JPH06256785A - Fluorosilicone-based lubricant - Google Patents

Abstract

PURPOSE:To obtain the subject lubricant, comprising a silicone oil having a specific structure and fluororesin powder as a thickener, excellent in cold resistance and lubricity and further boundary lubricity and load resistance ability under a high load. CONSTITUTION:This lubricant is composed of (A) 100 pts.wt. fluorosilicone oil expressed by formulas I and/or II [R is monovalent hydrocarbon; Z is monovalent hydrocarbon or C2H4(CF2).F; (a) is an integer of >=4; (m) and (n) are 0 or positive numbers; (m-l-n) is 0-1000, with the proviso that at least one Z is the C2H4(CF2)aF; (x) is a positive integer; (y) is 0 or a positive integer; (x+y) is >=3] and (B) 1-100 pts.wt. powder of a fluororesin (e.g. polytetrafluoroethylene). Furthermore, the compound expressed by formula I in the component (A) is obtained by hydrolyzing, e.g. a fluoroalkyldiorganochlorosilane. The compound expressed by formula II is prepared by cohydrolyzing e.g. a fluoroalkylorganodichlorosilane with a diorganodichlorosilane.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorosilicone lubricant, and more particularly to a fluorosilicone lubricant having excellent cold resistance and lubricity.

[0002]

2. Description of the Related Art A grease-like silicone lubricant comprising a silicone oil such as dimethyl silicone oil and methylphenyl silicone oil and a thickener such as silica fine powder, carbon, talc, clay and molybdenum disulfide is
Compared with organic oil-based lubricants, they are used in various fields because they are superior in heat resistance, cold resistance, and friction characteristics. In recent years, in order to further improve the lubricity of silicone-based lubricants, many silicone-based lubricants prepared by blending fluororesin powder such as polytetrafluoroethylene powder as a thickener have been proposed (JP-A-54). -163277, JP-A-54-49460, JP-A-57-34135
Japanese Patent Laid-Open No. 62-190290),
A number of fluorosilicone-based lubricants containing 3,3,3-trifluoropropyl group-containing silicone oil as a main component have also been proposed (see JP-A-56-52618 and JP-A-63-165493). In particular, fluorosilicone lubricants composed of 3,3,3-trifluoropropyl group-containing silicone oil and thickeners are used as lubricants with excellent oil resistance, load bearing capacity under high load, and boundary lubrication. Has been done.

However, the fluorosilicone lubricant has poor cold resistance, and when it is used at a low temperature, its lubricity is remarkably deteriorated, and it must be used as a lubricant for mechanical members that slide at high speed. There was a problem that I could not do it.

[0004]

The present inventors have arrived at the present invention as a result of extensive studies on fluorosilicone lubricants having excellent cold resistance and lubricity.

That is, an object of the present invention is to provide a fluorosilicone lubricant having excellent cold resistance and lubricity.

[0006]

Means for Solving the Problem and Its Action The present invention provides (A) general formula (a):

[Chemical 3] {Wherein, R is a monovalent hydrocarbon group, Z is a monovalent hydrocarbon group or the general _{formula: -C 2 H 4 (CF 2} ) a fluoroalkyl group represented by _a F, a is 4 or more Is an integer of 0, m is 0 or a positive integer, n is 0 or a positive integer, and m + n is an integer of 0 to 1000, provided that when m = 0, at least one of Z is The fluoroalkyl group. } And / or the general formula (b):

[Chemical 4] (In the formula, R is a monovalent hydrocarbon group, a is an integer of 4 or more, x is a positive integer, y is 0 or a positive integer, and x + y is an integer of 3 or more. The present invention relates to a fluorosilicone lubricant comprising 100 parts by weight of fluorosilicone oil represented by the formula (1) and 1 to 100 parts by weight of (B) fluororesin powder.

The fluorosilicone lubricant of the present invention will be described in detail below.

In the fluorosilicone-based lubricant of the present invention, the fluorosilicone oil as the component (A) is the main agent and has the general formula (a):

[Chemical 5] {Wherein, R is a monovalent hydrocarbon group, Z is a monovalent hydrocarbon group or the general _{formula: -C 2 H 4 (CF 2} ) a fluoroalkyl group represented by _a F, a is 4 or more Is an integer of 0, m is 0 or a positive integer, n is 0 or a positive integer, and m + n is an integer of 0 to 1000, provided that when m = 0, at least one of Z is The fluoroalkyl group. } And / or the general formula (b):

[Chemical 6] (In the formula, R is a monovalent hydrocarbon group, a is an integer of 4 or more, x is a positive integer, y is 0 or a positive integer, and x + y is an integer of 3 or more. ) Is a fluorosilicone oil.

