Low-dielectric-property polypropylene resin composition for automobile communication cable

Abstract

The present invention relates to a polypropylene resin composition having low dielectric properties for an internal coating material of an automobile communication cable, and an internal coating material of an automobile communication cable prepared therefrom. The polypropylene resin composition according to an embodiment of the present invention exhibits low dielectric properties, and can be effectively used as an internal coating material for an automotive communication cable.

Description

Technical Field

[0001] The present invention relates to a polypropylene resin composition with low dielectric properties for automotive communication cables and a molded article made therefrom. Specifically, the present invention relates to a polypropylene resin composition with low dielectric properties for use as an inner sheathing material for automotive communication cables and an inner sheathing material for automotive communication cables made therefrom. Background Art

[0002] Polypropylene resin is a general-purpose resin that is widely used as a material for films, pipes, automotive interior and exterior parts, components for electrical and home appliances, construction and industrial materials, etc. due to its excellent economy, mechanical properties, formability and chemical resistance.

[0003] In particular, polypropylene resin has excellent insulation properties, and therefore attempts have been made to use it as an insulation material for power cables.

[0004] For example, Korean Patent Application Publication No. 10-2018-0076413 discloses a polypropylene resin composition including a propylene homopolymer or a random copolymer of propylene and one or more α-olefins other than propylene, and the content of metal catalyst residue is controlled below a certain level.

[0005] In addition, Korean Patent Application Publication No. 10-2021-0054135 discloses a technology for improving insulation resistance by surface-treating inorganic nanoparticles through a sol-gel reaction between hydroxy acid and silane and mixing them with polypropylene resin.

[0006] However, there is a need to develop a polypropylene resin composition suitable for an inner coating material of an automotive communication cable.

[0007]

Prior art literature

[0008] [Patent Literature]

[0009] (Patent Document 1) Korean Patent Application Publication No. 10-2018-0076413;

[0010] (Patent Document 2) Korean Patent Application Publication No. 10-2021-0054135. Summary of the Invention

[0011] Technical issues

[0012] The object of the present invention is to provide a polypropylene resin composition with low dielectric properties suitable for use as an inner covering material for automobile communication cables, and a molded product made therefrom, specifically an inner covering material for automobile communication cables.

[0013] Technical Solution

[0014] To achieve the above object, according to one embodiment of the present invention, a polypropylene resin composition is provided, comprising a polypropylene resin (A), wherein the polypropylene resin (A) comprises: a first polypropylene resin (A1), wherein the first polypropylene resin (A1) has a melt index of 2.3 to 3.3 g / 10 min, as measured at 230° C. and a load of 2.16 kg, and a xylene soluble content of 18 to 22 wt%; and a second polypropylene resin (A2), wherein the second polypropylene resin (A2) has a melt index of 1.5 to 2.0 g / 10 min, as measured at 230° C. and a load of 2.16 kg, and a xylene soluble content of 13 to 17 wt%, and the weight ratio of the first polypropylene resin (A1) to the second polypropylene resin (A2) is 9:1 to 7:3.

[0015] In a specific embodiment of the present invention, both the first polypropylene-based resin (A1) and the second polypropylene-based resin (A2) may be ethylene-propylene block copolymers.

[0016] In a specific embodiment of the present invention, the polypropylene resin composition may further comprise, based on the total weight of components (A) to (D), 0 to 1.0 wt% of an antioxidant (B), 0 to 1.0 wt% of a long-term heat stabilizer (C), and 0 to 1.0 wt% of a neutralizer (D).

[0017] In a specific embodiment of the present invention, the antioxidant (B) may include at least one selected from pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, 2',3-bis[[3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionyl]]propionohydrazide, and tris(2,4-di-tert-butylphenyl)phosphite.

