JPS5857209A - Fluorine-containing elastic copolymer insulated wire - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an insulated wire, and more particularly to a fluorine-containing elastic copolymer insulated wire useful as a heat-resistant flexible wire having a specific fluorine-containing elastic copolymer coating layer. It is related to.

Fluorine-containing elastic copolymers have been used as a base for fluorine rubber with excellent heat resistance, oil resistance, and chemical resistance in various applications such as gaskets, panoki, diamond rams, and hoses. Although this material has high expectations as a coating material for electric wires, when applying known fluorine-containing elastic copolymer compositions to electric wire coatings, there are problems with electrical insulation properties and poor moldability, such as There are various disadvantages such as difficulty in forming a thin wall with a thickness of about 0.1 to 2 mm, and on the other hand, the mechanical strength of the coating layer is insufficient for those with good formability. The combined coated layer wire has not yet been put into practical use.

The present inventors have conducted intensive research to solve the above-mentioned problems and provide a fluorine-containing elastic copolymer coated electric wire useful as a heat-resistant flexible electric wire. A composition that is mainly composed of an elastic copolymer and contains specific amounts of an organic peroxide and a polyalkali compound has excellent extrusion moldability and can be coated with thin electrical wires, and its heat-crosslinked product is It has been found that this material satisfies the required properties as a wire covering material, such as characteristics and mechanical properties.

Thus, the present invention was completed based on the above-mentioned new findings, and has a number average molecular weight of 20,000 to 60,000, and a unit based on tetrafluoroethylene and a unit based on an α-olefin having 2 to 4 carbon atoms. A fluorine-containing elastic copolymer containing a main component and exhibiting rubber elasticity at room temperature, an organic peroxide, and a polyaryl/allyl compound, based on 100 parts by weight of the fluorine-containing elastic copolymer. An extrusion coating layer of a composition containing 0.1 to 5 parts by weight and 0.1 to 20 parts by weight of a peroxide and a polyanolyl compound, respectively, is formed on the conductor, and the coating layer is The present invention provides a fluorine-containing elastic copolymer insulated wire characterized by being thermally crosslinked.

In the present invention, it is important to use a fluorine-containing elastic copolymer having a number average molecular weight of 20,000 to 60,000, preferably 30,000 to 50,000. If the number average molecular weight is too large, cracks will occur in the coating layer when thinly coated, and if the power factor is too low, the mechanical strength of the crosslinked product will be insufficient, so both are not preferred.

In the present invention, the method for producing a fluorine-containing elastic copolymer having a number average molecular weight within the above-mentioned preferred range is not particularly limited. Although it is possible to directly adjust the molecular weight of the produced polymer by manipulating copolymerization reaction conditions such as polymerization temperature and chain transfer agent, it is also possible to produce a high molecular weight copolymer during the copolymerization reaction. It is also possible to smoothly employ a method of lowering the molecular weight by heat-treating this in the presence of oxygen.

The number average molecular weight of fluorine-containing elastic copolymers can be measured by the osmotic pressure method, but for relative comparisons between copolymers with the same structure, it is recommended to use the value converted from the measured value of intrinsic viscosity. can. For example, a 6-tetrafluoroethylene-propylene copolymer (content of units based on tetrafluoroethylene of 54 to 57 mol%) that can be suitably employed in the present invention
) for so' in sinatrahydrofuran according to the following equation:
The number average molecular weight can be calculated from the intrinsic viscosity [η) (az/V) measured at c.

Lower 1 = [η] 1・'X2.0
It is important to use olefin-based units as one component.

Even if it is a fluorine-containing elastic copolymer, if it contains units based on vinyl fluoride as its main component, the air and air properties of the coated wire will be impaired in terms of dielectric properties, electrical insulation properties, etc. Undesirable.

An a-olefin having 2 to 4 carbon atoms that is copolymerized with tetrafluoroethylene to give an elastic copolymer, and two types selected from Teha, propylene, and butene-1 alone, and motelun, globile/, buty/-1, and isobutyne. Although the above-mentioned combinations are exemplified, in order to achieve the object of the present invention, polypylene can be preferably employed.

