Lubricant additive composition

Abstract

To provide an additive composition that has good long-term storage property and that can be added to lubricating oil formulations to improve a low temperature performance and to have a higher viscosity index; a method of producing the additive composition; use of the additive composition as a lubricant additive in lubricating oil formulations; and lubricating oil formulations comprising the additive composition.SOLUTION: An additive composition contains a viscosity index improving agent polymer (V) and a pour point depressant polymer (P).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an additive composition and a method for producing the same. The present invention also relates to the use of the additive composition as a lubricant additive in a lubricating oil formulation and to a lubricating oil formulation containing the additive composition.

Background Art

[0002] Pour point depressants (PPDs) are additives that improve the low temperature performance of oils by modifying the wax crystallization process. A wide variety of chemical types are currently available and include polyalkyl methacrylates, styrenated polyesters, alkylated polystyrenes, ethylene-vinyl acetate, vinyl acetate-fumarate, styrene-maleic anhydride, and alkylated naphthalenes. In particular, polyalkyl methacrylates are commonly used as PPDs and contain linear C 16 or higher methacrylates, which can be easily polymerized to obtain polymers that can interact with paraffinic substances in the base oil.

[0003] U.S. Patent No. 8,143,202 (US8143202B2) describes polyalkyl methacrylates having 60 to about 96% by weight of C 12 to C 16 alkyl methacrylate and about 4 to about 40% by weight of C 18 to C 30 alkyl methacrylate, which provide excellent low temperature properties to lubricating oils.

[0004] U.S. Patent No. 6,255,261 (US6255261) describes poly(meth)acrylate copolymers useful as PPDs, containing about 5 to about 60% by weight of C 11 to C 15 alkyl (meth)acrylate and about 40 to about 95% by weight of C 16 to C 30 alkyl (meth)acrylate.

[0005] Therefore, the PPD, such as the above-mentioned one, is added to the lubricant formulation to improve the low-temperature properties of the lubricating oil, and in most formulations, an additional viscosity index improver (VII) is required to improve the viscosity performance of the lubricant. Therefore, an additive composition containing VII and PPD is preferred to reduce the number of additive components blended in the process of manufacturing the lubricating oil. However, an additive composition containing VII and PPD can cause compatibility problems and, as a result, some problems with storage stability.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Patent Document 8

Patent Document 9

Patent Document 10

Patent Document 11

Patent Document 12

Patent Document 13

Patent Document 14

[0007] [Non-Patent Document 1] Ullmann's Encyclopedia of Industrial Chemistry, 6th Edition [Non-Patent Document 2] J.-S. Wang, et al., J. Am. Chem. Soc, vol. 117, p. 5614-5615 (1995) [Non-Patent Document 3] Matyjaszewski, Macromolecules, vol. 28, p. 7901-7910 (1995) [Non-Patent Document 4] T. Mang, W. Dresel (eds.): “Lubricants and Lubrication”, Wiley-VCH, Weinheim 2001 [Non-Patent Document 5] R. M. Mortier, S. T. Orszulik (eds.): “Chemistry and Technology of Lubricants” [Summary of the Invention] [Problems to be Solved by the Invention]

[0008] Therefore, there is an interest in developing an additive composition containing VII and PPD that has good storage stability over a long period of time, can be added to a lubricating oil formulation to improve low-temperature performance, and can increase the viscosity index. [Means for Solving the Problems]

[0009] After thorough investigation, the inventors of the present invention surprisingly found that the additive composition defined in claim 1 provides good storage stability as an additive composition, a high viscosity index in a lubricant formulation, and improvement of low-temperature performance, thereby solving the above technical problems.

[0010] Therefore, in a first aspect, the present invention relates to an additive composition defined in claim 1.

[0011] In a second aspect, the present invention relates to a method for producing the additive composition.

[0012] In a third aspect, the present invention relates to the use of the additive composition as a lubricant additive in the lubricating oil formulation for improving storage stability, the viscosity index of the lubricating oil formulation, and low-temperature performance.

[0013] In a fourth aspect, the present invention relates to a lubricating oil formulation comprising an additive composition as defined in the present invention.

[0014] Detailed Description of the Invention The Additive Composition of the Present Invention In a first aspect, the present invention relates to an additive composition (A) comprising a viscosity index improver (V) and a pour point depressant (P), wherein the viscosity index improver (V) is a polymer having a weight average molecular weight (M w ) of 100,000 to 1,000,000 g / mol and comprises a monomer composition comprising: a) one or more polybutadiene-based macromonomers having a number average molecular weight of 500 to 10,000 g / mol, 10 to 30% by weight based on the total weight of the monomer composition for the viscosity improver, b) one monomer or a mixture thereof having 8 to 17 carbon atoms selected from methyl (meth)acrylate, butyl (meth)acrylate, styrene or a substituted styrene having an alkyl substituent in the side chain, 50 to 70% by weight based on the total weight of the monomer composition for the viscosity improver, c) one monomer or a mixture thereof selected from linear or branched C7 - C 30 alkyl (meth)acrylate, 1 to 15% by weight based on the total weight of the monomer composition for the viscosity improver which can be obtained by polymerizing, wherein the pour point depressant (P) is a polymer having a weight average molecular weight (M w ) of 10,000 to 60,000 g / mol and comprises a monomer composition comprising: e) one monomer or a mixture thereof selected from linear or branched C1 - C6 alkyl (meth)acrylate, 20 to 35% by weight based on the total weight of the monomer composition for the pour point depressant, f) linear or branched C7 - C 15One monomer selected from alkyl (meth) acrylates, 20 to 75% by mass based on the total mass of the monomer composition for the pour point depressant, g) Linear or branched C 16 ~C 24 At least one monomer selected from alkyl (meth) acrylates, 5 to 60% by mass based on the total mass of the monomer composition for the pour point depressant It can be obtained by polymerization, Here, the mass ratio of (V) to (P) is 99:1 to 80:20 based on the total solid polymer content of the polymer of (V) and the polymer of (P) in the additive composition.

[0015] Unless otherwise noted, the amounts by mass of the monomers are given relative to the total amount of monomers used to produce the polymer, i.e., the total mass of the monomer composition.

[0016] Preferably, the viscosity index improver polymer (V) has a mass average molecular weight (M w ) of 100,000 to 600,000 g / mol, more preferably 100,000 to 500,000 g / mol, even more preferably 100,000 to 400,000 g / mol.

[0017] Preferably, the polydispersity index (PDI) of the viscosity index improver (V) according to the present invention is in the range of 1.0 to 6.0, more preferably 2.0 to 5.5, even more preferably 3.0 to 5.0. The polydispersity index is defined as the ratio of the mass average molecular weight to the number average molecular weight (M w / M n ).

[0018] Preferably, the pour point depressant polymer (P) has a mass average molecular weight (M w ) of 15,000 to 60,000 g / mol, more preferably 15,000 to 50,000 g / mol.

[0019] Preferably, the polydispersity index (PDI) of the pour point depressant polymer (P) according to the present invention is in the range of 1.0 to 5.0, more preferably 1.5 to 4.5, and even more preferably 2.0 to 3.0. The polydispersity index is the ratio (M w / M n ) of the mass average molecular weight to the number average molecular weight and is defined as such.

[0020] In the present invention, the mass average molecular weight (M w ) of the polymer (pour point depressant (P) and viscosity index improver (V)) is determined by gel permeation chromatography (GPC) using a polymethyl methacrylate calibration standard under the following measurement conditions: Eluent: Tetrahydrofuran (THF) Operating temperature: 40°C Column set: The column set consists of one pre-column (PSS-SDV 100Å 10μm 8.0×50mm) and three columns (2×PSS-SDV Linear XL 10μm 8.0×300mm, 1×PSS-SDV 100Å 10μm 8.0×300mm), and all columns have an average particle size of 10μm (PSS Standards Service GmbH, Mainz, Germany) Flow rate: 1 mL / min Injection volume: 100 μL Equipment: Shodex GPC101 consisting of an autosampler, a pump, and a column oven Detector: Refractive index detector from Shodex.

[0021] In connection with the present invention, the term "(meth)acrylic acid" refers to acrylic acid, methacrylic acid, and a mixture of acrylic acid and methacrylic acid, with methacrylic acid being preferred. The term "(meth)acrylate" refers to an ester of acrylic acid, an ester of methacrylic acid, or a mixture of esters of acrylic acid and methacrylic acid, with an ester of methacrylic acid being preferred.

