EP1063655B1 - Carriers bearing functionalised organoorganooxysilanes in cable compositions - Google Patents

Abstract

Cable composition (I) comprises: (A) a liquid functional organylorganyloxysilane or a corresponding (co)condensate bonded to a support material, (B) a thermoplastic, polar functional group containing base polymer and (C) a reinforcing or extending mineral filler. An Independent claim is included for a cable comprising a metallic conductor sheathed in (I).

Description

The invention relates to the use of functional Organylorganyloxysilanen on carriers in cable compounds containing certain thermoplastic base polymers and fillers. The invention further relates to a mixture for producing a cable compound

State of the art

Cable compounds are mixtures of substances which comprise a base polymer and mineral (or inorganic) reinforcing, extending or flameproof fillers and are used to enclose metallic conductors in an electrically insulating manner. It is known that addition of functional organylorganyloxysilanes facilitates dispersion of the filler in the base polymer and improves adhesion between base polymer and filler. Functional organylorganyloxysilanes in this context are those silanes which carry an organic radical bonded via a carbon atom to the silicon atom, which in turn contains a functional group. The easier dispersion and the better adhesion are probably due to a silane-induced hydrophobization of the surface of the filler particles. The better adhesion leads to better mechanical properties of the cable sheath.

For example, EP 0 518 057 B1 discloses liquid mixtures containing vinyl groups of chain-shaped and cyclic siloxanes or siloxane oligomers and their use as crosslinking agents, eg. B. for high pressure polyethylene, known in cable compositions. However, liquid additives are problematic for users in that the usual means for weighing and dosing small amounts of additives are designed for solids only. Therefore, liquid small components must be manually be weighed and dosed. This is usually associated with higher costs and represents an additional source of error.

A known solution to this problem is to bind liquid functional organosilanes to highly adsorbing or absorbing solids which can then be readily weighed and metered as "dry liquids" (or "dry liquids") with the usual facilities. Thus, DE 195 03 779 A1 describes a combination of silica and trans-polyoctenamer as a carrier for liquid rubber chemicals, including vinyl and mercaptosilanes and sulfur silanes. In DE 44 35 311 A1 so-called reinforcing additives of oligomeric and / or polymeric sulfur-containing organylorganyloxysilanes and semi-active, active and / or highly active carbon blacks are described as the carrier, which are suitable for use in rubber mixtures or compounds and in plastic mixtures. In both mentioned writings, however, cable compounds are not mentioned. DE-A 22 37 354 describes an insulating material for whose production a mixture of polymer material and a filler coated with chemically bonded silane is used. The insulating material is u. a. for cable use. EP 0 428 073 B1 discloses a process comprising mixing (i) a base polymer, (ii) a sponge-like polymer or swellable polymer with a (meth) acryloxy-functional organosilane contained therein, and (iii) a free-radical producing substance; the mixture melts and homogenizes. Again, this method is not directed to the use of the homogenized blends for cable compounds. In contrast, it is stated in WO 97/07165 that the solid mixtures of functional organosilanes described there and certain large surface area silicas with low surface energy u. a. can be used in the insulation of wires and cables.

One of the objects of the present invention is the use of (1) a liquid functional organylorganyloxysilane reversibly bound to a carrier, or reversible to a carrier bonded liquid (co) condensate of an organylorganyloxysilane functional product for the preparation of cable compounds containing a (2) thermoplastic, polar functional group-bearing base polymer and (3) a reinforcing or extending mineral filler.

Another object of the invention are mixtures for the preparation of cable compounds, (1) a reversibly bound to a carrier liquid functional organylorganyloxysilane or reversibly bound to a carrier liquid (co) condensate of an organylorganyloxysilane functional, (2) a thermoplastic, polar functional Group-bearing base polymer and (3) a reinforcing, extending or flame-retardant mineral filler.

