Sheath composition having an excellent cool resistance and flame retardance and cable comprising a sheath layer formed from the same

Abstract

The present invention relates to a sheath composition having excellent cold resistance and flame retardancy, and a cable having a sheath layer formed therefrom. Specifically, the present invention relates to a sheath composition having excellent cold resistance and flame retardancy, which are mutually trade-off properties, as well as excellent room temperature mechanical properties, heat resistance, oil resistance, weather resistance, extrudability, etc., and a cable having a sheath layer formed therefrom, which reduces manufacturing costs.

Description

Technology Field

[0001] The present invention relates to a sheath composition having excellent cold resistance and flame retardancy, and a cable having a sheath layer formed therefrom. Specifically, the present invention relates to a sheath composition having excellent cold resistance and flame retardancy, which are mutually trade-off properties, as well as excellent room temperature mechanical properties, heat resistance, oil resistance, weather resistance, extrudability, etc., and a cable having a sheath layer formed therefrom, which reduces manufacturing costs. Background Technology

[0002] Depending on the installation environment, cables are classified into indoor wiring cables requiring properties such as flame retardancy, and outdoor wiring cables requiring properties such as ambient temperature mechanical properties, heat resistance, oil resistance, and weather resistance. Additionally, there are cables that must satisfy the characteristics required for both indoor and outdoor wiring cables, such as cables that transmit data, power, or both simultaneously between indoor base station equipment and outdoor devices like RRUs (Remote RF Units) and junction boxes in wireless communication base station systems, where parts are installed indoors and parts are installed outdoors.

[0003] Conventionally, flame retardants are added to cable sheaths to improve the flame retardancy required for indoor wiring cables, but the addition of such flame retardants generally reduces the cold resistance of the cable sheath. Therefore, there were limitations in improving both the flame retardancy required for indoor wiring cables and the cold resistance required for outdoor wiring cables.

[0004] In addition, flame retardants added to the cable sheath have the problem of further reducing the room temperature mechanical properties, heat resistance, oil resistance, extrudability, etc. of the cable sheath.

[0005] Therefore, there is an urgent need for a sheath composition and a cable having a sheath layer formed therefrom that not only have excellent cold resistance and flame retardancy, which are mutually trade-offs, but also have excellent room temperature mechanical properties, heat resistance, oil resistance, weather resistance, extrudability, etc., and reduce manufacturing costs. The problem to be solved

[0006] The present invention aims to provide a sheath composition having excellent cold resistance and flame retardancy, which are in a trade-off relationship, and a cable having a sheath layer formed therefrom.

[0007] In addition, the present invention aims to provide a sheath composition having excellent room temperature mechanical properties, heat resistance, oil resistance, weather resistance, extrudability, etc., and reduced manufacturing costs, and a cable having a sheath layer formed therefrom. means of solving the problem

[0008] To solve the above problem, the present invention,

[0009] A sheath composition is provided that includes polyvinyl chloride (PVC) resin as a base resin, includes a flame retardant and a plasticizer, and has a brittleness temperature of -48°C or lower as measured in accordance with the standard ASTM D 746.

[0010] Herein, a cis composition is provided, characterized by additionally including a modifier, wherein the modifier comprises a terpolymer resin of an olefin monomer and a polar monomer.

[0011] The present invention provides a cis composition characterized by comprising one or more selected from the group consisting of ethylene / vinyl acetate / carbon monoxide terpolymer, ethylene / n-butyl acrylate / carbon monoxide terpolymer, and ethylene / butyl acrylate / glycidyl methacrylate terpolymer.

[0012] In addition, the present invention provides a cis composition characterized in that the terpolymer has a weight-average molecular weight of 200,000 or more, a melting point of 35 to 80°C, a melting index of 30 to 50 g / 10 min, and a polar monomer content of 30 to 40 weight% based on the total weight of the terpolymer.

[0013] Furthermore, a cis composition is provided, characterized in that the content of the modifier is 7 to 18 weight% based on the total weight of the cis composition.

[0014] Meanwhile, the present invention provides a cis composition characterized by the fact that the plasticizer comprises a trimellitate-based plasticizer and an adipate-based plasticizer.

