JP6339593B2 - Lubricating composition - Google Patents

Description

  The present invention relates to a lubricating composition comprising a base oil and one or more performance additives for specific use in an internal combustion engine, particularly in a crankcase of an internal combustion engine used in a passenger car or light van. .

  In fact, various lubricating compositions for crankcase engines are known. Known crankcase engine oils may have undesirable fuel performance oil performance values, especially when based on conventional mineral group III base oils, and may be blended into those of lower SAE J300 viscosity grades. Has the disadvantage of being difficult. A further problem with known crankcase engine oils is that they have undesirable properties regarding one or more of wear performance and NOACK volatility, especially when blended into those of lower SAE J300 viscosity grades. Is that there is.

  Attempts have been made to overcome the above problems by blending with non-mineral Group III base oils such as Fischer-Tropsch derived base oils. WO2010020653 discloses the use of a Fischer-Tropsch base oil in a lubricating composition. The composition of Example 1 of WO2010020653 exhibits surprisingly low NOACK volatility compared to the composition of Comparative Example 1 (using a Group III mineral base oil).

  However, in low viscosity formulations such as OW-30 and OW-40 engine oils, the use of Fischer-Tropsch base oil alone is not sufficient to achieve the desired low NOACK volatility values for such formulations. It has been found that there are cases.

  One way to further reduce NOACK volatility is to use a polyalphaolefin base oil in combination with a Fischer-Tropsch derived base oil. However, since polyalphaolefin base oils are relatively expensive, it is possible to find an alternative method for reducing the NOACK volatility of OW-30 and OW-40 formulations, particularly those containing Fischer-Tropsch derived base oils. Expected to be desirable.

WO2010020653

  Surprisingly, it has been found that the NOACK volatility can be lowered to the desired level by including a non-silicone antifoam in the lubricating formulation.

Therefore, according to the present invention,
(I) a base oil;
(Ii) a non-silicone antifoaming agent;
(Iii) a lubricating composition comprising one or more performance additives, wherein the lubricating composition has a kinematic viscosity (ASTM D445 at 100 ° C. of 16.3 mm ² / sec or less). ), A low temperature cranking viscosity (ASTM D5293) of up to 6600 cP at −30 ° C., and a NOACK volatility of up to 11% according to CEC-L-40-93.

  According to another aspect of the present invention, there is a use of a non-silicone antifoam to reduce the NOACK volatility of a lubricating composition, particularly where the lubricating composition comprises a Fischer-Tropsch base oil. Provided.

  Another important advantage of the present invention is that the lubricating composition has a desirably low low temperature cranking viscosity (ie, dynamic viscosity according to ASTM D5293), ie, a cranking viscosity of up to 6600 cP at -30 ° C. (ASTM D5293). Is to have.

  An advantage of the present invention is that it provides alternative SAE J300 OW-30 and OW-40 crankcase engine oil formulations.

  There is no particular limitation on the base oil used in the lubricating composition according to the present invention, and various conventional mineral oils, synthetic oils, vegetable oils, etc., as long as the requirements regarding the lubricant composition according to the present invention are satisfied. The naturally occurring esters can be conveniently used.

  The base oil used in the present invention may conveniently comprise a mixture of one or more mineral oils and / or one or more synthetic oils. Thus, according to the present invention, the term “base oil” may refer to a mixture containing more than one base oil. Mineral oils include liquid petroleum-based oils, paraffinic, naphthenic, or mixed paraffinic / naphthenic type solvent-treated or acid-treated mineral oil-based lubricating oils, which further include hydrofinishing processes and / or It may be purified by dewaxing.

  Suitable base oils for use in the lubricating oil compositions of the present invention are Group III mineral base oils, Group IV polyalphaolefins (PAO), Group III Fischer-Tropsch derived base oils and mixtures thereof.

  “Group III” and “Group IV” base oils in this invention refer to base oils for lubricating oils in accordance with American Petroleum Institute (API) definitions for categories III and IV. These API categories are defined in API Publication 1509, 15th edition, Appendix E, April 2002.

  Fischer-Tropsch derived base oils are known in the art. The term “Fischer-Tropsch derived” means that the base oil is a synthetic product of or derived from a Fischer-Tropsch process. A Fischer-Tropsch derived base oil may also be referred to as a GTL (Gas-To-Liquids) base oil. Suitable Fischer-Tropsch derived base oils that may be conveniently used as base oils in the lubricating compositions of the present invention are, for example, EP0776959, EP0668342, WO97 / 21788, WO00 / 15736, WO00 / 14188, WO00 / 14187, WO00 / 14183, WO00 / 14179, WO00 / 08115, WO99 / 41332, EP1029029, WO01 / 18156 and WO01 / 57166.

