SU979430A1 - Vulcanizable rubber stock - Google Patents

Description

(54) VOLKANIZABLE RUBBER MIXTURE

The invention relates to the rubber industry, in particular to the development of a rubber mixture based on synthetic rubbers, in particular butadiene-nitrile- (SKN) and ethylene-propylene-diene (SKEPT). Known rubber mixture based on carbon-chain rubber, for example styrene-butadiene rubber (SKS-ZO-ARKM-15), containing 6 caprolactam or caprolactam as a secondary vulcanization accelerator 1. The use of caprolactam in this mixture practically does not improve the heat resistance of rubber and does not increase them module, which limits the use of such rubbers in a number of industries, for example, as facing for shafts, used in the metallurgical industry at elevated loads. Leaving as a monomer in vulcanization e, caprolactam exhibits svystva plasticizer and has no modifying effect upon the rubber matrix. The aim of the invention is to increase the strength properties and temperature resistance of rubber from this mixture. This goal is achieved by the fact that the vulcanizable rubber compound, including synthetic rubber and e-caprolactam, additionally contains phthalic anhydride in the following ratio of components, May. Rubber . 100-caprolactam 2-10 Phthalic anhydride2-10 13 of the proposed system. € -caprolactam - phthalic anhydride in the process of vulcanization of the rubber mixture undergoes a series of chemical reactions associated with the acylation of phthalic anhydride with caprolactam and oligomerization of the resulting dimer. Such a chemical process results in the production of thermostable acylated caproamide units inside the vulcanizer mesh, which can participate in the additional structuring of rubber. As a result, the modulus and thermal stability of the rubber are increased. Table 1 presents the formulation of rubbers based on nitrile-butadiene rubber, mac.h.

Table 2 presents the properties of rubbers based on nitrile-butadiene rubber.

Table 3 presents the compounding of rubbers based on ethylene-propylene of the new rubber, mac.h.

Table 4 presents the physico-chemical parameters of rubbers based on SKEPT-50.

Example. The composition of the formulations based on butadiene-nitrile rubber is given in Table 1.

The mixtures are vulcanized in an electric pressure in the mode of x 60 mi. ,

The properties of the obtained rubber are presented in table 2. It can be seen from them that the experienced rubber 4-6 have the best module performance compared with the control samples 1-3 (3.3-3.5 MPa vs. 2.6-2.8 MPa and higher temperature resistance {temperature resistance coefficients at 150 ° C in experimental samples of 0.34-0.35 compared with the control - 0.19-0.21).

Samples 1-2 - control

Noted. ie: Sample 3 characterizes prototd

PRI mme R 2. The composition of the formulations based on ethylene-propylene-diene rubber is given in table 3.

The mixtures are vulcanized in an electric pressure e mode 16/0 ° Cx 60 min.

The properties of the obtained rubber are presented in table 4. As can be seen from these data, experienced rubber 4-6 have higher modulus at 100% stretch compared with controls 1-3 (4.04, 2 MPa versus 2.6-3.1 MPa conditional strength at stretching (9.8-10.2 MPa versus 7.1-7.8 MPa) and higher values of temperature resistance coefficients (0.43-0.45 versus 0.240, 26 ;.

The use of the caprolactam-phthalic anhydride composition allows increasing the service life of rubber technical products based on butadiene-nitrile and ethylene-propylene-diene rubber, i.e. to increase their strength. properties and temperature resistance.

Table Stress (modulus) at 2.8 2, elongation at 100%, MPa Conditional tensile strength at 20 ° C, 18.0 18.2 MPa Relative elongation at break,% Conditional tensile strength at 150 ° С MPa 3, 7 3,4 Coefficient of temperature resistance at 150 ° С 0.21 0.19

Note: Mix 2 characterizes prototype

Table 2 2.6 8.0 18.0 6.4 6.2 3.5 6.3 0.19 0.35 0.35 0.34 Voltage (modulus) at 3.1 elongation at 100%, MPa Conventional strength 7.8 at stretching, MPa Temperature resistance coefficient at 120 ° С

Claims (1)

Invention Formula Vulcanized rubber compound, including synthetic rubber and t-caprolactam, characterized in that, in order to increase the strength properties and temperature resistance of rubber from this mixture, the latter additionally contains phthalic anhydride at the next coolant; wearing components / machine.ch: Table 4 Synthetic rubber E-Caprolactam Phthalic anhydride Sources of information taken into account during the examination 1. R. Frenkel. et al. Investigation of the effect of caprolactam on vulcanization rate and properties of rubbers, Rubber and rubber, 1968, 5f p.1618 (prototype). 2.8 2.6 4.2. 4.1 7.4 7.1 10.1 10.2 0.24 0.26