KR102150971B1 - Manufacture method of grease for reducer of robot - Google Patents

Abstract

The present invention relates to a method of manufacturing grease for a robot reducer. More particularly, the present invention provides a method for manufacturing grease which is to be applied to a speed reducer of a robot, a precision instrument, and which has excellent penetration by having good softness while exhibiting excellent wear resistance and load resistance.

Description

Manufacturing method of grease for robot reducer{MANUFACTURE METHOD OF GREASE FOR REDUCER OF ROBOT}

The present invention relates to a method of manufacturing a grease for a robot reducer.

The present invention is a research result conducted with the support of the'Government-funded Convergence R&D Support Project' of Daegu Techno Park.

In general, an industrial robot is provided with a robot arm that performs a rotation operation, and a reducer for a robot that reduces the power of a rotation motor and transmits it to the robot arm in order to perform the rotation operation of the robot arm is provided. Such a reducer for a robot is filled with a lubricating composition such as grease for lubricating the reducer for a robot, as disclosed in Korean Patent Laid-Open Publication No. 10-2015-0143953.

In particular, unlike other devices, since the robot corresponds to a very precise device, excellent permeability is required in a lubricant composition such as grease applied to a reducer for a robot. That is, the lubricating composition applied to the reducer for a robot is formed in a soft form, and when applied to the reducer, it must be sufficiently penetrated inside the reducer for a robot. In addition, the grease applied to the reducer for robots is required to have excellent permeability and at the same time excellent wear resistance and load resistance.

Meanwhile, as disclosed in Korean Patent Application Laid-Open No. 10-2006-0043765, the reducer is synthesized by reacting a conventional lubricant; a long-chain polyol having a number average molecular weight of 500 or more, a crosslinking agent having 3 or more active hydrogen groups in one molecule, and a polyisocyanate. A lubricant composition comprising; cushioning material particles of one polyurethane resin is applied.

However, since the disclosed lubricating composition is not specialized for a precise device such as a robot, it is not considered at all to improve the softness of the lubricating composition itself and increase the permeability. In addition, development of a lubricating composition excellent in abrasion resistance and load-resistance characteristics as well as good brittleness and excellent permeability for use as a reducer of a robot is insufficient.

Accordingly, there is a need for development of a lubricating composition that is applied to a speed reducer of a robot, which is an ultra-precision device, and has excellent permeability in parts due to its high softness and excellent wear resistance and load resistance.

Republic of Korea Patent Publication No. 10-2015-0143953 Republic of Korea Patent Publication No. 10-2006-0043765

An object of the present invention is to provide a method for producing a grease, which is applied to a speed reducer of a robot, which is a precision device, and has good brittleness and excellent penetration, but excellent wear resistance and load resistance.

The object of the present invention is not limited to the technical problem as described above, and another technical problem may be derived from the following description.

In order to achieve the above object, the present invention provides a method for producing a grease for a robot reducer comprising an oil composition, a thickener and an additive, comprising: (a) heating the first oil composition to 100 to 160° C.; (b) adding and mixing a thickener to the heated first oil composition to form a first mixture; (c) heating the first mixture to 180 ~ 220 ℃; (d) adding and mixing a second oil composition to the heated first mixture to prepare a second mixture, and cooling it to room temperature; And (e) adding and mixing at least one additive selected from the group consisting of Mo-DTC (Molybdenum dithiocarbamate), Mo-DTP (Molybdenum dithiophosphate), and PTFE (Polytetrafluoroethylene) to the cooled secondary mixture, followed by homogenization; Including, wherein the oil composition provides a method for producing a grease for a robot reducer, including a base oil and an ethylene-propylene copolymer.

The grease may include 75 to 92% by weight of an oil composition, 7 to 23% by weight of a thickener, and 0.1 to 5% by weight of an additive based on the total weight of the grease.

The oil composition may include a base oil and an ethylene-propylene copolymer in a weight ratio of 1: 0.01 to 0.1.

The thickener may include at least one selected from the group consisting of Sebacic acid, 12-Hydroxystearic acid, and lithium hydroxide (LiOH).

