JP2012227101A - Insulating composition and electric wire and cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve ease of peeling of an insulating composition in, for example, electric wire and cable terminal parts, by suppressing adhesion of a resin-mixed material with respect to a screw of an extrusion molding machine, or the like.SOLUTION: A resin-mixed material is employed. The resin-mixed material is obtained by mixing 3-8 parts by weight of polyamide having a melting point of 190°C or below, plasticizer and thermal stabilizer with respect to at least 100 parts by weight of vinyl chloride resin. The resin-mixed material may be one which is obtained by mixing filler according to a target insulating composition. The resin-mixed material is used by coating it onto, for example, a peripheral surface of a wire-shaped conductor in electric wire and cable.

Description

  The present invention relates to an insulating composition formed by extruding a resin kneaded material mainly composed of a vinyl chloride resin, and an electric wire / cable formed by coating the insulating composition on a conductor.

  Wires / cables, etc., including single wires, stranded wires, etc., formed by coating an insulating composition on a conductor by an extrusion molding method, etc., are formed by extruding a resin kneaded material mainly composed of a vinyl chloride resin, for example. An insulating composition is applied. This insulating composition mainly composed of polyvinyl chloride resin is considered to have characteristics such as sufficient electrical insulation, flexibility, heat resistance, cold resistance, mechanical properties (strength, etc.), and low cost. ing.

  In recent years, in order to obtain wear resistance in addition to the above-mentioned properties, polyamides such as nylon (registered trademark; for example, nylon 11 (PA-11), nylon 12 (PA-12)) are used for polyvinyl chloride resin. It is known to apply a blended resin kneaded product, and the blending amount of the polyamide is set in a range of 15 to 25 parts by weight with respect to 100 parts by weight of all resin components in the resin kneaded product (for example, Patent Document 1). ).

  However, as described above, the resin kneaded material containing a relatively large amount of polyamide has high adhesion to metal, and when the resin kneaded material is extruded (for example, the extrusion temperature is set to 180 ° C. using a single-screw extruder). In this case, the resin kneaded material adheres to the surface of the screw or the like of the extrusion molding machine and easily forms a film, which may cause a decrease in extrusion moldability. Moreover, when the coating film formed of the resin kneaded material is formed as described above, for example, a switching process of the extrusion molding machine (for example, a process of switching to a molding material for stopping when the extrusion molding machine is stopped) may be hindered. is there.

  In addition, an electric wire / cable coated with an insulating composition by extruding the resin kneaded material as described above is, for example, peeling off the insulating composition at the end of the electric wire / cable at the site where the electric wire / cable is wired. When performing work (work to peel off the ends of wires / cables with nippers, etc.), part of the insulating composition tends to remain on the conductor surface, which may interfere with the wiring work or There is a risk of disturbing the function.

JP 2006-291063 A

  The inventor of the present application has paid attention to the following problems in the insulating composition containing the vinyl chloride resin in association with the background art as described above.

  That is, in the case where an insulating composition is obtained by extruding a resin kneaded material containing a vinyl chloride resin, the adhesion of the resin kneaded material to a screw or the like of an extruder can be suppressed.

  Moreover, in the electric wire and cable in which the insulating composition is coated on a conductor, for example, it is possible to improve the peelability of the insulating composition at the end of the electric wire or cable.

  The insulating composition and the electric wire / cable formed by extrusion molding according to the present invention are technical ideas created after the earnest research of the inventor of the present application in order to solve the above-mentioned problems.

  Specifically, one embodiment of the insulating composition of the present invention is a resin kneaded material in which 3 to 8 parts by weight of a polyamide having a melting point of 190 ° C. or less, a plasticizer and a heat stabilizer are blended with at least 100 parts by weight of a vinyl chloride resin. It is characterized by being formed by extrusion. The resin kneaded product may contain a filler.

  Moreover, one aspect of the electric wire / cable of the present invention is characterized in that the above-mentioned insulating composition is coated on the outer peripheral surface of a wire-like conductor by an extrusion method.

