CS248459B1 - Composite insulating material for filling the interstitial spaces of all-plastic notification cables - Google Patents

Abstract

The mixed filling insulating compound is intended for filling the inter-core spaces of communication cables with an all-plastic sheath. The filling compound is composed of inhibited polypropylene oil and amorphous polypropylene and, depending on the requirements for the special properties of the cable, the mixture is further modified by adding high-pressure polyethylene or microcrystalline wax. The filling compound has good rheological properties and is advantageously used as a barrier against moisture penetration in the production of filled cables.

Description

SUMMARY OF THE INVENTION The present invention relates to a composite insulating material for filling inter-core spaces of plastic storage announcement cables, the conductors of which are typically isolated with special types of polyethylene full or foam. The purpose of the invention is to help with such a mass to provide protection against penetration and spreading of water in the cabinet by simultaneously improving the processing and operating properties of such a filler type.

In case of accidental damage to the cable in the field, when removing faults, or when manipulating other cables in the field, such as connecting and laying cables in the field or in the field. as a consequence of leakage of the cable joints, and also the penetration of moisture and its prolonged propagation in the cable. Water in the contactor with insulated conductors causes deterioration of transmission parameters, due to increased capacitance and damping of the cable, crosstalk occurs and the cable is degraded.

In order to cure the possibility of incrusting the water of the docular soul, the spaces between the veins are filled with raw materials of hydro-phobic nature, using natural raw materials based on their raw materials. The properties of filling masses, in addition to the main functional feature, ie the prevention of penetration and spread of the conduit in the cable, should ideally meet non-compliant requirements, which are essentially physical-chemical, electro-insulating and economical: or electro-insulating properties of polyethylene insulation over a long period of cable operation, their relative persistence to be as close to 1 as possible, must be sufficiently damp at low temperature windings so as not to adversely affect the flexibility of the cable, be stably ventilated individual components, the data must be easy to fill and must not leak out of the cable in operating conditions. The presence of the filler material has an unfavorable influence on the normal cable splicing process and the transmission characteristics of the bulbs. Matter must not be harmful to health and finally its application must not materially affect either the production process of the casks or the cost of the cables.

The known solutions fulfill the above-mentioned requirements of practice only partially, in a non-complex manner, to a limited extent by some technical, technological or economic advantage characteristic of individual types of mass.

The disadvantages of this state of the art are avoided by the present invention, the stage of which a composite insulating material for filling the interstitial spaces of plastic polyolefin labeling cables, such as polyethylene insulation, which serves to prevent and propagate water, consists of a homogenized mixture: a 39 to 98.9% by weight of a propylene oil having a density in the range of 815.0 to 940.0 kg / m 3, the viscosity at 100 ° C being 4 to 50 mm 2 / s, molecular weight of 168 to 3,000 specific internal the resistance at 90 T is 1,1010 ohm; b) 0.1 to 1.0 weight percent anti-oxidant, na. a base of shielded phenol, preferably 2.6 di-tert-butyl-p-cresol; 1 to 39 percent by weight of amorphous polypropylene, the freezing point of which is determined by the ring-bead method, the stage of ČSN 65 0760 is at least 100 cc and which has at least 20 percent by weight of steroblock and isotactic polypropylene, determined as insoluble matter in n-heptane-free Nafta; and / or d) a maximum of 15 percent by weight polyolefin, preferably a high pressure polyethylene having a melt index of 50 to 500 and a density of at most 920 kg / m 3, and / or adding: e) a maximum of 15 percent by weight of crystalline wax; advantageous electro-electrical applications, with a drop point of Ubbelohde's stage of at least 50 ° C.

The composite insulating material of the present invention is prepared by a conventional manufacturing process such that portions of the specified components in the order are gradually added after homogenization and dissolution of the previous component at normal pressure and a temperature of 150-170 ° C, utilizing the thermal energy of the premix to dissolve the microcrystalline powder, thereby preventing thermal degradation of wax.

