JPH08134485A - Lubricating solid and preparation thereof - Google Patents

Abstract

PURPOSE: To prepare a lubricating solid having excellent lubricity and thermal conductivity by dispersing particles, such as graphite or mica, in a particular inorg/org. fused product in a particular proportion. CONSTITUTION: 3 to 70vol% particles of at least one compd. selected from graphite, mica, molybdenum disulfide, tungsten disulfide, boron nitride, and phyllosilicate are dispersed in an inorg./org. fused product prepd. by replacing the skeleton, of an inorg. polymer comprising an M-O-M bond (wherein M is a metal or a semi-metal atom), with Si(Rn (O-)4-n (wherein R is an alkyl and n is 1 to 3). The dispersion is obtd. by dispersing particles of graphite, mica or the like in a soln. obtd. by hydrolyzing at least one of an alkoxide, an alkylalkoxysilane, a fluoroalkylalkoxysilane, and a chloroalkylalkoxysilane, followed by maturing and gelation of the dispersion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid having excellent lubricity and thermal conductivity, which is used, for example, as a sealing material and a method for producing the solid.

[0002]

2. Description of the Related Art Sealing technology plays an important role in preventing leakage and entry of foreign matter in a hermetic design of mechanical equipment, and the performance and durability of the seal influence the overhaul period of the mechanical equipment. Generally, the seal is divided into a motion seal packing and a static seal gasket. Particularly in packing, the operating surface is accompanied by friction, wear, temperature rise, etc., which governs performance and durability. As a sealing material for packing, for example, cotton thread, linen, asbestos, and recently synthetic rubber, that is, nitrile rubber is used.
It is not uncommon for sealing to take place in a dry environment such as vacuum or high temperature. In such a case, the condition is that the solid surface is in direct contact, and it is difficult to prevent damage and wear on the sealing surface. . Therefore, it is important to reduce friction on the operating seal surface to prevent power loss and suppress heat generation and seizure. As such a sealing material, fluororubber, silicon rubber, polyfluorinated ethylene resin, or the like is used.

On the other hand, there is an inorganic / organic fusion material as a new material. This has begun to be studied for the following reasons. Generally, an inorganic material such as ceramics has advantages such as high heat resistance and hardness, but has drawbacks such as brittleness and difficulty in processing. Organic materials are easy to mold and process, but have drawbacks such as weakness to heat and low hardness. Against these,
A material that combines inorganic and organic substances by chemically bonding (hybrid) at the molecular level can add new functions and special functions that complement the characteristics of inorganic and organic substances.
There are nearly endless combinations, low temperature synthesis is possible,
It has advantages such as As an example of such an inorganic / organic fusion material, an organic modified silicate (A. Kaiser e
t al. , J. et al. Membrance Soc. 22 ,
257-268 (1985)) and ceramer (GLW
ilkes et al. , Polym. Prep. 2
6 , 300-302 (1985), H.M. -H. Huan
g et al. , Polymer. Bull. 14 , 5
57-564 (1985)). These have been studied as flexible inorganic materials, organic dye encapsulation media, and the like.

[0004]

As a sealing material for packing, it is desired to reduce friction of the operating seal surface to prevent power loss and suppress heat generation and seizure, but fluororubber (0.12 Wm ^-1 K ^-1 ), silicone rubber (0.2W
m ^-1 K ^-1 ), polyfluorinated ethylene resin (0.3 Wm ^-1 K
The existing materials such as ^-1 ) have low thermal conductivity, and the generated heat easily raises the temperature, leading to deterioration in performance and durability.
In order to solve the above problems, it is an object of the present invention to provide a lubricating solid having a high thermal conductivity, which is obtained by providing an inorganic / organic fusion material with lubricity, and a method for producing the same.

[0005]

The lubricating solid of the present invention has a skeleton of an inorganic polymer composed of M--O--M bonds (M is a metal or a semimetal atom) as Si (R) _n (O--). _{One of} graphite, molybdenum disulfide, tungsten disulfide, mica, boron nitride, and layered silicate in an inorganic / organic fusion material substituted with _4-n group (R is an alkyl group, n = 1 to 3) or It is a lubricious solid in which two or more kinds of particles are dispersed in a proportion of 3 to 70% by volume.

[0006] The inorganic polymer is a polymer obtained by polymerizing the M-O-M bond as a skeleton, and the M-O-M bond represents an inorganic component.

