Patent Description:
Ether alcohols obtained by reaction of an epoxy alkane with a polyhydric alcohol are useful as raw materials for an emulsifier, a surfactant, and the like.

For example, Patent Document <NUM> discloses an ether alcohol obtained by reaction of an epoxy alkane having <NUM> to <NUM> carbon atoms with a mono- or polyfunctional alcohol having <NUM> to <NUM> carbon atoms and <NUM> to <NUM> alcoholic hydroxyl groups.

On the other hand, Patent Document <NUM> discloses a lubricating oil composition for an internal combustion engine containing a monoglyceride having a hydrocarbon group with <NUM> to <NUM> carbon atoms (a glycerin fatty acid ester in which a fatty acid is ester-bonded to one of three hydroxyl groups of glycerin).

The monoglyceride is added to a lubricating oil composition as a friction modifier.

However, unfortunately, the monoglyceride described in Patent Document <NUM> is hardly soluble in a lubricating oil, and the monoglyceride is precipitated in a lubricating oil composition when the added amount is increased in order to reduce the friction coefficient.

The present invention has been made in view of the above circumstances, and provides an oil agent additive that is easily soluble in an oil agent and has an excellent effect of reducing the friction coefficient, and an oil agent composition containing the oil agent additive.

As a result of intensive studies, the present inventors have found that the above problems can be solved by a compound having a specific structure.

The present invention relates to an oil agent additive comprising at least one kind of a compound represented by a Chemical Formula (<NUM>):
<CHM>
wherein R<NUM> and R<NUM> are each unsubstituted aliphatic hydrocarbon group having <NUM> or more and <NUM> or less carbon atoms, a total number of carbon atoms of R<NUM> and R<NUM> is <NUM> or more and <NUM> or less, X is a single bond and A is -O-CH<NUM>-CH (OH)-CH<NUM>OH or -O-CH(-CH<NUM>-OH)<NUM>.

Monoglycerides that have been used as conventional lubricating oil additives form an oil film and reduce friction when the hydroxyl group of the monoglycerides is adsorbed to metal, and the linear alkyl group of the monoglycerides is directed to the lubricating oil side. In order to form a stronger oil film and improve the effect of reducing the friction coefficient, it is necessary to lengthen the linear alkyl group of monoglycerides. However, it is considered that the longer the linear alkyl group of monoglycerides is, the higher the melting point of the monoglycerides is, and therefore the solubility of the monoglycerides in a lubricating oil decreases.

On the other hand, since the compound represented by the Chemical Formula (<NUM>) of the present invention has a characteristic structure having a glyceryl ether group and a hydroxyl group in the carbon chain, it is considered that the compound has a low melting point, is excellent in solubility in an oil agent, and also is excellent in the effect of reducing the friction coefficient.

Hereinafter, a detailed described is made of the present invention.

The oil agent additive of the present invention contains at least one kind of a compound represented by the following Chemical Formula (<NUM>) (hereinafter, also referred to as ether alcohol). In addition, the oil agent additive of the present invention may be composed of a compound represented by the following Chemical Formula (<NUM>). In addition, the oil agent additive of the present invention may be composed of one or more kinds of a compound represented by the following Chemical Formula (<NUM>). <CHM>
(In Chemical Formula (<NUM>), R<NUM> and R<NUM> are each an unsubstituted aliphatic hydrocarbon group having <NUM> or more and <NUM> or less carbon atoms, a total number of carbon atoms of R<NUM> and R<NUM> is <NUM> or more and <NUM> or less, X is a single bond and A is -O-CH<NUM>-CH (OH) -CH<NUM>OH or -O-CH (-CH<NUM>-OH)<NUM>.

R<NUM> and R<NUM> are each an unsubstituted aliphatic hydrocarbon group having <NUM> or more and <NUM> or less carbon atoms, preferably a linear alkyl group or a branched alkyl group (also referred to as a branched chain alkyl group), more preferably a linear alkyl group from the viewpoint of reducing the friction coefficient. and R<NUM> may be the same aliphatic hydrocarbon groups as each other or different aliphatic hydrocarbon groups from each other. In addition, the total number of substituents of R<NUM> and R<NUM> is <NUM> (that is, having no substituent) from the viewpoint of solubility in an oil agent.

