HU203167B - Method for making foamed insulating layers of high coating stress at the production of the signal transmission lines and cables - Google Patents

Abstract

SUMMARY OF THE INVENTION The present invention relates to a method for producing high-insulating foamed insulating layers for the production of signaling lines and cables having a density of 0.921 ± 0.05 kg / dm3 and a low density polyethylene of melt index of 0.2 to 20 dg / min and a medium density of up to 70% by weight. a mixture of high density polyethylene and / or polypropylene and / or linear polyethylene is prepared, the surfactant blowing agent of the composition known per se, and optionally at least one other additive, are blended and optionally the resulting mixture is granulated, cooled and dried and extruded onto its conductive surface. The essence is that 0.01 to 10% by weight of dispersant, such as silane, titanate, zirconate, hafnate, surfactant, is added to the material mixture to form a basic matrix, and the extrusion is made up of 130 to 290'C, preferably 150 to 240C, containing the base matrix. Preferably, at a temperature of C, a conductive surface preheated to a temperature of from 40 to 150 ° C, preferably from 60 to 120 ° C, is applied at a discharge rate of 16 to 40 m / s, and the extruded material is contacted with the conductor with a refrigerant, preferably water, at a temperature of 10 to 96 ° C. cool. EN 203167 A Scope of description: 12 pages -1-

Description

FIELD OF THE INVENTION The present invention relates to high-strength foamed insulating layers for use in the manufacture of signal transmission wires and cables of low density polyethylene having a density of 0.921 + 0.05 kg / dm ³ and a melt index of 0.2-20 dg / min and an intermediate density of up to 70%. respectively. forming a mixture of high density polyethylene and / or polypropylene and / or linear polyethylene with a surface-treated blowing agent of known composition and, if necessary, further at least one additive, in particular a heat stabilizer, kikker, nucleating agent, granulated, cooled and dried, then extruded onto a conductive surface.

One of the results of the product development of the telephone and radio frequency coaxial cables was the birth of a foamed wire insulated product line. The lower dielectric constant of the polyethylene foam insulating layer compared to other prior art solutions provides better transmission characteristics or the geometry of the cable may be smaller than that of a solid polyethylene core insulation.

There are basically two processes for the production of expanded polyethylene (polyolefin) vascular insulation:

1) Absorption of nitrogen gas under high pressure in the polyethylene melt, which exits the mold to foam the insulating layer.

2) Adding nitrogen-containing organic and inorganic compounds to the polymer, which undergoes thermal decomposition at the extrusion temperature to liberate nitrogen and other gaseous materials, which, as in the preceding process, foams the molten melt leaving the mold.

The latter of these two methods has become naturalized, although it is more expensive, but the bubbles have a better cross-sectional distribution and size. However, the disadvantage of the telephone cables made from foamed polyolefin core insulated cores of up to 4000 cores is that their performance and parameters deteriorate relatively quickly during use. The studies found two main reasons for this:

- the foam system has a low form strength: the laid and working cable strands are in contact with each other and obliquely along and press each other;

- the cable gaps of foam wires are filled with petroleum jelly to prevent water penetration into the puncture gaps in case of jacket damage or improper connection, and this space-filling petroleum jelly slowly but gradually penetrates into the foam structure cavities and causes an increase in the value of the plant capacity.

The above two disadvantages can be overcome by forming a thin layer of foam skin on the outer layer of the foamed polyolefin vascular insulation, which is followed by a thin layer of dense polyolefin following the foaming process (or a technological operation thereof). coextruding the foam layer to provide the desired functional properties. Another method is to foam the foamed skin layer in a manufacturing operation. In this case, the skin layer remains, after breaking the larger bubbles on the surface, as an irregular external surface in which bubbles can still be discovered. The thickness of the skin layer is approx. 0.01 mm.

The advantage of this latter solution is the simpler production technology, but the disadvantage is the relatively high uptake of petroleum jelly and rapid aging, which leads to a deterioration of the electrical parameters. Similarly, for the manufacture of telephone cables, the use of high-form foam structure is preferred for the production of high-frequency wires. Here the constant distance between the inner and outer conductor is required. In the event of deformation of the foam structure of the polyolefin insulating layer, the interface of the radio frequency wire is changed and the electrical circuit is tuned.

Deteriorating transmission properties may occur even due to the openness of the foam structure of the high frequency wires. Bubbles bursting on the outer surface of the foam insulation may cause condensation to form on the cell wall due to fluctuations in the outside temperature and may cause tuning due to the small thickness of the cell walls.

If the insulating layer is considered continuous - having the aforementioned skin size or 0.1-0.5 mm thick, moisture penetration is practically excluded. The strength of the formed skin layer prevents the penetration of the shield (outer conductor) into the insulation to a significant extent and thus the transmission quality of the wire remains unchanged. U.S. Pat. No. 3,645,929. U.S. Patent No. 1,274,645 to GB-A. English, and CA-A 857 942; A Canadian patent for producing a blend of low-density and high-density polyolefin with a suitable blowing agent, which also contains a viscosity-reducing additive known as a lubricant.

As a result of the additive, the foaming of the polymer occurs more easily and a lower extrusion temperature can be used. Using a material temperature of 200-230 ° C, they can produce a very good (about 40%) foamed vascular insulation with a typical density of approx. 0.5 g / ml.

