METHOD FOR PRODUCING REGENERATED OIL COMPOSITION AND METHOD FOR PRODUCING REGENERATED Industrial OIL COMPOSITION

Abstract

A method for producing a reclaimed oil composition, which is a method for producing a reclaimed oil composition by a purification treatment step in which a used industrial oil composition after mechanical lubrication or metal working is subjected to a purification treatment, and which comprises: performing an adsorption treatment, a hydrodesulfurization treatment, or a reduced pressure distillation treatment as the purification treatment; the industrial oil composition used before the mechanical lubrication or metal working and the used industrial oil composition used after the mechanical lubrication or metal working comprise: a mineral oil (A1), a synthetic oil (A2), or a vegetable oil or a derivative (A3) thereof as a base oil; a neutral phosphite derivative represented by formula (B) and a 2, 6-di-tert-butylphenol derivative represented by formula (C) as antioxidants, and a functional additive; the content of the functional additive in the used industrial oil composition after the mechanical lubrication or the metal working is less than that of the industrial oil composition before the mechanical lubrication or the metal working. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a method for producing a regenerated oil composition, a regenerated oil composition, and a regenerated industrial oil composition. Background Art

[0002] Patent Document 1 discloses a waste oil regeneration treatment system for obtaining regenerated heavy oil from waste oil which is a used industrial oil composition. Specifically, Patent Document 1 discloses a waste oil regeneration treatment system including: an impurity removal step of removing impurities from waste oil by centrifugal separation, and a distillation step of heating the waste oil from which impurities have been removed and further evaporating and removing impurities mixed in the waste oil by distillation to obtain regenerated heavy oil. The regenerated heavy oil obtained here can be used as fuel oil.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-306682 Summary of the Invention

[0006] Thus, used industrial oil compositions are often used as fuel oil, and there is a problem that CO2 cannot be reduced.

[0007] Therefore, an object of the present invention is to provide a method for producing a regenerated oil composition that can contribute to reducing CO2.

[0008] The method for producing a regenerated oil composition of the present invention produces a regenerated oil composition through a purification treatment step of purifying a used industrial oil composition after mechanical lubrication or metal processing. Adsorption treatment, hydrodesulfurization treatment, or vacuum distillation treatment is performed as the above purification treatment. The industrial oil composition before the above mechanical lubrication or metal processing and the used industrial oil composition after the above mechanical lubrication or metal processing contain mineral oil (A1), synthetic oil (A2), or vegetable oil or its derivative (A3) as a base oil, a neutral phosphite derivative represented by the following formula (B) and a 2,6-di-tert-butylphenol derivative represented by the following formula (C) as an antioxidant, and a functional additive. The content ratio of the above functional additive in the used industrial oil composition after the above mechanical lubrication or metal processing is less than that in the industrial oil composition before the above mechanical lubrication or metal processing.

[0009]

[0010] In the above formula (B), R b21 ~R b24 each independently represents an aliphatic hydrocarbon group having 10 to 16 carbon atoms, and R b25 ~Rb28 Each independently represents a linear or branched alkyl group having 1 to 6 carbon atoms, R b291 and R b292 Each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms, R b291 and R b292 The total number of carbon atoms of is 1 to 5.

[0011]

[0012] In the above formula (C), R c1 is a linear or branched alkyl group having 1 to 12 carbon atoms.

[0013] The method for producing the regenerated oil composition according to the present invention can contribute to reducing CO2. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Shows the measurement results of the used industrial oil composition (2-1') using high performance liquid chromatography.

[0015] Figure 2 Shows the measurement results of the regenerated oil composition (2-1-1) using high performance liquid chromatography. DETAILED DESCRIPTION OF THE INVENTION

[0016] The mode (embodiment) for carrying out the present invention will be described in detail. The present invention is not limited by the content described in the following embodiments. In addition, the constituent elements described below include those that can be easily conceived by those skilled in the art and substantially the same constituents. Furthermore, the constituents described below can be appropriately combined. In addition, various omissions, substitutions, or changes of the constitution can be made without departing from the gist of the present invention.

[0017] [Embodiment 1]

[0018] In the method for producing the regenerated oil composition of Embodiment 1, the regenerated oil composition is produced by a purification treatment step of purifying the used industrial oil composition after mechanical lubrication or metal processing. In Embodiment 1, an adsorption treatment is performed as the above purification treatment.

[0019] The industrial oil composition used before the above-mentioned mechanical lubrication or metal processing contains mineral oil (A1), synthetic oil (A2), or vegetable oil or its derivative (A3) as the base oil. It should be noted that in this specification, the industrial oil composition used before the above-mentioned mechanical lubrication or metal processing is also simply referred to as the industrial oil composition before use. In addition, the industrial oil composition used before the above-mentioned mechanical lubrication is also called the industrial oil composition before mechanical lubrication, and the industrial oil composition used before the above-mentioned metal processing is also called the industrial oil composition before metal processing.

[0020] As the mineral oil (A1), specifically, base oils belonging to Group I, Group II, and Group III in the base oil classification specified by the American Petroleum Institute (API) can be cited. The base oil belonging to Group I is, for example, a base oil obtained by the solvent refining method. The base oil belonging to Group II is, for example, a base oil obtained by the hydrotreating method. The base oil belonging to Group III is, for example, a base oil obtained by the hydrocracking method. In addition, as the synthetic oil (A2), specifically, base oils belonging to Group IV, Group V, etc. in the base oil classification specified by the American Petroleum Institute can be cited. The base oil belonging to Group IV, for example, can be polyalphaolefin (PAO) obtained by chemical synthesis. As the vegetable oil or its derivative (A3), hydrogenated vegetable oil can be used. More specifically, as the derivative, the hydroisomerization reaction product (CAS No.: 2241366-04-9) of [(the hydrogenation reaction product of the addition reaction product of (olefin (C = 16, 18, linear and branched) (limited to the number of double bonds being 1 and the position of the double bond being 1))] is suitable. The base oil can be used alone or in combination of two or more.

[0021] In addition, the industrial oil composition before use contains a neutral phosphite derivative and a 2,6-di-tert-butylphenol derivative as antioxidants.

[0022] The neutral phosphite derivative is represented by the following formula (B). The neutral phosphite derivative can be used alone or in combination of two or more. Since the neutral phosphite derivative is a dimer, it is not easily evaporated and can efficiently exhibit antioxidant performance.

[0023]

[0024] In formula (B), R b21 ~R b24Each independently represents an aliphatic hydrocarbon group having 10 to 16 carbon atoms.

[0025] The aliphatic hydrocarbon group having 10 to 16 carbon atoms may be a straight-chain, branched-chain or cyclic aliphatic hydrocarbon group, and may also be a saturated or unsaturated aliphatic hydrocarbon group. Specifically, as the aliphatic hydrocarbon group having 10 to 16 carbon atoms, linear alkyl groups such as decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl (cetyl) can be appropriately used.

[0026] R b25 ~R b28 Each independently represents a straight-chain or branched-chain alkyl group having 1 to 6 carbon atoms.

[0027] Examples of the straight-chain or branched-chain alkyl group having 1 to 6 carbon atoms include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, isopropyl, sec-butyl, isobutyl, tert-butyl, isopentyl, tert-pentyl, neopentyl, isohexyl.

[0028] Since the neutral phosphite has specific substituents on R b25 ~R b28 , it has excellent anti-wear properties in addition to excellent antioxidant properties. It is considered that when R b25 ~R b28 has specific substituents, the film of the industrial oil composition attached to the sliding part becomes stronger.

[0029] In particular, when R b25 and R b27 are straight-chain alkyl groups having 1 to 6, preferably 1 to 3 carbon atoms, and R b26 and R b28 are branched-chain alkyl groups having 3 to 6, preferably 3 to 4 carbon atoms, the effect of improving anti-wear properties is further enhanced.

[0030] R b291 and R b292 Each independently represents a hydrogen atom or a straight-chain or branched-chain alkyl group having 1 to 5 carbon atoms.

[0031] Examples of the straight-chain or branched-chain alkyl group having 1 to 5 carbon atoms include methyl, ethyl, n-propyl, n-butyl, n-pentyl, isopropyl, sec-butyl, isobutyl, tert-butyl, isopentyl, tert-pentyl, neopentyl.

[0032] Among them, the total number of carbon atoms of R b291 and R b292 is 1 to 5. Therefore, for example, when R b291 is a hydrogen atom, R b292 is a straight-chain or branched-chain alkyl group having 1 to 5 carbon atoms, and when R b291 is methyl, R b292is a linear or branched alkyl group having 1 to 4 carbon atoms, R b291 When R is an ethyl group, b292 is a linear or branched alkyl group having 2 to 3 carbon atoms.

[0033] To make the film of the industrial oil composition firmer, it is more preferable that R b291 is a hydrogen atom, R b292 is a linear or branched alkyl group having 1 to 5 carbon atoms.

[0034] The 2,6-ditertiarybutylphenol derivative is represented by the following formula (C). The 2,6-ditertiarybutylphenol derivative can be used alone or in combination of two or more.

[0035]

[0036] In formula (C), R c1 is a linear or branched alkyl group having 1 to 12 carbon atoms. Examples of the linear or branched alkyl group having 1 to 12 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, n-pentyl, isopentyl, tert-pentyl, neopentyl, hexyl, heptyl, isoheptyl, n-octyl, isooctyl, 2-ethylhexyl, nonyl, and decyl. If it is the above alkyl group, the compatibility of the 2,6-ditertiarybutylphenol derivative is improved.

[0037] In the industrial oil composition before use, relative to 100 parts by mass of the base oil, it is preferable to contain a neutral phosphite derivative in an amount of 0.001 part by mass to 6 parts by mass. In addition, relative to 100 parts by mass of the base oil, it is preferable to contain a 2,6-ditertiarybutylphenol derivative in an amount of 0.001 part by mass to 6 parts by mass or less. If the antioxidant is contained in the above amount, the antioxidant function can be maintained for a longer time.

[0038] In addition, the above industrial oil composition before use preferably further contains a hindered amine compound as an antioxidant.

[0039] The hindered amine compound is represented by the following formula (D). The hindered amine compound can be used alone or in combination of two or more.

[0040]

[0041] R d21 and R d22 each independently represent an aliphatic hydrocarbon group having 1 to 10 carbon atoms.

[0042] The aliphatic hydrocarbon group having 1 to 10 carbon atoms can be a linear, branched or cyclic aliphatic hydrocarbon group, and can also be a saturated or unsaturated aliphatic hydrocarbon group.

[0043] As the aliphatic hydrocarbon group having 1 to 10 carbon atoms, specifically, linear or branched alkyl groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, heptyl, octyl, nonyl, decyl, isopropyl, sec-butyl, isobutyl, tert-butyl, isopentyl, tert-pentyl, neopentyl, isohexyl, 2-ethylhexyl, etc. may be appropriately used. Among them, from the viewpoint of improving durability, linear or branched alkyl groups having 5 to 10 carbon atoms are more preferable.

