JPH0362409A - Resin covered wire and cable - Google Patents

Abstract

PURPOSE:To eliminate the occurrence of a cold flow and improve resistance against a crack even in service under a high temperature condition by covering a conducting wire with 3-methyl-1-butene resin having a specific fusing point. CONSTITUTION:A sheathed wire and cable comprises conducting wire covered with 3-methyl-1-butene resin having a specific fusing point. The fusing point of a 3-methyl-1-butene resin copolymer is within a range of 220 to 310 deg.C. The poly-3-methyl-1-butene having the aforesaid fusion point can be adjusted by copolymerizing the type of alpha-olefin with the 3-methyl-1-butene or changing the type of a catalyst used in polymerizing the 3-methyl-1-butene, or further changing a condition for polymerization. As the 3-methyl-1-butene resin for use, there are available a 3-methyl-1-butene homopolymer and a 3-methyl-1- butene.alpha-olefin copolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to coated electric wires and cables coated with a specific 3-methyl-1-butane copolymer, and more particularly, to coated wires and cables coated with a specific 3-methyl-1-butane copolymer. Regarding coated wires and cables with excellent properties.

TECHNICAL BACKGROUND OF THE INVENTION Wires and cables coated with polymers or copolymers of 4-methyl-1-pentene are already known from British Patent No. 1,074,241. 4-methyl-
Because of its high melting point, 1-pentene polymers are suitable for electric wires and wires used in high temperatures or areas that may be exposed to high temperatures.
It is suitable as a resin for coating cables.

However, the 4-
Electric wires coated with methyl-1-pentene polymers or copolymers are not satisfactory in heat resistance, bending strength, and impact resistance, and there is still room for further improvement in industrial productivity.

4 as a resin-coated electric wire/cable that improves these drawbacks.
- The applicant previously filed an application for an invention for electric wires and cables coated with a random copolymer of methyl-1-pentene and an α-olefin having 16 to 22 carbon atoms (Japanese Patent Laid-Open No.
(See Publication No. 3-110085).

Such a cable, for example, has a surrounding area of 4-methyl-1
- It has a structure in which a plurality of conductive wires coated with a pentene polymer or copolymer are bundled so as to be covered with an exterior material such as cloth, and the surroundings are further covered with iron wire.

This electric wire/cable exhibits excellent heat resistance and can be used without problems in ordinary applications that require heat resistance.

However, when used under extremely high temperature conditions, such as cables for deep oil well test drilling, electric wires coated with a resin having an intrinsic viscosity [η] of 2.3 dll/g as specifically shown in the above publication are used. It has been found that cables made of 4-methyl-1-pentene polymer or copolymer, which coats the conductor, may ooze out from the sheath due to cold flow.

Furthermore, it has been found that the crack resistance of such coated wires and cables may still be insufficient depending on the intended use.

OBJECTS OF THE INVENTION The present invention provides coated wires and cables that do not generate cold flow even when used under high temperature conditions, such as cables for deep oil well test drilling, and have excellent crack resistance. The purpose is to

Summary of the Invention The resin-coated electric wire/cable according to the present invention has a melting point of 220
It is characterized in that the periphery of the conductive wire is coated with 3-methyl-1-butene resin having a temperature in the range of ~310°C.

Since the resin-coated wire/cable of the present invention uses 3-methyl-1-butene resin having a specific melting point as described above, it may be coated with a 4-methyl-1-pentene polymer or copolymer. It can be used even under high temperature conditions where it would be difficult to use electric wires and cables.

Detailed Description of the Invention Next, the resin-coated wire/cable of the present invention will be specifically described. In the present invention, the coated wire/cable is coated around the conducting wire using 3-methyl-1-butene resin having a specific melting point.

The 3-methyl-(-butene resin copolymer used in the present invention has a melting point of 220°C to 310°C, preferably 240°C to 20°C).
It is within the range of 90°C.