  In a conventional insulating composition made of a vinyl chloride resin, for example, as in Patent Document 1, a relatively large amount of polyamide such as nylon is used to obtain the wear resistance of the insulating composition (100 parts by weight of the total resin component). 15-25 parts by weight) is known to be blended, but the adhesion of the polyamide to the screw of the extrusion molding machine and the peelability of the insulating composition to the conductor when applied to electric wires, cables, etc. Nothing was supposed.

  On the other hand, in the case of the present invention, polyamide is used to obtain characteristics such as sufficient electrical insulation, flexibility, heat resistance, cold resistance, mechanical properties (strength, etc.) and low cost in the insulating composition. Instead, a polyamide having a melting point of 190 ° C. or lower suitable for extrusion molding is used in a relatively small amount, assuming the above-described phenomenon of polyamide adhesion and peelability.

  According to the insulating composition according to the present invention, the adhesion phenomenon of polyamide to the screw or the like of the extrusion molding machine is suppressed, and sufficient extrusion moldability is obtained. Moreover, in the electric wire / cable using the above-mentioned insulating composition, for example, the insulating composition can be peeled off at the end of the electric wire / cable so that the wiring work can be easily performed, and the desired function of the electric wire / cable is achieved. Can be fully demonstrated.

Schematic explanatory drawing which shows an example by which the insulating composition which concerns on this invention was coat | covered with the conductor.

  The insulating composition and the electric wire / cable formed by extrusion molding according to the present invention are resins in which 3 to 8 parts by weight of polyamide having a melting point of 190 ° C. or less, plasticizer, and heat stabilizer are blended with respect to at least 100 parts by weight of vinyl chloride resin. The kneaded material is applied, and various materials and the like blended in the resin kneaded material include various materials as shown below.

<Vinyl chloride resin>
As the vinyl chloride resin, various vinyl chloride resins applied to electric wires and cables can be applied, and examples thereof include those having a polymerization degree of 1000 to 1400 used as a general extrusion grade. Specific examples include TK-1000 and TK-1300 manufactured by Shin-Etsu Chemical Co., Ltd., and TH-1000 and TH-1300 manufactured by Taiyo PVC Co., Ltd.

  In general, a resin kneaded product containing a large amount of vinyl chloride resin tends to have a high viscosity and pressure at the time of melting, for example, in an extrusion molding process, and has a lower elongation than a resin kneaded product containing a large amount of other resins. Although it is known as a thing, it becomes possible to improve the said extending | stretching force by mix | blending the polyamide mentioned later.

<Polyamide>
As the polyamide, various polyamides having a melting point of 190 ° C. or lower can be used. For example, polyamide (PA-11) obtained by ring-opening polycondensation of undecane lactam, polyamide (PA-) obtained by ring-opening polycondensation of lauryl lactam 12) and those obtained by copolymerizing various polyamides to lower the crystallinity and lower the melting point. Specific examples include UBESTA 3014U and 3024U manufactured by Ube Industries, and CM4001 and CM6241M manufactured by Toray.

<Additives>
In the case of a vinyl chloride resin, the resin itself has low processability. For example, a plasticizer may be blended within a range that does not impair the desired insulating composition and various characteristics of the wire / cable so that it can be easily heat-processed. good. About the compounding quantity of a plasticizer, setting in the range of 30-33 weight part is mentioned, for example, assuming the diameter reduction and thinning of a recent electric wire and cable. Specifically, when there is a high demand for heat resistance in addition to plasticity in the intended insulating composition, electric wire / cable, it is possible to use trimellitic acid ester, pyromellitic acid ester, etc. When the demand is low, it is possible to use a phthalate ester known as a general primary plasticizer.

