1. A process for the preparation of a cable comprising a conductor surrounded by one or more layers, the process comprising:
polymerizing ethylene and optionally at least one further olefin in a high pressure process by radical polymerization to form an LDPE homopolymer or LDPE copolymer,
wherein said polymerization occurs in the presence of a mixture of at least two chain transfer agents, the mixture comprising: a polar chain transfer agent (polar CTA) and a non-polar chain transfer agent (non-polar CTA), wherein the non-polar CTA is selected from the group consisting of cyclic alpha-olefins of 5 to 12 carbon atoms and straight or branched chain alpha-olefins of 3 to 12 carbon atoms;
and applying said LDPE homopolymer or LDPE copolymer onto said conductor to form said one or more layers.
2. The process of claim 1, wherein the feed ratio by weight % of polar CTA to non-polar CTA is of 1 to 99 wt. % of polar CTA and 1 to 99 wt. % of non-polar CTA, based on the combined amount of the feed of the polar CTA and the non-polar CTA.
3. The process according to claim 1, wherein the polar CTA is selected from one or more of a compound comprising one or more polar group(s) selected from nitrile, sulfide, hydroxyl, alkoxy, aldehydyl, carbonyl, carboxyl, and ester group(s), or a mixture thereof.
4. The process according to claim 1, wherein the polar CTA is selected from one or more of a compound containing one or more hydroxyl, alkoxy, aldehydyl, carbonyl, carboxyl, and ester group(s), or a mixture thereof.
5. The process according to claim 1, wherein the polar CTA is an aldehyde or ketone compound.
6. The process according to claim 1, wherein the polar CTA is methyl ethyl ketone or propionaldehyde.
7. The process according to claim 1, wherein the polar CTA is an aldehyde compound.
8. The process according to claim 1, wherein the polar CTA is propionaldehyde.
9. The process according to claim 1, wherein the non-polar CTA is selected from one or more of straight or branched chain alpha-olefin of 3 to 6 carbon atoms.
10. The process according to claim 1, wherein the non-polar CTA is propylene.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. In an air damper of the type comprising a cylindrical body and a reciprocating piston including a lip seal reciprocating within the cylindrical body, the improvement comprising a coating of graphite powder on said lip seal in order to increase smoothness of operation of said reciprocating piston.
2. The improvement of claim 1 wherein said graphite powder further includes a minimum 5%seal part weight graphite powdermolybdenum disulfide.
3. The improvement of claim 2 wherein said lip seal includes rubber or thermoplastic elastomer impregnated with a minimum of 3% molybdenum.
4. The improvement of claim 2 wherein said lip seal includes rubber or thermoplastic elastomer impregnated with a minimum of 2% polytetrafluoroethylene.
5. The improvement of claim 2 wherein said lip seal includes rubber or thermoplastic elastomer impregnated with a minimum of 2% silicone.
6. The improvement of claim 2 wherein said lip seal includes rubber or thermoplastic elastomer impregnated with a minimum of 2% wax.