Polypropylene cable jacket compositions with enhanced melt strength and physical properties
View Patent ↗The present invention is a cable comprising one or more telecommunication or power transmission media or a core of two or more such media, each medium or core surrounded by at least one jacketing or sheathing layer comprising a polypropylene homopolymer or copolymer and having a relaxation spectrum (RSI) and melt flow (MF) such that RSI*MF^a is greater than about 12 when a is about 0.5.
1. A cable comprising one or more telecommunication or power transmission media or a core of two or more such media, each medium or core surrounded by at least one jacketing or sheathing layer comprising a polypropylene having a relaxation spectrum (RSI) and melt flow (NE) such that RSI*MF^a is greater than about 12 when a is about 0.5.
2. The cable of claim 1 wherein the polypropylene being coupled.
3. The cable of claim 2 wherein the coupled polypropylene being characterized by the following formula
Y>1.25, wherein:
Y=a ratio of a melt strength of the coupled polypropylene to the melt strength of the comparable noncoupled polypropylene.
4. The cable of claim 1 wherein the polypropylene is an impact modified propylene copolymer.
5. The cable of claim 4 wherein the impact modified propylene copolymer comprises a continuous phase and an elastomeric phase, wherein the elastomeric phase being present in an amount of at least about 9 weight percent of the impact modified propylene copolymer.
6. The cable of claim 1 wherein the polypropylene being a foamed propylene-based polymer.
7. A cable comprising an inner jacketing or sheathing layer characterized according to any one of claims 1 - 6 and an outer layer comprising an ethylene polymer.
8. A cable comprising one or more telecommunication or power transmission media or a core of two or more such media, each medium or core surrounded by at least one jacketing or sheathing layer comprising a coupled impact modified propylene copolymer being characterized by the following formula
Y≧1.25, wherein:
Y=a ratio of a melt strength of the coupled polypropylene to the melt strength of the comparable noncoupled polypropylene,
comprising a continuous phase and an elastomeric phase, wherein the elastomeric phase being present in an amount of at least about 9 weight percent of the impact modified propylene copolymer,
and the propylene copolymer having a relaxation spectrum (RSI) and melt flow (MF) such that RSI*MF^a is greater than about 12 when a is about 0.5.
9. A cable comprising one or more telecommunication or power transmission media or a core of two or more such media, each medium or core surrounded by at least one jacketing or sheathing layer comprising a polypropylene homopolymer or copolymer having a melt strength greater then about 8 centiNewtons.