Copolymers comprising C.sub.14 to C.sub.50 olefins and at least two different olefindicarboxylic esters and optionally maleic acid or maleic acid derivatives. The olefindicarboxylic esters are firstly esters with linear C.sub.18- to C.sub.50-alkyl groups and secondly esters with short-chain linear, branched or cyclic alkyl groups, or esters with aromatic groups. The invention further relates to a process for preparing copolymers of this kind and to the use thereof as pour point depressant for crude oil, mineral oil and/or mineral oil products, preferably as pour point depressant for crude oil.

A method for enhancing the efficiency of a liquid fuel is described. The method involves the addition of cobalt hydroxystannate nanoparticles to the liquid fuel to produce an enhanced liquid fuel. The cobalt hydroxystannate nanoparticles may be present at a concentration of 50-200 ppm, and may increase the calorific value of the fuel by a factor of 25-52 times.

The present invention relates to a copolymer obtainable by copolymerization of

(A) at least one unsaturated dicarboxylic acid or derivatives thereof,
(B) at least one -olefin having from at least 6 up to and including 20 carbon atoms,
(C) optionally at least one C.sub.3- to C.sub.20-alkyl ester of acrylic acid or methacrylic acid or a mixture of such alkyl esters and
(D) optionally one or more further copolymerizable monomers other than monomers (A), (B) and (C),
with a molar incorporation ratio of (A):(B):(C):(D) of 1:0.5 to 2.0:0 to less than 0.5:0 to 0.1
followed by the reaction with at least one dialkylamine (E), where the two alkyl radicals in the at least one dialkylamine (E) are independently alkyl radicals having at least 17 up to 30 carbon atoms.

Copolymers comprising C.sub.14 to C.sub.50 olefins and at least two different olefindicarboxylic esters and optionally maleic acid or maleic acid derivatives. The olefindicarboxylic esters are firstly esters with linear C.sub.18- to C.sub.50-alkyl groups and secondly esters with short-chain linear, branched or cyclic alkyl groups, or esters with aromatic groups. The invention further relates to a process for preparing copolymers of this kind and to the use thereof as pour point depressant for crude oil, mineral oil and/or mineral oil products, preferably as pour point depressant for crude oil.

Copolymers comprising C.sub.14 to C.sub.50 olefins and at least two different olefindicarboxylic esters and optionally maleic acid or maleic acid derivatives. The olefindicarboxylic esters are firstly esters with linear C.sub.18- to C.sub.50-alkyl groups and secondly esters with short-chain linear, branched or cyclic alkyl groups, or esters with aromatic groups. The invention further relates to a process for preparing copolymers of this kind and to the use thereof as pour point depressant for crude oil, mineral oil and/or mineral oil products, preferably as pour point depressant for crude oil.

The present invention relates to an aqueous emulsion comprising: a) from 50% to 60% of an organic phase dispersed in an aqueous phase, said organic phase containing a mixture including from 24% to 30%, calculated with respect to the final emulsion, of ethylene-vinyl acetate copolymers and/or polyalkyl(meth)acrylates, indicated in the present description as polymeric component, and a high-boiling organic solvent, or a mixture of said solvents; b) a primary emulsifier at a concentration higher or equal to 0.1% and lower than or equal to 3% by weight, calculated with respect to the final emulsion; c) from 37% to 47% of an aqueous phase; wherein the ratio between said polymer component and said organic solvent in the final aqueous emulsion is at least 1/1 and where the organic solvent and any polymer of the polymeric component have a Hildebrand solubility parameter such that, the difference (.sub.solvent_.sub.polymer) is lower than 2 in absolute value for any polymer of the polymeric component.

The present invention relates to an aqueous emulsion comprising: a) from 50% to 60% of an organic phase dispersed in an aqueous phase, said organic phase containing a mixture including from 24% to 30%, calculated with respect to the final emulsion, of ethylene-vinyl acetate copolymers and/or polyalkyl(meth)acrylates, indicated in the present description as polymeric component, and a high-boiling organic solvent, or a mixture of said solvents; b) a primary emulsifier at a concentration higher or equal to 0.1% and lower than or equal to 3% by weight, calculated with respect to the final emulsion; c) from 37% to 47% of an aqueous phase; wherein the ratio between said polymer component and said organic solvent in the final aqueous emulsion is at least 1/1 and where the organic solvent and any polymer of the polymeric component have a Hildebrand solubility parameter such that, the difference (.sub.solvent_.sub.polymer) is lower than 2 in absolute value for any polymer of the polymeric component.

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.

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.

The invention provides dispersions comprising I) at least one oil-soluble polymer effective as a cold flow improver for mineral oils, II) at least one organic, water-immiscible solvent, III) a dispersant comprising, based on the total amount of dispersant, a) 10-90% by weight of a salt of an ethercarboxylic acid and b) 90-10% by weight of a nonionic surfactant, IV) water and V) at least one organic, water-miscible solvent.