JP2010144042A - Urea grease composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an improved urea grease composition. <P>SOLUTION: The improved urea grease composition is represented by the general formula (a): R<SB>1</SB>NHCONHR<SB>2</SB>NHCONHR<SB>1</SB>, the general formula (b): R<SB>3</SB>NHCONHR<SB>2</SB>NHCONHR<SB>3</SB>, and the general formula (c): R<SB>1</SB>NHCONHR<SB>2</SB>NHCONHR<SB>3</SB>respectively, wherein R<SB>2</SB>is a diphenylmethane group, R<SB>1</SB>is an 8C alkyl; and R<SB>3</SB>is 14-20C hydrocarbon group containing an unsaturated component at 20 mol% or more, and either one of the following compositions (1), (2) and (3) is included in a mineral oil or synthetic oil or a mixture thereof. The composition (1) is a mixture including: (a) compound and a (b) compound, wherein the (a) compound accounts for 80-20 mol% of the (a) compound+the (b) compound and the composition (2) is a mixture of the composition (mixture) (1) and the (c) compound; and the composition (3) consists of the (c) compound. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an improvement of a urea grease composition, and more particularly, to a grease suitable for use in a lubricated place where rolling or slipping, etc. in which one is made of metal and the other is made of a material other than metal.

  In recent years, parts of various industrial machines, including the automobile industry, include resin materials and rubber materials that are parts other than metal materials from many viewpoints such as weight reduction, cost reduction, low friction, wear resistance, quietness or recycling. The use of polymer materials such as these has become conspicuous, but as the components of the parts have diversified, many new problems have arisen and various techniques have been improved.

  For example, movable parts of automobile electric door mirrors, sliding parts of telescopic shafts of steering, various sliding parts such as rack guides of R & P steering, power transmission gears of electric power steering devices, various actuators, sliding parts inside air cylinders , Linear guides for machine tools, retainers for ball screws, retainers for various bearings, sliding parts for crane booms, resin gears for acoustic equipment such as radio cassettes, video tape recorders, CD players, printers, copiers, fax machines, etc. There are lubrication points where resin gear parts of OA equipment, sliding parts of various electric switches, etc. function in contact with polymer materials other than metal materials such as resin and resin, or resin and metal or rubber and metal. .

Conventionally, in the field of lubrication, most of the components of machinery have been metal materials, so research on friction and wear between metals such as iron, aluminum, their alloys, brass, bronze, etc. has a long history, Many technologies are accumulated through deep experience and knowledge.
For example, extreme pressure agents and antiwear agents containing elements such as phosphorus and sulfur are effective for friction and wear between metals, and these additives actively form a film by causing a chemical reaction with the metal surface. It is well known that it forms functions such as reducing friction and wear and preventing seizure. Engine oil, gear oil, and high-performance industrial lubricants and greases have these technologies. Widely applied.

However, in spite of the short history of lubrication technology between resins or between different materials such as resin and metal or rubber and metal, the application has recently been expanded and diversified as described above. However, the present situation is that it is not always possible to provide a technology that can satisfy all the requirements.
For example, if the technology using phosphorus-based or sulfur-based additives effective for friction and wear between metals described above is applied to lubrication points between resins or between resin and metal or rubber and metal, As a result, the frictional and wear-resistant performances are hardly obtained. On the contrary, there are many cases in which the performance of friction and wear is deteriorated and the life of the machine parts is shortened.

  This is because, in the case of polymer materials such as resins, the chemical activity at the interface is weak compared to metals, so the reaction with organic additives such as phosphorus and sulfur is almost performed on the sliding surface. In addition, since the adsorption is weak, the effect on friction and wear is small, and it is considered that the friction reducing action is weak. Also, when used in an environment where the temperature rises forcibly, the active sulfur and phosphorus of these additives penetrate into the resin, causing cracks and embrittlement, or promoting friction and wear. There may be a reaction such as letting go.

