JP6456468B1 - Viscosity index improver with improved low temperature viscosity and shear resistance - Google Patents

Abstract

Provided is a lubricant additive that provides a combination of good viscosity index, good low temperature viscosity properties, and excellent shear stability. (A) 10-70% by weight of one or more esters of (meth) acrylic acid and a hydroxylated hydrogenated polybutadiene having a number average molecular weight of 2,200 g / mol or less, (b) 1 A polyalkyl (meth) acrylate polymer obtained by polymerizing a monomer composition containing 10 to 80% by mass of C1-30 alkyl (meth) acrylate of at least one species is used as a lubricant additive. [Selection figure] None

Description

  The present invention relates to a polyalkyl (meth) acrylate polymer containing a polybutadiene-based monomer having a number average molecular weight of 2,200 g / mol or less, a lubricant composition containing the polymer, a method for producing the polymer, and It relates to the use of said polymers as additives for lubricant compositions for improving viscosity index, low temperature viscosity and shear resistance.

Prior Art As CO ₂ emission regulations become more stringent, the automotive industry is seeking systems that provide better fuel economy. While changes in mechanical equipment and the like are conceivable, one of the measures for cutting the fuel economy is to reduce the viscosity of the lubricant applied to the transmission or the engine. However, there is also a certain limit to the steady viscosity drop of the lubricant. This is because the viscosity of the lubricant must be high enough to reliably protect the metal member. Therefore, the viscosity must be adjusted to an optimum viscosity and desirably as constant as possible over the entire temperature range.

Viscosity index improvers (VII) are typically used to improve the temperature dependence of lubricants as measured by viscosity index (VI). The viscosity index is calculated from the dynamic viscosity at 40 ° C. (KV ₄₀ ) and the dynamic viscosity at 100 ° C. (KV ₁₀₀ ). The higher the VI, the lower the temperature dependence of the lubricant viscosity. That is, it means that the viscosity hardly changes with temperature. Polyalkyl (meth) acrylates are known to act as good viscosity index improvers in lubricants.

  The transmission startup phase is particularly important to improve fuel economy and save fuel. During this phase, the temperature of the lubricant is usually below 40 ° C. Therefore, it is important that the viscosity of the lubricant is as low as possible at this low temperature. In the prior art, this issue is not fully discussed.

  One important property of the lubricant is its resistance to shear forces. When the lubricant is not shear resistant, VI decreases with time, leading to a decrease in the viscosity of the lubricant at high temperatures, and protection of the metal member cannot be obtained. In order to extend the life of the lubricant, the demand for shearing has become more severe, and this property has become increasingly important in recent years.

  The shear stability of the viscosity index improver has a significant effect on the overall shear stability of the lubricant. One possibility to improve the shear stability of the polymer viscosity index improver is to reduce the overall molecular weight of the polymer backbone (main chain). However, this also leads to a drop in VI. For this reason, all modern products and lubricant preparations must be balanced between these properties.

  International Publication No. 2009/007147 (WO 2009/007147 A1) and International Publication No. 2010/142789 (WO 2010/142789 A1) use polymers containing macromonomers derived from polybutadiene as viscosity index improvers. This macromonomer has a number average molecular weight of 500 to 50,000 g / mol. However, there is no suggestion on how to improve shear stability and low temperature viscosity, and only VI is focused.

  Patent application WO 2007/003238 (WO 2007/003238) discloses the use of polymers containing macromonomers derived from polybutadiene as viscosity index improvers, which macromonomers include: It has a number average molecular weight of 500 to 50,000 g / mol. It is stated here that an increase in the molecular weight of VII leads to an improvement in VI, but there is no mention of the effect of the molecular weight of the macromonomer arm in terms of VI, low temperature properties or shear stability. Absent.

  EP-A-3093334 (EP 3 093 334 A1) discloses the use of polymers containing macromonomers derived from polybutadiene as viscosity index improvers, which macromonomers are It has a number average molecular weight of 1,000 to 25,000 g / mol. The inventive examples of this application use macromonomers having number average molecular weights of 1,100, 3,000 and 5,000 g / mol. However, looking at the results of the shear stability measurement, no improvement is observed due to the decrease in molecular weight (Inventive Examples 1, 4, and 7).

SUMMARY OF THE INVENTION Prior art efforts are not sufficient to provide a viscosity index improver that combines the combination of good VI, good low temperature viscosity, and excellent shear stability. Although the prior art has always focused on fixing one of these properties, it does not focus on realizing all these properties with a single polymer. However, for recent trends in lubricants, it is important to optimize all of these properties to solve the problems of improving fuel economy and protecting metal parts in automobiles and industrial applications over longer lifetimes It is.

  Accordingly, it is an object of the present invention to provide a lubricant additive that provides a combination of good viscosity index, good low temperature viscosity properties, and excellent shear stability.

  Surprisingly, certain polyalkyl (meth) acrylate polymers and their use as additives for lubricant compositions provide all these properties, i.e. as high as those of the prior art It has been found that it has a VI but has improved viscosity properties at low temperatures and has significantly improved shear stability.

Detailed Description of the Invention Polymers According to the Invention In a first aspect, the invention comprises:
(A) 10-70% by weight of one or more esters of (meth) acrylic acid and a hydroxylated hydrogenated polybutadiene having a number average molecular weight of 2,200 g / mol or less,
(B) 1 or more types of _C1-30 alkyl (meth) acrylate 10-80 mass%
It relates to a polyalkyl (meth) acrylate polymer obtained by polymerizing a monomer composition containing

  Unless otherwise stated, the amount of monomer is based on the total amount of monomer used.

  The amount of (a) and (b) is preferably 100% by mass in total.

  In the context of the present invention, the polymer contains a first polymer (also referred to as the backbone or backbone) and a plurality of further polymers (also referred to as side chains and covalently attached to the backbone). To do. In this case, the polymer skeleton is formed by the linked unsaturated group of the (meth) acrylic acid ester described above. The alkyl group of the (meth) acrylic acid ester and the hydrogenated polybutadiene chain form the side chain of the polymer.

  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 an acrylic ester and a methacrylic ester, with an ester of methacrylic acid being preferred.

The polymers according to the invention can preferably have a weight average molecular weight (M _w ) of 10,000 to 1,000,000 g / mol. Polymers with different weight average molecular weights can be used for various applications, such as for engine oil, transmission fluid, and tractor oil. The weight average molecular weight of the polymer can preferably be selected according to the intended use according to the table below.

The weight average molecular weight (M _w ) of the polymer according to the present invention is preferably 15,000-350,000 g / mol, more preferably 30,000-350,000 g / mol, even more preferably 50,000-320,000 g. / Mol, most preferably in the range of 70,000 to 300,000 g / mol. Polymers having this weight average molecular weight are particularly suitable for use in transmission fluids such as automatic transmission luds, manual transmission luds, and belt-type continuously variable transmission luds.

The number average molecular weight ( _Mn ) of the polymer according to the invention is preferably 10,000 to 90,000 g / mol, more preferably 15,000 to 80,000 g / mol, most preferably 20,000 to 70,000 g / mol. It is in the range of mol.

The polydispersity index (PDI) of the polymer according to the present invention is in the range of 1.5 to 6.0, more preferably 2.0 to 5.0, most preferably 2.9 to 4.6. The polydispersity index is defined as the ratio of the weight average molecular weight to the number average molecular weight (M _w / M _n ).

  Mass average molecular weight and number average molecular weight are determined by size exclusion chromatography (SEC) using commercially available polymethylmethacrylate standards. This identification is performed according to DIN 55672-1 by gel permeation chromatography using THF as eluent.

The polymer according to the invention can be characterized on the basis of its molar branching (f _branch ). The degree of molar branching refers to the percentage in mol% of the macromonomer (component (a)) used, based on the total molar amount of all monomers in the monomer composition. The molar amount of the macromonomer used is calculated based on the number average molecular weight ( _Mn ) of the macromonomer. The calculation of the degree of molar branching is described in detail in WO 2007/003238 (WO 2007/003238 A1), in particular on pages 13 and 14 thereof, which is hereby expressly referred to. deep.

The polymer preferably has a molar branching degree of f _branch of 0.1 to 6 mol%, more preferably 1 to 4 mol%, most preferably 1.5 to 3 mol%.

