JP2022172866A - Production method of urea grease - Google Patents

Abstract

To provide a production method of urea grease excellent in acoustic characteristics and fretting resistance.SOLUTION: A production method of urea grease comprises a step of mixing a fluid containing at least one monoamine compound selected from chain aliphatic monoamines, alicyclic monoamines, and aromatic monoamines, and a diisocyanate compound, using a mixer equipped with flow paths that can merge and mix fluids, and guide vanes.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for producing urea grease.

Greases, especially urea greases, are known to be contaminated with non-uniform particles, commonly referred to as clumps, including those believed to originate from reaction products of isocyanates and amines. Since lumps deteriorate the acoustic properties of grease, various methods for producing urea grease have been investigated to suppress the occurrence of lumps.

Patent Document 1 describes that urea grease with less clumps and excellent acoustic properties can be produced by shearing a mixture of a monoamine compound and a diisocyanate compound at a minimum shear rate of 10 ² s ⁻¹ or more. there is However, this method has problems such as a slow processing speed, and is not necessarily a satisfactory method for commercial production.

In addition, rolling bearings and the like are required to be excellent in fretting resistance, high-temperature and high-speed durability, reduction in rotational torque, etc., depending on their uses.

Japanese Patent No. 6609243

An object of the present invention is to provide a novel method for producing a urea grease that has improved acoustic characteristics and fretting resistance when compared with greases having the same type and amount of base oil and diurea compound. .

The present inventors have found that the above problems can be solved by mixing a fluid containing a predetermined monoamine compound and a diisocyanate compound using a mixer equipped with a flow path and guide vanes that can mix the fluid. perfected the invention.

That is, the present invention
[1] At least one monoamine compound selected from chain aliphatic monoamines, alicyclic monoamines, and aromatic monoamines using a mixer equipped with a flow path and guide vanes capable of merging and mixing fluids; A method for producing a urea grease, comprising a step of mixing a fluid containing a diisocyanate compound,
[2] At least one of base oil 1 containing at least one monoamine compound selected from chain aliphatic monoamines, alicyclic monoamines, and aromatic monoamines and base oil 2 containing a diisocyanate compound, The method for producing the urea grease according to [1] above, which includes the step of passing through guide vanes and the step of combining the base oil 1 and the base oil 2;
[3] The mixer has at least two flow paths that converge upstream of the guide vanes, and the step of mixing the fluid is selected from aliphatic monoamines, cycloaliphatic monoamines, and aromatic monoamines. a step of combining a base oil 1 containing at least one monoamine compound and a base oil 2 containing a diisocyanate compound upstream of the guide vane; The method for producing the urea grease according to [1] or [2] above, comprising the step of passing the
[4] The distance from the confluence of the two flow paths where the base oil 1 and the base oil 2 merge to the downstream end of the guide vane is X (mm), and the distance from the confluence of the flow paths to the guide vane Manufacture of the urea grease according to any one of [1] to [3] above, wherein X/Vx is 1.0 or less, where Vx (mm/s) is the average flow velocity of the fluid to the downstream end. Method,
[5] The method for producing a urea grease according to [4] above, wherein the Vx is 100 mm/s or more;
[6] The guide vane has a plurality of independent inlets through which the fluid flows, and contains at least one monoamine compound selected from chain aliphatic monoamines, alicyclic monoamines, and aromatic monoamines. The above [1] or [ 2] A method for producing the urea grease described above,
[7] Y (mm) is the distance from the downstream end of the guide vane to the outlet of the mixer, and Vy (mm/mm) is the average flow velocity of the fluid from the downstream end of the guide vane to the outlet of the mixer. s), the method for producing a urea grease according to any one of the above [1] to [6], wherein Y/Vy is 0.0005 or more;
[8] The method for producing urea grease according to any one of [1] to [7] above, wherein the mixer further has a projecting impactor on the inner wall of the flow path downstream of the guide vane;
[9] The method for producing a urea grease according to any one of [1] to [8] above, wherein the urea grease further contains a detergent-dispersant agent;
[10] The method for producing a urea grease according to any one of [1] to [9] above, wherein the content of the base oil in the urea grease is 50 to 95% by mass;
[11] A method for manufacturing a bearing, gear, or spindle, comprising a step of applying urea grease manufactured by the manufacturing method according to any one of [1] to [10] above.

