JP2009114293A - Grease composition and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a readily handleable grease composition capable of having a high anti-corrosive ability and water as a base, thereby affording a non-solvent-based grease composition, and hardly causing a risk of ignition. <P>SOLUTION: The grease composition is obtained by compounding at lease one kind of base oil selected from among a mineral oil-based lubricant base oil, a synthetic lubricating base oil, and a biodegradable lube base oil with a thickener, and further compounding the resultant grease with a wax, an additive, an anti-foaming agent, and water. The thickener is a soap comprising a calcium sulfonate complex. Carnauba wax is preferably used as the wax. Since comprising the grease and the wax as main components, the grease composition is extremely simply removed with a solvent such as methylene chloride, and is even environmentally friendly. Furthermore, the grease composition has extremely excellent contact pressure characteristics. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is a product in which at least wax and water are blended with grease, and is particularly effective as a product having functions such as rust prevention, mud prevention, contamination resistance, and lubrication for element parts that need to be environmentally friendly. In particular, the present invention relates to a grease composition having excellent rust prevention ability and a method for producing the same.

  Conventionally, a grease composition has to be coated with a very large amount of grease in order to have anti-corrosion ability, and since the adhesion to the member to which the grease is applied is low, the grease can be removed by rotating or reciprocating. It was necessary to give consideration to the environment for splashing and grease. Rust-preventing oil has been used for a long time as a material that has the same rust-preventing power as grease, but the rust-preventing oil is a solvent-diluted type. Various problems have occurred. For this reason, rust-preventing oils are excellent in rust-preventing ability, but often they are difficult to remove, which adversely affects product quality. The reason is that if these rust preventive oils are not completely removed, a dimensional difference corresponding to the film thickness of the rust preventive oil that could not be removed will occur, which will affect the accuracy of fastening of the mounting member to the mating member As a result, the surface treatment becomes mottled during the application of grease, and problems such as deterioration in quality during the application of grease have actually occurred. Further, in order to enhance the anti-corrosion ability of the grease composition, it is necessary to prevent the grease film from being lost during drying, and it is necessary to improve the hardness of the film or to make it gel.

  As a grease composition developed by the present applicant, it is known that it can be used in a wide temperature range from a low temperature to a high temperature and is excellent in rust prevention. The grease composition comprises a synthetic or mineral lubricating base oil excellent in low temperature, rust prevention, heat resistance and load resistance, and a calcium sulfonate complex compound excellent in low temperature as a thickener. 50 wt% is blended and the low temperature property is improved by taking advantage of the properties of calcium sulfonate complex compounds. (For example, refer to Patent Document 1).

A grease composition containing sodium thiosulfate that suppresses generation of rust and improves wear resistance while maintaining sufficient extreme pressure is known. The grease composition includes at least one selected from the group consisting of (A) calcium salicylate, magnesium salicylate, calcium phenate and calcium sulfonate in a grease composition containing 0.05 to 30 wt% sodium thiosulfate. 0.1 to 5 wt% of the total additive and 0.1 to 5 wt% of (B) benzotriazole based on the total composition as necessary (see, for example, Patent Document 2) .
JP 2002-265969 A JP 2002-53889 A

  As a conventional grease composition, it can be achieved by applying an appropriate amount of grease to provide anti-corrosive ability, and it has high adhesion to the grease-applied member, and the grease is scattered by rotational movement, reciprocating movement, etc. Therefore, there was a need to provide an environmentally friendly grease composition. In addition, it has been desired to provide a grease composition having an excellent rust prevention ability without using a rust prevention oil having various problems. Also, to prevent the grease film from being damaged when the applied grease composition is dried, to improve the hardness and adhesion of the grease film, and to improve the grease composition coatability, put it in an emulsion state and after drying, It has been desired to increase the rust prevention ability.

  Accordingly, the present inventor has developed a grease composition in an emulsion state by stirring water at high speed to a grease based on a calcium sulfonate complex-based thickener having a very high rust-preventing ability. In particular, after drying, it was confirmed that it had excellent rust prevention properties. That is, in this grease composition, it was confirmed that a calcium sulfonate complex film was formed on the coated surface upon drying after coating, and that the film had a high rust prevention ability. Unlike the conventional diluted antirust oils, this grease composition was able to improve the removal performance which is easy to remove before solidifying by softening.