[0015] Herein, a cis composition is provided, characterized in that the trimellitate-based plasticizer comprises triisononyl trimellitate (TINTM) and the adipate-based plasticizer comprises diisononyl adipate (DINA).

[0016] In addition, a cis composition is provided, characterized by including an antimony-based flame retardant and a metal hydroxide flame retardant.

[0017] In addition, a sheath composition is provided, characterized in that, based on the total weight of the sheath composition, the content of the flame retardant is 12 to 27 weight% and the content of the plasticizer is 13 to 33 weight%.

[0018] Herein, a sheath composition is provided, characterized in that, based on the total weight of the sheath composition, the content of the metal hydroxide flame retardant is 9 to 17 weight% and the content of the antimony-based flame retardant is 3 to 10 weight%.

[0019] In addition, the present invention provides a cis composition characterized in that, based on the total weight of the cis composition, the content of the trimellitate-based plasticizer is 2 to 10 weight% and the content of the adipate-based plasticizer is 11 to 23 weight%.

[0020] Furthermore, the present invention provides a sheath composition characterized in that the polyvinyl chloride (PVC) resin has a number average degree of polymerization of 1,000 to 1,700.

[0021] Herein, a sheath composition is provided, characterized in that, based on the total weight of the sheath composition, the content of the polyvinyl chloride (PVC) resin is 32 to 50 weight%.

[0022] In addition, the present invention provides a sheath composition characterized by further including 1 to 4 weight% of a heat stabilizer, 0.05 to 3 weight% of a UV stabilizer, and 1.5 to 4 weight% of a pigment, based on the total weight of the sheath composition.

[0023] Meanwhile, a cable is provided comprising one or more cores including a conductor and an insulating layer surrounding the conductor; and a sheath layer that completely surrounds the one or more cores and is formed from a sheath composition of any one of claims 1 to 5. Effects of the invention

[0024] The cis composition according to the present invention exhibits excellent effects, including not only excellent cold resistance and flame retardancy through a combination of specific flame retardants, plasticizers, and modifiers, but also excellent room temperature mechanical properties, heat resistance, oil resistance, weather resistance, extrudability, etc., and reduced manufacturing costs. Brief explanation of the drawing

[0025] FIG. 1 schematically illustrates a cross-section of one embodiment of a cable according to the present invention. FIG. 2 schematically illustrates a cross-section of another embodiment of a cable according to the present invention. FIG. 3 schematically illustrates a cross-section of another embodiment of a cable according to the present invention. Specific details for implementing the invention

[0026] Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed content is thorough and complete, and to ensure that the spirit of the present invention is sufficiently conveyed to those skilled in the art. Throughout the specification, the same reference numerals indicate the same components.

[0027] FIGS. 1 to 3 schematically illustrate cross-sectional views of embodiments of a cable according to the present invention.

[0028] As illustrated in FIGS. 1 to 3, the cable according to the present invention may include one or more cores (10) having a conductor (11) made of copper, aluminum, or an alloy thereof and an insulating layer (12) surrounding the conductor (11), a binding member (20) that surrounds the one or more cores (10) to maintain a stable structure, an interlayer that fills the empty space between the core (10) and the binding member (20) to improve the roundness of the cable, and a sheath layer (40) that surrounds the binding member (20) to protect the internal structure from external shock or pressure.

[0029] Additionally, the cable according to the present invention may further include a metal shielding layer (not shown) made of aluminum tape or tin-plated copper braided layer that wraps the binding member (20) and performs an electromagnetic shielding function, a rip cord (not shown) that facilitates the removal of the sheath layer (40), and the empty space between the core (10) and the sheath layer (40) may be filled with a filler to improve roundness, and the binding member may bind the core (10) with binding tape or binding yarn, etc.

[0030] The sheath composition according to the present invention forming the sheath layer (40) comprises polyvinyl chloride (PCV) resin as a base resin and may include additives such as flame retardants, plasticizers, modifiers, stabilizers, and pigments.

