SU1049507A1 - Rubber stock - Google Patents

Abstract

RUBBER MIXTURE based on unsaturated rubber, including a vulcanization accelerator, a filler and a vulcanizing agent, characterized in that, in order to prevent sulfur from fading on the surface of the rubber mixture and its vulcanizates, to increase the vulcanization rate of the mixture and the heat resistance of vulcanizates. As a vulcanizing agent, it contains lignin modified with 20–30% sulfur in an amount of 5–15 wt.h. the last, 40-95 ma.ch. filler, 0.9-3.2 ma.ch. Accelerator at 100 mph. rubber (L

Description

4 QD DM The invention relates to the rubber industry, in particular, in the development of vulcanizing rubber compounds based on unsaturated carbon chain rubber. It is known to use rubber compounds of lignins treated with nitrogen-containing compounds as vulcanization accelerators l, activators of resin vulcanization of butyl rubber 23. The most close to the invention to the technical essence is a rubber mixture based on carbon chain rubber containing a vulcanization accelerator, a filling agent and a vulcanizing agent an agent in which, in order to improve the technical and economic index and improve the physicomechanical properties of rubber from this mixture, as a vulcanizing agent with Chlorine-containing technical carbon modified with alkali metal polysulfides in an equivalent amount relative to carbon black chlorine in the amount of 10,100 mash. on 100 ma.ch. rubber This modified sulfur-free carbon black makes it possible to exclude. from the mixture elemental sulfur, which tends to fade on the surface of rubber compounds and volcanoes. The disadvantages of the known technical solution are the need for relatively large doses of modified carbon black to introduce into the mixture the amount required for vulcanization, the amount of sulfur and the impossibility of obtaining light mixtures when using this product as a vulcanizing agent. The aim of the invention is to eliminate the fading of sulfur on the surface of the rubber mixture and its vulcanizates, the increase in the rate of vulcanization of the mixture and the heat resistance of vulcanizates. The goal is achieved by introducing into the rubber mixture an unsaturated rubber, including a vulcanization accelerator and a filler, as a vulcanizing agent for lignin, modified with 20-30% sulfur, in an amount of 5-15 wt. H, last, 40-95 wt.h. filler, 0.9-3.2 May, h, accelerator per 100 wt.h. rubber The proposed sulfur-containing lignin (CL) can be used both as an effective vulcanizing agent in rubber compounds containing technical carbon and in mixtures containing light carbon fibers. With the introduction of SL in the mixture, an increase in the rate of vulcanization takes place, the heat resistance of the rubber and fading of sulfur on the surface of the mixture and vulcanizates is not observed even with its general content in the mixture up to 4.5 mph. on 100 ma.ch. rubber Example 1. In the rubber mixture based on isoprene rubber SKI-3 of the following composition, wt.h .; SKI-3 100 / zinc oxide 5.0; stearic acid 1.0; captax l, 0j technical carbon PM-100 50; trunk lines are entered. The dosage of SL and the properties of mixtures and vulcanizates of example 1 are given in table 1. For slides, the same table lists the properties of compositions containing sulfur and compositions containing carbon modified with sulfur. Table 1

Sulfur

Technical carbon PM-100-35

SL containing 30% sulfur

Wregg before the start of scorching at 403K, min

Scorch speed at, min

50.0

5.0

3.6

5.8 1.8 2.9

The optimal time of vulcanization at 403 ° K, min

Conventional strength at break, MPa

Relative extension , %

Relative residual strain,%

Heat aging resistance coefficient (72 h. 373 ° K)

by strength

relative elongation

Example 2. In the uterine rubber mixture based on styrene-butadiene rubber of the following composition, wt.h.:SСС-30 ARKP 100, zinc oxide 5.0, stearic acid 2.0, altax 1.0, carbon black PM-75 40.0, trunk lines are entered. Properties of mixtures and volcanite carbon PM-100-55 SL, containing 25% sulfur

Time started scorch at 403 ° K, pin

Speed scorch at 403 ° K, min

The optimal time of vulcanization at, min

Conventional strength at break, MPa

Continued table. one

0.49

0.68 0.53 0.55

costs of example 2 are presented in table 2. For comparison, the same table shows the properties of a mixture of the same composition, in which, instead of carbon PM-75, carbon black modified with PM-100-55 is introduced.

40

table 2

10.0

9.0

4.8

22.0

27.5

Relative extension,%

Relative residual strain,%.

Heat aging resistance coefficient (72 h "Х373 ° К)

by strength

relative elongation

Example 3. In the rubber mixture based on butadiene nitrile rubber: ka of the following composition, wt.h.: 25 SKN-26M-100; sulfenamide M 1.0; stearic acid 1.0, zinc oxide 5.0; dibutyl phthalate 10; carbon PM-50 50, introduced. SL, containing 30%

Sulfur

Technical carbon PM-100-58

SL containing 30% sulfur

Start time of scorching at 403 ° K, min

Scorch speed at 403K, min

The optimum time of vulcanization pr 423 ° K, min

Conventional strength at break, M Relative elongation,%

Relative residual strain,%

The presence of fading on the surface of the mixture after storage for

2 days 30 days

Continued table. 2

520 20

0.70 0.62

sulfur (by weight of lignin). The properties of the mixture obtained and vulcanizates, according to example 3, as well as the properties to: o the motions of the same composition containing sulfur as a vulcanizing agent and a composition containing PM-100-) 3, are presented in table 3.

Table 3

2.5

50.0

20

20

Not

Not

Example 4. A light rubber compound based on a combination of isoprene rubber and butadiene styrene is injected with a CL modified by 20%.

Properties of rubber compounds and vulcanizates

Start time scorch 1% at, min

Speed scorch at 403 ° K, min vulcanization mode

Conventional strength at break

MPa

Relative elongation,% Relative residual deformation,%

sulfur (by weight of lignin). The properties of the rubber mixture and the dosage of ingredients in example 4 are presented in table 4.

Table4

As can be seen from the above examples, the SP is an effective volcano and a zukhtsim agent for the carbon-based rubber compound. When it is introduced into the mixture, an increase in the cure rate increases, which leads to a reduction in the optimal cure time. Increasing the vulcanization rate allows reducing the accelerator content in the mixture (Table 4).

Sulfur does not fade on the surface of the mixtures even when it is contained in the mixture in the amount of 4.5 wt. on 100 ma.ch. rubber (table 3, a mixture of 3). In addition, the presence of SL in the mixture leads to an increase in the heat resistance of the vulcanizate (example 1 and 2). Compared to sulfur-modified carbon black, the use of SL allows the amount of sulfur required for vulcanization to be introduced into the rubber mixture at a much lower dosage of SL compared to the modified carbon black. It is necessary to answer that SL can be used as an effective vulcanizing agent: for color mixtures that do not contain carbon black.

The use of SL in the rubber industry not only expands its raw material base, but also solves the problem of utilization of the hydrolysis waste of the industry.

Claims (1)

RUBBER MIXTURE based on unsaturated rubber, including a vulcanization accelerator, a filler and a vulcanizing agent, characterized in that, in order to prevent fading of sulfur on the surface of the rubber compound and its vulcanizates, to increase the speed of vulcanization of the mixture and the heat resistance of vulcanizates, c. as a vulcanizing agent, it contains lignin, modified 20-30% sulfur, in an amount of 5-15 wt.h. the latter, 40-95 parts by weight filler, 0.9-3.2 parts by weight accelerator per 100 parts by weight rubber. 4 * OE SI about m>