However, during extrusion, the so-called "lead" on the surface of the vessel insulation does not develop. skin layer. Thus, the product can easily be compressed, and the product does not stand up to MKMMF 23836-77. the test referred to in paragraph 7.12. Also, the finished product does not meet the requirements of paragraph 9.156 of the abovementioned technical specification system, as the ready-to-use telephone cable received during twist control is charged at 10 ° C for 24 hours and then conditioned for 24 hours.

EN 203 167 Rises above the maximum allowable value of 40 nF / km or the insulation resistance drops below the required lower limit of 1000 Mohm.km.

This phenomenon can be explained by the fact that in the foamed polyethylene vascular insulation, vaseline filling the twisting cavities penetrates the individual cells, causing a change in electrical properties.

A further disadvantage of the process protected by the patents cited is that when approx. We want to achieve a production speed higher than 800-900 m / min. melt fracture: The surface of the product will be uneven (corrugated, kneaded), the degree of foaming will drop below 40% and the resistance of the finished product to the penetration of petroleum jelly will be reduced and its electrical parameters will be impaired.

Nor can this adverse effect be helped by increasing the extrusion temperature. At too high an extrusion temperature (240-250 ° C), the resulting bubbles become too large, open into each other, the foam structure becomes inhomogeneous, and the degree of foaming decreases below 30-35%. The operational capacity of the product then rises above the maximum allowable limit.

A further disadvantage is the GB-A 1 274 645. It is also claimed in British Patent Nos. 4,102,125 that the basic matrix used is prepared from polyolefin blend using first / second generation catalyst technology. In this case, relatively large amounts of catalyst traces, impurities that are not sufficiently deactivated, can be detected, which enter the insulation during extrusion, and the metal contaminants, particles and inclusions which impede the material continuity greatly impair the quality of the insulation. Impurities that accumulate in the extruder and occasionally hit the material appear as defects and make the quality of the product produced by continuous production unstable.

SUMMARY OF THE INVENTION It is an object of the present invention to overcome such drawbacks by providing a method for producing products that meet the requirements of high quality telecommunication cables at high speed extraction.

One important realization leading to the invention is that only high purity polyolefins should be used. The observation that certain dispersants and / or coupling agents (e.g. silanes, zirconates, titanates) and / or high surface-active surfactants and / or high surface-active (surfactant) blowing agents and fillers (solid coupling agents) has also proved to be relevant addition of polymer to the matrix can provide additional gas formation beyond that theoretically formed from the blowing agent. Beyond this, the regularity of the cell structure, its size uniformity is improved, and the size of the gas bubbles remains optimally small. The dispersants also act by catalytic accelerating action on the blowing agents and thereby activate them. In this way, the temperature level of the foaming and processing operations can be lowered and a finished product with a uniform surface layer can be produced.

The present invention is further based on the discovery that by combining a polyolefin base matrix, i.e., by grafting polymer chains, i.e., using a dynamic vulcanization operation, and by appropriately selecting the parameters of the extrusion operation, a cable skin insulation of at least 0.005 mm thick is obtained. is provided with a coating layer. It is now possible to virtually eliminate the vaseline uptake of the cable insulator, to provide good mechanical strength and elongation, and to provide good electrical stability without significant change after 14 · 24 hours at 60 ° C artificial aging.

In order to solve this problem, a process for the production of high-strength foamed insulating layers for signal transmission wires and cables, having a density of 0.921 ± 0.05 kg / dm ³ and a melt index of low density polyethylene of 0.2-20 dg / min and up to 70 wt. % medium density, or%. forming a mixture of high density polyethylene and / or polypropylene and / or linear polyethylene with a surface-treated blowing agent of known composition and, if necessary, further at least one additive, in particular a heat stabilizer, kikker, nucleating agent, granulated, cooled and dried, then extruded onto a conductive surface, and according to the invention, a dispersant, in particular silane, titanate, zirconate, hafnate, surfactant, is added in an amount of 0.01 to 10% by weight, preferably 0.1 to 2.0% by weight. and thereby forming a basic matrix, and then extruding the mixture containing the basic matrix at a temperature of 130 to 290 ° C, preferably 150 to 240 ° C, preferably at a pull-out speed of 40 to 150 ° C, preferably 60 to 120 ° C. is carried out on the surface of this preheated conductor and the extruded material is cooled together with the conductor covered therewith in contact with a refrigerant at 10-96 ° C, preferably water. The cooling is generally carried out with water at 90 ± 5 ° C, and the cooling water preferably contains a compound having a wetting effect, dissolved or dispersed.

In a preferred embodiment of the process of the invention, low-density polyethylene and linear polyethylene or other polyolefin (e.g., HDPE, PP) are mixed with small amounts of organic peroxide compounds, in particular 0.01 to 1.0 wt. The addition of a compound that delivers active activity radicals produces a dynamic vulcanizate (alloy) and / or a physically (mechanically) blended polyolefin blend. This mixture is separated or one dispersant and / or coupling agent is added to the polymer mixture in one step, and the other additives are added to the mixture and the compound is cooled, granulated and dried.

HU 203 167 A

In another highly preferred embodiment of the invention, a blowing agent and / or filler pre-coated with a dispersant in a Henschel type or similar rapid powder mixer is added to the polymer matrix and the final blend is granulated. Subsequently, in one operation, by selecting the appropriate extrusion parameters (mold dimensions, zone temperatures, extraction rate, etc.), the insulating layer is applied to the conductive surface preheated to 60-120 ° C and the foaming value is adjusted by adjusting the zone temperatures and controlled. It has been found to be very advantageous to pass the mixture through a sieve having a mesh size of at least 0.05 mm during extrusion.

