RU2231148C2 - Electric insulation composition - Google Patents

Abstract

FIELD: cable technology.

SUBSTANCE: invention is related polymer compositions intended for insulation and manufacture of sheaths of cables, which do not contain any halogens. Composition includes, percent by mass: trihydtrate of aluminum oxide 50.0-70.0; phenolformaldhyde resin 1.0-4.0; zinc borate 2.0-5.0, polyethylene wax 2.0-5.0, polyboid 2.0-5.0; irganox 1330 0.05-2.0; irganox MD 1024 0.1-0.5, copolymer of ethylene with vinyl acetate being the balance.

EFFECT: improved mechanical characteristics and resistance to action of copper ions.

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Description

The invention relates to the field of electrical engineering, namely cable technology, and can be used for the manufacture of insulation and sheaths of various grades of low-combustibility cables, in particular insulation and sheaths of power, control, signal-blocking and optical cables.

The polyvinyl chloride insulation (sheath) currently used in low-combustibility cables has satisfactory mechanical and dielectric characteristics, however, it has a significant drawback in that toxic and corrosive gases are released from it during fire conditions, leading to poisoning of people, as well as the failure of expensive electronic equipment and other equipment. The specified disadvantage is associated with the presence of halogen - chlorine in the composition of polyvinyl chloride.

In order to eliminate this drawback, a number of insulating materials have been developed that do not contain halogens. Such materials are compositions based on polyolefins and their copolymers containing inorganic fillers as flame retardants. A known composition based on a copolymer of ethylene with vinyl acetate, containing aluminum oxide trihydrate as a flame retardant (US patent No. 3832326, CL 260-42.29, 1974). This composition does not emit corrosive and toxic gases during combustion, however, in terms of combustibility, it does not meet the requirements of UL 94 standard for materials of class 94V-0. In addition, the insulation of the specified composition is not sufficiently resistant to thermal oxidative aging in contact with a copper core or screen.

The closest known to the proposed technical essence is an insulating composition containing (wt.%): A copolymer of ethylene with vinyl acetate 28.5-50 and a filler, which is a mixture of 1: 1 aluminum oxide trihydrate and zinc borate - the rest (US patent No. 4575184, CL 350 / 96.23, 1986).

The disadvantage of this composition is the low mechanical characteristics (tensile strength). In addition, this composition to obtain optimal properties requires crosslinking by irradiation.

The task was to develop an insulating composition that does not emit corrosive and toxic gases when burning, combining high mechanical characteristics and incombustibility with improved resistance to thermal oxidative aging when exposed to copper ions.

The technical result is achieved in that the electrical insulating composition containing a copolymer of ethylene with vinyl acetate, aluminum oxide trihydrate - Al (OH) ₃ , zinc borate, additionally contains novolac phenol formaldehyde resin, polyethylene wax or polyethylene wax modified with vinyl acetate, high density polyethylene modified with maleic anhydride - Polybond 3009, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene - Irganox 1330 and benzene propionic acid, 3,5-bis (1, 1-dimethylethyl) -4-hydroxy-, 2- [3- [3,5-bis (1 , 1-dimethiethyl) -4-hydroxyphenyl] -1-oxopropyl] hydrazide - Irganox MD1024 in the following ratio, wt.%:

Alumina Trihydrate 50-70

Phenol formaldehyde

novolac resin 1-4

Zinc Borate 2-5

Polyethylene wax

or polyethylene wax,

modified with vinyl acetate 2-5

High density polyethylene,

maleic modified

anhydride 2-5

1,3,5-Trimethyl-2,4,6-

tris (3,5-di-tert-butyl-

4-hydroxybenzyl) benzene - Irganox

1330 0.05-0.2

benzene propionic acid,

3,5-bis (1,1-dimethylethyl) -

4-hydroxy-, 2- [3- [3,5-

bis (1,1-dimethiethyl) -4-

hydroxyphenyl] -1-

oxopropyl] hydrazide -

Irganox MD 1024 0.1-0.5

Ethylene copolymer with

vinyl acetate the rest

The proposed composition contains known components.

The copolymer used is obtained by copolymerization of ethylene with vinyl acetate. The ethylene vinyl acetate copolymer is produced by the domestic industry (TU 6-05-1636-97).

Zinc borate is produced by the State Unitary Enterprise “Unihim S OZ” according to TU 113-07-015-91.

Polyethylene wax is manufactured by Clariant, Germany. Alumina trihydrate is manufactured by Martinswerk, Germany.

Phenol formaldehyde novolac resin is produced by Karbolit OJSC. Irganox 1330 and Irganox MD 1024 are manufactured by Ciba, Switzerland.

The composition according to the invention can be processed on typical equipment used for these purposes in cable production.

The following example illustrates but does not limit the invention.

Example:

Compositions for laboratory tests are made by mixing the components at 120-140 ° C for 10-15 minutes.

From the obtained compositions prepare standard samples for testing. The composition of compositions 1-7 are shown in table. one.

Compositions are tested for flammability according to the UL-94 standard, resistance to copper by the method TU 2243-052-05766563-98 and determine their strength and elongation at break according to GOST 11262. The test results are shown in table. 2.

From the test results it is clear that the proposed composition has high strength and elongation at break and resistance to the action of copper ions and in terms of these indicators exceeds the prototype.

Claims (1)

An insulating composition containing a copolymer of ethylene with vinyl acetate, aluminum oxide trihydrate, zinc borate, characterized in that it further comprises novolac phenol-formaldehyde resin, polyethylene wax or polyethylene wax modified with vinyl acetate, high density polyethylene modified with maleic anhydride - Polybond 3009, 1,3, 1,3 5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene - Irganox 1330 and benzene propionic acid, 3,5-bis (1,1-dimethylethyl) -4- hydroxy-, 2- [3- [3,5-bis (1,1-dimethiethyl) -4-hydroxyphe yl] -1-oxopropyl] hydrazide - Irganox MD 1024 with the following component ratio, wt.%: Alumina Trihydrate 50-70 Phenol-formaldehyde novolac resin 1-4 Zinc Borate 2-5 Polyethylene wax or modified polyethylene wax vinyl acetate 2-5 High density polyethylene, Modified by Maleic anhydride - Polybond 3009 2-5 1,3,5-Trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene - Irganox 1330 0.05-0.2 benzene propionic acid, 3,5-bis (1,1-dimethylethyl) - 4-hydroxy 2- [3- [3,5-bis (1,1-dimethiethyl) - 4-hydroxyphenyl] -1- oxopropyl] hydrazide - Irganox MD 1024 0.1-0.5 Ethylene copolymer with vinyl acetate