Functional organylorganyloxysilanes

Functional Organylorganyloxysilane in the context of the invention contain at least one bonded via a carbon atom to a silicon atom organic radical (organyl radical), for. B. a straight-chain or branched alkylene radical having 2 to 6 carbon atoms, which carries at least one functional group. The functional group may, for. Example, a hydroxyl, nitrile, carbonyl, carboxyl, acyl, acyloxy, carboalkoxy, mercapto, sulfane (X _x ), epoxy or optionally substituted by one or two hydrocarbon radicals having 1 to 6 carbon atoms Amino group and a halogen atom, in particular a chlorine atom or an olefinic double or a C-C triple bond. The organic radical may also contain several identical or different functional groups, for. B. two amino groups or an acyl radical having an olefinic double bond, such as the (meth) acryloxyrest. On the other hand, the functional organylorganyloxysilanes contain at least one hydrolyzable radical, preferably three hydrolyzable radicals, eg. B. one or more alkoxy or Alkoxyalkoxyreste each having 1 to 6 carbon atoms. The functional Organylorganyloxysilane can further one or two further, non-functional and non-hydrolyzable Contain residues, eg. Example, a hydrocarbon radical having up to 8 carbon atoms, such as methyl, propyl or n-hexyl.

Examples of suitable functional organylorganyloxysilanes are vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, 3-mercaptopropyltrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane and methacryloxypropyltris (2-methoxyethoxy) silane. Optionally functional organylorganyloxysilanes are optionally N-substituted aminoorganylorganyloxysilanes by 1 or 2 alkyl radicals each having 1 to 6 carbon atoms, because the coatings of the corresponding compounds have outstanding mechanical properties (such as tensile strength, elongation at break, tear strength and modulus of elasticity) and electrical properties (such as electrical loss factor , Dielectric constant). Of the suitable Aminoorganylorganyloxysilanen z. 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, N-aminoethyl-3-aminopropyltrimethoxysilane, triaminofunctional propyltrimethoxysilane (N-trimethoxysilylpropyl-diethylenetriamine, also referred to as DYNASYLAN® TRIAMO) and (N'-aminoethyl) - N-aminoethyl-3-aminopropylsilane called.

Instead of a functional organylorganyloxysilane, it is also possible to use a mixture of one or more of these substances. Furthermore, it is equally possible to use (co) condensates of the functional organylorganyloxysilanes having weight-average molar weights of up to about 10,000 according to the invention. These are understood to mean condensates (or oligomers) of the functional organylorganyloxysilanes or cocondensates of these substances with other non-functional organylorganyloxysilanes or organyloxysilanes. Among these, for example, methyltrimethoxysilane, methyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, i-butyltrimethoxysilane, i-butyltriethoxysilane, octyltriethoxysilane, hexadecyltrimethoxysilane and Called tetraethoxysilane. You put the (co) condensates z. B. in a known manner by hydrolysis or cohydrolysis of the silanes with limited amounts of water and subsequent condensation of the silanols ago. In the cocondensates, the proportion of (amino) -functional organylorganyloxysilanes should be at least 10% by weight, advantageously at least 50% by weight.

It is also possible, instead of a cocondensate, to place the functional organylorganyloxysilane together with a nonfunctional organylorganyloxysilane or organyloxysilane in the ratio specified for the cocondensates.

When the following is simplified for the discussion of functional organylorganyloxysilanes, it is meant substances which are always liquid at room temperature, the mentioned (co) condensates being included.

