JP6003023B2 - Electric wires / cables and compositions - Google Patents

Description

  The present invention relates to an electric wire / cable and a composition excellent in low friction property under a sliding environment.

  Cables and cables such as cabtyre cables are routed and dragged through conduits and ducts when wiring and laying. In use, there are cases in which the wires / cables or other members come into contact with each other and are used by sliding. For this reason, wire / cable coating materials are required to have low friction and good slipperiness as well as excellent wear resistance.

  In order to improve wear resistance, as proposed in Patent Documents 1 to 3, carbon black is mixed with diene rubber and fatty acid amide is added as a processing aid in order to improve processability. . However, in Patent Document 1 in which fine carbon black is added and in Patent Document 3 in which a large amount of carbon black is added, the viscosity of the compound is remarkably high, so that extrusion molding is difficult. It cannot be applied to a covering material. Moreover, in patent document 2 which uses sulfur as a vulcanizing agent, since it is inferior in heat resistance, an applicable product will be restrict | limited as an electric wire / cable coating | covering material use.

  As a technique for improving the lubricity of electric wires and cables, a general method is to mix a solid lubricant such as graphite, molybdenum disulfide, tetrafluoroethylene resin, silicone resin, or lubricant into the coating composition. However, when these are mixed, there is a drawback that the mechanical strength such as tensile strength is significantly lowered.

JP 2008-280438 A JP 2007-314697 A JP 2007-106897 A

  Therefore, various methods have been studied to make up for such drawbacks, but the situation is not necessarily sufficient. For example, methods such as pulverizing a solid lubricant to be mixed or surface treatment with a silane coupling agent have been studied, but the effect is not sufficient. For this reason, the range of use is often limited by these methods.

  Accordingly, an object of the present invention is to provide an electric wire / cable and a composition that solves the above-mentioned problems, has excellent wear resistance, good sliding properties, low friction, and has mechanical strength such as tensile strength. There is to do.

The invention of claim 1 in order to achieve the above object, salts fluorinated polyethylene, relative to 100 parts by weight of elastomer was blended singly or two or more of nitrile rubber, the reinforcing filler 10 parts by mass or more to 100 parts by mass or less, Furthermore, a composition in which fatty acid amide is dispersed in a range of 3 parts by mass or more and 20 parts by mass or less, and an epoxy compound is added in an amount of 0.5 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the elastomer. It is an electric wire / cable characterized in that the outer periphery is coated and crosslinked.

  According to a second aspect of the present invention, the reinforcing filler is any one of carbon black, hydrous silicic acid, silicic anhydride, wollastonite, carbon fiber, and cellulose fiber, and includes at least one of them. Item 1. An electric wire or cable according to item 1.

  The invention of claim 3 is the electric wire / cable according to claim 1 or 2, wherein the fatty acid amide has a weight average molecular weight of 250 or more.

  Invention of Claim 4 is an electric wire and cable in any one of Claims 1-3 whose fatty acid of the said fatty acid amide is unsaturated fatty acid.

  According to a fifth aspect of the present invention, there is provided a wire or cable according to any one of the first to fourth aspects, wherein the dynamic friction coefficient of the coating material obtained by coating the composition on the outer periphery of the conductor or the wire core and crosslinking is 0.6 or less. It is.

The invention of claim 6, salts fluorinated polyethylene, relative to 100 parts by weight of elastomer was blended singly or two or more of nitrile rubber, 100 parts by mass or less than 10 parts by weight of reinforcing filler, 3 parts by weight of further fatty acid amide The composition is characterized in that it is dispersed in the range of 20 parts by mass or less and 0.5 parts by mass or more and 10 parts by mass or less of an epoxy compound is added to 100 parts by mass of the elastomer.

  According to a seventh aspect of the invention, the reinforcing filler is any one of carbon black, hydrous silicic acid, silicic anhydride, wollastonite, carbon fiber, and cellulose fiber, and at least one of them is included. 6. The composition according to 6.

  The invention according to claim 8 is the composition according to claim 6 or 7, wherein the fatty acid amide has a weight average molecular weight of 250 or more.

  Invention of Claim 9 is a composition in any one of Claims 6-8 whose fatty acid of the said fatty acid amide is unsaturated fatty acid.

  The present invention has excellent wear resistance, low frictional tensile properties and extrusion moldability, and also has a good molded appearance, and greatly contributes to expanding the application and application range of electric wires and cables. .