[0044] R d23 represents a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms.

[0045] As the divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms, divalent linear or branched alkylene groups such as methylene, 1,2-ethylene, 1,3-propylene, 1,4-butylene, 1,5-pentylene, 1,6-hexylene, 1,7-heptylene, 1,8-octylene, 1,9-nonylene, 1,10-decylene, 3-methyl-1,5-pentylene, etc. may be appropriately used. Among them, from the viewpoint of improving durability, divalent linear or branched alkylene groups having 5 to 10 carbon atoms are more preferable.

[0046] From the viewpoint of improving durability at high temperatures, it is more preferable that the sum of the carbon atoms of R d21 , R d22 and R d23 is 16 to 30.

[0047] When a hindered amine compound is used in the industrial oil composition before use, it is preferably contained in an amount of 0.002 to 5 parts by mass relative to 100 parts by mass of the base oil.

[0048] Since the industrial oil composition before use is used in mechanical lubrication or metal processing, it further contains functional additives. When the industrial oil composition before use is used in mechanical lubrication, it is preferably further contained with the base oil and an antioxidant, for example, an oiliness agent and a metal deactivator as functional additives.

[0049] As the oiliness agent contained in the industrial oil composition before use for mechanical lubrication, sulfur compounds can be mentioned. As the above oiliness agent, for example, zinc dialkyldithiophosphate can be appropriately used. If zinc dialkyldithiophosphate is contained in the industrial oil composition before use for mechanical lubrication, the slidability can be improved even when used at high temperatures, and wear can be prevented. In addition, as the metal deactivator contained in the industrial oil composition before use for mechanical lubrication, for example, benzotriazole derivatives can be appropriately used. If benzotriazole derivatives are contained in the industrial oil composition before use for mechanical lubrication, the metal surface can be protected even when used at high temperatures, and corrosion can be prevented. If the above oiliness agent and metal deactivator are combined in the industrial oil composition before use for mechanical lubrication, the machinery can be lubricated for a longer time.

[0050] Examples of the alkyl group in zinc dialkyldithiophosphate include primary alkyl groups and secondary alkyl groups. It is possible to have both primary and secondary alkyl groups in one molecule. The alkyl group can be linear or branched. There is no particular limitation on the number of carbon atoms in the alkyl group, and from the viewpoint of preventing wear, it is preferably 3 to 12, more preferably 3 to 8. Zinc dialkyldithiophosphate can be used alone or in combination of two or more.

[0051] The benzotriazole derivative is preferably represented by the following formula (E). If such a benzotriazole derivative is contained, corrosion can be further prevented even when used at high temperatures.

[0052]

[0053] In the above formula (E), R e1 represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and R e2 and R e3 each independently represent an alkyl group having 1 to 18 carbon atoms. The benzotriazole derivative can be used alone or in combination of two or more.

[0054] In the industrial oil composition before use in mechanical lubrication, an oiliness agent is preferably contained in an amount of 0.1 to 5 parts by mass relative to 100 parts by mass of the base oil. In addition, in the industrial oil composition before use in mechanical lubrication, a metal deactivator is preferably contained in an amount of 0.01 to 5 parts by mass relative to 100 parts by mass of the base oil.

[0055] When the industrial oil composition before use is used in metal processing, it is preferably further contained, together with the base oil and an antioxidant, for example, an extreme pressure agent and a metal deactivator as functional additives.

[0056] As the extreme pressure agent contained in the industrial oil composition before use in metal processing, for example, a sulfur compound can be appropriately used. Specifically, an active sulfur compound can be cited. If an active sulfur compound is contained in the industrial oil composition before use in metal processing, workability can be improved even when used at high temperatures. In addition, as the metal deactivator contained in the industrial oil composition before use in metal processing, for example, a thiadiazole derivative can be appropriately used. If a thiadiazole derivative is contained in the industrial oil composition before use in metal processing, the metal surface can be protected and corrosion can be prevented even when used at high temperatures. In addition, processing of copper-based metals can also be performed. If the above extreme pressure agent and metal deactivator are combined in the industrial oil composition before use in metal processing, metal can be processed for a longer time.

[0057] The active sulfur compound may be any compound containing active sulfur in the molecule. Here, the active sulfur compound refers to, for example, a compound having a copper plate corrosion of 2 to 4 as determined by JIS K2513 (Petroleum products - Copper strip corrosion test method; Test tube method, heated at 100 °C for 1 hour) for a compound containing a sulfur atom and not containing a metal atom and a phosphorus atom and diluted with purified mineral oil to a sulfur content of 1% by mass. It should be noted that, on the other hand, a compound having a copper plate corrosion of 1 in the above test method for a compound containing a sulfur atom and not containing a metal atom and a phosphorus atom is called an inactive sulfur compound. Examples of the active sulfur compound include polysulfide, sulfurized oil and fat, powdered sulfur, sulfurized mineral oil, sulfurized ester, and sulfurized olefin. Among them, sulfurized olefin can be appropriately used. The active sulfur compound can be used alone or in combination of two or more. Even if the raw material and sulfur content are similar to these active sulfur compounds, it may sometimes be an inactive sulfur compound depending on the manufacturing conditions and the like.

[0058] The thiadiazole derivative is preferably 2,5-bis(alkyldithio)-1,3,4-thiadiazole, represented by the following formula (F). If such a thiadiazole derivative is contained, corrosion can be further prevented even when used at high temperatures.

[0059]

[0060] In the above formula (F), R f1 and R f2 each independently represent an alkyl group having 1 to 20 carbon atoms, and a and b each independently represent 1, 2, or 3. The thiadiazole derivative can be used alone or in combination of two or more.

[0061] In the industrial oil composition before use in metal processing, it is preferred to contain an extreme pressure agent in an amount of 0.01 parts by mass to 10 parts by mass relative to 100 parts by mass of the base oil. In addition, in the industrial oil composition before use in metal processing, it is preferred to contain a metal deactivator in an amount of 0.01 parts by mass to 10 parts by mass relative to 100 parts by mass of the base oil.

[0062] In addition, when the above metal deactivator is not contained in the industrial oil composition before use in metal processing, it can be appropriately used for the processing of metals containing iron, such as other than copper-based metals. In addition, when the above metal deactivator is not contained in the industrial oil composition before use in metal processing, as the extreme pressure agent, an inactive sulfur compound can be used instead of the active sulfur compound.

[0063] The industrial oil composition before use may further contain other functional additives. Examples of other functional additives include chlorinated paraffin. The other functional additives are preferably contained within a range that does not interfere with the effects such as long-term use of the industrial oil composition before use.

[0064] The kinematic viscosity at 40°C (JIS K 2283) of the industrial oil composition before use for mechanical lubrication is preferably 15 cSt to 100 cSt, more preferably 32 cSt to 68 cSt. In addition, the kinematic viscosity at 40°C (JIS K 2283) of the industrial oil composition before use for metal processing is preferably 2 cSt to 40 cSt. In particular, the kinematic viscosity at 40°C (JIS K 2283) of the industrial oil composition before use for cutting is more preferably 10 cSt to 40 cSt.

[0065] The industrial oil composition before use can be used as turbine oil, hydraulic oil, bearing oil, gear oil, compressor oil, and traction oil in mechanical lubrication by known methods. In addition, the industrial oil composition before use can be used as cutting oil, rolling oil, drawing / stretching oil, cleaning oil, plastic working oil, blanking oil, heat treatment oil, and heat transfer oil in metal processing by known methods. Through these uses, the industrial oil composition before use becomes the used industrial oil composition after mechanical lubrication or metal processing. It should be noted that in this specification, the used industrial oil composition after mechanical lubrication or metal processing is also simply referred to as the used industrial oil composition.

[0066] The used industrial oil composition can be mixed with a flushing oil used when replacing the used industrial oil composition used in mechanical lubrication. It should be noted that the flushing oil also preferably contains the above base oil and antioxidant.

[0067] In the used industrial oil composition, it is generally considered that most of the functional additives have been consumed. In addition, in the used industrial oil composition, the following deteriorated components are usually contained: functional additives, base oil, and antioxidant that have deteriorated and lost their functions due to decomposition, combination, etc. during use. In addition, in the used industrial oil composition, solid impurity components such as metals mixed in during use are usually also contained. The used industrial oil composition is often colored brown or the like because it contains deteriorated components and impurity components. On the other hand, in the used industrial oil composition, the base oil, antioxidant, and functional additives that remain in the state before use are usually also contained. The reason why the base oil and antioxidant can remain in a relatively high proportion in the used industrial oil composition is that in addition to the high stability of the antioxidant itself, the deterioration of the base oil is also inhibited by the antioxidant.

[0068] In Embodiment 1, in the purification treatment step, the used industrial oil composition after the above mechanical lubrication or metal processing is subjected to a purification treatment, that is, an adsorption treatment.

[0069] The adsorbents used in the adsorption treatment are, for example, acid clay, activated clay or silica-magnesia-based preparations. Acid clay is a clay mainly composed of montmorillonite clay minerals having a three-layer structure of silica-alumina-silica and soluble silicic acid. Activated clay is a compound having a porous structure with a large specific surface area and adsorption capacity, obtained by treating naturally occurring acid clay (montmorillonite-based clay) with mineral acids such as sulfuric acid. Activated clay is preferably in particle form. The particle size of the activated clay is, for example, preferably from 0.1 μm to 100 μm, more preferably from 10 μm to 50 μm. Here, the particle size of the activated clay is the volume-based median particle size measured by the laser diffraction / scattering method. In addition, the specific surface area of the activated clay is preferably 1 m 2 / g to 500 m 2 / g, more preferably 50 m 2 / g to 350 m 2 / g. Here, the specific surface area of the activated clay is the value measured by the BET method. The silica-magnesia-based preparation contains a silica component and a magnesia component. In the silica-magnesia-based preparation, a state is formed in which a matrix phase composed of fine particles of silica contains a three-layer structure portion in which a magnesia component layer is sandwiched in a sandwich manner by a silica component layer. The adsorbent can selectively adsorb substances having polar groups. From the viewpoint of the removal ability of deteriorated components and impurity components, etc., activated clay and silica-magnesia-based preparations are preferably used. In addition, since the removal ability of deteriorated components and impurity components, etc. is high, the usage amount can also be suppressed, so a silica-magnesia-based preparation is more preferably used. The adsorbent can be used alone as one kind, or two or more kinds can be used in combination.