According to the present invention, it is possible to produce a urea grease with improved acoustic properties and fretting resistance when compared to greases having the same type and amount of base oil and diurea compound.

FIG. 2 is a partial cross-sectional view of the pipe cut along the longitudinal direction of the pipe of the mixer according to one embodiment of the present invention. FIG. 4 is a partial cross-sectional view showing another embodiment of a mixer; FIG. 4 is a partial cross-sectional view showing another embodiment of a mixer; FIG. 4 is a partial cross-sectional view showing another embodiment of a mixer; FIG. 4 is a partial cross-sectional view showing another embodiment of a mixer; FIG. 6 is a cross-sectional view taken along line AA of FIG. 5;

The method for producing a urea grease according to the present embodiment uses a mixer equipped with a flow path and guide vanes that allow fluids to merge and mix, and and mixing a fluid comprising at least one monoamine compound and a diisocyanate compound.

A method for producing a urea grease according to the present embodiment comprises a base oil 1 containing at least one monoamine compound selected from chain aliphatic monoamines, alicyclic monoamines, and aromatic monoamines, and a base oil containing a diisocyanate compound. It is preferable to include the step of passing at least one of the oils 2 through the guide vanes and the step of combining the base oils 1 and 2 .

In the method for producing urea grease according to this embodiment, the mixer has at least two flow paths that merge upstream of the guide vanes, and a step of combining a base oil 1 containing at least one monoamine compound and a base oil 2 containing a diisocyanate compound upstream of the guide vane; , through said guide vanes.

A method for producing a urea grease according to one embodiment of the present invention will be described in detail below. However, the following description is an example for explaining the present invention, and is not intended to limit the technical scope of the present invention only to the scope of this description. In this specification, when a numerical range is indicated using "-", the numerical values at both ends are included.

<Urea grease and its manufacturing method>
The urea grease according to the present embodiment includes a diurea compound obtained by reacting at least one monoamine compound selected from aliphatic chain monoamines, alicyclic monoamines, and aromatic monoamines with a diisocyanate compound, and a base oil. contains In addition, components other than the above components (other components) may be contained within a range that does not impair the effects of the present invention.

(Diurea compound)
The diurea compound according to the present embodiment is obtained by reacting at least one monoamine compound selected from chain aliphatic monoamines, alicyclic monoamines, and aromatic monoamines with a diisocyanate compound.

The number of carbon atoms in the chain aliphatic monoamine is preferably 6 to 24, more preferably 6 to 20, even more preferably 8 to 18, from the viewpoint of boiling point and solubility. Specific examples of chain aliphatic monoamines include hexylamine, octylamine, dodecylamine, hexadecylamine, stearylamine and eicosylamine. These chain aliphatic monoamines may be used singly or in combination of two or more.

Specific examples of alicyclic monoamines include cycloalkylamines or substituted alkylcycloalkylamines having 4 to 12 carbon atoms, specifically cyclohexylamine, 4-alkyl-substituted cyclohexylamine, cyclobutylamine, cyclopentylamine, cycloheptylamine and the like. These alicyclic monoamines may be used singly or in combination of two or more.

Specific examples of aromatic monoamines include tolylamine, aniline, trimethylaniline and the like. These aromatic monoamines may be used singly or in combination of two or more.

As the diisocyanate compound, an aromatic diisocyanate is preferably used because the heat resistance of the grease is good. , a mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, 3,3′-dimethyldiphenyl-4,4′-diisocyanate, and the like. Diphenylmethane-4,4'-diisocyanate and 2,6-tolylene diisocyanate are particularly preferred from the standpoint of good availability, and diphenylmethane-4,4'-diisocyanate is more preferred from the standpoint of good heat resistance.