  In order to improve the friction between the above-mentioned resins or between different materials such as resin and metal, it contains a lubricant base oil, a thickener, polytetrafluoroethylene particles, and boron nitride particles. A technology that can sufficiently reduce the friction between the lubricating member and the base material such as polyoxyalkylene and ether derivatives and lithium soap is increased. And a composition comprising an alkenyl succinic acid-based rust preventive agent does not adversely affect the rubber member, and a technique for improving excellent lubricity and rust preventive property for a metal material is disclosed. (Patent Document 2), however, further improvement is desired.

JP 2006-89575 A JP-A 63-309591

  The present invention improves the urea grease composition, in particular, rolling, sliding, etc. in which at least one of a resin and a resin or a resin and a metal or a different material such as a rubber and a metal is made of a material other than a metal. This is intended to reduce the friction and obtain good lubricity at the lubrication point where the occurrence of the friction occurs.

  The present inventor has conventionally studied and investigated the lubrication behavior of grease in polymer materials other than metal materials, and found that the viscosity of a specific urea-based thickener that forms grease. Depending on the elasticity and polarity, a physical elastic film peculiar to this urea grease is appropriately formed at the interface between resin and resin, or resin and metal or rubber and metal. It is considered that the polarity interacts with the weak electricity generated at the interface of the opposing polymer material, and it is possible to more reliably form and maintain a lubricating film including grease, reducing friction. The inventors have found that good lubricity can be obtained and have completed the present invention.

The present invention relates to the following general formula (a) R ₁ NHCONHR ₂ NHCONHR ₁
(B) R ₃ NHCONHR ₂ NHCONHR ₃
(C) R ₁ NHCONHR ₂ NHCONHR ₃
(In the formula, R ₂ is a diphenylmethane group, R ₁ is an alkyl group having 8 carbon atoms, R ₃ is a hydrocarbon group having 14 to 20 carbon atoms, and contains 20 mol% or more of unsaturated components.)
A compound represented by
(1) (a) a compound containing 80 to 20 mol% of (a) compound + (b) compound, and a mixture containing (a) compound and (b) compound,
(2) a mixture obtained by mixing (c) the compound with the mixture of (1), or (3) (c) the compound,
(1), (2), or (3) is contained in mineral oil, synthetic oil or a mixed oil thereof to form a urea grease composition.

  The urea thickeners (1), (2), and (3) may be used in an amount of about 2 to 30% by mass based on the total composition based on mineral oil, synthetic oil, or a mixed oil thereof. This urea grease composition can be more effective when used for mechanical parts that are made of a material other than metal and one of which is made of metal at a lubrication point where rolling or sliding occurs. The effect is remarkable when it is used for a machine part composed of a polymer material such as resin or rubber.

  According to the present invention, a urea grease composition in which friction is reduced and good lubricity can be obtained at a lubrication location where rolling or slipping occurs between members at least one of which is made of a polymer material such as a resin. It can be used widely as a product.

The urea compound which is a thickener in the present invention has the following general formula (a) R ₁ NHCONHR ₂ NHCONHR ₁
(B) R ₃ NHCONHR ₂ NHCONHR ₃
(C) R ₁ NHCONHR ₂ NHCONHR ₃
In the formulas (a), (b), and (c), R ₂ is a diphenylmethane group, R ₁ is an alkyl group having 8 carbon atoms, and R ₃ is a hydrocarbon group having 14 to 20 carbon atoms. It contains 20 mol% or more of a saturated component. When the carbon number of R ₁ is other than 8 and when the carbon number of R ₃ is out of the range of 14 to 20, it is difficult to appropriately exhibit the structural viscosity of the grease, and the carbon number of R ₃ is 14 to 20 When the amount of the unsaturated component in the hydrocarbon group is less than 20 mol%, the polarity of the urea thickener becomes weak, and the electrochemistry interacts with the weak electricity generated at the interface with the polymer material. It is considered that the mechanical action does not work effectively, and the effect of reducing friction is small.

