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BR-102020025634-B1 - LUBRICANT COMPOSITION

BR102020025634B1BR 102020025634 B1BR102020025634 B1BR 102020025634B1BR-102020025634-B1

Abstract

LUBRICATING COMPOSITION, METHOD OF MODIFYING THE VISCOSITY AND DISPERSANCE OF A LUBRICATING COMPOSITION, AND USE OF A COMB COPOLYMER-BASED VISCOSITY MODIFIER. A comb copolymer-based viscosity modifier can be prepared by polymerization comprising at least, or consisting essentially of, the following monomers: (a) (optionally from 7.0% by weight to 18% by weight, of repeating units, of) a hydrogenated polybutadiene-based (alq)acrylate macromonomer; (b) (optionally from 33% by weight to 64% by weight, of repeating units, of) a C3-C8 alkyl (alq)acrylate ester monomer; (c) a C12-C24 alkyl (alq)acrylate ester monomer; and (d) (optionally from 3.0% by weight to 25% by weight, of repeating units, of) a C2-C6 oligo(glycol alkylene) or C2-C6 oxoalkyl chain-blocked (alq)acrylate (alq)acrylate monomer or a C6-C20 aryl, aralkyl, or alkaryl chain-blocked (alq)acrylate chain-blocked (alq)acrylate monomer, chain-blocked (alq)acrylate, wherein the repeating units based on monomer (c) and/or monomer (d) comprise at least 21.0% by weight (and optionally up to 35.0% by weight) (...).

Inventors

  • Ewan Galbraith
  • Nga Nguyen
  • RONALD M. LEWIS

Assignees

  • INFINEUM INTERNATIONAL LIMITED

Dates

Publication Date
20260310
Application Date
20201215
Priority Date
20191216

Claims (13)