A diurea compound, which is a reaction product obtained by the above reaction, is represented by the following general formula (I). In the formula, R ² is a hydrocarbon group derived from the diisocyanate compound. R ¹ and R ³ are each independently a hydrocarbon group derived from the chain aliphatic amine, the alicyclic amine, or the aromatic amine.

The content of the diurea compound can be appropriately adjusted so that the urea grease has a desired worked penetration. It can be in the range of up to 20% by mass.

(base oil)
The base oil is not particularly limited, and includes mineral base oils and synthetic base oils that are commonly used in grease production. Mineral base oils that can be used are those refined by appropriately combining vacuum distillation, solvent deasphalting, solvent extraction, hydrocracking, solvent dewaxing, sulfuric acid washing, clay refining, hydrorefining, and the like. Synthetic base oils include polyalphaolefin (PAO) base oils, other hydrocarbon base oils, ester base oils, alkyldiphenyl ether base oils, polyalkylene glycol base oils (PAG), and alkylbenzene base oils. etc.

The kinematic viscosity of the base oil at 40° C. is not particularly limited as long as it is within the viscosity range normally used as grease, but is preferably 5 to 3300 mm ² /s, more preferably 10 to 2000 mm ² /s, and more preferably 15 to 1000 mm ^{2 /} s. s is more preferred, and 20 to 500 mm ² /s is particularly preferred.

The content of the base oil in the urea grease is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and particularly preferably 75% by mass or more. If the content of the base oil is less than 50% by mass, the worked penetration of the grease composition tends to decrease, resulting in increased torque. Also, the content of the base oil is preferably 95% by mass or less, more preferably 94% by mass or less, and even more preferably 93% by mass or less. When the content of the base oil exceeds 95% by mass, excessive oil separation tends to occur, resulting in leakage and scattering from the point of use.

The urea grease according to the present embodiment contains a detergent-dispersant, an anti-wear agent, an antioxidant, an extreme pressure additive, a dye, a hue stabilizer, a thickener, and a structure stabilizer, as long as the effects of the present invention are not impaired. , a metal deactivator, a viscosity index improver, and an antirust additive may be added in appropriate amounts. When these various additives are contained, the total content of the additives in the urea grease is preferably 10% by mass or less, more preferably 8.0% by mass or less. 0% by mass or less is more preferable, and 4.0% by mass or less is particularly preferable.

Examples of detergent-dispersants include overbased metal sulfonates, metal sulfonates, metal phenates, metal salicylates, metal phosphanates, and succinimides, with metal sulfonates and succinimides being preferred. Constituents of overbased metal sulfonates, metal sulfonates, metal phenates, metal salicylates, and metal phosphanates include, for example, calcium and magnesium, with calcium being preferred. By using the detergent-dispersant, the generation of lumps can be more effectively suppressed.

The content of the detergent-dispersant can be appropriately adjusted so as to suppress the generation of lumps. It can be in the range of 3 to 1.5% by mass.

Anti-wear agents include, for example, methylenebisdithiocarbamate, polycarboxylate, zinc-based anti-wear agents, sulfur-based anti-wear agents, and phosphorus-based anti-wear agents.

The antioxidant is not particularly limited as long as it is generally added to grease compositions, but aromatic amine antioxidants are preferred, such as diphenylamine, alkylated diphenylamine, phenothiazine, N-phenyl- α-naphthylamine, p,p'-diaminodiphenylmethane, aldol-α-naphthylamine, p-dodecylphenyl-1-naphthylamine and the like.

Examples of extreme pressure additives include ashless dithiocarbamates (ashless DTC), sulfurized fats and oils, phosphates, ashless dithiophosphates (ashless DTP), and SP extreme pressure additives. Ash-type extreme-pressure additives; extreme-pressure additives other than ashless-type extreme-pressure additives, such as antimony dithiocarbamate (SbDTC), bismuth dibutyldithiocarbamate (BiDTC), and zinc dithiocarbamate (ZnDTC).

