JPH01500525A - Perfluoropolyether solid filler for lubricants - Google Patents

Abstract

Lubricants comprising perfluoropolyether oils containing perfluoropolyether solids as fillers are described.

Description

[Detailed description of the invention] Perfluoropolyether solid filler for lubricants Field of the invention The present invention is in the field of polymer chemistry and contains perfluoropolyether solid fillers. The present invention relates to a lubricant composition comprising a perfluoropolyether oil having the following properties.

Background of the invention Due to their excellent thermal properties and wide liquid range, perfluoropolyethers are It has been known since ancient times. These properties make this polymer suitable for high performance lubricants. It is an excellent base for Most perfluoropolyether lubricants are Polytetrafluoroethylene [TFE; , T6flon™ polymer]. ing. However, perfluoropolymer containing Teflon as filler Some problems are associated with ether-based lubricants.

Although these greases often have a reasonable shelf life of more than a few years, However, when exposed to high temperatures, they tend to separate into two phases: an oil phase and a solid phase. and For example, at 400 °C, K'ryto Approximately 11% of the oil in x: trademark) separates into a clear phase in 30 hours, resulting in much further concentration. A paste remains behind. The degree of separation becomes more pronounced as the temperature increases becomes.

Summary of the invention The present invention provides perfluoropolyether oil and perfluoropolyether solid filler. A lubricant composition comprising: perfluoropolyether solid filler , the viscosity of the base perfluoropolyether oil, the solid particle size and the lubricant composition. Depending on the desired consistency, it will constitute from about 20% to about 70% by weight of the composition.

The lubricant is simply a mixture of perfluoropolyether solid and perfluoropolyether oil. It can be manufactured by combining.

Greases made using perfluoropolyethers as thickeners are Since oils and solids of the same composition are very compatible, they do not exhibit this separation phenomenon. these Other notable advantages associated with the lubricants relate to stability and mechanism of degradation. Big Most perfluoropolyethers are about 50°C more stable than Teflon(TM). high temperature and therefore can often extend the useful temperature range of the grease. Furthermore, Te Unlike Freon(TM), perfluoropolyethers leave behind carbonaceous residues. Decomposes cleanly into gas and liquid by-products without leaving any residue behind. This unique advantage The system is designed to continuously supply lubricant to the surface to be lubricated. This makes it possible to lubricate very hot surfaces.

Grease is used in aircraft components, missiles, sanitary systems, spacecraft and associated ground support facilities. It is a useful lubricant for equipment. Due to their high degree of chemical inertness, it These include food processing equipment, valves and fittings, as well as high vacuum environments, pneumatic systems and refrigeration equipment. It is a useful lubricant for use in

Detailed description of the invention The lubricant composition of the present invention is filled with a solid perfluoropolyether; Grease consisting of oropolyether oil. The solid filler is approx. by weight of grease It accounts for 20 to about 70%, preferably about 20 to about 40%.

The amount of perfluoropolyether solids required to thicken the grease is Depends on the grain size of the body. Ideally, to require only the minimum amount of thickener Ultrafine particles are preferable. However, it is difficult to produce such extremely fine powder. The technology to create one does not yet exist. Approximately 200 mesh powders are currently It can be produced by direct fluorination of fine particles of ether. relatively large When fluorinating large particles, perfluoropolyether solids are immersed in liquid nitrogen. Freeze milling can be used to obtain microparticles.

Perfluoropolyether oils suitable for lubricant compositions include DuPont's Tara Itotox liquid, Montedison's 7-Onlblin [Fonlblin (trademark)] Y liquid and Huonpurin Z liquid, Daikin's Demnum (trademark) liquid as well as those which can be produced by direct fluorination of hydrocarbon polyethers. Other perfluoropolyethers are included. These are “perfluorinated polyethers” No. 756,781, filed July 18, 1985, entitled ``Liquid.'' A perfluorinated copolymer of hexafluoroacetone and a cyclic oxygen-containing compound as described in : “1:1 combination of difluoromethylene oxide and tetrafluoroethylene oxide U.S. Patent Application No. 796.625, filed November 8, 1985, entitled "Polymer" 1 of difluoromethylene oxide and tetrafluoroethylene oxide described in =1 copolymer; entitled “Perfluoropolyether”, November 8, 1985 Perfluoropolymethylene oxide as described in U.S. Patent Application No. 796,622 Perfume containing high concentrations of perfluoropolymethylene oxide and related perfluoropolymethylene oxides. including fluoropolyethers.