The thickener may include Sebacic acid, 12-Hydroxystearic acid, and lithium hydroxide (LiOH) in a molar ratio of 1: 0.5 to 1.2: 1 to 3.

The step (b) includes the steps of (b-1) adding and mixing Sebacic acid and 12-Hydroxystearic acid to the heated first oil composition; (b-2) cooling the first oil composition in which the sebacic acid and 12-hydroxystearic acid are mixed to 85 to 105°C; And (b-3) adding and mixing lithium hydroxide to the cooled first oil composition to form a first mixture.

The base oil may include one or more selected from the group consisting of mineral oil, polyalphaolefin (PAO), polyalkylene glycol (PAG), silicone oil, ester oil, and perfluoropolyether. .

The additive may include Mo-DTC (Molybdenum dithiocarbamate), Mo-DTP (Molybdenum dithiophosphate), and PTFE (Polytetrafluoroethylene) in a weight ratio of 1: 0.1 to 0.5: 0.1 to 1.

In the above (e), at least one auxiliary agent selected from the group consisting of a corrosion inhibitor, an antioxidant, and a wear inhibitor may be further added.

According to the manufacturing method of the present invention, it is for application to a speed reducer of a robot, which is an ultra-precision device, and has good brittleness and good penetration, and a grease having excellent wear resistance and load resistance can be produced.

The grease according to the above has good brittleness, so it is easy to penetrate between parts, and has excellent wear resistance and load resistance, so that it can have excellent properties as a lubricant. Accordingly, the reducer for a robot to which the grease according to the above is applied may reduce noise and vibration.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In the drawings, parts not related to the description are omitted in order to clearly describe the present invention.

The terms or words used in the specification and claims of the present invention are not limitedly interpreted in a conventional or dictionary meaning, and the inventor can appropriately define the concept of the term in order to describe his own invention in the best way. Based on the principle, it should be interpreted as a meaning and concept consistent with the technical idea of the present invention.

In the entire specification of the present invention, when a certain part "includes" a certain component, it means that other components may be further included rather than excluding other components unless otherwise stated. .

In the entire specification of the present invention, "A and/or B" means A or B, or A and B.

Hereinafter, the present invention has been described in detail, but the present invention is not limited thereto.

The present invention provides a method for producing a grease for a robot reducer.

In one embodiment of the present invention, as a method of manufacturing a grease for a robot reducer comprising an oil composition, a thickener, and an additive, (a) heating the first oil composition to 100 to 160 °C; (b) adding and mixing a thickener to the heated first oil composition to form a first mixture; (c) heating the first mixture to 180 ~ 220 ℃; (d) adding and mixing a second oil composition to the heated first mixture to prepare a second mixture, and cooling it to room temperature; And (e) adding and mixing at least one additive selected from the group consisting of Mo-DTC (Molybdenum dithiocarbamate), Mo-DTP (Molybdenum dithiophosphate), and PTFE (Polytetrafluoroethylene) to the cooled secondary mixture, followed by homogenization; Including, wherein the oil composition provides a method for producing a grease for a robot reducer, including a base oil and an ethylene-propylene copolymer.

According to the present embodiment, it is for application to a speed reducer of a robot, which is an ultra-precision device, and it is possible to manufacture a grease having good brittleness and excellent penetration between parts. At this time, good brittleness may mean good consistency (25°C).

Particularly, in an ultra-precision device such as a robot, the size of each component constituting the device is very small, and the coupling relationship between them is complex, and thus grease must sufficiently penetrate between the components. Accordingly, in this embodiment, by including one or more additives selected from the group consisting of Mo-DTC (Molybdenum dithiocarbamate), Mo-DTP (Molybdenum dithiophosphate), and PTFE (Polytetrafluoroethylene), the permeability of the grease was improved to remarkably improved. .

In addition, by improving the brittleness of the grease and remarkably improving the wear resistance and load resistance, the lubricating properties were improved.