The worked penetration of the urea grease according to the present embodiment is not particularly limited, and can be adjusted according to the application. In addition, the worked penetration in this specification conforms to JIS K 2220 7, and in an environment of 25 ° C., a cone attached to a consistency meter is dropped into the grease composition, and the depth of penetration over 5 seconds ( mm) multiplied by 10.

The urea grease according to the present embodiment includes power transmission devices such as reducers/gearboxes, gears, chains, and motors; traveling system parts; control system parts such as ABS; steering system parts; Automotive reinforcement parts such as power window motors, power seat motors, sunroof motors; hinge parts for electronic information equipment, mobile phones, etc.; food industry, pharmaceutical industry, steel industry, construction industry, glass industry, cement industry, film tenter It can be applied and used on various parts in the rubber/resin industry, environment/power equipment, paper/printing industry, wood industry, textile/apparel industry, and machine parts that move relative to each other. It is also applicable to bearings such as rolling bearings, thrust bearings, hydrodynamic bearings, resin bearings, linear motion devices, and the like. Since the urea grease according to the present embodiment is excellent in acoustic properties and fretting resistance, it is preferably applied to bearings, gears, spindles and the like before use.

[Method for producing urea grease]
The method for producing urea grease according to the present embodiment uses a mixer having a flow path and guide vanes that allow fluids to merge and mix, and at least one selected from aliphatic monoamine, alicyclic monoamine, and aromatic monoamine. The method is characterized by including a step of mixing a fluid containing one monoamine compound and a diisocyanate compound.

The mixer used for producing the urea grease according to the present embodiment is not particularly limited as long as it has flow paths and guide vanes that allow fluids to merge and mix. Mixing of the fluid is carried out by a process of merging the fluid, a process of agitating the fluid by a spiral flow after passing through the guide vanes 12, and a process of making fine particles by making the fluid collide with the impactor 16 as necessary. .

In this specification, a "guide vane" is a mechanism that has an inlet for inflowing fluid and generates a spiral flow while changing the angle from the inlet.

FIG. 1 is a cross-sectional view showing the configuration of a mixer according to one embodiment of the present invention, but the present invention is not limited to such an aspect. The mixer 1 includes a guide vane 12 provided in a pipe, and flow paths 2 a and 2 b that join upstream of the guide vane 12 . The flow paths 2a and 2b may be formed by two different pipes (see FIGS. 1 to 4) that merge with each other, or may be formed by separating one pipe with a partition or the like. The mixer 1 contains a base oil 1 containing the predetermined monoamine compound via either one of the flow paths 2a and 2b, and a base oil 2 containing the diisocyanate compound via the other of the flow paths 2a and 2b. merge at a confluence point (for example, a point where the axes of the flow paths 2a and 2b intersect) in the flow path, and pass through the guide vanes 12 provided in the flow path. As the merged fluid passes through the guide vanes 12, the fluid is converted into a helical flow, creating a violent centrifugal force. At this time, due to the difference in the specific gravity of the fluid, the heavy fluid is distributed radially outward and the light fluid radially inward of the flow channel. . It is believed that the heavy fluid microparticle groups and the light fluid microparticle groups continuously and violently collide with each other due to centrifugal force and centripetal force, and further, the generated urea grease is reduced to fine particles.

The mixer 1 may further include a projecting impactor 16 on the inner wall of the flow path on the downstream side of the guide vane 12 in order to further promote the urea grease to be finely divided. The collision body 16 protrudes radially inward from the inner wall of the flow path (the inner surface of the pipe). In this embodiment, a plurality of collision bodies 16 are provided in the axial direction of the pipe. The number, shape and height of the collision bodies 16 are not particularly limited and can be changed arbitrarily. The height of the impactor 16 may be set so that there is a gap between the tips of the impactor 16 when viewed in the axial direction of the tubular body of the mixer 1 as shown in FIG. The impingement bodies 16 may overlap or intersect (that is, the length of the impingement bodies 16 is longer than the inner radius of the pipe) when viewed in the axial direction of one pipe.

