JP2012172013A - Lubricant viscosity conditioner, additive composition for lubricant, and lubricant composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubricant viscosity conditioner which has excellent resin handing properties, and a composition for lubricant which has excellent thickenability.SOLUTION: The lubricant viscosity conditioner is composed of a propylene-ethylene copolymer which includes 70 to 83 mol% of a structural unit derived from propylene and 17 to 30 mol% of a structural unit derived from ethylene wherein the following conditions are satisfied: (i) an isotactic index is 5 to 40%; (ii) a mesotriad (mm) is 85 to 95%; and (iii) a limiting viscosity [η] is 0.5 to 2.5 dl/g.

Description

  The present invention relates to a lubricating oil viscosity modifier, a lubricating oil additive composition and a lubricating oil composition.

  Petroleum products generally have a so-called viscosity temperature dependency in which the viscosity changes greatly when the temperature changes. For example, in a lubricating oil composition used for an automobile or the like, it is preferable that the temperature dependence of the viscosity is small. Therefore, in the lubricating oil, for the purpose of reducing the temperature dependency of the viscosity, a certain polymer that is soluble in the lubricating oil base is used as the lubricating oil viscosity modifier.

  Conventionally, ethylene / α-olefin copolymers have been widely used as such lubricating oil viscosity modifiers, and various improvements have been made to further improve the performance balance of the lubricating oil (for example, Patent Document 1). , See Patent Document 2).

In recent years, proposals have been made to use a propylene / α-olefin copolymer as a lubricant viscosity adjusting agent. (For example, refer to Patent Document 3).
However, since the copolymer described in Patent Document 3 has strong tackiness, it has poor handling properties when manufactured (for example, after-treatment step after polymerization) or when handled as a viscosity modifier, and a lubricating oil composition The thickening is not sufficient.

International Publication No. 00/034420 International Publication No. 06/028169 JP 2009-029983 A

  The present invention is used to obtain a lubricating oil composition which is made of a copolymer having a good handling property at the time of production (for example, a post-treatment step after polymerization) or when handled as a viscosity modifier and is excellent in thickening. Lubricating oil viscosity modifier, lubricant composition containing the lubricating oil viscosity modifier, and an additive composition for lubricating oil that can be used to obtain a lubricating oil composition having excellent viscosity, and a lubricating oil composition having excellent viscosity increase The purpose is to provide.

  As a result of intensive studies, the present inventors have shown that a specific propylene / ethylene copolymer has good handling properties at the time of production (for example, a post-treatment step after polymerization) or when handled as a viscosity modifier, It has been found that the use of a propylene / ethylene copolymer as a lubricating oil viscosity modifier results in excellent thickening of the resulting lubricating oil composition, thus completing the present invention.

That is, the present invention
[1]
A lubricating oil viscosity adjuster comprising a propylene / ethylene copolymer (A) containing 70 to 83 mol% of propylene-derived structural units, 17 to 30 mol% of ethylene-derived structural units and satisfying the following requirements.
(I) Isotactic index is 5-40%
(Ii) Mesotriad fraction (mm) of 85-95%
(Iii) Intrinsic viscosity [η] is 0.5 to 2.5 dl / g
Preferably, it is one of the following.

[2]
The above-mentioned lubricating oil viscosity adjusting agent, wherein the isotactic index and the mesotriad fraction (mm) of the propylene / ethylene copolymer (A) further satisfy the following formula.
(I-2) Isotactic index ≧ −2.24 × E + 64
(Ii-2) Mesotriad fraction (mm) ≧ −0.4492 × E + 95
(However, E is mol% of the structural unit derived from ethylene of the propylene / ethylene copolymer (A)).

[3]
1 to 50% by weight of the propylene / ethylene copolymer (A) and 50 to 99% by weight of the oil (B) (provided that the weight% of the (A) and (B) is in the additive composition) (A) and (B) calculated based on the total charge).

[4]
A lubricating oil composition comprising the propylene / ethylene copolymer (A) and a lubricating oil base (BB), wherein the propylene / ethylene copolymer (A) is contained in 100% by weight of the lubricating oil composition. A lubricating oil composition containing 0.1 to 5% by weight.

[5]
The lubricating oil composition as described above, which contains 0.05 to 5% by weight of the pour point depressant (C) in 100% by weight of the lubricating oil composition.

  The lubricating oil viscosity modifier of the present invention is excellent in handling properties at the time of production (for example, a post-treatment step after polymerization) or when handled as a viscosity modifier. Moreover, the lubricating oil composition containing the lubricating oil viscosity modifier or lubricating oil additive composition of the present invention is excellent in thickening.