(a) heating the first oil composition to 100 ~ 160 ℃

In step (a) of the present embodiment, the first oil composition is heated to 100 to 160 °C. The first oil composition includes a base oil and an ethylene-propylene copolymer.

For example, the first oil composition of the present embodiment contains a base oil and an ethylene-propylene copolymer in a weight ratio of 1: 0.01 to 0.1, specifically 1: 0.01 to 0.05, more specifically 1: 0.02 to 0.03. It can be included in a weight ratio.

If the base oil and the ethylene-propylene copolymer are not included in the weight ratio of 1: 0.01 to 0.1 in the first oil composition, the smoothness of the grease prepared according to the present embodiment is not sufficiently improved, and the formulation stability is There may be a problem that the wear resistance and load resistance are not sufficiently improved due to the decrease.

The base oil may include one or more selected from the group consisting of mineral oil, polyalphaolefin (PAO), polyalkylene glycol (PAG), silicone oil, ester oil, and perfluoropolyether. . Specifically, the base oil of this embodiment may be a polyalphaolefin, but is not limited thereto.

In step (a) of the present embodiment, the first oil composition may be heated to 100 to 160 °C, specifically to 120 to 155 °C, and more specifically to 130 to 150 °C.

If the first oil composition is heated to a temperature of less than 100 °C in step (a) of the present embodiment, there may be a problem in that the base oil and the ethylene-propylene copolymer are not sufficiently mixed. On the other hand, when the first oil composition is heated to a temperature exceeding 160° C. in step (a) of the present embodiment, by-products may be generated or cured due to a side reaction between the base oil and the ethylene-propylene copolymer. . Thereby, the characteristic as a grease may be remarkably deteriorated.

(b) forming a first mixture by adding and mixing a thickener to the heated first oil composition

In step (b) of this embodiment, at least one selected from the group consisting of Sebacic acid, 12-Hydroxystearic acid, and lithium hydroxide (LiOH) was added to the heated first oil composition. The containing thickener is added and mixed to form a primary mixture. The thickener allows the grease of the present embodiment to have excellent softness as a reducer for a robot. At this time, the excellent brittleness of Greece may mean that the capital is high.

In addition, in step (b) of the present embodiment, the thickener comprises sebacic acid, 12-hydroxystearic acid, and lithium hydroxide in a molar ratio of 1: 0.5 to 1.2: 1 to 3, specifically 1: 0.7 to 1: 1.5 to 2 It may be included in a molar ratio of 1: 1: 2 more specifically.

If the thickener of this embodiment does not contain sebacic acid, 12-hydroxystearic acid, and lithium hydroxide in a molar ratio of 1: 0.5 to 1.2: 1 to 3, the consistency of the grease is not sufficiently improved, so that the permeability is lowered. I can.

Step (b) of the present embodiment includes (b-1) adding and mixing Sebacic acid and 12-Hydroxystearic acid to the heated first oil composition, (b- 2) cooling the first oil composition in which the sebacic acid and 12-hydroxystearic acid are mixed to 85 to 105° C. and (b-3) adding and mixing lithium hydroxide to the cooled first oil composition 1 It can be divided into steps of forming a tea mixture.

In step (b-1) of this embodiment, sebacic acid and 12-hydroxystearic acid are added and mixed in the first oil composition heated to 100 to 160° C. according to step (a), and the first oil composition is Sebacic acid and 12-hydroxystearic acid can be allowed to dissolve. For example, in step (b-1) of the present embodiment, sebacic acid is added and mixed to the heated first composition to be dissolved, and then 12-hydroxystearic acid is added and mixed to dissolve.

In step (b-2) of the present embodiment, the first oil composition in a state in which the sebacic acid and 12-hydroxystearic acid are mixed and dissolved may be cooled to 85 to 105°C. At this time, cooling may be performed by flowing cooling water outside the reactor, but is not limited thereto, and cooling may be performed by any known method.

