Eco-friendly plastic sheet piles and sheet pile compositions

Abstract

The present invention relates to plastic sheet piles used for embankment protection or soil erosion protection walls during civil engineering or construction work.

Description

Technology Field

[0001] The present invention relates to an eco-friendly plastic sheet pile and a sheet pile composition. More specifically, it relates to an eco-friendly plastic sheet pile used as an underground cutoff wall, embankment protection, or soil erosion protection wall during civil engineering or construction work, and a sheet pile composition used in the manufacture thereof. Background Technology

[0002] In civil engineering or construction projects, it is necessary to form cutoff walls underground, protect embankments, or create protective walls in areas at risk of soil erosion. Additionally, when excavating the ground, retaining walls are installed to prevent the soil on the excavation surface from collapsing. An artificial wall used for such purposes is a sheet pile.

[0003] While steel sheet piles are currently used to replace concrete walls, plastic sheet piles have been developed and are being used to reduce costs or improve constructability.

[0004] Polyvinyl chloride (PVC) plastic sheet piles are used as a leading example of such plastic materials. Compared to conventional steel sheet piles, PVC plastic sheet piles not only reduce costs but also offer advantages such as easier construction due to their lightweight nature and superior workability, including cutting capabilities. However, despite these benefits, the continuous production of new PVC sheet piles results in a large volume of waste being discarded into the environment, causing environmental problems. Furthermore, because they are difficult to recycle, there have been attempts to limit their total volume. In an effort to restrict this total, methods utilizing previously used recycled plastic products as raw materials have been continuously explored and researched, but a new plastic recycling technology that meets the required physical properties has yet to be perfected.

[0005] When using the aforementioned recycled plastic material, processability is inferior to that of virgin material, making it difficult to secure extrusion processability. Furthermore, there are problems such as failure to process or carbonization due to insufficient processability during the processing stage. Additionally, even if processing is partially possible, various properties such as mechanical strength and water resistance are poor, failing to achieve the properties of conventional virgin material; consequently, there is a problem preventing commercialization due to these mechanical properties.

[0006] For example, when manufacturing pile sheets using recycled plastic, there are problems that make practical application difficult, as the rigidity is lower compared to conventional plastic sheet piles, making it difficult to withstand soil pressure or easily damaged by impact, and performance rapidly deteriorates due to exposure to high temperatures or light for a certain period, weathering by acidic water, or infestation by pests.

[0007] Therefore, research and development are necessary for recycled plastic sheet piles that possess excellent mechanical strength and elasticity despite using recycled plastic materials, allowing them to fully perform their inherent functions while maintaining properties that do not significantly degrade even after prolonged exposure to extreme external environments, and exhibiting superior chemical resistance and discoloration resistance. Prior art literature

[0008] Korean Registered Patent No. 10-1074881 (2011.10.12) Korean Registered Patent No. 10-2043182 (2019.11.05) The problem to be solved

[0009] One objective of the present invention is to provide a new recycled plastic sheet pile that, despite using recycled plastic materials, has excellent processability, superior mechanical strength including tensile strength, flexural strength, and impact strength, excellent resistance to earth pressure and water pressure, good elasticity, and is easy to cut, thereby improving work efficiency during construction. In other words, it provides an eco-friendly sheet pile that has excellent processability and sufficient physical properties while using crushed plastic sashes recovered after use as the main component.

[0010] In addition, one objective of the present invention is to provide a plastic sheet pile using a recycled material that exhibits excellent resistance to corrosion and pest infestation, as well as superior resistance to saltwater or acidic water, thereby preventing the deterioration of physical properties even after a long period of time, and thus possessing the physical properties of a plastic sheet pile utilizing new material.

[0011] In addition, one objective of the present invention is to recover used PVC-based sashes and use the crushed PVC-based sash powder to develop a new composition with excellent chemical resistance, discoloration resistance, and heat resistance, and to provide a new eco-friendly sheet pile manufactured through this. means of solving the problem

[0012] To achieve the above objectives, the present invention comprises a PVC-based sash powder, methyl methacrylate butadiene styrene (MBS), chlorinated polyethylene (CPE), a composite stabilizer including a calcium-based stabilizer, and a functional polymer.

[0013] The above functional polymer provides a sheet pile selected from ethylene-ethyl acrylate and polyamide-polyether block copolymers, or a mixture thereof.

[0014] In addition, the present invention comprises “recycled PVC-based sash powder” obtained by crushing PVC-based sashes recovered after use, methyl methacrylate butadiene styrene (MBS), chlorinated polyethylene (CPE), a composite stabilizer including a calcium-based stabilizer, and a functional polymer.

