DE2508298A1 - Plastic pipe with conducting coating - consisting of bonded thermosetting resin containing sufficient conducting particles to impart conductivity - Google Patents

Abstract

Plastic pipe is coated on its inside and/or outside with an uninterrupted layer of a thermosetting resin that is completely bonded to the surface of the pipe, and contains a sufficient amt. of conducting particles to import electrical conductivity to the coating layer. Accumulation of an electrical charge is prevented efficiently for a long period. It is easily produced and resists damage, e.g. when imparted. The coating layer pref consists of an epoxide resin, which may be modified, the conducting particles of carbon, and the pipe of a thermoplastic resin, esp. PVC. The carbon particles are desired from the combustion of an unsatd. cpd. e.g. acetylene.

Description

Plastic pipe with conductive cover layer The invention relates on a plastic tube that has a continuous on its inside or outside conductive cover layer is provided.

In known plastic pipes, in particular made of PVC, collect when conveying dry media such as air and air enriched with dust particles through such pipes on the surfaces of the plastic pipe parts electrical charges which causes a pipe system made from these pipes to be electrostatically charged will. Such plastic pipes are therefore for use in places where the electrostatic charge can cause explosions, e.g. B. in mine shafts etc., not asked.

Attempts have been made to remedy this disadvantage by wrapping the plastic pipe parts with a conductive plastic film that is less electrostatically charged, to eliminate.

However, such wrapping presents difficulties in practice. In addition, the films used are easily damaged, so that the desired Effect is lost.

It has also been proposed that the plastic pipe parts with a spray antistatic paint. However, these lacquers generally do not adhere flawless and lose their properties over time. When using such Antistatic paints are also two consecutive pipe parts because of the presence an intermediate insulating sealing member not electrically conductive connected to each other, which is why it is necessary to separate each plastic pipe part with the help of supports or similar ladders attached to the plastic pipe parts to ground. This, in turn, creates all sorts of troubles and difficulties.

The invention aims to provide a remedy here and see this primarily Line before that each plastic pipe part on its inside and / or outside with an uninterrupted, completely connected to the pipe part surface and on this adhesive plastic, in particular thermosetting plastic cover layer is provided, which one of the top layer electrical conductivity imparting Contains amount of conductive particles.

The plastic pipe is preferably made of polyvinyl chloride and the thermosetting top layer made of a modified epoxy resin, while the conductive Particles consist of carbon particles, particularly soot particles. The resin can also still leading be. This is used to apply the layer Resin with conductive particles diluted with solvent sprayed on the pipe or the tube dipped in the liquid composition.

Further features and advantages emerge from the claims and the description in conjunction with the drawing, in the two exemplary embodiments of the subject matter of the invention are illustrated in more detail. In the drawing show: Fig. 1 is a broken representation of a plastic pipe system with pipe parts of the invention in section, in which separate sleeves are used as female pipe parts and FIG. 2 shows a longitudinal section through a connection area of a plastic pipe system, where socket pipe parts with molded sockets are used.

In Fig. 1 a number of plug-in pipe parts 1 are made of polyvinyl chloride shown, by means of socket pipe parts 2 in the form of separate plastic sleeves made of polyvinyl chloride are interconnected. Between each plug-in pipe part 1 and each socket pipe part 2 is a sealing member in the form of a rubber ring 8th.

On each plug-in pipe part 1 and each socket pipe part 2 is located on the outside a cover layer made of a sprayed-on thermosetting resin, in particular a sprayed-on epoxy resin with conductive carbon particles. Used in particular a modified epoxy resin varnish, which commercially under the name Finch 453-1-1 modified epoxy resin of Finch Paint and Chemical Division of Bostik GmbH, Oberursel.

For maintaining electrical conduction between the cover layers Thin metal strips can be placed on the plug-in pipe parts 1 and the socket pipe parts 2 ' 10 on the one hand on the cover layer of the socket pipe part 2 and on the other hand on the Cover layer of the plug-in pipe part 1 are glued on. For this, z. B.

Find aluminum foil application.

The entire pipe system is connected to earth by means of a connecting conductor 11 placed.

Instead of socket pipe parts 2 in the form of separate sleeves, it is also possible Plastic pipes with molded socket 4 are used, which on their outside are provided with the above-mentioned conductive cover layer. This conductive cover layer sits with its area 7 in front of the end face 5 of the socket end 4 and along the inside of the socket end to form an on the inside Top layer area 6 continued. These layers can be removed by dipping the end of the pipe raise.

The plug-in pipe part 1 made of polyvinyl chloride is also included provided the aforementioned conductive cover layer.

There is also the same between the socket pipe part and the plug-in pipe part a Sealing ring 8 attached, however, when it consists of rubber-elastic material one to ensure electrical conduction between the top layer 3 of the Insert pipe part 1 and the cover layer area 6 on the socket pipe part 2 sufficient Contains amount of soot particles. It contains at least 8%, better at least 10%, and in particular and preferably about 20% carbon particles.

As the carbon particles, generally known soot particles can be one Typeq that guarantees proper electrical conduction must be used.

The carbon black used in DES is ground and generally consists from one of the combustion of highly unsaturated compounds, preferably acetylene, accumulating soot.

It can also be made tensile pipe connections in which the tensile strength inducing agents are effective as electrical conduction means could be. These tensile strength inducing agents can be used for this purpose be provided with a top layer of aluminum particles or soot particles.

However, here too, as above for the pipe parts already mentioned, other conductive particles are used.

In making branch connections, one is also electrical A conductive connection between branch pipe and main pipe can be provided.

Finally, with a socket connection of pipe parts with an inner conductive cover layer which extends inside the plug-in pipe part Continue top layer at the end of this part on its outer surface to create a conductive Get connection.

Claims (6)

Patent claims: W Plastic pipe that has a. On its inside and / or outside continuous conductive cover layer is provided, characterized in that Each plastic pipe part (1, 2) on its inside and / or outside with one uninterrupted, completely connected to and on the pipe part surface adhesive plastic, in particular thermosetting plastic cover layer which is an amount of conductive material which imparts electrical conductivity to the cover layer Contains particles. 2. Plastic pipe according to claim 1, characterized in that the Top layer contains an epoxy resin. 3. Plastic pipe according to claim 2, characterized in that the Cover layer is a modified epoxy resin that adheres firmly to the plastic pipe material contains. 4. Plastic pipe according to one of claims 1 to 3, characterized in that that the conductive particles are made of carbon. 5. Plastic pipe according to claim 4, characterized in that the Carbon particles from unsaturated compounds, in particular by burning them, such as acetylene, soot particles formed. 6. Plastic pipe according to one or more of claims 1 to 5, characterized in that the plastic pipe made of thermoplastic material, especially PVC.