JPH01217098A - Thickening agent for lubricating oil and lubricating oil - Google Patents

Abstract

PURPOSE:To obtain the subject thickening agent having high viscosity index, low low-temperature viscosity, excellent shear stability, heat resistance, oxidation resistance, load resistance and dispersibility, consisting of a carboxyl group- or acid anhydride group-containing ethylene/alpha-olefin cooligomer having specific physical properties. CONSTITUTION:The aimed thickening agent consisting of carboxyl group- or acid anhydride group-containing ethylene/alpha-olefin cooligomer having 40-10,000cst (especially preferably 200-5,000cst) kinetic viscosity at 100 deg.C and 0.1-50mgKOH /g (especially preferably 0.5-35mgKOH/g) acid value. Preferably the oligomer has 100-5,000 number-average molecular weight, <=4 Q value and 0-2 standard deviation value of ethylene composition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thickener for lubricating oil and a lubricating oil containing the same.

[Conventional technology]

As a lubricating oil with a high viscosity index and excellent shear stability and oxidation resistance, ■Kinematic viscosity at 100℃ is 40-10
0 cst polyalpha-olefin, 0 synthetic hydrocarbons with kinematic viscosity at 100°C of 1 to 10 cSt, esters with kinematic viscosity of 1 to 1 Ocst at 0100°C, and 0 essentially dispersants, antioxidants, and corrosion inhibitors.

A lubricating oil has been proposed consisting of an additive package containing at least one additive selected from the group consisting of anti-wear agents, pour point depressants, rust inhibitors, foam inhibitors and extreme pressure agents (JP-A-Sho). 59-89397).

This lubricating oil uses the above ■ and ■ as base oil, and this
This is a mixture of thickener (1) and additive (2). As the thickener (2), relatively long-chain α-olefin oligomers such as 1-octene, 1-decene, and 1-dodecene are used.

[Problem to be solved by the invention]

However, such conventional lubricating oils still do not have a high viscosity index and their viscosity is highly dependent on temperature, so if they are designed to maintain high-temperature viscosity at a certain value, their low-temperature viscosity will increase and their viscosity will also increase. The problem was that it was small.

Furthermore, the conventional lubricating oils described above do not have sufficient load-bearing performance, so it is necessary to use extreme pressure agents.

Due to poor dispersibility, there was a problem in that it became cloudy when a lateral pressure agent was used.

An object of the present invention is to provide a lubricating oil thickener and lubricating oil for solving the above problems.

Another object of the present invention is to provide a lubricating oil thickener with excellent thickening properties.

Still another object of the present invention is to obtain a lubricating oil that has a high viscosity index, low low-temperature viscosity, excellent shear stability, heat resistance, and oxidation resistance, and excellent load-bearing performance and dispersibility. An object of the present invention is to provide a thickener for a lubricant and a lubricant containing the same.

[Means to solve the problem]

This invention relates to the following lubricating oil thickener and lubricating oil.

(1) Kinematic viscosity at 100°C is 40 to 10,000c
A thickener for lubricating oils comprising a carboxyl group- or acid anhydride group-containing ethylene/α-olefin co-oligomer having St and an acid value of 0.1 to 50 gKOH/g.

(2) (A) Kinematic viscosity at 100°C is 40-1O
OOOcSt.

and one or more thickeners selected from carboxyl group- or acid anhydride group-containing ethylene/α-olefin cooligomers having an acid value of 0.1 to 50+agKOH/g, and (B) 1
Mineral oil with a kinematic viscosity of 1 to 20 cSt at 00°C.

A lubricating oil containing one or more base oils selected from synthetic hydrocarbon oils and esters.

The lubricating oil thickener of the present invention has a kinematic viscosity of 40 to 10,000 cSt at 100°C, preferably 100 to 8,000 cSt.
cSt.

Particularly preferably 200 to 5000 cSt and an acid value of 0
．． 1 to 50 gKOH/g, preferably 0.2 to 40 gKOH/g, particularly preferably 0.5 to 35 mgKOH
/g carboxyl group- or acid anhydride group-containing ethylene/α
- consists of olefin cooligomers.