[0015] The above functional polymer provides a sheet pile selected from ethylene-ethyl acrylate and polyamide-polyether block copolymers, or a mixture thereof.

[0016] The above PVC-based sash powder is not specifically limited in size, but, for example, may have an average particle size of 0.01 mm to 10 mm.

[0017] In one embodiment, the above CPE is not particularly limited as long as it is commercially available, but for example, it may have a weight-average molecular weight of 50,000 g / mol to 1,000,000 g / mol and a chlorine content of 30 to 45 weight%. However, it is not particularly limited as long as it is a CPE that is processable and satisfies the physical properties of the present invention.

[0018] In one embodiment, the composition ratio of the MBS, CPE, and PVC-based sash powder is not particularly limited as long as the purpose of the present invention is achieved. As an example, the composition ratio may be, for example, 0.1 to 10 parts by weight of MBS and 0.1 to 10 parts by weight of CPE per 100 parts by weight of PVC-based recycled sash powder, the composite stabilizer may be 3 to 10 parts by weight, and the functional polymer may be 0.1 to 3 parts by weight, but is not limited thereto.

[0019] In one embodiment, the sheet pile may have a Charpy impact strength of 10 KJ / ㎡ to 100 KJ / ㎡ or 10 to 50 KJ / ㎡ as measured according to KS M ISO 179-1:2012.

[0020] In one embodiment, the sheet pile may have a flexural strength of 50 to 200 MPa, 50 to 150 MPa, or 50 to 100 MPa as measured according to KS M ISO 178:2012.

[0021] In one embodiment, the sheet pile may have a flexural modulus of 2.0 GPa or more, and 2 to 5 GPa.

[0022] In one embodiment, the extrusion temperature of the sheet pile may be 180°C to 300°C or 200°C to 250°C.

[0023] In one embodiment, the sheet file may have a tensile strength of 30 MPa to 100 MPa or 30 MPa to 80 MPa as measured according to KS M ISO 527-2:2012.

[0024] In one embodiment, regarding the Charpy impact strength, the rate of change in Charpy impact strength measured after 24 hours of exposure at 6500W Xenon Arc, 0.51W / ㎡, 63℃±3℃, and 50%±5% RH (humidity) may be 20% or less, and regarding the flexural strength, the rate of change in flexural strength measured after 20 hours of exposure at 100℃ may be 25% or less.

[0025] Another aspect of the present invention provides a sheet pile composition comprising PVC-based sash powder, methyl methacrylate butadiene styrene (MBS), chlorinated polyethylene (CPE), a composite stabilizer including a calcium-based stabilizer, and a functional polymer, wherein the functional polymer is selected from ethylene-ethyl acrylate and polyamide-polyether block copolymer or a mixture thereof.

[0026] In one embodiment, the PVC-based sash powder may be powder obtained by crushing recycled PVC-based sashes.

[0027] In one embodiment, the composition may comprise 0.1 to 10 parts by weight of MBS, 0.1 to 10 parts by weight of CPE, 3 to 10 parts by weight of a composite stabilizer, and 0.1 to 3 parts by weight of a functional polymer, based on 100 parts by weight of the PVC-based sash powder. Effects of the invention

[0028] The sheet pile according to the present invention can provide a sheet pile having mechanical strength, including tensile strength, flexural strength, and impact strength equivalent to that of a plastic sheet pile manufactured from a new PVC composition produced by the applicant in the past, even though the powder of a PVC-based sash that has been discarded and recovered after use is used as a main component.

[0029] In addition, the sheet pile according to the present invention is lightweight, has excellent elasticity, and has good cutting properties, which can maximize work efficiency during construction.

[0030] In addition, the sheet pile of the present invention has excellent extrusion processability and can provide the effect of excellent extrusion processability without deteriorating or carbonizing during processing.

[0031] In addition, the sheet pile according to the present invention has excellent chemical resistance, corrosion resistance, discoloration resistance, and heat resistance, good resistance to insect intrusion, and does not deteriorate in physical properties even after long-term use, thereby providing the effect of being usable for a long period of time.

[0032] In addition, the sheet pile according to the present invention uses powder recycled from recycled polyvinyl chloride resin-based window frames obtained from waste, so it has the advantage of being environmentally friendly in terms of resource recycling.

[0033] In addition, the sheet pile according to the present invention is more economical than conventional sheet piles and has the advantage of providing excellent aesthetics by enabling custom production in various colors, and facilitating simple painting of exposed parts after construction.