[0031] Here, the polyvinyl chloride (PVC) resin is not particularly limited and may include a polyvinyl chloride (PVC) resin having a number average degree of polymerization of 1,000 to 1,700, preferably 1,300 to 1,500. If the number average degree of polymerization of the polyvinyl chloride (PVC) resin is less than 1,000, the physical properties of the sheath layer (40), such as room temperature mechanical properties, heat resistance, and oil resistance, may be significantly reduced, whereas if the number average degree of polymerization exceeds 1,700, the manufacturing cost may increase unnecessarily.

[0032] Here, based on the total weight of the sheath composition, the total content of the polyvinyl chloride (PVC) resin may be 32 to 50 weight%. If the total content of the polyvinyl chloride (PVC) resin is below the standard, the room temperature mechanical properties of the sheath composition may be significantly reduced, whereas if it exceeds the standard, the heat resistance and extrudability of the sheath composition may be reduced.

[0033] The above flame retardant performs the function of improving the flame retardancy of the sheath layer (40), and may be used in combination with metal hydroxide flame retardants such as aluminum hydroxide and magnesium hydroxide, and antimony-based flame retardants such as antimony trioxide. By combining metal hydroxide flame retardants and antimony-based flame retardants, the manufacturing cost of the sheath composition can be minimized while achieving an effect of increased flame retardancy.

[0034] Here, based on the total weight of the sheath composition, the total content of the flame retardant may be 12 to 27 weight%, in particular, the content of the metal hydroxide flame retardant may be 9 to 17 weight%, and the content of the antimony-based flame retardant may be 3 to 10 weight%. The antimony-based flame retardant functions as a gaseous fire extinguisher through a mechanism different from that of the metal hydroxide when decomposed by high heat. Here, if the total content of the flame retardant is below the standard, the flame retardancy of the sheath composition may be significantly reduced, whereas if it exceeds the standard, the cold resistance, room temperature mechanical properties, heat resistance, oil resistance, extrudability, etc. of the sheath composition may be significantly reduced.

[0035] In addition, assuming that the content of the flame retardant satisfies the above standards, if the content of the metal hydroxide flame retardant is below the standard, the flame retardancy of the sheath composition may be insufficient, whereas if the content of the metal hydroxide flame retardant exceeds the standard, the manufacturing cost of the sheath composition may increase unnecessarily.

[0036] And, assuming that the content of the flame retardant satisfies the above standards, if the content of the antimony-based flame retardant is below the standard, the flame retardancy of the cis composition may be insufficient, whereas if the content of the antimony-based flame retardant exceeds the standard, it may not be able to address environmental issues.

[0037] Although polyvinyl chloride (PVC) resin, used as the base resin, exhibits excellent flexibility and elasticity, when mixed with a flame retardant to improve flame resistance, its cold resistance is significantly reduced. Furthermore, when a plasticizer is added to compensate for the reduced cold resistance, the plasticizer has the drawback of being prone to migration, volatilization, and leaching.

[0038] Accordingly, the present invention is characterized by adding a specific modifier to modify the base resin in order to suppress the migration, volatilization, and leaching of the plasticizer within the base resin, while compensating for the reduced cold resistance resulting from the addition of the flame retardant described above to achieve the desired flame retardancy by adding a specific plasticizer combination.

[0039] The above plasticizers may be mixed with trimellitate-based plasticizers such as trioctyl trimellitate (TOTM) and triisononyl trimellitate (TINTM), which have a lower unit cost compared to conventional phthalate-based plasticizers and can reduce the manufacturing cost of the above cis composition, and adipate-based plasticizers such as diisononyl adipate (DINA), dioctyl adipate (DOA), diisooctyl adipate (DIOA), and diisodecyl adipate (DIDA). Preferably, triisononyl trimellitate (TINTM), which has excellent heat resistance and migration resistance, and diisononyl adipate (DINA), which has excellent cold resistance, may be mixed.

[0040] Based on the total weight of the sheath composition, the total content of the plasticizer may be 13 to 33 weight%, in particular, the content of the trimellitate-based plasticizer may be 2 to 10 weight%, and the content of the adipate-based plasticizer may be 11 to 23 weight%. Here, if the content of the plasticizer is below the standard, the cold resistance, extrudability, etc. of the sheath composition may be significantly reduced, whereas if the content of the plasticizer exceeds the standard, the mechanical properties, heat resistance, etc. of the sheath composition may be significantly reduced.

