Power cable containing thermoplastic and electric insulating layer with voltage stabiliser

FIELD: electricity.

SUBSTANCE: invention is related to a cable for transportation and distribution of medium- and high-voltage energy. The cable (1) comprises at least one electrical conductor (2) and at least one electric insulating layer surrounding the above electrical conductor, at that this electric insulating layer (4) contains: (a) thermoplastic polymer material selected from at least one propylene copolymer (i) with at least one olefine comonomer selected from ethylene and α-olefin, not being propylene, at that the above copolymer has melting point higher or equal to 130°C and enthalpy of melting from 20 up to 90 J/g; mixture of at least one copolymer (i) with at least one ethylene copolymer (ii) with at least one α-olefin, at that the above copolymer (ii) has enthalpy of melting from 0 up to 70 J/g; mixture of at least one propylene homopolymer with at least one copolymer (i) or copolymer (ii); at that at least one of copolymer (i) and copolymer (ii) is a heterophase copolymer; (b) at least one dielectric liquid mixed thoroughly with thermoplastic polymer material, at that the above at least one dielectric liquid is aromatic dielectric liquid with the ratio of carbon aromatic atoms number towards the total number of carbon atoms is higher or equal to 0.3; (c) at least one voltage stabiliser selected from substituted bensophenones and hindered amines.

EFFECT: invention improves breakdown strength of the cable dielectric.

20 cl, 2 tbl, 1 dwg

 

Background of the invention

The present invention relates to a power cable. In particular, the present invention relates to a cable for transporting or distributing electricity, especially electricity medium or high voltage, and the said cable has at least one thermoplastic insulating layer.

Cables to transmit electricity typically contain at least one cable core. Cable lived usually formed of at least one conductor, consistently covered the inner polymer layer having semiconducting properties, the intermediate polymer layer having electrically insulating properties, the outer polymer layer having semiconducting properties. Cables for electricity transport medium or high voltage, typically have at least one cable core surrounded by at least one shielding layer, typically made of metal or of metal and polymer material. The shielding layer can be made in the form of wire (braid), tape spirally wrapped around the cable core, or sheet, longitudinally surrounding the cable core. Polymer layers surrounding the mentioned at least one conductor, usually made of cross-linked polymer based on the polyolefin, in particular, the C cross-linked polyethylene (XLPE), or elastomeric copolymers of ethylene/propylene (EPR) or ethylene/propylene/diene (EPDM), also made, as described, for example, in WO 98/52197. The step of stitching is carried out after the extrusion of polymeric material on the conductor, gives the material with satisfactory mechanical and electrical properties even at high temperatures as in continuous use, and current overload.

To meet the requirements of materials that should not be harmful to the environment either in obtaining or in the application and which shall be suitable for processing at the end of the service life of the cable, have been recently developed power cables, lived of which are made from thermoplastic materials, i.e., polymeric materials, which are not crosslinked and which therefore can be returned into circulation at the end of the service life of the cable.

In this regard, electrical cables containing at least one coating layer, for example, the insulation layer, based on the polypropylene matrix, thoroughly mixed with a liquid dielectric, known and described in WO 02/03398, WO 02/27731, WO 04/066317, WO 04/066318, WO 07/048422 and WO 08/058572. Polypropylene matrix, suitable for cables of this type contains a homopolymer or copolymer of polypropylene or both, is characterized by a relatively low degree of crystallinity, so that KAB is Liu suitable flexibility, but not to degrade the mechanical properties and resistance to armodafinil at operating temperatures and overloading of the cable. On the operational characteristics of the coating of the cable, in particular an insulating layer of the cable is also influenced by the presence of the dielectric fluid, thoroughly mixed with the above-mentioned polypropylene matrix. A dielectric fluid should not affect the mentioned mechanical properties and resistance to armodafinil and should be to thoroughly and uniformly mixed with the polymer matrix.

In the field of power cables having as the insulating layer crosslinked polyolefin composition, for example, cross-linked polyethylene (XLPE) or crosslinked elastomeric copolymers of ethylene/propylene (EPR) or ethylene/propylene/diene (EPDM), it is known that to improve the electrical characteristics, in particular, dielectric strength, the material forming the insulating layer, add a small amount of additives, commonly known as "voltage regulators", which should be able to reduce negative effects on the dielectric strength caused by defects, such as voids, protrusion and pollutants which usually occur in the insulating layer during extrusion.

For example, international patent application WO 01/08166 relates to electric cables having at least one ring is operating the covering layer based on a polyolefin, in particular, is made of XLPE, which contains at least one voltage regulator, representing benzophenone, substituted by at least one group selected from alkyl, arylalkyl and alkylaryl, and referred to the group: a) linked to the phenyl ring of the benzophenone directly or through an oxygen bridge (-O -); (b) contains the optional one or more oxygen bridge (-O -), and c) optional linked to the phenyl ring by at least one other benzophenone group, provided that, when the said at least one group is an alkyl, optionally substituted, the carbon atom of the above alkyl, which is directly linked to the phenyl ring mentioned benzophenone is tertiary. Above benzophenone derivatives practically inert to commonly used cross-linking agents such as organic peroxides, thus preventing the phenomenon of inhibition of the crosslinking reaction and/or the alteration or destruction of the additive in the process of knitting.

U.S. patent No. 4870121 refers to the product or device used in high-voltage (HV) applications, and the device comprises a polymeric dielectric material, usually not exposed to sunlight. The dielectric material contains ultraviolet (UV) stabilizer, etc is sustuli in sufficient quantity, to slow the decomposition of the polymer material due to UV radiation generated by the electric field, a portable device, and thereby extend the time before the formation of tree-like conductive track (electric trying) in the dielectric. The resistance of trying is facilitated and enhanced by lowering the concentration of oxygen in the material. The device may be a device selected from the group consisting of underground cables, submarine cables, HV circuit breakers, transformers, capacitors and other equipment, insulation which is usually not experiencing the sunshine. Polymer dielectric material contained in the device, preferably selected from the group consisting of: polyolefins such as low density polyethylene, or a ternary copolymer of ethylene-propylene-diene (EPDM), ethylene-propylene rubber and epoxy resin. UV stabilizer selected from the group consisting of: benzotriazole, light stabilizers based on sterically obstructed amines, chelates of Nickel and substituted benzophenone.

The invention

The applicant has faced the problem of improving the electrical characteristics of the power cables, in particular in relation to the strength of the dielectric breakdown, especially when the applications for high-voltage (HV) transmission, with the quality of the ve insulating layer thermoplastic coating on the basis of polypropylene, thoroughly mixed with the liquid dielectric.

In order to solve the above problem, the applicant has considered the possibility of adding insulating layer additive, which acts as a voltage regulator, but does not affect other properties of the insulating material and, in particular, do not have a negative impact on the fragile balance of properties achieved by a combination of thermoplastic polymer with a liquid dielectric.

The applicant has found that by adding a stabilizer selected from substituted benzophenone and sterically obstructed amines, in the insulating layer based on a thermoplastic polymer material, thoroughly mixed with a liquid dielectric, it is possible to achieve the desired and for other purposes, if the dielectric fluid is an aromatic liquid dielectric, in which the ratio of the number of aromatic carbon atoms to the total number of carbon atoms greater than or equal to 0.3.