The alkyl group R is, for example, --CH ₃ , --C
_{2 H 5, -C 3 H 7} , -C 4 H 9, a -C ₆ H _5, etc., is representative of the organic component. In the present invention, a hydrogen atom of an alkyl group is replaced with a fluorine atom, a chlorine atom or both of them, and a molar ratio of X / (X + H) (X = F
+ Cl) is preferably 0.01 to 1. In this case, the particles have a low coefficient of friction, a high thermal conductivity, and a particle having a layered structure dispersed, so that the thermal conductivity and lubricity of the particles can be exhibited. 0.01
If it is less, the friction coefficient is high and sufficient lubricity cannot be obtained. X / (X + H) = 1, that is, all hydrogen atoms may be replaced with fluorine atoms, chlorine atoms, or both of them.

In order to chemically bond the Si (R) _n (O-) _4-n group to the inorganic skeleton, it is necessary that n = 1 to 3. n
= 4, all the four bonds of Si are occupied by alkyl groups, and chemical bonds cannot be made to the inorganic skeleton. n = 0 means that an alkyl group is not bonded to Si, and an alkyl group bonded with a fluorine atom or a chlorine atom, which exerts lubricity, cannot be introduced into the system.

The particles have 3 to 7 particles in the inorganic / organic fusion material.
It is included at a rate of 0% by volume. If it is less than 3%, the strength and thermal conductivity cannot be sufficiently improved. On the other hand, 70%
When it exceeds, it becomes difficult to include a sufficient inorganic / organic fusion material between particles, and the shape cannot be maintained.

The size of the dispersed particles is 0.05 to 20 μm.
A range of m is preferred. Since particles of less than 0.05 μm are very fine, it is difficult to uniformly disperse the particles.
It is difficult to uniformly disperse particles having a size of more than μm in a solution because the particles settle in the solution quickly.

The lubricating solid of the present invention comprises a solution obtained by hydrolyzing one or two of alkoxide, alkylalkoxysilane, fluoroalkylalkoxysilane, and chloroalkylalkoxysilane, and graphite,
It can be produced by dispersing particles of one or more of molybdenum disulfide, tungsten disulfide, mica, boron nitride and layered silicate, and aging and gelling, or alkoxide, alkylalkoxysilane, fluoroalkylalkoxy. One or two of silane and chloroalkylalkoxysilane, graphite, molybdenum disulfide, tungsten disulfide, mica,
It can be produced by dispersing particles of one kind or two or more kinds of boron nitride and layered silicate, and aging and gelling a hydrolyzed solution.

The alkoxide used in the present invention is not particularly limited, and examples thereof include methoxide, ethoxide, propoxide, butoxide and the like. Further, the alkoxide is one in which a part of the alkoxy group is substituted with β-diketone, β-ketoester, alkanolamine, alkylalkanolamine, organic acid and the like. Therefore,
The metals and metalloids constituting the inorganic component are limited to those capable of forming alkoxides. For example, Si,
Al, Ti, Zr, Ta, Nb, Y, Co and the like. These metal alkoxides can be used alone or in combination of two or more.

Examples of the alkylalkoxysilane used in the present invention include monoalkyltrialkoxysilane, dialkyldialkoxysilane and trialkylalkoxysilane. Examples of these alkyl groups include a methyl group, an ethyl group, a propyl group, a butyl group, a phenyl group, and a vinyl group. Moreover, examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

The fluoroalkylalkoxysilane used in the present invention includes monofluoroalkyltrialkoxysilane, monofluoroalkylmonoalkyldialkoxysilane, difluoroalkylalkoxysilane,
There are monofluoroalkyldialkylmonoalkoxysilanes, difluoroalkylmonoalkylmonoalkoxysilanes, and trifluoroalkylmonoalkoxysilanes. The fluoroalkyl group, -CF _3, -C ₂ F
_{5, -C 3 F 7, -C} 4 H 9, CH 2 CH 2 CF 3, -
_{CH 2 CH 2 C 6 F 13} , etc. -CH ₂ CH ₂ C ₈ F ₁₇ and the like. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a phenyl group, and a vinyl group. Moreover, examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

Examples of the chloroalkylalkoxysilane used in the present invention include monochloroalkyltrialkoxysilane, monochloroalkylmonoalkyldialkoxysilane, dichloroalkylalkoxysilane, monochloroalkyldialkylmonoalkoxysilane, dichloroalkylmonoalkylmonoalkoxysilane and trichloro. There is an alkyl monoalkoxy silane. The chloroalkyl _{group, -CCl 3, -C 2 Cl 5} , -C 3 Cl
_{7, -C 4 Cl 9, CH} 2 CH 2 CCl 3, -CH 2 C
H ₂ C ₆ Cl _13, such as -CH ₂ CH ₂ C ₈ Cl ₁₇ and the like. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a phenyl group, and a vinyl group. Moreover, examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

In the hydrolysis of the alkoxide according to the present invention, water is added up to 10 mole times the alkoxide for hydrolysis. At this time, an inorganic acid, an organic acid or both of them may be used as a catalyst. The water to add is
It may be diluted with an organic solvent such as alcohol. It is not preferable to use 10 molar times or more of water because it will gel immediately.

