RU2356917C2 - Oil resistant rubber composition - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: present invention relates to the rubber industry, particularly to oil resistant rubber composition with good operational characteristics. The rubber composition is based on butadiene-nitrile rubber mixed with, wt.pts, 1.8-2.0 tetramethylthiuram disulphide, 1.4-1.6 hexachloro-n-xylol, 0.9-1.1 N-phenyl- N¹-isopropyl-n-phenylenediamine and 1.0-2.0 oligomer of 2,2,4tetramethyl-1,2 dihydroquinoline, 0.9-1.1 antifatigue agent and heat stabiliser of dioctylamine(4-phenylaminophenyl) thiophosphonic acid ("Б"-26) with technical carbon, sulphur and target additives.

EFFECT: increased tear resistance and improved physical and mechanical properties of the rubber.

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Description

The present invention relates to the rubber industry, namely, to obtain an oil-resistant rubber composition, which is used in the oil industry and has high strength, hardness and high tear resistance.

Known oil-resistant rubber composition is similar in technical requirements and composition - patent RU No. 99115077 from 12.07.99. This composition is based on butadiene nitrile rubber, including: sulfur, altax (di-2-benzthiazolyl disulfide), N-cyclohexylbenzo-thiazolsulfenamide-2, zinc white, stearin, dibutyl phthalate (DBP) or technical dibutylbenzoate 2 , 2,4 trimethyl-1,2-dihydroquinoline, dianylide (4-phenylaminophenyl) thiophosphonic acid, 2,4,6 tri (dibutylaminomethyl) phenol (M-9) in the indicated amounts in mass. parts:

Nitrile butadiene rubber one hundred Sulfur 1.8-2.0 Altax 1.3-1.5 N-cyclohexylbenzothiazole sulfenamide-2 3.0-3.5 Stearin 1.2-1.5 Indencumarone resin 3.0-3.5 Zinc White 3.0-5.0 Dibutyl Sebacinate or Dibutyl Phthalate 12-15 Carbon black 50-55 Trimethyl-1,2-dihydroquinoline oligomer 2,2,4 1.0 Dianylide (4-phenylaminophenyl) thiophosphonic 0.5-1.0 acids (B-25) 2,4,6 tri (dibutylaminomethyl) phenol (M-9) 0.5-1.0

The disadvantage of this rubber composition is its unsatisfactory strength (18.2 MPa), hardness (72-73) at both normal and elevated temperatures, and insufficient tear resistance (62.0 MPa).

The invention is aimed at increasing the tear resistance of rubber and increasing its physical and mechanical characteristics.

The solution to this problem is achieved by the proposed rubber composition based on butadiene nitrile rubber, containing sulfur, tetramethylthiuram disulfide (thiuram D), N-cyclohexylbenzothiazole-sulfenamide-2 (sulfenamide "C"), stearin, indencumarone resin, mild zinc oxide, depending on the temperature range, the requirements to the products, hexachloro-n-xylene, as well as carbon black, heat stabilizers oligomer of 2,2,4-trimethyl 1,2-dihydroquinoline (atsetonanil), N-phenyl-N ¹ -isopropyl-n-phenylene Jamin (diafen FP) and protivoutomitel dioctylamine (4-phenyl-aminophenyl) tiofosfonovoy acid (B-26) with the following proportions of ingredients in parts by weight:

Nitrile butadiene rubber 100.0 Sulfur 0.4-0.6 Tetramethylthiuram disulfide 1.8-2.0 N-cyclohexylbenzothiazolsulfenamide-2 2.0-2.2 Stearin 2.2-2.5 Indencumarone resin 2.5-3.5 Zinc White 4.0-6.0 Hexachlor-n-xylene 1.4-1.6 Dibutyl Sebacinate or Dibutyl Phthalate 10-12 Carbon black 35-45 Trimethyl-1,2-dihydroquinoline oligomer 2,2,4 1.0-2.0 N-phenyl-N ¹ -isopropyl-n-phenylenediamine 0.9-1.1 Dioctylamine (4-phenylaminophenyl) thiophosphonic acid 0.9-1.1

A distinctive feature of the new composition is the introduction of additional ingredients: tetramethylthiuram disulfide (Tiuram "D") as a curing agent to increase the strength and hardness, to increase the dispersibility of the ingredients and to improve the physical and mechanical properties, hexachlor-n-xylene was introduced, and to increase A tear resistance was injected with a new multifunctional antioxidant and thermal stabilizer dioctylamine (4-phenylaminophenyl) thiophosphonic acid (B-26). The use of the proposed distinguishing features leads to an increase in physical and mechanical characteristics, as well as to an increase in tear resistance both at normal and at elevated temperatures.