[0041] In addition, assuming that the content of the plasticizer satisfies the standard, if the content of the trimellitate-based plasticizer is below the standard, the heat resistance of the cis composition may be insufficient and problems such as migration, volatilization, and leaching of the plasticizer may occur, whereas if the content of the trimellitate-based plasticizer exceeds the standard, the room temperature mechanical properties and heat resistance of the cis composition may be reduced.

[0042] In addition, if the content of the adipate-based plasticizer is below the standard, the cold resistance of the cis composition may be insufficient, whereas if the content of the adipate-based plasticizer exceeds the standard, the room temperature mechanical properties, cold resistance, and heat resistance of the cis composition may be reduced.

[0043] The above modifier inhibits the migration, volatilization, and leaching of the plasticizer within the polyvinyl chloride (PVC) resin as the base resin and improves the impact resistance of the base resin, thereby maintaining the improvement in cold resistance caused by the plasticizer and inhibiting the deterioration of the base resin.

[0044] The above modifier may include copolymer resins of olefin monomers and polar monomers, for example, ethylene / vinyl acetate / carbon monoxide terpolymer, ethylene / n-butyl acrylate / carbon monoxide terpolymer, ethylene / butyl acrylate / glycidyl methacrylate terpolymer, etc.

[0045] The above terpolymer has a weight-average molecular weight of 200,000 or more, for example, 250,000 to 300,000, a melting point of 35 to 80°C, a melting index of 30 to 50 g / 10 min, and may contain 30 to 40 weight% of polar monomers such as vinyl acetate and butyl acrylate based on the total weight of the above terpolymer.

[0046] Here, based on the total weight of the sheath composition, the content of the modifier may be 7 to 18 weight percent. If the content of the modifier is below the standard, the plasticizer may migrate, volatilize, or leach out, causing the cold resistance of the sheath composition to be significantly reduced and the base resin to be altered, which may cause the room temperature mechanical properties, heat resistance, oil resistance, weather resistance, etc. to be significantly reduced, whereas if the content of the modifier exceeds the standard, the cold resistance and impact resistance may be reduced.

[0047] Additionally, the stabilizer may include a thermal stabilizer, such as a zinc-based stabilizer, that improves the thermal stability of the sheath composition, and a UV stabilizer, that improves the UV stability of the sheath composition. Based on the total weight of the sheath composition, the content of the thermal stabilizer may be 1 to 4 weight%, and the content of the UV stabilizer may be 0.05 to 3 weight%. Furthermore, the pigment is an additive for realizing a specific color of the sheath layer (40), and based on the total weight of the sheath composition, the content of the pigment may be 1.5 to 7 weight%.

[0048] A sheath layer specimen formed from the sheath composition according to the present invention can have a brittleness temperature (ASTM D 746) of -48°C or lower, preferably -52°C or lower, through the combination of the specific base resin, plasticizer, and modifier described above, thereby possessing cold resistance capable of passing the low-temperature impact test according to standard UL1581.

[0050] [Example]

[0052] 1. Preparation Example

[0054] A sheath composition, a sheath layer specimen, and a cable specimen of FIG. 2 having a sheath layer formed from the sheath composition were prepared using the components and contents listed in Table 1 below. The unit of the contents listed in the table below is weight%.

[0056] Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 profit 42.3 39.8 48.9 47.4 37.0 38.4 42.1 Flame retardant 1 5.7 6.0 7.2 1.8 8.2 5.0 7..7 Flame retardant 2 12.0 12.7 13.7 11.0 9.3 17.1 14.3 Plasticizer 1 5.2 5.0 - 4.6 3.9 4.6 5.0 Plasticizer 2 17.9 18.5 - 18.9 18.3 15.2 20.0 Plasticizer 3 - - 9.4 - - - - Plasticizer 4 - - 16.4 - - - - Modifier 12.5 13.6 - 11.9 18.9 14.8 6.5 Stabilizer 1 2.5 2.5 2.5 2.5 2.5 2.5 2.5 Stabilizer 2 0.1 0.1 0.1 0.1 0.1 0.1 0.1 pigment 1.8 1.8 1.8 1.8 1.8 1.8 1.8