Such a carboxyl group- or acid anhydride group-containing ethylene/α-olefin cooligomer preferably has a number average molecular weight (Mn) of 1000 to 5000, more preferably 1000 to 5000, as measured by gel permeation chromatography (GPC). 1500-4500, most preferably 200
0 to 4000, Q value (weight average molecular weight/number average molecular weight...molecular weight distribution) measured by GPC is preferably 4
Below, it is more preferably 3.5 or less, most preferably 3 or less.

The above carboxyl group or acid anhydride group-containing ethylene/α-
Olefin cooligomers are obtained by graft-modifying or oxidatively modifying unmodified ethylene/α-olefin cooligomers with carboxylic acids or their anhydrides.

The unmodified ethylene/α-olefin cooligomer usually contains 20 to 80 mol% of ethylene component units, preferably 30 to 70 mol%, particularly preferably 40 to 60 mol%, and 20 to 80 mol% of α-olefin component units. The number average molecular weight (
Ml+1) is usually 1000 to 10000, preferably 1
300-5000, particularly preferably 1600-4500
A transparent liquid low molecular weight ethylene/α-olefin copolymer with a Q value measured by GPC of usually 4 or less, preferably 3.5 or less, particularly preferably 3.0 or less is preferred. When the value is within the above range, the shear stability will be particularly good and the weight loss due to volatilization of the composition will be reduced.

The standard deviation value σ of the ethylene composition of this ethylene/α-olefin cooligomer is usually O~3, preferably O~2,
The standard deviation value σ of the ethylene composition of the ethylene/α-olefin cooligomer, which is particularly preferably in the range of O to 1, is determined by solvent extraction of the oligomer using acetone/hexane mixed solvents having different mixing ratios; Divided into 5 fractions with different compositions, the ethylene composition of the ethylene/α-olefin cooligomer in each fraction was analyzed by IR.
It is determined by analysis and calculated according to the following formula using the ethylene composition and weight fraction of each fraction. The larger the standard deviation value σ of the ethylene composition, the wider the composition distribution.

100=ΣEiWi/ΣWi In the above formula, Ei represents the ethylene composition of the i fraction, 1wi represents the weight fraction of the i fraction, and E represents the average ethylene composition of the copolymer.

When the standard deviation value σ of the ethylene composition is within the above range, the lubricating oil obtained will be transparent and have an excellent appearance, and will also have good thermal stability.

In the present invention, kinematic viscosity is measured according to JIS K2283. In addition, the ethylene content in the ethylene/α-olefin cooligomer is measured by C-NMR analysis.The number average molecular weight is measured using a standard substance with a known molecular weight (
measured by pre-calibrated GPC using monodisperse polystyrene and squalane). In addition, the Q value was determined using a standard material with a known molecular weight (monodisperse polystyrene, My 50G
~840
A correlation diagram (calibration curve) of lume) is created, a GPC pattern of the sample is taken using the GPC method, the molecular weight is determined from the calibration curve, and then the Q value is calculated.

The α-olefin component units that are the constituent components of the ethylene/α-olefin cooligomer include propylene,
1-butene, l-pentene, l-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, l-tetradecene,
Examples include α-olefins having 3 to 20 carbon atoms such as l-hexadecene and 1-octadecene,
A mixed component of two or more of these α-olefins may be used.

The method for producing the ethylene/α-olefin cooligomer involves continuous copolymerization of ethylene and α-olefin in a liquid phase in the presence of hydrogen using a catalyst formed from a soluble vanadium compound and an organoaluminum compound. At that time, the vanadium compound concentration in the polymerization system was adjusted to liquid phase I.
There is a method in which the vanadium compound is diluted in the polymerization medium to a concentration of 5 times or less than the concentration of the vanadium compound in the polymerization system, and the vanadium compound is supplied to the polymerization system at 0.3 mmol or more per Q.

Vanadium compounds include VOCl3, VO(QC,
H5) C1,,VO(OC,H,),,,C1,,,,
General formula VO(OR)nX, n or vx such as VCl4
4 (Kokote R is an aliphatic hydrocarbon group, X is a halogen, O≦
n≦3. ) can be used. In addition, as an organoaluminum compound, (C,H,)IAl
, (C,H,)IAICI, (CJs)x, 1AIC
1t, s-(igO-CJJz, 5AIC1t, s.

