JP5907079B2 - Electric wires and cables using silane-grafted chlorinated polyethylene - Google Patents

Description

The present invention relates to wire and cable using the silane-grafted chlorinated polyethylene emissions. More particularly, to wire and cable using the silane-grafted chlorinated polyethylene emissions obtained by grafting vinyl silane coupling agent chlorinated polyethylene.

  Chlorinated polyethylene is a kind of thermoplastic elastomer obtained by allowing chlorine to act on polyethylene as a raw material by a method such as an aqueous suspension method. It is flexible, weather resistant, oil resistant, chemical resistant, flame retardant. It is an excellent material in a wide range of properties such as heat resistance and wear resistance, and is used in various applications such as industrial rubber products, blends with resins, especially impact modifiers for polyvinyl chloride. Of course, it is also widely used as a covering for electric wires and cables (for example, a covering member in the case of electric wires and a sheath in the case of cables), and is often made into a product by performing a crosslinking treatment. As a cross-linking method, chemical cross-linking by using a peroxide as a radical generator is widely used, but a silane cross-linking method using a silane coupling agent and a peroxide, which are often used in polyethylene and the like, is also used. (For example, refer to Patent Document 1).

  A method for producing electric wires and cables using a silane crosslinking method includes a silane grafting step of grafting a silane coupling agent onto chlorinated polyethylene using radicals generated by thermal decomposition of peroxide, and coating of electric wires and cables (for example, It is roughly divided into a compound process for kneading various additives for imparting necessary properties as a covering member in the case of an electric wire and a sheath in the case of a cable, and a cable extrusion process in which the prepared compound is covered with a cable. The silane grafting step and the compounding step can be performed individually or in combination.

  Chlorinated polyethylene is actively produced not only in Japan but also overseas, particularly in China, and a great number of grades have been commercialized.

JP-A-62-34323

  However, depending on the type of chlorinated polyethylene to be used, there is a problem that in the silane grafting step, pellets after the silane grafting aggregate in the storage container, so that handling workability in the next step is remarkably lowered.

The present invention has been made in view of the above problems, when stored as pellets, with excellent silane-grafted chlorinated polyethylene in to extrudability with agglomeration of the pellets can be suppressed during its storage The purpose is to provide electric wires and cables.

  As a simple anti-agglomeration measure, it is conceivable that the pellet or chlorinated polyethylene (powder), which is a raw material or raw material, is applied to the pellet. It is industrially preferable to have.

To achieve the above object, according to the present invention, there is provided wire and cable using the following silane-grafted chlorinated polyethylene emissions.

[ 1 ] One or more conductors and chlorinated polyethylene formed on the outer periphery of the conductor and having a Mooney viscosity at 121 ° C. (measured value after 4 minutes after preheating for 1 minute) of 45 to 85 are added to vinylsilane. An electric wire having a covering member made of silane-grafted chlorinated polyethylene obtained by grafting a coupling agent .

[2] Compound A formulated with stabilizers chlorinated polyethylene described in [1], and the catalyst master batch was further blended a silanol condensation catalyst, the silane-grafted chlorinated polyethylene described in [1], further additives The electric wire according to [1] , comprising a covering member formed by extrusion-coating a compound B to which is added to a conductor.

[ 3 ] The electric wire according to [2] , wherein the additive is at least one selected from the group consisting of a plasticizer, an antioxidant, a flame retardant, and carbon black.

[ 4 ] The electric wire according to [ 2 ] or [ 3 ], wherein the silanol condensation catalyst is dibutyltin dilaurate.

[ 5 ] The electric wire according to any one of [ 2 ] to [ 4 ], wherein a mass blending ratio of the compound B and the catalyst master batch (compound B: catalyst master batch) is 100: 1 to 100: 10.

[ 6 ] The electric wire according to any one of [ 1 ] to [ 5 ], wherein the silane-grafted chlorinated polyethylene constituting the covering member is formed by the action of moisture after being formed as the covering member.

[ 7 ] To one or more electric wires and a chlorinated polyethylene formed on the outer peripheral side of the electric wires and having a Mooney viscosity at 121 ° C. (measured value after 4 minutes of preheating for 4 minutes) of 45 to 85, A cable having a sheath made of silane-grafted chlorinated polyethylene obtained by grafting a vinylsilane coupling agent .