  In addition, in a composition containing a vinyl chloride resin, a deHCl reaction occurs as a specific deterioration mechanism. Therefore, in order to suppress the deHCl reaction, for example, a target insulating composition, electric wire / cable You may mix | blend a heat stabilizer etc. in the range (for example, 4-6 weight part) which does not inhibit various characteristics. In the case of an electric wire / cable insulating composition that requires electrical insulation, for example, use of a Ca / Zn-based stabilizer can be mentioned.

  Further, the filler and the like may be blended within a range not impairing the intended insulating composition and various characteristics of the electric wire / cable, and specific examples thereof include use of calcium carbonate and the like. When this calcium carbonate is used, it can be read that there are obtained not only a few supplemental effects on the abrasion resistance of the insulating composition but also an action of suppressing the deHCl reaction.

<Production method>
If the compounding material containing the above-mentioned vinyl chloride resin, polyamide, etc. can be kneaded and the resin kneaded material can be extruded, a technique known in the extrusion molding field (kneading machine, extrusion molding machine, etc. is used). Can be used as appropriate. For example, as an example of an electric wire or cable formed by coating a wire-like conductor with an insulating composition, as shown in FIG. 1, a pressure type crosshead in which a core 2 is disposed inside a base 1 The use of an extrusion molding machine equipped with a die 10 is mentioned.

  In the gap between the base 1 and the core 2 of the crosshead die 10 in FIG. 1, the molten resin kneaded material 3 flows in the direction of the base outlet 1 a, and on the inner peripheral side of the core 2, a wire shape By guiding the conductor 4 in the direction of the cap outlet 1a, an electric wire / cable 6 in which the outer peripheral surface of the conductor 4 is coated with the insulating composition 5 is obtained.

  Next, based on this embodiment, as shown below, samples of various resin kneaded materials (samples S1 to S3 (Examples) and P1 to P5 (Comparative Examples) described later) are prepared, and the samples are extruded. Observe the formability, verify the various insulating compositions obtained by the extrusion, the cold resistance, heat resistance, wear resistance, and windability of the wires / cables and verify the results. 2 and 3.

<Each sample>
0 to 30 parts by weight of PA-12 (UBEST 3014U made by Ube Industries), 30 parts by weight plasticizer (TOTM made by J Plus) with respect to 100 parts by weight of polyvinyl chloride resin (TH-1300 made by Taiyo PVC Co., Ltd.) Parts, stabilizer (MTX-38V manufactured by Daikyo Kasei Co., Ltd.) 5 parts by weight, 10 parts by weight filler (vigot-10 manufactured by Shiraishi Calcium Co., Ltd.) were mixed and kneaded, and the resin kneaded material as shown in Table 1 below Samples S1 to S3 (Examples) and P1 to P5 (Comparative Examples) were prepared.

<Extrudability>
In the samples S1 to S3 and P1 to P5, melting was performed when extrusion was performed using a capillograph manufactured by Toyo Seiki Co., Ltd. according to JIS K 7199; a set temperature of 190 ° C. and a capillary die of Φ1.0 × 10 mm. The viscosity (piston speed 10, 50, 100, 200 mm / min) and melt extensibility (piston speed 100 mm / min, winding speed 10 m / min) were relatively examined. In the melt viscosity column of Table 2 below, the symbol “◯” indicates that the melt viscosity is relatively low and the extrusion molding is easy, and the symbol “X” indicates that the melt viscosity is relatively high and the extrusion molding is difficult. Suppose. In the column of melt extensibility, the symbol “◯” indicates that the melt extensibility is relatively good, and the symbol “Δ” indicates that the melt extensibility is relatively inferior.

  Further, in the samples S1 to S3 and P1 to P5, after extrusion molding using an extrusion molding machine (Φ40mm) manufactured by Omiya Seiki Co., Ltd. at a set temperature of 190 ° C and a screw diameter of Φ40mm, the screw surface of the extrusion molding machine Was visually observed to determine the presence or absence of film formation by the resin composition.