[0022] Preferably, the additive composition (A) has a solid polymer content of at least 25% by mass based on the total mass of the polymers (P) and (V) in the additive composition (A).

[0023] Preferably, the amount of monomer e) is 25 to 30% by mass based on the total mass of the monomer composition of the pour point depressant (P). The monomer e) is selected from methyl (meth)acrylate, butyl (meth)acrylate or a mixture thereof, preferably methyl (meth)acrylate.

[0024] Preferably, the amount of monomer f) is 20 to 60% by mass, more preferably 25 to 55% by mass based on the total mass of the monomer composition of the pour point depressant (P).

[0025] Preferably, the amount of monomer g) is 20 to 50% by mass, more preferably 25 to 50% by mass based on the total mass of the monomer composition of the pour point depressant (P).

[0026] Preferably, the amounts of monomers e), f), and g) in the monomer composition of the pour point depressant (P) total 95 to 100% by mass, preferably 100% by mass based on the total mass of the monomer composition of the pour point depressant (P).

[0027] Preferably, the amount of monomer a) is 15 to 30% by mass, more preferably 15 to 29% by mass based on the total mass of the monomer composition of the viscosity index improver (V).

[0028] Preferably, the amount of monomer b) is 55 to 70% by mass based on the total mass of the monomer composition of the viscosity index improver (V).

[0029] The monomer b) according to the present invention is selected from one monomer having 8 to 17 carbon atoms or a mixture thereof, which is selected from the group consisting of methyl (meth) acrylate, butyl (meth) acrylate, styrene or a substituted styrene having an alkyl substituent in the side chain. Suitable styrene monomers having 8 to 17 carbon atoms are selected from the group consisting of styrene, substituted styrenes having an alkyl substituent in the side chain, such as α-methylstyrene and α-ethylstyrene, substituted styrenes having an alkyl substituent on the ring, such as vinyltoluene and p-methylstyrene, halogenated styrenes, such as monochlorostyrene, dichlorostyrene, tribromostyrene and tetrabromostyrene, and nitrostyrene, and styrene is preferred.

[0030] Preferably, the monomer c) is a linear C 12~14 alkyl methacrylate, linear C 16~18 alkyl methacrylate or a mixture thereof, more preferably a mixture thereof.

[0031] Preferably, the monomer composition of the viscosity index improver (V) further contains 0 to 20% by mass, more preferably 0.1 to 20% by mass, even more preferably 0.1 to 15% by mass, and most preferably 0.1 to 10% by mass of a monomer d) selected from the group consisting of (meth) acrylates of ether alcohols, aminoalkyl (meth) acrylates, aminoalkyl (meth) acrylamides or mixtures thereof.

[0032] Preferably, the amounts of the monomers a), b), c), and d) in the monomer composition of the viscosity index improver (V) total 95 to 100% by mass, preferably 100% in total, based on the total mass of the viscosity index improver monomer composition.

[0033] The polybutadiene-based macromonomer a) of the present invention is an ester of (meth)acrylic acid, and the ester is a reaction product (by transesterification) of one kind of ester of (meth)acrylic acid and one kind of hydroxylated hydrogenated polybutadiene, or a reaction product (by direct esterification) of one kind of (meth)acrylic acid and one kind of hydroxylated hydrogenated polybutadiene.

[0034] In relation to the present invention, the polymer (V) includes a first polymer, also called a backbone or main chain, and a number of further polymers called side chains and covalently bonded to the backbone. In this case, the backbone of the polymer is formed by the linked unsaturated groups of the (meth)acrylate ester. The alkyl group of the (meth)acrylate ester and the hydrogenated polybutadiene chain form the side chain of the polymer. A reaction product of one kind of ester of (meth)acrylic acid and one kind of hydroxylated hydrogenated polybutadiene or a reaction product of one kind of (meth)acrylic acid and one kind of hydroxylated hydrogenated polybutadiene corresponds to monomer a), and in the present invention, it is also called a macromonomer or a polybutadiene-based macromonomer a).

[0035] The viscosity index improver polymer (V) according to the present invention can be characterized based on its molar branching degree ("f-branching"). The molar branching degree refers to the percentage in mol% of the macromonomer (monomer a)) used, based on the total molar amount of all the monomers in the monomer composition. The molar amount of the macromonomer used is calculated based on the number average molecular weight M n of the macromonomer. The calculation of the molar branching degree is described in detail in International Publication No. 2007 / 003238 (WO 2007 / 003238 A1), particularly on pages 13 and 14, and the specification is explicitly incorporated herein by reference.

[0036] Preferably, the polymer has a molar branching degree f 分岐 of 0.1 to 5 mol%, more preferably 0.5 to 4 mol% and most preferably 1.0 to 2.5 mol%.

[0037] Macromonomer a) According to the present invention, the monomer composition of the polymer (V) contains, as monomer a), 10 to 30% by mass, preferably 10 to 29% by mass, more preferably 15 to 29% by mass of a polybutadiene-based macromonomer having a number average molecular weight (M n ) of 500 to 10000 g / mol based on the total mass of the monomer composition.

[0038] Preferably, the polybutadiene-based macromonomer a) for use according to the present invention has a number average molecular weight (M n ) of 1000 to 6000 g / mol, more preferably 1500 to 5500 g / mol.

[0039] The number average molecular weight (M n ) of the macromonomer is determined by gel permeation chromatography (GPC) using a polybutadiene calibration standard (PSS Standards Service GmbH, Mainz, Germany) in accordance with DIN 55672-1 under the following measurement conditions: Eluent: Tetrahydrofuran (THF) Operating temperature: 35 °C Column set: The column set consists of 1 pre-column (PSS-SDV, 10 μ, 8×50 mm), 4 PSS-SDV columns (SDV-LXL, SDV-LinL, 2 columns SDV 100 Å (PSS Standards Service GmbH, Mainz, Germany)) with a size of 300×8 mm and an average particle size of 10 μm, and 1 solvent peak separation column (KF-800D from Shodex) with a size of 8×100 mm Flow rate: 1 mL / min Injection volume: 100 μL Equipment: Agilent 1100 series consisting of an autosampler, a pump, and a column oven Detector: Refractive index detector from the Agilent 1100 series.

[0040] Preferably, the hydroxylated hydrogenated polybutadiene has a hydrogenation level of at least 99%. An alternative measure of the hydrogenation level that can be determined for the polymers of the present invention is the iodine value. The iodine value refers to the number of grams of iodine that can be added to 100 g of the polymer. Preferably, the polymers of the present invention have an iodine value of 5 g or less of iodine per 100 g of the polymer. The iodine value is determined according to DIN 53241-1:1995-05 by the Wijs method.

[0041] Preferred hydroxylated hydrogenated polybutadiene can be obtained according to UK Patent Application Publication No. 2270317 (GB 2270317).

[0042] As used herein, the term "hydroxylated hydrogenated polybutadiene" refers to a hydrogenated polybutadiene containing one or more hydroxyl groups. The hydroxylated hydrogenated polybutadiene may further contain additional structural units, such as polyether groups derived from the addition of alkylene oxides to the polybutadiene or maleic anhydride groups derived from the addition of maleic anhydride to the polybutadiene. These additional structural units may be introduced into the polybutadiene when the polybutadiene is functionalized with hydroxyl groups.

[0043] Preferred is monohydroxylated hydrogenated polybutadiene. More preferably, the hydroxylated hydrogenated polybutadiene is a hydrogenated polybutadiene having hydroxyethyl or hydroxypropyl as a terminal group. Particularly preferred is a polybutadiene having hydroxypropyl as a terminal group.

[0044] These monohydroxylated hydrogenated polybutadienes can be produced by first converting butadiene monomers to polybutadiene by anionic polymerization. Subsequently, hydroxy-functionalized polybutadiene can be produced by the reaction of the polybutadiene monomers with an alkylene oxide, such as ethylene oxide or propylene oxide. The polybutadiene may be reacted with more than 1 alkylene oxide unit to yield a polyether-polybutadiene block copolymer having terminal hydroxyl groups. The hydroxylated polybutadiene can be hydrogenated in the presence of a suitable transition metal catalyst.