Carriers for the functional organylorganyloxysilanes

• Flammkieselsäure, die im großtechnischen Maßstab durch kontinuierliche Hydrolyse von Siliciumtetrachlorid in einer Knallgasflamme hergestellt wird. Dabei wird das Siliciumtetrachlorid verdampft und reagiert anschließend innerhalb der Flamme mit dem aus der Knallgasreaktion stammenden Wasser spontan und quantitativ. Die Flammkieselsäure ist eine amorphe Modifikation des Siliciumdioxids in Form eines lockeren, bläulichen Pulvers. Die Teilchengröße liegt im Bereich von wenigen Nanometem, die spezifische Oberfläche ist daher groß und beträgt im allgemeinen 50 bis 600 m²/g. Die Teilchen sind nicht porös, die Aufnahme der funktionellen Organylorganyloxysilane beruht allein auf Adsorption.
• Fällungskieselsäuren werden im allgemeinen aus Natronwasserglas-Lösungen durch Neutralisation mit anorganischen Säuren unter kontrollierten Bedingungen hergestellt. Nach Abtrennung von der flüssigen Phase, Auswaschen und Trocknen wird das Rohprodukt feingemahlen, z. B. in Dampfstrahlmühlen. Auch Fällungskieselsäure ist ein amorphes Siliciumdioxid, das aber in der Regel eine kleinere spezifische Oberfläche hat, meist im Bereich von 50 bis 150 m²/g. Fällungskieselsäure weist im Gegensatz zur Flammkieselsäure eine gewisse Porosität auf (ca. 10 %). Die Aufnahme der funktionellen Organylorganyloxysilane erfolgt daher sowohl durch Adsorption an der Oberfläche als auch durch Absorption in den Poren.
• Calciumsilikat wird technisch durch Zusammenschmelzen von Quarz oder Kieselgur mit Calciumcarbonat bzw. -oxid oder durch Fällung von wäßrigen Natriummetasilikat-Lösungen mit wasserlöslichen Calciumverbindungen hergestellt. Das sorgfältig getrocknete Produkt ist porös und kann Wasser oder Öle bis zur fünffachen Gewichtsmenge aufnehmen.
• Poröses Polyethylen wird durch spezielle Polymerisationstechniken und -verfahren hergestellt und z. B. von AKZO und DSM in technischen Mengen angeboten. Die Teilchengrößen liegen zwischen 3 und < 1 mm, die Porosität beträgt über 50 %, so daß die Produkte große Mengen an funktionellen Organylorganyloxysilanen zu absorbieren vermögen, ohne ihre Freifließ-Eigenschaften zu verlieren.
• Als Wachse eignen sich insbesondere Polyolefinwachse auf Basis von LDPE (verzweigt, mit langen Seitenketten). Der Schmelz- und Erstarrungspunkt liegt in der Regel zwischen 90 und 120 °C. Die Wachse lassen sich in der niedrigviskosen Schmelze gut mit den funktionellen Organylorganyloxysilanen mischen. Die erstarrte Mischung ist hinreichend hart, so daß sie granuliert werden kann.
• Ruß in seinen verschiedenen Handelsformen eignet sich z. B. zur Herstellung von schwarzen Kabelummantelungen. Ruß wird hauptsächlich in Verbindung mit schwefelhaltigen Silanen verwendet.

Suitable carriers are a variety of materials known per se as carriers. In particular, it should be mentioned:

• Flame silica, which is produced on an industrial scale by continuous hydrolysis of silicon tetrachloride in a blast gas flame. The silicon tetrachloride is vaporized and then reacts spontaneously and quantitatively within the flame with the water resulting from the oxyhydrogen gas reaction. The flame silica is an amorphous modification of the silica in the form of a loose, bluish powder. The particle size is in the range of a few nanometers, the specific surface area is therefore large and is generally from 50 to 600 m ² / g. The particles are not porous, the uptake of the functional Organylorganyloxysilane is based solely on adsorption.
• Precipitated silicas are generally prepared from soda water solutions by neutralization with inorganic acids under controlled conditions. After separation from the liquid phase, washing and drying, the crude product is finely ground, z. B. in steam jet mills. Precipitated silica is also an amorphous silica, but usually has a smaller specific surface area, usually in the range of 50 to 150 m ² / g. Precipitated silica, in contrast to flame silica, has a certain porosity (about 10%). The uptake of the functional Organylorganyloxysilane therefore takes place both by adsorption on the surface and by absorption in the pores.
• Calcium silicate is produced industrially by fusing quartz or diatomaceous earth together with calcium carbonate or oxide or by precipitating aqueous sodium metasilicate solutions with water-soluble calcium compounds. The carefully dried product is porous and can absorb water or oils up to five times the weight.
• Porous polyethylene is produced by special polymerization techniques and processes, and e.g. B. offered by AKZO and DSM in technical quantities. The particle sizes are between 3 and <1 mm, the porosity is over 50%, so that the products are able to absorb large amounts of functional Organylorganyloxysilanen without losing their free-flow properties.
• As waxes are particularly suitable polyolefin waxes based on LDPE (branched, with long side chains). The melting and solidification point is usually between 90 and 120 ° C. The waxes can be mixed well with the functional Organylorganyloxysilanen in the low-viscosity melt. The solidified mixture is sufficiently hard so that it can be granulated.
• Soot in its various forms of trade is suitable for. B. for the production of black cable sheathing. Carbon black is mainly used in conjunction with sulfur-containing silanes.

