JP2669993B2 - Silicone grease composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silicone grease composition, and more particularly to a silicone grease composition having excellent lubricating properties without using a thickener.

[0002]

2. Description of the Related Art Silicone grease is basically composed of a silicone oil and a thickener. For this, diorganopolysiloxane, R ₃ SiO _1/2 unit (R is a monovalent hydrocarbon, Abbreviated as M), R ₂ Si
An organopolysiloxane composition composed of O units (hereinafter abbreviated as D units) and SiO ₂ units (hereinafter abbreviated as Q units) and a thickener (see Japanese Patent Publication No. 53-776), diorganopoly Siloxane, M unit, RSiO
Organopolysiloxane composition consisting of _3/2 unit price (hereinafter abbreviated as T unit) and Q unit and a thickening agent (see Japanese Patent Publication No. 60-45240), branched organopolysiloxane, and M unit An organopolysiloxane composition comprising Q units and a thickener (Japanese Patent Publication No. 3-76359)
And the like, have been proposed.

[0003]

However, the MDQ unit,
An organopolysiloxane composition comprising MTQ units and MQ units dissolves in a diorganopolysiloxane or a branched organopolysiloxane, and therefore aluminum, lead, zinc, manganese, lithium, sodium and sodium are required to make the composition a grease. , Potassium, calcium, barium, strontium, copper, mercury, bismuth, chromium,
Inert oxides of fine particles of inorganic elements such as metal soaps of fatty acids having at least 8 carbon atoms, including metals such as iron and nickel, silica, alumina, iron oxide, titanium oxide, zinc oxide, glass fiber, clay, etc. It is essential to add thickeners such as boron, aryl urea, phthalocyanine, indusulene, polytetrafluoroethylene powder, graphite and carbon black.

For this reason, there has been proposed a composition comprising an organopolysiloxane containing no thickener and an organopolysilsesquioxane represented by M units (see Japanese Patent Publication No. 2-22797). Since the thickener has a weak thickening effect because it is not an essential component and it gives only a thick (soft) grease, it is still necessary to add a thickener to obtain a stable consistency. Regarding this, the present inventors have proposed a silicone grease composition containing no long-chain alkyl-modified silicone oil and MQ resin powder, which is inferior in heat resistance and lubricity. It turned out to be disadvantageous.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a silicone grease composition which has solved such disadvantages, which is represented by A) the general formula

Embedded image (Where R ¹ is a perfluoroalkyl group having 1 to 10 carbon atoms, R ² is a monovalent hydrocarbon group selected from an alkyl group having 1 to 12 carbon atoms, an alkenyl group and an unsubstituted or substituted aryl group, a , B is 0 or 1, m is 0 to 1,000, n
Is 5 to 1,000, m + n is a positive number of 5 to 1,000)
R ¹ is 5 to 50 mol% of all substituents, a perfluoroalkyl-modified silicone oil to 100 parts by weight of a viscosity of 100 to 100,000 cS at _{^{25 ℃, B) R 3 3}} SiO 1/2 units (R ³ is a group selected from an alkyl group, an alkenyl group and an aryl group) and a SiO ₂ unit, and R ³ ₃ SiO _1/2
Powdered organopolysiloxane 20 to 300 parts by mole ratio of 0.5 to 0.95 between the units and SiO ₂ units and is characterized in that it consists city.

That is, the inventors of the present invention have conducted various studies to develop a silicone grease composition capable of forming a good tacky grease without adding a thickener, and as a result, the organopolysiloxane used here has been described above. A perfluoroalkyl-modified silicone oil represented by the formula (1) is prepared, and an organopolysiloxane composition comprising M units and Q units added to the oil is made into a powder form, and these are mixed and kneaded with a three-roll mill. We found that this was an adhesive grease with good heat resistance and good lubricity without the addition of a thickener, and confirmed that this can significantly reduce the manufacturing time and cost. Then, the present invention was completed. This will be described in detail below.

[0007]

The present invention relates to a silicone grease composition, which comprises A) 100 parts by weight of the perfluoroalkyl-modified silicone oil represented by the general formula (1), and B) M units and Q units, M / Q molar ratio
0.5 to 0.95 powdery organopolysiloxane 2
It is characterized by comprising 0 to 300 parts by weight, but since this gives a good tacky grease having lubricity without adding a thickener, the silicone grease composition can be efficiently treated, It offers the advantage of being cheap to obtain.

