JPH0559119A - Imido group-containing low-molecular weight ethylene copolymer, its production and use - Google Patents

Abstract

PURPOSE:To obtain the title copolymer capable of giving excellent cleanliness, shear stability and thermal stability when formulated in e.g. lubricating oils by graft copolymerization of a unsaturated dicarboxylic anhydride to a liquid ethylene-based random copolymer followed by reaction with an amino compound. CONSTITUTION:Firstly, a unsaturated dicarboxylic anhydride and radical polymerization initiator are added over a period of 2-20hr at 150--200 deg.C to a liquid ethylene-based random copolymer 1500-5000 in number-average molecular weight in a molten state to carry out graft copolymerization so as to be one to two molecules of the anhydride per molecule of the random copolymer to produce a graft-modified copolymer. Thence, an amino compound having a combination of primary amino group and at least one group selected from tertiary amino group and hydroxyl group etc. is added to the graft-modified copolymer to make a reaction of the primary amino group with the unsaturated dicarboxylic anhydride group, thus giving the objective copolymer capable of giving excellent cleanliness, shear stability and thermal stability when formulated in lubricating oils.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an imide group-containing low molecular weight ethylene copolymer, a method for producing the same, and an engine oil composition and a gear oil composition prepared by blending the copolymer. Especially when added to industrial gear oils, automobile engine oils, automobile gear oils, refrigerating machine lubricating oils, rolling lubricating oils, etc., where the requirements for cleanliness and shear stability have become more stringent than before. A low molecular weight ethylene copolymer having an imide group as a useful novel compound that can be imparted to give a composition having excellent shear stability, a method for producing the same, and an engine oil composition prepared by blending the copolymer. And to provide a gear oil composition.

[0002]

2. Description of the Related Art Conventionally, polybutenyl succinimide-based additives are used as ashless detergents for automobile engine oils, and ethylene copolymers and alkyl acrylates having a molecular weight of tens of thousands or more are used as viscosity index improvers. Ester polymers, methacrylic acid alkyl ester polymers and the like have been used. However, as the performance of automobile engines has increased, engine oils having higher temperature and longer-term lubricity and clean dispersibility have been required. In order to meet such requirements, engine oils having even better cleanliness and shear stability are required.

Further, the gear oil is used in severe environments regardless of whether it is used for automobiles or industrial use. Accordingly, there has been a demand for gear oils having excellent cleanliness and shear stability. Similar to engine oils, gear oils are conventionally viscosity improvers such as polybutenyl succinimide-based detergents and ethylene copolymers with a molecular weight of tens of thousands or more, acrylic acid alkyl ester polymers, and methacrylic acid alkyl ester polymers. Combinations have been used, but are insufficient to meet the demands of the harsh environment of use. Therefore, there has been a demand for a gear oil having more excellent cleanliness and shear stability.

Therefore, various additives have been proposed which are added to these lubricating oils to improve cleanliness and shear stability. For example, JP-A-54-95604 discloses that an olefin copolymer is graft-polymerized with maleic anhydride,
Further, it has been proposed to use a graft polymer obtained by reacting a polyamino compound as a detergent-dispersion type viscosity index improver. Further, Japanese Patent Publication No. 54-21392 discloses a succinimide derivative of an ethylene / α-olefin copolymer.

[0005]

However, the substances described in the above publications or the products obtained by the production method are still insufficient in detergency and shear stability even if they are added to lubricating oils. However, due to insufficient shear stability, it has not been possible to meet the severe demands for lubricating oils in recent years.

Accordingly, the first object of the present invention is to provide an imide group-containing low molecular weight ethylene copolymer which can be added to a lubricating oil to impart excellent detergency and shear stability. A second object is to provide a lubricating oil composition having excellent cleanliness and shear stability by adding the copolymer, and further imparting a viscosity index having extremely excellent shear stability to the lubricating oil. By doing so, it is to provide a more excellent engine oil composition and gear oil composition.

[0007]

In order to solve the above problems, the present invention has a number average molecular weight of 1,500 to 5,
000 substantially colorless and transparent liquid ethylene-based random copolymer (A) is copolymerized with an unsaturated dicarboxylic acid anhydride,
Average 1 per molecule of ethylene-based random copolymer (A)
Graft-modified copolymer (B) containing not less than 2 molecules and less than 2 molecules of an unsaturated dicarboxylic acid anhydride group, a primary amino group, and at least one group selected from a tertiary amino group and a hydroxyl group. The present invention provides an imide group-containing low molecular weight ethylene copolymer obtained by reacting an amino compound (C) containing

The substantially colorless and transparent liquid ethylene-based random copolymer (A) has a number average molecular weight of 1,800 to 4,
Ethylene, the ethylene composition is in the range of 45 to 65 mol%, the molecular weight distribution is 3 or less, the pour point is 20 ° C. or less, and the iodine value is 1.5 or less.
It is preferably a propylene random copolymer.