The introduction of a new, specially developed polyfunctional anti-tacifier and thermal stabilizer together with acetonanil and diafen FP, with which it forms synergistic mixtures, can significantly increase the physical and mechanical characteristics of rubbers, and in particular tear and abrasion resistance not only with abrasive materials, but with sharp edges of stones and gravel.

The synthesis of dioctylamine (4-phenylaminophenyl) thiophosphonic acid (B-26) is carried out according to the following procedure.

In a 4-necked flask with a stirrer and a reflux condenser connected to a hydrogen sulfide absorption flask containing 70 ml of 30% NaOH, 200 ml of chlorine or bromobenzene, 0.1 mol of phosphorus pentasulfide P ₄ S ₁₀ (11.1 g) and 0.4 mol (67.6) are added g) diphenylamine C ₆ H ₅ -NH-C ₆ H ₅ . The reaction is carried out at 150 ° C for 1-1.5 hours. Then, octylamine NH ₂ C ₈ H _{17 was} added to the reaction flask in an amount of 20.6 g and the reaction was continued at the same temperature for another 2 hours. After the reaction, the solution is cooled, the precipitate is filtered and dried to constant weight. Product yield ≈ 80%.

Elemental composition for C ₂₈ H ₄₆ N ₃ PS:

Calculated,%: C - 61.37;

H - 11.76;

N - 10.74;

P-91;

Found,%: C - 60.81, 60.76;

H - 11.35, 11.51;

N - 9.19, 9.37;

P - 8.14, 8.31.

In the IR spectra, absorption bands characteristic of the NH, P = S and CP groups are observed in the regions of 3400 cm ^-1 , 750-700 cm ^-1 , 1450 cm ^-1 groups, respectively, and

1600-1560 cm ^-1 - fluctuations in the aromatic ring.

The molecular weight of the substance is 493, the melting point is 220 ° C, the compound is soluble in benzene and toluene when heated.

Table 1 shows the compositions of rubber compounds and their rheological indicators. Physico-mechanical and dynamic characteristics of the vulcanizates are given in table. 2. The optimum vulcanization was determined on a rheometer "Monsanto". Rubber compounds were examined for ductility (GOST 415-75), Mooney viscosity (GOST 10722-76), scorching. Volcanizates were examined for conditional strength, relative and residual elongation (GOST 270-75), tear resistance, Shore A hardness (GOST 263-75) and ISO (GOST 20403-75), temperature limit of brittleness (ST SEV 2050-79). The dynamic characteristics of rubbers were determined, such as heat generation on a Goodrich flexometer (GOST 266-78), abrasion tests (GOST 12251-75). Aging of rubbers was carried out in an air thermostat with fivefold air exchange at a temperature of 140 ° C for 24 hours, at 150 ° C 168 hours and in standard liquid SZhR-1 at a temperature of 140 ° C for 144 hours. Physico-mechanical characteristics of vulcanizates after aging of rubber are given in table.3.