In step (b-3) of the present embodiment, lithium hydroxide may be added to and mixed with the cooled first oil composition to form a first mixture. For example, the lithium hydroxide may be mixed with distilled water and introduced and mixed in a lithium hydroxide aqueous solution state, but is not limited thereto. If lithium hydroxide is mixed with distilled water and added and mixed in a lithium hydroxide aqueous solution state, a certain amount of lithium hydroxide aqueous solution may be slowly added and mixed for about 30 to 1 hour.

In step (b-3) of the present embodiment, a saponification reaction between the first oil composition cooled by the step (b-2) and lithium hydroxide may be performed.

In step (b) of this embodiment, by sequentially performing steps (b-1), (b-2), and (b-3), a grease having good softness and excellent abrasion resistance and load resistance can be prepared. I can.

If the steps (b-1), (b-2), and (b-3) are not sequentially performed, there is a problem that the grease is not sufficiently soft and the wear resistance and load resistance are significantly reduced. I can.

According to this embodiment, the first mixture prepared according to step (b) including steps (b-1), (b-2) and (b-3) is uniformly dissolved and mixed with each component. It can be formed in a state of being.

(c) heating the first mixture to 180 ~ 220 ℃

In step (c) of this embodiment, the first mixture is heated to 180 ~ 220 ℃. In more detail, in step (c) of the present embodiment, the first mixture having a temperature of 100 to 160 °C may be heated to 180 to 220 °C, specifically 190 to 210 °C, and more specifically 195 to 205 °C.

If the first mixture is heated to a temperature of less than 180° C. in step (c) of the present embodiment, there may be a problem in that reactivity and miscibility between the oil composition and the thickener are deteriorated. On the other hand, when the first mixture is heated to a temperature exceeding 220° C. in step (c) of the present embodiment, the hardness increases, and it is formed in a form that is hardened and broken, making it difficult to use as a grease. Thereby, the characteristic as a grease may be remarkably deteriorated.

(d) preparing a second mixture by adding and mixing a second oil composition to the heated first mixture, and cooling it to room temperature

In step (d) of the present embodiment, a second oil composition is prepared by adding and mixing the second oil composition to the first mixture heated to 180 to 220° C. according to step (c), and cooled to room temperature. In this case, the room temperature may mean a temperature of about 20 ~ 28 ℃, but is not limited thereto.

The second oil composition includes a base oil and an ethylene-propylene copolymer, and is the same as the first oil composition. In particular, the second oil composition of the present embodiment comprises a base oil and an ethylene-propylene copolymer in a weight ratio of 1: 0.01 to 0.1, specifically 1: 0.01 to 0.05, more specifically 1: 0.02 to 0.03. Can include.

If, in the second oil composition, the base oil and the ethylene-propylene copolymer are not included in a weight ratio of 1: 0.01 to 0.1, the formulation stability of the grease prepared according to this embodiment is lowered, and the consistency is insufficient. It may not be possible.

The base oil may include one or more selected from the group consisting of mineral oil, polyalphaolefin (PAO), polyalkylene glycol (PAG), silicone oil, ester oil, and perfluoropolyether. . Specifically, the base oil of this embodiment may be a polyalphaolefin, but is not limited thereto.

At this time, according to steps (a) to (d) of the present embodiment, the thickener expands or contracts by heating and cooling, so that the tissue in the composition becomes dense by the thickener, and durability may be improved. As a result, the grease of the present embodiment may have excellent permeability due to good brittleness and excellent wear resistance and load resistance.

(e) homogenizing after adding and mixing an additive to the cooled secondary mixture

In step (e) of the present embodiment, an additive is added to the cooled secondary mixture, mixed, and then homogenized. In more detail, in step (e) of the present embodiment, additives are added to and mixed with the secondary mixture cooled to room temperature according to step (d), and then a 3-roll mill and a high-pressure homogenizer are used. homogenizer). At this time, when using a high-pressure homogenizer than the 3-roll mill, dispersion of the additive and homogenization of the mixture or composition may be easier.

For example, the additive may include at least one selected from the group consisting of Molybdenum dithiocarbamate (Mo-DTC), Molybdenum dithiophosphate (Mo-DTP), and Polytetrafluoroethylene (PTFE).