Not being tied to any theory to explain the present invention, assume that the above compounds are particularly effective as voltage stabilizers for insulating materials based on polypropylene, as they are very well soluble in the above aromatic liquid dielectric, so they are able to migrate through the insulation material, with the benefits of the Oh taking advantage of the dielectric fluid as a medium, to reach and fill the microscopic defects responsible for premature electrical breakdown.

Thus, according to the first aspect of the present invention relates to a cable containing at least one electrical conductor and at least one insulating layer surrounding the mentioned electrical conductor, and the at least one insulating layer includes:

(a) a thermoplastic polymer material selected from:

at least one copolymer (i) of propylene with at least one olefin with co monomer selected from ethylene and α-olefin, non-propylene, and the above-mentioned copolymer has a melting point equal to or greater than 130°C, and the enthalpy of fusion of from 20 j/g to 90 j/g;

- a mixture of at least one copolymer (i) at least one copolymer (ii) of ethylene with at least one α-olefin, and the above-mentioned copolymer (ii) has an enthalpy of fusion of 0 j/g to 70 j/g;

- a mixture of at least one homopolymer propylene with at least one copolymer (i) or copolymer (ii);

and at least one copolymer (i) and copolymer (ii) is a heterophase copolymer;

(b) at least one liquid dielectric, thoroughly mixed with a thermoplastic polymer material, and upon is wrapped at least one liquid dielectric is aromatic liquid dielectric with respect to the number of aromatic carbon atoms to the total number of carbon atoms, greater than or equal to 0.3;

(c) at least one stabilizer selected from substituted benzophenone and sterically obstructed amines.

For the purposes of the present description and the subsequent claims, unless explicitly stated otherwise, all numbers expressing quantities, values, interest, etc., should be understood as modified in all instances by the term "about". All ranges include any combination of the detected maximum and minimum values and include any intermediate ranges, which may or may not be specifically listed.

In the present description and in the subsequent claims under the "conductor" refers to a conductive element, usually made of a metallic material, preferably aluminum, copper or their alloys, or in the form of a rod or rod or twisted stranded wire, or a conductive element which is above, is covered with a semi-conducting layer.

For the purposes of the invention, the term "medium voltage" generally means a voltage in the range from 1 kV to 35 kV, while the "high voltage" means a voltage above 35 kV.

Under the "insulating layer" refers to a coating layer from a material having insulating properties, namely having a dielectric strength (dielectric strength, the battle) of at least 5 kV/mm, preferably above 10 kV/mm

Under the "semiconductor layer" refers to a coating layer made of a material having semi-conducting properties, such as polymer matrix with such additives, for example, carbon black, to obtain a volume resistivity at room temperature below 500 Ohm·m, preferably below 20 Ohm·m Typical amount of carbon black can be from 1 to 50 wt. -%, preferably from 3 to 30 wt%. by weight of the polymer.

Under "heterophase copolymer" means a copolymer in which the elastomeric region, for example, ethylene-propylene elastomer (EPR), distributed in a matrix of homopolymer or copolymer of propylene.

Preferably thermoplastic polymer material (a) has a melt flow index (MFI), measured according to ASTM D1238-00 at 230°C under a load of 21.6 N, 0.05 DG/min to 10.0 DG/min, more preferably from 0.4 DG/min to 5.0 DG/min

Olefinic of comonomer in the copolymer (i) may be ethylene or α-olefin of the formula CH2=CH-R, where R is a linear or branched C2-C20alkyl selected from, for example, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-mission 1-dodecene or mixtures thereof. Particularly preferred copolymers of propylene/ethylene.

Olefinic of comonomer in the copolymer (i) is preferably present in quantities equal to or smaller than 15 mol%, more preferably equal to or smaller than 10 mol%.

Olefinic of comonomer in the copolymer (ii) can be an olefin of the formula CH2=CHR, where R is a linear or branched alkyl group containing from 1 to 12 carbon atoms. Preferably the said olefin is selected from propylene, 1-butene, isobutylene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-dodecene or mixtures thereof. Particularly preferred propylene, 1-hexene and 1-octene.

According to a preferred implementation variant, the copolymer (i) or copolymer (ii) are statistical copolymers. Under "statistical copolymer" means a copolymer in which the comonomers are randomly distributed along the polymer chain.

Mainly in the copolymer (i) or copolymer (ii) or both of them, when he(and the) one(s)heterophase(and), the elastomeric phase is present in amounts greater than or equal to 45% of the mass. the total weight of the copolymer.

Especially preferred heterophase copolymers of (i) or (ii) are those in which the elastomeric phase consists of an elastomeric copolymer of ethylene and propylene containing from 15% of the mass. up to 50% of the mass. ethylene and from 50 wt%. up to 85% of the mass. propylene based on the weight of the elastomeric phase.

The preferred copolymers (ii) are the heterophase propylene copolymers, in particular:

(ii-a) copolymers having the following monomial the RNA composition: 35-90 mol%. ethylene; 10-65 mol%. aliphatic α-olefin, preferably propylene; 0-10 mol%. polyene, preferably diene, more preferably 1,4-hexadiene or 5-ethylene-2-norbornene (this category includes rubber EPR and EPDM);

(ii-b) copolymers having the following monomer composition: 75-97% mol., preferably 90-95 mol%. ethylene; 3-25 mol%, preferably 5-10 mol%. aliphatic α-olefin; 0-5 mol%, preferably 0-2 mol%. polyene, preferably diene (for example, copolymers of ethylene/1-octene).

Heterophase copolymers can be obtained by sequential copolymerization of: 1) propylene, possibly containing minor amounts of at least one olefinic co monomer selected from ethylene and α-olefin, non-propylene; and then 2) a mixture of ethylene with α-olefin, in particular propylene, optionally with a minor proportion of Polyana.

The term "Polian" usually means a conjugate or non-conjugate diene, triene or tetraen. When the diene is present in comonomer, this comonomer usually contains from 4 to 20 carbon atoms and is preferably selected from: linear conjugate or non-conjugate of diolefins, such as, for example, 1,3-butadiene, 1,4-hexadiene, 1,6-octadien etc.; monocyclic or polycyclic dienes, such as 1,4-cyclohexadiene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, vinile borne or mixtures thereof. When there is Tranby or terenowy comonomer, this comonomer typically contains from 9 to 30 carbon atoms and is preferably selected from trienol or tetraene containing the vinyl group in the molecule or 5-norbornene-2-strong group in the molecule. Particular examples of tranovich or tetraenoic of comonomers that can be used in the present invention are: 6,10-dimethyl-1,5,9-undecatrien, 5,9-dimethyl-1,4,8-decatriene, 6,9-dimethyl-1,5,8-decatriene, 6,8,9-trimethyl-1,6,8-decatriene, 6,10,14-trimethyl-1,5,9,13-pentadecatriene or mixtures thereof. Preferably Polian is a diene.

Preferably the copolymer (i), the copolymer (ii) or both have a melting point from 140°C to 180°C.