[0045] These monohydroxylated hydrogenated polybutadienes can also be selected from products obtained by hydroboration of (co)polymers having terminal double bonds (such as those described in U.S. Patent No. 4,316,973), maleic anhydride-ene-amino alcohol adducts obtained by the ene reaction of (co)polymers having terminal double bonds with maleic anhydride and amino alcohol, and products obtained by hydroformylation of (co)polymers having terminal double bonds followed by hydrogenation (such as those described in JP-A-63-175096).

[0046] The macromonomer a) for use according to the present invention can be produced by transesterification of an alkyl (meth)acrylate. The reaction of the alkyl (meth)acrylate with the hydroxylated hydrogenated polybutadiene forms the ester of the present invention. Preferably, methyl (meth)acrylate or ethyl (meth)acrylate is used as the starting material.

[0047] This transesterification is widely known. For example, for this purpose, a heterogeneous catalyst system such as a lithium hydroxide / calcium oxide mixture (LiOH / CaO), pure lithium hydroxide (LiOH), lithium methoxide (LiOMe) or sodium methoxide (NaOMe), or a homogeneous catalyst system such as isopropyl titanate (Ti(OiPr)4) or dioctyltin oxide (Sn(OCt)2O) can be used. The said reaction is an equilibrium reaction. Therefore, the low molecular weight alcohol released is typically removed, for example, by distillation.

[0048] Moreover, the said macromonomer can be obtained directly by an esterification method, for example, from (meth)acrylic acid or (meth)acrylic anhydride, preferably under acid catalysis by p-toluenesulfonic acid or methanesulfonic acid, or from free methacrylic acid by the DCC method (dicyclohexylcarbodiimide).

[0049] Furthermore, this hydroxylated hydrogenated polybutadiene can be converted to an ester by reaction with an acid chloride such as (meth)acryloyl chloride.

[0050] Preferably, in the production of the esters of the present invention detailed above, a polymerization inhibitor such as 4-hydroxy-2,2,6,6-tetramethylpiperidinooxyl radical and / or hydroquinone monomethyl ether is used.

[0051] Monomer c) Regarding the said monomer c), the term "C 7~30 alkyl (meth)acrylate" refers to an ester of (meth)acrylic acid having a linear or branched alkyl chain having 7 to 30 carbon atoms. The said term includes individual (meth)acrylic acid esters with alcohols of a specific length, and likewise mixtures of (meth)acrylic acid esters with alcohols of different lengths.

[0052] Suitable C 7~30Alkyl (meth)acrylate includes, for example, 2-butyloctyl (meth)acrylate, 2-hexyloctyl (meth)acrylate, decyl (meth)acrylate, 2-butyldecyl (meth)acrylate, 2-hexyldecyl (meth)acrylate, 2-octyldecyl (meth)acrylate, undecyl (meth)acrylate, 5-methylundecyl (meth)acrylate, dodecyl (meth)acrylate, 2-methyldodecyl (meth)acrylate, 2-hexyldodecyl (meth)acrylate, 2-octyldodecyl (meth)acrylate, tridecyl (meth)acrylate, 5-methyltridecyl (meth)acrylate, tetradecyl (meth)acrylate, 2-decyltetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, 2-methylhexadecyl (meth)acrylate, 2-dodecylhexadecyl (meth)acrylate, heptadecyl (meth)acrylate, 5-isopropylheptadecyl (meth)acrylate, 4-tert-butyloctadecyl (meth)acrylate, 5-ethyloctadecyl (meth)acrylate, 3-isopropyloctadecyl (meth)acrylate, octadecyl (meth)acrylate, 2-decyloctadecyl (meth)acrylate, 2-tetradecyloctadecyl (meth)acrylate, nonadecyl (meth)acrylate, eicosyl (meth)acrylate, cetyleicosyl (meth)acrylate, stearyleicosyl (meth)acrylate, docosyl (meth)acrylate, eicosyltetratriacontyl (meth)acrylate, 2-decyl-tetradecyl (meth)acrylate, 2-decyloctadecyl (meth)acrylate, 2-dodecyl-1-hexadecyl (meth)acrylate, 1,2-octyl-1-dodecyl (meth)acrylate, 2-tetradecyloctadecyl (meth)acrylate, 1,2-tetradecyl-octadecyl (meth)acrylate, and 2-hexadecyl-eicosyl (meth)acrylate, n-tetracosyl (meth)acrylate, n-triacontyl (meth)acrylate, and / or n-hexatriacontyl (meth)acrylate.

[0053] The term "C" 12~14"Alkyl (meth) acrylate" refers to an ester of (meth) acrylic acid and a linear or branched alcohol having 12 to 14 carbon atoms. The term includes individual (meth) acrylic acid esters with alcohols of a specific length, as well as mixtures of (meth) acrylic acid esters with alcohols of different lengths. Suitable C 12~14 Alkyl (meth) acrylate includes, for example, dodecyl methacrylate, 2-methyldodecyl methacrylate, tridecyl methacrylate, 5-methyltridecyl methacrylate and / or tetradecyl methacrylate.

[0054] Similarly, the C 16~18 Alkyl (meth) acrylate includes hexadecyl (meth) acrylate, 2-methylhexadecyl (meth) acrylate, heptadecyl (meth) acrylate, 5-isopropylheptadecyl (meth) acrylate, 4-tert-butyloctadecyl (meth) acrylate, 5-ethyloctadecyl (meth) acrylate, 3-isopropyloctadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, eicosyl (meth) acrylate, cetyleicosyl (meth) acrylate, stearyleicosyl (meth) acrylate, docosyl (meth) acrylate, behenyl (meth) acrylate, eicosyltetratriacontyl (meth) acrylate, cycloalkyl (meth) acrylate, 2,4,5-tri-t-butyl-3-vinylcyclohexyl (meth) acrylate, and 2,3,4,5-tetra-t-butylcyclohexyl (meth) acrylate, and may be independently selected, for example, from the group consisting of these. Particularly preferred C 16~18 Alkyl (meth) acrylate is stearyleicosyl (meth) acrylate.

[0055] Particularly preferred monomer c) is a (meth) acrylic acid ester of a linear C 12~14 alcohol mixture (C 12~14 alkyl methacrylate), a (meth) acrylic acid ester of a linear C 16~18 alcohol mixture (C 16~18It is an alkyl methacrylate) or a mixture thereof.

[0056] Monomer e) The monomer composition of the pour point depressant (P) according to the present invention contains 0 to 35% by mass of one monomer selected from linear or branched C1-C6 alkyl (meth) acrylates or a mixture thereof.

[0057] Examples of the C1-C6 alkyl (meth) acrylate monomers having 1 to 6 carbon atoms in the linear or branched alkyl group are methyl methacrylate (MMA), methyl and ethyl acrylate, propyl methacrylate, butyl methacrylate (BMA) and acrylate (BA), isobutyl methacrylate (IBMA), hexyl and cyclohexyl methacrylate, cyclohexyl acrylate and combinations thereof. The most preferred C1-C6 alkyl (meth) acrylate monomer is methyl methacrylate.

[0058] Monomer f) The monomer composition of the pour point depressant polymer (P) according to the present invention contains 20 to 95% by mass, preferably 25 to 95% by mass, of one monomer selected from linear or branched C7-C 15 alkyl (meth) acrylates, based on the total mass of the monomer composition. Preferred C7-C 15 alkyl (meth) acrylates are C 12 -C 14 alkyl (meth) acrylates.

[0059] Examples of the C7-C 15Examples of alkyl (meth)acrylate monomers are 2-ethylhexyl acrylate (EHA), 2-ethylhexyl methacrylate, octyl methacrylate, nonyl methacrylate, decyl methacrylate, isodecyl methacrylate (IDMA, based on a branched (C10) alkyl isomer mixture), undecyl methacrylate, dodecyl methacrylate (also known as lauryl methacrylate), tridecyl methacrylate, tetradecyl methacrylate (also known as myristyl methacrylate), pentadecyl methacrylate and mixtures thereof. More preferred C7-C 15 The alkyl (meth)acrylate monomers are mixtures of linear and branched isomers of dodecyl-pentadecyl methacrylate (DPMA), dodecyl, tridecyl, tetradecyl and pentadecyl methacrylate, decyl-octyl methacrylate (DOMA), mixtures of decyl and octyl methacrylate, nonyl-undecyl methacrylate (NUMA), mixtures of nonyl, decyl and undecyl methacrylate, and lauryl-myristyl methacrylate (LMA), mixtures of dodecyl and tetradecyl methacrylate. Preferred C7-C 15 The alkyl (meth)acrylate is lauryl-myristyl methacrylate (LMA).