[8] the compound A formulated with stabilizers chlorinated polyethylene according to [7], and the catalyst master batch was further blended a silanol condensation catalyst, the silane-grafted chlorinated polyethylene according to [7], further additives The cable according to [ 7 ], including the sheath configured by extrusion-coating the compound B to which is added on the electric wire.

[ 9 ] The cable according to [ 8 ], wherein the additive is at least one selected from the group consisting of a plasticizer, an antioxidant, a flame retardant, and carbon black.

[ 10 ] The cable according to [ 8 ] or [ 9 ], wherein the silanol condensation catalyst is dibutyltin dilaurate.

[ 11 ] The cable according to any one of [ 8 ] to [ 10 ], wherein a mass blending ratio (compound B: catalyst masterbatch) between the compound B and the catalyst masterbatch is 100: 1 to 100: 10.

[ 12 ] The cable according to any one of [ 7 ] to [ 11 ], wherein the silane-grafted chlorinated polyethylene constituting the sheath is cross-linked by the action of moisture after being formed as the sheath.

According to the present invention, when stored as pellets, it is possible to provide an electric wire and cable using an excellent silane-grafted chlorinated polyethylene in to extrudability with agglomeration of the pellets can be suppressed during its storage.

  Specifically, if the silane-grafted chlorinated polyethylene of the present invention is used, for example, in the production of electric wires and cables, it is more industrial in all production processes from the silane grafting process of chlorinated polyethylene to cable extrusion and crosslinking processes. It is possible to obtain a high-quality manufacturing method with respect to the appearance of the manufactured electric wires and cables, the degree of crosslinking after the crosslinking treatment, and the like.

  The manufacture of electric wires and cables using such a silane water cross-linking method is based on the current method of manufacturing vulcanized (cross-linked) rubber-coated cables. Compared with methods, etc., manufacturing / equipment costs can be reduced, resulting in great economic merit.

It is a perspective view which shows typically the cable extruder used in the Example and comparative example of this invention.

[Summary of embodiment]
The silane-grafted chlorinated polyethylene used in this embodiment is grafted with a vinyl silane coupling agent on chlorinated polyethylene having a Mooney viscosity at 121 ° C. (measured value after 4 minutes after preheating for 4 minutes) of 45 to 85. Can be obtained.

  Moreover, the electric wire and cable of this Embodiment have the coating | cover (the coating member in the case of an electric wire, and the sheath in the case of a cable) comprised using the above-mentioned silane graft chlorinated polyethylene.

[Silane-grafted chlorinated polyethylene]
As described above, the silane-grafted chlorinated polyethylene used in the present embodiment is a chlorine having a Mooney viscosity at 121 ° C. (measured value after 4 minutes after preheating for 1 minute) of 45 to 85 as a silane grafting step. It is obtained by grafting a vinyl silane coupling agent to a modified polyethylene.

The ease of agglomeration of the pellet is considered to greatly depend on the viscosity of the material when the shape is the same. That is, in order to suppress the aggregation of the pellets, it is effective to increase the viscosity of the material.
(1) Use a raw material (chlorinated polyethylene) having a high viscosity.
(2) Add filler.
(3) It is conceivable to form a crosslink during silane grafting.

  However, with regard to (2), if a vinylsilane coupling agent is grafted in the presence of a filler such as carbon, the grafting reaction is inhibited, and the vinylsilane coupling agent can be sufficiently grafted onto chlorinated polyethylene. Can not.

  Moreover, about (3), since bridge | crosslinking formation in a grafting stage worsens the workability after the following process, it is unsuitable. In particular, when cable extrusion is performed as a covering member for electric wires and cables, there is a concern about appearance problems such as generation of so-called protrusions due to the crosslinked body.

  This embodiment is based on the above knowledge and adopts the concept of (1). Mooney viscosity of chlorinated polyethylene as a raw material (measured value at 121 ° C., after 1 minute of preheating and after 4 minutes) Is in the range of 45 to 85, aggregation of the silane-grafted chlorinated polyethylene can be prevented, and when used as a covering member and a sheath for the electric wire and the cable, the workability at the time of the electric wire and the cable extrusion, the electric wire and The appearance of the covering member and the sheath of the cable can be improved.