  1. 1. Lubricating composition, characterized in that it comprises: a lubricating base oil comprising a Group I base oil, a Group II base oil, a Group III base oil, or a mixture thereof; a lubricant additive comprising one or more of an antioxidant, a corrosion inhibitor, an anti-wear additive, a friction modifier, a dispersant, a detergent, a defoaming agent, an extreme pressure additive, a pour point depressant, and a seal expansion control agent; and a comb copolymer-based viscosity modifier prepared by polymerization comprising at least the following monomers: (a) a hydrogenated polybutadiene-based (alq)acrylate ester macromonomer; (b) a C3-C8 alkyl (alq)acrylate ester monomer; (c) a C12-C24 alkyl (alq)acrylate ester monomer; (e) and (d) a C2-C6 oligo(alkylene glycol) or C2-C6 oxyalkyl (alq)acrylate-based chain-terminated aryl, aralkyl or alkaryl monomer having the following structure (II): where R2 represents hydrogen or C1-C2 alkyl, m is from 2 to 6, such that -(CH2)m- represents a linear, branched and/or cyclic alkyl group between oxygens; n is from 1 to 10, and R1 represents a chain-terminal block with C6-C20 aryl, aralkyl, or alkyl, wherein repeating units based on the C12-C24 alkyl (alq)acrylate ester monomer comprise at least 21.0% by weight of repeating units of the comb copolymer-based viscosity modifier, wherein repeating units based on the C2-C6 oligo(alkylene glycol) or C2C6 oxyalkyl (alq)acrylate ester monomer chain-terminal blocked with C6-C20 aryl, aralkyl, or alkyl comprise from 3.0% by weight to 25% by weight of the repeating units of the comb copolymer-based viscosity modifier; and wherein: (i) repeating units based on the hydrogenated polybutadiene (alq)acrylate ester macromonomer comprise from 7.0% by weight to 18% by weight of the repeating units of the copolymer-based comb viscosity modifier; and (ii) repeating units based on the C3-C8 alkyl (alq)acrylate ester monomer comprise 33% by weight to 64% by weight of the repeating units of the copolymer-based comb viscosity modifier.
  2. 2. Lubricating composition according to claim 1, characterized in that: the comb copolymer-based viscosity modifier does not comprise styrene monomer-based repeating units; and in that repeating units based on C12-C24 alkyl (alq)acrylate ester monomer comprise up to 35.0% by weight of repeating units of the comb copolymer-based viscosity modifier.
  3. 3. Lubricating composition according to claim 1 or 2, characterized in that R2 represents hydrogen or methyl, m is from 2 to 4, n is from 1 to 6, and R1 represents aryl, aralkyl or C6-C11 alkaryl.
  4. 4. Lubricating composition according to any one of claims 1 to 3, characterized in that R2 is methyl, m is 2 or 3, n is 1 to 6, and R1 is phenyl or benzyl.
  5. 5. Lubricating composition according to any one of claims 1 to 4, characterized in that: (i) the C3-C8 alkyl (alq)acrylate ester monomer is a butyl acrylate and/or a butyl methacrylate; (ii) the C12-C24 alkyl (alq)acrylate ester monomer comprises a lauryl acrylate, a lauryl methacrylate, a myristyl acrylate, a myristyl methacrylate, a palmityl acrylate, a palmityl methacrylate, a heptadecanoyl acrylate, a heptadecanoyl methacrylate, or a combination thereof; or (iii) both (i) and (ii).
  6. 6. Lubricating composition according to any one of claims 1 to 5, characterized in that the C2-C6 oligo(alkylene glycol) or C2-C6 oxyalkyl (alq)acrylate ester monomer chain-blocked with an aryl, aralkyl or C6-C20 alkaryl group comprises an ethylenic glycol phenyl ether acrylate, an ethylenic glycol phenyl ether methacrylate, an ethylenic glycol benzyl ether acrylate, an ethylenic glycol benzyl ether methacrylate, an ethylenic glycol oligo(glycol) phenyl ether acrylate, an ethylenic glycol oligo(glycol) phenyl ether methacrylate, an ethylenic glycol benzyl ether acrylate, an ethylenic glycol oligo(glycol) benzyl ether methacrylate, an ethylenic glycol oligo(glycol) benzyl ether methacrylate, an ethylenic glycol benzyl ether acrylate, an ethylenic glycol oligo(glycol) benzyl ether methacrylate, an ethylenic glycol benzyl ether acrylate oligo(ethylenic glycol), a naphthyl ether oligo(ethylenic glycol) methacrylate, a propylene glycol phenyl ether acrylate, a propylene glycol phenyl ether methacrylate, a phenyl ether oligo(propylenic glycol) acrylate, a phenyl ether oligo(propylenic glycol) methacrylate, a benzyl ether oligo(propylenic glycol) acrylate, a benzyl ether oligo(propylenic glycol) methacrylate, a naphthyl ether oligo(propylenic glycol) acrylate, a naphthyl ether oligo(propylenic glycol) methacrylate, or a combination thereof.
