RU1812194C - Rubber mix - Google Patents

Abstract

Usage: production of tires and rubber products. The inventive rubber mixture contains, wt.%: Chlorobutyl rubber 100; stearic acid 2.5-3.5; sulfur 1.8-2.2; tetramethylthiuramdisulfide 1.1-1.5; carbon black with a specific geometric surface of 90-100 m2 / g 40-60; barium sulfide 7-15; 2-mercaptoimidazoline 0.5-0.8 and aerosil, modified with 10 wt.% Ammonia, 5-10. The vulcanization time of rubber compounds at 153 ° C is 30-45 minutes. Characteristics of rubbers: conditional tensile strength 20-21.6 MPa, relative elongation 470-540%, residual elongation 8-14%, Shore hardness 58-62 u, multiple tensile strength at е 0.4 Јр 340-380 thousand cycles, after aging at 125 ° C for 5 days. The tensile strength is 80-88 of the original, the elongation is 93-98% of the original. 2 tab.

Description

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The invention relates to the production of a rubber mixture based on chlorobutyl rubber (CBC), the products of which can be widely used in the manufacture of tires and rubber products (RTI) for various purposes.

The purpose of the invention is to reduce the vulcanization time of the rubber composition and increase the resistance to repeated stretching of the rubber from the mixture.

This goal is achieved in that the rubber mixture based on chlorobutyl rubber, including stearic acid, sulfur, tetramethylthiuramdisulide, carbon black with a specific geometric surface of 90-110 m / g and metal sulfide, contains barium sulfide as a metal sulfide and additionally contains 2-mercaptoimidazoline and aerosil, modified 10 wt.% ammonia, in the following ratio, wt.h .:

Chlorobutyl rubber 100 Stearic acid 2.5-3.5 Sulfur 1.8-2.2 Tetramethylthiuram disulfide. 1.1-1.5 Carbon black with a specific geometric surface of 90-110 m2 / g 40-60 Barium sulfide 7-15 2-Mercaptimidazoline 0.5-0.8 Aerosil, modified 10 wt.% Ammonia 5-10. Characteristics of the components of rubber compounds.

Chlorobutyl rubber (CBC, TU 38-403-54-80). the bound chlorine content is 1.2%, the antioxidant is 0.15%, and volatile at 105 ° C is not

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more than 0.3%, moisture not more than 0.25%, ash not more than 0.35%; Mooney viscosity at 100 ° С 55-65 units, density 920 kg / m3,

Stearic acid (GOST 6484-64): pour point 53-58 ° C, density 960 kg / m3.

Sulfur (GOST 127-76); the content of the basic substance is not less than 99.5%, hearth not more than 0.5%, manganese not more than 0.001%, copper not more than 0.001%, ash not more than 0.2%; melting point 114 ° C.

2-Mercaptobenzthiazole (GOST 739-74): the content of the main substance is not less than 95%, water not more than 0.5%. ash not more than 0.2%; the residue after sieving on sieve No. 014K is not more than 0.15%, the melting point is not more than 174 ° C, and the density is 1500 kg / m3.

Tetramethylthiuramdisulfide (GOST 740-76): content of the basic substance of at least 98%. water not more than 0.5%, ash not more than 0.3%; the residue after sieving on sieve No. 014K is not more than 0.15%, melting point 140-145 ° C, density 1290-1400 kg / m3.

Carbon black (K 354, GOST 7885-86): specific geometric surface 90-110 m2 / g, pH of the aqueous suspension of 3.7-4.5 weight loss at 105 ° C not more than 1.5%, ash content not more than 0, 05%, the residue after sieving on sieve No. 014K is not more than 0.004%, density 1800 kg / m3.

Cadmium sulfide (TU 6-09-3750-84); the content of the main substance is 98-99%, oligon 0, 3%, melting point 1475 ° C, density 4800 kg / m3.

Barium sulfide (TU 6-09-3961-75): content of the main substance 98-99%, moisture 0.1-0.3%; melting point greater than 1200 ° C. density 4250 kg / m3,

2-Mercaptoimidezoline (2-MI; TU 6-14- 261-78): content of 2-MI 98-99.5%, moisture 0.1-0.4%; residue after sieving on sieve No. СН4К 0.1-0.15%, temperature, melting point 194-196 ° C, density 1430 kg / m3.

