JP2005268047A - Cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cable having a cable allowable temperature of 90° without using non-crosslinked polyolefin and making recycling possible. <P>SOLUTION: A conductor is covered with an insulator comprising 100 pts.wt. polyolefin family thermoplastic elastomer having a melting point of 150° or more and 10-35 pts.wt. polyolefin resin, and furthermore covered with a sheath comprising nonhalogen flame-resistant polyethylene or a polyvinyl chloride family compound. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a cable insulator material, and more particularly to a cable that can satisfy an allowable temperature of 90 ° C. even when the cable insulator is exposed to a high temperature.

  In general, in a low voltage cable of 600 V or less that is wired indoors or outdoors, the one that the allowable temperature of the insulator covering the conductor satisfies 90 ° C. is widely used. As a material that satisfies the allowable temperature of 90 ° C., the conventionally used low-voltage cable insulator of 600 V or less is a bridge that has good electrical insulation and good thermal and mechanical characteristics to withstand the increase in operating temperature. Polyethylene is used. In this crosslinked polyethylene, a chain is formed with Si (silane) contained in the polymer (olefin resin) molecule, and the same phenomenon occurs in the other polymer (olefin resin) molecule, resulting in two polymers ( The cross-linking reaction (silane cross-linking) is performed with the olefin resin) molecule having Si (silane) in the middle and oxygen (O) in the middle, and the two polymer (olefin resin) molecules are connected to form a cross-linked state. Formed.

  In this way, crosslinked polyethylene is crosslinked by silane compound and has a huge three-dimensional network structure, so it is resistant to heat and molded without melting even when heated above the melting point of polyethylene. The shape can be maintained, and it has excellent thermal characteristics. Cables using such cross-linked polyethylene as insulators are made from materials such as copper, which are used as conductors, but the cross-linked polyethylene used in cable insulators has good thermal characteristics. Even when heated to exceed the melting point of polyethylene, crosslinked polyethylene is not melted and cannot be reused by melt molding, and is not suitable for material recycling. For this reason, in the case of a cable using crosslinked polyethylene as an insulator, since the insulator is not suitable for material recycling, it has been disposed of by disposal of thermal recycling used for fuel and the like. For this reason, it has been demanded to improve the cable using a material recyclable insulator from the viewpoint of protecting the global environment.

Therefore, in recent years, even when the conductor temperature is 230 ° C. (allowable temperature at short circuit) for 2 seconds, the insulating material hangs down or is stretched in the vicinity of the lead-through portion and breaks. There has been proposed an insulated electric wire for electric power transmission that is easy to use and can be easily regenerated and used. This Patent Document 1 discloses that a polyolefin-based thermoplastic elastomer satisfying the conditions that the Young's modulus at room temperature is 200 MPa or more and the Young's modulus at 130 ° C. is 30 MPa or more is non-cross-linked and insulated so that it can be easily recycled. It is an insulated wire for power transmission used as a material.
JP 2003-100157 A (page 2)

  In this Patent Document 1, a polyolefin-based thermoplastic elastomer is used as a cable insulator in a non-crosslinked manner so that it can be easily reused. For this reason, the insulated wire for electric power transmission of patent document 1 is a thing suitable for material recycling. However, the insulated electric wire for power transmission of Patent Document 1 has a problem that electrical characteristics, thermal characteristics, and mechanical characteristics as an insulator material are not sufficient.

  An object of the present invention is to provide a cable capable of maintaining a cable allowable temperature of 90 ° C. without using non-crosslinked polyethylene and enabling material recycling.

  The invention according to claim 1 is a non-halogen hard coating which covers an insulator formed by blending 10 to 35 parts by weight of a polyolefin resin with respect to 100 parts by weight of a polyolefin-based thermoplastic elastomer having a melting point of 150 ° C. or higher on a conductor. A sheath made of polyethylene or polyvinyl chloride compound is coated.

  The invention according to claim 2 comprises a polyolefin-based thermoplastic elastomer composed of one or more of melting points of 150 ° C. or higher and different melting points.

  The invention according to claim 3 is characterized in that the polyolefin resin is any one of polyethylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, or It consists of two or more.

  According to the first aspect of the present invention, it is possible to maintain a cable allowable temperature of 90 ° C. without using non-crosslinked polyethylene and to enable material recycling.

  According to the second aspect of the present invention, it is possible to maintain a cable allowable temperature of 90 ° C. without using non-crosslinked polyethylene and to enable material recycling.