Amorphous polypropylene is produced as a byproduct in the production of isotactic polypropylene. For this application, it requires a heat treatment in which the solvent and water are removed from the mother liquor. There is thus obtained an excellent electrical properties which contain a mixture of atactic, stero-block and isotactic polypropylene, each of which, as part of the insulating material, performs a specific and at the same time favorable effect on the properties of the material. The present atactic polymer, with a molecular weight of about 10,000, provides good solubility in polypropylene oil, stero-block structures with a wide range of molecular weights up to 300,000 with the isotactic polymer are limited at the cable operating temperature, the mixtures are dispersed and thus form a barrier to migration by impregnating the act of acting as a potent point-drop enhancer and pop-point. In the case of the amorphous polypropylenes, which include the above-mentioned high molecular weight structures, the addition of another polymer, preferably polyethylene, to the mixed insulator is achieved. The addition of microcrystalline wax makes it possible to change the theological properties of the viscosity and consistency. As a result, the filler material has excellent processing properties, the ability to continuously change viscosity and consistency allow the filling of the cables both at ambient temperature and at elevated temperatures.

By a suitable combination of components, the optimum compatibility of the various systems of the filling material is achieved, sufficient hydrophobic and stable gels of different consistency are obtained, and no separate components of the filler material are obtained, nor is the process of manufacturing the filled wiring during their long-term operation. The necessary components of the mixture are available and their cost is relatively low, advantageous and the solution allows either to partially replace or totally exclude the use of the microcrystalline sieve by using an amorphous polypropylene compound.

The composite insulating material has excellent electrical properties throughout the temperature range that can be used to operate the filled cables and the entire high frequency range used for digital transmission networks, for example, PCM I and II systems. Mass, is wholesome and has no adverse health effects on workers either in the manufacturing process or in the process of manufacturing cable and anipri cable assemblies and repairs. The composite insulating material does not degrade, it does not change the properties of the processes when the temperatures increase during its production and the cable filling, nor in the operating conditions, so that it permanently ensures the good transmission characteristics of the cables.

The solution according to the invention thus fulfills the needs of the practice comprehensively and is as close as possible when the properties of the filling chamber meet the requirements of both physico-chemical and electro-insulating as well as economic requirements. Example 1 To 100 parts by weight of Propyloil Z-800 polypropylene oil having a low molecular weight of 800, viscosity at 100 ° C of 22.55 mm 2 s -1. density at 20 ° C 850.3 kg / m 3 and specific internal resistance at 90 ° C 1.8.1011 ohm.m 0.125 parts by weight of 2.6 di-tert-butyl-p-cresol was added with stirring at about 80 ° C. The so-doped polypropylene oil was heated to 160-170 ° C with stirring at atmospheric pressure, and an amorphous polypyropylene with a pellet ring of 147 ° C containing 8.7 weight percent was added to the heated oil phase with stirring at 12.55 weight parts. insolubles in n-heptane at room temperature and 12.51 parts by weight of polyethylene with a density of 916 kg / m 3 and a melt index of 208.3. The blended components were mixed until homogenized to give about 3 kg of isolation weight within 60 minutes. The resulting insulating filler had a composition of 79.9% by weight of propylene oil, 10% by weight of amorphous polypropylene, 0.1% by weight of 2,6-di-tert-butyl-p-cresol as antioxidant and 10% by weight. % by weight of polyethylene and exhibited the following properties: kinematic viscosity at 100 ° C 640mm 2 s -1, Ubbelohde stage drop point 96 ° C, snap point ring ball 87 ° C, cone foam at 23 ° C 295X0.1 mm, Fraasa Stage below -50 ° C, specific internal resistance at 80 ° C 8.9.1011 ohm.m, loss factor and relative perivity at 80 ° C and 50 Hz 0.00021, resp. 1.82, at 23 ° C - at 100 kHz 0.00073, resp. 2.31, at 2 MHz 0.00299, respectively. 2.21 and at 10 MHz0.01426, respectively. 2.38. Example 2 To 100 parts by weight of polypropylene oil (as in Example 1) was added 0.13 parts by weight of 2.6 di-tert-butyl-p-cresol with stirring at about 80 ° C. with stirring at atmospheric pressure, the oil was heated to 163-170 ° C and amorphous polypropylene (as in Example 1), 3.9 parts by weight of polyethylene having a density of 916 kg / m 3 was added to the heated oil with stirring in an amount of 13 parts by weight. melt index of 208.3 and 13 weight percent microcrystalline petroleum wax having a drop point of Ubbelohde82 ° C and a viscosity at 100 ° C of 14.3 mm 2 s * 1. The proportions were mixed until homogenized to which about 3 kg of insulating material was prepared in 70 minutes to prepare a total amount of the resulting insulating filler composition of 76.9 weight percent polypropylene oil, 10 weight percent amorphous polypropylene, 10 weight percent polypropylene oil percent of the microcrystalline petroleum wax - ceresin, 3 wt.% polyethylene and 0.1 wt.% 2.6 di-tert-butyl-p - cresol as antioxidant and exhibited the following properties: kinematic viscosity at 100 ° C 235 mm 2 s -1, drop point podiumUbbelohdeho 88 ° C, punch point ring ball 60 ° C, cone penetration at 23 ° C177X0.1 mm, Fraasap fracture point —50 ° C, specific internal resistance at 80 ° C2), 1.1011 ohm.m, loss factor and relative permittivity at 80 ° C and 50 Hz0.00422, respectively. 2.14, at 23 ° C - at 100 kHz0.00086, respectively. 2.30, at 2 MHz 0.00244, and 2.30 and at 10 MHz 0.01092, respectively. 2.30.