The unsaturated dicarboxylic acid anhydride group contained in the imide group-containing low molecular weight ethylene copolymer has an average chain length in the range of 1.0 to 1.3, or the amino compound (C) is More preferred is 3- (aminomethyl) pyridine.

In the present invention, the liquid ethylene-based random copolymer (A) is added with the unsaturated dicarboxylic acid anhydride and the radical polymerization initiator in a molten state at a temperature of 150 to 200 ° C. for 2 to 20 hours. The imide group-containing low content of the imide group-containing copolymer (B) obtained by graft-copolymerizing on average one molecule or more and less than 2 molecules per molecule of the liquid ethylene random copolymer (A) It also provides a method for producing a molecular weight ethylene copolymer.

The present invention further has a kinematic viscosity at 100 ° C. of 3 to 2.
To 100 parts by weight of base oil (D) consisting of 0 cSt mineral oil and / or synthetic oil, a viscosity modifier (E) consisting of mineral oil and / or synthetic oil having a kinematic viscosity of 15 to 35 cSt at 100 ° C. is 5 to 200. 0.5 to 2 parts by weight of a viscosity index improver (F) made of an ethylene-based random copolymer having a number average molecular weight of 2,000 to 10,000.
An engine oil composition comprising 0 part by weight and 0.1 to 20 parts by weight of the imide group-containing low molecular weight ethylene copolymer is provided.

Further, the present invention has a kinematic viscosity at 100 ° C. of 2 to 4.
The number average molecular weight is 1,500 per 100 parts by weight of the base oil (G) consisting of 0 cSt mineral oil and / or synthetic oil.
To 0.5 to 100 parts by weight of a viscosity index improver (H) comprising a liquid ethylene-based random copolymer of 0.1 to 10,000 and 0.1 to 100 parts by weight of the imide group-containing low molecular weight ethylene copolymer. A gear oil composition comprising the above is provided.

The present invention will be described in detail below.

The substantially colorless and transparent liquid ethylene-based random copolymer (A) constituting the imide group-containing low molecular weight ethylene copolymer of the present invention is ethylene and α having 3 to 20 carbon atoms.
A random copolymer with olefins. Examples of the α-olefin having 3 to 20 carbon atoms include propylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1, decene-1, undecene-1, dodecene-.
1, tridecene-1, tetradecene-1, pentadecene-1, hexadecene-1, heptadecene-1, octadecene-1, nonadecene-1, eicosene-1 and the like can be exemplified. In the present invention, the liquid ethylene-based random copolymer (A) contains 1 part of these α-olefins.
The seeds may be used alone or in combination of two or more. Of these, α-olefins having 3 to 20 carbon atoms are preferable, and propylene is particularly preferable. As the ethylene-based random copolymer, the ethylene / propylene copolymer gives good low-temperature viscosity characteristics, thermal stability and a high viscosity index,
Particularly preferred.

The liquid ethylene random copolymer (A) has a substantially transparent appearance and gives a lubricating oil composition having good low temperature viscosity characteristics, and has good solubility in a base oil. And the like, the ethylene content is 45 to 6
It is preferably in the range of 5 mol%, particularly 48 to 60 mol%.

The number average molecular weight of the liquid ethylene random copolymer (A) is blended with a lubricating oil such as engine oil or gear oil to improve the viscosity index, and a lubricating oil composition having excellent shear stability is obtained. 1,500 to 5,000 in points obtained
It is preferably in the range of 0, preferably 1,800 to 4,000.

Further, the molecular weight distribution (weight average molecular weight / number average molecular weight) of the liquid ethylene random copolymer (A) of the present invention shows that the obtained imide group-containing ethylene copolymer has good solubility in lubricating oil. In order to have excellent shear stability, it is preferably 3 or less, and further 2.8.
The following is more preferable.

The liquid ethylene random copolymer (A) of the present invention has a pour point of 20 ° C. or lower in that an imide group-containing low molecular weight ethylene copolymer having excellent low-temperature fluidity and good handling property can be obtained. The temperature is preferably 15 ° C. or lower.

The liquid ethylene random copolymer (A) preferably has an iodine value of 1.5 or less from the viewpoint that an imide group-containing low molecular weight ethylene copolymer excellent in oxidation stability can be obtained. Further, it is preferably 1.2 or less.