The total number of carbon atoms of R<NUM> and R<NUM> is <NUM> or more and <NUM> or less, or from the viewpoint of reducing the friction coefficient, preferably <NUM> or more, more preferably <NUM> or more, further preferably <NUM> or more, or from the viewpoint of solubility in an oil agent, preferably <NUM> or less, more preferably <NUM> or less, further preferably <NUM> or less, still more preferably <NUM> or less.

The total number of carbon atoms of R1 and R<NUM> is or more and <NUM> or less, or from the viewpoint of reducing the friction coefficient, preferably <NUM> or more, more preferably <NUM> or more, further preferably <NUM> or more, or from the viewpoint of solubility in an oil agent, preferably <NUM> or less, more preferably <NUM> or less, further preferably <NUM> or less, still more preferably <NUM> or less, still more preferably <NUM> or less.

From the viewpoint of production efficiency and ease of production, the oil agent additive preferably contains two or more kinds of the compound, between which the total numbers of carbon atoms of R<NUM> and R<NUM> are the same, but the numbers of carbon atoms of R<NUM> and the numbers of carbon atoms of R<NUM> are each different.

When the oil agent additive contains two or more kinds of the compound in which X is a single bond and between which the total numbers of carbon atoms of R<NUM> and R<NUM> are different, the total content of the compound in which the total number of carbon atoms of R<NUM> and R<NUM> is <NUM> and the compound in which the total number of carbon atoms of R<NUM> and R<NUM> is <NUM> is preferably <NUM> mass% or more, more preferably <NUM> mass% or more, further preferably <NUM> mass% or more, still more preferably <NUM> mass% from the viewpoint of solubility in an oil agent.

When the oil agent additive contains two or more kinds of the compound represented by the Chemical Formula (<NUM>) between which the total numbers of carbon atoms of R<NUM> and R<NUM> are the same, but the numbers of carbon atoms of R<NUM> and the numbers of carbon atoms of R<NUM> are each different, the content ratio of the compound in which the number of carbon atoms of R<NUM> is <NUM> or more and the number of carbon atoms of R<NUM> is <NUM> or more is preferably <NUM> mass% or more, more preferably <NUM> mass% or more, further preferably <NUM> mass% or more, and preferably <NUM> mass% or less, more preferably <NUM> mass% or less, further preferably <NUM> mass% or less from the viewpoint of solubility in an oil agent.

From the viewpoint of solubility in an oil agent, the melting point of the ether alcohol is preferably <NUM> or lower, more preferably <NUM> or lower, further preferably <NUM> or lower, and may be -<NUM> or higher.

The method for producing the ether alcohol is not particularly limited. For example, the ether alcohol can be produced by oxidizing the double bond in an internal olefin with a peroxide such as hydrogen peroxide, performic acid, or peracetic acid to synthesize an internal epoxide, and reacting the obtained internal epoxide with glycerin. In the case of a mixture in which the total numbers of carbon atoms of internal olefins are constant but the double bonds are present at different positions, the compound represented by the Chemical Formula (<NUM>) obtained by the above producing method is a mixture of a plurality of compounds in which X is a single bond and between which the total numbers of carbon atoms of R<NUM> and R<NUM> are the same, but the numbers of carbon atoms of R<NUM> and the numbers of carbon atoms of R<NUM> are each different. The compound represented by the Chemical Formula (<NUM>) obtained by the above producing method is usually a mixture of a compound <NUM> in which the A is -O-CH<NUM>-CH(OH)-CH<NUM>OH (hereinafter, also referred to as ether alcohol <NUM>) and a compound <NUM> in which the A is -O-CH(-CH<NUM>-OH)<NUM> (hereinafter, also referred to as ether alcohol <NUM>).

The internal olefin used for the production of the ether alcohol may contain a terminal olefin. In this case, the content of terminal olefin contained in olefin is, for example, <NUM> mass% or more, <NUM> mass% or more, and <NUM> mass% or less, <NUM> mass% or less, <NUM> mass% or less, <NUM> mass% or less, <NUM> mass% or less.

When the oil agent additive contains the ether alcohol <NUM> and the ether alcohol <NUM>, the content of the ether alcohol <NUM> is preferably <NUM> mass% or more, more preferably <NUM> mass% or more, further preferably <NUM> mass% or more, still more preferably <NUM> mass% or more, and preferably <NUM> mass% or less, more preferably <NUM> mass% or less, further preferably <NUM> mass% or less with respect to the total amount of the ether alcohol <NUM> and the ether alcohol <NUM>, from the viewpoint of reducing the friction coefficient. From the same viewpoint, the content is preferably <NUM> to <NUM> mass%, more preferably <NUM> to <NUM> mass%, further preferably <NUM> to <NUM> mass%, still more preferably <NUM> to <NUM> mass%.