In addition to the main components tetrafluoroethylene and propylene, preferred tetrafluoroethylene-zolopylene copolymers in the present invention include components copolymerizable with these, such as ethylene, pudene-1, isobutene, acrylic acid, and alkyl thereof. Chlorofluoropropene/, chloroethyl vinyl ether, glycidyl vinyl ether, chlorotrifluoroethylene,
It may also contain a suitable amount of perfluoroalkyl vinyl ether or the like.

In such a copolymer, the molar ratio of tetrafluoroethylene/propylene is 9515 to 30/70,
In particular, it is preferable to select from the range of 90/10 to 45155 from the viewpoint of heat resistance, moldability, etc. Also, the content of components other than the main component that may be added as appropriate is usually 50 mol% or less, particularly 60 mol% It is preferable to select from the following ranges.

In the present invention, an extrusion coating layer of a composition mainly composed of the above-mentioned fluorine-containing elastic copolymer and containing specific amounts of an organic peroxide and a polyacrylic compound is formed on a conductor, and It is important that the coating layer is heat-crosslinked.

Here, the organic peroxide plays a role as a crosslinking agent, and specifically, diacyl peroxide such as dihenzoyl peroxide, dicumyl peroxide, di-
Monoperoxy compounds such as peroxy esters such as t-butyl peroxide, t-butyl peroxyacetate, butyl peroxyinoglopyl carbonate, t-bunal peroxybenzoate, and 2°5-dimethyl-2,5 -G(shi-butylperoxy)
-hexyne-3,2,5-dimethyl-2゜5-di(1
-butylperoxy)-hexane, 1,4-bis-(1
-butylbaroxy-isoglobil)benzene, 1,3
-bis-(t-butylbaroxy-isogropyl)bencef, 2,5-dimethyl-2,5-di(benzoylperoxy)-hexane, and other ciba-oxy compounds. These may be used alone or in combination of two or more. The amount of the organic peroxide to be used is selected from a range of about 0.1 to 5 parts by weight, preferably about 0.5 to 3 parts by weight, based on 100 parts by weight of the fluorine-containing elastic copolymer.

Further, the multi-aryl/IJ compound plays a role as a crosslinking aid, and specific examples thereof include diallyl phthalate, triallyl phosphate, triallyl cyanurate, triallyl ynoneanurate, diallylmelamine, and the like. The amount of the poly/IJ compound added is selected from 0.1 to 20 parts by weight, preferably 0.2 to 10 parts by weight, based on 100 parts by weight of the fluorine-containing elastic copolymer. .

By performing peroxide vulcanization using a combination of an organic peroxide and a multi-arc/IJ compound as described above,
It is possible to prevent ionic impurities from remaining in the crosslinked body and the resulting deterioration in electrical properties.

In the present invention, a filler,
Various additives such as reinforcing agents, pigments, lubricants, extrusion aids, antioxidants, and stabilizers can be blended. Such a composition has a Mooney viscosity M L 144 (100°C) of 20
~1sci, particularly preferably about 30 to 90, from the viewpoint of moldability of the composition, surface condition of the coating layer, and further insulation properties, and it is desirable to adjust the formulation to give such a Mooney viscosity. . It is desirable that each compounded component is uniformly dispersed in the tri composition, and uniform dispersion can be achieved, for example, by mixing with a conventionally used rubber.

In the present invention, the extrusion coating, which could not be applied to the thin coating where the specific composition described above is defective, is
It can be smoothly applied even when coating as thin as ~2III. Although the conditions for extrusion coating are not particularly limited, an extrusion temperature of approximately FiSO to 150°C, preferably approximately 70 to 130°C is employed.

In the present invention, it is desirable that the operating conditions during heat crosslinking be optimally selected depending on the raw materials and formulation used.

The temperature is usually about 80 to 250'C, preferably about 130 to 210'C, and the time is about 0.5
About 200 minutes, preferably about 1 to 100 minutes is employed. The heating time can be shortened by increasing the heating temperature.