The urea thickener (1) is a mixture of the above compound (a) and the compound (b), and the amount of the compound (a) is adjusted with respect to the sum of the compound (a) and the compound (b). 80 to 20 mol%. In this case, when the ratio of the compound (a) to the compound (b) exceeds the range of 80:20 to 20:80 mol%, the dropping point is lowered and the heat resistance becomes insufficient, or the friction is reduced. The reduction effect may not be seen.
What mixed the said (c) compound further with the said urea thickener (1) can be used as a urea thickener (2).
As the urea thickener (3), the compound (c) can be used alone.
A urea grease composition can be obtained by including any of the above-described urea thickeners (1), (2), (3) in a base oil of mineral oil, synthetic oil or a mixed oil thereof. .

  The blending amount of such a urea thickener is preferably about 2 to 30% by mass based on the total amount of the composition in mineral oil, synthetic oil or mixed oil thereof. If the blending amount of the urea thickener is less than 2% by mass, the thickening effect is small, the grease becomes too soft and there is a risk of leakage, etc. If it exceeds 30% by mass, the grease Since it becomes too hard and the flow resistance increases, the friction torque increases, and the intervention property also decreases, so that a sufficient lubricating effect may not be obtained, and the price increases.

The base oil in the present invention is generally used as a base oil for lubricating oil or a base oil for grease, and is not particularly limited. For example, mineral oil, synthetic oil, animal and vegetable oil, and These mixed oils are mentioned.
In particular, base oils belonging to Group 1, Group 2, Group 3, Group 4, etc. in the API (American Petroleum Institute) base oil category can be used alone or in combination.

For Group 1 base oils, for example, paraffin obtained by applying a combination of refining means such as solvent refining, hydrorefining, and dewaxing to a lubricating oil fraction obtained by atmospheric distillation of crude oil. There are mineral oils.
For Group 2 base oils, for example, paraffinic mineral oils obtained by appropriately combining refining means such as hydrocracking and dewaxing for lubricating oil fractions obtained by atmospheric distillation of crude oil There is. Group 2 base oils refined by hydrorefining methods such as the Gulf Company method have a total sulfur content of less than 10 ppm and an aroma content of 5% or less, and can be suitably used in the present invention.

  Group 3 base oil and Group 2 plus base oil include, for example, a paraffinic mineral oil produced by advanced hydrorefining and a dewaxing process for a lubricating oil fraction obtained by atmospheric distillation of crude oil. There are base oils refined by the ISODEWAX process for converting and dewaxing the produced wax to isoparaffins, and base oils refined by the mobile WAX isomerization process, and these can also be suitably used in the present invention.

  Specific examples of synthetic oils include, for example, polyolefins, polyalkylene glycols such as polyethylene glycol and polypropylene glycol, diesters such as di-2-ethylhexyl sebacate and di-2-ethylhexyl adipate, trimethylolpropane ester and pentaerythritol ester. Polyol esters, perfluoroalkyl ethers, silicone oils, polyphenyl ethers and the like.

  The polyolefin includes polymers of various olefins or hydrides thereof. Any olefin may be used, and examples thereof include ethylene, propylene, butene, and α-olefins having 5 or more carbon atoms. In the production of polyolefin, one of the above olefins may be used alone, or two or more may be used in combination. Particularly preferred are polyolefins called poly α-olefins (PAO), which are Group 4 base oils.

  GTL (Gas Liquid) synthesized by the Fischer-Tropsch method, which is a natural gas liquid fuel technology, has an extremely low sulfur content and aromatic content compared to mineral oil base oil refined from crude oil. Is extremely high, so that it has excellent oxidation stability and very low evaporation loss, and can be suitably used as the base oil of the present invention.

Representative examples of animal and vegetable oils include castor oil and rapeseed oil.
The various oils described above can be used alone or in combination as a base oil, but the above are merely examples, and the present invention is not limited thereby.

