RU2296782C1 - Rubber mixture for the sealing layer - Google Patents

Abstract

FIELD: rubber industry; automotive industry; production of the sealing layer at manufacture of the tubeless tires and the pneumatic constructions.

SUBSTANCE: the invention is pertaining to rubber industry and the automotive industry and is dealt with production of the sealing layer at manufacture of the tubeless tires and the pneumatic constructions. The rubber mixture contains the isoprene rubber, the filled chlorbutyl rubber produced by interaction at comixing of the butyl rubber and the hlorinated hydrocarbon of the common formula C_nН(2_n+2)_-x Cl_x, where n = 10-30, x = 7-24, at the temperature of 80-150°C at the presence of the colloid silicon dioxide introduced into the mixture in the process of their comixing, brimstone, the sulfonamide accelerant, the stearic acid, zinc oxide, the high-pressure polyethylene, the engineering carbon, the alkylphenolamide resin. The technical result of the invention consists in the increased protection of the rubber mixture from the possible premature vulcanization in the processes of its preparation and reprocessing.

EFFECT: the invention ensures the increased protection of the rubber mixture from the possible premature vulcanization in the processes of its preparation and reprocessing.

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Description

The invention relates to the rubber industry, to the production of rubber compounds and can be used in the manufacture of tubeless tires and pneumatic structures.

A rubber composition based on isoprene rubber is known, which includes a vulcanizing group — sulfur, di- (2-benzthiazolyl) disulfide, N-cyclohexylbenzothiazole sulfenamide-2, RU modifier, softeners and plasticizers — PN-6 oil, stearin and rubrax, fillers - carbon black and white soot, to enhance cohesive strength and increase the carcass - low-density polyethylene HDPE, as well as zinc white and rosin, hexol, and as heat stabilizers and anti-tackifiers diaphen FP, dianylide (4-phenyl-aminophenyl) thiophosphonic acids and 2.6 dimorpholylmethyl, 3 nonylphenol (RU 2215756, 07.20.2003). This composition has improved performance properties (tensile strength, tear resistance, satisfactory thermal aging and fatigue endurance). However, it has a rather complicated composition and is mainly intended for the manufacture of axial bearings of a railway gearbox.

Known sealing compositions based on rubber compounds. So, the known composition in the form of a sealing composition used in the rubber industry (RF 2103306, 01/27/1998). The composition is based on (parts by weight) chlorobutyl rubber-100 and pine rosin 30-50. In addition, the composition contains (parts by weight) vacuum oil 15-45, stearic acid 2-4, zinc oxide 8-12, white carbon 8-16 and calcium carbonate 50-95. The composition has elasticity. The harnesses used to seal and seal the structure are formed from this composition.

Another sealing composition based on a mixture of rubbers using synthetic and natural resins is known, including {wt.%}: Butyl rubber 9-12, polybutene 26-30, terphenol formaldehyde resin 6-8, rosin 2-3, ethylene propylene diene rubber 9-12 and fillers - chalk and talc (RF 2115683, 07.27.1998). This composition is used mainly in the construction industry for sealing joints in prefabricated house-building, in vehicles and does not have the complex of all necessary properties that allow it to be used in the production of tires and pneumatic structures.

A sealing composition based on mixtures of rubbers (butyl rubber and isoprene rubber) in combination with components such as rosin, polybutene, chalk, white carbon black, zinc oxide, stearic acid is known from RU 2204580, 05.20.2003. However, this composition, although it provides good tightness, is a vacuum putty used to ensure the tightness of vacuum and vacuum-autoclave molding of polymer products

composite materials (PCM) and metals at temperatures from +125 to + 180 ° С.

From SU 1260374, 09/30/1986 a rubber compound based on isoprene rubber is known, used in the manufacture of tires and rubber products. This rubber compound includes sulfur, sulfenamide, N-dithiodimorpholine, stearin, zinc white, N-nitrosadiphenylamine, N-phenyl-N-isopropyl-n-phenylenediamine, phenylnaphthylamine, hexachloroparaxylene, furnace carbon black and a modifier - blocked isocyanate-containing product an oligomer based on divinyl and isoprene in a mass ratio of 80-20 with toluene diisocyanate, while it contains as hexachloroparaxylene as such or a mixture with paraffin hydrocarbon in mass co wearing 80:20, as sulfenamide - 2-benzthiazolyl-N-morpholylsulfenamide or N-cyclohexyl-2-benzothiazolylsulfenamide, and as a modifier - isocyanate oligodien blocked by a compound selected from the group comprising aminocaproic acid, 2-amino thiomethylbutanoic acid, a zinc salt of 2-amino-4-thiomethylbutanoic acid and a zinc salt of aminobenzoic acid, and further comprises a disulfide alkylphenol formaldehyde resin or a molecular complex of resorcinol with urotropine at certain ratios of components s. However, the composition is quite complex, toxic, although it has good heat resistance, tear resistance.

