Abstract: An internal combustion engine includes an exhaust-gas aftertreatment device, and an operating method is for operating the internal combustion engine. The internal combustion engine is operable with a lean mixture and a rich mixture, the internal combustion engine having an exhaust-gas aftertreatment device, which includes a nitrogen oxide storage catalytic converter and a particle filter. When lean exhaust gas flows through the nitrogen oxide storage catalytic converter, it removes nitrogen oxides from the exhaust gas by storing them, and, when reducing exhaust gas flows through the nitrogen oxide storage catalytic converter, it produces ammonia through reduction of stored and/or supplied nitrogen oxides and releases it to the exhaust gas. Downstream from the nitrogen oxide storage catalytic converter, the exhaust-gas aftertreatment device includes a SCR catalytic converter, which reduces nitrogen oxides contained in the exhaust gas, using ammonia produced by the nitrogen oxide storage catalytic converter.

Abstract: An exhaust-gas aftertreatment device with a nitrogen oxide storage catalytic converter for an internal combustion engine, and a method for operating an exhaust-gas aftertreatment device which is assigned to an internal combustion engine and has a nitrogen oxide storage catalytic converter. An SCR catalytic converter is arranged in the exhaust-gas aftertreatment device, it being possible for the exhaust gas which emerges from the nitrogen oxide storage catalytic converter to be fed to the SCR catalytic converter when the internal combustion engine is in a desulphating operating mode with a reducing exhaust-gas composition, in order for H2S which is formed during the desulphating to be removed.

Abstract: An exhaust-gas aftertreatment device with a nitrogen oxide storage catalytic converter for an internal combustion engine, and a method for operating an exhaust-gas aftertreatment device which is assigned to an internal combustion engine and has a nitrogen oxide storage catalytic converter. An SCR catalytic converter is arranged in the exhaust-gas aftertreatment device, it being possible for the exhaust gas which emerges from the nitrogen oxide storage catalytic converter to be fed to the SCR catalytic converter when the internal combustion engine is in a desulphating operating mode with a reducing exhaust-gas composition, in order for H2S which is formed during the desulphating to be removed.

Abstract: An exhaust-gas aftertreatment device with a nitrogen oxide storage catalytic converter for an internal combustion engine, and a method for operating an exhaust-gas aftertreatment device which is assigned to an internal combustion engine and has a nitrogen oxide storage catalytic converter. An SCR catalytic converter is arranged in the exhaust-gas aftertreatment device, it being possible for the exhaust gas which emerges from the nitrogen oxide storage catalytic converter to be fed to the SCR catalytic converter when the internal combustion engine is in a desulphating operating mode with a reducing exhaust-gas composition, in order for H2S which is formed during the desulphating to be removed.

Abstract: Synthetic oils comprising 5-100 percent by weight of an oligomer ofA) 0-75 wt. % of at least one 1-alkene,B) 20-100 wt. % of at least one (meth)acrylic acid ester of the formula ##STR1## wherein R is hydrogen or methyl and R.sub.1 is optionally branched alkyl or cycloalkyl, andC) 0-65 wt. % of a (meth)acrylic acid ester of the formula ##STR2## wherein R' is hydrogen or methyl and R.sub.2 is alkyl substituted with at least one hydroxy group or is ##STR3## wherein R.sub.3 and R.sub.4 are hydrogen or methyl, R.sub.5 is hydrogen or optionally branched alkyl, but if n is 1, then R.sub.5 is exclusively optionally branched alkyl.

Abstract: Multifunctional additives for lubricating oils containing n-paraffins, said additives comprising a solvent and a blend of polymers containing(I) from 10 to 99 percent by weight of one or more polymers P1 composed of monomers of(A) esters of methacrylic acid, acrylic acid, or both(a) with a linear alcohol having from 16 to 30 carbon atoms,(b) with a branched alcohol having from 8 to 40 carbon atoms, and optionally, other alcohols, and(II) from 1 to 90 percent by weight to one or more polymers P2 composed of monomers of(A') esters of methacrylic acid, acrylic acid, or both(a') with a linear alcohol having from 16 to 30 carbon atoms, and, optionally other alcohols.

Abstract: Additives for n-paraffin-containing lubricating oils, which additives are mixtures of acrylates containing(I) from 10 to 99 weight percent of polymers P.sub.1 composed of(a) esters of methacrylic acid and/or acrylic acid and linear C.sub.6 to C.sub.15 alcohols;(b) esters of methacrylic acid and/or acrylic acid and linear C.sub.16 to C.sub.30 alcohols;(c) esters of methacrylic acid and/or acrylic acid and branched C.sub.8 to C.sub.40 alcohols;(d) esters of methacrylic acid and/or acrylic acid and C.sub.1 to C.sub.5 alcohols; and(e) monomers having functional groups, the amount of (b) being at the most 5 mol percent; and(II) from 90 to 1 weight percent of polymers P.sub.2 composed of(a') esters of methacrylic acid and/or acrylic acid and linear C.sub.6 to C.sub.15 alcohols;(b') esters of methacrylic acid and/or acrylic acid and linear C.sub.16 to C.sub.30 alcohols;(c') esters of methacrylic acid and/or acrylic acid and branched C.sub.8 to C.sub.