Next, the present invention will be specifically described.
[Lubricating oil viscosity modifier]
The lubricating oil viscosity modifier of the present invention comprises propylene / ethylene copolymer (A) containing 70 to 83 mol% of propylene-derived structural units, 17 to 30 mol% of ethylene-derived structural units and satisfying the following requirements. Become.
(I) Isotactic index is 5-40%
(Ii) Mesotriad fraction (mm) of 85-95%
(Iii) Intrinsic viscosity [η] is 0.5 to 2.5 dl / g
Moreover, it is preferable that (i) isotactic index and (ii) mesotriad fraction (mm) further satisfy the following expressions.
(I-2) Isotactic index ≧ −2.24 × E + 64
(Ii-2) Mesotriad fraction (mm) ≧ −0.4492 × E + 95
(However, E is mol% of the structural unit derived from ethylene of the propylene / ethylene copolymer (A)).

[Propylene / ethylene copolymer (A)]
The propylene-ethylene copolymer (A) of the present invention has a propylene-derived structural unit of 70 to 83 mol%, and a lubricating oil composition containing a copolymer having a propylene-derived structural unit of 70 mol% or more. A lubricating oil composition containing a copolymer having a propylene-derived structural unit of 83 mol% or less is preferred because of its excellent low-temperature storage properties.

The isotactic index of the propylene / ethylene copolymer (A) of the present invention is 5 to 40%, preferably 10 to 40%, more preferably 10 to 25%.
The isotactic index of the propylene / ethylene copolymer (A) of the present invention is measured by infrared (IR) spectroscopy. The infrared (IR) spectrum of polypropylene occurs peak two observation 997 cm ^-1 and 973 cm ^-1, the absorbance of the 997 cm ^-1 the value multiplied by 100 to the quotient in absorbance at 973 cm ^-1 It is defined as the isotactic index of polypropylene. The isotactic index of the propylene / ethylene copolymer (A) of the present invention is also the same.

The mesotriad fraction (mm) of the propylene / ethylene copolymer (A) of the present invention is ¹³ C using the method described in the pamphlet of International Publication No. 2004-087775, page 21, line 7 to page 26, line 6. -It can be measured by NMR. The mesotriad fraction (mm) of the propylene / ethylene copolymer (A) of the present invention is 85 to 95%, preferably 87 to 93%. In order to obtain a propylene / ethylene copolymer (A) having a high mesotriad fraction (mm), generally, a lower polymerization temperature is preferred, a higher polymerization pressure is preferred, and a lower polymer concentration is preferred. .

  The intrinsic viscosity [η] of the propylene / ethylene copolymer (A) of the present invention is 0.5 to 2.5 dl / g, preferably 1.0 to 2.5 dl / g, more preferably 1. It is 1-2.4 dl / g, More preferably, it is 1.3-2.3 dl / g. A lubricating oil composition containing a propylene / ethylene copolymer (A) having an intrinsic viscosity [η] within the above range is preferable because of excellent shear stability.

The density of the propylene / ethylene copolymer (A) of the present invention is preferably 867 kg / m ³ or less, more preferably 853 to 867 kg / m ³ , and still more preferably 857 to 867 kg / m ³ . . The lubricating oil composition containing the propylene / ethylene copolymer (A) having a density in the above range is preferable because it is excellent in low temperature storage property and low temperature viscosity characteristic balance. In addition, the low temperature storage property shows the fluidity of the lubricating oil at a low temperature, and the lubricating oil excellent in the low temperature storage property maintains the fluidity without causing gelation even at a low temperature.

  The propylene / ethylene copolymer (A) of the present invention preferably satisfies at least one of the following requirements (a1) or (a2), and simultaneously satisfies the following requirements (a1) and (a2): Further preferred.

  (A1) Propylene / ethylene copolymer (A) is preheated for 5 minutes using a hot press molding machine set at 190 ° C., then pressurized for 2 minutes, and cooled in a cooling tank set at 20 ° C. for 4 minutes. A press sheet having a thickness of 2 mm obtained by the above method was used as a test specimen after being stored at 20 ° C. for 4 weeks, cooled to −20 ° C., held at −20 ° C. for 5 minutes, and then heated at a rate of 10 ° C./min. The melting point (Tm1) observed in the differential scanning calorimeter (DSC) curve obtained when the temperature is raised to 200 ° C. is 30 ° C. to 80 ° C., preferably 40 ° C. to 60 ° C.

  (A2) The propylene / ethylene copolymer (A) is preheated for 5 minutes using a hot press molding machine set at 190 ° C., then pressurized for 2 minutes, and cooled in a cooling tank set at 20 ° C. for 4 minutes. A press sheet having a thickness of 2 mm obtained by the above method was used as a test specimen after being stored at 20 ° C. for 4 weeks, cooled to −20 ° C., held at −20 ° C. for 5 minutes, and then heated at a rate of 10 ° C./min. The temperature was raised to 200 ° C., held at 200 ° C. for 5 minutes, cooled to −100 ° C. at a temperature drop rate of 10 ° C./min, held at −100 ° C. for 5 minutes, and then heated at a rate of 10 ° C./min. In the differential scanning calorimeter (DSC) curve obtained when the temperature is raised to 0 ° C., the heat of fusion (ΔH 2) observed in the second temperature raising process is 5 J / g or less, preferably 1 J / g or less.

