JPH0192296A - Lubricant composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition outstanding in lubricating performance, by dispersing powdery solid lubricating material in a base oil consisting partly or wholly of specific naphthene oil to enable dispersion of said lubricating material stably for a long period of time. CONSTITUTION:The objective composition can be obtained by dispersing (A) a base oil consisting partly or wholly of a naphthene oil with a total of the carbon constructing the rings of condensed polycyclic alicyclic hydrocarbon and the carbon directly linked to said rings accounting for >=80% of the whole carbon, ratio: H/C falling between 1.65 and 1.80 and also specific gravity (15/4 deg.C) of 0.98-1.20 with (B) powdery solid lubricating material made of e.g., graphite, molybdenum disulfide, boron nitride, tungsten disulfide, graphite fluoride, polytetrafluoroethylene powder, mica, talc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lubricant composition comprising a powdered solid lubricant mixed with a base oil.

[Prior Art] A wide variety of lubricants have been used to reduce frictional resistance and wear between relatively moving objects or parts, and to save energy consumption. Such lubricants include liquid lubricating oil, semi-solid or viscous paste grease at room temperature, and powder solid lubricant, but in any case, there are lubricants that are suitable for any usage conditions. There is no lubricant, but the properties of the lubricant are improved and put into practical use depending on the use and purpose.

From this perspective, the extreme pressure properties and lubrication performance of lubricating oils and greases used in various mechanical elements such as shafts and bearings, gears, etc. that are used by very large carts, and in plastic processing, etc. have traditionally been evaluated. For the purpose of improving the properties of
Solid lubricants have also been added as additives.

However, solid lubricants generally have poor affinity for lubricating oils and greases, and also have poor dispersion stability in lubricating oils and greases due to large differences in specific gravity. When adding a solid lubricant to oil or grease as an additive, a large amount of an inorganic or organic dispersant is required, and if adding a dispersant is not desirable, It may not be possible to add a solid lubricant to the lubricant, or even if it is added, separation will occur and uniform mixing will be difficult, resulting in insufficient extreme pressure properties and lubricating performance. Ta.

In order to improve the dispersibility of powdered solid lubricants, a method of adding a dispersant or modifying the surface of powdered solid lubricants has been proposed (Japanese Unexamined Patent Publication No. 112,995/1982). However, there are problems such as the manufacturing process becoming complicated [Problems to be solved by the invention] The present invention can stably disperse a powdered solid lubricant for a long period of time,
Moreover, it is an object of the present invention to provide a lubricant composition that has excellent performance as a lubricant.

[Means for Solving the Problems] The present invention provides a lubricant composition in which a powdered solid lubricant is dispersed in a base oil, in which a fused polycyclic alicyclic hydrocarbon is used as part or all of the base oil. The total of ring-constituting carbons and carbons directly bonded to the ring is 80% or more of all carbons, and hydrogen/
This is a lubricant composition using naphthenic oil having a carbon atomic ratio (H/C) of 1.65 to 1.80.

Examples of powdered solid lubricants include graphite, molybdenum disulfate, boron nitride, tungsten disulfide, graphite fluoride, polytetrafluoroethylene powder, mica, and talc. , or may be man-made. Moreover, these may be modified by grafting the surface.

The naphthenic oil used as part or all of the kite oil is a condensed polycyclic alicyclic hydrocarbon with few substituents. Such naphthenic oils are disclosed in, for example, JP-A-61-120.898.
It can be manufactured by the method described in the publication.

Examples of the raw material oil containing a condensed polycyclic aromatic compound used as a raw material include coal tar, coal tar pitch, and various coal liquefied oils that are produced as by-products during the production of steel coke.

When any of the above feedstock oils is used, when the feedstock oil is distilled, thermally cracked or hydrocracked, either the ring-constituting carbon of the aromatic compound or alicyclic compound or the carbon directly bonded to the ring More than 80% of the total carbon belongs to
It is necessary to provide a hydrocarbon oil that preferably accounts for 90% or more. If the proportion of carbon that belongs to either the ring-constituting carbon or the carbon directly bonded to the ring in the hydrocarbon oil is less than 80%, in order to obtain the lubricating base oil composition of the present invention, it is necessary to carry out nuclear hydrogenation. A step for removing the chain alkyl carbon is required afterwards, which is disadvantageous in terms of cost.

Examples of feedstock pyrolysis oil include byproduct oil during pitch coke production, and examples of hydrocracked oil include coal tar, coal tar pitch, and hydrocracked oil of coal tar oil. It is preferable that these have a boiling point range of 300 to 500'C and a 1/C of 0.60 to 1.00.

The hydrocarbon oil obtained in this way usually contains 0.0 sulfur compounds derived from the feedstock oil in terms of elemental sulfur content.
It contains 2 to 2% by weight, and 0.1 to 3% by weight of nitrogen compounds in terms of elemental nitrogen, but these sulfur and nitrogen contents are necessary to facilitate the next nuclear hydrogenation step. In order to carry out the process, it is preferably hydrorefined in the presence of a catalyst containing at least one metal component selected from Group VI or Group II metals of the periodic table, such as MOLW, Ni, and Co. Sulfur content is 1100 pp or less, nitrogen content is 1. Oo o
It is better to keep it below ppm.

Desulfurization and denitrification are performed as necessary to reduce the sulfur content to 1,100 pp or less and the nitrogen content to 1. The hydrocarbon oil refined to below OOOppm is then subjected to nuclear hydrogenation. This nuclear hydrogenation is carried out in a batch method, a flow method, preferably a flow method, in the presence of a catalyst containing at least one metal component selected from metals of group Ⅰ of the periodic table, such as Ni, pt, Ru, etc. It can be done by formula. This nuclear hydrogenation is performed until the hydrogen/carbon atomic ratio (T1/C) becomes 1.65 to 1.80.

