RU2288254C1 - Plastic lubricant - Google Patents

Abstract

FIELD: lubricants.

SUBSTANCE: invention proposes a lubricant comprising the following components, wt.-%: perfluoropolyester based on product of the oligomerization reaction of hexafluoropropylene oxide, 93.5-96, and hydrophobized silica gel, 4-6.5. Proposed lubricant can be used in friction units working in broad range of environment temperatures. Invention provides expanding the temperature working range (from -45°C to +150°C), enhancing stability to components of rocket fuel and gaseous oxygen.

EFFECT: improved properties of lubricant.

2 tbl

Description

The invention relates to greases for friction units operating in a wide range of ambient temperatures.

Known lubricant containing, wt.%:

Diisooctylsebacinate 3-7 Water-repellent silica gel 14-16 Molybdenum disulfide 3-17 Polytetrafluoroethylene 1-5 Zinc dialkyldithiophosphate 0.5-1.5 Copper Naphthenate 0.1-1.0 Triethanolamine 0.5-1.5 Mineral oil Rest

(RF patent No. 20177796, C 10 M 161/00).

The disadvantages of this lubricant are its high volatility, instability in contact with rocket fuel and oxygen, insufficient performance at low temperatures.

Known lubricant containing perfluoropolyether based on hexafluoropropylene and low molecular weight polytetrafluoroethylene in the following ratio, wt.%:

Polytetrafluoroethylene 25-35 Perfluoropolyether 65-75

(Reference "Industrial organofluorine products" B.N. Maksimova and others L .: Chemistry, 1990, pp. 433-434).

Lubrication is characterized by insufficient performance of products at temperatures below minus 40 ° C, low colloidal stability.

Closest to the claimed composition is a lubricant containing perfluoropolyether based on the product of oligomerization of hexafluoropropylene oxide and, as a thickener, low molecular weight polytetrafluoroethylene in the following ratio, wt.%:

Perfluoropolyether 50-75 Low molecular weight polytetrafluoroethylene 24-40 Perfluorocarbon Oil Fraction 1,0-10

(RF patent No. 2150490, C 10 M 169/04).

The disadvantages of this lubricant are insufficient performance at low temperatures, instability to the components of rocket fuel, as well as a fairly high volatility.

The objective of the invention is to provide a grease that is operable at temperatures from minus 45 ° C to plus 150 ° C and is resistant to rocket fuel components, as well as to gaseous oxygen.

The problem is achieved by the proposed composition of a grease containing perfluoropolyether based on the oligomerization product of hexafluoropropylene oxide and a thickener. The lubricant is characterized in that it contains hydrophobized silica gel as a thickener in the following ratio of components, wt.%:

Perfluoropolyether 93.5-96 Water-repellent silica gel 4-6.5

To obtain the lubricant, perfluoropolyester of the PEF - 180 grade according to TU 6-02-1072-86 and organosilica gel of the RT and RTu brands according to STP-3-2-81 are used.

The proposed lubricant is prepared as follows. The calculated amount of lubricant components is manually loaded into the prepared container. The loaded components are manually periodically mixed at the temperature of the production room (10-35 ° C) for 3-4 hours. During this time, the thickening component swells and its distribution is uniform in the dispersion medium. After that, the entire mass of the prepared lubricant is homogenized 1-3 times. In the process of homogenization, the homogenizer and lubricant are heated. To prevent overheating, cold water is fed into the homogenizer jacket during the entire homogenization process. The temperature of the lubricant at the outlet of the homogenizer should not be higher than 100 ° C. Then the grease is processed on a regrinding machine or manually 1-2 times through a nylon cloth for sieves article 76K.

According to the above technology, 3 samples of grease were prepared, covering the entire spectrum of the claimed concentrations (table 1).

The following properties of the prepared lubricants were studied (Table 2).

1. Viscosity effective according to GOST 7163 at + 50 ° C and D = 1000 s ^-1 ;

2. Shear strength at + 50 ° С according to GOST 7143;

3. Colloidal stability according to GOST 7142;

4. Resistance to hostile environment;

5. Resistance to gaseous oxygen.

The proposed composition of grease with the stated ratio of the components ensures the operation of the moving components of the product at temperatures from minus 45 ° С to plus 150 ° С, is resistant to rocket fuel components and to gaseous oxygen (can withstand oxygen pressure up to 250 atm).

Table 1 The compositions of the prepared samples of lubricants No. Name of components The content of components in the lubricant, wt.% one 2 3 one Perfluoropolyether 93.5 95 96 2 Water-repellent silica gel 6.5 5 four table 2 Properties of tested samples No. The name of indicators Composition No. one 2 3 one Effective viscosity, Pa · s 3,5 2.7 1.8 2 Shear strength, Pa 690 550 250 3 Colloidal stability in% of oil released 1,2 2,5 3.0 four Resistance to aggressive environments Not interacting 5 Resistance to gaseous oxygen Withstands oxygen pressure up to 250 atm

Claims (1)

Grease containing perfluoropolyether based on the product of oligomerization of hexafluoropropylene oxide and a thickener, characterized in that the grease contains hydrophobized silica gel as a thickener in the following ratio, wt.%: Perfluoropolyether 93.5-96 Water-repellent silica gel 4-6.5