RU2181732C1 - Friction composition and method of preparation thereof - Google Patents

Abstract

FIELD: friction materials. SUBSTANCE: composition contains, wt %: powderlike phenolformaldehyde resin 15-21, drying oil 2-5, fibrous filler 39- 48, metal-containing compound 8-23, carbon filler 2-7, and mineral additive. Composition is prepared by mixing phenol- formaldehyde resin, drying oil, metal-containing compound, carbon filler, and mineral additive, after which fibrous filler is added during agitation. EFFECT: increased wear resistance and flowability of composition, reduced treatment expenses, and simplified manufacture of friction pieces. 2 cl, 2 tbl, 4 ex

Description

 The group of inventions relates to friction materials based on powdered phenol-formaldehyde resins and to a method for their production, used for the manufacture of friction products used in mechanical engineering for various sectors of the economy.

 Known press material for frictional purposes and the method of its production - see SU 359954 A, 08/15/1990. The press material contains an anilinophenol formaldehyde resin with nitrile rubber in a ratio of 4: 1 to 5: 1 in combination with target additives - asbestos, barite, graphite and copper powder. According to the method, the molding mixture for friction material is made by dry mixing of the components in closed mixers.

 Also known is a polymer composition of frictional purposes, including anilinophenol formaldehyde resin, nitrile rubber, asbestos, barite, aluminum oxide, copper powder, bronze chips and graphite, which additionally contains calcium fluoride to increase wear resistance. Obtaining a friction composition is carried out by simultaneous mixing of all components / see SU 593468 A, 02.23.1991 /.

 Compositions obtained by known methods have insufficient wear resistance, have high hardness and low fluidity of mixtures, which complicate their processing in the manufacturing process of manufacturing friction structural elements.

 The closest in technical essence and the achieved result to the proposed group of inventions are the friction composition and the method for its preparation according to SU 1114340 A, 09/15/1984 (prototype).

Known friction composition on an organic basis, including phenolic resin, a fibrous filler in the form of asbestos or a mixture of glass and mineral fibers, a metal-containing compound in the form of a substance from the group: zinc, bronze, copper, iron, oxides of these metals and aluminum oxide or an oxide of their mixture, organic modifier - a substance from the group: cashew seed powder, rubber, natural latex, molasses, asphalt or a mixture thereof; inorganic modifier - a substance from the barite group, chalk, talc, tripoli, cryolite, wollastonite or cm here and the friction modifier - particles or powder of coal and / or graphite in the following ratio of components, wt.%:
Phenolic resin - 8 - 14
Fibrous filler - 25 - 34
Metal-containing compound - 4 - 22
Organic Modifier - 1 - 7
Friction Modifier - 18 - 34
Inorganic Modifier - Else
The friction composition is obtained by mixing simultaneously all of these components until a homogeneous mixture is formed.

 A disadvantage of the known composition obtained by simultaneous mixing of the components is the low fluidity of the mixture and the high hardness of friction products made from it, which impede processing in the technological process of their production, friction products from this composition do not have sufficient wear resistance.

 The technical problem underlying the group of inventions is to create a cheap friction composition that provides increased wear resistance of products made from it and has improved technological properties that contribute to lower processing costs and simplify the manufacturing process of friction products.

The problem is solved in that the friction composition, including a powdery phenol-formaldehyde resin, a fibrous filler, a metal-containing compound, a carbon filler and a mineral additive, additionally contains drying oil in the following ratio of components, wt.%:
Powdered Phenol-Formaldehyde Resin - 15-21
Drying oil - 2 - 5
Fibrous filler - 39 - 48
Metal-containing compound - 8 - 23
Carbon filler - 2 - 7
Mineral Supplement - Else
The composition as a fibrous filler contains - asbestos, mineral, synthetic fibers or mixtures thereof, metal-containing compounds - powders of copper, iron, brass, bronze, steel shavings, as well as dispersed metal oxides - aluminum, iron, chromium or a mixture thereof, carbon filler - graphite, coal, carbon black or mixtures thereof, and mineral additives - barite, kaolin.

 A method of obtaining the specified friction composition, carried out by mixing powdered phenol-formaldehyde resin, a fibrous filler, a metal-containing compound, a carbon filler and a mineral additive, consists in introducing an additional component - drying oil, mixing, then introducing the fibrous filler and mixing the entire mass until homogeneous. Introduction to the composition of drying oil - a cheap affordable product allows you to increase the fluidity of mixtures, reduce the hardness of the material, increase the wear resistance of friction products. This is achieved by the fact that drying oil, being a film-forming substance containing vegetable oils, acts as a softener at the stage of processing mixtures. Subsequently, during the heat treatment of the material, it is structured together with the resin, providing a more elastic polymer structure, which leads to a decrease in polymer hardness and an increase in wear resistance.

 The introduction of drying oil into the mixture of these components before the introduction of the fibrous filler ensures its uniform distribution in the manufactured composition. According to the invention, natural (linen polymerized), combined (Oxol brand) and synthetic oil-polymer drying oils are used.

 Compliance with the quantitative ratio of the components of the composition and the specified sequence of operations of the method for its preparation allows you to create a new low-cost composition that provides high wear resistance of friction products, sufficient fluidity and hardness of the material, facilitating and cheapening the process and manufacturing of friction products.

 Examples of formulations of the known and proposed compositions containing drying oil and without it are shown in table 1. Physico-mechanical properties of the compositions are shown in table 2.

 The friction composition is prepared as follows.