In addition, for the purpose of improving the physical properties of the crosslinked product, 150
Reheating treatment at ~250°C for about 2 to 25 hours can also be employed.

The insulated wire of the present invention can be used as a heat-resistant flexible wire in terms of characteristics.
It is not only useful in electrical and electronic applications used in high temperature atmospheres, such as motor wires and wires around high-temperature furnaces, but also in the form of extrusion coatings.

Next, the present invention will be explained in more detail with reference to Examples.

Examples 1 to 3 and Comparative Examples 1 to 3 The molar ratio of tetrafluoroethylene/furopyrene is 5
5/45 and a number average molecular weight of 130,000, by heat-treating the tetrafluoroethylene-propylene/copolymer in the air under various conditions to produce various fluorine-containing elastic copolymers with different molecular weight levels. Get it.

To 100 parts by weight of the fluorine-containing elastic copolymer thus obtained, dicumyl peroquinde (organic peroxide), triallyl isocyanurate (polyacrylic compound), MT carbon (filler), and sodium stearate ( lubricant)
were blended in proportions of 1 part by weight, 5 parts by weight, 40 parts by weight, and 1 part by weight, respectively, and maintained at a temperature of 50 to 60°C.
The mixture was kneaded for 15 minutes using an inch roll.

Each of the above-obtained formulations was prepared at 4°C, which was set at 100°C for head, 100°C for cylinder 1, and 80°C for cylinder 2.
Using a 0-adjustment ψ extruder (L/I)=22), a diameter of 1.
6 gates were destroyed on the tin-plated copper tun line with a thickness of 1 yen, and 13
It was brought into contact with water vapor at atmospheric pressure (approximately 190° C.) for 3 minutes to thermally crosslink it.

The surface smoothness and strength of the obtained covered wire were compared with the number average molecular rH (M n ) of the fluorine-containing elastic copolymer and the Mooney viscosity (Ml (100°C)) of the blended composition by 1+4. They are summarized in the table.

Table 1 *Unheated treatment Examples 4 and 5 Same formulation as Example 2 except that the blending ratio of filler (MT carbon) was 0 parts by weight (Example 4) and 80 parts by weight (Example 5) The surface smoothness and strength of the coated wire obtained in the same manner as in Example 2 were both good.

Example 6 The molar ratio of tetrafluoroethylene/ethylene/inobutylene was 52/24/24, and the number average molecular weight was 4.
Wire coating was carried out in the same manner as in Example 1 except that a terpolymer having a molecular weight of 60,000 was used.

The obtained coated wire had good surface smoothness and g1 degree.

Comparative Example 4 A covered wire similar to Example 2 was obtained using the following formulation.

100 parts by weight of vinylidene fluoride-hexafluorogopene copolymer (DAIEL G301 manufactured by Daikin Industries, Ltd.) 1.5 parts by weight of 2,5-dimethyl-2,5-di(t-butylperoxy)hexane・Triaryl isocyanurate 4 ・MT carbon
20 The surface smoothness and strength of the obtained covered wire were good, but the insulation resistance was as low as 5QMΩ-1.

On the other hand, the coated wire of Example 2 has a bow of 5000 Ω.
It had high insulation resistance.

Claims (1)

[Scope of Claims] 1. Contains a fluorine-containing elastic copolymer having a number average molecular weight of 20,000 to 60,000 and exhibiting rubber elasticity at tetrahedral room temperature, an organic peroxide, and a multi-alcohol compound. , Extrusion of a composition in which the content of the organic peroxide and polyallylic compound in 100 parts of the fluorine-containing elastic copolymer is 0.1 to 5 parts by weight and 0.1 to 20 parts by weight, respectively. A fluorine-containing elastic copolymer insulated wire, characterized in that a coating layer is formed on a conductor, and the coating layer is thermally crosslinked. 2. The electric wire according to claim 1, wherein the α-olefin is globylene. 3. Mooney viscosity Mr of the composition, 1. ,4(100℃
) is 20 to 150, the electric wire according to claim 1. 4. The electric wire according to claim 1, wherein the thickness of the coating layer is 0.1 to 2 mm.