  According to the invention described in claim 3, it is possible to maintain the cable allowable temperature of 90 ° C. without using non-crosslinked polyethylene and to enable material recycling.

BEST MODE FOR CARRYING OUT THE INVENTION

  Hereinafter, embodiments of the cable according to the present invention will be described in detail.

  FIG. 1 shows a cross-sectional view of a cable 1 according to the present invention.

  In FIG. 1, a conductor 2 is covered with an insulator 3, and a sheath 4 is covered on the insulator 3.

  The conductor 2 is made of a conductive metal material such as copper, a copper alloy, aluminum, and an aluminum alloy. The sheath 4 is made of non-halogen flame retardant polyolefin or polyvinyl chloride synthetic resin. In the sheath 4, known additives such as a flame retardant, an ultraviolet absorber, and a heat stabilizer may be blended as necessary.

  The insulator 3 is configured by blending a polyolefin resin with one or more polyolefin-based thermoplastic elastomers. The polyolefin-based thermoplastic elastomer is a synthetic resin having a melting point of 150 ° C. or higher, for example, a polymerizable polyolefin-based thermoplastic elastomer. The insulator 3 may be a mixture of two or more types of polyolefin thermoplastic elastomers having melting points of 150 ° C. or higher and different melting points.

  The ratio of the polyolefin resin to be blended with the polyolefin-based thermoplastic elastomer is 10 to 35 parts by weight of the polyolefin resin with respect to 100 parts by weight of the polyolefin-based thermoplastic elastomer. The reason why the polyolefin resin is blended with the polyolefin-based thermoplastic elastomer is to improve the processability of the insulator 3. That is, when the polyolefin-based thermoplastic elastomer is used alone, the processability of the insulator 3 is lowered, and is blended in order to improve the processability of the insulator 3. The polyolefin-based thermoplastic elastomer 100 has a blending ratio of the polyolefin-based thermoplastic resin to the polyolefin-based thermoplastic elastomer of 10 to 35 parts by weight with respect to 100 parts by weight of the polyolefin-based thermoplastic elastomer. When the blending amount of the polyolefin resin is less than 10 parts by weight with respect to parts by weight, the processability of the insulator 3 is lowered and the processing becomes difficult. Also, with respect to 100 parts by weight of the polyolefin-based thermoplastic elastomer, It is because the heat deformation rate of the insulator 3 cannot be maintained when the resin is blended in an amount exceeding 35 parts by weight.

  The blending ratio of the polyolefin-based thermoplastic resin to the polyolefin-based thermoplastic elastomer is such that 10 to 30 parts by weight of the polyolefin resin is blended with 100 parts by weight of the polyolefin-based thermoplastic elastomer to improve the processability of the insulator 3. Preferred above.

  As the polyolefin-based thermoplastic resin of the insulator 3, polyethylene resin (HDPE, MDPE, LDPE, L-LPE, V-LDPE), polypropylene resin, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene- Known polyolefin-based thermoplastic resins such as a methyl acrylate copolymer and an ethylene-ethyl acrylate copolymer resin can be used.

  The insulator 3 can be blended with known additives such as a flame retardant, an ultraviolet absorber, and a heat stabilizer, if necessary.

[Example 1]
In Example 1, a thermoplastic polyolefin elastomer (specifically Zelas 5013) having a melting point of 150 ° C. or more and 100 parts by weight of ethylene-ethyl acrylate resin (EEA) (specifically, A710 manufactured by Mitsui DuPont Polychemical) 30 parts by weight.

[Example 2]
In Example 2, 100 parts by weight of a polyolefin-based thermoplastic elastomer (specifically Zelas 5013) having a melting point of 150 ° C. or higher and 30 parts by weight of low-density polyethylene resin (LDPE) (specifically, UBEC 530 manufactured by Ube Industries) It is a blend.

[Comparative Example 1]
In Comparative Example 1, a polyolefin thermoplastic elastomer having a melting point of 150 ° C. or higher (specifically Zelas 5013) and ethylene-ethyl acrylate resin (EEA) (specifically, A710 manufactured by Mitsui DuPont Polychemical) 40 parts by weight.

[Comparative Example 2]
In Comparative Example 2, a polyolefin thermoplastic elastomer having a melting point of 150 ° C. or higher (specifically Zelas 5013) is added to 40 parts by weight of a low density polyethylene resin (LDPE) (specifically UBEC 530 manufactured by Ube Industries). It is a blend.