[0070] In the adsorption treatment, the used industrial oil composition is brought into contact with the adsorbent. Thereby, the adsorbent adsorbs the deteriorated components and impurity components in the used industrial oil composition, and the deteriorated components and impurity components can be removed. Therefore, in the regenerated oil composition obtained by the treatment with the adsorbent, the degree of coloring is reduced. It should be noted that it is considered that a part of the impurity components (sulfur-containing components) originally contained in the base oil and a part of the deteriorated components obtained by deterioration of the impurity components due to use are also removed by the adsorbent.

[0071] Specifically, in the adsorption treatment, first, an adsorbent is added to the used industrial oil composition to obtain a mixture. In order to appropriately remove the deteriorated components and impurity components, the adsorbent is preferably brought into contact with 100 parts by mass of the used industrial oil composition in an amount of 10 parts by mass or more, more preferably in an amount of 10 parts by mass to 100 parts by mass.

[0072] Next, stir the mixture. As the stirring method, stirring using a stirrer, propeller stirring, rotation-revolution type planetary stirring, stirring using a stirring rod, continuous stirring flowing through a pipe causing stirring, etc. can be cited. The stirring time only needs to be a condition under which the adsorbent and the used industrial oil composition can be sufficiently contacted in the mixture, and is preferably 5 minutes or more. Stirring is preferably carried out at room temperature (for example, 15°C) or higher, more preferably at 80°C to 130°C. If the temperature at which stirring is carried out is too low, there is a case where the viscosity is high and the stirring efficiency decreases. On the other hand, if the temperature at which stirring is carried out is too high, sometimes the functional additive undergoes thermal decomposition to generate new deteriorated components.

[0073] Finally, separate and remove solid components such as the adsorbent that has adsorbed deteriorated components and impurity components from the mixture to obtain a regenerated oil composition. As the separation and removal method, centrifugation, filtration through a filter can be cited. The conditions for centrifugation and the mesh of the filter are not particularly limited as long as the solid components can be separated and removed. The mesh of the filter is preferably 4 μm or less, for example. In addition, in the case of centrifugal filtration, as long as it is a condition under which the solid components can settle and be separated from the supernatant (liquid) components.

[0074] The above adsorption treatment can be carried out multiple times. It should be noted that in this case, the adsorbent used multiple times is preferably contacted in an amount such that the total amount thereof is 10 parts by mass or more relative to 100 parts by mass of the used industrial oil composition, and more preferably in an amount of 10 parts by mass to 100 parts by mass. In addition, the adsorbent used in the adsorption treatment can be applied as a heat source and extender in cement manufacturing.

[0075] Through such an adsorption treatment, while removing many deteriorated components and impurity components, antioxidants and functional additives remaining in the state before use are also removed. Therefore, it is considered that the obtained regenerated oil composition is mostly composed of the base oil remaining in the state before the industrial oil composition was used.

[0076] In addition, in Embodiment 1, when the functional additive used in the industrial oil composition before use further contains sulfur (specifically, when a sulfur compound containing sulfur is used as the functional additive), it preferably includes a sulfur amount measurement step of measuring the amount of sulfur in the used industrial oil composition. Here, the amount of sulfur can be specifically measured by ICP analysis. It should be noted that it is considered that the amount of sulfur measured in the sulfur amount measurement step generally comes from sulfur compounds, their deteriorated components, and the base oil.

[0077] After the sulfur content measurement step, the above purification treatment step is carried out. Specifically, in the adsorption treatment of the purification treatment step, when the amount of sulfur obtained in the sulfur content measurement step is set to 100 parts by mass, it is preferable to use an adsorbent in an amount of 10 to 100 parts by mass, and more preferably in an amount of 30 to 90 parts by mass. When performing the adsorption treatment multiple times, the total amount of the adsorbent used multiple times is preferably used in such a way as to reach the above amount. If the adsorbent is used in the above amount, in addition to sulfur compounds and their deteriorated components, antioxidants and functional additives remaining in the state before use and their deteriorated components can also be appropriately removed.

[0078] Next, it is preferable to carry out a sulfur content confirmation step of measuring the amount of sulfur in the regenerated oil composition obtained in the purification treatment step to confirm that the sulfur has been reduced. It should be noted that after the purification treatment, the degree of reduction of the sulfur content can also be confirmed by measuring the sulfur content in the same manner as above. In addition, it is considered that the amount of sulfur measured in the sulfur content confirmation step is derived from the base oil because sulfur compounds and their deteriorated components are usually removed.

[0079] As described above, according to Embodiment 1, the above regenerated oil composition is obtained. It is considered that this is because at least a neutral phosphite derivative and a 2,6 - di - tert - butylphenol derivative are contained as antioxidants in the industrial oil composition before use. That is, due to the above antioxidants, even when used in mechanical lubrication or metal processing, a high proportion of the base oil remains. If a hindered amine compound is contained as an antioxidant, the deterioration of the base oil can be further suppressed even when used in mechanical lubrication or metal processing. It should be noted that since the above antioxidants have high stability, they remain in a high proportion even when used in mechanical lubrication or metal processing. Therefore, if the deteriorated components and impurity components are removed together with the antioxidants and functional additives remaining in the state before use by adsorption treatment, a regenerated oil composition mainly composed of the base oil remaining in the state before being used by the industrial oil composition is obtained (it should be noted that the regenerated oil composition also contains a small amount of the adsorbent that has not been completely separated). Since the base oil contained in the regenerated oil composition is the same as the base oil contained in the industrial oil composition before use, it can also be directly used for the manufacture of the regenerated industrial oil composition. It should be noted that when used for the manufacture of the regenerated industrial oil composition, the regenerated oil composition can be used by adding the above base oil as new oil, or the regenerated oil compositions can be mixed with each other. Therefore, according to Embodiment 1, the regenerated oil composition can be used in the regenerated industrial oil composition for mechanical lubrication or metal processing instead of being used in the fuel - use regenerated industrial oil composition as in the past, which helps to reduce CO2.

[0080] It should be noted that since the used industrial oil composition deteriorates severely after use, most of the conventional recycled oil compositions are used as fuel oil as described in Patent Document 1 even after regeneration. In addition, when using the conventional recycled oil composition, in order to obtain the desired performance, it is necessary to mix a large amount of new base oil. Thus, in the regeneration process for obtaining the conventional recycled oil composition, there is a problem that it cannot contribute to reducing CO2.

[0081] [Embodiment 2]

[0082] In the method for producing a recycled oil composition according to Embodiment 2, the recycled oil composition is produced by a purification treatment step of purifying the used industrial oil composition after mechanical lubrication or metal processing. In Embodiment 2, as the above purification treatment, an adsorption treatment is performed, followed by a vacuum distillation treatment. Thus, in Embodiment 2, it is different from Embodiment 1 in that the vacuum distillation treatment is performed after the adsorption treatment to produce the recycled oil composition. Hereinafter, the differences from Embodiment 1 will be described. It should be noted that for Embodiment 2, the description of the aspects the same as those in Embodiment 1 is omitted.

[0083] In Embodiment 2, a vacuum distillation treatment is performed on the used industrial oil composition (the industrial oil composition after the adsorption treatment) that has undergone the adsorption treatment. The vacuum distillation treatment is preferably performed at a reduced pressure of 24 mmHg or less, and preferably at a heating temperature of 230°C to 280°C. For example, if the vacuum distillation treatment is performed under the condition of 24 mmHg, the base oil with a kinematic viscosity (JIS K 2283) of 10 cSt to 80 cSt at 40°C boils near 240°C, so that this base oil can be distilled. In Embodiment 2, there is an advantage that the deteriorated components and impurity components remaining in the industrial oil composition after the adsorption treatment can be further removed by the vacuum distillation treatment. It is considered that in the recycled oil composition obtained through such adsorption treatment and vacuum distillation treatment, a larger part is composed of the base oil remaining in the state before the industrial oil composition was used (it should be noted that the recycled oil composition also contains a small amount of the adsorbent that has not been completely separated).

[0084] In addition, by adjusting the heating temperature in the vacuum distillation treatment, it is also possible to obtain a recycled oil composition containing a variety of base oils with different ranges of kinematic viscosity (JIS K 2283) at 40°C.

[0085] In addition, in Embodiment 2, as the purification treatment, an adsorption treatment can be performed. After the adsorption treatment is completed, the above antioxidant is added to the industrial oil composition, and then a vacuum distillation treatment is performed. The industrial oil composition after the adsorption treatment is mostly composed of the base oil remaining in the state before the industrial oil composition was used. If the above antioxidant is added thereto, the stability of the base oil can be improved. If the industrial oil composition after the adsorption treatment to which the antioxidant has been added is subjected to a vacuum distillation treatment, deterioration of the base oil can be appropriately suppressed even when heated during the vacuum distillation treatment. In particular, during the vacuum distillation treatment, even the base oil boiling at a high temperature (for example, a temperature exceeding 240°C, preferably 260°C to 280°C) can be inhibited from deteriorating.

[0086] As described above, according to Embodiment 2, the above-described regenerated oil composition is obtained. Similar to Embodiment 1, the regenerated oil composition obtained in Embodiment 2 is not used as fuel as in the past and can be used in a regenerated industrial oil composition for mechanical lubrication or metal processing, and thus can contribute to reducing CO2.

[0087] [Embodiment 3]

[0088] In the method for producing a regenerated oil composition according to Embodiment 3, a regenerated oil composition is produced through a purification treatment step of subjecting an industrial oil composition that has been used up after mechanical lubrication or metal processing to a purification treatment. In Embodiment 3, as the above purification treatment, a hydrodesulfurization treatment is performed, or a hydrodesulfurization treatment is performed followed by a vacuum distillation treatment. In this way, in Embodiment 3, the point that a hydrodesulfurization treatment is performed instead of an adsorption treatment to produce a regenerated oil composition is different from Embodiments 1 and 2. Hereinafter, the points different from Embodiments 1 and 2 will be described. It should be noted that the description of the points common to Embodiments 1 and 2 is omitted for Embodiment 3.

[0089] The hydrodesulfurization treatment is performed under high temperature and high pressure using a hydrodesulfurization catalyst. Thereby, denatured components and impurity components can be removed together with the antioxidant and functional additives remaining in the state before use in the used-up industrial oil composition. Therefore, the degree of coloring is reduced in the regenerated oil composition obtained by the hydrodesulfurization treatment. It should be noted that in the hydrodesulfurization treatment, in particular, sulfur compounds directly remaining in the used-up industrial oil composition and their denatured components can be removed. It is considered that the regenerated oil composition obtained through such a hydrodesulfurization treatment is mostly composed of the base oil remaining in the state before the industrial oil composition was used.

[0090] The industrially used oil composition after hydrodesulfurization treatment can be further subjected to vacuum distillation treatment. There are the following advantages: through the vacuum distillation treatment, deteriorated components and impurity components remaining in the industrially used oil composition after hydrodesulfurization treatment can be further removed. It is considered that in the regenerated oil composition obtained through such hydrodesulfurization treatment and vacuum distillation treatment, a larger part is composed of the base oil remaining in the state before the industrially used oil composition was used.

