106] The ethylene-propylene rubber component of the ethylene-propylene block copolymer (i.e., the solvent extract obtained from the ethylene-propylene block copolymer using a xylene solvent at 135°C) was measured using a viscometer under a decalin solution at 135°C.

[0107] (5) Density of polyethylene

[0108] It was measured at 23℃ in accordance with ASTM D1505.

[0109] (6) Melt strength of polyethylene

[0110] The stabilizing force was measured as the speed of pulling the resin was increased at a resin temperature of 200℃ and a chamber temperature of 180℃.

[0111] (7) Flexural modulus

[0112] It was measured at 23℃ in accordance with ASTM D770.

[0113] (8) Notch Izod impact strength

[0114] According to ASTM D256, Izod impact strength was measured at each temperature (room temperature: 23℃, low temperature: -10℃) using a notched specimen with a thickness of 3.2 mm.

[0115] (9) Glossiness

[0116] A flat sheet of 100*100*2 mm was prepared from a resin composition, and the glossiness was measured at a 45° reflection angle using a glossmeter.

[0117] Glossiness measured at 45° was indicated as “O” if it was 50% or more, and “X” if it was less than 50%.

[0118] (10) Tensile strength

[0119] It was measured at 23℃ using a Universal Test Machine (UTM) in accordance with ASTM D638.

[0120] (11) Elongation at break

[0121] It was measured at 23℃ using a UTM device in accordance with ASTM D638.

[0122]

[0123]

[0124] As can be seen from Table 4 above, Examples 1 and 2 according to the present invention had superior room temperature and low temperature notched Izod impact strength compared to Comparative Example a-1, superior flexural modulus, tensile strength, and glossiness at 45° compared to Comparative Example a-2, superior room temperature and low temperature Izod impact strength compared to Comparative Example a-3, and superior flexural modulus, tensile strength, and glossiness at 45° compared to Comparative Example a-4.

[0125] In addition, as can be seen from Tables 4 and 5 above, when comparing Example 2 according to the present invention with Comparative Examples b-1 to b-4 using the same ethylene-polypropylene block copolymer, Example 2 showed superior room temperature and low temperature notched Izod impact strength compared to Comparative Example b-1, superior flexural modulus, tensile strength, and low temperature notched Izod impact strength compared to Comparative Example b-2, superior flexural modulus and glossiness at 45° compared to Comparative Example b-3, and superior room temperature and low temperature notched Izod impact strength compared to Comparative Example b-4.

Claims

1. (A) an ethylene-propylene block copolymer comprising an ethylene-propylene rubber component; and (B) High-density polyethylene; comprising, The ethylene content as a polymerization unit per 1 part by weight of the ethylene-propylene rubber component in the above ethylene-propylene block copolymer is greater than 0.15 parts by weight and less than 0.46 parts by weight, and The intrinsic viscosity of the above ethylene-propylene rubber component is greater than 2.3 dl / g and less than 8.7 dl / g, and The melt strength of the above high-density polyethylene is 20 mN or more, and Based on 100 parts by weight of the total of the above components (A) and (B), the content of component (B) is less than 10 parts by weight, Resin composition.

2. The resin composition according to claim 1, wherein the ethylene-propylene block copolymer exhibits a melt index greater than 0.1 g / 10 min and less than 1 g / 10 min when measured at 230°C with a 2.16 kg load.

3. A resin composition according to claim 1, wherein the ethylene content as a polymerization unit within 100 weight% of the ethylene-propylene block copolymer is 1 weight% to 10 weight%.

4. A resin composition according to claim 1, wherein the content of the ethylene-propylene rubber component in 100 weight% of the ethylene-propylene block copolymer is 2 weight% to 20 weight%.

5. A resin composition according to claim 1, wherein the ethylene-propylene block copolymer is obtained by block copolymerizing an ethylene-propylene rubber component with a propylene homopolymer component or an ethylene-propylene random copolymer component.

6. A resin composition according to claim 1, wherein the ethylene-propylene block copolymer is polymerized in the presence of a Ziegler-Natta catalyst.

7. A resin composition according to claim 6, wherein the Ziegler-Natta catalyst is prepared by reacting a titanium compound with a non-phthalate-based internal electron donor on a magnesium compound carrier.

8. A resin composition according to claim 1, wherein the high-density polyethylene exhibits a melt index greater than 0.1 g / 10 min and less than 10 g / 10 min when measured at 190°C with a 2.16 kg load.

9. In claim 1, the density of the high-density polyethylene is 0.930 g / cm³ 3 Up to 0.970 g / cm³ 3 Phosphorus, resin composition.

10. A resin composition according to claim 1, which does not include inorganic fillers.

11. In paragraph 1, 17,500 kgf / cm² 2 A resin composition exhibiting a greater flexural modulus.

12. In paragraph 1, 345 kgf / cm² 2 A resin composition exhibiting greater tensile strength.

13. A resin composition according to claim 1, exhibiting a fracture elongation greater than 135%.

14. A resin composition according to claim 1, exhibiting a room temperature (23℃) notched Izod impact strength greater than 55 kgfcm / cm.

15. A resin composition according to claim 1, exhibiting a low-temperature (-10℃) notched Izod impact strength greater than 4.8 kgfcm / cm.

16. A resin composition according to claim 1, wherein the glossiness expressed as a reflection angle at 45° is 50% or more.

17. (A) a step of adding and mixing (B) high-density polyethylene to an ethylene-propylene block copolymer containing an ethylene-propylene rubber component, and The ethylene content as a polymerization unit per 1 part by weight of the ethylene-propylene rubber component in the above ethylene-propylene block copolymer is greater than 0.15 parts by weight and less than 0.46 parts by weight, and The intrinsic viscosity of the above ethylene-propylene rubber component is greater than 2.3 dl / g and less than 8.7 dl / g, and The melt strength of the above high-density polyethylene is 20 mN or more, and A method for preparing a resin composition, wherein the amount of added component (B) is less than 10 parts by weight, based on 100 parts by weight of the total of the components (A) and (B).

18. An article comprising a resin composition of any one of paragraphs 1 to 16.

19. In paragraph 18, the above article is an article that is a pipe.

20. Article 19, wherein the pipe is a non-pressure sewer pipe or drain pipe.

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