  If the Mooney viscosity exceeds 85, pellet agglomeration at the silane grafting stage can be prevented, but workability such as a significant increase in torque (extruder load current) during cable extrusion and abnormal heat generation of the material deteriorates. In addition, problems such as roughness of the surface of the cable covering member and fluctuations in the outer diameter of the cable also occur. Accordingly, it is practically difficult to increase the Mooney viscosity of the raw material chlorinated polyethylene above 85, and considering the stable cable extrudability, the Mooney viscosity of the raw material chlorinated polyethylene is 45 to 70. A range is preferable.

  When the Mooney viscosity is less than 45, when the pellets are stored in the form of pellets, they are aggregated in the storage container, so that the handling workability in the next process is significantly lowered.

  In the silane grafting process of the present embodiment, it is preferable to graft a vinyl silane coupling agent by blending a peroxide with chlorinated polyethylene and using an extruder.

  In addition to the vinyl silane coupling agent, a graft reaction can be suitably performed by heating and kneading in an extruder using a peroxide that generates radicals in order to graft this onto the raw material chlorinated polyethylene.

  Further, in the silane grafting process of the present embodiment, a stabilizer for capturing hydrogen chloride generated from chlorinated polyethylene and the above-mentioned peroxide are blended with chlorinated polyethylene and an extruder is used. It is preferable to graft a vinylsilane coupling agent.

  Here, as a vinylsilane coupling agent, vinyltrimethoxysilane or vinyltriethoxysilane can be mentioned as a suitable example. Examples of the radical generator for grafting the vinylsilane coupling agent onto the polyolefin include dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, 2,5- Dialkyl peroxides such as dimethyl-2,5-di (t-butylperoxy) hexane, α, α′-bis (t-butylperoxy-m-isopropyl) benzene; m- (t-butylperoxyisopropyl) Suitable examples include radical generators such as -isopropylbenzene, p- (t-butylperoxyisopropyl) -isopropylbenzene and dicumyl, either singly or in combination.

  The extruder can use a single-screw, twin-screw or more multi-screw, and the screw shape, L / D, etc. are not subject to restrictions on equipment.

  In addition, when performing the above-mentioned silane grafting process and the compound process used for manufacturing the electric wire mentioned later each independently, at the time of a silane grafting process, without including additives, such as carbon black and a plasticizer, chlorine When only a stabilizer for trapping hydrogen chloride generated from chlorinated polyethylene, a vinyl silane coupling agent, and a peroxide are blended, the vinyl silane coupling agent can be efficiently grafted onto chlorinated polyethylene.

[Electric wires and cables]
The electric wire and cable of the present embodiment are configured to have a coating (for example, a coating member in the case of an electric wire and a sheath in the case of a cable) configured using the above-described silane-grafted chlorinated polyethylene.

  Specifically, the electric wire of the present embodiment is configured as an insulated electric wire, for example, a conductor made of a general tin-plated copper stranded wire and the outer periphery thereof, a compound process, and an electric wire extrusion process (that is, the above-described process). A silane-grafted chlorinated polyethylene, and a step of preparing a compound by adding an additive thereto, and a step of extruding and coating it to form a coated member). Configured. The covering member may be either a single layer structure or a multilayer structure. Moreover, you may give a separator, a braiding, etc. as needed.

  In addition, the cable according to the present embodiment is configured as an insulated cable, and in this case, the cable includes an electric wire, and further includes a sheath or the like on the outer periphery thereof. For example, in the case of 1 to 3 electric wires and a plurality of electric wires, the above-described silane-grafted chlorinated polyethylene is used as the outermost layer with the interposition of paper or the like twisted together with the electric wires, and the presser wound tape wound around the outer periphery. And a sheath using the. In this case, generally used materials such as polyethylene, cross-linked polyethylene, and ethylene-propylene rubber can be used as the wire covering member. The cable according to the present embodiment can be obtained by forming a sheath by extrusion-coating the above-mentioned silane-grafted chlorinated polyethylene after single or plural twisting of these electric wires.

  In the compounding process, for silane-grafted chlorinated polyethylene, plasticizers, antioxidants, anti-aging agents, copper-discoloration-preventing agents, lubricants, flame retardants, and crosslinks that are commonly used for wire and cable coating members and sheaths Various additives such as an auxiliary agent, a crosslinking catalyst (including a silanol condensation catalyst), a stabilizer (hydrogen chloride scavenger), carbon black, and other fillers can be blended. Moreover, in this Embodiment, there is no restriction | limiting about said additive.