[0060] Monomer g) The monomer composition of the pour point depressant polymer according to the present invention contains at least one monomer selected from linear or branched C 16 -C 24 alkyl (meth)acrylate in an amount of 5 to 60% by mass, preferably 5 to 50% by mass, based on the total mass of the monomer composition.

[0061] The linear or branched alkyl group having 16 to 24 carbon atoms of the C 16 -C 24Examples of alkyl (meth) acrylate monomers are hexadecyl methacrylate (also known as cetyl methacrylate), heptadecyl methacrylate, octadecyl methacrylate (also known as stearyl methacrylate), nonadecyl methacrylate, eicosyl methacrylate, behenyl methacrylate, and mixtures thereof. More preferred C 16 ~C 24 alkyl (meth) acrylate monomers are cetyl-eicosyl methacrylate (CEMA), a mixture of hexadecyl, octadecyl, and eicosyl methacrylate, cetyl-stearyl methacrylate (SMA), or a mixture of hexadecyl and octadecyl methacrylate. Most preferred C 16 ~C 24 alkyl (meth) acrylate is selected from the group consisting of cetyl-eicosyl methacrylate (CEMA), cetyl-stearyl methacrylate (SMA), or a mixture thereof.

[0062] Method for producing an additive composition according to the present invention The present invention also relates to a method for producing an additive composition (A) according to the present invention, the method comprising the following steps: (x) A step of producing a viscosity index improver (V), preparing a monomer composition defined in the above section "Additive composition of the present invention", and initiating radical polymerization in the monomer composition to produce the polymer (V). (y) A step of producing a pour point depressant (P), preparing a monomer composition defined in the above section "Additive composition of the present invention", and initiating radical polymerization in the monomer composition to produce the polymer (P). (z) A step of mixing the viscosity index improver polymer (V) with the pour point depressant polymer (P) to provide an additive composition (A) according to the present invention including.

[0063] Standard free radical polymerization is described in detail, inter alia, in Ullmann's Encyclopedia of Industrial Chemistry, 6th Edition. Generally, polymerization initiators and optionally chain transfer agents are used for this purpose.

[0064] The ATRP method is known per se. Although it is presumed to be "living" free radical polymerization, it is not intended to be limited by the description of the mechanism. In these methods, a transition metal compound is reacted with a compound having a movable atomic group. This involves the transfer of the movable atomic group to the transition metal compound, as a result of which the metal is oxidized. This reaction forms free radicals, which add to the ethylene group. However, the transfer of the atomic group to the transition metal compound is reversible, and thus the atomic group moves back to the growing polymer chain, resulting in the formation of a controlled polymerization system. Accordingly, it is possible to control the formation, molecular weight and molecular weight distribution of the polymer.

[0065] This reaction mode is described, for example, in J.-S. Wang, et al., J. Am. Chem. Soc, vol. 117, p. 5614-5615 (1995), Matyjaszewski, Macromolecules, vol. 28, p. 7901-7910 (1995). Moreover, the patent application specifications of International Publication No. 96 / 30421 (WO 96 / 30421), International Publication No. 97 / 47661 (WO 97 / 47661), International Publication No. 97 / 18247 (WO 97 / 18247), International Publication No. 98 / 40415 (WO 98 / 40415) and International Publication No. 99 / 10387 (WO 99 / 10387) disclose modified ATRP methods as described above. Moreover, the polymers of the present invention can also be obtained, for example, by the RAFT method. This method is described in detail, for example, in International Publication No. 98 / 01478 (WO 98 / 01478) and International Publication No. 2004 / 083169 (WO 2004 / 083169).

[0066] The polymerization can be carried out under standard pressure, reduced pressure or elevated pressure. The polymerization temperature is not critical either. However, the polymerization temperature generally ranges from -20 to 200 °C, preferably from 50 to 150 °C and more preferably from 80 to 130 °C.

[0067] Preferably, the oil used to dilute the monomer composition for polymer (V) or polymer (P) is an oil of API Group I, II, III, IV or V, or a mixture thereof. Preferably, Group III oil or a mixture thereof is used to dilute the monomer composition.

[0068] Preferably, the polymerization step for polymer (V) or polymer (P) involves the addition of a radical initiator.

[0069] Suitable radical initiators are, for example, azo initiators such as azobis-isobutyronitrile (AIBN), 2,2'-azobis(2-methylbutyronitrile) (AMBN) and 1,1-azobiscyclohexanecarbonitrile, and peroxy compounds such as methyl ethyl ketone peroxide, acetylacetone peroxide, dilauryl peroxide, tert-butyl peroxy-2-ethylhexanoate, ketone peroxide, tert-butyl peroctoate, methyl isobutyl ketone peroxide, cyclohexanone peroxide, dibenzoyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxyisopropyl carbonate, 2,5-bis(2-ethylhexanoylperoxy)-2,5-dimethylhexane, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxy-3,5,5-trimethylhexanoate, dicumyl peroxide, 1,1-bis(tert-butylperoxy)cyclohexane, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, cumyl hydroperoxide, tert-butyl hydroperoxide and bis(4-tert-butylcyclohexyl) peroxydicarbonate.

[0070] Preferably, the radical initiator is selected from the group consisting of 2,2′-azobis(2-methylbutyronitrile), 2,2-bis(tert-butylperoxy)butane, tert-butyl peroxy 2-ethylhexanoate, 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane, tert-butyl peroxybenzoate, and tert-butyl peroxy-3,5,5-trimethylhexanoate. Particularly preferred initiators are tert-butyl peroxy 2-ethylhexanoate and 2,2-bis(tert-butylperoxy)butane.

[0071] Preferably, the total amount of the radical initiator relative to the total mass of the monomer composition of polymer (V) or polymer (P) is 0.01 to 5% by mass, more preferably 0.02 to 1% by mass, and most preferably 0.05 to 0.5% by mass.

[0072] The total amount of the radical initiator may be added in a single step, or the radical initiator may be added in several steps over the course of the polymerization reaction. Preferably, the radical initiator is added in several steps. For example, a portion of the radical initiator may be added to initiate radical polymerization, and another portion of the radical initiator may be added 0.5 to 3.5 hours after the first dosage.

[0073] Preferably, step (y) also includes the addition of a chain transfer agent. Suitable chain transfer agents are, in particular, oil-soluble mercaptans such as n-dodecyl mercaptan or 2-mercaptoethanol, or alternatively chain transfer agents from the terpene type such as terpinolene. Particularly preferred is the addition of n-dodecyl mercaptan.

[0074] Preferably, the total reaction time of the radical polymerization is 2 to 10 hours, more preferably 3 to 9 hours.

[0075] After completion of the radical polymerization, the resulting polymers (P) and (V) are mixed to provide the additive composition (A) according to the invention. Subsequently, the additive composition (A) is preferably further diluted to a desired viscosity with the above oil. Preferably, the additive composition (A) has a solid polymer content of at least 25% by mass based on the total mass of the polymers (P) and (V) in the additive composition (A).

[0076] Use of the additive composition according to the invention The invention also relates to the use of the additive composition as a lubricant additive in the lubricating oil formulation for improving the storage stability, viscosity index and low temperature performance of the lubricating oil formulation.

[0077] The invention also relates to a method for improving the storage stability, viscosity index and low temperature performance of a lubricating oil formulation by adding and mixing the additive composition (A) according to the invention as a lubricant additive in the lubricating oil formulation.

[0078] The additive composition (A) of the invention can thereby be used as a lubricant additive in a lubricating oil formulation, and as a result, not only improves the compatibility and storage stability, but also improves the low temperature performance and the viscosity index. Therefore, this approach can avoid any incompatibility between different package components, dispersants and other additives in the lubricant formulation. This is because the additive composition of the invention already combines two additive lubricant polymers, namely VII and PPD, which exhibit extremely good compatibility and viscosity performance.

[0079] Lubricating oil formulation comprising the additive composition according to the invention The invention relates to (i) one base oil or a mixture of a plurality of base oils, and (ii) the additive composition (A) according to the invention and also relates to a lubricating oil formulation containing the same.