In the hydrolysis, an organic solvent which can uniformly disperse and dissolve the alkylalkoxysilane, the fluoroalkylalkoxysilane and the alkoxide is used. For example, methanol, ethanol, propanol,
Various alcohols such as butanol, acetone, toluene,
Xylene and the like.

Gelation is carried out after hydrolysis by removing the solvent, alcohol produced by hydrolysis and the like while aging at room temperature to a temperature not higher than the boiling point of the solvent. Moreover, after gelation, it can also be heat-treated if necessary.

[0019]

EXAMPLES Examples of the present invention will be specifically described. However, the present invention is not limited to these examples.

The particles were dispersed in a hydrolysis solution of alkoxide under the conditions shown in Tables 1 and 2, put in a cylindrical container having a diameter of 25 mm and gelled at an aging temperature of 80 ° C., and then taken out for 48 hours at the same temperature. A sample was prepared by aging, and thermal conductivity and friction coefficient were measured. The thermal conductivity was measured by the laser flash method. The coefficient of friction is Bowde
Place the sample on the steel surface using the n-Leben tester,
It was measured at a load of 2 kg and a sliding speed of 0.01 cm / sec.

[0021]

[Table 1]

[0022]

[Table 2]

The coefficient of friction of unlubricated steel is about 1, and
The friction coefficient of rubbers is 1 to 4. Compared to these values, No. 1-5 showed low friction coefficient. This is a value close to that of a polyfluorinated ethylene resin having a low friction coefficient of 0.04. No. The thermal conductivity of 1 to 5 is 0.12 Wm ^-1 K ^-1 for fluororubber and 0.2 Wm for silicon rubber.
⁻¹ K ⁻¹ , and 0.3 Wm ⁻¹ K ⁻¹ of the polyfluorinated ethylene resin showed a high value. However, no. No. 6 had a relatively high thermal conductivity but a high friction coefficient. This is because the content of fluorine is small. No. No. 8 had a low coefficient of friction, but had a low thermal conductivity. This is because there are few graphite particles. No. No. 7 did not solidify because there were too many graphite particles.

[0024]

INDUSTRIAL APPLICABILITY The lubricating solid of the present invention is suitable as a sealing material, especially as a sealing material for packing, and can reduce friction on the operating sealing surface to prevent power loss and suppress heat generation and seizure. Therefore, since the performance and durability of the seal are high, the overhaul period of mechanical equipment can be lengthened.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location C10M 103: 06 E 103: 02 Z 103: 00 A 107: 50) C10N 50:08 70:00 (72) Invention Noriyoshi Shia 5-3 Tokai-cho, Tokai-shi, Aichi Nippon Steel Co., Ltd. Nagoya Steel Works

Claims (4)

[Claims] 1. A skeleton of an inorganic polymer composed of an MOM bond (M is a metal or a semimetal atom) is Si (R) _n (O).
−) One of graphite, molybdenum disulfide, tungsten disulfide, mica, boron nitride, and layered silicate in an inorganic-organic fusion material substituted with _4-n group (R is an alkyl group, n = 1 to 3) Lubricating solid in which particles of one kind or two kinds or more are dispersed at a ratio of 3 to 70% by volume. 2. A hydrogen atom of R is substituted with a fluorine atom, a chlorine atom or both of them, and X / (X +
The lubricating solid according to claim 1, wherein the molar ratio of (H) (X = F + Cl) is 0.01 to 1. 3. A solution obtained by hydrolyzing one or two of alkoxide, alkylalkoxysilane, fluoroalkylalkoxysilane, and chloroalkylalkoxysilane is added to graphite, molybdenum disulfide, tungsten disulfide, mica, boron nitride, and layered. 2. The method for producing a lubricious solid according to claim 1, wherein one or more particles of the silicate are dispersed and aged and gelled. 4. One or two of alkoxide, alkylalkoxysilane, fluoroalkylalkoxysilane, and chloroalkylalkoxysilane, graphite, molybdenum disulfide, tungsten disulfide,
One or two of mica, boron nitride and layered silicate
The method for producing a lubricious solid according to claim 1, wherein at least one kind of particles is dispersed and the hydrolyzed solution is aged and gelled.