RU2295546C1 - Antifriction composition - Google Patents

Abstract

FIELD: chemistry of polymers.

SUBSTANCE: invention relates to filled polymeric compositions designated for making large-scaled articles of antifriction profile. Antifriction composition comprises carbon fabric with fiber of average size of crystallites by basic plane 3.0-6.0 nm and package thickness of basic planes 1.0-4.0 nm. Composition comprises the following ratio of components, wt.-%: carbon fabric, 35-50; phenolformaldehyde binding agent, 35-50; oleic acid, 1.5-5; tin or tin babbit alloy powders, 5-10. Invention provides reducing friction coefficient of antifriction composition in water and retaining high strength and wear resistance in working under control by controlling bodies of different hardness.

EFFECT: improved and valuable properties of composition.

3 cl, 1 tbl, 8 ex

Description

The invention relates to filled polymer compositions, in particular to polymer compositions based on carbon fabric and phenol-formaldehyde binder. These compositions are intended for the manufacture of anti-friction products, such as plain bearings and mechanical seals for various devices, equipment for oil production, oil refining, mining and chemical industries. Bearings and mechanical seals of such equipment work in contact with water, oil and aggressive fluids.

Known anti-friction composition, including carbon fabric and a thermosetting binder (RF patent No. 2153107, Mcl ⁷ C 08 63/00, publ. 20.07.2000, Bull. No. 21). Carbon fabric has an average crystallite size along the basal plane of 3.0-6.0 nm and a thickness of the package of basal planes of 1.0-4.0 nm. As a polymer binder, the composition contains a phenol-formaldehyde resin with the addition of 4-10 wt.% Unsaturated fatty acids, such as oleic, or epoxy.

The specified antifriction composition has high wear resistance during friction on solid steels with a Rockwell hardness above 40, strength and dimensional stability during friction in water. Bearings, including those for hydraulic turbines and propeller shafts, and mechanical seals made from this composition, are successfully operated with water lubrication. However, this composition has a relatively high coefficient of friction.

The closest set of essential features to the claimed composition is an antifriction composition comprising carbon fabric and a polymer binder (RF patent No. 2181128, MKI ⁷ C 08 L 63/00, publ. 2002, BI No. 10). The composition contains carbon fabric the same as in RF patent No. 2153107, and as a thermosetting binder - phenol-formaldehyde resin with the addition of oleic acid or epoxy resin. Carbon fabric before impregnation with a polymer binder is treated with an aqueous dispersion of polytetrafluoroethylene with a particle size of 0.1-0.4 microns. The antifriction composition has high strength and wear resistance during friction in air on solid steel. This allows you to use the composition according to the patent of Russian Federation 2181128 for the manufacture of friction parts of equipment that works alternately with water lubricant and in air; such equipment is, for example, pumps, hydraulic turbines, hoisting mechanisms, drilling rigs.

The disadvantage of this composition is its high coefficient of friction in water. In addition, according to our data, antifriction compositions according to RF patents No. 2153107 and No. 2181128 have low abrasion resistance upon viscous stainless steels with a Rockwell hardness below 40. Viscous stainless steels characterized by high technological, strength and corrosion properties are less prone to cracking and are widely used in mechanical engineering.

There are many details of friction for which the value of the coefficient of friction of the material is the main requirement. In some cases, for design reasons, such as restrictions on weight, dimensions, etc., it is impossible to increase the drive power. With limited drive power, it is not possible to start the mechanism when the coefficient of friction of a friction pair is high. Thus, the value of the coefficient of friction determines the operability of the mechanism.

The technical result to which the claimed invention is directed is to reduce the coefficient of friction in water of the antifriction composition while maintaining high strength and wear resistance when working on counterbodies of different hardness.

The specified technical result is achieved by the fact that the antifriction composition comprising carbon fabric with an average crystallite size in the fiber along the basal plane of 3.0-6.0 nm and a thickness of the package of basal planes of 1.0-4.0 nm, phenol-formaldehyde binder, oleic acid and dispersed metal filler, as the latter contains a metal powder selected from the group comprising tin and tin babbit, in the following ratio of components (wt.%):

carbon fabric 43.5-50

phenol formaldehyde binder 35-50

oleic acid 1.5-5

tin or tin babbit powder 5.0-10.0

The carbon fabric used in the inventive composition is obtained as described in the patent of the Russian Federation No. 2153107.

Phenol-formaldehyde resin, taken as a binder, is produced by industry according to GOST 901-78.

Oleic acid is produced in accordance with GOST 7580-91.

