RU2369931C1 - Electric insulating self-extinguishing composition - Google Patents

Abstract

FIELD: electric engineering.

SUBSTANCE: invention is related to the field of electric engineering, in particular to electric insulating self-extinguishing composition, which may be used to manufacture insulation of cables and wires of various purpose. Composition comprises the following components, in wt %, organic halogen-containing compound 5.3÷14.3, antimony trioxide 2.2÷5.7, calcium stearate 0.1÷0.4, vinyl trimetolsilane or vinyl trietoxysilane 1.0÷3.0, organic peroxide 0.1÷0.4, tetra-bis-methylene- (3.5-di-tret-butyl-4-hydroxyphenyl)propionate 0.05÷0.3, benzo propionic acid 3.5-bis (1.1-dimethylethyl)-4-hydroxy-2-[3-[3.5-bis(1.1-dimethyl)-4-hydroxyphenyl]-1-oxopropyl] hydrazide 0.1÷0.5, homo- or copolymers of olefins - the rest.

EFFECT: high resistance of composition to thermal oxidising ageing in process of contact with copper, and also high physical-mechanical characteristics of insulating material from it in manufacturing of cable products from it.

1 ex, 2 tbl

Description

The invention relates to the field of electrical engineering, namely to cable technology, and can be used for the manufacture of insulation and sheathing of cables and wires for various purposes, such as power, control, ship, signal-blocking cables, self-supporting overhead wires.

Low combustibility cables are known in which the insulation and the sheath are made of polyvinyl chloride compositions (D.S. Bachelis et al. Electrical cables, wires and cords, Directory, M.-L., Gosenergoizdat, 1963, 188-189).

These materials have satisfactory mechanical and dielectric characteristics, however, they have a significant drawback, namely, that in conditions of fire toxic corrosive gases are released from them, leading to poisoning of people, as well as damage to electronic equipment and other equipment.

In order to eliminate this drawback, a number of electrical insulating materials based on homo- or copolymers of olefins have been developed, which, to impart to them self-extinguishing properties, contain aluminum oxide trihydrate as a flame retardant (US Pat. No. 3832326, CL 260-42.29, 1974).

This composition does not emit toxic corrosive gases during combustion. However, in terms of combustibility, it does not meet standard requirements, and the insulation is not sufficiently resistant to thermo-oxidative aging upon contact with a copper core or screen.

Also known is an insulating composition based on polyolefins, containing, to impart to it self-extinguishing properties, a mixture of halogen-containing compounds with antimony trioxide (USSR author's certificate No. 374338, class C08L 23/06, 1973).

The disadvantage of this composition is the low elongation at break, which complicates the processing of the composition and limits the possibility of using products from it.

The closest known property to the proposed combination of features is an electrical insulating self-extinguishing composition containing (wt.%): Homo- or copolymer of olefins 63.9-87.3, organic halogen-containing compound 5-16, organic thiophosphate 1-20, antimony trioxide 3-16, thermostabilizer 0.1-0.3 (USSR auto certificate 604859, class C08L 23/6, 1978).

However, the known composition has insufficiently high physical and mechanical characteristics and low resistance to thermo-oxidative aging in contact with copper.

The task was to develop an electrical insulating self-extinguishing composition with high physical and mechanical characteristics combined with resistance to copper ions under thermal aging, incombustibility (class PV-1) and the ability to crosslink with silanes. The technical result is achieved in that the insulating self-extinguishing composition containing a homo- or copolymer of olefins, a heat stabilizer, an organic halogen-containing compound, antimony trioxide, additionally contains organosilane and organic peroxide, and tetra-bis-methylene- (3- (3,5 -di-tert-butyl-4-hydroxyphenyl) propionate) and benzopropionic acid 3,5-bis (1,1-dimethiethyl) -4-hydroxy-2- [3- [3,5-bis (1,1-dimethiethyl ) -4-hydroxyphenyl] -1-oxopropyl] hydrazide in the following ratio of components:

Organic halogen-containing compound 5.3-14.3 Antimony trioxide 2.2-5.7 Calcium stearate 0.1-0.4 Vinyltrimethoxoxysilane or Vinyltriethoxysilane 1.0-3.0 Organic peroxide 0.1-0.4 Tetra bis-methylene- (3- (3,5-di-tert-butyl- -4-hydroxyphenyl) propionate 0.05-0.3 benzopropionic acid 3,5-bis (1,1-dimethylethyl) - -4-hydroxy-2- [3- [3,5-bis (1,1-dimethiethyl) -4- -hydroxyphenyl] -1-oxopropyl] hydrazide 0.1-0.5 Homo- or copolymer of olefins rest

According to the invention, as a polymer base, the composition may contain low and high density polyethylene, polypropylene, a copolymer of ethylene and propylene with a content of propylene (1-12) wt.%, A copolymer of ethylene and vinyl acetate with a content of vinyl acetate (3-25) wt.% . These polymers are commercially available.