Known rubber mixture used in the manufacture of tires, in particular for the manufacture of the sealing layer, including isoprene rubber, butadiene rubber, chlorobutyl rubber HBK NT - 1066, 1068, sulfur, sulfenamide accelerator, stearic acid, zinc oxide, low pressure polyethylene, microcrystalline wax 3 1, sulfur-containing alkyl phenol-formaldehyde resin (Octophor 105), carbon black at certain proportions of components (Technical documentation No. 30-85 for the industrial production of passenger tires with a quality level and 1990 - M., 1985, p. 241, Fig. 83-79). This rubber compound is the closest in technical essence to the claimed invention. However, the known rubber composition does not provide the necessary bond strength with rubbers based on isoprene rubber and dynamic rubber endurance.

From SU 1707025, 08/22/1989, the rubber mixture for the sealing layer in the manufacture of tubeless tires is known. This well-known invention allows to increase the bond strength with isoprene rubber-based rubbers and the dynamic rubber endurance for the sealing layer due to the additional introduction of butyl rubber (BK) and asphaltene-resinous softener (ASMG). The rubber composition according to the invention contains halogenated butyl rubber, butyl rubber, sulfur, sulfenamide accelerator, alkyl phenol disulfide resin, stearic acid, zinc oxide, wax, low pressure polyethylene, asphaltene-resin softener and carbon black in the following ratio of components, respectively, wt.h. 25-75: 75-25: 0.5-2.0: 0.7-1.5: 2.0-10.0: 1.0-3.0: 3.0-5.0: 1, 0-3.0: 1.0-3.0: 15.0-35.0: 50-65.

However, it also does not provide the whole range of necessary operational properties: environmental safety, premature vulcanization of the rubber compound in the processes of its manufacture and processing.

The technical task of the claimed invention is to increase the protection of the rubber compound from possible premature vulcanization in the processes of its manufacture and processing. The stated technical problem is achieved in that the rubber mixture for the sealing layer, including chlorobutyl rubber, sulfur, sulfenamide accelerator, stearic acid, zinc oxide, carbon black, alkylphenolamine resin, contains isoprene rubber, high-pressure polyethylene, and the resulting chlorobutyl rubber contains filled chlorobutyl rubber the interaction when mixing 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 its mixing in the following ratio of components in parts by weight

Isoprene rubber 35.0-75.0 The above chlorobutyl rubber 25.0-65.0 Sulfur 0.4-0.7 Sulfenamide accelerator 0.3-1.0 Stearic acid 1.0-3.0 Zinc oxide 2.0-7.0 Alkylphenolamine Resin 1.5-4.0 High pressure polyethylene 2.0-4.0 Carbon black 40.0-60.0

As isoprene rubber, the rubber mixture according to the invention contains, for example, SKI-3 isoprene rubber, as a sulfenamide accelerator, for example, contains N-cyclohexyl-2-benzthiazolylsulfenamide (sulfenamide C), sulfenamide M (N-oxide-diethylene-2-benzthiazolylsulfenamide) as an alkylphenolamine resin, contains Octophor N.

Used filled halogenated (chlorinated rubber) chlorobutyl rubber is obtained, for example, as follows. A chlorine-containing elastomer (chlorobutyl rubber) is obtained by reacting an elastomer and a chlorine-containing reagent in a rubber mixer at 80-150 ° C for 10-30 minutes. As a chlorine-containing reagent, chlorinated hydrogen is used with the general formula C _n H _{(2n + 2) -x} Cl _x , where n = 10-30, x = 7-24. In this case, the elastomer is taken in an amount of 75-95 parts by weight, and the chlorinated hydrocarbon is 5-25 parts by weight, and at 11-21 minutes of mixing the elastomer with a chlorine-containing hydrocarbon, 5-50 parts by weight are introduced into the rubber mixer. colloidal silicon dioxide (silicic acid).