The oil agent additive can be obtained as one kind of the compound represented by the Chemical Formula (<NUM>), a mixture of two or more kinds of the compound represented by the Chemical Formula (<NUM>), or a mixture of the above compound and a trace component other than olefin contained in the raw material olefin and a derivative thereof.

The oil agent additive can be suitably used as a lubricating oil additive or a friction coefficient reducing agent.

In addition, the oil agent additive can be suitably used for reducing the friction coefficient of an engine or a gear.

The oil agent composition of the present invention contains at least an oil agent and the oil agent additive.

The melting point of the oil agent is preferably - <NUM> or higher, and preferably -<NUM> or lower, more preferably -<NUM> or lower, further preferably -<NUM> or lower, still more preferably -<NUM> or lower from the viewpoint of ease of handling. The melting point of the oil agent can be measured using a high sensitivity type differential scanning calorimeter (manufactured by Hitachi High-Tech Science Corporation, trade name: DSC 7000X).

The oil agent can be used without particular limitation, and is preferably a lubricating oil from the viewpoint of lubricity. Examples of the lubricating oil include an engine oil and a gear oil. The oil agent is preferably a paraffinic lubricating oil.

The content of the oil agent additive in the oil agent composition is not particularly limited, but is preferably <NUM> mass% or more, more preferably <NUM> mass% or more, further preferably <NUM> mass% or more, still more preferably <NUM> mass% or more, and preferably <NUM> mass% or less, more preferably <NUM> mass% or less, further preferably <NUM> mass% or less from the viewpoint of decreasing the friction coefficient.

The oil agent composition may contain various additives as necessary. Examples of the additive include an antioxidant, a metal inactivator, an anti-wear agent, an antifoaming agent, a viscosity index improver, a pour point depressant, a clean dispersant, a rust inhibitor, and publicly known oil agent additives.

Hereinafter, a specific description is made of the present invention with reference to Examples. The content of each component is expressed in mass% unless otherwise indicated in Tables. Various measuring methods are as follows.

The double bond distribution in olefin was measured by gas chromatography (hereinafter, abbreviated as GC). Specifically, dimethyl disulfide was reacted with olefin to form a dithioated derivative, and then respective components were separated by GC. The double bond distribution in olefin was determined from respective peak areas. The apparatus used for measurement and analyzing conditions are as follows.

Measurement was performed by <NUM>H-NMR for a mixture of <NUM> of alkyl glyceryl ether, <NUM> of trifluoroacetic anhydride, and <NUM> of deuterated chloroform. Measuring conditions are as follows.

Nuclear magnetic resonance apparatus: Agilent <NUM>-MR DD2, manufactured by Agilent Technologies, Inc.

A flask equipped with a stirrer was charged with <NUM> (<NUM> mol) of <NUM>-hexadecanol (Product name: KALCOL <NUM>, manufactured by Kao Corporation) and <NUM> (<NUM> wt% with respect to the raw material alcohol) of γ-alumina (STREM Chemicals, Inc. ) as a solid acid catalyst, followed by reaction at <NUM> for <NUM> hours under stirring with circulation of nitrogen (<NUM>/min) in the system. The alcohol conversion after completion of the reaction was <NUM>%, and the purity of C16 olefin was <NUM>%. The obtained crude C16 internal olefin was transferred to a distiller, followed by distillation at <NUM> to <NUM>/<NUM> mmHg to yield an internal olefin <NUM> having an olefin purity of <NUM>%. The double bond distribution in the obtained internal olefin <NUM> was <NUM>% at the C1 position, <NUM>% at the C2 position, <NUM>% at the C3 position, <NUM>% at the C4 position, <NUM>% at the C5 position, <NUM>% at the C6 position, and <NUM>% at the C7 position and the C8 position in total.