The tin babbits of grades B88, B83 and B83C (GOST 1320-74) contained 81-90 wt.% Tin and 10-19 wt.% Impurities such as antimony and copper (grade B83) and additionally lead (grade B83C) or cadmium and Nickel (grade B88). They are used for filling plain bearings or other anti-friction parts working with oil lubrication. A soft base - tin allows the bearing to run in to the shaft and form a microrelief on the surface that holds the lubricant. Powder babbits were not used in polymer antifriction compositions.

Tin grades PO-1 (GOST 9723-73) and PO-0 (TU 48-0220-42-92) are not used for anti-friction purposes.

Babbit powders are produced by industry according to GOST 1320-74. They have a dispersion of 5-100 microns, the smallest particle size is 5 microns.

Tin powders have a dispersion of 5-100 microns (PO-1) and 5-112 microns (PO-0).

Further, the claimed invention is illustrated by examples, but not limited to.

Example 1

115.8 kg of a 38% solution of phenol-formaldehyde resin in ethanol (bakelite varnish of the LBS-9 grade according to GOST 901-78) are loaded into the reactor; in terms of the dry residue, the solution contains 44 kg (44 wt.%) Of phenol-formaldehyde resin. 3 kg (3 wt.%) Of oleic acid are added with stirring. The solution is poured into the bath of the impregnation machine and impregnated with 45 kg (45 wt.%) Of carbon fabric. The impregnation rate is 1 kg / min, the temperature in the drying chamber of the impregnation machine is 100-120 ° C. 8 kg (8 wt.%) Of tin babbitt powder B83 is applied to the impregnated carbon fabric (prepreg). Samples are made from the obtained antifriction composition by hot pressing at a temperature of 140 ° C and a pressure of 5 MPa. The exposure time at the pressing temperature was 2 hours

The resulting antifriction composition was investigated by the following indicators.

1. Friction coefficient f: f × l0 ^-3 at a contact pressure of 10 MPa, sliding speed 1 m / s, SMC-2 type friction machine, water lubrication, counterbody steel (18X2H4MA HRC ... 60) and mild stainless steel ( 08X18H10T, HRC ... 20) method No. 11-114-345-2002, with friction in parallel and perpendicular to the layers of fabric in the composition.

2. Wear rate (wear resistance) I: I × 10 ^-8 at a contact pressure of 10 MPa, sliding speed 1 m / s, friction machine type SMTs-2, lubrication with water, counterbody - steel (18X2N4MA, HRC ... 60) and mild stainless steel (08X18H10T, HRC ... 20) method No. 11-114-345-2002, with friction in parallel and perpendicular to the fabric layers in the composition.

3. Strength indicators:

tensile stress, MPa, according to GOST 23802-79;

breaking stress during compression parallel to the layers, MPa, according to GOST 23803-79.

The composition and physico-mechanical properties of the composition are presented in the table.

Examples 2 and 3.

Antifriction compositions were obtained as in example 1, but the composition of composition 2 was added tin babbit powder in an amount of 10 wt.%, And the composition of composition 3 was introduced tin babbit powder in an amount of 5 wt.%.

The compositions and physico-mechanical properties of the compositions are presented in the table.

Examples 4 and 5. Antifriction compositions were obtained as in example 1, but the composition of composition 4 was introduced tin powder PO-1, and the composition of composition 5 was introduced tin powder PO-0,

The compositions and physico-mechanical properties of the compositions are presented in the table.

Example 6 (control according to the patent of the Russian Federation No. 2153107).

118 kg (45 wt%) of a solution of phenol-formaldehyde resin in ethanol (bakelite varnish of the LBS-9 grade according to GOST 901-78. The concentration of the solution is 38%) is loaded into the reactor. 3.5 kg (3.5 wt.%) Of oleic acid are added with stirring. The solution is poured into the bath of the impregnation machine and soaked in 51.5 kg (51.5 wt.%) Of carbon cloth. The impregnation rate is 1 kg / min, the temperature in the drying chamber of the impregnation machine is 100-120 ° C.

The obtained antifriction composition was pressed and investigated as in example 1.

The composition and physico-mechanical properties of the compositions are presented in the table.

Example 7 (control).

115.8 kg of a 38% solution of phenol-formaldehyde resin in ethanol (bakelite varnish of the LBS-9 grade according to GOST 901-78) are loaded into the reactor; in terms of the dry residue, the solution contains 44 kg (44 wt.%) Of phenol-formaldehyde resin. 3 kg (3 wt.%) Of oleic acid are added with stirring. The solution is poured into the bath of the impregnation machine and impregnated with 45 kg (45 wt.%) Of carbon fabric. The impregnation rate is 1 kg / min, the temperature in the drying chamber of the impregnation machine is 100-120 ° C. 8 kg (8 wt.%) PNE-1 nickel powder is applied to the impregnated carbon fabric (prepreg) according to TU 1793-001-07622839-2002.