In another very preferred embodiment of the process according to the invention, the extruded material is passed through a tube heated to 200-500 ° C, preferably 300 ± 10 ° C, at least five times the outside diameter of the extruded material before being cooled.

In general, from 0.01 to 0.5%, preferably about 0.05% by weight of dye is added to the mixture prior to extrusion, preferably dye pigment when coloring of the finished product is required, whereas in radio frequency applications the conductive layer is formed by weaving, twisting, taping or extruding. Who.

To effectively protect the surface, shape retention is achieved by applying a co-extruded polymer layer to the surface of the extruded material.

A preferred way to implement the color markings used in the cable is to apply paint, pigment, or dye to the surface of the conductor-extruded material, either continuously or intermittently or in the form of a thread of any pitch.

The products of the present invention have been found to improve compatibility with other substrates (blowing agent, filler, etc.) at the interfaces of polymers, increase the efficiency of the foaming operation, improve the coating strength and abrasion resistance of the finished cable insulation. Foam insulated cable insulators can be used at extraction speeds of at least 1200-1600 m / min to achieve operating capacities of up to 46 nF / km measured at 800-1000 Hz, adequate petroleum resistance, and foaming over 40%. The proposed method is particularly effective in the manufacture of 0.4, 0.6 and 0.8 mm diameter copper conductor foam insulated telephone cables and in the manufacture of radio frequency cables. The use of a high extraction rate of up to 2500 m / min results in a smooth skin-like formation on the surface of the insulating layer, which does not exhibit the appearance of an ovary fracture, even at high extrusion rates. Consequently

- the pore distribution in the foam layer will be uniform, essentially due to the homogeneous distribution of smaller pores, the rate of foaming will increase to 45-48%,

during the petroleum jelly uptake test (60 'C)

10 * 24 hours of exercise) does not change the electrical parameters and the operating capacity of the pair remains in the range of 40-42 nF / km.

The process of the present invention will now be described in more detail by way of exemplary embodiments and exemplary embodiments.

In carrying out the proposed process, firstly, low density polyethylene having a density of 0.921 +0.05 kg / dm ³ and a melt index of 0.2-20 dg / min and generally but not less than 5% by weight, up to 70% by weight of medium density high density polyethylene and / or a mixture of polypropylene and / or linear polyethylene is prepared. The proportion of low density polyethylene is at least 30% by weight. To the mixture thus obtained is added 0.01 to 10% by weight, preferably 0.1 to 2.0% by weight, of a dispersant, in particular silane, titanate, zirconate, hafahate, surfactant, to form a basic matrix, a surface-treated blowing agent of known composition. and mixing, if necessary, at least one additional additive, in particular a heat stabilizer, a kicker, a nucleating agent, a silane-treated filler, a metal deactivator, and optionally granulating, cooling and drying the mixture, and extruding it to a conductive surface using a suitable extruder. For extrusion, the mixture containing the basic matrix is heated to a temperature of 130-290 ° C, preferably about 150-240 ° C, preferably to a conductive surface preheated to a temperature of 40-150 ° C, preferably 60-120 ° C, at an extraction rate of 16-40 m / s. and extruding the extruded material together with the coated conductor by contacting it with a refrigerant at a temperature of 10-96 ° C, such as cooling water containing various additives.

Particularly preferred materials for the polyolefin matrix matrix in the process of this invention include low, medium and high density polyethylenes, linear polyethylenes, chlorinated and chlorosulfonated polyethylenes, polypropylenes, polybutene-1, poly-4-methylpentene-1, olefin-based rubbers, EPMs, EPDM elastomers, copolymers of ethylene and propylene with one another or reactive comonomers, graft polymers or olefinic thermoelastoplastomers (alloys, dynamic vulcanizates) and / or mixtures thereof.

In the proposed process, various organic peroxide compounds such as dilauroyl peroxide, benzoyl peroxide, peresters, peracetals and other so-called "grafting agents" can be used as grafting agents, dynamic vulcanizers and modifiers. organic peroxide compounds that provide low reactivity peroxide radicals.

Known conventional exothermic and endothermic blowing agents and concentrates, such as azo compounds (azodicarbonanamide), N-nitrosating compounds (e.g. dinitrosopentamethylene tetramine), sulfonyl hydrazides, are particularly suitable as chemical blowing agents. a (p, p'-oxy-41

Mixtures of bis) benzenesulfonylhydrazyl], sulfonylcarbazides, triazoles, tetrazides, polyazides, hydrazocarboxylates, polycarboxylic and urea derivatives, trihydrazine-triazines, NaHCO3 and oxalic acids, , benzoxazines, or mixtures thereof. ZnO, metal stearates, A1 (OH) 3 (alumina hydrate), urea, cadmium and other heavy metal salts, cationic surfactants and the like are very useful as the accelerator. As nucleating agents, mica, talc, silica, zeolite, etc. may be added. Important components of the mixtures prepared by the process of the present invention are coupling agents and coupling agents fixed on a chemically solid support, which may be various silanes, titanates, zirconates and hafnates, or mixtures thereof. Dispersants that play an important role in the proposed process are preferably selected from various silanes, surfactants, surfactants such as the hyper dispersant Solsperse manufactured by ICI Ltd.