  Hereinafter, a preferred embodiment of the present invention will be described in detail.

The present invention, salt fluorinated polyethylene, nitrile rubber alone or blended with an elastomer 100 parts by mass of reinforcing filler 10 parts by mass or more to 100 parts by mass or less with respect to, 3 parts by mass or more further fatty acid amide 20 parts by weight The composition was dispersed in the following range, and the outer periphery of the conductor or electric wire core was coated with a composition in which an epoxy compound was added in an amount of 0.5 to 10 parts by mass with respect to 100 parts by mass of the elastomer, and this was crosslinked. It was an electric wire / cable, and it was found that it was possible to impart wear resistance and low friction, and the present invention was achieved.

The elastomer, nitrile rubber (NBR), include rubber-based coating material, such as chlorinated polyethylene, used in blends alone or two or more of these. It is also possible to blend plastics such as polyethylene, ethylene vinyl acetate copolymer, and ethylene ethyl acrylate copolymer for the purpose of these modifications.

  Reinforcing fillers include carbon black, hydrous silicic acid, anhydrous silicic acid, hydrous magnesium silicate, hydrous aluminum silicate, powders represented by wollastonite (wollastonite), carbon fiber, cellulose fiber, CNT (carbon Nanotubes) and the like. Among these, carbon black, hydrous silicic acid, silicic anhydride, wollastonite, carbon fiber, and cellulose fiber are particularly effective because they can impart high wear resistance and tensile properties. It is also possible to mix these without treatment or use a surface treatment with a surface treatment agent such as a silane coupling agent, titanate coupling agent or fatty acid as necessary to improve the affinity with the elastomer. is there.

  These reinforcing fillers can be used alone or in combination of two or more reinforcing fillers.

  By dispersing reinforcing fillers in the polymer, they are physically bonded to the polymer, thereby improving the mechanical strength of the coating material.

  The reinforcing filler is mixed in the range of 10 to 100 parts by mass with respect to 100 parts by mass of the elastomer. If it is less than the limit value, the reinforcing property by mixing cannot be expected, and if it exceeds the limit value, the moldability is remarkably lowered.

  Typical examples of fatty acid amides include oleic acid amide, dioleic acid amide, ethylenebisoleic acid amide, gadrenic acid amide, digadrenic acid amide, erucic acid amide (erucic acid amide), linoleic acid amide, dilinoleic acid amide and the like. is there.

  The fatty acid amide is added in an amount of 3 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the elastomer.

  If it is less than the limit value, it is difficult to obtain the expected effect of slipperiness, and if it exceeds the limit value, mechanical properties such as wear resistance and tensile properties are greatly reduced, and surface stickiness and whitening by bleeding out to the surface. The appearance is poor.

  The mechanism of expression of such effects of fatty acid amide is not clear, but it is known that a network structure is formed by hydrogen bonding of amide, and this is thought to greatly improve the lubricity of the material surface. ing. Fatty acid amides preferably have a weight average molecular weight of 250 or more, and those having a molecular weight lower than this tend to bleed out on the surface and easily cause poor appearance due to surface stickiness or whitening. As fatty acid of fatty acid amide, unsaturated fatty acid is desirable from the viewpoint of imparting high lubricity. The reason for this is not clear, but saturated fatty acids have a straight-chain molecule, whereas unsaturated types may be related to a three-dimensional structure due to a bent structure of the molecule.

  In the present invention, it is desirable to add an epoxy compound to the above composition in an amount of 0.5 to 10 parts by mass with respect to 100 parts by mass of the elastomer. By adding an epoxy compound, it is possible to maintain low friction for a long period of time. This is presumed to be because epoxy and fatty acid amide react during the cross-linking process, a chemical bond is formed between them, and a low friction effect is exhibited over a long period of time.

  Examples of the epoxy compound include bisphenol A type epoxy resin, bisphenol F type epoxy resin, polyfunctional epoxy resin, flexible epoxy resin, glycidyl ester type epoxy resin, bisphenyl type epoxy resin, and the like. Two or more types can be used in combination. Specific examples of the product include bisphenol A type Epicoat 828 (manufactured by Yuka Shell Epoxy Co., Ltd.) and Epon 828 (manufactured by Shell Chemical Co., Ltd.).

