JP6114304B2 - Grease composition - Google Patents

Description

  The present invention relates to a grease composition. More specifically, the present invention relates to a grease composition that has little influence on the environment, exhibits good extreme pressure characteristics, and further suppresses corrosiveness to metals and alloys.

  In recent years, environmental problems have become increasingly serious on a global scale, and implementation of terrestrial biosphere protection regulations has become an important issue in all industrial fields. The field of grease is no exception to the regulations, and the risk of contamination of rivers and soils, especially the risk of contamination of rivers and soils caused by the release of the base oil, the main component of grease, to the natural environment. In applications involving the possibility of leakage, improvements in grease base oils, particularly in terms of biodegradability, are currently expected. At the same time, it is necessary to use higher-power machinery under severer conditions than ever. Lubricant materials used in such machinery are not only biodegradable but also extreme pressure characteristics and corrosion. Significant improvements are required in terms of characteristics.

  Patent Document 1 is a grease composition with improved anti-corrosion properties, and includes at least one base oil, a fatty acid metal soap, and an extreme pressure agent, and the extreme pressure agent is formed from sulfurized fatty acid ester and PTFE. A grease composition is described that may be selected. However, this document does not describe a specific combination of a fluorine-containing polymer and a sulfurized fatty acid ester. Further, this document does not show any amount of active sulfur derived from the above-mentioned sulfurized fatty acid ester.

US Pat. No. 6,316,392

  The present invention is a grease composition that can be used in equipment having a risk of leakage of grease to the external environment, such as automobiles, construction machines, and agricultural machines. The present invention relates to a grease composition that exhibits good characteristics below and has low corrosiveness to metals and alloys.

  Applicant is a grease obtained by combining a sulfurized fatty acid ester having a specific amount of active sulfur at 150 ° C. and a fluorine-containing polymer in a polyol ester base oil with a measured value based on the ASTM D1662 standard. It has been surprisingly found that the composition has a very good extreme pressure characteristic while reducing the environmental burden, and has a low corrosiveness to metals and alloys, especially copper.

  The present invention is a grease composition comprising at least one polyol ester base oil, at least one fatty acid metal soap, at least one fluoropolymer, and at least one sulfurized fatty acid ester. Further, the present invention relates to a grease composition in which the amount of active sulfur derived from the sulfurized fatty acid ester is 0.15% or more based on the total mass of the grease composition as measured at 150 ° C. in accordance with ASTM D1662 standard.

  Preferably, the polyol ester is at least one selected from neopentyl glycol ester, trimethylol ethane ester, trimethylol propane ester, pentaerythritol ester and dipentaerythritol ester.

  Preferably, in the grease composition, the polyol ester base oil is 50% to 95%, more preferably 60% to 90%, and still more preferably 70% to 80% in terms of mass% with respect to the total mass of the grease composition. Including.

  Preferably, the fluorine-containing polymer is polytetrafluoroethylene.

  Preferably, the grease composition contains the fluorine-containing polymer in an amount of 1 to 10%, more preferably 2 to 8%, and further preferably 3 to 5% by mass based on the total mass of the grease composition.

  Preferably, the sulfurized fatty acid ester is at least one selected from fatty acid triglycerides and fatty acid methyl esters.

  Preferably, in the grease composition, the sulfurized fatty acid ester is 0.5 to 5%, more preferably 1 to 4%, and still more preferably 2 to 3% by mass based on the total mass of the grease composition. Including.

  Preferably, the fatty acid metal soap is a single type of fatty acid metal soap, more preferably a fatty acid lithium soap or a fatty acid calcium soap.

  Preferably, the fatty acid metal soap is lithium = 12-hydroxystearate.

  Preferably, the grease composition includes a fatty acid metal soap in an amount of 1 to 20%, more preferably 2 to 15%, and even more preferably 4 to 12% by mass based on the total mass of the grease composition.

  Preferably, the polyol ester or a mixture of polyol esters has a kinematic viscosity at 40 ° C. measured according to the ASTM D445 standard of 3 to 2,000 cSt, more preferably 10 to 1,500 cSt, more preferably Is 40 to 500 cSt, and still more preferably 50 to 200 cSt.

  Preferably, the grease composition has a consistency (1/10 mm) measured in accordance with ASTM D217 standard of 220 to 430, more preferably 265 to 295.