[0034] In addition, it can provide excellent physical properties that maintain durability not only in freshwater but also in seawater. Brief explanation of the drawing

[0035] Figure 1 schematically illustrates an example of the application of a plastic sheet pile. 1 : Plastic sheet file Specific details for implementing the invention

[0036] Hereinafter, the eco-friendly plastic sheet pile of the present invention and the eco-friendly sheet pile composition for manufacturing the same will be described in detail. However, the following specific examples or embodiments are merely references for the detailed explanation of the present invention and the present invention is not limited thereto and can be implemented in various forms.

[0037] Furthermore, unless otherwise defined, all technical and scientific terms have the same meaning as generally understood by one of the art to which the present invention pertains. The terms used in the description of the present invention are merely for the purpose of effectively describing specific embodiments and are not intended to limit the present invention.

[0038] Additionally, the singular form used in the specification and the appended claims may be intended to include the plural form unless specifically indicated otherwise in the context.

[0039] As used in this specification, "comprising" is an open description equivalent to expressions such as "comprising," "containing," "having," and "characteristics," and does not exclude elements, materials, or processes not additionally listed.

[0040] Furthermore, unless otherwise specifically defined in the present invention, when a layer or member is described as being located “on” another layer or member, this includes not only cases where a layer or member is in contact with another layer or member, but also cases where another layer or member exists between two layers or two members.

[0041] Additionally, terms used herein such as “about,” “substantially,” etc., are used to mean at or near the stated value when inherent manufacturing and material tolerances are presented in the said sense, and are used to prevent unscrupulous infringers from unfairly exploiting the disclosed content in which precise or absolute values ​​are mentioned to aid in understanding the invention.

[0042] In the present invention, “PVC-based sash powder” is used with the same meaning as recycled PVC-based sash powder obtained by recovering and crushing PVC-based sashes that are discarded after use. The above-mentioned PVC-based sash powder may be a recycled raw material obtained by recovering and crushing PVC-based sashes used for windows in homes or offices after use.

[0043] The present invention will be described in detail below.

[0044] The present invention relates to a sheet pile composition comprising PVC-based sash powder, methyl methacrylate butadiene styrene (MBS), chlorinated polyethylene (CPE), a composite stabilizer including a calcium-based stabilizer, and a functional polymer, wherein the functional polymer is selected from ethylene-ethyl acrylate and polyamide-polyether block copolymer or a mixture thereof, and to a sheet pile manufactured by extruding the same.

[0045] In one embodiment, the PVC-based sash powder refers to recycled PVC-based sash powder obtained by recovering and crushing PVC-based sashes, for example, window frames. For example, the PVC-based sash powder may be a recycled raw material obtained by recovering and crushing PVC-based sashes used for windows in homes or offices after use. Alternatively, it may refer to by-products that are discarded during sash manufacturing in a factory or generated by cutting during the manufacturing process, in which case it may exhibit superior physical properties.

[0046] In the present invention, the category of recycled PVC-based sash powder includes, although recycling is best for achieving the eco-friendly purpose of the present invention, powder obtained by crushing new sashes may also be included.

[0047] In the present invention, the sash powder may be a recycled raw material obtained by collecting and pulverizing PVC-based sashes commonly used in buildings such as homes or offices. Sashes mainly refer to window frames, door frames, windows, etc., and most of these are manufactured using PVC as a raw material with the addition of fillers, etc.

[0048] In one embodiment of the present invention, the recycled PVC-based sash powder is not specifically limited in size, but for example, it may have an average particle size of 0.01 mm or more, 0.02 mm or more, 0.1 mm or more, 0.5 mm or more, 10 mm or less, or 5 mm or less, but is not necessarily limited thereto. For example, the average particle size may be 0.01 to 10 mm, 0.1 to 5 mm, or 0.1 to 2 mm, or any value between the above values. When satisfying the above range, processability is good and extrusion stability is high.

[0049] In the present invention, the CPE (chlorinated polyethylene) is not specifically limited and can be used as long as it is a conventional chlorinated polyethylene in the art. For example, it may be manufactured by chlorinating polyethylene powder or particles in an aqueous suspension, and may have, for example, a weight-average molecular weight of 50,000 g / mol to 1,000,000 g / mol and a chlorine content of 30 to 45 weight%. In addition, according to ASTM D1238, the melt flow index measured under conditions of 190°C and 5 kg may be 0.25 to 1.0 g / 10 min and the molecular weight distribution may be 4 to 8. In addition, the ratio of the melt flow index MI21.6 measured at 190°C and 21.6 kg to the melt flow index MI5 measured at 190°C and 5 kg, MI21.6 / MI5, may be 8 to 15. In addition, it may be a chlorinated polyethylene resin produced by chlorinating a polyethylene resin having an average particle size of 100 to 200 μm, and the chlorine content may be 30 to 45 weight% or 35 to 44 weight%, but is not limited thereto. Any CPE that is processable and satisfies the physical properties of the present invention is not particularly limited.