(CJs)AlCl2. General formula R of these mixtures etc.
", ALX13-, (::: teR' is an aliphatic hydrocarbon group, xl is a halogen, and 1≦m≦3) can be used.

Hydrocarbons such as pentane, hexane, heptane, kerosene, cyclohexane, toluene can be used as polymerization medium. The concentration of vanadium compound in the liquid phase is 0.3 mmol/Q or more, preferably 0.5 to 20 mmol/Q,
In addition, the organoaluminum compound concentration is Al/V (atomic ratio)
may be in the range of 2 to 50, particularly 3 to 20.

The copolymerization temperature is 0 to 100°C, especially 20 to 80°C, and the polymerization pressure is 0 to 50 kg/aJ (gauge pressure), especially 0 to 30
kg/d (gauge pressure), average residence time is 5 to 300 minutes,
In particular, polymerization conditions such as 10 to 250 minutes may be adopted.

Carboxyl group- or acid anhydride-containing ethylene of the present invention/
The α-olefin cooligomer can be obtained by graft modification or oxidative modification of the above unmodified ethylene/α-olefin cooligomer.

The first type of graft-modified ethylene/α-olefin cooligomer used as a thickener in the present invention is obtained by graft-modifying the ethylene/α-olefin cooligomer with an unsaturated fatty acid or anhydride thereof.

Specific examples of unsaturated fatty acids or anhydrides thereof used for graft modification include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, and bicyclo[2,2,1]hept- 2-
Unsaturated carboxylic acids such as ene-5,6-dicarboxylic acid, as well as maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, bicycloj2.2.
Examples include anhydrides of unsaturated carboxylic acids such as 11hept-2-ene-5,6-dicarboxylic anhydride.

Such graft modification with an unsaturated carboxylic acid or anhydride is carried out in an amount such that the acid value falls within the above range.

Graft modification can be performed by a method known per se,
For example, it can be carried out in accordance with the method disclosed in Japanese Patent Application Laid-Open No. 57-123205.

The second type of oxidatively modified ethylene/α-olefin cooligomer is obtained by oxidizing the unmodified ethylene/α-olefin cooligomer using a monomolecular oxygen-containing gas and/or an ozone-containing gas.

In this case, the oxygen-containing functional groups formed by oxidation include, in addition to carboxyl groups, oxycarbonyl groups (ester bonds), formyl groups, carbonyl groups, hydroxyl groups, and the like.

In addition, molecular oxygen-containing gases used for oxidative modification include:
In addition to oxygen, air, and the like, a mixed gas in which oxygen is diluted to an appropriate concentration with an inert gas such as nitrogen, argon, or carbon dioxide can be used.

Examples of ozone gas include ozone and mixed gases of ozone and oxygen or air, as well as mixed gases obtained by diluting ozone and/or oxygen or air to an appropriate concentration with an inert gas such as nitrogen, argon, or carbon dioxide. can do. Examples of ozone-containing gases include ozone and mixed gases of ozone and oxygen or air, as well as mixtures of ozone and/or oxygen or air appropriately diluted with an inert gas such as nitrogen, argon, or carbon dioxide. can do.

Specific examples of the inert hydrocarbon medium that may be used in the oxidation reaction include pentane, hexane, heptane, octane, decane, dodecane, kerosene, light oil, benzene, toluene, and xylene.

The oxidation of the unmodified ethylene/α-olefin cooligomer is usually carried out in the absence of a catalyst, but it may also be carried out in the presence of a radical initiator or an oxidation catalyst. , benzoyl peroxide,
Ditertiary-butyl peroxide, tertiary-butyl hydroperoxide, dicumyl peroxide, 2,5
-Dimethyl-2゜5-di(peroxybenzoate)hexene-3 and other organic peroxides can be exemplified, and specific examples of fluorination catalysts include cobalt acetate, manganese chloride, copper, nickel oxide, manganese dioxide, and naphthene. Examples include inorganic compounds such as cobalt acid.