  Synthetic oils include hydrocarbon oils such as olefin oligomers (polyalphaolefin base oil; PAO, etc.), dibasic acid esters, polyol esters, polyalkylene glycols (PAG), alkylnaphthalenes and dewaxed waxy isomers ( dewaxed waxy isomerate). A synthetic hydrocarbon base oil sold under the name “Shell XHVI” ™ by the Shell group can be conveniently used.

Polyalphaolefin base oils (PAO) and their production are well known in the art. Suitable polyalphaolefins base oils that may be used in the lubricating compositions of the present invention is a linear C ₂ -C _32, preferably may be those derived from alpha olefins C ₆ -C _16. Particularly preferred feeds for the polyalphaolefin are 1-octene, 1-decene, 1-dodecene and 1-tetradecene.

  The base oil as used in the lubricating composition according to the present invention preferably comprises a Fischer-Tropsch derived base oil.

  In view of the high production cost of PAO, it is highly preferable to use a Fischer-Tropsch derived base oil rather than a PAO base oil. Therefore, preferably the base oil is 50 wt. %, Preferably 60 wt. %, More preferably 70 wt. %, Even more preferably 80 wt. %, Most preferably 90 wt. Contains more than% Fischer-Tropsch derived base oil. In a particularly preferred embodiment, 5 wt. % Or less, preferably 2 wt. % Or less is not a Fischer-Tropsch derived base oil. In a preferred embodiment herein, the lubricating composition is essentially free of polyalphaolefin base oil, ie, the polyalphaolefin base oil is 2 wt. % Or less. In particular, in a preferred embodiment herein, the lubricating composition does not comprise a polyalphaolefin base oil. In another preferred embodiment herein, 100 wt% of the base oil is based on one or more Fischer-Tropsch derived base oils.

  The total amount of the base oil incorporated into the lubricating composition of the present invention is preferably 60 to 99 wt. %, More preferably 65-90 wt. %, Most preferably 70-85 wt. Present in an amount in the range of%.

  According to the present invention, the base oil (or base oil blend) preferably has a kinematic viscosity at 100 ° C. of at least 3.5 cSt (according to ASTM D445), preferably at least 3.8 cSt, most preferably at least 4.1 cSt. Have

  The lubricating composition of the present invention further comprises a non-silicone antifoaming agent. The term “antifoam”, as used herein, is added to a lubricating composition at a low level (typically a level of about 10 ppm to about 500 ppm) to help eliminate surface bubbles. A compound.

  Preferably, the non-silicone antifoaming agent is selected from acrylate, polyacrylate, and polymethacrylate (PMA) polymers. A preferred non-silicone antifoaming agent for use herein is a polyacrylate antifoaming agent. The term polyacrylate antifoaming agent as used herein includes copolymers of polyalkyl acrylate antifoams and acrylic acid.

  The non-silicone antifoam is preferably present at a level of 10 ppm to 500 ppm, preferably 30 ppm to 200 ppm, more preferably 100 ppm to 200 ppm, based on the weight of the lubricating composition.

  An example of a suitable polyalkyl acrylate antifoam is PC1644, commercially available from Cytec. PC1644 is an acrylic acid copolymer including a copolymer of ethyl acrylate and 2-ethylhexyl acrylate. Another commercially available polyalkyl acrylate defoamer for use herein is PC2544, commercially available from Cytec. PC2544 is a modified acrylic acid copolymer.

  As described above, the lubricating composition according to the present invention satisfies predetermined specific requirements concerning dynamic viscosity at -30 ° C, kinematic viscosity at 100 ° C, and NOACK volatility.

  The dynamic viscosity (according to ASTM D5293) at −30 ° C. of the composition is typically up to 6600 cP.

  The dynamic viscosity (according to ASTM D5293) at −35 ° C. of the composition is typically up to 6200 cP.

  The kinematic viscosity (according to ASTM D445) of the composition at 100 ° C. is typically a maximum of 16.3 cSt, preferably 9.3 to 16.3 cSt, more preferably 9.3 to 12.5 cSt.

  The high temperature high shear viscosity (“HTHS”; according to ASTM D4683) of the lubricating composition is typically in the range of 2.9 to 3.7 mPa · sec, preferably in the range of 2.9 to 3.5 mPa · sec. Is within.

  The NOACK volatility (according to CEC-L-40-93) of the composition is typically 11 wt% or less, preferably 10.5 wt% or less, even more preferably 10.0 wt. % Or less. NOACK volatility (according to CEC-L-40-93) is typically at least 8 wt. %.