Production of "Dry Liquids" from Functional Organylorganyloxysilanes and Carriers

• Mineralische Träger oder poröse Polymere werden vorgewärmt, z. B. in einem Wärmeschrank auf 60°C, und in einen zylindrischen Behälter gegeben, der mit trockenem Stickstoff gespült und gefüllt wurde. Anschließend wird das funktionelle Organylorganyloxysilan zugegeben und der Behälter in eine Rollvorrichtung gelegt, durch die er ca. 30 min lang in Rotation versetzt wird. Nach dieser Zeit hat sich aus dem Trägerstoff und dem flüssigen funktionellen Organylorganyloxysilan ein rieselfähiges, oberflächlich trockenes Granulat gebildet, das zweckmäßig unter Stickstoff in lichtundurchlässigen Behältern gelagert wird.
  Alternativ kann man den erwärmten Trägerstoff in einen mit trockenem Stickstoff gespülten und gefüllten Mischer, z. B. einen Pflugscharmischer vom Typ LÖDIGE oder einen Propellermischer vom Typ HENSCHEL. Das Mischwerk wird in Betrieb genommen und das funktionelle Organylorganyloxysilan nach Erreichen der maximalen Mischleistung □ber eine Düse eingesprüht. Nach beendeter Zugabe wird noch ca. 30 min homogenisiert und danach das Produkt, z. B. mittels einer mit trockenem Stickstoff betriebenen pneumatischen Förderung, in lichtundurchlässige, mit Stickstoff gefüllte Behälter abgefüllt.
• Wachs/Polyethylenwachs in pelletierter Form mit einem Schmelzpunkt von 90 bis 120 °C wird in einem beheizbaren Gefäß mit Rührer, Rückflußkühler und Flüssigkeitszugabevorrichtung portionsweise aufgeschmolzen und im schmelzflüssigen Zustand gehalten. Während des gesamten Herstellprozesses wird trockener Stickstoff durch die Apparatur geleitet. Über die Flüssigkeitszugabevorrichtung wird nach und nach das flüssige funktionelle Organylorganyloxysilan in die Schmelze gegeben und durch intensives Rühren mit dem Wachs vermischt. Danach wird die Schmelze zum Erstarren in Formen abgelassen, und das erstarrte Produkt wird granuliert. Alternativ kann man die Schmelze auf ein gekühltes Formband auftropfen lassen, auf dem sie in gebrauchsfreundlicher Pastillenform erstarrt.

The following methods are available for the production of "dry liquids":

• Mineral carriers or porous polymers are preheated, e.g. B. in a heating cabinet at 60 ° C, and placed in a cylindrical container, which was purged and filled with dry nitrogen. Subsequently, the functional organylorganyloxysilane is added and the container placed in a rolling device, by which it is rotated for about 30 minutes. After this time, a free-flowing, superficially dry granulate has formed from the carrier and the liquid functional Organylorganyloxysilan, which is expediently stored under nitrogen in opaque containers.
  Alternatively, the heated carrier may be placed in a dry nitrogen purged and filled mixer, e.g. As a ploughshare mixer type LÖDIGE or a propeller mixer type HENSCHEL. The mixer is put into operation and sprayed the functional Organylorganyloxysilan after reaching the maximum mixing power □ via a nozzle. After completion of the addition is homogenized for about 30 min and then the product, for. B. filled by means of a dry nitrogen operated pneumatic conveying, in opaque, filled with nitrogen containers.
• Wax / polyethylene wax in pelleted form with a melting point of 90 to 120 ° C is in a heatable vessel with a stirrer, reflux condenser and Flüssigkeitszugabevorrichtung in portions melted and kept in the molten state. Throughout the manufacturing process, dry nitrogen is passed through the apparatus. The liquid functional organylorganyloxysilane is gradually added to the melt via the liquid addition device and mixed with the wax by vigorous stirring. Thereafter, the melt is allowed to solidify in molds, and the solidified product is granulated. Alternatively, the melt can be dropped onto a chilled forming belt, on which it solidifies in a convenient pastille mold.