  Specifically, a compound master B in which a stabilizer is added to the above chlorinated polyethylene, a catalyst master batch in which a silanol condensation catalyst is further added, and a compound B in which an additive is further added to the above silane-grafted chlorinated polyethylene. It is preferable to have a covering member formed by extrusion coating on a conductor.

  In this case, it is preferable to use the above-mentioned additives, and among these, at least one selected from the group consisting of a plasticizer, an antioxidant, a flame retardant, and carbon black is more preferable.

  The mass blending ratio of compound B to catalyst master batch (compound B: catalyst master batch) is preferably 100: 1 to 100: 20, and more preferably 100: 2 to 100: 10. If it exceeds 20, chlorinated polyethylene in the catalyst masterbatch in which silane is not grafted (that is, it becomes a non-crosslinked component even after the crosslinking treatment) increases, so the degree of crosslinking may be reduced, and less than 1 If this is the case, poor dispersion of the catalyst master batch in the compound may occur, making it difficult to obtain a uniform crosslinked product.

  In the present embodiment, the silane-grafted chlorinated polyethylene constituting the covering member is preferably cross-linked by the action of moisture after being formed as the covering member, from the viewpoint of improving the appearance and the degree of cross-linking. That is, it is preferable to crosslink the silane-grafted chlorinated polyethylene compound used as a covering member and a sheath for electric wires and cables by a silanol condensation reaction with moisture and heat.

  In order to efficiently cause the silanol condensation reaction, a silanol condensation catalyst may be added. Silanol condensation catalysts include Group II such as magnesium and calcium, Group VIII such as cobalt and iron, or elements and metal compounds such as tin, zinc and titanium, metal salts of octylic acid or adipic acid, amine compounds, acids, etc. Can be mentioned. More specifically, dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dioctate, stannous acetate, stannous caprylate, lead naphthenate, zinc caprylate, cobalt naphthenate, ethylamine, dibutylamine, hexylamine, Examples thereof include inorganic acids such as pyridine, sulfuric acid and hydrochloric acid, and organic acids such as toluenesulfonic acid, acetic acid, stearic acid and maleic acid. Of these, dibutyltin dilaurate is preferable.

  Hereinafter, the silane-grafted chlorinated polyethylene of the present invention and electric wires and cables using the silane-grafted chlorinated polyethylene will be described more specifically. Note that the present invention is not limited in any way by the following examples.

  Graft extrusion of vinyl silane coupling agent onto chlorinated polyethylene, evaluation experiment on presence / absence of aggregation of silane grafted chlorinated polyethylene pellets, addition of additives to silane grafted chlorinated polyethylene, production of electric wires and cross-linking treatment were carried out as follows did. The condition is an example. In addition, although it does not explain in particular about manufacture of a cable, it can manufacture by the method used widely using the obtained electric wire.

(Pretreatment of chlorinated polyethylene)
The chlorinated polyethylene used for graft extrusion was pretreated as follows. Powdered chlorinated polyethylene was kneaded using an 8-inch roll machine, and a stabilizer was added thereto. A stabilizer is a compound having a function of capturing hydrogen chloride released from a chlorinated polyethylene molecule. The stabilizer may be uniformly dispersed in chlorinated polyethylene, and there is no problem in kneading in a short time of about 5 to 5 minutes at a roll surface temperature of about 100 to 120 ° C. The sheet after kneading the stabilizer was pelletized into a shape of about 5 mm square.

(Graft extrusion of vinyl silane coupling agent)
For the graft extrusion, a single screw extruder (L / D = 25) having a screw diameter of 20 mm was used. The screw was extruded into a strand shape using a full flight shape and a compression ratio of 2.0. The set temperatures were 80 ° C., 180 ° C., and 180 ° C. in this order from the hopper side, and the screw rotation speed was 30 rpm.

  The pretreated chlorinated polyethylene was sufficiently impregnated with a vinylsilane coupling agent in which a peroxide was dissolved in a plastic bag. Depending on the grade of the raw material chlorinated polyethylene, it was blocked at the time of impregnation, and in such a case, it was supplied to the extruder while being loosened by hand. The extruded silane-grafted chlorinated polyethylene strand was water cooled and pelletized. The pellets were collected in a stainless cylindrical container (diameter 24 cm, height 30 cm) up to a height of 20 cm.