Hydroxylated hydrogenated polybutadiene for use as component (a) in accordance with hydroxylated hydrogenated polybutadiene present invention has a number average molecular weight M _n of less than 2,200g / mol. Hydroxylated hydrogenated polybutadiene is sometimes referred to as macroalcohol in the context of the present invention because of its high molecular weight. The corresponding ester of (meth) acrylic acid can also be called a macromonomer in the context of the present invention.

  Component (a) may contain one type of macromonomer or a mixture of different types of macromonomers based on different types of macroalcohols.

  By combining a macromonomer based on a macroalcohol having a number average molecular weight of less than 2,200 g / mol with an alkyl (meth) acrylate according to the invention, a combination of good VI, excellent low temperature properties, and good shear resistance Is obtained.

The number average molecular weight M _n is determined by size exclusion chromatography using commercially available polybutadiene standards. This identification is performed according to DIN 55672-1 by gel permeation chromatography using THF as eluent.

  The hydroxylated hydrogenated polybutadiene referred to in component (a) is also referred to in the context of the present invention as the “first” hydroxylated hydrogenated polybutadiene.

  The first hydroxylated hydrogenated polybutadiene may be a single polybutadiene having a single number average molecular weight of 2,200 g / mol or less, or different having a different number average molecular weight of 2,200 g / mol or less. It may be a mixture of polybutadiene.

  The monomer composition preferably comprises one or more esters of (meth) acrylic acid as component (a) and a hydroxylated hydrogenated polybutadiene having a number average molecular weight of 1,500 g / mol to 2,200 g / mol. 20 to 60% by mass, more preferably 20 to 50% by mass, even more preferably 20 to 45% by mass, and most preferably 20 to 35% by mass.

  The hydroxylated hydrogenated polybutadiene of component (a) is preferably 1,500-2,200 g / mol, more preferably 1,500-2,100 g / mol, even more preferably 1,800-2,100 g. / Mol, most preferably having a number average molecular weight of 1,900-2,100 g / mol.

  The composition optionally further comprises, as part of component (a), one or more additional (meth) acrylic esters, and a hydroxylated hydrogenated polybutadiene having a number average molecular weight greater than 2,200 g / mol. Can be contained. The amount of these monomers in the monomer composition is preferably limited to 10% by weight or less, more preferably 8% or less, and most preferably 6% or less. The hydroxylated hydrogenated polybutadiene of these monomers is preferably 3,500 to 7,000 g / mol, more preferably 4,000 to 6,000 g / mol, and most preferably 4,500 to 5,000 g / mol. Having a number average molecular weight of These hydroxylated hydrogenated polybutadienes are also referred to as “second” hydroxylated hydrogenated polybutadienes in the context of the present invention. If these monomers are included, they are also considered as macromonomers in order to calculate the degree of branching.

  The first and / or second hydroxylated hydrogenated polybutadiene preferably has a hydrogenation level of at least 99%. An alternative measure of the hydrogenation level identifiable by the polymer of the present invention uses iodine value. The iodine value refers to the number of grams of iodine that can be added to 100 g of polymer. The polymer according to the invention preferably has an iodine number of 5 g or less per 100 g of polymer. The iodine value is specified according to DIN 53241-1: 1995-05 by the Wijs method.

  Preferred hydroxylated hydrogenated polybutadienes can be obtained according to GB 2270317 (GB 2270317).

  As used herein, the term “hydroxylated hydrogenated polybutadiene” refers to a hydrogenated polybutadiene having one or more hydroxyl groups. The hydroxylated hydrogenated polybutadiene further contains further structural units, such as polyether groups derived from alkylene oxide added to polybutadiene, or maleic anhydride groups derived from maleic anhydride added to polybutadiene. be able to. These additional structural units can be introduced into the polybutadiene when the polybutadiene is functionalized with hydroxy groups.

  Monohydroxylated hydrogenated polybutadiene is preferred. The hydroxylated hydrogenated polybutadiene is more preferably a hydrogenated polybutadiene terminated with hydroxyethyl or hydroxypropyl. Polybutadiene terminated with hydroxypropyl is particularly preferred.

  Monohydroxylated hydrogenated polybutadiene can be prepared by first converting the butadiene monomer into an polybutadiene by anionic polymerization. Subsequent reaction of the polybutadiene monomer with an alkylene oxide (eg, ethylene oxide or propylene oxide) can produce a hydroxy-functionalized polybutadiene. Polybutadiene can also be reacted with more than one alkylene oxide unit, resulting in a polyether-polybutadiene block copolymer having terminal hydroxy groups. Hydroxylated polybutadiene can be hydrogenated in the presence of a suitable transition metal catalyst.

  These monohydroxylated hydrogenated polybutadienes can also be selected from: products obtained by hydroboration of (co) polymers having terminal double bonds (eg US Pat. No. 4,316,16). No. 973 (described in US Patent No. 4,316,973), a maleic anhydride-ene obtained by reacting a (co) polymer having a terminal double bond with a maleic anhydride having an amino alcohol Amino alcohol adducts and products obtained by hydrogenation followed by hydroformylation of (co) polymers having terminal double bonds (for example described in JP 63-175096 (JP Publication No. S63-175096)).

  Macromonomers for use in accordance with the present invention can be made by transesterification of alkyl (meth) acrylates. Reaction of alkyl (meth) acrylates with hydroxylated hydrogenated polybutadiene forms the esters of the present invention. It is preferable to use methyl (meth) acrylate or ethyl (meth) acrylate as the reactant.

Such transesterification is well known. For this purpose, for example, heterogeneous catalyst systems such as lithium hydroxide / calcium oxide mixtures (LiOH / CaO), pure lithium hydroxide (LiOH), lithium methoxide (LiOMe), or sodium methoxide (NaOMe), Alternatively, homogeneous catalyst systems such as isopropyl titanate (Ti (OiPr) ₄ ), or dioctyl tin oxide (Sn (OCt) ₂ O) can be used. This reaction is an equilibrium reaction. Thus, the released low molecular weight alcohol is usually removed, for example by distillation.

  Furthermore, by direct direct esterification, for example from (meth) acrylic acid or (meth) acrylic anhydride, preferably under acid catalysis with p-toluenesulfonic acid or methanesulfonic acid, or DCC (dicyclohexyl). A macromonomer can be obtained from free methacrylic acid by the carbodiimide method.

  Furthermore, the hydroxylated hydrogenated polybutadiene according to the invention can be converted into an ester by reaction with an acid chloride, for example (meth) acryloyl chloride.

  In the preparation of the esters according to the invention as described above, it is preferred to use polymerization inhibitors, for example 4-hydroxy-2,2,6,6-tetramethylpiperidinooxyl radical and / or hydroquinone monomethyl ether.

Alkyl (meth) acrylate The term “C _1-30 alkyl (meth) acrylate” refers to (meth) acrylic acid and linear or branched alcohols having 1 to 30 carbon atoms. The term encompasses each (meth) acrylate ester having a particular length of alcohol, as well as mixtures of (meth) acrylate esters having different lengths of alcohol.

C _{1 to 30} alkyl (meth) acrylate preferably comprises a mixture of C _{1 to 4} alkyl (meth) acrylates and C _{10 to 30} alkyl (meth) acrylate.

The term “C _1-4 alkyl (meth) acrylate” refers to an ester of (meth) acrylic acid and a linear or branched alcohol having 1 to 4 carbon atoms. The term encompasses each (meth) acrylate ester having a particular length of alcohol, as well as mixtures of (meth) acrylate esters having different lengths of alcohol.

Suitable C _{1 to 4} alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, n- propyl (meth) acrylate, iso - propyl (meth) acrylate, n- butyl (meth) acrylate, Iso-butyl (meth) acrylate, and tert-butyl (meth) acrylate are included. Particularly preferred C _1-4 alkyl (meth) acrylates are methyl (meth) acrylate and n-butyl (meth) acrylate. Methyl methacrylate and n-butyl methacrylate are particularly preferred.

The term “C _10-30 alkyl (meth) acrylate” refers to an ester of (meth) acrylic acid and a linear or branched alcohol having 10 to 30 carbon atoms. The term encompasses each (meth) acrylate ester having a particular length of alcohol, as well as mixtures of (meth) acrylate esters having different lengths of alcohol.

Suitable _C10-30 alkyl (meth) acrylates are, 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-hexyldecyl ( (Meth) acrylate, 2-octyldodecyl (meth) acrylate, tridecyl (meth) acrylate, 5-methyltridecyl (meth) acrylate, tetradecyl (meth) acrylate, 2-decyltetradecyl (meth) acrylate, penta Sil (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, cetyl eicosyl (meth) acrylate, stearyl eicosyl (meth) acrylate, docosyl (medium) 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.