base polymers

It is an important feature of the invention that the base polymer of the cable compounds is thermoplastic and carries polar groups. Such base polymers give z. B. improved fire performance (i.e., lower flammability and smoke density) and increase filler uptake capability. Polar groups are z. As hydroxyl, nitrile, carbonyl, carboxyl, acyl, acyloxy, carboalkoxy or amino groups and halogen atoms, in particular chlorine atoms. Non-polar are olefinic double bonds or C-C triple bonds. Suitable polymers are in addition to polyvinyl chloride copolymers of one or more olefins and one or more comonomers containing polar groups, for. As vinyl acetate, vinyl propionate, (meth) acrylic acid, (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid butyl ester, acrylonitrile. In the copolymers, the polar groups are generally found in amounts of from 0.1 to 50 mol%, preferably from 5 to 30 mol%, based on the polyolefin units. Highly suitable base polymers are ethylene-vinyl acetate copolymers. For example, a suitable commercial copolymer contains 19 mole% vinyl acetate and 81 mole% ethylene building blocks.

fillers

The fillers are mineral (or inorganic) and may be reinforcing or merely stretching. They at least bear on their surfaces Groups which react with the organyloxy groups of the functional organylorganyloxysilane. As a result, the silicon atom with the functional organyl group attached thereto is chemically fixed on the surface. Such groups on the surface of the filler are especially hydroxyl groups. Accordingly, preferred fillers are metal hydroxides with a stoichiometric proportion or, in their different dehydration stages, with a substoichiometric proportion of hydroxyl groups up to oxides with comparatively few remaining hydroxyl groups which can be detected by DRIFT-IR spectroscopy. Examples of suitable fillers are aluminum trihydroxide (ATH), alumina hydrate (AlOOH), magnesium hydroxide, brucite, huntite, hydromagnesite, mica and montmorillonite.

Quantity ratios of the various components in the cable compounds

The ratio of functional Organylorganyloxysilan to carrier may, depending on the nature and the capacity of the carrier and depending on the particular silane, vary within wide limits. By orienting experiments can be easily determined what amounts of the desired functional Organylorganyloxysilan a bestimm ter carrier can absorb without losing its free-flowing properties. In general, from 20 to 80% by weight of functional organylorganyloxysilane, based on the carrier, is used.

The proportion of the filler depends on its type, the respective base polymer and the stresses to which the compounds are exposed when used as intended. In general, the filler is used in an amount of from 5 to 80% by weight, advantageously from 50 to 70% by weight, based on the compound.

The amount of functional Organylorganyloxysilans must be such that the surface of the filler is sufficiently occupied and hydrophobed.

These are relatively small quantities. In general, from 0.1 to 5% by weight and advantageously from 0.5 to 2% by weight of functional organylorganyloxysilane, based on the filler, is used.

For all mentioned quantitative ratios, the optimum values for a given purpose of use and given components can be determined easily by an orientation experiment.

Other components in the cable compounds

The cable compounds according to the invention may contain the usual additives for compounds in the usual amounts. Examples of these additives include UV and heat stabilizers, lubricants, extruding aids and peroxides. Their proportion of the compound is generally below 5 wt.%.

Production of Cable Compounds from Base Polymer, Filler and "Dry Liquid"

The cable compounds are prepared by mixing the components in the melt, expediently with exclusion of moisture. For this purpose, the usual heatable homogenizers, z. As kneader or, advantageously in continuous operation, extruder, in particular twin-screw extruder. The components are continuously, in each case or in part mixtures, supplied in the predetermined quantity ratio to the extruder heated to a temperature above the melting point of the base polymer. The temperature is expediently allowed to increase towards the end of the screw in order to set a lower viscosity and thus to allow intimate mixing. The extrudates can still be fed liquid to a device for sheathing of electrical conductors. Alternatively, they may be allowed to solidify and then chopped to suitable particle sizes.