As a solid carrier which must be chemically active, in particular natural micro-ground zeolites, synthetic zeolites, talc, mica, precipitated chalk and silica, calcium silicate, kaolin, amorphous silica, diatomaceous earth, carbon black, etc. and mixtures thereof.

Other additives and excipients used in the polymer composition used in the process include antioxidants, heat and cost stabilizers, metal deactivators, lubricants, pigments, and the like.

The production of communication cables and wires containing leather-coated cable bundles produced by the process of the present invention is illustrated in detail by the following examples. The following materials were used in their implementation:

(1) Tipolen KA 2321-S4 (manufactured by TVK): low density stabilized polyethylene type, density 0.921 kg / dm ³ , nominal melt index 0.3 g / 10 min.

(2) Tipelin KC 440-35 (TVK brand): linear polyethylene type with 5% by weight of hexene-1 comonomer, nominal flow index 1.5 g / 10 min, density 0.944 kg / dm ³ .

(3) Tauroprene PP (Taurus G.V.): Dynamic vulcanizate of atactic PP and EPDM, thermoplastic polyolefin elastomer with 50% white filler (kaolin, chalk).

(4) Tipplen K 899 (TVK brand): Propylene-ethylene-based polypropylene block comonomer with a nominal melt index of 0.4 g / 10 min and a density of 0.9 kg / dm ³ .

(5) Vestopren 10000 (manufactured by Hüls AG): Dynamic vulcanizate of isotactic PP and EPDM, thermoplastic polyolefin elastomer, nominal melting ide 1.1 g / 10 min.

(6) Tipelin FA 381-10 (TVK brand): linear polyethylene type with a nominal flow index of 0.28 g / 10 min and a density of 0.938 kg / dm ³ .

(7) Evipor (EVM, Budapest, manufactured): Azodicarboxylic acid amide 98 weight%, C2H4N4O2, fine yellow powder, molecular weight

116.1, particle size 1-15 µm, density 1.6 kg / dm ³ , gas yield 200-220 ml / g.

(8) Zinc oxide (ZnO) (Harzer Zinkoxyde VHZ): amorphous white powder, density 5470 kg / m ³ , m.p. 1975 ° C, molecular weight 81.37.

(9) Gasil 114 (Crosfield Silicas Ltd.): amorphous silica gel S1O2, untreated, average particle size 5.7 µm, BET surface area 320 m ² / g.

(10) Porophor DNO / F (Bayer AG): N, N'-dinitro-pentamethylenetetramine blowing agent, light yellow powder, molecular weight 186, gas yield 190-205 ml / g.

(11) Lifofoam 720 UN (manufactured by Lifocolor GmbH): Universal carrier matrix blowing agent matrix containing 70% by weight of an endothermic blowing agent.

(12) Gasil 664 (Crosfield Silicas Ltd.): amorphous silica gel S1O2, inorganic surface treatment, average particle size 4.0 µm, BET surface area 320 m ² / g.

(13) Tilcom TIPT (manufactured by Tioxide Chem. Ltd.): Tetrisopropyl titanate, a colorless liquid, a titanate-based coupling agent with a typical titanium content of 16.9% by weight and a density of 0.970 kg / dm ³ .

(14) Wacker Silan XL10 (manufactured by Wacker-Chemie GmbH): vinyltrimethoxysilane, molecular weight 148.2.

(15) Ucarsil PC 1 A (Union Carbide Organosilicon Chem. Corp.): one member of a composition containing a two-component silane compound. (16) Ucarsil PC 1 B (Union Carbide Organosilicon Chem. Corp.): another member of a composition containing a two-component silane compound.

(17) Porophor AZ (Bayer AG): micronized azodicarboxylic acid amide, C2H4N4O2, molecular weight 116.1, density 1.66 kg / dm ³ , gas yield 200-220 ml / g, particle size 5 µm.

(18) Ken-React NZ 69 (manufactured by Kenrich Petrochemicals Corp.): Heterocyclic Organozirconate, C48H84O122P2S5Zr, Zirconium IV-Bis-alkenolato-cyclo (pentathio) -dialkenyl diphosphate-0.0, tan liquid, mild sulfur material.

(19) Sylobloc 41 (W. Grace AB): amorphous silica gel, S1O2 uncoated, BET surface area 400 m ² / g, average particle size 9 µm.

(20) Crodamid ER (Croda Chem. Corp.) or Armid E (Akzo Chemie GmbH) or Loxamid E (Henkel KGaA): Erucic acid amide, recrystallized, min. 94% by weight, m.p. 75-80 ° C, acid number max. 3 mg KOH / g, iodine number 70-80 g I2 / 100 g.

(21) Irganox 1010 (manufactured by Ciba-Geigy AG): pentaerythritol tetra-bis-di-tert-butylhydroxyphenyl propionate, antioxidant heat stabilizer, molecular weight 1112.

EN 203 167 A (22) Irganox 1024 MD (manufactured by Ciba-Geigy AG): metal deactivator, 1,2-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid] hydrazide, molecular weight 552.

(23) Sicostab AO3 (manufactured by BASF AG): A mixture of vitamin E and organic aromatic phosphite (TN PP).

(24) Weston 619 F (manufactured by General Electric Co.): di-styryl pentaerythritol diphosphite, containing 1% by weight triisopropanolamine.

(25) Naugard XL 1 (manufactured by Uniroyal Chem. Co.): metal deactivator and high potency phenolic antioxidant, 2,2'-oxamido-bis-ethyl-3- (3,5-ditertiary-butyl-4-hydroxyphenyl) propionate, molecular weight 697.