[0050] The above CPE can be combined with the components of the composition of the present invention to improve durability, flexibility, and chemical resistance. Examples of commercially available products include Shangdong Changtai 135A, LG Chem’s CE2030K, CE2080, CE6040K, etc., but are not limited thereto.

[0051] The content of the above CPE (chlorinated polyethylene) may be 0.1 parts by weight or more, 1 part by weight or more, 2 parts by weight or more, 3 parts by weight or more, 4 parts by weight or more, 5 parts by weight or more, 10 parts by weight or less, or 8 parts by weight or less, based on 100 parts by weight of the above PVC-based sash powder, and may be a value between the values ​​of each of the above figures. For example, it may be 0.1 to 10 parts by weight, 1 to 8 parts by weight, 2 to 8 parts by weight, or 3 to 7 parts by weight, and within the above range, it can be combined with the PVC-based sash powder and MBS to improve durability, flexibility, and chemical resistance.

[0052] In the present invention, the methyl methacrylate butadiene styrene (MBS) can be combined with other components of the sheet composition of the present invention to provide excellent mechanical properties and further improve processability and weather resistance.

[0053] In other words, by combining with the sheet pile composition of the present invention, an eco-friendly sheet pile with excellent impact strength, high transparency, and excellent light resistance and chemical stability can be provided.

[0054] The above MBS is a methyl methacrylate-butadiene-styrene resin, and is not specifically limited as long as it is commercially available. Examples of commercially available resins include Kaneka's Kane Ace, Samwoo Chem's MB838A, and Formosa's M-series, but are not limited thereto.

[0055] The content of the methyl methacrylate butadiene styrene (MBS) above may be 0.1 parts by weight or more, 1 part by weight or more, 2 parts by weight or more, 3 parts by weight or more, 4 parts by weight or more, 5 parts by weight or more, 10 parts by weight or less, or 8 parts by weight or less, based on 100 parts by weight of the PVC-based sash powder, and may be a value between the values ​​of each of the above figures. For example, it may be 0.1 to 10 parts by weight, 1 to 8 parts by weight, 2 to 8 parts by weight, or 3 to 7 parts by weight, and within the above range, when combined with other components of the sheet composition of the present invention, it can provide the effect of having excellent mechanical properties and further improved weather resistance.

[0056] In one embodiment of the present invention, the composite stabilizer comprises a calcium-based stabilizer, and by including the calcium-based stabilizer, thermal stability, durability, processability, etc., can be improved. The composite stabilizer may be in an amount of 3 parts by weight or more, 4 parts by weight or more, 5 parts by weight or more, 10 parts by weight or less, or 7 parts by weight or less, with respect to 100 parts by weight of the PVC-based sash powder, and may be a value between the values ​​of each of the above figures. For example, it may be 3 to 10 parts by weight or 4 to 8 parts by weight, and within the above range, the thermal stability, weather resistance, and chemical resistance of PVC can be improved.

[0057] The above composite stabilizer is not specifically limited as long as it is a composite stabilizer containing a calcium-based stabilizer, but, for example, using a composite stabilizer containing both a calcium-based stabilizer and a lead stabilizer is preferred as it is better for obtaining the physical properties and processability of the present invention. In the case of the above composite stabilizer, the composition ratio is not specifically limited, but, for example, a composition ratio of calcium-based stabilizer to lead stabilizer in a weight ratio of 1:0.5 to 1.5 may be used, but is not limited as long as the purpose of the present invention is achieved.

[0058] More specifically, in the present invention, the calcium-based complex stabilizer is not limited as long as it is specifically commercially available, but for example, a salt such as calcium stearate may be used as the calcium salt. For example, as an additional stabilizer, a salt such as lead stearate may be used as the lead-based stabilizer. While the calcium-lead stabilizer is preferred as the calcium-based complex stabilizer because it exhibits superior effects in achieving the effects of the present invention, a calcium-zinc-based stabilizer may also be included within the scope of the present invention. If a zinc-based stabilizer is used, for example, a zinc alkanoate compound such as zinc stearate may be used.

[0059] In addition, the above-mentioned complex stabilizer may include, along with the above-mentioned complex metal salt, one or more components selected from metal hydroxide and metal carbonate, and one or more components selected from wax and oil. The above-mentioned calcium-based complex stabilizer may contain 10 to 40 weight% of a calcium salt, 10 to 40 weight% of other metal salts, and 20 to 40 weight% of one or more components selected from metal oxides or metal carbonates, based on 100 weight parts of the complex stabilizer, but is not limited thereto. For example, commercially available calcium-zinc-based complex stabilizers may include products such as LTX-620N, LTX-630, LTX-630L, LTX-630Q, LTX-630T, and LTX-200PF from KD Chem. Calcium-lead complex stabilizer products containing calcium stearate and lead stearate, such as K-WP09B from Prochem Korea Co., Ltd., may be used.