(Evaluation experiment of the presence or absence of aggregation of silane-grafted chlorinated polyethylene pellets)
After the silane grafting, a crosslinking reaction (silanol condensation reaction) is likely to occur due to moisture in the atmosphere. Therefore, after collecting the pellets, a bag containing a desiccant was attached to the inner surface of the container, and the pellets were stored sealed for 24 hours. After storage for 24 hours, the pellets in the container were taken out from a metal tray to confirm the presence or absence of aggregation.

(Addition of additives to silane-grafted chlorinated polyethylene)
Using an 8-inch roll machine, a plasticizer, an antioxidant, a flame retardant, and carbon black were added and kneaded in order with respect to the chlorinated polyethylene in which no pellet aggregation was observed. The roll surface temperature was 100 to 120 ° C., carbon black was added, and kneading was performed for 5 minutes. The kneaded sheet was pelletized into an approximately 5 mm square shape.

  Separately, a silanol condensation catalyst was kneaded with chlorinated polyethylene to which only the stabilizer before silane graft extrusion was added under the same equipment and conditions, and the sheet was pelletized into a shape of about 5 mm square (silanol condensation master batch). ).

(Manufacture of electric wires and cross-linking treatment)
As shown in FIG. 1 and Table 1, using a single screw extruder (L / D = 15) with a screw diameter of 20 mm, the compound kneaded with the additive and the silanol condensation catalyst master batch were transferred to a copper conductor 10 (conductor). The electric wire 11 was produced by extrusion coating so as to have a coating thickness of 1.4 mm on a nominal cross-sectional area of 1.5 mm ² ). The screw 3 of the extruder 1 has a full flight shape and a compression ratio of 2.0, and the set temperature is from the hopper 2 side to the cylinder (1) 8, cylinder (2) 9, head 6, neck 5, die. The order of 7 was 100 ° C., 120 ° C., 120 ° C., 110 ° C., 110 ° C., and the screw rotation speed was 15 rpm. The coated electric wire 11 was subjected to crosslinking treatment by being left in 70 ° C. saturated steam for 24 hours. In FIG. 1, reference numeral 4 indicates a breaker plate.

  In order to achieve the above kneading / grafting reaction, there is no particular limitation as long as it is a kneading / reacting apparatus commonly used for kneaders, mixers, autoclaves and the like other than roll machines and extruders, and these kneading and graft reaction conditions ( The temperature and time are not limited to the above ranges.

(Example 1)
As shown in Table 2, 100 parts by mass of chlorinated polyethylene (manufactured by Showa Denko Co., Ltd., trade name: Eraslen 30 2NA ) and 6 masses of hydrotalcite (manufactured by Kyowa Chemical Industry Co., Ltd., trade name: Magseller 1) as a stabilizer Parts and epoxidized soybean oil (manufactured by Nippon Oil & Fats Co., Ltd., trade name: Neusizer 510R) and kneaded (compound A) with peroxide (dicumyl peroxide, Shin-Etsu Chemical Co., Ltd.) Silane-grafted chlorinated polyethylene obtained by grafting 4 parts by mass of vinylsilane coupling agent (vinyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM-1003) with 0.04 parts by mass dissolved therein Was extruded and pelletized. Evaluation of pellet agglomeration will be described later.

  As a plasticizer, 100 parts by mass of silane-grafted chlorinated polyethylene in which pellet aggregation was not observed, 10 parts by mass of naphthenic process oil (trade name: NP-24, manufactured by Idemitsu Kosan Co., Ltd.), as an antioxidant, 0.08 parts by mass of sulfur-based antioxidant (Ouchi Shinsei Chemical Co., Ltd., trade name: NOCRACK 300R) and amine-based antioxidant (Ouchi Shinsei Chemical Co., Ltd., trade name: NOCRACK 224) 1.5 3 parts by mass of antimony trioxide (manufactured by Sumitomo Metal Mining) as a flame retardant, 40 parts by mass of FEF carbon black (manufactured by Asahi Carbon Co., Ltd., trade name: Asahi Carbon 60G) as a carbon black (compound B) (This means silane-grafted chlorinated polyethylene)). Further, 1 part by mass of dibutyltin dilaurate was kneaded as a silanol condensation catalyst with respect to 100 parts by mass of Compound A to prepare a silanol condensation master batch.

  An electric wire was produced by extrusion coating a copper conductor with 2.5 parts by mass of a silanol condensation masterbatch with respect to 100 parts by mass of Compound B. The produced electric wire was subjected to crosslinking treatment by leaving it in 70 ° C. saturated steam for 24 hours.