  Preferably, the amount of active sulfur derived from the sulfurized fatty acid ester is a value measured at 150 ° C. in accordance with ASTM D1662 standard, and is 0.15% or more, more preferably 0% by mass with respect to the total mass of the grease composition. .18% or more, more preferably 0.20% or more.

  Preferably, the grease composition has a fusion load measured in accordance with ASTM D2596 standard of more than 315 kg, more preferably 400 kg or more.

  Preferably, the grease composition has a fusion load measured in accordance with the DIN 51350/4 standard of more than 300 daN, more preferably 320 daN or more, still more preferably 340 daN or more, even more preferably 360 daN or more. It is.

  Preferably, the grease composition is classified according to the ASTM D4048 standard, and the corrosion degree of copper is 1 or 2.

  The invention further relates to extreme pressure properties measured according to ASTM D2596 standard and / or DIN 51350/4 standard of grease compositions comprising at least one polyol ester base oil and at least one fatty acid metal soap. The use of at least one fluorine-containing polymer and at least one sulfurized fatty acid ester in the grease composition in order to improve the active sulfur amount derived from the sulfurized fatty acid ester conforms to ASTM D1662 standard The measured value at 150 ° C. according to the use relates to the use of 0.15% or more based on the total mass of the grease composition.

(Sulfurized fatty acid ester)
The grease according to the present invention contains at least one sulfurized fatty acid ester.

  The sulfurized fatty acid ester is obtained by sulfurizing a fatty acid ester. Such fatty acid esters can be prepared by reacting at least one fatty acid with any kind of alcohol or by transesterification of at least one fatty acid ester with any kind of alcohol. The sulfurized fatty acid ester is an ester of at least one sulfurized fatty acid, and is usually an ester of a sulfurized mixture of fatty acids.

  In preparing the sulfurized fatty acid ester, any fatty acid having 6 to 24 carbon atoms, preferably 14 to 22 carbon atoms, and more preferably 16 to 20 carbon atoms can be used. The fatty acid that is the main component, that is, the fatty acid that is 50% or more based on the total mass of the sulfurized fatty acid ester may be a fatty acid having 18 carbon atoms.

  The sulfurized fatty acid ester may be at least one selected from sulfurized fatty acid monoester, sulfurized fatty acid diester, sulfurized fatty acid triester, and sulfurized fatty acid polyvalent ester.

Suitable sulfurized fatty acid monoester include C ₁ -C ₄ alkyl monoesters, for example: methyl monoesters; ethyl monoesters; n-propyl monoesters; i-propyl monoesters; n- Butyl monoesters; s-butyl monoesters; t-butyl monoesters; Preferably, the monoester is a methyl monoester. Preferably, the sulfurized fatty acid ester is a sulfurized fatty acid methyl ester.

  Examples of sulfurized fatty acid triesters include sulfurized fatty acid triglycerides. The glycerides in that case are either completely esterified or partially esterified. That is, in some cases, a diester and / or a monoester may be included in addition to the triester.

  Examples of the sulfurized fatty acid polyvalent ester include sulfurized pentaerythritol fatty acid ester.

  An advantage of the present invention is that a grease composition that does not contain sulfurized olefins and / or polysulfides can be provided. Sulfurized fatty acid esters are compounds derived from recyclable resources (oils and fats and fatty acids), and have a large proportion of recyclable carbon, and therefore have a low environmental impact. This is not the case with sulfurized olefins obtained by sulfiding olefins, which are products derived from hydrocarbons, and polysulfides obtained by sulfiding hydrocarbon raw materials. In particular, it is noteworthy that good extreme pressure characteristics are realized by using sulfurized fatty acid esters instead of sulfurized olefins and polysulfides known to provide good extreme pressure characteristics. Specifically, this extreme pressure characteristic is realized by blending a fluorine-containing polymer in the grease composition in addition to the sulfurized fatty acid ester.

  In the present invention, “active sulfur” refers to sulfur that a given compound breaks or releases under the conditions of ASTM D1662. The ASTM D1662 standard defines the active sulfur level of a compound at a given temperature as the weight percentage of the difference in sulfur content before and after the reaction when the sulfurized compound is reacted with a given amount of copper for a certain period of time. ing.