  Furthermore, in the above composition, flame retardants such as zinc oxide and magnesium oxide, fillers such as calcium carbonate, flame retardant aids such as antimony trioxide, crosslinking aids such as dicumyl peroxide and sulfur, phenyl-isopropylphenylenediamine An antioxidant such as bisphenol, a plasticizer such as dibenzothiazyl disulfide, tetramethylthiuram disulfide, dioctyl phthalate, chlorinated paraffin, and naphthenic process oil can be added.

  In addition to these, it is also possible to appropriately add compounding agents such as a stabilizer, a reinforcing agent, a coloring agent, and a softening agent.

  After the composition comprising these is extrusion coated on a conductor or electric wire core, the coating material is crosslinked with saturated water vapor, superheated water vapor, hot air, far infrared, molten salt, electron beam or the like.

  A composition in which these are dispersed in the above-described elastomer used in the present invention is excellent in wear resistance when crosslinked to form a molded product.

  In the present invention, the dynamic friction coefficient (hereinafter, the dynamic friction coefficient is simply referred to as a friction coefficient) is preferably 0.6 or less. Usually, the ethylene propylene rubber, butyl rubber, chloroprene rubber, nitrile rubber and the like described above as elastomers have a high friction coefficient and are inferior in slipperiness. On the other hand, in the present invention, by using the above-mentioned blending prescription, the friction coefficient can be greatly reduced, specifically, 0.6 or less.

  Various evaluations of the friction coefficient have been proposed. In the present invention, the surface property measuring instrument (apparatus: Haydon 14FW) manufactured by Shinto Kagaku Co., Ltd. is used according to JIS K7125. The measurement conditions are a load of 200 g, a moving speed of 50 mm / min, an atmosphere: in the air, at 24 ° C., the slip properties of the same kind are evaluated, and the lowest dynamic friction coefficient in the measurement for 10 seconds is defined as the friction coefficient. In addition, the surface smoothness of the test piece is adjusted to 0.2 ± 0.1 μm with an average roughness Ra.

Reference examples, examples and comparative examples of the present invention will be described below.

  After mixing the compounding agent for 5 minutes with a hot roll maintained at 90 ° C. according to the compounding composition shown in Table 1, molding is performed by hot pressing at 120 ° C. for 3 minutes and a press pressure of 10 MPa, a thickness of 2 mm, a length of 150 mm, and a width of 100 mm. A sheet was produced. This sheet was crosslinked by contacting with 1.3 MPa water vapor for 3 minutes to obtain a sample for evaluation.

  As evaluation items, friction coefficient, wear resistance sliding characteristics, tensile characteristics and appearance evaluation were performed.

The processability was evaluated using an uncrosslinked sheet mixed with a hot roll.
These detailed evaluation methods will be described.

(1) Friction coefficient As described above, the surface property measuring device (apparatus: Haydon 14FW) manufactured by Shinto Kagaku Co., Ltd. was used according to JIS K7125. The measurement conditions are a load of 200 g, a moving speed of 50 mm / min, an atmosphere: in the air, at 24 ° C., the same type of slip properties are evaluated, and the minimum dynamic friction coefficient is taken as the friction coefficient within 10 seconds, and 0.6 or less is passed. It was. The surface smoothness of the test piece was 0.2 ± 0.1 μm in terms of average roughness Ra.

(2) Abrasion resistance A thrust abrasion tester was used for the test. In accordance with JIS K7218, a sheet sample is cut into a 40 mm square and a thickness of 2 mm to obtain a test piece. ) Was used. The cylindrical ring and the sheet sample were slid and a wear test was performed. The surface pressure was 0.1 MPa, the peripheral speed was 30 m / min, the measurement time was 30 minutes, the atmosphere was dry, and the temperature was room temperature. After the test, the mass was measured, and the specific wear amount was calculated from the mass change. Two points were measured by this method, the arithmetic average was shown, and 100 or less was considered acceptable.

(3) Tensile properties A dumbbell-shaped No. 4 test piece described in JIS K6251 was cut out from the cross-linked sheet, and a tensile test was performed using this with a shopper tensile tester in an atmosphere of 20 ° C and a tensile speed of 500 mm / min. Five points were measured for each sample, and the arithmetic average was obtained.

(4) Mooney viscosity Measured at 130 ° C. using an L-shaped rotor according to JIS K6300, and the minimum viscosity at that time was taken as the Mooney viscosity.

