JP3406003B2 - Coated wire and method of manufacturing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a coated electric wire. More specifically, it relates to a method for producing a covered electric wire and a crosslinked electric wire covered with a copolymer of a specific olefin.

[0002]

2. Description of the Related Art A covered electric wire in which a metal wire is covered with a molten resin is used for various electric purposes. Among them, polyethylene is used and crosslinked by irradiation with radiation (usually an electron beam). Electric wires have excellent heat resistance and are widely used.

[0003]

The conventional cross-linked coated electric wire needs to be irradiated with a relatively large amount of electron beams, requires expensive irradiation equipment, and cross-linking hardly progresses with polyolefins other than polyethylene. There is a problem that it is not possible to make a good cross-linked coated electric wire, and especially when using an inorganic oxide or hydroxide as a flame retardant because of the tendency not to use a recent halide, the electron beam energy is significantly increased. There was a problem that it could not be cross-linked without it. On the other hand, what was crosslinked with water using a polyolefin grafted with alkoxysilanes on the polyolefin and then crosslinked with water, the water resistance of the crosslinked coated electric wire, which does not require expensive equipment such as electron beam irradiation equipment,
There is a problem that heat resistance is poor.

If there is a covered electric wire which is crosslinked by irradiating a small amount of electron beam, it can be further developed into various applications and its development is desired. Furthermore, it is desired to develop a method for producing a coated electric wire with excellent performance by utilizing the method.

[0005]

Means for Solving the Problems The present inventors have completed the present invention by solving the above problems and earnestly investigating a new method for producing a covered electric wire and a crosslinked electric wire.

That is, the present invention is a coated electric wire obtained by heating and melting a metal wire with a copolymer of an alkenylsilane having at least one Si—H bond represented by the general formula (Formula 6) and an olefin. .

[0007]

[Chemical 6] (In the formula, n is 0 to 12, p is 1 to 3, R is carbon number 1 to 12
Hydrocarbon residue of. )

The coated electric wire of the present invention will be further described below by showing its manufacturing method.

In the present invention, as the alkenylsilane, specifically, vinylsilane, allylsilane, butenylsilane, pentenylsilane, or a hydrocarbon residue of some of these monomers where H of Si--H bond has 1 to 12 carbon atoms. Examples thereof include compounds substituted with.

As the olefin, a compound represented by the following general formula (Formula 2),

[0011]

Embedded image H ₂ C═CH—R (wherein R is hydrogen or a hydrocarbon residue having 1 to 12 carbon atoms.)
Can be exemplified, and specifically, ethylene, propylene, butene
In addition to α-olefins such as -1, pentene-1, hexene-1, 2-methylpentene, heptene-1, and octene-1, styrene and its derivatives are also exemplified.

In the present invention, the copolymer of olefin and alkenylsilane can be produced by a bulk polymerization method or a gas phase polymerization method in addition to the solvent method using an inert solvent. As a catalyst used for production, a catalyst composed of a transition metal compound and an organometallic compound is generally used, and a titanium halide is preferably used as the transition metal compound and an organoaluminum compound is preferably used as the organometallic compound.

Specifically, titanium trichloride obtained by reducing titanium tetrachloride with metallic aluminum, hydrogen or organoaluminum, modified with an electron donating compound, an organoaluminum compound, and optionally an oxygen-containing organic compound. Such as a catalyst system composed of an electron-donating compound, a carrier such as magnesium halide, or a transition metal compound catalyst obtained by supporting titanium halide on the carrier treated with an electron-donating compound and an organoaluminum compound, if necessary. A catalyst system consisting of an electron-donating compound such as an oxygen-containing organic compound or a reaction product of magnesium chloride and alcohol is dissolved in a hydrocarbon solvent, and then treated with a precipitating agent such as titanium tetrachloride to form a hydrocarbon solvent. Insolubilize, treat with electron donating compounds such as ester and ether if necessary, then Examples thereof include a catalyst system comprising a transition metal compound catalyst obtained by a method of treating with titanium rogenide and an organoaluminum compound, and optionally an electron-donating compound such as an oxygen-containing organic compound (for example, various references in the following documents). An example is given of: Ziegler-Natta Ca
talysts and Polymerization by John Boor Jr (Academi
c Press), Journal of Macromorecular Science Reviews
in Macromolecular Chemistry and Physics, C24 (3) 355
-385 (1984), C25 (1) 578-597 (1985)).