Specifically, the additive may include Molybdenum dithiocarbamate (Mo-DTC), Molybdenum dithiophosphate (Mo-DTP), and Polytetrafluoroethylene (PTFE).

More specifically, the additive may include Mo-DTC (Molybdenum dithiocarbamate), Mo-DTP (Molybdenum dithiophosphate), and PTFE (Polytetrafluoroethylene) in a weight ratio of 1: 0.1 to 0.5: 0.1 to 1. In step (e) of this embodiment, when the additives include Mo-DTC (Molybdenum dithiocarbamate), Mo-DTP (Molybdenum dithiophosphate) and PTFE (Polytetrafluoroethylene) in a weight ratio of 1: 0.1 to 0.5: 0.1 to 1, the present The grease prepared according to the embodiment may have excellent permeability due to its brittleness and improve wear resistance and load resistance.

Most specifically, the additive may include Mo-DTC (Molybdenum dithiocarbamate), Mo-DTP (Molybdenum dithiophosphate), and PTFE (Polytetrafluoroethylene) in a weight ratio of 1: 0.2 to 0.3: 0.1 to 0.5.

In step (e) of the present embodiment, together with the additive, an auxiliary agent including at least one selected from the group consisting of a corrosion inhibitor, an antioxidant, and a wear inhibitor may be further included. The corrosion inhibitor, antioxidant, and abrasion inhibitor may include all known components.

The corrosion inhibitor may be further included in an amount of 0.1 to 1% by weight based on the total weight of the grease. For example, the corrosion inhibitor may be a triazole-based compound. The triazole-based compound is N,N-bis(2-ethylhexyl)-4-methyl-1H-benzotriazole-1-methylamine (N,N-Bis(2-ethylhexyl)-4-methyl-1H-benzotriazole -1-methylamine) and 1-n-butyrylbenzotriazole may include one or more selected from the group consisting of, but is not limited thereto.

The antioxidant may be further included in an amount of 0.5 to 3% by weight based on the total weight of the grease.

The anti-wear agent may be further included in an amount of 0.01 to 0.5% by weight based on the total weight of the grease.

In steps (a) to (e) of the present embodiment, 75 to 92% by weight of an oil composition, 7 to 23% by weight of a thickener, and 0.1 to 5% by weight of an additive may be included based on the total weight of the grease.

The grease prepared according to the present embodiment may contain 75 to 92% by weight of the oil composition based on the total weight of the grease. If the oil composition is included in an amount of less than 75% by weight based on the total weight of the grease prepared according to the present embodiment, there may be a problem that the effect as a lubricant is significantly reduced due to low permeability and fluidity due to low grease softness. . On the other hand, when the oil composition exceeds 92% by weight based on the total weight of the grease prepared according to the present embodiment, it is formed in a viscous liquid formulation, so that the characteristics of the grease cannot be realized, and abrasion resistance and load resistance There may be a problem that the characteristics of the remarkably deteriorate.

The oil composition of the present embodiment includes a first oil composition and a second oil composition, and the content of the oil composition refers to the total amount of the first oil composition and the second oil composition.

The grease prepared according to this embodiment may contain 7 to 23% by weight of the thickener composition based on the total weight of the grease. If the thickener is included in an amount of less than 7% by weight based on the total weight of the grease manufactured according to the present embodiment, there may be a problem of lowering the lead, abrasion resistance, and load resistance. On the other hand, when the thickener is included in an amount exceeding 23% by weight based on the total weight of the grease prepared according to the present embodiment, there may be a problem in that the lead, abrasion resistance, and load resistance are deteriorated.

In particular, when the thickener is included in an amount of 16 to 20% by weight based on the total weight of the grease prepared according to the present embodiment, it may be possible to prepare a grease having an appropriate softness and excellent abrasion resistance and load resistance characteristics.

The grease prepared according to the present embodiment may contain 0.1 to 5% by weight of the additive based on the total weight of the grease. If the additive is included in an amount of less than 0.1% by weight based on the total weight of the grease prepared according to the present embodiment, the consistency may not be sufficiently improved. On the other hand, when the additive is included in an amount exceeding 5% by weight based on the total weight of the grease prepared according to the present embodiment, there may be a problem in that the consistency is rather reduced, and abrasion resistance and load resistance are remarkably decreased.