[0060] The above functional polymer may be any one selected from ethylene-ethyl acrylate (EEA) and polyamide-polyether block copolymers, or a mixture thereof. The above functional polymer may be included in the sheet composition of the present invention to further enhance mechanical properties and significantly improve moldability.

[0061] The content may be 0.1 to 3 parts by weight per 100 parts by weight of PVC-based sash powder, and within the above content range, any one selected from ethylene-ethyl acrylate and polyamide-polyether block copolymer or a mixture thereof may be used.

[0062] For example, when ethylene-ethyl acrylate and polyamide-polyether block copolymer are used simultaneously, they can be mixed in a weight ratio of 20 to 80: 80 to 20, but are not limited thereto.

[0063] For example, with respect to 100 parts by weight of PVC-based sash powder, 0.1 to 3 parts by weight or 0.1 to 2 parts by weight of ethylene-ethyl acrylate may be used, and 0.1 to 3 parts by weight or 0.1 to 2 parts by weight of polyamide-polyether block copolymer may be used. Although not limited thereto, within the above content range, the uniformity of the appearance of the molded article can be further enhanced, mechanical properties can be improved, and the generation of carbons due to localized temperature runaway during processing can be controlled.

[0064] When the above functional enhancers are used individually, each component may be in an amount of 0.1 to 3 parts by weight and 0.1 to 2 parts by weight, and the total of the two components may be in an amount of 3 parts by weight or less and 2 parts by weight or less, and within this range, excellent mechanical properties and processability can be provided simultaneously. In addition, when both components include a functional polymer, it is more preferred as it exhibits even better mechanical properties and processability.

[0065] The above ethylene-ethyl acrylate (EEA) is not specifically limited, but may be, for example, an ethylene-ethyl acrylate copolymer (EEA) containing ethyl acrylate in an amount of 5 to 30 mol%, and commercially available products such as Exxon Mobil's Escor 5100, 5200, etc. may be used.

[0066] The above polyamide-polyether block copolymer is not particularly limited, but commercially available examples include Pelastat 230, Crodastat 400, Arkema PEBAX® Rnew® 1100, etc.

[0067] As an example, the composition ratio of the above eco-friendly sheet pile composition is not particularly limited, but, for example, with respect to 100 parts by weight of PVC-based recycled sash powder, it may be 0.1 to 10 parts by weight of MBS and 0.1 to 10 parts by weight of CPE, 3 to 10 parts by weight of a composite stabilizer and 0.1 to 3 parts by weight of a functional polymer, but is not limited thereto.

[0068] In addition, for every 100 parts by weight of PVC-based recycled sash powder, 0.1 to 10 parts by weight of MBS, 0.1 to 10 parts by weight of CPE, 3 to 10 parts by weight of a composite stabilizer, 0.1 to 3 parts by weight of EEA, and 0.1 to 3 parts by weight of a polyamide-polyether copolymer may be used, but are not limited thereto.

[0069] The present invention may also provide a sheet pile by manufacturing pellets using the sheet pile composition and then extruding them. The extrusion temperature of the sheet pile may be 180 to 300 ℃, 200 to 280 ℃, 230 to 270 ℃, or a value between these values. The manufacturing temperature of the pellets may be 180 to 230 ℃, but is not limited thereto.

[0070] The sheet pile of the present invention may have a Charpy impact strength measured according to KS M ISO 179-1:2012 of 10 KJ / m² or more, 12 KJ / m² or more, 14 KJ / m² or more, 15 KJ / m² or more, 16 KJ / m² or more, 18 KJ / m² or more, 20 KJ / m² or more, 30 KJ / m² or more, 40 KJ / m² or more, and 100 KJ / m² or less, for example, 10 to 100 KJ / m², 12 to 70 KJ / m², 13 to 50 KJ / m², and 15 to 40 KJ / m², but is not necessarily limited thereto.

[0071] In addition, the sheet pile of the present invention may have the characteristic of having a Charpy impact strength value measured after 24 hours of exposure to 6500W Xenon Arc, 0.51 W / ㎡, 63℃±3℃, and 50%±5% RH (humidity) as S2, and an initial Charpy impact strength value of the sheet pile before exposure to the weathering acceleration conditions as S1, wherein the rate of change in Charpy impact strength according to the following Equation 1 is 20% or less, 18% or less, 15% or less, 10% or less, 5% or less, 0% or less, or even better weather resistance.