Poly 3-methyl-1-butene having such a melting point can be obtained by copolymerizing 3-methyl-1-butene with an α-olefin, or by copolymerizing 3-methyl-1-butene. It can be prepared by changing the type of catalyst used or by changing the conditions during polymerization. Usually, the relationship between these factors and melting point is determined experimentally in advance, and then poly-3-methyl-1-butene having a desired melting point can be produced by conducting polymerization according to the determined conditions. .

Therefore, the 3-methyl-l-butene resin used in the present invention includes a 3-methyl-l-butene homopolymer and a 3-methyl-t-butene/α-olefin copolymer. For example, when copolymerizing α-olefins, examples of α-olefins that can be used include ethylene, propylene, 1-butene, 1-hexene, l-
C2-C22 α-olefins such as octene, l-decene, l-tetradecene, and 1-octadecene can be mentioned.

In the present invention, as the 3-methyl-1-butene resin,
When using the above 3-methyl-1-butene◆a-olefin copolymer, the content of the above α-olefin is 1
A 3-methyl-1-butene copolymer in the range ˜40% by weight, preferably 2-18% by weight, is used.

The above-mentioned 3-methyl-l-butene resin used in the present invention is usually melt flow rate (MFR: load 5k).
g5 temperature 320℃) is 0.01~500g710 minutes,
Preferably, the resin is in a range of 2 to 50 g/10 minutes. In the present invention, the 3-methyl-(-butene resin is preferably a crystalline resin.

In the present invention, the melting point of the 3-methyl-1-butene resin as described above is shown as a value measured by the following method using a differential scanning calorimeter.

That is, the sample was heated at 320°C for 1 minute to melt it, then cooled to room temperature at a cooling rate of 20°C/min, crystallized, kept at room temperature for 1 minute, and then heated at a rate of 10°C/min. Obtain the endothermic curve of the sample when it is heated at a certain speed, and indicate its peak temperature. Note that when the melting point of a sample used in the present invention, for example, a 3-methyl-t-butene polymer, is measured as described above, multiple endothermic peaks may be detected, in which case the highest peak temperature Let be the melting point of the resin.

The 3-methyl-1-butene resin copolymer used in the present invention may contain heat-resistant stabilizers, weather-resistant stabilizers, lubricants, copper damage-resistant stabilizers, antifogging agents, etc., within a range that does not impair the purpose of the present invention. It is also possible to add compounding agents that are normally added to polyolefins.

The method of coating electric wires and cables with the 3-methyl-1-butene resin is already known, and in the present invention,
Coating can be performed using known methods. That is, for example, a coating method using a conventional thermoplastic resin such as polyvinyl chloride or polyethylene using a wire coating device consisting of a wire feeder, an extruder, a cross-layer die, a cooling water tank, a pulling device, a winding device, etc. A similar method can be adopted.

The resin-coated electric wire/cable of the present invention has the above-mentioned 3-methyl-l
- Butene resin is coated as an insulating material around conductors such as copper, copper alloys such as silver-containing copper, chromium copper, zirconium copper, and tin-containing copper, copper-clad aluminum, No. 1 aluminum alloy, aluminum-clad steel wire, etc. It is something. The thickness of the resin coating is usually in the range of 0.5 to 20 m11.

In addition, the surface of the resin coating material is roughened so that the surface roughness measured with a surface roughness meter (manufactured by Koita Laboratory ■, model 5E-3ASRJ27) is in the range of 0.05 to 1 degree. It is preferable to

By roughening the surface in this way, when the coated conductors are bundled to form a cable, the coated conductors and/or the coated conductors and the outer peripheral wall forming material such as cotton, cloth, jute, etc. will not be mis-wound. preferable.

The electric wire/cable of the present invention can be used as it is by coating the conductor with 3-methyl-1-butene resin as described above, or it can be further used by bundling a plurality of coated electric wires as described above and surrounding the conductor with 3-methyl-1-butene resin. It is also possible to form a cable by winding the cable with an outer peripheral wall forming material such as cotton, cloth, jute, etc., and further covering the periphery with a resin or the like, if desired.

