RU2374312C1 - Method of preparing aqueous lubricating compositions - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a method of preparing aqueous lubricating compositions, mainly meant for lubricating close steel surfaces, such as a "rail-wheel" system, "tractor-trailer" and other friction assemblies under large loads. A binding agent is prepared by mixing aqueous solutions of urea-formaldehyde resin (A), polyethyleneglycol (B) and polyvinylacetate (C) in weight ratio in terms of dry components A:B:C ranging from 65:25:10 to 92:6:2 in an agitation tank of not less than 1000 rpm for 20 to 100 minutes. An acid hardener for the urea-formaldehyde resin is then added - H-montmorillonite in amount of 15 to 60 wt % per 100 pts. wt of the dry mixture and while constantly stirring, a solid lubricant is added - powdered mixture of pentlandite with a carbon component in ratio ranging from 97:3 to 3:97. While stirring, a friction modifier is added and the mixture is stirred for 20 to 60 minutes. The obtained composition contains the following, in pts. wt: binding agent 10 to 20, solid lubricant 5 to 40, friction modifier 5 to 40, water 75 to 95.

EFFECT: high adhesion and good strength properties and given friction characteristics of the composition.

2 tbl, 9 ex

Description

The invention relates to a method for producing aqueous lubricating compositions intended primarily for the lubrication of welded steel surfaces, such as a rail-wheel system, a tractor-trailer and other friction units subjected to heavy loads.

The most common lubricant for the above systems is a grease consisting of mineral oils and various additives. Most of this lubricant is lost immediately after contact of the mating surfaces due to poor adhesion, which leads to the need for excessive consumption of material and environmental pollution by non-biodegradable components.

A known example of the preparation and use of an aqueous lubricant composition, which is an aqueous dispersion of graphite (see Swiss application 669207 A5). The disadvantage of this composition is the complete lack of adhesion (adhesion) to the steel surface and, as a result, its rapid removal. CH 669207A5 describes a method for producing a composition containing a polymer resin, but since the resin does not change its properties after application to the steel surface, this drawback is not eliminated.

The closest prototype of the claimed invention is a lubricant for use on railways and for heavy loads and a method for its production (see RU (11) 2220.189 (13) C2, claimed by American authors). The production method consists in preparing an aqueous composition containing 60-90% water, 5-18% binding agent, 3-32% friction modifier, 3-32% solid lubricant and 0.002% non-wetting agent nonylphenoxypolyol.

As a solid lubricant, molybdenum sulfide, graphite and metal stearates, previously widely described for these purposes, are offered as a friction modifier - a wide range of substances: metal salts (carbonates, silicates, sulfates), metal oxides, various modifications of quartz, aluminosilicates, naphthalene and polyethylene. A bonding agent providing adhesion of the composition to a metal surface is sodium - montmorillonite (bentonite).

However, montmorillonite, which is a calcium-aluminum silicate and one of the types of natural clays (bentonite clay) in any form, including sodium montmorillonite, does not significantly increase the adhesion of lubricating compositions to metals due to its extremely low cohesive strength.

The aim of the invention is a method for producing aqueous lubricating compositions containing a bonding agent based on biodegradable components, which, after application to abutting steel surfaces and evaporation of water, provides high adhesion and increased strength properties of the composition as the most important factors in increasing its service life while achieving specified frictional characteristics due to the introduction of a solid lubricant and a friction modifier in a certain ratio.

This goal is achieved in that the binding agent is prepared by mixing aqueous solutions of urea-formaldehyde resin (A), polyethylene glycol (B) and polyvinyl acetal (C) in a weight ratio in terms of dry components A: B: C from 65:25:10 to 92: 6: 2 in a container with a stirrer of at least 1000 rpm for 20-100 min, followed by the introduction of an acid hardener for urea-formaldehyde resin - N-montmorilonite and in an amount of 15 to 60 parts by weight per 100 parts by weight dry mixture and stirring at room temperature for 30-90 min and further introducing with constant stirring a solid lubricant — a ground mixture of pentlandite primary mineral with a carbon component in a ratio of 97: 3 to 3:97, and then introducing a friction modifier with stirring, wherein the composition contains in parts by weight

Bonding agent 10-20 Solid lubricant 5-40 Friction modifier 5-40 Water 75-95

Example 1

Preparation of H-montmorilonite.

100 parts by weight are charged into a stirred reactor. water and 100 parts by weight Montmorilonite mineral (industrial name is bentonite or bentonite clay), after which 50 parts by weight are added. 20% hydrochloric acid. The mixture is stirred for two hours, as a result of which the H-ion is introduced into the structure of montmorillonite, converting it to H-montmorillonite, and the Cl-ion remains in solution. After water washing on the filter, the Cl-ion is removed, and the wet H-montmorilonite is sent to another reactor, where a mixture of the remaining components of the aqueous lubricating composition is prepared.

Preparation of an aqueous lubricant composition

In a reactor equipped with a high-speed stirrer, at least 1000 rpm, load 85 wt.h. water and one after another 15 wt.h. the components of the binding agent is urea-formaldehyde resin (A), polyethylene glycol (B), polyvinyl acetate (C) in the ratio A: B: C = 78: 16: 6. The mixture was stirred at room temperature for 60 minutes, after which a urea-formaldehyde resin hardener, N-montmorilonite, was added in an amount of 4 parts by weight. (i.e. 38 parts by weight per 100 parts by weight of the urea-formaldehyde resin present in the composition. H-montmorilonite cures the urea-formaldehyde resin only after evaporation of the water.), after which 22 parts by weight of solid lubricating agent is a ground mixture of the primary mineral pentlandite, formula (Ni, Fe) ₉ S ₈ and graphite in a ratio of 50:50, then 22 wt.h. friction modifier - ground calcium silicate. After stirring for 15 minutes, the resulting aqueous lubricant composition is poured into an airtight container.

The aqueous lubricant composition is applied by spray gun or brush, followed by drying at 20 ° C for 12 hours in the absence of precipitation.

Examples 2-9 are carried out analogously to example 1, but with a change in parameters and components in accordance with table 1. The properties of aqueous lubricating compositions in comparison with the prototype are shown in table.2, which shows the advantage of the claimed invention.

Claims (1)

A method of obtaining an aqueous lubricating composition comprising mixing a binding agent, a solid lubricating agent and a friction modifier, characterized in that the binding agent is prepared by mixing aqueous solutions of urea-formaldehyde resin (A), polyethylene glycol (B) and polyvinyl acetal (B) in a weight ratio in terms of dry components A: B: C from 65:25:10 to 92: 6: 2 in a container with a stirrer of at least 1000 rpm for 20-100 min, followed by the introduction of an acid hardener for urea-formaldehyde resin - N-montmorilonite in an amount from 15 to 60 parts by weight per 100 parts by weight dry mixture and with constant mixing of a solid lubricant with a ground mixture of pentlandite with a carbon component in a ratio of 97: 3 to 3:97, and then introducing a friction modifier with stirring and holding all components for 20-60 minutes while stirring, while the composition contains, parts by weight:
binding agent 10-20 solid lubricant 5-40 friction modifier 5-40 water 75-95