  7. 7. Lubricating composition according to any one of claims 1 to 6, characterized in that it comprises from 0.5% by mass to 9.0% by mass of comb copolymer-based viscosity modifier, based on the total mass of the lubricating composition.
  8. 8. Lubricating composition according to any one of claims 1 to 7, characterized in that it comprises from 75% by mass to 95% by mass of lubricating base oil, based on the total mass of the lubricating composition.
  9. 9. Lubricating composition according to any one of claims 1 to 8, characterized in that said comb copolymer-based viscosity modifier exhibits a weight-average molecular weight of less than or equal to 625,000 g/mol, as measured by gel permeation chromatography (GPC) at 35°C on tetrahydrofuran (THF) using polystyrene standards.
  10. 10. Lubricating composition according to any one of claims 1 to 9, characterized in that said comb copolymer-based viscosity modifier is prepared by polymerization of monomers consisting essentially of: (a) the hydrogenated polybutadiene-based (alq)acrylate macromonomer; (b) the C3-C8 alkyl (alq)acrylate ester monomer; (c) the C12-C24 alkyl (alq)acrylate ester monomer; and (d) the C2-C6 oligo(alkylene glycol) or C2-C6 oxyalkyl chain-blocked (alq)acrylate monomer with a C6-C20 aryl, aralkyl or alcaryl chain-terminated (alq)acrylate monomer.
  11. 11. Lubricating composition according to any one of claims 1 to 10, characterized in that said comb copolymer-based viscosity modifier: (i) is prepared by polymerization of monomers that do not comprise styrene or styrenic monomers; and (ii) does not comprise styrene-based repeating units or styrenic monomer-based repeating units.
  12. 12. Lubricating composition according to any one of claims 1 to 10, characterized in that said comb copolymer-based viscosity modifier is prepared by polymerization comprising monomers (a), (b), (c), (d), and (e) and at least one additional olefinic monomer, other than monomers (a), (b), (c), and (d), and which is not an aryl, aralkyl, or C6-C20 alkaryl (alq)acrylate ester monomer.
  13. 13. Lubricating composition, characterized in that it comprises: a lubricating base oil comprising a Group I base oil, a Group II base oil, a Group III base oil, or a mixture thereof; a lubricant additive comprising one or more of an antioxidant, a corrosion inhibitor, an anti-wear additive, a friction modifier, a dispersant, a detergent, a defoaming agent, an extreme pressure additive, a pour point depressant, and a seal expansion control agent; and a comb copolymer-based viscosity modifier prepared by polymerization comprising at least the following monomers: (a) a hydrogenated polybutadiene-based (alq)acrylate ester macromonomer; (b) a C3-C8 alkyl (alq)acrylate ester monomer; (c) a C12-C24 alkyl (alq)acrylate ester monomer; (d) an (alq)acrylate ester monomer based on C2-C6 oligo(alkylene glycol) or C2-C6 oxyalkyl chain-blocked aryl, aralkyl or alkaryl C6-C20 having the following structure (II): where R2 represents hydrogen or C1-C2 alkyl, m is from 2 to 6, such that -(CH2)m- represents a linear, branched and/or cyclic alkyl group between oxygens; n is from 1 to 10, and R1 represents a chain-terminal block with C6-C20 aryl, aralkyl, or alkyl, wherein the sum of the repeating units of C12-C24 alkyl (alq)acrylate ester monomer plus the repeating units with hydroxyalkyl and/or C2-C6 oligo(alkylene glycol) (alq)acrylate ester monomer or C2-C6 oxyalkyl chain-terminal blocked with C6-C20 aryl, aralkyl, or alkyl collectively comprise at least 21.0% by weight of the repeating units of the comb copolymer-based viscosity modifier; wherein: (i) repeating units based on hydrogenated polybutadiene-based (alq)acrylate ester macromonomer comprise from 7.0% by weight to 18% by weight of the repeating units of the viscosity modifier-based (i) comb copolymer; and (ii) repeating units based on the C3-C8 alkyl (alq)acrylate ester monomer comprise from 33% by weight to 64% by weight of the repeating units of the comb copolymer-based viscosity modifier; and wherein: repeating units based on monomer (d) comprise at least 3.0% by weight and up to 28% by weight of the repeating units of the comb copolymer-based viscosity modifier.

