RU2365606C1 - Rubber mixture for production of diaphragms of formator-vulcanisers - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to rubber industry and deals with production of rubber products such as tyres, etc. Rubber mixture contains mixture of caoutchoucs, wt.p - butylcaoutchouc - 75-90, chloroprene caoutchouc - 0-10 and chloride-containing ethylene-propylene-diene filled caoutchouc 7-20. Chloride-containing ethylene-propylene-diene caoutchouc is obtained by mixing ethylene-propylene-diene and chloride-containing caoutchouc in presence of silicon colloidal dioxide. Rubber mixture contains also per 100 wt.p of mixture of caoutchoucs: stearic acid -1-3, zinc oxide - 4-10, technical carbon-30-60, mineral oil "stabiloil" -3-8 and phenol-formaldehyde resin "amberol137" -5-10.

EFFECT: obtaining rubber which has reduced creep and pitching, as well as increased dynamic durability.

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Description

The invention relates to the formulation of rubber compounds and can be used in the rubber industry in the manufacture of tires and rubber products.

A well-known rubber mixture based on chloroprene and isoprene rubbers, including chlorolefin as a modifier (SU 516718, 1976). However, the rubber obtained from this rubber compound has significant abrasion.

Another rubber mixture based on chloroprene and butadiene-methylstyrene rubbers is known, including zinc white, carbon black, N-phenylnaphthylamine-2, di (2-benzothiazolyl) disulfide, sulfur, stearic acid, paraffin and industrial oil. The resulting rubbers have high strength characteristics, but have high abrasion (Technical specifications for automotive and tractor engineering parts, No. 38-005-204-71).

A rubber mixture based on chloroprene and butadiene-methylstyrene rubbers is known from SU 1054379, 11/15/1983, including zinc white, carbon black, N-phenylnaphthylamine-2, di (2-benzothiazolyl) disulfide, sulfur, stearic acid, paraffin, industrial oil, polyoxypropylene diurethane diallylate or polyoxypropylene triurethane triallylate in certain ratios of these components. The resulting rubber mixture has a high resistance to abrasion, but does not have the necessary properties, which are the technical task of the invention.

A rubber compound is known from RU 2296782, 04/10/2007, which contains isoprene rubber filled with chlorobutyl rubber obtained by reacting a mixture of butyl rubber and a chlorinated hydrocarbon of the general formula C _n H _{(2n + 2) x} Cl _x , where n = 10-30, x = 7-24 at a temperature of 80-150 ° C in the presence of colloidal silicon dioxide introduced into the mixture during their mixing, sulfur, sulfenamide accelerator, stearic acid, zinc oxide, carbon black, high-pressure polyethylene, alkyl phenolamine resin. The technical task is to increase the protection of the rubber compound from possible premature vulcanization in the processes of its manufacture and processing. However, the known rubber compound does not have the necessary set of properties and is intended for the sealing layer in the manufacture of tubeless tires and pneumatic structures.

The technical task of the claimed invention is to reduce creep, osmolability and increase the dynamic endurance of rubbers for diaphragms of vulcanizer formators.

The stated technical problem is achieved in that the rubber mixture for the manufacture of diaphragms for the vulcanizer formators includes butyl rubber, chloroprene rubber and chlorine-containing ethylene-propylene-diene-filled rubber obtained by mixing ethylene-propylene-diene rubber and a chlorine-containing hydrocarbon of the general formula C _n H _{(2n + 2 ) x} Cl _x , where n = 10-30, x = 7-24 at a temperature of 80-150 ° C in the presence of colloidal silicon dioxide introduced into the mixture during mixing, and the rubber mixture contains per 100 wt. h mixture of rubber stearin hydrochloric acid, zinc oxide, carbon black, mineral oil "Stabiloil" and phenol-formaldehyde resin "Amberol-137" in the following ratio of the components of the rubber mixture in parts by weight:

Butyl rubber 75.0-90.0 Chloroprene rubber 0-10,0 The above chlorine ethylene propylene diene filled rubber 7.0-20.0 Stearic acid 1.0-3.0 Zinc oxide 4.0-10.0 Carbon black 30.0-60.0 Mineral oil "Stabiloil" 3.0-8.0 Phenol-formaldehyde resin "Amberol-137" 5.0-10.0

In the rubber composition according to the invention, for example, butyl rubber BK-1675 is used as butyl rubber, carbon black N 330 (PM-75), mineral oil is Stabiloil oil, phenol formaldehyde resin is Amberol-137 resin.