Alternatively, the polymerization can be carried out by using a transition metal catalyst soluble in a hydrocarbon solvent and a catalyst comprising aluminoxane.

As the electron-donating compound, oxygen-containing compounds such as ethers, esters, orthoesters and alkoxysilicon compounds can be preferably exemplified, and alcohols, aldehydes, water and the like can also be used.

As the organoaluminum compound, trialkylaluminum, dialkylaluminum halide, alkylaluminum sesquihalide and alkylaluminum dihalide can be used, and examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group and hexyl group. Examples of the halide include chlorine, bromine and iodine. Further, an aluminoxane which is an oligomer or a polymer obtained by reacting the above organoaluminum with water or water of crystallization can also be used.

Here, the polymerization ratio of alkenylsilane and olefin is not particularly limited, but when it is used as a mixture with polyolefin, alkenylsilane is usually 0.001.
It is about 30 to 30 mol%, preferably 0.1 to 10 mol%. When used alone, it is about 0.0001 to 1 mol%.

The molecular weight of the polymer is not particularly limited, but when it is mixed with a polyolefin, the molecular weight is preferably the same as or lower than the molecular weight of the polyolefin. As a preferable molecular weight, the intrinsic viscosity measured with a tetralin solution at 135 ° C. is about 0.1 to 10 dl / g .

A graft copolymer obtained by graft-polymerizing an alkenylsilane onto a polyolefin (for example, the following mixed polyolefin can be used) can be used for the purpose of the present invention. There is no particular limitation as to the method for grafting alkenylsilane to, and the method and conditions used for ordinary graft copolymerization can be used. Normally, the polyolefin and alkenylsilane used are radical initiator in the presence of a radical initiator such as peroxide. Graft copolymerization can be easily carried out by heating above the decomposition temperature of.

In the present invention, the polyolefin used as a mixture with the above-mentioned copolymer, if necessary, is an olefin represented by the general formula (Formula 2), specifically ethylene, propylene, butene-1, pentene-1, hexene. 1, α-olefins such as 2-methylpentene, heptene-1, and octene-1, or a homopolymer of styrene or a derivative thereof,
Random copolymers with each other, or first with olefins alone or with small amounts of other olefins, then 2
Examples thereof include so-called block copolymers produced by copolymerizing at least one olefin.

Methods for producing these polyolefins are already known and various brands are available on the market. It can also be produced by the same method as the method for producing a copolymer of olefin and alkenylsilane except that alkenylsilane is not used.

In the present invention, as the additive used by mixing with the copolymer of alkenylsilane and olefin, various known additives such as stabilizers and fillers can be used in addition to polyolefin. If a substance or a hydroxide is used, it becomes excellent in flame retardancy.

In the present invention, examples of the inorganic oxide or hydroxide include oxides or hydroxides of Group I, II, and III of the Periodic Table, or a mixture thereof or a mixture with another inorganic compound. Particularly, oxides and hydroxides of Group II and III metals can be preferably used. Specifically, magnesium hydroxide, magnesium oxide, aluminum hydroxide, aluminum oxide, barium hydroxide, barium oxide, or a mixture or complex thereof is preferably used. Here, the proportion of the inorganic oxide or hydroxide used is from 1 to 80% by weight, preferably from 5 to 80% by weight, based on the total composition, including polyolefins and additives, which will be described later.
It is generally set to 50 wt%. As the additive used by mixing the alkenylsilane / olefin copolymer with the inorganic oxide or hydroxide, various known additives such as stabilizers can be used in addition to polyolefin. When the above-mentioned inorganic oxide or hydroxide is used for flame retardance, it is preferable that the crosslinking is brought into contact with the catalyst, and it is necessary to use radiation having a large penetrating power when using radiation.

In the present invention, a copolymer of an alkenylsilane and an olefin is mixed with a polyolefin or an additive as required to form a composition, which is heated and melted to be molded so as to coat a metal wire. As a molding method for coating the metal, a general method can be applied as it is, and an extruder equipped with a crosshead die or an angular offset die is generally used. The extrusion conditions are not particularly limited, but extrusion at 150 to 300 ° C. is common.