  The lubricating composition according to the present invention comprises one or more additives such as antioxidants, antiwear additives, dispersants, cleaning agents, overbased cleaning agents, extreme pressure additives, friction modifiers. , Base oils for viscosity index improvers, pour point depressants, metal passivators, corrosion inhibitors, demulsifiers, defoamers, seal compatibility agents, and additive diluents In addition.

  Those skilled in the art are familiar with these and other additives and will not be discussed in further detail herein. Specific examples of such additives are described, for example, in Kirk-Othmer Encyclopedia of Chemical Technology, 3rd edition, volume 14, pages 477-526.

  A preferred additive is a silicone-based antifoam, which may be present as is or may be present as part of the performance additive package. The silicone-based antifoaming agent is preferably present at a level of 20 to 200 ppm based on the weight of the lubricating composition.

  A preferred silicone-based antifoam is polysiloxane. In order to provide lubricating compositions with reduced NOACK volatility, it is particularly useful herein to combine a silicone-based antifoam with a non-silicone antifoam.

  Antioxidants that may be conveniently used include phenyl-naphthylamine (eg “IRGANOX L-06” available from Ciba Specialty Chemicals) and diphenylamine (eg Ciba -"Irganox L-57" available from Specialty Chemicals), for example, those disclosed in WO2007 / 045629 and EP1058720B1, and phenolic antioxidants. The teachings of WO2007 / 045629 and EP1058720B1 are hereby incorporated by reference.

  Antiwear additives that may be conveniently used include zinc-containing compounds such as zinc dithiophosphate compounds selected from zinc dialkyl-, diaryl- and / or alkylaryl-dithiophosphates, molybdenum-containing compounds, Examples include boron-containing compounds, and ashless antiwear additives such as substituted or unsubstituted thiophosphoric acids, and salts thereof.

  Examples of such molybdenum-containing compounds may include, as convenient forms, molybdenum dithiocarbamates, trinuclear molybdenum compounds such as those described in WO 98/26030, molybdenum sulfides and molybdenum dithiophosphates. .

  Boron-containing compounds that may be conveniently used include borate esters, borated aliphatic amines, borated epoxides, alkali metal (or mixed alkali metal or alkaline earth metal) boron. Acid salts, and borated overbased metal salts.

  The dispersant used is preferably an ashless dispersant. Suitable examples of ashless dispersants are polybutylene succinimide polyamines and Mannich base type dispersants.

  The detergent used is preferably an overbased detergent or detergent mixture containing, for example, salicylate, sulfonate and / or phenate type detergents.

  Examples of viscosity index improvers that may be conveniently used in the lubricating compositions of the present invention include styrene-butadiene star copolymers, styrene-isoprene star copolymers, and polymethacrylic acid copolymers and ethylene-propylene copolymers. Can be mentioned. Dispersant-viscosity index improvers may be used in the lubricating composition of the present invention.

  Preferably, the composition has at least 0.1 wt. % Pour point depressant. As an example, alkylated naphthalene and phenolic polymers, polymethacrylates, esters of maleic / fumaric acid copolymers may be conveniently used as effective pour point depressants. Preferably, 0.3 wt. % Pour point depressant is used.

  In addition, as corrosion inhibitors, compounds such as alkenyl succinic acids or their ester moieties, benzotriazole-based compounds and thiodiazole-based compounds may be conveniently used in the lubricating compositions of the present invention.

  In the lubricating composition of the present invention, examples of compounds that may be conveniently used as a seal fixing or seal matching agent include commercially available aromatic esters.

  The lubricating composition of the present invention can be conveniently prepared by mixing one or more additives, such as non-silicone defoamers, with the base oil.

  The aforementioned additives are typically 0.01-35.0 wt.% Based on the total weight of the lubricating composition. %, Preferably 0.05 to 25.0 wt.% Based on the total weight of the lubricating composition. %, More preferably 1.0 to 20.0 wt. Present in an amount in the range of%.

  Preferably, the composition comprises an additive comprising a combination of additives including an antioxidant, a zinc-based antiwear additive, an ashless dispersant, an overbased detergent mixture, and a silicone-based antifoaming agent. The package is 10 wt. % To 15 wt. Contained in%.

  According to a particularly preferred embodiment of the present invention, the composition meets the requirements of SAE J300 OW-30 or OW-40 formulations, preferably the requirements of OW-30 formulations.

  In another aspect, the present invention is the use of a non-silicone defoamer to reduce the NOACK volatility of a lubricating composition, particularly where the lubricating composition comprises a Fischer-Tropsch derived base oil. I will provide a.

  The present invention is also a method for improving NOACK volatility characteristics, the method comprising lubricating an engine, in particular a crankcase of a motor engine of a passenger car, using the lubricating composition according to the present invention. A method is also provided.