Table 1 The composition of the rubber compositions. INGREDIENTS EXAMPLES prototype one 2 3 four Nitrile butadiene rubber 100.0 100.0 100.0 100.0 100.0 Sulfur 1.8 0.4 0.5 0.5 0.6 Altax 1.3 - - - - Tiuram "D" - 2.0 1.9 1.9 1.8 Sulfenamide "C" 3.5 2.0 2.1 2.1 2.2 Indencumarone resin 3.0 2.5 3.0 3.0 3.5 DBF or DBS 12.0 10.0 11.0 12.0 12.0 Stearin 1.5 2.2 2.4 2.4 2.5 Hexol - 1.4 1.5 1.5 1.6 Zinc White 5.0 6.0 5.0 5.0 4.0 Carbon black 50.0 35.0 40.0 40.0 45.0 Acetonanil 1.0 1.0 1.0 2.0 2.0 Diafen FP - 1.1 1.0 0.9 0.9 Thermostabilizat.B-25 1.0 - - - - Thermostabilizer M-9 0.5 - - - - Anti-Fatigue B-26 - 1.1 1.0 1.0 0.9 Table 2. Rheological, physico-chemical and dynamic characteristics of rubber. MIX Ciphers TESTING Prototype one 2 3 four Carrera ductility 0.27 0.13 0.12 0.11 0.11 Mooney viscosity, 100 ° C, units Mooney 62 66 68 68 70 Scorching, 120 ° С, min 40 25 25 25 25 The vulcanization mode of 155 ° C, min 13 12 eleven eleven 12 Tensile strength, MPa 18.2 21.8 22.0 21.6. 22.4 Relative extension, % 320 500 420 450 350 relative residual. elongation,% 12 fourteen 12 10 10 Tear resistance, kg / cm ² 62.0 108.0 109.0 108.0 107.0 SHOR A hardness 72 75 76 77 77 Fragility temperature, ° С -22 -40 -40 -40 -39 Heat generation during multiple compression, ° С 48 44 44 45 46 Wear resistance, cm ³ / kWh 108 105 104 106 105 Multiple stretching E _din. 100%, thousand cycles before cracking 702 252.0 250.6 252.4 251.6

Table 3. Physico-mechanical characteristics of rubber after aging. TESTING MIX Ciphers Prototype one 2 3 four Air aging 140 ° C 24 hours The coefficient of thermal aging tear 0.72 0.92 0.94 0.88 0.88 Air aging 150 ° C 168 hours Strength coefficient of thermal aging 0.50 0.54 0.56 0.55 0.55 Aging in SZHR-1 140 ° C 144 hours Strength coefficient of thermal aging 0.65 0.71 0.73 0.73 0.72

Comparative analysis with the prototype allows us to conclude that the proposed composition of the rubber compositions, which differs from the prototype by the introduction of a number of additional ingredients, leads to an improvement in the physicomechanical and dynamic characteristics (Table 2), the most important for the operation of this rubber. In terms of strength, the inventive rubber exceeds the prototype by ≈ 20%, in tear resistance ≈ 76%, in tear resistance after aging by more than 30%.

Claims (1)

Oil-resistant rubber composition based on nitrile butadiene rubber containing sulfur, N-cyclohexylbenzothiazolsulfenamide-2, stearin, indencumarone resin, zinc white, softeners dibutyl sebacinate or dibutyl phthalate, as well as carbon black, thermo-stabilizer 1,2-oligomene that it additionally contains, as a vulcanizing agent, tetramethyltiuramdisulfide, it contains hexachlor-n- to increase the dispersibility of the ingredients and improve the physical and mechanical properties silol inhibitor, N-phenyl-N ¹ -isopropyl-n-phenylenediamine and protivoutomitel dioctylamine (4-phenylaminophenyl) tiofosfonovoy acid at the following ratios of ingredients, mass parts .:
Nitrile butadiene rubber 100.0 Sulfur 0.4-0.6 Tetramethylthiuram disulfide 1.8-2.0 N-cyclohexylbenzothiazolsulfenamide-2 2.0-2.2 Stearin 2.2-2.5 Indencumarone resin 2.5-3.5 Zinc White 4.0-6.0 Hexachlor-n-xylene 1.4-1.6 Dibutyl Sebacinate or Dibutyl Phthalate 10-12 Carbon black 35-45 Oligomer 2,2,4 trimethyl-1,2 dihydroquinoline 1.0-2.0 N-phenyl-N ¹ -isopropyl-n-phenylenediamine 0.9-1.1 Dioctylamine (4-phenylaminophenyl) thiophosphonic acid 0.9-1.1