[0080] The lubricating oil composition may optionally contain the further additive (iii) described below.

[0081] The concentration (also referred to as the treatment rate) of the additive composition (A) according to the present invention in the lubricating oil composition may range, for example, from 0.1 to 99.5% by mass, or from 0.5 to 99.5% by mass. Preferably, the amount of the one or more base oils (component (i)) is 0.5 to 80% by mass, more preferably 50 to 80% by mass, and the amount of the additive composition (component (ii)) is preferably 20 to 99.5% by mass, more preferably 20 to 50% by mass, respectively, based on the total mass of the lubricating oil composition.

[0082] Preferably, the amounts of (i) and (ii) total 95 to 100% by mass.

[0083] The additive composition (A) of the present invention and the lubricating oil composition containing the additive composition according to the present invention are advantageously used in drive system lubricating oils (e.g., manual transmission oils, differential gear oils, automatic transmission oils, and belt-type continuously variable transmission oils, axle fluid formulations, dual clutch transmission oils, and hybrid-exclusive transmission oils), hydraulic oils (e.g., hydraulic oils for mechanical devices, power steering oils, shock absorber oils), engine oils (for gasoline engines and diesel engines), and industrial oil formulations (e.g., wind turbines).

[0084] When the lubricating oil composition according to the present invention is used as an engine oil, preferably, based on the total mass of the lubricant composition, it contains 0.5% to 10% by mass, more preferably 0.5% to 8% by mass, of the additive composition according to the present invention, and provides a kinematic viscosity at 100 °C in the range of 4 mm 2 / s to 10 mm 2 / s.

[0085] When the lubricating oil composition of the present invention is used as an automotive gear oil, preferably, based on the total mass of the lubricant composition, the additive composition according to the present invention is 0.5% by mass to 10% by mass, more preferably 0.5% by mass to 8% by mass, and has a kinematic viscosity at 100 °C within the range of 2 mm 2 / s to 15 mm 2 / s as measured according to ASTM D445.

[0086] When the lubricant composition of the present invention is used as an automatic transmission oil, preferably, based on the total mass of the lubricant composition, the additive composition according to the present invention is 0.5% by mass to 10% by mass, more preferably 0.5% by mass to 8% by mass, and has a kinematic viscosity at 100 °C within the range of 2 mm 2 / s to 6 mm 2 / s as measured according to ASTM D445.

[0087] The kinematic viscosity can be measured according to ASTM D445. Preferably, the kinematic viscosity is measured at temperatures of 100 °C and 40 °C.

[0088] The base oil (i) that can be used in the lubricating oil composition preferably includes oils of lubricating viscosity. Such oils include natural and synthetic oils, oils derived from hydrocracking, hydrogenation, and hydrofinishing, unrefined oils, refined oils, recycled oils, or mixtures thereof.

[0089] The base oil can also be defined as specified by the American Petroleum Institute (API) (see the April 2008 edition of “Appendix E - API Base Oil Interchangeability Guidelines for Passenger Car Motor Oils and Diesel Engine Oils”, section 1.3, subheading 1.3. “Base Stock Categories”).

[0090] The API currently defines five groups of lubricant base stocks (API 1509, Annex E - API Base Oil Interchangeability Guidelines for Passenger Car Motor Oils and Diesel Engine Oils, September 2011). Groups I, II, and III are mineral oils classified by the amount of saturates and sulfur they contain and their viscosity index, Group IV is polyalphaolefin, and Group V is everything else, including, for example, ester oils. Table 1 below illustrates these API classifications.

[0091] Table 1 :

Table 1

[0092] The kinematic viscosity (KV 100 ) at 100 °C of a suitable base oil used to produce the lubricant composition according to the present invention is preferably in the range of 1 mm 2 / s to 10 mm 2 / s, more preferably in the range of 1 mm 2 / s to 8 mm 2 / s, even more preferably in the range of 1 mm 2 / s to 5 mm 2 / s, as per ASTM D445.

[0093] Further base oils that can be used according to the present invention are Group II - III Fischer - Tropsch derived base oils.

[0094] The Fischer-Tropsch derived base oil is known in the art. The term "Fischer-Tropsch derived" means that the base oil is a synthetic product of the Fischer-Tropsch process or is derived from said synthetic product. The Fischer-Tropsch derived base oil may also be referred to as GTL (Gas to Liquid) base oil. Suitable Fischer-Tropsch derived base oils that can be advantageously used as the base oil in the lubricating composition of the present invention are disclosed, for example, in European Patent Application Publication No. 0776959 (EP0776959), European Patent Application Publication No. 0668342 (EP0668342), International Publication No. 97 / 21788 (WO97 / 21788), International Publication No. 00 / 15736 (WO00 / 15736), International Publication No. 00 / 14188 (WO00 / 14188), International Publication No. 00 / 14187 (WO00 / 14187), International Publication No. 00 / 14183 (WO00 / 14183), International Publication No. 00 / 14179 (WO00 / 14179), International Publication No. 00 / 08115 (WO00 / 08115), International Publication No. 99 / 41332 (WO99 / 41332), European Patent Application Publication No. 1029029 (EP1029029), International Publication No. 01 / 18156 (WO01 / 18156), International Publication No. 01 / 57166 (WO01 / 57166) and International Publication No. 2013 / 189951 (WO2013 / 189951).

[0095] In particular, for the transmission oil formulation, base oils of API Group III and mixtures of different Group III oils are used. In a preferred embodiment, said one or more base oils (i) are API Group III base oils or mixtures of API Group III base oils.

[0096] The lubricating oil formulations according to the present invention are further characterized by their low kinematic viscosities at temperatures of 40 °C or less. Said KV 40 is preferably less than 40 mm 2 / s, more preferably 20 - 40 mm 2 / s. Said KV 40 is the kinematic viscosity at 40 °C and can be measured in accordance with ASTM D445.

[0097] The lubricating oil composition preferably has a viscosity index of more than 180, more preferably more than 200, and most preferably more than 210. The viscosity index can be measured according to ASTM D2270.

[0098] The lubricating oil composition according to the present invention is preferably a transmission oil or a lubricating engine oil composition.

[0099] The lubricating oil composition according to the present invention may contain, as component (iii), a further additive selected from the group consisting of a friction modifier, a dispersant, an antifoaming agent, a detergent, an antioxidant, an antiwear additive, an extreme pressure additive, a corrosion inhibitor, a dye, and mixtures thereof.

[0100] Suitable dispersants include poly(isobutylene) derivatives such as poly(isobutylene) succinimides (PIBSIs) including boronated PIBSIs, and ethylene-propylene oligomers having N / O functionality.

[0101] The dispersant (including the boronated dispersant) is preferably used in an amount of 0 to 5% by mass based on the total amount of the lubricant composition.

[0102] Suitable antifoaming agents are silicone oil, fluorosilicone oil, and fluoroalkyl ether.

[0103] The antifoaming agent is preferably used in an amount of 0.005 to 0.1% by mass based on the total amount of the lubricant composition.

[0104] Preferred detergents include metal-containing compounds such as phenoxides, salicylates, thiophosphonates, especially thiopyrophosphonates, thiophosphonates and phosphonates, sulfonates and carbonates. As the metal, these compounds may especially contain calcium, magnesium and barium. These compounds may preferably be used in neutral or overbased form.

[0105] The detergent is preferably used in an amount of 0.2 to 1% by mass based on the total amount of the lubricant composition.

[0106] Suitable antioxidants include, for example, phenolic antioxidants and amine antioxidants.

[0107] Phenolic antioxidants include, for example, octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 4,4′-methylenebis(2,6-di-tert-butylphenol), 4,4′-bis(2,6-di-t-butylphenol), 4,4′-bis(2-methyl-6-t-butylphenol), 2,2′-methylenebis(4-ethyl-6-t-butylphenol), 2,2′-methylenebis(4-methyl-6-t-butylphenol), 4,4′-butylidenebis(3-methyl-6-t-butylphenol), 4,4′-isopropylidenebis(2,6-di-t-butylphenol), 2,2′-methylenebis(4-methyl-6-nonylphenol), 2,2-isobutylidenebis(4,6-dimethylphenol), 2,2′-methylenebis(4-methyl-6-cyclohexylphenol), 2,6-di-t-butyl-4-methylphenol, 2,6-di-t-butyl-4-ethylphenol, 2,4-dimethyl-6-t-butylphenol, 2,6-di-t-amyl-p-cresol, 2,6-di-t-butyl-4-(N,N′-dimethylaminomethylphenol), 4,4′-thiobis(2-methyl-6-t-butylphenol), 4,4′-thiobis(3-methyl-6-t-butylphenol), 2,2′-thiobis(4-methyl-6-t-butylphenol), bis(3-methyl-4-hydroxy-5-t-butylbenzyl)sulfide, bis(3,5-di-t-butyl-4-hydroxybenzyl)sulfide, n-octyl-3-(4-hydroxy-3,5-di-t-butylphenyl)propionate, n-octadecyl-3-(4-hydroxy-3,5-di-t-butylphenyl)propionate, 2,2′-thio[diethyl-bis-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]. Among these, bisphenolic antioxidants and phenolic antioxidants having an ester group are particularly preferred.

