Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M133/00—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing nitrogen
  • C10M133/02—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing nitrogen having a carbon chain of less than 30 atoms
  • C10M133/16—Amides; Imides
  • C10M133/18—Amides; Imides of carbonic or haloformic acids
  • C10M133/20—Ureas; Semicarbazides; Allophanates
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M115/00—Lubricating compositions characterised by the thickener being a non-macromolecular organic compound other than a carboxylic acid or salt thereof
  • C10M115/08—Lubricating compositions characterised by the thickener being a non-macromolecular organic compound other than a carboxylic acid or salt thereof containing nitrogen
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M169/00—Lubricating compositions characterised by containing as components a mixture of at least two types of ingredient selected from base-materials, thickeners or additives, covered by the preceding groups, each of these compounds being essential
  • C10M169/02—Mixtures of base-materials and thickeners
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M177/00—Special methods of preparation of lubricating compositions; Chemical modification by after-treatment of components or of the whole of a lubricating composition, not covered by other classes
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2205/00—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions
  • C10M2205/02—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions containing acyclic monomers
  • C10M2205/028—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions containing acyclic monomers containing aliphatic monomers having more than four carbon atoms
  • C10M2205/0285—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions containing acyclic monomers containing aliphatic monomers having more than four carbon atoms used as base material
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2215/00—Organic non-macromolecular compounds containing nitrogen as ingredients in lubricant compositions
  • C10M2215/10—Amides of carbonic or haloformic acids
  • C10M2215/102—Ureas; Semicarbazides; Allophanates
  • C10M2215/1026—Ureas; Semicarbazides; Allophanates used as thickening material
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2020/00—Specified physical or chemical properties or characteristics, i.e. function, of component of lubricating compositions
  • C10N2020/01—Physico-chemical properties
  • C10N2020/02—Viscosity; Viscosity index
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
  • C10N2030/30—Anti-misting
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2040/00—Specified use or application for which the lubricating composition is intended
  • C10N2040/02—Bearings
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2040/00—Specified use or application for which the lubricating composition is intended
  • C10N2040/06—Instruments or other precision apparatus, e.g. damping fluids
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2050/00—Form in which the lubricant is applied to the material being lubricated
  • C10N2050/10—Semi-solids; greasy
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2070/00—Specific manufacturing methods for lubricant compositions

Definitions

• the present invention relates to a grease and a method for softening the grease, more specifically, low dusting grease and a method for further softening the grease.
• a precision electronics manufacturing device such as a semiconductor manufacturing device and a liquid crystal manufacturing device requires very clean environments and, therefore, is set in a clean room.
• a food manufacturing plant, a medicine manufacturing plant and the like also require clean environments in order to avoid invasion of foreign substances into products.
• Machinery and devices used in such environments are provided with various bearings, sliding portions and connection portions. In lubricating portions of the bearings, sliding portions and connection portions, low dusting grease is used.
• a fluorine grease As the low dusting grease, a fluorine grease is exemplarily used. However, since the fluorine grease is generally expensive and lacks of lubricity, torque of the bearings filled with the fluorine grease may be increased. Moreover, in manufacturing precision electronics, mixing of a halogen component is unfavorable. Further, low dusting characteristics are not sufficient. As low dusting grease containing no halogen, lithium soap grease and lithium complex soap grease are used.
• a urea grease is also used.
• a grease containing 50% or more of an ester oil as the base oil and 20% or more of an aliphatic diurea thickener and exhibiting 220 to 300 of a worked penetration see Patent Literature 2. Since a large amount of the ester oil is contained in the grease, hydrolysis resistance may be affected to shorten a lifetime of the grease. Further, low dusting characteristics are also not sufficient.
• Patent Literature 1 JP-A-2004-352953
• Patent Literature 2 JP-A-2005-272764
• Patent Literature 3 JP-A-11-166191
• An object of the invention is to provide a grease exhibiting lower dusting characteristics in view of the above related art. Further, when the grease is softened (i.e., when a consistency is increased), dusting characteristics are generally increased. Accordingly, an object of the invention is also to provide a method for reducing the dusting characteristics while increasing the consistency.
• the invention provides a grease and a method for softening the grease as described below.