Among the fluorosilicone oils of component (A), the general formula (a):

[Chemical 7] The fluorosilicone oil represented by is a linear silicone oil having an aloalkyl group at the molecular chain terminal and / or the molecular chain side chain. In the above formula, R is a monovalent hydrocarbon group, and specifically as the monovalent hydrocarbon group of R,
Alkyl groups such as methyl group, ethyl group, propyl group and butyl group; alkenyl groups such as vinyl group, allyl group, butenyl group, pentenyl group and hexenyl group, aryl groups such as phenyl group, tolyl group, xylyl group and naphthyl group An aralkyl group such as a benzyl group or a phenethyl group is exemplified. Z is a monovalent hydrocarbon group or a fluoroalkyl group represented by the general formula: —C ₂ H ₄ (CF ₂ ) _a F (wherein a is an integer of 4 or more), and Z is Specific examples of the monovalent hydrocarbon group include the same groups as those described above for R, and specific examples of the fluoroalkyl group for Z include a fluoroalkyl group in which a is 4 to 8. In the above formula, m is 0 or a positive integer, n is 0 or a positive integer, and m + n is an integer of 0 to 1000. This is because the component (A) fluorosilicone having a m + n of more than 1000 has an excessively high viscosity and is not suitable for use as a lubricant. When m = 0, at least one Z is a fluoroalkyl group represented by the general formula: —C ₂ H ₄ (CF ₂ ) _a F (wherein a is an integer of 4 or more). It is necessary to be. Also, in the above formula,
a is an integer of 4 or more, and preferably an integer of 4-8. In the fluorosilicone lubricant of the present invention, the viscosity of the fluorosilicone oil represented by the general formula (a) is not particularly limited, but it is preferably 10 to 10,000 centipoise.

The fluorosilicone oil represented by the general formula (a) is represented by the general formula:

[Chemical 8] (In the formula, R, n and a are the same as the above.) A fluorosilicone oil having a fluoroalkyl group at both ends of the molecular chain, a general formula:

[Chemical 9] (In the formula, R and a are the same as above, and p is a positive integer.) A fluorosilicone oil having a fluoroalkyl group in the side chain of the molecular chain, a general formula:

[Chemical 10] (In the formula, R, a and p are the same as above, and q is a positive integer.) A copolymerized fluorosilicone oil having a fluoroalkyl group in the side chain of the molecular chain is exemplified.

The method for preparing the fluorosilicone oil represented by the general formula (a) is not particularly limited. Specific examples of the preparation method include a method of hydrolyzing a fluoroalkyldiorganochlorosilane and a fluoroalkyl oil. A method of co-hydrolyzing diorganochlorosilane and diorganodichlorosilane, and then reacting this hydrolyzate with triorganochlorosilane or hexaorganodisilazane, a fluorosilicone oil having fluoroalkyldiorganosiloxy groups at both ends of the molecular chain. And a cyclic diorganosiloxane are polymerized in the presence of a basic catalyst, a fluoroalkylorganodichlorosilane is reacted with zinc oxide in the presence of an organic solvent, and a fluoroalkyl having hydroxydiorganosiloxy groups at both ends of the molecular chain. Organopo A method of synthesizing siloxane, and then reacting the polysiloxane with triorganochlorosilane or hexaorganodisilazane, co-hydrolyzing fluoroalkylorganodichlorosilane and diorganodichlorosilane, and then hydrolyzing the hydrolyzate with fluoroalkyldiorganosilane. Method for reacting with chlorosilane or 1,3-difluoroalkyltetraorganodisilazane, copolymerization of cyclic fluoroalkylorganosiloxane, cyclic diorganosiloxane and 1,3-difluoroalkyltetraorganodisiloxane in the presence of a basic catalyst An example of the method is shown.

Among the fluorosilicone oils of component (A), the general formula (b):

[Chemical 11] The fluorosilicone oil represented by is a cyclic silicone oil. In the above formula, R is a monovalent hydrocarbon group,
Specific examples of the monovalent hydrocarbon group include the same groups as described above. Further, in the above formula, a is an integer of 4 or more, preferably an integer of 4-8. Further, in the above formula, x is a positive integer, y is 0 or a positive integer, and x + y is an integer of 3 or more, preferably x + y is an integer of 3 to 30. This is because there are no cyclic silicone oils in which x + y is less than 3, while it is difficult to prepare cyclic silicone oils in which x + y exceeds 30. Cyclic silicone oils in which x + y exceeds 30 generally have the general formula It is produced as a by-product in the process of producing the linear silicone oil represented by (a). In the fluorosilicone lubricant of the present invention, the viscosity of the fluorosilicone oil represented by the general formula (b) is not particularly limited, but it is preferably 10 to 10,000 centipoise.