In a particularly preferred embodiment, C _{1 to 30} alkyl (meth) acrylate, a C _{1 to 4} alkyl (meth) acrylate, preferably containing a mixture of C _{10 to 18} alkyl (meth) acrylate.

The term “C _10-18 alkyl (meth) acrylate” refers to an ester of (meth) acrylic acid and a linear or branched alcohol having 10 to 18 carbon atoms. The term encompasses each (meth) acrylate ester having a particular length of alcohol, as well as mixtures of (meth) acrylate esters having different lengths of alcohol.

Suitable _C10-18 alkyl (meth) acrylates are, for example, decyl methacrylate, undecyl methacrylate, 5-methylundecyl methacrylate, dodecyl methacrylate, 2-methyldodecyl methacrylate, tridecyl methacrylate, 5-methyltridecyl methacrylate, tetradecyl Methacrylate and / or pentadecyl methacrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, and / or octadecyl (meth) acrylate.

Particularly preferred C _{10 to 18} alkyl (meth) acrylates, linear C _{12 to 14} alcohol mixture (meth) acrylic acid ester (C _{12 to 14} alkyl (meth) acrylate), and the C _16-18 alcohol mixture ( (Meth) acrylic acid ester (C _16/18 alkyl (meth) acrylate).

The monomer composition is preferably 0.5 to 80% by weight of one or more C _1-4 alkyl (meth) acrylates and one or more C _10-18 alkyl (meth) acrylates, based on the total weight of the monomer mixture. 0.1 to 15% by weight, more preferably one or more C _1-4 alkyl (meth) acrylates 1.0 to 70% by weight and one or more C _10-18 alkyl (meth) acrylates 0.1 to 10% by weight, most preferably 9 to 70% by weight of one or more C _1-4 alkyl (meth) acrylates and 0.2 to 6% by weight of one or more C _10-18 alkyl (meth) acrylates, Contained as (b).

In one embodiment, the monomer composition comprises as component (b), methyl (meth) acrylate from 0.2 to 16 wt%, 9-55 wt% of butyl (meth) acrylate, and one or more _{C. 10 to It} contains 0.2 to 6% by mass of ₁₈ alkyl (meth) acrylate.

Additional monomers The monomer composition preferably contains additional monomers (component c) in addition to components (a) and (b).

  Further monomers that can be used according to the invention are styrene monomers having 8 to 17 carbon atoms, vinyl esters having 1 to 11 carbon atoms in the acyl group, 1 to 10 carbon atoms in the alcohol group. A vinyl ether having, a dispersible monomer functionalized with oxygen and / or nitrogen, a heterocyclic (meth) acrylate, a heterocyclic vinyl compound, a monomer containing a covalently bonded phosphorus atom, a monomer containing an epoxy group, and Selected from the group consisting of halogen-containing monomers.

  Suitable styrene monomers having 8 to 17 carbon atoms are styrene, substituted styrenes having an alkyl substituent in the side chain, such as α-methylstyrene and α-ethylstyrene, having an alkyl substituent on the ring Selected from the group consisting of substituted styrenes such as vinyl toluene and paramethyl styrene, halogenated styrenes such as monochlorostyrene, dichlorostyrene, tribromostyrene, and tetrabromostyrene, nitrostyrene. Styrene is preferred.

  Suitable vinyl esters having 1 to 11 carbon atoms in the acyl group are selected from the group consisting of vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, preferably 2-9 in the acyl group, and more Preferred are vinyl esters having 2 to 5 carbon atoms, wherein the acyl group may be linear or branched.

  Suitable vinyl ethers having 1 to 10 carbon atoms in the alcohol group are selected from the group consisting of vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, vinyl butyl ether, and the vinyl ether is preferably 1-8 in the alcohol group. , More preferably 1 to 4 carbon atoms, where the alcohol group may be linear or branched.

Suitable dispersible monomers functionalized with oxygen and / or nitrogen are aminoalkyl (meth) acrylates such as N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N , N-diethylaminopentyl (meth) acrylate, N, N-dibutylaminohexadecyl (meth) acrylate; aminoalkyl (meth) acrylamide, such as N, N-dimethylaminopropyl (meth) acrylamide; hydroxyalkyl (meth) acrylate, For example, 3-hydroxypropyl (meth) acrylate, 3,4-dihydroxybutyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2,5-dimethyl-1,6-hexa Diol (meth) acrylate, 1,10-decanediol (meth) acrylate, p-hydroxystyrene, vinyl alcohol, alkenol ((methyl) allyl alcohol having 3 to 12 carbon atoms), polyvalent (3 to 8 valences) ) Alcohol (glycerol, pentaerythritol, sorbitol, sorbitan, diglyceride, sugar), ether or meta (acrylate); C _1-8 alkyloxy-C _2-4 alkyl (meth) acrylate, such as methoxypropyl (meth) acrylate, methoxy -Butyl (meth) acrylate, methoxyheptyl (meth) acrylate, methoxyhexyl (meth) acrylate, methoxypentyl (meth) acrylate, methoxyoctyl (meth) acrylate, ethoxyethyl (meth) acrylate, Toxipropyl (meth) acrylate, ethoxy-butyl (meth) acrylate, ethoxyheptyl (meth) acrylate, ethoxyhexyl (meth) acrylate, ethoxypentyl (meth) acrylate, ethoxyoctyl (meth) acrylate, propoxymethyl (meth) acrylate, Propoxyethyl (meth) acrylate, propoxypropyl (meth) acrylate, propoxybutyl (meth) acrylate, propoxyheptyl (meth) acrylate, propoxyhexyl (meth) acrylate, propoxypentyl (meth) acrylate, propoxyoctyl (meth) acrylate, butoxy Methyl (meth) acrylate, butoxyethyl (meth) acrylate, butoxypropyl (meth) acrylate, butoxybutyl ( Selected from the group consisting of (meth) acrylate, butoxyheptyl (meth) acrylate, butoxyhexyl (meth) acrylate, butoxypentyl (meth) acrylate, and butoxyoctyl (meth) acrylate, and ethoxyethyl (meth) acrylate and butoxyethyl (meth) ) Acrylate is preferred.

  Suitable heterocyclic (meth) acrylates are 2- (1-imidazolyl) ethyl (meth) acrylate, 2- (4-morpholinyl) ethyl (meth) acrylate, 1- (2-methacryloyloxyethyl) -2-pyrrolidone , N-methacryloylmorpholine, N-methacryloyl-2-pyrrolidinone, N- (2-methacryloyloxyethyl) -2-pyrrolidinone, N- (3-methacryloyloxypropyl) -2-pyrrolidinone.

  Suitable heterocyclic vinyl compounds are 2-vinylpyridine, 4-vinylpyridine, 2-methyl-5-vinylpyridine, 3-ethyl-4-vinylpyridine, 2,3-dimethyl-5-vinylpyridine, vinylpyrimidine. , Vinylpiperidine, 9-vinylcarbazole, 3-vinylcarbazole, 4-vinylcarbazole, 1-vinylimidazole, 2-methyl-1-vinylimidazole, N-vinylpyrrolidone, N-vinylvinylpyrrolidine, 3-vinylpyrrolidine, N -Selected from the group consisting of vinyl-caprolactam, N-vinylbutyrolactam, vinyl oxolane, vinyl furan, vinyl oxazole, and hydrogenated vinyl oxazole.

  Monomers containing covalently linked phosphorus atoms include 2- (dimethylphosphato) propyl (meth) acrylate, 2- (ethylenephosphito) propyl (meth) acrylate, dimethylphosphinomethyl (meth) acrylate, dimethylphosphono Ethyl (meth) acrylate, diethyl (meth) acryloyl phosphonate, dipropyl (meth) acryloyl phosphate, 2- (dibutylphosphono) ethyl (meth) acrylate, diethyl phosphatoethyl (meth) acrylate, 2- (dimethyl phosphato)- 3-hydroxypropyl (meth) acrylate, 2- (ethylene phosphite) -3-hydroxypropyl (meth) acrylate, 3- (meth) acryloyloxy-2-hydroxypropyl diethylphosphonate, 3- (meth) acrylate Royloxy-2-hydroxypropyldipropylphosphonate, 3- (dimethylphosphato) -2-hydroxypropyl (meth) acrylate, 3- (ethylenephosphito) -2-hydroxypropyl (meth) acrylate, 2- (meth) acryloyl It is selected from the group consisting of oxy-3-hydroxypropyl diethylphosphonate, 2- (meth) acryloyloxy-3-hydroxypropyl dipropylphosphonate, and 2- (dibutylphosphono) -3-hydroxypropyl (meth) acrylate.