The substantially colorless and transparent liquid ethylene-based random copolymer used in the present invention uses, for example, a Ziegler catalyst composed of a soluble vanadium compound or a soluble titanium compound and an organic aluminum compound, for example, Japanese Patent Publication No. 2-1163. It can be produced by selecting the conditions using the method described in the publication and, if necessary, combining hydrogenation reactions. It can also be produced by subjecting a product obtained by polymerization using a catalyst composed of a zirconium compound and an alumoxane to a hydrogenation reaction, if necessary.

In the present invention, the above-mentioned liquid ethylene random copolymer (A) is graft-copolymerized with an unsaturated dicarboxylic acid anhydride to produce a graft-modified copolymer (B).

Examples of the unsaturated dicarboxylic acid anhydride used include maleic anhydride, itaconic anhydride, citraconic anhydride and the like. Of these, maleic anhydride is preferred because it gives a product of uniform quality in high yield.

The graft-modified copolymer (B) is produced by graft-copolymerizing the liquid ethylene random copolymer (A) with an unsaturated dicarboxylic acid anhydride in a molten state in the presence of a radical polymerization initiator. , For example, Japanese Patent Publication No. 1-3452
It can be manufactured by the method described in Japanese Patent Publication No. At this time, the reaction temperature is 150 to 200 ° C., preferably 160.
To 180 ° C., and the reaction time is 2 to 50 hours, preferably 3 to 10 hours. The addition time of the acid anhydride and the radical initiator is in the range of 2 to 20 hours, preferably 3 to 5 hours.

Here, the molten state means a solventless reaction state, and when the reaction is carried out in the molten state, the graft-modified copolymer (B) is efficiently prepared without graft reaction of the unsaturated dicarboxylic acid anhydride with the solvent. The amount of unsaturated dicarboxylic acid anhydride groups therein is preferably 1 molecule or more and less than 2 molecules per 1 molecule of the ethylene random copolymer (A), which is preferable. When the reaction time is less than 2 hours and the reaction temperature is less than 150 ° C., the chain length of the grafted unsaturated dicarboxylic acid anhydride becomes long.

In the graft-modified copolymer (B) thus obtained, the content of the unsaturated dicarboxylic acid anhydride group, that is, the graft amount is such that the graft-modified copolymer (B) has an appropriate viscosity and contains an imide group excellent in workability and anti-emulsification property. In terms of obtaining a low molecular weight ethylene copolymer, an ethylene-based random copolymer (A) on average
The number of unsaturated dicarboxylic acid anhydride groups (hereinafter referred to as graft copolymerization units) is 1 molecule or more and less than 2 molecules per molecule. The graft copolymerized units in the graft modified copolymer (B) are grafted as an unsaturated dicarboxylic acid anhydride group onto the ethylene-based random copolymer (A) which is the main chain. When it is less than 1 molecule, the detergency effect is insufficient, and when it is 2 molecules or more, detergency is adversely affected, which is not preferable.

For example, when maleic anhydride is used as the unsaturated dicarboxylic acid anhydride, it forms a succinic anhydride group, and its chain length has an appropriate viscosity and is excellent in workability. From the viewpoint of obtaining an imide group-containing low molecular weight ethylene copolymer excellent in compatibility with lubricating oil, anti-emulsification property and detergency, it is in the range of 1.0 to 1.3, preferably 1.0 to 1.2. The range is. If it is out of this range, the low-temperature fluidity is lowered and the cleanability is further lowered, which is not preferable.

Next, in the present invention, the graft modified copolymer (B) obtained as described above contains a primary amino group and at least one group selected from a tertiary amino group and a hydroxyl group. And an unsaturated dicarboxylic acid anhydride group of the graft-modified copolymer are reacted with a primary amino group.

Specific examples of the amino compound (C) having both the above-mentioned primary amino group and at least one group selected from a tertiary amino group and a hydroxyl group include, for example, 2
-Aminopyridines such as -aminopyridine, 3-aminopyridine, 4-aminopyridine, 2-amino-4,6-dimethylpyridine; 2- (aminomethyl) pyridine, 3
Aminomethylpyridines such as-(aminomethyl) pyridine and 4- (aminomethyl) pyridine; 1-aminopiperidine, 1-amino-2,6-dimethylpiperidine,
Piperidines such as 2,2,6,6-tetramethyl-4-aminopiperidine and N- (2,2,6,6-tetramethyl-4-piperidyl) -N-aminoxamide; 4-
Morpholines such as aminomorpholine, 4- (2-aminoethyl) morpholine and 4- (3-aminopropyl) morpholine; 1- (2-aminoethyl) piperazine, 1-amino-4- (2- (Hydroxyethyl) piperazine and other piperazines: monoethanolamine, 2-
Examples include alcohol amines such as (aminoethoxy) ethanol, isopropanolamine, and dimethylaminopropylamine. These can be used alone or in combination of two or more.
Among these, aminomethylpyridines and piperidines are preferable, and 3- (aminomethyl) pyridine is particularly preferable, from the viewpoint of obtaining an imide group-containing low molecular weight ethylene copolymer having more excellent detergency.