The method for preparing the fluorosilicone oil represented by the general formula (b) is not particularly limited. Specific examples of the method for preparing the fluorosilicone oil include a method for hydrolyzing a fluoroalkylorganodichlorosilane and a molecular chain. A method of cyclizing a fluoroalkylorganopolysiloxane whose both ends are blocked with a hydroxydiorganosiloxy group by a basic catalyst, a method of cohydrolyzing a fluoroalkylorganodichlorosilane and a diorganodichlorosilane, and both ends of the molecular chain are An example is a method of cyclizing a fluoroalkylorganosiloxane / diorganosiloxane copolymer capped with a hydroxydiorganosiloxy group with a basic catalyst.

In the fluorosilicone lubricant of the present invention, the component (B) is a fluororesin powder which acts as a thickener. The type of the fluororesin powder as the component (B) is not particularly limited, and specific examples of the fluororesin powder as the component (B) include polytetrafluoroethylene, a copolymer of tetrafluoroethylene and ethylene, hexafluoro Copolymer of propylene and ethylene, Copolymer of chlorotrifluoroethylene and ethylene, Copolymer of perfluoro (alkyl vinyl ether) and ethylene, Copolymer of perfluoro (alkoxyalkyl vinyl ether) and ethylene, Examples thereof include a copolymer of trifluoroethylene and ethylene, and a copolymer of perfluoroalkylethylene and ethylene.

The shape of the fluororesin powder as the component (B) is not particularly limited, and examples thereof include spheres, eggs, flakes, cylinders, whiskers, and fibers, and the average particle diameter thereof is There is no particular limitation, and for example, the average particle size is 0.0
The fluororesin powder in the range of 5 to 100 μm is preferable.

In the fluorosilicone lubricant of the present invention, the amount of the component (B) blended is in the range of 1 to 100 parts by weight based on 100 parts by weight of the component (A). This is because when the amount of the component (B) blended is less than 1 part by weight with respect to 100 parts by weight of the component (A), the lubricity of the obtained fluorosilicone-based lubricant decreases, and On the other hand, when it exceeds 100 parts by weight, the lubricity of the obtained fluorosilicone-based lubricant is lowered, and the lubricant is not grease-like.

The fluorosilicone lubricant of the present invention comprises
It consists of the above components (A) and (B), but as other components, for example, rust preventives; antifoaming agents; extreme pressure agents such as sulfurized olefins, sulfurized fats and oils; phosphorous acid esters, phosphoric acid esters, Antiwear agents such as phosphate amine salts, zinc thiophosphate, molybdenum sulfide dithiocarbamate, etc .; antioxidants such as phenol compounds, diarylamine compounds, colorants,
Further, inorganic fine powders such as titanium oxide, iron oxide, alumina, boron nitride, silicon carbide, silicon nitride and silica can be blended.

The fluorosilicone lubricant of the present invention comprises
It can be easily prepared by uniformly blending the components (A) and (B). Examples of the apparatus for uniformly blending the components (A) and (B) include a kneader mixer, Ross mixer, homomixer, Henschel mixer, spar mixer, colloid mill, and three-roll mill.
Further, it is preferable that the components (A) and (B) are mixed in an atmosphere of an inert gas such as nitrogen, if necessary.

The fluorosilicone lubricant of the present invention comprises
It has excellent cold resistance and lubricity, so it can be used as a lubricant at low temperatures and as a lubricant for mechanical parts that slide at high speed because it has excellent boundary lubrication and load bearing capacity under high loads. it can.

[0020]

EXAMPLES The present invention will be described in detail with reference to Examples. In the examples, the measurements of viscosity and lubricity are the values measured at 25 ° C. The cold resistance and lubricity of the lubricant were measured as follows.

<Cold Resistance Test> The running torque (g · cm) at 25 ° C. and −45 ° C. was measured by a method according to ASTM D-1478.