As described above, the silicone grease composition of the present invention comprises A) a perfluoroalkyl-modified silicone oil represented by the general formula (1) and B) M units and Q units, and the molar ratio of M / Q is M / Q. Is mixed with a powdery organopolysiloxane having a ratio of 0.5 to 0.95. The perfluoroalkyl-modified silicone oil as the component A) constituting the silicone grease composition is represented by the general formula (1), and R ¹ represents a perfluoroalkyl group having 1 to 10 carbon atoms by an alkylene group. be those bound, -CF ₃ as the perfluoroalkyl group, -C ₂ F _5, etc. -C ₄ F ₉ and the like,
Examples of the alkylene group -CH ₂ -, - (CH
_{2) 2 -, - (CH} 2) 3 -, - (CH 2) 4 -, - C
H ₂ —CH (CH ₃ ) —, —CH ₂ —C (CH ₃ ) ₂ —
And the like, but-(CH ₂ ) ₂ -is preferred from the viewpoint of production. R ² is a methyl group, a propyl group,
A monovalent hydrocarbon group having 1 to 12 carbon atoms selected from alkyl groups such as butyl group and octyl group, alkenyl groups such as vinyl group and allyl group, and aryl groups such as phenyl group and tolyl group, preferably methyl group Wherein R ¹ is 5 to 50 mol% of all substituents, a and b are 0 or 1 and m
Is a positive number of 0 to 1,000, n is a positive number of 5 to 1,000, and m + n is a positive number of 5 to 1,000.

When the viscosity of this perfluoroalkyl-modified silicone oil at 25 ° C. is less than 100 cS, the obtained grease has poor stability, and when it has a viscosity of more than 100,000 cS, the viscosity of the grease decreases and the grease It has a viscosity at 25 ° C that is difficult to manufacture.
It is required to be in the range of 100 to 100,000 cS, but the preferred range is 500 to 10,000 cS.

[0010] The component B) constituting the silicone grease composition of the present invention is an MQ siloxane comprising M units and Q units, which has an M / Q molar ratio of 0.5.
If it is less than 0.95, it is difficult to manufacture and powdering becomes difficult, and 0.95
If it is larger than this, sufficient adhesiveness cannot be obtained, so that it is necessary to set the molar ratio of M / Q to 0.5 to 0.95.

However, since the MQ siloxane itself does not dissolve in the perfluoroalkyl-modified silicone oil as the component A), when the mixture is solvent stripped, it is separated into two layers of the perfluoroalkyl-modified silicone oil and the MQ siloxane. However, even if it is made into grease, it is not possible to obtain a grease with stable adhesion and consistency, but this MQ siloxane is powdered and added to perfluoroalkyl-modified silicone oil, and then mixed with three It has been discovered by the present inventors that kneading with a roll or the like provides a grease having excellent lubricity and adhesiveness without adding a thickener, and therefore it is necessary to supply this in powder form. It is said that

Therefore, it is necessary that the MQ siloxane is obtained by mixing the M unit silane and the Q unit silane, and then hydrolyzing and polycondensing the resulting solid into powder. If the amount of this powdery MQ siloxane is less than 20 parts by weight with respect to 100 parts by weight of the perfluoroalkyl-modified silicone oil as the component A), the obtained grease will have a weak adhesive force and a large consistency and softness. If the amount is more than 300 parts by weight, the product will have a low consistency (hard) and will not meet the intended purpose. A preferred range is 30 to 270 parts by weight.

The silicone grease composition of the present invention is a mixture of the above-mentioned perfluoroalkyl-modified silicone oil as the component A) and a powdered MQ siloxane as the component B) in a predetermined amount. Things are mixed well with a mixer such as a planetary mixer and then kneaded again with a three-roll mill to give a grease-like product.This product has heat resistance, lubricity, and adhesion without adding a thickener. This has the advantage that grease having excellent properties can be obtained.

Further, a rust preventive or an antioxidant may be added to the silicone grease composition if necessary. Examples of the rust preventive include benzotriazole and the like.
Antioxidants 4.4 ^'- methylenebis -2.6 - such as ditertiary-butylphenol and the like. The silicone grease made from this silicone grease composition has excellent adhesive strength, a small torque value reduction rate after running, and excellent lubricity, so for example, a rotary volume shaft, bearing feel-up lubricant. ,
It can be used as a damper lubricant for door hinges, and also for automation lines and robot arm dampers.