The choice of solid perfluoropolyether can vary depending on the application. death However, for most applications, solids with the same composition as the liquid are usually used. Perfluoropolyethers are preferred. By matching solid and liquid, the heat of the solid The stability matches the thermal stability of the liquid, and it goes without saying that the compatibility between solid and liquid is maximum. becomes. For example, Thalytox, Huonpurin Y1 Huonpurin 2 or Dem When using a commercially available liquid perfluoropolyethylene oxide solution such as Namu , comparable polyethers can be produced using direct fluorination methods. . For example, poly(propylene oxide) with a high molecular weight (750,000) A solid polyester having the same composition as chlorine, talitox, or 7-on-purine Y solution. Give a tell. Similarly, poly(methylene oxide-ethylene oxide) copolymer (U.S. Patent Application No. 796,625) and fluorine in poly(trimethylene oxide) Using Perfluoropolyethers can be produced.

Produced by direct fluorination; perfluoropolyethers are free-flowing white. It is a powder. They are usually made of high molecular weight polyether powder (over 50°000). , mixed (1:3 ratio) with a hydrogen fluoride scavenger such as sodium butoxide. Manufactured by Then rotate the polyether/sodium fluoride mixture It is placed in a drum and gaseous fluorine diluted with nitrogen is passed through it. Usually 6-2 A reaction time of 4 hours is used, during which time 10-30% of the initial fluorine concentration reacts.

A final treatment in pure fluorine at temperatures between 60 and 150°C generally ensures perfluorination. It is necessary to make it a reality. Different yields are generally obtained in the range of 75-90%, but , yields of 80-85% are common. Verfluoroboriether generation The material is separated from the hydrogen fluoride scavenger, usually by dissolving the scavenger in water.

The lubricants of this invention generally require simply mixing the solid and oil and allowing the two to stand for about 12 hours. Manufactured by Heating the mixture to a temperature below the decomposition temperature will cause the grease to Helps reduce the time required to reach its final form, which is a transparent gel. Two. In order to improve the transparency and uniformity of the grease, it is made with high pressure and low porosity. Just push it through the filter.

Alternatively, perfluoropolyether oils such as t; Reduces the time required to lubricate solids with oil by dissolving them in a suitable solvent. can be reduced. When producing grease using this method, thickener The grease is mixed with the solvent/oil mixture and the temperature is raised to evaporate the solvent and leave behind the grease. and then immediately filter it.

Uses solid perfluoropolyether instead of Teflon polymer as filler There are many benefits to doing so. Same as or similar to perfluoropolyether liquid Polyether solids, which have a very similar structure, have a similar structure due to the affinity of liquids for solids. is essentially the same as the affinity of the fluid itself, so it shows no signs of separation. So Therefore, the driving force of the dispersion reservoir is eliminated. The perfluoropolyether solid is T Does not melt or melt like FE and FEP Teflon polymers. If you follow it, Grease filled with fluorocarbon polymers exhibits oily solids around the edges at approximately 400°C. Separates into freon husk. Under the same conditions, perfluoropolyether solid The grease filled with will not separate and the only change observed in the lubricant , slight densification with time. No crust forms on hot surfaces and The base retains most of the original perfluoropolyether oil.

Another advantage is that solid perfluoropolymer This means that oil has essentially the same properties as oil. solid purfle Olopolyethers, like oils, leave no residue when they decompose. So In contrast, Teflon polymers leave about 2% residue when decomposed at high temperatures.

As mentioned above, the thermal stability of solid perfluoropolyethers with the same structure solid perfluoropropylene oxide oil (i.e. solid perfluoropropylene oxide oil) Can be matched with oil by using (oropropylene oxide) Ru. However, the same structure can be used to obtain the aforementioned advantages, including improved compatibility. It is not absolutely necessary to use it. Same structure in solid and oil By continuously supplying the grease of the present invention by using Grease can be used to lubricate parts that are hotter than the temperature becomes.

For Teflon-filled greases, some residue may be present in such applications. seems to cause problems.

The invention is further illustrated by the following examples.

Example 1 20g solid perfluoropolymer (passed through ethylene oxide X100 mesh) mixed with 30 g of perfluoropoly(ethylene oxide) liquid with a molecular weight of 5000. did. After processing the resulting paste at 200°C for 1 hour, a 50 micron fibre. Filtered through a router to obtain a clear gel.