  Further, as the additive of the urea grease composition of the present invention, other additives such as an antioxidant, a rust inhibitor, an oily agent, an extreme pressure agent, an antiwear agent, a solid lubricant, a metal deactivator, and a polymer are further added. Agents can be added as appropriate.

  Examples of the antioxidant include 2,6-di-tbutyl-4-methylphenol, 2,6-di-tbutylparacresol, P, P′-dioctyldiphenylamine, N-phenyl-α-naphthylamine, and phenothiazine. and so on.

  Examples of the rust preventive include oxidized paraffin, carboxylic acid metal salt, sulfonic acid metal salt, carboxylic acid ester, sulfonic acid ester, salicylic acid ester, succinic acid ester, sorbitan ester, and various amine salts.

  Examples of oily agents, extreme pressure agents, and antiwear agents include zinc sulfide dialkyldithiophosphate, zinc sulfide diallyldithiophosphate, zinc sulfide dialkyldithiocarbamate, zinc sulfide diallyldithiocarbamate, sulfurized dialkyldithiophosphate molybdenum, sulfide diallyldithiophosphate molybdenum. , Sulfurized dialkyldithiocarbamate molybdate, diallyldithiocarbamate molybdate, organic molybdate complex, sulfurized olefin, triphenyl phosphate, triphenyl phosphorothioate, tricresyl phosphate, other phosphate esters, sulfurized fats and oils, various fatty acids and so on.

Examples of the solid lubricant include molybdenum disulfide, graphite, boron nitride, melamine cyanurate, PTFE (polytetrafluoroethylene), tungsten disulfide, mica, and graphite fluoride.
Examples of metal deactivators include N, N'disalicylidene-1,2-diaminopropane, benzotriazole, benzimidazole, benzothiazole, thiadiazole and the like.
Examples of the polymer include polybutene, polyisobutene, polyisobutylene, polyisoprene, and polymethacrylate.
In addition, all the above-mentioned other additives are examples, and are not limited thereto.

  In the present invention, friction is reduced and good lubrication is achieved particularly in a lubricating part where at least one of the opposing surfaces is seen to roll or slip between members composed of a substance other than a metal such as a polymer material such as a resin. It is possible to obtain sex. Therefore, the members facing the material other than one metal include various metal materials such as iron, copper, aluminum and other metals, and alloys thereof, polymer materials such as resins, rubber, glass, ceramics, etc. It may be a nonpolar material and can be widely used without any particular limitation.

  In addition, the resin material can be used for various materials regardless of general-purpose plastics and engineering plastics. For example, polyamide, polyacetal, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polybutylene naphthalate, polyphenylene ether , Polyphenylene sulfide, fluorine resin, polyarylate, polyamide imide, polyether imide, polyether ether ketone, polysulfone, polyether sulfone, polyimide, polystyrene, polyethylene, polypropylene, phenol resin, AS resin, ABS resin, AES resin, AAS Resin, ACS resin, MBS resin, polyvinyl chloride resin, epoxy resin, diallyl phthalate resin, polyester resin, methacrylic resin Examples of the rubber agent include acrylic rubber, acrylonitrile butadiene rubber, isoprene rubber, urethane rubber, ethylene propylene rubber, epichlorohydrin rubber, chloroprene rubber, silicone rubber, styrene butadiene rubber, butadiene rubber. , Fluorine rubber, polyisobutylene and the like, but are not limited thereto.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited at all by these Examples.
Abbreviations regarding the raw material components of the thickener and the lubricating base oil used in the examples and comparative examples are as follows.
1. The diisocyanate raw material for the urea thickener is diphenylmethane-4,4′-diisocyanate (MDI) (molecular weight 250.26).
2. The raw materials for the amine of the urea thickener are as follows.
Amine A: An industrial octylamine having an average molecular weight of 128.7 mainly composed of a saturated hydrocarbon group having 8 carbon atoms (90% by mass or more).
Amine B: An industrial dodecylamine having an average molecular weight of 184.6 mainly composed of a saturated hydrocarbon group having 12 carbon atoms (90% by mass or more).
Amine C: Industrial stearylamine having an average molecular weight of 258.7 mainly composed of a saturated hydrocarbon group having 18 carbon atoms (90% by mass or more).
Amine D: An industrial tallow amine having an average molecular weight of 255.7 in which an unsaturated hydrocarbon group having 14 to 18 carbon atoms and a saturated hydrocarbon group are mixed (unsaturated / saturated: about 43/57).
Amine E: An industrial oleylamine having an average molecular weight of 255.0 mainly composed of an unsaturated hydrocarbon group having 18 carbon atoms (70% by mass or more).
3. Base oil Base oil A: A mineral oil having a kinematic viscosity at 40 ° C. of 101.1 mm ² / s.
Base oil B: a poly α-olefin oil having a kinematic viscosity at 40 ° C. of 31.2 mm ² / s.
Base oil C: kinematic viscosity at 40 ° C. 47.08 mm ² / s, kinematic viscosity at 100 ° C. 8.04 mm ² / s, viscosity index 146,% CA is 1 or less,% CN is 11.9,% CP Is a highly refined oil having a ≧ 85.