  An object of the present invention is to solve the above-mentioned problems, in particular, by adding a wax to a grease containing a base oil and a thickener such as a calcium sulfonate complex, so that water exists in an emulsion state. In addition to adding a surfactant, antifoaming agents are added to prevent foaming during coating, and a mixture of these is formed into a paste, which is stirred at a high speed while adding 30 to 70 wt% water. Non-solvent dilution type with excellent rust prevention ability, anti-sludge property, stain resistance, lubrication function, and easy removal that does not cause environmental impact An object of the present invention is to provide a grease composition capable of adding an extreme pressure agent or an oily agent in addition to a surfactant and an antifoaming agent as an additive, and a method for producing the same.

  The present invention relates to a grease produced by blending a thickener with at least one base oil selected from mineral oil base oils, synthetic base oils and biodegradable base oils. And a grease composition characterized by containing water.

  In this grease composition, the thickener is a soap and / or a urea-based non-soap containing at least a calcium sulfonate complex.

  In this grease composition, it is preferable to use carnauba wax as the wax.

  In this grease composition, the water is present in the form of an emulsion in the composition.

  In this grease composition, the grease is blended with 15 to 40 wt% and the wax is blended with 15 to 30 wt%, and the water and the additive are blended as the balance.

  Further, this grease composition contains 0 to 5 wt% of an antifoaming agent as the additive. Further, 0 to 10 wt% of a surfactant having an emulsion forming function is blended as the additive. In some cases, the grease composition may contain a solid lubricant, an extreme pressure additive and / or an oily agent as the additive.

  In this grease composition, the emulsion is produced by stirring using a mixer or a homogenizer when the water is mixed with the composition composed of components other than the water.

  This grease composition is prepared as a lubricating grease by adjusting the mixing ratio of the wax and the grease to 2: 1. Alternatively, this grease composition is prepared as a steel surface treatment grease for preventing mud or marine organism adhesion by adjusting the blending ratio of the wax and the grease to 1: 2.

  The present invention also provides a first step in which an emulsion is formed by gradually adding water to grease obtained by blending a calcium sulfonate complex as a thickener with a base oil, and the wax is stirred into the emulsion. The second step of gradually adding a paste to form a paste, the third step of adding the remaining water to the paste to form an aqueous solution in an emulsion state, and the step of filtering the aqueous solution to produce a grease composition The present invention relates to a method for producing a grease composition comprising four steps.

  In addition, in the method for producing the grease composition, in the first step, a surfactant is added together with the water to promote the formation of the emulsion, and further, the aqueous solution formed in the third step is erased. Add foaming agent.

  Since the grease composition and the manufacturing method thereof according to the present invention are configured as described above, a thickening agent of calcium sulfonate complex having excellent rust prevention ability is used. The wax can strengthen the adhesion to the steel material, prevent the grease composition from scattering, and since it is based on water to make it into a paste, it becomes a non-solvent grease composition and may cause ignition. Is easy to handle and apply to steel, and since grease and wax are the main components, removal with methylene chloride and other solvents is very simple and environmentally friendly. The base calcium sulfonate complex has very good surface pressure characteristics. It is possible to use the gear or gears without removing things.

  Hereinafter, the grease composition according to the present invention and the production method thereof will be described. In particular, this grease composition is a grease produced by blending a thickener with at least one base oil selected from mineral oil base oil, synthetic base oil and biodegradable base oil. It is characterized by blending wax, additives, and water. As the grease in this grease composition, for example, those disclosed in Japanese Patent Application Laid-Open No. 2002-265969 according to the present applicant can be used. As the wax, among waxes, carnauba wax prepared from a plant-derived carnauba palm tree leaf is most preferable. In addition, when paraffin wax is used as the wax, it is dried after being applied, but it re-emulsifies even after drying, and the phenomenon that the film on the coated surface cannot be maintained occurs. is there.

  In the grease composition according to the present invention, first, a grease having a base calcium sulfonate as a thickener is prepared. The main functions of this grease are rust prevention and extreme pressure. After that, a base lubricant is made by adding a wax composed mainly of plant-derived wax, sodium alkylsulfonate as a surfactant, and silicone oil as an antifoaming agent. Wax is necessary to prevent stickiness after drying. Without wax, it is very sticky and may cause dust adhesion and damage the surface of the protective member. Without an antifoaming agent or surfactant, the quality of the film during drying will not be stable and rust prevention performance will be achieved. It has been found to fall.