Although there are no particular restrictions on the piping configuration of the flow paths 2a and 2b located upstream of the guide vanes 12, for example, as shown in FIG. and a second pipe having a flow path 2b extending obliquely with respect to the flow path 2a and joining the flow path 2a, as shown in FIG. and a second pipe having a flow path 2b inclined on the opposite side of the first flow path with respect to the flow path downstream of the guide vane 12. type of piping. In this way, when the flow paths 2a and 2b are merged upstream of the guide vane 12, (1) the shearing action due to the conversion of the laminar flow to the spiral flow by the guide vane, and (2) the boundary layer due to the impactor An advantage is that the exfoliation facilitates the dispersion of the urea grease.

Further, as shown in FIG. 4 , the flow path 2 b led from the upstream side of the mixer 1 may be passed through the central axis of the guide vane 12 . In this way, when the flow paths 2a and 2b are joined downstream of the guide vane 12, the fluid passing through the flow path 2b is not subjected to shearing action by the guide vane, so the effect of miniaturization is inferior, but the impact force caused by the impactor 16 is strong. Since the reaction is started under the generation of turbulent flow, there is an advantage that aggregation of the produced urea grease is suppressed.

Further, each of the flow paths 2a and 2b is independently connected to a plurality of inlets of the guide vane 12, and the base oil 1 containing the predetermined monoamine compound and the base oil 2 containing the diisocyanate compound are They may pass through the guide vane 12 via separate flow paths and inlets and join downstream of the guide vane 12 to initiate the reaction (see FIG. 5). In this case, since the base oil 1 and the base oil 2 are each subjected to shearing action by the guide vanes, there is no reduction in the refinement effect, and the reaction starts under the strong turbulent flow generated by the impactor 16, so the urea There is an advantage that agglomeration of grease is suppressed. 5 and 6, flow paths 2a and 2b are formed by dividing the pipe into two by a partition plate 15 on the upstream side of the guide vane 12 in the radial direction. The base oil 1 flowing in the flow path 2a flows downstream of the guide vane 12 along the surface of the elliptical disk 13 of the guide vane 12, and the base oil 12 flowing in the flow path 2b and the surface of the elliptical disk 14 of the guide vane 12 flow to the downstream side of the guide vane 12 along.

The guide vane 12 shown in FIG. 1 has a structure in which chord side edges 13a and 14a of a pair of split elliptical discs 13 and 14 cross each other in an X shape. Further, the guide vane 12 has a structure in which a partition plate 15 that divides the inside of the mixer 1 into two in the axial direction closes the chord side edges 13a and 14a on the upstream side of the intersection. Although the shape of the partition plate 15 is not particularly limited, a triangular shape is preferable. Circular side edges 13b and 14b of the pair of split elliptical discs 13 and 14 are arranged in the mixer 1 so as to be joined to the inner wall of the channel.

The base oils constituting the base oil 1 and the base oil 2 are not particularly limited, and the base oils described above can be used. Base oil 2 preferably has similar polar or viscous properties. For this reason, it is more preferable to use the same base oil as the base oil 1 and the base oil 2.

The temperature of the base oil 1 containing the predetermined monoamine compound is preferably room temperature to 120° C. from the viewpoint of the solubility of the monoamine compound. The mass ratio of the monoamine compound to the base oil in the base oil 1 is preferably 2 kg or less of the monoamine compound per 1 kg of the base oil.

The temperature of the base oil 2 containing the diisocyanate compound is preferably 50 to 100° C. from the viewpoint of the solubility of the diisocyanate compound. The mass ratio of the diisocyanate compound to the base oil in the base oil 2 is preferably 2 kg or less of the diisocyanate compound per 1 kg of the base oil.

The reaction temperature between the monoamine compound and the diisocyanate compound is not particularly limited, and may be the same as in ordinary reactions of this type. The reaction temperature is preferably 50 to 170°C, more preferably 60 to 150°C, from the viewpoint of the solubility and volatility of the monoamine compound and the diisocyanate compound.

