Patent ID: 7988748

Claim:
An additive as component of mineral oil compositions with trace portions of additives wherein the additive is a comb polymer containing ester linkages and consisting of either: 1) two segments (a) and (b), wherein segments (a) and (b) are covalently bonded to each other and wherein segment (a) is based on ethylene-vinylester copolymers modified by hydroxy groups or glycidyl groups with molecular mass weight averages from 3000 to 50000 and an ethylene portion of 50 to 90 mass %, and wherein segment (b) is based on partially imidated and/or partially esterified maleic anhydride copolymers, wherein segment (a) is connected by means of ester linkages to segment (b), or 2) two segments (c) and (d), wherein segments (c) and (d) are covalently bonded to each other and wherein segment (c) is based on ethylene-vinylester copolymers modified by acid and/or acid anhydride groups with molecular mass weight averages from 3000 to 50000 and an ethylene portion of 50 to 90 mass %, and wherein segment (d) is based on polyalcohols partially esterified with C 12 -C 40 -monocarboxylic acids wherein segment (c) is connected by means of ester linkages to segment (d), and whereby the content of the comb polymer in the mineral oil is 0.005 to 1 mass %, and the weight ratio of the segments comb polymer segment a/comb polymer segment b based on components a and b, or the segments comb polymer segment c/comb polymer segment d based on components c and d is 10:90 to 90:10, respectively.