Below, for illustration, we give a specific example of the preparation of chlorobutyl rubber (filled) in accordance with the above-described general method for its preparation.

Example. BK butyl rubber is loaded into the rubber mixer 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 = 10 and x = 7 in an amount of 5 parts by weight. The mixture is processed for 15 minutes at t 90 ° C and rotor speed, rpm: front 40, rear 60. At 16 minutes, 5 parts by weight are loaded into the rubber mixer. colloidal silicic acid (SiO ₂ ). At 25 minutes, the mixture is unloaded. The resulting product contains bound chlorine of 0.8-1.5 wt.%.

The use of new chlorine-containing butyl rubber (CBC-2.5), obtained by mechanochemical halide modification, allows you to keep the basic specific properties of the rubber of the sealing layer at a fairly high level.

Table 1 shows as an example the possible compositions of the known and proposed rubber compounds for the sealing layer.

Table 1 Components The content of components in parts by weight per 100 parts by weight rubber and mixtures Famous Proposed Isoprene rubber SKI-3 50,0 50,0 Chlorobutyl rubber HBK NT-1066, 1068 50,0 - Chlorobutyl rubber HBK-2.5 - 50,0 Sulfur 0.52 0.52 Sulfenamide C 0.40 0.40 Stearic acid 2.0 2.0 Zinc oxide 3.0 3.0 Alkylphenolamine resin (Octophor N) 2.0 2.0 High pressure polyethylene 3.0 3.0 Carbon black 40,0 50,0

Rubber compounds are made in a rubber mixer in 2 stages. The first stage - the speed of rotation of the rotors of the rubber mixer 40 rpm, the discharge temperature of 150 ° C, the duration of mixing 3 minutes; the second stage is the rotor speed of 20 rpm, the discharge temperature is 110 ° C, the mixing time is 5 minutes.

The vulcanization of rubber compounds is carried out in the press at a temperature of 155 ° C for 20 minutes Plastoelastic, physico-mechanical and some specific properties of rubber compounds and vulcanizates are determined in accordance with existing GOSTs.

The properties of the proposed and known rubber compounds are given in table 2.

table 2 The properties Indicators of properties of rubber compounds and vulcanizates Famous Proposed Plasticity, conventional units 0.37 0.40 Cohesive strength, MPa 3.49 3.45 Mooney viscosity (100 ° C), conventional units 58.5 66.0 Tests on the Firestone Plastometer Expiration time, s 25.8 16,2 Shrink% 62.0 58.5 Tests on the Monsanto Rheometer Minimum torque, N m 9.0 9.8 The start time of vulcanization, min 4.4 9.3 The rate of vulcanization,% / min according to GOST 12535-84 7.9 9,4 Optimal vulcanization time, min 17.0 20,0 The maximum torque, N m 16,0 24.5 Physical and mechanical characteristics Conditional strength at elongation of 300%, MPa 2,5 8.3 Conditional tensile strength, MPa 10.5 10.0 Elongation at break,% 650 550 Tear resistance, kN / m 31 39 Breathability, cm ² / s at 10 ^-8 0.42 0.40

Thus, as follows from the data presented in table 2, the rubber mixture according to the invention can significantly increase both the time of the beginning of vulcanization and the optimal time of vulcanization of rubber compounds, which reduces the tendency of rubber compounds to premature vulcanization, while slightly improving properties such as ductility , strength, tear resistance, breathability.

Claims (1)

The rubber mixture for the sealing layer, including isoprene rubber, chlorobutyl rubber, sulfur, sulfenamide accelerator, stearic acid, zinc oxide, carbon black, alkylphenolamine resin, characterized in that the rubber mixture additionally contains isoprene rubber, high pressure polyethylene, and the rubber contains chlorobutyl chlorobutyl rubber, obtained by reacting by mixing butyl rubber, and chlorinated hydrocarbon of the formula C _n H _{(2n + 2) = x} Cl _x, where n = 10-30, x = 7-24, at a temperature of 80-150 ° C under utstvie colloidal silica, introduced into the mixture in the process of mixing, with the following component ratio, mass parts .: Isoprene rubber 35.0-75.0 The above chlorobutyl rubber 25.0-65.0 Sulfur 0.4-0.7 Sulfenamide accelerator 0.3-1.0 Stearic acid 1.0-3.0 Zinc oxide 2.0-7.0 Alkylphenolamine Resin 1.5-4.0 High pressure polyethylene 2.0-4.0 Carbon black 40.0-60.0