The reaction between the amino group of the monoamine compound and the isocyanate group of the diisocyanate compound is considered to proceed quantitatively. The molar ratio of the monoamine compound and the diisocyanate compound is preferably 1.0 to 1.1 mol of the diisocyanate compound per 2 mol of the total amount of the monoamine compound.

The distance from the confluence point of the two flow paths where the base oil 1 and the base oil 2 merge to the downstream end of the guide vane 12 is X (mm), and the distance from the confluence point of the flow paths to the downstream end of the guide vane 12 is When the average flow velocity of the fluid is Vx (mm/s), X/Vx (s) is preferably 1.0 or less, more preferably 0.75 or less, and even more preferably 0.50 or less. Since the reaction between the monoamine compound and the diisocyanate compound is very fast, the longer the arrival time from the confluence point of the base oil 1 and the base oil 2 to the guide vane 12, the more the reaction between the monoamine compound and the diisocyanate compound progresses, resulting in the urea grease. agglomerates and lumps are likely to occur. By setting X/Vx within the above range and causing the fluid to pass through the guide vanes 12 and generate a spiral flow before the reaction between the monoamine compound and the diisocyanate compound is completed, shearing of the urea grease is accelerated. Grease can be effectively reduced to fine particles. The lower limit of X/Vx is not particularly limited.

In this specification, the term "the confluence point of the two flow paths where the base oil 1 and the base oil 2 merge" means the intersection of the cross-sectional center lines (axial centers) of the flow paths 2a and 2b. In addition, the average flow velocity Vx (mm/s) is the volume and length of the fluid discharged from the discharge port 17 per unit time. ) is calculated based on the cross-sectional area in the pipe.

From the viewpoint of suppressing the occurrence of lumps due to aggregation of the urea grease and from the viewpoint of improving the mixing property of the fluid due to the turbulence effect, it is preferable to increase the average flow velocity Vx, for example, 100 mm / s or more, 300 mm / s or more. , 500 mm/s or more, 700 mm/s or more, 900 mm/s or more, or 1100 mm/s or more. The upper limit of the average flow velocity Vx is not particularly limited as long as the performance of the pump and the durability of the flow path allow it.

When the distance from the downstream end of the guide vane to the discharge port 17 of the mixer is Y (mm) and the average flow velocity of the fluid from the downstream end of the guide vane to the discharge port 17 of the mixer is Vy (mm/s), Y/Vy(s) is preferably 0.0005 or more, more preferably 0.001 or more, and even more preferably 0.002 or more. By setting Y/Vy within the above range and securing the arrival time from the downstream end of the guide vane to the discharge port 17 of the mixer, the reaction between the monoamine compound and the diisocyanate compound is completed, and the urea grease is effectively applied. It can be made into fine particles. Y/Vy(s) is preferably 0.10 or less, more preferably 0.050 or less, and even more preferably 0.030 or less. If Y/Vy(s) is more than 0.10, the refining action is insufficient and coarse particles are likely to be generated.

The reaction rate with the diisocyanate compound differs depending on the type of monoamine compound. For this reason, it is preferable to increase Y/Vy within an appropriate range for monoamine compounds with a slow reaction rate, and to decrease Y/Vy within an appropriate range for monoamine compounds with a fast reaction rate. Examples of monoamine compounds having a slow reaction rate include behenylamine, paradodecylamine, and toluidine. On the other hand, monoamine compounds having a fast reaction rate include, for example, octylamine and cyclohexylamine.

The average flow velocity Vy can be, for example, 1000 mm/s or more, 3000 mm/s or more, 5000 mm/s or more, 7000 mm/s or more, 9000 mm/s or more, or 11000 mm/s or more. The upper limit of Vy is not particularly limited as long as the performance of the pump and the durability of the flow path allow it.

The average flow velocity Vy (mm/s) is calculated based on the volume of the fluid discharged from the discharge port 17 per unit time and the cross-sectional area of the discharge port 17 .