  Suitable monomers containing epoxy groups are, for example, glycidyl (meth) acrylate and glycidyl (meth) allyl ether.

  Examples of the halogen-containing monomer include vinyl chloride, vinyl bromide, vinylidene chloride, (meth) allyl chloride, and halogenated styrene (dichlorostyrene and the like).

  The monomer composition preferably contains 0 to 80% by weight, more preferably 0.01 to 70% by weight, most preferably 0.2 to 60% by weight of further monomers as component (c).

  The further monomer preferably contains a styrene monomer having 8 to 17 carbon atoms and optionally a dispersible monomer functionalized with oxygen and / or nitrogen. The further monomer is preferably a styrene monomer having 8 to 17 carbon atoms.

  In one embodiment, the monomer composition contains 0.01 to 80% by mass, more preferably 0.1 to 70% by mass, as component (c), of one or more styrene monomers having 8 to 17 carbon atoms. %, Most preferably 0.2 to 60% by mass.

In one embodiment, the monomer composition comprises 0.01 to 80% by weight, more preferably 0.1 to 70% by weight, as component (c), of one or more styrene monomers having 8 to 17 carbon atoms, Most preferably 0.2 to 60% by weight, and 0.01 to 10% by weight, preferably 1 to 8% by weight, most preferably 2 or more of one or more dispersible monomers functionalized with oxygen and / or nitrogen. ˜5 mass% contained. Dispersible monomers functionalized with oxygen and / or nitrogen include aminoalkyl (meth) acrylates, aminoalkyl (meth) acrylamides, hydroxyalkyl (meth) acrylates, and C _1-8 alkyloxy-C _2-4 alkyl ( It is preferably selected from (meth) acrylates.

  The amount of components (a) to (c) is preferably 100% by mass in total.

Preferred monomer composition In one embodiment, the monomer composition comprises the following (a), (b) and (c):
(A) one or more esters of (meth) acrylic acid and a hydroxylated hydrogenated polybutadiene having a number average molecular weight of 2,200 g / mol or less, preferably 1,500 g / mol to 2,200 g / mol 20 to 60% by weight, more preferably 20 to 50% by weight, most preferably 20 to 45% by weight,
(B) 0.5 to 80% by weight of one or more C _1-4 alkyl (meth) acrylates and 0.01 to 15% by weight of one or more C _10-18 alkyl (meth) acrylates, more preferably 1 1.0 to 70% by weight of one or more C _1-4 alkyl (meth) acrylates and 0.1 to 10% by weight of one or more C _10-18 alkyl (meth) acrylates, most preferably one or more C _{1 to 4} alkyl (meth) acrylates 9 to 70% by weight and one or more C _10-18 alkyl (meth) acrylates 0.2 to 6% by weight, and (c) one or more having 8 to 17 carbon atoms 0.01 to 80% by weight of styrene monomer, more preferably 0.1 to 70% by weight, most preferably 0.2 to 60% by weight, and optionally one type functionalized with oxygen and / or nitrogen Dispersible monomer 0 01 to 10 wt%, preferably 1 to 8 wt%, and most preferably 2 to 5 wt%
contains.

In one embodiment, the monomer composition has the following (a), (b) and (c):
(A) One or more esters of (meth) acrylic acid and hydroxylated hydrogenated polybutadiene having a number average molecular weight of 2,200 g / mol or less, preferably 1,500 to 2,200 g / mol. ~ 60% by mass,
(B) one or more C _{1 to 4} alkyl (meth) acrylate from 1.0 to 70 mass%, and one or more C _{10 to 18} alkyl (meth) acrylate 0.1-10 wt%,
(C) 0.2 to 60% by weight of one or more styrene monomers having 8 to 17 carbon atoms, and optionally 1 to 1 or more dispersible monomers functionalized with oxygen and / or nitrogen. 8% by mass
contains.

In one embodiment, the monomer composition has the following (a), (b) and (c):
(A) One or more esters of (meth) acrylic acid and hydroxylated hydrogenated polybutadiene having a number average molecular weight of 2,200 g / mol or less, preferably 1,500 to 2,200 g / mol. ~ 60% by mass,
(B) 0.2 to 16% by mass of one or more C ₁ (meth) acrylates, 10 to 55% by mass of one or more C ₄ (meth) acrylates, one or more C _10-18 alkyl (meta) ) 0.2-6% by weight of acrylate,
(C) 0.2 to 60% by weight of one or more styrene monomers having 8 to 17 carbon atoms, and optionally 2 or more of one or more dispersible monomers functionalized with oxygen and / or nitrogen. 5% by mass
contains.

In one embodiment, the monomer composition has the following (a), (b) and (c):
(A) 20-60% by weight of one or more esters of (meth) acrylic acid and a hydroxylated hydrogenated polybutadiene having a number average molecular weight of 1,900-2,100 g / mol,
(B) 0.2 to 16% by mass of one or more C ₁ (meth) acrylates, 10 to 55% by mass of one or more C ₄ (meth) acrylates, one or more C _10-18 alkyl (meta) ) 0.2-6% by weight of acrylate,
(C) 0.2 to 60% by weight of one or more styrene monomers having 8 to 17 carbon atoms, and optionally 2 or more of one or more dispersible monomers functionalized with oxygen and / or nitrogen. 5% by mass
contains.

  The aforementioned (meth) acrylic acid ester is preferably an ester of methacrylic acid.

Production Method The present invention also relates to a method for producing the polymer, which comprises the following steps:
(A) a step of preparing the monomer composition described above, and (b) a step of starting radical polymerization in the monomer composition.

  Standard free radical polymerization is described in particular in Ullmann's Encyclopedia of Industrial Chemistry, Sixth Edition. In general, polymerization initiators, and optionally chain transfer agents, are used for this purpose.

  The ATRP method is known per se. Although this is considered to be a “living” free radical polymerization, no limitation is intended by the description of this mechanism. In these procedures, the transition metal compound is reacted with a compound having a transferable atomic group. In this case, the movable atomic group moves toward the transition metal compound, and as a result, the metal is oxidized. This reaction forms free radicals that add to the ethylenic group. However, because the transfer of atomic groups relative to the transition metal compound is reversible, the atomic groups are returned to the growing polymer chain, resulting in the formation of a controlled polymerization system. Thus, it is possible to control polymer formation, polymer molecular weight and molecular weight distribution.

  This reaction regime is described by J.-S. Wang et al. In J. Am. Chem. Soc, vol. 117, p. 5614-5615 (1995) and by Matyjaszewski in Macromolecules, vol. 28, p. 7901-7910 (1995). )It is described in. Further, patent applications WO 96/30421 (WO 96/30421), WO 97/47661 (WO 97/47661), WO 97/18247 (WO 97/18247), WO 97/18247, No. 98/40415 (WO 98/40415) and WO 99/10387 (WO 99/10387) disclose variations of the ATRP described above. Furthermore, the polymers according to the invention can also be obtained, for example, by the RAFT method. This method is described in detail in, for example, WO 98/01478 (WO 98/01478) and WO 2004/083169 (WO 2004/083169).

  The polymerization can be performed, for example, under standard pressure, reduced pressure, or high pressure. The polymerization temperature is also not critical. Generally, however, the polymerization temperature is in the range of -20 to 200 ° C, preferably 50 to 150 ° C, and more preferably 80 to 130 ° C.

  The monomer composition prepared in step (a) is preferably diluted by adding oil in order to prepare a reaction mixture. The amount of the monomer composition, that is, the total amount of monomers is preferably 20 to 90% by mass, more preferably 40 to 80% by mass, and most preferably 50 to 70% by mass, based on the total mass of the reaction mixture.

  The oil used to dilute the monomer mixture is preferably an API Group I, II, III, IV or V oil, or a mixture thereof. Group III oils or mixtures thereof are preferably used to dilute the monomer mixture.

  Step (b) preferably includes the addition of a radical initiator.