Preferably the copolymer (i) has an enthalpy of fusion of 25 j/g to 80 j/g

Preferably the copolymer (ii) has an enthalpy of fusion of 10 j/g to 30 j/g

Mainly, when thermoplastic material of the insulating layer contains a mixture of the copolymer (i) and copolymer (ii), the latter has a lower enthalpy of melting point than the first.

Mainly, when thermoplastic material of the insulating layer contains a mixture of the copolymer (i) and copolymer (ii), the ratio between the copolymer (i) and copolymer (ii) is from 1:9 to 8:2, preferably from 2:8 to 7:3.

Mainly, when thermoplastic material of the insulating layer contains a mixture of g is of sopolimera propylene and at least one copolymer (i) and copolymer (ii), the ratio between homopolymer propylene and the copolymer (i) or copolymer (ii) or both is from 0.5:9.5 to 5:5, preferably from 1:9 to 3:7.

As for the dielectric fluid (b), there is a high compatibility between the liquid dielectric and the material on the polymeric base necessary to obtain microscopically homogeneous dispersion liquid of dielectric material on a polymer basis. A dielectric fluid, suitable for forming the coating layer of the cable according to the present invention should not contain polar compounds or may contain only a limited number of them, in order to avoid a significant increase in dielectric loss.

Preferably the weight concentration of the mentioned at least one liquid dielectric in said thermoplastic polymer material is lower than the saturation concentration mentioned liquid dielectric in said thermoplastic polymer material. The concentration of the saturated liquid dielectric thermoplastic polymer material can be measured by the method of absorption of liquid samples for testing in the form of bilateral shoulder blades, as described, for example, in WO 04/066317.

When using a liquid dielectric in a higher amount of stored thermomechanical properties of the insulating layer and prevents fluid selection the first dielectric thermoplastic polymer material.

The mentioned at least one liquid dielectric is usually compatible with thermoplastic polymer material. "Compatible" means that the chemical composition of the dielectric and thermoplastic polymer material is to cause a microscopically homogeneous dispersion liquid of dielectric polymeric material after contact dielectric strength of the polymer, similar to the plasticizer.

Typically, the weight ratio between the said at least one liquid dielectric (b) and thermoplastic polymer material (a) may be from 1:99 to 25:75, preferably from 2:98 to 15:85.

It should also be noted that the use of liquid dielectric with a relatively low melting point or low temperature fluidity (for example, with a melting point or temperature yield strength not higher than 80°C) allows easy handling of liquid dielectric, which can be fused without the need for additional and complex technological stages (for example, the step of melting the dielectric fluid) and/or devices for mixing the fluid with the polymer material.

According to the following preferred implementation variant the dielectric liquid has a melting point or temperature fluidity from -130°C to +80°C.

The melting temperature can be determined by the known methods such as, for example, analysemethoden differential scanning calorimetry (DSC).

According to the following preferred implementation variant a dielectric fluid has a predetermined viscosity in order to prevent the rapid diffusion of the liquid in the insulating layer and, therefore, its outward migration, as well as to the dielectric liquid can be easy to apply and blend with a thermoplastic polymeric material. Typically, the dielectric liquid according to the invention has a viscosity at 40°C from 10 cSt to 800 cSt, preferably from 20 cSt to 500 cSt (measured according to ASTM D445-03).

The number of aromatic carbon atoms refers to the number of carbon atoms that are part of an aromatic ring.

A dielectric fluid according to the invention has the ratio of the number of aromatic carbon atoms to the total number of carbon atoms (also referred to below as Car/Ctot) greater than or equal to 0.3. Preferably Car/Ctotbelow 1. For example, Car/Ctotranges from 0.4 to 0.9.

The ratio of the number of aromatic carbon atoms to the total number of carbon atoms in liquid dielectrics according to the invention is a measure of the aromaticity. As will be seen later in the description, only in the presence of the dielectric fluid with a degree of aromaticity voltage stabilizers according to the invention is able to perform its function.

The ratio of the number of aromatic carbon atoms to p is lnmu the number of carbon atoms can be defined according to the standard ASTM D3238-95(2000)e1.

Liquid dielectrics, particularly preferred for implementing the present invention, are having an aniline point equal to or less than 50°C. In this case, the aniline point is the minimum temperature for complete Miscibility of equal volumes of aniline and the sample - liquid dielectric. Preferably, the dielectric liquid according to the invention had an aniline point of not lower than -50°C.

Examples of suitable liquid dielectrics are: aromatic oils, monocyclic, polycyclic (condensed or not) or heterocyclic (i.e., containing at least one heteroatom selected from oxygen, nitrogen or sulfur, preferably oxygen), and aromatic or heteroaromatic fragments substituted by at least one alkyl group of C1-C20and mixtures thereof. When there are two or more cyclic fragment, such fragments can be linked alkenylphenol group C1-C5.

For example, the dielectric liquid comprises at least one alcylaryl hydrocarbon having the structural formula (I):

where R1, R2, R3and R4identical or different, represent hydrogen or methyl;

n1and n2identical or different, are zero, 1 or 2 provided that the sum of n1+n 2less than or equal to 3.

In another example, the dielectric liquid comprises at least one simple diphenyl ether having the following structural formula:

where R5and R6are identical or different and denote hydrogen, phenyl group, unsubstituted or substituted by at least one alkyl group, or alkyl group, unsubstituted or substituted by at least one phenyl. Under alkyl group means a linear or branched hydrocarbon radical C1-C24preferably C1-C20provided that the ratio of the number of aromatic carbon atoms to the total number of carbon atoms greater than or equal to 0.3.

Suitable dielectric fluid for use in the cable according to the invention are described, for example, in WO 02/027731 and WO 02/003398, both for the applicant's name.

Voltage stabilizer according to the present invention can be selected from substituted benzophenone and sterically obstructed amines.

Examples of the substituted benzophenone, suitable for use in the present invention are: 2,2'-dihydroxy-4,4'-dacryocystitis, 2,4-dihydroxybenzophenone, 4,4'-dihydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 4,4'-dimethoxybenzophenone, 2,4'-dimethylbenzophenone, 3,4'-dimethylbenzidine is, 3,4-dimethylbenzophenone, 2.5-dimethylbenzophenone, 4,4'-dimethylbenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzylamine, 2-hydroxy-4-alloxanthine, 2-hydroxy-4-octyloxybenzophenone, 2-hydroxy-4-alliancebernstein, 2,3,4,4'-tetrahydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,2',4-trihydroxybenzophenone, 2,3,4'-trihydroxybenzophenone, 2,4,4'-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,3,4-trimethoxybenzoate, 2,4,5-trimethoxybenzene, 2,4,6-trimethoxybenzene and mixtures thereof.

With regard to the position of Deputy, it is particularly preferred 2-substituted benzophenone. With regard to the nature of the substituent, it is particularly preferred hydroxybenzophenone.

According to one particularly preferred variant of the implementation of the said at least one stabilizer selected from 2-hydroxybenzophenones.