• a grease according to an aspect of the invention includes: a base oil including hydrocarbon; and diurea that is represented by a formula (1) below as a thickener and is in a range from 15 mass % to 25 mass % based on a total amount of a composition, the grease exhibiting a worked penetration in a range from 170 to 295,
• R 1 and R 3 are mutually different and represent a hydrocarbon group having 6 to 18 carbon atoms; and R 2 is a divalent aromatic hydrocarbon group having 6 to 13 carbon atoms.
• a worked penetration of the grease is in a range from 230 to 265.
• the hydrocarbon group is a saturated hydrocarbon group.
• the hydrocarbon group is an alkyl group or a cycloalkyl group.
• the cycloalkyl group is a cyclohexyl group.
• R 1 and R 3 are an octyl group or a cyclohexyl group.
• an average ratio of the cycloalkyl group in the diurea is in a range from 15 mol % to 85 mol % based on a total amount of the alkyl group and the cycloalkyl group as functional groups.
• the average ratio of the cycloalkyl group is in a range from 15 mol % to 50 mol %.
• the average ratio of the cycloalkyl group is in a range from 75 mol % to 85 mol %.
• a content of the hydrocarbon group is 90 mass % or more based on a total amount of the base oil.
• the hydrocarbon group is a poly- ⁇ -olefin.
• a kinematic viscosity at 40 degrees C. of the base oil is 400 mm 2 /s or less.
• a softening method of the grease according to the above aspect of the invention includes: stirring the grease while applying centrifugal force on the grease.
• the grease according to the above aspect of the invention is suitable for machinery and devices used particularly in a clean room. Further, when the grease is softened (i.e., when a consistency is increased), the amount of the generated dust is generally increased. However, by stirring the grease according to the above aspect of the invention while applying centrifugal force on the grease, the dusting characteristics of the grease can be further reduced although the consistency thereof is further increased.
• a grease according to an exemplary embodiment (hereinafter, also referred to as “the present grease”) is provided by containing a hydrocarbon base oil and diurea having a specific structure as a thickener.
• a base oil used for manufacturing the present grease contains hydrocarbon as a main component.
• the base oil is an ether oil (e.g., alkyl diphenyl ether) and an ester oil, dusting characteristics of the grease are unfavorably increased. Further, when the base oil having such a polar group is used, hydrolysis may occur to impair a function of the grease. In view of the above, it is preferable to avoid mixing the above oils as much as possible.
• the base oil preferably contains 90 mass % or more of hydrocarbon, most preferably, consists of hydrocarbon.
• the hydrocarbon used as the base oil is preferably a poly- ⁇ -olefin in terms of low dusting characteristics.
• a kinematic viscosity at 40 degrees C. of the base oil is preferably 400 mm 2 /s or less.
• stirring resistance is increased to excessively increase torque, thereby deteriorating wear resistance.
• fretting wear may be increased.
• the kinematic viscosity at 40 degrees C. of the base oil is preferably 100 mm 2 /s or less, more preferably 50 mm 2 /s or less.
• the grease is advantageously used under a low load.
• the kinematic viscosity at 40 degrees C. of the base oil is measured in accordance with JIS K 2283.
• a thickener used for manufacturing the present grease is diurea represented by a formula (1) below.
• R 1 and R 3 independently represent a hydrocarbon group having 6 to 18 carbon atoms.
• R 1 and R 3 in diurea of the formula (1) are mutually different.
• Diurea of the formula (1) is generally used as a mixture. Since R 1 and R 3 are mutually different, an average ratio of a saturated hydrocarbon group in each of R 1 and R 3 is less than 100 mol %. When the average ratio of one of the above functional groups is 100 mol %, a favorable worked penetration and low dusting characteristics may not be simultaneously achieved.
• the average ratio of a cycloalkyl group in diurea is preferably in a range from 15 mol % to 85 mol % based on a total amount of an alkyl group and the cycloalkyl group (functional groups) in terms of low dusting characteristics.
• the average ratio of the cycloalkyl group is preferably in a range from 15 mol % to 50 mol % or in a range from 75 mol % to 85 mol %.
• the hydrocarbon group having 6 to 18 carbon atoms is classified into a saturated one and an unsaturated one.
• the saturated hydrocarbon group is defined as an alkyl group and a cycloalkyl group.
• the unsaturated hydrocarbon group is defined as an alkenyl group.
• the alkyl group preferably has a linear structure.