[0018] In a specific embodiment of the present invention, the long-term heat stabilizer (C) may include at least one selected from the group consisting of distearyl thiodipropionate, dilauryl thiodipropionate, dimyristyl thiodipropionate, ditridecyl thiodipropionate, dioctadecyl 3,3-thiodipropionate, 2,2'-thiobis(4-methyl-6-tert-butylphenol), tetrakis(3-laurylthiopropionyloxymethyl)methane, pentaerythritol tetrakis(3-dodecylthiopropionate), lauryl 3,3'-thiodipropionate, stearyl 3,3'-thiodipropionate, dioctadecyl disulfide, and didodecyl 3,3'-thiodipropionate.

[0019] In a specific embodiment of the present invention, the neutralizing agent (D) may include at least one selected from calcium stearate and hydrotalcite.

[0020] In a specific embodiment of the present invention, the antioxidant (B) may be pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), the long-term heat stabilizer (C) may be distearyl thiodipropionate, and the neutralizer (D) may be calcium stearate.

[0021] In a specific embodiment of the present invention, the polypropylene resin composition may further comprise at least one additive selected from the group consisting of a slip agent, an anti-blocking agent, a filler, a weathering stabilizer, an antistatic agent, a lubricant, a nucleating agent, and a dye.

[0022] According to another embodiment of the present invention, the present invention provides a polypropylene resin molded article produced by molding the polypropylene resin composition.

[0023] In a specific embodiment of the present invention, the polypropylene resin molded product can meet the following conditions: Shore D hardness of 58 to 65; capacitance of 104±5nF; characteristic impedance of 50±2Ω / ㎞; and attenuation conditions of,

[0024] Less than or equal to 0.76dB / m at 900MHz,

[0025] Less than or equal to 1.04dB / m at 1,500MHz,

[0026] Less than or equal to 1.08dB / m at 1,600MHz,

[0027] Less than or equal to 1.20dB / m at 1,900MHz,

[0028] Less than or equal to 1.23dB / m at 2,000MHz,

[0029] Less than or equal to 1.40dB / m at 2,500MHz,

[0030] Less than or equal to 1.59dB / m at 3,000MHz.

[0031] In a specific embodiment of the present invention, the polypropylene resin molded product can be an inner coating material for an automotive communication cable.

[0032] Beneficial effects

[0033] The polypropylene resin composition according to an embodiment of the present invention exhibits low dielectric properties and can be effectively used as an inner coating material for automotive communication cables. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A cross section of a wire is shown to illustrate a capacitance measurement. DETAILED DESCRIPTION

[0035] Hereinafter, the present invention will be described in detail.

[0036] According to one embodiment of the present invention, the present invention provides a polypropylene resin composition, comprising a polypropylene resin (A), wherein the polypropylene resin (A) comprises: a first polypropylene resin (A1), wherein the first polypropylene resin (A1) has a melt index of 2.3 to 3.3 g / 10 min, as measured at 230° C. under a load of 2.16 kg, and a xylene soluble content of 18 to 22 wt%; and a second polypropylene resin (A2), wherein the second polypropylene resin (A2) has a melt index of 1.5 to 2.0 g / 10 min, as measured at 230° C. under a load of 2.16 kg, and a xylene soluble content of 13 to 17 wt%, and the weight ratio of the first polypropylene resin (A1) to the second polypropylene resin (A2) is 9:1 to 7:3.

[0037] (A) Polypropylene resin

[0038] The polypropylene resin composition according to the embodiment of the present invention includes a polypropylene-based resin (A). In the polypropylene resin composition according to the embodiment of the present invention, the polypropylene-based resin (A) includes a first polypropylene-based resin (A1) and a second polypropylene-based resin (A2).

[0039] In a specific embodiment of the present invention, both the first polypropylene resin (A1) and the second polypropylene resin (A2) may be ethylene-propylene block copolymers. The ethylene-propylene block copolymers may be obtained by staged polymerization of a matrix component of a propylene homopolymer, a propylene-ethylene random copolymer, or a propylene-α-olefin random copolymer with an ethylene-propylene rubber copolymer component in a reactor.

[0040] The preparation method of the ethylene-propylene block copolymer is not particularly limited, and the preparation method of the ethylene-propylene block copolymer known in the technical field to which the present invention belongs can be directly used, or can be used after being appropriately modified. For example, the preparation of the ethylene-propylene block copolymer can be carried out in a commercial process according to polymerization methods known to those skilled in the art, such as the Spherizone preparation process of LyondellBasell, the Hypol preparation process of Mitsui, or the Unipol preparation process of Grace.