Steric dull amines, are particularly preferred for the present invention are, in particular, derivatives of 2,2,6,6-tetramethylpiperidine. Examples of suitable sterically obstructed amines are:

bis(2,2,6,6,-tetramethyl-4-piperidyl)sebacate;

poly[[6-[(1,1,3,3-TETRAMETHYLBUTYL)amino]-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidinyl)imino]-1,6-hexandiol[(2,2,6,6-tetramethyl-4-piperidinyl)-imino]]);

the polymer of 1,6-hexanediamine,N,N'-bis(2,2,6,6-tetramethyl-4-Pieper is dinyl) with 2,4,6-trichloro-1,3,5-triazine, the reaction products with N-butyl-1-butanamine and N-butyl-2,2,6,6-tetramethyl-4-piperidylamine (CAS 192268-64-7);

1,3,5-triazine-2,4,6-triamine,N,N"'-[1,2-atanderson[[[4,6-bis[butyl(1,2,2,6,6-pentamethyl-4-piperidinyl)amino]-1,3,5-triazine-2-yl]imino]-3,1-probandi-yl]] bis-[Ν',Ν"-dibutil-N',N"-bis(1,2,2,6,6-pentamethyl-4-piperidinyl)- (CAS 106990-43-6);

the polymer dimethylsuccinic with 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinemethanol;

bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidinyl)sebacate

and mixtures thereof.

Preferably, the aforementioned at least one voltage stabilizer is present in the insulating layer in an amount of from 0.05 to 5 wt. -%, more preferably from 0.1 to 2% of the mass. the total weight of the insulating layer.

In thermoplastic resin material according to the present invention it is possible to add other components in small quantities, such as antioxidants, processing AIDS, moderators water trying or mixtures thereof.

Conventional antioxidants suitable for this purpose are, for example, DISTEARYL or dilaurentiis, pentaerythrityl-tetrakis[3-(3,5-decret-butyl-4-hydroxyphenyl) propionate], or a mixture thereof.

Technological additives that can be added to the polymer composition include, for example, calcium stearate, zinc stearate, stearic acid or mixtures thereof.

According to one preferred VA is Ianto implementation of the cable according to the present invention also includes at least one semi-conducting layer. Semi-conducting layer is preferably formed of semi-conductive material containing the above components (a) and (b) and optionally at least one stabilizer (c) at least one conductive filler (d), preferably a particulate filler.

Adding a voltage regulator according to the invention in a semi-conducting material layer does not change significantly the electrical characteristics of the layer, but may provide an additional contribution to the stabilization voltage of the insulating layer, in particular, to the nearest boundary.

The mentioned at least one conductive filler is usually dispersed in a thermoplastic polymeric material in such quantity to give the semi-conducting material properties, namely, to obtain the value of the volume resistivity at room temperature is less than 500 Ω·m, preferably less than 20 Ohm·m Typical amount of carbon black can be from 1 to 50 wt. -%, preferably from 3 to 30 wt%. by weight of the polymer.

Using the same base polymer composition and the insulating layer and semiconductor layers is particularly advantageous in the manufacture of cables for medium or high voltage, because this provides excellent adhesion between adjacent layers, and thus good electrical x is tion, especially at the interface between the insulating layer and the inner semi-conducting layer, where the electric field and, consequently, the risk of partial discharges above.

Polymeric composition for a cable according to the present invention can be obtained by mixing together a thermoplastic polymer material, a liquid dielectric, voltage regulator, and any other optional additives, using methods known in the art. Mixing can be effected, for example, an internal mixer type mixer Bunbury (with tangential rotors) or mixers with penetrating rotors; in continuous mixers of the type sophistication (firm BUSS), twin-screw type with screws rotating in the same or different parties, or in a single screw extruder.

According to one preferred variant of realization of the dielectric liquid can be added to thermoplastic polymer material during extrusion by direct injection into the cylinder of the extruder, as described, for example, in international patent application WO 02/47092 on the applicant's name.

Although the present description focuses mainly on the cables for the transportation or distribution medium or high voltage polymer compositions according to the invention can be used to cover electrical condition is of hardware in General, and in particular, cables of different types, for example, low-voltage cables (i.e. cables carrying voltages below 1 kV), telecommunication cables, or combined power/telecommunications cables, or accessories used in electrical lines, such as terminals, terminals, electrical joints, connectors, etc.

Brief description of drawings

Further features will appear from the detailed description below with reference to the attached drawing, on which Fig.1 shows a perspective view of the proposed invention the power cable, especially suitable for medium or high voltage.

A detailed description of the preferred implementation options

In Fig.1 cable (1) comprising a conductor (2), the inner layer (3) with semi-conducting properties, the intermediate layer (4) with the insulating properties of the outer layer (5) with semi-conducting properties of the metal shielding layer (6) and shell (7).

Conductor (2) usually consists of a metal wire, preferably of copper or aluminum or their alloys, twisted together in the usual ways, or solid aluminum or copper rod.

The insulation layer (4) can be obtained by extrusion around the conductor (2) the composition according to the present invention.

Semi-conducting layers (3) and (5) t is the train made by extrusion of polymeric materials, usually polyolefin, preferably a composition according to the present invention, which is made semi-conducting by adding at least one conductive filler, usually carbon black.

Around the outer semi-conducting layer (5) is usually placed metal shielding layer (6) made of electrically conductive wires or strips, spirally wound around the cable core, or from conductive tape longitudinally wrapped with overlapping (preferably glued) on the underlying layer. Conductive material mentioned wire, strip or tape is usually copper or aluminum or their alloys.

The shielding layer (6) can be coated (7), usually made of polyolefin, usually polyethylene.

The cable can also be fitted with a protective structure (Fig.1 not shown), the main purpose of which is to mechanically protect the cable from impact or compression. This protective structure may be, for example, a metal reinforcement or layer of foamed polymer as described in WO 98/52197 on the applicant's name.

The cable according to the present invention can be manufactured according to known methods, for example, by extrusion of various layers around the Central conductor. The extrusion of two or more layers, typically the military carry out in one go, for example, in a parallel process, when the individual extruders installed in series, or coextrudable with multiple extrusion heads. Then around the thus obtained cable conductor impose shielding layer. In conclusion, is applied to the membrane according to the present invention, typically an additional stage extrusion process.

The cable according to the present invention preferably is used to transmit electricity to alternating current (AC).

Fig.1 shows only one embodiment of the cable according to the invention. In this alternative implementation can be made appropriate changes in accordance with the specific technical needs and requirements of the application without deviating from the scope of invention.

The following examples are provided to further illustrate the invention.

Examples 1-5

Prepared with the following compositions, with quantities given in table 1 (expressed in % of the mass. the total weight of the composition).

In all the examples of the propylene copolymer was applied directly into the hopper of the extruder. Then the dielectric liquid, pre-mixed with antioxidants and voltage stabilizer (if available), were injected under high pressure into the extruder. Used extruder with a diameter of 80 mm and a ratio L/D of 25. Injection during extrusion was performed n is approximately 20D from the beginning of the auger extruder through three points of injection, located on the same section at an angle of 120° to each other. The dielectric liquid was injectively at 70°C and a pressure of 250 bar.