[0015]

EXAMPLES Examples of the present invention and comparative examples will now be described.
The parts in the examples are parts by weight, the viscosities show the measured values at 25 ° C., and the physical properties of the grease in the examples show the measured values according to the following. [Measurement of physical properties] Measured according to JIS-K-2220. [Adhesive Strength] Using a 4 mmφ × 8 mmL shaft and bearing, measurement was performed at a clearance of 35 μm and a rotation speed of 10 rpm. [Lubricity] The wear trace diameter of 1,500 rpm, load 40Kg, time 1 minute, 1/2 inch steel ball was measured using a high speed four-ball tester. The smaller the wear trace diameter, the better the lubricity. Show.

Example 1 The trifluoropropyl group content was 50 mol% and the viscosity was
Trifluoro-modified silicone oil 100 with 1,000 cS
To 100 parts, add 100 parts of MQ resin powder with a molar ratio of (CH ₃ ) ₃ SiO _1/2 units to SiO ₂ units of 0.70, mix well with a planetary mixer, and then knead with three rolls. A silicone grease composition having a consistency (unmixed) of 254 was prepared, and the grease properties of the composition were examined. The results were as shown in Table 1 below.

Example 2 A trifluoropropyl group content of 50 mol% and a viscosity of 10
Trifluoro-modified silicone oil that is 0,000 cS 100
40 parts of MQ resin powder having a molar ratio of (CH ₃ ) ₃ SiO _1/2 units to SiO ₂ units of 0.85, and treated in the same manner as in Example 1 to give a consistency (unmixed) of 350. The grease properties of this silicone grease composition were determined, and the results shown in Table 1 below were obtained.

Example 3 The trifluoropropyl group content was 25 mol% and the viscosity was
100 parts of a trifluoro-modified silicone oil of 100 cS is added with (CH ₂ ＣＨCH) (CH ₃ ) ₂ SiO _1/2 unit and S
MQ resin powder having a molar ratio to iO ₂ units of 0.80
122 parts were added and treated in the same manner as in Example 1 to prepare a silicone grease composition having a consistency (unblended) of 220. The grease properties of this composition were examined, and the results shown in Table 1 below were obtained. Was obtained.

Example 4 The trifluoropropyl group content was 5 mol% and the viscosity was
Trifluoro-modified silicone oil with 10,000 cS 100
100 parts of MQ resin powder in which the molar ratio of (CH ₃ ) ₃ SiO _1/2 units to SiO ₂ units is 0.55,
A silicone grease composition having a consistency (unmixed) of 180 was prepared by treating in the same manner as in Example 1, and the grease characteristics of this composition were examined. The results shown in Table 1 below were obtained.

Example 5 The trifluoropropyl group content was 25 mol% and the viscosity was
1,000 cS trifluoro-modified silicone oil 100
In the part, CH ₂ ＣＨCH (CH ₃ ) ₂ SiO _1/2 unit and Si
MQ resin powder 2 whose molar ratio to O ₂ unit is 0.95
50 parts were added and treated in the same manner as in Example 1 to prepare a silicone grease composition having a consistency (unmixed) of 142, and the grease properties of this composition were examined. The results shown in Table 1 below were obtained. Was obtained.

Example 6 The content of a nonafluorohexyl group was 30 mol% and the viscosity was
100 parts of perfluoroalkyl-modified silicone oil of 5,000 cS was added with (CH ₃ ) ₃ SiO _1/2 unit and SiO ₂
Add 150 parts of MQ resin powder having a molar ratio to the unit of 0.67, and treat in the same manner as in Example 1 to obtain consistency (unmixed).
Was made into a silicone grease composition, and the grease properties of this composition were examined. As a result, the results shown in Table 1 below were obtained.

COMPARATIVE EXAMPLE 1 100 parts of a long-chain alkyl-modified silicone oil having a viscosity of 1,000 cS and a content of a long-chain alkyl group having 10 (C ₁₀ ) carbon atoms of 25 mol% was added to (CH ₃ ) ₃ 100 parts of MQ resin powder having a molar ratio of SiO _1/2 unit to SiO ₂ unit of 0.70 was added and treated in the same manner as in Example 1 to prepare a silicone grease composition having a consistency (unmixed) of 330. ,
When the grease properties of this product were examined, the results as shown in Table 1 below were obtained.