In the production of the imide group-containing low molecular weight ethylene copolymer, the amount of the amino compound used is 1 to 1.5 molecules per 1 molecule of the unsaturated dicarboxylic acid group contained in the graft modified copolymer (B). The amount is preferably such that

The unsaturated dicarboxylic acid anhydride group of the graft-modified copolymer (B) is reacted with the primary amino group of the amino compound to form an imide group. For example, a graft-modified copolymer may be used. Amino compound is added to (B) and heated, nitrogen bubbling and / or
Examples include a method of connecting to a reduced pressure system. At this time, the reaction temperature is about 100 to 200 ° C., and the reaction time is about 2 to 20 hours. The reaction atmosphere is preferably an atmospheric pressure or a reduced pressure in an inert gas atmosphere.

The imide group-containing low-molecular-weight ethylene copolymer obtained by the above method is blended with a base oil comprising a mineral oil and / or a synthetic oil to obtain a lubricating oil composition excellent in detergency and shear stability. You can get things. Examples of such lubricating oil include engine oil for automobiles, gear oil for automobiles, gear oil for industry, and the like, and they are also suitable as various lubricating oils such as lubricating oil for refrigerators and lubricating oil for rolling.

The engine oil composition of the present invention comprises a base oil (D).
100 parts by weight of a mineral oil and / or a synthetic oil having a kinematic viscosity of 100 ° C. of 3 to 20 cSt is used as a viscosity adjusting agent (E) having a kinematic viscosity of 15 to 35 c of 100 ° C.
5 to 200 parts by weight of the above-mentioned mineral oil and / or synthetic oil of St, and 0.5 of an ethylene-based random copolymer having a number average molecular weight of 2,000 to 10,000 as a viscosity index improver (F). To 20 parts by weight, and 0.1% of the above-mentioned imide group-containing low molecular weight ethylene copolymer.
To 20 parts by weight.

The base oil (D) used in the engine oil composition of the present invention is not particularly limited as long as it is a base oil of a commonly used lubricating oil. Such base oils include, for example, neutral oil, bright stock, hydrogen contact refined oil,
Mineral oils such as catalytically dewaxed refined oils, α-olefin oligomers such as liquid polybutene and liquid decene oligomers, and hydrocarbon-based synthetic oils such as liquid ethylene / α-olefin cooligomers; diisooctyl adipate, diisooctyl sebacate, dilauryl sebacate And ester type synthetic oils such as polyol ester obtained by esterifying a polyol such as trimethylolpropane, pentaerythritol, and dipentaerythritol with a fatty acid. These may be used alone or in combination of two or more. Can also be used in combination.

The blending amount of the viscosity modifier (E) comprising a mineral oil and / or a synthetic oil having a kinematic viscosity at 100 ° C. of 15 to 35 cSt is such that the engine oil composition of the present invention has a viscosity suitable as an engine oil. The amount is 5 to 200 parts by weight, preferably 10 to 150 parts by weight, based on 100 parts by weight of the base oil (D).

Number average molecular weight of 2,000 to about 10,0
The viscosity index improver (F) comprising a substantially colorless and transparent liquid ethylene-based random copolymer of 00 is the liquid ethylene-based random copolymer as the starting material of the imide group-containing ethylene copolymer. It is similar to the one. The number average molecular weight is preferably in the range of 2,500 to 8,000, more preferably 3,000 to 5,000, and the resulting engine oil composition has a good viscosity index and excellent shear stability.

The ethylene composition of this ethylene-based random copolymer shows a liquid that is substantially colorless and transparent in appearance and has a uniform solubility in the above-mentioned base oil (D) of 45 to 65.
It is in the range of mol%, preferably 48 to 60 mol%.

The ethylene-based random copolymer has a molecular weight distribution (weight average molecular weight / number average molecular weight) of 3 or less, preferably 2.8 or less in view of excellent shear stability.

Further, its iodine value is 1.5 or less in that the obtained engine oil composition has excellent oxidative stability,
It is preferably 1.2 or less.

The blending amount of the viscosity index improver (F) comprising an ethylene-based random copolymer is such that the engine oil composition of the present invention has an excellent viscosity index, and further has a viscosity suitable as an engine oil. Base oil (D)
The amount is 0.5 to 20 parts by weight, preferably 1 to 15 parts by weight with respect to 100 parts by weight.