[Evaluation]
The obtained silane-grafted chlorinated polyethylene and electric wires were evaluated as follows. The evaluation results are shown in Table 2.

(Pellet aggregation)
The pellets of silane-grafted chlorinated polyethylene collected in a stainless steel cylindrical container were visually checked for aggregation after storage for 24 hours, and those in which aggregation was not observed were accepted and those in which aggregation was observed were rejected.

(Extrudability: Torque during cable extrusion)
In the cable extrusion, the relatively small 20 mm extruder used this time, when the extrusion torque exceeds 35 N · m, the torque increases when considering the scale-up to an extruder of about 100 mm, making the worst extrusion impossible. Therefore, those having an extrusion torque of 35 N · m or less were accepted, and those exceeding 35 N · m were rejected.

(Extrudability: Appearance)
The appearance of the covering member was evaluated by visual observation and touch, and a good one was accepted, and one with a bad appearance due to roughness, melt fracture or the like was rejected.

(Gel fraction)
The gel fraction was determined by adding 0.5 g of the cross-linked coating member into a 40-mesh brass wire mesh, extracting with xylene in a 110 ° C. oil bath, and then vacuum drying at 80 ° C. for 4 hours. It weighed and calculated by the following formula from the ratio with the mass before extraction. If the gel fraction of the coated member after the crosslinking treatment was 60% or more, it was judged to be acceptable, and if it was less than 60%, the crosslinking was judged to be inadequate.

  Gel fraction (%) = (mass after extraction (g) / mass before extraction (g)) × 100

(Comprehensive judgment)
Comprehensive judgment is one item of these if the presence / absence of pellet aggregation after silane grafting, the torque at the time of wire extrusion, the appearance of the wire after the wire extrusion, and the gel fraction after the crosslinking treatment are all passed (○: passed). However, if it failed, it was written as (×: failed).

  In addition, the Mooney viscosity of chlorinated polyethylene measured the Mooney viscosity when test temperature was 121 degreeC using the test method based on JISK6300-1.

(Examples 2 to 4)
In Example 1, it carried out similarly to Example 1 except having used the chlorinated polyethylene from which Mooney viscosity shown in Table 1 differs. Table 2 shows the blending amounts and the evaluation results.

(Comparative Examples 1-2)
In Example 1, it carried out similarly to Example 1 except having changed into the mixing | blending shown in Table 1. Table 2 shows the blending amounts and the evaluation results.

  Table 2 shows the following.

  Example 1 shows an example in which silane grafting was performed using a material having a Mooney viscosity (measured at 4 minutes after preheating at 121 ° C. for 1 minute) of 45 as a raw material. Aggregation of the pellets was not particularly observed. Moreover, the torque at the time of electric wire extrusion was 17 N · m, and the appearance of the covering member was good. The gel fraction after the electric wire was subjected to crosslinking treatment in saturated steam at 70 ° C. for 24 hours was 65%, and a sufficient degree of crosslinking could be obtained.

  Example 2 shows an example in which silane grafting was performed using a material having a Mooney viscosity (measured at 4 minutes after preheating at 121 ° C. for 1 minute) of 55 as a raw material. Aggregation of pellets was not particularly observed. Moreover, the torque at the time of electric wire extrusion was 19 N · m, and the appearance of the covering member was good. The gel fraction after the electric wire was subjected to a crosslinking treatment in saturated steam at 70 ° C. for 24 hours was 67%, and a sufficient degree of crosslinking could be obtained.

  Example 3 shows an example in which silane grafting was performed using a material having a Mooney viscosity (measured at 4 minutes after preheating at 121 ° C. for 1 minute) of 70 as a raw material. Aggregation of pellets was not particularly observed. Moreover, the torque at the time of wire extrusion was 27 N · m, and the appearance of the covering member was good. The gel fraction after the electric wire was subjected to crosslinking treatment in saturated steam at 70 ° C. for 24 hours was 74%, and a sufficient degree of crosslinking could be obtained.

  Example 4 shows an example in which silane grafting was performed using a material having a Mooney viscosity of 85 (measured value after 4 minutes after preheating at 121 ° C. for 1 minute) of 85 as a raw material. Aggregation of pellets was not particularly observed. Moreover, the torque at the time of wire extrusion was 34 N · m, and the appearance of the covering member was good. The gel fraction after the electric wire was subjected to crosslinking treatment in saturated steam at 70 ° C. for 24 hours was 79%, and a sufficient degree of crosslinking could be obtained.