  Grease and water are made into an emulsion using a homogenizer at a ratio of 1: 1. In this embodiment, since the lubricant and water are present in an emulsified state, only the lubricant remains by drying after application, and a film having antirust performance can be formed. Since the film thickness is controlled by the ratio of water, the necessary ratio of rust prevention performance can be changed according to the application. If the ratio of water: lubricant is 1: 1, it can have the same rust-preventing ability as rust-preventing oil, but if it is 2: 1, the rust-preventing ability is reduced, but a grease composition with high workability of application is obtained. .

  Next, the manufacturing method of the grease composition according to the present invention will be described. This grease composition is produced by adding a surfactant to a grease obtained by blending a calcium sulfonate complex as a thickener with a base oil, and gradually adding a surfactant together with water to promote the formation of an emulsion. Next, wax is gradually added to the emulsion while stirring to form a paste, and the remaining water is added to the paste to form an aqueous solution in an emulsion state, and the aqueous solution is defoamed. Finally, the aqueous solution was filtered using, for example, a 60 to 100 mesh filter to prepare a grease composition, transferred to a container, and the container was sealed to complete the product. In addition, the grease penetration used here is No. 2 (265-295). However, the grease consistency range is No. 0-No. 3 (385-220) can be used, and it is thought that this consistency range is the appropriate grease hardness range.

  In this method for producing a grease composition, when water is gradually added to the grease, it is preferable to add a surfactant to make an emulsion. As the surfactant, for example, a surfactant containing at least one of anionic, nonionic, zwitterionic, and cationic is used. A surfactant is necessary to facilitate the mixing of grease and water. However, when a calcium sulfonate complex grease is used as a thickener, mixing is possible even without a surfactant. In addition, when the wax is mixed in an emulsion of water and grease, it can be easily mixed to form a paste by dissolving it by heating or the like. In addition, the stirring for mixing the grease with water and the surfactant is first performed at 500 to 800 rpm using a high-speed mixer or an ultrasonic mixer, and the rotational speed is gradually increased. Stir at a high speed of about 3000 rpm until the whole becomes a uniform emulsion. Alternatively, the grease, water, and surfactant are mixed using a homogenizer so that the whole is in a uniform emulsion state. In particular, when a wax is mixed with an emulsion of water and grease to produce a wax emulsion, the mixture is first stirred at a low speed and gradually mixed at a high speed, so that the wax emulsion scatters and adheres to the stirring vessel at the time of stirring. And solidification can be avoided. In this grease composition, a wax emulsion, which is easy to solidify, is mixed well with an emulsion of water and grease, and further water is added to make a solvent-type product that improves the coating property on the surface of steel members. It is.

  In Tables 1 and 2, salt spray tests were conducted on Examples 1 to 8 and Comparative Examples 1 to 4 in which various additives were blended with grease obtained by blending a base oil thickener. The results are shown. In Table 1 and Table 2, the result of applying the grease composition of each sample (Examples 1 to 8 and Comparative Examples 1 to 4) to a steel plate by brushing is ◎, which is very easy to apply. Is indicated by ○, and difficult items are indicated by ×. After each sample was applied to the steel plate, the steel plate was set in a salt spray test tank and sprayed with 5% salt water at a rate of 1 to 3 ml / hr. After 72 hours, 144 hours and 500 hours had passed, The degree of rusting was compared. The degree of rusting on the steel sheet indicates that there is no rust in class A, and there is a large rusting area from class B to class D.

  As can be seen from Table 1, Example 1 has a large proportion of water and does not contain a surfactant and an antifoaming agent. However, it can be seen that the coating property is good and the rust prevention property is slightly deteriorated. Therefore, it can be seen that the grease composition of Example 1 can sufficiently exhibit rust prevention depending on the object to be used and can be used. In Examples 2 to 4, the proportion of water is gradually decreasing and a surfactant is added, but no antifoaming agent is added. For the grease compositions of Examples 2 to 4, the coatability is good, and in Example 2, the salt spray test is slightly reduced due to the large amount of water, but in Examples 3 and 4, the salt spray test is reasonable. I understand that. In Examples 5 to 8, water is 50 to 30 wt%, and a surfactant and an antifoaming agent are added. In Examples 5 to 8, it can be seen that the salt spray test is good and the antirust property is excellent. In Example 8, since the ratio of water was small, there was difficulty in coating properties, but it can be seen that the practical value is sufficiently high.