[0041] The first polypropylene-based resin (A1) has a melt index of 2.3 to 3.3 g / 10 min, when measured at 230° C. under a load of 2.16 kg according to ASTM D1238, and a xylene soluble content of the first polypropylene-based resin (A1) of 18 to 22 wt %. When the melt index and xylene soluble content of the first polypropylene-based resin (A1) satisfy the above ranges, respectively, excellent moldability, excellent roundness, hardness (Shore D), and low dielectric properties (capacitance) can be exhibited.

[0042] The second polypropylene-based resin (A2) has a melt index of 1.5 to 2.0 g / 10 min, and a xylene soluble content of 13 to 17 wt %, when measured at 230° C. under a load of 2.16 kg in accordance with ASTM D1238. When the melt index and xylene soluble content of the second polypropylene-based resin (A2) satisfy the above ranges, excellent moldability, excellent roundness, hardness (Shore D), and low dielectric properties (standard attenuation) can be exhibited.

[0043] The xylene soluble content of the first polypropylene resin (A1) and the second polypropylene resin (A2) can be measured according to ASTM D5492. Specifically, the polypropylene resin is dissolved in xylene at a concentration of 1 wt% at 140°C for 1 hour, and then the weight of the extracted solution is measured after 2 hours at room temperature (23°C). The obtained weight is expressed as a percentage relative to the weight of the polypropylene resin.

[0044] The weight ratio of the first polypropylene-based resin (A1) to the second polypropylene-based resin (A2) in the polypropylene-based resin (A) is in the range of 9:1 to 7:3. Preferably, the weight ratio of the first polypropylene-based resin (A1) to the second polypropylene-based resin (A2) in the polypropylene-based resin (A) is in the range of 8.5:1.5 to 7.5:2.5. If the weight ratio of the first polypropylene-based resin (A1) to the second polypropylene-based resin (A2) exceeds the above range, the desired low dielectric properties of the present invention may not be achieved.

[0045] The polypropylene resin composition according to an embodiment of the present invention can basically only comprise polypropylene resin (A), and can further comprise components (B) to (D) described later as required. Therefore, based on the gross weight of components (A) to component (D), the polypropylene resin composition according to an embodiment of the present invention can comprise 97.5 to 100 weight % of polypropylene resin (A). Preferably, the content of polypropylene resin (A) in polypropylene resin composition can be 98 to 99.5 weight %. If the content of polypropylene resin (A) is less than 97.5 weight % in the polypropylene resin composition, the desired low dielectric performance effect of the present invention can be reduced, or the effect of adding components (B) to (D) no longer increases, so possible economy is poor.

[0046] In a specific embodiment of the present invention, the polypropylene resin composition may further comprise, based on the total weight of components (A) to (D), 0 to 1.0 wt% of an antioxidant (B), 0 to 1.0 wt% of a long-term heat stabilizer (C), and 0 to 1.0 wt% of a neutralizer (D).

[0047] (B) Antioxidants

[0048] The polypropylene resin composition according to an embodiment of the present invention may include an antioxidant (B).

[0049] In a specific embodiment of the present invention, the antioxidant (B) may include at least one selected from pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, 2',3-bis[[3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionyl]]propionohydrazide, and tris(2,4-di-tert-butylphenyl)phosphite. Preferably, the antioxidant (B) may include pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate).

[0050] The polypropylene resin composition according to one embodiment of the present invention may contain 0 to 1.0 wt% of the antioxidant (B) based on the total weight of components (A) to (D). When the antioxidant (B) is included, the antioxidant effect of the resin composition can be improved, but if the content of the antioxidant (B) exceeds 1.0 wt%, the antioxidant effect will not be further increased, and thus the economic efficiency may be poor.

[0051] (C) Long-term heat stabilizer

[0052] The polypropylene resin composition according to an embodiment of the present invention may include a long-term heat-resistant stabilizer (C).