When the coated electric wire thus obtained is cross-linked, it is then irradiated with radiation or brought into contact with a catalyst.

Examples of radiation include electron beams, γ rays, X rays, and ultraviolet rays. From the viewpoint of transparency, γ-rays and X-rays are preferable, and the irradiation dose is usually about 0.1 to 100 Mrad,
It is preferably about 1 to 50 Mrad. 50 as the irradiation temperature
It is carried out at a temperature of not higher than 0 ° C., and it is not necessary to carry out at a particularly low temperature and it may be carried out at room temperature. When irradiation is performed at a high temperature, there are problems such as deformation of the molded product and inefficient crosslinking. Therefore, it is preferable that the irradiation is performed at a relatively low temperature and the radicals are completely erased by heating after the irradiation.

As a catalyst preferably used, a salt of rhodium such as a triphenylphosphine complex of rhodium chloride, or an alkoxy compound of a metal of Group IVB of the periodic table represented by the following general formula (Formula 3) such as a titanate ester is used. It is illustrated.

[0028]

Embedded image R ¹ _n M (OR ² ) _4-n (wherein R ¹ and R ² are the same or different hydrocarbon residues having 1 to 12 carbon atoms, n is an integer of 0 to 3 and M is titanium). , A metal selected from zirconium and hafnium.).

Contact is carried out by dissolving the above catalyst in a solvent described below and immersing the solution continuously or batchwise. Specific examples of the solvent to be used include 1 to 1 carbon atoms.
Twenty hydrocarbon compounds and halogenated hydrocarbon compounds can be used, and particularly halogenated hydrocarbon compounds and aromatic hydrocarbon compounds are preferably used. Specific examples include benzene, toluene, xylene, ethylbenzene, dichloromethane, chloroform, dichloroethane, trichloroethane, perchloroethane and the like. The catalyst concentration is 0.
About 000001 to 1000g / liter, usually 0.00001 to 10g /
It is done in liters. The contact time varies depending on the concentration of the catalyst, the temperature of the catalyst solution, the shape of the copolymer, the concentration of alkenylsilane in the copolymer, and the like, but is usually several minutes to several tens hours. The temperature at the time of dipping is preferably a high temperature in the range where the molded product is not deformed when it comes into contact with the molded product after contact with the molded product, from the viewpoint of the speed of the crosslinking reaction, but usually from room temperature to 200 ° C., preferably Room temperature ~ 150 ℃. At this time, it is of course possible to stir to assist the dispersion of the catalyst.

The copolymer of alkenylsilane and olefin has an advantage that the wire is difficult to twist in applications where the coating does not need to be peeled off because it is extremely adhesive to metal.
In a usual application of a coated electric wire, the coating is difficult to peel off, so that it is difficult to peel off the coating because it is used by connecting with a contact. On the other hand, by coating the metal wire with a fluorine-based resin prior to coating the electric wire with the copolymer, it is possible to obtain a covered electric wire in which the coating can be easily peeled off.

As the fluorinated resin, a high molecular weight fluorinated olefin polymer or a fine powder of an inorganic compound (eg, alumina, silica, kaolin, talc, mica) is dispersed in a liquid fluorinated olefin low molecular weight polymer. Those can be preferably used. Treatment with a fluorine-based resin can usually be accomplished by bringing a metal wire into contact with the grease-like fluorine-based resin, wiping off the excess resin, and then sending the wire to the special die.

The content of the alkenylsilane in the molded product depends on the content of the alkenylsilane in the copolymer, but the content of the copolymer in the molded product is usually 0.1 wt% or more. It is preferable that 0.0001 wt% or more is present. The alkenylsilane content in the molded product is preferably about 0.0001 to 1.0 wt%.

[0033]

EXAMPLES The present invention will be further described with reference to the following examples.