Comparative Example 2 100 parts of dimethyl silicone oil having a viscosity of 1,000 cS
When 67 parts of MQ resin powder with a molar ratio of (CH ₃ ) ₃ SiO _1/2 units to SiO ₂ units of 0.85 was added, mixed well with a planetary mixer and then kneaded with a three-roll mill, MQ resin The powder was dissolved in dimethyl silicone oil and became oily. To this, 25 parts of silica surface-treated with (C ₆ H ₅ ) ₂ Si (OH) ₂ was added, and mixed again with a three-roll mill. When kneaded, a silicone grease having a consistency (unmixed) of 290 was obtained. When the grease characteristics of this product were examined, the results shown in Table 1 below were obtained.

Comparative Example 3 (CH ₃ ) ₃ was added to 100 parts of methylphenyl silicone oil having a viscosity of 1,000 cS and a phenyl group content of 5 mol%.
After adding 107 parts of MQ resin powder with a molar ratio of SiO _1/2 unit to SiO ₂ unit of 0.67, mixing well with a planetary mixer and kneading with a triple roll, the MQ resin powder was methylphenyl silicone. (C ₆ H ₅ ) ₂ S
When 25 parts of silica surface-treated with i (OH) ₂ was added and the mixture was kneaded again with a three-roll mill, a silicone grease with a consistency (unmixed) of 295 was obtained. The grease characteristics of this product were examined. The results shown in Table 1 were obtained.

[0025]

[Table 1]

(Evaluation of Experimental Results) In all of the examples, the grease-like state was sufficiently maintained without using a thickener, which is proved by the low degree of oil separation.
In addition, all of these were excellent in adhesiveness, the rate of reduction in torque value after running was small and stable, and this was also small in wear marks and it was confirmed that lubricity was good,
Since the change in the consistency at 180 ° C. is small, it has been proved that the heat resistance is good. However, in Comparative Example 1, grease can be formed without adding a thickening agent, and although the lubricity is reasonably good, it is inferior in heat resistance, and in Comparative Examples 2 and 3, both are inferior. Grease-like properties cannot be maintained unless a thickener is used, and the torque values of these greases are relatively high, but the down rate after running is also large, and the wear marks are large, and lubrication It has been shown to be of poor sex.

[0027]

The present invention relates to a silicone grease composition, which comprises 100 parts by weight of A) a perfluoroalkyl-modified silicone oil represented by the general formula (1) and B) R ³ ₃ SiO _{1 as described above. / 2} units (M units)
And SiO ₂ units (Q units), and the molar ratio of M / Q is
0.5-0.95 powdery organopolysiloxane
It is characterized by comprising 20 to 300 parts by weight, but when this perfluoroalkyl-modified silicone oil and powdered MQ organopolysiloxane are kneaded with a triple roll or the like, no thickening agent is added. Since grease having good lubricity and tackiness can be easily obtained, this gives the advantage that a silicone grease composition can be easily and inexpensively obtained in a short time.

Claims (2)

(57) [Claims] 1. A) General formula: ## STR1 ## (Where R ¹ is a perfluoroalkyl group having 1 to 10 carbon atoms, R ² is a monovalent hydrocarbon group selected from an alkyl group having 1 to 12 carbon atoms, an alkenyl group and an unsubstituted or substituted aryl group, a , B is 0 or 1, m is 0 to 1,000, n
Is 5 to 1,000, m + n is a positive number of 5 to 1,000)
R ¹ is 5 to 50 mol% of all substituents, a perfluoroalkyl-modified silicone oil to 100 parts by weight of a viscosity of 100 to 100,000 cs at _{^{25 ℃, B) R 3 3}} SiO 1/2 units (R ³ consists alkyl group, an alkenyl group, a group selected from aryl group) and SiO ₂ Prefecture, the molar ratio of R ³ ₃ SiO _1/2 units and SiO ₂ units 0.
5 to 0.95 powdered organopolysiloxane 20
~ 300 parts by weight, and a silicone grease composition. 2. The silicone grease composition according to claim 1, wherein R ² is a methyl group.