Table 1
Example1(*)234(*)5(*)
Polypropylene blend94,093,593,594,093,5
Marlotherm™ SHthe 5.7the 5.7the 5.7--
Nyflex™ 210B---the 5.7the 5.7
Chimassorb™ 944-0,5--0,5
Chimassorb™ 81--0,5 --
Antioxidant0,30,30,30,30,3
(*) comparative

Propylene mixture: a mixture of 25/75 statistical copolymer of propylene-ethylene (enthalpy of melting of 65.1 j/g) and heterophase copolymer polypropylene (enthalpy of fusion of 30 j/g);

Marlotherm™ SH: dibenzyltoluene (DBT), the ratio of aromatic carbon atoms to all atoms of carbon = 0,86 (Sasol Olefins &Surfactants GmbH);

Nyflex™ 210B: naphthenic oil (3% of the mass. aromatic carbon atoms, 41% of the mass. naphthenic carbon atoms, 56% of the mass. paraffin carbon atoms), the ratio of the number of aromatic carbon atoms to the total number of carbon atoms = 0,03 (Nynas AB);

Chimassorb™ 944: poly[[6-[(1,1,3,3-TETRAMETHYLBUTYL)amino]-1,3,5-triazine-2,4-diyl]-[(2,2,6,6-tetramethyl-4-piperidinyl)imino]-1,6-hexandiol[2,2,6,6-tetramethyl-4-piperidinyl)imino]]) (Mn=2000-3100):

Chimassorb™ 81: 2-hydroxy-4-(octyloxy) benzophenone:

Antioxidant: 4,6-bis(actitioner)-o-cresol.

Electric strength dielectric breakdown (DS) samples of cable (length 20 m), with an insulating layer on the basis of the compositions of examples 1-5, canevali in terms of AC. Dimension DS conducted with these samples cables alternating current frequency of 50 Hz, since the voltage of 50 kV and increasing in increments of 10 kV every 10 minutes until the emergence of perforations on a test specimen. Each measurement was repeated on three test samples. The values in table 2 are the arithmetic mean of the individual measured values.

Table 2
ExampleDielectric strength
(kV/mm)
1(*)50
258
358
4(*)50
5(*)40
(*) comparative

The cables of examples 1 and 4 had insulation that contains no stabilizer. The insulation of the cable 1 contains a dielectric fluid with a Car/Ctotabove 0.3 according to the invention, while the insulation of the cable 4 contains a dielectric fluid with a Car/Ctotless than 0.3, however, these cables had almost the same dielectrics the Yu strength, which, apparently, is not affected by the relation Car/Ctotin the liquid dielectric. Cables in examples 2 and 3 had insulation containing a dielectric fluid with a Car/Ctotabove 0.3, according to the invention, and the voltage stabilizer according to the invention (substituted benzophenone in the case of cable 3 and a sterically hindered amine in the case of cable 2). Dielectric strength of both cables 2 and 3 was significantly improved in comparison with cable 1 (in which the insulation contains the same liquid dielectric, but without voltage regulator). The cable of example 5 had insulation containing a dielectric fluid with a Car/Ctotless than 0.3, and the voltage stabilizer is a sterically hindered amine. The dielectric strength of the cable 5 is unexpectedly lower than that of the cable 4 (with insulation containing the same liquid dielectric, but without voltage regulator).

Voltage stabilizers according to the invention can improve the dielectric strength of the cable having an insulating layer based on a thermoplastic material mixed with a liquid dielectric, as in the present invention, only if the dielectric fluid has a Car/Ctotabove 0.3.

1. A cable containing at least one electrical conductor and at least one insulating layer, OCD is concerned with the aforementioned electrical conductor, moreover, the aforementioned at least one insulating layer includes:
(a) a thermoplastic polymer material selected from:
at least one copolymer (i) of propylene with at least one olefin with co monomer selected from ethylene and α-olefin, non-propylene, and the above-mentioned copolymer has a melting point equal to or greater than 130°C, and the enthalpy of fusion of from 20 j/g to 90 j/g;
- a mixture of at least one copolymer (i) at least one copolymer (ii) of ethylene with at least one α-olefin, and the above-mentioned copolymer (ii) has an enthalpy of fusion of 0 j/g to 70 j/g;
- a mixture of at least one homopolymer propylene with at least one copolymer (i) or copolymer (ii);
and at least one copolymer (i) and copolymer (ii) is a heterophase copolymer;
(b) at least one liquid dielectric, thoroughly mixed with a thermoplastic polymer material, and the aforementioned at least one liquid dielectric is aromatic liquid dielectric with respect to the number of aromatic carbon atoms to the total number of carbon atoms greater than or equal to 0.3;
(c) at least one stabilizer selected from substituted benzophenone and sterically obstructed amines.

2. The cable under item 1, and the copolymer (i) is a copolymer of propylene/ethylene.

3. The cable under item 1, and the copolymer (i) or copolymer (ii) or both of them, when he(and the) one(s)heterophase(and), the elastomeric phase is present in a quantity equal to or greater 45% of the mass. the total weight of the copolymer.

4. The cable under item 1, and the copolymer (i) has an enthalpy of fusion of 25 j/g to 80 j/g

5. The cable under item 1, and the copolymer (ii) has an enthalpy of fusion of 10 j/g to 30 j/g

6. The cable under item 1, and the aforementioned at least one liquid dielectric (b) is the ratio of the number of aromatic carbon atoms to the total number of carbon atoms is less than 1.

7. The cable under item 6, and the aforementioned at least one liquid dielectric (b) is the ratio of the number of aromatic carbon atoms to the total number of carbon atoms from 0.4 to 0.9.

8. The cable under item 1, and the aforementioned at least one liquid dielectric has an aniline point equal to or less than 50°C.

9. The cable under item 1, and the aforementioned at least one liquid dielectric is selected from monocyclic aromatic oils; fused or unfused polycyclic aromatic oils; aromatic heterocyclic oils containing at least one heteroatom selected from oxygen, nitrogen or sulfur; and mentioned mono-, poly - or heterocyclic aromatic fragments substituted by at least one alkyl group of C 1-C20, and mixtures thereof.

10. The cable under item 9, and mentioned at least one of the dielectric liquid comprises at least one alcylaryl hydrocarbon with the structural formula (I):

where R1, R2, R3and R4identical or different, represent hydrogen or methyl;
n1and n2identical or different, are zero, 1 or 2 provided that the sum of n1+n2less than or equal to 3.

11. The cable under item 9, and mentioned at least one liquid dielectric contains at least one simple diphenyl ether having the following structural formula:

where R5and R6are identical or different and denote hydrogen, phenyl group, unsubstituted or substituted by at least one alkyl group, or alkyl group, unsubstituted or substituted by at least one phenyl.

12. The cable under item 1, and the aforementioned at least one voltage stabilizer (c) is selected from: 2,2'-dihydroxy-4,4'-dacryocystitis, 2,4-dihydroxybenzophenone, 4,4'-dihydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 4,4'-dimethoxybenzophenone, 2,4'-dimethylbenzophenone, 3,4'-dimethylbenzophenone, 3,4-dimethylbenzophenone, 2,5-dimethylbenzophenone, 4,4'-dimethyl what endovenosa, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxyphenylacetone, 2-hydroxy-4-alloxanthine, 2-hydroxy-4-octyloxybenzophenone, 2-hydroxy-4-alliancebernstein, 2,3,4,4'-tetrahydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,2',4-trihydroxybenzophenone, 2,3,4'-trihydroxybenzophenone, 2,4,4'-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,3,4-trimethoxybenzoate, 2,4,5-trimethoxybenzene, 2,4,6-trimethoxybenzene and mixtures thereof.