Example 1 A vibrating mill equipped with four grinding pots having an inner volume of 4 liters and containing 9 kg of steel balls having a diameter of 12 mm was prepared. In each pot under a nitrogen atmosphere, 300 g of magnesium chloride, 60 ml of tetraethoxysilane and 45 of α, α, α-trichlorotoluene
ml was added and crushed for 40 hours. Co-ground product 300 thus obtained
In a 5 liter flask, add 1.5 liters of titanium tetrachloride and 1.5 liters of toluene, and add 30 liters at 100 ° C.
After stirring for a minute, the supernatant was removed. Add again 1.5 liters of titanium tetrachloride and 1.5 liters of toluene,
The mixture was stirred at 100 ° C for 30 minutes, and the supernatant was removed. Then, the solid content was repeatedly washed with n-hexane to obtain a transition metal catalyst slurry. When a part of the sample was sampled and the titanium content was analyzed, the titanium content was 1.9 wt%.

40 ml of toluene, 100 mg of the above transition metal catalyst, 0.128 ml of diethylaluminum chloride, 0.06 ml of methyl p-toluate and 0.20 ml of triethylaluminum are placed in an autoclave having an internal volume of 5 liters under a nitrogen atmosphere, and 1.5 kg of propylene and 40 g of vinylsilane are added. In addition, hydrogen
After 1N liter pressure injection, polymerization was carried out at 75 ° C for 2 hours. After polymerization, purge unreacted propylene, take out powder,
It was filtered and dried to obtain 480 g of powder.

Intrinsic viscosity (hereinafter abbreviated as η) measured with a tetralin solution at 135 ° C., using a differential thermal analyzer at 10 ° C. /
When the melting point and crystallization temperature were measured as the maximum peak temperature by raising or lowering at min, the obtained powder had η of 1.72, melting point 153 ℃, crystallization temperature 118 ℃
Was a crystalline propylene copolymer. According to elemental analysis, it contained 1.2 wt% of vinylsilane unit.

50 g of the obtained copolymer was produced by homopolymerizing propylene (polymerization by the above method without adding vinylsilane, η was 2.25, and the extraction residue when extracted with boiling n-hexane for 6 hours. The ratio is 97.3%.) 100 g, 0.1 g of a phenolic antioxidant and well mixed were granulated at 250 ° C. with a 20 mmφ extruder. Then, a coated electric wire was formed by using a 20 mmφ extruder equipped with a crosshead type die at 250 ° C. such that a copper wire having a diameter of 1 mm was coated with a resin having a thickness of 0.1 mm. An attempt was made to remove the coating from the coated electric wire thus obtained, but it did not come off.

On the other hand, before introducing the copper wire into the crosshead die, a grease in which fine powder of polytetrafluoroethylene is dispersed in a low molecular weight polymer of polytrifluoroethylene (Daiflon grease manufactured by Daikin Co., Ltd.) Then, the excess grease was wiped off with a non-woven fabric, and the coated electric wire was easily peeled off.

Example 2 Polymerization was carried out in the same manner as in Example 1 except that 1 g of allylsilane was used instead of vinylsilane to produce a propylene copolymer having an allylsilane content of 0.25 wt%. The η of the copolymer was 1.85, the melting point was 158 ° C., the crystallization temperature was 115 ° C., and the extraction residue ratio after extraction with boiling n-heptane for 6 hours was 96.8%.
To 1000g of this powder, 1.0g of phenolic antioxidant
When pellets obtained by mixing and granulating were molded in the same manner as in Example 1 to obtain a coated electric wire, those not treated with diflon grease were treated with diflon grease because the coating did not peel off from the copper wire. The coating was easily peeled off.

Example 3 In 50 g of the copolymer obtained in Example 1, a homopolymer of propylene (manufactured by polymerizing without adding vinylsilane by the above-mentioned method, η is 2.25, boiling in n-hexane for 6 hours) The content of the extraction residue at the time of extraction was 97.3%.) 100 g and a well-mixed mixture of 0.1 g of a phenolic antioxidant were granulated in the same manner as in Example 1 to form a coated electric wire.

The coated electric wire thus obtained was immersed in a toluene solution in which 10 g / l of n-butyl titanate was dissolved and treated at 90 ° C. for 30 minutes. When the treated coated wire was extracted with boiling xylene for 12 hours, the insoluble content was 82.1 wt%
The coated polypropylene did not sag even at 250 ° C. When the coated wire before dipping was directly extracted with boiling xylene for 12 hours, the insoluble content was 0.1 wt%.
At 50 ° C, the coating started to sag in about 10 minutes.