• the alkyl group is preferably an octyl group in terms of low dusting characteristics.
• the cycloalkyl group is preferably a cyclohexyl group in terms of balance between the worked penetration and the low dusting characteristics.
• the alkenyl group is exemplified by an oleyl group.
• R 1 and R 3 are preferably an octyl group and a cyclohexyl group.
• R 2 is a divalent aromatic hydrocarbon group having 6 to 13 carbon atoms.
• the divalent aromatic hydrocarbon group is exemplified by 4,4′-diphenylmethyl group and a toluyl group.
• Diurea of the formula (1) can be easily manufactured by reacting an aromatic diisocyanate and monoamine.
• the aromatic diisocyanate is exemplified by diphenylmethane-4,4′ -diisocyante and tolylenediisocyanate.
• Monoamine is exemplified by octylamine and cyclohexylamine.
• the grease according to the exemplary embodiment contains the above base oil and the above thickener.
• the worked penetration of the grease according to the exemplary embodiment is in a range from 175 to 295, preferably from 180 to 275, more preferably from 180 to 265, further preferably from 230 to 265.
• a content of the thickener needs to be in a range from 15 mass % to 25 mass % based on the total amount of the composition, more preferably from 15 mass % to 20 mass %.
• the worked penetration of the grease becomes excessively high, thereby increasing the amount of the generated dust.
• the content of the thickener is excessively large, the worked penetration of the grease becomes low, resulting in a hard grease. In this case, although the amount of the generated dust is small, penetration (permeability) of the grease to a friction surface becomes insufficient, thereby causing a poor lubrication.
• the content of the thickener is equal to a content of diisocyanate and amine providing the thickener.
• the dusting characteristics of the grease are extremely low. Further, since the base oil is formed of hydrocarbon, the grease also exhibits an excellent hydrolysis resistance. Particularly, although the worked penetration of the grease is in an easily applicable range of 230 or more to show a soft grease, the grease also exhibits low dusting characteristics. Moreover, since not necessarily containing halogen and a metal salt, the grease is suitable for a precision electronic device.
• the centrifugal force is preferably 200 G or more, more preferably 300 G or more.
• additives such as an antioxidant, rust inhibitor, solid lubricant, filler, oiliness agent, and metal deactivator may be added as needed within a range where an object of the invention is achieved.
• antioxidants examples include: an amine antioxidant such as alkylated diphenylamine, phenyl- ⁇ -naphthylamine and alkylated- ⁇ -naphthylamine; and a phenol antioxidant such as 2,6-di-t-butyl-4-methylphenol and 4,4′ -methylenebis(2,6-di-t-butylphenol). These antioxidants are used in a ratio of the order of 0.05 mass % to 2 mass %.
• amine antioxidant such as alkylated diphenylamine, phenyl- ⁇ -naphthylamine and alkylated- ⁇ -naphthylamine
• phenol antioxidant such as 2,6-di-t-butyl-4-methylphenol and 4,4′ -methylenebis(2,6-di-t-butylphenol).
• rust inhibitor examples include: sodium nitrite, petroleum sulphonate, sorbitan monooleate, fatty acid soap and an amine compound.
• solid lubricant examples include polyimide, PTFE, graphite, metal oxide, boron nitride, melamine cyanurate (MCA) and molybdenum disulfide.
• a worked penetration was measured in accordance with JIS K 2220.7.
• a degree of dust generation from each of the greases was evaluated. Specifically, a 10-g grease was filled entirely over a screw surface of a ball screw (diameter: 16 mm, lead: 8 mm). A 50-hour operation was carried out under the conditions of a ball-nut speed being 100 mm/s and a stroke being 150 mm. Air was sucked from an intake port (sucking speed: 3 L/min) provided immediately near the screw at a middle of reciprocation.
• Fine particles of 0.3 ⁇ m or more were counted by a particle counter (manufactured by RION CO., LTD.: KC-03B) and defined as a dust generation number.
• a total counted number during the test time (50 hours) was shown in piece(s) per 10L and evaluated based on the following standard.
• a grease was manufactured as follows. It should be noted that the poly-a-olefin used as the base oil was also used in other Examples and Comparatives. Properties of the poly- ⁇ -olefin were as follows.
• the resultant solution was vigorously stirred once so as to entirely flow, whereby the solution was uniformed.