Furthermore, in order to remove impurities remaining in the hydrocarbon oil, purification treatment by sulfuric acid washing treatment and/or solid adsorption treatment may be performed as necessary before and/or after the nuclear hydrogenation. In this case, either one of these processes may be performed, or both may be performed, and when performing both processes, the order may be arbitrary, and either one of the processes may be performed as the core. One treatment may be performed before hydrogenation, and the other treatment may be performed after nuclear hydrogenation.

The product oil produced by nuclear hydrogenation and purified by sulfuric acid washing treatment and/or solid adsorption treatment as necessary is separated into fractions with an appropriate boiling point range by distillation, preferably vacuum distillation, Alternatively, by appropriately blending the fractions thus obtained, base oils of various viscosities can be obtained.

The fraction used as this base oil is a naphthenic oil mainly composed of condensed polycyclic alicyclic hydrocarbon oil, which includes the ring-constituting carbons of the condensed polycyclic alicyclic hydrocarbons and the carbon atoms directly bonded to the rings. The total of is 80% or more, and the hydrogen/carbon atomic ratio (
H/C) needs to be 1.65 to 1.80. These can be adjusted by selecting the coal-based feedstock oil or cracked oil, by selecting the nuclear hydrogenation conditions, and further by selecting the fraction.

Since this naphthenic oil has an extremely high specific gravity, it is difficult to separate it even if a powdery solid lubricant is dispersed therein.

The base oil may be only this naphthenic oil, but depending on the specific gravity of the powdered solid lubricant, other oils may be used in combination as part of the base oil. As such oil,
It is preferable to use one or a combination of two or more selected from lubricating oils, organic solvents, synthetic resins, and the like. Here, the lubricating oils include paraffinic, naphthenic or aromatic mineral oils, olefin polymerized oils, alkylated aromatic oils, polyether oils, ester oils, halogenated hydrocarbon oils, silicone oils, fluorinated parts, and hydrogen. Examples include lubricants such as synthetic oils such as additive oils, animal and vegetable oils, solid or semi-solid paraffin, and alcohols, and greases obtained by adding soaps such as metal soaps and soapless soaps to these lubricants. Examples of organic solvents include hydrocarbons, halogenated hydrocarbons, alcohols, phenols or ethers, acids or esters, aldehydes, acetals or ketones, nitrogen-containing compounds, sulfur compounds, thinners, etc. can. In general, synthetic resins include phenols, ABS resin, acetal resin, polycarbonate resin, epoxy resin, DVB resin, furan resin,
Fluororesin, polyethylene, silicone resin, methacrylic resin, polyester resin, vinyl chloride resin, nylon,
Examples include melamine resin, acrylic resin, synthetic rubber, asphalt, pitch, and tar.

The content of the powdered solid lubricant can be changed as appropriate depending on the various properties required for the manufactured lubricant composition, and is not particularly limited, but generally O9' 1-20% by weight, preferably 0.5-10@
The amount is %. However, if necessary for greases for special purposes, it may be added up to about 70% by weight.

[Examples] The present invention will be specifically described below based on Examples and Comparative Examples.

370-470°C fraction of hydrocracked oil produced by hydrocracking coal tar pitch (H/C=0.70.N=
1000pI)m SS=5500t)pm), N
! In the presence of Mo/Al2O3 catalyst, 350-400
'C1180Kg/cut-G, SV=0.2,
Hydrogenated under the condition of G/L=1000, H/C=1°50
, N<2000ppm, 3<11)I)m purified cracked oil was obtained. Next, this was treated with white clay to reduce N<10ppm.
Then, 200'CC118 in the presence of stabilizing Ni
The naphthenic oil of the present invention was obtained by complete nuclear hydrogenation under the conditions of ON/cIi·G, 5V=0.3, and G/L=1000.

This naphthenic oil has H/C=1.72, 0.1% aromatic hydrogen, 5% hydrogen directly bonded to the ring, 10% hydrogen bonded to the alkyl group, N<1 oppm, S< 1
pl)m, average molecular ff1270.

This naphthenic oil is distilled to obtain a 300-320°C fraction (19 yield 41.4%>, a 320-345°C fraction (yield 31.0%>, a 345-365°C fraction). Rate 12.4
%) and 365-390'C fraction yield rate 15.2%)
Each fraction was obtained.

Among these fractions, the 345-390'C fraction was further divided to obtain base oils of various viscosities. These base oils and 3 for comparison
Various solid lubricants (particle size 0.1~
1.0μ) was added and dispersed in an amount of 0.5% by weight.
0. The solid lubricant was centrifuged at ooorpm for 2 hours, and the separated solid lubricant was measured to determine its proportion (% by weight).

The results are shown in Table 1.

The specific gravity of each solid lubricant used in this example is
Graphite is 2.23 and molybdenum disulfide is 4
．． 80, boron nitride is 2°27, and carbon fluoride is 2.34.

Table 1 [Effects of the Invention] The lubricant composition of the present invention has excellent dispersion stability, so it can be used stably for a long period of time. It also has excellent demulsifying properties and can be advantageously used as gear oil.

Patent applicant: Nippon Steel Chemical Co., Ltd.

Claims (1)

[Claims] In a lubricant composition formed by dispersing a powdered solid lubricant in a base oil, the sum of the ring-constituting carbons of the condensed polycyclic alicyclic hydrocarbon and the carbons directly bonded to the rings as part or all of the base oil is It is 80% or more of the total carbon, has a hydrogen/carbon atomic ratio (H/C) of 1.65 to 1.80, and has a specific gravity (15
A lubricant composition characterized by using a naphthenic oil having a temperature of 0.98 to 1.20.