The following examples are intended to further illustrate the invention, but not to limit its scope, as set forth in the claims.

Example 1 - "Dry Liquid" of 3-aminopropyl-triethoxysilane and flame-silica

In a laboratory mixer of type HENSCHEL FM / A 10 with a capacity of about 9 liters of 500 g of flame silica (AEROSIL® 200) are given, and the mixer is set in motion. The speed of the mixing tool is set to 400 rpm. First, the air is replaced by dry nitrogen via the metering device. Thereafter, the flame silica is heated to 50 ° C via the double jacket of the mixing vessel by means of a thermostat and heat transfer oil. After about 30 minutes, 3-aminopropyltriethoxysilane (DYNASYLAN® AMEO from DEGUSSA-HÜLS AG) is metered in via the metering device of the mixer, namely 50 g / min, a total of 1,500 g. After completion of the addition, the heat is adjusted and the mix is mixed for another 30 minutes. Thereafter, the mix, the "dry liquid", the mixer is removed and filled under nitrogen in opaque containers.

Example 2 - "Dry Liquid" from precipitated silica and N-aminoethyl-3-aminopropyltrimethoxysilane

800 g of precipitated silica (ULTRASIL® VN3 from DEGUSSA-HÜLS AG) are introduced into a cylindrical vessel having an outer diameter of 20 cm and a length of 35 cm. The filling is overlaid with dry nitrogen and the vessel is closed. In a heating cabinet, the mixture is heated to 60 ° C for 1 h. The heated vessel is opened and the contents are mixed with 1,200 g of N-aminoethyl-3-aminopropyltrimethoxysilane (DYNASYLAN® DAMO from DEGUSSA-HÜLS AG). The vessel is closed again and then placed on a roll device for 30 min in rotation. The product thus obtained is superficially dry and free-flowing. It is filled under dry nitrogen into opaque containers.

Example 3 - Determination of Extractable Content of a "Dry Liquids"

Into the extraction sleeve of a 100 ml Soxhlet extraction apparatus, 30 g each of the "dry liquid" are added, and 180 ml of dry, analytically pure methyl ethyl ketone are introduced into the flask. The methyl ethyl ketone is heated to boiling and the "dry liquid" extracted over 2 h. The extraction tube with the extraction residue is dried and weighed. The weight loss is calculated as "extractable silane". The results are shown in the following Table 1. <b> Table 1 </ b> "Dry Liquid" Silane content in "Dry Liquid" extraction residue "Extractable silane" [%] [g / 30 g] [g / 30 g] [g / 30 g] [%] example 1 75 22.5 7.9 22.1 98.2 Example 2 60 18.0 12.8 17.2 95.6

From the table it can be seen that the silane is bound almost completely reversibly to the carrier.

Example 4 - Processing of "Dry Liquids" to Cable Compounds / Comparison of Liquid Silane with Silane on Vehicle

For the production of halogen-free cable compounds with flame-retardant properties ("halogen free flame retardant" [HFFR] compounds), the following components were used: component amount Aluminum hydroxide (ATH) 160 parts Ethylene-vinyl acetate copolymer (EVA, 19% VA) 100 parts IRGANOX® 1010 (UV stabilizer) Part 1

1. (1) 3-Aminopropyltriethoxysilan (DYNASYLAN® AMEO)
2. (2) N-Ethylamino-3-aminopropyl-trimethoxysilan (DYNASYLAN® DAMO)
3. (3) DYNASYLAN® 1291 (Mischung aus 3-Aminopropyl-trimethoxysilan und Methyltriethoxysilan im Gewichtsverhältnis 2 : 1)
   • als Flüssigkeit lt. Tabelle
   • als "Dry Liquid" mit Fällungskieselsäure It. Tabelle (ULTRASIL® VN3) als Trägerstoff

Functional organylorganyloxysilanes:

1. (1) 3-aminopropyltriethoxysilane (DYNASYLAN® AMEO)
2. (2) N-ethylamino-3-aminopropyltrimethoxysilane (DYNASYLAN® DAMO)
3. (3) DYNASYLAN® 1291 (Mixture of 3-aminopropyltrimethoxysilane and methyltriethoxysilane in a weight ratio of 2: 1)
   • as a liquid according to the table
   • as "Dry Liquid" with precipitated silica It. Table (ULTRASIL® VN3) as carrier

The compounding is carried out in a twin-screw extruder, type ZE 25, Berstorff, Hannover, DE (UD ratio = 33, screw diameter 25 mm, 125 rpm). First, the base polymer EVA is dried in an air circulating oven at 60 ° C for one hour. When using liquid silane, this is added to the dried EVA and absorbed therein within one hour. If the silane is used as a "dry liquid", the EVA is mixed with it. The stabilizer is mixed with the ATH. EVA / silane on the one hand and ATH / stabilizer on the other hand are dosed gravimetrically into the extruder. The extruder temperature increases from the addition to the screw end of 135 to 170 ° C. The residence time is a maximum of 150 seconds. Strips are extruded from which test specimens are produced.

The following values were determined on the test specimens according to the following instructions: tensile strenght [N / mm], determined after EN ISO 527 elongation [%] determined after EN ISO 527 tear strength [N / mm], determined after EN ISO 527 water absorption [mg / cm ² ], determined by weighing

The following Table 2 shows the proportions and the results obtained. The parts are parts by weight. <b> Table 2 </ b> silane liq. [Tle.] "Dry Liquid" test results Silane content [%] Quantity [Tl.] Tensile strength [N / mm] Elongation at break [%] Tear strength [N / mm] Water uptake [mg / cm ² ] (1) 1.5 - - 16.3 210 10.2 4.02 (1) - 75 2 16.5 215 10.0 3.96 (2) 1.5 - - 17.3 220 10.9 3.85 (2) - 60 2.5 17.7 215 10.5 3.81 (3) 1.5 - - 16.6 226 12.4 3.40 (3) - 75 2 16.8 222 12.7 3.34

The values obtained with liquid silane and the values with silane on carrier are comparable. The advantage of the easier handling of the "dry liquids" is therefore not paid for by worse characteristics of the cable compounds.

Claims (11)

1. The use of (1) a liquid functional organylorganyloxysilane reversibly bound to a carrier, or of a liquid (co)condensate derived from a functional organylorganyloxysilane and reversibly bound to a carrier for preparing cable compounds which comprise (2) a thermoplastic base polymer having polar functional groups and (3) a reinforcing or extending mineral filler.
2. The use according to claim 1,
   characterized in that
   the carrier is pyrogenic silica.
3. The use according to claim 1,
   characterized in that
   the carrier is precipitated silica.
4. The use according to claim 1,
   characterized in that
   the carrier is calcium silicate.
5. The use according to claim 1,
   characterized in that
   the carrier is a wax.
6. The use according to claim 5,
   characterized in that
   the wax is an LDPE-based polyolefin wax.
7. The use according to any one of claims 1 to 6,
   characterized in that the functional organylorganyloxysilane is an aminoorganylorganyloxysilane, if desired N-substituted by one or two alkyl radicals each having from 1 to 6 carbon atoms.
8. The use according to claim 7,
   characterized in that
   the functional organylorganyloxysilane is used in the form of a (co)condensate with nonfunctional organylorganyloxysilanes with a weight-average molecular weight of up to 10,000.
9. The use according to any one of claims 1 to 8,
   characterized in that
   the base polymer is polyvinyl chloride or a copolymer made from one or more olefins and one or more comonomers which contain polar groups.
10. The use according to any one of claims 1 to 8,
    characterized in that the mineral filler is a metal hydroxide having a stoichiometric or substoichiometric proportion of hydroxyl groups or a metal oxide with residual hydroxyl groups.
11. A mixture for preparing a cable compound which comprises (1) a liquid functional organylorganyloxysilane reversibly bound to a carrier, or a liquid (co)condensate derived from a functional organylorganyloxysilane and reversibly bound to a carrier, (2) a thermoplastic base polymer having polar functional groups and (3) a reinforcing or extending mineral filler.