13. The cable under item 1, and the aforementioned at least one voltage stabilizer (c) is selected from 2-substituted benzophenone.

14. The cable under item 1, and the aforementioned at least one voltage stabilizer (c) is selected from hydroxybenzophenones.

15. The cable according to p. 14, and the aforementioned at least one stabilizer selected from 2-hydroxybenzophenones.

16. The cable under item 1, and the aforementioned at least one voltage stabilizer (c) is selected from sterically obstructed amines.

17. The cable according to p. 16, and the aforementioned at least one voltage stabilizer (c) is selected from: bis(2,2,6,6,-tetramethyl-4-piperidyl)sebacate, poly[[6-[(1,1,3,3-TETRAMETHYLBUTYL)amino]-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidinyl)imino]-1,6-hexandiol[(2,2,6,6-tetramethyl-4-piperidinyl)-imino]]); a polymer of 1,6-hexanediamine,N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl) with 2,4,6-trichloro-1,3,5-triazine, etc the products of the reaction with N-butyl-1-butanamine and N-butyl-
2,2,6,6-tetramethyl-4-piperidylamine (CAS 192268-64-7); 1,3,5-triazine-2,4,6-triamine,N,N"'-[1,2-ethane-diyl-bis[[[4,6-bis[butyl(1,2,2,6,6-pentamethyl-4-piperidinyl)amino]-1,3,5-triazine-2-yl]imino]-3,1-probandi-yl]] bis[N',N"-dibutil-N',N"-bis(1,2,2,6,6-pentamethyl-4-piperidinyl) (CAS 106990-43-6); polymer dimethylsuccinic with 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinemethanol; bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidinyl)sebacate and mixtures thereof.

18. The cable under item 1, and the aforementioned at least one voltage stabilizer (c) is present in an amount of from 0.05 to 5% wt. the total weight of the insulating layer.

19. The cable under item 1, and the aforementioned at least one voltage stabilizer (c) is present in an amount of from 0.1 to 2% of the mass. the total weight of the insulating layer.

20. The cable under item 1, having at least one semi-conducting layer containing at least one stabilizer selected from substituted benzophenone and sterically obstructed amines.



 

Same patents:

FIELD: chemistry.

SUBSTANCE: invention relates to polypropylene, a method for production thereof and a film capacitor made from said polypropylene. The polypropylene has a melting temperature (Tm) measured according to ISO 11357-3 of at least 151.0°C and xylene cold soluble fraction (XCS) of not more than 1.5 wt %. According to stepwise isothermal segregation technique (SIST) results, 45.0 to 67.0 wt % of the crystalline fraction has a lamella thickness in the range of 7.70 to 14.09 nm and 18.0 to 50.0 wt % of the crystalline fraction has a lamella thickness greater than 14.09 nm.

EFFECT: disclosed polypropylene has high heat resistance and enables to obtain biaxially oriented polypropylene (BOPP) and/or a film capacitor with high electrical breakdown strength and a high β parameter.

13 cl, 1 dwg, 9 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to a polyolefin composition with improved dielectric strength of insulation, to a wire or cable, in particular to a cable of middle, high or superhigh voltage, which includes such composition, as well as to application of such composition for production of wire or cable, in particular a cable of medium, high and superhigh voltage. Polyolefin composition contains polyolefin (A) and benzyl derivative (B) of a certain structure. Benzyl derivative (B) is used in the polyolefin composition as an additive for stabilisation of dielectric strength.

EFFECT: additive provides considerable improvement of dielectric strength, possesses good solubility in a polyolefin matrix and low predisposition to migration, and also possesses compatibility with respect to all other components of the polyolefin composition, in particular with cross-linking agents.

21 cl, 6 tbl, 5 ex

FIELD: chemistry.

SUBSTANCE: electrically insulating composition contains suspended polyvinyl chloride, an ester plasticiser, a lead stabiliser, diphenylol propane, chalk, stearic acid, calcium stearate, epoxidated soya bean oil, magnesium hydroxide, ammonium polyphosphate, chlorinated paraffins, antimony trioxide, zinc oxide, boric acid and organoclay.

EFFECT: low level of smoke emission in burning and glowing conditions while maintaining the degree of incombustibility.

2 cl, 1 tbl

FIELD: electricity.

SUBSTANCE: electric insulating composition includes suspension polyvinyl chloride, ester plasticiser, diphenyl propane, lead stabiliser, stearic acid, lubricating material, epoxidated soya oil, chlorinated paraffin, magnesium hydroxide, ammonia polyphosphate and organic clay.

EFFECT: invention makes it possible to produce a composition with lower combustibility, low release of smoke and hydrogen chloride during combustion, and to increase value of physical and mechanical characteristics.

1 tbl, 6 ex

FIELD: electricity.

SUBSTANCE: electroconductive peroxide cross-linkable composition comprises, wt %: polyolefin 49-62, benzopropionic acid 3,5-bis(1,1-dimethylethyl)-4-hydroxy-2-[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropyl] hydrazide -0.05-0.20, tetra-bis-methylene-(3-(3,5-di-tret-butyl-4-hydroxyphenyl) propionate)-0.05-0.20, organic peroxide-0.2-1.9, electroconductive technical carbon with specific volume resistance p=10±6 Ohm*cm - 29-34, technical carbon with specific volume resistance p=5±3 Ohm*cm - 2.5-5, 4,4'-thiabis(6-tret-butyl-m-cresol) - 0.05-0.25, zinc stearate - 0.15-1.0, polyethylene wax - 3-9. The composition of the specified compound is not exposed to substantial thermal-oxidative ageing and premature cross-linking during superimposition, and items from it have smooth surface.

EFFECT: improved physical and mechanical properties of cable products made with application of the proposed composition, and its manufacturability and stability.

2 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to electrical engineering, specifically to cable engineering and polymer compositions based on plasticised polyvinyl chloride (PVC) with low inflammability, release of smoke and hydrogen chloride during combustion, intended for insulating inner and outer sheaths of cables. The electrically insulating composition contains suspended polyvinyl chloride, an ester plasticiser - dioctyl phthalate, tricresyl phosphate, chalk, soot, a stabiliser - melanine, antipyrenes - magnesium hydroxide and ammonium polyphosphate, smoke absorber - chlorinated paraffins, lubricant agent - calcium stearate, antioxidant - diphenylol propane and filler - organoclay, which is a product of modifying montmorillonite from the Gerpegezh deposit of the Kabardino-Balkaria Republic with cation-exchange capacity of 95 mg-eq/100 g clay with urea, in amount of 10% of the mass of montmorillonite.

EFFECT: obtaining a composition characterised by high non-flammability and low release of smoke during combustion.

2 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to cable engineering and specifically to polymer compositions based on plasticised polyvinyl chloride (PVC) with low inflammability and release of smoke in combustion and smouldering conditions and release of hydrogen chloride during combustion, meant for insulating inner and outer sheaths of wires and cables used in high fire hazard conditions. The electrically insulating composition contains suspension polyvinyl chloride, an ester plasticiser, a lead stabiliser, calcium carbonate, a trihydrate of aluminium oxide or magnesium hydroxide, antimony trioxide, calcium stearate, zinc oxide, zinc borate, a bromine-containing fire retardant, boric acid and diphenylol propane.