[0091] As described above, according to Embodiment 3, the above-mentioned regenerated oil composition can be obtained. Similar to Embodiments 1 and 2, the regenerated oil composition obtained in Embodiment 3 is not used as fuel as in the past and can be used in a regenerated industrially used oil composition for mechanical lubrication or metal processing, so it can contribute to reducing CO2.

[0092] [Embodiment 4]

[0093] In the method for manufacturing a regenerated oil composition according to Embodiment 4, the regenerated oil composition is manufactured through a purification treatment step of purifying the industrially used oil composition after use for mechanical lubrication or metal processing. In Embodiment 4, vacuum distillation treatment is performed as the above-mentioned purification treatment. Thus, in Embodiment 4, the point of manufacturing the regenerated oil composition by performing vacuum distillation treatment instead of adsorption treatment is different from that of Embodiment 1. Hereinafter, the points different from Embodiment 1 will be described. It should be noted that for Embodiment 4, the description of the points the same as those of Embodiment 1 is omitted.

[0094] The vacuum distillation treatment is preferably carried out at a reduced pressure of 24 mmHg or less, and preferably at a heating temperature of 230°C to 280°C, similar to Embodiment 2. For example, if the vacuum distillation treatment is carried out under the condition of 24 mmHg, the base oil with a kinematic viscosity (JIS K 2283) of 10 cSt to 80 cSt at 40°C boils at around 240°C, so this base oil can be distilled. Thereby, deteriorated components and impurity components can be reduced together with the antioxidant and functional additives remaining in the state before use in the industrially used oil composition after use. Therefore, the degree of coloring is reduced in the regenerated oil composition obtained through the vacuum distillation treatment. It is considered that in the regenerated oil composition obtained through such vacuum distillation treatment, most of it is composed of the base oil remaining in the state before the industrially used oil composition was used.

[0095] It should be noted that since the used industrial oil composition contains antioxidants remaining in the state before use, deterioration of the base oil can be suppressed even when heated during vacuum distillation treatment. In particular, during vacuum distillation treatment, even for a base oil boiling at a high temperature (for example, a temperature exceeding 240°C, preferably 260°C to 280°C), deterioration can be suppressed. Additionally, the vacuum distillation treatment can be performed after adding the above antioxidants to the used industrial oil composition. Thereby, deterioration of the base oil can be further suppressed even when heated during vacuum distillation treatment.

[0096] In addition, during vacuum distillation treatment, by adjusting the heating temperature in the same manner as in Embodiment 2, a regenerated oil composition containing multiple base oils with different ranges of kinematic viscosity (JIS K 2283) including 40°C can also be obtained.

[0097] As described above, according to Embodiment 4, the above regenerated oil composition can be obtained. Similar to Embodiment 1, the regenerated oil composition obtained in Embodiment 4 is not used as fuel as in the past and can be used in a regenerated industrial oil composition for mechanical lubrication or metal processing, thus contributing to CO2 reduction.

[0098] When manufacturing a regenerated oil composition from a used industrial oil composition, which manufacturing method among Embodiments 1 to 4 to use can be determined by whether the functional additives used in the industrial oil composition before use contain sulfur compounds. Specifically, in the case of not containing sulfur compounds, any of the manufacturing methods in Embodiments 1 to 4 can be used. Additionally, in the case of containing sulfur compounds with a decomposition temperature of 260°C or higher, any of the manufacturing methods in Embodiments 1 to 4 can be used. On the other hand, in the case of containing sulfur compounds with a decomposition temperature less than 260°C, it is preferably carried out by any of the manufacturing methods in Embodiments 1 to 3. In the case of containing sulfur compounds with a decomposition temperature less than 260°C, if the vacuum distillation treatment is initially performed as in Embodiment 4, the inside of the apparatus used for vacuum distillation may turn black due to the above sulfur compounds.

[0099] In addition, in the manufacturing methods of Embodiments 1 to 4, defective products or defective inventories generated during the manufacture of the industrial oil composition can be used instead of the used industrial oil composition for purification treatment. Thereby, reuse of defective products or defective inventories can be achieved.

[0100] [Embodiment 5]

[0101] The method for manufacturing the recycled industrial oil composition according to Embodiment 5 includes an additive addition step of adding the above antioxidant and functional additive to the recycled oil composition obtained by the method for manufacturing the recycled oil composition according to Embodiments 1 to 4. Thereby, the recycled industrial oil composition is manufactured. Specifically, the antioxidant is a neutral phosphite derivative represented by the above formula (B) and a 2,6-di-tert-butylphenol derivative represented by the above formula (C). In addition, it is also preferable to use a hindered amine compound represented by the above formula (D). In addition, it is preferable to add the antioxidant and the functional additive to the recycled oil composition obtained in Embodiments 1 to 4 so as to achieve the above amounts in the recycled industrial oil composition. Thereby, it can be suitably used in mechanical lubrication or metal processing.

[0102] In addition, the above base oil as new oil can be further added to the recycled industrial oil composition to which the antioxidant and the functional additive have been added, or another recycled oil composition can be added. Alternatively, the additive addition step can be performed after adding the above base oil as new oil to the recycled oil composition, or after mixing the recycled oil compositions with each other. Thereby, the viscosity of the recycled industrial oil composition can be adjusted.

[0103] If the above purification treatment step is further performed on the used recycled industrial oil composition, a recycled oil composition is obtained again. If the above additive addition step is then performed, a recycled industrial oil composition is obtained again. In this way, the cycle of use and purification treatment can also be repeated, which can further contribute to reducing CO2.

[0104] In summary, the present invention relates to the following aspects.

[0105] 〔1〕A method for manufacturing a recycled oil composition, which manufactures a recycled oil composition through a purification treatment step of purifying a used industrial oil composition after mechanical lubrication or metal processing. As the above purification treatment, adsorption treatment, hydrodesulfurization treatment, or vacuum distillation treatment is performed. The industrial oil composition before mechanical lubrication or metal processing and the used industrial oil composition after mechanical lubrication or metal processing include: a mineral oil (A1) or a synthetic oil (A2) as a base oil, a neutral phosphite derivative represented by the following formula (B) and a 2,6-di-tert-butylphenol derivative represented by the following formula (C) as antioxidants, and a functional additive. Compared with the industrial oil composition before mechanical lubrication or metal processing, the content rate of the above functional additive in the used industrial oil composition after mechanical lubrication or metal processing is less. According to the above method for manufacturing a recycled oil composition, it can contribute to reducing CO2.

[0106]

[0107] (In the above formula (B), Rb21 ~R b24 Each independently represents an aliphatic hydrocarbon group having 10 to 16 carbon atoms, R b25 ~R b28 Each independently represents a linear or branched alkyl group having 1 to 6 carbon atoms, R b291 and R b292 Each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms, R b291 and R b292 The total number of carbon atoms of and R is 1 to 5.)

[0108]

[0109] (In the above formula (C), R c1 is a linear or branched alkyl group having 1 to 12 carbon atoms.)

[0110] [2] The method for producing a recycled oil composition according to [1], wherein the industrial oil composition before the above-mentioned mechanical lubrication or metal processing further contains a hindered amine compound represented by the following formula (D) as the above antioxidant. According to the method for producing the recycled oil composition, it is possible to further contribute to reducing CO2.

[0111]

[0112] (In the above formula (D), R d21 and R d22 Each independently represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms, R d23 represents a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms.)

[0113] [3] The method for producing a recycled oil composition according to [1], wherein, as the above purification treatment, the above adsorption treatment is carried out,

[0114] The above adsorption treatment is a treatment in which the used industrial oil composition is brought into contact with acid clay, activated clay or a silica-magnesia-based preparation as an adsorbent. According to the above purification treatment, deteriorated components and impurity components can be appropriately removed.

[0115] [4] The method for producing a recycled oil composition according to [1], wherein, as the above purification treatment, the above adsorption treatment is carried out and then the above vacuum distillation treatment is carried out. According to the above purification treatment, deteriorated components and impurity components can be more appropriately removed.

[0116] [5] The method for manufacturing a recycled oil composition according to [4], wherein, as the above purification treatment, the above adsorption treatment is carried out, an antioxidant is added to the used industrial oil composition after the above adsorption treatment, and then the above vacuum distillation treatment is carried out. According to the above purification treatment, deteriorated components and impurity components can be more appropriately removed.

[0117] [6] The method for manufacturing a recycled oil composition according to [3], wherein the above adsorption treatment is a treatment in which the adsorbent is brought into contact with 10 parts by mass or more of the used industrial oil composition per 100 parts by mass. If the adsorbent is used in the above amount, deteriorated components and impurity components can be more appropriately removed.

[0118] [7] The method for manufacturing a recycled oil composition according to [3] or [4], wherein, when the functional additive contains sulfur, it further includes a sulfur amount measurement step of measuring the amount of sulfur in the used industrial oil composition, and a sulfur amount confirmation step of measuring the amount of sulfur in the recycled oil composition obtained in the above purification treatment step to confirm that the sulfur has decreased. By performing the above steps, it can be confirmed that the sulfur has decreased.

[0119] [8] The method for manufacturing a recycled oil composition according to [1], wherein, as the above purification treatment, the above vacuum distillation treatment is carried out. According to the above purification treatment, deteriorated components and impurity components can be appropriately removed.

[0120] [9] A method for manufacturing a recycled industrial oil composition, including the following addition step: in the recycled oil composition obtained by the method for manufacturing a recycled oil composition according to [1] or [2], a neutral phosphite derivative represented by the following formula (B) and a 2,6-di-tert-butylphenol derivative represented by the following formula (C) as antioxidants, and a functional additive are added. The obtained recycled industrial oil composition can be appropriately used in mechanical lubrication or metal processing.

[0121]

[0122] (In the above formula (B), R b21 ~R b24 each independently represents an aliphatic hydrocarbon group having 10 to 16 carbon atoms, R b25 ~R b28 each independently represents a linear or branched alkyl group having 1 to 6 carbon atoms, R b291 and R b292 each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms, and the total number of carbon atoms of R b291 and R b292 is 1 to 5.)

[0123]

[0124] (In the above formula (C), R c1 is a linear or branched alkyl group having 1 to 12 carbon atoms.)

[0125] [Examples]

[0126] Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

[0127] <Preparation of industrial oil composition before use>

[0128] [Preparation Example 1-1]

[0129] A mineral oil (A1-1) was obtained by mixing a Group I base oil having a kinematic viscosity (JIS K 2283) of 30 cSt at 40°C (trade name: 150NEUTRAL, manufactured by ENEOS Corporation) and a Group I base oil having a kinematic viscosity (JIS K 2283) of 74 cSt at 40°C (trade name: 350NEUTRAL, manufactured by ENEOS Corporation). The kinematic viscosity (JIS K 2283) of the mineral oil (A1-1) at 40°C was 68 cSt. The sulfur concentration measured for the mineral oil (A1-1) by ICP analysis was 0.42% by mass.

