Insulating composition

 

(57) Abstract:

The invention relates to the field of electrical engineering, namely, cable technology, and can be used for the manufacture of insulation in different brands of cables, in particular for insulation flexible cables instead of the rubber insulation. Insulating composition comprises, by weight. 'clock, ethylene-propylene-diene rubber 100, polypropylene, or a block copolymer of propylene with ethylene 10-100 peroxide 0,2-4, destructively polypropylene with a melt flow index 100-3000 g/10 min, measured at a temperature of 230oC and a load of 2.16 kg, 3-10, propionic acid, 3,3' - THIOBIS-, dioctadecyl ether of 0.2-0.4, benzoylpropionic acid 3,5-bis (1,1-dimethylethyl(-4-hydroxy-2-[3,5-bis(1,1-dimethylethyl) - 4-hydroxyphenyl]-1-oxopropyl]hydrazide of 0.2-0.4, benzoylpropionic acid 3,5-bis ( 1,1-dimethylethyl)-4-hydroxy-, 2,2-bis[[ 3-[3,5-bis( 1,1-dimethylethyl)-4-hydroxy-phenyl]-1-oxopropoxy] methyl] -1,3-propanediylbis ether 0.07 to 0.15, and three -(2,4-di - tertbutylphenol)postit 0.15 to 0.3. The technical result is to improve the processing characteristics of the composition for insulation of wires and cables, its effective protection against thermal oxidation and the effects of copper, which improves the quality of the final product. table 2.

The process of isolating rubber mixtures usually consists in imposing the isolation using the extruder with subsequent vulcanization, which uses a continuous vulcanization.

This process is time consuming, inefficient and requires the use of special expensive equipment.

Currently known polymeric compositions of thermoplastic elastomers which can be processed on conventional extrusion equipment without requiring subsequent vulcanization, representing a mixture of the two components of the elastomer and thermoplastic (U.S. patent N 4454092, CL 264-349, 1982).

The elastomer is a thermoplastic polymer matrix as a filler and provides the flexibility and elasticity of the composition. Polymer matrix when heated, melted and transformed into a plastic Oplytechnic materials. The most widely used thermoplastic elastomers (TPE), in which the elastomer used ethylene-propylene and ethylene-propylene-diene rubbers, and thermoplastic - polyolefin, for example polypropylene and copolymers of propylene with ethylene. Such TEP is produced by the method of so-called "dynamic vulcanization". The mixture of components is carried out at elevated temperatures: 150-200oC with the addition of cross-linking agents, usually organic peroxides. The process of mixing is accompanied by simultaneous curing of the rubber, then as polypropylene or copolymers of propylene with ethylene under these conditions are not stitched.

Such compositions can be processed in extrusion and injection molding in large, thick-walled products. The disadvantage of these compositions is that during extrusion of a relatively thin-walled products, such as insulated wires and cables, films, there are difficulties associated with insufficient fluidity of the compositions at temperatures of processing. The lack of optimal technological properties leads to deterioration of the surface quality, reduced physical, mechanical and performance characteristics of the products and a significant enhancement the NGOs in contact with copper.

Most similar to that proposed by the technical nature and essential features is the composition containing the ethylene-propylene-diene rubber, destructibles in the presence of peroxide polyolefin, in particular polypropylene or block copolymers of propylene with ethylene, peroxide with a half-life of 2-20 min at 170oC and slivaushiesia in the presence of peroxide polyolefin, in particular polyethylene (U.S. patent N 4785045, CL 524-528, 1988).

The disadvantage of the composition is low workability during processing and, as a consequence, poor insulation of wires and cables at high extrusion speeds. In addition, this composition has a low resistance to oxidation when in contact with copper and thermal aging.

The technical result of this invention is to improve the processing characteristics of the composition for insulation of wires and cables and effective protection against thermal oxidation and the effects of copper, which improves the quality of the final product.