[0108] The amine-based antioxidant includes, for example, monoalkyl diphenylamine such as monooctyl diphenylamine, monononyl diphenylamine, dialkyl diphenylamine such as 4,4'-dibutyldiphenylamine, 4,4'-dipentyldiphenylamine, 4,4'-dihexyldiphenylamine, 4,4'-diheptyldiphenylamine, 4,4'-dioctyldiphenylamine, 4,4'-dinonyldiphenylamine, polyalkyl diphenylamine such as tetrabutyl diphenylamine, tetrahexyl diphenylamine, tetraoctyl diphenylamine, tetranonyl diphenylamine, naphthylamines, specifically α-naphthylamine, phenyl-α-naphthylamine and further alkyl-substituted phenyl-α-naphthylamine such as butylphenyl-α-naphthylamine, pentylphenyl-α-naphthylamine, hexylphenyl-α-naphthylamine, heptylphenyl-α-naphthylamine, octylphenyl-α-naphthylamine, nonylphenyl-α-naphthylamine. Among these, diphenylamines are more preferable than naphthylamines from the viewpoint of their antioxidant effects.

[0109] Suitable antioxidants may further be selected from the group consisting of compounds containing sulfur and phosphorus, such as metal dithiophosphates such as zinc dithiophosphate (ZnDTP), "OOS triester" = the reaction product of dithiophosphoric acid with activated double bonds from olefins, cyclopentadiene, norbornadiene, α-pinene, polybutene, acrylate, maleate (ashless during combustion), organic sulfur compounds such as dialkyl sulfide, diaryl sulfide, polysulfide, modified thiol, thiophene derivative, xanthate, thioglycol, thioaldehyde, sulfur-containing carboxylic acid, heterocyclic sulfur / nitrogen compounds, especially dialkyldimercaptothiadiazole, 2-mercaptobenzimidazole, zinc bis(dialkyldithiocarbamate) and methylenebis(dialkyldithiocarbamate), organic phosphorus compounds such as triaryl and trialkyl phosphite, organic copper compounds and overbased calcium and magnesium-based phenoxides and salicylates.

[0110] The antioxidant is used in an amount of 0 to 15% by mass, preferably 0.1 to 10% by mass, more preferably 0.5 to 5% by mass, based on the total amount of the lubricant composition.

[0111] Preferred antiwear additives and extreme pressure additives include sulfur-containing compounds such as zinc dithiophosphate, zinc di-C 3~12 -alkyldithiophosphate (ZnDTP), zinc phosphate, zinc dithiocarbamate, molybdenum dithiocarbamate, molybdenum dithiophosphate, disulfide, sulfurized olefin, sulfurized oil and fat, sulfurized ester, thiocarbonate, thiocarbamate, polysulfide, phosphorus-containing compounds such as phosphite, phosphate such as trialkyl phosphate, triaryl phosphate such as tricresyl phosphate, amine-neutralized monoalkyl and dialkyl phosphates, ethoxylated monoalkyl and dialkyl phosphates, phosphonate, phosphine, amine salts or metal salts of these compounds, sulfur- and phosphorus-containing antiwear agents such as thiophosphite, thiophosphate, thiophosphonate, amine salts or metal salts of these compounds.

[0112] The antiwear agent may be present in an amount of 0 to 3% by mass, preferably 0.1 to 1.5% by mass, more preferably 0.5 to 0.9% by mass, based on the total amount of the lubricant composition.

[0113] Preferred friction modifiers include mechanically active compounds such as molybdenum disulfide, graphite (including fluorinated graphite), poly(trifluoroethylene), polyamides, polyimides; compounds that form adsorption layers such as long-chain carboxylic acids, fatty acid esters, ethers, alcohols, amines, amides, imides; compounds that form layers by tribochemical reactions such as saturated fatty acids, phosphoric and thiophosphoric acid esters, xanthates, sulfurized fatty acids; compounds that form polymer-like layers such as ethoxylated dicarboxylic acid partial esters, dialkyl phthalates, methacrylates, unsaturated fatty acids, sulfurized olefins; and organometallic compounds such as molybdenum compounds (molybdenum dithiophosphates and molybdenum dithiocarbamates MoDTC) and combinations thereof with ZnDTPs, and may include copper-containing organic compounds.

[0114] Some of the compounds listed above can satisfy multiple functions. For example, ZnDTP is not only mainly an antiwear additive and an extreme pressure additive, but also has the characteristics of an antioxidant and a corrosion inhibitor (here: metal passivator / inactivator).

[0115] The additives detailed above are described in detail, inter alia, in T. Mang, W. Dresel (eds.): “Lubricants and Lubrication”, Wiley-VCH, Weinheim 2001, R. M. Mortier, S. T. Orszulik (eds.): “Chemistry and Technology of Lubricants”.

[0116] Preferably, the total concentration of one or more of the above additives (iii) is up to 20% by mass, more preferably 0.05% to 15% by mass, and even more preferably 5% to 15% by mass, based on the total mass of the lubricating oil formulation.

[0117] Preferably, the amounts of (i) to (iii) total 90 to 100% by mass, more preferably total 95 to 100% by mass, and even more preferably total 100% by mass, based on the total mass of the lubricating oil composition.

Examples

[0118] Experimental Section Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, which are not intended to limit the scope of the present invention in any way.

[0119] Abbreviation C1AMA C1-alkyl methacrylate = methyl methacrylate (MMA) C4AMA C4-alkyl methacrylate = n-butyl methacrylate C 12 / 14 AMA n-C 12 / 14 -alkyl methacrylate C 16 / 18 AMA n-C 16 / 18 -alkyl methacrylate CTA Chain transfer agent DDM Dodecyl mercaptan f 分岐 Degree of branching Initiator tert-butyl peroxy-2-ethylhexanoate KV 40 Kinematic viscosity at 40°C, measured according to ASTM D7042 KV 100 Kinematic viscosity at 100°C, measured according to ASTM D7042 MA-1 Macroalcohol of hydrogenated polybutadiene having a methacrylate functional group (M n = 2000 g / mol) MA-2 Macroalcohol of hydrogenated polybutadiene having a methacrylate functional group (M n = 4750 g / mol) MM-1 Macromonomer of hydrogenated polybutadiene having a methacrylate functional group (M n = 2000 g / mol) Macromonomer (M) of hydrogenated polybutadiene having an MM-2 methacrylate functional group n = 4750 g / mol M n Number average molecular weight M w Mass average molecular weight NB3020 Nexbase® 3020, KV of 2.2 cSt 100 Group III base oil from Neste having NB3043 Nexbase® 3043, KV of 4.3 cSt 100 Group III base oil from Neste having Base oils (C) with KV of 3.1 and 4.2 cSt respectively 100 Mixture of commercially available API base oils Yubase 3 (API Group II base oil) and Yubase 4 plus (API Group III base oil) from SK Lubricants Co., Ltd. having a mass ratio of 70 / 30 OEM partner trademark product manufacturer PDI Polydispersity index, M w / M n Molecular weight distribution calculated by Sty Styrene VI Viscosity index, measured according to ASTM D2270.

[0120] Test method The polymers according to the present invention and the comparative examples were characterized with respect to their molecular weights and PDI.