• a container of the mixed amine was washed with 5.0 g of the base oil.
• the used base oil was added to the separate flask.
• the obtained solution in the separate flask was vigorously stirred again.
• the grease obtained by the above method was stirred under 400 G of centrifugal force using a rotation-revolution stirrer (MAZERUSTAR manufactured by KURABO INDUSTRIES LTD.) until the consistency of the grease became 2.5 to 2.
• a composition and evaluation results of the grease are shown in Table 1.
• a grease of Example 2 was manufactured in the same manner as in Example 1 except that the amounts of the reagents to be used were changed to 18.9 g of MDI, 11.3 g of octyl amine, and 5.80 g of cyclohexylamine. Then, the softening treatment was conducted to the grease of Example 2 under the same conditions. A composition and evaluation results of the grease are shown in Table 1.
• a grease of Example 3 was manufactured in the same manner as in Example 1 except that the amounts of the reagents to be used were changed to 27.7 g of MDI, 22.3 g of octyl amine, and 4.01 g of cyclohexylamine. Then, the softening treatment was conducted to the grease of Example 3 under the same conditions. A composition and evaluation results of the grease are shown in Table 1.
• a grease of Example 4 was manufactured in the same manner as in Example 1 except that the amounts of the reagents to be used were changed to 27.7 g of MDI, 22.3 g of octyl amine and 4.01 g of cyclohexylamine and the rotation speed of the stirring fin during the manufacturing of the grease was changed from 250 rpm to 400 rpm. However, the softening treatment was not applied to the obtained grease.
• a composition and evaluation results of the grease are shown in Table 1.
• a grease of Example 5 was manufactured in the same manner as in Example 1 except that the amounts of the reagents to be used were changed to 27.7 g of MDI, 22.3 g of octyl amine, and 4.01 g of cyclohexylamine. However, the softening treatment was not conducted to the obtained grease. A composition and evaluation results of the grease are shown in Table 1.
• a grease of Comparative 1 was manufactured in the same manner as in Example 1 except that the amounts of the reagents to be used were changed to 21.3 g of MDI and 21.3 g of octyl amine and cyclohexylamine was not used. Then, the softening treatment was conducted to the grease of Comparative 1 under the same conditions. A composition and evaluation results of the grease are shown in Table 1.
• a grease of Comparative 2 was manufactured in the same manner as in Example 1 except that the amounts of the reagents to be used were changed to 30.5 g of MDI and 23.4 g of cyclohexylamine and octyl amine was not used. Then, the softening treatment was conducted to the grease of Comparative 2 under the same conditions. A composition and evaluation results of the grease are shown in Table 1.
• a grease of Comparative 4 was manufactured in the same manner as in Example 1 except that the amounts of the reagents to be used were changed to 11.6 g of MDI and 24.4 g of n-octadecyl amine and cyclohexylamine and octylamine were not used. However, the softening treatment was not conducted to the obtained grease. A composition and evaluation results of the grease are shown in Table 1.
• each of the greases of Examples 1 to 5 exhibits extremely low dusting characteristics as compared with the greases of Comparatives 1 to 4 and Reference Example (commercially available grease).
• Comparatives 1 and 3 due to the small content of the thickener for manufacturing the grease, even though a value of the worked penetration is favorable, the amount of the generated dust is large.
• Comparative 2 since the worked penetration exceeds the range defined by the invention, the amount of the generated dust is large.
• Comparative 4 since the amount of the thickener is small, the amount of the generated dust is slightly large although the value of the worked penetration is favorable.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Organic Chemistry (AREA)
• Lubricants (AREA)

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• 2013
  • 2013-02-19 JP JP2014500709A patent/JPWO2013125510A1/ja active Pending
  • 2013-02-19 CN CN201380010619.4A patent/CN104169404A/zh active Pending
  • 2013-02-19 WO PCT/JP2013/053959 patent/WO2013125510A1/fr active Application Filing
  • 2013-02-19 EP EP13751992.2A patent/EP2821465A4/fr not_active Withdrawn
  • 2013-02-19 KR KR1020147021888A patent/KR20140127241A/ko not_active Application Discontinuation
  • 2013-02-19 US US14/378,233 patent/US20150045273A1/en not_active Abandoned
  • 2013-02-22 TW TW102106265A patent/TW201336983A/zh unknown

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