  Suitable radical initiators include, for example, azo initiators such as azobis-isobutyronitrile (AIBN), 2,2′-azobis (2-methylbutyronitrile) (AMBN), and 1,1-azobiscyclohexanecarbox. Nitriles and peroxide compounds such as methyl ethyl ketone peroxide, acetylacetone peroxide, dilauryl peroxide, tert-butyl per-2-ethylhexanoate, ketone peroxide, tert-butyl peroxide, methyl isobutyl ketone peroxide, cyclohexanone peroxide, dibenzoyl peroxide, tert-butylperoxybenzoate, tert-butylperoxyisopropyl carbonate, 2,5-bis (2-ethylhexanoylperoxy) -2,5-dimethyl Ruhexane, tert-butylperoxy-2-ethylhexanoate, tert-butylperoxy-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.

  The radical initiator is preferably 2,2′-azobis (2-methylbutyronitrile), 2,2-bis (tert-butylperoxy) butane, tert-butylperoxy-2-ethylhexanoate, 1,1 -Selected from the group consisting of di-tert-butylperoxy-3,3,5-trimethylcyclohexane, tert-butylperoxybenzoate, and tert-butylperoxy-3,5,5-trimethylhexanoate. Particularly preferred initiators are tert-butylperoxy-2-ethylhexanoate and 2,2-bis (tert-butylperoxy) butane.

  The total amount of radical initiator is 0.01-5% by weight, more preferably 0.02-1% by weight, most preferably 0.05-0.6% by weight, based on the total weight of the monomer mixture. .

  The total amount of radical initiator can be added in one step, or the radical initiator can be added in multiple steps over the course of the polymerization reaction. The radical initiator is preferably added in a plurality of steps. For example, a portion of the radical initiator can be added to initiate radical polymerization, and a second portion of the radical initiator can be added 0.5 to 3.5 hours after the first addition. it can.

  Step (b) preferably 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 other chain transfer agents from the class of terpenes (for example terpinolene). It is particularly preferred to add n-dodecyl mercaptan.

  It is also possible to divide the monomer composition into a first part and a second part and add a portion of the radical initiator only to the first part to initiate the polymerization reaction therein. Then a second part of the radical initiator is added to the second part of the monomer composition, which is then added for 0.5-5 hours, preferably 1.5-4 hours, more preferably 2-3. Add to polymerization reaction mixture over 5 hours. After adding the second monomer mixture, the third portion of the radical initiator can be added to the polymerization reaction as described above.

  The total reaction time for radical polymerization is preferably 2 to 10 hours, more preferably 3 to 9 hours.

  After completion of radical polymerization, the obtained polymer is preferably further diluted with the aforementioned oil to obtain a desired viscosity. The polymer is preferably diluted to a concentration of 5 to 60% by weight, more preferably 10 to 50% by weight, most preferably 20 to 40% by weight, based on the weight of the polymer.

Use of Polymers The present invention also provides the aforementioned polyalkyl (meta) as an additive for lubricant compositions to improve the viscosity index of lubricant compositions, viscosity at temperatures below 40 ° C., and shear resistance. ) The use of acrylate polymers.

  Lubricant compositions containing the polymers of the present invention, and polymers according to the present invention, include drive system lubricants (e.g., manual transmission fluids, differential gear oils, automatic transmission fluids, and belt-type continuously variable transmission fluids, shaft fluid preparations, dual Clutch transmission fluids and dedicated hybrid transmission fluids), hydraulic fluids (eg hydraulic fluids for machines, power steering oils, shock absorbing oils), engine oils (for gasoline engines and diesel engines), and industrial oils It is preferably used for preparations (eg wind turbines).

  From the viewpoint of the dynamic viscosity of the polymer according to the present invention, the mass ratio of the polymer in the lubricant composition is 1% by mass to 50% by mass, preferably 1% by mass to 35% by mass, based on the total mass of the lubricant composition. % Is preferably included.

When the lubricant composition according to the present invention is used as an engine oil, the composition is based on the total mass of the lubricant composition and is 1% to 20% by weight, more preferably 1% by weight of the polymer according to the present invention. preferably contains 15 mass%, whereby in accordance with ASTM D445, a dynamic viscosity at 100 ° C., in the range of 4mm ² / s~10mm ² / s.

When the lubricant composition according to the invention is used as an automotive gear oil, the composition is based on the total mass of the lubricant composition, based on the polymer according to the invention from 1% to 35% by weight, more preferably 1% by weight. % to 25 wt% preferably contains, whereby according to ASTM D445, a dynamic viscosity at 100 ° C., in the range of 2mm ² / s~15mm ² / s.

When the lubricant composition according to the present invention is used as a transmission oil for automobiles, the composition is preferably based on the total weight of the lubricant composition, the polymer weight of the present invention is 1% by weight to 25% by weight, more preferably preferably to contain ~ 18 wt% 1 wt%, whereby in accordance with ASTM D445, a dynamic viscosity at 100 ° C., in the range of 2mm ² / s~6mm ² / s.

When the lubricant composition according to the invention is used as an industrial gear oil, the composition is based on the total weight of the lubricant composition, the polymer weight according to the invention is 10% to 50% by weight, more preferably preferably contains 10 mass% to 35 mass%, whereby in accordance with ASTM D445, a dynamic viscosity at 100 ° C., in the range of 10mm ² / s~40mm ² / s.

  This polymer is preferably used to increase the VI of the lubricating oil, to increase the dynamic viscosity below 40 ° C., and to prevent a decrease in dynamic viscosity after shearing.

  The viscosity index can be measured according to ASTM D2270.

  The dynamic viscosity can be measured according to ASTM D445.

  The shear resistance is preferably evaluated by measuring the properties of the lubricant before and after subjecting the lubricant to shear according to DIN 51350 Part 6. It is preferred to shear at 80 ° C. at 4000 rpm for 40 hours using a tapered roller bearing according to DIN 51350 Part 6.

Composition The present invention also provides the following (a) and (b):
The present invention relates to a composition containing (a) a base oil and (b) the aforementioned polyalkyl (meth) acrylate polymer.

  Due to the presence of the polymer according to the invention, the composition has excellent shear stability and can maintain its viscosity after shearing. Therefore, the composition according to the present invention is preferably used as a transmission fluid.

  This composition may be an additive composition containing the polymer according to the invention and a base oil as diluent. This additive composition can be added to a lubricant as a viscosity index improver, for example. The additive composition usually contains a relatively large amount of the polymer according to the invention.

  The composition may also be a lubricant containing a polymer according to the invention, a base oil, and optionally further additives as discussed below. The lubricant composition can be used, for example, as an engine oil or transmission fluid. Lubricant compositions usually contain a small amount of the polymer according to the invention compared to the additive composition described above.

  When this composition is used as an additive composition, the amount of base oil (component a) is preferably 40 to 80% by weight, more preferably 50 to 70% by weight, and the amount of polymer (component b) is , Preferably 20 to 60% by mass, more preferably 30 to 50% by mass.

  When this composition is used as a lubricant composition, the amount of the base oil (component a) is preferably 50 to 99.5% by mass, more preferably 65 to 99.5% by mass, and even more preferably 75 to The amount of the polymer (component b) is preferably 0.5 to 50% by mass, more preferably 0.5 to 35% by mass, and even more preferably 3 to 25% by mass.

  The amount of (a) and (b) is preferably 100% by mass in total.

  The base oil to be used in the composition preferably contains an oil of suitable viscosity for lubrication. Such oils include natural and synthetic oils, oils obtained from hydrocracking, hydrogenation and hydrofinishing, unrefined oils, refined oils, rerefined oils, or mixtures thereof.

  Base oil can be defined as specified by the American Petroleum Institute (API) (April 2008 edition of "Appendix E-API Base Oil Interchangeability Guidelines for Passenger Car Motor Oils and Diesel Engine Oils", section 1.3 Sub-heading 1.3. See "Base Stock Categories").

API has recently defined five groups for lubricant raw materials (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, which are classified according to the amount of saturation and sulfur contained in the mineral oil itself and its viscosity index. Group IV is a poly α-olefin and Group V is all other oils (including ester oils). The following table describes these API categories.

Suitable polar base oil used for preparing a lubricating oil composition, kinematic viscosity at 100 ° C. according to ASTM D445 (KV ₁₀₀₎ in accordance with the present ^{invention, 1mm 2 / s~10mm 2 / s} , More preferably, it is in the range of ² mm ² / s to 8 mm ² / s.

  Further base oils that can be used according to the invention are group II to III base oils derived from Fischer-Tropsch.

