RU2266930C2 - Rubber composition - Google Patents

Abstract

FIELD: rubber composition for production of cup-type seals.

SUBSTANCE: claimed butadiene-nitrile rubber composition contains (mass pts): powdered fluoroplastic as antiwear additive 10-18; sulfur 2.5; altax 2.7; zinc white 7.5; diphenylguanidine 0.25; aldol-α-naphthylamine 4.0; neozone D 1.0; furnace carbon black 120; dibutilsibacinate 20; santoflex IP 1.0; stearic acid 1.0.

EFFECT: cup-type seals with increased abrasive resistance, durability and reduced friction coefficient.

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Description

The invention relates to rubber mixtures intended for the manufacture of sealing cuffs of movable components of equipment.

Known sealing cuffs made of polytetrafluoroethylene used to seal moving joints of mechanisms (M. Lazer, R. Rado and others. Fluoroplasts. Publishing House "Energy", M., 1965, p. 267).

The disadvantage of such cuffs is relatively high hardness, low flexibility, significant irreversible deformation, which ultimately leads to a short life of the sealing cuffs.

Known rubber compounds based on fluororubber SKF-32, used for the manufacture of rubber-reinforced cuffs (Achievement of science and technology in the field of rubber. Collection of articles edited by Yu.S. Zuev. Publishing house "Chemistry", M., 1969, p. 288) .

The disadvantages of these rubber compounds is the formation during operation of the radial cracks on the working edge of the cuffs and loss of elasticity in the area of the working edge, resulting in a loss of tightness.

Known rubber mixture based on nitrile butadiene rubber with a nitrile content of acrylic acid of 17-23% wt. (SKN-18), including sulfur, di- (2-benzothiazolyl) disulfide (altax), diphenylguanidine, aldol-α-naphthylamine, zinc oxide, carbon black, stearic acid, fluoroplastic (RF Patent No. 21515068 C1).

This rubber compound is taken as a prototype.

The technical result of the invention is to increase the wear resistance, reduce the coefficient of friction of rubbers, and ultimately, increase the life of the sealing collars of the movable joints.

The problem is solved in that a powdery fluoroplastic F-32LN is introduced as a fluoroplastic into a well-known rubber mixture based on nitrile butadiene rubber as an antifriction additive and, in addition, Neozone D, Santoflex IP and dibutylsebacinate.

The proposed rubber mixture per 100 parts by weight nitrile butadiene rubber SKN-18 includes, parts by weight:

sulfur 2,5 altax-di- (2-benzothiazolyl) disulfide 2.7 zinc white 7.5 diphenylguanidine 0.25 aldol-α-naphthylamine 4.0 neozone D-phenyl β-naphthylamine 1,0 soot furnace PM-15 120 dibutyl sebacinate twenty santoflex IP - N-phenyl-N'-isopropyl-p-phenylenediamine 1,0 stearic acid (technical) 1,0 powdered fluoroplastic F-32LN is a low molecular weight trifluorochlorethylene polymerization product 10-18

The proposed rubber mixture is made by a known method, and the powdery fluoroplastic F-32LN is added to the mixture last.

In the process of pressing (vulcanization) of the cuffs of the proposed rubber mixture occurs (temperature (143 ± 3) ° C) melting of the fluoroplastic powder. As a result, a fluoroplastic film is formed in the volume of the cuff and on its surface, playing the role of an antifriction coating, which increases the wear resistance and reduces the friction force on the moving parts of the equipment. A decrease in the coefficient of friction helps to reduce the heating temperature, wear of the cuff and, ultimately, increase the life of the cuff.

The invention is illustrated by the examples given in tables 1, 2, 3. The corresponding indicators of the rubber compound taken as a prototype are also shown there. The abrasion of rubber compounds is determined according to GOST 426-77. The friction coefficient was determined according to GOST 426-77 in mode A (M. M. Raznikovsky, A. I. Lukomskaya. Mechanical testing of rubber and rubber. Publishing house "Chemistry", M., 1968, p. 466).

As can be seen from table 2, when the content of the proposed rubber composition of the powdery fluoroplastic F-32LN is less than 10 parts by weight abrasion and friction coefficient values increase. The increase in the content of fluoroplastic F-32LN - reduces the mechanical characteristics of the rubber compound, increases the value of residual deformation under compression, which adversely affects the operational characteristics of the products as sealing cuffs.

Table 1
The composition of the rubber compounds Ingredients Famous Proposed 1 2 3 4 5 6 Nitrile butadiene rubber SKN-18 100 100 100 100 100 100 Sulfur 2,5 2,5 2,5 2,5 2,5 2,5 Altax 2.7 2.7 2.7 2.7 2.7 2.7 Zinc white 7.5 7.5 7.5 7.5 7.5 7.5 Diphenylguanidine 0.25 0.25 0.25 0.25 0.25 0.25 Aldol-α-naphthylamine 4.0 4.0 4.0 4.0 4.0 4.0 Neozone D 1,0 1,0 1,0 1,0 1,0 1,0 Soot furnace PM-15 120 120 120 120 120 120 Dibutylsebacinate 2.0 2.0 2.0 2.0 2.0 2.0 Santoflex IP 1,0 1,0 1,0 1,0 1,0 1,0 Stearic acid (technical) 1,0 1,0 1,0 1,0 1,0 1,0 Ftoroplast F-32LN OST 6 05432-78 - 7.0 10 fifteen eighteen 22 table 2
Abrasion and coefficient of friction of rubbers Indicators 1 2 3 4 5 6 Abrasion (α), m ³ / tJ 332 261 306 301 298 296 Coefficient of friction (/) 0.32 0.44 0.22 0.25 0.21 0.21

Table 3
Mechanical indicators Indicators 1 2 3 4 5 6 Conditional tensile strength, MPa 18.2 18,4 19.1 18.1 19.3 15.4 Elongation at break,% 201 191 189 193 194 187 Relative residual deformation under compression by 20% for 24 hours in air (temperature 120 ° С),% fifteen 16 eighteen 17 17 28 Notes
1 Conditional tensile strength, elongation at break was determined according to GOST 270-75.
2 Relative residual deformation after compression - according to GOST 9.029-74.

Claims (1)

Rubber mixture based on nitrile butadiene rubber SKN-18, including sulfur, altax, zinc white, diphenylguanidine, aldol-α-naphthylamine, carbon black, stearic acid and fluoroplast, characterized in that it contains 32 fluoroplastic powder as a fluoroplast as an anti-friction additive and additionally Neozone D, dibutylsebacinate, Santoflex IP in the following ratio of mixture components, parts by weight: Nitrile butadiene rubber SKN-18 100 Sulfur 2,5 Altax 2.7 Zinc white 7.5 Diphenylguanidine 0.25 Aldol-α-naphthylamine 4.0 Neozone D 1,0 Soot soot 120 Dibutylsebacinate twenty Santoflex IP 1,0 Stearic acid 1,0 Powder fluoroplastic F-32LN 10-18