(Examples 1 to 10)
In the blending ratios shown in Tables 1 to 3, the total amount of MDI and half of the base oil (single or mixed base oil) were put in a grease kettle and heated to about 50 ° C. to dissolve MDI, and then 1/4 The required amount of amine A (octylamine) dispersed in the base oil was gradually added and stirred vigorously. After about 10 minutes, amine E (oleylamine) dissolved and dispersed in 1/4 base oil was further added, and stirring was continued.
The temperature of the contents of the grease kettle rises due to the reaction of diisocyanate and amine, but it is heated to 170 ° C, held at this temperature for about 30 minutes to complete the reaction, allowed to cool to room temperature, and then treated with three rolls. Thus, a urea grease composition was obtained.

(Example 11)
In the blending ratio shown in Table 3, the total amount of MDI and half of base oil A were put in a grease kettle and heated to about 50 ° C. to dissolve MDI, and then dispersed in 1/4 of base oil A. The required amount of amine A (octylamine) was gradually added and stirred vigorously. After about 10 minutes, a mixed solution of amine C (stearylamine) and amine E (oleylamine) dissolved and dispersed in 1/4 base oil A was added, and stirring was continued.
The temperature of the contents of the grease kettle rises due to the reaction of diisocyanate and amine, but it is heated to 170 ° C, held at this temperature for about 30 minutes to complete the reaction, allowed to cool to room temperature, and then treated with three rolls. Thus, a urea grease composition was obtained.

Example 12
The total amount of MDI and half of base oil A in a mixing ratio shown in Table 3 were put in a grease kettle, heated to about 50 ° C., dissolved in MDI, and then dispersed in 1/4 base oil A. A (octylamine) was gradually added and stirred vigorously. About 10 minutes later, amine D (tallow amine) dissolved and dispersed in 1/4 base oil A was added, and stirring was continued.
The temperature of the contents of the grease kettle rises due to the reaction of diisocyanate and amine, but it is heated to 170 ° C, held at this temperature for about 30 minutes to complete the reaction, allowed to cool to room temperature, and then treated with three rolls. Thus, a urea grease composition was obtained.

(Comparative Examples 1-5)
In the same manner as in the above examples, MDI and various amines were reacted in a base oil (single or mixed base oil) at the blending ratios shown in Table 4 to obtain various urea grease compositions.