The amount of the imide group-containing low-molecular-weight ethylene copolymer of the present invention blended in the engine oil composition of the present invention is such that the engine oil composition has excellent cleanability, good low-temperature fluidity, and appropriateness. 0.1 to 20 parts by weight with respect to 100 parts by weight of the base oil (D) described above,
It is preferably 0.5 to 15 parts by weight, more preferably 1 to 10 parts by weight.

The engine oil composition of the present invention contains a lubricating oil additive, which is added to general engine oil according to preference.
For example, a detergent dispersant, a viscosity index improver other than an ethylene-based random copolymer, an oiliness agent, a pour point depressant, an antioxidant, a corrosion inhibitor, an antifoaming agent, a friction modifier, or the like, or a commercially available product containing them. A package type additive can be blended.

The gear oil composition of the present invention comprises a mineral oil having a kinematic viscosity at 100 ° C. of 2 to 40 cSt and / or a base oil (G).
Alternatively, 100 parts by weight of synthetic oil is used, and the viscosity index improver (H) has a number average molecular weight of 1,500 to 10,
Of 0.5 to 100 parts by weight of substantially colorless and transparent liquid ethylene-based random copolymer, and 0.1 to 100 parts by weight of the above-mentioned imide group-containing low molecular weight ethylene copolymer of the present invention. It is prepared by

The base oil (G) used in the gear oil composition of the present invention is not particularly limited as long as it is a base oil of a commonly used lubricating oil. Examples of such base oils include mineral oils such as neutral oil, bright stock, hydrogen-catalyzed refined oil, catalytic dewaxed refined oil, liquid polybutene, liquid decene oligomer and other α-olefin oligomers, and liquid ethylene / α-olefins. Hydrocarbon synthetic oil such as cooligomer, dibasic acid ester such as diisooctyl adipate, diisooctyl sebacate and dilauryl sebacate, polyol ester such as trimethylol propane, pentaerythritol and dipentaerythritol esterified with fatty acid The ester-based synthetic oils and the like may be used, and these may be used alone or in combination of two or more.

Number average molecular weight of 1,500 to about 10,0
The viscosity index improver (H) consisting of a substantially colorless and transparent liquid ethylene-based random copolymer of 00 is the same as the liquid ethylene-based random copolymer as a starting material of the imide group-containing ethylene copolymer. It is similar to the one. When the number average molecular weight is preferably in the range of 2,000 to 8,000, more preferably 3,000 to 5,000, the resulting engine oil composition has a good viscosity index and excellent shear stability.

The ethylene composition in the ethylene random copolymer shows a liquid that is substantially colorless and transparent in appearance, and has a uniform solubility in the above-mentioned base oil (D) of 45 to 65.
It is in the range of mol%, preferably 48 to 60 mol%.

The molecular weight distribution (weight average molecular weight / number average molecular weight) is 3 or less, preferably 2.8 or less in view of excellent shear stability.

Further, the iodine value is 1.5 or less, preferably 1.2 or less, from the viewpoint that the obtained gear oil composition has excellent oxidation stability.

In the present invention, the blending amount of the viscosity index improver (H) comprising the ethylene-based random copolymer is such that the gear oil composition of the present invention has an excellent viscosity index, and is suitable as a gear oil. From the viewpoint that the viscosity can be adjusted so as to have a sufficient viscosity, it is in the range of 0.5 to 100 parts by weight, preferably 1 to 80 parts by weight, relative to 100 parts by weight of the base oil (G).

The amount of the imide group-containing low-molecular-weight ethylene copolymer of the present invention to be incorporated into the gear oil composition of the present invention is such that the gear oil composition has excellent cleanability, good low-temperature fluidity, and appropriateness. In terms of having a viscosity of 0.1 to 100 parts by weight, preferably 0.1 to 100 parts by weight with respect to 100 parts by weight of the base oil (G).
It is in the range of 5 to 80 parts by weight.

In the gear oil composition of the present invention, a lubricating oil additive which is added to general gear oil according to preference, for example,
Detergent dispersants, viscosity index improvers other than ethylene random copolymers, thickeners, extreme pressure agents, oiliness agents, corrosion inhibitors, pour point depressants, antioxidants, demulsifiers, defoamers, etc. Commercially available package-type additives including

The gear oil composition of the present invention has extremely excellent shear stability, detergency, thermal stability and viscosity index, and is used for automobile manual transmission oils, automatic transmission oils,
Suitable for final reducer oil. Further, the gear oil composition of the present invention can be expected to improve the cleanliness and viscosity index without impairing the shear stability, and also has excellent thermal stability, so that the use conditions are particularly severe, steelmaking, steelmaking, and rolling. It is suitable for long-term use in the paper industry, the plastic industry such as extrusion molding and stretching.

