Hydrogenated polymers with a radial structure having a core made up of calixarenes of the general formula (I), to the core of which is linked a number P of hydrogenated linear polymer segments selected from: hydrogenated homopolymers or co-polymers of conjugated dienes; or hydrogenated co-polymers of said conjugated dienes and monoalkenyl arenes, and mixtures thereof said formula (I) in which: R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are independently selected from hydrogen; a group containing carbon and hydrogen; a group also containing heteroatoms in addition to carbon and hydrogen; a group also containing silicon in addition to carbon, hydrogen and heteroatoms; one of the two substituents R.sub.5 and R.sub.6 is hydrogen, while the other may be hydrogen or alkyl, with a number of carbon atoms between 1 and 6, preferably methyl and ethyl; n is an integer in the range between 4 and 16.

##STR00001##

A defoaming agent including a polymer, the polymer including a repeating unit represented by the following general formula (1); and a repeating unit represented by the following general formula (3): ##STR00001##
wherein in the general formula (1), X.sup.1 is a repeating unit obtainable by polymerization of a first ethylenic unsaturated group; Y.sup.1 is a side chain including a linear or branched polysiloxane structure, the polysiloxane structure having a polymerization degree of 5 to 300; and Z.sup.1 is a linking group linking the repeating unit X.sup.1 and the side chain Y.sup.1; ##STR00002##
wherein in the general formula (3), X.sup.2 is a repeating unit obtainable by polymerization of a second ethylenic unsaturated group, Y.sup.2 is a C.sub.1-30 hydrocarbyl side chain; and Z.sup.2 is a linking group linking the repeating unit X.sup.2 and the side chain Y.sup.2.

A defoaming agent comprising: a polymer comprising a repeating unit represented by the following general formula (1): ##STR00001##
where in the general formula (1), X.sup.1 is a repeating unit obtainable by polymerization of an ethylenic unsaturated group; Y.sup.1 is a side chain comprising a linear or branched polysiloxane structure, the polysiloxane structure comprising a repeating unit represented by the following general formula (2) and having a polymerization degree of 5 to 300; and Z.sup.1 is a linking group linking the repeating unit X.sup.1 and the side chain Y.sup.1; ##STR00002##
wherein in the general formula (2), R.sup.1 and R.sup.2 are each independently an organic group having a carbon number of 1 to 18.

Disclosed herein is an oil additive and combination oil product comprising an effective amount of the oil additive. The oil additive comprises a bismuth-containing premix, the bismuth-containing premix comprising bismuth trioxide and a carrier, and a boron-containing premix, the boron-containing premix comprising boric acid, a carrier, and an anionic surfactant.

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.

Compositions resulting from the mixing of at least one copolymer A1, resulting from the copolymerization of at least one monomer functionalized by diol functions with at least one styrenic monomer, and at least one compound A2 comprising at least two boronic ester functions. They have very varied rheological properties depending on the proportion of compounds A1 and A2 used. Composition resulting from the mixing of at least one lubricating oil with such a composition of associative and exchangeable polymers and use of this composition for lubricating a mechanical part.

A defoaming agent obtainable by a process, the process including the step of: (i) polymerizing (B) at least one defoaming agent monomer in (A) a polymerization solvent under coexistence of (C) a polymer soluble in the polymerization solvent.

A graft copolymer can include, in its backbone, at least one segment having repeating units obtainable by ring-opening metathesis polymerization (ROMP) of an optionally substituted cycloalkene, and at least one segment comprising repeating units obtainable by atom transfer radical polymerization (ATRP) of a (meth)acrylate. The corresponding graft copolymer is highly suitable for use as an oil additive in internal combustion engines, in particular, in combustion engines which are operated for longer periods of time at substantially constant operating temperatures.

The present invention relates to novel uses of corrosion inhibitors in fuels and lubricants.

A graft copolymer can include, in its backbone, at least one segment having repeating units obtainable by ring-opening metathesis polymerization (ROMP) of an optionally substituted cycloalkene, and at least one segment comprising repeating units obtainable by atom transfer radical polymerization (ATRP) of a (meth)acrylate. The corresponding graft copolymer is highly suitable for use as an oil additive in internal combustion engines, in particular, in combustion engines which are operated for longer periods of time at substantially constant operating temperatures.