[0053] In a specific embodiment of the present invention, the long-term heat stabilizer (C) may include distearyl thiodipropionate, dilauryl thiodipropionate, dimyristyl thiodipropionate, ditridecyl thiodipropionate, dioctadecyl 3,3-thiodipropionate, 2,2'-thiobis(4-methyl-6-tert-butylphenol), tetrakis(3-laurylthiopropionyloxy-methyl)methane, pentaerythritol tetrakis(3-dodecylthiopropionate), ... At least one of tetrakis (3-dodecylthiopropionate), lauryl 3,3'-thiodipropionate, stearyl 3,3'-thiodipropionate, distearyl disulfide, and propionic acid 3,3'-thiobisdidodecyl ester. Preferably, the long-term heat-resistant stabilizer (C) may include distearyl thiodipropionate.

[0054] The polypropylene resin composition according to one embodiment of the present invention may include 0 to 1.0 wt% of the long-term heat-resistant stabilizer (C) based on the total weight of components (A) to (D). When the long-term heat-resistant stabilizer (C) is included, the long-term heat-resistant stability of the resin composition can be ensured, and the desired physical properties can be maintained even after long-term use. However, if the content of the long-term heat-resistant stabilizer (C) exceeds 1.0 wt%, the effect of the long-term heat-resistant stability will not be further improved, and thus the economic efficiency may be poor.

[0055] (D) Neutralizer

[0056] The polypropylene resin composition according to an embodiment of the present invention may include a neutralizer (D).

[0057] In a specific embodiment of the present invention, the neutralizing agent (D) may include at least one selected from calcium stearate and hydrotalcite. Preferably, the neutralizing agent (D) may include calcium stearate.

[0058] The polypropylene resin composition according to one embodiment of the present invention may contain 0 to 1.0 wt% of the neutralizer (D) based on the total weight of components (A) to (D). When the neutralizer (D) is contained, residual components of the catalyst used in preparing the polypropylene resin (A) can be effectively removed. However, if the content of the neutralizer (D) exceeds 1.0 wt%, the effect of removing the residual catalyst components will not be further improved, and thus the economic efficiency may be poor.

[0059] (E) Additives

[0060] Without departing from the scope of the present invention, the polypropylene resin composition according to the embodiment of the present invention may further include conventional additives. For example, the polypropylene resin composition according to the embodiment of the present invention may further include at least one additive selected from the group consisting of a slip agent, an antiblocking agent, a filler, a weathering stabilizer, an antistatic agent, a lubricant, a nucleating agent, and a dye.

[0061] The preparation method of the polypropylene resin composition according to the embodiment of the present invention is not particularly limited. The preparation method of the polypropylene resin composition known in the technical field to which the present invention belongs can be directly used, or used after being appropriately improved. In addition, the above-mentioned resin components and compounds can be freely selected and mixed in a desired order without being restricted by a particular order.

[0062] Specifically, for example, the above-mentioned resins and compounds can be mixed in required amounts in a kneading machine such as a Henschel mixer, a kneader, a roll, or a Banbury mixer for 1 to 2 hours, and then melted and kneaded at a temperature of 180 to 210° C. using a single-screw or twin-screw extruder to prepare a pelletized polypropylene resin composition.

[0063] In another embodiment of the present invention, the present invention provides a polypropylene resin molded article, which is produced by molding the polypropylene resin composition of the present invention.

[0064] The method for preparing a molded article using the polypropylene resin composition according to an embodiment of the present invention is not particularly limited, and methods known in the art to which the present invention pertains can be used. For example, the polypropylene resin composition according to an embodiment of the present invention can be molded by conventional methods such as injection molding, extrusion molding, and tape casting to prepare a polypropylene resin molded article.