A reactor equipped with a stirrer was charged with <NUM> (<NUM> kmol) of <NUM>-octadecanol (Product name: KALCOL <NUM>, manufactured by Kao Corporation) and <NUM> (<NUM> wt% with respect to the raw material alcohol) of activated alumina GP-<NUM> (Mizusawa Industrial Chemicals, Ltd. ) as a solid acid catalyst, followed by reaction at <NUM> for <NUM> hours under stirring with circulation of nitrogen (<NUM>/min) in the system. The alcohol conversion after completion of the reaction was <NUM>%, and the purity of C18 olefin was <NUM>%. The obtained crude C18 internal olefin was transferred to a distiller, followed by distillation at <NUM> to <NUM>/<NUM> mmHg to yield an internal olefin <NUM> having an olefin purity of <NUM>%. The double bond distribution in the obtained internal olefin <NUM> was <NUM>% at the C1 position, <NUM>% at the C2 position, <NUM>% at the C3 position, <NUM>% at the C4 position, <NUM>% at the C5 position, <NUM>% at the C6 position, <NUM>% at the C7 position, and <NUM>% at the C8 position and the C9 position in total.

A flask equipped with a stirrer was charged with the internal olefin <NUM> (<NUM>, <NUM> mol) obtained in Production Example A1, <NUM> (<NUM> mol) of acetic acid (manufactured by Wako Pure Chemical Industries, Ltd. ), <NUM> (<NUM> mol) of sulfuric acid (manufactured by Wako Pure Chemical Industries, Ltd. ), <NUM> (<NUM> mol) of <NUM>% hydrogen peroxide (manufactured by Wako Pure Chemical Industries, Ltd. ), and <NUM> (<NUM> mol) of sodium sulfate (manufactured by Wako Pure Chemical Industries, Ltd. ), followed by reaction at <NUM> for <NUM> hours. Thereafter, the temperature was raised to <NUM> to allow the mixture to react further for <NUM> hours. After the reaction, the layers were separated to remove an aqueous layer, and an oil layer was washed with ion-exchanged water, a saturated aqueous sodium carbonate solution (manufactured by Wako Pure Chemical Industries, Ltd. ), a saturated aqueous sodium sulfite solution (manufactured by Wako Pure Chemical Industries, Ltd. ), and <NUM>% saline (manufactured by Wako Pure Chemical Industries, Ltd. ), followed by concentration in an evaporator to yield <NUM> of an internal epoxide <NUM>.

A flask equipped with a stirrer was charged with the internal olefin <NUM> (<NUM>, <NUM> mol) obtained in Production Example A2, <NUM> (<NUM> mol) of acetic acid (manufactured by Wako Pure Chemical Industries, Ltd. ), <NUM> (<NUM> mol) of sulfuric acid (manufactured by Wako Pure Chemical Industries, Ltd. ), and <NUM> (<NUM> mol) of <NUM>% hydrogen peroxide (manufactured by Wako Pure Chemical Industries, Ltd. ), followed by reaction at <NUM> for <NUM> hours. Thereafter, the temperature was raised to <NUM> to allow the mixture to react further for <NUM> hours. After the reaction, the layers were separated to remove an aqueous layer, and an oil layer was washed with ion-exchanged water, a saturated aqueous sodium carbonate solution (manufactured by Wako Pure Chemical Industries, Ltd. ), a saturated aqueous sodium sulfite solution (manufactured by Wako Pure Chemical Industries, Ltd. ), and ion-exchanged water, followed by concentration in an evaporator to yield <NUM> of an internal epoxide <NUM>.

Hereinafter, the alkyl glyceryl ether is referred to as AGE. In addition, AGE1, AGE2 and the like represent alkyl glyceryl ether <NUM>, alkyl glyceryl ether <NUM> and the like, respectively.

A flask equipped with a stirrer was charged with <NUM> (<NUM> mol) of glycerin (manufactured by Wako Pure Chemical Industries, Ltd. ) and <NUM> (<NUM> mmol) of <NUM>% sulfuric acid (manufactured by Wako Pure Chemical Industries, Ltd. ), and the temperature was raised to <NUM>. Thereafter, the internal epoxide <NUM> (<NUM>, <NUM> mol) obtained in Production Example B1 was added dropwise over <NUM> hour, followed by reaction at <NUM>/<NUM> hours. Hexane was added to the liquid obtained by this reaction, followed by washing with ion-exchanged water. Subsequently, concentration was performed under reduced pressure in an evaporator to yield <NUM> of AGE1. The obtained AGE1 contained <NUM>% ether alcohol <NUM> in which R<NUM> and R<NUM> each contained an alkyl group having <NUM> to <NUM> carbon atoms, the total number of carbon atoms of R<NUM> and R<NUM> was <NUM>, X was a single bond, and A was -O-CH<NUM>-CH(OH)-CH<NUM>OH in the Chemical Formula (<NUM>) (AGE obtained by reacting the hydroxyl group at the <NUM>-position of glycerin with the epoxy group), and <NUM>% ether alcohol <NUM> in which R<NUM> and R<NUM> each contained an alkyl group having <NUM> to <NUM> carbon atoms, the total number of carbon atoms of R<NUM> and R<NUM> was <NUM>, X was a single bond, and A was -O-CH(-CH<NUM>-OH)<NUM> in the Chemical Formula (<NUM>) (AGE obtained by reacting the hydroxyl group at the <NUM>-position of glycerin with the epoxy group).