(26) Irganox 1035 (manufactured by Ciba-Geigy AG): Thiodiethyl tert-butyl hydroxyphenyl propionate, heat stabilizer, molecular weight 643.

(27) Laurox (Akzo Chemie GmbH): 98% pure organic peroxide (dilauroyl peroxide), grafting agent, solid.

(28) Lifofoam 220 PP (manufactured by Lifocolor GmbH): 20% w / w blowing agent with endothermic degradation profile, masterbatch polypropylene matrix.

(29) Zeolite RCL-L55 (manufactured by the National Mining Company of Ore and Minerals): micronized meal of zeolite of natural origin, specific surface area 18 m ² / g, average particle size 18 μτη.

(30) Treibsystem TMP 1940-4 (Hoechst AG): LDPE based 30% w / w endothermic foaming masterbatch.

(31) Ultrasil VN-3 (manufactured by Degussa AG): precipitated silica with a BET surface area of 170 to 210 m ² / g and an average particle size of 18 μτη.

(32) Irganox PS 800 (manufactured by Ciba-Geigy AG): sulfur-containing secondary co-stabilizer, dilauryl ester of beta-beta-thiothiopropionic acid (DLTDP), molecular weight 515.

(33) Ken-React TTS (manufactured by Kenrich Petrochemicals Corp.): isopropyl triisostearoyl thianate, brownish-red liquid, monoalkoxy titanate based additive, density 0.95 kg / dm ³ .

(34) Solsperse 12000 (manufactured by ICI Ltd.): Hyper dispersant, CTN pigment dispersant, blue powder, density 1.67 kg / dm ³ .

(35) Mowiol 40-88 (manufactured by Hoechst AG): Polyvinyl alcohol of saponified type with a degree of saponification of 87.7μ1.0 (mol%), a viscosity of 40 mPa.s and an ester of 140μ10 mg KOH / g.

(36) Solsperse 20000 (ICI Ltd.): Hyper Dispersant, C.T.N. type pigment dispersant, slightly colored liquid, density 1.02 kg / dm3.

(37) Ken-React KZ TPP (manufactured by Kenrich Petrochemicals Corp.): zirconate based coupling agent, cycloheteroatom, composed of zirconium IV2,2-bis (2-propenolate-methyl) -butanolatocyclo6

-di (2,2) -bis-2-propenolato-methyl (butanolato) pyrophosphate-0.0, a tan liquid.

(38) Ken-React KR 39 DS (manufactured by Kenrich Petrochemicals Corp.): monoalkoxy titanate based adhesive, composition alkoxy triacryl titanate, brownish red liquid, density 1.07 kg / dm.

(39) Tilcom CA-10 (Tioxide Ltd.): Isopropoxy Titanium Isostearate Complex, Reddish-Liquid, Associated Additive, Density 0.980 kg / dm ³ , Titanium Content 5.7%.

(40) Tracel S 235 (manufactured by Tramaco GmbH & Co.KG): white powder, toluenesulfosemicarbazide, C8H11SN3O3, molecular weight 229, gas yield 130 ml / g, decomposition temperature 225-235 ° C.

(41) Micafil 40 (E. Merck): Natural, untreated micronized mica.

(42) Ucarsil PA-1 (Union Carbide Corp.): Silane based internal lubricant and processing aid, colorless, honey-based.

Using the materials listed above, the following examples were used to demonstrate the utility of the process of the present invention (here, the numbers in parentheses refer to the above list, while t% represents weight%).

Example 1 (1) Tipolen KA-2321 S4 88.40% (2) Tipelin KC 440-35 10.00% (7) Evipor and (39) Tilcom CA-10

98: 2 mixture of 0.5% by weight (8) Zinc oxide 0.25% by weight (9) Gasil 114 and (33) Ken-React TTS or (38) Ken-React KR 39 DS or (13) Tilcom TIPT 77:23 Mixture 0.44% (20) Crodamid ER 0.03% (21) Irganox 1010 0.1% (21) Irganox 1024 MD 0.2%% 100.01%

In preparing the mixture, the two basic polymers are added to a 100 liter Banbury internal mixer, the polymers are mixed at 120-130 ° C, melted, and then the azodicarboxylic acid amide and the surface-treated silicate pre-prepared in the Henschel instant mixer. and the other additives are introduced into the mixer in any order or the last addition of the blowing agent.

Stirring is continued for a further 1-2 minutes and the homogeneous compound is introduced into a granulation-dispensing single-screw Bridge extruder at a discharge temperature of up to 130-135 ° C. Providing moderate temperature and adiabatic conditions, the material is exited and granulated by underwater cutting.

For the production of the cable vein, the granulated material mixture is sucked into a funnel of an extruder with a D-60 mm BM L / D-20 ratio without pre-drying operation. The extruder

A solid Cu wire of 0.4 mm diameter was pre-threaded on its crosshead. The wire preheater is turned on to preheat the wire at 60-120 ° C, preferably 90'C. The wire in the crosshead runs along the head for approx. At a temperature of between 180 ° C and 240 ° C, preferably at about 190 ° C, the foam passes into the open air after passing through a forming tool heated at a temperature of at least about 200 ° C. 600-800 m / min, preferably with a pull-out speed of 1200m / min. The forming tool smoothing part a.d. mm, where d is the diameter of the wire, while the value of the coefficient is between 4 and 40, the temperature of the tool is 130-250 'C, preferably 210' C.

