The invention relates to aqueous polymer dispersions comprising at least one polymer obtainable by the reaction of at least one monomer M1 of the general formula (I): H.sub.2C═CH—C(O)OR, wherein R is an unbranched alkyl chain comprising from 18 to 22 carbon atoms, and optionally at least one monomer M2. The invention relates moreover to a method for the preparing of such aqueous polymer dispersion and the use thereof as pour point depressant for crude oil, petroleum, and petroleum products.

The invention concerns additive compositions obtained by mixing at least two thermoassociative and exchangeable compounds and at least one boronic ester compound that enables the association of these two copolymers to be controlled; a lubricating composition obtained by mixing at least one lubricating base oil, at least two thermoassociative and exchangeable compounds, and at least one boronic ester compound that enables the association of these two copolymers to be controlled; a method for adjusting the viscosity of a lubricating composition obtained by mixing at least one lubricating base oil and at least two thermoassociative and exchangeable compounds; and the use of a boronic ester compound to adjust the viscosity of a lubricating composition.

Selected comb polymers include specified amounts of macromonomer and imide functionalization. Further, a method is useful for the preparation of such comb polymers. Lubricant compositions including such comb polymers are useful for reducing wear and fuel consumption of lubricant compositions, especially of engine oil (EO) compositions.

A vinyl-based comb copolymer includes a polyisobutylene-based macromonomer unit and a vinyl-based monomer unit. A polyisobutylene-based macromonomer has at least 0.8 (meth)acryloyl groups represented by a specific formula at one end of a main chain per molecule, and is copolymerized with a vinyl-based monomer. A method for producing the vinyl-based comb copolymer includes copolymerizing the polyisobutylene-based macromonomer with the vinyl-based monomer. A viscosity index improver includes the comb copolymer. A lubricating oil composition includes the comb copolymer.

The invention relates to a copolymer comprising: at least one motif of the following formula (I), and motifs of the following formula (II), between 5 and 95 mol % of the groups R of the motifs of formula (II) comprising at least one quaternary amino group. The invention also relates to the production of such a copolymer, and to the use thereof as a detergent additive and/or demulsifying additive in a liquid fuel for an internal combustion engine.

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The invention relates to aqueous polymer dispersions comprising at least one polymer obtainable by the reaction of at least one monomer M1 of the general formula (I): H.sub.2CCHC(O)OR, wherein R is an unbranched alkyl chain comprising from 18 to 22 carbon atoms, and optionally at least one monomer M2. The invention relates moreover to a method for the preparing of such aqueous polymer dispersion and the use thereof as pour point depressant for crude oil, petroleum, and petroleum products.

Polyalkyl(meth)acrylate based comb polymers with weight-average molecular weights of 700,000 g/mol or greater and number-average molecular weights of 130,000 g/mol or greater can be used to improve the high temperature-high shear performance of lubricant compositions, especially of engine oil (EO) compositions. These polymers can be obtained in a reaction mixture comprising monomers, a dilution oil, and an initiator. The resulting lubricant compositions can have improved kinematic viscosity and high temperature high shear performance.

Selected comb polymers include specified amounts of macromonomer and imide functionalization. Further, a method is useful for the preparation of such comb polymers. Lubricant compositions including such comb polymers are useful for reducing wear and fuel consumption of lubricant compositions, especially of engine oil (EO) compositions.

A vinyl-based comb copolymer includes a polyisobutylene-based macromonomer unit and a vinyl-based monomer unit. A polyisobutylene-based macromonomer has at least 0.8 (meth)acryloyl groups represented by a specific formula at one end of a main chain per molecule, and is copolymerized with a vinyl-based monomer. A method for producing the vinyl-based comb copolymer includes copolymerizing the polyisobutylene-based macromonomer with the vinyl-based monomer. A viscosity index improver includes the comb copolymer. A lubricating oil composition includes the comb copolymer.

The invention concerns additive compositions obtained by mixing at least two thermoassociative and exchangeable compounds and at least one boronic ester compound that enables the association of these two copolymers to be controlled; a lubricating composition obtained by mixing at least one lubricating base oil, at least two thermoassociative and exchangeable compounds, and at least one boronic ester compound that enables the association of these two copolymers to be controlled; a method for adjusting the viscosity of a lubricating composition obtained by mixing at least one lubricating base oil and at least two thermoassociative and exchangeable compounds; and the use of a boronic ester compound to adjust the viscosity of a lubricating composition.