  The amount of active sulfur at 150 ° C. (ASTM D1662 standard) in the grease composition is an important parameter for the grease composition to exhibit good performance, in particular, to exhibit good performance under extreme pressure. One. If the amount of active sulfur at 150 ° C. (ASTM D1662 standard) in the grease composition is too small, good behavior under extreme pressure cannot be obtained. On the other hand, when the amount of active sulfur is too large, the corrosiveness of grease, particularly corrosiveness to metals and metal alloys, more particularly corrosiveness to copper becomes a problem. Moreover, in the state which does not mix | blend a fluorine-containing polymer, even if there is too much active sulfur amount (ASTM D1662 standard) at 150 degreeC, it cannot obtain a favorable performance, especially a favorable performance under extreme pressure.

  Preferably, the amount of active sulfur derived from the sulfurized fatty acid ester in the grease composition, measured at 150 ° C. according to ASTM D1662 standard, is mass% with respect to the total mass of the grease composition, It is 0.15% or more, more preferably 0.18% or more, and further preferably 0.20% or more.

  Preferably, the amount of active sulfur derived from the sulfurized fatty acid ester in the grease composition is 5% by mass with respect to the total mass of the grease composition as measured at 150 ° C. according to ASTM D1662 standard. Below, more preferably 4% or less, still more preferably 2% or less, and still more preferably 1% or less.

  Preferably, the amount of sulfur derived from the sulfurized fatty acid ester in the grease composition is greater than 0.3% in mass% relative to the total mass of the grease composition as measured according to ASTM D2662 standard. More preferably, it is 0.34% or more.

  Preferably, in the grease composition, the sulfurized fatty acid ester is 0.5 to 5%, more preferably 1 to 4%, and still more preferably 2 to 3% by mass based on the total mass of the grease composition. Including.

Preferably, the grease composition according to the present invention comprises at least two different sulfurized fatty acid esters, more preferably at least one sulfurized fatty acid methyl ester and at least one sulfurized fatty acid triglyceride in order to improve extreme pressure properties. including. When two kinds of sulfurized fatty acid esters, particularly a combination of sulfurized fatty acid methyl ester and sulfurized fatty acid triglyceride, are used with respect to the amount of active sulfur at a predetermined 150 ° C., the release behavior of sulfur is different. The pressure function can be improved. Such as sulfurized fatty acid methyl ester,
Esters with low steric hindrance release active sulfur first, and esters with high steric hindrance such as sulfurized fatty acid triglycerides release active sulfur later.

  A commercially available product may be used for the sulfurized fatty acid ester used in the present invention, and for example, it can be obtained from manufacturers such as PCAS, King Industries, Dover, Magna, Arkema, and Rhein Chemie.

(Fluoropolymer)
The grease composition according to the present invention contains at least one fluorine-containing polymer (fluoropolymer) as an essential component for realizing good extreme pressure performance.

  The fluoropolymers include polytetrafluoroethylene (PTFE), poly (tetrafluoroethylene / hexafluoropropene) (FEP), poly (tetrafluoroethylene / perfluorinated vinyl ether) (PFA), perfluorinated polyether, poly (chlorotriethylene). Fluoroethylene) (PCTFE), poly (vinylidene fluoride) (PVDF), poly (ethylene / tetrafluoroethylene) (ETFE), poly (ethylene / chlorotrifluoroethylene) (ECTFE), poly (vinyl fluoride) (PVF) ), Poly (vinylidene fluoride / hexafluoropropene), poly (tetrafluoroethylene / perfluorinated vinyl ether), poly (tetrafluoroethylene / propylene), fluorosilicones and polyfluorophosphases It may be selected from.

  Preferably, the fluoropolymer is a fluoropolymer composed only of carbon atoms and fluorine atoms.

  Preferably, the fluoropolymer is polytetrafluoroethylene.

  Preferably, the polytetrafluoroethylene has an average particle size of 0.1 to 100 μm, more preferably 0.2 to 50 μm, still more preferably 0.2 to 10 μm, still more preferably 0.2 to 5 μm, Still more preferably, it is 0.2-1 micrometer, More preferably, it is 0.2-0.5 micrometer.

  The grease composition according to the present invention contains 1 to 10%, preferably 2 to 8%, more preferably 3 to 5%, by mass, of the fluorine-containing polymer based on the total mass of the grease composition. May be. When the content of the fluoropolymer is too small, good extreme pressure characteristics cannot be realized, and when the content of the fluoropolymer is too large, an environmental load increases.