The exposed sealing layer foams on the conductor surface and cools in water in a (movable) cooling trough 0.2-2 m from the outlet, the foam structure freezes and the shape is fixed.

The degree of foaming of the resulting vascular insulation is 35-50% (usually 45% of the volume is filled by bubbles) and the wall thickness of the insulation is approx. 0.08 mm, its surface is absolutely smooth, and the unevenness of melt fracture is not perceptible to either the eye or the hand (palpation). The insulated cores are twisted in the appropriate number and arrangement of the cable to be produced and filled with continuous or intermittent space filling, made of petroleum jelly or other filler in the range of 50-100 ° C, preferably 60 ° C, advantageously using the thixotropic property of the filler. Hungarian Patent No. 186,591). Completely screened and shielded telephone cable for the required tests

operating capacity values in the range of 40-42 nF / km, while

- after testing the insulation stability (petroleum jelly) at 60 ° C for 10-24 hours, neither the operating capacity nor the pitting resistance is reduced, due to the homogeneous foam structure and the dense skin-like coating.

Example 2

The granular material mixture was prepared as described in the previous example, having the following composition:

(1) Tipolen KA-2321 S4 61.85% (2) Tipel KC 440-35 30.0% (3) Tauroprene PP 5.0% (27) Laurox (dilauroyl peroxide) 0.1% (7) 1: 1 mixture of Evipor and Profor DNO / F, (33) Ken-React TTS or (18) Ken-React NZ 69 0.45% (11) Lifofoam 720 UN 1.0% (12) ) Gasil 644 and (14) Wacker Silan XL10

7: 3 mixture 2.1% (23) Sicostab AO3 0.2% (21) Irganox 1024 MD 0.2%

Total: 100,001%

In the exemplary embodiment, Tauroprene PP is added to the mixture of low density and linear polyethylene, followed by dilauroyl peroxide and kneading in a Banbury-type internal mixer for about 3-5 minutes to complete the grafting reaction. temperature. Thereafter, the blend-treated blowing agent blend, the universal blowing master blend in the carrier and the silane-treated silicate are introduced into the system and blending is continued for about 2 to 3 minutes. The discharge temperature is 125-130 ° C. The final mixture was granulated under water, cooled, separated on a shaker and dried.

To prepare a telephone cable for wire insulation, an extruder as described in Example 1 was used, using a breaking plate and a screen pack with holes 2.5mm in diameter. The latter perform the functions of filter homogenization and continuously reduce the impurities. The filter package shall consist of a total of 5 sieves with a mesh size of 250/150/100/150/150/150 micrometres, with a free cross-section of at least 15%, but preferably 25%.

The extruder is rotated at 60 rpm and, by turning on the screw cooling, 164/170/178/186 ° C is stabilized in each zone of the adiabatic extruder and the head temperature is adjusted to 198 ° C.

The copper wire, 0.6 mm in diameter, is preheated to 80 ° C and worked at a withdrawal speed of 1600 m / min.

The extrusion tool and the cooling conditions are as follows:

Selected as described in Example 1, a cable core with a very smooth outer skin layer having a wall thickness of 0.12 mm and a foaming rate of at least 42% was obtained.

The cable core thus prepared is made into an internal telephone cable filled with petroleum jelly, as detailed in Example 1. During the test of the finished cable, the operating capacity was measured to a maximum of 40 nF / km, and it was not checked after the stability test at 60'C for 10 * 24 hours, indicating that the skin layer formed was sufficiently blocking penetration of petroleum jelly into the insulation.

The longitudinal shrinkage of the cable insulation is less than 2 mm at a test length of 1 m.

As a result of the compression test, an average of about 100 N was measured, which was not less than about 70 N in any sample.

Example 3

The following products were used to make the raw material:

(1) Tipolen KA 2321-S4 87.16 t% (4) Tipplen K 899 5.00 t% (5) Vestopren 10000 2.5 t% (13) Tikom TIPT 0.5 t% (28) Lifofoam 220 PP 2.5%

HU 203 167 A

(29) Zeolite RCL-L5 and 20% by weight (15) Ucarsil PC 1 A and 80% by weight (16) Ucarsil PC 1 B 1: 1 mix 2.00% (20) Loxamid E 0.04% (21) Irganox 1010 0.1% (21) Irganox 1024 MD 0.2% altogether: 100.00%

(39) Tilcom CA 10 (98: 2 mixture) (41) Micafil 40 and Dynasilan MEMO 1.0%

(19) Sylobloc 41 0.37% (20) Annid E 0.03% (21) Irganox 1010 0.2% (24) Weston 619 F 0.3% (25) Naugard XL 1 0.2% altogether: 100.00%

In the exemplary embodiment, polypropylene, dynamic thermoelastoplastomer and polymer matrix are added to the low density polyethylene with 0.5 wt.% Tilcom? Titanate based binder at 135-145 ° C for about 4 minutes. To the molten and alloyed base matrix are added the blowing agent masterbatch and the filler preformed with the silane compounds in a Henschel mixer as well as other additives. After complete mixing for 1-3 minutes, the contents of the mixer are emptied into a single screw extruder and the finished compound is granulated by underwater cutting and the granulate is dried.