  Fischer-Tropsch derived base oils are known in the art. “Fischer-Tropsch derived” means that the base oil is a synthetic product of the Fischer-Tropsch process. A Fischer-Tropsch derived base oil can also be referred to as a GTL (gas liquefied) base oil. Suitable base oils derived from Fischer-Tropsch that can be conventionally used as base oils in the lubricant compositions according to the invention are, for example, EP 0 769 959 (EP 0 776 959), EP 0 668 342. (EP 0 668 342), International Publication No. 97/21788 (WO 97/21788), International Publication No. 00/15736 (WO 00/15736), International Publication No. 00/14188 (WO 00/14188), International Publication No. 00/14187 (WO 00/14187), International Publication No. 00/14183 (WO 00/14183), International Publication No. 00/14179 (WO 00/14179), International Publication No. 00/08115 ( WO 00/08115), International Publication No. 99/41332 (WO 99/41332), European Patent No. 1029029 (EP 1 029 029), International Publication No. 01/18156 (WO 01/18156), International Publication No. 01/57166 (WO 01/57166) and international public Is that disclosed in No. 2013/189951 (WO 2013/189951).

  Particularly for transmission oil preparations, API Group III base oils as well as mixtures of various Group III oils are used. In preferred embodiments, the base oil may also be a poly α-olefin base oil, or a mixture of a poly α-olefin base oil and an API Group III base oil, or a mixture of API Group III base oils.

The lubricant composition according to the present invention is further characterized by a low dynamic viscosity at 40 ° C. or lower. KV ₄₀ is preferably less than 25 mm ² / s, more preferably 18 to 24 mm ² / s, and most preferably 21 to 23 mm ² / s. KV ₄₀ is the dynamic viscosity at 40 ° C. and can be measured according to ASTM D445. KV ₂₀ is preferably less than 54 mm ² / s, more preferably 45 to 53 mm ² / s, and most preferably 50 to 52 mm ² / s. KV ₂₀ is the dynamic viscosity at 20 ° C. and can be measured according to ASTM D445. KV ₁₀ is preferably less than 90 mm ² / s, more preferably 75 to 89 mm ² / s, and most preferably 80 to 88 mm ² / s. KV ₁₀ is the dynamic viscosity at 10 ° C. and can be measured according to ASTM D445. KV ₀ is preferably less than 164 mm ² / s, more preferably 130 to 163 mm ² / s, and most preferably 140 to 162 mm ² / s. KV ₀ is the dynamic viscosity at 0 ° C. and can be measured according to ASTM D445.

  It is preferred that the lubricant composition has a viscosity index greater than 179, more preferably greater than 180, and most preferably greater than 184. The viscosity index can be measured according to ASTM D2270.

  The lubricant composition is preferably transmission fluid or engine oil.

  The lubricant composition according to the present invention also contains, as component (c), a dispersant, an antifoaming agent, a cleaning agent, an antioxidant, a pour point depressant, an antiwear additive, an extreme pressure additive, a corrosion inhibitor, An additive selected from the group consisting of friction modifiers, dyes, and mixtures thereof may further be included.

  Suitable dispersants include poly (isobutylene) derivatives such as poly (isobutylene) succinimide (including PIBSI, borated PIBSI), and ethylene propylene oligomers having N / O functionality.

  The dispersant (including boric acid type dispersant) is preferably used in an amount of 0 to 5% by mass based on the total amount of the lubricant composition.

  Suitable antifoaming agents are silicone oil, fluorosilicone oil, fluoroalkyl ether and the like.

  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.

  Preferred detergents include metal-containing compounds such as phenoxides, salicylates, thiophosphonates, especially thiopyrophosphonates, thiophosphonates, and phosphonates, sulfonates and carbonates. These compounds can contain as metals, in particular calcium, magnesium and barium. These compounds are preferably used in neutral or overbased form.

  The cleaning agent is preferably used in an amount of 0.2 to 1% by mass based on the total amount of the lubricant composition.

  Suitable antioxidants include, for example, phenolic antioxidants and amine antioxidants.

  Phenolic antioxidants include, for example: octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate; 4,4′-methylenebis (2,6-di-tert) 4,4′-bis (2,6-di-tert-butylphenol); 4,4′-bis (2-methyl-6-tert-butylphenol); 2,2′-methylenebis (4-ethyl) -6-tert-butylphenol); 2,2'-methylenebis (4-methyl-6-tert-butylphenol); 4,4'-butylidenebis (3-methyl-6-tert-butylphenol); 4,4'-isopropyl Redenbis (2,6-di-t-butylphenol); 2,2′-methylenebis (4-methyl-6-nonylphenol); 2,2′-isobutylidenebis ( , 6-dimethylphenol); 2,2′-methylenebis (4-methyl-6-cyclohexylphenol); 2,6-di-tert-butyl-4-methylphenol; 2,6-di-tert-butyl-4 -Ethyl-phenol; 2,4-dimethyl-6-t-butylphenol; 2,6-di-t-amyl-p-cresol; 2,6-di-t-butyl-4- (N, N'-dimethyl 4,4′-thiobis (2-methyl-6-tert-butylphenol); 4,4′-thiobis (3-methyl-6-tert-butylphenol); 2,2′-thiobis (4- Methyl-6-tert-butylphenol); bis (3-methyl-4-hydroxy-5-tert-butylbenzyl) sulfide; bis (3,5-di-tert-butyl-4-hydroxybenzyl) sulfide; -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] and the like. Of these, bisphenol antioxidants and phenolic antioxidants containing ester groups are of course particularly preferred.

  Amine antioxidants include, for example, the following: monoalkyldiphenylamines such as monooctyldiphenylamine, monononyldiphenylamine, etc .; dialkyldiphenylamines such as 4,4′-dibutyldiphenylamine, 4,4′-dipentyldiphenylamine, 4, 4′-dihexyldiphenylamine, 4,4′-diheptyldiphenylamine, 4,4′-dioctyldiphenylamine, 4,4′-dinonyldiphenylamine, etc .; polyalkyldiphenylamines such as tetrabutyldiphenylamine, tetrahexyldiphenylamine, tetraoctyldiphenylamine, Tetranonyldiphenylamine and the like; naphthylamine, specifically α-naphthylamine, phenyl-α-naphthylamine, and further alkyl groups. Substituted phenyl-α-naphthylamines such as butylphenyl-α-naphthylamine, pentylphenyl-α-naphthylamine, hexylphenyl-α-naphthylamine, heptylphenyl-α-naphthylamine, octylphenyl-α-naphthylamine, nonylphenyl-α- Naphthylamine etc. Of course, diphenylamine is preferable to naphthylamine from the viewpoint of its antioxidant effect.

  Suitable antioxidants can further be selected from the group consisting of: compounds containing sulfur and phosphorus, such as metal dithiophosphates, such as zinc dithiophosphate (ZnDTP), “OOS triester” = dithiophosphoric acid Product of activated double bonds from olefins, cyclopentadiene, norbornadiene, α-pinene, polybutene, acrylate, maleate (ashless upon combustion); organic sulfur compounds, eg dialkyl sulfides , Diaryl sulfides, polysulfides, modified thiols, thiophene derivatives, xanthates, thioglycols, thioaldehydes, sulfur-containing carboxylic acids; heterocyclic sulfur / nitrogen compounds, especially dialkyl dimercaptothiadiazoles, 2-mercaptobenzoimida Zinc bis (dialkyldithiocarbamate), and methylenebis (dialkyldithiocarbamate); organophosphorus compounds such as triaryl and trialkyl phosphites; organocopper compounds, and overbased calcium and magnesium-based phenoxides and salicylates .

  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.

  Pour point depressants include ethylene-vinyl acetate copolymers, chlorinated paraffin-naphthalene condensates, chlorinated paraffin-phenol condensates, polymethacrylates, polyalkylstyrenes, and the like. Polymethacrylate having a weight average molecular weight of 5,000 to 200,000 g / mol is preferred.

  The amount of pour point depressant is preferably 0.1-5% by weight, based on the total amount of the lubricant composition.

Preferred antiwear and extreme pressure additives include the following: sulfur containing compounds such as zinc dithiophosphate, zinc di-C _3-12 alkyl dithiophosphate (ZnDTP), zinc phosphate, zinc dithiocarbamate, molybdenum Dithiocarbamates, molybdenum dithiophosphates, disulfides, sulfurized olefins, sulfurized oils and fats, sulfurated esters, thiocarbonates, thiocarbamates, polysulfides, etc .; phosphorus-containing compounds such as phosphites, phosphates, eg tri Alkyl phosphates, triaryl phosphates, such as tricresyl phosphate, amine-neutralized mono and dialkyl phosphates, ethoxylated mono and dialkyl phosphates, phosphates Sulfonates, phosphines, amine salts or metal salts of these compounds. Sulfur and phosphorus containing antiwear additives such as thiophosphites, thiophosphates, amine salts or metal salts of these compounds.