The temperature during the above oxidation reaction is preferably 100 to 250°C.
Preferably 120 to 230°C, particularly preferably 130°C
The temperature is 10 minutes to 20 hours, preferably 30 minutes to 10 hours. This oxidation reaction may be carried out under either normal pressure or elevated pressure. By treating the mixture after the oxidation reaction by a conventional method, an oxidatively modified ethylene/α-olefin cooligomer can be obtained.

The thickener for lubricating oil of the present invention is obtained at 100°C.
It consists of a carboxyl group- or acid anhydride group-containing ethylene/α-olefin cooligomer having a kinematic viscosity of 40 to 10,000 cSt and an acid value of 0.1 to 50 mgKOH/g.

Next, the lubricating oil of the present invention contains, as component (A), one or more thickeners selected from the above carboxyl group- or acid anhydride group-containing ethylene/α-olefin co-oligomers, and (B
) component has a kinematic viscosity of 1 to 20 cS at 100°C.
It is a lubricating oil containing one or more base oils selected from mineral oil, synthetic hydrocarbon oil, and ester.

The base oil of component (B) used in the present invention is heated to 100°C.
The kinematic viscosity at is 1 to 20 cSt, preferably 3 to 10 cSt.
cSt mineral oil 1 Synthetic hydrocarbon oils or (and) esters that are conventionally used can be used 1 For example, mineral oils with a kinematic viscosity of 1 to 20 cSt at 100°C include paraffinic, naphthenic or naphthenic oils. Examples include mixed paraffinic/naphthenic type solvent-refined or acid-refined mineral lubricating oils.

Examples of synthetic hydrocarbon oils having a kinematic viscosity of 1 to 20 cSt at 100°C include α-olefin oligomers, alkylbenzenes, and alkylnaphthalenes, and these may be used alone or in combination of two or more.

Among these, α-olefin oligomer.

Low molecular weight oligomers of α-olefins consisting of cm (octene) to C1 (dodecene) or mixtures of these olefins can be used. Low viscosity α-olefin oligomers can be produced by Ziegler catalysis, thermal polymerization, free radical catalyzed polymerization, or polymerization using BF as a catalyst. These polymerization methods are described, for example, in US Pat. No. 4,045,508.

As alkylbenzenes and alkylnaphthalenes,
These alkylbenzenes or alkylnaphthalenes are prepared by the Friedel-Kraff alkylation of benzene or naphthalene with olefins; these alkylbenzenes or alkylnaphthalenes are usually predominantly dialkylbenzenes or dialkylnaphthalenes with an alkyl chain length of 6 to 14 carbon atoms. be. The alkylated olefins used in the production of alkylbenzenes or alkylnaphthalenes may be linear or branched olefins or combinations thereof; methods for their production are described, for example, in U.S. Pat. No. 3,909,432. ing.

Low-viscosity esters having a kinematic viscosity of 1 to 20 cSt at 100°C include, for example, monoesters produced from dibasic acids such as pelargonic acid and alcohol; dibasic acids and alcohols, or diols and dibasic acids or Diesters produced from acid mixtures; produced by reacting diols, triols (e.g. trimethylolpropane), tetraols (e.g. pentaerythritol), hexaols (e.g. dipentaerythritol), etc. with dibasic acids or acid mixtures. Examples include polyol esters. Examples of these esters include tridecylbelargonate, di-2-ethylhexyl adipate,
Examples include di-2-ethylhexyl azelate, trimethylolpropane triheptanoate, and pentaerythritol tetraheptanoate.

The lubricating oil of the present invention usually contains 0.2 to 50 parts by weight of component (A), preferably 5 to 40 parts by weight of component (B), and 5 parts by weight of component (B).
It preferably contains 0 to 99.8 parts by weight, preferably 60 to 95 parts by weight, and the blending ratio of component (A) and component (B) is set so that the kinematic viscosity of the composition becomes a predetermined value.

When the blending ratio of component (A) and component (B) is within the above range, shear exchangeability is excellent and the viscosity index is high.

An economical lubricating oil composition with low low-temperature viscosity, excellent load-bearing performance and dispersibility can be obtained.

In addition to the above-mentioned components, the lubricating oil of the present invention may contain other components such as various additives. Examples of additives that can be blended include neutral and basic sulfonates and phenates (metal salt type).
Detergents such as succinimide.