  As the fluorine-containing polymer used in the present invention, a commercially available product may be used. For example, it can be obtained from manufacturers such as Dupont, Solvay, Maflon, Xenon, and Shamrock.

(Polyol ester base oil)
The grease composition according to the present invention includes at least one polyol ester base oil derived from a recyclable raw material.

  Polyol esters that can be used as base oils are diesters, triesters, tetraesters, or complex esters having 5 or more ester functional groups.

  As the acid used for preparing the ester, a monocarboxylic acid or a dicarboxylic acid can be used.

  Preferably, the monocarboxylic acid has 3 to 22 carbon atoms, more preferably 4 to 20 carbon atoms, still more preferably 6 to 18 carbon atoms, still more preferably 8 to 16 carbon atoms, still more preferably carbon numbers. 10 to 12 monocarboxylic acids.

  Examples of the monocarboxylic acid include: hexanoic acid, octanoic acid, 2-ethylhexanoic acid, isooctanoic acid, nonanoic acid, decanoic acid, isodecanoic acid, oleic acid, stearic acid, and the like. Preferably, a saturated acid having no unsaturated portion is used.

  Preferably, the dicarboxylic acid has 3 to 22 carbon atoms, more preferably 4 to 20 carbon atoms, still more preferably 6 to 18 carbon atoms, still more preferably 8 to 16 carbon atoms, still more preferably 10 to 10 carbon atoms. 12 dicarboxylic acids. Examples of such dicarboxylic acids include: succinic acid; adipic acid; azelaic acid; sebacic acid;

  In preparing the ester, the alcohol may be a monohydric alcohol (in the case of a monohydric alcohol, a diester is produced by reacting with a dicarboxylic acid), a dihydric alcohol, a trihydric alcohol, or a tetrahydric alcohol. Can be used. Suitable alcohols include, for example, polyols such as: neopentyl glycol; trimethylolpropane; pentaerythritol;

  In order that the grease composition concerning this invention exhibits sufficient biodegradability, the said polyol ester is 50 to 95% by mass% with respect to the total mass of the said grease composition, Preferably it is 60 to 90%, More preferably, 70 to 80% may be contained.

  The reason why the ester base oil is used is that the load on the environment is negligible, unlike the base oil derived from petroleum. On the other hand, the polyol ester base oil tends to move toward the surface of the component to be lubricated and competes with other types of additives, which may adversely affect extreme pressure characteristics. Therefore, a specific combination of the fluoropolymer and the sulfurized fatty acid ester is utilized.

  The polyol ester base oil or the mixture of polyol ester base oils has a kinematic viscosity at 40 ° C. (ASTM D445 standard) of 3 to 2,000 cSt, preferably 10 to 1,500 cSt, more preferably 20 to 1. 1,000 cSt, more preferably 40 to 500 cSt, even more preferably 50 to 200 cSt. In these viscosity ranges, particularly in the viscosity range of 50 to 200 cSt, extreme pressure characteristics and biodegradability can be well balanced.

  Commercially available products may be used as the base oil used in the present invention, and for example, they can be obtained from manufacturers such as Uniquema, Croda, Oleon, Akzo, Nyco.

(Soap)
The grease composition according to the present invention is enriched with a fatty acid metal soap. The fatty acid metal soap may be prepared separately from the grease production or in the course of grease production (in the latter case, the fatty acid is dissolved in the base oil and then an appropriate metal hydroxide is added thereto). Added).

  Such thickeners can be readily available and economical products that are often used in the grease field. Grease thickened with fatty acid metal soap shows very good mechanical stability compared to grease thickened with, for example, a polyurea thickener, so even when using grease in an open space, Can be easily applied. Polyurea is also produced from isocyanates, which are extremely toxic compounds. Therefore, it is biodegradable, non-toxic, and CLP regulation no. When it is desired to obtain a grease that does not contain a substance regulated by 1272/2008 (EC), it is not desirable to add a polyurea thickener. Therefore, the grease according to the present invention does not contain a polyurea thickener as a thickener, but only contains a fatty acid metal soap thickener.

  Preferably, long chain fatty acids are used, typically saturated or unsaturated fatty acids having 10 to 28 carbon atoms. This long chain fatty acid may optionally be hydroxylated.