[0057] - Resin: Polyvinyl chloride (PVC) resin (Degree of polymerization: 1,300)

[0058] - Flame Retardant 1: Antimony Trioxide

[0059] - Flame Retardant 2: Aluminum Hydroxide

[0060] - Plasticizer 1: Triisononyl trimellitate (TINTM)

[0061] - Plasticizer 2: Diisononyl Adipate (DINA)

[0062] - Plasticizer 3: Dioctyl sebacate (DOS)

[0063] - Plasticizer 4: Diisodecyl phthalate (DIDP)

[0064] - Modifier: Ethylene / vinyl acetate / carbon monoxide terpolymer

[0065] - Stabilizer 1: Zinc-based stabilizer

[0066] - Stabilizer 2: UV stabilizer

[0067] - Pigment: Carbon Black

[0069] 2. Evaluation of physical properties

[0071] 1) Evaluation of mechanical properties at room temperature

[0072] In accordance with standard KS C 3008 18, tensile strength and elongation were measured for the sheath layer specimens of the examples and comparative examples at room temperature at a tensile speed of 200 ± 50 mm. Here, the tensile strength must be 13.8 MPa or higher, and the elongation must be 100% or higher.

[0074] 2) Heat resistance evaluation

[0075] In accordance with standard KS C 3008 19, tensile strength and elongation were measured for the sheath layer specimen of Example 1 after deterioration at 121°C for 336 hours, and the tensile retention and elongation retention were calculated based on room temperature tensile strength and elongation. Here, the tensile retention must be 75% or more, and the elongation retention must be 65% or more.

[0077] 3) Oil resistance evaluation

[0078] In accordance with the standard KS M 3156, the sheath layer specimen of Example 1 was immersed in IRM 902 oil at 70°C for 4 hours, and the tensile strength and elongation were measured. The tensile retention and elongation retention based on room temperature tensile strength and elongation were calculated. Here, the tensile retention must be 75% or more, and the elongation retention must be 65% or more.

[0080] 4) Flame Retardancy Evaluation

[0081] The oxygen index (LOI) was measured for the sheath layer specimens of the examples and comparative examples in accordance with the standard KS M 3032. Here, the oxygen index must be 30 or higher.

[0083] 5) Evaluation of Brittleness Temperature

[0084] The brittleness temperature of the sheath layer specimens of the examples and comparative examples was measured in accordance with the standard ASTM D 746. Specifically, the brittleness temperature of the sheath layer specimens was defined as the lowest temperature of the methyl alcohol solution at which no cracks occurred in all 10 specimens when 10 specimens prepared in the Type 1 form of ASTM D 746 were clamped in a jig, immersed in a methyl alcohol solution containing dry ice for 2 minutes and 30 seconds, and then struck at a speed of 2,000 ± 200 mm / s. Here, the brittleness temperature must be -48℃ or lower.

[0086] 6) Low-temperature impact test evaluation

[0087] In accordance with the standard UL1581, eight cable specimens of the example and comparative example were left at -40°C for 4 hours, and then within 15 seconds, a weight with a diameter of 25.4 mm and a weight of 1.36 kg was dropped from a height of 0.915 m at room temperature to strike them, and then a visual evaluation was conducted to see if any crack occurred in the sheath layer of any of the cable specimens.

[0089] The results of the above physical property evaluation are as described in Table 2 below.

[0091] Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 room temperature Tensile strength (MPa) 14.7 15.1 15.2 17.9 16.5 14.3 14.9 Growth rate (%) 331 268 317 299 218 92 223 heating Remaining Retention Rate (%) 150 132 171 83 91 143 129 Growth Remaining Rate (%) 85 88 76 62 72 84 71 Internal oil Remaining Retention Rate (%) 98 101 85 83 93 73 95 Growth Remaining Rate (%) 84 79 74 87 83 70 80 Oxygen index 32 33 30 27 28 31 30 Brittleness temperature (°C) -57 -55 -42 -52 -48 -45 -38 low-temperature impact test Passed Passed Failure Passed Failure Failure Failure

[0093] As shown in Table 2 above, the sheath layer specimens and cable specimens of Example 1 and Example 2 according to the present invention were confirmed to have excellent physical properties such as room temperature mechanical properties, heat resistance, oil resistance, flame retardancy, and cold resistance.