/ Modified Aerosil AM-50 was obtained for the first time as follows. A serial aerosil with a specific surface area of 75-100 m2 / g is pretreated with vapors of silicon tetrachloride in an inert medium (nitrogen or argon) at 60-80 ° C for 1-2 hours with stirring. The starting aerosil and silicon tetrachloride are taken in a weight ratio of 10: (0.8-1.0) to process it. The resulting aerosil is treated with ammonia in a mass ratio of 10: (1.0-1.2). The reaction is carried out in an inert medium (nitrogen) for 30-60 minutes at a temperature of 50-60 ° C. Modified Aerosil is treated with water vapor for 15 minutes.

dried at 50-60 ° C for 1 h, followed by cooling to room temperature, Characterization of modified aerosil AM-50: specific surface area 45-50 m2 / g, pH of the aqueous suspension 9.5-10.0, bulk density 110-120 kg / m2, moisture content not more than 1.5%, loss on ignition 9.9-10.2%, ammonia 9.8-10.0 wt.%.

0 The maximum amount of ammonia chemically bonded to the surface of aerosil is 10.0 wt.%, Which is confirmed by the data of thermal analysis (thermogravimetry) of modified azrosil in

5 nitrogen atmosphere at 20-1000 ° С and heating rate of 10 ° С / min: weight loss of a sample of modified aerosil is at a temperature up to 200 ° С 0%, at 300 ° С 7.2%, at 600 ° С 9.3 %, at 850 ° С 10.0%, then

0 is decomposes and the entire modifier disappears.

The composition of the rubber compounds and the properties of the rubber compounds obtained under optimal conditions are given in Tables 1 and 2.

5 As can be seen from the data in table 2, the introduction of barium sulfide into the rubber mixture prototype 1 instead of 1 cadmium sulfide used in this known mixture / and additionally the use of 2-MI (instead

0-mercaptobenzthiazole) and modified aerosil AM-50 can reduce the vulcanization time of experimental rubber compounds by 1.5-2.0 times and greatly increase resistance to repeated stretching

5 rubbers from these experimental rubber compounds (3.1-3.5 times) with the best level of physical and mechanical properties of these experimental rubbers 2-6 compared to the prototype rubber 1. Optimum dosage of sulfide

0 bari 7-15 parts by weight, 2-MI 0.5-0.8 parts by weight, and modified aerosil AM-50 5-10 parts by weight 100 ma.ch. rubber. A further increase in the dosage of these and other ingredients of experienced rubber compounds is more

5 of the maximum optimum dosage, they further do not reduce the vulcanization time of the rubber mixture and greatly reduce (worsen) the resistance to repeated stretching of rubber from this mixture (table, 2,

0 experienced control tires 8 in comparison with experimental tires 6). Reducing the dosage of all these ingredients of the experimental rubber compounds below the minimum optimal dosage does not allow them to reach

5 of the chain of the invention according to this application: all the properties of this rubber are much worse than those of the prototype 1 rubber (Table 2, experimental control rubber 7 in comparison with experimental rubber 5 and rubber prototype 1).

Claims (1)

SUMMARY OF THE INVENTION Chlorobutyl rubber-based rubber composition comprising stearic acid, sulfur, tetramethylthiuram disulfide, carbon black with a specific geometric surface of 9Q-110 m2 / g and metal sulfide, characterized in that in order to reduce the vulcanization time of the rubber composition and increase the resistance repeatedly stretching rubbers from this mixture, it contains barium sulfide and, additionally, 2-mercaptoimidazoin and aerosil, modified May 10, as metal sulfide. ammonia, in the following ratio of components, wt.h .: 0 5 Chlorobutyl Rubber Stearic Acid Sulfur Tetramethylthiuramdi sulfide Carbon black with a specific geometric surface of 90-110m2 / g 100 2.5-3.5 1.8-2.2 1.1-1.5 40-60 7-15 Barium sulfide 2-Mercaptoimidazoline 0.5-0.8 Aerosil, modified 10 wt.% Ammonia 5-10. Table 1 table 2 Continuation of the table. 2