  The present invention will now be described with reference to the following examples, which are not intended to limit the scope of the invention in any way.

Lubricating oil compositions were formulated with various engine oils for use in crankcase engines.

  Table 1 shows the characteristics of the base oil used.

  Table 2 shows the composition and properties of the fully formulated engine oil formulations that were tested, with component amounts based on the total weight of the fully formulated formulation wt. It is shown in%.

  All tested engine oil formulations contain a combination of base oil, additive package (additive package 1), and supplemental additive package (additive package 2), where the additive package is The same for all tested compositions.

  Additive Package 1 is Infineum P6660, commercially available from Infineum, which is an antioxidant, zinc-based antiwear additive, ashless dispersant, overbased detergent It contained a mixture and a combination of additives including a silicone based antifoam.

  Additive package 2 contained a combination of a dispersant, an antioxidant and a friction modifier.

  Examples 1-6 contained a non-silicone antifoam agent. The non-silicone antifoaming agent was a polyalkyl acrylate antifoaming agent commercially available from Cytec under the trade names PC1644 and PC2544.

  Comparative Examples 2-4 contained a silicone-containing antifoam (Synative AC AMH-2 commercially available from Cognis).

  In all formulations, the viscosity was adjusted using a conventional viscosity modifier concentrate and the pour point was adjusted using a conventional pour point depressant.

“Base oil 1” was a Fischer-Tropsch derived base oil (“GTL4”) having a kinematic viscosity at 100 ° C. (ASTM D445) of approximately 4 cSt (mm ² / sec).

“Base oil 2” was a Fischer-Tropsch derived base oil (“GTL8”) having a kinematic viscosity at 100 ° C. (ASTM D445) of approximately 8 cSt (mm ² / sec).

  These GTL4 and GTL8 base oils can be conveniently produced, for example, by the process described in WO-A-02 / 070631, the teachings of which are incorporated herein by reference.

  Using conventional lubricant blending techniques, the compositions of Examples 1-6 and Comparative Examples 1-4 are obtained by mixing the base oil with the additive package and antifoam, if present. It was.

  The compositions of Comparative Examples 1-4 and Examples 1-6 met the requirements for the OW-30 formulation according to SAE J300.

  In order to determine the lubricant compositions of the examples and comparative examples, their NOACK volatility, their dynamic viscosity at -35 ° C and their kinematic viscosity at 100 ° C, various tests as shown in Table 2 Processed in the way. Table 2 shows the results.

As can be seen from Discussion Table 2, Examples 1-6 containing non-silicone antifoam at 30 ppm, 100 ppm and 200 ppm are significantly lower NOACK than Comparative Examples 1-4 (no non-silicone antifoam). Has a volatile value.

  An important advantage of the present invention is that OW meets stringent NOACK volatility requirements (eg, less than or equal to 10 wt.%) Without the need to use (relatively expensive) polyalphaolefin (PAO) base oils. -30 formulations can be obtained.

Claims (6)

A lubricating composition comprising:
(I) base oil;
(Ii) a non-silicone antifoam agent; and (iii) one or more performance additives,
The non-silicone antifoam is an alkyl polyacrylate present at a level of 10 ppm to 500 pm based on the weight of the composition;
The base oil comprises one or more Fischer-Tropsch derived base oils; and
Kinematic viscosity (according to ASTM D445) at 16.3 mm ² / sec or less at 100 ° C., low temperature cranking viscosity (ASTM D 5293) up to 6600 cP at −30 ° C., and up to 11% according to CEC-L-40-93 The lubricating composition having a NOACK volatility of   The lubricating composition of claim 1 having a NOACK volatility of up to 10.5% according to CEC-L-40-93. The base oil, the base oil 80% or based on the weight of more of one or more of than Fischer - Tropsch derived base oil, the lubricating composition according to claim 1 or 2. The lubricating composition according to any one of claims 1 to 3 , which does not contain a polyalphaolefin base oil. The lubricating composition of any one of claims 1-4 , wherein the one or more performance additives comprise a silicone-based antifoam agent. Use of a non-silicone defoamer to reduce the NOACK volatility of a lubricating composition, the lubricating composition comprising:
(I) base oil;
(Ii) a non-silicone antifoam agent; and
(Iii) one or more performance additives
Including
The non-silicone antifoam is an alkyl polyacrylate present at a level of 10 ppm to 500 pm based on the weight of the composition;
The base oil comprises one or more Fischer-Tropsch derived base oils; and
Kinematic viscosity (according to ASTM D445) at 16.3 mm ² / sec or less at 100 ° C., low temperature cranking viscosity (ASTM D 5293) up to 6600 cP at −30 ° C., and up to 11% according to CEC-L-40-93 Said use having NOACK volatility .