  Examples of the long-chain fatty acids (typically fatty acids having 10 to 28 carbon atoms) include: capric acid; lauric acid; myristic acid; palmitic acid; stearic acid; arachidic acid; behenic acid; oleic acid; Acid; these hydroxylated derivatives; and the like. Of the hydroxylated derivatives, 12-hydroxystearic acid is the best known and preferred. A preferred thickener is lithium = 12-hydroxystearate.

  In general, the long-chain fatty acid is a long-chain fatty acid derived from a vegetable oil such as palm oil, castor oil, rapeseed oil or sunflower oil, or a long-chain fatty acid derived from animal fats (tallow, whale oil, etc.).

  It is possible to prepare a soap, referred to as a single type of soap, using at least one long chain fatty acid. Single-type soaps are more preferred than complex-type soaps because they are more readily biodegradable than complex-type soaps and do not accumulate in vivo.

  A soap called a complex-type soap may be prepared using a combination of at least one carboxylic acid having a short hydrocarbon chain having 8 or less carbon atoms and at least one long-chain fatty acid.

  Examples of the saponifying agent used in preparing the soap include metal compounds of metals such as lithium, sodium, calcium and aluminum, preferably lithium and calcium compounds, preferably hydroxides and oxides of these metals. Product or carbonate.

  The grease according to the present invention may contain at least one metal compound having the same or different metal cations. Therefore, it is also possible to mix | blend lithium soap and a calcium soap of a ratio smaller than this combining.

  The metal soap may be used in a content of about 1 to about 20%, preferably 2 to 15%, and more preferably 4 to 12% by weight based on the total weight of the grease composition.

(Grease preparation method)
The grease according to the present invention may be prepared in a process including a metal soap manufacturing process, or may be prepared using a soap manufactured in advance.

  To prepare the grease while producing the metal soap in situ, the following method can be used.

  At least one long chain fatty acid and / or at least one short chain fatty acid is part of a base oil or a mixture of base oils (typically included in the final grease) at a temperature of 80-90 ° C. Dissolved in about 40 to 60% by mass of the total mass of the base oil).

  The metal compound (preferably metal oxide, metal hydroxide or metal carbonate) is then added under the same temperature conditions.

  In this way, a single type of metal can be added, or multiple types of metals can be combined. The metal compound suitable for the grease composition according to the present invention is a lithium compound, but it may be added in combination with a lithium compound and a calcium compound in a proportion smaller than that if necessary.

  The saponification reaction of the long chain fatty acid and / or the short chain fatty acid and at least one metal compound is allowed to proceed at a temperature of 80 to 90 ° C.

  The resulting water is then evaporated by heating the mixture at a temperature of about 100 to about 200 ° C.

  The grease is cooled by adding the remaining proportion of base oil.

  Next, at a temperature of about 80 ° C., the fluoropolymer, the sulfurized fatty acid ester, and optionally other additives are added.

  Stirring is performed for a sufficient time to obtain a grease composition. Subsequently, the homogeneity of the grease composition is improved by subjecting the obtained grease composition to a milling treatment.

  The method of preparing the grease when using a pre-manufactured soap is the same as the preparation method described above, except that the soap is already formed and no saponification reaction is required. The preparation method in either case is a preparation method well known to those skilled in the art.

  The consistency of grease is a measure of the hardness or fluidity of the grease when it is left standing, and is given a numerical value depending on the penetration depth of a cone of a given size and weight. The grease is kneaded in advance. The conditions for measuring the consistency of grease are defined in the ASTM D217 standard.

(Grease consistency)
NLGI (American Lubricating Grease Association) consistency number, which classifies grease into 9 types (9 grades) according to its exactness, is commonly used in the grease field. The following table shows the consistency classification.

  Preferably, the grease composition according to the present invention has a consistency (1/10 mm) measured in accordance with ASTM D217 standard of 220 to 430, which is a consistency number of 00, 0, 1 2 or 3 is included.

  Preferably, the grease composition according to the present invention has a consistency (1/10 mm) measured according to the ASTM D217 standard of 265 to 295, which corresponds to a consistency number of 2.

(Other additives)
The grease composition according to the present invention further includes an antioxidant (for example, a phenol-based antioxidant), a rust inhibitor (for example, an oxidized wax, an amine phosphate), and a corrosion inhibitor (for example, tolyltriazoles). , Dimercaptothiadiazole derivatives, etc.).

