RU2393177C1 - Method of producing friction polymer materials - Google Patents

Abstract

FIELD: chemistry. ^ SUBSTANCE: invention relates to a method of obtaining friction polymer materials and can be used in making brake shoes of railway wagons and locomotives, for motor transport, cranes, structural articles in machine building and other articles. The method of producing friction polymer materials involves processing butadiene or butadiene-nitrile rubber on plastification equipment with their subsequent mixture with a vulcanising agent in form of organic peroxides (A) in form of mixtures with powder (B) and solid phenol-formaldehyde resin (C) in ratio A:B:C ranging from 2:96:2 to 8:70:22. Further, a water-soluble epoxy component is added, which is a product of reacting diane resin with glycol and an aliphatic expoxy resin in form of impregnation of an aqueous solution of the resin on fibre filler with subsequent drying at resin content of 4-30% in terms of the dry product. Fine mineral or metal powder is used. The material contains the following in pts. wt: rubber - 100, vulcanising agent - 30-100, saturated fibre material - 20-120. ^ EFFECT: improved strength characteristics with simultaneous prevention of diffusion penetration of sulphur into the steel surface of touched article, as well as increased labour safety when mixing components on the plastification equipment - rolls, rubber mixers etc. ^ 2 tbl, 1 ex

Description

The invention relates to a method for producing friction polymer materials and can be used in the manufacture of brake pads for railway cars and locomotives, for vehicles, cranes, structural products in mechanical engineering, and other products.

Friction polymeric materials are known and methods for their production on the basis of butadiene rubbers containing vulcanizing additives such as sulfur, tiuram and other sulfur-containing substances, including mineral powders, inorganic fibers and metal shavings (see Encyclopedia of Polymers, vol. 3, ed. "Soviet Encyclopedia" , M., 1977, pp. 786-788). Analog 1.

The disadvantages of this method and material are the low strength characteristics of the material due to poor adhesion of the polymer to the fibers, the destruction of the fibers during the mixing of the components, the formation of fibrous dust hazardous to the health of personnel, and insufficiently high antifriction properties. The authors also found that sulfur-containing brake pads during operation cause sulfur to diffuse into the surface of the steel wheel, followed by its interaction with alloying metals, which leads to accelerated destruction of the metal surface.

There are also known methods for producing rubber products based on butadiene rubbers using sulfur-free vulcanizing additives — phenol-formaldehyde resins and peroxides (see Encyclopedia of Polymers, vol. 1, ed. “Soviet Encyclopedia”, M., 1977, p. 543) . Analog 2.

However, the replacement of sulfur-containing components with phenol-formaldehyde resins or peroxides eliminates only one of the listed disadvantages of Analog 1, i.e. elimination of the diffusion effect of sulfur, keeping the rest.

The closest prototype of the proposed solution is a method of producing a friction polymer material by processing rubbers with an epoxy component on plasticizing equipment (rollers or a rubber mixer), followed by mixing with vulcanizing additives and fillers, fibrous and powder (see RU 2.175.335 C2, from 04.24.1999 g .).

This method allows to increase strength indicators, for example, tensile strength by 4 times. But it does not eliminate the diffusion of sulfur into the steel surface in contact with the resulting material.

The aim of the invention is to significantly increase the strength characteristics of friction polymeric materials while eliminating the diffusion penetration of sulfur into the steel surface of the product in contact, as well as improving labor safety during the mixing of components on plasticizing equipment - rollers, rubber mixers, etc.

This goal is achieved by the fact that when implementing the method, organic peroxides (A) are used as a vulcanizing additive in the form of mixtures with powder (B) and solid phenol-formaldehyde resin (C) in a ratio of A: B: C from 2: 96: 2 to 8: 70:22 and a water-soluble epoxy component, which is the product of the interaction of a diane resin with glycol and an aliphatic epoxy resin, is introduced as an impregnation applied from an aqueous solution of the resin onto a fibrous filler, followed by drying to remove water, when the resin is contained in a fiber leaf filler from 4% to 30% in terms of dry product, while the material contains in parts by weight:

Rubber one hundred Vulcanizing additive 30 ÷ 100 Impregnated fibrous material 20 ÷ 120

Example 1

Preparation of vulcanizing additives

In a paddle Z-shaped mixer load 83 wt.h. mineral powder consisting of a mixture of alumina (GOST 30558), crystalline graphite (GOST 5279), barite concentrate (GOST 4682) and calcined diatomaceous crumb (TU 5761-003-25310144-99) in a ratio of 1: 1: 1: 1, then in turn load 11 parts by weight ground phenyl formaldehyde resin brand resol-300 (GOST 10759-85) in ground form and 6 parts by weight benzene peroxide (GOST 14888-88). The powder mixture is stirred for 30 minutes and packaged.

Fibrous preparation

Preparation of Pre-Impregnated Fiber Filler

60 parts by weight are loaded into a paddle mixer. chopped glass fiber with a fiber diameter of 13 microns (K) simultaneously with a 50% aqueous solution of water-dispersed epoxy resin ETAL AK-732 (TU 2241-824-18826195-06), which is the product of the interaction of a mixture of diane and aliphatic epoxy resins with polyethylene glycol (L), when the ratio K: L = 78: 22, calculated on the dry component L. After stirring for 15 minutes, the impregnated fiber enters the dryer to remove water at 100 ° C. The impregnated dry fiber is an odorless elastic pulp, non-dusting, non-toxic, easily disintegrating with little tensile strength. Since the resin does not contain a hardener, the shelf life of the fiber impregnated with it is practically unlimited (tested over 2 years) and therefore it can be prepared in advance.

Obtaining friction polymer material

In the rubber mixer type RSVD 140-20 loaded 100 wt.h. butadiene rubber grade SKD-2 (GOST 14924), 65 wt.h. vulcanizing additives (powder mixture) and 60 parts by weight dried fiberglass impregnated with water-soluble epoxy resin. Stirring is carried out at 80 ° C for 25 minutes At the end of the production of the mixture, the lower shutter of the rubber mixer opens, the mass is unloaded and then sent for the manufacture of products (brake pads) at a temperature of 160 ° C for 15 minutes, followed by heat treatment in a thermostat for 30 minutes.

Examples 2 ÷ 6 are carried out analogously to example 1, but using components and parameters in accordance with table 1.

The properties of the material obtained in examples 1 ÷ 6 are shown in table 2. The data of the specified table indicate significant advantages of the proposed method, especially in terms of strength indicators.

Claims (1)

A method for producing friction polymer materials, including the processing of butadiene or nitrile butadiene rubbers on plasticizing equipment, followed by their mixing with a vulcanizing additive, an epoxy component and a fibrous filler in combination with finely divided mineral or metal powder, characterized in that organic additives are used as the vulcanizing additive peroxide (A) in the form of mixtures with powder (B) and solid phenol-formaldehyde resin (C) in the ratio A: B: C from 2: 96: 2 to 8:70:22 and in a soluble epoxy component, which is the product of the interaction of a diane resin with glycol and an aliphatic epoxy resin, is introduced as an impregnation applied from an aqueous solution of the resin onto a fibrous filler, followed by drying to remove water, when the resin content in the fibrous filler is from 4 to 30% in in terms of dry product, while the material contains, by weight:
rubber one hundred vulcanizing agent 30-100 impregnated fibrous material 20-120