EFFECT: invention improves fire safety of wires and cables, reduces smoke-formation during smouldering or combustion and provides low inflammability.

1 tbl, 15 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a heterophase polypropylene resin, a method of producing such a polypropylene resin and use thereof in making articles, particularly as material for making insulation and semiconductor layers of power cables. The heterophase polypropylene resin contains a matrix phase of a propylene radom copolymer and a rubber phase of an ethylene-propylene copolymer dispersed in the matrix phase. The heterophase polypropylene resin is characterised by melt flow rate (2.16 kg, 230°C) from 1.0 to 100 g/10 min, determined according to ISO 1133, and a fraction which is soluble in p-xylene at 25°C (XCS fraction), which is present in the resin in amount of 28 to 50 wt % and has molecular weight distribution (Mw/Mn) from 1.0 to 4.0.

EFFECT: heterophase polypropylene resin has high softness, improved low-temperature impact characteristics and a high melting point.

14 cl, 3 tbl, 6 ex

FIELD: chemistry.

SUBSTANCE: composition contains the following in pts.wt: suspended polyvinyl chloride 100, ester plasticiser 40-60, tribasic lead sulphate 3-7, calcium stearate 1-3, calcium carbonate 5-7, trihydrate of aluminium oxide and/or magnesium hydroxide 20-80, antimony trioxide 2-9, zinc oxide 1-5, ionol 0.1-0.5, zinc borate 0.5-6, diphenylol propane 0.1-0.5 percalite F 100 - 0-5 metal-containing lubricant 0.5-10, wherein the metal-containing lubricant is obtained by reacting oleic or stearic acid with glycerol in molar ratio 1:1 in the presence of 0.5-2.0 wt % of the total reaction mass of zinc oxide or magnesium oxide or two-component mixture thereof, with weight ratio thereof of 0.25-1.0:0.25-1.0 at 130-160°C and holding for 4-5 hours. High melt fluidity of the disclosed composition makes easier its processing in high-speed extruders.

EFFECT: low coefficient of smoke formation, high degree of incombustibility, processability of the composition and improved outer appearance of a bundle of the cable plastic compound.

1 tbl, 1 ex

FIELD: electrical engineering.

SUBSTANCE: method for production of insulated HV direct current (DC) eclectic cable or HV direct current (DC) eclectic cable or HV direct current (DC) lead or HV junction involves the stages of a polymer-based insulation system production (21), the system including a stirred polymer composition (12). Further thermal treatment (25) of the polymer-based insulation system is performed until the outside surface of the polymer-based insulation system is coated (24) with a coating impermeable for the substance present in the polymer-based insulation system as evenly distributed. Thus the concentration of the substance in the polymer-based insulation system is levelled.

EFFECT: manufacture time reduction, electric strength enhancement and maintenance simplification.

19 cl, 4 dwg

FIELD: electricity.

SUBSTANCE: invention is related to a cable for transportation and distribution of medium- and high-voltage energy. The cable (1) comprises at least one electrical conductor (2) and at least one electric insulating layer surrounding the above electrical conductor, at that this electric insulating layer (4) contains: (a) thermoplastic polymer material selected from at least one propylene copolymer (i) with at least one olefine comonomer selected from ethylene and α-olefin, not being propylene, at that the above copolymer has melting point higher or equal to 130°C and enthalpy of melting from 20 up to 90 J/g; mixture of at least one copolymer (i) with at least one ethylene copolymer (ii) with at least one α-olefin, at that the above copolymer (ii) has enthalpy of melting from 0 up to 70 J/g; mixture of at least one propylene homopolymer with at least one copolymer (i) or copolymer (ii); at that at least one of copolymer (i) and copolymer (ii) is a heterophase copolymer; (b) at least one dielectric liquid mixed thoroughly with thermoplastic polymer material, at that the above at least one dielectric liquid is aromatic dielectric liquid with the ratio of carbon aromatic atoms number towards the total number of carbon atoms is higher or equal to 0.3; (c) at least one voltage stabiliser selected from substituted bensophenones and hindered amines.

EFFECT: invention improves breakdown strength of the cable dielectric.

20 cl, 2 tbl, 1 dwg

FIELD: insulating materials for telecommunication cables.

SUBSTANCE: polyolefin insulation of conductors in hydrocarbon lubricant filled telecommunication cable which is then placed in junction box operating in the open is susceptible in particular to adverse impact of heat, oxygen, and moisture. In order to ensure reliable functioning of these conductors under mentioned conditions, use can be made of combination of one or more primary phenolic antioxidants chosen from N,N'-hexane-1.6-diilbis-(3(3.5-di-tertiary-butyl-4-hydroxyphenylpropionamide)), tris(3.5-di-tertiary-butyl-4-hydroxybenzyl)isocyanin-rhata, and tris(2-(3.5-di-tertiary-butyl-4-hydroxyhydrocinnamoyloxy)-ethyl)isocyanourate together wit one or more alkyl hydroxyphenyl alkanoylhydrazine metal deactivators.

EFFECT: enhanced oxidation resistance of polyolefin insulation of conductors.

8 cl, 1 tbl, 1 ex

FIELD: cable industry.

SUBSTANCE: proposed composition designed for insulating and sheathing cables and wires meant for operation under high fire hazard conditions incorporates following ingredients, parts by weight: suspension polyvinyl chloride, 100; ester plasticizer, 30 - 70; tribasic lead sulfate, 2 - 6; calcium carbonate, 20 - 300; zinc oxide, 0.5 - 10; aluminum oxide trihydrate, 20 - 70; antimony trioxide, 3 - 8; zinc borate, 0.5 - 8; zinc stearate, 0.25 - 4. Zinc borate and stearate introduced in definite proportion into proposed composition have made it possible to improve fire-safety characteristics of the latter.

EFFECT: reduced emission of smoke and hydrogen chloride in burning, enhanced degree of inflammability.

1 cl, 1 tbl

FIELD: electrical engineering.

SUBSTANCE: proposed polymeric insulating composition given in description of invention together with description of cables and wires covered with such composition to ensure their excellent performance in service has 60 to 90 mass percent of copolymer A of ethylene and α-olefin produced by copolymerization with aid of concentric catalyst and 40 to 10 mass percent of polyolefin resin B other than copolymer A and includes polyolefin incorporating grafted substituents with dipole moment 4 D or higher. One of alternative compositions uses semiconducting composition as semiconductor layer. In particular cases ethylene and α-olefin copolymer is produced by polymerization with aid of Ziegler-Natta catalyst.

EFFECT: facilitated production.

8 cl, 2 tbl

FIELD: cable industry.

SUBSTANCE: proposed composition designed for insulating general industrial cable and wire sheaths to reduce fire occurrences due to inflammation of cables and wires has following ingredients, mass percent: polyvinyl chloride suspension, 100; ester plasticizer, 25 - 75; lead stabilizer, 1 - 7; calcium stearate, 0.7 - 3; diphenylolpropane, 0.1 - 0.8; zinc oxide, 0.5 - 8; zinc borate, 0.5 - 5; calcium chloride, 0.1 - 2 or calcium oxide, 0.1 - 2; calcium carbonate, 5 - 90; antimony trioxide, 0.5 - 9; and carbon black, 1 - 8.