(Technical performance of grease)
The grease composition according to the present invention exhibits good extreme pressure characteristics. As a specific example, the grease composition according to the present invention has a fusion load measured in accordance with the ASTM D2596 standard exceeding 315 kg, preferably 400 kg or more. As another specific example, the grease composition according to the present invention has a fusion load measured in accordance with the DIN 51350/4 standard exceeding 300 daN, preferably 320 daN or more, more preferably 340 daN or more, and further preferably. 360 daN or more.

  The grease composition according to the present invention has reduced corrosiveness, particularly corrosiveness to metals and metal alloys, and more particularly to corrosiveness to copper. As a specific example, the grease composition according to the present invention discolors copper pieces only slightly (classification according to ASTM D4048 standard is 1), or does not cause discoloration of copper pieces too much (classification according to ASTM D4048 standard). Is 2.)

  The grease composition according to the present invention has good extreme pressure characteristics, has a low corrosiveness to metals and metal alloys, particularly copper, and has a low environmental load. Specifically, the grease composition according to the present invention exhibits biodegradability, does not accumulate in the body, is non-toxic to the aquatic environment, and is recyclable.

  Preferably, the grease composition according to the present invention may contain additives that are not harmful to the environment and the human body.

  Preferably, the grease composition according to the invention comprises: an organic halogenated compound; a nitrite compound; and a metal or metal other than sodium and / or potassium and / or magnesium and / or calcium and / or lithium and / or aluminum Does not contain compounds.

  Preferably, the grease composition according to the present invention is not toxic to the aquatic environment.

  Specifically, the aqueous toxicity that the grease composition according to the present invention has on algae, daphnia, and fish may be 1,000 mg / L or more as measured by OECD 201, 202, and 203, respectively. .

  Similarly, the main component in the grease composition, that is, the component contained in the grease composition in an amount of more than 5% by mass with respect to the total mass of the grease composition, for example, the base oil, the soap The aquatic toxicity to algae and Daphnia is 100 mg / L or more as measured by OECD 201 and OECD 202, respectively.

  Similarly, for a component in the grease composition having an aquatic toxicity value for algae and daphnia of 100 mg / L or more (category D) as measured by OECD 201 and OECD 202, the grease composition It may be contained at any concentration in the product. In the grease composition according to the present invention, the concentration of the component (category E) whose aqueous toxicity to algae and daphnia is 10 to 100 mg / L as measured by OECD 201 and OECD 202 may be 25% or less. . In the grease composition according to the present invention, the concentration of the component (category F) whose aqueous toxicity to algae and daphnia is 1 to 10 mg / L as measured by OECD 201 and OECD 202 is 2% by mass or less. It may be 1% or less. The above condition is a condition relating only to a component whose concentration in the grease composition is 0.1% or more by mass.

  The grease composition according to the present invention exhibits biodegradability and does not accumulate in the body. Specifically, in the grease composition according to the present invention, the concentration of components (OECD 301A to 301E, OECD 306, OECD 301 category A) excellent in biodegradability under aerobic conditions exceeds 75% by mass. Concentration of components that are essentially biodegradable under aerobic conditions (OECD 302B, Category B by OECD 302C) or components that are not biodegradable but do not accumulate in the body (category C) Furthermore, the concentration of the (category X) component that is not biodegradable and accumulates in the body may be 0.1% by mass or less. The above conditions are relevant only for components whose concentration in the grease composition is 0.1% or more by mass%.

  The grease composition according to the present invention contains 45% or more of carbon derived from a recyclable raw material by mass% with respect to the total mass of the grease composition.

  The present invention further relates to a lubrication method using the grease composition. This lubricating method includes a step of bringing a component to be lubricated into contact with the grease composition.