  As can be seen from Table 2, the grease compositions of Comparative Examples 1 to 4 had a small proportion of water (20 to 35 wt%) and were difficult to apply. Comparative Example 1 shows the coating property and the salt spray test result when no grease, surfactant, or antifoaming agent is added and grease is used alone. In Comparative Example 2, although the wax and the surfactant were slightly added, the properties of the grease alone were almost shown. In Comparative Example 3, the addition ratio of the wax was 30 wt%, but the ratio of water was as small as 27 wt%, the coating property was difficult, and the salt spray test was not sufficient. In Comparative Example 4, the proportion of wax was large and the proportion of water was small compared to the proportion of wax, and good results were not obtained in coating properties and rust prevention properties.

  From the above, it can be seen that the grease composition may have a water ratio of 30 to 70 wt%, preferably about 50 to 45 wt%. Further, it can be seen that the surfactant is preferably added in order to obtain an emulsion state, and the antifoaming agent is preferable because it suppresses the generation of bubbles when the grease composition is applied. Regarding the grease composition according to the present invention, the reason why the salt spray test is good is considered to be that the antifoaming agent is mixed. This is because it was discovered from the test results so far that the pattern of rust generation was similar to bubbles generated during application. Therefore, when an antifoaming agent that is often used in oil-based lubricants but not in a grease composition is mixed, no bubbles are generated during application, and a uniform film is obtained. In addition, very good results were obtained for rust prevention.

  In each of the above examples, a grease composition having anti-rust properties has been described. However, a grease composition having completely different performance can be obtained simply by changing the blending ratio of the wax and calcium sulfonate complex grease. It is possible to produce a product as For example, when the blending ratio of wax and calcium sulfonate complex grease is adjusted to about 2: 1, it can be used as a grease composition for thrust bearings, that is, lubrication with very little stickiness. Also, if the blending ratio of wax and calcium sulfonate complex grease is adjusted to about 1: 2, an oil film is formed on the surface of the steel material. It can also be applied to products as a surface treatment of steel for preventing marine organisms.

  The grease composition according to the present invention can be applied, for example, by sliding between members in various machines such as construction machines, civil engineering machines, vehicles, automobiles, ships, etc., bearings, application to the surface of steel, spraying, etc. , It is preferable for use in the sliding part.

Claims (14)

The grease produced by blending a thickener with at least one base oil selected from mineral base oil, synthetic base oil and biodegradable base oil contains wax, additives and water. A grease composition characterized by being formulated. 2. The grease composition according to claim 1, wherein the thickener is a soap and / or a urea-based non-soap containing at least a calcium sulfonate complex. The grease composition according to claim 1, wherein the wax is carnauba wax and / or wax. The grease composition according to claim 1, wherein the water is present in the form of an emulsion in the composition. The said grease is mix | blended with 15-40 wt% and the said wax of 15-30 wt%, The said water and the said additive are mix | blended as the remainder, The any one of Claims 1-4 characterized by the above-mentioned. The grease composition as described. The grease composition according to claim 5, wherein 0 to 5 wt% of an antifoaming agent is blended as the additive. 7. The grease composition according to claim 5, wherein 0 to 10 wt% of a surfactant having an emulsion forming function is blended as the additive. The grease composition according to claim 1, wherein a solid lubricant, an extreme pressure additive, and / or an oily agent can be blended as the additive. The said emulsion is produced | generated by stirring using a mixer or a homogenizer, when mixing the said water with the composition which consists of components other than the said water. The grease composition according to claim 1. The grease composition according to any one of claims 1 to 9, wherein the grease composition is prepared as a lubricating grease by adjusting a mixing ratio of the wax and the grease to 2: 1. 10. The steel surface treatment grease according to claim 1, wherein the mixing ratio of the wax and the grease is adjusted to 1: 2, and the steel surface treatment grease is prevented from adhering to mud or marine organisms. The grease composition according to item. The first step in which an emulsion is formed by gradually adding water to a grease obtained by blending a calcium sulfonate complex of a thickener with a base oil, and gradually adding wax to the emulsion while stirring. It comprises a second step of producing the whole into a paste, a third step of adding the remaining water to the paste to produce an aqueous solution in an emulsion state, and a fourth step of producing a grease composition by filtering the aqueous solution. A method for producing a grease composition. 13. The method for producing a grease composition according to claim 12, wherein in the first step, a surfactant is added together with the water to promote the formation of the emulsion. The method for producing a grease composition according to claim 12 or 13, wherein an antifoaming agent is added to the aqueous solution generated in the third step.