  The propylene / ethylene copolymer (A) is preheated at 190 ° C. and then pressurized, and then cooled. The cooling is preferably performed immediately after the pressurization. Specifically, the pressurized propylene / ethylene copolymer (A) is placed in the cooling tank within 1 minute after the pressurization.

  In the differential scanning calorimeter (DSC) curve, when a plurality of melting peaks are observed, the maximum peak is defined as the melting point (Tm1). The propylene / ethylene copolymer (A) having a melting point (Tm1) of 30 to 80 ° C. means forming a minute crystal component.

  A lubricating oil composition containing a propylene / ethylene copolymer (A) having a melting point (Tm1) and / or a heat of fusion (ΔH2) within the above range is preferable because of excellent balance between low-temperature storage and low-temperature viscosity characteristics.

  The weight average molecular weight measured by gel permeation chromatography (GPC) of the propylene / ethylene copolymer (A) of the present invention is preferably 10,000 to 500,000, more preferably 30,000 to 400,000. 50,000-350,000 is particularly preferred. In addition, a weight average molecular weight shows the weight average molecular weight of polystyrene conversion measured by GPC. A lubricating oil composition containing a propylene / ethylene copolymer (A) having a weight average molecular weight within the above range is preferred because of excellent shear stability.

  The molecular weight distribution (Mw / Mn, converted to polystyrene, Mw: weight average molecular weight, Mn: number average molecular weight) of the propylene / ethylene copolymer (A) of the present invention measured by GPC is 4.0 or less. More preferably, it is 3.0 or less, and particularly preferably 2.5 or less.

  Although there is no restriction | limiting in particular as a manufacturing method of the said propylene ethylene copolymer (A) of this invention, The well-known catalyst which can carry out the stereoregular polymerization of an olefin by an isotactic structure, for example, a solid titanium component, It is obtained by copolymerizing propylene and ethylene in the presence of a catalyst containing an organometallic compound as a main component or a metallocene catalyst using a metallocene compound as one component of the catalyst. Among them, a production method using a metallocene catalyst capable of stereoregular polymerization with an isotactic structure is preferable. Examples of such a metallocene catalyst include International Publication No. 2000/01745 and International Publication No. 2004/106430. And metallocene catalysts described in claims 6 to 8 of International Publication No. 2005/019283, International Publication No. 2006/025540, International Publication No. 2004/088775.

  Specific examples of the metallocene compound include μ-dimethylsilyl (bis-indenyl) hafnium dimethyl, diphenylmethylene (3-tert-butyl-5-ethylcyclopentadienyl) (2,7-di-tert-butylful). Oleenyl) zirconium dichloride, diphenylmethylene (3-tert-butyl-5-methylcyclopentadienyl) (2,7-di-tert-butylfluorenyl) zirconium dichloride, dimethylmethylene (3-tert-butyl-5) -Methylcyclopentadienyl) (fluorenyl) zirconium dichloride and the like.

[Additive composition for lubricating oil]
The additive composition for lubricating oil of the present invention comprises 1 to 50% by weight of the propylene / ethylene copolymer (A) and 50 to 99% by weight of the oil (B) (provided that the (A) and (B) %) Is calculated based on the total amount of (A) and (B) in the additive composition.

That is, the amounts of (A) and (B) are amounts when the total of (A) and (B) is 100% by weight.
Examples of the oil (B) contained in the additive composition for lubricating oil include mineral oils and synthetic oils such as poly-α-olefins, diesters, and polyalkylene glycols. A blend is preferably used. Examples of diesters include polyol esters, dioctyl phthalate, and dioctyl sebacate.

  Mineral oil is generally used through a refining process such as dewaxing, and there are several grades depending on the method of refining, but mineral oil containing a wax content of 0.5 to 10% is generally used. For example, a highly refined oil having a low pour point, a high viscosity index, and a composition mainly composed of isoparaffin produced by a hydrogenolysis refining method can be used. Further, a mineral oil having a kinematic viscosity at 40 ° C. of 10 to 200 cSt is generally used.

  As described above, mineral oil is generally used after a refining process such as dewaxing, and there are several grades depending on the refining method, and this grade is defined by API (American Petroleum Institute) classification. Table 1 shows the characteristics of the lubricant bases classified into each group.

表１におけるポリα−オレフィンは、少なくとも炭素数１０以上のα−オレフィンを原料モノマーの一種として重合して得られる炭化水素ポリマーであって、デセン−１を重合して得られるポリデセンなどが例示される。

The poly α-olefin in Table 1 is a hydrocarbon polymer obtained by polymerizing at least an α-olefin having 10 or more carbon atoms as a kind of raw material monomer, and examples thereof include polydecene obtained by polymerizing decene-1. The

Further, the oil (B) used in the present invention is preferably an oil belonging to any one of group (i) to group (iv). Particularly, among the mineral oils, the kinematic viscosity at 100 ° C. is 1 to 50 mm ² / s. And those having a viscosity index of 80 or more, or poly α-olefins are preferred. The oil (B) is preferably a mineral oil belonging to the group (ii) or the group (iii) or a poly α-olefin belonging to the group (iv). The group (ii) and the group (iii) tend to have a lower wax concentration than the group (i).