A plurality of different grease compositions were prepared in the proportions (mass%) shown in Table 1 below using the following materials:
Lithium = 12-hydroxystearate (thickening agent) [Aqueous toxicity to algae and daphnia is measured by OECD 201, 202, more than 100 mg / L (category D), and further according to OECD 301B The measured biodegradability is 83.8% (Category A)];
Polytetrafluoroethylene (PTFE) [Aquatic toxicity to algae and daphnia exceeds 100 mg / L (category D) as measured by OECD 201 and OECD 202, and further biodegradation measured according to OECD 301B Sex is category C];
Sulfurized fatty acid methyl ester (sulfurized ester 1) [containing 17% by mass of sulfur with respect to the total mass, the amount of active sulfur at 150 ° C. is 48% by mass with respect to the total amount of sulfur, and has aqueous toxicity to algae and daphnia The measured value by OECD201 and OECD202 is 10 to 100 mg / L (Category E), the biodegradability measured according to OECD 301B is Category C, and the amount of renewable carbon relative to the total amount of carbon is 95% by weight];
-Sulfurized fatty acid triglyceride (sulfurized ester 2) [containing 15% by mass of sulfur with respect to the total mass, the amount of active sulfur at 150 ° C. with respect to the total amount of sulfur is 33% by mass, and the component of 60% of the total mass is The aqueous toxicity to algae and daphnia is 10-100 mg / L (category E) as measured by OECD201 and OECD202, and 40% of the total mass of the components is measured by OECD201 and OECD202 for aqueous toxicity. The value is 1 to 10 mg / L (category F), the biodegradability measured according to OECD 301B is category C, and the amount of renewable carbon with respect to the total amount of carbon is 95% by mass ];
Ester of trimethylolpropane and saturated fatty acid (base oil 1) [kinematic viscosity at 100 ° C. (ASTM D445 standard) is 4.4 cSt, kinematic viscosity at 40 ° C. (ASTM D445 standard) is 19.6 cSt Yes, the aquatic toxicity to algae and daphnia is over 100 mg / L as measured by OECD201 and OECD202 (category D), and the biodegradability measured according to OECD 301B is 79% (category A), Furthermore, 81% by mass of recyclable carbon based on the total amount of carbon is contained];
Ester of trimethylolpropane and saturated fatty acid (base oil 2) [kinematic viscosity at 100 ° C. (ASTM D445 standard) is 32.2 cSt, kinematic viscosity at 40 ° C. (ASTM D445 standard) is 316 cSt, Aqueous toxicity to algae and daphnia is greater than 100 mg / L as measured by OECD201 and OECD202 (category D), biodegradability measured according to OECD 301B is 67% (category A), Having 55% recyclable carbon relative to the total amount of carbon];
-4,4'-methylenebis (2,6-di-tert-butylphenol) (antioxidant 1);
Octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propanoate (Antioxidant 2) [Aqueous toxicity to algae and daphnia exceeds 100 mg / L as measured by OECD201 and OECD202 (category D) and the biodegradability measured according to OECD 301B is category B];
Oxidized hydrocarbon wax (corrosion inhibitor 1) [biodegradation with aqueous toxicity to algae and daphnia is 10-100 mg / L (category E) as measured by OECD201 and OECD202, measured according to OECD 301B And tolyltriazole (corrosion inhibitor 2) [Aquatic toxicity value to algae measured according to OECD 201 and Aquatic to Daphnia measured according to OECD 202] The toxicity value is 1-10 mg / L (category F) and the biodegradability measured according to OECD 301B is 4% (category C)].

  The control grease and the grease according to the invention have the following biochemical properties (Table 2 below):

  These greases were subjected to an extreme pressure test and a corrosion test (Table 3 below):

  The grease composition 1 for control has an extremely low fusion load of 160 kg (ASTM D2596 standard) or 160 daN (DIN 51350/4 standard), and provides excellent extreme pressure characteristics in the presence of PTFE in the grease composition. It turns out to be insufficient.

  The grease composition for control 5 has a low fusing load of 315 kg (ASTM D2596 standard) or 300 daN (DIN 51350/4 standard), and the presence of the sulfurized fatty acid ester alone in the grease composition is excellent. It can be seen that the pressure characteristics cannot be guaranteed.

  The fusion load of the grease composition 3 for control is 315 kg (ASTM D2596 standard) or 300 daN (DIN 51350/4 standard). When 2% of the sulfide ester 2 is added, the fusion load is slightly improved. The performance is still unsatisfactory because the amount of active sulfur at 150 ° C. is too small.

  Since the grease composition 2 according to the present invention contains 4% of the sulfide ester 2 and PTFE, the fusion load can be 400 kg according to the ASTM D2596 standard and 360 kg according to the DIN 51350/4 standard.

  In the grease composition 4 according to the present invention, the presence of 2% sulfide ester 1 and PTFE allows the fusion load to be 400 kg according to the ASTM D2596 standard and 340 daN according to the DIN 51350/4 standard.