The urea grease discharged from the mixer 1 is held at, for example, 120 to 250° C. for 10 to 60 minutes, cooled to about 100° C., and homogenized using a homogenizer to obtain the urea grease according to the present embodiment. can be done. Further, the obtained grease may be further homogenized by a roll mill generally used in grease production.

EXAMPLES The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these.

In this example, the following raw materials were used.
MDI: Diphenylmethane-4,4′-diisocyanate Mineral oil: 500N mineral oil (40° C. kinematic viscosity: 97.5 mm ² /s)

A urea grease was produced using the mixer shown in FIG. The distance X from the confluence point of the two flow paths where the following base oil 1 and the following base oil 2 join to the downstream end of the guide vane is 140 (mm), and the distance from the downstream end of the guide vane to the discharge port of the mixer. Y is 45 (mm). A specific manufacturing method is as follows.

(Examples 1-3)
Base oil 1 (500N mineral oil containing the amine mixture described in Examples 1-3 heated to 60°C, the weight ratio of amine mixture to 500N mineral oil was 1:11) and base oil 2 (MDI heated to 60°C 500N mineral oil containing MDI and 500N mineral oil at a mass ratio of 1:11) was merged upstream of the guide vanes and continuously passed through the guide vanes at the flow rate shown in Table 1. After the urea grease discharged from the mixer was held at 160°C for 30 minutes, it was cooled to about 100°C and homogenized using a homogenizer. Table 1 shows the results of evaluating various properties of the obtained urea grease by the method described later. In addition, the molar ratio of MDI shows the molar ratio of MDI with respect to the total amount of 2 mol of monoamine compounds.

(Example 4)
Base oil 1 (500N mineral oil containing the amine mixture described in Example 4 heated to 60°C, weight ratio of amine mixture to 500N mineral oil was 1:5) and base oil 2 (containing MDI heated to 60°C 500N mineral oil (mass ratio of MDI and 500N mineral oil is 1:5) was merged upstream of the guide vanes and continuously passed through the guide vanes at the flow rate shown in Table 1. After the urea grease discharged from the mixer was held at 160°C for 30 minutes, it was cooled to about 100°C and homogenized using a homogenizer. Table 1 shows the results of evaluating various properties of the obtained urea grease by the method described later. In addition, the molar ratio of MDI shows the molar ratio of MDI with respect to the total amount of 2 mol of monoamine compounds.

(Comparative Examples 1 and 2)
A urea grease was prepared in the usual way. Specifically, according to the formulation in Table 1, a mixture of amine compounds and the same parts by mass of base oil were mixed, heated to 60° C. to dissolve, and a solution A was prepared. Separately, according to Table 1, MDI and the same parts by mass of base oil were mixed, calcium sulfonate was added, and the mixture was heated to 60° C. and dissolved to prepare solution B. Next, after heating the remaining base oil to 60° C., the solution A was mixed, and the solution B was gradually added while stirring the mixture. After holding at 160° C. for 30 minutes, the mixture was cooled to about 100° C. and homogenized using a homogenizer. Table 1 shows the results of evaluating various properties of the obtained urea grease by the method described later. In addition, the molar ratio of MDI shows the molar ratio of MDI with respect to the total amount of 2 mol of monoamine compounds.

<Measurement of worked penetration>
In accordance with JIS K 2220 7, in an environment of 25 ° C, drop a cone attached to a consistency meter into the grease, measure the depth (mm) of penetration for 5 seconds, and multiply the measured value by 10 The resulting penetration was taken as the worked penetration.

<Fafner wear amount>
A fretting resistance test was performed according to ASTM D4170, and the amount of Fafner wear (mg) was measured from the difference in mass before and after the test. The smaller the amount of fafner wear, the better the fretting resistance. The performance target value is 10 mg or less.