Abstract: Polymers adaptable to use as pour point lowering additives for petroleum oils, said polymers comprising as comonomers therein(a) from 10 to 30 mole percent of methyl methacrylate,(b) from 10 to 70 mole percent of alkyl methacrylates having linear alkyl groups with from 16 to 30 carbon atoms in the alkyl group,(c) from 10 to 80 mole percent of alkyl methacrylates having linear alkyl groups with from 4 to 15 carbon atoms in the alkyl group and/or having branched alkyl groups with from 4 to 40 carbon atoms in the alkyl group,(d) from 0 to 30 mole percent of a free-radically polymerizable nitrogen-containing monomer having dispersing action,and petroleum oils containing such polymers as pour point lowering additives.

Abstract: Multirange lubricating oils having high shear stability comprising paraffinic oils as their base and containing, as an additive improving the viscosity index, a mixture of at least two different polymer species, each of said polymer species being composed of monomers selected from the group consisting of(a) esters of methacrylic acid and acrylic acid with linear alcohols having 6 to 15 carbon atoms,(b) esters of methacrylic acid and acrylic acid with linear alcohols having from 16 to 30 carbon atoms,(c) esters of methacrylic acid and acrylic acid with branched alcohols having from 6 to 40 carbon atoms,(d) esters of methacrylic acid and acrylic acid with alcohols having from 1 to 5 carbon atoms, and(e) other monomers, different from (a)-(d), susceptible to free-radical copolymerization, and containing functional groups in the molecule,monomer or monomers (a) being from 0 to 100 mole percent of said polymer species, monomer(s) (b) being from 0 to 10 mole percent, monomers (c), (d) and (e) combined being from 0

Abstract: What is disclosed are the method of making a lubricating-oil additive which improves the viscosity index and has a dispersing and detergent action, which method comprises graft copolymerizing, onto an oil-soluble base polymer, from 0.5 to 10 parts of a polymerizable lactam together with 0.1 to 3 parts of a polymerizable N-heterocyclic compound, said parts being by weight of said base polymer, and the lubricating-oil additives so produced.

Abstract: What is disclosed is a concentrated polymer emulsion useful as a lubricating oil additive for improving the viscosity index thereof, said emulsion comprising:(1) a dispersed phase of an olefinic copolymer having a molecular weight complementary with respect to the thickening effect desired;(2) a dispersing phase of a polymer predominantly comprising at least one member selected from the group consisting of acrylate ester and methacrylate ester monomers;(3) a vehicle which is a good solvent for the esters in said dispersing phase and a substantially less good solvent for the olefinic copolymer by virtue of the esters dissolved in said vehicle; and(4) an emulsifier, stabilizing phase distribution, which is a member selected from the group consisting of graft copolymers and block copolymers formed from olefinic monomers and at least one member selected from the group consisting of acrylate ester and methacrylate ester monomers.

Abstract: What is disclosed are the method of making a lubricating-oil additive which improves the viscosity index and has a dispersing and detergent action, which method comprises graft copolymerizing, onto an oil-soluble base polymer, from 0.5 to 10 parts of a polymerizable lactam together with 0.1 to 3 parts of a polymerizable N-heterocyclic compound, said parts being by weight of said base polymer, and the lubricating-oil additives so produced.

Abstract: What is disclosed are methods for making polymer-in-oil solutions, useful for improving the viscosity-temperature relationship and low-temperature properties of lubricating oils when added thereto, which methods comprise polymerizing a methacrylic acid ester of an alcohol having 8 to 18 carbon atoms onto a polyolefin polymer of an olefinic hydrocarbon monomer having 2 to 4 carbon atoms in an oil solution of the polyolefin and ester monomers, then adding further polyolefin polymer to the solution and finally graft copolymerizing a polymerizable heterocyclic compound having a basic nitrogen atom in the ring thereof onto the resulting mixed polymers as backbone polymers or, in the alternative, separately graft copolymerizing a polymerizable heterocyclic compound having a basic nitrogen atom in the ring thereof onto a first backbone polymer which is itself a graft copolymer, in an oil solution, of a methacrylic acid ester of an alcohol having 8 to 18 carbon atoms on a polyolefin polymer of an olefinic hydrocarbon

Abstract: A method is disclosed for making a polymer-in-oil solution, useful for improving the viscosity-temperature relationship and low-temperature properties of lubricating oils when added thereto, which method comprises a first step of polymerizing a methacrylic acid ester of an alcohol having 8 to 18 carbon atoms in a solution, in a lubricating oil, of a polyolefin polymer of an olefinic hydrocarbon monomer having 2 to 4 carbon atoms, the oil solution of said polyolefin having a viscosity of less than 15,000 centistokes at 100.degree. C., and then, in a second step, adding further polyolefin polymer of the type defined herein until the total polymer content in the oil solution is from 20 percent to 55 percent by weight of said solution and said methacrylate ester comprises from 50 percent to 80 percent of said polymer content.