[0094] Meanwhile, it was confirmed that the sheath layer specimen of Comparative Example 1 had increased manufacturing costs due to the application of a high-cost phthalate-based plasticizer, and that cold resistance was significantly reduced due to migration, volatilization, and leaching of the plasticizer due to the non-application of a modifier.

[0095] It was confirmed that the sheath layer specimen of Comparative Example 2 had significantly reduced flame retardancy due to the lowered flame retardant content.

[0096] It was confirmed that the heat resistance properties of the sheath layer specimen of Comparative Example 3 deteriorated due to exceeding the modifier content.

[0097] It was confirmed that the sheath layer specimen of Comparative Example 4 had reduced cold resistance, room temperature mechanical properties, and oil resistance due to exceeding the metal hydroxide flame retardant content.

[0098] In addition, it was confirmed that the cold resistance properties of the sheath layer specimen of Comparative Example 5 deteriorated due to the reduced modifier content.

[0100] Although this specification has been described with reference to preferred embodiments of the present invention, those skilled in the art may modify and change the present invention in various ways without departing from the spirit and scope of the present invention as described in the claims below. Therefore, if a modified embodiment basically includes the components of the claims of the present invention, it should be considered to be included within the technical scope of the present invention. Explanation of the symbols

[0102] 10 : Core 20 : Binding part 30 : Intersection 40 : Sheath layer

Claims

Claim 1 A sheath composition comprising polyvinyl chloride (PVC) resin as a base resin, and comprising a flame retardant, a plasticizer, and a modifier, wherein the flame retardant comprises 9 to 17 weight% of a metal hydroxide flame retardant and 3 to 10 weight% of an antimony-based flame retardant based on the total weight of the sheath composition, the plasticizer comprises 2 to 10 weight% of triisononyl trimellitate (TINTM) and 11 to 23 weight% of diisononyl adipate (DINA) based on the total weight of the sheath composition, the content of the modifier is 7 to 18 weight% based on the total weight of the sheath composition, and the brittleness temperature measured in accordance with ASTM D 746 is -48°C or lower. Claim 2 A cis composition according to claim 1, characterized in that the modifier comprises a terpolymer resin of an olefin monomer and a polar monomer. Claim 3 A cis composition according to claim 2, characterized in that the terpolymer resin comprises one or more selected from the group consisting of ethylene / vinyl acetate / carbon monoxide terpolymer, ethylene / n-butyl acrylate / carbon monoxide terpolymer, and ethylene / butyl acrylate / glycidyl methacrylate terpolymer. Claim 4 A cis composition according to claim 3, wherein the terpolymer has a weight-average molecular weight of 200,000 or more, a melting point of 35 to 80°C, a melting index of 30 to 50 g / 10 min, and a polar monomer content of 30 to 40 weight% based on the total weight of the terpolymer. Claim 5 delete Claim 6 delete Claim 7 delete Claim 8 delete Claim 9 delete Claim 10 delete Claim 11 delete Claim 12 A cis composition according to any one of claims 1 to 4, characterized in that the polyvinyl chloride (PVC) resin has a number average degree of polymerization of 1,000 to 1,700. Claim 13 A sheath composition according to claim 12, characterized in that, based on the total weight of the sheath composition, the content of the polyvinyl chloride (PVC) resin is 32 to 50 weight%. Claim 14 A sheath composition according to any one of claims 1 to 4, characterized by further comprising, based on the total weight of the sheath composition, 1 to 4 weight% of a heat stabilizer, 0.05 to 3 weight% of a UV stabilizer, and 1.5 to 4 weight% of a pigment. Claim 15 A cable comprising one or more cores including a conductor and an insulating layer surrounding the conductor; and a sheath layer that completely surrounds the one or more cores and is formed from a sheath composition of any one of claims 1 to 4.

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