<Acoustic test>
An acoustic test was conducted in accordance with the More Quiet method (MQ method) of ISO 21250-3:2020. A grease-unfilled bearing dedicated to acoustic measurement was set in a grease-only acoustic measurement device (Grease Test Rig Be Quiet+) manufactured by SKF, and while rotating at a predetermined speed, acoustic data was collected from 32 seconds to 64 seconds after the start of rotation. Obtained. Next, a predetermined amount of sample (grease) was sealed in these bearings, and acoustic data was obtained from 32 seconds to 64 seconds after the start of rotation while rotating at a predetermined speed. These operations were performed 5 times, and the grease noise class was determined by analyzing with the program built into the acoustic measurement equipment.

From the results in Table 1, the urea grease according to the present invention was obtained by mixing a fluid containing a predetermined monoamine compound and a diisocyanate compound using a mixer equipped with a flow path and guide vanes capable of mixing the fluid. It can be seen that both the acoustic properties and the fretting resistance are improved when comparing greases with the same type and amount of base oil and diurea compound.

DESCRIPTION OF SYMBOLS 1... Mixer 2a, 2b, 2c... Flow path 12... Guide vane 13, 14... Half elliptical disk 13a, 14a... Chord side edge 13b, 14b... Circular arc side Side edge 15 Partition plate 16 Collision body 17 Discharge port

Claims (11)

At least one monoamine compound selected from chain aliphatic monoamines, cycloaliphatic monoamines, and aromatic monoamines, and a diisocyanate compound are mixed using a mixer equipped with flow paths and guide vanes that allow the fluids to merge and mix. A method for producing a urea grease, comprising mixing a fluid containing At least one of a base oil 1 containing at least one monoamine compound selected from chain aliphatic monoamines, alicyclic monoamines, and aromatic monoamines and a base oil 2 containing a diisocyanate compound is added to the guide vanes. 2. The method for producing a urea grease according to claim 1, comprising a step of passing and a step of combining said base oil 1 and said base oil 2. said mixer having at least two said flow passages that meet upstream of said guide vanes;
The step of mixing the fluids includes base oil 1 containing the monoamine compound of at least one of linear aliphatic monoamines, cycloaliphatic monoamines, and aromatic monoamines, and base oil 2 containing a diisocyanate compound. merging upstream of said guide vane, and passing a fluid obtained by merging said base oil 1 and said base oil 2 through said guide vane. . X (mm) is the distance from the confluence of the two flow paths where the base oil 1 and the base oil 2 merge to the downstream end of the guide vane, and the downstream end of the guide vane from the confluence of the flow paths The method for producing a urea grease according to any one of claims 1 to 3, wherein X/Vx is 1.0 or less, where Vx (mm/s) is the average flow velocity of the fluid up to. 5. The method for producing urea grease according to claim 4, wherein said Vx is 100 mm/s or more. The guide vane has a plurality of independent inlets for inflow of fluid,
The base oil 1 containing the monoamine compound of at least one of chain aliphatic monoamines, alicyclic monoamines, and aromatic monoamines and the base oil 2 containing the diisocyanate compound are fed through the independent inlets. 3. The method for producing urea grease according to claim 1, further comprising the step of passing through said guide vanes via a urea grease and joining said urea grease downstream of said guide vanes. Y (mm) is the distance from the downstream end of the guide vane to the outlet of the mixer, and Vy (mm/s) is the average flow velocity of the fluid from the downstream end of the guide vane to the outlet of the mixer. 7. The method for producing a urea grease according to any one of claims 1 to 6, wherein Y/Vy is 0.0005 or more. The method for producing urea grease according to any one of claims 1 to 7, wherein the mixer further has a projecting impactor on the inner wall of the flow path on the downstream side of the guide vane. The method for producing urea grease according to any one of claims 1 to 8, wherein the urea grease further contains a detergent-dispersant. The method for producing urea grease according to any one of claims 1 to 9, wherein the content of the base oil in the urea grease is 50 to 95% by mass. A method for manufacturing a bearing, gear, or spindle, comprising applying urea grease manufactured by the manufacturing method according to any one of claims 1 to 10.

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