Dispersants such as esters and benzylamine, copolymerized polymers (ashless type); pour points of condensates of chlorinated paraffin and naphthalene or phenol, polyalkyl acrylates and methacrylates, polybutene, polyalkylstyrene, polyvinyl acetate, etc. Depressants: Antioxidants such as zinc thiophosphate and trialkylphenols; sulfuric acid, sulfonic acid and phosphate esters, fatty acid derivatives, amine derivatives.

Emulsifiers such as quaternary ammonium salts and polyoxyethylene activators; demulsifiers such as quaternary ammonium salts, sulfated oils, and phosphate esters; mold prevention agents such as phenolic compounds, formaldehyde donor compounds, salicylanilide compounds, etc. anti-stinting agents; anti-chatter agents; anti-squake agents; and lateral pressure agents such as sulfur-sulfur-based agents.

Although the load-bearing performance is excellent even if the lateral pressure agent is not added, it may be used in combination.

The lubricating oil of the present invention is obtained by mixing the components (A) and (B) and other components blended as necessary. It can be used in the same way, and is particularly suitable for use in automobile or industrial gear oil; hydraulic oil for automobiles, aircraft, robots, molding machines, etc.; engine oil, etc.

The thickener for lubricating oil of the present invention has high thickening properties, and a lubricating oil with excellent properties can be obtained with a small amount of thickener used.

The lubricating oil of the present invention has the following characteristics.

(1) High viscosity index.

A lubricating oil with a high viscosity index has a lower viscosity at -40°C, that is, a lubricating oil with less temperature dependence of viscosity, than a lubricating oil with a low viscosity index that has the same viscosity at 100°C.

(2) Low temperature viscosity.

In particular, it has a low low-temperature viscosity under high shear rates (excellent cranking properties), excellent low-temperature startability of engine oil, and can reduce energy loss.

(3) Excellent shear stability.

When various thickeners (e.g., olefin copolymer type, polymethacrylate type, etc.) are used in place of the carboxyl group- or acid anhydride group-containing ethylene/α-olefin cooligomer that constitutes the lubricating oil of the present invention, the viscosity increases over time. However, this composition has extremely excellent shear stability, and conversely has a thickening effect when sheared.

(4) Excellent load-bearing performance.

Therefore, it has excellent load-bearing performance even without using a lateral pressure agent.

(5) Excellent dispersion performance.

In the crankcase oil of gasoline and diesel engines, additives such as detergents and dispersants are used in combination to stably disperse sludge generated by incomplete combustion of fuel or oxidation of lubricating oil into the oil in the form of fine particles. The lubricating oil has excellent dispersion performance even without the use of a detergent 1 dispersant. This performance is not found in conventional α-olefin oligomers and ethylene/α-olefin cooligomers, and it is expected that the use of dispersants during product formulation will be reduced and even better dispersion performance will be achieved through synergistic effects with these dispersants. can. Further, when an extreme pressure agent is used, conventional products become cloudy, but the lubricating oil of the present invention does not become cloudy even when a lateral pressure agent is used.

〔Effect of the invention〕

Since the lubricating oil thickener of the present invention has high thickening properties, excellent lubricating oil can be obtained with a small amount of use.

Furthermore, since the lubricating oil of the present invention contains the above-mentioned thickener, it has a high viscosity index, low low-temperature viscosity, shear stability, heat resistance,
In addition to oxidation resistance, it has excellent load-bearing performance and dispersibility.

[Examples] Examples of the present invention will be described below.Measurement methods in the present invention are shown in Table 1.

Example 1 Niletin/propylene co-oligomer A (ethylene composition 4
9 mol%, 100°C kinematic viscosity 102 cSt, Mn 124
0, Q value 1.74. σ value of 0.1 or less) was heated at 160°C in a nitrogen atmosphere, and while stirring, 6.25 parts by weight of maleic anhydride as a modifier was added, and di-tert-butyl as an initiator was added from another nozzle. 1.25 parts by weight of peroxide was added dropwise over 5 hours. Then 18
Unreacted maleic anhydride was removed under vacuum at 0°C to obtain a thickener consisting of a maleic acid-modified ethylene/propylene co-oligomer.