Claims (1)

7 8 EXAMPLE 3 Test specimens of two types of high-speed polyethylene insulating polyethylene A, B were immersed in a commercial Petro leum Jelly and mixed compound of the invention and maintained for 10 days at 70 ° C. The increase in the weight of the polyethylene bodies due to mass absorption as well as the decrease in tensile strength and ductility characterizing the change in the mechanical properties of the polyethylenes were monitored. It is clear from the properties of the polyethylenes included in the following table that, on the one hand, the absorption of the present invention in polyethylene of different origins is lower, and on the other hand, the degradation of the mechanical properties of the polyethylene after contact with the mass of the present invention is less than that of the commercial Petroleum Jelly, which gives good assumptions about the long-term viability of cables filled with the inventive stage. In the following table, the properties of PE after aging in contact with masses at 0 ° C are 10 days. Type of PE piece Type of material Mechanical properties of PE stage ČSN 64 30 10 _ Breaking strength Breaking elongation at break (MPa) (%) Weight gain PE (wt%) originally PE 14,95 526 0 Example 1 10,43 338 5.18 A Stage Example 2 10.50 383 5.48 Petroleum Jelly 10.12 320 7.25 Originally PE 17.41 572 0 Stage Example 1 11.40 392 5.29 B Example Stage 11.74 351 5 , 39 Petroleum Jelly 10,92 325 7,55 The solution of the invention can be used in the manufacture of filled full-cable cables. SUBSTITUTE Composite insulating material for the filling of intermediate spaces of all-plastic annunciator cables, suitable as protection against water penetration and propagation in the cable, characterized in that the mass is homogenized with 39 to 98.9% by weight of polypropylene oil of molecular weight. a weight of 168 to 3000, a density of 815 to 940 kg / m 3, viscosity at 100 ° C of 4 to 50 mm 2 / s and a specific internal resistance at 90 ° C of at least 10 10 10 ohm.m, 0.1 to 1.0 weight percent antioxidant of a dye-based phenol, preferably 2.6 di-tert-butyl-p-cresol, EXCEEDING 1 to 30% by weight of an amorphopolypropylene having a dip point of at least 100 ° C containing a maximum of 20% by weight of steroblock and isotactic structures dispersed in the atactic polymer and / or the further component of the mixture is at most 15% by weight of polyolefin, preferably high pressure polyethylene with a melt index of 50 to 500 and a maximum density of 920 kg / m 3, and / or a maximum of 15 wt.% Of microcrystalline wax, preferably ceresine for electrical purposes, with a drop point of at least 50 ° C. Severografia, n. P., Závod 7, Most Price 2,40 Kcs