<Lubricity Test> Lubricity of the lubricant was evaluated by standard test conditions (total load = 0.297 kg, single test piece vertical load = 0.20) of the Soda type pendulum type oil friction tester manufactured by Shinko Machinery Co., Ltd.
105 kg, maximum load on contact surface = 111 kg / mm ² , proportionality constant = 3.20), and the formula:

[Formula 1] [N: number of vibrations, A ₀ : initial amplitude (standard test A ₀ = 0.5
Radian), A _n : deflection angle (radian) at each vibration frequency, C: proportional constant (C = 3.2 in standard test)], and the dynamic friction coefficient f was measured.

[0023]

Example 1 Average formula:

[Chemical 12] 100 parts by weight of fluorosilicone oil having a viscosity of 750 centipoise and 50 parts by weight of fine powder of polytetrafluoroethylene resin having an average particle diameter of 3 μm are mixed at room temperature for 2 hours to form a uniform fluorosilicone grease. A lubricant was prepared. A lubricity test and a cold resistance test were performed on this fluorosilicone lubricant. The results are shown in Table 1.

[0024]

Example 2 Average formula:

[Chemical 13] 100 parts by weight of a fluorosilicone oil having a viscosity of 100 centipoise and 60 parts by weight of the polytetrafluoroethylene resin fine powder used in Example 1 were mixed at room temperature for 2 hours to obtain a uniform fluorosilicone in the form of grease. A system lubricant was prepared. A lubricity test and a cold resistance test were performed on this fluorosilicone lubricant. The results are shown in Table 1.

[0025]

Example 3 Average formula:

[Chemical 14] 50 parts by weight of fluorosilicone oil having a viscosity of 750 c centipoise and an average formula:

[Chemical 15] 50 parts by weight of a cyclic fluorosilicone oil having a viscosity of 100 centipoise and 60 parts by weight of a perfluoroalkyloxytrifluoroethylene-containing polytetrafluoroethylene resin fine powder having an average particle diameter of 5 μm
The mixture was mixed at room temperature for 2 hours to prepare a uniform grease-like fluorosilicone lubricant. A lubricity test and a cold resistance test were performed on this fluorosilicone lubricant.
The results are shown in Table 1.

[0026]

Example 4 Average formula:

[Chemical 16] 100 parts by weight of a fluorosilicone oil having a viscosity of 700 centipoise and 55 parts by weight of a polytetrafluoroethylene resin fine powder having an average particle diameter of 3 μm are mixed at room temperature for 2 hours to form a uniform grease-like fluorosilicone system. A lubricant was prepared. A lubricity test and a cold resistance test were performed on this fluorosilicone lubricant. The results are shown in Table 1.

[0027]

Example 5 Average formula:

[Chemical 17] Fluorosilicone oil represented by 60 parts by weight and average formula:

[Chemical 18] 100 parts by weight of fluorosilicone oil having a viscosity of 700 centipoise and 55 parts by weight of polytetrafluoroethylene resin fine powder having an average particle diameter of 3 μm are mixed at room temperature for 2 hours. A uniform grease-like fluorosilicone lubricant was prepared. A lubricity test and a cold resistance test were performed on this fluorosilicone lubricant. The results are shown in Table 1.

[0028]

Comparative Example 1 Average formula:

[Chemical 19] Of 100 parts by weight of fluorosilicone oil having a viscosity of 1200 centipoise and 50 parts by weight of fine powder of polytetrafluoroethylene resin having an average particle diameter of 3 μm,
The mixture was mixed at room temperature for 2 hours to prepare a uniform grease-like fluorosilicone lubricant. A lubricity test and a cold resistance test were performed on this fluorosilicone lubricant.
The results are shown in Table 1.

[0029]

[Table 1]

[0030]

The fluorosilicone lubricant of the present invention is characterized by excellent cold resistance and lubricity.

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Claims (2)

[Claims] 1. (A) General formula (a): {Wherein, R is a monovalent hydrocarbon group, Z is a monovalent hydrocarbon group or the general _{formula: -C 2 H 4 (CF 2} ) a fluoroalkyl group represented by _a F, a is 4 or more Is an integer of 0, m is 0 or a positive integer, n is 0 or a positive integer, and m + n is an integer of 0 to 1000, provided that when m = 0, at least one of Z is The fluoroalkyl group. } And / or the general formula (b): (In the formula, R is a monovalent hydrocarbon group, a is an integer of 4 or more, x is a positive integer, y is 0 or a positive integer, and x + y is an integer of 3 or more. A fluorosilicone lubricant comprising 100 parts by weight of fluorosilicone oil represented by the formula (1) and 1 to 100 parts by weight of (B) fluororesin powder. 2. The average particle diameter of the (B) fluororesin powder is 0.
The fluorosilicone lubricant according to claim 1, which has a thickness of 05 to 100 µm.