[0130] The mineral oil (A1-1), 4,4'-butylidenebis(3-methyl-6-tert-butylphenyl ditridecyl phosphite) as a neutral phosphite derivative, octyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (CAS 125643-61-0, trade name: Irganox® L135, manufactured by BASF JAPAN Ltd.) as a 2,6-di-tert-butylphenol derivative, bis(2,2,6,6-tetramethyl-1-(octyloxy)piperidin-4-yl) sebacate as a hindered amine compound, and sulfurized oil and fat (trade name: GS-110, manufactured by DIC Corporation) as a non-active sulfur compound were mixed to obtain an industrial oil composition (1-1) before use.

[0131] Here, in the industrial oil composition (1-1) before use, the mixing was carried out such that the concentration of the neutral phosphite derivative was 0.1% by mass, the concentration of the 2,6-di-tert-butylphenol derivative was 0.5% by mass, the concentration of the hindered amine compound was 0.1% by mass, and the concentration of the sulfurized oil and fat was 4% by mass.

[0132] [Preparation Example 1-1a]

[0133] For the industrial oil composition (1-1) before use, batches of Group I base oil (trade name: 350NEUTRAL, manufactured by ENEOS Corporation) with a kinematic viscosity at 40 °C (JIS K2283) of 68 cSt were different. Except for this, the operation was the same as in Preparation Example 1-1, and the industrial oil composition (1-1a) before use was also produced. The sulfur concentration of the mineral oil (A1-1) with different batches measured by ICP analysis was 0.43 mass%.

[0134] [Preparation Example 1-2]

[0135] The sulfurized oil and fat (trade name: S-220, manufactured by DIC Corporation) as an inactive sulfur compound was used instead of the sulfurized oil and fat (trade name: GS-110, manufactured by DIC Corporation) as an inactive sulfur compound. Except for this, the operation was the same as in Preparation Example 1-1, and the industrial oil composition (1-2) before use was obtained.

[0136] [Preparation Example 1-3]

[0137] The sulfurized olefin (trade name: GS-450, manufactured by DIC Corporation) as an inactive sulfur compound was used instead of the sulfurized oil and fat (trade name: GS-110, manufactured by DIC Corporation) as an inactive sulfur compound. Except for this, the operation was the same as in Preparation Example 1-1, and the industrial oil composition (1-3) before use was obtained.

[0138] [Preparation Example 1-4]

[0139] The sulfurized olefin (trade name: IS-30, manufactured by DIC Corporation) as an inactive sulfur compound was used instead of the sulfurized oil and fat (trade name: GS-110, manufactured by DIC Corporation) as an inactive sulfur compound. Except for this, the operation was the same as in Preparation Example 1-1, and the industrial oil composition (1-4) before use was obtained.

[0140] [Preparation Example 1-5]

[0141] In the industrial oil composition (1-1) before use, the sulfurized oil and fat (trade name: GS-110, manufactured by DIC Corporation) was mixed at a concentration of 1 mass% instead of 4 mass%. Except for this, the operation was the same as in Preparation Example 1-1, and the industrial oil composition (1-5) before use was obtained.

[0142] [Preparation Example 1-6]

[0143] In the industrial oil composition (1-1) before use, the concentration of the olefin sulfide (trade name: GS-450, manufactured by DIC Corporation) was mixed at 1% by mass instead of 4% by mass. Except for this, the industrial oil composition (1-6) before use was obtained by operating in the same manner as in Preparation Examples 1-3.

[0144] [Preparation Example 1-7]

[0145] Mineral oil (A1-1), 4,4'-butylidenebis(3-methyl-6-tert-butylphenyl ditridecyl phosphite) as a neutral phosphite derivative, octyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (CAS 125643-61-0, trade name: Irganox® L135, manufactured by BASF JAPAN Ltd.) as a 2,6-di-tert-butylphenol derivative, and sulfurized oil and fat (trade name: GS-110, manufactured by DIC Corporation) as an inactive sulfur compound were mixed to obtain the industrial oil composition (1-7) before use.

[0146] Here, in the industrial oil composition (1-1) before use, the concentration of the neutral phosphite derivative was 0.1% by mass, the concentration of the 2,6-di-tert-butylphenol derivative was 0.5% by mass, and the concentration of the sulfurized oil and fat was 4% by mass for mixing.

[0147] [Preparation Examples 1-8-1 to 1-8-6]

[0148] Using the compounds in Table 1 to replace 4,4'-butylidenebis(3-methyl-6-tert-butylphenyl ditridecyl phosphite) (in the above formula (B), R b21 ~R b24 = tridecyl, R b25 , R b27 = methyl, R b26 , R b28 = tert-butyl, R b291 = hydrogen atom, R b292 = n-propyl) as a neutral phosphite derivative, and except for this, the industrial oil compositions (1-8-1) to (1-8-6) before use were obtained by operating in the same manner as in Preparation Example 1-1.

[0149] Table 1

[0150] Example <![CDATA[R b21 ~R b24 > <![CDATA[R b25 、R b27 > <![CDATA[R b26 、R b28 > <![CDATA[R b291 > <![CDATA[R b292 > 1-8-1 Decyl Methyl tert-Butyl Hydrogen atom n-Propyl 1-8-2 Hexadecyl Methyl tert-Butyl Hydrogen atom n-Propyl 1-8-3 Tridecyl n-Propyl tert-Butyl Hydrogen atom n-Propyl 1-8-4 Tridecyl Methyl Isobutyl Hydrogen atom n-Propyl 1-8-5 Tridecyl Methyl tert-Butyl Hydrogen atom n-Pentyl 1-8-6 Tridecyl Methyl tert-Butyl Ethyl n-Propyl

[0151] [Preparation Examples 1-9-1 to 1-9-6]

[0152] Using the compounds in Table 2 to replace bis(2,2,6,6-tetramethyl-1-(octyloxy)piperidin-4-yl) sebacate (in the above formula (D), R d21 , Rd22 = n-octyl, R d23 = 1,8-octylene) as a hindered amine compound, and in addition, the industrial oil compositions (1-9-1) to (1-9-6) before use were obtained in the same manner as in Preparation Example 1-1.

[0153] Table 2

[0154] Example <![CDATA[R d21 ,R d22 > <![CDATA[R d23 > 1-9-1 Methyl Methylene 1-9-2 n-Propyl 1,3-Propylene 1-9-3 n-Pentyl 1,5-Pentylene 1-9-4 n-Pentyl 1,5-Pentylene 1-9-5 n-Hexyl 1,6-Hexylene 1-9-6 Decyl 1,10-Decylene

[0155] [Preparation Example 2-1]

[0156] A mineral oil (A1-2) was obtained by mixing a Group I base oil having a kinematic viscosity (JIS K 2283) of 30 cSt at 40 °C (trade name: 150NEUTRAL, manufactured by ENEOS Corporation) and a Group I base oil having a kinematic viscosity (JIS K 2283) of 68 cSt at 40 °C (trade name: 350NEUTRAL, manufactured by ENEOS Corporation). The kinematic viscosity (JIS K 2283) of the mineral oil (A1-2) at 40 °C was 32 cSt. The sulfur concentration measured by ICP analysis for the mineral oil (A1-2) was 0.34 mass%.

[0157] The mineral oil (A1-2), 4,4'-butylidenebis(3-methyl-6-tert-butylphenyl ditridecyl phosphite) as a neutral phosphite derivative, octyl = 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (CAS 125643-61-0, trade name: Irganox® L135, manufactured by BASF JAPAN Ltd.) as a 2,6-di-tert-butylphenol derivative, bis(2,2,6,6-tetramethyl-1-(octyloxy)piperidin-4-yl) sebacate as a hindered amine compound, and sulfurized oil and fat (trade name: GS-110, manufactured by DIC Corporation) as a non-active sulfur compound were mixed to obtain an industrial oil composition (2-1) before use.

[0158] Here, in the industrial oil composition (2-1) before use, they were mixed such that the concentration of the neutral phosphite derivative was 0.1 mass%, the concentration of the 2,6-di-tert-butylphenol derivative was 0.5 mass%, the concentration of the hindered amine compound was 0.1 mass%, and the concentration of the sulfurized oil and fat was 4 mass%.

[0159] [Preparation Examples 2-2 to 2-7]

[0160] Using the mineral oil (A1-2) in place of the mineral oil (A1-1), the industrial oil compositions (2-2) to (2-7) before use were obtained in the same manner as in Preparation Examples 1-2 to 1-7, respectively.

[0161] <Production of Used Industrial Oil Composition>

[0162] The use of the industrial oil composition (1-1) before use was simulated in mechanical lubrication or metal processing. That is, the industrial oil composition (1-1) before use was maintained at 290 °C in the atmosphere for 1 hour. The industrial oil composition (1-1) before use that had been maintained at this high temperature was used as the used industrial oil composition (1-1’).

[0163] The industrial oil compositions (1-1a), (1-2) to (1-7), (1-8-1) to (1-8-6), (1-9-1) to (1-9-6), (2-1) to (2-7) before use were used in place of the industrial oil composition (1-1) before use, and otherwise, the operation was the same as above to obtain the used industrial oil compositions (1-1’), (1-1a’), (1-2’) to (1-7’), (1-8’-1) to (1-8’-6), (1-9’-1) to (1-9’-6), (2-1’) to (2-7’).

[0164] <Manufacture of Recycled Oil Composition and Manufacture of Recycled Industrial Oil Composition>

[0165] [Example 1-1-1]

[0166] (Manufacture of Recycled Oil Composition)

[0167] The recycled oil composition (1-1-1) was manufactured from the used industrial oil composition (1-1’) according to Embodiment 1.

[0168] First, a sulfur content measurement step of measuring the amount of sulfur in the used industrial oil composition (1-1’) was performed. The measurement was carried out using ICP analysis. As a result, the sulfur concentration in the used industrial oil composition (1-1’) was 0.77 mass%.

[0169] Next, in the adsorption treatment of the purification treatment step, 30 parts by mass of an adsorbent (trade name: Activated Clay R-15, Nippon Activated Clay Co., Ltd.) was added to 100 parts by mass of the used industrial oil composition (1-1’) to obtain a mixture. The mixture was stirred using a stirrer at room temperature for 5 minutes. Then, the adsorbent was separated by centrifugation to obtain the processed industrial oil composition (1-1-1A).