  The antiwear additive is 0 to 3% by weight, preferably 0.1 to 1.5% by weight, more preferably 0.5 to 0.9% by weight, based on the total amount of the lubricant composition. Can exist.

  Preferred friction modifiers may include: mechanically acting compounds such as molybdenum disulfide, graphite (including fluorinated graphite), poly (trifluoroethylene), polyamide, polyimide; adsorption layer Compounds that form amides, such as long chain carboxylic acids, fatty acid esters, ethers, alcohols, amines, amides, imides; compounds from layers by tribochemical reactions, such as saturated fatty acids, phosphoric acid, and thiophosphates, xanthates, sulfur Fatty acids; compounds that form layers such as polymers, such as ethoxylated dicarboxylic acid partial esters, dialkyl phthalates, methacrylates, unsaturated fatty acids, sulfurized olefins, and organometallic compounds such as molybdenum compounds (molybdenum Dithiophosphate And molybdenum dithiocarbamates MoDTC), and combinations of these with ZnDTP, copper-containing organic compounds.

  Some of the aforementioned compounds can fulfill multiple functions. For example, ZnDTP is primarily an antiwear and extreme pressure additive, but also has antioxidant and corrosion inhibitor properties (herein a metal deactivator / deactivator).

  In particular, the aforementioned additives are in particular T. Mang, W. Dresel (eds), "Lubricants and Lubrication", Wiley-VCH, Weinheim 2001; RM Mortier, ST Orszulik (eds): "Chemistry and Technology of Lubricants" It is described in.

  The total concentration of the one or more additives (c) is preferably up to 20% by weight, more preferably 0.05-15% by weight, more preferably 5-15% by weight, based on the total weight of the lubricant composition. %.

  The amount of (a) to (c) is preferably 100% by mass in total.

Examples The invention is illustrated by the following examples.

Abbreviation C ₁ AMA ... C ₁ alkyl methacrylate (methyl methacrylate; MMA)
C ₄ AMA: C ₄ alkyl methacrylate (n-butyl methacrylate)
C _12/14 AMA: C _12/14 alkyl methacrylate C _16/18 AMA: C _16/18 alkyl methacrylate DMAPMMAm: N-3-dimethylaminopropyl methacrylamide f _{branch: at} mol% Degree of branching
Hydroseal G232H ・ ・ ・ Mineral oil derived from petroleum KRL ・ ・ ・ Tapered roller bearing KV ₀・ ・ ・ Dynamic viscosity at 0 ℃, measured according to ASTM D445 KV ₁₀・ ・ ・ Dynamic viscosity at 10 ℃, measured according to ASTM D445 KV ₂₀ ... Dynamic viscosity at 20 ° C, measured according to ASTM D445 KV ₄₀ ... Dynamic viscosity at 40 ° C, measured according to ASTM D445 KV ₁₀₀ ... Dynamic viscosity at 100 ° C, according to ASTM D445 Measurement MM-1 ... Macromonomer of hydrogenated polybutadiene having a methacrylate functional group (M _n = 1,000 g / mol)
MM-2: Macromonomer of hydrogenated polybutadiene having a methacrylate functional group (M _n = 2,000 g / mol)
MM-3: Macromonomer of hydrogenated polybutadiene having a methacrylate functional group (M _n = 4,750 g / mol)
_Mn: number average molecular weight _Mw: mass average molecular weight
NB3020 ... Nexbase (registered trademark) 3020, Group III base oil manufactured by Neste, KV ₁₀₀ is 2.2 cSt
NB3043 ... Nexbase (registered trademark) 3043, Group III base oil manufactured by Neste, KV ₁₀₀ is 4.3 cSt
OEM ... Contractor brand manufacturing PDI ・ ・ Polydispersity index, molecular weight distribution calculated by M _w / M _n PSSI ・ ・ ・ Permanent shear stability index
RC9300 ・ ・ ・ ADDITIN® RC9300, Lanxess DI package VI ・ ・ ・ Viscosity index, measured according to ASTM D2270
Yubase 4-Group III base oil from SK Lubricants, KV ₁₀₀ is 4.2 cSt

Test Methods Polymers according to the invention and comparative polymers were characterized for their molecular weight and PDI.

  The molecular weight of the polymer was determined by size exclusion chromatography (SEC) using a commercially available polymethacrylate (PMMA) standard. This identification is performed by gel permeation chromatography using THF as the eluent (flow rate: 1 mL / min, injection volume: 100 μL).

The number average molecular weight M _n of the macromonomer is determined by size exclusion chromatography using a commercially available polybutadiene standard. This identification is performed according to DIN 55672-1 by gel permeation chromatography using THF as eluent.

Additive compositions containing the polymers according to the invention and comparative examples, viscosity index (VI) according to ASTM D 2270, dynamic viscosity at 0 ° C. (KV ₀ ) according to ASTM D445, dynamic at 10 ° C. It was characterized for dynamic viscosity (KV ₁₀ ), dynamic viscosity at 20 ° C. (KV ₂₀ ), dynamic viscosity at 40 ° C. (KV ₄₀ ), and dynamic viscosity at 100 ° C. (KV ₁₀₀ ).

  Shear stability was investigated by KRL (tapered roller bearing, tapered roller bearing in English) according to a modified version of DIN 51350 Part 6 for 40 hours at 80 ° C. and 4000 rpm. To show the shear stability of the additive composition, PSSI (Permanent Shear Stability Index) is calculated based on data measured by this method according to ASTM D 6022-01 (Standard Practice for Calculation of Permanent Shear Stability Index) did.

Synthesis of hydroxylated hydrogenated polybutadiene (macroalcohol)
Three different macroalcohols (MA-1 to MA-3) were synthesized by anionic polymerization of 1,3-butadiene at 20 to 45 ° C. using butyllithium. When the desired degree of polymerization was reached, propylene oxide was added to stop the reaction and lithium was removed by precipitation with methanol. The polymer was subsequently hydrogenated in a hydrogen atmosphere in the presence of a noble metal catalyst at temperatures up to 140 ° C. and a pressure of 200 bar. After the hydrogenation was completed, the noble metal catalyst was removed and the organic solvent was extracted under reduced pressure. Finally, MA-3 was diluted with NB 3020 to make the polymer content 70% by weight. MA-1 and MA-2 were kept at 100%.

Table 1 is characterization data for MA-1, MA-2, and MA-3.

Synthesis of macromonomer (MM-1, MM-2 and MM-3) Saber-type stirrer, intake pipe, thermocouple with controller, heating jacket, column packed randomly with 3 mm helical wire, vapor distributor, top In a 2 L stirrer equipped with a thermometer, reflux condenser and substrate cooler, 1000 g of the aforementioned macroalcohol is stirred at 60 ° C. and dissolved in methyl methacrylate (MMA). To this solution is added 2,2,6,6-tetramethylpiperidine-1-oxyl radical 20 ppm, and hydroquinone monomethyl ether 200 ppm. After heating until the MMA is refluxed (bottom temperature is about 110 ° C.), about 20 mL of MMA is distilled off for azeotropic drying while passing air for stabilization. After cooling to 95 ° C., LiOCH ₃ is added and the mixture is heated to reflux again. After a reaction time of about 1 hour, the top temperature had dropped to about 64 ° C. due to methanol formation. The methanol / MMA azeotrope formed always distills off until a constant upper temperature of about 100 ° C. is established again. At this temperature, the mixture is allowed to react for an additional hour. For further work-up, most of the MMA is withdrawn under reduced pressure. Insoluble catalyst residues are removed by pressure filtration (Seitz T1000 depth filter).

Table 2 summarizes the amounts of MMA and LiOCH ₃ used to synthesize the macromonomers MM-1, MM-2 and MM-3.