  From the above, when a material having a Mooney viscosity (measured at 4 minutes after preheating at 121 ° C. for 1 minute) in the range of 45 to 85 was used as a raw material, the aggregation of pellets after silane grafting was particularly It was not seen, the torque at the time of wire extrusion could be suppressed to 35 N · m or less, and the appearance of the covering member was good. Moreover, the gel fraction after carrying out the bridge | crosslinking process in 70 degreeC 24h saturated water vapor | steam became 60% or more, and sufficient bridge | crosslinking degree was able to be obtained.

  Comparative Example 1 shows an example in which silane grafting was performed using a material having a Mooney viscosity (measured value at 4 minutes after preheating at 121 ° C. for 1 minute) of 20 as a raw material. Aggregation was seen in the pellet. As a result, the workability in the next process deteriorates, and even if countermeasures can be taken, it is assumed that a new process is required, which has industrial and economic disadvantages. .

  Comparative Example 2 shows an example in which silane grafting is performed using a material having a Mooney viscosity (measured value after passage of 4 minutes after preheating at 121 ° C. for 1 minute) of 90 as a raw material. As in -4, there was no particular aggregation of the pellets after grafting. However, the torque at the time of electric wire extrusion was as high as 37 N · m, and the appearance of the covering member was also rough.

  From the above, when the Mooney viscosity of the raw material chlorinated polyethylene decreases to about 20, the adhesiveness of the pellet after silane grafting increases, so that it aggregates as it is, and conversely the Mooney viscosity increases to about 90. It was found that there was a problem with the extrudability of the wires.

1 Extruder 2 Hopper 3 Screw 4 Breaker Plate 5 Neck 6 Head 7 Die 8 Cylinder 1
9 Cylinder 2
10 Conductor 11 Electric wire (after coating)

Claims (12)

One or more conductors and a chlorinated polyethylene formed on the outer periphery of the conductor and having a Mooney viscosity at 121 ° C. (measured value after 4 minutes after preheating for 4 minutes) of 45 to 85, a vinylsilane coupling agent An electric wire having a covering member formed using silane-grafted chlorinated polyethylene obtained by grafting a silane. In the compound A formulated with stabilizers chlorinated polyethylene according to claim 1, the catalyst masterbatch is further blended with a silanol condensation catalyst, the silane-grafted chlorinated polyethylene according to claim 1, it is added further additives The electric wire according to claim 1 , further comprising: a covering member formed by extrusion-coating the compound B on the conductor. The electric wire according to claim 2 , wherein the additive is at least one selected from the group consisting of a plasticizer, an antioxidant, a flame retardant, and carbon black. The electric wire according to claim 2 or 3 , wherein the silanol condensation catalyst is dibutyltin dilaurate. The electric wire according to any one of claims 2 to 4 , wherein a mass mixture ratio of the compound B and the catalyst master batch (compound B: catalyst master batch) is 100: 1 to 100: 10. The electric wire according to any one of claims 1 to 5 , wherein the silane-grafted chlorinated polyethylene constituting the covering member is cross-linked by the action of moisture after being formed as the covering member. Vinylsilane coupling to one or more electric wires and chlorinated polyethylene formed on the outer circumference side of the electric wires and having a Mooney viscosity at 121 ° C. (measured value after 4 minutes after preheating for 4 minutes) of 45 to 85 And a sheath made of silane-grafted chlorinated polyethylene obtained by grafting an agent . Stabilizers chlorinated polyethylene in the compound A was compounded as claimed in claim 7, the catalyst masterbatch is further blended with a silanol condensation catalyst, the silane-grafted chlorinated polyethylene according to claim 7, it is added further additives The cable according to claim 7 , further comprising the sheath formed by extruding and coating Compound B on the electric wire. The cable according to claim 8 , wherein the additive is at least one selected from the group consisting of a plasticizer, an antioxidant, a flame retardant, and carbon black. The cable according to claim 8 or 9 , wherein the silanol condensation catalyst is dibutyltin dilaurate. The cable according to any one of claims 8 to 10 , wherein a mass blending ratio of the compound B and the catalyst master batch (compound B: catalyst master batch) is 100: 1 to 100: 10. The cable according to any one of claims 7 to 11 , wherein the silane-grafted chlorinated polyethylene constituting the sheath is cross-linked by the action of moisture after being formed as the sheath.

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