The technical result is achieved in that the insulating composition comprising ethylene-propylene-diene rubber, polypropylene or block copolymers of propylene with ethylene and peroxide ilen with a melt flow index (MFR) 100-3000 g/10 min, measured at a temperature of 230oC and a load of 2.16 kg, and a stabilizing system comprising propionic acid, 3,3'-THIOBIS-, dioctadecyl ether, benzoylpropionic acid 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, 2-[3-[3,5-bis(1,1-dimethylethyl)- 4-hydroxyphenyl] -1-oxopropyl] hydrazide, benzoylpropionic acid 3,5-bis(1,1-dimethylethyl)-4-hydroxy,-2,2-bis[[3-[3,5-bis (1,1-dimethylethyl)-4-hydroxy-phenyl] -1-oxopropoxy] methyl]-1,3 - propanediylbis ether and three-(2,4-di-tertbutylphenol) postit in the following ratio, wt.h.:

Ethylene-propylene-diene rubber - 100

Polypropylene or block copolymers of propylene with ethylene - 10-100

Peroxide with a half-life of 2 to 20 minutes at a temperature of 170oC - 0,2-4,0

Destructively polypropylene with a melt flow index 100-3000 g/10 min, measured at a temperature of 230oC and a load of 2.16 kg - 3-10

Propionic acid, 3,3'-THIOBIS-, dioctadecyl ether - 0,2-0,4

Benzoylpropionic acid 3,5-bis(1,1-dimethylethyl)-4-hydroxy-,2- [3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropyl]hydrazide - 0,2-0,4

Benzoylpropionic acid 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, 2,2-bis[[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxy-phenyl] -1-oxopropoxy] methyl]-propanediylbis ether - 0,07-0,15 the first polypropylene. Such polypropylene is produced beforehand by mechanochemical degradation of polypropylene with a MFR of 0.3 to 30 g/10 min in a mixer of the type Bunbury or on single - or twin-screw extruders in the presence of 0.1 to 3.0 wt.% peroxide at a temperature of 150-190oC for 5-30 minutes After this treatment, the TPP increases to 100-3000 g/10 min.

The composition uses the following stabilizers.

A)

< / BR>
propionic acid, 3,3'-THIOBIS-, dioctadecyl ester,

Mol. weight 683, white powder with a melting point 63-66oC. Manufactured by a company Ciba, Switzerland, under the trade name Irganox PS 802.

B)

< / BR>
benzoylpropionic acid, 3,5-bis(1,1-dimethylethyl)-4 - hydroxy-,2-[3-[3,5-bis(1,1-dimethylether)-4-hydroxyphenyl]-1 - oxopropyl]hydrazide.

Mol. weight 553, white powder with a melting point 224-229oC. Manufactured by a company Ciba, Switzerland, under the trade name Irganox MD 1024.

IN)

< / BR>
benzoylpropionic acid, 3,5-bis(1,1-dimethylethyl)-4 - hydroxy-,2,2-bis[[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxy - phenyl]-1-oxopropoxy]methyl]-1,3-propanediylbis ether.

Mol. weight 1178, white powder with a melting point 110-125oC. Manufactured by a company Ciba, Switzerland, under the trade name Irganox 1010.

oC. Manufactured by a company Ciba, Switzerland, under the trademark Irgafos 168.

This composition may contain ethylene-propylene-diene rubber obtained by copolymerization of ethylene, propylene and diene, for example, marks Sept-30, Sept-40 or SKEPT-50, polypropylene, for example, the brand 01030 or block copolymers of propylene with ethylene, for example, the brand 02035.

Rubber, SKEPT is produced by JSC "bashneftechem" beyond 38.103252-92. Polypropylene and copolymers of propylene with ethylene manufactured by JSC bashneftechem" beyond 2211-020-00203521-96.

The composition according to the invention can be processed on standard equipment used for this purpose in cable production.

The following example illustrates but does not limit the invention.

Example.