(5) Extrusion processability Evaluation of extrusion processability was performed using a lab plast mill extruder of Toyo Seiki Co., Ltd. Using a main body 30C150, a full flight screw diameter φ20, L / D = 25, the die was extruded in a rod shape at a die φ5 mm, a die set temperature 90 ° C., and a screw rotation speed 20 rpm. The pressure at the time of extrusion was measured, and a pressure of 50 MPa or less was regarded as good extrudability. When the pressure exceeded 50 MPa, the extrusion pressure was very high and extrusion molding was impossible, and the extrusion processability was judged to be poor.

(6) Appearance The entire steam-crosslinked sheet was wrapped in aluminum foil, and allowed to stand at 20 ° C. for 7 days, and then the sheet surface was visually observed to check the whitening state. Those with no whitening were judged as good and those with whitening were judged as bad.

In each of Reference Examples 1 to 4 and Examples 1 and 2 , the friction coefficient is as low as 0.6 or less, the specific wear amount is small, and the wear resistance is excellent. Further, the tensile properties sufficiently satisfy, for example, the tensile strength of 10 MPa or more and the elongation of 300% or more, which are chloroprene rubber standards for electrical appliances. The Mooney viscosity is low and the extrusion processability is excellent. Further, after steam crosslinking, no whitening is observed on the sheet surface, and the appearance is also good.

  On the other hand, the amount of fatty acid amide added in Comparative Example 1 is less than the limit value (3 parts by mass) and the friction coefficient exceeds 1 and is very large. In Comparative Example 2, the amount of fatty acid amide added is limited ( 20 parts by mass), the specific wear amount is large and the wear resistance is inferior, and the sheet surface is whitened, resulting in poor appearance.

  In Comparative Example 3, the mixing amount of the reinforcing filler is less than the limit value (5 parts by mass) and the wear resistance is inferior. In Comparative Example 4, the mixing amount of the reinforcing filler is the limit value (100 mass). Part), the melt viscosity increases significantly as can be seen from the Mooney viscosity, making extrusion impossible.

  Further, in Comparative Example 5, oleic acid other than fatty acid amide is added with a lubricant, the friction coefficient is high, and a whitened product is deposited on the sheet surface, resulting in poor appearance.

From the above, the mixing amount of the reinforcing filler is preferably 10 to 100 parts by mass with respect to 100 parts by mass of the elastomer, and the mixing amount of the fatty acid amide is 3 to 20 parts by mass.

Claims (9)

Salts fluorinated polyethylene, relative to 100 parts by weight of elastomer was blended singly or two or more of nitrile rubber, 100 parts by mass or less than 10 parts by weight of reinforcing filler, further fatty acid amide 3 parts by mass or more 20 parts by weight or less of the range An electric wire obtained by coating the outer periphery of a conductor or an electric wire core with a composition in which an epoxy compound is added in an amount of 0.5 to 10 parts by mass with respect to 100 parts by mass of the elastomer. ·cable.   The electric wire / cable according to claim 1, wherein the reinforcing filler is any one of carbon black, hydrous silicic acid, silicic anhydride, wollastonite, carbon fiber, and cellulose fiber. .   The electric wire / cable according to claim 1 or 2, wherein the fatty acid amide has a weight average molecular weight of 250 or more.   The electric wire / cable according to any one of claims 1 to 3, wherein a fatty acid of the fatty acid amide is an unsaturated fatty acid.   The electric wire / cable according to any one of claims 1 to 4, wherein the outer peripheral surface of the conductor or the electric wire core is coated with the composition and has a dynamic friction coefficient of 0.6 or less. Salts fluorinated polyethylene, relative to 100 parts by weight of elastomer was blended singly or two or more of nitrile rubber, 100 parts by mass or less than 10 parts by weight of reinforcing filler, further fatty acid amide 3 parts by mass or more 20 parts by weight or less of the range And an epoxy compound is added in an amount of 0.5 to 10 parts by mass with respect to 100 parts by mass of the elastomer.   The composition according to claim 6, wherein the reinforcing filler is any one of carbon black, hydrous silicic acid, silicic anhydride, wollastonite, carbon fiber, and cellulose fiber, and at least one of them is contained.   The composition according to claim 6 or 7, wherein the fatty acid amide has a weight average molecular weight of 250 or more.   The composition according to any one of claims 6 to 8, wherein the fatty acid of the fatty acid amide is an unsaturated fatty acid.