[0052]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples of the present invention. However, the present invention is not limited to these examples.

The analysis and evaluation in Examples and Comparative Examples were carried out according to the following methods.

Compositional Copolymer of Ethylene Random Copolymer Using ¹³ C-NMR, characteristic spectra derived from ethylene and other α-olefins were detected, and the component ratio of the copolymer was determined from the area ratio of each spectrum. It was

Number average molecular weight vapor pressure osmometer (VPO, KNA
(Manufactured by UER), benzyl and squalane were used as standard samples of known molecular weight, toluene was used as a solvent, and the measurement was performed by a conventional method at 80 ° C.

Molecular weight distribution (weight average molecular weight / number average molecule)
The amount was measured under the following conditions according to "Gel Permeation Chromatography" published by Maruzen by Takeuchi. Equipment: WATERS 150C-ALC / GPC Column: Tosoh Corporation polystyrene gel G4000H8, G3000H8, G2000H8 × 2 Temperature: 70 ° C Flow rate: 1 ml / min Solvent: Toluene Standard sample: Tosoh Corporation, single Dispersed polystyrene

Pour point Measured in accordance with JIS K 2269.

The iodine value was measured according to JIS K 0070.

Graft-modified copolymer maleic anhydride group
Raft amount The amount of maleic anhydride grafted (mol / mol) was calculated from the obtained results by using the saponification value measuring method described in JIS K0070. (Saponification number x graft copolymer number average molecular weight) / (5
6.1 x 2 x 1000)

Succinic anhydride group chain length ¹³ C-NMR was used to measure the area of the characteristic absorption spectrum derived from each carbonyl group carbon bonded to methylene or methine of the acid anhydride chain grafted, and from the ratio, I asked.

Kinematic viscosity was measured according to JIS K 2283.

Low Temperature Viscosity Measured in accordance with ASTM D2983.

Shear Stability Measured according to ASTM D2603.

Thermal / Oxidation Stability Test In accordance with JIS K 25140, an oxidation stability tester described in the same standard is used, and a sample of 250 m is put in a sample container.
l was sampled in the presence of a metal catalyst (Fe / Cu) for 15
After heating and stirring at 0 ° C for 5 days, the kinematic viscosity change rate,
The total acid value, detergency and pentane insoluble matter were measured to evaluate the heat and oxidation stability.

Total acid value Measured according to JIS K 2283.

Detergency- 1 With respect to the sample container, varnish rod and stirring blade used in the heat / oxidation stability test, the adhesion state of lacquer and sludge was examined, and the detergency was judged by the 5-point method according to the following criteria. 1: With sludge 2: Light sludge 3: Medium lacquer, no sludge 4: Light lacquer, no sludge 5: Almost no lacquer, no sludge

Detergency- 2 (panel caulking test) F. S (US federal standard); 250 ml of a sample was sampled in a sample tank using a panel caulking tester manufactured in accordance with M791-3462, and oil temperature: 80 ° C., 5 seconds rotation / at a panel temperature of 220 ° C. The cleanliness was evaluated by observing the sludge adhesion amount (mg) and the adhered state on the panel after operating for 24 hours in a splasher cycle stopped for 15 seconds. The sludge adhesion state was determined by the 5-point method as follows. 1: Sludge (large) 2: Sludge (medium) 3: Sludge (light) 4: Lacquer light, no sludge 5: Almost no lacquer, no sludge

Pentane-insoluble content Measured in accordance with ASTM D 893.

Dispersion test 1 part by weight of SRF / carbon black, 2 parts by weight of a mixture of 1.5 g of liquid paraffin, 10 g of a sample and 88.5 g of kerosene were mixed and put in a 100 ml glass cylinder with a stopper, and SRF was added. -By comparing the sedimentation conditions of carbon black, the dispersibility was judged by the 5-point method according to the following criteria. 1: Start sedimentation within 2 hours 2: Start sedimentation within 1 day 3: Start sedimentation within 2 days 4: Start sedimentation within 4 days 5: No sedimentation for 1 week or more