Dry components: powdered phenol-formaldehyde resin, a metal-containing compound, a carbon filler and a mineral additive are loaded into the mixer and mixed for 3-5 minutes. Then, the drying oil is poured into the working mixer, continuing mixing, and only then the fibrous filler is loaded, continuing the mixing process until the mixture reaches a homogeneous state. Then the finished mixture is unloaded from the mixer. For the manufacture of friction products from the resulting composition, the mixture is processed according to any known technology. For example, preforms are briquetted in a mold under pressure, then subjected to hot molding at a temperature of 150-190 ^o With a pressure of the order of 300-400 kG / cm

 It was experimentally established that going beyond the specified wt.% Of the ratio of the components of the friction composition, as well as violating the above process sequence, do not provide a positive result for solving the problem.

 Example 1. In a paddle mixer is loaded into the mass parts: phenol-formaldehyde resin grade SFP-015A - 16, copper powder - 10, brass chips - 4, alumina - 4.5, graphite - 1, technical carbon - 2, barite - 17 5 and kaolin - 5, all mixed for 3 minutes. Then asbestos is loaded - 40 m.h. and again mixed until smooth. The total mixing time is 13 minutes. Then the finished mixture is unloaded from the mixer.

 Example 2. In a paddle mixer load, m.h .: resin SPF-015A - 20, brass shavings - 5, minium iron - 2, alumina - 4, graphite - 3, barite - 19 and kaolin - 5, mix for 5 minutes, load asbestos - 42 mph and stirred for another 10 minutes until the mixture is homogeneous, which is then discharged from the mixer.

 Example 3. In a paddle mixer load, m.h .: phenol-formaldehyde resin brand SFP-015A - 16, copper powder - 10, brass chips - 4, alumina - 4.5, graphite - 1, technical carbon - 2, barite - 14 5 and kaolin - 5, mix for 3 minutes Then, 3 mph are introduced into the working mixer. drying oils "Oxol", continuing mixing, and then load 40 m.h. asbestos and stirred for 20 minutes. The resulting homogeneous mass is discharged from the mixer.

 Example 4. In a paddle mixer load, m.h .: resin SFP-015A - 20, brass chips - 5, red iron ore - 2, alumina - 4, graphite - 3, barite - 15, kaolin - 5 and mix for 5 min Then pour 4 m.h. drying oils "Oxol" and, continuing mixing, load 42 m.h. asbestos. Mix the mixture for 10 min until smooth and unload from the mixer.

Example 5. In a paddle mixer was loaded, m.h .: resin SFP-015A - 16, copper powder - 10, brass chips - 4, alumina - 4.5, graphite - 1, industrial carbon - 2, barite - 14.5 and kaolin - 5, was stirred for 3 minutes Then, 3 mph was poured into the working mixer. flax polymerized drying oil, while continuing mixing, loaded 40 m.h. asbestos and mixed for 10 min until the mixture is uniform. The fluidity of the composition was 60 mm, the Brinell hardness was 270 MPa and the volumetric wear 0.3 / 10 ^-12 m ³ / J /.

Example 6. In a paddle mixer was loaded, m.h .: resin SFP-015A - 16, copper powder, red iron oxide - 2, alumina - 4, graphite - 3, barite - 15 and kaolin - 5, was mixed for 5 min. Then introduced 4 m.h. flax polymerized drying oil and, while continuing to mix, loaded 42 mph asbestos and mixed for 10 minutes. The resulting composition had indicators: fluidity - 42 mm, Brinell hardness - 260 MPa, linear wear - 0.5 / 10 ^-12 m ³ / J /.

Example 7. In the paddle mixer was loaded m.h .: resin SFP-015A - 16, copper powder - 10, brass chips - 4, alumina - 4.5, graphite - 1, industrial carbon - 2, barite - 14.5 and kaolin - 5, was stirred for 3 minutes and 3 mh were poured into a working mixer. oil polymer drying oil. Continuing mixing, loaded 40 m.h. asbestos and mixed for 10 minutes. The composition had indicators: fluidity - 55 mm, Brinell hardness - 290 MPa and volumetric wear of 0.4 / 10 ^-12 m ³ / J /.

Example 8. The following components were loaded into a paddle mixer, m.h .: resin SFP-015A - 20, brass shavings - 5, minium iron - 2, alumina - 4, graphite - 3, barite - 15 and kaolin - 5, were mixed in for 5 minutes and then poured 4 m.h. oil polymer drying oil. The last mixer was loaded 42 m.h. asbestos and mixed for 10 minutes. The fluidity of the composition was 38 mm, the Brinell hardness was 270 MPa and the linear wear was 0.6 / 10 ^-12 m ³ / J /.

 Friction compositions according to examples 1, 3, 5 and 7 are used for the manufacture of disc brakes, and according to examples 2, 4, 6 and 8 - for clutch linings.

 The wear rates of the known composition and the compositions of the examples were determined on samples of friction material for a disk brake / volumetric wear / and in the full-sized site of the clutch linings / linear wear / for the test program.

 The results shown in table 2 show that the proposed friction composition has the best indicators of wear and fluidity.

Claims (1)

1. Friction composition comprising a powdered phenol-formaldehyde resin, a fibrous filler, a metal-containing compound, a carbon filler and a mineral additive, characterized in that it additionally contains drying oil in the following ratio of components, wt. %:
Powdered Phenol-Formaldehyde Resin - 15-21
Drying oil - 2 - 5
Fibrous filler - 39 - 48
Metal-containing compound - 8 - 23
Carbon filler - 2 - 7
Mineral Supplement - Else
2. A method of obtaining a friction composition according to claim 1 by mixing a powdered phenol-formaldehyde resin, a fibrous filler, a metal-containing compound, a carbon filler and a mineral additive, characterized in that a drying oil is introduced into the mixture of a powdered phenol-formaldehyde resin, a metal-containing compound, a carbon filler and a mineral additive, mixed and then the fibrous filler is introduced.

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