DE2441106A1 - COPPER CONDUCTOR - Google Patents

Description

Patent attorneys:

Dipl.-Ing. Tiedtke
Dipl.-Chem. Bühling Dipl.-Ing. Chins

8 Munich 2

Bavariarfng 4, P.O. Box 202403

Tel.:(089)539653-56 Telex: 524845 tipat cable address: Germaniapatent Munich

Munich, August 28, 1974 B 6174 / ICI case Po.26415

Imperial Chemical Industries Limited
London, UK

Copper conductor.

The invention relates to copper conductors in contact with a polyethylene compound.

Since the discovery of polyethylene, it has been used to insulate copper conductors in telephone cables and radar

installations used. The polyethylene normally used as insulation contains small amounts of an antioxidant compound which reduces the decomposition effects of oxygen on the polyethylene, and polyethylene insulation which is in contact with copper often contains a so-called copper stabilizer ^{, such as N, N 1 -diacetyl}

509810/0855

ι) Account 51/61070 Dresdner Bank (Munich) Account 3339844 Postscheck (Munich) Account 67043-804

II / 8

Deutsche Bank (Munich

2U1106

(adipoyldihydrazide) or nickel-bis- (3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid monoethylate), which reduces brittleness, which occurs in the presence of copper. This. Suction. Copper stabilizers are generally expensive materials.

Antioxidants such as 2,2'-methylene-bis ^ 6- (ot-methylcyclohexyl) -4-methylphenol7 and similar compounds described in British Patent 744,875 available in stores for over 15 years and in non-irradiated polyethylene insulation in quantities of up to 0.1% has been used, although amounts on the order of 1% by weight of the antioxidants for use in thermoplastic Rubbers have been suggested where the loss of antioxidant by "blooming" (i.e. exudation of the Antioxidant from the thermoplastic) is of less importance and where it is assumed that the antioxidants also delay the onset of copper-catalyzed oxidation of rubber.

It has now been found that the presence of certain specified amounts of 2,2'-methylene-bis ^ 6- (OL-methylcyclohexyl) -4-methylphenol7 and similar antioxidants in polyethylene, which is in contact with copper, does not lead to excessive blooming and reduces the brittleness of the polyethylene by the copper, i.

509810/0855

Accordingly, the invention provides a copper conductor in contact with a polyethylene mass thereby characterized in that the polyethylene composition contains between 0.2 to 0.8 wt .-% of an antioxidant, namely Dihydrpxypheriol or a normal or basic aluminum, barium, calcium, magnesium, strontium or zinc salt thereof, where the dihydroxyphenol has the general formula

OH

in which R ₁ and R. are alkyl radicals, preferably primary alkyl radicals having 1 to 3 carbon atoms, R and R. are alkyl, cycloalkyl or alkyl-substituted cycloalkyl radicals and R ^ is an alkylene radical which can contain side chain alkyl groups. The radicals R- and R. can be identical or different, but are preferably both methyl groups. The radicals R_ and R ₃ can also be identical or different. R can be, for example, a methylene, ethylene, isopropylene or 4-methylpentylene radical. A preferred antioxidant is 2 # 2 '-methylene-bia ^ i) - (α, -methylcyclohexyl) -4-methylρhenol7.

The polyethylene composition preferably contains 0.3 to 0.5% by weight of antioxidant.

509810/0855

2U1106

It is particularly preferred that the polythene composition is foamed. The polyethylene mass can by means of blowing agents such as azodicarbonamide or diphenyloxyd-4,4'-disulphohydrazide be foamed. Other blowing agents are discussed in an article by Dr. AH. Scheurlen in "Kunststoffe", Volume 47, No. 8 (1957) ,. Pages 446 to 455.

The invention is explained in more detail by the following example.

example

A polyethylene mass with a melt flow index of 0.3 (measured according to British Standard 2782, part 1 / 105C / 1970 using a 2.16 kg load) and one

2
Density of 0.932 kg / cm (measured according to British Standard 3412, 1966) and with a content of 0.3% by weight of 2,2'-methylene bis ^ G (Ct-methylcyclohexyl) -4-methylphenol / and 0.6% by weight .-% azodicarbonamide was applied to copper wire by extrusion so as to produce a foamed polyethylene layer which was 0.1 mm thick. Samples of the coated conductor were then hung in an oven held at 105 ° C. for 1000 hours. The samples were then removed and found that they could all be flexed through 360 ° without cracking. From this it could be concluded that no serious embrittlement of the polyethylene had taken place.

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Claims (2)

2U1106 Claims I λ J copper conductor in contact with a polyethylene compound, the polyethylene compound containing a dihydroxyphenol or a normal or basic aluminum, barium, calcium, magnesium, strontium or zinc salt thereof as an antioxidant, and the dihydroxyphenol having the general formula has, wherein R ₁ and R are alkyl radicals, preferably primary alkyl radicals _/ with 1 to 3 carbon atoms, R and R are alkyl, cycloalkyl ^ - or alkyl-substituted cycloalkyl radicals and R _{5 is} an alkylene radical which contain side chain alkyl groups can, characterized in that the polyethylene composition contains 0.2 to 0.8% antioxidant. 2. A ladder according to claim 1, characterized in that the polyethylene mass is foamed. 50981 0/0855