[0065] In a specific embodiment of the present invention, the polypropylene resin molded product can meet the following conditions: Shore D hardness of 58 to 65; capacitance of 104±5nF; characteristic impedance of 50±2Ω / ㎞; and attenuation conditions of,

[0066] Less than or equal to 0.76dB / m at 900MHz,

[0067] Less than or equal to 1.04dB / m at 1,500MHz,

[0068] Less than or equal to 1.08dB / m at 1,600MHz,

[0069] Less than or equal to 1.20dB / m at 1,900MHz,

[0070] Less than or equal to 1.23dB / m at 2,000MHz,

[0071] Less than or equal to 1.40dB / m at 2,500MHz,

[0072] Less than or equal to 1.59dB / m at 3,000MHz.

[0073] In a specific embodiment of the present invention, the polypropylene resin molded product can be an inner coating material for an automotive communication cable.

[0074] [Example]

[0075] Hereinafter, the present invention will be described in more detail by way of examples and comparative examples. However, the following examples are only for illustrating the present invention, and the scope of the present invention is not limited thereto.

[0076] The raw materials used in Examples and Comparative Examples are as follows.

[0077] A1: Ethylene-propylene block copolymer resin (Hanwha Total Petrochemical, BJ200; MI of 3 g / 10 min, xylene soluble content of 18 to 22 wt%)

[0078] A2: Ethylene-propylene block copolymer resin (Hanwha Total Petrochemical, BJ100; MI of 2 g / 10 min, xylene soluble content of 13 to 17 wt%)

[0079] B1: Antioxidant (pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate))

[0080] C1: Long-term heat stabilizer (distearyl thiodipropionate)

[0081] D1: Neutralizer (calcium stearate)

[0082] E1: Antistatic agent (Sanyo Chemical Co., Ltd., Pelestat 230)

[0083] Preparation Example:

[0084] Resins and compounds of the types and contents (unit: parts by weight) shown in Table 1 below were melt-blended at a temperature of approximately 180°C to 210°C using a twin-screw extruder to obtain pellets. The pellets were co-extruded with electric wires and cables using a communication wire extruder to produce communication wires. The produced electric wires and cables were then metal-clad and coated with an outer coating to produce automotive communication wires.

[0085]

Table 1

[0086] Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 A1 79.45 - 99.45 99.15 98.95 A2 20 99.45 - - - B1 0.2 0.2 0.2 0.2 0.2 C1 0.25 0.25 0.25 0.25 0.25 D1 0.1 0.1 0.1 0.1 0.1 E1 - - - 0.3 0.5

[0087] Test Examples

[0088] The automotive communication cables obtained in each of the Examples and Comparative Examples were tested according to the following methods. The results are shown in Table 2 below.

[0089] 1. Hardness

[0090] A 6 mm thick test piece was injection molded and its hardness was measured using a Shore D durometer after 48 hours.

[0091] 2. Capacitor (KS C 3004)

[0092] Capacitance refers to the degree of charge stored between electrodes. In the case of shielded cables, charge accumulates between the wire cores or between the wire core and the shield, thus generating noise during signal transmission, which is called capacitance. A sample with a length of 50m is placed in air at a temperature of 20±5°C and a humidity of 65±5%. Figure 1 As shown, a capacitance meter (LCR meter) is used to measure capacitance between terminals A and B. The measurement frequency is 1000 Hz.

[0093] 3. Characteristic impedance (KS C 3610)

[0094] Impedance (Ω) is the ratio of the AC voltage applied to an AC circuit to the AC current flowing through it. This value is measured using a network analyzer using samples of cables 10 meters or longer. The value is then converted to a value relative to a 1-meter cable. The measurement frequency range is the same as the attenuation measurement range.

[0095] 4. Standard attenuation (KS C 3610)

[0096] The signal loss of the incident power is called standard attenuation (dB), which is the ratio of the transmitted power of the wire to the incident power. It is measured using a standard attenuation meter with the same measurement range as the impedance.

[0097] 5. Roundness of wire

[0098] The roundness of the produced electric wire was measured using a 3D measuring device.

[0099]

Table 2

[0100]

[0101] As can be seen from Tables 1 and 2, the automotive communication wires made from the polypropylene resin compositions of Examples within the scope of the present invention are excellent in hardness, capacitance, characteristic impedance, attenuation, and wire roundness.