[0072] [Equation 1] (S2 - S1) / S1 × 100

[0073] For example, the change in the above Sarpi impact strength may be a value of 0 to 20%, 0 to 15%, 0 to 10%, or 0 to 5%.

[0074] In addition, the Charpy impact strength value of the sheet pile measured after 24 hours of exposure to 6500W Xenon Arc, 0.51 W / ㎡, 63℃±3℃, and 50%±5% RH (humidity) may be 10 KJ / ㎡ or more, 12 KJ / ㎡ or more, 14 KJ / ㎡ or more, 15 KJ / ㎡ or more, 16 KJ / ㎡ or more, 18 KJ / ㎡ or more, 20 KJ / ㎡ or more, 30 KJ / ㎡ or more, 40 KJ / ㎡ or more, and 100 KJ / ㎡ or less, for example, 10 to 100 KJ / ㎡, 12 to 70 KJ / ㎡, 13 to 50 KJ / ㎡, and 14 to 40 KJ / ㎡, but is not necessarily limited thereto.

[0075] In addition, the flexural strength of the above sheet file measured in accordance with the standards of “KS M ISO 178:2012” may be 50 MPa or more, 60 MPa or more, 65 MPa or more, 70 MPa or more, 80 MPa or more, 100 MPa or more, and 200 MPa or less, for example, 50 to 200 MPa, and 60 to 100 MPa. In addition, the flexural strength of the above sheet file measured after exposure to 100℃ for 20 hours may be 50 MPa or more, 60 MPa or more, 70 MPa or more, 80 MPa or more, 100 MPa or more, and 200 MPa or less, for example, 50 to 200 MPa, and 60 to 100 MPa.

[0076] When the flexural strength measured after exposure to 100°C for 20 hours is denoted as F2 and the initial flexural strength as F1, the rate of change of flexural strength according to the following Equation 2 may be 25% or less, 20% or less, 15% or less, 10% or less, for example, 0 to 25%, 4 to 25%, 4 to 23%, 5 to 20%, and a value between the above values.

[0077] [Equation 2] (F2 - F1) / F1 × 100

[0078] The sheet file of the present invention may have a flexural modulus measured by the method of “KS M ISO 178:2012” of 2.0 GPa or more, 2.1 GPa or more, 2.2 GPa or more, 2.3 GPa or more, 2.4 GPa or more, 2.5 GPa or more, 5.0 GPa or less, 4 GPa or less, and values ​​between these values.

[0079] In addition, the sheet pile of the present invention may have a tensile strength measured according to KS M ISO 527-2:2012 of 30 MPa or more, 35 MPa or more, 38 MPa or more, 40 MPa or more, 50 MPa or more, 70 MPa or more, and 100 MPa or less, and may have a value between the above values. For example, it may be 30 MPa to 100 MPa or 35 to 55 MPa.

[0080] In addition, it may have the characteristic that the tensile strength does not decrease in a weathering test in which it is left for 1,000 hours according to the KS M ISO 4892-2:2017 method. That is, the tensile strength may not decrease according to the above weathering accelerated test, but rather remain the same or increase within 10%.

[0081] In addition, the sheet pile of the present invention may have a specific gravity of 1.35 or higher, 1.40 or higher, 1.45 or higher, 1.6 or higher, 1.7 or higher, or up to 1.8 as measured by KS M ISO 1183-1:2012 specific gravity ((23 / 23)℃) (Method A), so that when installed in seawater or freshwater, it may float or have high stability during long-term use due to sufficient specific gravity. Although the specific gravity of the pile sheet manufactured with the composition of the present invention is not specifically stated, it is advantageous that the specific gravity is higher than that of the comparative examples, thereby reducing the possibility of floating due to flow velocity and increasing stability.

[0082] The sheet pile of the present invention has excellent mechanical strength, including tensile strength, flexural strength, and impact strength, which prevents damage caused by earth pressure, water pressure, or impact; additionally, it has good elasticity and is easy to cut, resulting in excellent workability during construction.

[0084] Hereinafter, an example of a sheet pile resin composition according to the present invention and a sheet pile manufactured therefrom is described; however, the present invention is not limited to the following examples. That is, the present invention can be better understood by the following examples. The following examples are for the purpose of illustrating the present invention and are not intended to limit the scope of protection defined by the appended claims. Unless otherwise defined, technical and scientific terms used herein have the meanings commonly understood by those skilled in the art to which this invention pertains.

[0086] (evaluation)

[0087] (1) Tensile strength: Measured according to the specifications of KS M ISO 527-2:2013 (test speed: 2.9 mm / min, test specimen: Type 1B).