[0170] In addition, 30 parts by mass of an adsorbent (trade name: Activated Clay R-15, manufactured by Nippon Activated Clay Co., Ltd.) was added to 100 parts by mass of the processed industrial oil composition (1-1-1A) to obtain a mixture. The mixture was stirred for 5 minutes at room temperature using a stirrer. Subsequently, the adsorbent was separated by centrifugation to obtain the processed industrial oil composition (1-1-1B).

[0171] Furthermore, 30 parts by mass of an adsorbent (trade name: Activated Clay R-15, manufactured by Nippon Activated Clay Co., Ltd.) was added to 100 parts by mass of the processed industrial oil composition (1-1-1B) to obtain a mixture. The mixture was stirred for 5 minutes at room temperature using a stirrer. Subsequently, the adsorbent was separated by centrifugation to obtain the processed industrial oil composition (1-1-1C) (recycled oil composition (1-1-1)). Thus, the adsorption treatment was performed three times.

[0172] In addition, a sulfur amount confirmation step of measuring the amount of sulfur in the processed industrial oil composition (1-1-1A), the processed industrial oil composition (1-1-1B), and the recycled oil composition (1-1-1) was performed. The measurement was carried out by ICP analysis. As a result, the sulfur concentrations in the processed industrial oil composition (1-1-1A), the processed industrial oil composition (1-1-1B), and the recycled oil composition (1-1-1) were 0.57% by mass, 0.40% by mass, and 0.36% by mass, respectively. It is considered that sulfur other than that from the base oil can be removed by the three adsorption treatments (total amount of adsorbent used: 90 parts by mass). In addition, similar to Example 2-1-1 described later, it is considered that in the recycled oil composition (1-1-1), in addition to the antioxidant and functional additives remaining in the state before use, most of the deteriorated components and impurity components were removed, and most of it is composed of the base oil remaining in the state before the industrial oil composition was used.

[0173] (Manufacture of Recycled Industrial Oil Composition)

[0174] Next, the recycled oil composition (1-1-1), 4,4'-butylidenebis(3-methyl-6-tert-butylphenyl ditridecyl phosphite) as a neutral phosphite derivative, octyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (CAS 125643-61-0, trade name: Irganox® L135, manufactured by BASF JAPAN Ltd.) as a 2,6-di-tert-butylphenol derivative, bis(2,2,6,6-tetramethyl-1-(octyloxy)piperidin-4-yl) sebacate as a hindered amine compound, and sulfurized oil (trade name: GS-110, manufactured by DIC Corporation) as a non-active sulfur compound were mixed to obtain a recycled industrial oil composition (1-1-1').

[0175] Here, in the recycled industrial oil composition (1-1-1'), they are mixed such that the concentration of the neutral phosphite derivative is 0.1% by mass, the concentration of the 2,6-di-tert-butylphenol derivative is 0.5% by mass, the concentration of the hindered amine compound is 0.1% by mass, and the concentration of the sulfurized oil and fat is 4% by mass.

[0176] The measured values of density, flash point, kinematic viscosity (at 40 °C and 100 °C), acid value, copper plate corrosion test, pressure resistance, and coefficient of friction of the industrial oil composition (1-1) before use and the recycled industrial oil composition (1-1-1') were compared. As a result, no changes were seen, similar to Example 2-5-1 described later. In addition, when the colors of the industrial oil composition (1-1) before use and the recycled industrial oil composition (1-1-1') were compared, the recycled industrial oil composition (1-1-1') was slightly colored. Thus, it can be seen that the recycled industrial oil composition (1-1-1') can be used for mechanical lubrication and metal processing.

[0177] [Example 1-1a-1]

[0178] (Manufacture of recycled oil composition)

[0179] According to Embodiment 1, the recycled oil composition (1-1a-1) was manufactured from the used industrial oil composition (1-1a').

[0180] First, a sulfur content measurement step of measuring the amount of sulfur in the used industrial oil composition (1-1a') was performed. Measurement was carried out using ICP analysis. As a result, the sulfur concentration in the used industrial oil composition (1-1a') was 0.74% by mass.

[0181] Next, in the adsorption treatment of the purification treatment step, 10 parts by mass of an adsorbent (trade name: Activated Clay R-15, Nippon Activated Clay Co., Ltd.) was added to 100 parts by mass of the used industrial oil composition (1-1a') to obtain a mixture. This mixture was stirred using a stirrer at room temperature for 5 minutes. Then, the adsorbent was separated by centrifugation to obtain the treated industrial oil composition (1-1a-1A).

[0182] In addition, 10 parts by mass of an adsorbent (trade name: Activated Clay R-15, Nippon Activated Clay Co., Ltd.) was added to 100 parts by mass of the treated industrial oil composition (1-1a-1A) to obtain a mixture. This mixture was stirred using a stirrer at room temperature for 5 minutes. Then, the adsorbent was separated by centrifugation to obtain the treated industrial oil composition (1-1a-1B).

[0183] In addition, 10 parts by mass of an adsorbent (trade name: Activated Clay R-15, manufactured by Nippon Activated Clay Co., Ltd.) was added to 100 parts by mass of the processed industrial oil composition (1-1a-1B) to obtain a mixture. The mixture was stirred for 5 minutes at room temperature using a stirrer. Subsequently, the adsorbent was separated by centrifugation to obtain the processed industrial oil composition (1-1a-1C) (recycled oil composition (1-1a-1)). Thus, the adsorption treatment was performed three times.

[0184] In addition, a sulfur amount confirmation step of measuring the amount of sulfur in the processed industrial oil composition (1-1a-1A), the processed industrial oil composition (1-1a-1B), and the recycled oil composition (1-1a-1) was performed. The measurement was carried out by ICP analysis. As a result, the sulfur concentrations in the processed industrial oil composition (1-1a-1A), the processed industrial oil composition (1-1a-1B), and the recycled oil composition (1-1a-1) were 0.65% by mass, 0.57% by mass, and 0.50% by mass, respectively. It is considered that sulfur other than that from the base oil was almost removed by the three adsorption treatments (total amount of adsorbent used: 30 parts by mass). In addition, similar to Example 2-1-1 described later, it is considered that in the recycled oil composition (1-1a-1), most of the deteriorated components and impurity components were removed except for the antioxidant and functional additives remaining in the state before use, and most of it was composed of the base oil remaining in the state before the industrial oil composition was used.

[0185] (Manufacture of Recycled Industrial Oil Composition)

[0186] Next, the recycled oil composition (1-1a-1), 4,4'-butylidenebis(3-methyl-6-tert-butylphenyl ditridecyl phosphite) as a neutral phosphite derivative, octyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (CAS 125643-61-0, trade name: Irganox® L135, manufactured by BASF JAPAN Ltd.) as a 2,6-di-tert-butylphenol derivative, bis(2,2,6,6-tetramethyl-1-(octyloxy)piperidin-4-yl) sebacate as a hindered amine compound, and sulfurized oil (trade name: GS-110, manufactured by DIC Corporation) as a non-active sulfur compound were mixed to obtain a recycled industrial oil composition (1-1a-1').

[0187] Here, in the recycled industrial oil composition (1-1a-1'), the mixture was carried out such that the concentration of the neutral phosphite derivative was 0.1% by mass, the concentration of the 2,6-di-tert-butylphenol derivative was 0.5% by mass, the concentration of the hindered amine compound was 0.1% by mass, and the concentration of the sulfurized oil was 4% by mass.

[0188] For the industrial oil composition (1-1a) before use and the regenerated industrial oil composition (1-1a-1'), the measured values of density, flash point, kinematic viscosity (at 40 °C and 100 °C), acid value, copper plate corrosion test, pressure resistance, and friction coefficient were compared. As a result, no changes were observed as in Example 2-5-1 described later. In addition, when the colors of the industrial oil composition (1-1a) before use and the regenerated industrial oil composition (1-1a-1') were compared, the regenerated industrial oil composition (1-1a-1') was slightly colored. From this, it can be known that the regenerated industrial oil composition (1-1a-1') can be used for mechanical lubrication and metal processing.

[0189] [Example 1-1a-2]

[0190] (Manufacture of regenerated oil composition)

[0191] According to Embodiment 1, the regenerated oil composition (1-1a-2) is manufactured from the used industrial oil composition (1-1a').

[0192] First, a sulfur content measurement step of measuring the amount of sulfur in the used industrial oil composition (1-1a') is performed. The measurement is carried out using ICP analysis. As a result, the sulfur concentration in the used industrial oil composition (1-1a') is 0.74 mass%.

[0193] Next, in the adsorption treatment of the purification treatment step, 10 parts by mass of an adsorbent (trade name: Activated Clay GALLEON EARTH (registered trademark) V2, Mizusawa Chemical Industry Co., Ltd.) is added to 100 parts by mass of the used industrial oil composition (1-1a') to obtain a mixture. The mixture is stirred at room temperature using a stirrer for 5 minutes. Then, the adsorbent is separated by centrifugation to obtain the treated industrial oil composition (1-1a-2A).

[0194] In addition, 10 parts by mass of an adsorbent (trade name: Activated Clay GALLEON EARTH V2, Mizusawa Chemical Industry Co., Ltd.) is added to 100 parts by mass of the treated industrial oil composition (1-1a-2A) to obtain a mixture. The mixture is stirred at room temperature using a stirrer for 5 minutes. Then, the adsorbent is separated by centrifugation to obtain the treated industrial oil composition (1-1a-2B).

[0195] In addition, 10 parts by mass of an adsorbent (trade name: Activated Clay GALLEON EARTH V2, Mizusawa Chemical Industry Co., Ltd.) was added to 100 parts by mass of the processed industrial oil composition (1-1a-2B) to obtain a mixture. The mixture was stirred for 5 minutes at room temperature using a stirrer. Then, the adsorbent was separated by centrifugation to obtain the processed industrial oil composition (1-1a-2C) (recycled oil composition (1-1a-2)). Thus, the adsorption treatment was carried out three times.

[0196] In addition, a sulfur amount confirmation step of measuring the amount of sulfur in the processed industrial oil composition (1-1a-2A), the processed industrial oil composition (1-1a-2B), and the recycled oil composition (1-1a-2) was performed. The measurement was carried out by ICP analysis. As a result, the sulfur concentrations in the processed industrial oil composition (1-1a-2A), the processed industrial oil composition (1-1a-2B), and the recycled oil composition (1-1a-2) were 0.63% by mass, 0.52% by mass, and 0.40% by mass, respectively. It is considered that sulfur other than that derived from the base oil can be removed by three adsorption treatments (total amount of adsorbent used: 30 parts by mass). In addition, similar to Example 2-1-1 described later, it is considered that in the recycled oil composition (1-1a-2), in addition to the antioxidant and functional additives remaining in the state before use, most of the deteriorated components and impurity components are also removed, and most of it is composed of the base oil remaining in the state before the industrial oil composition was used.