Subsequently, the same procedure as in Examples 1 and 2 is followed to produce insulated cores, but no sieve package is used, only a chamfer. The BM extruder is turned to 55 rpm, the screw cooling is switched off, and the heating zone temperature is set to 170/175/180/190, respectively.

By controlling, the temperature of the effluent is 210-215 ° C.

The size of the forming tool's finishing length is selected as described in Example 1.

The 0.8 mm diameter copper wire is preheated to 100 ° C and a withdrawal rate of 1500 m / min is set on the apparatus.

The wall thickness of the cable core thus produced, after cooling, is on average 0.15 mm and has an expansion rate of 45%.

The surface of the vascular insulation is impeccably smooth, with no visible or unevenness in the skin of the bovono skin.

The rated capacitance of the conductor pairs of the insulated wire constructed as described in Example 1 is typically in the range of 42-44 nF / km and, after a petroleum jelly penetration test at 60 ° C for 10 * 24 hours, the value of the operating capacity and insulation resistance does not change.

In the following example, the operating parameters of the cables used for telecommunication purposes were investigated by carrying out a sliding agent according to the invention.

Example 4

In the example we start from the following receptor:

(2) Tipelin KC 440-35 97.16 wt% (42) Ucarsil PA-1 0.04 wt% (7) Evipor and (17) Porophor A 1: 1 blend and 0.7 wt%

In the exemplary embodiment, 400 ppm Ucarsil PA-1 silane based lubricant is added to the Tipelin KC-440-35 pure linear polyethylene matrix in powder or granule form, such that other additives are preferably in powder form by Henschel's in a blender. Production of the compound is carried out in a continuous intensive mixing machine (TITLE extruder) with continuous addition of additives. The extruder is agitated at a temperature of up to 130-140 ° C with a residence time of 2-5 minutes. The finished compound is granulated, cooled and dried.

Foamed insulation is produced as described in Examples 1 and 2 with the following exceptions:

- the wire was preheated to 110 ° C,

- the extruder temperature setting at the extruder heating zones was 170/180/190/200 'C,

- the plates of the sieve package used,

500/300/500 micrometers, the breaking plate about

2.5mm hole size was typical

- outlet material temperature 220 'C, screw speed 60 rpm, withdrawal speed

It was 1600 m / min.

The foam core insulation obtained after cooling has a minimum wall thickness of 0.16 mm and an expansion ratio of 45%.

According to the organoleptic tests, the surface of the vascular insulation is impeccable. The working capacity of the finished cable pairs constructed as described in Examples 1 and 2, after aging at 45 nF / km and 60 ° C for 10-24 hours (petroleum jelly penetration test), did not change either the insulation resistance or the working capacity.

Example 5

We have prepared the following mixture:

(1) Tipolen KA 2321-S4 89.32% (6) Tipelin FA 381-10 5.0% (30) Treibsystem TMP 1940-4 and (35)

Mowiol 40-88 3: 1 Mixture 4.0% (31) Ultrasil VN-3 and (38) Ken-React KR

DS 1: 1 Mixture 1.2% (20) Crodamid ER 0.03% (26) Irganox 1035 0.1% (32) Irganox PS 800 0.2% (21) Irganox 1024 MD 0, 15% by weight of ingredients: 100.00% by weight

In the exemplary embodiment, the polymers, the blowing agent concentrate and the polyvinyl alcohol are present in an amount of ca. Mp-81 at 130 'C

Stir in a floured internal mixer for 3 to 5 minutes and then knead the silicate pre-treated with the dispersant in the melt and the other additives for a further 1 to 2 minutes to homogenize the mixture. This material was introduced into an extruder at a discharge temperature of 140 ° C and granulated with an underwater granulator, cooled and then dried.

The BM screw extruder is then extruded onto the conductor surface with the following technological parameters:

- conductive copper conductor 0,6 mm in diameter preheated to 80 'C,

- pull-out speed about 24 m / s,

- extruder extrusion zone temperatures are 170/185/190/210 'C,

screw speed 55 rpm D = 60 mm,

The L / D ratio is 20, the outlet temperature of the material is 225 'C,

- the forming tool has a forming length of 18 mm,

- approx. It is located 40 cm from the outlet.

By extrusion, approx. A wall thickness of 0.12 mm was obtained with an expansion rate of about 45%.

According to the organoleptic examination, the surface of the insulation was of excellent quality. The compressive resistance of the insulating layer was adequate since no short circuit was observed at a compressive force of about 80 N.

1-4. When testing a communication cable made as described in Examples 1 to 4, the shrinkage should not exceed 1.5 mm and the operating capacity up to max. 40 nF / km. After 10 * 24 hours aging at 60 'C, neither the operating capacity nor the insulation resistance changed.

Example 6

For the process according to the invention, a mixture of the following compositions is prepared:

(1) Tipolen KA 2321-S4 61.35% (2) Tipelin KC 440-35 30.0% (3) Tauropren PP 5.0% (33) Ken-React TTS 0.5% (7) Evipor and (10) Porofor DNO / F 1: 1 blend for this 0.45% (33) Ken-React TTS 0.1% (11) Lifofoam 720 UN 0.1% (12 Gasil 664 and (14) Wacker Silan XL 10 7: 3 mixture 2.1% (23) Sicostab AO3 0.2% (21) Irganox 1024 MD 0.2% altogether: 100.00%

In the exemplary embodiment, the basic polymer matrix is combined with Tauroprene in the presence of the Ken-React TTS coupling agent and granulated in a Banbury internal mixer and a single screw Bridge extruder. In another step of the process, we use this basic matrix to make the mixture. The alloying was carried out at 135 ° C with a stirring time of 5 minutes. To the base material thus prepared, a blend of pre-surface-treated blowing agent with Ken-React TTS and a dispersant (titanium-treated filler) in Henschel mixer and other additives are added at a temperature of about 120 ° C. The melt was then stirred for an additional 1-3 minutes and the mass homogenized to a maximum of 130 ° C was discharged. The material is transported with an adiabatic extruder, granulated, then cooled and the final granulate dried.