<Cold resistance>
In accordance with JIS K6723, 2 mm sheet-like sample pieces were respectively produced from the samples S1 to S3 and P1 to P5, and the cold resistance of these sample pieces was relatively examined. In the column of cold resistance in Table 2 to be described later, the symbol “◯” indicates that the cold resistance is relatively good, the symbol “×” indicates that the cold resistance is relatively poor, and the symbol “△”. The case where the cold resistance is better than the case of the symbol “x” but is inferior to the case of the symbol “◯”.

<Heat resistance>
First, in the samples S1 to S3 and P1 to P5, an insulating composition is formed on the conductor by extruding at a set temperature of 190 ° C. and a screw diameter of Φ40 mm using an extrusion molding machine (Φ40 mm) manufactured by Omiya Seiki Co., Ltd. Coated electric wires and cables (finished diameter 0.86 mm, wall thickness 0.2 mm) were produced. Next, after placing the wires / cables in an oven in accordance with JIS K7212 and exposing them in an atmosphere at a temperature of 150 ° C. with air replacement in the oven at 8 times / h for 200 hours, the wires / cables are taken out. The presence or absence of cracks was examined by diameter winding evaluation.

<Abrasion resistance>
Each wire / cable produced by the cold resistance test was subjected to a scrape test (23 ° C., 7N) in accordance with ISO 6722, 9/3, thereby relatively examining the wear resistance. In the column of abrasion resistance in Table 2 described later, the symbol “◯” indicates that the wear resistance is relatively good, the symbol “×” indicates that the cold resistance is inferior, and the symbol “△”. In this case, the wear resistance is better than that of the symbol “×”, but is inferior to that of the symbol “◯”.

<Peelability>
In each electric wire / cable produced in the cold resistance test, the insulating composition was scraped off with a cutter blade, and the body surface was observed with a magnifying glass or the like to examine whether the insulating composition remained.

<Extension>
Of the electric wires and cables produced in the cold resistance test, the samples S2, P1 to P3 were used, and the melt tension (piston speed 100 mm / min, winding speed 10, 15, 20 m / min), strand diameter Was measured.

  From the results shown in Table 2, it can be seen that the resin kneaded material in which 3 parts by weight or more of polyamide is blended as in samples S1 to S3 and P3 to P5 has good melt viscosity and melt extensibility. In the case of a resin kneaded material in which 15 parts by weight or more of polyamide is blended as in samples P3 to P5, it can be read that the resin kneaded material adheres to a screw or the like of an extrusion molding machine and deteriorates extrusion moldability. That is, it was found that good extrudability can be obtained by using polyamide in the range of 3 to 8 parts by weight as in samples S1 to S3.

  In addition, according to the electric wire / cable formed by extruding the resin kneaded material blended with 3 to 8 parts by weight of polyamide as described above, the heat resistance, wear resistance and peelability are good as shown in Table 2. It was also found out. Furthermore, as shown in Table 3, it has been found that the coil can be wound with a relatively small take-up tension, and the strand diameter can be further reduced.

  Although the present invention has been described in detail only for the specific examples described above, it is obvious to those skilled in the art that various changes and modifications are possible within the scope of the technical idea of the present invention. Such variations and modifications are naturally within the scope of the claims.

  For example, in the examples, an example of an insulating composition obtained by extrusion molding into a wire shape, an example of an electric wire / cable was given, but even when extruded into a tube shape or a sheet shape, the same effect can be obtained. it is obvious.

DESCRIPTION OF SYMBOLS 1 ... Base 2 ... Mandrel 3 ... Resin kneaded material 4 ... Conductor 6 ... Electric wire and cable 10 ... Crosshead die

Claims (2)

  An insulating composition obtained by extruding a resin kneaded material in which 3 to 8 parts by weight of a polyamide having a melting point of 190 ° C. or less, a plasticizer, and a heat stabilizer are blended with at least 100 parts by weight of a vinyl chloride resin.   An electric wire / cable obtained by coating the outer peripheral surface of a wire-shaped conductor with the insulating composition according to claim 1 or 2 by an extrusion method.

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