SU1758046A1 - Composition for producing ebonite - Google Patents

Abstract

Usage: semiconductor materials, such as antistatic materials and coatings. SUMMARY OF THE INVENTION: The composition for producing ebonite comprises, by weight: a polymer or copolymer of diene hydrocarbons with a molecular weight of 800 to 10000 100; sulfur 30-50; diphenylguanidine 1-2; 2-mercaptobenzthiaol 2-4 and carbon black with a specific geometric surface of 12-18 m2 / g 10-20. The semiconductor materials obtained are characterized by a specific volume resistance of 103-105 ohm m and tensile strength of 20-30 MPa. 1 tab.

Description

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The invention relates to the formulation of a composition for producing ebonite used as a semiconductor material.

It is known to use as materials with increased electrical conductivity polymeric compositions obtained by introducing polymeric dielectrics, for example polyolefins, highly conductive substances (powders, metals, carbon black, graphite) into polymeric insulators.

The disadvantage in this case is the need to introduce large amounts of filler (up to 60%, by volume) - metal powders or carbon black, which leads to a sharp deterioration in the physicomechanical properties of the compositions.

A known composition for the preparation of ebonite based on polyisoprene rubber SKI-3, including vulcanizing

the agent is sulfur, the vulcanization accelerator is diphenylguanidine and the filler is talc.

The disadvantage of the material is a high specific resistivity of 10 m Ω-m.

The purpose of the invention is to increase the conductivity of ebonite.

The proposed composition for producing ebony used as a semiconductor material contains a polymer or copolymer of diene hydrocarbons with a molecular weight of 800-10000, a vulcanizing agent — sulfur, vulcanization accelerators — diphenylguanidine and captex (2-mercaptobenzthiazole) and filler — technical grade P-803 (PM-15) with a specific geometric surface of 12-18 m / g.

Low molecular weight synthetic rubbers with a molecular weight of 800-10,000 can be used as the basis of the composition: SKD-0 butadiene (TU-38X |

SL 00 O

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403-195-75), isoprene, pentadiene 1.3, butadiene-pentadiene 1.3 SKDP-N (TU - 38-103-242-82) and others.

The composition is obtained by intensive mixing of the components. To obtain ebonite, it is sufficient to warm it for 1-5 hours at 130-170 ° C. The proposed materials are used both in the form of coatings, and as sheet materials or products of any configuration.

As tests have shown, ebonites based on a liquid composition of this composition have a specific volume resistance of 10 -105 ohm-m, which allows their use as semiconductor materials.

In the process of vulcanization of low molecular weight sulfur rubbers, their intensive dehydrogenation occurs in the whole volume. When polymers or copolymers of diene hydrocarbons are used as such rubbers, vulcanization leads to the formation of a system of conjugated double bonds with a sufficiently large conjugation length in the chain.

A characteristic feature of molecules with conjugated double bonds is the ability to transfer the mutual influence of atoms, i.e. capacity for electrical conductivity, increasing with an increase in the length of conjugation in a circuit,

Obviously, such a vulcanization mechanism allows the use of these ebonites as semiconductor materials.

An example (prototype). The composition obtained on the rolls and consisting of 100 wt.h. polymer (100% isoprene) with a molecular weight of 500 thousand, 30 wt.h. sulfur, 3 wt.h. accelerator - diphenylguanidine, 15 wt.h. talcum filler, roll up to a thickness of 1 mm to obtain a sheet. Vulcanized for 1 h at 150 ° C.

Example 2, a composition obtained by mixing and consisting of 100 wt.h. copolymer (50% butadiene and 50% pentadiene-1,3) with a molecular weight of 4000, 30 wt.h. sulfur, 4.5 wt.h. accelerators (3 parts by weight of captax and 1.5 parts by weight of diphenylguanidine), 15 parts by weight the filler, carbon black P-803, is poured into molds with a thickness of 1 mm to obtain free films. Vulcanize the film for 5 h at 150 ° C. The specific volume resistance of the obtained ebonite is determined with an ohmmeter.

The physicomechanical properties are assessed by the strength of the films under stretching.

PRI me R 3. A composition consisting of 100 wt.h. polymer (100% butadiene) with a molecular weight of 1200. 40 wt.h. sulfur,

6 May h accelerators (4 parts by weight of captax and 2 parts by weight of DFG), 20 May hours of filler — P-803 carbon black, are vulcanized and tested in the same way as in Example 1.

Example 4. Composition consisting

from 100 wt.h. polymer (100% pentadiene-1,3) with a molecular weight of 800, 50 wt.h. sulfur, 3 parts by weight, accelerators (2 parts by weight of captax and 1 parts by weight of DFG), 10 parts by weight technical coal of the genus P-803, vulcanized and tested as in example 1.

PRI me R 5. Composition consisting of 100 wt.h. polymer (100% isoprene) with a molecular weight of 10,000.30 wt.h. sulfur,

5 3 wt.h. accelerators (2 parts by weight of captax and 1 parts by weight of DFG). 15 parts by weight carbon black P-803, vulcanized and tested as in example 1,

Example 6 (for comparison). A composition consisting of 100 parts by weight of a copolymer (70% butadiene and 30% pentadiene-1.3) with a molecular weight of 12,000, 30 parts by weight. sulfur, 4.5 May hours of vulcanization accelerators used in Example 1, and 15 May, hours Technical carbon P-803G is vulcanized and tested as in Example 1.

An example (for comparison). The composition consisting of 100 wt.h. polymer (100% butadiene) with a molecular weight

0 700, 30 wt.h. sulfur, 4.5 wt.h, vulcanization accelerators and filler used in example 1, is vulcanized and tested as in example 1.

Sample size (for comparison). A composition consisting of 100 wt.h. copolymer (70% butadiene and 30% styrene) with a molecular weight of 3500, 30 wt.h. sulfur, 4.5 hours of vulcanization accelerators used in example 1, and 15 May, hours technical carbon of the genus P-803, vulcanized and tested as in example 1.

The results for the examples are given in the table.

As follows from the above examples, ebonites based on the liquid composition of the specified composition have resistance allowing them to be used as a semiconductor material (examples 1-4).

0 The use of ebonite rubbers with a different molecular weight or other composition does not give the desired effect due to a sharp increase in resistance or a decrease in the strength of the material (examples 5-7).

5 The proposed polymeric semiconductor materials have significant tensile strength, for their preparation there is no need for a separate stage of introduction of highly conductive substances, i.e. simplified technology. Eliminating the use of certain metallic highly conductive substances (silver, nickel) provides substantial savings.

The possible application area of the proposed polymer semiconductor materials, such as antistatic materials and coatings.

Claims (1)

DETAILED DESCRIPTION OF THE INVENTION A composition for producing a diene polymer-based ebonite, comprising sulfur, diphenylguanidine, and a filler, in order to increase the conductivity of the ebonite, the composition contains a diene polymer or copolymer 0 hydrocarbons with mol. 800-10000. as a filler, carbon black with a specific geometrical surface of 12-18m2 / g and additionally 2-mercaptobenzthiazole in the following ratio of components, wt.h .: Polymer or copolymer diene hydrocarbons with mol.m. 800-10000100 Sulfur 30-50 Diphenylguanidine1-2 2-Mercaptobenzthiazole2-4 Carbon black with specific geometric surface 12-18 m2 / g10-20