According to the test results prepared above, a mixture of materials which is particularly advantageous for the production of high frequency wall insulated RF cables is granulated into a 60 mm screw diameter 20D-S BM screw extruder which has been pre-fed with a 1.2 mm red , preheated to 60 ° C. The granulate of the above formula is added to the extruder and the temperature of each heating zone in the extruder is adjusted to 160/175/190/205 'C, respectively.

The melt filter screen of the preferred filter screen had a mesh size of 250/150/60/150/250 micrometres and a breaker plate of at least 30% free passage cross-section. The punch plate had a hole size of 2.5 mm.

The extraction rate was 10-14 m / s, which was tuned to the speed of the auger to produce an insulating layer with an outer diameter of approximately 8.4 mm. The average degree of foaming in the insulating layer so produced was generally in the range of 38-42%, with a dielectric constant (epsilon) of about 1.64. On the outside of the insulation, a continuous coating layer of leather is formed which provides the functional properties of the conductor described above.

Example 7

In order to carry out the process according to the invention, a mixture of the following compositions is prepared:

(2) Tipelin KC-440-35 98.72% (7) Evipor 0.20% (40) Tracel S 235 0.35% (34) Sorsperse 12000 and (36) Sorsperse 20000 in a 1: 1 ratio mix 0.2% (20) Crodamid ER 0.03% (21) Irganox 1010 0.2% (25) Naugard XL 1 0.3% altogether: 100.00%

In the exemplary embodiment, the blowing agents are pre-homogenized in a Henschel mixer with a Solsperse hyper dispersant (34) and (36) (which forms a synergistic mixture of two components) at a temperature of 20-50 ° C. other powdered additives are added and so on

The expanded mixture was homogenized for an additional 5 minutes. The powder mixture is extruded in a CIM type homogeniser extruder for Eneiary polyethylene at a suitable dosing rate with a residence time of 150 ° C to 160 ° C for 2 to 5 minutes, and finally the mixture is granulated and subsequently controlled for both extrusion and use and process parameters. as described in Example 4 above.

The resulting material was re-examined inside the cable and it was found that this composition also provides an excellent, high surface area, high coating strength, coated with a solid skin layer, which can be used to make a cable with stable electrical transmission parameters.

Claims (10)

CLAIMS 1. A process for the production of high-strength foamed insulating layers for the manufacture of signal transmission wires and cables having low density polyethylene having a density of 0.921 + 0.05 kg / dm ³ and a melt index of 0.2-20 dg / min and an intermediate density of up to 70%. forming a mixture of high density polyethylene and / or polypropylene and / or linear polyethylene with a surface-treated blowing agent of known composition and optionally adding at least one additive, in particular a heat-stabilizer, a kicker, a nucleating agent, a surface-treated filler, , cooled and dried, then extruded onto a conductive surface, wherein a dispersant, in particular silane, titanate, zirconate, hafnate, surfactant, is added in an amount of 0.01 to 10% by weight, preferably 0.1 to 2.0% by weight. thereby forming a base matrix, and then extruding the mixture containing the base matrix at a temperature of 130 to 290 ° C, preferably 150 to 240 ° C, preferably at a extraction rate of 40 to 150 ° C, preferably 60 to 120 ° C, at and the extruded material, together with the coated conductor, is cooled in contact with a refrigerant at 10-96 ° C, preferably water. Process according to Claim 1, characterized in that, prior to the preparation of the basic matrix, its ingredients are mixed with 0.011.0% by weight of an organic peroxide compound, in particular perester, perketal, a compound with low activity radicals, to form a dynamic vulcanizate. 3. A process according to claim 1 or 2, characterized in that during the extrusion the mixture is passed through a sieve having a mesh size of at least 0.05 mm. 4. A method according to any one of claims 1 to 4, characterized in that the extruded material is passed through a tube heated to 200-500 ° C, preferably 300 ± 10 ° C, with a diameter of at least five times the outer diameter of the extruded material before cooling. 5. A process according to any one of claims 1 to 4, characterized in that the cooling is carried out with cooling water at 90 ± 5 ° C. 6. A process according to any one of claims 1 to 3, characterized in that cooling is carried out with water containing the wetting agent in dissolved or dispersed state. 7. A process according to any one of claims 1 to 3, characterized in that 0.01 to 0.5, preferably about 0.05% by weight of coloring agent, preferably coloring pigment, is added to the mixture prior to extrusion. 8. A method according to any one of claims 1 to 5, characterized in that a conductive layer is formed on the surface of the extruded material by weaving, twisting, ribbing or extruding. 9. A process according to any one of claims 1 to 3, characterized in that a co-extruded polymer layer is applied to the surface of the extruded material. 10. A method according to any one of claims 1 to 3, characterized in that a dye, pigment or dye is applied to the surface of the conductor-extruded material continuously or intermittently or in the form of a strip of any pitch.