[0121] In the present invention, the mass average molecular weight (M w ) of the said polymers (pour point depressant (P) and viscosity index improver (V)) is determined by gel permeation chromatography (GPC) using a polymethyl methacrylate calibration standard under the following measurement conditions: Eluent: Tetrahydrofuran (THF) Operating temperature: 40 °C Column set: The column set consists of one pre-column (PSS-SDV 100 Å 10μm 8.0×50mm) and three columns (2×PSS-SDV Linear XL 10μm 8.0×300mm, 1×PSS-SDV 100 Å 10μm 8.0×300mm), and all columns have an average particle size of 10μm (PSS Standards Service GmbH, Mainz, Germany). Flow rate: 1 mL / min Injection volume: 100 μL Equipment: Shodex GPC101 consisting of an autosampler, a pump, and a column oven Detector: Refractive index detector from Shodex.

[0122] The number average molecular weight (M n ) of the macromonomer is determined by gel permeation chromatography (GPC) using a polybutadiene calibration standard (PSS Standards Service GmbH, Mainz, Germany) in accordance with DIN 55672-1 under the following measurement conditions: Eluent: Tetrahydrofuran (THF) Operating temperature: 35 °C Column set: The column set consists of one pre-column (PSS-SDV, 10μ, 8×50mm), four PSS-SDV columns (SDV-LXL, SDV-LinL, two columns SDV 100 Å with a size of 300×8mm and an average particle size of 10μm (PSS Standards Service GmbH, Mainz, Germany)), and one solvent peak separation column (KF-800D from Shodex) with a size of 8×100mm Flow rate: 1 mL / min Injection volume: 100 μL Equipment: Agilent 1100 series consisting of an autosampler, a pump, and a column oven Detector: Refractive index detector from Agilent 1100 series.

[0123] The additive composition (A) containing polymers (P) and (V) according to the present invention and comparative examples were characterized in terms of their viscosity index (VI) according to ASTM D 2270, and their kinematic viscosities at 40 °C (KV 40 ) and 100 °C (KV 100 ) according to ASTM D7042.

[0124] The storage test was carried out at 25 °C for 1 week after the production of the additive composition consisting of blending (V) and (P), and determined by visual observation. "Good" means that the additive composition exhibits a clear appearance after the storage. "Poor" means that the additive composition exhibits a hazy appearance, which means inhomogeneity and has a risk of separation after long-term storage. Generally, the additive composition is stored in drums or bulk tanks. If the additive composition separates into two phases (VII and PPD) during storage, the fluid containing the additive composition does not provide appropriate viscosity characteristics. This is because the appropriate blending amounts of VII and PPD are not charged into the fluid due to the separation.

[0125] Synthesis of macroalcohols (hydroxylated hydrogenated polybutadiene) MA-1 and MA-2 The macroalcohols were synthesized by anionic polymerization of 1,3-butadiene using butyllithium at 20 - 45 °C. When the desired degree of polymerization was reached, the reaction was stopped by the addition of propylene oxide, and lithium was removed by precipitation with methanol. Subsequently, the polymer was hydrogenated at a maximum of 140 °C and a pressure of 200 bar in the presence of a noble metal catalyst under a hydrogen atmosphere. After the hydrogenation was completed, the noble metal catalyst was removed, and the organic solvent was withdrawn under reduced pressure. Finally, MA-2 was diluted with NB3020 to a polymer content of 70% by mass. MA-1 was maintained at 100%.

[0126] Table 2 summarizes the characterization data of MA-1 and MA-2.

[0127] Table 2: Characterization data of the macromonomers used.

Table 2

[0128] Synthesis of macromonomers MM-1 and MM-2 In a 2 L stirring device equipped with a servo stirrer, an air inlet tube, a thermocouple with a controller, a heating mantle, a column with an irregular filling of 3 mm wire spirals, a steam distributor, a top thermometer, a reflux condenser, and a cooling plate, 1000 g of the above-mentioned macroalcohol is dissolved in methyl methacrylate (MMA) by stirring at 60 °C. Added to the solution are 20 ppm of 2,2,6,6-tetramethylpiperidine-1-oxyl radical and 200 ppm of hydroquinone monomethyl ether. While passing air for stabilization, after heating to MMA reflux (bottom temperature about 110 °C), about 20 mL of MMA is distilled off for azeotropic drying. After cooling to 95 °C, LiOCH3 is added and the mixture is heated back to reflux. After a reaction time of about 1 hour, the top temperature decreased to about 64 °C due to methanol formation. The formed methanol / MMA azeotropic mixture is continuously distilled off until a constant top temperature of about 100 °C is re-established. At this temperature, the mixture is reacted for another 1 hour. For further post-treatment, most of the MMA is withdrawn under reduced pressure. The insoluble catalyst residue is removed by pressure filtration (Seitz T1000 depth filter).

[0129] Table 3 summarizes the amounts of macroalcohol, MMA, and LiOCH3 used in the synthesis of macromonomers MM-1 and MM-2.

[0130] Table 3 : Amounts of macroalcohol, MMA, and catalyst for transesterification of the macromonomer.

Table 3

[0131] The hydroxylated hydrogenated polybutadienes described above may also be referred to as macroalcohols in the context of the present invention because of their high molecular weights. The corresponding esters of (meth)acrylic acid may also be referred to as macromonomers in the context of the present invention (monomer a)).

[0132] Synthesis of the polymers according to the invention Viscosity Index Improver (V-1) of the Example The monomer mixture whose composition is shown in Table 5 is diluted with a 1.3 / 98.7 mixture of Nexbase 3020 and Hydroseal G232 H, so that the concentration of the monomers in the oil is 60% by weight. 50% by weight of the reaction mixture produced above is charged to an apparatus equipped with a four-necked flask and a precision glass servel stirrer. After heating to 90 °C under nitrogen, 0.18% by weight (relative to the amount of monomers) of the 2,2-bis(tert-butylperoxy)butane initiator is added to the reaction mixture to initiate the reaction. The same amount of initiator and Hydroseal G232 H is added to the remaining 50% of the reaction mixture, so that the concentration of the monomers in the oil is 40% by weight, and this is continuously added to the flask at 90 °C over 3 hours. The reaction is maintained at 90 °C for 1 hour after the dosing of the reaction mixture, and 0.2% by weight (relative to the amount of monomers) of 2,2-bis(tert-butylperoxy)butane is added. The reaction mixture is further stirred at 90 °C for 2 hours, 0.2% (relative to the amount of monomers) of 2,2-bis(tert-butylperoxy)butane is added, and then diluted with Hydroseal G232 H to a 35% by weight solution of the polymer in the oil to obtain the final VII (V-1).

[0133] Viscosity Index Improver (V-2) of the Example The monomer mixture whose composition is shown in Table 5 is diluted with a 15.52 / 65.45 / 19.03 mixture of Nexbase 3020, Hydroseal G232 H and Nexbase 3043, so that the concentration of the monomer in the oil is 60% by mass. 50% by mass of the reaction mixture produced above was charged into an apparatus equipped with a four-necked flask and a precision glass stirrer. After heating to 90 °C under nitrogen, 0.09% by mass (relative to the amount of monomer) of 2,2-bis(tert-butylperoxy)butane initiator was added to the reaction mixture to initiate the reaction. 0.29% (relative to the amount of monomer) of the initiator was added to the remaining 50% of the reaction mixture, and this was continuously added to the flask at 90 °C over 3 hours. The reaction was maintained at 90 °C for 1 hour after the dosing of the reaction mixture, and 0.18% by mass (relative to the amount of monomer) of 2,2-bis(tert-butylperoxy)butane and Nexbase 3043 were continuously added to the flask over 3 hours, so that the product solid after the end of the feed was 39.8% by mass. The reaction mixture was stirred at 90 °C for a further 2 hours, 0.18% (relative to the amount of monomer) of 2,2-bis(tert-butylperoxy)butane was added, and then diluted with Nexbase 3043 to a 25% by mass solution of the polymer in oil to obtain the final VII (V-2).

[0134] Pour Point Depressants P-1 to P-6 of the Example and Pour Point Depressant P-7 of the Comparative Example * and P-8 * A four-necked glass round-bottom flask equipped with a condenser, a stirrer and a thermocouple was charged with the monomer mixture consisting of the monomers shown in Table 4 and DDM and Hydroseal G232 H, so that the concentration of the monomer in the oil was 97.7% by mass. The monomer mixture was heated to 120 °C under nitrogen.

[0135] Production of the initiator solution: 0.2% by mass (relative to the total mass of the monomer) of 2,2-bis(tert-butylperoxy)butane initiator was diluted with Hydroseal G232 H, so that the concentration of the initiator in the oil was 20% by mass.