[0102] In contrast, Comparative Examples 1 to 4, which contain only a single type of ethylene-propylene block copolymer resin, exhibit poor performance in at least one of hardness, capacitance, characteristic impedance, attenuation, and wire roundness. In particular, in Comparative Examples 3 and 4, even with the inclusion of an antistatic agent, the standard attenuation failed to meet the required specifications.

[0103] Therefore, the polypropylene resin composition according to the embodiment within the scope of the present invention can be effectively used as an inner coating material for automotive communication cables.

Claims

1. A polypropylene resin composition comprising a polypropylene resin (A), wherein: The polypropylene resin (A) comprises: The first polypropylene-based resin (A1) has a melt index of 2.3 to 3.3 g / 10 min as measured at 230° C. under a load of 2.16 kg and a xylene-soluble content of 18 to 22 wt %; and The second polypropylene resin (A2) has a melt index of 1.5 to 2.0 g / 10 min as measured at 230° C. under a load of 2.16 kg, and a xylene soluble content of 13 to 17% by weight. The content ratio of the first polypropylene-based resin (A1) to the second polypropylene-based resin (A2) is 9:1 to 7:3 by weight.

2. The polypropylene resin composition according to claim 1, wherein Both the first polypropylene-based resin (A1) and the second polypropylene-based resin (A2) are ethylene-propylene block copolymers.

3. The polypropylene resin composition according to claim 1, wherein Based on the total weight of components (A) to (D), the polypropylene resin composition further comprises: 0 to 1.0 wt% of an antioxidant (B), 0 to 1.0 wt% of a long-term heat stabilizer (C), and 0 to 1.0 wt% of a neutralizer (D).

4. The polypropylene resin composition according to claim 3, wherein The antioxidant (B) comprises at least one selected from pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, 2',3-bis[[3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionyl]]propionohydrazide, and tris(2,4-di-tert-butylphenyl)phosphite.

5. The polypropylene resin composition according to claim 3, wherein The long-term heat stabilizer (C) includes at least one selected from the group consisting of distearyl thiodipropionate, dilauryl thiodipropionate, dimyristyl thiodipropionate, ditridecyl thiodipropionate, dioctadecyl 3,3-thiodipropionate, 2,2'-thiobis(4-methyl-6-tert-butylphenol), tetrakis(3-laurylthiopropionyloxymethyl)methane, pentaerythritol tetrakis(3-dodecylthiopropionate), lauryl 3,3'-thiodipropionate, stearyl 3,3'-thiodipropionate, distearyl disulfide, and didodecyl 3,3'-thiodipropionate.

6. The polypropylene resin composition according to claim 3, wherein The neutralizing agent (D) contains at least one selected from calcium stearate and hydrotalcite.

7. The polypropylene resin composition according to claim 3, wherein The antioxidant (B) is pentaerythritol tetrakis (3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate), the long-term heat stabilizer (C) is distearyl thiodipropionate, and the neutralizer (D) is calcium stearate.

8. The polypropylene resin composition according to claim 1, wherein The polypropylene resin composition further comprises at least one additive selected from the group consisting of a slip agent, an antiblocking agent, a filler, a weathering stabilizer, an antistatic agent, a lubricant, a nucleating agent, and a dye. 9 . A polypropylene resin molded article produced by molding the polypropylene resin composition according to claim 1 .

10. The polypropylene resin molded article according to claim 9, wherein Polypropylene resin molded products meet the following requirements: Shore D hardness of 58 to 65; capacitance of 104±5nF; characteristic impedance of 50±2Ω / ㎞; and attenuation conditions of, Less than or equal to 0.76dB / m at 900MHz, Less than or equal to 1.04dB / m at 1,500MHz, Less than or equal to 1.08dB / m at 1,600MHz, Less than or equal to 1.20dB / m at 1,900MHz, Less than or equal to 1.23dB / m at 2,000MHz, Less than or equal to 1.40dB / m at 2,500MHz, and Less than or equal to 1.59dB / m at 3,000MHz.

11. The polypropylene resin molded article according to claim 9, wherein Polypropylene resin molded products are used as inner covering materials for automotive communication cables.

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