In particular, the oil (B) is a mineral oil having a kinematic viscosity at 100 ° C. of 1 to 50 mm ² / s and a viscosity index of 80 or more and belonging to the group (ii) or the group (iii). Or the poly (alpha) -olefin which belongs to group (iv) is the most preferable.

  The additive composition for lubricating oil of the present invention contains the propylene / ethylene copolymer (A) and the oil (B), usually 1 to 50% by weight of the propylene / ethylene copolymer (A) and Oil (B) 50-99 wt% (however, the wt% of the (A) and (B) is calculated based on the total amount of (A) and (B) in the additive composition) To do. The additive composition for lubricating oil of the present invention preferably contains 2 to 40% by weight of the propylene / ethylene copolymer (A) and 60 to 98% by weight of the oil (B), more preferably the propylene / ethylene copolymer. It contains 3 to 30% by weight of ethylene copolymer (A) and 70 to 97% by weight of oil (B).

  Further, the additive composition for lubricating oil of the present invention may contain components other than the propylene / ethylene copolymer (A) and the oil (B). Examples of other components include emulsifiers, dispersants, oxidation stabilizers, and antiwear agents. When the additive composition for lubricating oil of the present invention contains other components, it is usually 0 with respect to 100% by weight in total of the propylene / ethylene copolymer (A) and the oil (B). 0.01 to 10% by weight.

  The lubricating oil additive composition of the present invention preferably contains the propylene / ethylene copolymer (A) and the oil (B) in the above-mentioned range. When producing a lubricating oil composition using the lubricating oil additive composition containing the propylene / ethylene copolymer (A) and the oil (B) in the above range, an additive composition for lubricating oil, By mixing with other components of the lubricating oil composition, it is possible to obtain a lubricating oil composition with excellent viscosity increase with a small propylene / ethylene copolymer (A) content.

  Moreover, since the additive composition for lubricating oil of the present invention is a composition containing oil (B) as described above, the workability when producing the lubricating oil composition is also good, and the lubricating oil composition Can be easily mixed with other ingredients.

The additive composition for lubricating oil of the present invention can be prepared by mixing the propylene copolymer (A) and the oil (B) by a conventionally known method.
[Lubricating oil composition]
The lubricating oil composition of the present invention contains the aforementioned propylene / ethylene copolymer (A) and the lubricating oil base (BB), and preferably further contains a pour point depressant (C).

First, each component forming the lubricating oil composition of the present invention will be described.
As the propylene / ethylene copolymer (A) contained in the lubricating oil composition, the propylene / ethylene copolymer (A) which is the above-described lubricating oil viscosity modifier is used.

  Examples of the lubricating oil base (BB) contained in the lubricating oil composition include mineral oils and synthetic oils such as poly α-olefins, diesters, polyalkylene glycols, and the like. A blend is preferably used. Examples of diesters include polyol esters, dioctyl phthalate, and dioctyl sebacate.

  Mineral oil is generally used through a refining process such as dewaxing, and there are several grades depending on the method of refining, but mineral oil containing a wax content of 0.5 to 10% is generally used. For example, a highly refined oil having a low pour point, a high viscosity index, and a composition mainly composed of isoparaffin produced by a hydrogenolysis refining method can be used. Further, a mineral oil having a kinematic viscosity at 40 ° C. of 10 to 200 cSt is generally used.

  As described above, mineral oil is generally used after a refining process such as dewaxing, and there are several grades depending on the refining method, and this grade is defined by API (American Petroleum Institute) classification. The characteristics of the lubricant bases classified into each group are as shown in Table 1 above.

  The poly α-olefin in Table 1 is a hydrocarbon polymer obtained by polymerizing at least an α-olefin having 10 or more carbon atoms as a kind of raw material monomer, and examples thereof include polydecene obtained by polymerizing decene-1. The

Further, the lubricating oil base (BB) used in the present invention is preferably an oil belonging to any one of group (i) to group (iv). Particularly, among mineral oils, the kinematic viscosity at 100 ° C. is 1 to 50 mm ^2. / S and a viscosity index of 80 or more, or poly α-olefin is preferable. Further, as the lubricating oil base (BB), mineral oil belonging to group (ii) or group (iii) or poly α-olefin belonging to group (iv) is preferable. The group (ii) and the group (iii) tend to have a lower wax concentration than the group (i).

In particular, the lubricant base (BB) is a mineral oil having a kinematic viscosity at 100 ° C. of 1 to 50 mm ² / s and a viscosity index of 80 or more, and is classified into group (ii) or group (iii). Most preferred are polyalphaolefins belonging to the group or group (iv).