Example 2 20 g of solid perfluoropolymer (passed through an ethylene oxide X100 mesh) 30 g of perfluoropoly(ethylene oxide) liquid with a molecular weight of 500 and 100 cc Freon 1] and 3 were mixed. Place the resulting mixture on a hot plate The Freon was allowed to evaporate. The resulting paste was filtered to obtain a clear gel.

Example 3 20g perfluoropoly(ethylene oxide) solid (passed through 200 meshes) mixed with 40 g of perfluoropoly(ethylene oxide) liquid with a molecular weight of 5000. did. The grease was allowed to stand for 24 hours and then filtered to obtain the final product.

Example 4 100 g of poly(propylene oxide) prepared from propylene oxide using a ferric chloride catalyst. Pyrene oxide) solid is fluorinated using 20% fluorine in a 24 hour reaction. Then, 150g of viscous, 7! / on 113 soluble liquid and 60g perfluor Ropoly(propylene oxide) solid was obtained. Freeze and grind the solid to 100 meshes. powder. 20g of this powder was mixed with 35g of Freon 113 along with 100cc of Freon 113. Mixed with Krytx 143AB liquid. placing the mixture in a vacuum oven Freon was removed by A clear gel was obtained by filtration.

Example 5 20g of high molecular weight perfluoropoly(methylene oxide-ethylene oxide) solids After freezing and grinding the body into 200 mesh powder, 50 g of 7-on-pudding z- Mixed with 25. Solid perfluoropoly(methylene oxide-ethylene oxide) ) is 1,3-dioxolane (IM) in methylene chloride!・Refluoromethane Prepared by polymerization with sulfonic acid (9X 10-'M). viscous After mixing the product as a solution with Na, F powder c9.7M), it was heated in a vacuum oven at 50°C. The methylene chloride was evaporated in an oven. Combine the remaining solid with 200 mesh powder. After grinding until dry, it was reacted for 24 hours using 20% fluorine (6M). It was fluorinated. Extracting sodium fluoride from the perfluorinated product with water (75Q) removed by extraction.

same effect Those skilled in the art will be able to use their ordinary experience to determine the particular implementation of the invention described herein. It may be possible to recognize or identify many equivalents to the form. This way Such equivalent products are intended to be included within the scope of the following claims of the present invention.

international search report ws-Ichinai IAe*lltsim"s, PCT/US 87101893

Claims (15)

[Claims] 1. Solid perfluoropolyether oil base and thickening amount as filler A lubricant characterized in that it consists of an oropolyether. 2. The weight percentage of solid perfluoropolyether is about 20-70%, claims The lubricant according to item 1. 3. The weight percentage of solid perfluoropolyether is about 20-40%, claims The lubricant according to item 1. 4. The lubricant according to claim 1, wherein the oil and the solid are polymers having the same chemical structure. 5. Perfluoropolyether oil or solid is perfluoropolyether (ethylene oxy perfluoropoly(propylene oxide) and perfluoropoly(methylene oxide) ethylene oxide). The lubricant according to item 1. 6. The solid perfluoropolyether is in the form of particles of approximately 200 meshes. The lubricant according to item 1. 7. Solid perfluoropoly(ethylene oxide) oil base and thickening amount A lubricant characterized in that it consists of Ropoly (ethylene oxide). 8. The weight percentage of solid perfluoropoly(ethylene oxide) is approximately 20-70% The lubricant according to claim 7, which is 9. Solid perfluoropoly(ethylene oxide) is about 20-40%, claims The lubricant according to item 7. 10. Perfluoropoly(propylene oxide) base oil and thickener as filler of solid perfluoropoly(propylene oxide) lubricant. 11. The weight percentage of solid perfluoropoly(ethylene oxide) is about 20-70 %, the lubricant according to claim 10. 12. The weight percentage of solid perfluoropoly(ethylene oxide) is about 20-40 %, the lubricant according to claim 10. 13. Perfluoropoly(methylene oxide-ethylene oxide) base oil and filler Thickening amounts of solid perfluoropoly(methylene oxide-ethylene oxide) as filler A lubricant characterized by consisting of (Cid). 14. The weight percentage of solid perfluoropoly(ethylene oxide) is about 20-70 %, the lubricant according to claim 14. 15. The weight percentage of solid perfluoropoly(ethylene oxide) is about 20-40 %, the lubricant according to claim 14.