Description

Field [001] This description refers in general to poly((alq)alkyl acrylate) comb copolymers useful in modifying the viscosity of compositions such as lubricating oil compositions, for example, for passenger car engines, heavy-duty diesel engines, and marine diesel engines, in functional fluids such as manual/automatic transmission fluids. More specifically, certain poly((alq)alkyl acrylate) comb copolymers may have specific repeating unit contents and chemistries, and lubricating oil compositions incorporating such copolymers may advantageously exhibit certain characteristics such as kinematic viscosities, viscosities under high shear and high temperature, and optionally also soot dispersancy that may meet increasingly stringent specifications. Fundamentals [002] Poly((alq)alkyl acrylates) — generally synthesized by simple copolymerization (via free radicals) of a mixture of different (alq)alkyl acrylates — can produce, as additives for lubricating base oils (although still dependent on molecular weight and composition), an increase in Viscosity Index (VI) comparable to, in comparison with other Viscosity Index Enhancers (VIAs), improved low-temperature properties (R. M. Mortier, S. T. Orszulik (eds.), “Chemistry and Technology of Lubricants”, Blackie Academic & Professional, 1st ed., London 1993, 124-159 & 165-167). A fundamental difficulty for the usability of a viscosity-modifying additive is, trivially, its compatibility/solubility in the component(s) to be thickened, which, in the case of polyacrylates, may depend on the presence of a sufficiently large number of alkyl side chains, typically having 6 to 24 carbon atoms. The viscosity index (VI) of poly((alq)acrylates) can sometimes be increased by copolymerization of short-chain alkyl (meth)acrylates, for example methyl methacrylate or butyl methacrylate (cf., for example, European Publications Nos. EP 0.637.332, EP 0.937.769, and EP 0.979.834). However, the comonomeric component with the shorter chain lowers solubility at low temperatures, so the proportion of methyl methacrylate can typically be restricted, for example, to about 25% by weight or less. The viscosity indices (VIs) of these comb-type polymers thus achievable are, depending on the concentration, the Permanent Shear Stability Index (PSSI), and the type of base oil, in the range of between 150 and 250. [003] Another class of AIVs involves alkyl styrene-maleate copolymers obtained by polymer-analog esterification of styrene-maleic anhydride copolymers with typically C6-C24 alcohols. Esterification can be intensified to a conversion of about 95% by the addition of butanol. Complete conversion of the acid functionalities can be achieved by the addition of an amine to form amide or imide groups (see, for example, U.S. Patent No. 3,702,300 and European Publication No. EP 0,969,077). [004] The viscosities of polymer solutions in mineral or synthetic oils may depend, to some degree, on molecular weight. This may also have the consequence that the dependence of viscosity on temperature decreases or the VI (viscosity index) increases with increasing molecular weight (cf. J, Bartz, “Additive für Schmierstoffe” [Additives for Lubricants], Verlag Expert, Renningen-Malmsheim 1994, 197252). In relation to increasing temperature, reference is also made to the clearing of collapsed nodes to provide the extended worm-like molecule. [005] Similar to molecular weight, shear stability, however, can typically decrease as a result of chain breakage under high shear. As a result of this counter-effect, shear-stable AIVs, as required for manual transmission oils, automatic transmission oils, hydraulic oils, motor oils, or the like, based on conventional polymer types such as poly(meth)acrylates can often be feasible only with the addition of undesirably high amounts. AIVs with a relatively low contribution to viscosity at relatively low temperatures, relatively moderate thickening in the IR range from about 20°C to about 100°C, relatively high contribution to viscosity above about 100°C, and simultaneously good solubility/dispersibility within a wide temperature range may therefore be of particular interest. [006] In addition to linear comb-type polymers such as poly(meth)acrylates, comb-based AIVs are already described in the patent literature. For example, European Publication No. EP 0,744,457 describes relatively high-order comb polymers based purely on poly((meth)acrylates) alkyl, in which the side arms themselves consist of oligomeric poly((meth)acrylate) alkyl. Additionally, the patent literature includes other patents related to comb polymers in which the side chains are saturated/hydrogenated polyolefins and the backbone is of short-chain monomers (such as alkyl (meth)acrylates or alkylstyrenes). For example, European Publication No. EP 0,621,293 describes comb polymer side chains formed of hydrogenated polybutadiene. Similarly, European Publication No. EP 0.699.694 describes comb polymer side chains base