Polymer synthesis Method 1
A monomer mixture (the composition of which is shown in Table 3) is charged into an apparatus equipped with a four-necked flask and a precision glass saber-type stirrer, and polymerized oil NB3020 is added, and the monomer concentration in the oil is 60 mass %. After heating to 115 ° C. under nitrogen, a 10 wt% solution of tert-butylperoxy-2-ethylhexanoate and dodecyl mercaptan in NB3020 are added at a constant feed rate within 3 hours. The reaction is maintained at 115 ° C. and 0.5 and 3.5 hours after the end of the initiator feed, 2,2-bis (tert-butylperoxy) butane is reduced to 0% (based on the total amount of monomer). Add 2%. The reaction mixture is stirred for an additional 2 hours at 115 ° C. and diluted with NB3020 to a 30% by weight polymer in oil to give the final VII.

  Table 3 shows the reaction mixtures used to produce the examples and comparative examples. The monomer components total 100%. The amount of initiator and chain transfer agent is relative to the total amount of monomer. The amount of monomer is 30% by weight of the final VII and the remaining 70% by weight is the diluent oil (NB3020) described above in the general procedure used to make this polymer.

Method 2
The monomer mixture (its composition is shown in Table 3) is diluted with a 50/50 mixture of Nexbase 3020 and Hydroseal G232 H so that the concentration of the monomer in the oil is 60% by weight. An apparatus equipped with a four-necked flask and a precision glass saber-type stirrer is charged with 50% by mass of the previously prepared reaction mixture. After heating to 120 ° C. under nitrogen, the proportion of 2,2-bis (tert-butylperoxy) butane initiator listed in Table 3 is added to the reaction mixture to initiate the reaction. The same amount of initiator is added to the remaining 50% of the reaction mixture, which is added to the flask at a constant rate over 3 hours at 120 ° C. The reaction was maintained at 120 ° C. and 2,2-bis (tert-butylperoxy) butane was added 0.2% (relative to the amount of monomer) after 2 and 4 hours from the supply of the reaction mixture. To do. The reaction mixture is stirred for an additional 2 hours at 120 ° C. and diluted with NB3020 to a 42.5 wt% polymer solution in oil to give the final VII.

  Table 3 shows the reaction mixtures used to produce the polymers according to the invention and the process for their production. The monomer components total 100%. The amount of initiator and chain transfer agent (CTA) is relative to the total amount of monomer. The polymer is diluted with oil (70% or 57.5% by weight) according to the above description of the two preparation methods.

Characteristic mass average molecular weights (M _w ) and their polydispersities (PDI) were obtained by GPC measurements.

Examples 1, 2 and 4 have similar compositions with respect to the relative amounts of each component listed in weight percent, but these examples are in turn for each of the three different macromonomers. 1, MM-2, and MM-3). Example 3 has a similar degree of branching as Example 4, but is based on MM-2 rather than MM-3. All four examples have similar M _w , allowing a performance comparison between the various examples and the macromonomer.

  Examples 5 and 6 use a combination of MM-2 and MM-3 with compositions having different backbones.

  Examples 7, 8 and 9 use MM-1 having a different backbone composition.

  Example 10 includes a dispersant monomer and MM-3.

Example 11 uses MM-2 and, in contrast to the other examples, C _16/18 alkyl methacrylate instead of C _12/14 alkyl methacrylate.

Examples 1-3, 5-9 and 11 are examples according to the present invention. The remaining examples are comparative examples.

Evaluation of Viscosity Index (VI) improver candidates An exemplary, having a target KV100 of 5.5 cSt in Nexbase 3043 in order to show the improving effect that the polymers according to the invention have on VI, shear stability and low temperature behavior A polymer additive composition was prepared. In addition, 0.6% of the package (RC9300) was added only for the purpose of KRL protection. VI, shear stability specified by KRL, and dynamic viscosity at various temperatures were measured. The results are shown in Table 4.

Examples 1, 2, and 4 all have the same monomer composition in weight percent and have the same overall M _w , but three different macromonomers MM-1, MM-2 and MM-3 are used. These examples show that Example 2 based on MM-2 has the most balanced performance. Example 2 shows the highest VI of these three examples, showing good solubility after shearing, as well as good dynamic viscosity at low temperatures.

Comparing Examples 3, 5, 6 and 11 with Comparative Examples 4 and 10 using MM-3, the examples according to the present invention show higher VI, significantly improved shear stability, and good low temperature properties. Show. This is particularly evident when comparing Example 3 and Example 4 (both of which have the same degree of branching and similar M _w ). The optimized composition of Example 3 is 7% lower for KV0, 9% better for VI and 62% lower for PSSI100 value compared to the value of Example 4, On the other hand, it still provides good solubility after shearing. This comparison shows that the performance of VI improvers in VI, low temperature performance and shear stability is significantly improved by the present invention.

  Examples 1, 7, 8 and 9 based on MM-1 also have better low temperature properties and in most cases have increased shear stability compared to Examples 4 and 10 based on MM-3. ing.

  However, when Examples 1, 7, 8 and 9 are compared to Examples 2, 5, 6 and 11 based on MM-2, the latter is equivalent to or higher in VI, increased shear stability, and equivalent low temperature properties. It is clear that A particular additional advantage of polymers based on MM-2 when compared to polymers based on MM-1 is excellent solubility after shearing. Examples 7, 8 and 9 may become turbid after shearing or even show precipitation, which is unacceptable for use in transmission fluids, for example.

Thus, the example based on MM-2 shows the best balance of overall performance in terms of VI, low temperature performance, and shear stability, and such performance is comparable to macromonomers (MM -1) or a macromonomer having a higher molecular weight (MM-3) cannot be used.

Claims (14)

Based on the total amount of monomers used,
(A) one or more esters of 10-70% by weight of (meth) acrylic acid and a hydroxylated hydrogenated polybutadiene having a number average molecular weight of 1,800-2,200 g / mol,
(B) 1 or more types of _C1-30 alkyl (meth) acrylate 10-80 mass%
A polyalkyl (meth) acrylate obtained by polymerizing a monomer composition in which the amount of (a) and (b) is 100% by mass in total, and having a degree of molar branching of 1.5 to 3 mol% polymer. The polymer of claim 1 having a weight average molecular weight ( _Mw ) of 15,000 to 350,000 g / mol.   The said monomer composition contains 20-60 mass% of 1 or more types of ester of (meth) acrylic acid and the said hydroxylated hydrogenated polybutadiene as a component (a). polymer. The monomer composition, as the component (b), containing the one or more C _{1 to 4} alkyl (meth) acrylate, a mixture of one or more C _{10 to 18} alkyl (meth) acrylate, according to claim 1 4. The polymer according to any one of items 1 to 3. The monomer composition, as the component (c), one or more styrene monomers 8-17 pieces have a carbon atom, containing 0.01 to 80 wt%, any one of claims 1 to 4 Polymer. The monomer composition is
(A) 20 to 60% by weight of one or more esters of (meth) acrylic acid and a hydroxylated hydrogenated polybutadiene having a number average molecular weight of 1,800 to 2,200 g / mol,
(B) one or more C _{1 to 4} alkyl (meth) acrylate from 1.0 to 70 mass%, and one or more C _{10 to 18} alkyl (meth) acrylate 0.1-10 wt%,
(C) The polymer according to any one of claims 1 to 5 , comprising 0.2 to 60% by mass of one or more styrene monomers having 8 to 17 carbon atoms. The polymer according to any one of claims 1 to 6 , wherein the hydroxylated hydrogenated polybutadiene has a number average molecular weight of 1,900-2,100 g / mol. The monomer composition further as component (c), oxygen and / or nitrogen functionalized one or more dispersing monomers were contained 0.01 to 10 mass%, any of the claims 1 to 7 The polymer according to item 1. A method for producing a polyalkyl (meth) acrylate polymer, comprising the following steps:
The said manufacturing method including the process of preparing (a) the monomer composition of any one of Claim 1-8 , and (b) starting the radical polymerization in the said monomer composition. The polyalkyl according to any one of claims 1 to 8 , as an additive for a lubricant composition for improving the viscosity index of the lubricant composition, the viscosity at a temperature of 40 ° C or less and the shear resistance. Use of (meth) acrylate polymers. A composition comprising (a) a base oil, and (b) the polyalkyl (meth) acrylate polymer according to any one of claims 1 to 8 . The base oil is a poly α-olefin base oil, an API Group III base oil, a mixture of a poly α-olefin base oil and an API Group III base oil, or a mixture of API Group III base oils. 11. The composition according to 11 . The composition according to claim 11 or 12 , comprising 40 to 80% by mass of the base oil and 20 to 60% by mass of the polymer. The composition according to claim 11 or 12 , comprising 50 to 99.5% by mass of the base oil and 0.5 to 50% by mass of the polymer.