Example 1 In a 3 liter capacity glass reactor equipped with a stirrer equipped with a nitrogen blowing tube, a water-cooled condenser, a thermometer and two dropping funnels, an ethylene / propylene copolymer (ethylene composition: 53 mol%, Number average molecular weight: 3,500, molecular weight distribution: 1.75, iodine value: 0.3, pour point: -2.
25 ° C (5 ° C) was added, and the atmosphere was sufficiently replaced with nitrogen. After that, the mixture was heated to an internal temperature of 180 ° C., and maleic anhydride (97.6 g) and di-tert-butyl peroxide (19.5 g), which had been previously put in each of the two dropping funnels, were added.
Was added dropwise over 4 hours. After completion of dropping, the mixture is further stirred for 2 hours and then distilled under a reduced pressure of 0.5 mmHg to remove unreacted maleic anhydride and di-tert-butyl peroxide decomposed products, and maleic anhydride graft-modified ethylene / propylene copolymer. Got

When the obtained maleic anhydride graft-modified ethylene / propylene copolymer was analyzed, the number average molecular weight was 3,600 and the maleic anhydride graft amount was 1.1.
Mol / mol, and succinic anhydride group chain length: 1.1.

Example 2 A 1 liter glass reactor equipped with a stirrer, a dropping funnel, a distillation apparatus, a thermometer and a nitrogen blowing tube was sufficiently replaced with nitrogen, and then the maleic anhydride graft-modified ethylene obtained in Example 1 was obtained. -Propylene copolymer 500g was charged.
Next, while stirring, the temperature was raised to 180 ° C., and 3- (aminomethyl) pyridine 2 was placed in the dropping funnel in advance.
6.2 g was gradually added dropwise for reaction. 4 after completion of dropping
Under reduced pressure of 00 mmHg, unreacted 3- (aminomethyl) pyridine and desorbed water were distilled off while bubbling nitrogen.
An imide group-containing ethylene copolymer (I) was obtained.

The obtained product was a yellowish brown transparent high-viscosity liquid, the yield was 513.5 g, and the nitrogen content by elemental analysis was 0.7 wt%.

Evaluation Example 1 The product obtained in Example 2, an olefin copolymer-based viscosity index improver (Mitsui Petrochemical Co., Ltd .; Orfus M-1210) and a mineral oil (Fuji Kosan Neutral 150) The mixture was prepared at the compounding ratio shown in Table 1, and the viscosity characteristics, shear stability, heat / oxidation stability and clean dispersibility were evaluated, and the results are summarized in Table 1.

Evaluation Example 2 In the same manner as the evaluation example 1, a commercially available detergent-dispersant (Amoco 8071) and a pour point depressant (Sanyo Kasei Acluve 136) were used in the same manner. The results are shown in Table 2.

Evaluation Comparative Example 1 Evaluation Example 1 was repeated except that the product obtained in Example 2 was not used. The results are shown in Table 1.

Evaluation Comparative Example 2 Evaluation Comparative Example 2 was repeated except that the product obtained in Example 2 was not used. The results are shown in Table 2.

Evaluation Example 3 The product obtained in Example 2, a commercially available ethylene / α-olefin cooligomer (Lucant HC-2000 manufactured by Mitsui Petrochemical Industry Co., Ltd.) as a viscosity index improver, and a pour point A depressant (Akurub 136 manufactured by Sanyo Kasei Co., Ltd.), an extreme pressure agent (Angramol 99 manufactured by Lubrizol Co., Ltd.) and a mineral oil (Neutral 150 manufactured by Fuji Kosan Co., Ltd.) were compounded at the compounding ratio shown in Table 3, and viscosity characteristics and shear stability The properties, thermal oxidation stability and clean dispersibility were evaluated. The results are summarized in Table 3.

Evaluation Example 4 In Evaluation Example 3, a highly refined mineral having a kinematic viscosity at 100 ° C. of 4.84 cSt, a pour point of -42.5 ° C. and a viscosity index of 90 was used in place of the neutral 150 mineral oil manufactured by Fuji Kosan. An oil (LP-40, Exxon Co.) was used and the same procedure was performed except that the pour point depressant was omitted. The results are summarized in Table 3.

Evaluation Example 5 In Evaluation Example 3, instead of Neutral 150 mineral oil manufactured by Fuji Kosan Co., Ltd., a polyalphaolefin having a kinematic viscosity of 5.7 cSt at 100 ° C. (Synfluid 60 manufactured by Nippon Steel Chemical Co., Ltd.) was used.
1) and diisodecyl adipate were used, and the procedure was the same except that the pour point depressant was omitted. The results are summarized in Table 3.

Evaluation Comparative Example 3 In Evaluation Example 3, a commercial ashless dispersant (OLOA-1 manufactured by Oronite Co., Ltd.) was used instead of the product obtained in Example 2.
200) was used in the same manner. The results are shown in Table 4.