As a chlorine-containing ethylene-propylene-diene rubber, the rubber mixture according to the invention contains a chlorine-containing ethylene-propylene-diene rubber HEPDK-2, obtained, for example, by the following technology:

In a rubber mixer of type RVSD (friction 1: 1.5), ethylene-propylene-diene elastomer (SKEPT-60) is loaded in an amount of 95 parts by weight Then, a chlorinated hydrocarbon of the formula C _n H _{(2n + 2) -x} Cl _{x is} loaded, where n = 20, x = 21 in an amount of 5 parts by weight The mixture is processed at a temperature of 80 ° C and rotor speed, rpm: front - 30, rear - 45. At 11 minutes, 5 parts by weight are loaded into the mixer. colloidal silicic acid (SiO ₂ ). The resulting product contains bound chlorine of 2.0-2.3 wt.%.

The use of a new chlorine-containing ethylene-propylene-diene rubber with a chlorine content of 2 ± 0.5% molar chlorine (HEPDK-2) instead of 15 parts by weight BK-1675 butyl rubber in diaphragm rubber recipes allows optimizing a number of specific characteristics (creep, dynamic endurance, osmolability), which can lead to a significant increase in the operating life of the diaphragms of the vulcanizer formators. The use of the new rubber HEPDK-2 can also slightly increase the conditional tensile strength, rebound elasticity and relative residual elongation after rupture, while maintaining the remaining properties of rubber compounds and vulcanizates at the required level.

The following example illustrates the invention but does not limit it (see table 1). For comparison with the rubber mixture according to the invention, a well-known rubber mixture was prepared for the production of diaphragms for vulcanizer formators (technological regulations of the Moscow tire plant No. 404 sh-89 “Production of passenger radial tires with metal cord breaker”).

Example.

Rubber mixtures are made in a rubber mixer RVSD-250-40 in two stages. The first stage is a mixing time of 15 minutes, the discharge temperature is 175 ° C, the second stage is a mixing time of 5 minutes, the discharge temperature is 120 ° C. In the second stage, zinc oxide and phenol-formaldehyde resin are introduced.

The vulcanization of the mixtures is carried out in a press at a temperature of 175 ° C. Plastoelastic, physico-mechanical and some specific properties of rubber compounds and vulcanizates are determined in accordance with existing GOSTs. The rubber osmolability is determined in accordance with the methodology given in the dissertation for the degree of candidate of technical sciences Turgumbaev Kh.Kh. (Study of SKEPT in tire rubbers, Moscow, MITT, 1968, 136 pp.).

Table 1 Components The content of components in parts by weight per 100 parts by weight rubber in the mixture known by regulation according to the invention Butyl rubber BK-1675 95.0 80.0 Chloroprene rubber 5,0 5,0 HEPDK-2 rubber - 15.0 Stearic acid 2.0 2.0 Zinc oxide 5,0 5,0 Carbon black N 330 (PM-75) 50,0 50,0 Stabiloil oil 5,0 5,0 Phenol-formaldehyde resin "Amberol-137" 8.0 8.0

The properties of the rubber composition according to the invention and the known are presented in table 2.

table 2 The properties Indicators of properties of rubber compounds and vulcanizates known by regulation according to the invention Plasticity, conv. units 0.41 0.42 Mooney viscosity at 140 ° C, conv. units 37 36 Conditional strength at elongation of 300%, MPa 5,0 6.0 Conditional tensile strength, MPa 10,2 12.6 Elongation at break,% 620 600 Relative residual elongation after rupture,% 34 twenty Tear resistance, kN / m 60 63 The coefficient of thermal aging at 180 ° C for 24 hours (conditional strength) 0.6 0.6 The coefficient of temperature resistance at 100 ° C (conditional strength) 0.7 0.62 Hardness according to TM-2, conv. units 74 78 Dynamic endurance to failure, thousand cycles 42 > 50 Creep at 160 ° C for 24 hours (at 30 gf / mm ² ), mm 119 53 Rebound elasticity after heat aging at 180 ° C in 24 hours,% at 20 ° C 16 eighteen at 100 ° C 28 thirty The osmolality,% 1,2 0.6

As follows from the above data, the rubber mixture according to the invention has high strength properties, resistance to heat aging, reduced creep and low osmolality.

Claims (1)

A rubber mixture for the production of diaphragms for vulcanizer formators, including butyl rubber, chloroprene rubber and chlorine-containing ethylene-propylene-diene-filled rubber obtained by mixing ethylene-propylene-diene rubber and a chlorine-containing hydrocarbon of the general formula C _n · H _{(2n + 2) -x} Cl _x where n = 10-30, x = 7-24 at a temperature of 80-150 ° C in the presence of colloidal silicon dioxide introduced into the mixture during mixing, and the rubber mixture contains per 100 wt.h. a mixture of rubbers, stearic acid, zinc oxide, carbon black, mineral oil "stable" and phenol-formaldehyde resin "amberol 137" in the following ratio of components of the rubber mixture, parts by weight:
butyl rubber 75-90 chloroprene rubber 0-10 the above chlorine ethylene propylene diene filled rubber 7-20 stearic acid 1-3 zinc oxide 4-10 carbon black 30-60 mineral oil "stable" 3-8 phenol-formaldehyde resin "amberol 137" 5-10