Various aliphatic and aromatic chloro and bromo substituted compounds, in particular chlorinated paraffin, decabromodiphenyl oxide, hexa-bromobenzene, octabromodiphenyl, and others, can be used as a halogen-containing organic compound. The composition contains industrial products: tetra-bis-methylene- ( 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate) - Irganox 1010 and benzopropionic 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 or Lowinox MD 24.

The proposed electrical insulating composition is processed on standard equipment using traditional technology for this type of composition.

The invention is illustrated by the following example, illustrating, but not limiting the invention.

Example

The composition is obtained by mixing the components in a mixer at a temperature below the decomposition temperature of the organic peroxide, but not higher than the melting point of polyethylene, the resulting homogeneous mixture is extruded in the form of strands, cooled and granulated. The granular composition is rolled or extruded, and then the plates are pressed.

Table 1 shows the formulations of the investigated compositions. For comparison, the composition of the known composition.

Table 1 Components, wt.% Example No. 1 Number 2 Number 3 No. 4 (famous) Polyethylene 88.2 81.0 77.05 76.9 Decabromodiphenyl oxide 5.3 9.8 14.3 - Chlorinated Paraffin - - - 9.0 Antimony trioxide 3.0 7.0 5,0 9.0 Calcium stearate 0.1 0.25 0.4 - Organic Thiophosphate - - - 5,0 Vinyltrimethoxysilane 2.5 1,0 3.0 - Organic Peroxide - Dicumyl Peroxide 0.3 0.4 0.1 - Tetra bis-methylene- (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate) - Irganox 1010 0.1 0.3 0.05 - Benzopropionic 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 or Lowinox MD 24 0.5 0.25 0.1 - Nonox WSP - - - 0.1

The test results of the compositions are presented in table 2:

table 2 Name of parameters Songs No. 1 Number 2 Number 3 No. 4 (famous) 1. Tensile strength, MPa 14.2 13.8 13,2 12.0 2. The relative elongation at break,% 650 610 690 500 3. Flammability class PV-1 PV-1 PV-1 PV-2 4. Resistance to copper ions at a temperature of 150 ° C, h > 2000 > 2000 > 2000 500 5, melt flow rate, g / 10 min 0.7 0.2 0.4 one

As follows from the data presented, the proposed composition in comparison with the known one has better physicomechanical characteristics: higher relative elongation at break and tensile strength, which will improve the processing conditions of the composition and increase the elastic and strength properties of the materials obtained.

In addition, the proposed composition has a higher resistance to the action of copper ions at a temperature of 150 ° C, which will increase the life of cable products with insulation (sheath) from this composition.

Also, the proposed composition has a higher combustibility class (PV-1), which indicates a higher degree of fire resistance compared to the known composition.

The proposed composition is also capable of crosslinking with a silane to obtain a silanol-crosslinkable insulation (sheath) of cable products.

Claims (1)

An insulating self-extinguishing composition containing a homo- or copolymer of olefins, an organic halogen-containing compound, antimony trioxide, a thermal stabilizer, characterized in that it additionally contains calcium stearate, vinyltrimethoxysilane and organic peroxide, and tetra-bis-methylene- as a thermal stabilizer (3- (3 ( , 5-di-tert-butyl-4-hydroxyphenyl) propionate) and benzopropionic acid 3,5-bis (1,1-dimethylethyl) -4-hydroxy-2- [3- [3,5-bis (1,1 -dimethylethyl) -4-hydroxyphenyl] -1-oxopropyl] hydrazide in the following ratio, ma .%:
organic halogen-containing compound 5.3 ÷ 14.3 antimony trioxide 2.2 ÷ 5.7 calcium stearate 0.1 ÷ 0.4 vinyltrimethoxysilane or vinyltriethoxysilane 1,0 ÷ 3,0 organic peroxide 0.1 ÷ 0.4 tetra-bis-methylene- (3- (3,5-di-tert-butyl -4-hydroxyphenyl) propionate) 0.05 ÷ 0.3 benzopropionic acid 3,5-bis (1,1-dimethylethyl) - 4-hydroxy-2- [3- [3,5-bis (1,1-dimethiethyl) -4- hydroxyphenyl] -1-oxopropyl] hydrazide 0.1 ÷ 0.5 homo- or copolymer of olefins rest