The obtained antifriction composition was pressed and investigated as in example 1.

Example 8 (control prototype).

Carbon fabric is pretreated with a dispersion of polytetrafluoroethylene (PTFE) on a vertical impregnation machine. The dispersion of 4DV grade (TU 6-05-1246-96) has a PTFE concentration of 58 wt.% And a polymer particle size of 0.1-0.4 microns. The dispersion is diluted with water to a concentration of PTFE of 4.5 wt.%, The carbon fabric is impregnated at a speed of 8-10 m / h and the treated fabric is dried in a drying shaft at a temperature of 155 + 5 ° C. The content of PTFE in the carbon fabric is 4% wt.%.

118 kg of a solution of phenol-formaldehyde resin in ethanol are loaded into the reactor (bakelite varnish of the LBS-9 grade according to GOST 901-78, the concentration of the resin in the solution is 38 wt.%). 3.5 kg of oleic acid is added with stirring. The solution is loaded into the bath of an impregnation machine and impregnated with 51.5 kg of carbon cloth pretreated with a dispersion of PTFE at a mass ratio of carbon cloth to PTFE of 49.0: 2. Impregnation rate - 1 kg / min. The temperature in the drying chamber of the impregnation machine is 100-120 ° C. The content of PTFE in carbon fiber is 2.5 wt.%.

The obtained antifriction composition was pressed and investigated as in example 1.

The composition and physico-mechanical properties of the compositions are presented in the table.

Table.
The composition and properties of antifriction compositions. Indicator Example Patent No.
2153107 With nickel According to the prototype one 2 3 four 5 6K 7K 8K The content of components, wt.% - phenol-formaldehyde resin (calculated on the dry residue) 44 35 fifty 44 44 55 44 45 - oleic acid 3 5 1,5 3 3 3,5 3 3,5 - carbon fabric 45 fifty 43.5 45 45 41.5 45 49.0 - tin babbit 8 10 5 - - - - - - tin PO-1 - - - 8 - - - - - tin PO-0 - - - - 8 - - - - copper - - - - - - - - - nickel - - - - - - 8 - ftoroplast - - - - - - 2,5 Properties: coefficient of friction, f - - - - - - - - along layers on steel 08X18H10T 0,03 0,025 0,03 0,03 0,025 0.09 0.10 0.06 at the end of the layers 08Х18Н10Т 0,03 0,03 0,03 0,03 0,03 0.09 0.12 0.06 along layers on 18Kh2N4MA steel 0,03 0,025 0,03 0,025 0,025 0.09 0.10 0.06 at the end of the layers for steel 18X2H4MA 0,03 0,03 0,03 0,03 0,03 0.09 0.11 0.06 - wear rate, × 10 ^-8 along layers on steel 08X18H10T 14.0 15.0 14.0 13.0 13.5 130 12.0 thirty at the end of the layers on steel 08X18H10T 6.5 6.2 7.0 6.0 6.1 80 5,0 twenty along layers on 18Kh2N4MA steel 0.6 0.5 0.7 0.6 0.6 0.9 0.4 0.8 at the end of the layers for steel 18X2H4MA 0.55 0.4 0.6 0.55 0.5 0.8 0.38 0.7 - ultimate tensile stress parallel to the layers, MPa 150 150 155 145 150 150 155 140 - destructive stress during compression parallel to the layers, MPa 180 175 182 180 180 180 185 170

As can be seen from the table, the claimed composition in comparison with the prototype and analogues has a significantly lower coefficient of friction when working in water even on steel of low hardness. At the same time, with friction on low hardness steel, the claimed composition has high wear resistance, as well as the prototype.

We unexpectedly found that it was tin babbits and tin that simultaneously reduced the coefficient of friction and the wear rate (increased wear resistance). Other modifiers (nickel, copper, fluoroplastic) either increase the coefficient of friction or do not affect it.

Claims (3)

1. An antifriction composition comprising carbon fabric with a fiber with an average crystallite size on the basal plane of 3.0-6.0 nm and a thickness of the package of basal planes of 1.0-4.0 nm and a polymer thermosetting binder based on phenol-formaldehyde resin and oleic acid, characterized in that it further comprises a metal powder selected from the group comprising tin and tin babbit, in the following ratio of components, wt.%: Carbon fabric 43.5-50 Phenol formaldehyde binder 35-50 Oleic acid 1,5-5 Tin or tin babbit powder 5-10 2. The antifriction composition according to claim 1, characterized in that it contains tin powder with a particle size of 5-112 microns. 3. The antifriction composition according to claim 1, characterized in that it contains tin babbit powder with a particle size of 5-100 microns.