Effects of the Invention The coated wire/cable of the present invention coats the conductor with a 3-methyl-1-butene resin copolymer, so it has better cold flow resistance and resistance than conventional resin-coated wires. Excellent crack resistance and impact resistance. Therefore, it can be suitably used as electric wires and cables used at very high temperatures, such as cables for drilling wells. It goes without saying that the coated wire/cable of the present invention can be used not only for applications requiring extremely high heat resistance as described above, but also for ordinary applications such as video wires and communication cables.

Furthermore, by appropriately roughening the surface of the coating resin, even when a plurality of coated wires are bundled together to form a cable, the individual wires can be firmly fixed without causing twisting.

EXAMPLES Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to these examples in any way unless the gist of the invention is exceeded.

Example 1 Melting point 285°C, melt flow rate 140g/10 minutes,
Crystalline copolymer of 3-methyl-1-butene and 1-decene (1-decene content: 4% by weight) (according to ASTM 12381, measured at 320°C and 5 charge gravity) (hereinafter 3Mb
(abbreviated as (1)), two types of heat-resistant stabilizers (trade name Irganox 1010, manufactured by Musashino Geigy ■ and trade name Sandstub, manufactured by P-EPQ Sand Company) and 0.02 parts of zinc stearate each. .0.01 and 0
．． After adding 0.3 parts by weight and mixing with a Henschel mixer, the mixture was melt-kneaded and extruded using a 60 mmφ single-screw extruder (molding temperature: 260° C.) to obtain Sample-1.

Next, this sample-1 was coated on a copper wire with an outer diameter of 0.2+n11φ using a wire coating molding machine equipped with a 65myiφ extruder and a solid cloth with a diameter of 2.10m1φ, and a coating thickness of 0. A resin-coated electric wire with 6 axes and a surface roughness of 0.25 was obtained.

The low-temperature crack resistance of the obtained resin-coated wire was measured by the following method.

Low-temperature crack test In an atmosphere of 20°C, a specified amount (2 kg, 1 kg and 0.5
kg) was tied to a weight, passed through an iron pulley with a diameter of 60 cm, and the other end was moved up and down for 1 m to measure the number of times (one reciprocating movement) until cracks occurred in the coating resin.

In addition, in order to separately evaluate cold flow properties and impact resistance, an injection molding machine with a mold clamping pressure of 100 tons (molding temperature 2
Izot impact test specimens (178 inch thick, no notch) having the same intrinsic viscosity [η] and MFR as the coating resin-■ from Sample-1 (178 inches thick, no notch) and 12 c+
A square plate for compression testing of n x 12 c + n x 8 mm was molded, and the following tests were conducted.

High-temperature compression test (cold flow resistance): In an air chamber at 170°C, a rectangular iron rectangular parallelepiped with a tip shape of 5 m x 5 mm was placed on a square plate, a load was applied to the rectangular parallelepiped, and a compression test was performed to determine Young's modulus and compressive yield point. The stress was determined by Jllll and used as a measure of cold flow property.

That is, the larger the compressive yield point stress, the better the cold flow resistance.

Izot impact test: ASTM D 256 results are shown in Table 1.

Example 2 Instead of 3MB (1) used in Example 1, melting point 26
Crystalline copolymer of 3-methyl-I-butene and l-decene (1
Resin wave T with a surface roughness of 0.15 m+1 was prepared in the same manner as in Example 1 except that -decene content 7% by weight) (hereinafter abbreviated as 3MB(II)) was used. I obtained the electric wire.

The obtained covered wire was tested in the same manner as in Example 1 for low-temperature cracking, high-temperature compression test (cold flow resistance), and Izot impact test.

The results are shown in Table 1.

Claims (1)

[Claims] (1) A resin-coated electric wire/cable characterized in that the periphery of the conductive wire is coated with 3-methyl-1-butene resin having a melting point in the range of 220 to 310°C.