An AGE2 was obtained in the same manner as in Production Example C1 except that the internal epoxide <NUM> (<NUM> mol) obtained in Production Example B2 was used in place of the internal epoxide <NUM> (<NUM> mol) obtained in Production Example B1. The obtained AGE2 contained <NUM>% ether alcohol <NUM> in which R<NUM> and R<NUM> each contained an alkyl group having <NUM> to <NUM> carbon atoms, the total number of carbon atoms of R<NUM> and R<NUM> was <NUM>, X was a single bond, and A was -O-CH<NUM>-CH(OH)-CH<NUM>OH in the Chemical Formula (<NUM>) (AGE obtained by reacting the hydroxyl group at the <NUM>-position of glycerin with the epoxy group), and <NUM>% ether alcohol <NUM> in which R<NUM> and R<NUM> each contained an alkyl group having <NUM> to <NUM> carbon atoms, the total number of carbon atoms of R<NUM> and R<NUM> was <NUM>, X was a single bond, and A was -O-CH(-CH<NUM>-OH)<NUM> in the Chemical Formula (<NUM>) (AGE obtained by reacting the hydroxyl group at the <NUM>-position of glycerin with the epoxy group).

Each of oil agent additives described in Table <NUM> was added to each of oil agents described in Table <NUM> in an added amount described in Table <NUM>, followed by sufficient mixing at <NUM> to prepare an oil agent composition. The oil agents and the oil agent additives described in Table <NUM> are as follows.

Using a high sensitivity differential scanning calorimeter (manufactured by Hitachi High-Tech Science Corporation, trade name: DSC 7000X), each oil agent additive was placed in a <NUM>µL pan, the temperature was raised from -<NUM> to <NUM> at <NUM>/min, and the temperature at the maximum peak of the temperature difference detected by the differential thermal electrode with respect to the temperature raising time was defined as the melting point.

The following measurement and evaluation were performed using the oil agent compositions prepared in Examples and Comparative Examples.

Using an MTM2 traction measuring instrument (manufactured by PCS Instruments Ltd. ), the friction coefficient of each of the prepared oil agent compositions was measured under the following measurement conditions. The results are shown in Table <NUM>. It can be said that the smaller the friction coefficient is, the more excellent the fuel-saving performance is.

Each of the prepared oil agent compositions was stored at <NUM>, and the appearance after <NUM> day and <NUM> days was visually observed and evaluated according to the following criteria. The results are shown in Table <NUM>.

Table <NUM> shows that the oil agent compositions of Examples <NUM> to <NUM> have high quality because these compositions have low friction coefficients at <NUM> and <NUM>, and do not precipitate the oil agent additive even when stored at a low temperature for a long period of time. On the other hand, the oil agents of Comparative Examples <NUM> and <NUM> have high friction coefficients at <NUM> and <NUM>. This is because an oil agent additive is not added. The oil agent compositions of Comparative Examples <NUM> to <NUM> have relatively low friction coefficients at <NUM> and <NUM>, but when stored at a low temperature, the oil agent additive precipitates. Accordingly, improvement is desired.

Claim 1:
An oil agent additive comprising at least one kind of a compound represented by a Chemical Formula (<NUM>):
<CHM>
wherein R<NUM> and R<NUM> are each an unsubstituted aliphatic hydrocarbon group having <NUM> or more and <NUM> or less carbon atoms, a total number of carbon atoms of R<NUM> and R<NUM> is <NUM> or more and <NUM> or less, X is a single bond, and A is -O-CH<NUM>-CH(OH)-CH<NUM>OH or -O-CH(-CH<NUM>-OH)<NUM> .