In steps (a), (b), (c), (d) and (e) of the present embodiment, separate stirring may be performed for mixing, dissolving, and mixing materials. For example, the stirring may be carried out at a reactor rpm of 40 to 50 Hz, but is not limited thereto.

In the steps (a), (b), (c), (d) and (e) of this embodiment, in addition to the oil composition, thickener and additives, water, solvent, extreme pressure additive, surfactant, thickener, plasticizer, It may further include a pH adjusting agent, a dispersing agent, an antifoaming agent, a floating agent, and the like, but is not limited thereto.

Hereinafter, a method of manufacturing the grease for a robot reducer of the present invention will be described in detail through Examples, Comparative Examples, and Experimental Examples. Since these examples are for illustrative purposes only, the scope of the present invention is not to be construed as being limited by these examples.

[Example]

Examples 1 to 7

Grease was prepared according to the following, and the first oil composition, second oil composition, thickener and additive were added and mixed in the composition of Table 1 [unit: wt%], and the thickener was sebacic acid, 12-hydroxystearic acid, and Lithium hydroxide was mixed in the molar ratio of Table 2 [unit: molar ratio].

(a) A first oil composition in which oil (polyalphaolefin) and ethylene-propylene copolymer were mixed in a weight ratio of 1:0.02 was heated to 130 to 150°C.

(b) After dissolving sebacic acid and 12-hydroxystearic acid in a first oil composition heated at 130 to 150° C. and mixing, a first oil composition in which the sebacic acid and 12-hydroxystearic acid are dissolved The mixture was cooled to about 95 to 105° C., and a lithium hydroxide aqueous solution in which lithium hydroxide and distilled water were mixed in the cooled first oil composition was slowly added and mixed for about 1 hour to form a first mixture. At this time, the distilled water was added in an amount of about 5 times that of lithium hydroxide.

(c) Then, the first mixture was heated to 195 ~ 205 °C.

(d) Into the first mixture heated to 195 to 205 °C, a second oil composition in which oil and ethylene-propylene copolymer are mixed in a weight ratio of 1: 0.02 is added and mixed, and each component is mixed to prepare a second mixture. Was prepared. After that, the secondary mixture was cooled to room temperature (20 ~ 25 ℃).

(e) Additives were added to the secondary mixture cooled to room temperature, mixed in a uniform state, and then homogenized using a high-presssure homogenizer to prepare a grease. At this time, as an additive, a mixture of Mo-DTC (Molybdenum dithiocarbamate), Mo-DTP (Molybdenum dithiophosphate), and PTFE (Polytetrafluoroethylene) in a weight ratio of 1: 0.25: 0.25 was used.

In the preparation of the grease, in each step, agitation was performed for a uniform composition, and agitation was performed at an rpm of 45 Hz.

weight% Examples 1 to 7 Oil composition First oil composition 40 Second oil composition 40 Thickener 17 additive 3

Molar ratio Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Sebacic acid One One One One One One One 12-hydroxystearic acid One - 0.1 1.5 One One One Lithium hydroxide 2 2 2 2 - 0.5 4

Examples 8 to 13

It was prepared in the same manner as in Example 1, except that an additive in which Mo-DTC (Molybdenum dithiocarbamate), Mo-DTP (Molybdenum dithiophosphate), and PTFE (Polytetrafluoroethylene) were mixed was used according to the weight ratio of Table 3.

Weight ratio Example 1 Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Mo-DTC One One One One One One One Mo-DTP 0.25 - 0.01 One 0.25 0.25 0.25 PTFE 0.25 0.25 0.25 0.25 - 0.01 2

[Comparative Example]

Comparative Examples 1 to 6

It was prepared in the same manner as in Example 1, except that it follows the composition of Table 4. In Table 4, the first oil composition and the second oil composition were used in the same amount.

weight% Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 oil
Composition First oil composition 70 97 95 69 82.99 75 Second oil composition Thickener 27 One 2 28 17 15 additive 3 2 3 3 0.01 10

Comparative Example 7

It was prepared in the same manner as in Example 1, except that step (b) was carried out as follows.