  Pour point depressants (C) preferably contained in the lubricating oil composition include alkylated naphthalene, alkyl (co) polymer, alkyl acrylate (co) polymer, alkyl fumarate and vinyl acetate. Examples thereof include copolymers, α-olefin polymers, copolymers of α-olefins and styrene, and among them, alkyl methacrylate (co) polymers and alkyl acrylate (co) polymers are preferably used. .

The lubricating oil composition of the present invention contains a propylene / ethylene copolymer (A) and a lubricating oil base (BB) as described above, and preferably further contains a pour point depressant (C). Yes.
In 100% by weight of the lubricating oil composition, the propylene / ethylene copolymer (A) is usually 0.1 to 5% by weight, preferably 0.2 to 4% by weight, more preferably 0.4 to 3% by weight. %, Particularly preferably in an amount of 0.6 to 2% by weight. When the lubricating oil composition of the present invention contains a pour point depressant (C), the pour point depressant (C) is usually 0.05 to 5% in 100% by weight of the lubricating oil composition. It is contained in an amount of% by weight, preferably 0.05 to 3% by weight, more preferably 0.05 to 2% by weight, most preferably 0.05 to 1% by weight.

  Components of the lubricating oil composition of the present invention other than the propylene / ethylene copolymer (A) and the pour point depressant (C) preferably contained are the lubricating oil base (BB) and those described later. It is a compounding agent. The compounding agent means components other than the propylene / ethylene copolymer (A), the lubricating oil base (BB) and the pour point depressant (C) contained in the lubricating oil composition.

  The content when the lubricating oil composition of the present invention contains a compounding agent is not particularly limited, but when the total of the lubricating oil base (BB) and the compounding agent is 100% by weight, The content is usually more than 0% by weight, preferably 1% by weight or more, more preferably 3% by weight or more, and further preferably 5% by weight or more. Moreover, as content of a compounding agent, it is 40 weight% or less normally, Preferably it is 30 weight% or less, More preferably, it is 20 weight% or less, More preferably, it is 15 weight% or less.

In the lubricating oil composition of the present invention, it is preferable that the content of the propylene / ethylene copolymer (A) is within the above range because the lubricating oil composition is excellent in viscosity.
The lubricating oil composition of the present invention has a small temperature dependence of viscosity, and has a small increase in pour point due to the interaction between the propylene / ethylene copolymer (A) and the pour point depressant (C), and any shear. Excellent low temperature characteristics in the speed range, excellent handling at low temperatures, and good lubrication performance.

  Moreover, the lubricating oil composition of the present invention may contain a compounding agent in addition to the propylene / ethylene copolymer (A), the lubricating oil base (BB), and the pour point depressant (C). Additives such as alkyl methacrylate (co) polymers, hydrogenated SBR (styrene butadiene rubber), SEBS (styrene ethylene butylene styrene block copolymer) and other additives having an effect of improving viscosity index, detergents, rust inhibitors Additives, dispersants, extreme pressure agents, antifoaming agents, antioxidants, metal deactivators and the like can be mentioned.

  The lubricating oil composition of the present invention is prepared by a conventionally known method by using the propylene / ethylene copolymer (A), the lubricating oil base (BB) and the pour point depressant (C), and, if necessary, other blends. It can be prepared by mixing or dissolving the agent.

  The lubricating oil composition of the present invention is excellent in low-temperature storage properties, low-temperature viscosity, and excellent in fuel efficiency at high temperatures. Therefore, lubricating oil for automobile engines, lubricating oil for heavy-duty diesel engines, lubricating oil for marine diesel engines, 2 It can be suitably used as cycle engine lubricating oil, automatic transmission base oil, manual transmission oil, gear oil, grease, and the like.

  EXAMPLES Next, although an Example is shown and this invention is demonstrated further in detail, this invention is not limited by these.

[Isotactic index]
The isotactic index of the propylene / ethylene copolymer (A) of the present invention was measured by infrared (IR) spectroscopy. The copolymer was hot-pressed to form a film, and then an infrared (IR) spectrum was obtained using an infrared spectrometer. The value obtained by multiplying the quotient obtained by dividing the absorbance at 997 cm −1 of the obtained infrared spectrum by the absorbance at 973 cm −1 by 100 was calculated as an isotactic index.

[Mesotriad fraction (mm)]
About the mesotriad fraction (mm) of the copolymer manufactured or used in the Example or the comparative example, it calculated | required by the analysis of < ¹³ > C-NMR spectrum.

(measuring device)
LA500 nuclear magnetic resonance apparatus (manufactured by JEOL Ltd.)
(Measurement condition)
4. In a mixed solvent of orthodichlorobenzene and benzene-d6 (orthodichlorobenzene / benzene-d6 = 3/1 to 4/1 (volume ratio)), 120 ° C., pulse width 45 ° pulse, pulse repetition time At 5 seconds, the mesotriad fraction (mm) of the copolymer produced or used in the examples or comparative examples was measured.