  The test result of grease 6 for control shows that when the amount of active sulfur derived from sulfurized fatty acid ester is less than 0.15% measured at 150 ° C. according to ASTM D1662 standard, sulfurized fatty acid ester and PTFE are used. It is shown that the combination of and is insufficient to ensure good extreme pressure characteristics.

  The test result of grease 7 according to the present invention is a combination of sulfurized fatty acid ester and PTFE in the grease composition, and the amount of active sulfur derived from the sulfurized fatty acid ester is a measured value at 150 ° C. in accordance with ASTM D1662 standard. When the content is 0.15% or more, it can be seen that the extreme pressure performance can be improved.

  Furthermore, the grease composition according to the present invention has extremely low corrosiveness to copper.

  The above results show that high extreme pressure performance is obtained when the amount of active sulfur at 150 ° C. is 0.1% or more by mass% with respect to the total mass of the grease composition. And a fluorine-containing polymer in combination. Such greases have good extreme pressure characteristics, have low corrosivity, are biodegradable, do not accumulate in the body, are non-toxic, and are derived from recyclable raw materials It is.

Claims (17)

A grease composition comprising at least one polyol ester base oil, at least one fatty acid metal soap, at least one fluorine-containing polymer, and at least one sulfurized fatty acid ester,
A grease composition, wherein the amount of active sulfur derived from the sulfurized fatty acid ester is 0.15% or more based on the total mass of the grease composition as measured at 150 ° C. in accordance with ASTM D1662 standard.   The grease composition according to claim 1, wherein the polyol ester is at least one selected from neopentyl glycol ester, trimethylol ethane ester, trimethylol propane ester, pentaerythritol ester and dipentaerythritol ester. Composition. A grease composition according to claim 1 or 2, the polyol ester based base oil, based on the total weight of the grease composition, in mass%, with containing 50% to 95%, the grease composition.   The grease composition according to any one of claims 1 to 3, wherein the fluorine-containing polymer is polytetrafluoroethylene. A grease composition according to claim 1, any one of 4, the fluoropolymer, based on the total weight of the grease composition, in wt%, with 1-10% free, grease compositions .   The grease composition according to any one of claims 1 to 5, wherein the sulfurized fatty acid ester is at least one selected from fatty acid triglycerides and fatty acid methyl esters. A grease composition according to any one of claims 1 to 6, the sulfurized fatty acid ester, based on the total weight of the grease composition, in wt%, with 0.5% to 5% free and grease Composition. A grease composition according to any one of claims 1 to 7, wherein the fatty acid metal soap, a fatty acid metal five regent houses down a single type, the grease composition.   The grease composition according to any one of claims 1 to 8, wherein the fatty acid metal soap is lithium = 12-hydroxystearate. A grease composition according to any one of claims 1 to 9, the fatty acid metal soap, based on the total weight of the grease composition, in wt%, with 1-20% free, grease compositions . It is a grease composition as described in any one of Claim 1 to 10, Comprising: The kinematic viscosity in 40 degreeC of the polyol ester contained or the mixture of several polyol ester is a measured value based on ASTMD445 specification. 3 to 2,000 cSt , a grease composition. A grease composition according to any one of claims 1 to 11, consistency measured according to ASTM D217 standard (1/10 mm) is a 220 to 43 0, the grease composition. The grease composition according to any one of claims 1 to 12, wherein the amount of active sulfur derived from a sulfurized fatty acid ester is a measured value at 150 ° C in accordance with ASTM D1662 standard, and the total mass of the grease composition. against, in mass%, it is over 0.18% or more, the grease composition. A grease composition according to any one of claims 1 to 13, weld load which is measured according to ASTM D2596 standard, exceeds the 315 kg, the grease composition. A grease composition according to any one of claims 1 to 14, weld load is measured according to DIN 51350/4 standard, exceeds the 300DaN, the grease composition.   16. The grease composition according to any one of claims 1 to 15, wherein the corrosive classification for copper measured according to ASTM D4048 standard is 1 or 2.   To improve extreme pressure characteristics measured in accordance with ASTM D2596 standard and / or DIN 51350/4 standard of a grease composition comprising at least one polyol ester base oil and at least one fatty acid metal soap, The use of at least one fluorine-containing polymer and at least one sulfurized fatty acid ester in the grease composition, wherein the amount of active sulfur derived from the sulfurized fatty acid ester is measured at 150 ° C. in accordance with ASTM D1662 standard. The value is 0.15% or more based on the total mass of the grease composition.