(b) 12-hydroxystearic acid is added to the first oil composition heated at 130 to 150° C., mixed and dissolved, and then lithium hydroxide and distilled water are mixed in the first oil composition in which the 12-hydroxystearic acid is dissolved. The lithium hydroxide aqueous solution was slowly added and mixed for about 30 minutes, and then sebacic acid was added and mixed, and the mixture was cooled to about 95 to 105° C. to prepare a first mixture. At this time, the distilled water was added in an amount of about 5 times that of lithium hydroxide.

Comparative Examples 8 to 11

It was prepared in the same manner as in Example 1, except that the temperature range of Table 5 was followed.

Comparative Example 8 Comparative Example 9 Comparative Example 10 Comparative Example 11 Heating temperature of step (a) (℃) 80 to 90 170 ~ 180 130 to 150 130 to 150 Heating temperature of step (c) (℃) 195 ~ 205 195 ~ 205 160 ~ 170 230 to 240

Comparative Example 12

It was prepared in the same manner as in Example 1, except that step (c) was not performed.

[Experimental Example]

Experimental Example 1: Evaluation of brittleness

After preparing the grease according to Examples 1 to 13 and Comparative Examples 1 to 12, the consistency thereof was evaluated, and the results are shown in Table 6 [unit: 0.1 mm].

At this time, the intensity was evaluated at about 25 ℃, 60 W conditions, and was evaluated according to the test method of KS M ISO 2137.

LED (25 ℃) LED (25 ℃) Example 1 395 Comparative Example 1 195 Example 2 260 Comparative Example 2 230 Example 3 270 Comparative Example 3 200 Example 4 267 Comparative Example 4 240 Example 5 255 Comparative Example 5 245 Example 6 269 Comparative Example 6 240 Example 7 275 Comparative Example 7 180 Example 8 280 Comparative Example 8 210 Example 9 281 Comparative Example 9 240 Example 10 290 Comparative Example 10 205 Example 11 275 Comparative Example 11 225 Example 12 288 Comparative Example 12 219 Example 13 290

Referring to Table 6, it can be seen that according to the present embodiment, the grease is formed soft due to high consistency. That is, the grease according to the present embodiment has good brittleness and excellent permeability.

Experimental Example 2: Evaluation of wear resistance

After preparing the grease according to Examples 1 to 13 and Comparative Examples 1 to 12, the wear resistance thereof was evaluated, and the results are shown in Table 7 [unit: mm].

At this time, the abrasion resistance was carried out according to the ASTM D 2266 test method (Four ball wear), and the test was carried out under conditions of 40 Kg, 75 °C, 1200 rpm, and 1 hr.

Wear resistance Wear resistance Example 1 0.33 Comparative Example 1 0.71 Example 2 0.42 Comparative Example 2 0.78 Example 3 0.40 Comparative Example 3 0.80 Example 4 0.49 Comparative Example 4 0.70 Example 5 0.49 Comparative Example 5 0.94 Example 6 0.47 Comparative Example 6 0.87 Example 7 0.50 Comparative Example 7 1.00 Example 8 0.48 Comparative Example 8 0.90 Example 9 0.50 Comparative Example 9 0.92 Example 10 0.51 Comparative Example 10 0.95 Example 11 0.50 Comparative Example 11 0.94 Example 12 0.49 Comparative Example 12 0.95 Example 13 0.51

Referring to Table 7, it can be seen that the grease according to the present embodiment has excellent wear resistance.

Experimental Example 3: Evaluation of load resistance

After preparing the grease according to Examples 1 to 13 and Comparative Examples 1 to 12, the load resistance thereof was evaluated, and the results are shown in Table 8 [unit: kgf].

At this time, the load resistance was carried out according to ASTM D 2596 test method (Four ball Extreme-Pressure Properties), and the test was carried out at 40 Kg, 75 °C, 1200 rpm, 1 hr.