[Intrinsic viscosity]
Measurements were made at 135 ° C. in decalin.
〔density〕
The density of the copolymer produced or used in Examples or Comparative Examples was measured according to the method described in ASTM D1505.

[DSC measurement]
The copolymer produced in Example or Comparative Example was preheated for 5 minutes using a hydraulic hot press molding machine set to 190 ° C., then pressurized for 2 minutes, and set to 20 ° C. within 1 minute after pressing. The sheet was placed in a cooling tank and cooled there for 4 minutes to prepare a press sheet having a thickness of 2 mm.

The press sheet stored at 20 ° C. for 4 weeks was used as a test specimen. The DSC measurement was performed using a differential scanning calorimeter (RDC220) manufactured by SEIKO calibrated with indium.
The test specimen was weighed on an aluminum DSC pan so as to be about 10 mg, and the lid was crimped on the pan to form a sealed atmosphere to obtain a sample pan.

A sample pan is placed in the DSC cell and an empty aluminum pan is placed as a reference. The DSC cell was cooled from 20 ° C. (room temperature) to −20 ° C. in a nitrogen atmosphere, held at −20 ° C. for 5 minutes, and then heated to 200 ° C. at 10 ° C./min. (First heating process)
Next, after maintaining at 200 ° C. for 5 minutes, the temperature was decreased at 10 ° C./min, and the DSC cell was cooled to −100 ° C. After holding at −100 ° C. for 5 minutes, the DSC cell was heated to 200 ° C. at 10 ° C./min. (Second heating process)

  The melting peak top temperature of the enthalpy curve obtained in the first temperature raising process was defined as the melting point (Tm1). When there are two or more melting peaks, the one having the maximum peak is defined as Tm1.

The melting peak area of the enthalpy curve obtained in the second temperature raising process was defined as the heat of fusion (ΔH2).
When two or more melting peaks are present, if two or more peaks are not completely separated (ie, the enthalpy curve connecting the peak tops does not return to the baseline), two or more Even when the peaks are completely separated (that is, when the enthalpy curve connecting the peak tops returns to the baseline), the heat of fusion (ΔH2) is the sum of the peak areas of the two or more peaks. It was supposed to be.
In addition, when a crystallization peak was observed in addition to the heat of fusion peak, the crystallization peak area was not added.

[Weight average molecular weight and molecular weight distribution]
The weight average molecular weight and molecular weight distribution of the copolymer produced or used in Examples or Comparative Examples were measured by the following methods.

(Pretreatment of sample)
30 mg of the copolymer produced or used in Examples or Comparative Examples was dissolved in 20 ml of 0-dichlorobenzene at 145 ° C., and then the solution was filtered through a sintered filter having a pore size of 1.0 μm as an analysis sample.

(GPC analysis)
The average molecular weight and molecular weight distribution curve were determined using gel permeation chromatography (GPC). Calculation was performed in terms of polystyrene.

(measuring device)
Gel permeation chromatograph alliance GPC 2000 (manufactured by Waters)
(Analysis device)
Data processing software Empower2 (Waters)
(Measurement condition)
Two columns TSKgel GMH ₆ -HT and two TSKgel GMH ₆ -HTL (both 7.5 mm in diameter x 30 cm in length, manufactured by Tosoh Corporation)
Column temperature 140 ° C
Mobile phase o-dichlorobenzene (containing 0.025% BHT)
Detector Differential refractometer Flow rate 1 mL / min Sample concentration 0.15% (w / v)
Injection volume 500μL
Sampling time interval 1 second Column calibration Monodisperse polystyrene (manufactured by Tosoh Corporation)
Molecular weight conversion PS conversion / standard conversion method

(Kinematic viscosity)
The kinematic viscosity at 100 ° C. of the lubricating oil compositions prepared in Examples or Comparative Examples was measured based on ASTM D446.

[Cold Cranking Simulator (CCS) viscosity]
The CCS viscosity (−30 ° C.) of the lubricating oil compositions prepared in Examples or Comparative Examples was measured based on ASTM D 2602. The CCS viscosity is used for evaluation of slidability (startability) at a low temperature on the crankshaft, and the smaller the value, the better the low temperature viscosity (low temperature characteristics) of the lubricating oil.

  Specifically, in the lubricating oil composition having the same kinematic viscosity using the copolymer (lubricating oil viscosity modifier) produced or used in Examples or Comparative Examples having substantially the same weight average molecular weight, the CCS viscosity The lower the value, the better the fuel efficiency at low temperatures.

[Shear Stability Index (SSI)]
The SSI of the lubricating oil compositions prepared in the examples or comparative examples was measured based on ASTM D 3945. SSI is a measure of the loss of kinematic viscosity due to the shearing force of the copolymer component in the lubricating oil and the molecular chain being broken, and the larger the SSI, the greater the loss of kinematic viscosity. Indicates.