[Comparative Example 3]
Comparative Example 3 is composed of 100 parts by weight of a polyolefin-based thermoplastic elastomer having a melting point of 100 ° C. (specifically, Kuraray Septon).

[Comparative Example 4]
Comparative Example 4 is composed of 100 parts by weight of a crosslinked polyethylene resin (XLPE) (specifically, XF800T manufactured by Mitsubishi Chemical Corporation).

[Comparative Example 5]
Comparative Example 5 is constituted by 100 parts by weight of a crosslinked polyethylene resin (XLPE) (specifically, HFDJ4201 manufactured by Nippon Unicar Co., Ltd.).

[Characteristic test]
"sample"
The material extruded from the extruder of the resin composition produced based on the composition of Examples 1 to 2 and Comparative Examples 1 to 5 is made into a sheet having a thickness of 1 to 2 mm, and is at room temperature for 24 hours or more after extrusion. The test piece (JIS No. 3 dumbbell piece) is prepared by leaving at

"Test method"
With respect to this sample, the heat deformation rate (%), tensile strength, elongation, tensile strength after heating, and elongation after heating were measured, and the presence or absence of crosslinking equipment and the possibility of material recycling are shown in Table 1.

  The heat deformation rate (%) in Table 1 is the deformation after the sample was left to stand at 120 ° C. for 30 minutes based on Japanese Industrial Standard (JIS) C3005, and then left to stand for 30 minutes under a load of 10N. The deformation rate is 40% or less, and it is acceptable.

  The tensile strength test in Table 1 is a thickness of 1 to 2 mm for materials extruded from extruders of resin compositions prepared based on the compositions of Examples 1 to 2 and Comparative Examples 1 to 5. And test specimens (JIS No. 3 dumbbell pieces) at room temperature for 24 hours or longer after extrusion, and properly and surely hold one end so that the specimen does not become distorted or other inconvenience during the test. Attached to a chuck, pulled at a predetermined tensile speed (200 mm / min), and simultaneously measured the maximum tensile load (tensile strength) of the test piece and the length (elongation) between the marked lines at the time of cutting for the same test piece It is.

Tensile strength indicates how much force (MPa) it can be torn when it is pulled, and the load when it is torn, that is, the maximum tensile load per cross-sectional area (mm ² ) of the specimen (N). Therefore, the mechanical strength can be determined by the magnitude of the tensile strength. The target value of this tensile strength is “10 MPa or more”.

  The target value of the tensile strength in Table 1 is set to 10 MPa or more because the tensile strength is low and the mechanical strength is low and brittle if the tensile strength is less than 10 MPa.

  The elongation in Table 1 is the length (mm) between the marked lines at the time of cutting per unit marked line distance (mm) by measuring the length between marked lines at the time of cutting.

  That is, the elongation (%) in Table 1 is the length (elongation) when one end of the produced press sheet (test piece) is fixed and the other end is pulled and pulled until the test piece is torn off. ) Divided by the length of the original test piece and expressed as a percentage (elongation). That is, the maximum elongation of the test piece when the test piece is stretched is obtained. The reference value of this tensile elongation is “350% or more”. The reason why the standard value of the elongation is 350% or more is that sufficient flexibility cannot be obtained if the elongation is less than 350%.

  In the tensile strength test after heating in Table 1, the material extruded from the extruder of the resin composition prepared based on the compositions of Examples 1 to 2 and Comparative Examples 1 to 5 is 1 to 2 mm. A test piece (JIS No. 3 dumbbell piece) made into a thick sheet and allowed to stand at room temperature for 24 hours or more after extrusion was left in a 90 ° C. atmosphere for 96 hours, and then one end was attached to a chuck, and a predetermined tensile speed was obtained. Tensile (200 mm / min), the maximum tensile load (tensile strength) of the test piece and the length (elongation) between the marked lines at the time of cutting are measured simultaneously for the same test piece.

Tensile strength after heating indicates how much force (MPa) the test knitting left in an atmosphere of 90 ° C. for 96 hours can be torn, and the load when torn That is, the maximum tensile load (N) per cross-sectional area (mm ² ) of the test piece is shown. Therefore, the mechanical strength can be determined by the magnitude of the tensile strength. The target value of the tensile strength is 80% or more before heating, that is, “8 MPa or more”.

  The target value of the tensile strength after heating is set to 8 MPa or more because the tensile strength after heating is low and the mechanical strength is low and brittle so that the tensile strength after heating is less than 8 MPa.

  The elongation after heating in Table 1 is the length (mm) between the marked lines at the time of cutting per unit marked line distance (mm) by measuring the length between marked lines at the time of cutting.