[0088] (2) Flexural strength (I), flexural strength (II) and flexural modulus: Measured according to the standards of KS M ISO 178:2012 (test speed: 2.9 mm / min, support distance: 110 mm). In addition, flexural strength (II) was measured after exposure to 100 ℃ for 20 hours.

[0089] (3) Charpy impact strength (I) and Charpy impact strength (II): Measured according to KS M ISO 179-1:2012 (notch type: A) (unit: KJ / ㎡). In addition, Charpy impact strength (II) was measured under the following conditions using an accelerated weathering tester.

[0090] - Light Source: 6500W Xenon Arc, Irradiance: 0.51W / ㎡

[0091] - BPT: 63℃±3℃, Humidity:50%±5% RH

[0092] - Exposure Period: 24hr

[0093] (4) Moldability: When extruding to a thickness of 0.5 mm using a Brabender Single extruder T-die, if there is no carbonization and the surface is smooth and defect-free, the moldability and appearance are very good, marked ◎; if it is generally good, marked ○; and if carbonization occurs and the moldability is poor, marked ×.

[0095] (Examples 1 to 8)

[0096] A resin composition was prepared by crushing used PVC-based LG Hausis window frames collected after use to produce sash powder with an average particle size of 1.2 mm, MBS (Samwoo Chem, MB838A), CPE (Shangdong Changtai 135A), a calcium-lead composite stabilizer (Prochem Korea Co., Ltd., K-WP09B), ethylene-ethyl acrylate (EEA, weight-average molecular weight of 73000 with 15 mol% ethyl acrylate), and a polyamide-polyether block copolymer (Arkema, PEBAX® Rnew® 1100) in the amounts shown in Table 1 below.

[0097] After producing pellets by melt-kneading the above resin composition in an extruder, a pile sheet was produced by melt-extruding the pellets in an extruder.

[0098] The above extruder was a twin-screw extruder with L / D=42 and Φ=40mm, and the pellets were formed by extrusion at 200°C. The pellets were melted using the extruder at an extrusion temperature of 260°C and extruded through a forming die to produce a sheet pile of the form shown in Fig. 1. It was found that the manufactured sheet pile had good surface smoothness and excellent processability as it was extruded well without carbonization.

[0099] In addition, to evaluate physical properties, specimens were separately prepared in an injection molding machine under conditions of 260°C, and the physical properties were analyzed according to the above evaluation method and recorded in Table 2 below. At this time, the composition of the above components is listed in Table 1 below.

[0100] (Comparative Example 1)

[0101] The same method as in Example 1 was used, except that MBS was not used in Example 1.

[0102] (Comparative Example 2)

[0103] The same method as Example 1 was used, except that CPE was not used in Example 1.

[0104] (Comparative Example 3)

[0105] The same method and composition as Example 1 were used, except that a complex stabilizer was not used in Example 1.

[0106] (Comparative Example 4)

[0107] The procedure was carried out using the same method and composition as in Example 1, except that a barium-zinc complex stabilizer was used instead of the calcium-based complex stabilizer used in Example 1.

[0108] (Comparative Example 5)

[0109] The same method and composition as in Example 1 were used, except that ethylene-ethyl acrylate and polyamide-polyether block copolymer were not used in Example 1.

[0110] PVC sash powder (parts by weight) MBS (Weighted Parts) CPE (weight part) EEA (weight part) Polyamide-polyether block copolymer (parts by weight) Complex stabilizer (parts by weight) Example 1 100 5 3.5 0.5 0.5 5.5 Example 2 100 2 3.5 0.2 0.5 5.5 Example 3 100 5 6 0.2 0.2 5.5 Example 4 100 5 6 1.5 1.0 8 Example 5 100 7.5 3.5 0.5 1.2 5.5 Example 6 100 5 6 0.3 0.9 4 Example 7 100 5 3.5 0.5 - 5.5 Example 8 100 5 3.5 - 0.5 5.5 Comparative Example 1 100 - 3.5 0.5 0.5 5.5 Comparative Example 2 100 5 - 0.5 0.5 5.5 Comparative Example 3 100 5 3.5 0.5 0.5 - Comparative Example 4 100 5 3.5 0.5 0.5 5.5(Ba-Zn) Comparative Example 5 100 5 3.5 - - 5.5

