DE1494046C - Process for the manufacture of crosslinked polyethylene-coated electrical conductors - Google Patents

Description

however, such a residue cannot be tolerated because it is a contamination and Causes defects, so that the electrical and physical properties of the coatings are considerable would be affected.

The invention is explained in detail below by means of examples.

example 1

0.5 part by weight of a phenolic antioxidant was 100 parts by weight of granulated polyethylene added. After the mixture was thoroughly mixed in a drum at 50 ° C, were 3 parts by weight of dicumyl peroxide previously melted at 50 ° C. were added. After continued stirring dicumyl peroxide and the antioxidant adhered uniformly to the surface of the polyethylene. After then cooled to room temperature, the mixture became a continuous Vulcanizer (autoclave) entered, using 2 mm thick conductors with cross-linked Polyethylene-covered lead wires having an outer diameter of 4.6 mm were obtained.

Example 2

A kneaded polyethylene mixture, consisting of 100 parts by weight of polyethylene, 50 parts by weight Carbon black and 0.5 part by weight of an antioxidant mixed with rollers or an internal mixer was placed in a drum held at 50 ° C and 3 parts by weight previously at about 50 ° C melted dicumyl peroxide added. It

ίο was continued to stir so that the dicumyl peroxide on adhered to the surface of the polyethylene mixture. In the manner described in Example 1 were with this Mixture made with cross-linked polyethylene coated electrical lead wires.

In the method according to the invention, the processability is much better than in the conventional one Method, and also have the electrical lead wires made in accordance with the present invention excellent heat resistance, electrical egg

ao properties, chemical resistance and appearance like conventional lead wires. In the end are in the method of the invention production method and productivity greatly improved.

Claims (2)

1 2 network! Polyethylene, which results in a non-uniform patent: extrusion. The object of the invention is to 1. Process for the preparation of difficulties with network- 'to eliminate and the partem Polyethylene-coated electrical conduction- 5 tial thermal decomposition of the crosslinking agent processing wires, being granals made of polyethylene as a result of the thermal hysteresis that occurs during the or its copolymers with a production of the material occurs, to suppress, wetting agents are coated, which is obtained by applying the surface of polyethylene resin particles Mixture on electrical conductors extruded in granulate form directly with the crosslinking agent and the coated with the mixture is electrically coated. This object is achieved according to the invention see lead wires for decomposing the Vernet- solved in that the crosslinking agent melts are heated, 'thereby gezene and the surface of the granals by mixing indicates that the crosslinking agent is coated with this melt at normal pressure *, melted and'the surface of the granals becomes. by mixing at normal pressure with this 15 Melt is coated. Polyethylene or its copolymers are an anti- 2. The method according to claim 1, thereby adding ge oxydans. indicates that the grartalen of polyethylene in the process of the invention can be applied to the or its copolymers are mixed with an antioxidant mixing process of the conventional process will. ao be drawn. There are polyethylene particles that ^! optionally with fillers such as carbon black, clay or Calcium carbonate antioxidant, such as thio-bis (6-tert.-butyl-3-methylphenol) or polymers! Trimethyl-i dihydroquinoline, pigment, such as titanium white or red 35 oxide, stabilizer, such as substituted benzophenone, and plasticizers, such as polybutene, are connected with rollers or an internal mixer with Dieumyl- The invention relates to a method for producing peroxide or 2,5-dimethyl-2,5-di (tert-butylperoxy) -lung of n-hexane coated with crosslinked polyethylene in the molten state as crosslinking electrical Conductor wires, with granals of 30 medium mixed, after which the whole thing in a trom polyethylene or its copolymers are stirred with mel or a mixer at one temperature a crosslinking agent which is obtained above the melting point of the crosslinking agent Mixture on electrical conductors ex- means, but below the softening point of the Trudiert and coated with the mixture is polyethylene, the softening point below tric lead wires for decomposing the Vernet- 35 the decomposition temperature of the crosslinking agent heating agent. located. In this way the polyethylene granals become In the conventional methods of manufacture or tablets coated with the crosslinking agent, of electrical covered with crosslinked polyethylene. The material obtained in this way is on see lead wires cooled by extruding a gel room temperature and then introduced into a mixture of polyethylene and crosslinking agent over 4 ° truder to be extruded over the ladder to the ladder are granulated polyethylene and ¹ Ve ^ - are. Since this material is not subjected to temperature setting with rollers or an internal mixer as it mixes the decomposition of the crosslinking. The spreading agents obtained from this mixture do not result in any only partial disintegration. They are comminuted in a granulator and the. wetting before introduction into the extruder, as granals are added to an extruder / around 45 of this is the case with conventional processes. That get extruded over the ladder. One material can therefore be extruded smoothly, and the same processes that have consistently been handed down to the crosslinking agent are highly satisfactory in dispersing the polyethylene. .mixed with rollers or a mixer with a Teni- "'From the German' Aüslegeschrift 1052681 is temperature kneaded, which the softening point of the poly 50 still an extrusion process for deformation - of ethylene, after which the kneaded product is low-pressure polyethylene with simultaneous crosslinking a granulate is ground. Known during the tongue, in which one mixes a mixture of admixing the crosslinking agent, the highly wetting agent and solvents under pressure on the too is heat-sensitive, this low-pressure polyethylene granulate is processed to a certain extent in decomposed because it sprays in the rollers or in the interior 55 very fine distribution. The use of a Mixer measured temperature always brings only a through-solvent, such as a liquefied gas Cutting temperature jst. It is physically impossible, but has significant problems with it. If namely to measure the maximum temperature that is only used at the liquefied gas or the like as a solvent the rolling occurs, as is exemplified, are for the preparation of the solution and that wise, with a grinder with a comparatively large spraying 60, special systems are required. Because Proximity of the rotor against the sidewalls of the interior of the high pressure and moreover because of the high mixer. The result is therefore that at the point of volatility there are special structural measures the maximum heat development the temperature necessary to guarantee health and safety Material at these points sometimes has the maximum output. In addition, the temperature of the solution used is exceeded at which the crosslinking agent does not completely volatilize; a residue is resistant to decomposition. This always remains together with the crosslinking agent Local decomposition, both in the rollers and in the polyethylene particles. In the manufacture of . jbei.e.ineni, internal mixer occurs, leads to only partial insulating coatings on electrical wires