Compositions for laboratory tests made by mixing the components in the mill at a temperature of 170oC for 10-15 minutes Beforehand using a laboratory mixer get destructively polypropylene by mixing polypropylene with MFR: 3.0 dicumylperoxide (concentration of 2 wt.%) at a temperature of 170-180oC for 15-20 minutes has been Removed from the rolls in the form of cloth, the mixture is pulverized using a knife to the edge of the
1. Test method

1.1 Resistance of the composition to heat ageing appreciate the change of physico-mechanical properties (tensile strength and elongation at break) after exposure to a temperature of 136oC for 10 days. According to the requirements of electrical insulating compositions, this indicator should be within 25%.

1.2 Resistance to heat aging in the presence of copper estimated on the same data, but the test specimens to temperature effects (136oC, 10 days) are in direct contact with the copper plate (foil).

According to the requirements of electrical insulating compositions, this indicator should be within 25%.

1.3 Technological characteristics of the compositions evaluated for melt flow index, measured at a temperature of 230oC and a load of 2.16 kg, and immediately upon isolation of the copper wires with a diameter of 0.6 mm, the insulation thickness of 0.4-0.5 mm, extrusion lines. Evaluate the surface quality (roughness).

2. The results are given in table 2.

Test results show that use of the composition 6 high MFR (MFR value, providing satisfactory technological characteristics when applying insulation shall be not less than 0.2). The roughened surface of the insulation. In addition, the composition has a low resistance to aging, especially in the presence of copper. Track 7 (control) contains a stabilizing system according to the invention, which provides resistance to aging, including and in contact with copper, corresponding to the requirements for insulating compositions. However, the technological characteristics of the composition (PTR, surface quality insulation) is unsatisfactory.

Composition 8 (control) contains destructively polypropylene according to the invention, which provides a satisfactory technological properties, however, the absence of a stabilizing system stabilizer Irganox MD 1024 leads to a low aging resistance of the composition in the presence of copper (changing the strength at break of 70%, the change in the relative elongation of 80%). The absence of a stabilizing system stabilizer Irganox PS 802 (composition 9, the control also leads to poor aging resistance. Use as insulation compositions 1-5, characterized by a content of a component of the practical characteristics. Insulation on all indicators meet the requirements for insulating compositions.

Insulating composition containing the ethylene-propylenediene rubber, polypropylene or block copolymers of propylene with ethylene, peroxide with a half-life of 2 to 20 minutes at a temperature of 170oC, characterized in that it further comprises destructively polypropylene with a melt flow index of 100 to 3000 g/10 min, measured at a temperature of 230oC and a load of 2.16 kg, and a stabilizing system comprising propionic acid, 3,3' - THIOBIS-, dioctadecyl ether, benzoylpropionic acid, 3,5-bis (1,1-dimethylethyl)-4-hydroxy-2-[3-[3,5-bis(1,1-dimethylethyl) - 4-hydroxyphenyl] -1-oxopropyl] hydrazide, benzoylpropionic acid, 3,5-bis (1,1-dimethylethyl)-4-hydroxy-2,2 bis[[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropoxy]methyl]-1,3-propanediylbis ether and three -(2,4-ditertbutyl)postit in the following ratio, wt.h:

Ethylene-propylene-diene rubber - 100

Polypropylene or block copolymers of propylene with ethylene - 10 - 100

Peroxide with a half-life of 2 to 20 minutes at a temperature of 170oC - 0,2 - 4

Destructively polypropylene with the index t is acid, 3-3'-THIOBIS-, dioctadecyl ether - 0,2 - 0,4

Benzoylpropionic acid, 3,5-bis (1,1-dimethylethyl)-4-hydroxy-,2-[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropyl]hydrazide - 0,2 - 0,4

Benzoylpropionic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-2,2-bis[[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxy-phenyl-1-oxopropoxy] methyl] -1,3 propanediylbis ether - 0,07 - 0,15

Three-(2,4-di-tertbutylphenol)postit - 0,15 - 0,3

 

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