Table 2 shows the physical properties of the thickener obtained.

Example 2 Ethylene/propylene co-oligomer B (ethylene composition 5
5 mol%, 100°C kinematic viscosity 576 cSt, Mn 19
50, Q value 2.3, σ value 0.1 or less) A thickener consisting of a maleic acid-modified ethylene/propylene co-oligomer was obtained in the same manner as in Example 1 except that 100 parts by weight was used.

Table 2 shows the physical properties of the thickener obtained.

Example 3 100 parts by weight of the ethylene/propylene co-oligomer B used in Example 2 was added to a glass reaction vessel equipped with a stirrer (operating capacity: 1.5
0) and heated to 150°C while stirring at a rotational speed of 11,000 rpm.
The air was blown from the air blowing tube at a rate of 1/hr for 8 hours. After that, the blowing of air is stopped, and nitrogen is instead blown into the nitrogen blowing pipe while cooling to room temperature. & A chemically modified ethylene/propylene cooligomer thickener was obtained.

Table 2 shows the physical properties of the thickener obtained.

Examples 4 to 6 Hydrogenation of maleic acid-modified ethylene/propylene cooligomer of Example 1, maleic acid-modified ethylene/propylene cooligomer of Example 2, oxidation-modified ethylene/propylene cooligomer of Example 3, and 1-decene oligomer Things PA
A lubricating oil was obtained by mixing O-4 (manufactured by Gulf Corporation, 5ynfluid 4cS, trade name, kinematic viscosity at 100°C: 3.7 cSt, viscosity index: 124) at 100°C for 30 minutes at the ratio shown in Table 3. evaluated.

Example 7 In Example 5, instead of PAO-4, diisodecyl azelate (manufactured by Otona Kagaku Co., Ltd., trade name, kinematic viscosity at 100°C 3.5 cSt, viscosity index 138) was mixed in the proportions shown in Table 3 and evaluated. did.

Example 8 In Example 4, mineral oil 100 neutral oil (manufactured by Fuji Kosan Co., Ltd., kinematic viscosity at 100° C., 40 cSt, viscosity index 102) was mixed in the ratio shown in Table 3 for evaluation.

Comparative Examples 1-2 Ethylene/propylene cooligomer B, ethylene/propylene copolymer (ethylene 60 mol, Mn 65000
, Q value 1.51, [η]1. OdQ/g) type viscosity index improver (hereinafter abbreviated as ■) and PAO-4 were mixed in the proportions shown in Table 3 and evaluated.

The above results are summarized in Table 3.

Examples 9-10. Comparative Example 3 A lubricating oil was prepared and evaluated using the maleic acid-modified ethylene/propylene cooligomer of Example 2, the oxidation-modified ethylene/propylene cooligomer of Example 3, and the ethylene/propylene cooligomer B at the ratios shown in Table 4. . However, the extreme pressure agent is Angramol 99 (manufactured by Nippon Lubrizol Co., Ltd.,
(product name) was used.

The above results are summarized in Table 4.

Example 11. Comparative Example 4 Maleic acid-modified ethylene/α-olefin cooligomer and ethylene/propylene cooligomer B of Example 2
were prepared and evaluated under the conditions shown in Table 5.

The above results are summarized in Table 56.

Claims (3)

[Claims] (1) Kinematic viscosity at 100℃ is 40 to 10,000cS
A lubricating oil thickener comprising a carboxyl group- or acid anhydride group-containing ethylene/α-olefin co-oligomer having t and an acid value of 0.1 to 50 mgKOH/g. (2) (A) Kinematic viscosity at 100°C is 40 to 1000
0 cSt and one or more thickeners selected from carboxyl group- or acid anhydride group-containing ethylene/α-olefin co-oligomers having an acid value of 0.1 to 50 mgKOH/g; (B) a kinematic viscosity at 100°C of 1; A lubricating oil containing one or more base oils selected from ~20 cSt mineral oil, synthetic hydrocarbon oil, and ester. (3) The lubricating oil according to claim (2), containing 0.2 to 50 parts by weight of component (A) and 50 to 99.8 parts by weight of component (B).