  That is, the tensile elongation (%) in Table 1 is the length when the one end of the produced press sheet (test piece) is fixed and the other end is pulled until the test piece is torn off. (Elongation) is divided by the length of the original test piece and expressed as a percentage (elongation). That is, the maximum elongation of the test piece when the test piece is stretched is obtained. The reference value for the elongation after heating is 80% or more before heating, that is, “280% or more”. The reason why the standard value of the elongation after heating is 280% or more is that sufficient flexibility cannot be obtained if the elongation after heating is less than 280%.

  Note that “heating deformation” is JIS C 3005 25, “tensile strength” is JIS C 3005 18, “elongation” is JIS C 3005 18, and “tensile strength after heating” is JIS C 3005 19, “ “Elongation after heating” was performed according to JIS C 300519.

  Looking at the determination results, the heating deformation rate (%) of each of Examples 1 to 2 satisfies “◯”, and all of the examples satisfy the target value “40% or less” of the heating deformation rate (%) doing. On the other hand, Comparative Example 4 and Comparative Example 5 both satisfy “◯” and the target value “40% or less” of the heat deformation rate (%), but Comparative Example 1 and Comparative Example 2 and Comparative Example 3 do not satisfy “×” and the target value “40% or less” of the heat deformation rate (%).

  As for the tensile strength (MPa), Examples 1 to 2 and Comparative Examples 1 to 5 are all “◯”, and all Examples and Comparative Examples are the target values of tensile strength “10 MPa. I'm satisfied.

  Furthermore, as for the elongation (%), Examples 1 to 2 and Comparative Examples 1 to 5 are all “O”, and the Examples (Comparative Examples) are both the target value (350%) of elongation (%). I'm satisfied.

  Moreover, about the tensile strength (MPa) after a heating, Example 1-Example 2, Comparative Example 1-Comparative Example 2, and Comparative Example 4-Comparative Example 5 are all "(circle)", and the tensile strength after a heating. Although the target value “8 MPa or more” (80% before heating) is satisfied, Comparative Example 3 shows “×” and the target value of tensile strength after heating “8 MPa or more” (80% before heating). Not satisfied.

  Furthermore, about elongation (%) after a heating, Example 1-Example 2, Comparative Example 1-Comparative Example 2, and Comparative Example 4-Comparative Example 5 are all (circle), and the target of elongation (%) after a heating The value “280% or more” (80% before heating) is satisfied, but in Comparative Example 3, “×” and the target value of elongation after heating (%) “280% or more” (80% before heating) ) Is not satisfied.

  As for the crosslinking equipment, Comparative Example 4 and Comparative Example 5 are “Yes”, but Examples 1 to 2 and Comparative Examples 1 to 3 are “No”. In addition, regarding the possibility of material recycling, Examples 1 to 2 and Comparative Examples 1 to 3 can be “Yes”, but Comparative Examples 4 and 5 cannot be “No”. is there.

  Therefore, from the results of Table 1, a sample using a polyolefin-based thermoplastic elastomer having a melting point of 150 ° C. or higher and a polyolefin-based thermoplastic resin blended with 30 parts by weight with respect to 100 parts by weight of the polyolefin-based thermoplastic elastomer (Example) 1, Example 2) has the same characteristics in terms of thermal characteristics and mechanical characteristics as compared with the crosslinked polyethylene samples (Comparative Example 4 and Comparative Example 5). 4 and Comparative Example 5) show that impossible material recycling can be performed. In Comparative Examples 1 to 3, material recycling is possible, but there is a problem in heat deformation, which is not preferable in terms of characteristics as an insulator.

Sectional drawing of the cable which concerns on this invention.

Explanation of symbols

1 …………………… Cable 2 ………………… Conductor 3 ………………… Insulator 4 ………………… Sheath

Claims (3)

  An insulator formed by blending 10 to 35 parts by weight of a polyolefin resin with respect to 100 parts by weight of a polyolefin-based thermoplastic elastomer having a melting point of 150 ° C. or higher is coated on the conductor, from non-halogen flame-retardant polyethylene or polyvinyl chloride compound. A cable comprising a sheath covered with   2. The cable according to claim 1, wherein the polyolefin-based thermoplastic elastomer is composed of one or more of melting points of 150 ° C. or higher and different melting points.   The polyolefin resin is composed of one or more of polyethylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, and ethylene-ethyl acrylate copolymer. The cable according to claim 1 or 2.

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