[Probe tack test]
The copolymer produced in Example or Comparative Example was preheated for 5 minutes using a hydraulic hot press molding machine set to 190 ° C., then pressurized for 2 minutes, and set to 20 ° C. within 1 minute after pressing. It cooled for 4 minutes with the cooling tank, and produced the press sheet of thickness 2mm.

The press sheet stored at 20 ° C. for 4 weeks was used as a test specimen. Further, as a pretreatment for the test, the sample was heated at 100 ° C. for 10 minutes, and then cooled for 4 minutes with a release agent solution in an ice bath. Moisture adhering to the specimen was removed with an air gun.
The probe tack test was conducted using a tacker tester (TAC-II) manufactured by Reska. A stainless steel cylindrical probe having a diameter of 5 mmφ was brought into contact with the test specimen, and the tack (gf) generated when peeling was evaluated. The contact speed of the probe to the test body was 120 mm / min, the applied pressure was 50 gf, the pressing time was 1 second, and the peeling speed was 120 mm / min.

[Example 1]
Example 1 is VistaMAX 6100 available from ExxonMobil Chemical Company. Properties are shown in Table 2.

[Example 2]
Example 2 is VistaMAX ™ 6200, available from ExxonMobil Chemical Company. Properties are shown in Table 2.

Example 3
At one feed port of a stirred-blade pressure-added continuous polymerization reactor with a capacity of 310 liters sufficiently purged with nitrogen, dehydrated and purified n-hexane was fed at a flow rate of 32.7 liters / hr, and methylaluminoxane (Tosoh Finechem). TMAO-341) 2.5 mmol / hr, diphenylmethylene (3-tert-butyl-5-ethylcyclopentadienyl) (2,7-di-tert-butylfluorenyl) zirconium dichloride 0.010 mmol / Hr, triisobutylaluminum (TiBA manufactured by Tosoh Finechem) was continuously supplied at a flow rate of 1.4 mmol / hr. At the same time, ethylene is continuously supplied to another supply port of the continuous polymerization reactor at a flow rate of 2.5 kg / hr, propylene at a flow rate of 15.2 kg / hr, and hydrogen at a flow rate of 2.3 normal liters / hr. Then, continuous solution polymerization was performed under the conditions of a polymerization temperature of 60 ° C., a total pressure of 1.3 MPa-G, and a stirring rotational speed of 190 rpm. The refrigerant is circulated through a jacket provided on the outer periphery of the polymerization reactor, and the gas phase part is forcibly circulated using a separately installed gas blower, and this is cooled by a heat exchanger, thereby Removal was performed.

  The hexane solution containing the propylene / ethylene copolymer produced as a result of the polymerization under the above conditions is passed through a discharge port provided at the bottom of the polymerization reactor so as to maintain an average solution volume of 100 liters in the polymerization reactor. The propylene / ethylene copolymer was continuously discharged at a rate of 8.0 kg / hr. The obtained polymerization solution was put into a large amount of methanol to precipitate a propylene / ethylene copolymer. The propylene / ethylene copolymer was dried under reduced pressure at 130 ° C. for 24 hours. Table 2 shows the properties of the obtained polymer.

[Comparative Example 1]
A polymerization vessel having an internal volume of 1500 mL sufficiently purged with nitrogen was charged with 500 mL of dry heptane, 0.9 mmol of triisobutylaluminum and 20 g of 1-butene at room temperature, and then the internal temperature of the polymerization vessel was raised to 54 ° C. Dimethylsilylene (tetramethylcyclopentadienyl) (3-tert-butyl-5-methyl-2-phenoxy) dissolved in heptane after pressurizing with propylene to 0.6 MPaG and then with ethylene to 0.65 MPaG Titanium dichloride (0.00131 mmol) and N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate (0.0065 mmol) dissolved in toluene were added into the polymerization vessel. While maintaining the internal pressure at 0.65 MPaG with ethylene pressure, polymerization was performed for 6.5 minutes, and 5 ml of methanol was added to terminate the polymerization. The internal temperature rose to 76 ° C. due to the heat of polymerization. After cooling and depressurization, the polymerization solution was added to 2 L of acetone / methanol to precipitate a polymer, and the polymer recovered by filtration was dried at 80 ° C. for 10 hours under reduced pressure. Table 2 shows the properties of the obtained polymer.

[Comparative Example 2]
Polymerization was carried out in the same manner as in Comparative Example 1 except that the pressures with propylene and ethylene were 0.5 MPaG and 0.7 MPaG, respectively, and the polymerization time was 4 minutes. The internal temperature rose to 61 ° C. due to the heat of polymerization. Table 2 shows the properties of the obtained polymer.