Example 4 The same procedure as in Example 1 was carried out except that the pellet obtained in Example 2 was molded into a coated electric wire and a 0.1 g / liter solution of a triphenylphosphine complex of rhodium chloride was used as a catalyst. When treated in the same manner as in Example 3, the insoluble content of the coated electric wire extracted with boiling xylene for 12 hours was 79.5 wt%, and there was no sagging. In addition, the boiling xylene insoluble content of the coated electric wire before the dipping treatment was 0.2 wt%, and sagging occurred.

Example 5 To 50 g of the copolymer obtained in Example 1, 100 g of propylene homopolymer, 50 g of magnesium hydroxide and 0.1 g of phenolic antioxidant were added and mixed well. An extruder of 20 mmφ was prepared. Granulated at 250 ° C in the same manner to form a coated electric wire in the same manner. This coated electric wire was treated with the catalyst solution in the same manner as in Example 4. When the treated coated electric wire was extracted with boiling xylene for 12 hours, the insoluble content was 93.5 wt% and the coated polypropylene did not sag even at 250 ° C. Moreover, it did not burn up even if it was brought into contact with the flame. When the coated wire before dipping was directly extracted with boiling xylene for 12 hours, the insoluble content was 1.2 wt%.
At 250 ° C, the coating dripped in about 10 minutes.

Example 6 A pellet obtained by mixing 1000 g of the copolymer obtained in Example 2, 200 g of aluminum hydroxide and 1.0 g of a phenolic antioxidant and granulating the mixture was molded in the same manner as in Example 1. The coated wire was treated in the same manner as in Example 3 except that a 0.1 g / l solution of a triphenylphosphine complex of rhodium chloride was used as a catalyst. The coated wire was insoluble when extracted with boiling xylene for 12 hours. The amount was 86.3wt%, and there was no dripping and it did not burn up even if it touched the flame. In addition, the boiling xylene insoluble content of the coated electric wire before the dipping treatment was 1.8 wt%, and sagging occurred.

[0045]

EFFECTS OF THE INVENTION The coated electric wire of the present invention is capable of exhibiting a variety of properties from the one in which the coating is hard to peel off from the metal wire to the one which can be peeled off very easily, and the crosslinked coated wire to the flame-retardant coated electric wire. , Its use is widespread and it is extremely valuable industrially.

Claims (5)

(57) [Claims] 1. A coated electric wire obtained by heating and melting a metal wire with a copolymer of an alkenylsilane having at least one Si—H bond represented by the general formula (Formula 1) and an olefin. [Chemical 1] (In the formula, n is 0 to 12, p is 1 to 3, R is carbon number 1 to 12
Hydrocarbon residue of. ) 2. A metal wire whose surface is treated with a fluorine-based resin is coated with a copolymer of an alkenylsilane having at least one Si—H bond represented by the general formula (Formula 2) and an olefin by heating and melting. A covered electric wire. [Chemical 2] (In the formula, n is 0 to 12, p is 1 to 3, R is carbon number 1 to 12
Hydrocarbon residue of. ) 3. A metal wire is coated with a copolymer of an alkenylsilane having at least one Si—H bond represented by the general formula (Formula 3) and an olefin, which is melted by heating, and then subjected to contact treatment with a catalyst. A method for producing a crosslinked electric wire, which is characterized. [Chemical 3] (In the formula, n is 0 to 12, p is 1 to 3, R is carbon number 1 to 12
Hydrocarbon residue of. ) 4. A metal wire is coated with a copolymer of an alkenylsilane having at least one Si—H bond represented by the general formula (Formula 4) and an olefin, which is melted by heating and then irradiated with radiation. And a method for producing a crosslinked covered electric wire. [Chemical 4] (In the formula, n is 0 to 12, p is 1 to 3, R is carbon number 1 to 12
Hydrocarbon residue of. ) 5. A composition comprising an alkenylsilane having at least one Si—H bond represented by the general formula (Formula 5) having a metal wire and an olefin copolymer and an inorganic oxide or hydroxide is melted by heating. A method for producing a crosslinked coated electric wire, which comprises contacting with a catalyst after being coated with a catalyst. [Chemical 5] (In the formula, n is 0 to 12, p is 1 to 3, R is carbon number 1 to 12
Hydrocarbon residue of. )