[0197] (Manufacture of recycled industrial oil composition)

[0198] Next, the recycled oil composition (1-1a-2), 4,4'-butylidenebis(3-methyl-6-tert-butylphenyl ditridecyl phosphite) as a neutral phosphite derivative, octyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (CAS 125643-61-0, trade name: Irganox (registered trademark) L135, manufactured by BASF JAPAN Ltd.) as a 2,6-di-tert-butylphenol derivative, bis(2,2,6,6-tetramethyl-1-(octyloxy)piperidin-4-yl) sebacate as a hindered amine compound, and sulfurized oil (trade name: GS-110, manufactured by DIC Corporation) as a non-active sulfur compound were mixed to obtain a recycled industrial oil composition (1-1a-2').

[0199] Here, in the recycled industrial oil composition (1-1a-2'), the mixture was carried out such that the concentration of the neutral phosphite derivative was 0.1% by mass, the concentration of the 2,6-di-tert-butylphenol derivative was 0.5% by mass, the concentration of the hindered amine compound was 0.1% by mass, and the concentration of the sulfurized oil was 4% by mass.

[0200] For the industrial oil composition (1-1a) before use and the regenerated industrial oil composition (1-1a-2'), the measured values of density, flash point, kinematic viscosity (at 40 °C and 100 °C), acid value, copper plate corrosion test, pressure resistance, and coefficient of friction were compared. As a result, no changes were observed as in Example 2-5-1 described later. In addition, when the color was compared between the industrial oil composition (1-1a) before use and the regenerated industrial oil composition (1-1a-2'), the regenerated industrial oil composition (1-1a-2') was slightly colored. Thus, it can be seen that the regenerated industrial oil composition (1-1a-2') can be used for mechanical lubrication and metal processing.

[0201] [Example 1-1a-3]

[0202] (Manufacture of regenerated oil composition)

[0203] According to Embodiment 1, a regenerated oil composition (1-1a-3) is manufactured from the used industrial oil composition (1-1a').

[0204] First, a sulfur content measurement step of measuring the amount of sulfur in the used industrial oil composition (1-1a') is performed. The measurement is carried out using ICP analysis. As a result, the sulfur concentration in the used industrial oil composition (1-1a') is 0.74 mass%.

[0205] Next, in the adsorption treatment of the purification treatment step, 10 parts by mass of an adsorbent (trade name: silica-magnesia preparation MIZUKALIFE (registered trademark) F-2G, Mizusawa Chemical Industry Co., Ltd.) is added to 100 parts by mass of the used industrial oil composition (1-1a') to obtain a mixture. The mixture is stirred using a stirrer at room temperature for 5 minutes. Then, the adsorbent is separated by centrifugation to obtain the treated industrial oil composition (1-1a-3A).

[0206] In addition, 10 parts by mass of an adsorbent (trade name: silica-magnesia preparation MIZUKALIFE (registered trademark) F-2G, Mizusawa Chemical Industry Co., Ltd.) is added to 100 parts by mass of the treated industrial oil composition (1-1a-3A) to obtain a mixture. The mixture is stirred using a stirrer at room temperature for 5 minutes. Then, the adsorbent is separated by centrifugation to obtain the treated industrial oil composition (1-1a-3B).

[0207] In addition, 10 parts by mass of an adsorbent (trade name: Silicate Preparation MIZUKALIFE (registered trademark) F-2G, Mizusawa Chemical Industry Co., Ltd.) was added to 100 parts by mass of the processed industrial oil composition (1-1a-3B), and a mixture was obtained. The mixture was stirred for 5 minutes at room temperature using a stirrer. Then, the adsorbent was separated by centrifugation to obtain the processed industrial oil composition (1-1a-3C) (recycled oil composition (1-1a-3)). In this way, the adsorption treatment was carried out 3 times.

[0208] In addition, a sulfur amount confirmation step of measuring the amount of sulfur in the processed industrial oil composition (1-1a-3A), the processed industrial oil composition (1-1a-3B), and the recycled oil composition (1-1a-3) was performed. The measurement was carried out by ICP analysis. As a result, the sulfur concentrations in the processed industrial oil composition (1-1a-3A), the processed industrial oil composition (1-1a-3B), and the recycled oil composition (1-1a-3) were 0.61% by mass, 0.50% by mass, and 0.35% by mass, respectively. It is considered that sulfur other than sulfur derived from the base oil can be removed by 3 adsorption treatments (total amount of adsorbent used: 30 parts by mass). In addition, similar to Example 2-1-1 described later, it is considered that in the recycled oil composition (1-1a-3), most of the deteriorated components and impurity components were removed in addition to the antioxidant and functional additives remaining in the state before use, and most of it is composed of the base oil remaining in the state before the industrial oil composition was used.

[0209] (Manufacture of recycled industrial oil composition)

[0210] Next, the recycled oil composition (1-1a-3), 4,4'-butylidenebis(3-methyl-6-tert-butylphenyl ditridecyl phosphite) as a neutral phosphite derivative, octyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (CAS 125643-61-0, trade name: Irganox (registered trademark) L135, manufactured by BASF JAPAN Ltd.) as a 2,6-di-tert-butylphenol derivative, bis(2,2,6,6-tetramethyl-1-(octyloxy)piperidin-4-yl) sebacate as a hindered amine compound, and sulfurized oil (trade name: GS-110, manufactured by DIC Corporation) as a non-active sulfur compound were mixed to obtain a recycled industrial oil composition (1-1a-3').

[0211] Here, in the recycled industrial oil composition (1-1a-3'), the mixture was carried out such that the concentration of the neutral phosphite derivative was 0.1% by mass, the concentration of the 2,6-di-tert-butylphenol derivative was 0.5% by mass, the concentration of the hindered amine compound was 0.1% by mass, and the concentration of the sulfurized oil was 4% by mass.

[0212] For the industrial oil composition (1-1a) before use and the recycled industrial oil composition (1-1a-3'), the measured values of density, flash point, kinematic viscosity (at 40 °C and 100 °C), acid value, copper plate corrosion test, pressure resistance, and coefficient of friction were compared. As a result, no changes were observed as in Example 2-5-1 described later. In addition, when comparing the colors of the industrial oil composition (1-1a) before use and the recycled industrial oil composition (1-1a-3'), the recycled industrial oil composition (1-1a-3') was slightly colored. From this, it can be known that the recycled industrial oil composition (1-1a-3') can be used for mechanical lubrication and metal processing.

[0213] [Example 2-1-1]

[0214] (Manufacture of recycled oil composition)

[0215] According to Embodiment 1, a recycled oil composition (2-1-1) was manufactured from the used industrial oil composition (2-1').

[0216] First, a sulfur content measurement step of measuring the amount of sulfur in the used industrial oil composition (2-1') was performed. The measurement was carried out using ICP analysis. As a result, the sulfur concentration in the used industrial oil composition (2-1') was 0.45 mass%.

[0217] Next, in the adsorption treatment of the purification treatment step, 30 parts by mass of an adsorbent (trade name: Activated Clay R-15, Nippon Activated Clay Co., Ltd.) was added to 100 parts by mass of the used industrial oil composition (2-1') to obtain a mixture. The mixture was stirred using a stirrer at room temperature for 5 minutes. Then, the adsorbent was separated by centrifugation to obtain the treated industrial oil composition (2-1-1A).

[0218] In addition, 30 parts by mass of an adsorbent (trade name: Activated Clay R-15, Nippon Activated Clay Co., Ltd.) was added to 100 parts by mass of the treated industrial oil composition (2-1-1A) to obtain a mixture. The mixture was stirred using a stirrer at room temperature for 5 minutes. Then, the adsorbent was separated by centrifugation to obtain the treated industrial oil composition (2-1-1B).

[0219] In addition, 30 parts by mass of an adsorbent (trade name: Activated Clay R-15, Nippon Activated Clay Co., Ltd.) was added to 100 parts by mass of the processed industrial oil composition (2-1-1B) to obtain a mixture. The mixture was stirred for 5 minutes at room temperature using a stirrer. Subsequently, the adsorbent was separated by centrifugation to obtain the processed industrial oil composition (2-1-1C) (recycled oil composition (2-1-1)). Thus, the adsorption treatment was performed three times.

[0220] In addition, a sulfur amount confirmation step of measuring the amount of sulfur in the processed industrial oil composition (2-1-1A), the processed industrial oil composition (2-1-1B), and the recycled oil composition (2-1-1) was performed. The measurement was carried out by ICP analysis. As a result, the sulfur concentrations in the processed industrial oil composition (2-1-1A), the processed industrial oil composition (2-1-1B), and the recycled oil composition (2-1-1) were 0.33% by mass, 0.30% by mass, and 0.20% by mass, respectively. It is considered that sulfur other than sulfur derived from the base oil can be removed by three adsorption treatments (total amount of adsorbent used: 90 parts by mass). In addition, it is considered that a part of the sulfur derived from the base oil can also be removed.

[0221] Figure 1 、 Figure 2 The measurement results obtained by high performance liquid chromatography for the used industrial oil composition (2-1') and the recycled oil composition (2-1-1) are shown respectively. In the measurement results of the used industrial oil composition (2-1'), peaks derived from antioxidants, sulfur compounds, etc. were also observed in addition to the mineral oil (A2-1). On the other hand, in the measurement results of the recycled oil composition (2-1-1), only the peak derived from the mineral oil (A2-1) was observed. It can be seen that by the adsorption treatment, in the recycled oil composition (2-1-1), in addition to the antioxidants and functional additives remaining in the state before use, most of the deteriorated components and impurity components were removed, and most of it is composed of the base oil remaining in the state before the industrial oil composition was used.

[0222] (Manufacture of Recycled Industrial Oil Composition)

[0223] Next, a regenerated industrial oil composition (2-1-1') is obtained by mixing a regenerated oil composition (2-1-1), 4,4'-butylidenebis(3-methyl-6-tert-butylphenyl ditridecyl phosphite) as a neutral phosphite derivative, octyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (CAS 125643-61-0, trade name: Irganox® L135, manufactured by BASF JAPAN Ltd.) as a 2,6-di-tert-butylphenol derivative, bis(2,2,6,6-tetramethyl-1-(octyloxy)piperidin-4-yl) sebacate as a hindered amine compound, and sulfurized oil and fat (trade name: GS-110, manufactured by DIC Corporation) as a non-active sulfur compound.

[0224] Here, in the regenerated industrial oil composition (2-1-1'), they are mixed such that the concentration of the neutral phosphite derivative is 0.1% by mass, the concentration of the 2,6-di-tert-butylphenol derivative is 0.5% by mass, the concentration of the hindered amine compound is 0.1% by mass, and the concentration of the sulfurized oil and fat is 4% by mass.