[0136] 10% by mass of the total initiator solution was added to the flask over 45 minutes. Subsequently, 20% by mass of the total initiator feed mixture was added to the flask over 45 minutes. Thereafter, the reaction temperature was raised to 105°C, and then the remaining initiator feed mixture was added to the flask over 30 minutes. The reaction mixture was held at 105°C for 60 minutes, and then Hydroseal G232 H was added, so that the product solid was 56.66% by mass and stirred at 105°C for 60 minutes to obtain the final PPD (Examples: P-1 to P-6 and Comparative Examples: P-7 * and P-8 * ).

[0137] Table 4 below shows the reaction mixtures used to produce the examples and comparative examples. The monomer components total 100%. The amount of the chain transfer agent is given relative to the total amount of the monomers. The weight-average molecular weight (M w ) is also shown in Table 4.

[0138] The above PPD (P-1 to P-6, P-7 * and P-8 * ) and VIIs (V-1 and V-2) were mixed, and an additive composition (Examples: Example A-1 to Example A-10 and Comparative Examples: Comparative A-1 * to Comparative A-3 * ) was obtained. The blend ratio, polymer content and appearance (storage test) are shown in Table 5 and Table 6 below.

[0139] The examples (Example A-1 to Example A-10) of the additive composition showed a clear appearance after the storage test, which means that the combination of VII and PPD according to the present invention results in an additive composition having good compatibility and good storage performance. In contrast, the comparative additive compositions (Comparative A-1 * to Comparative A-3 * ) showed a cloudy appearance due to the poor compatibility of the VII component and the PPD component.

[0140]

Table 4

[0141]

Table 5

[0142]

Table 6

[0143] Evaluation of Additive Composition Candidates Additive compositions A-1 to A-4 and A-6 according to the present invention, and comparison A-1 of comparative additive compositions * ~ Comparison A-3 * were blended with the ATF package and base oil (C) according to the blend ratios shown in Table 7, and KV 100 , KV 40 , VI and BF-40 were evaluated. Examples F of the lubricating oil formulations of the present invention and Comparative F of the comparative lubricating oil formulations and their viscosity performances are shown in Table 7 below.

[0144] To demonstrate that the effect on the viscosity index is improved when using the additive composition of the present invention in the lubricating oil formulation, the KV 100 of all fluids was adjusted to 4.9 to 5.0 cSt.

[0145] Examples F-1 to F-3 of the lubricating oil formulation and Comparative F-1 * all contain the same VII component V-1. While maintaining appropriate low-temperature characteristics (BF-40), the formulations according to the present invention (Examples F-1 to F-3) also have a difference of 3 to 7 points in the VI value compared to Comparative F-1 * of the comparative formulation and exhibit a much higher viscosity index.

[0146] Examples F-4 to F-5 of the lubricating oil formulation of the present invention, and Comparative F-2 * and Comparative F-3 *All contain the same VII component V-2. While maintaining appropriate low-temperature properties (BF-40), the formulations according to the invention (Examples F-4 to F-5) also have a difference of 6 to 8 points in the VI value compared to Comparative Formulations Comparative F-2 * and Comparative F-3 * and exhibit a much higher viscosity index, with a difference of 6 to 8 points in the VI value compared to them.

[0147]

Table 7

Claims

1. An additive composition (A) for adding to a lubricating oil formulation, comprising a viscosity index improver (V) and a pour point depressant (P), wherein the viscosity index improver (V) is a polymer having a mass average molecular weight (Mw) of 100,000 to 1,000,000 g / mol and a monomer composition comprising: a) one or more polybutadiene-based macromonomers a) having a number average molecular weight of 500 to 10,000 g / mol, 10 to 30% by mass based on the total mass of the monomer composition for the viscosity index improver, b) one monomer or a mixture thereof selected from the group consisting of methyl (meth)acrylate, butyl (meth)acrylate, styrene or a substituted styrene having an alkyl substituent in the side chain [wherein the styrene or substituted styrene has 8 to 17 carbon atoms], 50 to 70% by mass based on the total mass of the monomer composition for the viscosity index improver, c) linear or branched C ７ -C ３０ One monomer selected from alkyl (meth)acrylates or a mixture thereof, 1 to 15% by mass based on the total mass of the monomer composition for the viscosity index improver which can be obtained by polymerization, wherein the pour point depressant (P) is a polymer having a mass average molecular weight (Mw) of 10,000 to 60,000 g / mol and a monomer composition comprising: e) linear or branched C １ -C ６ one monomer selected from alkyl (meth)acrylates or a mixture thereof, 20 to 35% by mass, based on the total mass of the monomer composition for the pour point depressant (P) f) Linear or branched C ７ -C １５ One monomer selected from alkyl (meth)acrylates, 20 to 75% by mass based on the total mass of the monomer composition for the pour point depressant (P). g) linear or branched C １６ -C ２４ at least one monomer selected from alkyl (meth)acrylates, 5 to 60% by mass based on the total mass of the monomer composition for the pour point depressant (P) which can be obtained by polymerization, wherein the mass ratio of (V) to (P) is 99:1 to 80:20 based on the total solid polymer content of the polymer of (V) and the polymer of (P) in the additive composition, said additive composition (A).

2. The additive composition (A) according to claim 1, wherein the polymer (V) of the viscosity index improver has a mass average molecular weight of 100,000 to 600,000 g / mol.

3. The additive composition (A) according to claim 1 or 2, wherein the polybutadiene-based macromonomer a) has a number average molecular weight of 1,000 to 6,000 g / mol.

4. The additive composition (A) according to any one of claims 1 to 3, wherein the monomer e) is selected from methyl (meth)acrylate, butyl (meth)acrylate or a mixture thereof.

5. The additive composition (A) according to any one of claims 1 to 4, wherein the amount of monomer f) is 20 to 60% by mass based on the total mass of the monomer composition of the pour point depressant (P).

6. The amount of monomer (g) is 20 to 50% by mass based on the total mass of the monomer composition of the pour point depressant (P), and the additive composition (A) according to any one of claims 1 to 5.

7. The total amount of monomers (e), (f), and (g) in the monomer composition of the pour point depressant (P) is 95 to 100% by mass based on the total mass of the monomer composition of the pour point depressant (P), and the additive composition (A) according to any one of claims 1 to 6.

8. The amount of monomer (b) is 55 to 70% by mass based on the total mass of the monomer composition of the viscosity index improver (V), and the additive composition (A) according to any one of claims 1 to 7.

9. said monomer c) is linear C １２～１４ alkyl methacrylate, linear C １６～１８ The additive composition (A) according to any one of claims 1 to 8, which is selected from alkyl methacrylate or a mixture thereof.

10. The monomer composition of the viscosity index improver (V) further contains 0 to 20% by mass of a monomer (d) selected from the group consisting of aminoalkyl (meth)acrylate, aminoalkyl (meth)acrylamide, and mixtures thereof, and the additive composition (A) according to any one of claims 1 to 9.

11. The total amount of monomers (a), (b), (c), and (d) in the monomer composition for the viscosity index improver (V) is 95 to 100% by mass based on the total mass of the monomer composition for the viscosity index improver, and the additive composition (A) according to any one of claims 1 to 10.

12. The polymer of the viscosity index improver (V) has a mass average molecular weight (Mw) of 100,000 to 600,000 g / mol, and the additive composition (A) according to any one of claims 1 to 11.

13. A method for producing the additive composition (A) defined in any one of claims 1 to 12, the method comprising the following steps: (x) A step of producing a viscosity index improver (V), which comprises preparing a monomer composition and initiating radical polymerization in the monomer composition to produce a polymer (V). (y) A step of producing a pour point depressant (P), which comprises preparing a monomer composition and initiating radical polymerization in the monomer composition to produce a polymer (P). (z) A step of mixing the viscosity index improver (V) with the pour point depressant (P) to provide the additive composition (A). The method as described above.

14. (i) One base oil or a mixture of a plurality of base oils, and (ii)An additive composition (A) defined in any one of claims 1 to 12 contained in a lubricating oil formulation. **Claim 15** Use of an additive composition (A) defined in any one of claims 1 to 12 as a lubricant additive in the lubricating oil formulation for improving the storage stability, viscosity index and low temperature performance of the lubricating oil formulation.

Images