EFFECT: reduced inflammability and smoke-forming capacity due to introduction of zinc oxide, zinc borate, and calcium chloride or calcium oxide.

3 cl, 1 tbl

FIELD: cable industry.

SUBSTANCE: proposed composition designed for insulating sheaths of cables and wires operating under high fire hazard conditions has following proportion of ingredients, part by mass: suspension polyvinyl chloride, 100; ester plasticizer, 35 - 65; lead stabilizer, 2 - 7; calcium carbonate, 5 - 45; aluminum oxide trihydrate, 20 - 100; antimony trioxide, 5 - 9; zinc oxide, 0.5 - 8; and newly introduced zinc borate, 0.5 - 8; calcium stearate, 1 - 3; calcium chloride, 0.1 - 2 or calcium oxide, 0.1 - 2.

EFFECT: enhanced fire resistance at low degree of smoke emission under fire conditions.

1 cl, 1 tbl

FIELD: electrical communication components; cables whose conductors are covered with polymeric insulation extruded about conductor.

SUBSTANCE: proposed cable has its conductors covered with insulation that has at least one component incorporating maximum 20, and best of all 15, mass percent of polymer characterized in high degree of extrudate swelling. This polymer is defined as that characterized in extrudate swelling degree over 55% and higher, best of all that having extrudate swelling degree over 65%. Best insulation has at least second component of high degree of cracking resistance under stress; therefore, minimal combination of these polymers will provide for insulation layer possessing unique combination of physical properties, including high degree of foaming, fine uniform cellular structure, reduced attenuation, and cracking resistance under stress which is capable of sustaining temperature of 100 °C over 100 h without cracking in spirally coiled state at stress level one-fold higher than outer diameter of insulation.

EFFECT: improved electrical characteristics and mechanical strength of insulation.

23 cl, 6 dwg, 3 tbl

FIELD: insulation materials.

SUBSTANCE: invention relates to polyethylene composition for insulation of conductors and cables, which exhibits improved scorching resistance and consists of (i) polyethylene and scorching inhibitor having melting point under atmospheric pressure below 50°C and being compound depicted by general formula I, wherein R1 represents optionally phenyl-substituted С120-alkyl, С220-alkenyl, С320-alkynyl, С39-cycloalkyl, phenyl, or tolyl; R2 and R3, independently from each other, represent С120-alkyl optionally substituted by following substituents: phenyl, one or two hydroxyls, cyano group, formyl, acetyl, and -O-COR5; R5 represents С120-alkyl, С220-alkenyl, С320-alkynyl, or optionally hydroxyl-substituted С39-cycloalkyl; phenyl, 4-chlorophenyl, 2-methoxycarbonylphenyl, p-tolyl, 1,3-benzothiazol-2-yl, -(CHR6)nCOOR7, or -(CHR6)nCONR8R9, wherein n=1 or 2, R6 represents hydrogen atom or С16-alkyl; R7 С120-alkyl optionally interrupted with 1-5 O or S atoms, С57-cycloalkyl, phenyl, benzyl, or tolyl; R8 and R9 each represents hydrogen atom or С16-alkyl; R4 represents hydrogen atom or methyl; and (ii) organic peroxide. Composition may be extruded with minimum preliminary cross-linking, even at sufficient cross-linking rate. Polyethylene composition for insulation of conductors and cables with improved scorching resistance is described, which composition additionally contains an amine selected from group consisting of diphenylamine, 4-tert-butyldiphenylamine, 4-tert-octyldiphenylamine, 4,4'-di-tert-butyldiphenylamine, 2,4,4'-tris-tert-butyldiphenylamine, 4-tert-butyl-4'-tert-octyldiphenylamine, o,o', m,m'- or p,p'-di-tert-octyldiphenylamine, 2,4-di-tert-butyl-4'-tert-octyldiphenylamine, 4.4'-di-tert-octyldiphenylamine, 2,4-di-tert-octyl-4'-tert-butyldiphenylamine. This composition may be extruded with minimum preliminary cross-linking, even at sufficient cross-linking rate. Method for preparing cross-linked polyethylene composition is also disclosed. (I).

EFFECT: enhanced resistance against preliminary vulcanization at simultaneously preserved satisfactory vulcanization rate and density of cross linkages formed.

3 cl, 5 tbl

FIELD: electrical engineering; polymeric compositions based on reduced-inflammability plasticized polyvinyl chloride.

SUBSTANCE: proposed suspended polyvinyl chloride based polymeric composition designed for insulating internal and external sheaths of wires and cables has following ingredients, mass percent: suspended polyvinyl chloride, 100; ester plasticizer, 45-70; chlorinated wax and/or chlorinated alpha-olefins, 15-20; tribasic lead sulfate, 5-7; calcium stearate, 1-2; aluminum hydroxide or magnesium hydroxide, 45-60; antimony trioxide, 5-10; diphenyl propane, 0.1-0.5; 4.4'-isopropylidenediphenol epoxy resin, 23-4; carbon black, 0.5-2.0.

EFFECT: reduced inflammability, enhanced volume resistivity, thermal stability, and melt fluidity of composition.

2 cl, 1 tbl, 11 ex

FIELD: cable engineering.

SUBSTANCE: proposed smoke-emitting plasticized PVC based polymeric composition used for manufacturing insulation and cable sheaths has following ingredients, mass by part: suspension polyvinyl chloride, 100; ester plasticizer, 40-90; lead stabilizer, 2-8; antimony trioxide, 2-10; zinc oxide, 2-4; boron acid, 2-5; ocher, 10-70; calcium stearate, 1-3; diphenylolpropane, 0.1-0.4.

EFFECT: enhanced heat resistance of composition, its compliance with requirements to smoking under conditions of burning, smoldering, and hydrogen chloride emission in burning.

1 cl, 2 tbl

FIELD: chemistry; insulation.

SUBSTANCE: invention pertains to a cable with a coating layer, made from waste materials. The cable consists of at least, one conductor with at least one transfer element and at least one layer of coating. The coating material contains between 30 mass % and 90 mass % of the overal mass of the coating material, at least, first polyethylene with density not more than 0.940 g/cm3 and melt flow index from 0.05 g/10 min. to 2 g/10 min., measured at 190°C and a load of 2.16 kg in accordance with standard ASTM D1238-00, and quantity from 10 mass % to 70 mass % of the overall mass of the coating material, at least, second polyethylene with density of more than 0.940 g/cm3. The first polyethylene is obtained from waste material. Use of at least, one polyethylene with density of more than 0.940 g/cm3 in the recycled polyethylene allows for obtaining a layer of coating, capable of providing for mechanical characteristics, in particular, breaking stress and tensile strength, comparable to characteristics of primordial polyethylene. The stated coating layer is preferably used as an external protective coating.

EFFECT: obtaining of a new type of cable insulation.

43 cl, 9 dwg, 4 tbl, 10 ex

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