Load resistance Load resistance Example 1 315 Comparative Example 1 200 Example 2 250 Comparative Example 2 200 Example 3 250 Comparative Example 3 200 Example 4 250 Comparative Example 4 200 Example 5 200 Comparative Example 5 126 Example 6 250 Comparative Example 6 200 Example 7 250 Comparative Example 7 126 Example 8 250 Comparative Example 8 126 Example 9 250 Comparative Example 9 160 Example 10 250 Comparative Example 10 160 Example 11 250 Comparative Example 11 160 Example 12 250 Comparative Example 12 160 Example 13 250

Looking at Table 8, it can be seen that the grease according to this embodiment has excellent load resistance.

Summarizing the above Experimental Examples 1 to 3, it is understood that the grease prepared according to this embodiment is excellent in brittleness (leading) and excellent abrasion resistance and load resistance, so that it can be applied as a lubricant suitable for a speed reducer of a robot, which is an ultra-precision device. Able to know.

As described above, the description of the present invention is for illustrative purposes only, and those of ordinary skill in the art to which the present invention pertains can easily be modified into other specific forms without changing the technical spirit or essential features of the present invention. You can understand. Therefore, the embodiments described above are illustrative in all respects and should be understood as non-limiting. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as being distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the claims to be described later rather than the detailed description, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention. do.

Claims (9)

A method for producing a grease for a robot reducer comprising an oil composition, a thickener and an additive,
(a) heating the first oil composition to 100 ~ 160 °C;
(b) adding and mixing a thickener to the heated first oil composition to form a first mixture;
(c) heating the first mixture to 180 ~ 220 ℃;
(d) adding and mixing a second oil composition to the heated first mixture to prepare a second mixture, and cooling it to room temperature; And
(e) In the cooled secondary mixture, an additive containing Mo-DTC (Molybdenum dithiocarbamate), Mo-DTP (Molybdenum dithiophosphate), and PTFE (Polytetrafluoroethylene) in a weight ratio of 1: 0.1 to 0.5: 0.1 to 1 is added and mixed. And then homogenizing; including,
The oil composition is
Includes base oil and ethylene-propylene copolymer,
The above thickener
Sebacic acid (Sebacic acid), 12-hydroxystearic acid (12-Hydroxystearic acid), characterized in that it comprises lithium hydroxide (LiOH), a method for producing a grease for a robot reducer.
The method of claim 1,
The grease is
75 to 92% by weight of the oil composition, 7 to 23% by weight of the thickener, and 0.1 to 5% by weight of additives, based on the total weight of the grease.
The method of claim 1,
The oil composition is
A method for producing a grease for a robot reducer, comprising a base oil and an ethylene-propylene copolymer in a weight ratio of 1: 0.01 to 0.1.
delete The method of claim 1,
The above thickener
Sebacic acid (Sebacic acid), 12-hydroxystearic acid (12-Hydroxystearic acid), and lithium hydroxide (LiOH) in a molar ratio of 1: 0.5 to 1.2: 1 to 3, characterized in that the grease for robot reducer Manufacturing method.
The method of claim 1,
Step (b)
(b-1) adding and mixing Sebacic acid and 12-Hydroxystearic acid to the heated first oil composition;
(b-2) cooling the first oil composition in which the sebacic acid and 12-hydroxystearic acid are mixed to 85 to 105°C; And
(b-3) forming a first mixture by adding and mixing lithium hydroxide to the cooled first oil composition. A method of producing a grease for a robot reducer comprising:
The method of claim 1,
The base oil is
A robot, characterized in that it comprises at least one selected from the group consisting of mineral oil, polyalphaolefin (PAO), polyalkylene glycol (PAG), silicone oil, ester oil, and perfluoropolyether Method of producing grease for reducer
delete The method of claim 1,
In (e) above
A method for producing a grease for a robot reducer, characterized in that an auxiliary agent comprising at least one selected from the group consisting of a corrosion inhibitor, an antioxidant, and a wear inhibitor is further added.