[0111] Tensile strength (MPa) Flexural strength (MPa) Flexural modulus (GPa) Charpy impact strength (kJ / m²) Plasticity (I) (II) (I) (II) Example 1 58 93 88 3.8 42 35 ◎ Example 2 38 78 63 2.5 18 16 ◎ Example 3 41 75 64 2.4 16 14 ◎ Example 4 42 68 61 2.77 20 19 ◎ Example 5 50 78 62 2.3 19 18 ◎ Example 6 46 72 62 2.5 17 16 ◎ Example 7 45 80 78 2.6 33 30 ○ Example 8 44 79 80 2.7 33 31 ○ Comparative Example 1 30 56 50 1.8 12 11 × Comparative Example 2 28 64 48 1.7 8 7 × Comparative Example 3 25 60 45 2.1 10 9 × Comparative Example 4 35 71 48 2.4 34 20 × Comparative Example 5 42 68 50 2.0 14 12 X

[0112] As can be seen in Table 2 above, Example 1 according to the present invention exhibited excellent tensile strength, flexural strength, flexural modulus, and impact strength, and demonstrated very excellent formability. In addition, it was confirmed that it maintained excellent physical properties in heat resistance tests and accelerated weathering tests. Although Examples 2 to 6 show some changes in physical properties compared to Example 1 due to changes in component content, it can be seen that the sheet pile intended by the present invention can be manufactured with excellent Charpy impact strength, flexural strength, flexural modulus, and tensile strength. It is believed that these properties are well demonstrated by the excellent processability, extrudability, and miscibility of the composition of the present invention.

[0113] In addition, it was confirmed that the sheet piles manufactured from Examples 1 to 6 maintain their durability and mechanical properties in seawater as well as freshwater.

[0114] In addition, as seen in Examples 1 to 6 and Examples 7 and 8, it was confirmed that the moldability and mechanical properties are superior when using a mixture of ethylene-ethyl acrylate and polyamide-polyether block copolymer compared to when only one of these components is included.

[0116] As described above, the present invention has been explained by limited embodiments, but this is provided merely to aid in a more comprehensive understanding of the invention. The present invention is not limited to the above embodiments, and those skilled in the art can make various modifications and variations from this description.

[0117] Accordingly, the scope of the present invention is not limited to the described embodiments, and all things equivalent to or having equivalent variations to the claims set forth below, as well as the claims set forth below, shall be considered to fall within the scope of the concept of the present invention.

Claims

Claim 1 A sheet pile comprising PVC-based sash powder, methyl methacrylate butadiene styrene (MBS), chlorinated polyethylene (CPE), a composite stabilizer including a calcium-based stabilizer, and a functional polymer, wherein the functional polymer is a mixture of ethylene-ethyl acrylate and a polyamide-polyether block copolymer. Claim 2 In paragraph 1, the PVC-based sash powder is a sheet pile that is powder obtained by crushing recycled PVC-based sashes. Claim 3 In claim 1, the sheet pile has a Charpy impact strength of 10 KJ / ㎡ to 100 KJ / ㎡ as measured according to KS M ISO 179-1:2012, a flexural strength of 50 to 200 MPa as measured according to KS M ISO 178:2012, and a flexural modulus of 2.0 GPa or more. Claim 4 In paragraph 3, the sheet pile has a tensile strength of 30 MPa to 100 MPa as measured according to KS M ISO 527-2:2012. Claim 5 A sheet pile according to claim 3, wherein the rate of change in Charpy impact strength measured after 24 hours of exposure at 6500W Xenon Arc, 0.51W / ㎡, 63℃±3℃, and 50%±5% RH (humidity) is 20% or less, and the rate of change in flexural strength measured after 20 hours of exposure at 100℃ is 25% or less. Claim 6 The sheet pile according to claim 1, wherein the sheet pile comprises 0.1 to 10 parts by weight of MBS, 0.1 to 10 parts by weight of CPE, 3 to 10 parts by weight of a composite stabilizer, and 0.1 to 3 parts by weight of a functional polymer, based on 100 parts by weight of PVC-based sash powder. Claim 7 A sheet pile composition comprising PVC-based sash powder, methyl methacrylate butadiene styrene (MBS), chlorinated polyethylene (CPE), a composite stabilizer including a calcium-based stabilizer, and a functional polymer, wherein the functional polymer is a mixture of ethylene-ethyl acrylate and a polyamide-polyether block copolymer. Claim 8 In claim 7, the above-mentioned PVC-based sash powder is a sheet pile composition in which the PVC-based sash powder is a powder obtained by crushing recycled PVC-based sashes. Claim 9 In claim 7, the sheet pile composition comprises, with respect to 100 parts by weight of PVC-based sash powder, 0.1 to 10 parts by weight of MBS, 0.1 to 10 parts by weight of CPE, 3 to 10 parts by weight of a composite stabilizer, and 0.1 to 3 parts by weight of a functional polymer.

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