[0225] For the industrial oil composition (2-1) before use and the regenerated industrial oil composition (2-1-1'), the measured values of density, flash point, kinematic viscosity (at 40 °C and 100 °C), acid value, copper plate corrosion test, pressure resistance, and coefficient of friction were compared. As a result, no change was observed as in Example 2-5-1 described later. In addition, when the colors of the industrial oil composition (2-1) before use and the regenerated industrial oil composition (2-1-1') were compared, the regenerated industrial oil composition (2-1-1') was slightly colored. From this, it can be seen that the regenerated industrial oil composition (2-1-1') can be used for mechanical lubrication and metal processing.

[0226] [Example 2-5-1]

[0227] (Manufacture of regenerated oil composition)

[0228] According to Embodiment 1, a regenerated oil composition (2-5-1) is manufactured from the used industrial oil composition (2-5').

[0229] First, a sulfur amount measurement step of measuring the amount of sulfur in the used industrial oil composition (2-5') is performed. The measurement is carried out by ICP analysis. As a result, the sulfur concentration in the used industrial oil composition (2-5') is 0.48% by mass.

[0230] Next, in the adsorption treatment of the purification process, 90 parts by mass of an adsorbent (trade name: Activated Clay R-15, manufactured by Nippon Activated Clay Co., Ltd.) was added to 100 parts by mass of the used industrial oil composition (2-5'), and a mixture was obtained. The mixture was stirred for 5 minutes at room temperature using a stirrer. Then, the adsorbent was separated by centrifugation to obtain a regenerated oil composition (2-5-1).

[0231] In addition, a sulfur amount confirmation step of measuring the amount of sulfur in the regenerated oil composition (2-5-1) was performed. The measurement was carried out by ICP analysis. As a result, the sulfur concentration in the regenerated oil composition (2-5-1) was 0.32% by mass. It is considered that sulfur other than that from the base oil can be removed by the adsorption treatment (adsorbent usage amount: 90 parts by mass). In addition, similar to Example 2-1-1, it is considered that in the regenerated oil composition (2-5-1), most of the deteriorated components and impurity components were removed except for the antioxidant and functional additives remaining in the state before use, and most of it is composed of the base oil remaining in the state before the industrial oil composition was used.

[0232] (Manufacture of regenerated industrial oil composition)

[0233] Next, the regenerated oil composition (2-5-1), 4,4'-butylidenebis(3-methyl-6-tert-butylphenyl ditridecyl phosphite) as a neutral phosphite derivative, octyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (CAS 125643-61-0, trade name: Irganox (registered trademark) L135, manufactured by BASF JAPAN Ltd.) as a 2,6-di-tert-butylphenol derivative, bis(2,2,6,6-tetramethyl-1-(octyloxy)piperidin-4-yl) sebacate as a hindered amine compound, and sulfurized oil (trade name: GS-110, manufactured by DIC Corporation) as a non-active sulfur compound were mixed to obtain a regenerated industrial oil composition (2-5-1').

[0234] Here, in the regenerated industrial oil composition (2-5-1'), the mixture was carried out such that the concentration of the neutral phosphite derivative was 0.1% by mass, the concentration of the 2,6-di-tert-butylphenol derivative was 0.5% by mass, the concentration of the hindered amine compound was 0.1% by mass, and the concentration of the sulfurized oil was 1% by mass.

[0235] For the industrial oil composition (2-5) before use and the regenerated industrial oil composition (2-5-1’), the density (JIS K2249-1), flash point (JIS K2265-4), kinematic viscosity (at 40 °C and 100 °C, JIS K 2283), acid value (JISK2501), copper plate corrosion test (JIS K2513), pressure resistance (ASTM D 2783), and coefficient of friction (using a pendulum friction coefficient measuring device) were measured.

[0236] In the industrial oil composition (2-5) before use, the density was 0.876 g / cm 3 , the flash point was 218 °C, the kinematic viscosity (at 40 °C) was 33 cSt, the kinematic viscosity (at 100 °C) was 5.6 cSt, the acid value was 0.01 mgKOH / g, the copper plate corrosion test result was 1a, the pressure resistance was 200 kgf, and the coefficient of friction was 0.14.

[0237] In the regenerated industrial oil composition (2-5-1’), the density was 0.874 g / cm 3 , the flash point was 202 °C, the kinematic viscosity (at 40 °C) was 33 cSt, the kinematic viscosity (at 100 °C) was 5.6 cSt, the acid value was 0.01 mgKOH / g, the copper plate corrosion test result was 1a, the pressure resistance was 200 kgf, and the coefficient of friction was 0.12. Thus, there were hardly any changes in the measured values of the industrial oil composition (2-5) before use and the regenerated industrial oil composition (2-5-1’).

[0238] In addition, when comparing the colors of the industrial oil composition (2-5) before use and the regenerated industrial oil composition (2-5-1’), the regenerated industrial oil composition (2-5-1’) was slightly colored. Therefore, it is considered that the regenerated industrial oil composition (2-5-1’) can be used for mechanical lubrication and metal processing.

[0239] [Examples 1-2-1 to 1-7-1, 1-8-1-1 to 1-8-6-1, 1-9-1-1 to 1-9-6-1, 2-2-1 to 2-4-1, 2-6-1, 2-7-1]

[0240] Using the used industrial oil compositions (1-2’) to (1-7’), (1-8’-1) to (1-8’-6), (1-9’-1) to (1-9’-6), (2-2’) to (2-4’), (2-6’), (2-7’), except for this, the same operations as in Example 1-1-1 were carried out to manufacture the regenerated oil compositions.

[0241] Next, for each regenerated oil composition, antioxidants and functional additives of the same type and amount as those in the industrial oil composition before use were added to manufacture the regenerated industrial oil compositions.

[0242] For the industrial oil composition before use and the regenerated industrial oil composition, the measured values of density, flash point, kinematic viscosity (at 40 °C and 100 °C), acid value, copper plate corrosion test, pressure resistance, and friction coefficient were compared in the same manner as in Example 2-5-1. As a result, no changes were observed. In addition, when comparing the colors of the industrial oil composition before use and the regenerated industrial oil composition, the regenerated industrial oil composition was slightly colored. From this, it can be seen that the regenerated industrial oil composition can be used for mechanical lubrication and metal processing.

[0243] In the above examples, mineral oil was used as the base oil. However, it is not limited thereto, and any one of synthetic oil, vegetable oil, and its derivatives (such as hydrogenated vegetable oil and the above hydroisomerization reaction product) can be used instead of mineral oil as the base oil to obtain the same results as in the above examples. Specifically, regardless of whether synthetic oil, vegetable oil, or its derivative is used, for the industrial oil composition before use and the regenerated industrial oil composition, the measured values of density, flash point, kinematic viscosity (at 40 °C and 100 °C), acid value, copper plate corrosion test, pressure resistance, and friction coefficient were compared in the same manner as in Example 2-5-1, and no changes were observed as a result. In addition, when comparing the colors of the industrial oil composition before use and the regenerated industrial oil composition, the regenerated industrial oil composition was slightly colored. From this, it can be seen that the regenerated industrial oil composition can be used for mechanical lubrication and metal processing.

Claims

1. A method for manufacturing a recycled oil composition, which manufactures the recycled oil composition through a purification process for purifying an industrial oil composition that has been used after mechanical lubrication or metal processing. Perform an adsorption treatment, a hydrodesulfurization treatment, or a vacuum distillation treatment as the purification treatment. The industrial oil composition before the mechanical lubrication or metal processing and the used industrial oil composition after the mechanical lubrication or metal processing contain: Mineral oil (A1), synthetic oil (A2), or vegetable oil or its derivative (A3) as the base oil. A neutral phosphite derivative represented by the following formula (B) and a 2,6 - di - tert - butylphenol derivative represented by the following formula (C) as antioxidants, and Functional additives. Compared with the industrial oil composition before the mechanical lubrication or metal processing, the content rate of the functional additives in the used industrial oil composition after the mechanical lubrication or metal processing is less. In the formula (B), R b21 ~R b24 Each independently represents an aliphatic hydrocarbon group having 10 to 16 carbon atoms, R b25 ~R b28 Each independently represents a linear or branched alkyl group having 1 to 6 carbon atoms, R b291 And R b292 Each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms, and the total number of carbon atoms of R b291 And R b292 Is 1 to 5. In the formula (C), R c1 Is a linear or branched alkyl group having 1 to 12 carbon atoms.

2. The method for manufacturing a recycled oil composition according to claim 1, wherein The industrial oil composition before the mechanical lubrication or metal processing further contains a hindered amine compound represented by the following formula (D) as the antioxidant, In the formula (D), R d21 and R d22 each independently represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms, and R d23 represents a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms.

3. The method for manufacturing a recycled oil composition according to claim 1, wherein As the purification treatment, the adsorption treatment is carried out. The adsorption treatment is a treatment in which the used industrial oil composition is brought into contact with acid clay, activated clay or a silica-magnesia-based preparation as an adsorbent.

4. The method for manufacturing a recycled oil composition according to claim 1, wherein As the purification treatment, the adsorption treatment is carried out and then the vacuum distillation treatment is carried out.

5. The method for manufacturing a recycled oil composition according to claim 4, whereinAs the purification treatment, the adsorption treatment is carried out, the antioxidant is added to the used industrial oil composition after the adsorption treatment, and then the vacuum distillation treatment is carried out.

6. The method for manufacturing a recycled oil composition according to claim 3, wherein, The adsorption treatment is a treatment in which the adsorbent is brought into contact with 10 parts by mass or more of the used industrial oil composition per 100 parts by mass.

7. The method for manufacturing a recycled oil composition according to claim 3 or 4, wherein, It includes the following steps: A sulfur content measurement step of further measuring the sulfur content in the used industrial oil composition when the functional additive contains sulfur, and A sulfur content confirmation step of measuring the sulfur content in the regenerated oil composition obtained in the purification treatment step to confirm that the sulfur has been reduced.

8. The method for manufacturing a recycled oil composition according to claim 1, wherein, As the purification treatment, the vacuum distillation treatment is carried out.

9. A method for manufacturing a recycled industrial oil composition, comprising the following addition steps: adding a neutral phosphite derivative represented by the following formula (B) and a 2,6 - di - tert - butylphenol derivative represented by the following formula (C), which are used as antioxidants, and a functional additive to the recycled oil composition obtained by the method for manufacturing a recycled oil composition according to claim 1 or 2, In the said formula (B), R b21 ~R b24 each independently represents an aliphatic hydrocarbon group having 10 to 16 carbon atoms, R b25 ~R b28 each independently represents a linear or branched alkyl group having 1 to 6 carbon atoms, R b291 and R b292 each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms, and the total number of carbon atoms of R b291 and R b292 is 1 to 5, In the said formula (C), R c1 is a linear or branched alkyl group having 1 to 12 carbon atoms.

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