Evaluation Comparative Example 4 Instead of the product obtained in Example 2 and the ethylene / α-olefin cooligomer (Lucant HC-2000 manufactured by Mitsui Petrochemical Industry Co., Ltd.) in Evaluation Example 3, a commercially available modified poly A methacrylate-based clean dispersion type viscosity index improver was used in the same manner except that the pour point depressant was omitted. The results are shown in Table 4.

Evaluation Comparative Example 5 In the evaluation example 3, instead of the product obtained in Example 2 and the pour point depressant, a commercially available polymethacrylate-based viscosity index improver (Plexol 102 manufactured by Nippon Acrylic Co., Ltd.) was used.
The same procedure was performed except that 0) was used. The results are shown in Table 4.

[0084]

[0085]

[0086]

[0087]

[0088]

INDUSTRIAL APPLICABILITY The imide group-containing ethylene copolymer of the present invention can be added to a lubricating oil to impart excellent detergency and shear stability. Further, according to the method of the present invention, this imide group-containing ethylene copolymer can be obtained.

The engine oil composition and the gear oil composition of the present invention contain the imide group-containing ethylene copolymer and have a specific composition, and have cleanliness, shear stability and heat stability. Excellent in.

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Claims (8)

[Claims] 1. A number average molecular weight of 1,500 to 5,000.
1 molecule or more on average per 1 molecule of the ethylene-based random copolymer (A) obtained by copolymerizing an unsaturated dicarboxylic acid anhydride with the substantially colorless and transparent liquid ethylene-based random copolymer (A) A graft-modified copolymer (B) containing less than 2 molecules of an unsaturated dicarboxylic acid anhydride group;
An amino compound (C) having both a primary amino group and at least one group selected from a tertiary amino group and a hydroxyl group
An imide group-containing low molecular weight ethylene copolymer obtained by reacting with. 2. The ethylene-based random copolymer (A)
Has a number average molecular weight of 1,800 to 4,000 and an ethylene composition of 45 to 65 mol%,
The molecular weight distribution (weight average molecular weight / number average molecular weight) is 3 or less, the pour point is 20 ° C. or less, and the iodine value is 1.5.
The low molecular weight ethylene copolymer containing an imide group according to claim 1, which is: 3. The ethylene-based random copolymer (A)
Is an ethylene / propylene copolymer, and the imide group-containing low molecular weight ethylene copolymer according to claim 1 or 2. 4. The average chain length of unsaturated dicarboxylic acid anhydride groups contained in the graft-modified copolymer (B) is 1.0.
The imide group-containing low-molecular-weight ethylene copolymer according to any one of claims 1 to 3, which is in the range of 1 to 1.3. 5. The imide group-containing low molecular weight ethylene copolymer according to any one of claims 1 to 4, wherein the amino compound (C) is 3- (aminomethyl) pyridine. 6. A liquid ethylene random copolymer (A) having a number average molecular weight of 1,500 to 5,000 is initiated in a molten state at a temperature of 150 ° C. to 200 ° C. with an unsaturated dicarboxylic acid anhydride to initiate radical polymerization. Graft-modified copolymer (B) obtained by graft-copolymerizing the ethylene-based random copolymer (A) with an average of 1 molecule or more and less than 2 molecules per molecule by adding the agent over 2 to 20 hours.
Is reacted with an amino compound (C) having both a primary amino group and at least one type of group selected from a tertiary amino group and a hydroxyl group, and the graft-modified copolymer (B) has A process for producing an imide group-containing low molecular weight ethylene copolymer, which comprises reacting a saturated dicarboxylic acid anhydride group with a primary amino group of the amino compound. 7. A mineral oil and / or synthetic oil having a kinematic viscosity at 100 ° C. of 10 to 35 cSt relative to 100 parts by weight of a base oil (D) consisting of a mineral oil and / or a synthetic oil having a kinematic viscosity at 100 ° C. of 3 to 20 cSt. A viscosity modifier (E) consisting of 5
To 200 parts by weight, number average molecular weight of 2,000 to 1
0.5 to 20 parts by weight of a viscosity index improver (F) consisting of a substantially colorless and transparent liquid ethylene-based random copolymer having a imide group content of less than 0.5, An engine oil composition comprising 0.1 to 20 parts by weight of a molecular weight ethylene copolymer. 8. A number average molecular weight of 1,500 to 10,000 with respect to 100 parts by weight of a base oil (G) consisting of mineral oil and / or synthetic oil having a kinematic viscosity at 100 ° C. of 2 to 40 cSt.
0.5 to 100 parts by weight of a viscosity index improver (H) consisting of a substantially colorless and transparent liquid ethylene-based random copolymer, and the imide group-containing low-molecular-weight ethylene copolymer according to any one of claims 1 to 5. A gear oil composition comprising 0.1 to 100 parts by weight of the combined material.