In order to compare the properties and performance of Examples and Comparative Examples, the following measurements and tests were performed.
1. Consistency: Measured according to JIS K2220-7.
2. Dropping point: Measured according to JIS K2220-8.
3. Kinematic viscosity of base oil: Measured according to JIS K2283.
4). Friction test: A Bowden friction test was performed. That is, a friction coefficient between a material (test material 1a) other than a resin facing the resin (test material 1b) was measured using a Bowden friction test apparatus under the following test conditions.
(1) Test material 1a: Material: Steel material S45C and copper alloy ALBC2.
Dimensions: Outer 5.0mm, length 24mm, pin-shaped,
r = 2.5mm hemisphere,
The contact surface is processed into a plane having a diameter of about 1.0 mm.
(2) Test material 1b: Material: Polyamide resin (manufactured by Toray Industries, Inc., 66 nylon / amilan) and
Polyacetal resin (DuPont Delrin 500P)
Dimensions: A plate-like body having a length of 200 mm and a width of 52 mm.
(3) Temperature: 25 ° C
(4) Sliding speed: 1.0 mm / s
(5) Load: 870g
(6) Contact surface pressure: 10 MPa
In addition, between the polyamide resin and the steel material, the Bowden-type friction test was performed for all examples and all the comparative examples, and some tests were performed between the polyacetal resin and the copper alloy.

(Test results)
As shown in Tables 1-4.
(Discussion)
The urea grease compositions of Examples 1 to 8 and 10 to 12 all show a semi-solid grease shape, a consistency value in the range of 212 to 258, an appropriate hardness value, and a dropping point of 250 ° C. or more. It was in good condition. Moreover, since the thing of Example 9 has few thickeners, the consistency is 368 and the range of NLGI grade No. 0 consistency (soft consistency number), and a dropping point is a little low value at 221 degreeC. It was a good semi-solid grease state. Further, in Examples 1 to 12, the friction coefficient between polyamide resin and steel in the Bowden friction test was 0.051 to 0.068, and the friction coefficient between polyacetal resin and copper alloy was 0.050 to 0. 0.06, it is uniformly low, and it can be seen that particularly various materials and materials other than resins such as copper alloy and steel exhibit good lubricating performance.
On the other hand, the grease compositions of Comparative Examples 1 to 6 all show a semi-solid grease, have a consistency of 254 to 321 and an appropriate hardness value, and have good dropping points of 241 ° C. and 250 ° C. or higher. The friction coefficient between the polyamide resin and the steel in the Bowden friction test was 0.087 to 0.124, and the friction coefficient between the polyacetal resin and the copper alloy was also 0.097 to 0.131. Thus, it can be seen that the lubrication state between various resins and materials other than resins such as copper alloys and steels is inferior to that of the examples, and the effect of improving the lubrication performance is not obtained.
From these results, it can be seen that the urea grease composition of the present invention exhibits good lubricating performance without using a special additive by making the terminal group of the urea thickener appropriate.

Claims (5)

Formula (a) R ₁ NHCONHR ₂ NHCONHR ₁
(B) R ₃ NHCONHR ₂ NHCONHR ₃
(C) R ₁ NHCONHR ₂ NHCONHR ₃
(In the formula, R ₂ is a diphenylmethane group, R ₁ is an alkyl group having 8 carbon atoms, R ₃ is a hydrocarbon group having 14 to 20 carbon atoms, and contains 20 mol% or more of unsaturated components.)
A compound represented by
(1) (a) a compound containing 80 to 20 mol% of (a) compound + (b) compound, and a mixture containing (a) compound and (b) compound,
(2) a mixture obtained by mixing (c) the compound with the mixture of (1), or (3) (c) the compound,
Any of (1), (2), and (3) is contained in a mineral oil, a synthetic oil or a mixed oil thereof.   2. Any one of the above (1), (2) and (3) is contained in mineral oil, synthetic oil or mixed oil thereof in an amount of 2 to 30% by mass based on the total composition. The urea grease composition described in 1.   3. The urea grease composition according to claim 1, wherein the urea grease composition according to claim 1 is used in a lubricated portion where rolling or slipping occurs, wherein one is a metal and the other is a material other than a metal.   3. The urea grease composition according to claim 1, wherein the grease is used in a lubricating part where rolling or slipping occurs, wherein one is a material other than a metal and the other is a material other than a metal. .   The urea grease composition according to claim 3 or 4, wherein the material other than the metal at the lubrication site is a polymer material such as resin or rubber.