A process for the preparation of polyisobutene derivatives involves bringing an oxygen-containing gas in contact with polyisobutene, in the presence of a photosensitizer, and irradiating the reaction mixture. The polyisobutene derivatives are useful, for example, in hydrocarbon mixtures or hydrocarbon-containing oils.

A paraffin inhibitor composition that exhibits stable properties at low temperature is provided. The composition may contain, for instance, an alkylphenol copolymer having the following repeating units (A) and (B): ##STR00001##
wherein, x is an integer from 1 to 200; y is an integer from 2 to 200; R.sub.1 is a straight or branched C.sub.1-C.sub.15 alkyl; and R.sub.2 is a straight or branched C.sub.16-C.sub.40 alkyl.

A paraffin inhibitor composition that exhibits stable properties at low temperature is provided. The composition may contain, for instance, an alkylphenol copolymer having the following repeating units (A) and (B): ##STR00001##
wherein, x is an integer from 1 to 200; y is an integer from 2 to 200; R.sub.1 is a straight or branched C.sub.1-C.sub.15 alkyl; and R.sub.2 is a straight or branched C.sub.16-C.sub.40 alkyl.

An asphaltene dispersant composition is provided. The composition may contain an alkylphenol copolymer having the following repeating units (A) and (B): ##STR00001##
wherein, x is an integer from 1 to 200; y is an integer from 2 to 200; R.sub.1 is a straight or branched C.sub.1-C.sub.15 alkyl; and R.sub.2 is a straight or branched C.sub.2-C.sub.40 alkyl, wherein R.sub.2 is different than R.sub.1.

An asphaltene dispersant composition is provided. The composition may contain an alkylphenol copolymer having the following repeating units (A) and (B): ##STR00001##
wherein, x is an integer from 1 to 200; y is an integer from 2 to 200; R.sub.1 is a straight or branched C.sub.1-C.sub.15 alkyl; and R.sub.2 is a straight or branched C.sub.2-C.sub.40 alkyl, wherein R.sub.2 is different than R.sub.1.

An alkylphenol copolymer, such as for use in a petroleum composition, is provided. The alkylphenol copolymer has the following repeating units (A) and (B): ##STR00001##
wherein, x is an integer from 1 to 200; y is an integer from 2 to 200; R.sub.1 is a straight or branched C.sub.1-C.sub.15 alkyl; and R.sub.2 is a straight or branched C.sub.2-C.sub.40 alkyl, wherein R.sub.2 is different than R.sub.1.

An alkylphenol copolymer, such as for use in a petroleum composition, is provided. The alkylphenol copolymer has the following repeating units (A) and (B): ##STR00001##
wherein, x is an integer from 1 to 200; y is an integer from 2 to 200; R.sub.1 is a straight or branched C.sub.1-C.sub.15 alkyl; and R.sub.2 is a straight or branched C.sub.2-C.sub.40 alkyl, wherein R.sub.2 is different than R.sub.1.

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.

The invention relates to a polymer composition that can be obtained by means of the free radical polymerisation of A) 95-40 wt. % of alkyl (meth)acrylate containing Ai) 20-95 wt. % of at least one alkyl (meth)acrylate with 16 to 40 C-atoms in the alcohol group, and Aii) 5-80 wt. % of at least one (meth)acrylic acid ester of a C.sub.8-C.sub.22 alcohol carrying a C.sub.6-C.sub.20 alkyl group in the 2-position relative to the hydroxyl group, in the presence of B) 5-60 wt. % ethylene copolymer. The invention also relates to a method for producing same and to the use of same as a flow improver for mineral oils and mineral oil distillates.

The invention relates to a polymer composition that can be obtained by means of the free radical polymerisation of A) 95-40 wt. % of alkyl (meth)acrylate containing Ai) 20-95 wt. % of at least one alkyl (meth)acrylate with 16 to 40 C-atoms in the alcohol group, and Aii) 5-80 wt. % of at least one (meth)acrylic acid ester of a C.sub.8-C.sub.22 alcohol carrying a C.sub.6-C.sub.20 alkyl group in the 2-position relative to the hydroxyl group, in the presence of B) 5-60 wt. % ethylene copolymer. The invention also relates to a method for producing same and to the use of same as a flow improver for mineral oils and mineral oil distillates.