[Comparative Example 3]
A polymerization vessel having an internal volume of 1500 mL sufficiently purged with nitrogen was charged with 500 mL of dry heptane, 0.5 mmol of triisobutylaluminum and 20 g of 1-butene at room temperature, and then the internal temperature of the polymerization vessel was raised to 54 ° C. After introducing 500 mL of hydrogen, it was pressurized to 0.6 MPaG with propylene and then pressurized to 0.7 MPaG with ethylene. Dimethylsilylene (tetramethylcyclopentadienyl) (3-tert-butyl-5-methyl-2-phenoxy) titanium dichloride (0.00065 mmol) dissolved in heptane and N, N-dimethylanilinium tetrakis dissolved in toluene (Pentafluorophenyl) borate (0.0035 mmol) was added into the polymerization vessel. Polymerization was performed for 25 minutes while maintaining the internal temperature at 54 ° C. and the internal pressure at 0.7 MPaG by ethylene pressure, and 5 ml of methanol was added to terminate the polymerization. After cooling and depressurization, the polymerization solution was added to 2 L of acetone / methanol to precipitate a polymer, and the polymer recovered by filtration was dried at 80 ° C. for 10 hours under reduced pressure. Table 2 shows the properties of the obtained polymer.

  In Table 2, the notation “−” of the mesotriad fraction (mm) in the comparative example is calculated as the mesotriad fraction (mm) while ensuring accuracy because the copolymer of the comparative example is an atactic polymer. It is not possible, but it is 80% or less.

In Table 2, the notation "-" of the isotactic index in the comparative example indicates that the copolymer of the comparative example is an atactic polymer, and therefore does not have stereoregularity enough to calculate the isotactic index. Indicates.
In Table 2, the notation “n / d” of the melting point (Tm1) indicates that no melting point was observed.

Example 4
Using the polymer of Example 1, the performance of the lubricating oil was evaluated by the probe tack test and the formulation shown in Table 3. The results are shown in Table 4.

Example 5
Using the polymer of Example 2, the performance of the lubricating oil was evaluated by the probe tack test and the formulation shown in Table 3. The results are shown in Table 4.

Example 6
Using the polymer of Example 3, the performance of the lubricating oil was evaluated by the probe tack test and the formulation shown in Table 3. The results are shown in Table 4.

[Comparative Example 4]
Using the polymer of Comparative Example 1, the performance of the lubricating oil was evaluated by the probe tack test and the formulation shown in Table 3. The results are shown in Table 4.

[Comparative Example 5]
Using the polymer of Comparative Example 2, the performance of the lubricating oil was evaluated by the probe tack test and the formulation shown in Table 3. The results are shown in Table 4.

[Comparative Example 6]
Using the polymer of Comparative Example 3, the performance of the lubricating oil was evaluated by the probe tack test and the formulation shown in Table 3. The results are shown in Table 4.

上記表４から分かるとおり、同等の剪断安定性（ＳＳＩ）を有する潤滑油を得ようとした場合、実施例４〜６は比較例４〜６に比べてポリマー添加量が１０％以上少なくて済み、増粘性に優れることが分かる。また、同等の剪断安定性（ＳＳＩ）を有する潤滑油を得ようとした場合、実施例４〜６は比較例４〜６に比べて粘着力が小さく、粘度調整剤として取り扱う際のハンドリング性に優れることが分かる。

As can be seen from Table 4 above, when trying to obtain a lubricating oil having equivalent shear stability (SSI), Examples 4 to 6 require 10% or more less polymer addition than Comparative Examples 4 to 6. It can be seen that it is excellent in thickening. Moreover, when it was going to obtain the lubricating oil which has equivalent shear stability (SSI), Examples 4-6 have a small adhesive force compared with Comparative Examples 4-6, and are easy to handle at the time of handling as a viscosity modifier. It turns out that it is excellent.

Claims (5)

A lubricating oil viscosity adjuster comprising a propylene / ethylene copolymer (A) containing 70 to 83 mol% of propylene-derived structural units, 17 to 30 mol% of ethylene-derived structural units and satisfying the following requirements.
(I) Isotactic index is 5-40%
(Ii) Mesotriad fraction (mm) of 85-95%
(Iii) Intrinsic viscosity [η] is 0.5 to 2.5 dl / g The lubricating oil viscosity modifier according to claim 1, wherein the isotactic index and the mesotriad fraction (mm) of the propylene / ethylene copolymer (A) further satisfy the following formula.
(I-2) Isotactic index ≧ −2.24 × E + 64
(Ii-2) Mesotriad fraction (mm) ≧ −0.4492 × E + 95
(However, E is mol% of the structural unit derived from ethylene of the propylene / ethylene copolymer (A)) The propylene / ethylene copolymer (A) according to any one of claims 1 and 2 is 1 to 50% by weight, and the oil (B) is 50 to 99% by weight (provided that (A) and (B) % Is calculated based on the total amount of (A) and (B) in the additive composition. A lubricating oil composition comprising the propylene / ethylene copolymer (A) according to any one of claims 1 to 2 and a lubricating oil base (BB), wherein 100% by weight of the lubricating oil composition, A lubricating oil composition containing 0.1 to 5% by weight of the propylene / ethylene copolymer (A). The lubricating oil composition according to claim 4, comprising 0.05 to 5% by weight of the pour point depressant (C) in 100% by weight of the lubricating oil composition.